The present work aims to perform an evaluation of the customer service process in the service area, for which a study using a reliability of 90 with the process simulation technique was carried out. A descriptive analytical methodology was developed
Simulation of inventory system
Benzene alkylation with ethene and propene has been carried out under liquid-phase reaction conditions over zeolites MCM-22, Beta, and ZSM-5. MCM-22 seems to be a good catalyst for benzene…Full description
Guia de inspeção de validação de limpeza, segundo protocolos da FDA
Effects of Computer AddictionFull description
Types of Computer SystemsFull description
Types of Computer MemoryFull description
basics computer science
Descripción completa
wait for the chapter 3 we are not yet finish
Deskripsi lengkap
o f C o m p r e s s íOí O D - I g n i t í o n Engine Prncesses V Ganesan anesan
Universitíes Press
( () () () ( ( ^ •(> :() ( )
,
■(
/ ( í e d i c a t e t f ii ii s S o o ^ t o m y re re v e r ec ec C g u r u s ,
.)
( :
< P ro ro fe fe ss s s or or (B (B S M u r t f i y a t u í ( B r o f e s s o r ^ ^ a g a c f e e s a n
U*i»«nUlí» Pr««f ffndU) Prl»»U LlmlUd
V
j c .
J
.
(
Ktt Uur
( )
Biuil; IníoSunivcrtilieiptut^m
(
Dl itt lh ut ti by Orical Blackiwui Pñv«ie UmiUil Re fli ler ed OJfict
I
.
C)
cJ
3-6-7 {2 . Ht(myitni| Ht(myitni|ar ar Jiyitoibad SOO029 (A J*.).
( )
Otktf OJfictí OJfictí
(>
Bw f llore llore / Bhopil / Bbubu«ihw*r/Cheaeil EnakuL EnakuLun un / / Kydcnbtd / Jaipur Jaipur / K o IIl iu
(
( () () () ( ( ^ •(> :() ( )
,
■(
/ ( í e d i c a t e t f ii ii s S o o ^ t o m y re re v e r ec ec C g u r u s ,
.)
( :
< P ro ro fe fe ss s s or or (B (B S M u r t f i y a t u í ( B r o f e s s o r ^ ^ a g a c f e e s a n
j c .
V
U*i»«nUlí» Pr««f ffndU) Prl»»U LlmlUd
J
.
(
I
Ktt Uur
( )
Biuil; IníoSunivcrtilieiptut^m
(
.
C)
Dl itt lh ut ti by Orical Blackiwui Pñv«ie UmiUil
cJ
Re fli ler ed OJfict
3-6-7 {2 . Ht(myitni| Ht(myitni|ar ar Jiyitoibad SOO029 (A J*.).
( )
Otktf OJfictí OJfictí
(>
Bw f llore llore / Bhopil / Bbubu«ihw*r/Cheaeil EnakuL EnakuLun un / / Kydcnbtd / Jaipur Jaipur / K o IIl iu
(
LDdUow / Mumbai Mumbai / New Ddhl / n tm
O Ua lvcnitie i Press Press (IndU) Prívale Prívale Uroited 2000 Fint pubtí>hed2000 Reprinied 2013
Pt bl hh td by Usiversllies Press (IndU) Privilc Umilcd 3-&-747/1/A 3-&-747/1/A & 3-6 -7Í4 /I, lUfluyauiif ir,
H)^íenb3d3 H)^íenb3d300 00 029 (AÍ .).ln
)
o
.
() () C )
)-
) ) ) ) ) ) ) ) ) ) )
CONTENTS
P n fa cc L ü l o f if tn io U
Ch»pt«r 1
INTRODUC TION
1.t
SindUlon
1.2 1.3
Advuilt| et of compaUr ilmBUtio* Obj«ctiv« ef lU i book
1.4
SU p-by- «t«p
pproadi
C h a pU pU r 2 REACTIVE PR0CES3E3 2.1 Inlrodactios 2.2 Heit oí r«»etba 2.3 Mcuoremeot of 2.< MíunrtmtBt oí B, f 2 i Cilcnk tloB of h!|litr h!|litr tnil iower iower L«tt vilae of fatli Enrcii* C h ap ap tM tM S ADIABATIC rLAME TEMPERATU RB 3.1 Introdactioa 3.2 CompfcU combtt combttrtl rtlon on io C/ H /O /N iyit«mi
xi
ziv
)-
) ) ) ) ) ) ) ) ) ) )
CONTENTS
P n fa cc L ü l o f if tn io U
Ch»pt«r 1
xi
ziv
INTRODUC TION
1.t
SindUlon
1.2 1.3
Advuilt| et of compaUr ilmBUtio* Obj«ctiv« ef lU i book
1.4
SU p-by- «t«p
pproadi
C h a pU pU r 2 REACTIVE PR0CES3E3 2.1 Inlrodactios 2.2 Heit oí r«»etba 2.3 Mcuoremeot of 2.< MíunrtmtBt oí B, f 2 i Cilcnk tloB of h!|litr h!|litr tnil iower iower L«tt vilae of fatli Enrcii* C h ap ap tM tM S ADIABATIC rLAME TEMPERATU RB 3.1 Introdactioa 3.2 CompfcU combtt combttrtl rtlon on io C/ H /O /N iyit«mi 3.3 Con*tuit>voluai Con*tuit>voluai«« adUbttU comb iutbn CoftttuiUpretit etittn tn iJitbtllc combutton ÍA CoftttuiUpr 3.( CklcnUUon CklcnUUon oí »dUb«(lc flun* Itmpt rttart 3.6 SolYíd cxamplet Sxtrcbe
Chapla- l 4.1 4.2 C h ap ap le le r E 5.1 5.2 5.5 6.4
I 3 E N T R 0 P I C C H A N C E S OT STATE Introdacdon SammiTy Exereáe C O M P R ES ES S IO IO N - IG IG N IT IT I ON ON E N C IN IN E S Intixxiaction Somc bu le dctt lb tnd tnd DomcscUtart Cylioder preMurt preMurt iadictlor dUg mn IndicaUd poww
40
)
vUl
CoattaU
CompoUt SlmüUltoa oí d Eaíli» Pto cM itt
iS iJt S.7 Chapter a 0.1 ej OJ S.4
ts Cbapter T 7.1 7.2 7J 7.< Ti Cbaptcr 6
t, l ta &.Í
L i Cbtptcr 9
B r ^ po wc wc r Working principie Eagioc kiaem^ics Excrcac C I E N G I N E 8 I M U L A T IO IO N W I T H A m A S W OH KI NG M E DI U M btrodsclloa Uctl DUm I cyck SlmuUlíon wUh *Sr *Sr u the workim médium Dtvi^ioa betmea utaU ta i IdeU cycli Solvtd «xunple* Cxtrcke C 1 E N G IN IN E S I M U I ^ I O N W I T H A D IA B A T IC C OM B US TI ON laUodaction Engíae detul* Nu vti ly uptraied uptraied openiioa openiioa Work Work ontput ontput u d «Scienc «Sciencyy cak oUliou Supercbirgcd Supercbirgcd open iioa Exiutitt CI ENGINE 8IMULATI0N WITH PHOGUESSIYE COMBUSTION laUodactioa . lf*rogrtuivi comboftioQ Combuilloii iiiodilEfi{ 7->nw
«1 « j41 i Aj AA A « 47 47 4S 49 51 62 S4
S ol a t b n j for F ( T } = O Newtoa- Riphion UctUíod tcduiiqae Ap pe nd ix C Ait cbr ilc ex pic ttl ou for tb tn no jya un ic (a ac tb oi Ap pe nd bc D Propun Meuing oí mkjor vuUblei ujed mtH m tHcc progn m ¿iilíofrapAy
hdts
ix 123 121 121 127 127 13S 13S ISS 19? 197 200
S5 ss -65 -65 66 62 66 72 7} 73 75 SI S2 83 69 95 Í7
(
vUl
CoattaU
CompoUt SlmüUltoa oí d Eaíli» Pto cM itt
B r ^ po wc wc r Working principie S.7 Eagioc kiaem^ics Excrcac C I E N G I N E 8 I M U L A T IO IO N W I T H a A m A S W OH KI NG M E DI U M 0.1 btrodsclloa e j Uctl DUm I cyck *Sr u the workim médium OJ SlmuUlíon wUh *Sr S.4 Dtvi^ioa betmea utaU ta i IdeU cycli t s Solvtd «xunple* Cxtrcke C 1 E N G IN IN E S I M U I ^ I O N W I T H T A D IA B A T IC C OM B US TI ON 7.1 laUodaction 7.2 Engíae detul* uptraied openiioa openiioa 7J Nu vti ly uptraied Work ontput ontput u d «Scienc «Sciencyy cak oUliou 7.< Work Supercbirgcd open iioa T i Supercbirgcd Exiutitt CI ENGINE 8IMULATI0N WITH 6 PHOGUESSIYE COMBUSTION t, l laUodactioa . ta lf*rogrtuivi comboftioQ Combuilloii iiiodilEfi{ &.Í 7->nw
iS iJt
Chapter
Cbapter
Cbaptcr
Cbtptcr
«1 « j41 i Aj AA A « 47 47 4S 49 51 62 S4
S ol a t b n j for F ( T } = O Newtoa- Riphion UctUíod tcduiiqae Ap pe nd ix C Ait cbr ilc ex pic ttl ou for tb tn no jya un ic (a ac tb oi Ap pe nd bc D Propun Meuing oí mkjor vuUblei ujed mtH m tHcc progn m ¿iilíofrapAy
hdts
ix 123 121 121 127 127 13S 13S ISS 19? 197 200
S5 ss -65 -65 66 62 66 72 7} 73 75 SI S2 83 69 95 Í7 87 106 106 109 109 111 111 • 111 111 111 111 111 113 113 114 114 li s li s 118 118 117 117 117 117 123 123
(
c
( ( (
c. c c c \
c
) ) )
PREFACE
laUnikl laUnikl Combnitiea Combnitiea Eailnti c u bt broully cU tiiled iato ipuk-i(aitiaB ipuk-i(aitiaB (SI) u>d comprttiIoD-lfnhloB comprttiIoD-lfnhloB (CI) Tb t ipvk*l(oUtoB eafint datci bu k to 1878 1878 «he n Ao fiiit Otto GM derttoped the the SI tafln t u d comprcatloncomprcatloniinitloB iinitloB cB(ine to 1S92 1S92 whtB whtB R«dolf Dlettl iavtB(*d iavtB(*d tlie C1 C1 capae. O m tbe lu í OB OBC eeatnry, eeatnry, eaginet coatian coatianed ed to devtlop, u onr kaowledie of engíoe proce* proce*««< ««< b u bc r«u «d . N o «e «e « u d f o r b o i ld ld i o i p o w e i f o l,l, ¡ n tegrUed databu e «yitenu. C ompater itmnlatio itmnlatioB B pro cedo m kave beea bnilt bnilt by tbeoretical fooB datioo i ud «*ed ia a large atimber atimber o( appIkatioBf. la
) ) )
PREFACE
laUnikl laUnikl Combnitiea Combnitiea Eailnti c u bt broully cU tiiled iato ipuk-i(aitiaB ipuk-i(aitiaB (SI) u>d comprttiIoD-lfnhloB comprttiIoD-lfnhloB (CI) Tb t ipvk*l(oUtoB eafint datci bu k to 1878 1878 «he n Ao fiiit Otto GM derttoped the the SI tafln t u d comprcatloncomprcatloniinitloB iinitloB cB(ine to 1S92 1S92 whtB whtB R«dolf Dlettl iavtB(*d iavtB(*d tlie C1 C1 capae. O m tbe lu í OB OBC eeatnry, eeatnry, eaginet coatian coatianed ed to devtlop, u onr kaowledie of engíoe proce* proce*««< ««< b u bc r«u «d . N o «e «e « u d f o r b o i ld ld i o i p o w e i f o l,l, ¡ n tegrUed databu e «yitenu. C ompater itmnlatio itmnlatioB B pro cedo m kave beea bnilt bnilt by tbeoretical fooB datioo i ud «*ed ia a large atimber atimber o( appIkatioBf. la receBt receBt yeir» the avaüabili avaüability ty of fut digital digital pe no nil co mputen have revolurevolutiosÍMd the worid. Heace, the lyitemi which were bitherio bitherio aot amenible for tmolatioB tmolatioB techaiqaei kave come oader the purvUw o f limolation itndie*. O ae nc h ue a b the Computer Computer iIsml iIsmlati atioB oB of comprtailoa-igaiti comprtailoa-igaitioB oB eagisef.
I
I
I I
developisg u d luicg In «B^eertag, timolatioa proceu h*< come to Bieu developisg the appropriate combioatioa of auamptioai u d eqaati eqaatioai oai that permit crítical featorei of the proceu to be ualyMd. The modelliag of eagiae proeeuei contia contiasca sca to develop develop u oor bu k Bodentudiag of the Phy«lc« u d Chembtry of the phcBomeaa of út«re*t itead iteadily ily expu di, u d u the the capabí capabíllt lltyy of com puten to loWe complex equatiou coBtinaet to tacreaM. Computer lúnulatioB actívitiet actívitiet c u make make major coBtributbai to eagiae detiga at dlffertat kveb of geaerallty or detail, correipoadiag lo a differeot ttagee ttagee of m odcl dtvelopmeat. Al of Bow two baú c type* of modela have beea developcd. They c u b< catcgoriied aa IhennodyBamk-or Suid dyaamlc ia aatun dependiag oa
) )
I I
I) I 1
I;
l;
jd l
Cempatu StaiUth» • StaiUth» • / O Eagia* Eagia* Ptocmm* wlittkcr lk« c<)aktloi» wbidt |iv( Ihc model ¡K pndamliiuil alructarc *r« bw«d OB catrgy catrgy conurvU ioo or oo » fnll fnll uxly tii o í tbc íai
Thii book ku b oí the Oiuel cycle and to get him ínto tbe groove of engine limulation. In Chapter 7, fael-air cycle limBUlioa (FCS) has been carríed ont uiiag appropriate equatiom Tb ii will make make the the reader ondent and the eCfec eCfectt of
Prt íia
xlil
Appe ndice * í ndad e rel evant e qa U io u and d u a . Tablc * are alj o p rovided witb required required data whcrever whcrever ae cU wy . Fnrtber, Fnrtber, a bard copy of the compaUr program ú alto giren giren io tbat ibeitude ntj uid thc Ua chcn may take take advutage oí the aame. IT asyoae r«iu¡r e* a floppy (hii can b« tupplied al a nominal co«t. It is the detire of the anthor that the teader shoaU develop bis ova cede. TboM wbo anderttand thc theocT- provided in varíonj chapten can v t r j caaily wrile tbe vurtout «Qb-routtnet giviug tbe atcetsary inpnt data and make bil progr am work and compare the resolti p ven in variaas tablea. Henee, Henee, it is itrongly adviied tbat tbe reader ihouU make attempti in thii dirtction, dirtction,
Ktany individuáis have attisled me in various wayt as I have worked on this book over the pasl three yean. I am graUful l o my coUea^ue coUea^ueaa in tbe tbe l.C. £ngine« Laboratoiy at ladian Institute Institute of Technology Technology,, M ulr u, fcr tbeir eaeonragemenl and and (upport. Many of my Punctili out and highiy Devoted Kholan, have helped me in tbe preparation of (exl materials and I am veiy gratefttl to tbem for the aame. I am particu lirly thankful t o my QIP acholar, Mr. J. M. Mallikarjuna Mallikarjuna for bii l upport in ninnlag the pr ogrun and making making vubus tables and grapbi in tbe book. The interest he took in this regard a very much appreciated. 1 wish to thank the Centre for Co&tlnolng Edvcatioa of the Indian Institute of Technology, Madras for the help rtndered in the preparation preparation of ibis book. I am apeci ally indebted ( o my tecretary, Ms. V|jayash V|jayashree ree and ion G. Venkatasabramaniui who have put tbeir heart and soul to bríng out this book by belping belping me ia DTP and otber otber tompnltr operations. Witbont tbeir unstintmg belp it would not have have been poasibk to bring out this book b this fuhlon. My wife Rajalakshmi, son Veokatuubramanian and daughtei Apaña have encooraged me throughout this k>ng and tlme-consumlng work which took many boors away {rom them. V/ilhout tbeir continuing lopport it would aever have been finiihed; for tbeir patience and faith that it wcnúd wcnúd ultimately
jd l
Cempatu StaiUth» • StaiUth» • / O Eagia* Eagia* Ptocmm* wlittkcr lk« c<)aktloi» wbidt |iv( Ihc model ¡K pndamliiuil alructarc *r« bw«d OB catrgy catrgy conurvU ioo or oo » fnll fnll uxly tii o í tbc íai
Thii book ku b oí the Oiuel cycle and to get him ínto tbe groove of engine limulation. In Chapter 7, fael-air cycle limBUlioa (FCS) has been carríed ont uiiag appropriate equatiom . Tb ii will make make the the reader ondent and the eCfec eCfectt of adding fael to the analyiii, and heJp him to appreciit« the inBueact of vatioai opcrating paramcteri on engine engine perfonnance. perfonnance. Som* parainelrie parainelrie itadiei have been made, and are given ia the form of tablea. L> Cbapter B, B, progrtajive progrtajive combgttio» fimuU lion.(PC S] uib g rate equaequationa and and a Kn^di meni ional model, have b«ea incotpor ated. Heat Iranafer Iranafer hu bccn lak fa into accouot by meani of, again, erapirícal erapirícal relationa relationa.. Thls will will take (he reader reader a litt k cloter to (he actaal engine. In Chapter 9, the actual cycle «imalation (ACS) has been atterapted, taJdng into account the gai excbange proccM and frictbn. A uumber of par»* tnelrtc iludi et have been cairied out and the reiu lti are provided k> k> varíoui tablea. It is hoped that thli «tep-by>itep approach will make (he readfr under•tand and appreciate the complexitic* involved la the Computer limulatioB of comprcaiion-ignilion enginu.
Prt íia
xlil
Appe ndice * í ndad e rel evant e qa U io u and d u a . Tablc * are alj o p rovided witb required required data whcrever whcrever ae cU wy . Fnrtber, Fnrtber, a bard copy of the compaUr program ú alto giren giren io tbat ibeitude ntj uid thc Ua chcn may take take advutage oí the aame. IT asyoae r«iu¡r e* a floppy (hii can b« tupplied al a nominal co«t. It is the detire of the anthor that the teader shoaU develop bis ova cede. TboM wbo anderttand thc theocT- provided in varíonj chapten can v t r j caaily wrile tbe vurtout «Qb-routtnet giviug tbe atcetsary inpnt data and make bil progr am work and compare the resolti p ven in variaas tablea. Henee, Henee, it is itrongly adviied tbat tbe reader ihouU make attempti in thii dirtction, dirtction,
Ktany individuáis have attisled me in various wayt as I have worked on this book over the pasl three yean. I am graUful l o my coUea^ue coUea^ueaa in tbe tbe l.C. £ngine« Laboratoiy at ladian Institute Institute of Technology Technology,, M ulr u, fcr tbeir eaeonragemenl and and (upport. Many of my Punctili out and highiy Devoted Kholan, have helped me in tbe preparation of (exl materials and I am veiy gratefttl to tbem for the aame. I am particu lirly thankful t o my QIP acholar, Mr. J. M. Mallikarjuna Mallikarjuna for bii l upport in ninnlag the pr ogrun and making making vubus tables and grapbi in tbe book. The interest he took in this regard a very much appreciated. 1 wish to thank the Centre for Co&tlnolng Edvcatioa of the Indian Institute of Technology, Madras for the help rtndered in the preparation preparation of ibis book. I am apeci ally indebted ( o my tecretary, Ms. V|jayash V|jayashree ree and ion G. Venkatasabramaniui who have put tbeir heart and soul to bríng out this book by belping belping me ia DTP and otber otber tompnltr operations. Witbont tbeir unstintmg belp it would not have have been poasibk to bring out this book b this fuhlon. My wife Rajalakshmi, son Veokatuubramanian and daughtei Apaña have encooraged me throughout this k>ng and tlme-consumlng work which took many boors away {rom them. V/ilhout tbeir continuing lopport it would aever have been finiihed; for tbeir patience and faith that it wcnúd wcnúd ultimately come to &isIt¡on, I will always be gratefol.
V . GA N E SA N
) )
LUt LUt otSfmboU
XV
vilve diunctcr H lotiie vilve
Hrf H,
LIST OF SYMBOLS
Sym'bol Dwcrlptlon
Á, Á f A ,x
Ain Ain AC S Á/F AL Sp B B BD C BL Cp
t n x ot ihe piiton wide open cxhtiut vilve are are& &
wide open inlet vilvf ir ei letaxl cydc liraaliti liraalition on úr-fatl ritió cotfficient cotfficient for ibe cdcuUtion cdcuUtion of C , br»ke povfer bore bottom deid centre centre coefficie coefficient nt for the ulcu litio a of Cp mcut pUlon tpMd ipecifie beiC tt coattul preuure pcciGc pcciGc bc*t« of úr
If. lie ip
IC íe s k kj, kj, kf K L M M mp
TTif n n N N
Nt Nn N a » '
Ifp Nf Nf N f, ti,
bett (ddcd «stbiJpy «stbiJpy of probad beit of rtutioa U ccnitut preuiut preuiut entbal entbalpy py of rta ctu t ejitli(] ejitli(]p)r p)r of wtter itart ct injection liidiealtd power útct sd combuit combuition ion Meil cyde «ImulitioB «ImulitioB ipeciSc beat ratlo tpecific tpecific beat beat ratio of tbe prodncli tpeóGc beat ratio of ibt rtactaou Bunber of cylindera connectlag rod lengtb mw piitoa ikirt leajtb mau of producía mau of reactaot mau fnction nunber of «rorkiag atrol atrolte te per minóte (rpm /2) per cylisder Dombtr Dombtr of mole* mole* of viriotu iptciei ipeed ia rpm mole* mole* oí air air cnteriaf tbe cubnretor mole* mole* of fael rapoo r and alr ia cafiae durtng compreuioa itroke kOomole kOomole** of air-fuel viponr ia a mixtor* tontain iog 1 kinol of fael küoniole küoniole** of prodocU íortned íortned from Ibe combaition o f W* + mola of (aieoo* prodacti mola of prodoctf afte afterr combulloa kilomole kilomole** of prodacti fonned fror froraa tbe tbe combattioa of molea molea of gu ecu i reactaata reactaata
) )
LUt LUt otSfmboU
XV
vilve diunctcr H lotiie vilve
Hrf H, If. lie ip
LIST OF SYMBOLS
IC íe s k kj, kj, kf K L M M mp
Sym'bol Dwcrlptlon
Á, Á f
TTif
t n x ot ihe piiton
n n N N
wide open cxhtiut vilve are are& &
A ,x
Ain Ain AC S Á/F AL Sp B B BD C BL
wide open inlet vilvf ir ei letaxl cydc liraaliti liraalition on úr-fatl ritió cotfficient cotfficient for ibe cdcuUtion cdcuUtion of C , br»ke povfer bore bottom deid centre centre coefficie coefficient nt for the ulcu litio a of Cp mcut pUlon tpMd Cp ipecifie beiC tt coattul preuure pcciGc pcciGc bc*t« of úr C(^ tpecific bc*l« of fa«I Cr, coMliot volumí tptcific tptcific beiti of the the reic linl mixtur mixturee c :( r ) meul vUoe vUoe of ipecific ipecific bett coiut»nt volii voliitne tne ipe<¡Gc híU of Wíler Wíler C, ipe<¡Gc coeflScie& ie&tt for (be cilcn lrii on of Cp, CL ' coeflSc DL coefficient coefficient for tbe ctlculitioa of C f f imount of bypau «xb»uit gu ia exh& exh&uít uít drírea ioperchirger fmtp fric tion me»n effcct ive preMure ¡p friction power F forcé FC S fuet-iir eycle liniutatioa otimber of iottie vilvc j per cylinder cylinder G otimber X ipecific enthilpy coefEcient ht be»t trini fer coefEcient hif hett of vapouriiilion
l]
Nt Nn N a » '
Ifp Nf Nf N f, ti, ' ti, N-, p p p, p,
Pí Pí Pn pnnt pnnt Pf PC S PRctit f.
bett (ddcd «stbiJpy «stbiJpy of probad beit of rtutioa U ccnitut preuiut preuiut entbal entbalpy py of rta ctu t ejitli(] ejitli(]p)r p)r of wtter itart ct injection liidiealtd power útct sd combuit combuition ion Meil cyde «ImulitioB «ImulitioB ipeciSc beat ratlo tpecific tpecific beat beat ratio of tbe prodncli tpeóGc beat ratio of ibt rtactaou Bunber of cylindera connectlag rod lengtb mw piitoa ikirt leajtb mau of producía mau of reactaot mau fnction nunber of «rorkiag atrol atrolte te per minóte (rpm /2) per cylisder Dombtr Dombtr of mole* mole* of viriotu iptciei ipeed ia rpm mole* mole* oí air air cnteriaf tbe cubnretor mole* mole* of fael rapoo r and alr ia cafiae durtng compreuioa itroke kOomole kOomole** of air-fuel viponr ia a mixtor* tontain iog 1 kinol of fael küoniole küoniole** of prodocU íortned íortned from Ibe combaition o f W* + mola of (aieoo* prodacti mola of prodoctf afte afterr combulloa kilomole kilomole** of prodacti fonned fror froraa tbe tbe combattioa of molea molea of gu ecu i reactaata reactaata motel motel of reactaat before combsjtbn nomber of mole* of water water kSomoIe* of reiidaal exbaoit from previom cycle preunre almoípberic presinre preísore at tbe iaatant comb aitu n endi endi preñare before tbe apark paatet paatet inlel masifold preuure manifoid preuú re meaa effeetive prtu nre iadicated neaa effective preusre fiaal preua re of tbe piodacta profreative comb iuti oa aimalation aimalation critica] critica] preuvre rallo Heat Heat added
I!
.. .. .
yvi
.
......
i ^-
- -
- -
ZifC 0Í S/aboli
CoiDpal«rSImBl»»toooíCÍ£iiíío#P/oe»«M*
f, Qf Qv
Keit rtjKUd tatiTpf tatiTpf r t k u * at at c o u t u t p n t i o r c tntriy ttk u* U conitut vptuB vptuB**
r conprtMioa conprtMioa ntio
R fW coulu il air-fatl n lw RA F nUliv* air-fatl A«
tbtn atl condactivity oT |u foactioa foactioa lo calcaUu calrap calrapyy cruik kügU
cruk ug k whu combo comboiti itioa oa «adi «adi cru k ug k at t(i« t(i« itart of igmtio igmtion n .
K»v
S I iptrk'iinJlion <4. lak t waUr Umpen ture ( mii oalk t wUer Umpctatitre Umpctatitre T tcmptntnr* c^nUibr ibríam íam U ap
c <
c
c c (
c,
c c (.
c;
c;
C
c .L ) ) ) ) ) ) )
INTRODUCTION
1.1
Simulation StmnIittoD ú a broully uied »ad tomcwbtt Ul-dt6oed Urra írom the enjinc«rin{ po bt of view. Accordiai to Wcbiter'l inUrnUiontl inUrnUiontl dict!oaary dict!oaary *lo limtlatc' limtlatc' meizu *(« fe íi n, te cttain cttain lAc turnee «ntAo«{ t kt kt n M f * . How-
evcr, tbc iiznpUtt mcuiing of úmBliti úmBlitioii oii ú ‘ ímitatún*. Thcic dictionar dictionaryy n e u i n p do oot brtng ont • cltu- pkcnn of tbe worti '«tmaUtion* for ca> tinet rb( ^pticat'>oiu. ^pticat'>oiu. Tbercfore, Tbercfore, i definitioa definitioa of the word b duired in thu cont«xt. cont«xt. W i(h ioroe Ircpidttion, Ircpidttion, Iht Iht uth or d
Compster Compster limaltlioa limaltlioa hu fused t ireittr importuce thcu diyt bcciofe of the aYail aYailabü abüIty Ity of fu t d iii lil coropaten. It can be dcfined u foUowi: foUowi: Computer Computer timtlation timtlation it tke pm eii ef formtiatinj a moJel moJel of a fKftUal fKftUal
.L ) ) ) ) ) ) )
INTRODUCTION
1.1
Simulation StmnIittoD ú a broully uied »ad tomcwbtt Ul-dt6oed Urra írom the enjinc«rin{ po bt of view. Accordiai to Wcbiter'l inUrnUiontl inUrnUiontl dict!oaary dict!oaary *lo limtlatc' limtlatc' meizu *(« fe íi n, te cttain cttain lAc turnee «ntAo«{ t kt kt n M f * . How-
evcr, tbc iiznpUtt mcuiing of úmBliti úmBlitioii oii ú ‘ ímitatún*. Thcic dictionar dictionaryy n e u i n p do oot brtng ont • cltu- pkcnn of tbe worti '«tmaUtion* for ca> tinet rb( ^pticat'>oiu. ^pticat'>oiu. Tbercfore, Tbercfore, i definitioa definitioa of the word b duired in thu cont«xt. cont«xt. W i(h ioroe Ircpidttion, Ircpidttion, Iht Iht uth or d
Compster Compster limaltlioa limaltlioa hu fused t ireittr importuce thcu diyt bcciofe of the aYail aYailabü abüIty Ity of fu t d iii lil coropaten. It can be dcfined u foUowi: foUowi: Computer Computer timtlation timtlation it tke pm eii ef formtiatinj a moJel moJel of a fKftUal fKftUal ¡fitem npretentinf ael%al prveciiei cn¿ sna/ynnf the tam e. Utuúllf, the mpJel ts a mathematieal one npreitnltnf the aettai procenei throtfk a let of ei ft tn ie , Jíff ertn tial or intefr aí eju at úi u and and Che analfiii ti iruJe mtnf a eampHttr.
In niodtrn reMarch, compoter ilmuUtioa bai bccome a powtxíul lool tn Ibat il lavet tune and b abo «OBomlcal compartí to experíroeatal itady. A propoied theory can be aaalyied qoldjy «jíb2 a compater and (be coet of aettiag np an experimeotal apparatu cao be poatponed natQ optLnbation U acbiered. acbiered. llowever, it may be noitd thit ilisalati oa b oniy a itep prior to cxperímtalation and (he reiulu ob(ti««l from ilmulatioa itndiu miut be validated with experimenta] experimenta] rtiolla lo ut ablb h the reliabllity. reliabllity. Once ralidaled, compater limalation can provide a dccp lnti|ht into the perfonnance cbar* acteHitici of tbe lyitem . Tb b itatemenl b partlculaily truc in the ca u of inter interna} na} combus combustión tión en ^ e itsdiej.
V K
M IV l
____
i
(
• ________ _______ L ___
3
Coa pulM SImiUtliea SImiUtliea oí Cí Ettíat Pncmtm
1.2
3
Advanlagu oí com putcf stmulati stmulation on
alr u the workiag workiag SUp I: Al a Sn t tlcp, tbe eagiae ii auumtd to wo ik with alr médium in ui idctl úr-«lasd*rd diúel cycte. Wt wiB caU caU tbii anilytis aa ideal
In ui iaUroal corabutlion corabutlion (IC) th« proctue» involvcd u e extmncly complcx. Uotil Ihe lu t ¿tc*dt, lb« dosta of an cngine rtlied fa
cycle limoUtioa (ICS). Mere, heat addilioa and bcit rejectioa are loppoted to take plue by meinj of a hcat tranjfer proceu at coiutut preutire and con3tant volame, rcjpectively.
prcvioiu upcríencc uid ksow-how. Am rastt of tliú, tliú, ia eagüe eagüe du ijs, u t t a j i v t l u l ú i f o í t li li e pr e pr ol ot yp t ú ci»*Ídu*il b*c*Mt*ry. b*c*Mt*ry. S«lecünf tbe tbe W t d«ii(a (rom lucli lucli lctlÍB lctlÍB| | it ft ft twk of wui4cra bl« m*(a¡tud<. Bcc um o í
lh u« düEcullit*, düEcullit*, kH4ly»ti by m cu u s í compaicr *¡mal»tk *¡mal»tk>& >& h u becomt <)uile <)uile po p» lu m rcccAl rcccAl ycan. Purtbcr, Purtbcr, compaUr compaUr lünabtio lünabtio n oS cn tbe toU toUcw cwín íngg «dv«aU|M:
(i) U ttrvu u • to«l for » belter belter «sdcntuiilUf of th« th« vuiiblt* iavotv«i tnd tbitr ifftct oa M|ia« puforntact. (ü) l( lyiCtintCúei lyiCtintCúei Lao«rt(d(e ob(tia«d tbiougli tbiougli expc uivc eagi at tuÜBg. (üi) It «Kuiderably «Kuiderably reducei tkc tiroc-coUDima; tiroc-coUDima; te«U b / nvrowÍBg ¿owa the vamblcJ (hit miut be ftadicd. (iv) Ic btipt ia aplimliiat the engúe detifa for « particslv «prlMtioa, (hereby reduclat to*t u d túne túne..
1. 3
btroductloa
ObJecÜve of thls book Tb t múa objtclive objtclive of ibU book it to pment tbe theoiy theoiy u d compater compater pío* pío* {Tami neceiiuy for úmolttiiig lh« performaaee of ftconveationtl hydToearboafucUe fucUedd compreuion igaitioo (C I} «agme, for &sy &sy fael o f the form QcB^O ,. Tbe modtl descnbej the proceue* occuriog wiChia the vcrlúng Soid of « compretiioa igattios igattios eagme u d providei providei u indiaUion oí tiie liaiit liaiit** and and tresdi o f tbe pet{omaace> u » fuDC fuDCtÍM tÍM oí *ome lyitem vvUblei. Tbii wili eaable 0D« la wbit OBc could expect (rom in cngin* working wilbm lacb
SUp SUp / / ; Al the lecoaii il tp , ideal cyclc limuUtion íj modi£td by taking fael
luto accoaat, iacoqx>rat¡ag adiabatic Same temperatnre calcolatioiu for heat add itbn/ comb utioB analyi'u. Ib ibis asalytti, ioitead of air, the working médium ú auumed to be a mixture of fuel and air. air. We wiU wiU cali tbi i analyi'u u fuel-air cycle timilation (FCS) . Kere, combiutioa is aaiumed to take place at coutant preuure and uoder adiabatic conditioa.
Síep Il¡: In tbii ttep, tbe adiabatic flame temperatnre calcutationi are modi* fied by asiomlng combuttioa to be progreulve, Le., heit release ii not ÍBstan> taneon» but ipreadi.over a period of time. In otber wordj, the duralion of combuition ii taken into account. In CI eaginei, the heat releaje releaje a oalytii can be done either by meaoj of progreuive combtutk>n at cooitant preuure, or as meani oí tero-, oae- or two-dimeiuioaal heat releau roodeli. In tbij bo okj two typei of a nilyili have been explained explained.. The Sn t oae ii the progreaiive combajtion at cooitut prcuare. The lecond oae is the progreuive combuition uiing a iux>-dimetuiaaal lingle -ione mod eL Forther, extenaion to oae> or two^tmeuiiona] modeis niing two- or mnlti-ione approach ii alio poMÍbte. We will cali tbii analyiis progreulve combuitba lúnalatlon (PCS). However, io receot yean, attempta bave becn made to uie mnUi-dimeniional models. Thii requirei high ipeed, bigb memory computen. limpUSed auampttoo i, the engine engine heat traniSU SUpp IV : In this taal itep, uiing limpUSed fer can be takeo into account by meuu of empirical eqaatioDi. Gaa exchasge pcoceiie» are inlroduced in ordtr to analyie the engine intake and exhaiut. We will cali tbii analyiti actual cycle limulation (ACS). In this itep, intake
(' ( ( ( ( ( ( r (
c
c
c
( /
____
i
(
• ________ _______ L ___
3
btroductloa
Coa pulM SImiUtliea SImiUtliea oí Cí Ettíat Pncmtm
1.2
3
Advanlagu oí com putcf stmulati stmulation on
alr u the workiag workiag SUp I: Al a Sn t tlcp, tbe eagiae ii auumtd to wo ik with alr médium in ui idctl úr-«lasd*rd diúel cycte. Wt wiB caU caU tbii anilytis aa ideal
In ui iaUroal corabutlion corabutlion (IC) th« proctue» involvcd u e extmncly complcx. Uotil Ihe lu t ¿tc*dt, lb« dosta of an cngine rtlied fa
cycle limoUtioa (ICS). Mere, heat addilioa and bcit rejectioa are loppoted to take plue by meinj of a hcat tranjfer proceu at coiutut preutire and con3tant volame, rcjpectively.
prcvioiu upcríencc uid ksow-how. Am rastt of tliú, tliú, ia eagüe eagüe du ijs, u t t a j i v t l u l ú i f o í t li li e pr e pr ol ot yp t ú ci»*Ídu*il b*c*Mt*ry. b*c*Mt*ry. S«lecünf tbe tbe W t d«ii(a (rom lucli lucli lctlÍB lctlÍB| | it ft ft twk of wui4cra bl« m*(a¡tud<. Bcc um o í
lh u« düEcullit*, düEcullit*, kH4ly»ti by m cu u s í compaicr *¡mal»tk *¡mal»tk>& >& h u becomt <)uile <)uile po p» lu m rcccAl rcccAl ycan. Purtbcr, Purtbcr, compaUr compaUr lünabtio lünabtio n oS cn tbe toU toUcw cwín íngg «dv«aU|M:
(i) U ttrvu u • to«l for » belter belter «sdcntuiilUf of th« th« vuiiblt* iavotv«i tnd tbitr ifftct oa M|ia« puforntact. (ü) l( lyiCtintCúei lyiCtintCúei Lao«rt(d(e ob(tia«d tbiougli tbiougli expc uivc eagi at tuÜBg. (üi) It «Kuiderably «Kuiderably reducei tkc tiroc-coUDima; tiroc-coUDima; te«U b / nvrowÍBg ¿owa the vamblcJ (hit miut be ftadicd. (iv) Ic btipt ia aplimliiat the engúe detifa for « particslv «prlMtioa, (hereby reduclat to*t u d túne túne..
1. 3
ObJecÜve of thls book Tb t múa objtclive objtclive of ibU book it to pment tbe theoiy theoiy u d compater compater pío* pío* {Tami neceiiuy for úmolttiiig lh« performaaee of ftconveationtl hydToearboafucUe fucUedd compreuion igaitioo (C I} «agme, for &sy &sy fael o f the form QcB^O ,. Tbe modtl descnbej the proceue* occuriog wiChia the vcrlúng Soid of « compretiioa igattios igattios eagme u d providei providei u indiaUion oí tiie liaiit liaiit** and and tresdi o f tbe pet{omaace> u » fuDC fuDCtÍM tÍM oí *ome lyitem vvUblei. Tbii wili eaable 0D« la m i wbit OBc could expect (rom in cngin* working wilbm lacb (yiten (yitenii w itblcf.
1.4
Step-by-step approach A four-itroke comp reuio a ignitioa eogiae woikj o a tbe f our-tlroke, ive-tve nt priaciple. The fivt ev«Bt« we given belov. (i) SuctioB (ii) Compreuioa • (üi) Combiulion (iv) Expuuion (v) Exbaoit Theu five five evenu are are completed completed la two revolutiou of the cr u l ibaft o f the cDgúic. Siraulatioa la thb book ti atteapted io a »tep-by-*l«p approich.
SUp SUp / / ; Al the lecoaii il tp , ideal cyclc limuUtion íj modi£td by taking fael
luto accoaat, iacoqx>rat¡ag adiabatic Same temperatnre calcolatioiu for heat add itbn/ comb utioB analyi'u. Ib ibis asalytti, ioitead of air, the working médium ú auumed to be a mixture of fuel and air. air. We wiU wiU cali tbi i analyi'u u fuel-air cycle timilation (FCS) . Kere, combiutioa is aaiumed to take place at coutant preuure and uoder adiabatic conditioa.
Síep Il¡: In tbii ttep, tbe adiabatic flame temperatnre calcutationi are modi* fied by asiomlng combuttioa to be progreulve, Le., heit release ii not ÍBstan> taneon» but ipreadi.over a period of time. In otber wordj, the duralion of combuition ii taken into account. In CI eaginei, the heat releaje releaje a oalytii can be done either by meaoj of progreuive combtutk>n at cooitant preuure, or as meani oí tero-, oae- or two-dimeiuioaal heat releau roodeli. In tbij bo okj two typei of a nilyili have been explained explained.. The Sn t oae ii the progreaiive combajtion at cooitut prcuare. The lecond oae is the progreuive combuition uiing a iux>-dimetuiaaal lingle -ione mod eL Forther, extenaion to oae> or two^tmeuiiona] modeis niing two- or mnlti-ione approach ii alio poMÍbte. We will cali tbii analyiis progreulve combuitba lúnalatlon (PCS). However, io receot yean, attempta bave becn made to uie mnUi-dimeniional models. Thii requirei high ipeed, bigb memory computen. limpUSed auampttoo i, the engine engine heat traniSU SUpp IV : In this taal itep, uiing limpUSed fer can be takeo into account by meuu of empirical eqaatioDi. Gaa exchasge pcoceiie» are inlroduced in ordtr to analyie the engine intake and exhaiut. We will cali tbii analyiti actual cycle limulation (ACS). In this itep, intake and exbauit pr oceuei using Suid dynamic dynamic equatto u, heat traaifer and frictioa are included by meani of empirical equatioas. By means of thb itep-by-itep limulatioa, the valúes of presture, volome and temperatnre at lalieat points in the the cycle u e calcutated. Work output ai well as thermal thermal eScienc y is evaluated; evaluated; Ptxmii oni have been made in the making paramelrtc paramelrtc studics. studics. Thii itep-by-step approach, Computer program for making it b haped, will make the reader appreciate the complexitiei Involvcd in actual engine limulation. Compared to other proceitcs, Ihe combustión procesa is not amenable to thermodyn amic analysis. analysis. However, an attempt has beea made to bríng combustión analyiis within the purvlew of thermodynamks. In order to get a bisic undcnlindbg of the comboitioo pcocets pertainisg to engines, tbe next two chapten are devoted to providing a bockground for analyiing the combustión combustión pheo omcni using using thcrmodyaamics. These chaptert deal with reactive processes and adiabitic Sune temperalure calculatioos, reipectivelyj
) ) ÍU i£tl n P to ctM t
) C,oHn CHjOH CiHiOH
)
) )
15.S O, hí O, J.0 O,
— —
10 CO, CO, ICO,
+ + +
11 H ,0. 2 H3O. H3O. SH,0.
No te; All the above fatU cao be a»»d ia IC cofiaca.
)
12
Heat of reaction reaction
REACTIVE PROCESSES
) 2.1 h
+ + +
Iniroducüon When k fuel come» iaU) contul with oxygea or ur nndex tke proper environmcat environmcat,, t ekesücil rMc(i rMc(io& o& ttke« ttke« plice. "^e r eictioa c»n be íioíAtnníc, whtre heit esersy ii rekued; or loinettme* ««¿otAírmiV, where Keit energy ii ilMOfbed. The híU esergy releued In ta exothamic rcKtion cin be oie4, for ex&mpk, to nm ta iatemil combaition entine. entine. In the the ui üy iú of intenitl intenitl combiutioa eagiae eagiae proctuet, we ire interated u tKe tKe itody of cxo them ic reactioni involv involviflg iflg th o« m bitancci th»t cu i be nied u fntU. In olbtr wofdi, We woold like to mqotfe into cliemic«l reactiotu opto the extent ihit ibeíe reactioni *tt i tonrce of he»t cscrgy for h'eU engin enginet, et, e«pec¡ally the íat«rat] combnitioa Bafine*. M uy booki ttlk abou aboutt nactive proctuet. L«t tu ice what it meut by » reaefiM f mvolvLag ag eAtmúoi rtwtíon c&n be coiuidered u fr roten. A pr octíi mvolvL
Ueder conditioni that promott eomboitloDi tha active cotutilueala of a fuel rtac l witk oxy feo . Thia comboitio n proceaa proceaa bvohres bvohres the ooddatioii of the carboB carboB aad bydrogea preteal in lk« fatL fatL The com butioa proce u ¡a a complex reaction or, more exaclly, a rapldly occorting atriea of rtactiotu. Whenever comboatioa occnn, the energy aasociiled wilh the chemical bon di ia the foel and oxyges molecnte* molecnte* b releaaed. The chemica) energy i< ' coaverled into heat energy and appeart Snt u a heatbg effect in the pto ds cl gue«. The final lemperaisra lemperaisra of the the prodocta of combution dependa dependa on a nnmber of faetón. The impoitant onea ara aj foUowi. (i) (ü) (ui) (tv)
the fuel and Ita Ita compoaitloa, compoaitloa, the prtaiora and tempcratorc of the reaelant mixtore, mixtore, the álate of the fael, fael, «htthtr Uqoid Uqoid or gueeoa, aad the externa] conatrainta impoaed on the reactlng »ylle ra, Le. w hether the combuition takea place at conatast volome or al conatant prcaaort.
la order to ulccJate the &bi1(«mp &bi1(«mp entor* o f the ptodscla of combaiUon, the energy characteriilica of the fail ihonld bt known. The energy characteritlica of fnela are Tariouly knova aa talKaipici of comlailton, comlailton, JteaKn; «o/vet, Ktal Ktal of eomitution eomitution uí i ktút «f ncctian. In thiabook, the tenn heat o/naction wiü be uaed.
(' ( ( ( ( ( ( r (
c
c
c
( /
c
c
) ) ÍU i£tl n P to ctM t
) C,oHn CHjOH CiHiOH
)
) )
— —
10 CO, CO, ICO,
+ + +
11 H ,0. 2 H3O. H3O. SH,0.
12
Heat of reaction reaction
REACTIVE PROCESSES Ueder conditioni that promott eomboitloDi tha active cotutilueala of a fuel rtac l witk oxy feo . Thia comboitio n proceaa proceaa bvohres bvohres the ooddatioii of the carboB carboB aad bydrogea preteal in lk« fatL fatL The com butioa proce u ¡a a complex reaction or, more exaclly, a rapldly occorting atriea of rtactiotu. Whenever comboatioa occnn, the energy aasociiled wilh the chemical bon di ia the foel and oxyges molecnte* molecnte* b releaaed. The chemica) energy i< ' coaverled into heat energy and appeart Snt u a heatbg effect in the pto ds cl gue«. The final lemperaisra lemperaisra of the the prodocta of combution dependa dependa on a nnmber of faetón. The impoitant onea ara aj foUowi.
) 2.1 h
Iniroducüon When k fuel come» iaU) contul with oxygea or ur nndex tke proper environmcat environmcat,, t ekesücil rMc(i rMc(io& o& ttke« ttke« plice. "^e r eictioa c»n be íioíAtnníc, whtre heit esersy ii rekued; or loinettme* ««¿otAírmiV, where Keit energy ii ilMOfbed. The híU esergy releued In ta exothamic rcKtion cin be oie4, for ex&mpk, to nm ta iatemil combaition entine. entine. In the the ui üy iú of intenitl intenitl combiutioa eagiae eagiae proctuet, we ire interated u tKe tKe itody of cxo them ic reactioni involv involviflg iflg th o« m bitancci th»t cu i be nied u fntU. In olbtr wofdi, We woold like to mqotfe into cliemic«l reactiotu opto the extent ihit ibeíe reactioni *tt i tonrce of he»t cscrgy for h'eU engin enginet, et, e«pec¡ally the íat«rat] combnitioa Bafine*. M uy booki ttlk abou aboutt nactive proctuet. L«t tu ice what it meut by » reaefiM f mvolvLag ag eAtmúoi rtwtíon c&n be coiuidered u fr roten. A pr octíi mvolvL reactive proceu. Then, whU ii a chemIcU rtaction? A ekemü rMiruigement of the atoms atoms of ekemüí] í] rcatlwn mt y be deEoed is < rMiruigement the reactanta dne to the redUtríbation of etcctrou lo form producía that are dlfereot froto rtacta«U. The iroplicatíoa of Ihit dcSnitioD ii tbat the namber of atomi of euh element partidpatlng is a reactun remami nachauged, i-«., the coue ivat bn o f matter. matter. Thú principie principie willbe willbe oaed in writing writing the eqm tiou for chemical reactiou. It ti known that a cheniicaliy correct or itoiduooietric mixture of hydrocarbón fuel aad air reacU to produce oaly HjO or COj or both. Fot example; H,0, 0.5 0.5 0 } — + Ha C 0„ CO 0.5 0.5 0 , + 2 H ,0 ,0 , COi + 2.0,0, 2.0,0, -> CH« + 9 H , 0, 8 COj + 12.6 12.6 0 , C,U„ +
l }
Ki i I;
I
15.S O, hí O, J.0 O,
No te; All the above fatU cao be a»»d ia IC cofiaca.
)
I
+ + +
)
i;
•I
(i) (ü) (ui) (tv)
the fuel and Ita Ita compoaitloa, compoaitloa, the prtaiora and tempcratorc of the reaelant mixtore, mixtore, the álate of the fael, fael, «htthtr Uqoid Uqoid or gueeoa, aad the externa] conatrainta impoaed on the reactlng »ylle ra, Le. w hether the combuition takea place at conatast volome or al conatant prcaaort.
la order to ulccJate the &bi1(«mp &bi1(«mp entor* o f the ptodscla of combaiUon, the energy characteriilica of the fail ihonld bt known. The energy characteritlica of fnela are Tariouly knova aa talKaipici of comlailton, comlailton, JteaKn; «o/vet, Ktal Ktal of eomitution eomitution uí i ktút «f ncctian. In thiabook, the tenn heat o/naction wiü be uaed. 2.2.1
Oelinhton Oelinhton of heat heat of reicüon rtaclún at The leal of rtaclún at coiuUnC tofinu, tnJ a tnJ a ( ceiutan ceiutantt pm ivr t, Hrp, M áefineii lu áefineii lu lAc t n t r f f t i i t i i o (rín; o (rín; (X< prodvtU 0 / comU >l>on to the inih'aJ Umptratun, m . 198 K, vktn > anít gMiiliry o f f nt nt l m i um ct OTfjen OTfjen ( u m at conitint conitint toltmt toltmt 0t *l uiulant prtii tn, rtiptelítclf. rtiptelítclf.
The impUcationa impUcationa of the above definitlon are u foUowi. foUowi. (i) Ur^ and Ilrp are both negalhre. Hrp are prbperttei of the fneL (ü) Uff and Hrp (Si) Urf and and H,p refer apeclScaQy apeclScaQy lo chemlcalty co tm t fueUutygen mixtorei reactlng at 29t K. it may be noled that both
and i/rp are are meunra ble quantltiea. quantltiea.
f l
(. (
( Rtt cün
Com ftU t SüülUilo» •/Ct SMfiat PntMMt
( (
Foc ti t Ma iytit oí (Bfue tombo ilion, we we will dcEnc two rtl^tcd rtl^tcd eatr jy ’ u n i u , Q , a n d Q,-, Q,-, w l i « « tbc U n a < J, J, . U i u i* i* f o r e » e r * y w U u t U c U c o w t u i t
Imulatioa
volo volomi mi ud Q „ tht mtrsf rtUu* rtUu* al cooiUat pr«uurc.
( (
Í Í 7
DcSattIoa ol Q , «nd Q ,
(
T h* h* t i i t m r t U u t i «I u u í t i t U 9c h m t , <3„
oiKÍ oiKÍ 0 «< r t U v U o t e o n t l a nf nf
<
pnint rt, Qp, «Tt dtfint i 44 Út kt»t tMrfiti nUutd, «A«i» tkt proJueit en ' caoítJ tú (Ac to«¡tive. They «rt propertií* oí th« reielmt N*U: Q , u d Qf wt '.tnvtBft, r(ítrr»d to »ny Ump
( (
(
rtullo*.
(
2.3
Musurement oí
c c
V ,,
L«t u tuu mt tb ai » ditmical rcietioa lii e i pUce in a clostd rígú rígútt container container oí iu d volome. L«t tht tht laUcrípti r, p and v denote the reactaata, tbe * prodacl* and tk« volnmt, r«tp«cUv())r< «yitem can b« writlea u
Q,~W
=
Ay.
(2.1) (2.1)
Since Since (lier* (lier* ¡i no change change in (lie voiuoe c f the fjritem, fjritem, Le. K' « O, cq.(2 .l) becomei g.
=
á u .
(2.2)
FJg.3.1 Bon^ ul orímtU r withoBt deíonnation. If there i« « deíonnattoo, irark will be done on the veuel by the product gaies and the reeol u repoited bccom e ipurioss . The v c i m I is placed in a Urge tab containing water al rooni temperatore and ii leít íor a period *o that temperatnre eqnilibriiim eqnilibriiim ai veD ai ihorough mixtcg o í fael and oxygea ii achieved. achieved. The fuel fuel is igtiited igtiited a ipwk plag. Heat U traniíeired to (he water through the the waüi o í the veueL The entire eyitem, which íi íninlated
c ( <
c
c
{
(. (
( (
Rtt cün
Com ftU t SüülUilo» •/Ct SMfiat PntMMt
(
Foc ti t Ma iytit oí (Bfue tombo ilion, we we will dcEnc two rtl^tcd rtl^tcd eatr jy ’ u n i u , Q , a n d Q,-, Q,-, w l i « « tbc U n a < J, J, . U i u i* i* f o r e » e r * y w U u t U c U c o w t u i t
(
Imulatioa
volo volomi mi ud Q „ tht mtrsf rtUu* rtUu* al cooiUat pr«uurc.
( Í Í 7
DcSattIoa ol Q , «nd Q ,
(
T h* h* t i i t m r t U u t i «I u u í t i t U 9c h m t , <3„
oiKÍ oiKÍ 0 «< r t U v U o t e o n t l a nf nf
<
pnint rt, Qp, «Tt dtfint i 44 Út kt»t tMrfiti nUutd, «A«i» tkt proJueit en ' caoítJ tú (Ac to«¡tive. They «rt propertií* oí th« reielmt N*U: Q , u d Qf wt '.tnvtBft, r(ítrr»d to »ny Ump
( (
(
rtullo*.
(
2.3
Musurement oí
c c
V ,,
L«t u tuu mt tb ai » ditmical rcietioa lii e i pUce in a clostd rígú rígútt container container oí iu d volome. L«t tht tht laUcrípti r, p and v denote the reactaata, tbe * prodacl* and tk« volnmt, r«tp«cUv())r< «yitem can b« writlea u
Q,~W
=
Ay.
(2.1) (2.1)
Since Since (lier* (lier* ¡i no change change in (lie voiuoe c f the fjritem, fjritem, Le. K' « O, cq.(2 .l) becomei g.
=
á u .
(2.2)
The chango ¡a intemal energy doe to the chemical reaction it jiven by
¿y
(2.3)
-
The (ubeeripta i and / itand for the varioai varioai ipccie* in (he prodacta and rcactante, respectiveljr, and /f repreaenle repreaenle the number oí molee oí the»e apeciu (fael, oxytc a, carbondioxide, carbondioxide, etc.), and S i< i< the ipecific inteniU inteniU energy u kJ/WI. Since there are at leut two reactuU and often thue U more tbas one ptodact o í reuti on, the lununatioo lununatioo tiga tiga i* sied in c<}.[2.S) c<}.[2.S).. Tkt quantity U,p u meuutd uiag t coutant-volu me bomb calorimeter. calorimeter. A icbea iatic d iafra m oí the bomb c aloiimetcr ii eb own in Fi(.2.1. A meu ure d quantily o í Ihe fnel alan; with e xce u air ti introduced inlo k rigid vcaMÍ, which ¡i deilgned to wilhitand the hi(h preuure oí combiution
c
FJg.3.1 Bon^ ul orímtU r
( <
withoBt deíonnation. If there i« « deíonnattoo, irark will be done on the veuel by the product gaies and the reeol u repoited bccom e ipurioss . The v c i m I is placed in a Urge tab containing water al rooni temperatore and ii leít íor a period *o that temperatnre eqnilibriiim eqnilibriiim ai veD ai ihorough mixtcg o í fael and oxygea ii achieved. achieved. The fuel fuel is igtiited igtiited a ipwk plag. Heat U traniíeired to (he water through the the waüi o í the veueL The entire eyitem, which íi íninlated againit heat traoiíer to the iniroundingi, come* io temperatore e
c
c
{ (
c c
Por oct&ne (C|Hn)i the v;ilac of Utp c&n be cilcuUUd u yr(2 yr(298 98)) »(¡ Ic ,H „+ (12 (12.S .S + i)C o, + 5.76( 5.76(12 12.5 .5+ + i)Ü N ,l„„
where x denotes the narober oí molei oí exceu ozygen and 3.76 ii the ritió oí N) to O) in air, calculated on molai buii. Sobililutiag eqt.(2.5) and (2.6) in eq.(2.4), íre hive t/,p = [8ü c o , + 9 5 h , o - S c . H u - 12.5ü o ,1 j „ .
(2.7)
1 )
8
Coapattc StmaUtha o f CI Eofice Pníeuct
ÍU uU rt PfocuMíí
If Ihe Ihe •(«cific «nlliiJpitj of thí vino iu cotutUuenlt cotutUuenlt »r« kaown, t/,p cu be from «j.(2.7).
2.4
Mcasurement Mcasurement of The he»l of ríiclkm it coiut»nt prewure, i/rp, U meunied in t lUuly-aow cilorimtter. The detüb tliown in Fig.2.2 »it refaced to the b»r« eueotiJj. Fuel tnd »ir ¡n txcttt oí the ehemiciUy torree» rcqnirement enter the re»clioa thimbtr it 298 K, md Ihe producU trt cookd to the inlet temp«r»tore by the the wxter circuUtiog La Ihe lorrounding jidcet.
The lubscripU r, p and w reíer to the rtactaoti, prodacl* and coolúg water, re»pectively. The tenn* tenn* íj, and refer to the the InW InWt and oo tk t water temperaturti, retpectively. The kft-haad ild* of
Ifn
For exampk, whes decaae (dieMl); C|oHn, b bomt, the two tcmu ob the ríghv-hand lide of eq.(2.I2], with z denotiof the moki of txceu oxygea, can be wrítten a*
Ccxitrol volume
I
9
Products ‘ 298K
(2.1S)
(2.K)
for decane ¡s {¡ven by = [lOÍcOi + Il^HiO
(2.15)
The point to be noted in tht meaiaremeot meaiaremeot of U,p and b that th« rtactaat mixture contalni exceia exceia ur, u d not cbemkally earrect oxygen. Tfaerc are three rtaaoni for maiia| meunrementa nilni ejceeai ain (i) Air b rcadily tviilablt whSt cxygen b not. (¡i) A chemicaUy correet fne)>
1 )
8
Coapattc StmaUtha o f CI Eofice Pníeuct
ÍU uU rt PfocuMíí
If Ihe Ihe •(«cific «nlliiJpitj of thí vino iu cotutUuenlt cotutUuenlt »r« kaown, t/,p cu be from «j.(2.7).
2.4
Mcasurement Mcasurement of The he»l of ríiclkm it coiut»nt prewure, i/rp, U meunied in t lUuly-aow cilorimtter. The detüb tliown in Fig.2.2 »it refaced to the b»r« eueotiJj. Fuel tnd »ir ¡n txcttt oí the ehemiciUy torree» rcqnirement enter the re»clioa thimbtr it 298 K, md Ihe producU trt cookd to the inlet temp«r»tore by the the wxter circuUtiog La Ihe lorrounding jidcet.
The lubscripU r, p and w reíer to the rtactaoti, prodacl* and coolúg water, re»pectively. The tenn* tenn* íj, and refer to the the InW InWt and oo tk t water temperaturti, retpectively. The kft-haad ild* of
Ifn
If the chingei in (he kínetic u d potentiil caergie* caergie* are Degligibl Degligible, e, u U uíuilly the e i« , for a ittadjr-fiw ceaiervilion of ener?y ener?y
i|
ti
/í. (2 98 ) + / f , ( t „ )
=
ffp( 29 8) + i/ .(í <, ui ),
(2.8}
/ í- ( t u . ) - /í - ( » . u . )
=
.f fp (2 9 8 )- /í ,( 2 9 8 ).
(2.8)
(2.1S)
(2.K)
for decane ¡s {¡ven by (2.15)
= [lOÍcOi + Il^HiO
‘ 298K
i|
(2 . 12 )
For exampk, whes decaae (dieMl); C|oHn, b bomt, the two tcmu ob the ríghv-hand lide of eq.(2.I2], with z denotiof the moki of txceu oxygea, can be wrítten a*
Ccxitrol volume
I
9
The point to be noted in tht meaiaremeot meaiaremeot of U,p and b that th« rtactaat mixture contalni exceia exceia ur, u d not cbemkally earrect oxygen. Tfaerc are three rtaaoni for maiia| meunrementa nilni ejceeai ain (i) Air b rcadily tviilablt whSt cxygen b not. (¡i) A chemicaUy correet fne)>
(2. 10)
H
The temperatore tabt aipl hu been dropped lince lince itit b nndento od alwayi to be 298 K. For f u n , we can can write write
The left-hand lide cf eq.(2.9) can be wrillen ai / f . C . { í ,. - t o u .) -
(2.10 ;
X -H
RT
(2.17)
c
„ :í i ....
( (
10
i{«ictiv« Pn ccu tt
ComputtíSin^UtioñctCitMglauPi » b t ( « R ii th« onivinal ( u coajUnt, úace tbc «atli «atliaJp aJpyy Ti «ad iatcnial caersy D v « la BuU ptr mo b. For tiqúiU kwl lolid* lolid*
K- 0
w
0.
Th« difftnac* b«lw*«a Ihe cotu iut-p rcuo n u d coiutu coiutuiU\' iU\'olaiiie o laiiie k«at k«at oí
[N ,-N ,)R r .
=
the the coiutuit-piuiare he^ of reictioa with with gueoiu H3O, H3O, the the conit ut-p reuu fe h<^ cf reittion with liqutd liqutd H3O. H3O.
Tbeo
ntctloa mijr (bta b« wirUUa u
u „-v „
Hr¡, Hr¡, =
2 4 8 0 ( A V - / r ,) ,
wbtr* Nf u u d Nf dto dto oU , re*pc«tiv«l/, the mole mole niunber niunber in the product w d is lh< nictutl mutu« U thi thi | m ou ip«ciei for &ckemlu &ckemluUy Uy correet correet fie)
2.S CiIcuUtio CiIcuUtion n o( highe higherr «nd «nd bn w h u t valué valué of fuds fuds • Coulder the fuel fuel CiHn . We caa wríu the the ntctio a eqoition u C,Hj,
.S
8C0
( (
Í^K.oxR;,(H,0).
(
Witii
(2.18)
(2.19)
(
(
4J9S8 4J9S8 kJ/ kmol,
With R = t.SU kJ/kmol-K tsd T « 29$ K, lb« vilne vilne of (he prodact prodact JtT will will be 2477.S7, 2477.S7, wkicb cu b« kpjiradmUtd to 2480. Tliiu, *»
• Couádcr the íoel, Cio H », We c u write the reiction equUion u CjoHjj + 16.50, 16.50,
13.5 13.5,, 17.
-
c
lOCOj lOCOj + IIH3 IIH3O O
c
c c
Firom Tibie 2.4, for gueoui CioH» and gueoiu H^O, «re hive
Htf =
fVam fVam IVbk 2.i, for for (uc oo i C|Hk u d gueoiu E] 0 ú tho tho prod product uct =
(
S9Sfl04 kJ/kmol,
=
8 C 0a 0a + « H , 0 ,
N, »
(
6x43959
2.S CiIcuUtio CiIcuUtion n o( highe higherr «nd «nd bn w h u t valué valué of fuds fuds • Coulder the fuel fuel CiHn . We caa wríu the the ntctio a eqoition u
(
Witii
(2.18)
wbtr* Nf u u d Nf dto dto oU , re*pc«tiv«l/, the mole mole niunber niunber in the product w d is lh< nictutl mutu« U thi thi | m ou ip«ciei for &ckemlu &ckemluUy Uy correet correet fie)
C , H j , + 1 2. 2. S0 S0 ,
(
Í^K.oxR;,(H,0).
With R = t.SU kJ/kmol-K tsd T « 29$ K, lb« vilne vilne of (he prodact prodact JtT will will be 2477.S7, 2477.S7, wkicb cu b« kpjiradmUtd to 2480. Tliiu, *»
-5089100 kJ/kmoL kJ/kmoL
Urp =
-6312300 -6312300 kJ/kmol, kJ/kmol, -6312JOO-(21-16.5 ) X 2480 2480
c
-6323460 kJ/kmol (>ee (>ee Tibie 2J!).
c.
W« cta now cilculite U,y uu| eq.(2.18):
U,f = =
=
-5089100 - 2480 2480 X (17-I J.6 )
t chsage of leu thui 0.2^,
-S0977Í0 kJAmol {*« TibU 2.2), 2.2),
» chu ge o f leu tbaa 0.2%. 0.2%. It u a «uUy be ehoirn thU the effcct of coaduulsg the wiUr Vipoor in the prodact oa Htp uid U,^ U,^ v»Iac* U qn¡l« «abitutiü. Let
L«t Ejf denote the coMlwit-preuart heat of reutioa with
c j »m o i u
HjO in
the product, tad let let denote the conitsa t-preu ure heat of reactioa «¡t h liqold E] 0 in tbe product. Kow
Similuly, it « n be «hown tliit Ibc cBinge in th< th< ü,p v»lue will ilf o be of Ihe tune onler. onler. Tte ibort cilcnUtbai «how lli»t wUl* Mcorint htxt of reMlion i^ae» from publálied t»ble*, greite tt « r e muit be txíKÚ ed to note ihe con<ütio con<ütion n of HjO m ibe producl. Al menlioned e»rD«r, e»rD«r, aonn üly, the term /oo er ctlorific ctlorific Hr^ or U,^ for ihe c»ie of futouM HjO in tk* pnxiact and the vdue refer» lo Hr^ term kifher cdorific vxlue to tho«e for the cu e oí HjO ia ihe prodnct. T&blei 2.1 »nd 2.2 liit Ihe Utv Utv »»loe i for ywioiu fael» ibU c»n be tued in the ukDlUioa oí temperitore ríse ríse due due lo hctí of rckctioo in tatemil comb oli'on enjinet. Similirly, Similirly, Tkblej 2.J »nd 2.4 2.4 Ikt the the v»lae« for vtriotu fnel». fnel». When the ind v»loe$ üited in the tibi e t n divided by the mokciilir weight, weight, the uníü ire converted to kJ/kg wilh numericU reítilt» reítilt» thit differonly •liíhtly. •liíhtly. It m»y be ooted th a the eoa»t»nt heU oí rewtton per ttnll ttnll bim ú hydrocarbon Kríet. k chiru teriitic of the hydrocarbon
) \.
‘í I
I
Tkble 3.1
í I;
rucl
Urp co rp co ulut-v olum * heat of reiction reiction rttuci for Ihe ciM of Uqutd Uqutd H} 0 bi thi prodoct FormuU
M o l wt .
IS
tli« cue oí Ury coM Ury coM tut.rolBtne he»t ol ftitlloa for tli«
P M o» HjO Ib Ib Ibt Ibt prodtct prodtct
Witk A/, (H ,0 ) = 43956 43956 kJ/kmol, we we h»ve h»ve
(
( c
k
i
( (
the the coiutuit-piuiare he^ of reictioa with with gueoiu H3O, H3O, the the conit ut-p reuu fe h<^ cf reittion with liqutd liqutd H3O. H3O.
Tbeo
ntctloa mijr (bta b« wirUUa u
u „-v „
Hr¡, Hr¡, =
11
Liqnid fael kJ/ k l k J/ J/ k
GMeooj fad kJ/kmol kJ/kg
F\iel M ethue £(htoe Propine n-Bntue n-P en en tu tuie n-Htxine n-Heptue n>Octane n-Nonane n-Decine Methuol Ethanol Bentene
tli« cue oí Ury coM Ury coM tut.rolBtne he»t ol ftitlloa for tli«
P M o» HjO Ib Ib Ibt Ibt prodtct prodtct
Witk A/, (H ,0 ) = 43956 43956 kJ/kmol, we we h»ve h»ve =
11 X 43955 43955
=
483516 kJ/kmol.
F\iel M ethue £(htoe Propine n-Bntue n-P en en tu tuie n-Htxine n-Heptue n>Octane n-Nonane n-Decine Methuol Ethanol Bentene
Thcn. - M 1 2 3 00 00 - «3 «3 5 1 6 )
i
«
-e795SI6 kJ/knioI, kJ/knioI,
)
t chuije of more {h»n 7.0%.
)
Similuly, it « n be «hown tliit Ibc cBinge in th< th< ü,p v»lue will ilf o be of Ihe tune onler. onler. Tte ibort cilcnUtbai «how lli»t wUl* Mcorint htxt of reMlion i^ae» from publálied t»ble*, greite tt « r e muit be txíKÚ ed to note ihe con<ütio con<ütion n of HjO m ibe producl. Al menlioned e»rD«r, e»rD«r, aonn üly, the term /oo er ctlorific ctlorific Hr^ or U,^ for ihe c»ie of futouM HjO in tk* pnxiact and the vdue refer» lo Hr^ term kifher cdorific vxlue to tho«e for the cu e oí HjO ia ihe prodnct. T&blei 2.1 »nd 2.2 liit Ihe Utv Utv »»loe i for ywioiu fael» ibU c»n be tued in the ukDlUioa oí temperitore ríse ríse due due lo hctí of rckctioo in tatemil comb oli'on enjinet. Similirly, Similirly, Tkblej 2.J »nd 2.4 2.4 Ikt the the v»lae« for vtriotu fnel». fnel». When the ind v»loe$ üited in the tibi e t n divided by the mokciilir weight, weight, the uníü ire converted to kJ/kg wilh numericU reítilt» reítilt» thit differonly •liíhtly. •liíhtly. It m»y be ooted th a the eoa»t»nt heU oí rewtton per ttnll ttnll bim ú hydrocarbon Kríet. k chiru teriitic of the hydrocarbon
) \.
‘í ( I
I í I;
rucl
FormuU
Methine Ethine Propin e n-Bntue n -P -P en en tu tu e n-Hexine Tv-Hepl»ne n>Octane n-Noatae n - D ícia e M tt tt hi hin ol ol Eth&nol Beniene
298.16 K) • 43956 43956 kJ/kmoL kJ/kmoL UoU: For H ,0 J¡„ (25*C, 298.16
Eterdsc Wriu t compsUr progrim progrim to calcuUU calcuUU tHc tHc kt»t oí rcKtioa ia kj/km ol u d ia kci¡/k[ lor th« foUowúg faelj, for tbe etglit (ooditioiu givcn ia tbe C»Hu, C „H a . CHjOH, CaH CaH*O *OH, H, CH,. CO. H,.
( ) C j 0
ADIABAT ADIA BATÍC ÍC FLAME TEMPERATURE
( ) C ) c>
C' C ' 3.1 introductíon VirtuaUy «v«ty probUm bvotving comb oilion wiQ úrvolvt úrvolvt tbe ctk ok tia n of «dúbatic flime tcmpcnto n. Tli« SsU Ump], (U) (U) tbe cbemiul compodlion oí tbe re»c lu t mixlnre, mixlnre,
c
c
(
( ;c 1 c
c
( ) í. '
Compatu Simulit Simulitloa loa ol Cí Eaflot en cta ttt
H
( .)
coutul-pnwBr* btU oT nulloa for Uie cut ot Utf
T*bl« 3.4
( )
(UMU HaO HaO U U « pnxlMt pnxlMt
FbnauU
T í ü ís r " EtkMt Prop»a« fvBulu* tv-P«ntue n-Hexu>« n-Htptue n-Octwi< n-NoBue iv-Dccue Mttbuol Etbksol B«aiutt
3.1 introductíon VirtuaUy «v«ty probUm bvotving comb oilion wiQ úrvolvt úrvolvt tbe ctk ok tia n of «dúbatic flime tcmpcnto n. Tli« SsU Ump
Eterdsc Wriu t compsUr progrim progrim to calcuUU calcuUU tHc tHc kt»t oí rcKtioa ia kj/km ol u d ia kci¡/k[ lor th« foUowúg faelj, for tbe etglit (ooditioiu givcn ia tbe
298.16 K) • 43956 43956 kJ/kmoL kJ/kmoL UoU: For H ,0 J¡„ (25*C, 298.16
CoMtr>lnt Co utu t volsm volsmee Co njtu t volu volutn tnee C ou tu t volu voluta taee Cou tast volum volumee Co&itut preuure preuure Conitaal preuure . Conttut prtuure Comlant preuure
tbe fael(>], tbe cbemiul compodlion oí tbe re»c lu t mixlnre, mixlnre, tbe pretsor« pretsor« of tbe rcactut mixture, mixture, tbe temperatnre temperatnre oí tbe rea ctu t mixtore, tbe coiutrúnU oo tbe lyitem, vii. wbetber tbe tbe combiutioa tiicci pU
Fbeli witb dlferent bydrogea.(o.carboD ratiot produce differeat Bame temperaturef. Likewite, Likewite, u tbe eo mpo eitb a oí tbe reactant núxture núxture variet variet (le u , cbenúcally cbenúcally correct correct orricb) , tbe flame flame temperatn temperatnre re abo va ria. Fttei-oxygen Fttei-oxygen mixtur«< mixtur«< produce bigber Umperatnret Ib u fuel-air mixtar a witb u equirakat oxyges oxyges cootCAl; cootCAl; tbe altrogen altrogen pr««eat in air b tMentially tially ioert u d , a i tncb, doe« doe« Bot contríbaU contríbaU to tbe combutioD reaction bat mer«]y ab«orb« caergy. A kigberiaitia i temperatur temperaturee of th« reactaat imxtare imxtare before com bn itb a iacrease* crease* tbe tbe &am &ame teraperat teraperatire. ire. C oula nt-v olna e «u sbu tíon doet oot tranxí tranxíer er work to tbe tnrroiudia gi u costraat to couitaoC-pcewaTe couitaoC-pcewaTe combu jtion; bence, tbe «diabatic fliioe temperat temperature ure at conitaat-voli conitaat-voliuae uae k mucb bigber tb u that
•a-
le
at cooíUaVprtJJure. FWther, the reutinC prainre c»n »1ío »ff«t lh« flune
AdUbttIc F li at T ^ p tn tv t
1 mole' ¿f fnel fnel + ^ 0 , +3.T
$ y
y > ^ . N i^ O ,
N i ^ 2 { Y - Y ^ ) ,
ff , « N „c , U 3 = O.SNmH„
3.761', íf i = 3.761',
í 1 ÍV )
(3J)
= S.liY, A i - r - n c
Complete Complete combustión In C-H -O -N systems AaTO AaTOtn tnin ingg complete combuition, we can decide the compo«itton of the convconvbwtio n prodn cli merely by inipectüig the reactant reactant mútnre. For a reactant reactant mUtore (bat contain* C, B, O, N aloms, aloms, we will formoUte the rolíJ ai foUomrj;
n-
11
Henee, for a reactant mixtore conlalnug
Ni = 0. 3.2
(i) (ü) (üi) (iv)
AU bydrogen ú fin t caúdiied caúdiied to HjO. Alt carbón i* initially initially
Keeping m núnd the abcve rtJe«, let
(
( ;c 1 c
c r \ Q
C C C c;
c
’C
Computer SimnItt SimnIttloB loB of C1 Ecx/oe Prx Ecx/oe Prx eu< » Umperatu^e. AccQr»t< AccQr»t< d ka lit io n of the a im t Umpcratnre inv olra a « ( of conipU conipU-ctltd tqaUioo*. tqaUioo*. Howívtr, for two reuo iu we wfli confine our alUntion alUntion only lo a limpie fct of eqaatiou: ( ] Accorate caltola tioa Un<]i Un<]i to obtcore the phyilcj of what is taidng taidng plice. (ü} Approodmat Approodmatee flune temperatnn computation oftcn prodsccs jooJ altboogh we cajuiot w y how good nnlU nnlU appranmale and atcurate atcurate vaina are compareá. T le adiib atk flatne flatne tempcratnn calcnlatíoni, tí done mannally, mannally, are car* car* ried OB OBI by IrUl aad error. Tbi i can t>« t>« done very eaaüy eaaüy by a lytUma tic teirck willi a compatcr. Th» main empliasa in (bii cliapter will b« toward» ttU *nd. *nd.
c
Ni Ni throagh Nt cao Nt cao be uied ai lubtcríbed vamblet in the Computer program, 10 that the inbtcript* 1 lo $ can be made to denote (3.<) Witb the abovt background, we wQl sow examine the calculation of adtabatic íame temperature for (i) eoMlant-volame corobuitton, and (ii) conitant
le
AdUbttIc F li at T ^ p tn tv t
Computer SimnItt SimnIttloB loB of C1 Ecx/oe Prx Ecx/oe Prx eu< » Henee, for a reactant mixtore conlalnug
at cooíUaVprtJJure. FWther, the reutinC prainre c»n »1ío »ff«t lh« flune
Umperatu^e. AccQr»t< AccQr»t< d ka lit io n of the a im t Umpcratnre inv olra a « ( of conipU conipU-ctltd tqaUioo*. tqaUioo*. Howívtr, for two reuo iu we wfli confine our alUntion alUntion only lo a limpie fct of eqaatiou: ( ] Accorate caltola tioa Un<]i Un<]i to obtcore the phyilcj of what is taidng taidng plice. (ü} Approodmat Approodmatee flune temperatnn computation oftcn prodsccs jooJ altboogh we cajuiot w y how good nnlU nnlU appranmale and atcurate atcurate vaina are compareá. T le adiib atk flatne flatne tempcratnn calcnlatíoni, tí done mannally, mannally, are car* car* ried OB OBI by IrUl aad error. Tbi i can t>« t>« done very eaaüy eaaüy by a lytUma tic teirck willi a compatcr. Th» main empliasa in (bii cliapter will b« toward» ttU *nd. *nd.
1 mole' ¿f fnel fnel + ^ 0 , +3.T
$ y
y > ^ . N i^ O ,
N i ^ 2 { Y - Y ^ ) ,
ff , « N „c , U 3 = O.SNmH„
3.761', íf i = 3.761',
Ni Ni throagh Nt cao Nt cao be uied ai lubtcríbed vamblet in the Computer program, 10 that the inbtcript* 1 lo $ can be made to denote
Witb the abovt background, we wQl sow examine the calculation of adtabatic íame temperature for
AU bydrogen ú fin t caúdiied caúdiied to HjO. Alt carbón i* initially initially
Keeping m núnd the abcve rtJe«, let
1 ÍV ) t. ) í ; f.. ) b;
JV„C+0.25A'„H,-0.5ír„o.
(3.1)
Let Knta denote the minimntn amonnt of oxygen re
11-
i
(3.<)
(i) (ü) (üi) (iv)
í
A i - r - n c
Complete Complete combustión In C-H -O -N systems AaTO AaTOtn tnin ingg complete combuition, we can decide the compo«itton of the convconvbwtio n prodn cli merely by inipectüig the reactant reactant mútnre. For a reactant reactant mUtore (bat contain* C, B, O, N aloms, aloms, we will formoUte the rolíJ ai foUomrj;
(i) eoMlant-volame corobuitton, and (ii) conitant
3.3
Constanl-volume «diabatlc combuslion combuslion An illnitnUioa oí the problem ii givtn in Fig.3.1. Fig.3.1. The rea ctanli at temperatnre 29S K and preunrc P, are ignited and both the flame temperatnr* T aad the Eoal preunre art lo b« calcalated. Since presiure and and temperatar* are inteaiive inteaiive qnaatitiei, qnaatitiei, the líie of the vtiaet li of ao coacera, and they are independeat of the «yitem. ^ A «aU !• tk* tk*
{ 3. 3. 2) 2)
tt ««biUSM •( a «n liK
«MtUiu u aMi aMigr g r tUwm twr
rRtII rRtIIlMM lMM llMn wt cmrWa u t u U O.OIt OIt t| cwVm. T>< T>< •li ais ur r lUllln B ul lIMcUrd IkfT mhf mhf loiladt loiladt u«im, B*l««ki, Uu, «Iniraaa m»4 «Urr putJcUi w * ((Htlltd ((Htlltd fno p
»
i )
c ( ( IB
Ádiibttlc f U a t Tu np tnt an
Computv Simt SimtJt JtUo UoB B ol Cl Eaflat F n ct tt t
(
10
Sobítituling the viloe of 5 c , h „ £»n» tq.{S.10) lato eq.(3.9) uid íimpliíyúif, •re |«i
U miy b« Doled thtt tke left*hAnd tide of eq.(3.11) á t. mcMiuAble qnu(ity tad the rl(ht-huid úde eonttúu pún of ialernal «nei^y diffenncu. c . « W K - i o á i' i'^ n c Flg.S.l
Eqaatiooj (S.S) to (3.7) rcmun nodivoged. In plt£« of eq.(3.S), w« cía oow write
l7p( l7p(T) T) = (2(1 (2(12. 2.S S - yjüco t í í ! ' - 8^)Cco. +8 5h,o +S.76KwN,lr +S.76KwN,lr (S.U) (S.U)
( ( ( ( (' (
Proc<«d¡n{ u io the prtvioos prtvioos cu «, we h»ve h»ve C|H i,+yO, + J.7ar J.7arNa. Na.
(
Síbm tke coaiibulloa takc* pl *u ia » rij ii iiualited iiualited Üi*w Üi*w b no work »ad kcU Utiuftr. H«bc«, H«bc«, thc thc tn «i y «ittUíon »n b« wriltta M t/,(2M)
Por genenlity and ia »«ord»ac« with eq.(3.ll), wt aeed lo tna ifana the the t<{.(S.H) t<{.(S.H) kt o » fona thit conttiai oniy pi in of [atersil eaergy eaergy differescei differescei oa the nght-bud (id«. We Mn d» ¡t by «dding »ad (obtmlisg the tcnn* 2(12.5-y)5Zco(29fl)
tad
2(K-8.5]Sco,(298)
c ( c
c
c ( ( IB
10
Ádiibttlc f U a t Tu np tnt an
Computv Simt SimtJt JtUo UoB B ol Cl Eaflat F n ct tt t
(
Sobítituling the viloe of 5 c , h „ £»n» tq.{S.10) lato eq.(3.9) uid íimpliíyúif, •re |«i
U miy b« Doled thtt tke left*hAnd tide of eq.(3.11) á t. mcMiuAble qnu(ity tad the rl(ht-huid úde eonttúu pún of ialernal «nei^y diffenncu. c . « W K - i o á i' i'^ n c Flg.S.l
Eqaatiooj (S.S) to (3.7) rcmun nodivoged. In plt£« of eq.(3.S), w« cía oow write
l7p( l7p(T) T) = (2(1 (2(12. 2.S S - yjüco t í í ! ' - 8^)Cco. +8 5h,o +S.76KwN,lr +S.76KwN,lr (S.U) (S.U)
( ( ( ( (' (
Proc<«d¡n{ u io the prtvioos prtvioos cu «, we h»ve h»ve C|H i,+yO, + J.7ar J.7arNa. Na.
(
Síbm tke coaiibulloa takc* pl *u ia » rij ii iiualited iiualited Üi*w Üi*w b no work »ad kcU Utiuftr. H«bc«, H«bc«, thc thc tn «i y «ittUíon »n b« wriltta M t/,(2M)
Por genenlity and ia »«ord»ac« with eq.(3.ll), wt aeed lo tna ifana the the t<{.(S.H) t<{.(S.H) kt o » fona thit conttiai oniy pi in of [atersil eaergy eaergy differescei differescei oa the nght-bud (id«. We Mn d» ¡t by «dding »ad (obtmlisg the tcnn* 2(12.5-y)5Zco(29fl)
I/p(r) = 18000. + W h . o + (i' - U.S)Co. + 3.76KuM, 3.76KuM,lr* lr*
|»aco,+M B.o + (V'-lJ-6)no,+3.76yvH ,!r.
( J. J. 9) 9)
(S.I (S.IS) S)
[ S í c O i + W u , o - 1 2. 2. S C o ,1 ,1m , - l ^ r p
r
The importaat point al thU jioclcre b to ttcogakt Ibe tcnn
C
( B o o + 1/ 2^ 2^
r-
-^Oi)»|
a« the heat of retclion U^ , for the dÍMOcialio dÍMOcialioaa o f CO 3. Now, Now, t/^ u a be compnUd oaag iha nlalion nlalion
FVom FVom cq.().fij wt c u writt ® Ci Ci Ki Ki i
C
(»•> (»•>))
+ l'Co,+S-78 ü h ,1, j , -
c
-U^ - 2(12 2(12.5 .5 - y)(Oco + 1/Wo, -
The »bov« íour íour eqnUloM eqnUloM Ie
c
c
(5.7) (5.7) = 2(12.5-y 2(12.5-y )A 2 co + 2( K -8.5)¿ -8.5)¿LUCO. + ÍAUh . o + 3.76^^ %,.
(
c
2(K-8.5]Sco,(298)
on the righUbud lide of «q.(3.1i). We cía groap them tad óblala
y.(J9í) = (Ec.h„ + YX¡0. +3.7 6yC K,l«.,
c
=
{ 3 -1 -1 0) 0)
C
c c
Jrp-24f|[Ap-//r).
r C'
30
Arf/t bilk n un * nmpcn lBra
CoapnUr Simdithci of CI EnfUe Procttsc»
31
The vilue o( //,p whkk ú » po«ilive he»t of re»ction for COj c»n b« found
from ttimdixd hmdtxxiki to be 282ÍOO kJ/kmoL Tbtrefore, (t/,p)co,
=
212*00-2480(1.5-1)
=
281560 281560 kJ/kmolCO a
a
281600 281600 kJ/kmatCO i.
The rtjulls of the two cuta of Y, vil, Y >Y,f »oJ »oJ Y < < Ytt, »re tivín by Ya, we eould »dd tbe tcrm tcrm WjA uco o® right-hujd tide of eq.(S.ll) wilhont wilhont iffecting iffecting ¡U vilidity. SimIUrly, SimIUrly, w« c u iJd oa tbe ri|bt-h»nd «ide of e.(S.ll) uid (3.15) tike Ihe íorm
Q, = ffi AU co + ^ j A u c o i + ^ j A ü h jO Ní¿.X¡h, + Ni&mo, jO + Ní¿.X¡h,
(3-16)
The reutinls enter »a inisUted combattioa chunber U a teraperttore oí 298 K. The probiem i* to Gad Gad the tcmpen tnre, T, o í the the prodact« . Sisee thcrt ii no heat trniufcr, ihe entr^y e<]nUion cim be wrítteB u
or, in » (impler sotatioo, 1{-
ff,{29 ff,{298) 8) Q,
..í llí' MI
ni ii| ii|
Aüi
=
is =
-
//^(D .
(3.18)
(í=1,2,S.<,5)/
- ü ,p - 2416 241600 00 xAT„ o, -( :n -n f( 29 8 ).
Equttion (3-17) (3-17) repre*cn repre*cnU U the gener general al expreuion expreuion for u y cou tuc -vo lun e tdiabitic combuitlan probtero. Tbe finU preutire preutire ó obtúoed from
L«t tu choose to work with n reutist mixture e«olaiaÍn| oae mok of fiel. The fael we have «elected for iUaitratioa li CioIIn. The beat of rcactioa for C|oHn ia (rtler to tq.(2.1S)] ^ n . “ ( W ’ ^ 0 , + n lf lf u .O .O -
C w « íy r > r . . We have
- IS 5)Co,)„,.
( 3. 3. 19 19 )
30
Arf/t bilk n un * nmpcn lBra
CoapnUr Simdithci of CI EnfUe Procttsc»
31
The vilue o( //,p whkk ú » po«ilive he»t of re»ction for COj c»n b« found
from ttimdixd hmdtxxiki to be 282ÍOO kJ/kmoL Tbtrefore, (t/,p)co,
=
212*00-2480(1.5-1)
=
281560 281560 kJ/kmolCO a
a
281600 281600 kJ/kmatCO i.
The rtjulls of the two cuta of Y, vil, Y >Y,f »oJ »oJ Y < < Ytt, »re tivín by Ya, we eould »dd tbe tcrm tcrm WjA uco o® right-hujd tide of eq.(S.ll) wilhont wilhont iffecting iffecting ¡U vilidity. SimIUrly, SimIUrly, w« c u iJd oa tbe ri|bt-h»nd «ide of e.(S.ll) uid (3.15) tike Ihe íorm
Q, = ffi AU co + ^ j A u c o i + ^ j A ü h jO Ní¿.X¡h, + Ni&mo, jO + Ní¿.X¡h,
The reutinls enter »a inisUted combattioa chunber U a teraperttore oí 298 K. The probiem i* to Gad Gad the tcmpen tnre, T, o í the the prodact« . Sisee thcrt ii no heat trniufcr, ihe entr^y e<]nUion cim be wrítteB u
(3-16)
or, in » (impler sotatioo, ff,{29 ff,{298) 8)
1{-
Q,
..í Aüi
llí' MI
=
is =
- ü ,p - 2416 241600 00 xAT„ o, -( :n -n f( 29 8 ).
ii| ii|
^ n . “ ( W ’ ^ 0 , + n lf lf u .O .O -
t f p ( T ) = ( l O T ^ o , + IIX h . o + 3.76YK s , + ( y - I S . S j X o ,),) ^ .
where Nf md Nt denote» (he (he numbtr of mok « oí the gaatoiu gaatoiu prodacU ud rcKtanU, reipeclively.
- f f r j , = l O A V c o , + MAJÍh . o + ( K - 1 S .5 .5 ) AK AK o . + 3 . 7 e y A K „ „
An iU oitrui oa of ibe probiem ta {ivcn ia Fig.3.2. Since the coaitant
lí
( 3. 3. 20 20 ) ( 3. 3. 21 21 )
Constant-prcjsurc adiaballc combusllon
M 1-1
( 3. 3. 19 19 )
The*« four eqaationi, ed theo elimijiatini elimijiatini that term from eq.(3.20) reinlti ¡n
lü 3.4
- IS 5)Co,)„,.
^ . ( 2 9 8 ) = ( X c . , H „ + r X o , + 3 .7 .7 6KX 6KX n , ) „ , .
N^T
ISi
(3.18)
C w « íy r > r . . We have
P. N.29S '
Hi «i
//^(D .
L«t tu choose to work with n reutist mixture e«olaiaÍn| oae mok of fiel. The fael we have «elected for iUaitratioa li CioIIn. The beat of rcactioa for C|oHn ia (rtler to tq.(2.1S)]
Equttion (3-17) (3-17) repre*cn repre*cnU U the gener general al expreuion expreuion for u y cou tuc -vo lun e tdiabitic combuitlan probtero. Tbe finU preutire preutire ó obtúoed from
ni
-
(í=1,2,S.<,5)/
M
( 3 .2 .2 2 )
where -
K((71-Í,{2íB).
(3.23)
Note that the left>haadiide of eq.(3.22) is a meunrable qoantit^ and the ri{ht>hand itdt costaiiu pairt of uthalpy differcacet.
C , o H j , + Y O j + S ,7 ,7 aY aY Ns Ns
i¡
33
Aditbtlic 7 íu b ( 7Voipcn
CompíU/ Slmtitlha Slmtitlha o/ d £i(J<* Pne
cs^¿ijjy^uce of c<).(3Ji) wc now b»vc ^p(T) =(2(15.5 =(2(15.5 - Y)K o o + 3 [ y - W .5 .5)K c o ,
Pro««dLni u befoK, we ki.v ki.vcc •*
IIAC h i O + S.TOK T OKAJÍíJ JÍíJtt + 2(15.5 —y ) íc o { r } + 2{Y - 10.5)Kco,(T) + {15.5 {15.5 - y)JTo,(29í) y)JTo,(29í) -10Kco,(298)
(3-25)
W« nt«4 lo bríag cq.(3.2S) bto &farat Ibit coslúoi onlj pun of CBthklpjr diSurenc diSurencM M oa the rifhUhia d údc. Tiii* cu b« done by ftdding ftdding »sd lobCrtetini lEe URiii 2(15.5-y)Hc 2(15.5-y)Hc o(2 »8)
CalcuUtion of adiabíitlc Hame tempcrature Let tu Ent cooiidcr the the cue of cotulutUvolame cotulutUvolame comboitioii. For thú proc tn, . <3, t> jivtn by e
+llJiB,o + S-WKÍu,jj. S-WKÍu,jj.
ffrp
3.5
*nd 2(y - I0.5)Aco,( I0.5)Aco,(2M) 2M)
33
=
(. = I,2,3.4 .S).
ü,' cui be ejcprtutd ia terms of C, and T. Since the the b te m il energy incxeues incxeues witb tempertturt, and the the itope aUo aUo iacreuej with temperaton, thi NewtoaRaphjoa itentív# icheme icheme provide» a rapidly rapidly coavírgia j lyitematic Karth for • the Same temperatare. temperatare. Rewrituii eq.(3.17), we gtt X ;í ^ iC i( r )- A r iü ¡( 2 9 8 )l -9 .
(3.19)
Fcr the Newtos-Raphioa itexative icheme, we reqaire the derivative of thú ftmction with fttpect to T, whkh ú iiothiag but
on tlii ri(bt
(3.30)
- H „ - 2 (1 (1 5. 5.8 - y ) ( X c o + 1 / J Í o , - Í c o . ) m * o 2 ( 15 15.8 - K ) A Ko Ko o + 2 ( r - 10 .5 .5 )A )A X c o , + H / í X h . o + j . t s k a I h , ( í . 2e 2e ) Tbe únportut pokt U to recognÍM the ttrm
(jico + j S o t ~ Ihe h
Append ix B givt* givt* a brief discuaiion o f the Newtoa -Raphson method of 10lutioa. Appeodlx C deta ibei the forma formalat latioD ioD of algébr algébrale ale exprtulonj for (nthaJpy, (nthaJpy, iatersal tn
(
c c c (
(,
For 400 400 < r < 1600 1600 po
(
33
Aditbtlic 7 íu b ( 7Voipcn
CompíU/ Slmtitlha Slmtitlha o/ d £i(J<* Pne
cs^¿ijjy^uce of c<).(3Ji) wc now b»vc ^p(T) =(2(15.5 =(2(15.5 - Y)K o o + 3 [ y - W .5 .5)K c o ,
3.5
CalcuUtion of adiabíitlc Hame tempcrature Let tu Ent cooiidcr the the cue of cotulutUvolame cotulutUvolame comboitioii. For thú proc tn, . <3, t> jivtn by e
+llJiB,o + S-WKÍu,jj. S-WKÍu,jj. Pro««dLni u befoK, we ki.v ki.vcc ffrp
•*
IIAC h i O + S.TOK T OKAJÍíJ JÍíJtt + 2(15.5 —y ) íc o { r } + 2{Y - 10.5)Kco,(T) + {15.5 {15.5 - y)JTo,(29í) y)JTo,(29í) -10Kco,(298)
(3-25)
W« nt«4 lo bríag cq.(3.2S) bto &farat Ibit coslúoi onlj pun of CBthklpjr diSurenc diSurencM M oa the rifhUhia d údc. Tiii* cu b« done by ftdding ftdding »sd lobCrtetini lEe URiii 2(15.5-y)Hc 2(15.5-y)Hc o(2 »8)
*nd 2(y - I0.5)Aco,( I0.5)Aco,(2M) 2M)
33
=
(. = I,2,3.4 .S).
ü,' cui be ejcprtutd ia terms of C, and T. Since the the b te m il energy incxeues incxeues witb tempertturt, and the the itope aUo aUo iacreuej with temperaton, thi NewtoaRaphjoa itentív# icheme icheme provide» a rapidly rapidly coavírgia j lyitematic Karth for • the Same temperatare. temperatare. Rewrituii eq.(3.17), we gtt X ;í ^ iC i( r )- A r iü ¡( 2 9 8 )l -9 .
(3.19)
Fcr the Newtos-Raphioa itexative icheme, we reqaire the derivative of thú ftmction with fttpect to T, whkh ú iiothiag but
on tlii ri(bt
(3.30)
- H „ - 2 (1 (1 5. 5.8 - y ) ( X c o + 1 / J Í o , - Í c o . ) m * o 2 ( 15 15.8 - K ) A Ko Ko o + 2 ( r - 10 .5 .5 )A )A X c o , + H / í X h . o + j . t s k a I h , ( í . 2e 2e ) Tbe únportut pokt U to recognÍM the ttrm
(jico + j S o t ~
aK coj + ^jAS hiO +
+ í'f»AÍ í'f»AÍoi oi
A L + {B L -R )T -y C L ln(T).
(3.31)
A H + [B H -R )T + CH la{T ).
(3.32)
For 1600 < T $.6000 C(r)
=
Tbe heat capacíly capacíly ^ (T ) ú givca u foUowi foUowi For For «W < r < 1600 1600 C-(T)
=
iBL-R) + ^
=
{Bfí - f i)i) +
(3.33)
fot 1 6 0 0 < r < 6 0 0 0
-
(»=I.2,3.4,8), ÜT(T)
Qf
=
ijli
»
(
(, (
ü{r)
(S«2 (S«27) 7)
or, in « itmpli£ed itmpli£ed form,
Q,
c c c
For 400 400 < r < 1600 1600
u Ihe h vi]u« th» t c u be íound íound íb hudbooki; Now compirt cqi.(3.22) cqi.(3.22) u d (3.26). (3.26). Aj AT ATi = O for K > Yt „ w« tould «dd th« (tnn Ni áK co oa tbt righ ^hu d tid* of eq.(3.22) eq.(3.22) withoat iltcria{ it« rílidily. Sima«/1/, when Ymia < V S Jc « “ O, m the tenn AT»A AT»AXo, Xo, e*a b« added on the the righuhkad ikie of *<(.{3.2 *<(.{3.26). 6). W heo thU U doae, «{(.(3 .22) u d (3.29) (3.29) tt ^ the the fonn fonn
Qp » Ni áK co +
Append ix B givt* givt* a brief discuaiion o f the Newtoa -Raphson method of 10lutioa. Appeodlx C deta ibei the forma formalat latioD ioD of algébr algébrale ale exprtulonj for (nthaJpy, (nthaJpy, iatersal tn
(
CH
(3.34)
The valuet of tbe coeScient» A L, B L, .,. and for vaiiom gaiei txe lúted in Tiibltt 3.1 and 3.2, retpectively. Sisee the expresión íor intemal
í¡(r)-^(2 98 )
c c
c: c c c c. c
(
c C'
c
34
CktmpaUr Slmditba CktmpaUr Slmditba oí CI Eítlm Pmkmm*
Adh btile Flim t Ttmp tniare
entrcr {cq.(3.32]| <]m( not extcod apto 2^3 K, U^p u d Vf,, Ytiae* 29S X wt liitód m TiMc } J for foor |u««. In ordcr (o uicvUte tk« flun« Umpentore, the Newtoa-RapUoD iUr* Uiv í »cK«ib« co*ld b« coavtnúntlx «mplojred. «mplojred. For Ihíi, lUrt with « hn>0" hn>0" ihetkal vilo* oí lie Hime Unipenture. Thtn, tbe ntw-lune Umperanro b cttiined fron r
. .
.
T - m
II thc difTcrtace difTcrtace bítweta T uid can be itoppcd.
CktmpaUr Slmditba CktmpaUr Slmditba oí CI Eítlm Pmkmm*
Adh btile Flim t Ttmp tniare
entrcr {cq.(3.32]| <]m( not extcod apto 2^3 K, U^p u d Vf,, Ytiae* 29S X wt liitód m TiMc } J for foor |u««. In ordcr (o uicvUte tk« flun« Umpentore, the Newtoa-RapUoD iUr* Uiv í »cK«ib« co*ld b« coavtnúntlx «mplojred. «mplojred. For Ihíi, lUrt with « hn>0" hn>0" ihetkal vilo* oí lie Hime Unipenture. Thtn, tbe ntw-lune Umperanro b cttiined fron r
. .
.
T - m
II thc difTcrtace difTcrtace bítweta T uid can be itoppcd.
TkbJe S.1 ViloM or « .a cU .u ÁL, BL.C L u d DL h t 4 » K< T S l«oo l«oo K 4 «*d h tlit cOciUtloa of Caí 00 CO , H Ha H ,0 N, 0 0, OH NO N
Thete calcoUtbiu are illaitrated by mean* of uamplei In MCtioa SA. Let 01 DO DOWconiider the geae nl cate. Auo me tbat the reactaat* are are at tenperatnre T, and not U 29S K. Thot, we thootd cakolate Qf and «t the temperatnre T,. Siace both Qf and Q, tnvolve tnvolve heaU heaU of reaction, «« bqnire iato the varutioa oí Hff and t/,p witb temperatnre. The difference can be igaored except íor Urge cbanget in temperatnre, For exampte, (3.41) where tbe inbt oipt ce rtíer» to a chemkalJy chemkalJy co mc t rtactioa. Uioally, T, differ* from 298 by only a few hasdred de ír«« i. Futh ensor e, the differencc differencc
bttwMS ffpC^ u d N, C, h Mktom Mktom luye . Á* » cosMijatoc*, it i* UfUinkU* to igno ignora ra (k* Umj>«rUin varálioa ia ud T]i«a, f or tk« ( ca trd cu e o í catt cattft> ft>at at>v >vol olBt Bti> i>cc kdiib«t¡c c cmbutioik witlt n t c U s U U T „ ib* flt4a flt4au u Umptntare á iñc a hf
3T
Tbercfor«, n.
12.5.
<7.
-
E W r)-B í(T,)), (3.«)
Q.
=
Tbos, tke reutut mutore tt (
-Ur,~Nco^Ul600,
C,H i, + 12.5 12.5 O, + 47 Nj,
»di*}>»t »tic ic combuUoa Ui i for coiu luUpre uore »di*}>
Ne o Ne o, Nh .o N h , No,
(S.«) - F „ - //// c o x M 2 S 0 0 (Kt (tstn l ctM, tlti ueceiuor «xp rwio M íor tke Nevtoa-IUph Nevtoa-IUphfOB fOB fo r (Kt it«r«tlon Mppur sow for cauUat'Vo cauUat'Volami lami combu tioi u r -B B z M ib S i
(
u d iKe iKe prodnct prodnct mole uamben are are
(j.«)
AT,
=
= = = =
Ni Ni Ni Ni Nt
= = = ==
O, «. 9, <7,
( (
.
0
eo X 281400. wilb Q, = - U ^ - N eo In *Iible *Iible 2.2,1/^ íor C »H „ ú givtn u -50589S0 kJ/kmoL Aj Ne o - 0. Q, xs -f$0SS96O -f$0SS96O (liquid íaet «ad gat eau p rodacU), Betweeo 400 and 1600 K, tbe vatoe vatoe of H,(T) b givca givca by
c,(n
Cp(T)
ta i íor coBit*aUprt»iow cambailion tt (5.«)
c
==
=
á L + [ B L -R ]T
+ C L ] iiii (T]
(
The valué» oí AL, BL and CL are taiea &om &om Table 3.1. 3.1. Ai = O and Ni CEO, tke tummatioa b doae oaly íor ikree ipeci cs: Nt,N i and Ni. Tkú
(
yleU»
(
-ÍUd-S. ....
Ad l^a tic Fl us * Timptntan 30
Com pat tf SUotal SUotaltÜo tÜoaa o í CJ EagU* Pi
bttwMS ffpC^ u d N, C, h Mktom Mktom luye . Á* » cosMijatoc*, it i* UfUinkU* to igno ignora ra (k* Umj>«rUin varálioa ia ud T]i«a, f or tk« ( ca trd cu e o í catt cattft> ft>at at>v >vol olBt Bti> i>cc kdiib«t¡c c cmbutioik witlt n t c U s U U T „ ib* flt4a flt4au u Umptntare á iñc a hf
3T
Tbercfor«, n.
12.5.
<7.
-
E W r)-B í(T,)), (3.«)
Q.
Tbos, tke reutut mutore tt (
-Ur,~Nco^Ul600,
=
C,H i, + 12.5 12.5 O, + 47 Nj,
»di*}>»t »tic ic combuUoa Ui i for coiu luUpre uore »di*}>
u d iKe iKe prodnct prodnct mole uamben are are
Ne o Ne o, Nh .o N h , No,
(S.«) - F „ - //// c o x M 2 S 0 0 (Kt (tstn l ctM, tlti ueceiuor «xp rwio M íor tke Nevtoa-IUph Nevtoa-IUphfOB fOB fo r (Kt it«r«tlon Mppur sow for cauUat'Vo cauUat'Volami lami combu tioi u r -B B z M ib S i
(j.«)
Cp(T)
ta i íor coBit*aUprt»iow cambailion tt (5.«)
Whüt d«vtlo pbi( a compaUr progrun, wlcttUtíoaf for iTp(T], í/’p{7), p {7), C,(7) u d C,(T) c«a bt doat by muju ot fuctioa rabprognnu. rabprognnu.
AT,
=
= = = =
Ni Ni Ni Ni Nt
= = = ==
=
1.
O, «. 9, <7,
( (
.
0
á L + [ B L -R ]T
(
+ C L ] iiii (T]
The valué» oí AL, BL and CL are taiea &om &om Table 3.1. 3.1. Ai = O and Ni CEO, tke tummatioa b doae oaly íor ikree ipeci cs: Nt,N i and Ni. Tkú
(
yleU»
(
t /p /p (T (T )
=
%
+ (fli - fi)r + Ciln(r)l„.o
+ =
Com puli tbt Sunt Umjx nture «h tn » cktmktUy correct correct mixtura mixtura of Uquid C|U]f 4ad air úUUUy úUUUy a 400 400 K utd 1 Um, bonu U eooiUn t
(
//co,[^£ + (B£ -R)r+C Lln(r)|co , +
Sotve Sotved d m m plcs
c
==
eo X 281400. wilb Q, = - U ^ - N eo In *Iible *Iible 2.2,1/^ íor C »H „ ú givtn u -50589S0 kJ/kmoL Aj Ne o - 0. Q, xs -f$0SS96O -f$0SS96O (liquid íaet «ad gat eau p rodacU), Betweeo 400 and 1600 K, tbe vatoe vatoe of H,(T) b givca givca by
C,Hi, + Y „O j + 3.76Y 3.76Yc. c.K3, K3, wh«r« Ya ú ti » chtfflktUy com ct cucy^ cucy^ea ea to íneJ íneJ r»tio. Utrt
=
r\
1338331kJ
Let ci auume the flame temperature temperature to be 7 .= 3000 K. For temperaturei bítween 1600 1600 and 6000 K '
/ / * o » í ,
A i» a i« W i
A'm Qi“ 0. (
(
i,. ) ) 36
AdtAbtIle F ita * Tbmptsr*
Compottí’SU nalitha af CI Eoglüt Proc^M^
) )
U¡,{T)
-
+ /^h . o I/ í h + ( B f f - • f i ) r+ r+ C H l n ( r ) I i,i, . o
)
+ Nti, [A H + [B B ~ R ]T + CH ln(r)I„, ln(r)I„,
’) )
=
+ 47 X l«e39 + {39.32 {39.32 - 8.3U) x 3000 - 6753 6753 x k{5000)| k{5000)|
)
') ) )• i 1^!
a X [93048 + (6 8^8 - Í.3J4) X SO SOOO- :6979 X ln{3000)]
+ 9 X [15< [15<9r 9rO+ O+ (M .« - Í.JM) Í.JM) X SOOO- 192J2 x In(JOOO In(JOOO)l )l
)
)
/ f co co . ( -4 -4 ^ + ( 5 f f - ^ ) r + < 7 £ f i a ( r ) | c o .
=
=
T „. t/p (r )
= 2977 2977.S .S K. =r 6397297,534 6397297,534 kJ,
C T( T( r) r) =x 21 98 98.1 8 k J/ J/ ki ki no no lK lK , r«, = 2977 2977.4 .499 K. Al ibc lu t vil ac o f 7 m . ú witbin dbS
(B - 8.314) + CI T (kJ/kmoI K)
=
9? n , 0 ^ 22 _ -.
^ c o , ( 5 / f - 8 .3 .314+ C f f /T /T ) c o ,
+
30T 7.4 0 K .
%r , ^mOi N ^c + — ----------- ----4
Thi« givo =
=
C i ( ,H ,H „ + Y „ 0 , + S . 7 6 Y„ Y„ N ,
400 S T < 1600 1600 K, lflOO
+ ^ u , o ( B f f - U U + C/ C/ f/ f/ T) T) g^ g^ o
!|i !|i
r
Kqaid Kqaid CioHn »ad « r mitiiUy mitiiUy tt 400 400 K md I atro, atro, bure» *l conjt* o( preuoTt. For For CjoH n, tbe tiaetw t mixtutt mixtutt á
5T(r) U cJcalttcd from
C.(T)
‘1;
tcmptr*tar<. tcmptr*tar<. Olhcnrác, tüiini w T, tltc procttt á rep
2. Compute tb« Same Icmperatare whcn » cbeinictliy corrc ct mixture o(
CioH jj + IS.SO} IS.SO} + 58.28^2 58.28^2 and the product mole noinbert are
ff co ff co . tfH,0
= = 3
Ni N, Ni
0. 10 ,
II,
i,. ) ) 36
AdtAbtIle F ita * Tbmptsr*
Compottí’SU nalitha af CI Eoglüt Proc^M^
) -
U¡,{T)
)
tcmptr*tar<. tcmptr*tar<. Olhcnrác, tüiini w T, tltc procttt á rep
/ f co co . ( -4 -4 ^ + ( 5 f f - ^ ) r + < 7 £ f i a ( r ) | c o . + /^h . o I/ í h + ( B f f - • f i ) r+ r+ C H l n ( r ) I i,i, . o
)
r
+ Nti, [A H + [B B ~ R ]T + CH ln(r)I„, ln(r)I„,
’) =
)
)
=
')
M48774.07 kJ
C.(T)
400 S T < 1600 1600 K, lflOO
=
%r , ^mOi N ^c + — ----------- ----4 9? n , 0 ^ 22 _ -.
^ c o , ( 5 / f - 8 .3 .314+ C f f /T /T ) c o , + ^ u , o ( B f f - U U + C/ C/ f/ f/ T) T) g^ g^ o +
=
8.31 8.314+ 4+ C if/r )„,
and the product mole noinbert are
ff co ff co . tfH,0 fÍH. No,
+ 47(39.32 - 8.314 8.314 - 6753.4/3000)
lí I
=
lí;
í ilí t
2199.74 2199.74 VJ/kmol K
Ni N, Ni N, Ni
= = 3 S
TZ
0. 10 ,
II, 68.28,
0.
with
-Hn, - Ne o X
Qf =
Thí new Bune límperUure ii givcn by - ¡ [ / , { T } - c/ , ( Z ] - q ,]/ ü : ( t }
H^p yalue for CjoH n (liqn FVom TaMe 2.4, the H^p (liqnMi Mi f«t ! and ga«eo(u prod* octj) i« -6261300 kJ/kmoL A» N q o *= *= O, Q , « 6261300 kJ/k mol. BetwecD BetwecD 400 and 1600 K, tbe valué of Hf( Tj ii fíven by the rtlacioa M r)
ÁL + B L x T + CL\n[T)
=
The valúes of Á L ,B Í and CL are taken taken from Tkble 3.1. Here, for a chcmically correct mixture,
Tkü Tm, ú compired with tht tiiomed T oí 3000 K- If the differeno; b«twe«n them ii leu (huí lay lay dbS, dbS, thea ii takca takca u thc iJub Ui c 9un«
}
15.5
CioH jj + IS.SO} IS.SO} + 58.28^2 58.28^2
+ 9(60.43 - 8.314 8.314 - 19212/3000) 19212/3000)
!|i !|i
O
The rew tu t mixture mixture tt
8(68.6 8-8.31 4- 16979 16979/3 /300 000} 0}
‘1;
30T 7.4 0 K .
C i ( ,H ,H „ + Y „ 0 , + S . 7 6 Y„ Y„ N ,
Thi« givo
1^!
=
Kqaid Kqaid CioHn »ad « r mitiiUy mitiiUy tt 400 400 K md I atro, atro, bure» *l conjt* o( preuoTt. For For CjoH n, tbe tiaetw t mixtutt mixtutt á
(B - 8.314) + CI T (kJ/kmoI K) wherc B = BL lot = BH for
= 2977 2977.S .S K. =r 6397297,534 6397297,534 kJ,
+ 47 X l«e39 + {39.32 {39.32 - 8.3U) x 3000 - 6753 6753 x k{5000)| k{5000)|
)
=
C T( T( r) r) =x 21 98 98.1 8 k J/ J/ ki ki no no lK lK , r«, = 2977 2977.4 .499 K. Al ibc lu t vil ac o f 7 m . ú witbin dbS
a X [93048 + (6 8^8 - Í.3J4) X SO SOOO- :6979 X ln{3000)]
+ 9 X [15< [15<9r 9rO+ O+ (M .« - Í.JM) Í.JM) X SOOO- 192J2 x In(JOOO In(JOOO)l )l
)
30
o O and
» O
l!
ñ
.ÍJ .ÍJU.
____
....... —~
c 80
A dl ib it k fU m t T ka pt nt an
CompiUr Slmoíttloo o/'C1 £ii(la« Fn>cc
Henee, Henee, íor lammUtoa only thrte tpecUi, le . Nj ,N i and ext¿, wilK / / , = 10, A r, =i U , //«>= 68.2S .
ire eoiuld-
Tlü* yieldi
ítAT)
-
=
SI
10 X (6Í.58 + 189T9/ 189T9/300 3000) 0) + l í x (60.43 -1921 2/3000 )
Tbii Tatw ú co mpired wíth the usom ed vtlae oí 7 , Le. Le. 3000 K. II tbcir txy ii , Tu « ia Ukea u the adubat ic EL diSeienc diSeiencee ú leu t hu txy ELuse tcmpcrUore . OlktrwiM, the proceu ts npeUed wUh wUh díw vilue o f r , „ (it. T = T^rw) tül coavtfKence. coavtfKence. Tb iu,
19U767 19U767 kJ.
L«t oj u ioin e tht Suac Umperttore to b« T » SOCOK. For tempeiUare* b<(wt«B ISOO tnd 6000 K ffp (r) -«
A r c o , [/ [ / tí t í T + B i íx í x r + c f f in i n ( r ) lc lc o , + /fu.olAff + + s í r X T + C H i n (r (r ) iB iB , o + //h. lAií lAií + J3£T X r + C íf
^Nu, ^Nu,o[ o[ÁL ÁL + B L xT +C L b ( r ) ] + V / « , ( A ¿ + f l L x r + C L k ( r )| )| . For u inl;iil Umperxtox* Umperxtox* ot iOO iOO K, i.e. 7 , = <00K, <00K, »
Tbii Tatw ú co mpired wíth the usom ed vtlae oí 7 , Le. Le. 3000 K. II tbcir txy ii , Tu « ia Ukea u the adubat ic EL diSeienc diSeiencee ú leu t hu txy ELuse tcmpcrUore . OlktrwiM, the proceu ts npeUed wUh wUh díw vilue o f r , „ (it. T = T^rw) tül coavtfKence. coavtfKence. Tb iu,
T =
19U767 19U767 kJ.
A r c o , [/ [ / tí t í T + B i íx í x r + c f f in i n ( r ) lc lc o , + /fu.olAff + + s í r X T + C H i n (r (r ) iB iB , o + //h. lAií lAií + J3£T X r + C íf
As tb b To,^ vilae To,^ vilae U witkis ±5 of tbe prevbtu Tn,«, it ú tbe idUbatic &uiie t«mp«ratare t«mp«ratare oí CtoHn . Thos, Thos, *' AdUbatíe flm e tmpe rature = 2469.0 2469.0 K.
f li for 400 400 <.T < 1600 1600 K,
C
Exefclse 1. V M U > c o m p a t t r p r o t ra ra m l o c i l c o l i t t t b e a d U b u i c & u a e t e m p c ra ra t u re re of u y fuel for ujr givts ¡opal tondUbni.
2. Uaing the above proprara eakuUte tbe a^Uabatíc &une («np«ritare for tbe fueU fueU CiKtt asd CioH » (rom Y»\e¡ to Vniu Vniuci ci «b crc 1-6 Ytt (tnder conatant-volnme and coutaiil>preaaare comboitioB. Draw a grapb of idiabatic Baine l«raptra(sr« vergas Y aud aud dlscuu.
o BH íor 1600 1600 < r < 6000 6000 K. K. For tbt Miumed v»]a« o í T = 3000 X
C,(T)
=
^ c o . ( i ?i ?i í + < 7 ^ / r ) c o . + ^ 8 . o ( 5 t f + í 7 ír ír / J ')') „ ,o ,o
+ N h AB H + CI Í/ T¡ „,
)..-..v.*-v. -v.Tui- i -M :5firí firíii2tz30LLUíaM «t. «t.yj.j.',VJ:evr¿. vr¿.vv vv
Miny o[ the combnjtion combnjtion e np a« involv involvaa t tomprtMioa proíeti ind »U of »hem involv involvee »» «pu u'nj n proceii. The workinj workinj Buid Buid Ma mixture mixture of ju e» . The tnüo qae«tton b how to eilenlate the the lempe ntore oí tbe {uc * U the the cnd of the próce « oí compreuioii or cjcpuuioa. In the puton tDgisc, tDgisc, la order to ulcolUe the wort wort don* by or oa the g u «, the*« the*« CsaJ CsaJ t«rap«atoret t«rap«atoret m t u l be known. IdetUy IdetUy ipetldng, the comprcMt comprcMtoo oo u d expuuion procttiei ihoaid tike plu « npidjyi «ith negC{ib!e negC{ib!e hest trttuf trttufer^ er^ Reoec, compreo ioa u d cxpiAsion cxpiAsion c^ctüitioiu ctQ be mtde on the auamptton of bentioptc bchtvioar. Where the the process process iiii not benlropic benlropic,, e.g. b compreMon u d torbmci, the the ñeatropic tímpírtto re comp otílioo ii »{ill re<}aire re<}aired, d, iin « «Ecieaeies tre
/IlfLflníion /IlfLflníion of »n ttf at uio n pre ctii
Referriat to Fi(.4.1, kt pi and T| denote the initta] date of a mixtnre oí gM«». We wiíh to detennine the terapera tun, Tj, when the mixture expanda úentropíciUy to pj. We can proveed tn thre« wayi. (¡} We can apply eq.('<.l) , End Tj and let it fo.at that. (íi} We can modify the error of thi &nt roethod by Cnding Cnding an avcraje valse of k. For example, witb k¡ found at Ti, we End T> and the correspondini valae of J:j. Now we can tai e an average average between between and kj, which thoald lead to a better approximation for Tj. Thit can be repeate d nntU nntU two valúes of 7 j differ by only a imall amount, whatever amount iQCCeuivt valúes we chooK to caU tmalL tmalL Bul the maln qoeatíoa t« how to Gnd the the averaje. Sinee k¡ {i Exed for a fixed temperature T¡ wbüe kj rariei with «ach new valué of Tj, what average ahal) we takeT An arilhmetk average Uke (fcj (fcj + ií )/2 or a geometri geometricc average average v^ii v^ii •tj •tj , or whateUe? There » no appartnt logic to guide uj.
C
)..-..v.*-v. -v.Tui- i -M :5firí firíii2tz30LLUíaM «t. «t.yj.j.',VJ:evr¿. vr¿.vv vv
tiettlro; tiettlro;)íc )íc Ci án ftt ofS tU e
SS
ISENTROPIC CHANCES OF STATE Fí g.4 .1
4.1
Referriat to Fi(.4.1, kt pi and T| denote the initta] date of a mixtnre oí gM«». We wiíh to detennine the terapera tun, Tj, when the mixture expanda úentropíciUy to pj. We can proveed tn thre« wayi. (¡} We can apply eq.('<.l) , End Tj and let it fo.at that. (íi} We can modify the error of thi &nt roethod by Cnding Cnding an avcraje valse of k. For example, witb k¡ found at Ti, we End T> and the correspondini valae of J:j. Now we can tai e an average average between between and kj, which thoald lead to a better approximation for Tj. Thit can be repeate d nntU nntU two valúes of 7 j differ by only a imall amount, whatever amount iQCCeuivt valúes we chooK to caU tmalL tmalL Bul the maln qoeatíoa t« how to Gnd the the averaje. Sinee k¡ {i Exed for a fixed temperature T¡ wbüe kj rariei with «ach new valué of Tj, what average ahal) we takeT An arilhmetk average Uke (fcj (fcj + ií )/2 or a geometri geometricc average average v^ii v^ii •tj •tj , or whateUe? There » no appartnt logic to guide uj.
Inífoductlon
Miny o[ the combnjtion combnjtion e np a« involv involvaa t tomprtMioa proíeti ind »U of »hem involv involvee »» «pu u'nj n proceii. The workinj workinj Buid Buid Ma mixture mixture of ju e» . The tnüo qae«tton b how to eilenlate the the lempe ntore oí tbe {uc * U the the cnd of the próce « oí compreuioii or cjcpuuioa. In the puton tDgisc, tDgisc, la order to ulcolUe the wort wort don* by or oa the g u «, the*« the*« CsaJ CsaJ t«rap«atoret t«rap«atoret m t u l be known. IdetUy IdetUy ipetldng, the comprcMt comprcMtoo oo u d expuuion procttiei ihoaid tike plu « npidjyi «ith negC{ib!e negC{ib!e hest trttuf trttufer^ er^ Reoec, compreo ioa u d cxpiAsion cxpiAsion c^ctüitioiu ctQ be mtde on the auamptton of bentioptc bchtvioar. Where the the process process iiii not benlropic benlropic,, e.g. b compreMon u d torbmci, the the ñeatropic tímpírtto re comp otílioo ii »{ill re<}aire re<}aired, d, iin « «Ecieaeies tre bw íd on iíentropic iíentropic ptríormiace. The rel itbn betweea betweea pr e« n« , pi, voloinc, Vi, tnd the temp temperm ermtu ture, re, Ti, mlxtore oí ¡de*J ¡de*J gtáes gtáes t t the time eatropy time eatropy U jiven by (or (A idcU g u or « mlxtore
li i!
1 'i M M
T,
C!
\PtJ
(üi) We can aolv» aolv» for thi» Tj accurately by determloing the valué valué that eqaatei the initial initial and final entropie* of the | u mixture. The total enlropy 5 (p ,r ) o f a mixtur mixturee of ideal ideal gaiet ii gíven gíven by
[i .1 ]
\V^J
S(p,r)
li i! I!
«
(4.2)
whert denotei the mole numbert of the ipecie t, M the total mole number, A the univenal gu conita nt and and a fvnction of temperainrt.
Theie e;ipre uioiii u t deHved on the the uiompt ioD that k a contlaat. Ac> tn»Uy, Cf »nd C, is ae ue iríth iríth tempertt tempertture, ure, while while k decreuu. Since C, ind C, dlffer by t c oni tinl iroonnt, the chtnje ¡n i wUh temperUure temperUure tt tt not very very predominant. However, However, the ippb'cxtioa oíe
Sí
/IlfLflníion /IlfLflníion of »n ttf at uio n pre ctii
where ^,(0) ii an integration coMtant.
i| II
si
iMctropJc ct ropJc Cbutf butf et ct SUtt SUtt
Com pttu SlmaU lmaUtloM tloM ot C! BagU* BagU* F nctua t
35
f o t »a y | u , 4i{ T) U Ibe caUopy p«r mole mole kt tcm pcnto re T u d 1 «t «t m . TkbU C.4 ú App«Bdix App«Bdix O glvu A t v^lac* v^lac* oí ^ for (U«* Uut tr« camioo»(y
íound in in comb utioa pro4ucU.
T»bl«* T»bl«* 3.1 u<] S.2 ia Cb ipUr 3 (iy« tbe c m S c í c b u t ii iiU c u b « w d ia tbe foUowÍBl txpruiio&i; CL 400áTSl«00. i - D L h > lT )- -^ -¥ V L 4
CH B H h { T ) - ~ + DH DH I 6 0 0 < r < í 0 0 0
“
l<-4)
Ti ú foaad by *oIvía| thi cqa&tiosj áS
«
Si-5i tbat ú,
0.
(
O,
5,(p„r,)-j,o>i,Tj)
(
r
(4.5)
.
0
wkicb wkicb u a h* cJcpudcd h* cJcpudcd te
AS-
(^(r,)- f,(r,)|- ivíu
(4.6)
For lb« lolatlos oí tb« abovt c
SI
(4-7)
-
Pig.4.3
N tw tc n- R ap ki on iU nt üm (ee&nifve
( 4.2
Summary
wbere C, = E'vCpi* • r* T b e r « c a n i o i i t ^ a U i o a w a a ld ld I b e a t p p u r u
T ,„,
-
T , ^ l -------------- gr^5Tj
j.
(4.8)
(
Tbe lut two cbipten tlong witb tbii cbipter provided tbe neceunty bukg rooad t beoiy re^uired re^uired to itari tbe limoUtioa proc eu. Howevcr Howevcr,, tbe faada nentt lj of workiag priacip priaciple* le* uid tbe nomeacUtores woc tal ed witb Ihe
( r
si
iMctropJc ct ropJc Cbutf butf et ct SUtt SUtt
Com pttu SlmaU lmaUtloM tloM ot C! BagU* BagU* F nctua t
35
f o t »a y | u , 4i{ T) U Ibe caUopy p«r mole mole kt tcm pcnto re T u d 1 «t «t m . TkbU C.4 ú App«Bdix App«Bdix O glvu A t v^lac* v^lac* oí ^ for (U«* Uut tr« camioo»(y
íound in in comb utioa pro4ucU.
T»bl«* T»bl«* 3.1 u<] S.2 ia Cb ipUr 3 (iy« tbe c m S c í c b u t ii iiU c u b « w d ia tbe foUowÍBl txpruiio&i; CL 400áTSl«00. i - D L h > lT )- -^ -¥ V L 4
l<-4)
CH B H h { T ) - ~ + DH DH I 6 0 0 < r < í 0 0 0
“
Ti ú foaad by *oIvía| thi cqa&tiosj áS
«
Si-5i tbat ú,
0.
(
O,
5,(p„r,)-j,o>i,Tj)
(
r
(4.5)
.
0
wkicb wkicb u a h* cJcpudcd h* cJcpudcd te
AS-
(^(r,)- f,(r,)|- ivíu
(4.6)
For lb« lolatlos oí tb« abovt c
SI
(4-7)
-
Pig.4.3
(
N tw tc n- R ap ki on iU nt üm (ee&nifve
( 4.2
Summary
(
wbere C, = E'vCpi* • r* T b e r « c a n i o i i t ^ a U i o a w a a ld ld I b e a t p p u r u
T ,„,
-
T , ^ l -------------- gr^5Tj
(4.8)
j.
Uowtvcr, lornt e m m ut be uerciM d bt cu ut th< th< c&Ien c&IenUt Utto ton n wUl wUl itop « b u Tu,m t u r o f u p B C g ai ai iv iv t u t r « a U o í i h t l » f s r í i b m f u c t i o a k « i i.i. (4 (4 . 4 }.}. (« i l b « p r o b l e a . T b t f b p « e l Ú S plotUd »|üast T j wÚl F i f v t 4.2 i i J u jljl r * (« d e o T i M u i b o w a b «c «c «B «B M T j l s a « u < « f u t c r i b i n C , . Tb i Umitlai v»li« for tbt ialiUl goeti for for Tj U ü tbowo in tbt Cgort. Tb) cUcolulon «ill ilop tf tbt iUntioa b«|úu witb » Urger vilae. Siact U u Bot Bot poiaiblc poiaiblc to koow tb« limitb| v ilat l í t b e o a tM tM t , wo wo c u y c b o o t t u y T] lo btgía witb Ibt {Itrtlioa kad tbta decrtiM T ) by a fixed unoaa t luitS luitS Tjtttw w » posi(iv« T j t i v ú o b l ú n e d tn m (b'c reconioo «tUenitst. Theniñer, Tjt irÜl irÜl remtia po iltivc. For tbe tbe cu e o í úeatropic úeatropic t x f t a t h a t « «orne ipecified ipecified volune, V ¡, tbe « * A t b u i c i n e t b o d o f i l t r t l i o n i c í a b e e m p lo lo y ed ed p í, beiag fixed by
Pí
=
PJ j^jT
Tbui, Ibt compatatioa o( T ¡ wil willl help lo obtUn (be vilae vilae of
r
Tbe lut two cbipten tlong witb tbii cbipter provided tbe neceunty bukg rooad t beoiy re^uired re^uired to itari tbe limoUtioa proc eu. Howevcr Howevcr,, tbe faada nentt lj of workiag priacip priaciple* le* uid tbe nomeacUtores woc tal ed witb Ihe campmtioa igaitioo cagiae tenniaology will belp tbe reider in undentudíng tbe lironlitioa proceu . Heace, Heace, tbe next next cbipter ¡i devoted to expliia lome importia t detúls (maay of tbe readen inay know know tbete tbiog i atready atready)) abont tbe eoinpreuion ignitioa engíae, *o tbat evea a beginser caá leara lúnulalioo witboot macb diCcnlty.
•c
Excrdse
l
e (
VKi te a Co mp ute r pro gr am to et lb na te tb e fia al te mp era tur e dnr íag a compreuioa or exp^uloa proceu wíkii initial conditioae ksowa, uiiag tbe lií te metb odt detcribed in tbi> tbi> cbapter.
(<-9) (<-9) tlso.
)
Camp nmk» ¡ftlIloM ¡ftlIloM Eaíl ntt
ÍT
) ) ) ) )
COMPRESSION IGNITION ENGINES
)
Pto»««lBDC
) CxuMtlng n i
5.1
Iníroducilon In order to umolate the compreubs ¡ sq Uío d (Cl) eogtne oa &digital com< pater, Gnt of tU it tt necmvy to know the vtríoat proccuci of thc CI engioe, wtd iu workiB workiBgg príocíple príocíple u well well u the nomencUinre nomencUinre us oci it«d with it. it. la thLi ch»pt«r we wiil rcview brícSy tbe wofkiai principk of a fonr-itroke CI eagine.
i!
•¡ M )
5.2
Some baste baste dcUiIs and nomenclature U t IU fint deEiic deEiic a cycfc. A cfcle ii a complett leqoenc* of eríct» «tuiint ftom o nt it ate and rctttnúiig rctttnúiig to the lame (tat « ii^the unt e «ray. «ray. For exunple, it may b« an intcnral or a períod of time occapíed by ene round or conne of cvent* cvent* repeating repeating in the the Hjne order in a «trie», loth u the cycle of fe i, with
Creakilnfl
Fig.S.l BatU fOwt r-dtft lofÍBf com font nlt nlt o / » CI tnfint
The cyllader ha* a imooth inrface *o that thc piitoa, with the aid of pi*ton tingi aad aad i labricu t, caá cRit< i ital todi (hU do |U |U uq tia p< bctwMS bctwMS tbe piiton aad the cyCnder cyCnder walb. The p btoo ti eonaected eonaected to the craalahaft by meanj of a eonnectbig rod *o that the redprocaitag moiton Si converUd to rotaiy tnotion by mtaaa of the coBoeeting rod and «raak auembly. Tbo pctition of the workiag pliton aad the moving pane, whkh are inft inft--
)
Camp nmk» ¡ftlIloM ¡ftlIloM Eaíl ntt
ÍT
) ) ) ) )
COMPRESSION IGNITION ENGINES
)
Pto»««lBDC
) CxuMtlng n i
5.1
Creakilnfl
Iníroducilon In order to umolate the compreubs ¡ sq Uío d (Cl) eogtne oa &digital com< pater, Gnt of tU it tt necmvy to know the vtríoat proccuci of thc CI engioe, wtd iu workiB workiBgg príocíple príocíple u well well u the nomencUinre nomencUinre us oci it«d with it. it. la thLi ch»pt«r we wiil rcview brícSy tbe wofkiai principk of a fonr-itroke CI eagine.
i!
5.2
•¡
Some baste baste dcUiIs and nomenclature U t IU fint deEiic deEiic a cycfc. A cfcle ii a complett leqoenc* of eríct» «tuiint ftom o nt it ate and rctttnúiig rctttnúiig to the lame (tat « ii^the unt e «ray. «ray. For exunple, it may b« an intcnral or a períod of time occapíed by ene round or conne of cvent* cvent* repeating repeating in the the Hjne order in a «trie», loth u the cycle of fe uon i, with ipring, lummer, anlumn aad winter foUowing ctch other and thea recnrring. Similtrly, an IC tnjint cfcle i« a »eríet of eveat* eveat* that aa iotem al comhs** comhs** tion engine undergoe* whSe it ij operating aad deliveríng power. Stace thcie eveoti occuT in a certaia xquence, they are MÍd to be tímed. Al already tt ated, cor intereft lie* ia revicviag the worktng priacipte priacipte of a four-ilroke Cl engine. engine. The com prtuia a ignítion ignítion cngine wu orífina orífinalJy lJy devetoped devetoped by Rndolf Diuel la Gtnn any in 1892. 1892. Moit o f the reciprocatisg reciprocatisg engine* oper ite on a foBMtroke five-event eyd«. There are foo r itroket oí the púton, two op and two down, down, for each engine engine operating operating cyc k. The baiie power-developing compoaeati of a typical Cl engine are ihown in Fig,5.1. They are:
M )
'i
)
fíi fíi
K|
(i)
(ü)
iS
the cylinder, the piitOB,
(iü) (iv)
the connecting tod, the craakihaft.
Fig.S.l BatU fOwt r-dtft lofÍBf com font nlt nlt o / » CI tnfint
The cyllader ha* a imooth inrface *o that thc piitoa, with the aid of pi*ton tingi aad aad i labricu t, caá cRit< i ital todi (hU do |U |U uq tia p< bctwMS bctwMS tbe piiton aad the cyCnder cyCnder walb. The p btoo ti eonaected eonaected to the craalahaft by meanj of a eonnectbig rod *o that the redprocaitag moiton Si converUd to rotaiy tnotion by mtaaa of the coBoeeting rod and «raak auembly. Tbo pctition of the workiag pliton aad the moving pane, whkh are inft inft-dhanicaQy conneeted to the piitoa, at the moment when the dircction of iti motbn u revened at either oí the cnd polnta d the atroke, atroke, m called tbe dead centre. There are two dead dead centre*, centre*, vii ,, lo p dead centre (TDC ) aa d bolkom dead centre (BDC). The limit of travel to which the p'utott can move, u calJed TOO and the limit to «hich it more* in the oppoeite directloa ii calkd BDC. For each revoloiba of the craoktwo revotationi of thc oraakihaft. oraakihaft. Figure S.l Olutratei the bore and itroke of the eagúe. The oom lntl Inner Inner diameter’of the cylinder cylinder ii caOed caOed the k rt, tbat 1* 1* deilgnated deilgnated u B aad i» cxprcMed la Rua. The nominál diit iac e throagh which a working pitto o movet between two aaccotlve rtvtnUi of Iti directian of motioa ii caUed the and it deiignated deiignated u S aad eicpreued ia mm. itroU and
CoapaUe SUaatillon atillon ol aEat l t * Ptoi
Compntiíoa Igíltha Eaihu
39
As cogio e ba vliig » bore eqaU l o tEe tEe itroka ii o lUtd » «aji ne. lí tti< tti< »troV« »troV« is lu í thu » iL t boce, U i»i» t«lled «a ovei^»
(
c ( ( c ( ( fig.E.S Fig.C.3 JH uln íün « / t o n « n i tlnit
U u Ím|>o Ím|>ort rtia iatt to «m denlwd tbe po*itbn» po*itbn» oí TDC ind BDC, u thtu potitwai o f th« pifton V f OMd ia Mlting Mlting the the ínjecliott ínjecliott »« well well w v the túningt túningt
Tep ané íottam ¿tai c«n
(
ComprcMioa ralio, r, ii tbe ralio of eylinder vokme lo dearaace volame; '
-
fe -
c í (
iS
CoapaUe SUaatillon atillon ol aEat l t * Ptoi
Compntiíoa Igíltha Eaihu
39
As cogio e ba vliig » bore eqaU l o tEe tEe itroka ii o lUtd » «aji ne. lí tti< tti< »troV« »troV« is lu í thu » iL t boce, U i»i» t«lled «a ovei^»
(
c ( ( c ( ( fig.E.S Fig.C.3 JH uln íün « / t o n « n i tlnit
^0
(
c
ComprcMioa ralio, r, ii tbe ralio of eylinder vokme lo dearaace volame;
U u Ím|>o Ím|>ort rtia iatt to «m denlwd tbe po*itbn» po*itbn» oí TDC ind BDC, u thtu potitwai o f th« pifton V f OMd ia Mlting Mlting the the ínjecliott ínjecliott »« well well w v the túningt túningt tad dtUrtmning Ib* vUvt ovuUp. Top d«id c«a(rt a iy *1m ba dtSaed u the poin t when tbe pUtoa U a mtxiinan dUtutce from tbe ccotre Un* Un* ot (be crutk ibtft. Bottom dead dead ceatre ceatre miy tlio b< dtfiaed u tbe poíat wber« tbe tbe ptitoa k ftt a mioimum mioimum dú tu ce from tb« ceatre ceatre liae liae oí tbe tbe a uü u W t. Pisare Pisare 5.3 Uliulr»tei tbe púlan potitioa »( to p dckd eenlrc u d U bottom dead ceatre. ceatre. volame iwept by tbe workiag workiag pliloa Diíflattm Vdi.> " (6-1)
Cíunnc* lolutru ii tbe aoaiaal volune of tbe iptce above tbe putea whea it ii U TD C. U ii deaifnaled u and expjrcwed expjrcwed la M. CjlUitr ttiumt er tbe loUl loUl 9ohn t is tbe ipace abcve tbe putoa wbea Ike púloo ii it BDC. U It datgaaied u V^e uid oiualiy e^r«ü«d in cc.
Tep ané íottam ¿tai c«n
'
-
í
fe -
(
Compreuion ralio b aa importaal importaal paraneter wbkh delermia u tbe type aad effid eaey .of tbe eogiae. Piutber, ít coatrol» the maximam power thal can be devtloped by tbe eagiae, provided olheríattor» rexnaia the »»me. The mudrauni mudrauni power iaa ea «» wilh iacrea iacrea*e *e in compreaiba ralio, However However,, for CI eagiae* tbe limit limit of tbe compreiiioa ratio ii decidid by ili power to weigbl weigbl rallo nace, witb iacreue ia compreuion tbe eagiaet bave to be iturdy. lacreaiiag lacreaiiag the comprtMioa ratlo of aa eagiae iacrtatej iU therroal efficieacy aad bwen •pedfic (ael coaaoniplioa. It wiU wiU be uea that the eS cies cy a sd power oolpat of C í eagiae* eagiae* aot oaly dependa opoa the compreuion ratio bul a lio on a ralio called tbe cat-oí ratio (Ke Cbapler 6).
5.3
(
CyUn dcr pressure pressure Indicator dlagrim
c
A typical cyliader pre uuw indicator diagraai ii jhown ia Fig.5.< for foU load op éra tba o ader ideal coaditioai. FVom FVom Fig.S.4, the icdicate d power caa
CompatiT Simalithn Simalithn of CI Espine ProccMÉ
CompntsloD !fi ilíha Eagln EaglneM eM
be cilculatd. The dUpun ninrtr»Ui tbe prt«ar« _r«K dnriag the tompre^ «ion itrokí »ad comtiat prmnre daría* he»! «ddilion. Further, ¡l »howí the príMUm príMUm drop wilb the the expiniioa of the c « « duriag duriag the povfer povfer itroke u weü u doricg he»t rejecfion. rejecfion. ComputUioM oí tle indicUed power ir» loniewhit «únplified bjr oiinj »he »he avenje prewur prewuree iít b j o q the píiton thniBghon thniBghontt the wor kk í »troke, »troke, T hi. »ver»ge preunre, ofUn oU td the nwia effetlivt prw ort , tt Qormall Qormallyy obtuntd frotn thú indic»lor dUpim.
41
ncmber of cyliaden on oper^ioa |ive* the work done by the catire engine, per Krcoad, in WitU. Indicited power b then given by •F "
whert
A ' K n » f l* » S =
5.5
¡\^SAnK «X»0
(S.3)
u-et of the pUton ia nomber of cyliaden Btun Btunber ber of workiaf workiaf (troke* (troke* per miaute miaute (rpm/2) per cylioder cylioder ladieited m eu effect effecthr hree prtuur* ta N/m’ length length of the itrok* la m
Brake power
Br»ke power, power, ip, ii the Mt uJ power deliv delivered ered by an engin enginee tt the e r»a bh iít. It ii the dlfference between the indicited power, i>, ind the frietion power, /p . FVictio FVictioaa power is thtt pir t o f the tota l power aec eut ry lo overeome the ftictbn of the moving pirU ia the engine «Jid lu acce»»oríe*. The relitioajhip between them m»y be exprttted u »> - /p-
It m»y tlio be ttU«d thU hp ti hp ti (hit pirt of ihe tolü power developed by the engine which cía be nied to perfortn work.
1 I, 5.6
í;
f!
(5.<)
Flg.6.4
Prtn«re-»olum« {náiator ¿t’ajmm
Wo fklna principie principie Id 1 four'itroke cytk eofine, th i cytle of opcratb a U compitted compitted tn four four ttroke* ttroke* of (he (he piitoa, tnch tnch u lactioa, comprtuioa, expuuion lad exhisat. £ich
^0
CompatiT Simalithn Simalithn of CI Espine ProccMÉ
41
CompntsloD !fi ilíha Eagln EaglneM eM
be cilculatd. The dUpun ninrtr»Ui tbe prt«ar« _r«K dnriag the tompre^ «ion itrokí »ad comtiat prmnre daría* he»! «ddilion. Further, ¡l »howí the príMUm príMUm drop wilb the the expiniioa of the c « « duriag duriag the povfer povfer itroke u weü u doricg he»t rejecfion. rejecfion. ComputUioM oí tle indicUed power ir» loniewhit «únplified bjr oiinj »he »he avenje prewur prewuree iít b j o q the píiton thniBghon thniBghontt the wor kk í »troke, »troke, T hi. »ver»ge preunre, ofUn oU td the nwia effetlivt prw ort , tt Qormall Qormallyy obtuntd frotn thú indic»lor dUpim.
ncmber of cyliaden on oper^ioa |ive* the work done by the catire engine, per Krcoad, in WitU. Indicited power b then given by •F "
whert
A ' K n » f l* » S =
5.5
¡\^SAnK «X»0
(S.3)
u-et of the pUton ia nomber of cyliaden Btun Btunber ber of workiaf workiaf (troke* (troke* per miaute miaute (rpm/2) per cylioder cylioder ladieited m eu effect effecthr hree prtuur* ta N/m’ length length of the itrok* la m
Brake power
Br»ke power, power, ip, ii the Mt uJ power deliv delivered ered by an engin enginee tt the e r»a bh iít. It ii the dlfference between the indicited power, i>, ind the frietion power, /p . FVictio FVictioaa power is thtt pir t o f the tota l power aec eut ry lo overeome the ftictbn of the moving pirU ia the engine «Jid lu acce»»oríe*. The relitioajhip between them m»y be exprttted u »> - /p-
(5.<)
It m»y tlio be ttU«d thU hp ti hp ti (hit pirt of ihe tolü power developed by the engine which cía be nied to perfortn work.
1 I, 5.6
í;
Flg.6.4
f!
Id 1 four'itroke cytk eofine, th i cytle of opcratb a U compitted compitted tn four four ttroke* ttroke* of (he (he piitoa, tnch tnch u lactioa, comprtuioa, expuuion lad exhisat. £ich •troke coQittt« of one revolnlbn of (he crinbhift or 180* of crink rotitíon »nd henee a cyde co n« il« of 720* oí cra crain ink k rotition.
Prtn«re-»olum« {náiator ¿t’ajmm
I!i
•I
5.<
Wo fklna principie principie
The vtnotu tlrokei ire illutrated in Fig.5.5 ind (he comtponding idetl cycW cycW p-V d iig rm it iliowa iliowa in Fig.5. Fig.5.8. 8.
IndJcatd powtr
The working principie of the engine ii deicribed below.
J’ i IndicUed power b defiaed u the t«tal pw er convertid by tbe engine from he»t energy to mechwicil energy. It á tuniBy »bbrc viutd u «>. «>. If the chtnclerótici of la engine u t knoirn, the indicited power riting c»n be CMÍly tilcoUted. The tot»l forcé «cting on the pUton in e»ch cyliader ti the product of tbe indkited mein effectiv effectivee preMu preMure re (K/ra’ ) uid «•«», Á, of the pbton hetd in The prodact of the totul forcé uid the dtitifice through which it act» i? one íecond give» the wMk done per tetond. Thii product mntlipUed by ti
«i i
ll ll
I
42
$.6.1
Suctbn itroke p e inction itroke itroke ii repreae repreaente ntedd by 0—1 in Fig.5.6. Fig.5.6. It itu tj when the p'uton p'uton b it TDC, ind ibout lo move downwtrdj. downwtrdj. The blet vilve b in Ihe open poíition lad (he exhioj l nlr e b b the cloied po*ition po*ition [Pig.5.5(»)]. [Pig.5.5(»)]. Dnriag Ihb Itroke, dae lo ihe lucking iclion of the pbton, lir from the ilmoaphere i] driwn into the cylinder. At (be end of ihe luction itroke, the inlet vilve cloiej.
CooiprMiiaa 2{sillaa ¿cf iiiM
Co mp ou i SlmiíUtioB SlmiíUtioB o f C¡ Eagla» C¡ Eagla» Ptoctu4t
S.6.2 ¡tltur
43
ComprosJon ComprosJo n itroks TKe compresaloo t(roke ú repretentcd by l->2 ia Fíg-5.6. The air tikea inlo ihe cylmdcr doring the «action itroke, doog «riih tbe producU of comboition of the previooi eycle, u compreited bjr Ihe return «troke of the púUin l-»2. Durúig the comprtsiioD (troke, b«t h ¡alet u d exhauiC exhauiC valvet valvet remain clo*ed |Pt{.5.S(b)j. This ú r U compre ued Uto the cleuan ce volume at the tud cí the alroke. However, joit beíore the esd of the comprtuioa itrokc, the fací ú injected with with the help help of as b jeetor. Even Even though though combiutioa onght to it vt únmediately, in actual engiaei, it itarts after a vtiy imall mterval of (¡me called the deUy períod. ( (
c
latekfnimdMn
(a) SuctioB
[b] Coinpres*b&
c c c CtWtM
(' (
42
CooiprMiiaa 2{sillaa ¿cf iiiM
Co mp ou i SlmiíUtioB SlmiíUtioB o f C¡ Eagla» C¡ Eagla» Ptoctu4t
S.6.2 ¡tltur
43
ComprosJon ComprosJo n itroks TKe compresaloo t(roke ú repretentcd by l->2 ia Fíg-5.6. The air tikea inlo ihe cylmdcr doring the «action itroke, doog «riih tbe producU of comboition of the previooi eycle, u compreited bjr Ihe return «troke of the púUin l-»2. Durúig the comprtsiioD (troke, b«t h ¡alet u d exhauiC exhauiC valvet valvet remain clo*ed |Pt{.5.S(b)j. This ú r U compre ued Uto the cleuan ce volume at the tud cí the alroke. However, joit beíore the esd of the comprtuioa itrokc, the fací ú injected with with the help help of as b jeetor. Even Even though though combiutioa onght to it vt únmediately, in actual engiaei, it itarts after a vtiy imall mterval of (¡me called the deUy períod. ( (
c
latekfnimdMn
(a) SuctioB
[b] Coinpres*b&
c c c CtWtM
(' ( ( Flg.6.0
(
¡dtal p-V dii¡rcm
•C Durini the combualion proce u, the chemicU energy of the futí b rtleaacd is th; f^nii of heat eaer^, prodadog a temperatuje riúe of aboat 1800 K and the p:t«aan wUl rcmain conitaat (rtpreieated by 2->3 in FIg.5.6).
(c) Expauion Fig.5.5
(d)
KaniM Uroka in C / ( n ; tn tn (
S. ( 3
Ejtpans^M tUoke The expaniloa lUxjke á lepreM&tcd by 3-»4 ia Fig. Fig.S.O S.O.. The buming gu«a forcé the piitos towaida botto m dtad centre. During During tiiii «troke, «troke, botb inlet inlet and exhaust v)üve v)üveii remún closed [t«e F¡g.5.5(c]|. F¡g.5.5(c]|. T hsi, power ii obtim cd only during thii «troke. «troke. Both preíJiire preíJiire and temperatnre temperatnre dec re« e during expajuioa.
r
«
Computer SImdtlion cf Cí Entiat Peocetta S.S.4
Compnmh* IfaJlJoa E ef ht »
áS
Exlutiit strol x
The cxliiias cxliiiastt ilro le ti rtpreitnlcd rtpreitnlcd by <-*0 ín Fig.5.6 Fig.5.6.. At tbe cnd oí «pu ui oa itrak«, tbc exhtiut n lre op«&i op«&i in d tbe bk t n tre remúat clos« clos«<] <] |Fig. |Fig.S.5 S.5(d)j (d)j.. The pbtcm i o o t c í from BDC to TDC tnd txptli the the burnt burnt { u u from the the cyiinder throDgla ike cxl iui l vilve, Tke exh»n»t exh»n»t vilve cloaet cloaet tt th« tnd of the the exl aiut ilr oke la d «orne «orne rctidaU gu ci rcmún in the cyliader. In s maUicylia maUicylia-der englae, e « i cylindw of the four-«troke enjine completct the »bove foar op ert tbiu ia two cngin cnginee rcvolutionj. Whcn ui engine engine exccotei (hese foor »trok£«, doring the crwk rot»t!oa of 720* the preuiire virie* coiuidtribly. The varialian of the pre*iure with rtjpect to crink »ngle (p-f) a iHiutrited in Fig.$.7 for > CI cngíae cngíae workbg on an idcil Oietel cyde. One of the mún iÜTU oí the eompater limaUtion ü to produce the virUtioa p- í, ind »ce bow cióse we are to u actual etigine. etigine. ) Ki.
FIg.5.8
,1^ ,1^
of connecting rod i and compreailon ratlo r. The diipUcement yolome V^u, i) iwept col ai (he pistón moni from BDC to TDC. Now,
lí h
Geomttri Geomttri o ¡ Ikt ncipnci tinf pistón pistón topnt
; (5-«)
ití
Sinec
iii
tí III'
we may write
«
Computer SImdtlion cf Cí Entiat Peocetta S.S.4
Compnmh* IfaJlJoa E ef ht »
áS
Exlutiit strol x
The cxliiias cxliiiastt ilro le ti rtpreitnlcd rtpreitnlcd by <-*0 ín Fig.5.6 Fig.5.6.. At tbe cnd oí «pu ui oa itrak«, tbc exhtiut n lre op«&i op«&i in d tbe bk t n tre remúat clos« clos«<] <] |Fig. |Fig.S.5 S.5(d)j (d)j.. The pbtcm i o o t c í from BDC to TDC tnd txptli the the burnt burnt { u u from the the cyiinder throDgla ike cxl iui l vilve, Tke exh»n»t exh»n»t vilve cloaet cloaet tt th« tnd of the the exl aiut ilr oke la d «orne «orne rctidaU gu ci rcmún in the cyliader. In s maUicylia maUicylia-der englae, e « i cylindw of the four-«troke enjine completct the »bove foar op ert tbiu ia two cngin cnginee rcvolutionj. Whcn ui engine engine exccotei (hese foor »trok£«, doring the crwk rot»t!oa of 720* the preuiire virie* coiuidtribly. The varialian of the pre*iure with rtjpect to crink »ngle (p-f) a iHiutrited in Fig.$.7 for > CI cngíae cngíae workbg on an idcil Oietel cyde. One of the mún iÜTU oí the eompater limaUtion ü to produce the virUtioa p- í, ind »ce bow cióse we are to u actual etigine. etigine. ) Ki.
FIg.5.8
,1^ ,1^
of connecting rod i and compreailon ratlo r. The diipUcement yolome V^u, i) iwept col ai (he pistón moni from BDC to TDC. Now,
lí
Geomttri Geomttri o ¡ Ikt ncipnci tinf pistón pistón topnt
;
h
(5-«) Sinec
ití iii
tí
we may write
III' (5.9)
r -1
p-i -i Ji Jiagn agnm m of ofan an iáeal Dicicl cfctt Flg.S.T p
Ui:
Vuc
N-
Hi
ñ
5.7
Engine kinematlcs kinematlcs
j _
)
íí*
1
(S.7)
r -1
With 6 denoting tbe angular diapUcemen diapUcementt of the craak from BDC, tbe voIome / ( í ) at any cnudt aagte aagte ii repftaenUd by
Pi:' )
ti
-
)
Foor-itroke inteniai combuition «ngineí are corrently produced in two ccaBgtiratiou, reciprocating püton and rotary. The basic geometry of a reciprocating púton engb e is ihown in Fig.S.S. Fig.S.S. It ii dcKiibtd in term» of cyiinder bor« (diameter) B, length of itroke S, ¡englh
)
\
l - c o » » . L
1 / / 2¿ V
(5,8)
k3l¿ k3l¿
l'
- t ia ia í
(5.9)
ffi
i6
CoBpa CoBpatu tu SlfliBUÜM e SlfliBUÜM e l « E «f «fU « Ptottuim « Ptottuim DispUc(m
6
Exexcise
CI ENGINE SIMULATION WITH AIR AI R AS WORKING WOR KING MEDIU ME DIUM M
Duivc (he cxpr uiloai (S.6) (S.6) u d (5.6) ud write write » compnttr compnttr progrvn to calcucalculu t u d prinl prinl out Ikt vüue* vüue* oí V{t) u d V'[t\ kt V'[t\ kt uy crwlt u {le #. Dtvelop Dtvelop ikt profru n b lucli • «ay IkU It It cu prút eul 720 viluei in «t«p« oí culi dcp t* tr uk u|U . Sulliblt headi headis|i s|i »ucli »ucli u lactioo itrokc, campreutoa campreutoa urak«, «U., in»y »1m b« midt ( o príat príat U tp propríu t pitea . 4
(
r c
6.1
InUoduction
M uy work-productn work-productngg dcvicc$, dcvicc$, *.g. laUr&U laUr&U com butio n en gúei, liway* ntil¡s« ntil¡s« ft gueoBS «OTkiBg «OTkiBg finid. finid. Mott ugiaecHag itndtBU ir e fun ilúr wUh comp rotion ignition ignition «ntomotive «agine «agine** oied in tnid u, b u ei and loiríes. loiríes. In the
i6
CoBpa CoBpatu tu SlfliBUÜM e SlfliBUÜM e l « E «f «fU « Ptottuim « Ptottuim DispUc(m
6
Exexcise
CI ENGINE SIMULATION WITH AIR AI R AS WORKING WOR KING MEDIU ME DIUM M
Duivc (he cxpr uiloai (S.6) (S.6) u d (5.6) ud write write » compnttr compnttr progrvn to calcucalculu t u d prinl prinl out Ikt vüue* vüue* oí V{t) u d V'[t\ kt V'[t\ kt uy crwlt u {le #. Dtvelop Dtvelop ikt profru n b lucli • «ay IkU It It cu prút eul 720 viluei in «t«p« oí culi dcp t* tr uk u|U . Sulliblt headi headis|i s|i »ucli »ucli u lactioo itrokc, campreutoa campreutoa urak«, «U., in»y »1m b« midt ( o príat príat U tp propríu t pitea . 4
(
r c
6.1
InUoduction
M uy work-productn work-productngg dcvicc$, dcvicc$, *.g. laUr&U laUr&U com butio n en gúei, liway* ntil¡s« ntil¡s« ft gueoBS «OTkiBg «OTkiBg finid. finid. Mott ugiaecHag itndtBU ir e fun ilúr wUh comp rotion ignition ignition «ntomotive «agine «agine** oied in tnid u, b u ei and loiríes. loiríes. In the advuttgeoui to deviw cíoted cyd e* tbat approximtte op^n cycle*. One incb tpproacb i* tdetl cycle (jjnnlttion (jjnnlttion (IC 3] witb air a* tbe workb g mediitm. Ideal cycle limalatioa i
I ií
(i) The working finid throngbont throngbont the cycle is a fixed mau o í air. (ii) Tbe worLisg mediara mediara ti unuoe d to be u ideal ideal gaj. (iü) Tbere ii no btak« or exba ut proceu. (iv}-Tb e com biu tbs 'pro cM i i repUced repUced by a beat beat addilion prx> prx>ce ceu u b-om u . extemal lonrte. (r) Tbe beat addition takei pUce pUce at conitant preuore. il.
L ) > )
49
(vi) Tbc cjrcle U compl( U>( be luiroBDdínp. (ix) Tbc rc á no frkCt frkCton on invotved. . (x) Tlie workúig workúig rscdium rscdium hu conttuit ipcdfic btaU (C , uid C,).
Caapattr SImalilha o fC Í Ettfbit Pcocet*C Pcocet*Cii
Ideal Diesel cyde The m ü i idc» of C1 engloe liravUlion oiing idet l Dietel cyc k U to ea»t ea»t>l >lee Ibe reíder to qu»l¡t»tively *x»jnm« th« ínButac» of ilit di^crent wúblei OD ilj pcr fonn ucc, Th< retolli obtuaed from ideil cycle úmnluion, lacb M p ie u v tt , temp«r*turei, (fficieBcy uid meui eSectivc prHinrt, víU difer a jr tU det l from tboíe p«r tüa in( lo ih t K to il esgm t. Th etm pli uíj , thertfore, thertfore, ¡9 cor c«iuidention of tht liiniiUtion of ut idcil cyck wiU be prinuríljr on tbe quklilativa upecti. diijrim. Figure B.l B.l ¡Uajtrilu «o ideil Diexi cyck on {l« p-V diijrim.
(proccu 2->3), hett (dditioa b « tuted whea the the patos ¡s U tbc TDC. B cctoie oí ktU addition, addition, the the tempcrttnrt ri« *. Ptocím 3- »i rtprei«at« úentropic ezpuuion u thc patoa move moveii {iont {iont TDC to BDC; lad pctKtu 4 -« l rtprcMsti iaittatueoQ i h »t rcject rcjectloa loa »t cooitaat prtuarc wbcn wbcn tbe tbe púloB púloB u it BDC. 6.3
SImulalíon wíth alr as Ihe workino me
a
^» (7j - Tj)i
Hcít rtjíctíd, rtjíctíd, ?,
a
C ,(r 4 - Ti).
Tberefore, tbe act work work oatput per unit qaiattty oí ilr ú
- c,(r,-r,)-c,(r«-r,). Tboj the tbermil ctSckacy f)n, b >Itk
Caapattr SImalilha o fC Í Ettfbit Pcocet*C Pcocet*Cii
(proccu 2->3), hett (dditioa b « tuted whea the the patos ¡s U tbc TDC. B cctoie oí ktU addition, addition, the the tempcrttnrt ri« *. Ptocím 3- »i rtprei«at« úentropic ezpuuion u thc patoa move moveii {iont {iont TDC to BDC; lad pctKtu 4 -« l rtprcMsti iaittatueoQ i h »t rcject rcjectloa loa »t cooitaat prtuarc wbcn wbcn tbe tbe púloB púloB u it BDC.
(vi) Tbc cjrcle U compl( U>( be luiroBDdínp. (ix) Tbc rc á no frkCt frkCton on invotved. . (x) Tlie workúig workúig rscdium rscdium hu conttuit ipcdfic btaU (C , uid C,).
) )
) )
6,2
6.3
)
He»t He»t iddtd,
a
^» (7j - Tj)i
Hcít rtjíctíd, rtjíctíd, ?,
a
C ,(r 4 - Ti).
Tberefore, tbe act work work oatput per unit qaiattty oí ilr ú
- c,(r,-r,)-c,(r«-r,). Tboj the tbermil ctSckacy f)n, b
) lí
SImulalíon wíth alr as Ihe workino me
Ideal Diesel cyde The m ü i idc» of C1 engloe liravUlion oiing idet l Dietel cyc k U to ea»t ea»t>l >lee Ibe reíder to qu»l¡t»tively *x»jnm« th« ínButac» of ilit di^crent wúblei OD ilj pcr fonn ucc, Th< retolli obtuaed from ideil cycle úmnluion, lacb M p ie u v tt , temp«r*turei, (fficieBcy uid meui eSectivc prHinrt, víU difer a jr tU det l from tboíe p«r tüa in( lo ih t K to il esgm t. Th etm pli uíj , thertfore, thertfore, ¡9 cor c«iuidention of tht liiniiUtion of ut idcil cyck wiU be prinuríljr on tbe quklilativa upecti. diijrim. Figure B.l B.l ¡Uajtrilu «o ideil Diexi cyck on {l« p-V diijrim.
.)
49
y.-ir
>Itk
t.
I
n
1
í;
Coiuideríng tbe prvccn 1—í
(6. 1) Coiuiderínf Coiuiderínf tbe coait ut prcunre prcunre proceu 2 -«3, wc btve V, Ti
íi íí '
T, Ti
Flg.e.l p-V Jiúfnm o/oB i¿eil l}üiel cfcU
t!
r,
It i
We wil willl wiiune wiiune »com pr«ub nntio(r) of i6;l, icut -oí nt iolr t = Vj/Vj) Vj/Vj) oí i ind &iptcifi &iptcificc ht»t r»lio (k) oí 1.4. luntiapic compmtioa of úr occnn bctwmi 1 u d 2 (ri{[.0.1) (ri{[.0.1) «a thc thc püCoo novel {rom BDC to TDC. KeU ts tbcn kdded tt couluit proiitrc
1
U;
MÍ
Ti
-r,r.
( « 2)
).we hkve T,
= riri-»'
(8.S)
l|Í
Mi
(
( (O
d i Et/U* SlaaUtka wítli wítli AJj AJj- u WorklBf Mtdit a
Ccwpai u Slat¡iUoB Slat¡iUoB oí Cí Eaila t FnctutM
(
SI
(
CoBiidcnBf the pr octa S->4, w« Kkvc Kkvc
(
,h-»)
(«.<) b->»
-
(6.5)
c (
Rom
T, -
TirJ
r ,r ,r < »»- ‘ í r . { ^ )
(
iDUtd .
FlS.6.3 EJeel o ¡ comprti${o% ratio c» i 1-
.
1-
-
rb-'»r,-r
[ r; -l
1
vrktr vrktr** r b th« comprtwtoo r»lio u d r. ii tbe cut-off rUio, ftvcü by. Va
6.4
ntú> on tffitUiUf
( (
DevIsUo DevIsUon n between sclu tl and and Idu t qtde
c c
Some of (be moi( importuU wtyi b wbicb wbicb (be «cla*i cyd e compreaioB igú(ioB eogiae eogiae deviitei (rom tbe idetl cycle irt u foUowt:
{
(i) Tbe working medi(.m ú not tir ud tbe ipecific ke4(4 of tbo ictna] guKj iscrtue witb tempentBN. (ü) Tbe combBition proceu repUcej (be beit tnnifer process U bigb tempentores u d (be combDiti combDition on cuy b« bcompIe(e.
c c'
(
( (O
d i Et/U* SlaaUtka wítli wítli AJj AJj- u WorklBf Mtdit a
Ccwpai u Slat¡iUoB Slat¡iUoB oí Cí Eaila t FnctutM
(
SI
(
CoBiidcnBf the pr octa S->4, w« Kkvc Kkvc
(
,h-»)
(«.<) b->»
-
(6.5)
c (
Rom
T, -
TirJ
r ,r ,r < »»- ‘ í r . { ^ )
(
( (
iDUtd .
FlS.6.3 EJeel o ¡ comprti${o% ratio c» i 1-
.
-
rb-'»r,-r
1-
[ r; -l
1
vrktr vrktr** r b th« comprtwtoo r»lio u d r. ii tbe cut-off rUio, ftvcü by. Va
Figur« Figur« 0.2 «baws (k c eff«c( oí r oa the cScieocy for variou cu(-o 7 ratíof. ratíof. The importUkt poUt to bou b tbu (be cfficicBcy oí tb* ideti Dieael cycU Í>ft fanetion fanetion so l only o f tbt camprtuíoo raiio baC'tUo o5 (be cuC-off rsiio. Bven (boagb «Scuacy ucr«M«« witb (be comprcuioi'n(io t( dtcreue* dtcreue* «i(b M iocrtu e Is (be ci( ^f f ri(io. Tbú ú dae (o (he ÍKt (bit (be exp«n exp«nik ik>a >a n( io dccrcAM* dccrcAM* wUb wUb u iacreue in (be CQ( CQ(-a -aH H n( io . I( is »lio (m e oí u »c(aal compreuioB ignUioB eB(ine (bU (be e&cieficy t u be ÍBcreued by compreuíoD ntio . Tbe írend ( o w u d i bi{bercampret>ion n(t03 ¡acrtuiog (be compreuíoD is promp(«d by (be effoit (o ob(«in bigbei (bermil cScjeacy. Uowever, in (be »c(u*I cagiae t h u t k l a ¡ b ou wei(h(( of (be (be en^ e u tbe corapretttoo ou m i íb wei(h n( io is Ucreu ed. Tbertfore, Tbertfore, (be mudmum comp miioB rUio (bat ctn be ui
6.4
ntú> on tffitUiUf
DevIsUo DevIsUon n between sclu tl and and Idu t qtde
c c
Some of (be moi( importuU wtyi b wbicb wbicb (be «cla*i cyd e compreaioB igú(ioB eogiae eogiae deviitei (rom tbe idetl cycle irt u foUowt:
{
(i) Tbe working medi(.m ú not tir ud tbe ipecific ke4(4 of tbo ictna] guKj iscrtue witb tempentBN. (ü) Tbe combBition proceu repUcej (be beit tnnifer process U bigb tempentores u d (be combDiti combDition on cuy b« bcompIe(e. (üi) Eicb mecbuiictl eycle eycle of tbe engin enginee iavolve iavolveii an inlet inlet u d exku st proceu u d , due to tbe preuore drop tbroo ^ tbe ralvet, ralvet, k MrtuB MrtuB uaouit of Work Work is reqoired reqoired (o cb tfge (be cyimder wilb (ael>ur mixture ud alio to dríve dríve out (be product* product* of c ombutioa. (iv} T b e» will be considerable beat traaifer betw betweea. eea. tbe gases is tbe eyüc
c c' c L
(
(
c c c ( (
c
63
CI Eath$ SiaiUtlct frllh Alt u Workhf M
Cofljpatv SinuJílfan SinuJílfan o/ CI Eatk » Ptoctatt*
6.5
2j
Solved Solved «amp ie
V,
=
Te X Vj
=
147.8 147.8 cc.
=
3M7.6K, 3M7.6K, 4 X 3«.9
- “-“ - ( I S )
l .«
7 tlm»
í X «(J «(J’’ X 110 110 X 10"’ IS2. IS2.99 « ,
r
VUc 1 ) f ) t
=
Al potnt'4 (ead o ( tx puul oB) ;
í X B’ X S
) i.
r,xTt
m‘ 4x009.4
Tl e compttMioa ruio for in tdcil Die*tl cyrie b 16. At th« bífíaning of Ihe comprtnion ftrole Ihc pre*»nr« ú I »tni ind tli« ttraptrittire 300 K. The cnt-off ritió Mi . Determin Determinee (i) p,V ,T T»loe» T»loe» al Ihe Ihe end end oí íic i p ro «« oí the the cycle, cycle, (üj tbe therma thermall eSctency, eSctency, ud H the meui «fectlve «fectlve preñare. preñare. Tkke Tkke tbe bore bore (B ) u 80 mm, mm, u d «troke «troke (5) of tbe ejigine ejigine u 110 mm; tbe ritSo of ipecific bett» for »ir ii 1.4, Cp ii 1.0W kJ/kg K ind C, ú 0.717 kJ/kj IC We b»v«
“
X Vdup Vdup
la X 552.9
18-1
V| V|d5
=
5Í9.Í te,
=
UmI j j —Vjup
=
S0.9CC.
Now p, V T vUnet U poiat l (before compre*iton) ire:
=
V,
2090.1 K,
m Vk,,
.
Ai ia m iof aait m tu o( »Ir expuuion work,
ÍVop - C,(r,-T«) ,(r,-T«)
ÍN .I tt .
ít
63
CI Eath$ SiaiUtlct frllh Alt u Workhf M
Cofljpatv SinuJílfan SinuJílfan o/ CI Eatk » Ptoctatt*
6.5
2j
Solved Solved «amp ie
“
r,xTt
m‘ 4x009.4
Tl e compttMioa ruio for in tdcil Die*tl cyrie b 16. At th« bífíaning of Ihe comprtnion ftrole Ihc pre*»nr« ú I »tni ind tli« ttraptrittire 300 K. The cnt-off ritió Mi . Determin Determinee
V,
(i) p,V ,T T»loe» T»loe» al Ihe Ihe end end oí íic i p ro «« oí the the cycle, cycle, (üj tbe therma thermall eSctency, eSctency, ud H the meui «fectlve «fectlve preñare. preñare. Tkke Tkke tbe bore bore (B ) u 80 mm, mm, u d «troke «troke (5) of tbe ejigine ejigine u 110 mm; tbe ritSo of ipecific bett» for »ir ii 1.4, Cp ii 1.0W kJ/kg K ind C, ú 0.717 kJ/kj IC We b»v«
ít
=
Te X Vj
=
147.8 147.8 cc.
= =
3M7.6K, 3M7.6K, 4 X 3«.9
Al potnt'4 (ead o ( tx puul oB) ;
- “-“ - ( I S )
í X B’ X S
l .«
7 tlm»
í X «(J «(J’’ X 110 110 X 10"’
)
i.
IS2. IS2.99 « ,
r
VUc 1
X Vdup Vdup
la X 552.9
18-1
) f ) t
V| V|d5
=
=
5Í9.Í te,
=
UmI j j —Vjup
=
S0.9CC.
V,
expuuion work,
At p ciot 2 ( tt the end of comprtttio n): 1 X 16 '*
At polnt 3 {i t the end of b eii Iru uítr ); f>3 c3 p j
«!
=
.
ÍN .I tt .
ÍVop - C,(r,-T«) ,(r,-T«)
pi = 1 »tm; Tj = 500 K; Vj =Vmc = 6B9. 6B9.88 cc.
Pi
m Vk,,
Ai ia m iof aait m tu o( »Ir
V, T vUnet U poiat l (before compre*iton) ire: Now p, V, r. fr)
2090.1 K,
= 45,5 45,5 tttn, tttn,
=
0.717 X (3M7.6 - 2090.1)
=
1109.6 kJ/k|,
=
/{ x (Tj - Tj)
=
0.287 X (3637.6 (3637.6 - 909.4)
»
783 783 kJ/kg
=
C.[T, - T|)
-
0.717 0.717 X (909.4 - 300)
o
436.939 436.939 kJ/k|,
t
M
Cea palt r SlatUÜoM SlatUÜoM ot Ct
Pr
HtU »ad.
-
C , (T (T , - r , ) L004x(J«7.«-«(».i) 17S9.1 17S9.1 kJ/k i,
Thtrtíoi», K^tnp +
aci *n>fk doa«,
CI ENGINE SIMULÁTION WITH ADIABAT ADIA BATIG IG COMBUSTI COMB USTION ON
1109.6 1109.6 + 7ÍJ~4MJ> 1455.7 kJ/kj,
r
U5S.7 J7J9.1
( 7.1
m t u t ffff ec ec üv üv * pr tM tMw rt rt
o.
introductlon
flS L íL ÍÍ )
c
\ViuJ\ItTxJ\ 101305 J 14S8.7
101S2S X 6Í9.8 X 10“* 10» X itf* X — — — X 101S25 2S7X300 SS2.9
»
(
(
ty..i lÍ M
tltcmiAl «fficUncy
(
I B .» .» b u .
cat>off ntlo ¡f tmamúd w 4 which ú • iiUla too ffotr, la (U« «z uip it, tk< cat>off Ut(c . Hidm, th« «SciicBcy «SciicBcy i( ooly SS.lX . NonnkUr, NonnkUr, U wül b« b«hr Ma 2 u d S. TliSi TliSi Qliut QliutraU raU** tkU Ihf cal-oS rU b b ako » de cidkf f tclor in a Dictcl
k tbe Lut eh ^U r we discuutd CI esgíne esgíne lúnoU tbn wilb atr u Ike workworkin{ mediun. la (hit cbipt er we will will coiuider fa«l*tir fa«l*tir mixtuM mixtuM u the workioi median and abo iaclcde Ihe iotikt proceM witli iom« üaplityiai aaamptb o« . F^uthe F^uther, r, we wiO iacorporate tk« cooitant-prcaaor e adiibat ic cambti>cambti>tbn ca leo litbu , ia order order to ibialat« ibialat« tbe combutíon proceu. We wiü wiü csU csU tbis analyiU fnel-air cycle limoJatba (FCS). Fignre Fignre 7.1 illutrate* a typical cyde, ib owiog all tbe proceuet, iaclsdiag tbe iatake iatake and ex ba ut etroke. It ibottld ibottld be ooted tbat, ¡a tbii imnlatbn, tbe tatake proce** b ratbef bit ovtMlsipli&ed. We will coatider coatider tbe iatake acd
C
(, • ♦
C
M
Cea palt r SlatUÜoM SlatUÜoM ot Ct
Pr
HtU »ad.
-
C , (T (T , - r , ) L004x(J«7.«-«(».i) 17S9.1 17S9.1 kJ/k i,
Thtrtíoi», K^tnp +
aci *n>fk doa«,
CI ENGINE SIMULÁTION WITH ADIABAT ADIA BATIG IG COMBUSTI COMB USTION ON
1109.6 1109.6 + 7ÍJ~4MJ> 1455.7 kJ/kj,
(
(
(
ty..i lÍ M
tltcmiAl «fficUncy
r
U5S.7 J7J9.1
( 7.1
m t u t ffff ec ec üv üv * pr tM tMw rt rt
o.
c
flS L íL ÍÍ )
\ViuJ\ItTxJ\ 101305 J k tbe Lut eh ^U r we discuutd CI esgíne esgíne lúnoU tbn wilb atr u Ike workworkin{ mediun. la (hit cbipt er we will will coiuider fa«l*tir fa«l*tir mixtuM mixtuM u the workioi median and abo iaclcde Ihe iotikt proceM witli iom« üaplityiai aaamptb o« . F^uthe F^uther, r, we wiO iacorporate tk« cooitant-prcaaor e adiibat ic cambti>cambti>tbn ca leo litbu , ia order order to ibialat« ibialat« tbe combutíon proceu. We wiü wiü csU csU tbis analyiU fnel-air cycle limoJatba (FCS). Fignre Fignre 7.1 illutrate* a typical cyde, ib owiog all tbe proceuet, iaclsdiag tbe iatake iatake and ex ba ut etroke. It ibottld ibottld be ooted tbat, ¡a tbii imnlatbn, tbe tatake proce** b ratbef bit ovtMlsipli&ed. We will coatider coatider tbe iatake acd txbaut procéis ia |rtat«r detaü ia Cbipter S.
14S8.7
101S2S X 6Í9.8 X 10“* 10» X itf* X — — — X 101S25 2S7X300 SS2.9
»
introductlon
I B .» .» b u .
cat>off ntlo ¡f tmamúd w 4 which ú • iiUla too ffotr, la (U« «z uip it, tk< cat>off Ut(c . Hidm, th« «SciicBcy «SciicBcy i( ooly SS.lX . NonnkUr, NonnkUr, U wül b« b«hr Ma 2 u d S. TliSi TliSi Qliut QliutraU raU** tkU Ihf cal-oS rU b b ako » de cidkf f tclor in a Dictcl cycla.
Exercise
7.2
WríK » profru n to ilmaltU CI eaglat proccuc* u b | u ideal I>ies«l I>ies«l cycle. cycle. C«acn t« tki rM)iü rM)iür«l r«l daU »t
C
(, • ♦
C
(
Engine details
Tbe limaUtioo tbat foUow* ia tbis cbapter and ia tbe rcit oí tbe book wiü ex imio c tbe performance cbaracteiistia of a piiton-cjrliader eagine. Tbe detaili of tbe eagioe oader coaaldexatuo for tbe limutatbo are givea ¡a Tabl« 7.1. Tbe maia aim of tbe limuUtioa limuUtioa uiing uiing adiabatic adiabatic co mb ulb a ealcnlaüoa* ealcnlaüoa* ii to evaloate Ibe p«wcr eatpat asd tbemal eSciency lor a pvea eagine ipe«d, ambieot air air te m p la re , (ael «sd (nel-air ratb . la tbii cbapter cbapter we we wiD wiD ilmulate ilmulate CI engine engine íor natvaliy upirated and inpcnliarged coad itb u. It ii boped tbat tbli wiQ müe tbe reader sodentaad and appreclate tbe effect of intake ptocesi aad aii^fsel riiio on engine períotmaace, wbicb were nol indaded in tbe ideal cycie aimalation.
r í
i
C¡ Enflat SlwaUtloa irltk Ad/t&il/c Combiulha
S6Cemp ii iil « Sím SímoUIfoo oUIfoo o f CTEaf be Pra cet ttt L«C
Tt
5T
unbicnl ur Umperalsre uid
= ialil* mui/bld tempcritut; tempcritut; Tkert wiD wiD be no Umpcratara Umpcratara drop ú Iht icttlu m uifo ld u lliii lliii foci U úij tht tylinder, Thtrefo re,
T„
r ..
(7.1)
Lh «i >o » ikEnt ccrtaía ccrtaía temu thit are are lutd lutd qoilc of ua in th« limaUtion. limaUtion.
Nao
Iflomolt» oí »ir »ir pío» fuel viponr ia ia a mu tgn coatiia iag 1 kmol of fnd.
Npt
küomolcj oí prodscU formtd from küomolct küomolct of úr tUen In dariot tactioa. kQomoIo kQomoIo of fucl iiijKttd. küamol küamolet et of retidokl uh ttu l from cBfíae darías tba compmiioa itroke.
tfx ffp
Ibe combu tioa of ffgto ffgto-
tk« previooi cycU lo tbe
kilomolci kilomolci oí prodocU formed formed from ibe ibe comboition of N, + Ni-i- Nt. ipocific b«U of tir.
Ftg.T.l Diticl tfclc al tuiiunlly aipiraltá eowíiltsn
Tkbla r. l
B S
U l M tonada tbe «ajía e cyele cyele (rij.7 .1) » aí it irt from poiat l. InilU InilUUy Uy,, we h»ve h»ve to «wi ne tbe vilnet vilnet oí N, u d Ti, bolh depead'mg on tbe prtviooi cycle, wbkb !n tora, dependí oa tbe cyde before before tbit, wid to on. To iltrt withi let iti uiame
Dttalbolthtciitiattortiinslaüoii Bore Stroke
iMfltrop iMfltropkk compftulon compftulon pro cai l-*2
80.0 Eun 110.0 mm
// = 0
tad
r jB r
(7.2)
^
C¡ Enflat SlwaUtloa irltk Ad/t&il/c Combiulha
S6Cemp ii iil « Sím SímoUIfoo oUIfoo o f CTEaf be Pra cet ttt Tt
L«C
5T
unbicnl ur Umperalsre uid
= ialil* mui/bld tempcritut; tempcritut; Tkert wiD wiD be no Umpcratara Umpcratara drop ú Iht icttlu m uifo ld u lliii lliii foci U úij tht tylinder, Thtrefo re,
T„
r ..
(7.1)
Lh «i >o » ikEnt ccrtaía ccrtaía temu thit are are lutd lutd qoilc of ua in th« limaUtion. limaUtion.
Nao
Iflomolt» oí »ir »ir pío» fuel viponr ia ia a mu tgn coatiia iag 1 kmol of fnd.
Npt
küomolcj oí prodscU formtd from küomolct küomolct of úr tUen In dariot tactioa. kQomoIo kQomoIo of fucl iiijKttd. küamol küamolet et of retidokl uh ttu l from cBfíae darías tba compmiioa itroke.
tfx ffp
Ibe combu tioa of ffgto ffgto-
tk« previooi cycU lo tbe
kilomolci kilomolci oí prodocU formed formed from ibe ibe comboition of N, + Ni-i- Nt. ipocific b«U of tir.
Ftg.T.l Diticl tfclc al tuiiunlly aipiraltá eowíiltsn
Tkbla r. l
Bore Stroke Conaectiai rod lengtb Compreuioa ritió DkpUcemeat voldine Volttiae Volttiae it TDC Voloine U BDC
Kiup
V kí . Vuc 7.3
U l M tonada tbe «ajía e cyele cyele (rij.7 .1) » aí it irt from poiat l. InilU InilUUy Uy,, we h»ve h»ve to «wi ne tbe vilnet vilnet oí N, u d Ti, bolh depead'mg on tbe prtviooi cycle, wbkb !n tora, dependí oa tbe cyde before before tbit, wid to on. To iltrt withi let iti uiame
Dttalbolthtciitiattortiinslaüoii
B S L T
80.0 Eun 110.0 mm 2J0.0 mm ie.5 552.9 cc 35.7 te 68S.( ce
Miximum powcr of thc compríMioa-ifnilbu «afiní wM bt obtúned wlitii it
Pi
Pi
// , = 0
tad
r jB r ,,
(7.2)
Pi V ^ RTy RTy •
(7.J)
Al tbe be jian ún of t be comprt$iJon proee*$, proee*$, there m tbe workiaf Raid.
mole* of
Let Cf, be tbe coulint-preuurt beU e»p»c¡ty (kJ/kmol K} for tht reICtMt ff^ + A , .
iMfltrop iMfltropkk compftulon compftulon pro cai l-*2
<= C,/ C,) cui be wrUlea Tbea tbe polytroplc índex for compresjíon [k <=
tW» condilion, *n hivt, P.
imbitnt preMUrt
V,
Vw c
1 Um{My)
(Cpc-/i)
(7.4)
wbere wbere iJ = Í .3U ( kj k mol"' K"*). Siace Siace we we kaow kaow Ti u wtU wtU u r, we jel
( ) (
68
CI Eefüit Süoahtha Süoahtha n iti ÁdUbttíc CoabasUoD
Conpo<«/SIfl>o]iUan«rCTS»/ia»Ffo«»*«
7JJ
r.
=
Tir^-‘.
(7.5)
pi
=
Pit^'i
(7.6)
Vi
=
Vtd.. Vtd..
(7.7)
AdUbatk AdUbatk combuit combuitloa loa ^oce w 2->3 2->3 Lcl iii uium e tbU tha tha comb ution pUc« uliibatic&Uy uliibatic&Uy «J>d «J>d co ni tu l preuore. S ínct Ihm is ao beU (r uuíer , tke cncrgy e<}a»t e<}a»tioa ioa cta b« wrítUa u
We bive íf».- =
=
Fp(r,)
( 7J )
«k «4:c «4:c ti>« ti>« laffixt* r, f and p dcaoU Ike Ike moles oí nactanU, fael *ad t]i« t]i« prodacti of coabottioii. Tka (o la lka oí c^.(7.S) wiU k« U kta np akortljr. akortljr. By aolvútg e
=
fí.
" -“ -“ ( B
17+ 3.70 3.70 y,
=
4JS 4JS + 4 .7 6 r ,
(7.1J)
füC füC 10.5 10.5 < y < 15.5 15.5 í o r Y ¿ l 6 .S
1015 1015 < y < 15.5
y > 15.5 15.5
A r i= 2 ( lS J -y )5 , /Í2 /Í2 = ( 2 y - 21)5 21)5',', JVj = US/
/f} = o
A i- «3 .7 6y S y ^ *= 0
(7.14)
^'a = 105/ fí i = US/
f (7.1S)
No«r No«r k( u coulder lh« combu lioa proceu 3-«3 ia d«laiL For a (ciutant'
r .(
Ar« Ar« = 3 .7 6 y j/ = ( y - 1 5 .5 .5 ) 5 /
;!(
H i
wbere (7.10)
( (
“ (ffn*-rífcox232ÍCO)j^ (ffn*-rífcox232ÍCO)j^ ÍTi
(7.6)
KmwIb( pt and Tj, «r« c u «afciUU
y»
=
1+ 0 9 7
* From Tibie 2.3 in Cliipter 2, tbe valué valué of ¿Tr ¿Trpp c u be oblaine d, whicb ii do»« to -6,796,000 -6,796,000 kJ/kffl kJ/kfflot ot oí CioH » v»poiii. v»poiii. Han tbe aote nnmbera and tbe vake of Qp r«q
cntlialpy cntlialpy of til* til* R K (u t <3iatlit) 3iatlit){> {>]r ]r of tbe prodact,Le. a,[T,]+B,{,T,)
60
(7-3*} (7-3*}
j(
Tbe valse al Y ñxu Nmo and
(
( ) (
68
CI Eefüit Süoahtha Süoahtha n iti ÁdUbttíc CoabasUoD
Conpo<«/SIfl>o]iUan«rCTS»/ia»Ffo«»*«
7JJ
Tir^-‘.
(7.5)
pi
=
Pit^'i
(7.6)
Vi
=
Vtd.. Vtd..
(7.7)
r.
=
We bive íf».- =
AdUbatk AdUbatk combuit combuitloa loa ^oce w 2->3 2->3
cntlialpy cntlialpy of til* til* R K (u t <3iatlit) 3iatlit){> {>]r ]r of tbe prodact,Le. =
( 7J )
Fp(r,)
«k «4:c «4:c ti>« ti>« laffixt* r, f and p dcaoU Ike Ike moles oí nactanU, fael *ad t]i« t]i« prodacti of coabottioii. Tka (o la lka oí c^.(7.S) wiU k« U kta np akortljr. akortljr. By aolvútg e
=
=
4JS 4JS + 4 .7 6 r ,
(7.14)
í o r Y ¿ l 6 .S
y > 15.5 15.5
A r i= 2 ( lS J -y )5 , /Í2 /Í2 = ( 2 y - 21)5 21)5',', JVj = US/
/f} = o
(7.10)
(7.11)
-
Equation Equation (7.11) caa b< convesÍMtly aotvt aotvtdd oi k g tbe Niwtoa-Rapluoa iltfUioB tcdiB¡qa«, oact w« kitow U>« valau oí tbe product gw mote niunl>cn, bi •q.(7.11). •q.(7.11). W* wiO wiO «valaal* «valaal* IhtM mok aomb en in Un ni of tbe actsal Uf bi valoe* hr U i « apaa aadar aadar coajIdcx coajIdcxaUoo aUoo.. ?or CI tnfia u aornally dleiel, C ieH », i* tbt fue) iu«d. Ecnc*, Iho Iho vitieu prodocU moUi trt m I u AT*= K,;
Having caleulited tbe valueí oí Tj,p: and V-, we caa now proceed to cjjcu lue tbe vahea ct Ti and Ti and pt doring ihe expwuioii expwuioii pioceM 3 -»4. Kow,
» O,.
( (
(7.17) c.
mole oí CtoH j], thea the reactanl reactanl foel-air L il Y Kprt wal m olu oí O j per mole mixture i*
(7.18) C,oHn + YO ,+3.7 flYN j
( (
wbere
" -“ -“ ( B
• N ,- C O ; N t - C O t;
füC füC 10.5 10.5 < y < 15.5 15.5
1015 1015 < y < 15.5
(7.6)
fí.
(7.1J)
“ (ffn*-rífcox232ÍCO)j^ (ffn*-rífcox232ÍCO)j^ ÍTi
No«r No«r k( u coulder lh« combu lioa proceu 3-«3 ia d«laiL For a (ciutant' pmsura tdiabadc co mb utbo j w« cas writ writaa {rtíer {rtíer lo eq.(3.43} eq.(3.43}]]
17+ 3.70 3.70 y,
A i- «3 .7 6y S y ^ *= 0
KmwIb( pt and Tj, «r« c u «afciUU
y»
=
1+ 0 9 7
* From Tibie 2.3 in Cliipter 2, tbe valué valué of ¿Tr ¿Trpp c u be oblaine d, whicb ii do»« to -6,796,000 -6,796,000 kJ/kffl kJ/kfflot ot oí CioH » v»poiii. v»poiii. Han tbe aote nnmbera and tbe vake of Qp r«q
Lcl iii uium e tbU tha tha comb ution pUc« uliibatic&Uy uliibatic&Uy «J>d «J>d co ni tu l preuore. S ínct Ihm is ao beU (r uuíer , tke cncrgy e<}a»t e<}a»tioa ioa cta b« wrítUa u
a,[T,]+B,{,T,)
60
( 7. 7. 12 12 )
( ( (,
c
60
Cl Eaf íat Slmalttha wUb wUb Acffibilfc Oombattha
Cojaps(«5ima]ilíon of Cl Eattn» Proctttt»
01
where
Cpp {C,p-lí)' Vbdc. Vbdc. 7J.4
(7.19) (7.20)
EAb«t» EAb«t»(( »nd »nd bulte ptoceuti l-» 5 iml 5-» l Al point 4, we uin me »h»l the ex iu iit y»Ne opea» md lfc« presiure dropi lo unbient, uid IhU the t«mper»turt oí th« exbtiut dropi to r.
=
r .(y
( 7. Í 1 )
Al «te pbto n move» from B DC to T DC , mo«t o f the ex hio jl ju e» we piuhed oot, »iid whit reraiint in the tngíne »t TDC ú
N. r
fe
%
JlTt JlTt
(7.22)
The cxh(U«t nl vc now cV»e< aad the intake intake ntv e opent. The ptitoo more» lUrwJ lUrwJyy lo BDC pooition, dnriB dnriBj which time / / , mole* of *ir »re dr»wn Jfx, the rttdtiag lemptrUnre will into the workiog tpice; »fter múdng wilh Jfx, be T|. T|. Note (ht l ff , i$ not given given bjr e
Tig.T.l
Intake Intake i ln lt ia púton-tfUnétT iñfint
and by gronpbg the U and pV Umu, we p t r. ) - N,¡i^{Tt] + + / / . / » . ( r , ) . N,h^{ Tt) + W . A . ( r. Repbci ng enthalpy termi by
ff .
control control mus a
/ / . S ( l 6) + ^ .« .( r . )
(7.23)
A» the pistón movts throogh the length of the ttrole, an unount of Work Work
the energy eqnalioa reduce» to
im
prodncU and oot iog thit PiV'bd. RT, — Nn,
(7.29)
60
Cl Eaf íat Slmalttha wUb wUb Acffibilfc Oombattha
Cojaps(«5ima]ilíon of Cl Eattn» Proctttt»
01
where
Cpp {C,p-lí)'
(7.20)
Vbdc. Vbdc. 7J.4
(7.19)
EAb«t» EAb«t»(( »nd »nd bulte ptoceuti l-» 5 iml 5-» l Al point 4, we uin me »h»l the ex iu iit y»Ne opea» md lfc« presiure dropi lo unbient, uid IhU the t«mper»turt oí th« exbtiut dropi to r.
=
r .(y
( 7. Í 1 )
Al «te pbto n move» from B DC to T DC , mo«t o f the ex hio jl ju e» we piuhed oot, »iid whit reraiint in the tngíne »t TDC ú
N.
(7.22)
JlTt JlTt
The cxh(U«t nl vc now cV»e< aad the intake intake ntv e opent. The ptitoo more» lUrwJ lUrwJyy lo BDC pooition, dnriB dnriBj which time / / , mole* of *ir »re dr»wn Jfx, the rttdtiag lemptrUnre will into the workiog tpice; »fter múdng wilh Jfx, be T|. T|. Note (ht l ff , i$ not given given bjr e
r
fe
%
Tig.T.l
Intake Intake i ln lt ia púton-tfUnétT iñfint
and by gronpbg the U and pV Umu, we p t r. ) - N,¡i^{Tt] + + / / . / » . ( r , ) . N,h^{ Tt) + W . A . ( r. Repbci ng enthalpy termi by
prodncU and oot iog thit PiV'bd. RT, — Nn,
ff .
control control mus a
/ / . S ( l 6) + ^ .« .( r . )
(7.23)
A» the pistón movts throogh the length of the ttrole, an unount of Work Work eqaa] lo (7.2<)
im
(7.29)
the energy eqnalioa reduce» to (7.S0)
will be done by the gue* in the working.ipace, whUe work amoonting lo
l'
p.V;
(7.2S)
ii done on the control masa by the air behínd N^. in the N^. Al BDC, the energy in control mau ti w *«p (r,)+ //.«.(r,) ( 7. 7. 26 26)
where where ia the conitant-preamr conitant-preamr** heal capadty oí air air b k l kmol'* K *‘ . Bqnatioa (7.30) cas be lotvcd fot Ti. However, ií the düfertnce betweeo Cpf and Cp, it igsored, eq.(7.30) rtdgcet le
rT,
Now w« can combine e<]i.(7.23) to (7.26) to fonn the energy e
^«u p{r,)+ JV .u.(ri)
r - i + ( r. r . / r» r» ) -
(7.S1)
To retnni to the ehain oí eaJculatlou, wilh the new valué» íor T| (e
N, (.q.(7.2S)| and N , h.(7.22)|, a new vilne for C^, U cakulated and the computation» procetd throngh a «econd cycle beglaning with the compreaiion
c ( ,( 6
3
Ci £agln« £IiDiiUtioa wHh AdUbtth Combait¡oa
C o m p o U r S i a a U l h a o í C t E e f h it P t o c t M t
itroke (iq.(7J}|. A lhir4 cyclc c u foUow foUow th« th« *«x>nd *«x>nd tjid to oa. The costpalk»accc«*>y *>yee cyclo prodnce Umcat tbc um e vtlac*. üoat üoat u t to b« halu d w bu »accc«
Tbe meu cScctive preuurt, pati, » dcEaed dcEaed u ihc bfpotbetical prtunrc wUcb, if ut u g tbrougbout tbe power power itrokc, itrokc, would proiuce tbe «J calU cd wcrk of tbut itrokt, itrokt, le .
lopa t coodlUooJ coodlUooJ uxd predlctcd rcsulU ChcmicAUy ChcmicAUy co m ct mixture Sp ««d ISOO ISOO rpm pj l Um r ia.5
VarUble*
=
l á K
SlmaUU SlmaUUon on wlth wlth tdUbttlc comb combsttk sttkiA iA
FttU ttU load optn tion ÍVid CioUn r. MOK FVic FVicti tion on ud heU tr uuícr oc|kcted
(
fVom cqt.(7.22) cqt.(7.22) u d (7.29), it it folkwi thu
Gtatrilly, Gtatrilly, ibt co nvtriwc* b ^oilc ^oilc npkl.
Tibl* 7.3 fivcs lh« rottb* ai Uii compntuioa (wtlh (cmr decimai kccancjrl] for thc cogin* cogin* dt*cjib«
(
OS
f (
r
•o that H'. Pmrf “ (7J8) Vaup Vaup Anotber w» y o f «x tmln inj tbe ratio oí net Work (o r power) to diipU cemtnt volujne ñ to itart witb W'mji 'mji + lícomb ~ ^nmp,
(
im
whicb whicb cu be wnttea wnttea u
< »' «t = « p (up(T,) (up(T,) - up(T4 up(T4)} )} + N,R (T (T , - T , ) - N, (u,(T,) - u,(Ti)}
(7.4 (7.40) 0)
wbu-e ¡fp »nd N, denote tbe mole» of piodncti &nd reactut*, reipectívety. Now
( (
c ( ,( 6
Ci £agln« £IiDiiUtioa wHh AdUbtth Combait¡oa
C o m p o U r S i a a U l h a o í C t E e f h it P t o c t M t
3
itroke (iq.(7J}|. A lhir4 cyclc c u foUow foUow th« th« *«x>nd *«x>nd tjid to oa. The costpalk»accc«*>y *>yee cyclo prodnce Umcat tbc um e vtlac*. üoat üoat u t to b« halu d w bu »accc«
Tbe meu cScctive preuurt, pati, » dcEaed dcEaed u ihc bfpotbetical prtunrc wUcb, if ut u g tbrougbout tbe power power itrokc, itrokc, would proiuce tbe «J calU cd wcrk of tbut itrokt, itrokt, le .
(
Vih Vih
lopa t coodlUooJ coodlUooJ uxd predlctcd rcsulU ChcmicAUy ChcmicAUy co m ct mixture Sp ««d ISOO ISOO rpm pj l Um r ia.5
VarUble*
=
l á K
SlmaUU SlmaUUon on wlth wlth tdUbttlc comb combsttk sttkiA iA
FttU ttU load optn tion ÍVid CioUn r. MOK FVic FVicti tion on ud heU tr uuícr oc|kcted
(
fVom cqt.(7.22) cqt.(7.22) u d (7.29), it it folkwi thu
Gtatrilly, Gtatrilly, ibt co nvtriwc* b ^oilc ^oilc npkl.
Tibl* 7.3 fivcs lh« rottb* ai Uii compntuioa (wtlh (cmr decimai kccancjrl] for thc cogin* cogin* dt*cjib«
=
•o that H'. Pmrf “ (7J8) Vaup Vaup Anotber w» y o f «x tmln inj tbe ratio oí net Work (o r power) to diipU cemtnt volujne ñ to itart witb W'mji 'mji + lícomb ~ ^nmp,
(
im
whicb whicb cu be wnttea wnttea u
< »' «t = « p (up(T,) (up(T,) - up(T4 up(T4)} )} + N,R (T (T , - T , ) - N, (u,(T,) - u,(Ti)}
(7.4 (7.40) 0)
(
wbu-e ¡fp »nd N, denote tbe mole» of piodncti &nd reactut*, reipectívety. Now <í,
-
RTi
~ . í V l^ l^
-
(
— V. r - 1 diip'
(
Heoce,
7.4
Wark output and and elfidency elfidency calculttloas \r-lRTj
Vdup Vdup we c u now . Htriag ulcolU«d p ,V ,T valnti «t tbi (alient poinU ta (b« cycle, we *ctkalaU tbc work work outpat outpat ud cScieocy oí tbc cycle. Nel work ooiput o(- tb« cycle M'iwl iwl
=
w.
w.tcmp tcmp
H'.XJ H'.XJ +
(7.32)
“ Wtompi Wtompi
í'pírO-í^píU
(7J3)
( / /. + W p , - J ? ) { r a - r , ) .
(7.3Í)
^
{ Up Up (r (r ,),) - u p( p( T« T« )) )) - { « . (T (T j ) - u , ( r , ) } + y ,R ( r , - r^ ) (7.41)
In Tibie 7.3, calcuUttona wt ahowa ahowa íor > SS3 cc diaplacemeat voloine eapae . The mcstMO mcstMO of dúplMemest volu volunie nie bu no rneulog , or rtiber li d j no meumg. AU 16.5 comprenioo ntio engiuej wtil exhibil the valuu ibown in Tkble 7.2. Por tbat matter, 2Íl 16.5 16.5 campreuion n tia engmei operxting on cbeoúcally correct diei«l-uf mixture wül produce 21.21 kW/litre niining al ISOO rpm (mder nalurally upirated cosdition «ítb 30C K intake manlfold
««mptntu re »nd with = 3.44. Howí w , H Buy b« noted noted th»t die»*l die»*l tniinei nonnil nonnilíy^ íy^ opent « oa lein mixtorc* »nd rtrtly oa chemktJly correct mxtam. Tht-importuit ftUarc fti eq.(7.41) eq.(7.41) ii the the í« t »b»t Ihe coraprewto coraprewton n ntio, prtnore, tmper^ urc imd imd mole ntio quintitin t1i»t apptir oa the rigKt-kud
Input condltiom and prcdIcUd remita Fall toad operation Chemicaily correct miatare Puel CioHn Speed 1500 rpm r« 3 00 00 K 1 atm pt n. 15.5 15.5 r 16.5 fHctioo and heat heat trassfer trassfer aejkcted
Y„/Y /í a f y Ti K Ti K T» K r . K 3» K Pt atm Pi atm Pi atm
Y„/Y /í a f y Ti K Ti K T» K r . K 3» K Pt atm Pi atm Pi atm
u k. P(kWj Plm.f I«tm| 1%1
««mptntu re »nd with = 3.44. Howí w , H Buy b« noted noted th»t die»*l die»*l tniinei nonnil nonnilíy^ íy^ opent « oa lein mixtorc* »nd rtrtly oa chemktJly correct mxtam. Tht-importuit ftUarc fti eq.(7.41) eq.(7.41) ii the the í« t »b»t Ihe coraprewto coraprewton n ntio, prtnore, tmper^ urc imd imd mole ntio quintitin t1i»t apptir oa the rigKt-kud (ide «re iateiuivc iateiuivc paran cten; that U, the ilie of the eogine doet oot mflDcnce
II is «ten thal Ihe peak ttniptraturt and powtr art prodaced by the chemIcaUy correct mixtorc. The thcrmal tIEciency tends to {aerease with the Icaner mixtore «hile the power ttnds lo decrtaac wilh (he leaner mixtnre.
them.
í' i
N
Input condltiom and prcdIcUd remita Fall toad operation Chemicaily correct miatare Puel CioHn Speed 1500 rpm r« 3 00 00 K 1 atm pt n. 15.5 15.5 r 16.5 fHctioo and heat heat trassfer trassfer aejkcted
7.5
Superchar ged opefsUon Diesel engines are somially lapercharfed in order to iacreue the power outpat. This is achieved by inslaUini a comprcaior ia iht inltke lyiltm, ihtreby iocrtasing the density of air at the start of the compretiioQ slroke. Usnally, Usnally, the cojnprt i»ot n place d in the inUl manifoid pipe. Becausa of the sopercharger both iatake presiore and temperatiirc temperatiirc !acrea>«. !acrea>«. Theie two factors may improve the fuej vaponiation when the futí i» injected.
)
■ -
- -
■ (
-
. (
08
Eofú< SltaaUllos witb AJUbtIle Combutha C¡ Eofú<
Compal*/Sietíill Compal*/Sietíillei ei e/CZ Íi/U * Pa k w w
00
( ( (
(' ( t
( r:
c VTOC VTOC
Flg.r.S
''ol
Th* ti Ké ut -UUU loof /or an an ti U u t
c
VBDC VBDC
(
c
H t t K m tvpenhirgtr
( Tb« p«titioa ct tic vilv« detcrmÍAet tke frtclioB ol the exhaast Sow tbkt puMU tkroa|h lb« tu bU t. Thtu, th« povcr ootpat ootpat oí Ui« tarbine !i puMU tkroa|h coDU coDUÓl ÓlUb UbU. U. TkU (cilurt (cilurt ii aot avtlUb avtlUbU U b • {u x lm ta lapercbuier. la gttiMlrivtn lapcrcbtrgtr, to codUoI tbe poixr mpot to tbe compreuor, t
r i g . r . 6 An «xAsMt itrh'nt ínjxreAaryír
( (
■ -
■ (
-
.
- -
( 08
Eofú< SltaaUllos witb AJUbtIle Combutha C¡ Eofú<
Compal*/Sietíill Compal*/Sietíillei ei e/CZ Íi/U * Pa k w w
00
( ( (
(' ( t
( r:
c VTOC VTOC
Flg.r.S
c
VBDC VBDC
''ol
Th* ti Ké ut -UUU loof /or an an ti U u t
(
c
H t t K m tvpenhirgtr
( Tb« p«titioa ct tic vilv« detcrmÍAet tke frtclioB ol the exhaast Sow tbkt puMU tkroa|h lb« tu bU t. Thtu, th« povcr ootpat ootpat oí Ui« tarbine !i puMU tkroa|h coDU coDUÓl ÓlUb UbU. U. TkU (cilurt (cilurt ii aot avtlUb avtlUbU U b • {u x lm ta lapercbuier. la gttiMlrivtn lapcrcbtrgtr, to codUoI tbe poixr mpot to tbe compreuor, t gt«r box would b« rt
( The rtquired «xKiuit muiifold prMnire, prMnire, pt, c*a be eomputed eomputed by equitiog coraprtMor work inpot wilb tbe tarbine work oatpat:
u ibowa in Fig.7.S. Fig.7.S. Ttble 7.S givc4 givc4 tbe tbe p«r{onn uce detiQi o f 4n exb iu t drivea inpcrcbarger inpcrcbarger engine, engine, witb lU tbe exbt ott prodact i flowing tbroagb the toibise . T be gain
