ABSTRACT
The purpose of this experiment was carried out to demonstrate the relationship between the pressure and temperature of saturated steam ste am in equilibrium. Besides that, to demonstrate the vapor pressure curve. In this experiment, steam temperature was observed as the water boils rised. The steam temperature and pressure was recorded when the boiler was heated until the steam pressure reaches 10.0 bar (abs). The steam temperature was recorded when the boiler boiler was cooled cooled until until the steam steam reached reached atmosp atmospher heric ic pressur pressure. e. rom rom the !raph !raph shown, shown, the relationship between temperature and pressure is directl" proportional as the temperature increased, the pressure increased. rom the table showed, the measured slope and calculated slope were decreased as the temperature increased. #s a conclusion,the experiment was successful based on the theor" even there were some error.
1
Table of contents
#bstract..................................................................................................................1 Table of $ontents...................................................................................................% 1.1 1.% 1.& 1.* 1. 1.
Introduction.....................................................................................................& 'bectives& Theor"..*+ -ia!ram and -escription of #pparatus+/ eneral 'peratin! rocedure/+2 3xperimental rocedures.2+10
1.4 5esults and -iscussion11+1& 1./ 6ample calculations.1*+1 1.2 $onclusion and 5ecommendation...1+14 1.10 5eferences..1/ 1.11 #ppendices.1/
2
1.1 INTRODUCTION The Marcet Boiler is designed to demonstrate the principal in thermodynamic studies
which is the
boiling
phenomenon. At the
temperature of 100°C the temperature of the water constant due to the amount of latent heat needed to brea! the bond between water particles. At this stage "apor and li#uid are in the same ratio. The "olume begins to change rapidly as the li#uid is being transformed into "apor $%&. The process continued until the last drop of li#uid "apori'ed this is called as (saturated "apor) $1&. The units help to study the relationship between the pressure and the temperature of saturated steam in e#uilibrium with water. The pressure increases with the increase of the boiler temperature this is due to the gas ideal law in e#uation *1+.The boiling point of the water in this e,periment is 100 °C this is due to the e,periment that had been done in the atmospheric pressure. -f the pressure is increase 2 atm the water will start boiling at 200 °C $1&. The steam was allowed to come out at "al"e % for at least %0 seconds before temperature was recorded. This step is important to remo"e air from the boiler as the accuracy of the e,perimental results will be signi/cantly aected when air is present $2&. The increase of temperature was recorded from 1 to 10 bar of absolute pressure.
1.2 OBJECTIVES
%
The obecti"e for this e,periment is to demonstrate the relationship between the pressure and temperature of saturated steam in e#uilibrium and to demonstrate of "apor pressure cur"e. The temperature was recorded and determine at the pressure within 10 bar. The increases energy within water increasing of acti"ities among molecules which increase the number of molecules escaped from the surface.
1.3 THEORY The Marcet Boiler was used to in"estigate the relationship between the pressure and temperature of the saturated steam in e#uilibrium with water at 1 bar to 10 bar of absolute pressure. An ideal gas can be di"ided to three states "ariables they are absolute pressure *p+ absolute temperature *T+ and "olume *+. The relationship between them had been deduced from the !inetic theory and becoming ideal gas law. The ideal gas law e#uation managed to predicts the 3"3T beha"ior of a gas accurately within some properly selected region. The simplest and best3 !nown e#uation that in"ol"e gas phase is the ideal gas law. 4 n5T66666666666666 *1+ 7here 4 Absolute pressure 4 "olume n 4 amount of substances *moles+
8
5 4 ideal gas constant T 4 absolute temperature *9+ 7hen a gas law beha"e e,actly li!e a ideal gas law. -t were predicted to beha"e in terms of "olume pressure and temperature then the gas is said to be an ideal gas. -f the gas are opposite from the ideal gas law then the gas is said to beha"e li!e a :real gas;. The energy continuously supply to the boiler until it reach boiling point. The temperature increases as the acti"ities among molecules also increases. The increase in temperature causes the bond between particles of water to brea! and the number of molecule escape from the surface also increase. The acti"ities continue until an e#uilibrium states is reached. At lower pressure less of energy is needed to achie"e e#uilibrium states which is less energy is re#uired to achie"e e#uilibrium states. The temperature where the e#uilibrium state achie"ed is !nown as saturated temperature. Clapeyron e#uation is to determine the enthalpy of "apori'ation hfg at a gi"en temperature by simply measuring the slope of the saturation cur"e on a 3T diagram and the speci/c "olume of saturated li#uid and saturated "apor at the gi"en temperature $2&. The measured "alue that is obtained from the gradient of the graph *dT
?
dT ¿ dP
*
(
dT ) dP
4
TVfg hfg
4
T ( Vf −Vg ) hf −hg
=AT
=AT
And hf @ hfg 4 hg ence hfg 4 hg 3 hf
(
dT ) dP
=AT
4
T ( Vf −Vg ) hfg
4
TVg hfg
As g f -n which > f
4 =peci/c "olume of saturated li#uid
g
4 =peci/c "olume of saturated "apor
hf
4 nthalpy of saturated li#uid
hg
4 nthalpy of saturated "apor
hfg
4 Datent heat of "apori'ation
1.4 DIAGRAM AND DISCRIPTION OF APPARATUS
The unit used in the experiment consists of a stainless steel pressure vessel which equipped with hi!h pressure immersion electrical heater. This unit also connected to a safet" relief valve, temperature and pressure measurin! devices and to allow the water, the feed port of water is installed. The unit consists of temperature and pressure transducers to !et the readin! of value easil" on the di!ital indicators. The temperature is settin! usin! a temperature controller to the maximum operatin! temperature. E
1
%
4
/ & *
2 10
Fig!e 1" Unit Const!ction fo! Ma!cet Boile! #Mo$el" %&1'()
1. %. &. *. .
ressure Transducer ressure Indicator Temperature $ontroller7Indicator $ontrol anel Bench
. Bourdon Tube ressure au!e 4. Temperature 6ensor /. ressure 5elief 8alve 2. 9eater 10. :ater Inlet ort ; 8alve
The Ma!cet Boile! #Mo$el" %& 1'() consists of mainl" the followin! items< a) P!ess!e *essel $apacit" < & =iters >aterial < 6tainless 6teel &0* -esi!n ressure < &0 bar 'peratin! ressure < 10 bar $ertification < -'69 certified F
b) P!ess!e Gage T"pe < Bourdon Tube 5an!e < 0+%0 bar (!) c) P!ess!e T!ans$ce! :etted >aterial < 6tainless 6teel $ase >aterial < 6tainless 6teel 5an!e < 0+1 bar (abs) d) &lect!ical %eate! ower < %000: T"pe < Immersion T"pe 6afet" < 9i!h temperature cut+off b" means of a temperature controller e) Te+,e!at!e Senso! T"pe < 5T- ($lass #) 5an!e < 0+%00 o$ f) Safet- Feat!es ressure 5elief 8alve (6et at 1 bar), Temperature $ontroller (6et at 1/.0 o$) &,e!i+ental Ca,abilities
a) -emonstration of relationship between the pressure and temperature of saturated steam in equilibrium with water b) -emonstration of the vapor pressure curve O/e!all Di+ensions
9ei!ht < 1.1 m :idth < 1.00 m -epth < 0.0 m Gene!al Re0i!e+ents
3lectrical
< %*0 8#$71+phs709?
:ater 6uppl" < -istilled water
1. G&N&RA2 OP&RATING PROC&DUR&S 1.3 Gene!al Sta!t, P!oce$!es
G
1. >a@e sure the unit was operated in conditioned properl" and the unit was connected to the power suppl". %. The valves at feed port and level si!ht tube were opened which are 81,8% and 8&. &. The boiler was filled with distilled water throu!h the feed port and the water level has been determined at about the half of hei!ht of the boiler. *. #t the level si!ht tube, the valves, 81 ; 8% were closed bac@ and turned on the power suppl" switch. . The experiment was read" to be performed.
5.3 Gene!al S6t$o7n P!oce$!es 1. The heater was switched off and the temperature was allowed to drop until same as
room temperature. %. The main switch and the main power suppl" were switched off. &. :ater was retained for the subsequent use. *. The water was drained off b" opened 8& at the upper part of the level si!ht tube and 81 and 8% were opened then. Note" The water inlet port was hi!hl" pressuri?ed at hi!h temperature. -o not open
the valve at the water inlet port.
1.' &8P&RIM&NTA2 PROC&DUR&
1. The !eneral start+up procedures as mentioned in section 1.0 were implemented. %. :hen the water had been filled into the boiler, the valves at the level si!ht tube, 8% and 8& were then opened to chec@ the water level. -istilled water can be added if needed then the valves ware closed bac@. &. The temperature controller was set up to 1/.0 o$ where was sli!htl" above the expected boilin! point of the water at absolute pressure, 10.0 bar. *. The vent valve, 8& was opened and the heater was turned on. . The increased of steam temperature was observed as the water was boiled.
H
. 6team was allowed to come out for about &0 seconds from the valve, 8& and the valve was closed bac@. This is because the presence of air could be si!nificantl" affected to the accurac" of the experimental results. 4. The steam temperature and pressure were observed and recorded while the boiler is heated until the pressure was reached at 10.0 bar (abs). /. The heater was turned off and then the temperature and pressure were started to descend. The steam temperature was recorded until the steam pressure reached at atmospheric pressure while the boiler was allowed to cool down at room temperature. 2. The readin! of steam temperatures at different pressure when the boiler is heated and cooled. P!ecations"
1. The valve at the water inlet port should not be opened as it is hi!hl" pressuri?ed as the temperature increased when switched off the heater. %. Before the heater was turned on, the valves at the level si!ht tube must have been ensured to be closed due to the si!ht tube unable to withstand hi!h pressure and temperature. &. :hile the boiler was heated, never open the valve as pressuri?ed steam and it ma" cause serious inur". *. -o not touch an" part of the boiler durin! it was heated at hi!h temperature. . Aever closed near to the valve, 8& the place where the steam was allowed to release out because it ma" cause inur". 1.9 R&SU2T AND DISCUSSION R&SU2T Table 1" 6aturated temperature of water at different pressure
ressure , (bar)
Temperature, T ( $)
au!e
#bsolute
Increase ( $)
0.00 0.10
1.00 1.10
10%.0 10.&
-ecrease ( $) 10&. 10.4
#vera!e Tav! ( $) 10%.4 10.00 10
>easured 6lope, dT7d
$alculated 6lope, Tv!7hf!
+ 0.&%0
0.0400 0.01
#vera!e Tav! (C) &4.4 &42.00
0.%0 0.&0 0.*0 0.0 0.0 0.40 0./0 0.20 1.00 1.10 1.%0 1.&0 1.*0 1.0 1.0 1.40 1./0 1.20 %.00 %.0 &.00 &.0 *.00 *.0 .00 .0 .00 .0 4.00 4.0 /.00 /.0 2.00
1.%0 1.&0 1.*0 1.0 1.0 1.40 1./0 1.20 %.00 %.10 %.%0 %.&0 %.*0 %.0 %.0 %.40 %./0 %.20 &.00 &.0 *.00 *.0 .00 .0 .00 .0 4.00 4.0 /.00 /.0 2.00 2.0 10.00
104. 102./ 11%.1 11*.& 11.& 11/.% 1%0.1 1%1.2 1%&. 1%.% 1%./ 1%/.& 1%2./ 1&0.2 1&%. 1&&.4 1&.1 1&.& 1&4. 1*%. 1*4.2 1%.% 1.% 10.0 1&.& 1. 12. 14%.& 14.1 144. 1/0.1 1/%.* 1/*.
102.* 111.2 11&.2 11.% 11/.% 1%0.1 1%%.1 1%&./ 1%.% 1%.2 1%/. 1&0.0 1&1. 1&%./ 1&&.2 1&.& 1&.* 1&4.4 1&/./ 1**.% 1*2.0 1&.& 14.% 10.2 1*.& 14.* 140.* 14&.% 14.2 14/. 1/0./ 1/&.% 1/*.
10/.* 110./ 11&.00 11.% 114.% 112.0 1%1.10 1%%./ 1%*.*0 1%.0 1%4.40 1%2.1 1&0. 1&1./ 1&&.%0 1&*.0 1&.4 1&4.00 1&/.1 1*&. 1*/.* 1%.4 1.40 10.* 1&./0 1.2 12.2 14%.4 14.0 14/.0 1/0.* 1/%./ 1/*.
11
&/1.* &/&./ &/.00 &//.% &20.% &2%.0 &2*.10 &2./ &24.*0 &22.0 *00.40 *0%.1 *0&. *0*./ *0.%0 *04.0 *0/.4 *10.00 *11.1 *1. *%1.* *%.4 *%2.40 *&&.* *&./0 *&2.2 **%.2 **.4 **/.0 *1.0 *&.* *./0 *4.0
0.%*% 0.%*0 0.%1% 0.%%% 0.124 0.%%% 0.1/ 0.14& 0.1& 0.1& 0.1& 0.1*& 0.1*/ 0.11/ 0.1&& 0.1%/ 0.1%& 0.1%& 0.11* 0.104 0.024 0.0/ 0.04/ 0.04* 0.0 0.0% 0.02 0.0 0.0* 0.00 0.0*4 0.0* 0.0&
0.000 0.0/4 0.0% 0.0& 0.01 0.0*21 0.0*4 0.0*0 0.0** 0.0*&1 0.0*1/ 0.0*0 0.0&2 0.0&/ 0.0&44 0.0&4 0.0&0 0.0&1 0.0&** 0.0&11 0.0%/ 0.0% 0.0%*2 0.0%&& 0.0%%& 0.0%11 0.0%01 0.012% 0.01/* 0.014/ 0.0141 0.01 0.011
Graph of Temperature er!u! "re!!ure ?00 800 %00 Temperature #&%
200 100 0 0
2
8
E
G
10
12
"re!!ure #a$! $ar%
i!ure 1.1< raph of Temperature versus ressure
Graph of 't('p er!u! " a)' Tf*(hf* er!u! " 0.0G 0.0E S+ope
dt
0.08
T"fg
0.02 0 0
2
8
E
"re!!ure #a$! $ar%
i!ure 1.%< raph of dT7d versus and Tv f!7hf!
12
G
10
12
DISCUSSION
In >arcet Boiler experiment, before the experiment be!in, the air in the boiler must removed to !et the accurate value. The result will affected if the air was presence in the boiler. The result was ta@in! after the water in the boiler was boiled and the steam was out. raph plotted from fi!ure 1.1 shows that the relationship between temperature and pressure in absolute was increased. The temperature was increased when the pressure increase. raph plotted from fi!ure 1.% shows that the relationship between measured slope and calculated slope versus pressure in absolute is inversel" proportional. The slope was decreased when the pressure is increase. There are some sources of error of the experiment which is measurement, room temperature, pressure and calculation. -urin! a vapori?ation process, a substances exits as a part of liquid and a part of vapor. The properties of the saturated liquid were same whether it exists alone or in a mixture with saturated vapor. The amount of saturated liquid was chan!ed when process of vapori?ation happened but not its properties and also same with saturated vapor. :hen the liquid absorbed enou!h heat ener!", it will chan!e to vapour form where vapor carried out activities amon! the molecule that enable molecule to escape from the surface until vapor reached equilibrium. #s the steam is not allowed to exit, it will cause an increase in pressure and thus causin! the temperature to increase. #pplications of >arcet Boiler in industr" that include water boiler, !asifier, power plant and coo@in! utilities.
1%
1.: SAMP2& CA2CU2ATION
rom the data < 107.5
Tav! (D$) <
+ 109.4 2
< 10/.* D$ T av! (C) < 10/.* E %4& < &/1.* C
dT dP
>easured 6lope,
at T1 F &/1.* C and T % F &/&./ C
dT F &/&./ C G &/1.* C F %.* C #t 1 F 1.% bar and % F 1.& bar d F 1.& bar G 1.% bar 1.01325 1 atm
F 0.1 bar x
dT dP
F
¯¿
x
¿
2.4 K 10 kP a
$alculate measured slope ,
v f
F 10 @a
1 atm
F 0.%*
T vg
$alculate
101.325 kPa
hfg
F
T ( v g−V ) f
hfg
, 18
,
−105 x − 0.001047 = 110−105 0.001052 −0.001047
109.8
f =¿ v¿
3
− 3 m kg 1.0518 × 10
vg
$alculate
,
−105 x −1.4186 = 110−105 1.2094 −1.4186
109.8
3
vg
F 1.%144/
h fg
$alculate
m kg
,
−105 x − 224.31 = 110−108 2229.7 −2243.1
109.8
h fg
F %%10.2*
kJ kg
$alculated slope,
T ( v g−v hfg
f
)
−3 ¿ 1.217768 −1.0518 × 10 ¿ F ( 109.8 ) ¿ ¿
F 0.0
1?
1.( CONC2USION AND R&COMM&NDATION Conclsion The relationship between pressure and temperature of saturated steam is observed. The pressure and temperature were showed on the pressure indicator and temperature controller. To ma@e the experimentHs result as efficient as possible, the Ideal as 3quations and thermod"namics theor" were used. 3valuate the slope from derivation of formula and used the data !iven from the steam table. $ompared the calculated slope (Tv !7hf!) and measured slope (dT7d) from the table and !raphs. #fter anal"?in! the experimental and theoretical results, the experimental slope is similar to the theoretical slope which shows the accurac" of the test. The plotted !raphs showed that the pressure is directl" proportional to the temperature which is the relationship between temperature and pressure in absolute was increased. The temperature of saturated steam was increased when the pressure of saturated steam increase. It can be proved that the fluid used for the experiment was pure water because the fluid boils at &4&C. #s conclusion the experiment was successful even there were small possible errors in this experiment. To improve the accurac" of the result the experiment should be performed carefull" and the instruction should be followed.
Reco++en$ation
1E
1. Ta@e pressure readin!s with li!ht" tapped. %. 5emove the air from the >arcet boiler. &. 6et the boiler at room temperature at the initial state.
1.13 R&F&R&NC&S
;1< unus #. $. and >ichael #. B., Thermod"namic, th ed., Aew or@, A< >craw+9ill,
pp. 11*+11, 44 ,(%004). ;5<. =aborator" >anual of $hemical 3n!ineerin!. Marcet Boiler . Jniversit" Te@nolo!i >ara
ulau inan!.
K&L 3dward 3. #., Thermod"namic, 4 th ed., Jnited 6tates of #merica, 9enr" A. 6aw"er $ompan" Inc. pp 22, %0 (122*)
1.11 APP&NDIC&S
$egC
>Pa Sat. Te+,. ,!ess. 3 T C ,EsatT
0.01 10 1 %0 % &0 & *0
0.11& 0./4%1 1.%%4 1.401 %.&&2 &.12 *.%* .%/ 4.&/*
Sat!ate$ =ate! #%5O)Te+,e!at!e Table Spec. Volume Internal Energy Enthalpy +?@>g >>g >>g Sat. Sat. Sat. Sat. Sat. Sat. li0i$ /a,o! li0i$ /a,o! li0i$ /a,o! v f v g u f u g h f h g
0.001000 %0.1* 0.001000 1*4.1% 0.001000 10.&/ 0.001001 44.2& 0.00100% 4.42 0.00100& *&.& 0.00100* &%./2 0.00100 %.%% 0.00100/ 12.%
0.00 %0.24 *%.00 %.22 /&.2 10*.// 1%.4/ 1*.4 14. 1F
%&4.& %&/%.& %&/2.% %&2.1 %*0%.2 %*02./ %*1. %*%&.* %*&0.1
0.00 %0.2/ *%.01 %.22 /&.2 10*./2 1%.42 1*./ 14.4
%01.* %10. %12./ %%/.2 %&/.1 %*4.% %.& %.& %4*.&
Entropy >>g Sat. Sat. li0i$ /a,o! s f s g
0.0000 0.041 0.110 0.%%* 0.%2 0.&4* 0.*&2 0.0& 0.4%
2.1% 2.0%4 /.200/ /.4/1* /.4% /./0 /.*&& /.&&1 /.%40
* 0 0 40 4 /0 / 20 2 100 10 110 11 1%0 1% 1&0 1& 1*0 1* 10 1 10 1 140 14 1/0 1/ 120 12 %00
2.2& 1%.&*2 1.4/ 12.2*0 %.0& &1.12 &/./ *4.&2 4./& 40.1* /*. 0.101& 0.1%0/% 0.1*&%4 0.120 0.12/& 0.%&%1 0.%401 0.&1&0 0.&1& 0.*1* 0.*4/ 0.*&1 0.14/ 0.400 0.4214 0./2%0 1.00%1 1.1%%4 1.%** 1.&24/
0.001010 0.00101% 0.00101 0.001014 0.0010%0 0.0010%& 0.0010% 0.0010%2 0.0010&& 0.0010& 0.0010*0 0.0010** 0.0010*/ 0.0010% 0.0010 0.00100 0.0010 0.001040 0.00104 0.0010/0 0.0010/ 0.001021 0.00102 0.00110% 0.00110/ 0.00111* 0.0011%1 0.0011%4 0.0011&* 0.0011*1 0.0011*2
1.% 1%.0& 2./ 4.41 .124 .0*% *.1&1 &.*04 %./%/ %.&1 1.2/% 1.4%2 1.*12* 1.%10% 1.0& 0./212 0.440 0./ 0./%% 0.0/2 0.**& 0.&2%/ 0.&*/ 0.&041 0.%4%4 0.%*%/ 0.%1/ 0.12*0 0.14*02 0.1* 0.1*10
1.&/ 0.00114 0.1%4&
1//.** %02.&% %&0.%1 %1.11 %4%.0% %2%.2 &1&.20 &&*./ &./* &4./ &24.// *1/.2* **0.0% *1.1* */%.&0 0&.0 %*.4* *.0% 4.& //.4* 10.1/ &1./ &.%* 4*./4 2. 41/.&& 4*0.14 4%.02 4/*.10 /0.12 /%/.&4
%*&./ %**&. %*0.1 %*. %*&.1 %*2. %*4.2 %*/%.% %*//.* %*2*. %00. %0. %1%.* %1/.1 %%&.4 %%2.& %&*. %&2.2 %*.0 %0.0 %*.2 %2. %*.1 %/.* %4%. %4. %/0.% %/&.4 %/4.0 %20.0 %2%./
1//.* %02.&& %&0.%& %1.1& %4%.0 %2%.2/ &1&.2& &&*.21 &.20 &4.2% &24.2 *12.0* **0.1 *1.&0 */%.*/ 0&.41 %*.22 *.&1 4.2 /2.1& 10.& &%.%0 &./* 4. 24.&* 412.%1 4*1.14 4&.%% 4/.&4 /04.% /%2.2/
%/&.% %2%.1 %00.2 %02. %1/.& %%./ %*&.4 %&.& %1.2 %0.1 %/.1 %4.1 %/&./ %21. %22.0 %40.& %41&. %4%0. %4%4.& %4&&.2 %4*0.& %4*. %4%.* %4/.1 %4&. %4/.4 %44&. %44/.% %4/%.* %4/.* %420.0
0.&/4 0.40&/ 0.442 0./&1% 0./2& 0.2*2 1.01 1.04& 1.1&*& 1.12% 1.%00 1.&02 1.&&0 1.*1/ 1.*4&* 1.%4 1./1& 1.&** 1./40 1.4&21 1.4204 1./*1/ 1./2% 1.2*%4 1.22% %.0*12 %.0202 %.1&2 %.1/42 %.%&2 %.%/&
/0. %2.& /%.* %42&.% %.&&02
Fig!e 1 " Temperature table for saturated water
1G
/.1*/ /.04& 4.221& 4.202 4./&10 4.4& 4./%* 4.1%% 4.** 4.*421 4.*12 4.&*2 4.%2/ 4.%&/4 4.1/&& 4.1%2 4.044 4.0%2 .2444 .2%22 .//&& ./&42 .42& .40% .404/ .& .% ./4 .* .042 .*2/ .*&%&
1H
