REPORT ON VOCATIONAL TRAINING.
PREPARED BY MIHIR G. PURABIARAO [06BEER045] B.E. 3RD YEAR ELECTRICAL & ELECTRONICS ENG. INDUS INSTITUTE OF TECHNOLOGY & ENGINEERING. RANCHARDA, AHMEDABAD.
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INDIAN OIL CORPORATION. [I.O.C.]
GUJARAT REFINERY P.O. JAWAHARNAGAR,BAJUWA DIST. : VADODARA,GUJARAT-391 VADODARA,GUJARAT-391 320. WEBSITE : www.iocl.com
TRAINING PERIOD : [05/15/2009 TO 07/16/2009] TRAINING TIMING : 10:30AM TO 5:30PM Page | 2
ACKNOWLEDGEMENT. Training Training at INDIAN INDIAN OIL CORPORATI CORPORATION ON [I.O.C.] [I.O.C.] has very helpful to increase our skill capability & ability to understand what I have studied so far in in our engineering engineering course. Being Being here I have gained knowledge knowledge about about various electric electrical al equipments equipments used for generatio generation n& distribution of electrical energy to various plants running continuously. It is pleasure and an opportunity for me to expresss my feelings of thanks & respect to the people have at INDIAN OIL CORPORATION LIMI LIMITE TED D who who have have alwa always ys help helped ed & guid guided ed me in unde unders rsta tand ndin ing g various concepts, which were unknown to me. I am also thankful to Mr. Ashok Jambur from the training center who helped in arranging my visits to various departments here. I am also very thankful to Mr. Om Prakash (MNMEL) EL), Mr. A. S. Patel (SMNMEL) EL), Mr. P.V. Ramkrishna (PUM), Mr. K S Ramarao (MNMEL), Mr. S. Saini (MNMEL) and Mr. P.J. Shah (MNMEL), who also helped me during my training.
- PURABIARAO PURABIARAO MIHIR G.
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GUJARAT REFINERY [I.O.C.L] The Gujarat Gujarat Refine Refinery ry at Bajuva Bajuva in Gujarat Gujarat in Wester Western n India is Indian Indian Oil’s largest largest refinery. refinery. The refinery refinery was commissio commissioned ned in 1965. Its facilities include five atmospheric crude distilition units. The major units include CRU,FCCU and first Hydrocracking unit of the country. The products produced by the refinery is serves to the demand for petroleum products in western and northern India. When commissioned , the Gujarat refinery had a design capacity of 3.0 3.0 MMTP MMTPA. A. It was was subs subseq eque uent ntly ly incr increa ead d to 4.3 4.3 MMTP MMTPA A by the the revamping of three distillation units. In 1978, its processing capacity was furth urther er incre ncreaad to 7.3 7.30 MMTP MMTPA A by the addit dditio ion n of a crud crudee distillation unit. A fluidized catalyist cracking unit was added to the refine refinery ry in 1981 1981 to increa increase se produc productio tion n of middl middlee disti distilla llates tes,su ,such ch as diesel and LPG. In 1990 capacity of the refinery was further increased to 9.5 9.5 MMTP MMTPA A thro throug ugh h low low cost cost reva revamp mpin ing g / de-b de-bot ottl tlen enec ecki king ng and and addi additi tion on of a hydr hydroc ocra rack cker er in 1992 1992 for for maxi maximi miza zati tion on of midd middle le dist distil illa late tes. s. Suse Susequ quen ente tely ly the the crud crudee capa capaci city ty was was incr increa ease sed d to 12.5 12.5 MMTPA in 1999 by addition of new Atmospheric Unit of 3 MMTPA alon along g with with reva revamp mp of FCC FCC unit unit.. The The capa capaci city ty was was incr increa ease sed d to its its present capacity of 13.70 MMTPA by low cost de-bottlenecking. The company has already comissioned the facilities for MTBE and Butene-1 production. The refinery also produce also produce a wide range of specility products like Benzene, Toluene, MTO, Food Grade Hexane, Solvents, LABFS, etc. The refinery achived the distinction of becoming first refinery in the country country to have completed completed the DHDS (Diesel Hydro De-sulphu De-sulphurisat risation ion refinery started production of HSD with low Sulpher content of 0.25% wt (max.)). Page | 4
A project for production of high value LAB (Linear Alkyle Benzene) which is one of the major raw materials used in manufacturing of dete deterg rgen ents ts from from kero kerose sene ne stre stream amss is unde underr impl implem emen enta tati tion on and and scheduled for completion in 2004. In order to meet future fuel quality requir requirem ement ents, s, MS Qualit Quality y impro improvem vement ent facil faciliti ities es are planne planned d to be installed by 2006.
DIFFERENT PRODUCTS REFINARY :-
OF
GUJARAT
At pres presen entt the the refi refine nery ry prod produc uces es 15 prod produc ucts ts whic which h are are as follows : LPG BENZENE TOLUENE NAPTHA MOTOR SPIRIT (87 OCTANE) MOTOR SPIRIT (93 OCTANE) AVIATION TURBINE FUEL SUPERIOUR KEROSENE HIGH SPEED DIESEL LIGHT DIESEL OIL Page | 5
LOW SULPHER HEAVY STOCK FUEL OIL BITUMEN N-HEPTENE ALUMINIUM ROLLING.
ELECTRICAL SYSTEM ENGINEERING INTRODUCTION :Gujarat refinery is equipped with two power plants – Co-Generation Power Plant (CGP) and Thermal Power station (TPS). Complexity of power system is due to different Generation voltage levels, Groinding and Protection system employed. Even a small lapse while designing for the expansion / modification modification of generation generation / distribution distribution system may may lead to catastrophic consequence in the stability of power system. Variou Variouss equipm equipment ent speci specific ficati ation on standa standards rds for selec selectio tion n of equipment are available in the refinery. Expertise for engineering and sele select ctio ion n of equi equipm pmen entt are are also also avai availa labl ble. e. Need Need has has been been felt felt to cons consol olid idat atee all all good good desi design gn prac practi tice cess gain gained ed thro throug ugh h expe experi rien ence ce,, equipment selection dpecification etc. to serve as a guideline to the electr electrica icall design design engine engineers ers of the refine refinery ry to achie achieve ve consis consisten tency cy in design on regular basis.
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The role role of an Elet Eletri rica call engi engine neer er in Engi Engine neer erin ing g Serv Servic ices es Depa Depart rtme ment nt incl includ udes es but but not not limi limite ted d to stud study y the the Proc Proces esss sche scheme me,, evaluate the scope of electrical jobs involved, design a suitable electrical scheme to provide stable power supply and procurement of suitable materials required required for the same etc. Accordingly, the chapter on Design bas basis is is deve develo lope ped d to prov provid idee an over overvi view ew of Powe Powerr Gene Geneat atio ion, n, Dist Distri ribut butio ion n and and Main Mainte tena nanc ncee of the the Equip Equipme ment nt / Syst System em is to be designed.
POWER GENERATION The total Power Generation of Gujarat Refinery is 126.5 MW. TPS (Thermal Power Station) = 12+12+12.5 = 36.5 MW. CGP (Co-Generation Plant) = 30+30+30 = 90 MW.
Therefore the total Power Generation is 126.5 MW.
THERMAL POWER STATION (TPS). In Thermal Power Station there are three Generators. Two Generators are manufactured by Russia and other is manufactured by BHEL (Bharat Heavy Electrical Limited). Generator manufactured by Russia is of 12 MW and 3000 RPM while the one manufactured by the BHEL is of 12.5 MW and 5000 RPM.
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The Power Generation is done at 11 kV is converted to 6.6 using Transforme rmers (which comes from CGP, in case of backup). backup). The Generation Generation at TPS is done at 6.9 kV using reactor. Thes Thesee reac reacto tors rs are are used used for for the the prot protec ecti tion on purp purpos osee also also.. It reduces the fault current. There are also Reserve Reactor for stand by purpose. In TPS the Bus couples are also used at 6.6 kV and supply system. There are also PCC Power Control circuit for small supply. First the Power goes to PCC then to MCC. There are 3 Russian Boiler steam capacity of 75 tonnes/hour and one Indian Boiler (BHEL) having capacity of 130 tonnes/hour. Stem Pressure in drum = 44kg/cm2 . Steam Pressure after main Steam gate = 39 kg/cm kg /cm2 . Super Stem temp. = 440 0 C . Safety valve drum pressure = 44 kg/cm2.
SPECIFICATION OF RUSSIAN BOILER DESIGN DATA :
Generation Capacity = 75 T/hr.
Steam pressure in drum = 44 kg/cm2.
Steam Pressure after main steam gate = 39 kg/cm k g/cm2. Page | 8
Super Steam temp. = 4400C.
Safety Valve drum Pressure = 44 kg/cm2.
OPERATING PERAMETERS :
Steam Drum Pressure = 40 ata ± 1 kg/cm2.
Superheated Steam Pressure = 36 ata ± 1 kg/cm2.
Fuel oil line Pressure = 20 ata ± 1 kg/cm2.
Superheated Steam Temp. = 435 ± 5 0 C.
Feed Water without h.p heater = 100 ± 50 C.
Safety Valve Super heater = 39 kg/cm2 .
SPECIFICATION OF BHEL MADE BOILER Type = Front wall fired pressurized furnace. Natural circulation. Radiant closed bottom with oil and gas fire. Boiler
: F 16/22 vv 60.66/25.36 .
Location
: Outdoor.
Generation Cap. : 125 T/hr . Furnace
Superheater
: Type vv 60. : Stage – spaced 225 m2. Page | 9
Air heater
Drum
: Regenerative horizontal shaft pressurize jung storm rotary. : Twin Drum.
PROCESS IN TPS : The TPS consist of four boilers and three turbine generators sets. The boiler generate superheated stem by burning the fuel obtained from other plants of the refinery itself. This superheated steam can be utilize to supply steam yo other plants and can also be used for generating power using steam turbines. This This stea steam m rota rotattes the the blad blades es whic which h in turn turn prod produc ucee s the induced voltage. This voltage is then transferred to reactor. The Steam produced is through fuel OIL or REFINERY GASSES (RCO). The feed water to the boiler comes from a CM plant that the de-minerilize the feed water to prevent the corrosion of boilers vessels. All Russian Boilers are water tube boiler while the Indian boiler operates on forced draft.
CO-GENERATION PLANT (CGP) :
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E UI UIPM PMEN ENT T SPE SPECI CIF FIC ICAT ATIO IONS NS
Gas Turbine Frame
: 6
Make
: BHEL / GE
Type
: MS 6000, Single shaft Design.
Base load capacity
: 30 MW
Fuel
: Dual (Gas & Distillate) Page | 11
Compressor type & size
: Axial flow type 17 state
Rated Speed
Compressor with air handling capacity 400 T/H and Compression ratio 11:1 : 5100 RPM
Generator Make
: BHEL
Type
: TARI 800-26P
Rating
: 30MW, 37.5 MVA
Stator Current
: 1968 A
Voltage
: 11KV + 10%
Frequency
: 50 Hz
Power Factor
: 0.8 Lag
1st Critical Speed
: 27.77 Hz
2nd Critical Speed
: >83.3 Hz
Moment of Inertia of rotor shaft
: 1330 Kgm2
Weight of Stator
: 50000 Kg
Weight of Rotor
: 14500 Kg
Cooling Cooling Air Flow
: Forced Air Cooling : 18 M3/ Sec.
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Turbine Number of stages
: 3
Type
: Impulse
Casing
: Horizontal split
Max. Blade tip speed
: 450 M/Sec.
Minimum continuous speed
: 5089 RPM
Ignition speed
: 940 RPM
Self sustaining speed
: 2640 RPM
Critical speed (GT only)
: 16 1 658 – 1877 RPM 3256 – 3908 RPM 7049 – 7360 RPM
Mechanical trip speed
: 57 5737 + 50 RPM
Rotor construction
: Di Disc & Through Bolts
1st , 2nd & 3rd Stage tage buck bucket et mate materi rial al
: Ni base based d supe superr Allo Alloyy
1st & 2nd Stage nozzle material
: Co based super Alloy
Material of Turbine wheel
: Cr Cr-MO-V st steel forging
Material of Turbine shell
: Ductile Iron
No. of of Turbine nozzle 1st stage
: 2 x 18 = 36
2nd stage
: 3 x 16 = 48
3rd stage
: 4 x 16 = 64
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No. of Turbine buckets 1 st stage
: 92
2nd stage
: 92 9 2 (Tip shrouded)
3rd stage
: 92 9 2 (Tip shrouded)
Compressor No. of stages Type Direction of rotation Casing Compressor ratio
: 17 : Axial flow : CC CCW as seen from Inlet end. : Horizontal split : 1 : 11
Rated speed
: 5100 RPM
Blade tip speed
: 340 M/Sec.
Rotor construction
: D Diiscs and through Bolts
Blade attachment
: Dove tail
Extraction
: From 5th , 11th and 17th Stages
Blade material
: 12 12% Cr Steel, Nickel-Cadmium coated
Inlet, forward &
: Grey cast Iron
After casing material Discharge casing
: Ductile Cast Iron
Combustors Page | 14
Type
: Reverse flow type
No. of combustion
: 10
No. of fuel nozzle
: 10 10 (one in each combustor)
No. of Ignition
: 2 (Located in 1st & 10th Cumbustor) Automatic retractable retractable
No. of flame detector
: 2 (Located in 3,4,7 & 8 Cumbustor) Ultra violet type
Firing temperature
: 11 1104 C at at trailing edge of 1st stage nozzle
Auxilliary oil pump (AOP)
Type
: Centrifugal, vertical mounted.
Driver
: 50HP, 2900 RPM IND Motor.
Capacity
: 1741 LPM
Discharge pressure
: 4.57 kg/cm2
Minimum suction pressure
: 0.0278 kg/cm2 .
The CGP has at present 3 nos. BHEL make, Gas turbine Gener nerators (GTG) withni hnindivi divid dual Heat Recover ver Stem Generator (HRSG). The GTGs are rated 30 MW each. The generation voltage is at 11 kv. For further distributioin voltagr is step steppe ped d down down by of 11/0 11/0.4 .415 15kv kv,, 11/6 11/6.6 .6kv kv and and 6.6/ 6.6/0. 0.41 415k 5kv v Page | 15
distribution Transformers.
Support system of Gas Turbine typically includes following 1.
The lube oil system for furnishing normal lubrication and
absorbing the heat rejection of the gas turbine. 2.
The hyd hydrau raulic lic sup supply ply sys system tem
which which provides provides
the
necessary hydraulic flows and pressures for control devices on the turbine 3. The trip oil system which operates devices for the control, hydraulic trip sub-system 4.
The cooling water system which cools the lube oil. Page | 16
5. The starting system including the starting device and the requi require red d
logi logicc seque sequenc ncee for for star starti ting ng the gas turbin turbinee and and
bringing it up to operating speed. 6. The cooling and sealing air system which provides the necessary airflow from the turbine compressor to the other parts of the turbine rotor and stators to prevent excessive temperature build up and prevent bearing oil leakage. 7.
The fuel system
which supplies, controls the flow and
directs the fuel to the fuel noz nozzles in the gas turbin bine combustors . The fuel system includes gas , liquid and dual fuel systems. 8.
The atomizing air system provides sufficient pressure in
the air atomizing chamber of the fuel nozzle to break the fuel
jet up to a fin fine mis mist
permitting ign ignition and and
combustion with increased efficiency. efficiency. 9.
Thee ve Th vent ntil ilat atin ing g an and d he heat atin ing g sy syst stem em provi provide dess the the
ventilation of hot air from compartments so that various devi devicces in thes thesee compa ompart rtm ments ents work work in the the all allowa owable ble compartment temperatures. 10.
The fire protection system is provided to extinguish extinguish fires
in the compartments, in case any fire takes place. 11. 11.
The inlet and exhaust system provides atmosphere air to
be brought into the compressors through inlet ducting and let Page | 17
exha exhaus ustt gase gasess to atmo atmosp sphe here re or to heat heat reco recove very ry stea steam m generators.
ELECTRICAL TESTING. MEASUREMENT OF EARTH RESISTANCE :
The earthing connection of all the machines are linked to an unde underg rgro roun und d netw networ ork k call called ed as grid grid.. The The valu valuee of the the eart earth h resistance should be minimum. This is done using “THE DIGITAL EARTH TESTER.” Two metallic rods sction as eltrodes are inserted into ground and are connected to the tester. A third wire is connected to the body of the machine and is connected to the tester. The voltage drop is measured by the electrodes. Hence resistence can be found by R = V/I.
GREASING : Greasing of some machine bearing is done by isolating it from the supply, wherever online greasing facility is not avai availa labl ble. e. Grea Greasi sing ng is also also done done duri during ng the the work workin ing g condition also.
FIND FINDIN ING G THE THE LOCA LOCATI TION ON OF UNDE UNDERG RGRO ROUN UND D CABLE FAULT : Page | 18
Whenever there is breakdown of insulation of long underground cable, very high voltage is sent by using “ The Surge generator ” which will burn the affected point completely and aso detects the distance. To measure the distance “ TELEFEX “ is used.Here distance is measured by sending & receiving the signal and finally location of the fault is pointed by “ SEISMIC VIBRATION DETECTOR. “ MEGGER :
It is an instrument used to measure the insulating resist resistance ance of the “ INDUCT INDUCTION ION MOTOR MOTOR.. “ Actual Actually, ly, the value should be very high above some particular value. If there is some damage to the insulation, the value decrease and hence it can be detected.
TRANSF TRANSFORM ORMERS ERS RESIST RESISTANC ANCE E MEASUR MEASUREME EMENT NT METER : This is an instrument, used to measure the resistance of the transformer coils. Here, the current is passed through the transformer coils by the instrument and then the voltage acro across ss the the coil coil is meas measur ured ed.. Cons Conseq eque uent ntly ly the the valu valuee is measured R = V/I. Thisis done both input and output of transformer.
HRC FUSES : Page | 19
In the industries the HRC (HIGH RUPTURING CAPA CAPACI CITY TY ) fuse fusess are are used used.. This This beca becaus usee they they don’ don’tt produce any spark of smoke. TYPES OF TRIPPING : 1)
Electrical Electrical Tripping Tripping : In case of circuit circuit breaker. breaker. The The trip is energ energiz ized ed throu through gh the the actua actuati tion on of the the trip trip curre current nt either through the control or protection current.
2)
Mechanical Tripping : it occurs due to some mech mechan anis ism, m, gener general ally ly prot protec ecti tion on rele releas ases es whic which h are are mech mechan anic ical al in nature nature.. Thes Thesee rele releas ases es are are actua actuate ted d by certain insult coils and mechanism.
CONTACTOR :
A contactor is an electromagnetic switchwhich can be operated remotely. Switchgear is used to the standard require uirem ments of switching various loads under norm ormal ndabnormal condition with in built features of protection against various hazards. One such devuce is contactor.
BREAK DOWN VOLTAGE TEST : (Tranformer Oil) The BDV test is done to find out the breakdown any liquid. There is an instrument consist of a box which is fill filled ed with with the the nece necess ssar ary y oil. oil. Two Two elec electr trod odes es whic which h is sepa separa rate ted d by a smal smalll gap gap of appr approx ox.. 25mm 25mm.. volt voltag agee is supplied to both the ends of electrodes. Slowly the voltage Page | 20
is incread, the moment the breakdown occur voltage is noted. This is the breakdown of the liquid. RELAYS :
A device that is operated by a variation in the condition in one electric ckt & serves to make one or more connections in the same or another electric ckt. In relay one of the pair of the contacts that are closed or opened by the movement of the armature relay. Relay ckt is asso associ ciat ated ed with with a sele select ctor or,, cons consis isti ting ng of magn magnet etic ic impu impuls lsee counter for registering digits & holding a ckt.
ELECTRICAL WORKSHOP Electrical workshop is a very important and very essential unit for the primary maintenance of the electrical equipments. Here as we reffered most of the load the industry in the form of the the INDU INDUCT CTIO ION N MOTO MOTOR. R. So we reff reffer ered ed in the the elec electr tric ical al work worksh shop op that that here here the the most ost of the the jobs obs are are rel related ated to the the induction motors. We saw no. of induction motors of different sizes and of different ratings. Page | 21
WHY NEED FOR THE WORKSHOP ? : In IOCL we know that it’s a Petroleum Industry so that every plant conta ntain diff diffeerent types of pumps, blo blowers, compresser, fans of different ranges. For the operation of all these equipments the motor is very important. Here if there is any fault or any other constructional or operational failure arises with any motor then it will be informed to the workshop. MAINTENANCE AND TESTING OF MOTORS : •
•
•
•
•
First of all in the workshop Earthing contacts of the motors are tested. Then Then othe otherr test testin ing g like like Megge Meggerr test test and and othe otherr Wind Winding ing tested done. After opening the motor, it will be cleaned by the Kerosene. Than it will be put in the Oven for removing the moisture from the motor. The The moto motorr need needss prope properr insu insula lati tion on over over the the condu conduct ctors ors throughout the length. So the body and stator windings are pai paint nted ed with ith Red Becto ectol. l. It impr improv oves es the the insu insula lati tion on strength. Then the bearing maintenance is another important job in the workshop, here the bearings are tested and replaced (if necessary) for all the motors.
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•
After that motor is once again fitted and again put into yhe oven for same reason as we mentioned above.
•
Now Balancing Process is also done at Workshop. Here there are three types of the balancing and vibration in the motor. Vertical Balancing. Horizontal Balancing. Shaft balancing.
•
•
And finally all after test and maintenance we measure the ratings of the motor. Generally we measure the ratings with no load test but for the high rating of motor ( e.g. above 55 kw ), we have to test with the on load condition by using Variac.
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