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P.Kumar, Lecturer/Dsl FUEL OIL SYSTEM

Fuel Oil System by p.k

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Page 1: Fuel Oil System by p.k

P.Kumar, Lecturer/Dsl

FUEL OIL SYSTEM

Page 2: Fuel Oil System by p.k

FUEL OIL SYSTEM OF FUEL OIL SYSTEM OF WDM2 LOCOWDM2 LOCO

Requirements of fuel system.Associated components of fuel system.Schematic Diagrams of fuel oil system.Fuel efficient kits of fuel oil system.Trouble shooting of fuel oil system.

Page 3: Fuel Oil System by p.k

ºº

REQUIREMENT OF FUEL SYSTEM

The fuel oil system is designed to introduce fuel oil in to the engine cylinders at correct time ,in correct quantity and at correct pressure.

At correct time: The fuel should be introduce in to the combustion chamber within precisely

defined period of the cycle.

Fuel injection start- 18º 15' before TDC

Termination of injector– 14º 45'After TDC

Total Period of injection -18º 15'+14º 45'=33º

Page 4: Fuel Oil System by p.k

CORRECT QUANTITY-CORRECT QUANTITY-..Correct quantity of fuel is Correct quantity of fuel is important to maintain the variable speed of important to maintain the variable speed of locomotive engine at variable load.locomotive engine at variable load.

Usually, The distribution of the fuel among Usually, The distribution of the fuel among each cylinder is done uniform.each cylinder is done uniform.

CORRECT PRESSURECORRECT PRESSURE: : High pressure also helps inHigh pressure also helps in proper atomization proper atomization so that the small droplets come in so that the small droplets come in

better contact with the fresh air in the combustion better contact with the fresh air in the combustion chamberchamber

High pressure of fuel is required High pressure of fuel is required to lift the nozzle to lift the nozzle valve and for better penetration of fuel in to valve and for better penetration of fuel in to combustion chambercombustion chamber

The beginning and the end of The beginning and the end of injection should be injection should be sharpsharp,i.e there should not be any dribbling or after,i.e there should not be any dribbling or after injection. injection.

.

Page 5: Fuel Oil System by p.k

PUMP

PRIMARYFILTER

SECONDARYFILTER

Rt. FUEL OIL HEADER RE

GU

LA

TIN

GV

AL

VE

4.2

Kg/

cm2

RELIEF VALVE5.3 Kg/cm2

FOP Gauge

FUEL OIL SYSTEM - WDM2

LEAK OFF HEADER

FIP

Injector

MOTOR

Fuel tank

Lt. FUEL OIL HEADER

Cross Over Pipe

Page 6: Fuel Oil System by p.k
Page 7: Fuel Oil System by p.k

The fuel oil system consists two integrated system.The fuel oil system consists two integrated system.

(A)(A) Fuel feed system.Fuel feed system.

(B)(B) Fuel injection systemFuel injection system..

(A)(A) Fuel feed systemFuel feed system:- The fuel feed system provides the :- The fuel feed system provides the back up support to the fuel injection pump by back up support to the fuel injection pump by maintaining steady supply of fuel at required pressure.maintaining steady supply of fuel at required pressure.

(B)(B) Fuel injection systemFuel injection system:- The Fuel injection pump :- The Fuel injection pump started according to firing order. All F.I.P start & started according to firing order. All F.I.P start & discharging fuel oil at high pressure to their respective discharging fuel oil at high pressure to their respective nozzle.nozzle.

Page 8: Fuel Oil System by p.k

Associated Components(Fuel feed system)-Associated Components(Fuel feed system)-

(a)Fuel oil tank-Fabricated under the super structure of locomotive and (a)Fuel oil tank-Fabricated under the super structure of locomotive and located between two bogies.Capacity-5000ltslocated between two bogies.Capacity-5000lts

(b)Fuel primary filter-(paper type filter)(b)Fuel primary filter-(paper type filter)

(c )Booster pump(fuel transfer pump)(c )Booster pump(fuel transfer pump)

Pump capacity- 14 lts/ minutes(at 1725 rpm)Pump capacity- 14 lts/ minutes(at 1725 rpm). pressure-4-4.8 kg/cm2. pressure-4-4.8 kg/cm2

(d)Fuel relief valve-The spring loaded relief valve( (d)Fuel relief valve-The spring loaded relief valve( . Adjusted at-5kg/cm2(70 p.s.i). Adjusted at-5kg/cm2(70 p.s.i)(e) Fuel secondary valve- (Paper type filter )(e) Fuel secondary valve- (Paper type filter )

(f)Fuel regulating valve-The spring loaded valve(f)Fuel regulating valve-The spring loaded valve. Adjusted at- 4.0 to 4.2kg/cm2(50-55p.s.i). Adjusted at- 4.0 to 4.2kg/cm2(50-55p.s.i)

Page 9: Fuel Oil System by p.k

Associated components( Fuel Injection system)

A.Fuel injection pump- It is single acting constant stroke plunger type pump

Function- a.To raise the fuel oil pressure to nozzle which will efficiently atomize the fuel.

b.To supply the correct quantity of fuel to nozzle as per power and speed requirement of the engine.

c.To accurately time the delivery of the fuel for efficient economical operation of engine.

B.Fuel injection nozzle-a.To inject fuel at a sufficiently high pressure so that the fuel enters the cylinder with a high velocity

b.Fuel injection nozzle injects fuel oil to combustion chamber at 4000psi.

Page 10: Fuel Oil System by p.k

Fuel injection pump

Some important parts of FIP are as below-

1. Control Rack2. Barrel & plunger3. Control sleeve4. Plunger spring 5. Guide cup6. Lower spring seat.7. Snubber valve assembly.

Page 11: Fuel Oil System by p.k

Calibration of FIPCalibration of FIPPurpose: It is done after overhauling to ensure that it

delivers the same and stipulated amount of fuel at a particular rack position.

Process of FIP calibration & testing The calibration and testing of FIPs are done on a specially designed

machine. The blended test oil of recommended viscosity under controlled

temperature is circulated through a pump at a specified pressure for feeding the pump under test.

The oil discharged for 300 stroke of the pump is measured at idle and full load. For WDM2,it is as –

9mm rack position(idle) - 34 CC +1/-5

30 mm rack position (Full load ) - 351 CC +4/-11 If test results are not within limit ,adjustment of fuel rack position is

done by moving the rack pointer with addition or removal of shims behind it.

Page 12: Fuel Oil System by p.k

PHASING & CALIBRATION OF FIP

•PHASING: Setting of Pump according to Injection Timing

•CALIBRATION: Calibrating delivery of the pump according to Rack Position

Checked by hartridge 1100 calibrating machine at 300 rpm and 300 stroke

9mm = 45 ml

28 mm= 401 ml

Page 13: Fuel Oil System by p.k

Fuel injection nozzle

Some important parts of fuel injection nozzle are as below-

1. Nozzle body2. Nozzle Valve3. Spacer4. Pressure adjusting spring5. Nozzle holder body.6. Cap nut

Page 14: Fuel Oil System by p.k

Testing of Fuel Injection Nozzle Testing of Fuel Injection Nozzle Purpose:Good atomization ,correct spray pattern

and no leakage or dribbling are the criteria of a good FIN.

The following tests are conducted on a specially designed machine-

Spray pattern( by taking impression on blotting paper)

Spray pressure (3900-4050 PSI for new & 3700-3800 PSI for reconditioned nozzle)

Dribbling : This occur due to improper pressure setting or dirt stuck up between the valve & valve seat. Or improper contact between the valve and valve seat.

Page 15: Fuel Oil System by p.k

TESTING OF NOZZLE•Opening Pressure: 3900-4050 psi (New), 3700- 3800 psi (Old)

•Spray Pattern/ Blotter test: Uniform pattern

•Dribbling: Holding at 3500 PSI for 10 secs ( No drop)

•Leak off: 3500 to 1000 PSI drop down time 6-16 secs

•Valve Lift: .026" (max), .005 to .007" (New)

Page 16: Fuel Oil System by p.k

Continue…Continue… Nozzle chatter: This sound creates due to

free movement of the nozzle valve inside the valve body. it should be proper.

Nozzle leak off rate: the process of checking the leak off rate is by creating pressure in nozzle up to 3500 PSI and hold the pressure till it drop to 1000PSI.( 5sec)

Page 17: Fuel Oil System by p.k

ORIFICE TEST ORIFICE TEST Purpose: This test is conducted to check

the efficiency of the fuel feed system under full load condition.

Process: Fit a orifice plate of 1/8 inch in the system

before the regulating V/V. Place a container to collect the leak off oil. Switch on the Fuel booster P/P for 60 sec. The rate of leak should be about 9 ltrs per

minute.

Page 18: Fuel Oil System by p.k

FUEL EFFICIENT KITFUEL EFFICIENT KIT

PURPOSEPURPOSE- To improve specific fuel consumption by - To improve specific fuel consumption by 6%,Reduction in existing exhaust gas temp by 1006%,Reduction in existing exhaust gas temp by 100ººand and

reduction in lub oil consumption.reduction in lub oil consumption.

1.Modified water connection to after cooler -Water inlet of the after cooler is connected from outlet of the radiator to provide water at min. possible temp into the after cooler.

2.17 mm fuel injection pump-15 mm pumps are replaced by 17mm pump to have sharper fuel injection.Max rack. it has increased injection rate also.

3.Modified cam shaft with 140 degree over lap-The cam shaft increase the over lap from 123 to140 degree to improve the scavenging.

Page 19: Fuel Oil System by p.k

4.Larger after cooler-increased core size, Introduced four passes instead of two passes,it has increased the effectiveness of after cooler to over 25%. Higher effectiveness has been introduced to provide cooled air to engine.5.Steel cap pistons-In the fuel efficient engine ,peak firing –1800 psi ,lower lub oil consumption. steel cap piston provides greater strength compared to the all AL pistons used earlier.6.High efficiency turbo charger-High efficiency turbo super charger ABB -VTC 304, NAPIER NA295 having capacity to develop 2.2kg/cm2 booster pressure.

Page 20: Fuel Oil System by p.k

MOVE THE NATIONDLW OUR LOCOS

Successive Power Upgradation and Specific Fuel Consumption reduction

HP/Cylinder

162.5

193.75

206.25

225

2600 HP

3100 HP

3300 HP

3600 HP

4500 HP

154

152

150

166

156

SFCgm/bhp-hr.

1960-90 90-2000 2001 - 08

Oct,1993

Oct,2001

Nov,2002

May,1990

Oct,1995

Nov,2002

TECHNOLOGY PROGRESSION

Page 21: Fuel Oil System by p.k

Reasons of low fuel oil pressureReasons of low fuel oil pressure

Due to insufficient fuel in fuel oil tank.(less than 700Ltrs)

Primary or Secondary filter may be choked. Defective Fuel booster pump & Motor. Wrong adjustment/Sticking of Relief valve. Due to fuel leakages in the system. Wrong adjustment/Sticking of Regulating

valve.

Page 22: Fuel Oil System by p.k

TROUBLES IN DIESEL ENGINE DUE TO FUEL OIL TROUBLES IN DIESEL ENGINE DUE TO FUEL OIL

The use of dirty and unsuitable fuel frequently causes the following troubles – Piston ring groove deposits- Dirty contaminated fuel oil is

responsible for gummy carbonaceous deposits in piston ring grooves which induce the rings to stick and causes Blow by, ineffective lubrication, Inefficient air compression ,Poor combustion, High fuel consumption and contamination of the crank case oil.

Exhaust valve deposit- Resulting in poor air compression, Poor combustion ,and high fuel consumption.

Cylinder wall deposit –it will interfere with the lub oil film and causes excessive metallic wear.

Fuel pump wear-Due to heavy close fit between the plunger and their barrel ,impurities may causes seizures, reduce the quantity fuel delivery per stroke .

Page 23: Fuel Oil System by p.k

TO ENHANCE RELIABILITY OF FOSTO ENHANCE RELIABILITY OF FOS

The following preventive actions should be taken to avoid loco failures on account of fuel oil system and to enhance their reliability-

Torqueing of FIP foundation bolts,T-jumper bolts and Banjo bolts are to done in sequence during fitment and it should to tightened to the recommended torque range.

It must be a normal practice to fit matched fuel injector, H.P pipe and FIP duly calibrated and tested on test bench during yearly schedule or if removed together.

• Check fuel oil P/P vacuum in every schedule .if less, P/P should be removed for overhauling .

• It loco is giving repeated problem of el oil pressure ,clean the fuel oil tank by filling up the water and draining out the same after opening dummy provided at bottom of the fuel tank.

Page 24: Fuel Oil System by p.k

Continue---Continue---Check distorsion of Banjo bolt and fit copper

washer of appropriate thickness in each removal.Primary/ Secondary filter must be replaced in due

time.Ensure only Zyglo tested High pressure tubes to

be fitted in loco.Ensure that clamping of all fuel hoses has been

done properly to avoid its rubbing.During overhauling of FIP, avoid excessive

clearance in barrel and plunger assembly to avoid fuel oil leakage from leak off hole which leads to its excessive consumption

Page 25: Fuel Oil System by p.k

Continue…Continue…Drain out water and Sludge from the fuel oil tank

of loco at least in every monthly schedule by opening drain cock of the fuel tank. (Must do, if loco is giving repeated problem of fuel oil pressure dropping)

Before turn out of loco from shed, ensure that strainer at fuel filling plug of fuel tank is not in distorted condition through which foreign material like cotton waste, cloth, rag , jute etc may block suction line to fuel booster pump.

Page 26: Fuel Oil System by p.k

FUEL OIL TESTS AND FUEL OIL TESTS AND SIGNIFICANCESSIGNIFICANCES

Water contamination (by Crackle test) Specific gravity (Co-relates with calorific value of fuel

so tested at 15’C) Viscosity ( Spray pattern affects) Flash point(Temp.at which it gives sufficient vapour to

form a mixture with air). Carbon residue. Sulphur content.( high sulphur contain may cause

corrosion in engine parts) Cetane number( indicate ignition quality ) Colour comparision (with potassium dichromate

solution)

Page 27: Fuel Oil System by p.k

TROUBLE SHOOTING OF FUEL OIL SYSTEMTROUBLE SHOOTING OF FUEL OIL SYSTEM A.Fuel oil pressure not building up.

B.Fuel pump motor not working.

C.Fuel pump contactor not picking up.

D. Oil leakage from fuel T jumper o ring.

E.T jumper cap screws worked out.

F.Fuel pump/support cap screw worked out.

G.Fuel oil primary/secondary filter chocked.

H.Fuel oil cross over pipe burst.

I.Fuel oil hose pipes burst/damaged due to rubbing.

J.Fuel oil leaking from hose pipe joint/union –defective.

K.Fuel oil contaminated with water.

Page 28: Fuel Oil System by p.k