railway locomotive engine various systems

8/9/2019 railway locomotive engine various systems

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2.2.2 FUEL OIL SYSTEM

The fuel oil system is designed to supply fuel to the engine in correct quantity and at

the right time according to the engine requirements. The fuel oil system draws fuel from

fuel tank, filter the fuel, pressurise the fuel, and inject the fuel into the engine in correct

quantity in atomized condition.

Fuel oil system consist of

1. Fuel feed system

2. Fuel injection system

FUEL FEED SYSTEM: -

Fuel is drawn from the fuel oil tank through a suction strainer y the fuel pump. The

strainer separates foreign particles from the fuel oil, and protects the fuel pump. The

pump is designed to supply adequate quantity of fuel to the engine at !arious speeds and

load conditions.


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LIE DI!"#!M OF T$E FUEL OIL SYSTEM

Fuel then goes to primary fuel filter. This primary filter is pro!ided with a "#$%&' ye

pass !al!e with sight glass, which should e normally empty. (hene!er the primary filter

is )hoked*clogged and the pressure difference reaches "# %&' this ye$pass !alue open

allowing the fuel oil directly to the system, which can e noticed y the flow of ye$pass

fuel in the sight glass. +nder such cases the primary filter element is changed. The fuel

then passes to #2 engine mounted secondary filters, which are of spin$on type. &econdary

fuel filters are also pro!ided with a ye$pas !alue, which is set at # %&'. (hene!er the

filters are choked*clogged and the pressure difference across the secondary filters reaches

# %&', this ye$pass !al!e opens and di!erts the fuel oil ack to fuel tank, a!oiding

damage to fuel injectors due to unfiltered fuel oil. - ye$pass sight glass is also pro!ided

to indicate the condition of the fuel secondary filters and the sight glass should e

normally empty. From the secondary filters the fuel oil is supplied to all unit injectors

through fuel supply manifolds located inside the top deck on the oth anks. The

go!ernor controls the quantity of fuel to e injected through the injectors to the engine. -t

the end of the fuel supply manifolds, a regulating !al!e with a sight glass is pro!ided


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which is set to 1# %&'. The regulating !al!e ensures constant fuel supply to all unit

injector in all working conditions. 'f the system is working properly the sight glass should

indicate clear and clean fuel oil flow all the time. -ir ules, interrupted fuel flow or no

fuel flow in the return sight glass indicates prolem in the fuel feed system.

FUEL I%E&TIO SYSTEM :-

Fuel supplied y the fuel feed system is always a!ailale at all the unit fuel injectors. The

fuel oil a!ailale at each injector are to e pressurized to !ery high pressure, timed and to

e injected in the cylinder in atomized form. The timing of each unit injector is decided

y the camshaft and the fuel is pressurized y the in$uilt fuel injection pump which is

operated y indi!idual cam loe of the cam shaft. The quantity of fuel to e injected wille regulated and controlled y engine mounted wood word go!ernor according to the

notch and load conditions. The go!ernor operates fuel control shaft, linkage mechanism

and fuel racks. The indi!idual fuel injector nozzle does the atomization of the fuel to e


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injected in the cylinder.

DELI'E#Y

The deli!ery side of the system consists of the fuel injectors, the layshaft mechanism,

and the control de!ice or go!ernor.

The measuring and timing of the fuel must e carried out simultaneously, or in

the proper sequence and in the simplest manner y e!ery fuel$injection system

regardless of type.

The fuel must rst e deli!ered to the injection mechanism.


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and through water return header to radiator. - water pipe line from the water pump carry

water to compressor to cool the compressor liners, cylinder head, !al!es and the

compressed air inside the inter cooler. -ir compressor cooling is done whene!er engine is

running. The radiators are located in a hatch at the top of the long hood end of the

locomoti!e. The hatch contains the radiator assemlies, which are grouped in two anks.

/ach radiator ank consists of two quad length radiator core assemlies, olted end$to$

end. 7eaders are mounted on the radiator core to form the inlet and outlet ends of the

radiator assemly, a ypass line is pro!ided etween the inlet and outlet lines in order to

reduce !elocity in the radiator tues. Two 8$lade 926 cooling fans, which operate

independently, are located under the radiators in the long hood carody structure. They

are numered 1, and 2,with the :o. 1 fan eing closest to the dri!er ca. The water pump

inlet side is connected to an e;pansion tank for makeup water in the water system. The

e;pansion tank is located in the equipment rack.

The engine cooling system consists of engine dri!en centrifugal water pumps, replaceale

inlet water manifolds with an indi!idual jumper line to each liner, cylinder head discharge

elows, and an outlet manifold through which cooling water is circulated. The centrifugal

water pumps one on an 8 cylinder engine are mounted on the accessory dri!e housing

and are dri!en y the go!ernor dri!e gear.

)oolant is drawn from the e;pansion tank through an aspirator y the water pumps.

%ump outlet elows conduct the water from the pumps to the water inlet manifolds

located in each air o;. /ach manifold is connected at the rear end plate to an aftercooler

water inlet pipe.


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/ach cylinder liner is indi!idually supplied with coolant from the water manifold through

a water inlet tue assemly. - de


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)oolant temperature for the after coolers therefore was limited to the same le!el as

required for the power assemlies. 3ecause the cores were equipped with only two


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2.2.* !I# IT!+E SYSTEM

-ir intake system consists of the following components.

Turo charger,

'nertial air intake filters,

3aggie type fire glass air intake filters,

-fter cooler

TU#,O &$!#"E#: -

The primary use of the turo charger is to increase air supply to engine to produce more

horsepower and pro!ide etter fuel efficiency y the utilization of e;haust gases. The

turo charger has a single stage turine with a connecting gear train. The connecting gear

train work in the condition of engine starting* light load operation and rapid acceleration.

(hen the engine work on full load appro;imately in th notch the energy of the e;haust

gases is sufficient to dri!e the turo charger and the turine rotor rotates without any

mechanical help from the engine. -t this point, an o!er riding clutch in the dri!e gear


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train disengages and the turo charger dri!e is disconnected from the engine gear train.

The rotor shaft assemly of turo is di!ide into " parts=

a Sun-gear hat: -(hen engine is starting or it works on slow speeds or lower notch

operations, the sun$gear shaft recei!e dri!e from the engine through the planet gear

system and a clutch.

E/haut ga dri0en tur1ine: - The urnt e;haust gases are directed to passage

through a fi;ed nozzle ring etween e;haust manifold and turine. The e;haust gases is

directed y the fi;ed nozzle ring on to the turine wheel lades and the heat energy is

con!erted into mechanical rotary motion. The diffuser is another aerodynamic de!ice

located in the turine section of the turo. The diffuser is asically an arrangement of " to

> !anes, which are placed ehind the turine lades these pro!ide a smooth transition

path for the gas to flow, there y eliminating turulance. Then e;haust gases are e;pelled

out through e;haust duct. - uilt in aspirator tue pro!ided in e;haust ducts contains an

4eductor tue6 which pro!ide suction in the engine crank case and maintains !acuum in

the engine crankcase.

c Ime33er 4ith diuer: - 5n the other end of the rotor assemly, an impeller

compressor with a diffuser ring is pro!ided. The impeller induces a partial !acuum in


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the air inlet casing. The impeller inducer draws air from the clean air room where the

clean air a!ailale after passing through cyclonic air inlet filter and secondary through a

aggy type fire glass secondary filter. The air drawn y the lower is compressed in the

lower causing and presses through a compressor diffuser directs the flow of compressed

air to pro!ide a smooth air deli!ery which is free from turulance.

Inertia3 !ir Inta5e Fi3ter

The inertial air inlet filters are cyclonic types consisting of many filter tues mounted in a

single assemly. The reduction in pressure in the clean air compartment causes the

outside air to rush through the filters to fill the depression. -s the air passes through the

filter tues and stationary !anes in the intake throats imparts a spinning motion to the air.

3y spinning motion dirt particles are thrown to the outer wall of the tue y a centrifugal

force. These particles are carried to he leeds duct dustin, where they are remo!ed y

dustin lower and thrown out from the locomoti!e. The resulting clean air enters in the

air compartment. 'n addition to clean the filters, the dust in lower increases their

efficiency y increasing the !elocity of the air passing from the filter tues.

,aggie Tye !ir Inta5e Fi3ter

The diesel engine requires fine clean air for comustion of the fuel. The inertial air filters

approach ?#@ efficiency on throttle 8th ut it is not adequate to the engine. - secondary

engine air filters are pro!ides to filter the reminder contaminants. These filters are oil

coated and made y fierglass material. This material is !ery efficient in filtration.

!tercoo3er

- four$passage aftercooler is pro!ide on the engines. (hich cools the compressed air

efore entering the air o; y its efficient heat e;change capacity. Thus the density of the

air also increases and high density fresh, clean and compressed air is a!ailale for

comustion of the fuel.


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stream of oil also luricate the ring elt. &ome of this oil enters oil groo!es in the piston

pin earing for lurication. 5il after cooling and lurication drains ack in to the oil

sump.

(.Main Lu1ricating Oi3 Sytem

The main luricating oil system supplies oil under pressure to most of the mo!ing parts

of the engine. The main lue oil pump takes oil from the strainer housing through a

common suction. 5il from the pump goes to the main oil manifold, which is located

ao!e the crankshaft, e;tends to the length of the engine. Aa;imum oil pressure in the

system is control y a relief !al!e in the passage etween the pump and the main oil

manifold. The pressure relief !al!e is set to 129%&', which reli!es e;cess oil ack to the

sump. 5il tues in the centre of the each main earing recei!es oil from the main

manifold to the upper half of the crankshaft main earings. Brilled passage in the

crankshaft supplies oil to the connecting rod earings, !iration damper and accessory

dri!e gear at the front end of the crankshaft. 5il from the manifold enters gear train at the

rear end of the engine at the idler gear stu shaft. 5il passes in the ase of the stu shaft

from where oil is distriuted to !arious parts through passage. 5ne passage conducts oil

to the left ank camshaft dri!e gear stu shaft racket through a jumper. -nother passage

conducts oil to the Cight 3ank camshaft dri!e stu shaft racket and the turo charger oil

filter supply line.


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)onsiderale heat will remain in the metal parts of the turine when the engine is

shutdown and due to sudden cut off oil supply to the earings, damage or more wear will

take place in the earings since the turo rotor will e rotating e!en after the engine stops

due to its momentum. To a!oid the thermal stressing and unwanted wear in the earings

due to no oil supply, this soak ack pump automatically start working after shutting down

of the engine. &oak ack pump will e working for "# to "9 minute appro;imately e!en

after engine shutdown. This ultimately increases the life of the turo.

2.2.9 &OM8#ESSED !I# SYSTEM


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)ompressed air in A locomoti!e is used for the locomoti!e rake system as well as for

au;iliary systems such as sanders, ell, horn, windshield wipers, rail lue systems, and

radar head air cleaner. The A locomoti!e uses (D:-?33 model three cylinder air

compressor which is a two stage low$pressure and high$pressure compressor. The

compressor is water$cooled. The compressor is mechanically dri!en y a dri!eshaft from

the front or accessory end of the locomoti!e engine. This dri!eshaft is equipped with

fle;ile couplings to couple the compressor.

The compressor is equipped with three cylinders, two low pressures and one in the

center high pressure. -ir is sucked through two dry pamic type air filters and

compressed y the two low pressure cylinders. -fter that the low$pressure compressed air

passed through an intercooler. The intercooler reduced the compressed air temperatures.

- pressure relief !al!e is pro!ided on the intercooler for intercooler safety. -fter this the

compressed air mo!es on to the high$pressure cylinder where it is again compressed to


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main reser!oir pressure. 3etween the compressor and main reser!oir an aftercooler

cooling coil is pro!ided to reduced the air temperature.

The compressor has itsG own internal oil pump and pressure luricating system with an oil

filter. The oil le!el is checked during running y means of the dipstick mounted on the

side of the compressor crankcase. (hen adding oil in the compressor it must e in stop

position.

-t idle speed and normal operating temperature, the oil pressure should e etween 18$29

psi. - plugged opening is pro!ided for installation of an oil pressure gauge.


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(. E"IE S8EED &OT#OL

3y alancing generator load with a set engine speed, the go!ernor maintains a

constant kilowatt output y the engine*generator comination for each throttle

position. &peed selection is accomplished through the actuation of cominations of

electric solenoids within the go!ernorH fuel control through the go!ernors internal

hydraulicsystem, hence the term electro $ hydraulic.

The go!ernor senses engine C%A and adjusts the position of the layshaft, which

in turn regulates fuel injector output to maintain engine C%A at the operator

selected le!el.

The (oodward go!ernor is a comple; precision de!ice. 't

regulates the amount of fuel deli!ered to the engine cylinders y the fuel

injectors.

assists in controlling main generator output y regulating main generator

e;citation through the load regulator.


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The go!ernor has three main systems=

speed sensing

speed control

load regulation

't also has a completely self contained hydraulic system with reser!oir, pump, and

accumulators to luricate the internal parts and operate !arious parts of the go!ernor.

The go!ernor has protecti!e de!ices which will shut the engine down should there e a

loss of pressure in the enginesG lue oil system or a failure of the engines cooling system.

S8EED SESI" !D FUEL &OT#OL The asic operation of the

(oodward go!ernor is illustrated


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railway locomotive engine various systems