Diesel Engine Power Plant Prepared By: Nimesh Gajjar

1
Diesel Engine Power PlantPrepared By Nimesh
Gajjar
2
Plant Layout of DPP
3
(No Transcript)
4
Schematic Layout of a Diesel power plant
The essential components of a Diesel Electric
Plant are (1) Engine (2) Engine air intake
system (3) Engine fuel system (4) Engine exhausts
system (5) Engine cooling system
(6) Engine lubrication system (7)
Engine starting system.
5
Engine Related Terms

• TDC (top dead center)
• BDC (bottom dead center)
• Stroke
• Bore
• Revolution
• Compression Ratio
• Displacement
• Cycle

6
Diesel Engine
7
Exhaust system of DPP
8
Fuel Injection System
1. The common rail system 2. The
distributor-injection system and 3. The pump and
pressure operated nozzle systems.
Types of Fuel Injection System
9
Common Rail Fuel Injection System
A high pressure header or 'common rail' is
supplied by a single pump with built in pressure
regulation which adjusts pumping rate to maintain
the desired injection pressure.
10
Common Rail Fuel Injection System cont
11
Common Rail Fuel Injection System cont
12
(No Transcript)
13
Distributor-injection system
In this system, a single injection pump supplies
fuel to a distributor. The distributor directs
fuel to the injectors in the right firing order.
The metering of fuel is done at the pump.
14
Individual Pump Injection system
In this system, the injection pump and injector
are combined into one unit and are driven by the
overhead camshaft. The plunger is a part of the
injector. Pressurization, timing, and metering of
the fuel all take place in the unit injector. An
engine with this system has one unit injector for
each cylinder.
15
Air Cooling System
In this system fins or extended surfaces are
provided on the cylinder walls, cylinder head,
etc. Heat generated due to combustion in the
engine cylinder will be conducted to the fins and
when the air flows over the fins, heat will be
dissipated to air.
16
Air Cooling System cont
Advantages of Air Cooled System Following are the
advantages of air cooled system (a)
Radiator/pump is absent hence the system is
light. (b) In case of water cooling system there
are leakages, but in this case there are no
leakages. (c) Coolant and antifreeze solutions
are not required. (d) This system can be used in
cold climates, where if water is used it may
freeze. Disadvantages of Air Cooled System (a)
Comparatively it is less efficient. (b) It is
used in aero planes and motorcycle engines where
the engines are exposed to air directly.
17
Liquid Cooling System
18
Liquid cooling System cont.
Natural Circulation
19
Liquid cooling System cont.
Forced Circulation
20
Liquid cooling System cont.
21
Liquid Cooling System
22
Lubrication System
Need for Lubrication In an I.C. engine, moving
parts rub against each other causing frictional
force. Due to the frictional force, heat is
generated and the engine parts wear easily. Power
is also lost due to friction, since more power is
required to drive an engine having more friction
between rubbing surfaces. To reduce the power
lost and also wear and tear of the moving part
substance called lubricant is introduced between,
the rubbing surfaces. Function of
Lubrication (a)   Lubricant reduces friction
between moving part (b)   It reduces wear and
tear of the moving parts. (c)   It minimizes
power loss due to friction. (d)  It provides
cooling effect. While lubricating it also carries
some heat from the moving   parts and delivers it
to the surroundings through the bottom of the
engine (crank case). (e)    It helps reduce noise
created by the moving parts. Engine parts which
are lubricated The following are some engine
parts that require adequate lubrication. 1. Crank
shaft             2. Crank pin   
3. Big and small end of the connecting
rode 4. Piston pin                5. Internal
surfaces of cylinder walls 6. Piston
rings             7. Valve mechanisms  8.
Cam shaft etc.
23
Piston
Ref http//www.marinediesels.info/2_stroke_engine
_parts/crosshead.htm
Piston rings
Piston skirt
Piston rod
Platform separating cylinder from crank case
Stuffing box
Crosshead, crosshead bearing (reciprocating)
Oil pumped at a certain pressure
Connecting rod
Crank pin, bottom end bearing (rotatory motion)
Journal, journal bearing (rotatory motion)
Web
24
Lubrication System cont.
Lubrication Systems The main lubrication systems
are 1.  Mist lubrication system. 2.   Wet sump
lubrication system. (a) Splash lubrication
system (b) Pressure / Forced Feed Lubrication
system (c) Splash and Pressure feed lubrication
system 3. Dry sump lubrication system. 1. Mist
Lubrication System. This system of lubrication is
used in scooters and motor cycles. About 3 to 6
of lubricating oil is added with petrol in the
petrol tank. The petrol evaporates when the
engine is working. The lubricating oil is left
behind in the form of mist. The parts of the
engine such as piston cylinder walls, connecting
rod are lubricated by being wetted with the oil
mist Disadvantage (i) If the added oil is less,
there will not be sufficient lubrication and even
result in seizure of the engine, (ii) If the
added oil is more, it will lead to excess exhaust
smoke and carbon deposits in the cylinder,
exhaust parts and spark plugs.
25
Splash Lubrication system
As the engine is operating, dippers on the ends
of the connecting rods enter the oil supply, pick
up sufficient oil to lubricate the connecting-rod
bearing, and splash oil to the upper parts of the
engine. The oil is thrown up as droplets, or fine
spray, which lubricates the cylinder walls,
piston pins and valve mechanism.
26
Splash type lubrication
Cylinder liner
Piston rings
Oil is picked up by the webs while rotating, and
splashed onto the piston and liner
Gudgeon pin
Connecting rod
Crank pin, bottom end bearing (rotatory motion)
Journal, journal bearing (rotatory motion)
Web extension
Web
Oil
27
Pressure feed lubrication system
In the pressure-feed system, oil is forced by the
oil pump through oil lines and drilled
passageways. The oil, passing through the drilled
passageways under pressure, supplies the
necessary lubrication for the crankshaft main
bearings, the connecting-rod bearings piston-pin
bushings, camshaft bearings, valve lifters, valve
push rods, and rocker studs.
28
Splash and Pressure feed Lubrication system
Cylinder walls are lubricated by splashing oil
thrown off from the connecting-rod bearings
In a combination splash and force feed, oil is
delivered to some parts by means of splashing and
other parts through oil passages under pressure
from the oil pump. The oil from the pump flows to
the main bearings and camshaft bearings. The main
bearings have oil-feed holes or grooves that feed
oil into drilled passages in the crankshaft. The
oil flows through these passages to the
connecting rod bearings. From there, on some
engines, it flows through holes drilled in the
connecting rods to the piston-pin bearings.
29
Dry sump lubrication system
Dry Sump engines carry their oil in an oil tank
that is separate from the engine. This can be an
actual tank or inside of the tubes of the frame.
This engine lubrication type uses two oil pumps.
One to pump oil to the engine, where it lubes
everything and then drops to the bottom of the
engine. From there, the second or scavenge pump
pumps the oil back to the oil tank. Sometimes the
scavenge pump also pumps oil to the transmission,
valves and other places in the engine. The
scavenge pump is twice as big as the main oil
pump.
30
Staring System

• Auxiliary Engine starting system
• 2) Electric Motor Starting System
• 3) Compressed Air Starting System