Diesel Engine Power Plant
Prepared By: Nimesh Gajjar
Definition
A generating station in which diesel engine is used as the prime mover for the
generation of electrical energy is known as diesel power station.
Diesel power plant
 Introduction:
 Diesel power plants produce power in the range of 2 to 50 MW.
 They are used as standby sets for continuity of supply such as hospitals,
telephone exchanges, radio stations, cinema theatres and industries.
 They are suitable for mobile power generation and widely used in railways
and ships.
 Generally 2 stroke diesel engine used for power generation.
USES OF DIESEL ENGINES
TODAY, DIESEL ENGINES ARE USED TO
PROVIDE POWER IN A VARIETY OF
APPLICATIONS IN MANY INDUSTRIES
THERE ARE SIX MAJOR USES OF
DIESEL ENGINES
AGRICULTURE/FARM
TRANSPORTATION
CONSTRUCTION
FORESTRY
MARINE
ELECTRICAL GENERATION PLANTS
Advantages and Disadvantages of DPP
Advantages
(a)
The design and layout of the plant are quite simple.
(b)
It occupies less space as the number and size of the auxiliaries is small.
(c)
can be located at any place.
(d)
It can be started quickly and it can pickup load in a short time.
(e)
There are no standby losses.
(f)
It requires less quantity of water for cooling.
(g)
The overall cost is much less than that of steam power station of same capacity.
(h)
The thermal efficiency of the plant is higher than that of a steam power station.
(i)
It requires less operating staff.
Disadvantages
(a)
The plant has high running charges as the fuel (diesel) used is costly.
(b)
The plant doesn’t work satisfactorily under overload conditions for a longer period.
(c)
The plant can only generate small power.
(d)
The cost of lubrication is generally high.
(e)
The maintenances charges are generally high
Fundamental of Diesel Engine
Four Stroke Cycle
• Intake / Suction
Compression
Power / Expansion
Exhaust
Four stroke cycle theory
Intake stroke
Piston moving down
Intake valve open
Exhaust valve closed
Four stroke cycle theory
Compression stroke
Piston moving up
Intake valve closed
Exhaust valve closed
Four stroke cycle theory
Power stroke
Piston moving down
Intake valve closed
Exhaust valve closed
Four stroke cycle theory
Exhaust stroke
Piston moving up
Intake valve closed
Exhaust valve open
Four Stroke Cycle Animation
Four-Stroke Cycle Diesel Engine
• The piston travels from one end of the cylinder to the other four times during
each cycle.
• The fuel is ignited at the beginning of the third stroke of each cycle.
• Intake air flows into each cylinder through intake valves in the cylinder head.
• Exhaust gases leave through exhaust valves.
• On the intake stroke, atmospheric pressure pushes air into the cylinder through
the intake valve.
• The exhaust stroke forces burned gases out through the exhaust valve.
• During the compression and power strokes, both valves are closed.
Diesel Animation
Useful\Dieselcycle 4 s.swf
Two-Stroke Cycle Diesel Engine
• They have only two strokes per cycle.
• The fuel is ignited on every other stroke of the piston.
• In the two-stroke diesel engine, air is forced in and exhaust
gases are forced out on a single stroke.
• Usually a blower forces air into the cylinder through intake
ports.
• The incoming air pushes remaining exhaust gases out of the
cylinder through an exhaust valve.
Two Stroke Animation
Useful\two-stroke.swf
Difference between 2S and 4S Engine
Advantages & Disadvantages
to a 4-Stroke Cycle Engine
Disadvantages:
Advantages:
•
•
•
•
•
High torque output
Smooth running
Quieter operation
Lower emissions output
More forgiving to poor
operational practices
• Higher horse power
availability
• Heavier construction
• No Gas/Oil mixing
u
u
u
Heavy
Limited slope operation
More moving parts
Advantages & Disadvantages
to a 2-Stroke Cycle Engine
Advantages:
u
u
u
u
Lighter
Can be operated in all positions
Less moving parts
Higher horse power per cc
displacement
Disadvantages:
• Low torque output
• Erratic running
Characteristic
• Noisy
• Higher emissions output
• Gas/Oil mixing
2 Stoke Engines part names
Cylinder
Combustion
Exhaust port
chamber
Still uses a flywheel
(not shown)
Crankcase
Reed valve
Piston
Connecting
Intake port
Rod
Transfer port
Crankshaft
Diesel
Plant Layout of DPP
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.
Useful\MAN Diesel Powerplant Medium.flv.flv
Engine Related Terms
•
•
•
•
•
•
•
•
TDC (top dead center)
BDC (bottom dead center)
Stroke
Bore
Revolution
Compression Ratio
Displacement
Cycle
Useful\Diesel engine.mp4
Diesel Engine
Useful\Diesel Engine Working.mp4
Exhaust system of DPP
Fuel Injection System
1. The common rail system;
Types of Fuel
Injection System
2. The distributor-injection system; and
3. The pump and pressure operated nozzle systems.
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.
Common Rail Fuel Injection System cont…
Common Rail Fuel Injection System cont…
Useful\Common rail diesel.mp4
Useful\Caterpillar Common Rail - YouTube.flv
Useful\Diesel Common Rail Injection Facts 1.mp4
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.
Useful\diesel fuel inector - how it works.mp4
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.
Useful\Diesel fuel injection system - YouTube.flv
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.
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.
Liquid Cooling System
Liquid cooling System cont….
Natural Circulation
Useful\Air cooled and Water Cooled Engine.png
Liquid cooling System cont….
Forced Circulation
Useful\Cooling system.mp4
Liquid cooling System cont….
Liquid Cooling System
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.
Useful\engine cooling and lubricating.mp4
Ref:
http://www.marinediesels.in
fo/2_stroke_engine_parts/cr
osshead.htm
Piston
Piston rings
Piston skirt
Platform separating cylinder
from crank case
Piston rod
Stuffing box
Crosshead, crosshead
bearing (reciprocating)
Oil pumped at
a certain
pressure
Connecting rod
Crank pin, bottom end
bearing (rotatory
motion)
Web
Journal, journal bearing
(rotatory motion)
Lubrication system
•
•
TG- Temperature gauge
PG- Pressure gauge
PG
TG
ENGINE
Shaft
Bearings
PG
Cooler
TG
PG
Storage tank
Pump
Useful\Car engine lubrication system.mp4
Filter
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.
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.
Useful\Splash Lubrication.mp4
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
Crank pin, bottom end
bearing (rotatory
motion)
Connecting rod
Journal, journal bearing
(rotatory motion)
Web extension
Oil
Web
Useful\Crankshaft oil lubrication simulation.mp4
Pressure feed lubrication system
Useful\Pressure Lubricated Air Compressor Pump.mp4
Useful\Pressure_System.flv.mp4
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.
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.
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.
Useful\16-Dry Sump Oil Tank.swf.mp4
Staring System
1) Auxiliary Engine starting system
2) Electric Motor Starting System
3) Compressed Air Starting System