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

Four Stroke Cycle

• Intake / Suction Compression Power / Expansion Exhaust

Fundamental of Diesel Engine

Four stroke cycle theory

Intake strokePiston moving downIntake valve openExhaust valve closed

Four stroke cycle theory

Compression strokePiston moving upIntake valve closedExhaust valve closed

Four stroke cycle theory

Power strokePiston moving downIntake valve closedExhaust valve closed

Four stroke cycle theory

Exhaust strokePiston moving upIntake valve closedExhaust 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

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

Difference between 2S and 4S Engine

Advantages & Disadvantagesto a 4-Stroke Cycle Engine

• 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

Advantages: Disadvantages:

Heavy Limited slope operation More moving parts

Advantages & Disadvantagesto a 2-Stroke Cycle Engine

• Low torque output• Erratic running

Characteristic• Noisy• Higher emissions output• Gas/Oil mixing

Advantages: Disadvantages:

Lighter Can be operated in all positions Less moving parts Higher horse power per cc

displacement

2 Stoke Engines part names

Piston

Cylinder

CrankshaftConnectingRod

Still uses a flywheel(not shown)Combustion

chamber

Intake port

Exhaust port

Reed valve

Transfer port

Crankcase

Diesel