ME8792

POWER PLANT ENGINEERING

Prof.V.Tamil Selvi , HOD/EEE

Ms.P.Aileen Sonia Dhaas , AP/EEE

UNIT- II DIESEL, GAS TURBINE AND

COMBINED CYCLE POWER PLANTS

Otto, Diesel, Dual & Brayton Cycle - Analysis &Optimisation. Components of Diesel and GasTurbine power plants. Combined Cycle PowerPlants. Integrated Gasifier based CombinedCycle systems.

OTTO CYCLE

• Generally petrol and gas engines follow ottocycle. This consists of four processes.

1. Two reversible adiabatic or isentropic processes

2. Two constant volume processes.

DIESEL CYCLE

• Diesel cycle is used in Diesel engines. It consists of the following four processes.

– Two reversible adiabatic

–One constant volume and

–One constant pressure processes.

DUAL CYCLE

• Dual cycle is the combination of Otto and Diesel cycles. This cycle consists of

– Two reversible adiabatic

– Two constant volume processes

– One constant pressure process

BRAYTON CYCLE

• Baryton cycle is the theoretical cycle for gasturbines.

• It consists of two reversible adiabaticprocesses and two constant pressureprocesses.

IMPROVISATION OF BRAYTON CYCLE IN POWER PLANTS

• The efficiency of gas turbine power plants can be improved in four ways such as

1. Brayton cycle with regeneration

2. Brayton cycle with intercooling

3. Brayton cycle with reheating

4. Brayton cycle with combined regeneration,

intercooling and reheating.

DIESEL ENGINE POWER PLANT

• The essential components of Diesel electric power plants are as follows.

1. Engine

2. Air intake system

3. Engine starting system

4. Fuel system

5. Exhaust system

6. Cooling system

7. Lubricating system

Applications of Diesel power plant

GAS TURBINE POWER PLANT

• Main components of Gas Turbine Power Plant

1. Compressor

2. Combustion chamber

3. Turbine

Improvisations of Gas Turbine Power Plants

• Gas turbine power plants performance can be improved in three ways. The following devices are used for it.

1. Intercooler

2. Regenerator

3. Reheater

Types of Gas Turbine Engines

COMBINED POWER PLANTS

INTEGRATED GASIFICATION COMBINED CYCLE

• An integrated gasification combinedcycle (IGCC) is a technology that uses a highpressure gasifier to turn coal and other carbonbased fuels into pressurized gas—synthesisgas (syngas).

• IGCC plants are advantageous in comparisonto conventional coal power plants due to theirhigh thermal efficiency, low non-carbongreenhouse gas emissions, and capability toprocess low grade coal.

• The disadvantages include higher capital andmaintenance costs, and the amount of CO2released without pre-combustion capture.