This document discusses various methods for improving the efficiency of the Rankine cycle used in steam power plants. It describes: 1. Increasing the pressure difference between the boiler and condenser to increase the net work produced. 2. Using superheaters and reheaters to increase steam temperature after saturation and partial expansion, improving quality. 3. Preheating feedwater using regenerative heating to reduce irreversibilities and improve thermodynamic efficiency. 4. Employing combined cycles by raising boiler pressure to increase steam temperature and cycle efficiency. It then discusses regeneration and how it works to heat feedwater using steam between turbine stages to improve efficiency. Superheaters and economizers are also described as

1. ASSIGNMENT OF PEAT
POWER PLANT
REG: 19RP02771
19RP04488
19RP09055
19RP04114
19RP05692

2. Q1. Discuss Rankine Cycle
The Rankine cycle, also called the Rankine vapor cycle, is a thermodynamic cycle that converts heat into
mechanical energy.
The Rankine cycle is the fundamental operating cycle of all power plants where an operating fluid is
continuously evaporated and condensed. The selection of operating fluid depends mainly on the
available temperature range.

3. Q2. Discuss methods of increasing the efficiency of Rankine cycle
1.Pressure difference
The net work produced in the Rankine cycle is represented by the area of the cycle
process in. Obviously, this area can be increased by increasing the pressure in the boiler
and reducing the pressure in the condenser.
2.Superheating and reheating
•Superheater – increases the steam temperature above the saturation temperature
it increase the temperature of saturated steam without raising its pressure.
•Reheater – removes the moisture and increases steam temperature after a partial
expansion.
• It increase quality of steam at the end of section of the turbine

4. 3. Feed water preheating
Preheating the feedwater reduces the irreversibilities involved in steam
generation and therefore improves the thermodynamic efficiency of the
system. This reduces plant operating costs and also helps to avoid thermal
shock to the boiler metal when the feedwater is introduced back into the
steam cycle.
4. Combined cycles
Increasing the operating pressure of the boiler leads to an increase in the
temperature at which heat is transferred to the steam and thus raises the
efficiency of the cycle.

5. Q3. Discuss Regeneration as a method used for improvement of steam power plant
One of the more common ways to improve the efficiency of a steam cycle is to use regeneration,
a process where heat is taken from steam between turbine stages and used to heat water as
it goes through pump stages.
In the regenerative cycle the dry saturated steam from the boiler enters the turbine at a higher
temperature and then expands entropically to a lower temperature in the same way as that of
Rankine and Carnot cycle. Now the condensate from condenser is pumped back and circulated
around the casing, in the direction opposite to the steam flow in turbine. The steam is thus heated
before entering into the boiler. Such a system of heating is known as regenerative heating, as the
steam is used to heat the steam itself.

6. Q4.Discuss the use of super-heater as a method used for improvement of steam power plant
A superheater is a device used to convert saturated steam or wet steam into superheated steam or
dry steam.
Superheated steam is used in steam turbines for electricity generation, steam engines, and in
processes such as steam reforming.

7. Q5. Discuss the use of Economizer as a method used for improvement of
steam power plant
Mechanical device that is used to reduce the consumption of energy is
referred to as an economizer. Sometimes the device is used to perform a
different function within the machine. Preheating of a fluid is an example of
an important function for which the device can be used. The main essence of
using the device is to reduce the amount of energy that is being consumed
in an industrial process. In industry, the device has found usage in many
processes such as boilers, air conditioning, power plant processes,
ventilation and heating. Economizers are generally regarded as heat
exchangers