What is Rankine Cycle || Working Principle of Rankine Cycle || Draw Schematic & T-S Diagram of Rankine Cycle

What is Rankine Cycle || Working Principle of Rankine Cycle || Draw  Schematic & T-S Diagram of Rankine Cycle

Rankine Cycle: It is the ideal cycle for Steam Turbine. Heat is added and rejected at constant pressure.

State   Points	Process	P	V	T	S
1-2	Isentropic compression (in pump)	Increases	Decreases	Increases	Constant
2-3	Isobaric heat addition (P=Constant) in boiler	Constant	Increases	Increases	Increases
3-4	Isentropic expansion (in turbine)	Decreases	Increases	Decreases	Constant
4-1	Isobaric heat Rejection (P = Constant) in condenser	Constant	Decreases	Decreases	Decreases

Principle components of Rankine cycle: 

1. Pump: It is a device used to convert low pressure liquid to high pressure liquid. 

2. Boiler: It is a device used to convert liquid to steam by heating. 

3. Turbine: It is a device used to convert high pressure steam to low pressure steam. 

4. Condenser: It is a device used to convert steam to liquid by condensing. 

Figure: Schematic & T-S Diagram of Rankine Cycle

Working:

Pump (process 1-2): Pump pressured the liquid water which coming from the condenser to going back to the boiler. W(pump), in = h2 - h1 

Boiler (process 2-3): Liquid water enters the boiler and it heated to convert to steam. Qin=h3-h2

Turbine (process 3-4): Steam from the boiler, which has high temperature and pressure, expands through the turbine to produce work and then is discharged to the condenser with low pressure. W(turbine), out = h3 - h4 

Condenser (process 4-1): Steam from the turbine converts to liquid water in the condenser. Q(out) = h4 - h1

Thermal Efficiency of Rankine cycle: Ƞth = 𝑊𝑛𝑒𝑡 / 𝑄𝑖𝑛 = 1 − [ 𝑄𝑜𝑢𝑡 /𝑄𝑖𝑛 ]