Explanation:

The efficiency of a Rankine cycle is determined by the mean temperature of heat addition, which is the average temperature at which heat is added to the working fluid. The superheat Rankine cycle has a higher efficiency than the simple Rankine cycle because of the following reasons:

Mean temperature of heat addition is higher for superheat cycle:

- In the simple Rankine cycle, the working fluid is vaporized and then expanded in the turbine. The steam is then condensed and pumped back to the boiler.
- In the superheat Rankine cycle, the steam is generated at a higher temperature and then heated further to a higher temperature by the superheater before entering the turbine.
- This results in a higher mean temperature of heat addition in the superheat Rankine cycle, which leads to a higher thermal efficiency.

Enthalpy of main steam is higher for superheat cycle:

- The enthalpy of the main steam is the energy content of the steam at the inlet to the turbine.
- In the superheat Rankine cycle, the steam is heated to a higher temperature, which results in a higher enthalpy of the main steam.
- This higher energy content of the steam results in a higher power output from the turbine and higher efficiency.

Temperature of steam in the condenser is high:

- The temperature of the steam in the condenser is a function of the cooling medium used to condense the steam.
- In the superheat Rankine cycle, the higher temperature of the steam entering the condenser results in a higher temperature of the cooling medium required to condense the steam.
- This higher temperature of the cooling medium results in a lower efficiency due to the higher temperature difference between the working fluid and the cooling medium.

Quality of steam in the condenser is low:

- The quality of the steam in the condenser is the ratio of the mass of vapor to the total mass of the working fluid at the condenser outlet.
- In the superheat Rankine cycle, the higher temperature of the steam entering the condenser results in a lower quality of the steam at the condenser outlet.
- This lower quality of the steam results in a lower efficiency due to the higher moisture content of the working fluid at the turbine inlet.

Conclusion:

The superheat Rankine cycle has a higher efficiency than the simple Rankine cycle because of the higher mean temperature of heat addition, which is a result of the higher temperature of the steam entering the turbine.

It's simple. superheater is heated the steam then the stream is get more efficient due to use the component supper heater. but simple Rankine cycle is not used superheater.so superheater rankine cycle is more efficiency.