Gas Turbine Cycle with Heat Exchange and Reheating

Introduction
A gas turbine cycle with heat exchange and reheating is a modification of the basic gas turbine cycle that incorporates additional components to improve the overall performance of the cycle. This modification involves the inclusion of a heat exchanger and a reheater in the cycle.

Heat Exchanger
The heat exchanger is added to the cycle to utilize the waste heat from the turbine exhaust gases. The exhaust gases are used to heat the compressed air before it enters the combustion chamber. This preheating of the air increases its temperature and decreases the work required for the compression process. As a result, the thermal efficiency of the cycle improves.

Reheating
Reheating is another modification that is incorporated into the gas turbine cycle. After the gas expands in the first turbine stage, it is sent back to the combustion chamber for reheating before it enters the second turbine stage. Reheating increases the temperature and the enthalpy of the gas, which in turn increases the work output from the turbine. This increase in work output leads to an increase in the specific power output of the cycle.

Improvements in Thermal Efficiency
The addition of a heat exchanger in the gas turbine cycle allows for the recovery of waste heat, which would otherwise be lost to the environment. By utilizing this waste heat to preheat the compressed air, the overall thermal efficiency of the cycle increases. The preheating of the air reduces the amount of fuel required for combustion and improves the efficiency of the combustion process. This results in a higher thermal efficiency for the gas turbine cycle.

Improvements in Specific Power Output
The addition of reheating in the gas turbine cycle increases the work output from the turbine. By reheating the gas before it enters the second turbine stage, its temperature and enthalpy are increased, leading to a higher work output. This increase in work output translates to a higher specific power output for the cycle.

Conclusion
In conclusion, a gas turbine cycle with heat exchange and reheating improves both the thermal efficiency and specific power output of the cycle. The heat exchanger allows for the recovery of waste heat, improving the thermal efficiency, while the reheating process increases the work output from the turbine, leading to a higher specific power output.