Thermodynamic Cycles

1- Thermodynamic Power Cycle

Heat Flows from Higher Temperature to Lower Temperature and Work is an output.  

1a- Vapor Power Cycle (Vapor is the main Working Fluid)

      Carnot Cycle 
      Ideal Cycle, Indicating the maximum possible efficiency between two temperature reservoirs. It is a hypothetical cycle assuming processes are isentropic and adiabatic. Which can be seen on T-S Diagram of Carnot Cycles. The concept of entropy is not available in the Carnot Cycle. 

Actual Situation

Isentropic expansion will result in increase in moisture content which is harmful for turbine blades. Isentropic compression of mixture requires more work input. 

      Rankine Cycle

It is an idealized cycle for heat engines. The Rankine Cycle is much more practical then the Carnot Cycle because the working fluid typically exists as a single phase (liquid or vapor) for the two pressure change processes. 

1b- Gas Power Cycle (Gas/Air is main Working Fluid)

      Brayton Cycle

      Otto Cycle

      Diesel Cycle

2- Heat Pump / Refrigeration Cycle

Heat Flows from Lower Temperature to Higher Temperature through input of Work.