1) Gas power cycle - The working fluid remains in the gaseous
state throughout the entire cycle.
- Example for Gas Power cycles are Otto cycle, Diesel cycle,
Brayton cycle.
- Petrol engine, diesel engine, Natural gas power plants are
objects working on concept of Gas power cycle.
2) vapor power cycle -  The working fluid exist in two
phase. one part of the cycle will be in vapor phase and other part
will be in liquid phase.
- Thermal power plants, Nuclear power plants are objects working
on concept of vapour power cycle.
3)  refrigeration cycle
- Refrigerator, Air conditioner, Heat pumps are
objects  working on concept of .refrigeration cycle.