An energy utilization system composed of gas turbines and flue gas heat pumps, gas turbines, flue gas turbines and flue gas heat pumps, or gas turbines, waste heat boilers, steam heat pumps, as well as gas turbines, waste heat boilers, steam turbines, and steam (flue gas) heat pumps. After completing the energy utilization cycle of gas turbines, flue gas turbines, waste heat boilers, steam turbines, and other equipment, the system further utilizes heat pumps to deeply recover and utilize the waste heat from flue gas, steam, hot water, and cooling water, or directly drives the heat pump with power. This process can be used for cogeneration, thermoelectric cooling cogeneration, heat cooling cogeneration, electric cooling cogeneration, direct heating or direct cooling. The system has extremely high thermal efficiency, and if used for direct heating, the thermal efficiency can reach 150%, which is one of the main trends in future energy utilization.

The circulating system composed of a gas turbine and a flue gas turbine further drives the flue gas turbine to generate electricity by utilizing the remaining pressure and enthalpy in the flue gas emitted by the gas turbine. Compared with the gas steam combined cycle system, this system does not require water at all, but the cost of the flue gas turbine is relatively high and has not yet been widely used.