Introduction  The high exhaust temperature of gas turbine can increase the bottom cycle and generate electricity by using the waste heat of exhaust gas, so as to improve the total energy utilization rate of fuel. In view of its high thermal efficiency, simple system, compact structure, flexible operation and other potential advantages, supercritical CO₂ cycle can be combined with gas turbine to form a new type of gas-supercritical CO₂ combined cycle.

  Method  In order to make full use of the exhaust heat of the gas turbine, a simple regenerative supercritical CO₂ cycle was constructed on the basis of a simple regenerative supercritical CO₂ cycle, and the thermal efficiency of the PG9351 (FA) gas turbine was calculated and analyzed. At the same time, by adding waste heat utilization device in the system, the residual heat could be used for heating, converting into cold energy or generating electricity.

  Result  The results show that for the selected gas turbine, the maximum temperature of supercritical CO₂ cycle can reach 600 C, the cycle power generation efficiency is about 32%, the heat recovery temperature is above 170 ℃, the heat recovery accounts for 9% of the exhaust heat of gas turbine, and the combined cycle power generation efficiency is about 54%.

  Conclusion  The gas-supercritical CO₂ combined cycle power generation system has high thermal efficiency and retains some high-grade waste heat, which can be further used in power plant operation.