HIGH-PRESSURE REHEATING GAS-STEAM COMBINED CYCLE POWER GENERATION SYSTEM AND POWER GENERATION METHOD

摘要

The invention relates to a high-pressure reheating gas-steam combined cycle power generation system and a power generation method. The system consists of a gas turbine sub-system and a steam turbine sub-system. The gas turbine sub-system comprises a device used for two-stage air compression, twice combustion as well as high-pressure and medium-pressure twice turbine working; after initial working of high-temperature gas, the high-temperature gas enters a medium-pressure combustion chamber and is reheated for secondary working, improving the average heat absorption temperature of the whole cycle; and at least a one-stage intercooler is arranged between two-stage compressors, and the heat flow of the intercooler is connected with the two-stage compressors. The steam turbine sub-system adopts a three-pressure reheating type boiler and a steam turbine, the cooling water of the intercooler is connected with high-pressure water, and high-pressure, medium-pressure and low-pressure water as well as the cooling water of the intercooler absorbs heat at different stages for multiple times, thus utilizing the heat energy efficiently. When the high-pressure reheating gas-steam combined cycle power generation system by the present invention is operated with the optimum parameters, the combined cycle efficiency is increased by 3-5 percentage points compared with a combined cycle system mainly adopting a gas turbine class F, and the single-machine output power is increased by more than 70%, reaching level 800MW.