The invention belongs to the technical field of secondary reheating
steam turbine generating and energy saving and discloses a
coal-fired secondary reheating
steam turbine generator unit integrated with supercritical CO2 circulation. The unit comprises a
coal-fired boiler, a secondary reheating
steam turbine generator unit and a supercritical CO2 circulating generation
system. Six-stage extractionsteam connected with a
high pressure cylinder and an
intermediate pressure cylinder is connected with steam-CO2 heat exchangers and enters corresponding feed water regenerative heaters after heatingCO2; in the CO2 circulating generation
system, CO2 at an outlet of a compressor is divided into two streams, the two streams are heated by three stages of steam-CO2 heat exchangers respectively and are converged to enter a CO2
turbine for working, and CO2 exhaust enters the compressor after passing through a CO2-feed
water heater and a CO2-
air preheater sequentially; in a
flue at the
tail of the boiler, air is divided into two streams, and the two streams are preheated by the CO2-
air preheater and a low-temperature
air preheater respectively and are converged to enter a main air preheater. Bythe aid of the integrated
system, the superheat degree of regenerative extraction steam of the secondary reheating unit and the
exergy loss of air preheating are substantially reduced, the work of a steam
turbine is increased, and the efficiency is improved.