RESEARCH ON THERMAL EFFICIENCIES OF VARIOUS POWER CYCLES FOR GFRS

摘要

The vast majority of nuclear-power plants (NPPs) are thermal-spectrum reactors, and only two Russian sodium-cooled reactors are fast-spectrum reactors. Water-cooledNPPs have relatively low thermal efficiencies (30 - 36%) compared to SFR NPPs (40%), AGR NPPs (42%), and modern advanced thermal power plants, such as combined cycle (up to 62%) and supercritical-pressure coal-fired power plants (up to 55%). Gas-cooled Fast Reactor (GFR) is considered as one of the most efficient fast nuclear-power reactors of the next generation (Generation-IV). To transfer internal energy of heated helium into electrical energy it was proposed to use a direct Brayton helium-turbine cycle. However, indirect cycle is now considered to be more feasible idea, having various secondary and tertiary configurations. The objective of the current paper is estimation of thermal efficiencies of various power cycles, which include indirect nitrogen-helium gas-turbine cycle, supercritical-pressure carbon-dioxide gas-turbine cycle and others. Also, thermodynamic properties of certain working fluids are discussed.