Brayton power cycles for fusion reactors have been investigated, using Helium in classical configurations and CO2 in a recompression layout. Thermal sources from the reactor have strongly constrained the cycle configu...Brayton power cycles for fusion reactors have been investigated, using Helium in classical configurations and CO2 in a recompression layout. Thermal sources from the reactor have strongly constrained the cycle configurations, hindering use of a recuperator in Helium cycles and conditioning the outlet turbine temperature in CO2 ones. In both cycles, it is possible to take advantage of the exhaust thermal energy by coupling the Brayton to a Rankine cycle, with an organic fluid in the helium case （iso-butane has been investigated） and steam in the CO2 case. The highest efficiency achieved with Helium cycle is 38.5% using Organic Rankine Cycle and 32.6% with Helium alone. The efficiency changes from 46.7% using Rankine cycle to 41% with CO2 alone. The Helium cycle is highly sensitive to turbine efficiency and in a moderate way to compressor efficiency and pressure drops, being nearly insensitive to thermal effectiveness in heat exchangers. On the other hand, CO2 is nearly insensitive to all the parameters.展开更多
文摘Brayton power cycles for fusion reactors have been investigated, using Helium in classical configurations and CO2 in a recompression layout. Thermal sources from the reactor have strongly constrained the cycle configurations, hindering use of a recuperator in Helium cycles and conditioning the outlet turbine temperature in CO2 ones. In both cycles, it is possible to take advantage of the exhaust thermal energy by coupling the Brayton to a Rankine cycle, with an organic fluid in the helium case （iso-butane has been investigated） and steam in the CO2 case. The highest efficiency achieved with Helium cycle is 38.5% using Organic Rankine Cycle and 32.6% with Helium alone. The efficiency changes from 46.7% using Rankine cycle to 41% with CO2 alone. The Helium cycle is highly sensitive to turbine efficiency and in a moderate way to compressor efficiency and pressure drops, being nearly insensitive to thermal effectiveness in heat exchangers. On the other hand, CO2 is nearly insensitive to all the parameters.
