Economic Analysis of Nuclear Cogeneration System Based on High-Temperature Gas-Cooled Reactor

Nuclear cogeneration system, coupling of high-temperature gas-cooled reactor (HTGR) power plants with heating and hydrogen production systems, provides clean electricity, heat and hydrogen for the petrochemical parks and has good economic, social and environmental benefits. In this paper, a thermal economic model of the 600 MWth HTGR cogeneration system is established under two operational modes of thermo-power cogeneration and hydrogen-power cogeneration. The thermo-power cogeneration system is a combination of the Rankine cycle and heat supply process, and the hydrogen-power cogeneration system is a combination of the Brayton cycle and IS hydrogen generation process. The influences of heat-electricity ratio, extraction steam parameter, hydrogen production efficiency and HTGR fixed investment cost on the thermal economic performance of the two cogeneration systems are discussed. The results show that the unit heat and the unit hydrogen supply cost respectively remain 117 yuan/t and 1.07 yuan/m3 under different heat-electricity ratios. The unit heat supply cost decreases from 117 yuan/t to 97 yuan/t with extraction steam parameter reducing from 540 ℃/9.8 MPa to 250 ℃/1.5 MPa, and the unit hydrogen supply cost decreases from 1.07 yuan/m3 to 0.92 yuan/m3 with improved hydrogen production efficiency from 50% to 60%. The unit heat and hydrogen supply cost respectively decrease by 29.2% and 25.23% when the unit HTGR fixed investment cost varies from 10000 yuan/kWth to 6000 yuan/kWth. Besides, due to different power cycles and turbine inlet parameters, the electricity supply thermal efficiencies of the HTGR thermo-power and hydrogen-power cogeneration system are respectively 37.45% and 50.49% when the heat-electricity ratio is 0, resulting in the unit electricity supply cost of 0.3 yuan/kWe and 0.22 yuan/kWe, respectively. With the development of nuclear technology, the nuclear thermo-power and hydrogen-power cogeneration technologies based on HTGR will become more economic competitive.