Thermodynamic Study On The Waste Heat Utilization In The High Temperature Gas Cooled Reactor Nuclear Power Plant

High temperature gas cooled reactor is a kind of inherent safety reactor, to ensure its high efficiency,a reasonable thermodynamic cycle is the premiss. In the nuclear closed Brayton cycle or helium gas/ steam combined cycle, the pre-cooler has a lot of waste heat to recycle,and the entered helium temperature is about 125℃. In this temperature range, using the water as a working fluid to recycle the waste heat is ineffience, However, the low-temperature cogeneration technology provides a feasible method. This topic in high temperature gas cooled reactor closed Brayton cycle precooler emissions in the low temperature waste heat as the research object, Based on the first and the second law of thermodynamics,building a new thermodynamic cycle which can recycle the low temperature exhaust heat produced by the nuclear closed Brayton cycle, in order to research the advanced utilization of the exhaust heat discharge by the high temperature gas cooled reactor power plant.This paper constructed a nuclear closed Brayton/ORC cycle that the net output power and the heat efficiency are about 3.1×105k W and 52.14% under the optimal conditions of ORC,respectively. Surpass the closed Brayton cycle 1.16×104k W and 2.45%,respectively. Among on which the pre-cooler inlet temperature(398.8K) based. Use three different ways to optimize the function, one, single objective optimization of ORC to evaporation temperature and condensation temperature, respectively, analyze the performance of different objective function,The results shows that when the condensing temperature is constant,the outlet temperature of the heat source and the heat efficiency increased with the evaporation temperature. The total irreversible loss and the unit output power’s required heat exchange area is reducing, the exergy efficiency and net power output of others were increased at first and then decreased,unless R227 ea.When the evaporation temperature is constant, the heat efficiency, the exergy efficiency, the unit output power and the total irreversible loss is reducing with the condensing tempertaure. Two,multi-objective optimization of ORC, this paper aim at 8 kinds of work fluid include R245 fa, make the thermal efficiency and the exergy efficiency form the multiple objective function, the multi-objective optimization coordinates the relationships among various performance indicators and optimize the evaporation temperature and condensation temperature at the same time,then find that exists an optimal evaporating temperature and condensing temperature. Three, technology economy ooptimization of ORC, analyzes the influence of the evaporation pressure and condensing pressure on the performance of the ORC with more comprehensive analysis of the circulation system, and reveal that R123 have the minimum values about comprehensive objective function and have the best evaporation temperature and condensing pressure, and it’s power generation cost is the lowest and payback period is the shortest, generally,R123 is the best working fluid.This paper constructed a nuclear closed Brayton/Kalina combined cycle and carried out it’s thermomechanical analysis. The results shows that this combined cycle’s net output power and the thermal efficiency are about 3.24×105k W and 54.53% under the optimal conditions of Kalina cycle, respectively.Surpass the closed Brayton cycle 2.57×104k W and 4.84%,respectlvly. Among on which the pre-cooler inlet temperature(398.8K) based. Use three different ways to optimize the function. The results shows that improve the entrance temperature or pressure of the turbine’s, reduce the condensing pressure or temperature, and increas the concentration of ammonia solution can improve the net power output and the thermal efficiency of Kalina cycle.