Analysis And Study On The Effect Of Steam Parameters On Thermal Economy Of 1000MW Nuclear Power Plant

The analysis and study of the influence of the steam parameters changes of nuclear power plants on the thermal economy is of great significance for the nuclear power plants economic operation,increasing the market competitiveness,developing the low-carbon economy and building the sustainable society.This paper takes a 1060 MW nuclear power unit as the research object.Based on the first law of thermodynamics,the energy balance method is used to analyze and discuss the influence of steam parameters changes of nuclear power plants on the thermal economic indexs.Firstly,the common calculation methods of nuclear power unit thermodynamic system were compared and analyzed.The calculation flow block of was established,and the evaluation criteria and indicators of thermal power system were determined.Secondly,the thermodynamic models of the main equipment of the secondary circuit system of the nuclear power plant were analyzed and established.The steam flow and the performance of the thermal system calculations under the full power operation were performed.The results show that the main reason for energy loss in nuclear power units is heat loss and dissipation.The heat loss of heat exchange equipment accounts for 98.21% of the total heat loss and is mainly lost in the condenser.Finally,the models for the influence of steam parameter changes on the economic performance were established,including the new steam pressure,back pressure and reheat temperature,and the data fitting formulas were gave.The results showed that when the new steam pressure increases 0.2MPa,the ideal internal power linear increases3.99 MW,the ideal cycle thermal efficiency increases 0.39%,the relative internal efficiency decreases 0.085%,and the heat rate decreases 31.46kJ/(kW·h).When the back pressure decreases 0.5kPa,the ideal internal power increases 7.58 MW,the ideal cycle thermal efficiency increases 0.73%,the relative internal efficiency decreases 0.08%,and the heat rate decreases 67.63kJ/(kW·h),and haved the more sensitive to lower exhaust pressure.When the reheat temperature increases 5?,the ideal cycle thermal efficiency only increases 0.017%,the relative internal efficiency increases 0.039%,and the heat rate decreases 5.80kJ/(kW·h).The thermodynamic analysis model established in this paper and the formula fittingout the calculated results can provide reference for the calculation of the thermal economic index of the nuclear power plant in the future.