Analysis And Research On Thermal Economy Of 1000MW Nuclear Power Plant

The analyzing and evaluating the degree of improvement of the thermal power conversion process,discussing the energy loss and ways to improve the thermal economic performance of nuclear power plants is of great significance for 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 second law of thermodynamics,the exergy method is used to analyze and discuss the thermal economy of thermal system.The weak links were identified and the direction of efforts was pointed out,laying a theoretical foundation for the economic operation and energy saving and consumption reduction of nuclear power units.First,the loss of the typical thermal process of the nuclear power plant was deduced,the evaluation criteria and calculation methods of the exergy analysis were determined,and the calculation flow block of was establishedThen,the exergy analysis model of each major equipment in the first and second loop systems of nuclear power plants were analyzed and established,including reactors,steam generators,main pumps,main steam pipelines and valves,steam turbines,reheating systems,regenerative systems,condensers,condensate pumps and feed pumps,main water supply pipes,etc.Finally,the exergy loss,exergy loss factor and exergy efficiency of each equipment under rated conditions are calculated and obtained.The results showed that the main reason for the exergy loss of thermal systems in nuclear power plants is that there are many irreversible factors in the process of energy conversion,transmission,and distribution,leading to a decline in the doing Work.The total exergy loss was 1955.39 MW,and the exergy loss coefficient was 65.35%,of which the one-loop loss was the highest,52.06%.The reactor is the equipment with the largest exergy loss,with a loss of nearly 50%,accounting for 76.38% of the total loss of nuclear exergy losses;The turbine exergy loss is 7.45% in the second place,and the condenser is the largest exergy loss equipment of the heat exchange equipment with the exergy loss of 3.45%,the steam generator exergy loss coefficient is 2.02%.The sum of the exergy loss factor of other heat transfer equipment,pipelines and pumps was only 2.51%,and the exergy loss rate was 3.85%.