Study On Optimal Design Cold-End System Of An AP1000 Nuclear Power Plant

According to the national industrial policy, a large number of nuclear power projects are to be scheduled. The nuclear power plants have the basic load characteristic which is different from coal-fired power plants. The turbine generator of conventional island is required to have the maximum output power in order that the thermal power of the reactor can convert into useful power and improve the economy of units. Cold-end system is a crucial cold source of the thermal cycle in the nuclear power plants and has a important impact on the economy of nuclear power plants. Therefore, it is of importance to study the optimization of cold-end system.Based on the basic principles of the cold-end system in nuclear power plants, the performance calculation of turbine low-pressure cylinder, condenser and cooling tower is investigated in this paper. The cold-end system of a coastal nuclear power plant is optimized with minimum-annual-expense method when considering the investment, the operating costs and the benefit of the plant. The unit type of a coastal nuclear power plant includes three-cylinder four-exhaust single, dual pressure unit and four-cylinder six-exhaust single pressure, triple pressure unit. The cases of temperature rise of cooling water including no restrictions, being less than 8 degrees and less than 7 degrees are examined, and then the economic performance of different types of steam turbine and condenser are compared. According to the condition of an inland nuclear power plant in south China, the cold-end system is optimized with minimum-annual-expense method, and the several type of the units including three-cylinder four-exhaust single, dual pressure and four-cylinder six-exhaust single pressure, triple pressure are optimized for cold-end system. The sensitivity analysis of cold-end configuration of four-cylinder six-exhaust triple pressure with the lowest annual-expense is conducted, and the best cold-end configuration is obtained. The above results can provide a reference for the optimization of the cold-end system of the coastal and inland nuclear power plants.