Method and system for supplying water to vapor generator of nuclear power station under low-power work condition

Abstract

The invention relates to the technical field of auxiliary water supply systems of nuclear power stations, in particular to a method and system for supplying water to a vapor generator of a nuclear power station under the low-power work condition. An auxiliary water supply pump is started, a main water supply pump is shut down, a main water supply adjusting valve is closed, and water in a water supply deaerator is supplied to the vapor generator through an auxiliary water supply pump and a valve loop; and water returns into theater supply deaerator to be cyclically used through a loop of a cooler, a desalting bed, a condenser and a condensate water supply pump after being used by the vapor generator. According to the scheme, the problems that a first electric water supply pump and the mainwater supply pump are used for supplying water under low power, water is frequently supplemented to an auxiliary water supply storage box manually, operation is complex, a conventional water supply loop stops for a long time, dead water in pipelines needs to be replaced when the conventional water supply loop is restarted to be used, a large amount of conventional island water needs to be consumed, and the main water supply pump is damaged when running under low power are avoided.

Description

technical field [0001] The invention relates to the technical field of auxiliary water supply systems of nuclear power plants, in particular to a method and system for supplying water to steam generators of nuclear power plants under low power working conditions. Background technique [0002] A nuclear power plant is a power plant that uses the energy released by nuclear fission reactions to generate electricity. Nuclear power plants use nuclear reactors instead of boilers in thermal power plants, and use nuclear fuel to generate heat in a special form of "combustion" in nuclear reactors, turning nuclear energy into thermal energy to heat water and generate steam. Use steam to enter the steam turbine through the pipeline, drive the turbo generator to generate electricity, and convert mechanical energy into electrical energy. [0003] At present, there are two water supply methods for nuclear power plants under low-power conditions such as thermal shutdown: 1. Use the first ...

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Problems solved by technology

The disadvantage of method 1 is that part of the water in the first electric feedwater pump is used by the steam generator, and the other part is returned to the auxiliary feedwater storage tank through the circulation pipeline. Long-term circulation operation will cause the temperature of the auxiliary feedwater storage tank to rise. In order to meet the requirements of safety regulations, it is necessary to frequently replenish anaerobic water to the auxiliary feed water storage tank. The temperature of anaerobic water is about 35°C, which is higher than the normal water temperature in the auxiliary feed water storage tank, which will further increase the temperature of the auxiliary feed water storage tank. The temperature rises. In addition, when the first electric water supply pump is used to supply water, the conventional water supply circuit is partially out of service for a long time. When it is restarted, it needs to replace the stagnant water in the pipeline, which consumes a lot of water in the conventional island.

The defect of method 2 is that part of the water in the main feedwater pump is used by the steam generator, and the other part is returned to the feedwater deaerator through the circulation pipeline. Since the main feedwater pump is a high-power pump, it will The steam generator does not need much water, so the main feed water pump needs to be in the state of low power and small flow for a long time, which will damage the performance of the main feed water pump. In addition, the low flow operation of the high power pump will increase the power consumption quantity

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