Essential service water system for nuclear power station

Abstract

The invention discloses an essential service water system for a nuclear power station. The essential service water system comprises more than one safety series which comprises an SEC pump and an RRI/SEC heat exchanger, each safety series is provided with a mixing forebay in the upstream of the SEC pump, and a separation gate for separating the mixing forebay into a water intake area and a drainage area is arranged in the mixing forebay; a water return pipeline which is connected into the drainage area of the mixing forebay is arranged in the exit of the heat exchanger. According to the essential service water system for the nuclear power station, by additionally arranging the mixing forebay on the front end of a pump house, and by adopting the method that hot water backflows into the mixing forebay instead of using an overflow well, the overall water temperature of the SEC pump entrance is enabled to be increased, and the operation method of the system in winter is the same with that in summer when the seawater temperature is higher; only the adjustment on a total capacity of the mixing forebay and a subarea proportion of the water intake area and the drainage area are required to be carried out, and the problem of not meeting the requirement on a low temperature of nuclear island users caused by an overlow cooling water temperature possibly brought by the nuclear power station in a frozen water area in the north in winter can be solved in any places and conditions.

Description

technical field [0001] The invention belongs to the design field of the important plant water system of nuclear power plants. More specifically, the invention relates to a universally applicable nuclear power plant important plant water system which is not subject to changes in seawater temperature. Background technique [0002] Part of the heat generated by the nuclear power plant reactor and its primary circuit system is used to heat the secondary circuit water of the steam generator to generate steam and drive the steam turbine to generate power, and the other part (the waste heat that the steam turbine cannot use) is discharged into the final heat through the nuclear island cold chain system. trap. In the case of a nuclear power plant accident or in the late stage of reactor shutdown, the steam generator cannot discharge heat, and the waste heat of the entire nuclear island will be discharged through the cold chain system. The nuclear island SEC system (Essential Water ...

AI Technical Summary

Problems solved by technology

However, these improvement schemes all need to add control logic, instruments and control equipment. First, the transformation of the DCS system is relatively large and the design is difficult. Second, new pipelines and equipment need to be added in the limited workshop space of the original nuclear power plant, and the layout is also very difficult. , and the third is that the shifting and switching during winter operation a

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