Nuclear power plant capacity control box nitrogen purging efficiency optimization method

Abstract

The invention discloses a nuclear power plant capacity control box nitrogen purging efficiency optimization method. The method comprises the steps of establishing a geometric model of a capacity control box nitrogen purging system; meshing on the geometric model; importing the divided grids into computational fluid mechanics software and establishing a simulation calculation reference model of thenitrogen purging system of the capacity control box; optimizing parameter values of key factors influencing the nitrogen purging efficiency based on the simulation calculation reference model, the key factors comprise geometric structure parameters of the capacity control box and operation parameters of the capacity control box. The physical deoxygenation process of the volume control box is optimized and analyzed based on the computational fluid simulation technology, so that the nitrogen purging process can be optimized on the premise that the dynamic and static exhaust qualification standard and the nitrogen purging stage target of the volume control box are not changed; moreover, the method provided by the invention provides a theoretical scheme for improving the purging efficiency ofthe capacity control box, can greatly reduce the research cost compared with a common test bed method, can effectively improve the purging process of the capacity control box, and improves the economic benefits.

Description

technical field [0001] The invention relates to the field of nuclear power, in particular to a method for optimizing nitrogen purging efficiency of a capacity control box of a nuclear power plant. Background technique [0002] The pressurized water reactor nuclear power plant chooses water as the coolant and moderator of the primary circuit of the reactor (hereinafter referred to as the primary circuit). Since the corrosion phenomenon has more serious consequences in the nuclear power plant under the condition of strong radioactive irradiation, it is used as one of the anti-corrosion methods. First, during the operation of the unit, it is necessary to strictly control the oxygen content of the primary circuit. However, after the unit is opened and refueled for overhaul, the equipment pipeline of the primary circuit is full of air. Therefore, during the upward process of the unit, the primary circuit needs to be degassed through dynamic and static exhaust to reduce the air co...

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Problems solved by technology

However, this action increases the total amount of oxygen contained in the primary circuit coolant during the nitrogen purge of the capacity control box. If the purging process does not change, the nitrogen purging period of the capacity control box will increase, which may become a critical path for overhaul. Specific defects include:

[0007] 1) The existing nitrogen purging process of the volume control box has two deoxygenation processes: pressure-holding purging and intermittent purging. The operating regulations of the current regulations lack quantitative reference data, and it is difficult to follow the operation;

[0008] 2) Since the results of dynamic and static exhaust have a great influence on the qualified time of nitrogen purge in the capacity control box, the number of nitrogen purge in actual operation depends on the experience and judgment of the operator, and there is no rigorous test calculation data to provide guidance for the operation, which may lead to The cleaning period is extended;

[0009] 3) Due to the unclear understanding of the nitrogen purge principle of the volume control box, the unit planners only adjusted the nitrogen purge time from the perspective of optimizing the critical path of overhaul, resulting in a decrease in nitrogen purge efficiency;

[0010] 4) After the researchers increased the standard value of dynamic and static exhaust, the nitrogen purge and oxygen removal load of the volume control box increased, and the qualified time of nitrogen purge of the volume control box increased, which may affect the critical path of overhaul;

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