A passive heat conduction device and a secondary side passive cooling system

Abstract

The invention discloses a passive heat conduction device, which includes a U-shaped tube and an auxiliary unit. One end of the U-shaped tube extends into a water exchange tank, and the other end communicates with the outside. A sealing medium is placed inside the U-shaped tube. The auxiliary unit includes a heat collecting tank, a steam pipeline, an emptying pipeline, and a first control part and a second control part. The first control part is used to control the opening of the steam pipeline under accident conditions; the two ends of the emptying pipeline are respectively connected with the U-shaped pipe and the heat collector, and the emptying pipeline is closed under normal conditions. state, the second control component is used to control opening of the emptying pipeline under accident conditions. The invention also discloses a secondary-side passive cooling system comprising the above-mentioned heat conduction device. The device of the invention can automatically lead out the high-temperature steam in the exchange water tank, and improves the safety and stability of the passive cooling system on the secondary side.

Description

technical field [0001] The invention belongs to the technical field of the nuclear industry, and in particular relates to a passive heat conduction device and a secondary side passive cooling system. Background technique [0002] In the case of power outage in the nuclear island plant and the loss of the auxiliary water supply steam-driven pump or the loss of all water supply, the PRS system is started, and the heat of the primary circuit is exported to the heat exchanger in the water exchange tank through the evaporator in the PRS system In the process, the cooling water in the heat exchange tank exchanges heat with the heat exchanger to export the heat of the heat exchanger. At the same time, the temperature of the cooling water in the heat exchange tank gradually rises and converts into high-temperature steam, which will make the heat in the heat exchange tank The air pressure rises. In order to prevent the air pressure and temperature in the heat exchange tank from being...

AI Technical Summary

Problems solved by technology

[0005] (1) In the initial stage of accident conditions, the emptying of the water seal in the U-shaped water seal pipe mainly depends on the impact force of the steam pressure accumulated in the heat exchange tank on the water seal from the inside to the outside and the heating and evaporation of the water stored in the water seal , the emptying process of the sealing water in the U-shaped water-sealed pipe is relatively slow, and it is difficult to realize the connection between the water exchange tank and the external environment in time, and the high-temperature steam in the water exchange tank cannot be released in time, and it is easy to damage the water exchange tank and other equipment. have a huge negative impact

[0006] (2) Since the sealing effect of the U-shaped water-sealed pipe is related to the height of the vertical section of the U-shaped water-sealed pipe, the higher the water-sealed height, the better the sealing effect, but the higher the water-sealed height will further slow down the discharge during accident conditions The speed of the sealing water in the U-shaped water-sealed pipe, so the water-sealed height of the U-shaped water-sealed pipe in the existing secondary-side passive cooling system is generally only about 300mm, and the water-sealed height cannot be freely increased according to the design requirements. which in turn may affect the sealing effect

[0007] (3) The U-shaped water-sealed tube is directly connected to the external atmosphere. During the normal standby period, if the external atmospheric pressure fluctuates abnormally (such as during a typhoon), it will cause impact on the water seal in the U-shaped water-sealed tube, which will easily make the external atmosphere Unfavorable ions in the environment (mainly chloride ions) enter the water exchange tank through the U-shaped water seal tube, which will not only affect the water quality in the water exchange tank, but also affect the metal equipment in the water exchange tank (such as the heater) causing corrosion

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