Passive heat conduction device and secondary side passive cooling system

Abstract

The invention discloses a passive heat conduction device, which comprises a U-shaped pipe and an auxiliary unit, wherein one end of the U-shaped pipe extends into a heat exchange water box, the otherend of the U-shaped pipe is communicated to the outside, a sealing medium is placed in the U-shaped pipe, the auxiliary unit comprises a heat collection box, a steam pipeline, an emptying pipeline, afirst control member and a second control member, the two ends of the steam pipeline are respectively communicated to the heat exchange water box and the heat collection box, the steam pipeline is ina closed state under a normal working condition, the first control member is used for controlling the steam pipeline to be opened under an accident working condition, the two ends of the emptying pipeline are respectively communicated to the U-shaped pipe and the heat collection box, the emptying pipeline is in a closed state in a normal state, and the second control member is used for controllingthe emptying pipeline to be opened under an accident working condition. The invention further discloses a secondary side passive cooling system comprising the passive heat conduction device. According to the passive heat conduction device of the invention, high-temperature steam in a heat exchange water box can be automatically guided out, and the safety and the stability of a secondary side passive cooling system can be improved.

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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