Siphon destroying device

Abstract

The invention provides a siphon breaking device which has a simple structure, and is safe and reliable. When an out-pile conduit rupture event is happened, the siphon breaking device can reduce sodium leakage and delay developing speed of the event so that operating staff has enough time to process the event. The siphon breaking device comprises: a fetching sodium tube is connected with a circulating pump via the out-pile conduit; the other end of the circulating pump is connected with a return sodium tube via the out-pile conduit; the fetching sodium tube and the return sodium tube are fixed on an isolation board and separately extend into two protective casings in the pile; an inlet orifice plate is arranged on the bottom of the fetching sodium tube; a fracture structure of the protective casing into which the fetching sodium tube extends is a venturi tube and is provided with four mesopores all around; aperture of the inlet orifice plate is 45mm; and elevation of the fetching sodium tube is reduced.

Description

technical field [0001] The invention relates to the field of additional adjustment devices for flow, in particular to a siphon breaking device. Background technique [0002] The primary sodium of the reactor is purified outside the reactor, and the elevation of most of the pipes and equipment in the purification circuit is lower than that of the sodium liquid level in the reactor vessel. Once the pipeline outside the reactor breaks, the high-temperature and highly radioactive liquid sodium in the pool will be ejected from the pipeline breach under the joint action of the reactor pressure and siphon force, resulting in a sodium loss accident. This not only poses a threat to the safety of the reactor itself, but also the highly radioactive aerosol discharged with the liquid sodium will seriously pollute the surrounding environment. [0003] Internationally, only Russia has proposed the preliminary design of the passive siphon breaker for pool-type fast reactors, but it has no...

AI Technical Summary

Problems solved by technology

Through experiments, it is found that the performance of this design cannot meet the design requirements when the purification circuit is in normal operation and a sodium loss accident occurs at a large breach in the external reactor pipeline. The performance is as follows: (1) When the purification flow rate is ≥5m 3 / h, the top of the outlet ring chamber of the purification circuit returning to the sodium pipe section (in the stack) produces a gas-liquid two-phase foam-like overflow, and directly falls to the free surface of the high-temperature liquid sodium in the hot sodium pool; (2) when the purification flow rate is ≥ 5m 3 / h, a large amount of gas entrainment occurs in the downcomer of the protection casing of the purification circuit back to the sodium pipe section. When the liquid level is changed, the gas volume content is as high as about 30%. Once the entrained gas passes through the cold pool and the main circulation pump If it enters the core, it will cause serious problems such as reactor power oscillation, heat transfer deterioration, and cavitation of the circulating pump.

In addition, due to the possible accumulation and rupture of gas in the cold pool, pressure pulsation will be generated and flow-induced vibration of reactor internals and core components will be induced, which will seriously affect the safe operation of the reactor; During the accident, the leakage of sodium was too large, which may expose the sodium inlet of the accident cooler (independent heat exchanger) to the gas, affecting its normal operation, and causing serious consequences due to the inability to discharge the waste heat of the reactor; (4) When a sodium loss accident occurs through a breach, the system lacks effective human intervention measures to make the accident end as soon as possible, but can only be terminated naturally

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