地坑滤网性能评价及下游效应分析中通常需要开展大破口失水事故(LOCA)喷放模拟实验。本研究采用双膜爆破片结合气动阀实现大破口LOCA喷放模拟实验启动压力的精确控制和高能流体的瞬间释放。压力测量结果表明:双膜放气启动压力损失最大,单膜启动压力爬升较慢,双膜充气启动在压力损失、压力爬升速度和压力精度上都能准确模拟大破口LOCA喷放物理过程。最后采用双膜充气启动方法对双壁盒式保温结构进行射流破坏试验,结果表明本装置提供的冲击力度足够。 Pit filter performance evaluation and downstream effect analysis usually need to carry out large-breach water loss accident (LOCA) discharge simulation experiment. In this study, double diaphragm rupture disk combined with pneumatic valve was used to realize the precise control of the starting pressure and the instantaneous release of high-energy fluid in large-break LOCA simulation experiment. The results of pressure measurement show that the starting pressure loss of double-membrane deflation is the largest, and the start-up pressure of single membrane climbs slowly. The double-membrane inflation startup accurately simulates the physical process of large-breach LOCA discharge under pressure loss, pressure climb speed and pressure accuracy. Finally, the double-membrane inflatable start-up method was used to test the jetting failure of the double-walled box-type insulation structure. The results show that the impact strength provided by the device is sufficient.