爆燃波在含内构件管道中传播现象的实验研究

为了评估高温气冷核反应堆热交换器H2泄漏、爆炸的安全性，研究含内构件管道的H2/空气爆燃传播现象，建造了几何相似、尺寸相同的实验管道（真空筒）。分别充入不同初压和当量比H2/空气混合物，在真空筒顶部点火并引发爆燃，利用多通道瞬态压力测量和数据采集系统，记录各测点压力时间曲线。结果表明:对化学计量比H2/空气混合物，在慢化剂室和真空筒顶部空间产生爆燃，邻近测点的压力时间曲线显示了冲击波特征。该冲击波通过慢化剂室和真空筒侧壁的狭缝（2.5 mm），进入含内构件的扩张管道并形成爆燃。冲击波在真空筒端部反射、向后传播并与火焰相互作用，爆炸流场波系复杂。对富油和低初压化学计量比混合物，在慢化剂室和真空筒顶部空间产生燃烧，高温富油燃气的压力上升速率较慢。当燃气通过上述狭缝时，在真空筒突扩空间内再次点火并形成较强爆燃，压力时间曲线显示了冲击波特征及其在端面的反射。

Experimental studies on H2-air deflagration propagating in a tube containing inner components

A test tube is designed to experimentally evaluate the accidental explosion of a H2-He heat exchanger in a nuclear reactor when hydrogen leaks during work.The test tube is identical to the exchanger in size and geometry.In the experiments,H2-air mixture is filled into the tube at the different initial pressures and equivalence ratios.A spark igniter is located at the top of the designed tube.The transient pressure and data acquisition systems were used to record the pressure histories at the specified stations.Results show that deflagration can occur at the tops of the vacuum tube and the coolant box and characteristics of shock wave can be seen from pressure curves at neighboring test points.The shock waves pass through the slot between the coolant box and the tube side-wall and propagate into the divergent section to develop deflagration.The induced shock wave reflects on the end wall of the tube.The backward propagating shock interacts with the forward traveling flame following the shock wave initially,and the complex shock wave field can be generated.Compared with the stand atmospheric pressure,in the case of low initial pressure and rich fuel mixtures,combustion rather than deflagration occurs at the top of the tube,the pressure of the high-temperature gas rises lowly,and the pressure history does not appear at the shock wave character.The fuel-riched products move into the divergent section of the tube and are re-ignited to induce strong detonation.