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为研究不同充装条件下超细干粉灭火剂在水平直管内的气固两相流动特性,搭建超细干粉灭火剂水平直管喷放试验台,改变充装比和起始充装压力,测量管内的沿程压力分布,比较喷放流量和气固比的变化,重点分析了超细干粉灭火剂在水平管内的释放过程、沿程压降和充装比临界值。结果表明,超细干粉灭火剂的释放过程有喷放前期、平稳喷放和喷放后期3个阶段,其中平稳喷放阶段是灭火剂有效作用时间。沿程压降几乎不受灭火剂充装比的影响,但随起始充装压力增大而增大。此外,喷放流量曲线上的临界转捩曲线与气固比计算值曲线上转捩曲线相吻合,起始充装压力为2.5 MPa、4.2 MPa和10 MPa时,喷放流量曲线对应的充装比临界值分别为0.412 kg/L、0.439 kg/L和0.458 kg/L。充装比小于临界充装比时,喷放流量随充装比增大而减小;充装比大于临界充装比时,喷放流量变化不大。而且临界充装比随充装压力单调递增。
In order to study the gas-solid two-phase flow characteristics of ultrafine powder fire extinguishing agent in horizontal straight pipe under different filling conditions, a horizontal straight pipe discharge test bed of ultrafine dry powder fire extinguishing agent was set up to change filling ratio and initial filling pressure, The pressure distribution along the pipeline and the change of discharge flow rate and gas-solid ratio were compared. The release process of ultra-fine dry powder fire extinguishing agent in the horizontal pipe was analyzed emphatically. The pressure drop along the process and the critical value of filling ratio were analyzed. The results showed that the release process of the superfine powder fire extinguishing agent has three stages: pre-discharge, smooth discharge and post-discharge, and the smooth discharge stage is the effective time of fire extinguishing agent. The pressure drop along the way is almost unaffected by the filling ratio of the fire extinguishing agent, but increases with the initial filling pressure. In addition, the critical transition curve on the discharge flow curve is in good agreement with the transition curve on the calculated gas-solid ratio curve. When the initial filling pressure is 2.5 MPa, 4.2 MPa and 10 MPa, Than the critical values were 0.412 kg / L, 0.439 kg / L and 0.458 kg / L. When the filling ratio is less than the critical filling ratio, the discharge flow rate decreases with the filling ratio increasing. When the filling ratio is greater than the critical filling ratio, the discharge rate does not change much. Moreover, the critical filling ratio increases monotonically with filling pressure.