充装条件对超细干粉灭火剂水平直管内喷放流量的影响  

On the effects of the filling conditions on the discharge releasing rate of the superfine fire-extinguishing powder in the horizontal pipeline

作　　者：蔡宇武[1] 宣扬[2] 李权威[1] 王华[1] 潘仁明[1] 

机构地区：[1]南京理工大学化工学院,南京210094 [2]上海飞机设计研究院,上海201210

出　　处：《安全与环境学报》2015年第2期154-157,共4页Journal of Safety and Environment

基　　金：教育部高等学校博士学科点专项科研基金项目(20123219120017)

摘　　要：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。The aim of the paper is to pursue the correlated relation- ship between the flowing features of the superfine fre-extinguishing powder in the horizontal pipeline and its initial filling conditions. By using an experimental discharge device developed by the present au- thor for the given purpose, we have done a series of experiments by changing the initial filling pressures and filling ratios. To promote the accuracy and reliability with our experiments, we have repeatedly measured the sets of pressure data with a UNIK 5000 type pressure transducer in the different points of the horizontal pipelines. At the same time, we have made careful comparisons of the trends of dis- charge releasing rate with the intentionally set gas-solid ratios. How- ever, the focus of our analysis has been put on the releasing process, the pressure drop and the critical filling ratios. The results of our ex- periments indicate that the releasing process can be divided into three steps in the superfine powder, including the pre-releasing step, the stead-fast releasing step and the late releasing step. Of the said three steps, the stead-fast releasing step should be the most efficient one in effective releasing or discharging of the powder extinguishing agent. However, careful observation helps us to find that the initial filling ratio has little effect on the pressure drop in the pipeline. Thus, the pressure drop tends to increase gradually with the increase of the ini- tial filhng pressure of the vessel. What is more, the critical transition curve of the discharge releasing rate proves in accord with that of the calculated gas-solid ratio. More accurately speaking, the critical fill- ing ratio of the discharge rate profiles can be worked out at 0.412 kg/L, 0.439 kg/L and 0.458 kg/L with the initial filling pressure being 2.5 MPa, 4.2 MPa and 10 MPa, respectively. However, if the initial filling ratio is below the critical filling ratio, the discharge releasing rate is likely to drop with the increase of the filling ratio. Nevertheless, s

关 键 词：安全工程 超细干粉灭火剂 充装比 喷放流量 压降 气固比 

分 类 号：X9[环境科学与工程—安全科学]