室内天然气泄漏过程试验研究

Experimental study on indoor natural gas leakage process

为了研究厨房内泄漏天然气的体积分数分布及其变化规律,根据典型居民厨房尺寸,建立了1:1全尺寸厨房天然气泄漏试验模型,对不同泄漏模式下房间内燃气体积分数分布进行了实测研究,并对室内天然气泄漏的扩散规律进行了分析。结果表明,封闭厨房内发生天然气泄漏时,天然气在屋顶处体积分数最高,特别是泄漏位置上方的屋顶,最快可在1200 s左右达到爆炸下限。房间内的天然气体积分数随高度降低而降低。对比不同泄漏方式,在燃气管道产生裂缝的情况下,室内各处天然气体积分数到达爆炸下限最快,并且同时间泄漏天然气的体积分数最高,在泄漏2400 s时可达到最高体积分数7.3%。燃气管道产生小孔的泄漏情况比天然气管脱落和天然气开关未关紧的情况后果要严重。

To study the distribution of the volume fraction of leaked natural gas in the kitchen and its changing law,a 1:1 full-scale kitchen natural gas leak test model was established according to the size of a typical residential kitchen.The gas volume fraction distribution in the room under different leakage modes was measured and studied.The curves of the natural gas volume fraction change at different locations under different leakage modes were obtained,and the diffusion law of indoor natural gas leakage was analyzed.The results show that when a natural gas leak occurs in a closed kitchen,the volume fraction of natural gas at the roof is the highest,especially the roof above the leak location,which can first reach the lower explosion limit at about 1200 s.The volume fraction of natural gas in the room decreases with decreasing height.Therefore,in the kitchen,special attention should be paid to the ignition on the roof and other higher places.Comparing different leakage methods,it can be seen that the gas leakage is the largest when the gas pipeline cracks.In this leakage mode,the indoor natural gas volume fraction reaches the lower explosive limit first,and the leakage natural gas volume fraction is the highest at the same time,and the highest volume fraction can reach 7.3%at 2400 s.Besides,the volume fraction of natural gas in all leakage modes exceeded the lower explosive limit before the 2000 s.Furthermore,the leakage of small holes in the gas pipeline is more serious than the case of the natural gas pipe falling off and the gas switch is not tightly closed.Therefore,special attention should be paid to the occurrence of cracks on the gas pipeline.And it is very necessary to check the condition of the gas pipeline regularly and strengthen the repair and maintenance of the pipeline.