球接管容器气体爆炸尺寸效应的试验研究与数值分析

Experimental study and a numerical analysis of the effects of vessel size on the gas explosion in a spherical one connected to the pipes

为了解尺寸对球形容器连接管道甲烷-空气混合物爆炸的影响规律,利用Fluent软件,采用κ-ε湍流模型、涡耗散模型(简称EDC模型)、壁面热耗散、热辐射模型及SIMPLE算法,建立了球形容器连接管道内甲烷-空气混合物爆炸的数值模型,对容器与管道内甲烷-空气预混气体爆炸的尺寸效应进行了数值模拟。结果表明:随管道内径增大,球形容器内最大爆炸压力逐渐增大,管道末端最大爆炸压力变化无明显规律;而随管道长度增加,球形容器内最大爆炸压力逐渐减小;改变管道内径,较大体积球形容器内最大爆炸压力均大于较小体积球形容器内最大爆炸压力,最大爆炸压力上升速率的规律则相反,容器体积对管道末端最大爆炸压力的影响无明显规律。

This paper intends to bring about its study results of the effects of the vessel size on the methane-air mixture explosion. For the research purpose,we have been trying lots of models,such as the turbulent model,the eddy-dissipation-concept（ EDC） model,the wall thermal dissipation model,and the SIMPLE algorithm in the Fluent so as to establish a numerical model for the gas explosion in a spherical vessel to the pipes connected.At the same time,it has been agreed to set up the volume of the spherical vessels at about 22 L and 110 L,whereas the three pipes to be used are set with their inner diameters of 0. 03 m,0. 06 m,0. 09 m when each pipe is settled as 1 m long. What is more,the initial content volumes have been settled at 9. 5 percent in the content concentration of methane,300 K at the environmental temperature,and 0 in the gauge pressure,correspondingly. The experimental results we have gained show that the maximum explosion pressure in a spherical vessel tends to be arrived at with the increase of the diameter of the connecting pipe in the linear relation. In addition,the maximum explosion pressure likely to be suffered at the pipe end tends to change irregularly with the diameter of the pipe. And,then,with the increase of the length of the connecting pipe,the maximum explosion pressure in the spherical vessel would begin to decrease gradually. Therefore,it seems to be irregular when for the maximum explosion pressure to be arrived at for the end of the connecting pipe. Thus,it can be seen that,the maximum explosion pressure in a big vessel remains always higher than in a small one regardless of the diameter and the length of the pipe. However,on the opposite,the change of the maximum rising rate of the explosion pressure in the big vessel turns to be always lower than the small one. Furthermore,the effect of a spherical vessel volume on the maximum explosion pressure of the pipe end cannot at all be made obvious or clear.Such a conclusion can be expected to provide an important reference to the safety design of the gas vessels.