管道内径与壁温对高压氢气自发点火的数值研究

Numerical study on spontaneous ignition of high pressure hydrogen gas by tube inner diameter and wall temperature

氢气在高压储存中的泄漏容易导致自燃。为探究影响氢气自燃的因素,运用Realizable模型、EDC模型、21步氢/空气化学反应机理对加压氢气在不同管道壁温和管径中突然释放的自燃过程进行了数值模拟。研究结果发现:管道壁温的降低能显著降低氢气自燃的可能性;输送压力小于8 MPa时,管道内径的增加不利于氢气点火自燃,当输送压力过大时(10 MPa),管道内径的增大为氢气射流的膨胀和扩散提供更多空间,利于氢/空气混合物的生成,促进氢气自燃点火。

Hydrogen leakage in high pressure storage is easy to lead to spontaneous combustion.In order to explore the factors affecting the spontaneous combustion of hydrogen,the spontaneous combustion process of pressurized hydrogen in different pipe wall temperature and pipe diameter was simulated by using Realizable model,EDC model and 21-step hydrogen/air chemical reaction mechanism.The results show that the decrease of pipe wall temperature can significantly reduce the possibility of hydrogen spontaneous combustion.When the conveying pressure is less than 8 MPa,the increase of pipe inner diameter is not conducive to hydrogen ignition and spontaneous ignition.When the conveying pressure is too large(10 MPa),the increase of pipe inner diameter provides more space for expansion and diffusion of hydrogen jet,which is conducive to the formation of hydrogen/air mixture and promotes hydrogen spontaneous ignition.