承压设备接管结构对气体泄放影响的数值模拟研究

Numerical Simulation on the Effects of Different Connecting Pipe Structures on Gas Venting

根据承压设备气体超压泄放研究中泄放接管的结构往往被忽略的现状,对插入型接管、平齐式接管、倒圆角接管这3种常用泄放接管结构进行模拟分析,得出3种接管结构在其不同结构尺寸、不同亚临界条件和临界条件下的泄放规律,并将其与ISO标准综合泄放系数比较,分析其适用条件。结果表明,亚临界条件下,插入型接管结构的插入管长对泄放没有影响,倒圆角接管结构的圆角半径与泄放系数保持线性正相关。在临界条件下,插入型接管结构在插入管长80-100mm内对泄放阻碍明显,管长再增加则对泄放无影响;倒圆角型接管圆角半径在35-50mm时,对实际泄放有参考意义。同时发现国际标准规定的插入型接管结构的泄放系数（0.68）,在亚临界条件下存在部分不安全泄放,但临界条件下偏保守;平齐式接管泄放系数（0.73）和倒圆角接管泄放系数（0.80）在临界条件下都将引起不安全泄放,临界条件下较合理。

With the extensive literature on overpressure gas venting in pressure equipment,comparatively little research has focused on the connecting pipe structures.The gas venting with three common pipe structures was simulated and the venting characteristics with different structures at subcritical and critical pressures were analyzed,comparing with discharge coefficients of international standards to obtain the applicable conditions.Results indicated that the venting process with the insertion pipe was not affected by inline length under subcritical conditions.On the contrary,fillet pipe discharge coefficient had positive linear correlation with corner radius（R）.Under critical conditions,inline length of insertion pipe affected the venting with less than80~100mm significantly.With increasing the pipe length there was no significant variations.35~50mm of fillet radius for fillet pipe will be a reference value for actual venting.Simultaneously,0.68 of insertion pipe given by ISO is partly unsafe for subcritical conditions and conservative for critical conditions.Discharge coefficient 0.73 for flush type pipe would induce dangerous venting under the critical conditions,but reasonable for critical conditions,as the same as 0.80 for fillet pipe.