基于导流方法的天然气管道高后果区安全防护措施研究

Safety Protection Measures in High Consequence Areas of Natural Gas Pipeline Based on Diversion Principle

管道在高后果区发生的泄漏事故往往导致十分严重的后果。提出基于导流方法的管道安全防护方法,探索将高后果区泄漏的天然气导流至非高后果区的可行性。通过数值模拟对安全防护导流措施强度进行校核,研究管道泄漏后天然气在导流PE套管内的扩散结果,并对比无套管条件和设置套管条件下,对火灾热辐射强度的影响。结果表明:1)7 MPa条件下PE套管产生的弹塑性变形,远远低于12 MPa条件下的位移,短时间所产生的塑形变形尚在可接受范围。2)在设置导流套管后,初始压力12 MPa管道发生泄漏后,套管出口处压力降至0.9 MPa。其他条件相同情况下,经过套管降压后导流出口处火灾热辐射强度明显降低,证明导流套管安全防护措施能够有效减轻火灾对人体的伤害,起到防护作用。

The leakage accident in the high consequences areas(HCA) often brings to serious consequences.This article proposes a pipeline security protection method based on the principle of diversion,exploring the feasibility of diverting leaked natural gas in the high consequences areas to the non-high-consequences areas.Checks the intensity of safety protection diversion measures through numerical simulation.Studies the diffusion of natural gas in the PE diversion sleeve after pipeline leakage.Analyzes the changes in the heat radiation intensity of the fire after leakage of the pipelines under conditions with and without diversion sleeve.The results show that:1) When the pipeline pressure level is 7MPa,the elastic plastic displacement generated by the PE sleeve is far lower than the displacement under 12 MPa conditions.The plastic deformation generated in a short time is acceptable.2) Under the condition with diversion sleeve,the pressure at the exit of the diversion sleeve drops to 0.9 MPa after the leakage of the pipeline with initial pressure of 12 MPa.The fire thermal radiation density at the diversion sleeve outlet significantly decreases due to the decrease of pressure under the same other conditions,proving that the safety protection measures with the diversion sleeve can effectively reduce the harm of fire to people.