保温层失效比例对热油管道安全停输时间的影响

针对热油管道的保温层由于特定原因而出现部分失效,进而导致在维修过程中安全停输时间难以控制的问题,结合有限容积法,建立了热油管道二维、非稳态模型。该模型考虑了凝固潜热的影响,对比分析了热油管在5种情况(即保温层未失效、1/8失效、1/4失效、1/2失效及全部失效)下的温降规律。在此基础上,运用SPSS软件,拟合了停输时间与热油的平均温度的关系曲线,最终确定了上述5种情况下的安全停输时间。研究结果表明,5种情况下管内热油温降规律基本相似,且安全停输时间分别为205、148、118、99和74h;由于凝固潜热弥补了部分散热损失,因此1/4失效和1/2失效情况下的安全停输时间差仅为19h。

Influence of Insulation Failure Ratio on Safe Shutdown Time for the Hot Oil Pipeline

According to the problem of uncontrollable safe shutdown time when the insulation layer was partial failure under the specific conditions,a two-dimension,unsteady-state model of hot oil pipe was established by the finite volume method.In the model the influence of the latent heat of solidification was considered and the law of temperature drop in the hot oil pipe was compared and analyzed in five cases(i.e.no insulation failure,1/8 insulation failure,1/4 insulation failure,1/2 insulation failure and complete insulation failure).Based on the above,the relative curve between the shutdown time and the average temperature of hot oil after line turndown was fitted by SPSS 18.0,and the safe shutdown time of the above five cases were determined finally.The results show that the laws of temperature drop of hot oil pipe is similar in the above five cases,and the safe shutdown time is 205,148,118,99 and 74 hours.Due to the latent heat of solidification could partly make up for the heat loss,safe shutdown time of 1/2 insulation failure was only 19 hours less than 1/4 insulation failure's.