炼油火炬系统水封罐设计压力研究

水封罐作为炼油火炬系统防止回火爆炸的重要安全设施,其设计应能保证在发生回火爆炸事故时不被破坏。采用数值模拟技术,利用FLACS工具,建立水封罐三维模型,模拟计算水封罐内的典型气体爆炸,据此提出水封罐的设计压力。结果表明:烃类气体(如甲烷、丙烷)在水封罐密闭空间内发生爆炸产生的压力为气体初始压力(绝压)的7~8倍,氢气爆炸产生的压力为气体初始压力(绝压)的10~12倍。对于炼油火炬系统,建议富氢气体排放系统的水封罐设计压力不低于1.0MPa(绝压),一般烃类火炬气排放系统的水封罐设计压力不低于0.7MPa(绝压)。

Study on the Design Pressure for Water-sealed Drum in Refinery Flare System

A water-sealed drum is the most important facility for the prevention of back-fire and explosion in the refinery flare system,and its integrity should be properly designed to make sure it will not be destroyed during back-fire and explosion.In this study,a 3-D model of water-sealed drum was built,and a numerical simulation with FLACS software was utilized in the simulation of gas explosion in the drum.The results show that,in the confined space,pressure caused by the hydrocarbon gas explosion(such as methane and propane) is 7-8 times of the initial gas pressure(Absolute pressure),and pressure caused by hydrogen explosion is 10-12 times of the initial gas pressure(Absolute pressure).Therefore,the design pressure for water-sealed drum is suggested not to be less than 1.0 MPa(Absolute pressure) in hydrogen-rich gas discharge system and not to be less than 0.7 MPa(Absolute pressure) in hydrocarbon gas discharge system.