液化石油气储罐分层增压过程研究

STUDY ON STRATIFICATION BOOSTING PROCESS OF LPG TANK

液化气储罐受到火焰侵袭时 ,靠近壁面的液化气温度首先升高 ,自然对流上升至储罐上部后形成热分层区 :分层区温度较高 ,并决定了储罐内的温度。研究液化气储罐中的分层现象有利于我们认识液化气在存储和出现事故时的压力变化过程 ,为工业生产提供安全保障。为此 ,主要针对液化石油气储罐在受到外部热源侵袭时出现的分层现象进行了分析 ,建立了液化石油气分层模型 ,并将分层模型和均相模型的计算结果进行了比较 ,得出了分层区对增压过程的影响。另外还分析了热流密度和液化石油气充装度对分层区形成的影响。结果认为 :①由于分层区的存在 ,液化石油气储罐受热增压速度显著加快 ;②在一定的范围内 ,热流密度和充装度的增大会使液化气储罐内压力上升速度加快 。

When a LPG tank is heated,the temperature of LPG near the wall will first increases,and this part of LPG will rise to the top and form the thermal stratification zone The zone has higher temperature and dominates the temperature of the tank Studying the phenomenon of stratification in LPG tank is useful for us to know the pressure variation process in the LPG tank when LPG is stored or an accident happens So,the operation safety of the LPG tank can be guaranteed. With the analysis of the stratification phenomenon happened when the LPG tank is heated,the stratification model is developed. And the results calculated respectively by the stratification model and the homo phase model are compared to identify the influence of the stratification zone on the boosting process Also,the influence of the heat flux and filling level on the stratification zone forming is analyzed. The results indicates:① the boosting velocity of LPG tank increases obviously when it is heated because the stratification zone exists;② in a certain range,the pressure in the tank rises faster as the heat flux and filling level increases So,the time when the safety valve is opened is shortened