振动环境下液化气罐内饱和液体状态变化规律研究

Numeral simulation of thermal process in vibrating LPG tank

液化气在储运过程中存在安全隐患,为分析在运输途中的液化气罐内部压力变化情况,建立液化气罐在受迫振动下的一维数学模型,分析运动过程中饱和液体和气罐的相对运动以及对罐内压力的影响。根据经验公式计算过热液中气泡的生长和消失,并用商业CFD软件CFX模拟在振动过程中罐内介质的状态变化过程,计算由于气泡的生长和消失导致的压力波动。根据这些数据进一步分析罐的振动频率和液体的填充量对汽化速率和压力波动的影响,并得出变化规律。

The hidden danger in the transportation of LPG frequently results in accidents such as fire, leakage, crash and exploration. Therefore it is necessary to analyze the pressure change in the LPG tank. This paper firstly sets up a mathematical model on bubbles growing and disappearing during the LPG tank vibration, and then simulates the phase changes of over-heated liquid with the help of commercial software CFX. The above mathematical model is applied to analyze the relative motion between saturated liquid and LPG tank, as well as the pressure change caused by such relative motion. Based on empirical formula and law of mass conservation, this model calculates the process of bubbles growing and disappearing in the overheated liquid as well as their pressure changes. This study further explores the effect of tank vibrating frequency on the liquid cavitations speed and LPG tank pressure fluctuation. The simulation through CFX software is concluded as follows： higher the vibration frequency increases the cavitations speed of saturated liquid and the pressure of LPG tank; higher liquid amount in the tank induces higher pressure fluctuation after cavitations; the pressure fluctuation tends to decrease when the amount of liquid up to 98 %. This paper is expected to offer some references for safe storage and transportation in future.