大型LNG储罐罐底保冷层结构优化研究

Study on structure optimization of insulation layer in large-scale LNG storage tank bottom

针对大型LNG储罐罐底漏热量大及基础保冷性能差等问题,对储罐底部保冷结构进行了优化,并对不同储罐底部基础的温度场分布和漏热量进行了数值模拟和现场对比分析。结果表明:储罐冷损失与泡沫玻璃砖厚度呈双曲线函数关系,在内外壁温差为185 K时泡沫玻璃砖保冷层厚度设置为600 mm保冷效果显著,再增加厚度时保冷损失减小缓慢;储罐基础采用夯土基础时保冷性能优于柱桩基础,而夯土基础需在罐底设置加热系统,因此工程上大型LNG储罐需根据实际情况进行选择。

Aiming at the problems of large thermal leakage and poor heat-insulating property at the bot- tom of large-scale LNG storage tank,the optimization of the tank bottom structure was carried out accompa- nied with the numerical simulation and field comparison of the temperature distribution and the heat leakage at the bottom of different tanks. It is found that the cold energy loss fitted with the thickness of foam glass block in a hyperbola function. When the temperature difference between the inner and outer tank wall is 155 K,600 mm foam glass block exhibits significant heat-insulating effect. While the cold energy loss decreases slowly as the thickness of foam glass block further increases. The heat insulation of a LNG storage tank with rammed-soil foundation is better than that of the tank with piled foundation. But the latter need to set a heating system at the bottom of the tank,so the type of foundation of the large-scale LNG storage tank should be chosen based on the actual situation.