Thermal-Fluid Mechanism of Double Diffusive Convection in LNG Model Tank Exposed to a Fire Environment

报道了一种用于评估火灾环境下稳定分层液化天然气储罐热响应的建模方法。实验在一个矩形LNG模型罐体中进行，罐体部分由侧壁加热，热流均匀。在充满和部分充满的罐中设置由上层水和下层蔗糖水溶液组成的液体层。用束状热电偶测量液体中的垂直温度分布。讨论了液体自由表面温度随时间升高的特性。本文还对层流自然对流进行了数值分析。采用伽辽金有限元法。根据实验条件对Pr=7, Le=300, Ra*=2 × 10^6进行了计算。数值计算结果与实验数据进行了比较。在定性和定量论证上都取得了令人满意的一致。

The modeling method used to evaluate the thermal response of a stably stratified LNG tank exposed to a fire environment is report. The experiments are carried out in a rectangular LNG model tank heated partially from the sidewall with a uniform heat flux. The liquid layers composed of the upper layer of water and the lower layer of sucrose aqueous solution are set up in the full and partially filled tank. The vertical temperature profiles in liquid are measured by the bundled thermocouples. The characteristics of temperature at the free surface of liquid rising with the lapse of time are discussed. The numerical analysis of laminar natural convection is also performed. A Galerkin finite element method is employed. Computations are carried out for Pr=7, Le=300, Ra*=2 x 10^6 corresponding to the experimental conditions. The numerical results are compared with the experimental data. Both on qualitative arid quantitative arguments, a satisfactory agreement is obtained.