【摘要】 以球作为贮能单元,建立了球体内凝固过程的数学模型,并用Lighthill奇异摄动法给出了球体内对称凝固问题的近似分析解,以Ba(OH)2·8H2O为相变材料,得到了相变介质温度、冷却介质温度、球囊半径等随时间的变化规律,同时还讨论了对流换热系数对凝固时间的影响,从理论上证明了相变贮能装置用于车辆冷启动是可行的。更多还原

【Abstract】 In this paper, spheres are taken for the units to storage energy. The mathematical model, which could reveal the process of freezing in spheres, was set up. Then a singular perturbation method was adopted to solve the freezing problem, the analytical solution was obtained.With Ba(OH)2·8H2O as the phase change material,the variation laws of the temperatures of the phase change material, the cooling material and the radius of the sphere with time and the effect of heat convection coefficient on freezing time were given.These testify that energy storage device be used for the engine’s cold start is practicable.更多还原