固液相变蓄能数学模型中有效导热系数的理论及实验研究

引入有效导热系数经验公式 ,将固液蓄能数学模型简化为仅用能量方程加以描述 ,运用热焓法求解能量方程 ,得到计算相变位置随时间变化曲线。并通过实验测得相变过程的实际温度场 ,得到实验相变位置随时间变化曲线。二者比较 ,证明了自然对流对固液相变换热的影响不可忽略 ,验证了该公式在Ra <10 1 0 ,Pr<10 5下的正确性。

The Study on Effective Heat Transfer Coefficient in the Math Model of Energy Storage System with Solid-liquid Phase Change by Theory and Experiments

With the introduction of the empirical formula of effective heat transfer coefficient , the math model of energy storage system with solid liquid phase change is simplified to be described only by energy equation. Using enthalpy method, the energy equation can be solved and the curve can be obtained that describes the change of solid liquid interface displacement with the change of time. With a series of experiments, the temperature fields of actual phase change process and the actual curve can be gained that describes the change of solid liquid interface displacement with the change of time. The comparison of the two results proves that the effect of natural convection on phase change can't be neglected and that the empirical formula is correct in the range of Ra <10 10 , Pr <10 5.