套管封装相变材料准稳态传热模型研究

Study on Quasi-Steady-State Heat Transfer Model for Casing Pipe-encapsulated PCM

本文建立了套管封装相变材料的准稳态简化传热模型,对定温边界条件下相变套管凝固、熔化过程的传热特性进行了模拟分析。进一步将准稳态简化模型的模拟结果与套管封装相变材料CFD数值传热模型的计算结果进行对比分析。结果表明,在相变过程中,准稳态简化模型计算的套管内工质(不流动)的温度与通过内、外套管表面热流及其变化趋势与数值计算结果一致,温度平均误差小于0.5℃,热流平均误差小于10%,模型准确性较好。准稳态简化传热模型的计算时间不到数值模型计算时长的1%,计算效率高,易于嵌入建筑热湿软件包进行集成模拟分析。

In this paper, a quasi-steady-state simplified heat transfer model of casing pipe-encapsulated PCM is developed, and the thermal characteristics of the solidification and melting process in the constant temperature boundary of the casing pipe-encapsulated PCM based on this model are simulated and analyzed. Furthermore, the results of the simplified model are compared with the results of this numerical model of the casing pipe-encapsulated PCM. The results show that the temperature of the working medium （no-flow） in the inner casing pipe in the solidification or melting process by using the simplified model matches well with that by using the numerical model. The mean temperature difference of the working medium is less than 0.5 ℃ , the mean error of the heat flux through the outer and inner casing pipe surface is less than 10%, and the accuracy of the quasi-steady-state simplified heat transfer model is good. The computation time of the simplified model is less than 1% of the calculation time by the numerical model. The simplified model is highly efficient and easy to be integrated with building thermal and humidity software package for simulation analysis.