管束式相变蓄热器的蓄放热性能分析

Analysis of heat storage and release performance of tube bundle phase change heat accumulator

建立多排管束式相变储热单元模型,数值模拟了方腔中不同管子数量、不同排列方式以及不同管壁温度对相变储热单元蓄放热性能的影响。结果表明,在保持填充PCM数量不变及其他相同约束条件下,随着管子数量增加即排列方式改变时,可以增强自然对流作用,增大圆管与周围流体传热面积,而且其对应的液相曲线初期几乎呈线性变化,随着管子数量的增加,曲线斜率逐渐增大。表明排列方式的改变可以加快PCM熔化和凝固过程,大大提高其蓄放热性能。此外管壁温度对蓄放热性能也存在重要影响,但随着管壁温度的升高,影响逐渐减弱。

The model of multi row tube bundle phase change heat storage unit is developed,and the effects of a varying number of tubes in the square cavity,as well as various arrangement approaches and tube wall temperatures on the heat storage and release of phase change heat storage unit are numerically simulated.The findings reveal that the natural convection can be improved and the heat transfer area between the circular tube and the surrounding fluid can be increased,with an increasing number of tubes,that is,the change of the arrangement mode and the corresponding liquid phase curve almost changes linearly at the first,and the curve’s slope increases gradually with the number of tubes’increase.The findings reveal that the arrangement’s change can hasten the melting and solidification process of PCM and substantially improve its heat storage and release performance.Additionally,the pipe wall temperature also has a crucial effect on the heat storage and release performance,but the influence decreases with the pipe wall temperature’s increase.