新型套管式相变蓄热器结构优化及传热研究

Structure optimization and heat transfer research for new type casing phase change heat sequencer

针对相变材料导热系数小而影响相变蓄热器换热效率的问题,对蓄热器结构进行改进,提出应用三角形直列、同心圆排列、正方形直列和正方形错列4种不同的换热管束排布方式对相变蓄热器的结构性能进行优化及数值模拟。模拟结果表明:换热管束采用正方形直列和正方形错列排布的蓄热器内相变材料熔化所需时间基本相同,同心圆排列所需的融化时间最短;换热管束采用三角形直列排布、正方形直列和正方形错列3种排布方式的蓄热器在蓄热后期会出现死区,与同心圆排列方式相比,其相变材料熔化所需时间分别增加了57.20%、26.47%和26.48%。

The low heat conductivity of the phase change material directly decreases the heat transfer efficiency of the phase change heat exchanger. To solve this problem, the structure of the heat exchanger was improved. Four arrangement methods were applied to optimize the phase change regenerator and carry out numerical simulation, namely the triangular inline, the concentric circles, the square inline and the square misalignment. The simulation results show that, the melting time required for phase change material in the heat exchanger using square inline and square misalignment arrangement is the same, and that for the concentric arrangement is the shortest. With the triangular inline, square inline and square misalignment arrangement, dead zone will appear at later stage of the heat storage, which prolongs the time required for melting of the phase change material, and the melting time increases by 57.20%, 26.47% and 26.48%, respectively, compared with the concentric arrangement.