【摘要】 为了改善相变材料导热系数低的缺陷,提出了一种由套筒-肋片复合结构组成的多层套筒蓄热单元结构。基于焓法模型对多层套筒蓄热单元结构的相变蓄热过程进行了数值模拟,计算结果和实验数据吻合良好。将多层套筒蓄热单元结构与光管蓄热单元结构以及单层套筒蓄热单元结构进行了对比分析,结果表明,相比光管结构,多层套筒蓄热单元结构内相变材料的完全熔化时间极大降低;相比单层套筒结构,多层套筒蓄热单元结构内相变材料的总蓄热量增加了1.5倍,相变材料的完全熔化时间增加了1.4倍。通过分析多层套筒蓄热单元结构的蓄热过程,发现套筒-肋片复合结构存在较大热阻,会影响相变材料的对流传热过程。将多层套筒蓄热单元结构进行开孔得到了多孔套筒蓄热单元结构,多层套筒和多孔套筒蓄热单元结构的蓄热效果对比结果表明,相比多层套筒蓄热单元结构,多孔套筒蓄热单元结构的蓄热面积降低了8%,相变材料的完全熔化时间增加了2.4%。更多还原

【Abstract】 In order to improve thermal conductivity of phase-change materials, a new structure of multi-layer sleeve heat storage unit consisting of sleeve-fin structure was introduced. Numerical simulations based on the enthalpy-porosity model were carried out to study the heat storage process of the multi-layer sleeve heat storage unit, and the numerical results were in good agreement with the experimental data. A comparison with the light tube heat storage unit and the single-layer sleeve heat storage unit was made. The results show that the total melting time of phase-change material of the multi-layer sleeve structure greatly decreases in comparison with the light tube structure. Compared with the single-layer sleeve structure, the total heat storage quantity of phase-change material of the multi-layer sleeve structure increases by 1.5 times and the total melting time of phase-change material increases by 1.4 times. With the heat storage process analysis of the multi-layer sleeve structure, it is found that the sleeve-fin structure had a large thermal resistance and suppressed natural convection of phase-change material. The multi-layer sleeve structure was optimized to obtain the porous sleeve heat storage unit. The heat storage effect of the multi-layer sleeve and porous sleeve structure was compared, the results show that the heat storage area of the porous sleeve structure reduces by 8%,while the total melting time of phase-change material increases by 2.4% in comparison with the multi-layer sleeve structure.更多还原