三维Y肋相变蓄热器的热性能数值模拟及分析

Numerical Simulation and Analysis of Thermal Performance of a Three-Dimensional Y-Ribbed Phase Change Heat Accumulator

摘要: 运用数值模拟的方法，研究了三维Y型肋片不同分布时模型对相变蓄热器蓄放热过程以及入口流速对蓄热过程的影响。结果表明：首先，在轴向不同位置处，蓄放热过程有明显差异，特别是蓄热过程；其次，Y型肋片越向底部聚集，自然对流持续时间越长，蓄热效果越好；在蓄热过程中，模型5 (30˚ Y型肋片模型)相比于模型2 (72˚ Y型肋片模型)蓄热时间缩短了19.01%，在放热过程中，模型2、模型3、模型4和模型5相比于模型1放热时间分别缩短了67.77%、44.39%、22.65%和12.20%。最后，提高换热流体入口流速可明显缩短熔化时间，但对蓄热速率的增大程度有一定范围。当入口速度大于0.1 m/s时，入口速度对熔化时间的影响显著降低。

Abstract: Using the method of numerical simulation, the effects of the model with different distribution of three-dimensional Y-shaped fins on the heat storage and release process of phase change heat storage unit and the inlet velocity on the heat storage process were studied. The results show that: firstly, there are obvious differences in the heat storage and release process at different axial posi-tions, especially in the heat storage process; Secondly, the more Y-shaped fins gather to the bottom, the longer the duration of natural convection, and the better the heat storage effect; In the heat storage process, the heat storage time of model 5 (30˚ Y-rib model) is shortened by 19.01% com-pared with model 2 (72˚ Y-rib model), and in the heat release process, the heat release time of model 2, model 3, model 4 and model 5 is shortened by 67.77%, 44.39%, 22.65% and 12.20% re-spectively compared with model 1. Finally, increasing the inlet flow rate of heat exchange fluid can significantly shorten the melting time, but it has a certain range for the increase of heat storage rate. When the inlet velocity is greater than 0.1 m/s, the effect of inlet velocity on melting time de-creases significantly.