石蜡与低熔点合金双级联相变材料强化板翅式散热器换热性能的数值模拟

Numerical simulation of heat transfer performance of plate-fin radiator reinforced with double cascade phase change material of paraffin and low melting point alloy

相变散热技术可以通过相变材料的物态变化,有效吸收或释放热量,从而实现被动式热管理。本文建立了一种板翅式相变散热器的结构模型,研究级联相变技术的相变传热过程及优化传热性能的措施,重点分析了相变材料(PCM)的组合方式、翅片结构以及不同的PCM体积比工况对相变散热器传热性能的影响。研究结果表明,改变PCM的组合方式对相变材料传热过程有显著影响,对于采用双PCM的级联相变散热器,PCM1和PCM2呈相变温度递减排列具备更优的热管理性能;当翅片数为16时,具备更低的工作温度,并且相比于四翅片结构的相变散热单元,两种级联PCM组合的相变散热单元的凝固时间分别缩短了25.3%和22.5%。因此,当翅片数为16及翅片厚度为0.5 mm时,热管理性能较优;采用石蜡和低熔点合金材料,当PCM体积比为1∶2时,两个临界温度下的热管理时间分别延长了17.2%和15%,温升速率也随着低熔点合金所占体积增多而逐渐减小,综合考虑热管理时间和温升速率,可知PCM体积比为1∶2时级联相变散热器的热管理性能较优。

This article focuses on the relationship between phase change materials(PCMs),fin structures,and various PCM volume ratio working conditions on the heat transfer performance of the phase change radiator.We developed a plate-fin phase change radiator model to study the phase change heat transfer process of cascade phase change technology and measures to optimize the heat transfer performance.The results show that changing the combination of PCMs significantly influences the heat transfer process of PCMs.For a cascaded phase change radiator with dual PCMs,PCM1 and PCM2 are arranged with decreasing phase change temperatures for optimal thermal management performance.Compared with 4-fin units,16 fins yield lower operating temperatures and 25.3% and 22.5% shorter solidification times for the two cascaded PCM combinations of phase change cooling units.Moreover,the thermal management performance is optimal under the setting of 16 fins with a fin thickness of 0.5 mm.Using paraffin and low melting point alloy materials,when the PCM volume ratio is 1∶2,the thermal management times at two critical temperatures are prolonged by 17.2% and 15%,respectively,and the temperature rise rate also decreases gradually with an increase in the volume occupied by the low melting point alloy.Considering the thermal management time and temperature rise rate together,the thermal management performance of the cascaded phase change radiator is optimal when the PCM volume ratio is 1∶2.