【摘要】 基于CFD-DPM模型研究定热流壁面条件下二维微槽道内相变微胶囊悬浮液的层流对流换热特性,并结合DSC测试结果采用等效比热模型对相变微胶囊相变特性进行表征,和水的特点进行对比,讨论了相变微胶囊质量分数、有无壁面热阻等因素的影响。结果发现:相变微胶囊悬浮液冷却特性明显优于单质水,并且随着质量分数的增加,模拟相变融化区长度不断增加,最大强化率可达15.7%;从模拟结果中可以明显看出:由于存在微胶囊的相变吸热,流体温度明显低于单质水,平均流体温度明显降低。当存在相变微胶囊颗粒壁面热阻时,换热强度明显小于无壁材情况,对比有无壁面热阻情况下,结果可以发现当存在壁面热阻时,其融化起始点要晚一点,但是对相变吸热的效果影响不大。更多还原

【Abstract】 Based on the CFD-DPM model, which is by studying the laminar-flow convective heat transfer characteristics of microencapsulated phase change material suspension in two-dimensional micro-channel in the condition of constant heat flow wall. The phase change characteristics of microencapsulated phase change material by using the equivalent specific heat model in combination with DSC test results. By comparing with the characteristics of water, the effects of microencapsulated phase change material mass concentration, thermal wall resistance and other factors were analyzed. The results show that the cooling characteristics of microencapsulated phase change material suspension are obviously better than that of elemental water. With the increase of mass fraction, the length of the simulated phase change melting zone continuously increases, and the maximum strengthening rate will increase to 15.7%. It can be found clearly that the fluid temperature is obviously lower than that of elemental water because of the existence of the endothermic heat of microcapsules, and the average fluid temperature is obviously decreased. When the thermal resistance of the microencapsulated phase change material particle wall material exists, the heat transfer intensity is obviously smaller than that of the non-wall material. By comparing the presence or absence of the thermal resistance of the wall surface, it can be found when the thermal resistance of the wall surface exists, little impact on the phase change endothermic effect.更多还原