Abstract:

As a potential material for thermal energy storage and thermal management, phase change material (PCM) has a reasonable energy storage density and a negligible temperature variation, where undergoing low thermal conductivity leads to poor thermal transfer efficiency. In this study, copper foam was used to enhance the thermal properties of paraffin. By measuring the temperature variation during the heating and cooling process of PCM, the effect of adding copper foam on the heat storage and release rate and temperature uniformity was investigated. On the basis of experiments, the heat release model of PCM was established and solved, and the temperature cloud diagram was obtained which could provide better guidance for the practical applications of PCMs. The results showed that after adding copper foam, the latent heat storage and release time of paraffin were reduced by 16.67% and 14.71%, respectively. The maximum temperature difference between the center point of the center layer and the outer layer during the heating and cooling process was reduced by 91.5% and 87.5%, respectively. The model of temperature change with time in the exothermic process of PCM was established. The correlation coefficient and standard error were 0.99℃ and 0.13℃, respectively by comparing the actual value with the predicted value, which proved that the model had high accuracy and could effectively predict the temperature change of PCM.

Key words: phase change, paraffin, copper foam, heat conduction, numerical simulation

摘要：

作为储热和热管理技术的重要材料之一，相变储能材料通常具有储热密度较大、相变温度变化较小的优势，但其热导率较低，热传递效率较差。本文将泡沫铜用于石蜡相变储能材料的传热强化，通过测定相变储能材料储放热过程的温度变化，考察了添加泡沫铜对相变储能材料储放热速率和温度均匀性的影响，且在实验基础上对储能材料的放热过程进行建模并求解，得到温度云图，为实际应用提供理论依据。结果表明，添加泡沫铜后，石蜡的相变储热和放热时间分别缩短了16.67%和14.71%；储放热过程复合材料中心层与外层中心点的最大温差分别降低了91.5%和87.5%；建立放热过程相变储能材料温度随时间变化的模型，对比实际值和模型预测值，得到相关系数及标准误差分别为0.99℃和0.13℃，证明该模型准确度较高，可有效预测相变储能材料的温度变化情况。

关键词: 相变, 石蜡, 泡沫铜, 传热, 数值模拟