| 摘要: |
| 针对潜热蓄热装置内部相变材料（PCM）导热系数偏小，蓄热速率过低的问题，对基于复合相变材料的两级串联式梯级蓄热装置的相变过程进行了数值研究。通过对不同热物性PCM工况的对比与分析，得到了装置在不同工况下的蓄热特性。结果表明，存在最佳的热扩散系数，使固定熔点的PCM实现“均匀等速相变”。同时，增大PCM的热扩散系数可以有效降低加热面温度，但随着热扩散系数的增大，加热面温度降低幅度减小。通过分析Stefan数，得到了装置最佳的参数，使工况蓄热效果最佳。最后，通过Stefan数为2.88时的实验工况验证了相关规律的正确性。 |
| 关键词: 蓄热特性 梯级蓄热 复合相变材料 热扩散系数 |
| DOI： |
| 投稿时间：2019-05-29 修订日期：2019-07-16
|
| 基金项目:国家自然科学基金（11472295）项目资助。 |
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| A Study on the Heat Storage Characteristics of Cascade Heat Storage Based on Composite Phase Change Material |
| Guo Shaozhen,Xiao Guangming,Zhang Nan,Du Yanxia,Wang Xian |
| (State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi’an Jiaotong University; Shaanxi Key Laboratory of Environment and Control for Flight Vehicle;China Aerodynamics Research and Development Center, State Key Laboratory of Aerodynamics) |
| Abstract: |
| The thermal conductivity of phase change materials (PCM) within latent heat storage devices is small and the rate of heat storage is low, which is problematic to the widespread utilization of latent heat storage devices. Consequently, the phase change process of a two-stage series cascade heat storage device based on composite phase change materials was numerically studied. By comparing and analyzing the results of different PCM with different thermal properties, the heat storage characteristics of the device were obtained. The results show that there is an optimal thermal diffusivity, so that the PCM with fixed melting point achieves "a uniform constant-velocity phase change". At the same time, increasing the thermal diffusivity of the PCM can effectively reduce the heating surface temperature, but the decline in heating surface temperature was minimized with a continuous increase in thermal diffusivity. By analyzing the Stefan number, the optimal parameters of the device were obtained. Finally, the correctness of the rule was verified by an experimental study when the Stefan number was 2.88. |
| Key words: heat storage characteristics cascade heat storage composite phase change material thermal diffusivity |
