[关键词]
[摘要]
针对管壳式相变蓄热器换热速率较慢的问题,建立多管束大空间相变蓄热器模型数值模拟的研究换热管排列方式及翅片参数对换热效果的影响。通过观察温度和速度场、固液相界面、Nu及液相分数与时间的关系,分析蓄/放热传热过程。研究结果表明:采用正三角排列可增强换热管间热扰的影响,提高相变材料(phase change material,PCM)熔化速率;蓄热过程中传热以自然对流为主,放热过程中传热以导热为主;合理调整不同位置换热管节距,可改善蓄热器温度分布均匀性;适当增加翅片数量及高度有利于提高PCM换热速率,蓄热器最佳翅片数量为8组,高度为25 mm。
[Key word]
[Abstract]
Aiming at the slow heat transfer rate of shellandtube phase change accumulator,the phase change accumulator model with multitube bundles and large space was built to numerically simulate and investigate the influence of heat exchange tube arrangement and fin structure parameters on the heat transfer effect. The heat transfer process of heat accumulation and release was analyzed by observing the variations of temperature and velocity fields, solidliquid interface, Nu number and liquid phase fraction with time. The research results show that the use of positive triangular arrangement can enhance the influence of thermal disturbance between heat exchanger tubes and improve the melting rate of phase change material (PCM).The heat transfer in the heat accumulation process is mainly natural convection, and the heat transfer in the heat release process is mainly heat conduction. Reasonable adjustment of the heat exchanger tube pitch in different spatial positions can improve the temperature distribution uniformity inside the heat accumulator. The appropriate increase in the number and height of fins is beneficial to improve the heat transfer rate of PCM. The optimal number of fins for the accumulator is 8 groups, and the height is 25 mm.
[中图分类号]
TK124
[基金项目]
陕西省重点研发计划(2020GY-133)