固体蓄热砖孔道结构参数对蓄/释热性能的影响

Influence of Pore Structure Parameters of Solid Thermal Storage Bricks on the Heat Storage/Release Performance

电加热固体储能供热装置通过将低谷电转化为热能,可以实现电力调峰,对减少环境污染、提高能源利用率具有十分重要的意义.结合工程实际中的蓄热砖结构,基于流固耦合换热原理,对不同孔道结构固体蓄热单元的蓄/释热过程进行仿真研究,分析和比较了蓄热砖孔道结构和进口空气流速等参数对蓄热单元蓄/释热性能的影响.模拟结果发现:与不加矩形孔道的蓄热单元相比,在蓄热阶段,添加矩形孔道的蓄热单元的平均温度和温升速率降低,与空气的换热量增加.在释热阶段,添加矩形孔道的蓄热单元的温降速率增加,与空气的换热量增加,热量释放更充分;在蓄/释热过程中,随着矩形孔道宽高比增加,蓄热单元的温度分布更加均匀;在释热过程中,进口空气流速和矩形孔道宽高比越小,释热速度越慢,所需释热时间越长.当进口空气流速为1.5 m/s时,模型1释热33.5 h,模型4释热18.2 h.

The solid thermal storage device with the electric heating can realize power peak shaving by converting low-valley electricity into heat energy, which is of great significance to reducing environmental pollution and improving energy utilization. Based on the principle of fluid-solid coupling heat transfer, the thermal storage/release process of solid heat storage units with different pore structures were simulated, and the effects of parameters such as the duct structure of heat storage brick and inlet air velocity on the thermal storage/release performance of heat storage units were analyzed and compared. The simulation results show that compared with the heat storage units without rectangular channel, the average temperature and temperature rise rate of the heat storage units with rectangular channel decrease, and the heat exchange with air increases. In the heat release stage, the temperature drop rate of the heat storage units with rectangular channel increases, the heat exchange with air increases, and the heat release is more sufficient. In the process of thermal storage/release, with the increase of the width to height ratio of rectangular channel, the temperature distribution of heat storage units becomes more uniform. In the process of heat release, the smaller the inlet air flow rate and the width to height ratio of rectangular channel, the slower the heat release rate, the longer the heat release time is. When the inlet air velocity is 1.5 m/s, the heat release of model 1 is 33.5 h, and that of model 4 is 18.2 h.