相变蓄能墙多因素热特性分析及优化研究

Multivariate Thermal Performance Analysis and Optimization for Phase Change Thermal Storage Wallboard

建筑围护结构的热损失是建筑内部热量散失的主要途径。与传统墙体保温材料不同,相变蓄能技术可以利用潜热蓄能达到数倍于普通围护结构的蓄热和热惰性效果。该文针对我国北方地区夏季蓄冷,利用热焓法建立相变蓄能墙体物理模型并进行数值模拟,通过蓄热量、延迟性及熔化过程3个指标为依据来分析相变蓄能墙的因素影响特性。结果表明:夏季相变材料层设置在室内侧位置更有利;随着室内对流换热系数的增大,相变材料层的蓄热量随之增大,而延迟时间减小;相变材料层存在蓄热性能最优的最佳厚度;墙体材料和厚度的选择同样起到关键性作用,墙体材料厚度越大反而越不利于相变材料的蓄热性。该文所得出的优化结论对相变墙结构的优化与应用提供参考。

Heat transmitting through the building envelope was the main route of internal building heat loss. It was different from the traditional wall insulation materials, because phase change energy storage technology could achieve much better effects on heat storage and thermal inertia by using latent heat of PCM than ordinary building envelopes. Aiming at cold storage in the summer of North China, a physical model of phase change heat storage wallboard （PCHSW） was built through an enthalpy method and its numerical simulation was conducted in this paper as well. Factors affecting thermal characteristics of PCHSW were analyzed based on three indexes, i. e. , heat storage capacity, lag time and melting process. According to results, the indoor side was the best position for PCM layer in summer; the heat storage capacity of PCM was enhanced and lag time of PCM reduced with the increase in indoor convective heat transfer coefficient; there was an optimum thickness of the PCM layer based on which the largest heat storage capacity could be achieved ; the material type and thickness of wallboard also played a key role, and the heat storage capacity reduced with the thickness of wallboard increasing. Optimization conclusions in this paper provided referenced to the improvement and application of phase change wallboard structure.