不锈钢球封装相变材料太阳能热水系统性能实验研究
Experimental studies on phase change material packaged in stainless steel balls for solar hot water system
摘要：
对居住建筑集中式太阳能热水系统的蓄放热性能进行了研究，选取直径为60 mm的不锈钢球封装添加膨胀石墨的石蜡相变材料，对比了相变温度为55 ℃和60 ℃的相变材料在不同太阳辐照量情况下的相变水箱蓄热、放热和保温性能。以用户日最大需求为基准，对太阳能保证率进行了计算。结果表明：热水系统的蓄热时间为2.0～4.5 h；55 ℃和60 ℃相变材料对应的太阳能保证率平均值分别为75%和80%，相变蓄热效果好于无蓄热工况，且相变蓄热使系统的太阳能保证率有明显提升；相变温度为60 ℃的材料较适用于集中式太阳能热水系统。
Abstract：
Studies the heat storage and release performances of centralized solar hot water system of a residential building. Packages the phase change material (PCM) of paraffin with expanded graphite in stainless steel balls with a diameter of 60 mm. Compares heat storage and release and heat insulation performances of two PCMs with a phase-transition temperature of 55 ℃ and 60 ℃ under different solar radiation. Calculates the solar fraction based on the maximum day demand of users. The results show that the heat storage time of the hot water system is 2.0 to 4.5 hours. An average solar fraction is 75% and 80% for PCMs with a phase-transition temperature of 55 ℃ and 60 ℃, respectively. Phase change heat storage can enhance the solar fraction and is better than that without heat storage. PCMs with a phase-transition temperature of 60 ℃ is suitable for centralized solar hot water systems.
Keywords:solar hot water system, phase change material, stainless steel ball, heat storage, heat release, thermal insulation, solar fraction