石蜡/泡沫铝复合相变材料对太阳池热性能的影响

Effect of paraffin/aluminum foam composite phase change materials on thermal performance of solar pond

传统盐梯度太阳池以显热储热,储热密度较低。提出了在储热层添加石蜡/泡沫铝复合多孔介质相变层的方法,构建了宽度为300mm,长度为400mm,深度为500mm的小型实验太阳池,分别进行了传统盐梯度太阳池和添加石蜡/泡沫铝复合多孔介质相变材料(PCM)的太阳池热性能对比实验。实验研究与理论分析表明:未添加石蜡/泡沫铝复合PCM的下对流层(LCZ)的储存(火用)和(火用)效率的最大值分别13.814 MJ/m^(3)与9.38%;添加4块石蜡/泡沫铝复合PCM的LCZ的储存(火用)和(火用)效率的最大值分别为15.659 MJ/m^(3)与12.05%,同前者对比分别提高了1.845 MJ/m^(3)与2.67%,从而证明石蜡/泡沫铝复合PCM能够有效提高LCZ的储存(火用)与(火用)效率。此外,后者在太阳池LCZ的温度上升期可使其温度提高3℃左右,因此,添加石蜡/泡沫铝复合PCM能够提升太阳池LCZ的蓄热能力。

Traditional salt gradient solar ponds storage heat by sensible heat and show low heat storage density.An approach which is adding a paraffin/foam aluminum composite porous medium phase change materials layer to the Lower Convective Zone(LCZ)is proposed.A small experimental solar pond with a width of 300 mm,a length of 400 mm and a depth of 500 mm is constructed.The thermal performance of the traditional salt gradient solar pond and the experimental solar pond are compared.Experimental research and theoretical analysis show that the maximum storage exergy and exergy efficiency of LCZ without paraffin/aluminum foam composite PCM are 13.814 MJ/m^(3) and 9.38%,respectively,while the corresponding values of LCZ added with four layers of composite PCMs are 15.659 MJ/m^(3) and 12.05%,respectively,which are 1.845 MJ/m^(3) and 2.67%higher than those of the former,indicating that paraffin/aluminum foam composite PCM can effectively improve the storage exergy and exergy efficiency of solar ponds.In addition,the latter can increase the temperature by about 3℃during the temperature rise period of LCZ.Therefore,the addition of paraffin/aluminum foam composite PCM can improve the heat storage capacity of solar ponds.