基于自然冷源的蓄冷材料制备及蓄释冷实验研究  

Preparation of Cold Storage Materials and Experimental Study on Cold Charge and Discharge Based on the Natural Cold Source

作　　者：张润霞 顾兆林(指导)[2] 王赞社[2] 康彦青[3] ZHANG Run-xia;GU Zhao-lin;WANG Zan-she;KANG Yan-qing(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China;City College,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能动学院,西安710049 [2]西安交通大学人居学院,西安710049 [3]西安交通大学城市学院,西安710049

出　　处：《建筑节能（中英文）》2021年第2期86-90,132,共6页Building Energy Efficiency

基　　金：陕西省教育厅科学研究计划项目(19JK0497)。

摘　　要：降低空调能耗是建筑节能的热点问题之一。自然冷源在居住建筑中的主动式应用,可有效降低空调能耗。采用熔融共混加物理吸附方法,以膨胀石墨(EG)为基体,癸酸-月桂酸(CA-LA)低共熔混酸为相变材料,制备了复合相变材料,并对材料热物性进行表征;搭建了叉排管式相变蓄冷实验台,测试复合相变材料封装于换热器后在环境温度下的蓄冷、释冷性能。结果表明,CA∶LA的值为65∶35时材料实现了低共熔,膨胀石墨含量为5.9wt.%时对混酸具有较好的包覆性,CA-LA/EG5.9wt.%的凝固点温度为19.93℃,相变焓值为122.45 kJ/kg。复合材料封装于铜管后,在管间风速为0.5 m/s,蓄冷、释冷入口空气平均温度分别为18.0℃和30.0℃条件下,蓄冷时长为5 h,释冷时长为3 h,蓄冷、释冷过程均能顺利进行。It is well known that there is a need to develop technologies to achieve thermal comfort in buildings lowering the cooling demand. The natural cooling source used in residence can reduce the conventional energy consumption. In this paper,the composite phase change materials was prepared by melt blending and physical adsorption. The expanded graphite( EG) used as matrix and CA-LA eutectic binary mixed acid as phase change materials, and the thermal properties of the materials were characterized. The experimental platform of phase change thermal storage with intercalation tube was established to test the cold charge and discharge performance in natural ambient temperature. The results show that the eutectic occurs when the mass ratio of CA: LA is 65: 35,and the mixed acid is well coated when the content of expanded graphite( EG) is 5. 9 wt.%,and the adsorption between CA-LA and EG is physical adsorption. The freezing point temperature of CA-LA/EG5. 9 wt.% is 19. 93 ℃ and the phase transition enthalpy is 122. 45 kJ/kg. When the phase change materials are encapsulated in copper tubes,the air velocity between the tubes is 0. 5 m/s and the average air temperature at the inlet of cold charge and discharge are 18. 0 ℃ and 30. 0 ℃ respectively,both the process of cold charge and discharge can be carried out smoothly. The cold charge and discharge duration are five hours and three hours when the temperature difference between the gas temperature and the phase change temperature of the phase change materials are 1~2. 5 ℃ and 8~ 11 ℃ respectively. And the accumulated heat transfer during the cooling process indicates that the phase transformation of all phase change materials has occurred in the tube.Also,it is understood that increasing air flow rate can enhance heat transfer and the cold charge duration can be shortened. The free cooling potential can further be increased by reducing the losses and optimizing the design of heat exchanger,the requirement of mechanical air conditioners may totally be eliminated in

关 键 词：自然冷源 相变材料 蓄冷 释冷 实验研究 

分 类 号：TU831[建筑科学—供热、供燃气、通风及空调工程] TK02[动力工程及工程热物理]