根据轨道车辆空调储能的要求,选择固-固相变石蜡作为储能材料,但石蜡存在导热系数较低、传热性能差的缺点。为了提高石蜡的导热性,缩短相变时间,使之达到轨道车辆对放冷时间的要求,在固-固相变石蜡中分别添加质量分数3%、5%、10%的氧化钛纳米粒子和氧化铝纳米粒子制备了组成不同的复合相变材料。采用差示扫描量热仪和稳态导热系数测试仪研究了复合相变材料的相变性能和导热性能。结果表明:组成不同的复合相变材料的相变温度均在19～21℃之间,满足轨道车辆空调储能的要求;添加纳米金属粒子在一定程度上可以提高相变材料的导热系数。

According to the requirements of energy storage for rail vehicle air-conditioning systems,solid-solid phase change paraffin was selected as energy storage material.However,paraffin had the disadvantages of low thermal conductivity and poor heat transfer performance.In order to improve the thermal conductivity and shorten phase transition time to meet the requirement of cooling time for railway vehicles,titanium oxide nanoparticles and alumina nanoparticles with mass fractions of 3%,5% and 10% were added into paraffin to prepare different composite phase change materials.The phase change properties and thermal conductivity of the materials were studied by differential scanning calorimeter and steady-state thermal conductivity tester.The results shown that phase transition temperatures of the materials were between 19～21℃,which met the requirements of air conditioning and energy storage for rail vehicles.The thermal conductivity of the materials can be improved to some extent by adding metal nanoparticles.