石蜡基复合相变材料的研究及在热泵系统中的应用
发布时间：2018-09-04 10:00
【摘要】：本文的主要目的是开发一种新型复合蓄冷材料和蓄热材料应用于空气源-太阳能双热源热泵。通过理论分析、实验研究和数值模拟相结合的方法对石蜡基复合材料进行了研究。制备了分别作为蓄冷材料和蓄热材料的不同质量分数的石蜡基碳纳米管复合材料和石蜡基纳米铝粉复合材料,用DSC差热分析仪表征复合材料的相变特性,导热系数仪测试材料的导热系数,经过20次熔化凝固循环判断复合材料的热稳定性。实验表明采取浓硝酸酸化碳纳米管,超声震荡10min并且添加分散剂十二烷基苯磺酸钠的分散方法,碳纳米管质量分数为0.1%的石蜡(RT6)基复合材料稳定性很好,导热系数为0.487W/(m·K)(固态)和0.262W/(m·K)(液态),较纯石蜡(RT6)提高了21.1%和29.1%。质量分数为0.5%的稳定性较好的石蜡基(RT6)纳米铝粉复合材料,导热系数可以增加到0.513W/(m·K)(固态)和0.277W/(m·K)(液态),相变温度为5~8℃,相变焓为155.3~161.6kJ/kg,是一种较好的蓄冷材料。作为蓄热材料的质量分数为0.5%的石蜡基碳纳米管复合材料和石蜡基纳米铝粉复合材料的导热系数值分别为0.341W/(m·K)和0.359W/(m·K),相比纯石蜡提高了26.1%和32.2%,相变温度和相变焓的变化很小。将研究的新型复合材料在双热源热泵蓄能换热器里的熔化和凝固过程进行了数值模拟,对比纯石蜡的熔化凝固过程,导热系数较大的复合材料使得蓄能箱内蓄冷、释冷和释热时间都有减少。
[Abstract]:The main purpose of this paper is to develop a new composite heat storage material and heat storage material for air source solar dual heat source heat pump. Paraffin-based composites were studied by theoretical analysis, experimental study and numerical simulation. Paraffin based carbon nanotube composites and paraffin based aluminum nanocomposites were prepared as thermal storage materials and thermal storage materials, respectively. The phase transition characteristics of the composites were characterized by DSC differential thermal analyzer. The thermal conductivity of the composites was measured by a thermal conductivity meter, and the thermal stability of the composites was evaluated after 20 cycles of melting and solidification. The results showed that the stability of paraffin (RT6) matrix composites with 0.1% mass fraction of carbon nanotubes was very good by using the dispersion method of concentrated nitric acid acidified carbon nanotubes (CNTs), ultrasonic oscillating 10min and adding sodium dodecylbenzene sulfonate as dispersant. The thermal conductivity is 0.487W/ (m K) (solid) and 0.262W/ (m K) (liquid), which is higher than that of pure paraffin (RT6) by 21. 1% and 29. 1%. The paraffin-based (RT6) nano-aluminum powder composites with 0.5% mass fraction have better thermal conductivity to 0.513W/ (m K) (solid) and liquid (0.277W/ (m K) (). The phase transition temperature is 5 ~ 8 鈩，
本文编号：2221755
[Abstract]:The main purpose of this paper is to develop a new composite heat storage material and heat storage material for air source solar dual heat source heat pump. Paraffin-based composites were studied by theoretical analysis, experimental study and numerical simulation. Paraffin based carbon nanotube composites and paraffin based aluminum nanocomposites were prepared as thermal storage materials and thermal storage materials, respectively. The phase transition characteristics of the composites were characterized by DSC differential thermal analyzer. The thermal conductivity of the composites was measured by a thermal conductivity meter, and the thermal stability of the composites was evaluated after 20 cycles of melting and solidification. The results showed that the stability of paraffin (RT6) matrix composites with 0.1% mass fraction of carbon nanotubes was very good by using the dispersion method of concentrated nitric acid acidified carbon nanotubes (CNTs), ultrasonic oscillating 10min and adding sodium dodecylbenzene sulfonate as dispersant. The thermal conductivity is 0.487W/ (m K) (solid) and 0.262W/ (m K) (liquid), which is higher than that of pure paraffin (RT6) by 21. 1% and 29. 1%. The paraffin-based (RT6) nano-aluminum powder composites with 0.5% mass fraction have better thermal conductivity to 0.513W/ (m K) (solid) and liquid (0.277W/ (m K) (). The phase transition temperature is 5 ~ 8 鈩，
本文编号：2221755
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