高效节能低过冷高导热相变蓄冷材料

High Efficiency and Energy Saving Phase Change Cold Storage Material with Low Undercooling and High Thermal Conductivity

传统冰蓄冷的蓄冷系统其制冷温度通常需要达到-10℃左右,若使用相变温度高于冰的材料作为相变蓄冷材料,可提升制冷系统的蒸发温度,从而提升蓄冷系统整体能效。四丁基溴化铵(TBAB)水溶液是一种可替代冰的相变蓄冷材料,相变温度分布在5~15℃范围内,可与双工况及单工况空气源热泵机组联用,与常规冰蓄冷相比可大大提高蓄冷整体能效。但TBAB水溶液相变过程具有过冷度大,导热性较低等问题。将提出一种基于有机-无机纳米掺杂工艺,采用分散改性导热鳞片石墨与花状纳米氧化铝作为改性材料的低过冷高导热相变蓄冷材料制备方法。蓄冷材料可与空气源热泵联用,相变温度区间为6~12℃,相变焓为157.3 J/g,过冷度不大于2℃,导热率与未改性前相比提升70%以上。

The refrigeration temperature of the traditional ice storage system usually needs to reach about-10 ℃. If the material with phase change temperature higher than ice is used as the phase change cold storage material, the evaporation temperature of refrigeration system can be increased, so as to improve the overall energy efficiency of the cold storage system. Tetrabutylammonium bromide(TBAB) aqueous solution is a phase change cold storage material that can replace ice, and the phase change temperature is within the range of 5~15 ℃. TBAB aqueous solution is suitable for dual-condition and single-condition air source heat pump units. Compared with conventional ice storage, it can greatly improve the overall energy efficiency of cold storage. However, the phase change process of TBAB aqueous solution has problems such as high undercooling and low thermal conductivity. A method for preparing a phase change cold storage material with low undercooling and high thermal conductivity is proposed, based on organic-inorganic nano-doping process, using dispersed modified thermally conductive flake graphite and flower-like nano alumina as modified materials. The cold storage material can be used in combination with an air source heat pump. The phase change temperature range is 6~12 ℃, the phase change enthalpy is 177.3 J/g, the undercooling degree is less than 2 ℃, and the thermal conductivity is increased by more than 70% compared with the unmodified one.