新型空调蓄冷材料四丁基溴化铵-水相变条件和相变热实验研究

Experiment on Phase Change Conditions and Phase Change Latent Heat of Tetra-n-butyl Ammonium Bromide Aqueous Solutions for Cold Storage

四丁基溴化铵水溶液在适当的浓度范围内可在常规空调冷冻水温区内发生固-液相变,形成半笼水合物,是一种潜在的空调蓄冷理想材料。利用实验室的水合物形成实验装置测量了四丁基溴化铵水溶液固-液相变条件,实验结果表明当溶液的质量浓度低于45%时,相变温度随着溶液浓度的增大而增大,但当溶液浓度超过25%,相变温度增加的幅度减小。四丁基溴化铵水溶液的浓度超过45%后,其固-液相变温度反而下降。利用DSC测量了四丁基溴化铵水溶液的相变热,相变热达到195.9kJ/kg。

Tetra-n-butyl ammonium bromide （TBAB） aqueous solution can form semi-clathrate hydrate at suitable solution concentration and temperature of chilled water at atmosphere pressure. It is a potential solid-liquid phase change material for cold storage in air conditioning systems. The solid-liquid phase change conditions of TBAB aqueous solutions were experimentally measured using the test rig for hydrate formation. The experimental results show that the phase change temperature of the TBAB hydrate increased with the increase of the concentration of the TBAB aqueous solution when the solution concentration was less than 45%, but the increment of the phase change temperature decreased when the TBAB solution mass fraction exceeded 25%. The phase change temperature of the TBAB hydrate decreased with the increase in the concentration of the TBAB aqueous solution when the solution concentration was more than 45%. The phase change latent of the TBAB aqueous solution was measured using the DSC rig and the test result shows that the phase change latent was about 195.9 kJ/kg.