不同球径的多孔球层内无机盐溶液过冷度的实验研究

Experimental investigation on inorganic salt solution's supercooling degree under porous spherical layer with different spherical diameters

无机盐溶液的过冷度极大地影响了相变材料的蓄冷特性。实验以NH4Cl溶液为例,研究了浓度与多孔介质对无机盐溶液的过冷度影响机理。通过改变无机盐溶液浓度与构建多孔介质小球的球径,探究无机盐溶液强化传热传质的方法。实验结果表明:浓度越高,无机盐溶液过冷度越低,离散程度越低,稳定性越高。当浓度达到15%时,溶液平均过冷度较5%浓度溶液可降低17.5%。构建多孔介质小球球径越小,无机盐溶液过冷度越低,离散程度越低,稳定性越高。当球径为5 mm时,溶液平均过冷度较无多孔介质情况下可降低21.7%。

The supercooling degree of inorganic salt solution has great effect on the characteristic of the phase change meterials in cool storage. Ammonium chloride solution was chosen as a kind of inorganic salt solution, the experimental system was built to study the influence on supercooling degree of inorganic salt solution under the effection of concentration and porous media. The method of heat transfer enhancement was studied by changing the concentration of inorganic salt solution and the diameter of balls which is constituting the porous media. The experimental results show that with the increase of concentration, the value of inorganic salt solution＇s supercooling degree and dispersion degree reduced, while the stability increased. Compared with the ammonium chloride solution at the concentration of 5%, the supercooling degree decreased 17.5% when the concentration of chloride solution reached 15%. With the decrease of the diameter of balls which is constituting the porous media, the average value of chloride solution＇s supercooling degree and dispersion degree decreased, while the stability increased. Compared with the ammonium chloride solution without porous media, the average value of chloride solution＇s supercooling degree decreased 21.7% when the diameter of balls was 5 mm.