Research On The Crystalline Hydrated Salt Phase Changing Material

In CaCl2·6H2O system, added2.0wt%borax, barium carbonate, magnesium chloride hexahydrate, sucrose, the degree of subcooling averages taken after1,10,20cycling were6.85℃,7.84℃,9.76℃,9.66℃, compared with the control group AR system,were reduced by23.89%,12.89%,-8.4%,-7.3%, thus borax is ideal over-refrigerant for the system. The results of industrial-grade samples of their best amount of borax added(the degree of accuracy to0.1%),for the Shandong Haihua sample, the optimal dosage were1.6wt%borax, made the degree of subcooling at6.02℃; Lianyungang crown Su Industrial samples optimal dosage were2.4wt%, made the degree of subcooling at6.20℃. Experiments performed at the optimum amount of addition (2.4wt%borax) in cycle of the crown Su Industrial samples, in white carbon, black carbon black, starch, sucrose, the best effect of anti-phase separation is black carbon black, in800times per cycle, no significant phase separation occured, followed by silica, effectively delay the phase separation,of sucrose and starch, system already complete phase separation in the circulation of about600times, contributes to the loss of a phase change energy storage capacity. DSC tests show that in the optimal amount of addition of borax enthalpy of CaCl2·6H2O was120.51J/g.For mirabilite system, added2.0wt%of urea, borax, anhydrous magnesium chloride, sucrose,the average of the degree of subcooling of the system after1,10,20cycles were17.00℃,6.08℃,9.27℃,17.24℃,compared with the control group,were reduced by8.06%,67.09%,49.86%,6.76%, The results of industrial-grade samples of their best amount of borax added(the degree of accuracy to0.1%),for Chuanmei, the optimal dosage were2.6wt%borax,the degree of supercooling was4.93℃; for Jinan Devant chemical samples as2.2wt%, so that the degree of supercooling down to4.13℃. In the experiment, the anti-phase separation cycle best remains black carbon black, in the cycle of800times or so, without significant phase separation occurs, followed by silica, sucrose and starch still in poor performance, in700cycle times already completed the full phase separation, contributing to the loss of phase change energy storage capacity, at which the degree of supercooling peaked at about18℃. DSC tests show that the enthalpy at optimal amount of addition of borax was156.56J/g.For potassium alum crystal system, added2.0wt%of NiSO4·6H2O、Mg(NO3)2·6H2O、 MgCl2, sucrose,the average of the degree of subcooling of the system afterl,10,20cycles were9.16℃、6.56℃、8.00℃、8.75℃,compared with the control group,were reduced by 7.29%、33.60%、19.03%、11.44%, The results of industrial-grade samples of their best amount of Mg(NO3)2·6H2O added(the degree of accuracy to0.1%),for Qidi, the optimal dosage were3.0wt%borax,the degree of supercooling was4.74℃; for Huayang samples as1.4wt%, so that the degree of supercooling down to5.17℃. In the circulation experiment, after500cycles, no significant phase separation phenomena was observed,which confirms the literature proposal on otassium alum crystal system.