低温相变蓄冷纳米流体成核过冷度的实验研究

Experimental Study on Super-cooling Degree of Nanofluids for Cryogenic Cool Storage

在共晶盐BaCl2水溶液中添加亲水性分散剂,经过超声振动制备了粒径为20nm四种不同体积分数的TiO2_BaCl2_H2O纳米流体。对BaCl2水溶液和纳米流体同步进行蓄冷实验,实验表明:加入纳米TiO2粉体后,可大幅度降低BaCl2水溶液的结晶成核过冷度,并且纳米流体的起始成核时间比BaCl2水溶液提前,结晶结束所花时间也要大大少于BaCl2水溶液。最后对纳米粒子影响基液的结晶机理进行了分析。

Four different concentration TiO2-BaCl2-H2O nanofluids with 20nm TiO2 were prepared by supersonic oscillator through adding hydrophilic dispersant into BaCl2 solution. BaCl2-H2O and TiO2-BaCl2-H2O nanofluids were tested experimentally. The results show that nanofluids have remarkably lower supercooling degree than BaCl2-H2O, and the beginning nucleation time of nanofluids is ahead of BaCl2-H2O. Moreover, their crystallization time is lower than that of BaCl2-H2O. Also, the crystallization mechanism was analyzed for the influence of the nano TiQ2 particles on BaCl2-H2O.