储能科学与技术 ›› 2019, Vol. 8 ›› Issue (2): 326-332.doi: 10.12028/j.issn.2095-4239.2018.0224

• 研究开发 • 上一篇    下一篇

超声波作用下甘露醇相变体系过冷特性

刘璐, 章学来, 陈跃, 张永一川   

  1. 上海海事大学蓄冷技术研究所, 上海 201306
  • 收稿日期:2018-10-15 修回日期:2018-12-04 出版日期:2019-03-01 发布日期:2018-12-06
  • 通讯作者: 章学来。E-mail:xlzhang@shmtu.edu.cn
  • 作者简介:刘璐(1995-),女,硕士研究生,主要研究方向为外场强化蓄冷技术,E-mail:820742177@qq.com
  • 基金资助:
    国家自然科学基金资助项目(51376115);上海市科委项目(16040501600)

Supercooling characteristics of a mannitol based phase change system under a ultrasonic action

LIU Lum, ZHANG Xuelai, CHEN Yue, ZHANG Yongyichuan   

  1. Cool Storage Technology Institute, Shanghai Maritime University, Shanghai 201306, China
  • Received:2018-10-15 Revised:2018-12-04 Online:2019-03-01 Published:2018-12-06

摘要: 相变储能技术作为一种高效的能源利用技术已被应用于冷链行业中。针对水产品微冻储存需要的-2~-3 ℃的温度段,筛选出适宜相变温度的甘露醇相变材料。为了解决甘露醇溶液的过冷问题,研究超声波外场对甘露醇相变体系过冷度的影响,探求超声功率及单双外场作用下甘露醇相变体系的过冷特性。讨论了超声外场作用下的声压模型及其对相变溶液过冷特性的影响。构建了超声外场作用下相变体系过冷特性研究的实验系统,研究发现超声波引起的空化效应可以改变甘露醇相变体系的过冷度。3%甘露醇相变体系和添加了K2SO4的甘露醇相变体系过冷度随着超声功率的增大先减小后增大,当超声功率过大将产生无用空化泡减小空化效应,增大了体系的过冷度。K2SO4甘露醇相变体系,150 W+150 W的双超声外场效果最佳,K2SO4质量分数为1%时过冷度最低为0.8 ℃。碳纳米管水分散剂甘露醇相变纳米流体,50 W+50 W的双超声外场效果最优,当多壁碳纳米管质量分数为0.4%和0.5%时体系过冷度仅为0.1 ℃。

关键词: 甘露醇, 过冷度, 成核剂, 超声功率

Abstract: The mannitol based phase change material has phase transition temperature of 2-3℃ required for micro-frozen storage of aquatic products. Such a material has an issue of supercooling. This article aims to understand the supercooling characteristics of mannitol based phase change system under an ultrasonic action from both single and double external fields. The sound pressure model under the action of an external ultrasonic field and the associated influence on the supercooling characteristics of phase change solution were discussed. An experimental system for studying the supercooling characteristics of the phase change system was constructed. It was found that the cavitation effect caused by ultrasonic waves can change the degree of subcooling of the mannitol based phase change system. The supercooling degree of the 3% mannitol based phase change system and the mannitol phase change system containing K2SO4 decreased first and then increased with an increase in the ultrasonic power. When the ultrasonic power was too high, the use of cavitation bubbles would reduce the cavitation effect, leading to an increased the degree of supercooling. The K2SO4-containing mannitol phase change system showed the best effect under a double ultrasonic field of 150W+150W. When the concentration of K2SO4 was 1%, the degree of supercooling was 0.8℃. For the carbon nanotube water dispersant (TNWDIS) mannitol phase change nanofluid, a 50W+50W double ultrasonic external field effect was optimal at a MWCNT concentration of 0.4% and 0.5%, with a supercooling degree of only 0.1℃.

Key words: mannitol, supercooling, nucleating agent, ultrasonic power

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