储能科学与技术 ›› 2022, Vol. 11 ›› Issue (10): 3123-3132.doi: 10.19799/j.cnki.2095-4239.2022.0229

• 储能材料与器件 • 上一篇    下一篇

十五烷微胶囊潜热型功能流体的制备及其性能

常洋珲(), 孙志高()   

  1. 苏州科技大学环境科学与工程学院,江苏 苏州 215009
  • 收稿日期:2022-04-28 修回日期:2022-06-13 出版日期:2022-10-05 发布日期:2022-10-10
  • 通讯作者: 孙志高 E-mail:2469733974@qq.com;szg.yzu@163.com
  • 作者简介:常洋珲(1997—),男,硕士研究生,主要从事储能技术研究,E-mail:2469733974@qq.com
  • 基金资助:
    江苏省高校自然科学研究重大项目(16KJA480001);苏州市科技计划项目(SS202149);江苏省研究生科研创新计划项目(SJCX20_1093)

Preparation and properties of pentadecane microcapsule latent heat functional fluid

Yanghui CHANG(), Zhigao SUN()   

  1. School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, Jiangsu, China
  • Received:2022-04-28 Revised:2022-06-13 Online:2022-10-05 Published:2022-10-10
  • Contact: Zhigao SUN E-mail:2469733974@qq.com;szg.yzu@163.com

摘要:

为了防止相变过程中材料的泄漏,采用原位聚合法制备了以十五烷(Pen)为芯材,脲醛树脂(UF)为壁材的低温相变微胶囊。研究了升温速率、聚合pH值和聚合转速对微胶囊制备的影响,采用SEM、FT-IR、DSC和马尔文激光粒度仪测试了微胶囊的形貌、化学构成、热力学性质和粒径分布。升温速率为1.0 ℃/min、聚合pH值为3.5和聚合转速500 r/min为十五烷微胶囊的最佳制备条件,在此条件下制备的微胶囊球形形貌明显,表面光滑,仅有少数UF颗粒粘附,粒径分布均匀,相变温度和相变潜热分别为8.20 ℃和115.3 J/g,平均粒径为50.0 μm,包裹率达到77.3%。实验结果表明,芯材和壁材仅为简单的物理嵌合,具有良好的储热性能和热稳定性。以不同质量分数的乙醇溶液为基液分散十五烷微胶囊,采用24 h静置实验得到了稳定的潜热型功能流体(LHFF),LHFF在乙醇含量为70%的基液中最为稳定。采用导热系数测定仪和旋转黏度计对LHFF的导热率和黏度进行测试分析表明,LHFF的导热率随着温度的升高而增加,随着微胶囊的添加量的增加而逐步降低。LHFF的黏度随着温度的升高而逐步减小,随着微胶囊的添加量增加而逐步升高。潜热型功能流体作为空调系统的载冷剂,提高了制冷机组的性能,降低泵的输送能耗,提高了蓄冷空调系统的经济性。

关键词: 十五烷, 相变材料, 微胶囊, 原位聚合法, 潜热型功能流体, 相变焓

Abstract:

To prevent the leakage of materials during the phase-change process, low-temperature phase-change microcapsules with pentadecane (Pen) as the core material and urea-formaldehyde resin (UF) as the wall material were prepared using insitu polymerization. The effect of heating rate, polymerization pH, and polymerization speed on the microcapsules preparation was studied. The morphology, chemical composition, thermodynamic properties, and the particle-size distribution of microcapsules were tested using SEM, FT-IR, DSC, and Malvern laser particle-size analyzer. A heating rate of 1.0 ℃/min, polymerization pH value of 3.5, and polymerization speed of 500 r/min are the optimal preparation conditions for pentadecane microcapsules. The microcapsules prepared under the above conditions have spherical morphology, smooth surface, a few UF particle adherence, and the particle-size distribution is uniform. The phase-change temperature and latent heat of the microcapsules are 8.20 ℃ and 115.3 J/g, respectively. The average particle size of the microcapsules is 50.0 μm, and the encapsulation rate reaches 77.3%. The experimental results show that the core and wall materials are held by physical forces. The microcapsules have good heat storage performance and thermal stability. Pentadecane microcapsules are dispersed with different mass fractions of ethanol solution as the base solution. A stable latent-heat functional fluid (LHFF) is obtained using a static experiment for 24 h. The LHFF is the most stable in the base solution with 70 wt% ethanol. The thermal conductivity and viscosity of the LHFF are tested and analyzed using a thermal conductivity tester and rotational viscometer. The thermal conductivity of the LHFF increases with an increase in temperature and decreases with an increase in the mass fraction of microcapsules. The viscosity of the LHFF decreases with an increase in temperature and increases with an increase in the mass fraction of microcapsules. As the secondary refrigerant of the air conditioning system, LHFF can improve the performance of the refrigeration unit, reduce the energy consumption of the pump, and improve the economy of cold storage of the air conditioning system.

Key words: pentadecane, phase change materials, microcapsules, in situ polymerization, latent heat functional fluids, phase change enthalpy

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