储能科学与技术 ›› 2021, Vol. 10 ›› Issue (1): 287-294.doi: 10.19799/j.cnki.2095-4239.2020.0254

• 储能测试与评价 • 上一篇    下一篇

相变混凝土墙体的传热性能研究

涂航(), 张航, 刘丽辉, 李杰(), 孙小琴   

  1. 长沙理工大学能源与动力工程学院,湖南 长沙 410114
  • 收稿日期:2020-08-03 修回日期:2020-08-12 出版日期:2021-01-05 发布日期:2021-01-08
  • 作者简介:涂航(1994—),男,硕士研究生,研究方向为相变围护结构传热性能,E-mail:540203016@qq.com|李杰,博士,讲师,研究方向为相变储能数值模拟,E-mail:lijie@csust.edu.cn
  • 基金资助:
    国家自然科学基金项目(51608051);湖南省自然科学基金项目(2019JJ30027);湖南省科协人才托举工程(2017TJQ05);长沙市杰出创新青年培养计划(kq1905038)

Study on heat transfer of phase change materials imbedded in a concrete wall

Hang TU(), Hang ZHANG, Lihui LIU, Jie LI(), Xiaoqin SUN   

  1. Changsha University of Science & Technology, Changsha 410114, Hunan, China
  • Received:2020-08-03 Revised:2020-08-12 Online:2021-01-05 Published:2021-01-08

摘要:

为减少室内外环境之间的传热,降低室外环境的波动对室内环境的影响,在建筑围护结构中加入相变材料(phase change materials,PCMs)是有效手段之一。PCMs是一种在温度不变的情况下通过改变物质状态吸收或释放大量的潜热的物质,其与建筑围护结构的结合可实现室内外环境之间的传热管理。本文采用宏观封装的方法将相变温度为25 ℃的PCMs封装于内径为24 mm、外径为25 mm的高密度聚乙烯球壳中,均匀整齐排列置于截面尺寸均为880 mm×500 mm的混凝土中形成PCMs-混凝土层,采用电加热膜模拟建筑围护结构外表面的太阳辐射,实验研究了PCMs-混凝土层在不同太阳辐射强度下不同位置时的热工性能,并采用Ansys软件对墙体的热工性能进行数值模拟,最后引入相对导热系数分析不同PCMs-混凝土组合墙体的传热性能。研究发现,当太阳辐射强度小于等于80 W/m2或大于等于200 W/m2时,PCMs-混凝土层靠近墙体内表面时相对导热系数最小,墙体热性能更好;当太阳辐射强度处于两者中间时,PCMs-混凝土层靠近墙体外表面时,相变材料更能发挥其吸热特性,墙体热性能更好。

关键词: 相变材料, 围护结构传热, 内表面温度, 热工特性, 相对导热系数

Abstract:

Adding phase change materials (PCMs) to building envelopes is an effective method to reduce the heat transfer between the outdoor and indoor environments. PCMs are materials that can change their phase by absorbing or releasing large amounts of energy, which prevents a large temperature variation. The utilization of PCMs in building envelopes realizes this heat transfer regulation between the indoor and outdoor environments. This paper reports the use of PCMs with a phase change temperature of 25 ℃ encapsulated in hollow HDPE balls with inner diameter of 24 mm and outer diameter of 25 mm. The PCM balls were evenly distributed in a concrete panel with dimensions of 880 mm×500 mm to form a PCM-concrete layer. Outdoor solar radiation was simulated using an electrical heating film. The thermal performance of walls with a PCM-concrete layer at various positions in a building envelope were measured and simulated using Ansys software. The effective thermal conductivity of the PCM-concrete layer was calculated to evaluate the thermal performance of the walls. It was found that when the solar radiation is less than 80 W/m2 or greater than 200 W/m2, the effective thermal conductivity is lowest when the PCM-concrete layer is adjacent to the interior surface. When the solar radiation is between these values, it is more effective to place the PCM-concrete layer adjacent to the exterior surface to allow the PCM to absorb heat and achieve better thermal performance.

Key words: phase change material, heat transfer through building envelope, interior surface temperature, thermal performance, effective thermal conductivity

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