储能科学与技术 ›› 2022, Vol. 11 ›› Issue (11): 3674-3680.doi: 10.19799/j.cnki.2095-4239.2022.0315

• 储能测试与评价 • 上一篇    下一篇

梯形蓄热罐形状对蓄热性能影响的数值研究

张军1(), 赵凤霞1, 杜昭1,2, 阳康1, 李元基2, 杨肖虎2()   

  1. 1.中国建筑西北设计研究院有限公司,陕西 西安 710061
    2.西安交通大学人居环境与建筑 工程学院,陕西 西安 710049
  • 收稿日期:2022-06-12 修回日期:2022-06-25 出版日期:2022-11-05 发布日期:2022-11-09
  • 通讯作者: 杨肖虎 E-mail:120273252@qq.com;xiaohuyang@xjtu.edu.cn
  • 作者简介:张军(1968—),男,教授级高级工程师,研究方向为建筑节能、建筑给排水,E-mail:120273252@qq.com
  • 基金资助:
    校企合作重点项目(20210851)

Influence of tank shape on heat storage performance: A numerical study

Jun ZHANG1(), Fengxia ZHAO1, Zhao DU1,2, Kang YANG1, Yuanji LI2, Xiaohu YANG2()   

  1. 1.China Northwest Architecture Design and Research Institute Co. , Ltd, Xi'an 710061, Shaanxi, China
    2.School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
  • Received:2022-06-12 Revised:2022-06-25 Online:2022-11-05 Published:2022-11-09
  • Contact: Xiaohu YANG E-mail:120273252@qq.com;xiaohuyang@xjtu.edu.cn

摘要:

蓄热可应对太阳能光热利用中的间歇性问题,可提供平稳的热能输出,提高能源品质。固液相变蓄热因其蓄热密度大、蓄/放热过程温度恒定等优点备受关注。固液相变蓄热过程中存在相变材料熔化与温度不均匀的现象,难熔区域极大地延长了整体相变蓄热时间。本工作提出了一种通过改变蓄热罐形状来改善熔化不均匀现象的设计方法,设计了5种具有不同梯度比的梯形相变蓄热罐;通过数值模拟方法研究了5种梯形蓄热罐的蓄热性能,得出以下结论:增加上部区域相变材料的比例有利于将热量及时传递到固态区域,减小了热量传递的阻力,加快了整体传热速率。增加上部区域相变材料比例(即模型1和模型2)的完全熔化时间较基准模型3的完全熔化时间都有缩短,分别减少了39.06%和29.37%。研究结果为相变蓄热罐结构设计和工程应用提供一定参考。

关键词: 潜热蓄热, 固液相变, 梯形蓄热罐, 相界面, 传热热阻

Abstract:

Thermal storage can solve the intermittent problem of solar energy, which is providing a stable thermal output and improving energy quality. Solid-liquid phase change heat storage has attracted attention due to its advantages of large heat storage density and relatively constant temperature during heat storage/release. However, during solid-liquid phase change heat storage, there is constant inhomogeneity in the melting times and temperatures of the phase change materials (PCMs). The refractory zone greatly prolongs the overall phase change heat storage time. Therefore, this paper proposes improving the unevenness of the melting times by changing the shape of the heat storage tank. Five trapezoidal phase change heat storage tanks with different gradient ratios were designed. The heat storage performance of these tanks were examined using numerical simulations. The results indicated that increasing the proportion of PCMs in the upper region was conducive to the timely transfer of heat to the unmolten PCMs and reduced the resistance of heat transfer, thereby improving the overall heat transfer rate. The complete melting time of Cases 1 and 2 with a larger proportion of PCMs in the upper region was shortened compared to that of Case 3, with reduction ratios of 39.06% and 29.37%, respectively.

Key words: latent heat storage, solid-liquid phase transition, trapezoid heat storage tank, phase interface, heat transfer resistance

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