Low-energy resilient cooling through geothermal heat dissipation and latent heat storage
Low-energy resilient cooling through geothermal heat dissipation and latent heat storage
复制标题
DOI：
10.1016/j.est.2023.108377
复制
发表时间：
2023
影响因子：
9.4
通讯作者：
S. Mehmood;J. Lizana;D. Friedrich
中科院分区：
文献类型：
--
作者：
S. Mehmood;J. Lizana;D. Friedrich
传统的被动冷却技术在南亚极其炎热的气候中提供的好处有限，该地区的特点是白天和夜间温度较高，并且经常出现与气候相关的中断，例如断电。这项研究提出并展示了一种针对南亚极热地区的新型低能耗、弹性冷却解决方案。新颖之处在于将地热散热与潜热储存相结合，专为南亚极热气候的特殊条件而设计；考虑到与气候相关的中断（例如停电）的影响，该地区停电的频率正在增加；并使用不适时间作为指标来衡量建筑物在没有空调的情况下的被动生存能力（遵循自适应舒适模型）。 TRNSYS 开发了一个数值模型，用于使用巴基斯坦三个气候地区的典型多户建筑原型，对集成到天花板中的相变材料 (PCM) 进行最佳尺寸和配置。对不同的 PCM 熔化温度、PCM 含量、对流传热能力和等效导热系数进行了参数数值分析。而且，白天被认为是停电概率较高的时段。结果表明，将基于 PCM 的天花板与地热散热相结合，可以在极热气候下将不适时间减少 28%，在极热气候下减少 55%，在电力间歇性的炎热气候地区减少 91%。与没有 PCM 的情况相比，潜热存储在极热和极热气候下将热舒适期延长 13% 和 18%，从而最大限度地发挥了地热散热的优势。这种低能耗的弹性冷却解决方案将 PCM 集成为冷却电池，可以在没有电力时使房屋保持更长时间的凉爽。这项研究证明了在建筑设计中考虑这些极热地区与气候相关的特定干扰（例如极端高温事件或停电）的重要性，以增强城市的耐热能力。
Conventional passive cooling techniques provide limited benefits in extremely hot climates in southern Asia, characterised by high daytime and night temperatures and frequent climate-related disruptions, such as power cuts. This study proposes and demonstrates a novel low-energy and resilient cooling solution for extremely hot regions in southern Asia. The novelty lies in the combination of geothermal heat dissipation and latent heat storage, specifically designed for the particular conditions of extremely hot climates in Southern Asia; considering the influence of climate-related disruptions such as power cuts, whose frequency is increasing in the region; and using discomfort hours as an indicator to measure the passive survivability of buildings in the absence of air-conditioning (following the adaptive comfort model). A numerical model was developed in TRNSYS for optimal sizing and configuration of the phase change material (PCM) integrated into a ceiling panel using a typical multi-family building archetype in three climatic regions of Pakistan. A parametric numerical analysis was performed concerning different PCM melting temperatures, amount of PCM, convective heat transfer capacity, and equivalent thermal conductivity. Moreover, daytime was considered the period with a higher probability of power cuts. The results showed how integrating PCM-based ceiling panels with geothermal heat dissipation can mitigate discomfort hours by 28 % in extremely hot climates, 55 % in very hot climates, and 91 % in hot climate areas with intermittent access to electricity. Latent heat storage maximised the benefits of geothermal heat dissipation by extending thermal comfort periods by 13 % and 18 % in extremely hot and very hot climates compared to the scenario without PCM. This low-energy resilient cooling solution, integrating PCM as a cool battery, can keep the home cool for longer when electricity is unavailable. This study demonstrates the importance of considering the specific climate-related disruptions from these extremely hot regions in building design, such as extreme heat events or power cuts, to enhance the heat resilience capacity of cities.