Kalbasi Rasool, Samali Bijan, Afrand Masoud
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
Centre for Infrastructure Engineering, Western Sydney University, Penrith, NSW, 2751, Australia.
Chemosphere. 2023 Jan;311(Pt 2):137100. doi: 10.1016/j.chemosphere.2022.137100. Epub 2022 Nov 2.
Considering the share of 40% and 35% of buildings in energy consumption as well as CO emissions, adding phase change materials (PCMs) is an effective technique to tackle high energy demand and considerable CO emissions. When PCMs are injected into the building envelopes, they improved the sensible/latent storage features of the envelopes. In this study, using numerical methods, defining first (no PCM), second (PCM without phase transition), and third building (with phase transition), the importance of sensible storage feature was compared to latent one. It was found that the sensible/latent importance is dependent on the thermal resistance of the envelopes and setpoint. At setpoint 22 °C, it was found that the PCM-enhanced building consumed less power by 32.4 kWhm. Under this condition, the share of sensible storage as well as latent storage was 54% and 46%, respectively. The reason for the lower share of latent storage was that PCM never participated in phase change about 40% of the year. To boost PCM effectiveness, it was found that the PCM installation near the uppermost layer enhanced energy-saving by 3.72 kWhm. The presence of phase change in PCM is not always considered a positive point. In one situation, it was observed that if PCM did not undergo phase transition, it reduces energy consumption by 9.4 kWhm, while for PCM with phase transition this value was 7.1 kWhm. PCM was also beneficial on CO reduction either with phase change or without phase change. In the former, CO emissions declined by 34.9 kgm, and under the latter circumstances it was 23.9 kgm.
考虑到建筑物在能源消耗以及二氧化碳排放中所占比例分别为40%和35%，添加相变材料（PCM）是应对高能源需求和大量二氧化碳排放的有效技术。当将相变材料注入建筑围护结构时，它们改善了围护结构的显热/潜热存储特性。在本研究中，使用数值方法，定义了第一种（无PCM）、第二种（无相变的PCM）和第三种建筑（有相变），比较了显热存储特性与潜热存储特性的重要性。结果发现，显热/潜热的重要性取决于围护结构的热阻和设定温度。在设定温度为22°C时，发现添加PCM的建筑能耗降低了32.4千瓦时/平方米。在此条件下，显热存储和潜热存储的比例分别为54%和46%。潜热存储比例较低的原因是PCM在一年中约40%的时间里从未发生相变。为了提高PCM的有效性，发现将PCM安装在最上层附近可节能3.72千瓦时/平方米。PCM中相变的存在并不总是被视为一个优点。在一种情况下，观察到如果PCM不发生相变，能耗降低9.4千瓦时/平方米，而对于有相变的PCM，该值为7.1千瓦时/平方米。PCM在有相变或无相变的情况下对减少二氧化碳排放也有益。在前一种情况下，二氧化碳排放量下降了34.9千克/平方米，在后一种情况下为23.9千克/平方米。
