Investigation on the thermal performance of the novel phase change materials wall with radiative cooling

• Published in: Applied thermal engineering Vol. 176; p. 115479
• Main Authors: Shen, Dongmei, Yu, Cairui, Wang, Wanfen
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.07.2020; Elsevier BV
• Subjects: Building envelopes; Cooling; Cooling loads; Emissivity; Heat pipes; Micro-channel heat pipe; Microchannels; Numerical methods; Phase change materials; Phase transitions; Radiative cooling; Studies; Temperature effects; Thermal performance; Thickness; Wind speed; Phase change materials; Micro-channel heat pipe; Radiative cooling; Thermal performance
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2020.115479

•A novel RC-PCM wall combining radiative cooling (RC) with the PCMs was introduced.•The mathematical model of the RC-PCM wall was developed and validated.•The influence of wind speed, emissivity, and PCM thickness on the temperature variation of the RC-PCM wall were explored.•The energy saving of the RC-PCM wall with different parameters was investigated. In order to reduce the cooling loads of the building envelope, a novel wall (radiative cooling-phase change materials; RC-PCM) is presented, which takes the advantage of the phase change materials (PCMs), micro-channel heat pipes (MHPs), and radiative cooling (RC). In this study, the primary experiments were first conducted on the emissivity of the radiative plate and the uniform temperature of the MHPs. Next, the mathematical model of the RC-PCM wall was established, which was in good agreement with the field testing results. Afterwards, the parameters were investigated with the numerical methods, including the outdoor wind speed, emissivity of the radiative plate, and thickness of the PCMs. The results showed that the interior surface temperature of the RC-PCM was negatively correlated with the wind speed and positively correlated with the emissivity. In addition, good PCMs utilization was achieved, wherein the cooling loads of the RC-PCM wall was approximately 25% lower than that of the same thickness of the brick wall, and was 42% under the ideal condition. Additionally, in the RC-PCM wall, the cooling loads of the 20-mm-thick PCMs were about 6% lower than that of the 15-mm-thick PCMs. Overall, the RC-PCM wall exhibited good potential in engineering applications.