Characteristics optimization of composite phase-change wall during intermittent heating process

• Published in: HVAC&R research Vol. 26; no. 4; pp. 541 - 551
• Main Authors: Li, Yanru, Long, Enshen, Ding, Pei, Guo, Shurui
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 20-04-2020; Taylor & Francis Ltd
• Subjects: Energy consumption; Energy storage; Heat conductivity; Heat loss; Heat storage; Heat transfer; Heating; Indoor environments; Latent heat; Optimization; Phase change materials; Phase transitions; Thermal conductivity; Thermal environments; Transition temperature
• ISSN: 2374-4731; 2374-474X
• DOI: 10.1080/23744731.2019.1634933

The indoor thermal environment under an intermittent heating condition can be maintained by rationally utilizing the heat storage and release processes of the composite phase-change wall (composite-PCW), leading to heating time and energy consumption reductions. In order to optimize its heat storage and release processes, the influences of different parameters on the dynamic thermal processes of composite-PCW were studied, including the position and thickness of phase-change material (PCM), phase transition temperature, phase-change latent heat, and PCM thermal conductivity, according to two typical intermittent conditions summarized by experimental data. With large heat storage efficiency η and small heat loss rate ε, the optimized composite-PCW that was adaptive for intermittent heating was the composite-PCW with 10 mm PCM integrated to the wall inside. Its phase-transition temperature was 19-20 °C (66.2-68 °F), the phase-change latent heat was 220 kJ/kg (95.58 btu/lb), and the thermal conductivity was 0.4 W/(m·K) (0.23 btu/(ft·h·°F)) at liquid states and 0.8 W/(m·K) (0.46 btu/(ft·h·°F)) at solid states.