Energy Storage Science and Technology ›› 2021, Vol. 10 ›› Issue (1): 287-294.doi: 10.19799/j.cnki.2095-4239.2020.0254

• Energy Storage Test: Methods and Evaluation • Previous Articles     Next Articles

Study on heat transfer of phase change materials imbedded in a concrete wall

Hang TU(), Hang ZHANG, Lihui LIU, Jie LI(), Xiaoqin SUN   

  1. Changsha University of Science & Technology, Changsha 410114, Hunan, China
  • Received:2020-08-03 Revised:2020-08-12 Online:2021-01-05 Published:2021-01-08

Abstract:

Adding phase change materials (PCMs) to building envelopes is an effective method to reduce the heat transfer between the outdoor and indoor environments. PCMs are materials that can change their phase by absorbing or releasing large amounts of energy, which prevents a large temperature variation. The utilization of PCMs in building envelopes realizes this heat transfer regulation between the indoor and outdoor environments. This paper reports the use of PCMs with a phase change temperature of 25 ℃ encapsulated in hollow HDPE balls with inner diameter of 24 mm and outer diameter of 25 mm. The PCM balls were evenly distributed in a concrete panel with dimensions of 880 mm×500 mm to form a PCM-concrete layer. Outdoor solar radiation was simulated using an electrical heating film. The thermal performance of walls with a PCM-concrete layer at various positions in a building envelope were measured and simulated using Ansys software. The effective thermal conductivity of the PCM-concrete layer was calculated to evaluate the thermal performance of the walls. It was found that when the solar radiation is less than 80 W/m2 or greater than 200 W/m2, the effective thermal conductivity is lowest when the PCM-concrete layer is adjacent to the interior surface. When the solar radiation is between these values, it is more effective to place the PCM-concrete layer adjacent to the exterior surface to allow the PCM to absorb heat and achieve better thermal performance.

Key words: phase change material, heat transfer through building envelope, interior surface temperature, thermal performance, effective thermal conductivity

CLC Number: