Thermal Performance Investigation of Greenhouse Glazing Units Containing PCM with Different Thermophysical and Optical Properties

Abstract

Improved thermal storage capacity and reduced building energy consumption can be attained by utilizing phase-change materials (PCM) in glass enclosure structures, which can effectively utilize solar energy to improve the building’s thermal performance. This article investigates the thermal performance of double-layer glass filled with PCM as a function of relevant thermal physical parameters. Numerical analyses were conducted on the PCM glass units to assess the glass greenhouse thermal performance. Results indicate that the temperature distribution of the glass channel is mainly influenced by the absorption coefficient of the paraffin material. Compared to the absorption coefficient, the refractive index has a smaller impact on the temperature of the glass channel. On the other hand, the transmittance of the interior surface of the glass channel is greatly affected by solar radiation. According to the outdoor meteorological conditions of different seasons, increasing the latent heat of paraffin materials within a certain range with a reasonable density and melting temperature can greatly improve the thermal performances. Meanwhile, the thermal conductivity of paraffin materials and the change in the specific heat of paraffin materials have little impact on the improvement of thermal performance.