Use of PCM Boards for Solar Cell Cooling

作者：Zmeskal O^*; Stefkova P; Dohnalova L; Barinka R

来源：International Journal of Thermophysics, 2013, 34(5): 926-938.

DOI：10.1007/s10765-012-1196-y

• PCM-Phase-change materials
• Solar cells
• Specific heat
• Thermal conductivity
• Thermal diffusivity
• Thermal fractal systems

This contribution explains the use of fractal theory to describe thermal properties of materials. The basic idea is rooted in the theory of fractal fields defined in E-dimensional Euclidian space. Generic equations describing heat distribution are then specialized to describe the changes in heat transfer as a response to step-wise increases in the amount of heat added to the system. This model was then applied to the study of properties of a systems consisting of solar cells attached on a phase-change material (PCM) back sheet board. The aim of this study is to evaluate the ability of PCM boards to decrease the working temperature of solar cells and thus to increase the efficiency of the cells. Regression of experimental data was used to obtain model parameters. The parameters obtained this way were the thermal diffusivity, thermal conductivity, and specific heat, as well as parameters of the heat source and parameters related to the heat losses of the system. The method was then verified against parameters of the system based on poly-methyl-methacrylate and then applied to a PCM with a phase-change temperature of 25 A degrees C. The values of the thermal parameters were determined at temperatures where both components of the PCM composite (Micronal(A (R)) and gypsum wall) were solid and below the phase-change temperature and then again at temperatures where one of the components (gypsum) was still solid, while the other one was already liquid (wax). The attempt to determine the parameters during the phase change was not made due the physicochemical processes taking place which would alter the measured data.

• 出版日期2013-5