Evaluation and optimization of the performance and efficiency of a hybrid flat plate solar collector integrated with phase change material and heat sink

This study presents an experimental real case study on the performance optimization of a flat plate solar collector (FPSC) by integrating a layer of phase change material (PCM) and a heat sink. The system was tested under the semi-arid climatic conditions of Abha, Saudi Arabia. Based on preliminary experimental testing on conventional FPSCs, the novel composite structure of the PCM material was developed by mixing polyethylene glycol (PEG) and magnesium hydroxide (Mg (OH)2) in an absolute ethanol solution. The PEG/Mg (OH)2 PCM was installed beneath the pipe and had a lower supercooling value, a higher latent heat value, and thermal stable characteristic, thus increasing the thermal performance of the FPSC. The results showed that using a PCM ensured that the collector continued to deliver hot water for a longer period of time. Furthermore, a heat sink was attached to the PCM layer for proper temperature distribution. The results demonstrated that the FPSC equipped with a PCM and heat sink produced hot water for a longer period of time in the evening while having a lower output temperature in the morning. Also, the average daily FPSC thermal efficiency was enhanced by 6–8% by adding only PEG/Mg (OH)2 PCM as compared with conventional FPSCs and those with PCMs and heat sinks.