Enhancing reliability and efficiency of solar chimney by phase change material Integration: An Experimental study

Abstract

The Solar Chimney Power Plant (SCPP) presents an eco-friendly and straightforward technique for converting solar radiation into electricity. However, the performance limitations and reliability challenges of SCPPs are inherently linked to the variability and intermittency of solar radiation. To tackle this issue, using phase change materials (PCMs) can enhance the thermal energy storage and release capabilities of SCPPs. This study aims to explore the impact of PCM on the exergy efficiency and performance of a solar chimney. Two pilot solar chimneys with identical dimensions were constructed, each featuring a 4 m height chimney and a 5 m diameter collector. One solar chimney was equipped with hydrated salt PCM as an energy storage layer, while the other operated without PCM. Both systems' power production and ventilation potential were evaluated using theoretical turbines, and subsequent exergy analysis discerned the operational behavior and efficiency of the systems. Results indicate that PCM increased the average air mass flow rate through the solar system during the day. The average daily air mass flow rate was 0.045 kg/s with PCM and 0.033 kg/s without PCM. Notably, mean pressure drops resulting from the airflow through the turbine were 2.44 and 1.83 Pa in the presence and absence of PCM, respectively, over a complete day. Additionally, PCM improved exergy efficiency by about 19 % due to enhanced thermal energy storage.