Performance studies on a solar PV-powered multi-stage cooling system

Post-harvesting losses are significant in India. The storage requirements for vegetables and fruits are different, and they can be stored for shorter and longer periods. The power supply in rural and remote areas is irregular during summer; hence, the cooling system can be powered using renewable energy sources like solar. Hence, in this study, a three-stage cooling system consisting of an indirect evaporative cooler, direct evaporative cooler, and vapor compression-based cooling system was fabricated and tested using power developed by a solar photovoltaic system. The developed three-stage cooling system is the most promising and can be operated based on the storage conditions required for the particular products to be stored. A performance study was undertaken for the same, and from the experimental results, it was observed that it could reduce the dry bulb temperature up to 14.2° C and increase cooling efficiency by up to 86% with a significant reduction in power consumption. The higher fan speed of 3000 rpm results in the lowest DBT reductions of 16.33, 29.67, and 52.66% for the IEC, IDEC, and IDEC + VCR stages, respectively. The higher fan speed produces a better cooling effect but increases power consumption and reduces the exergy efficiency. The proposed solar three-stage cooling system is a multipurpose, affordable, and renewable energy-driven cooling system for different applications. Small-scale growers, distributors, and merchants could utilize the multi-stage cooling system to store and chill horticulture goods, minimizing spoilage of fresh produce after harvest.