Preliminary investigation on pilot-scale photovoltaic-driven cold storage with ice thermal storage based on vapor compression refrigeration cycle

Abstract

This work built a PV driven cold storage with ice thermal storage based on vapor compression refrigeration, where the compressor power was 4.41 kW. The system was designed in two modes of driving by utility electricity or PV array, and was expected to operate continuously via cascade evaporation in the cold storage. The hourly and daily performance was analyzed and compared between the two modes. The results indicate that the system driven by the stable utility electricity obtains the hourly refrigeration and system coefficient of performance (COP) between 1.02–5.73 and 0.85–4.58, respectively. The daily average refrigeration COP is between 2.75 and 3.02, and the daily average system COP is between 2.27 and 2.46; the highest daily cumulative ice mass reaches 178.45 kg. For the system driven by the PV array, the most daily ice mass of 144.10 kg is obtained with the PV capacity of 5.4 kW and the highest cumulative solar insolation of 20.41 MJ/m2, of which the daily refrigeration and system COP are 1.33 and 0.19, respectively. The characteristics of the ice thermal storage gives that the stored ice of 88.5 kg could sustain the cold storage temperature below 5 °C for about 11 h. Results show a positive trend indicating that this system could be a viable alternative for developing chain logistics service.