Modeling of a Novel Cascade Cycle for the Simultaneous Production of Desalinated Water and Cooling Using Various Refrigerants

This study proposes a cogeneration system for the simultaneous production of cooling and freshwater. A double-stage cascade compression cooling system consists of two interconnected vapor compression cycles. The proposed system integrates a double-stage cascade compression cooling system with a water desalination unit, which takes advantage of the heat released by the cascade system. The system performance was evaluated using various refrigerants selected based on their energy efficiency, environmental impact, and widespread use. Multiple combinations of the fluids were used in the high-temperature cycle (HTC) and low-temperature cycle (LTC) to analyze their impact on system performance. A parametric analysis was conducted by developing a mathematical model in MATLAB. The model’s input parameters were the evaporation temperature and the temperature difference between the inlet and discharge of both compressors (ΔLTC and ΔHTC). System performance was assessed from a first-law point of view through the coefficient of performance (COP), the energy utilization factor (EUF), and the gain output ratio (GOR). The results revealed that the maximum (105 °C) and minimum (−13 °C) temperatures, essential for desalination and cooling, respectively, were achieved using R134a in the LTC and R123 in the HTC, with ΔLTC = 65 °C and ΔHTC = 70 °C. However, the best performance was observed with R123 in both cycles, with ΔLTC = 45 °C and ΔHTC = 70 °C. This configuration achieved a COP of 1.06, a GOR of 1.61, and an EUF of 2.74.