Investigating the effects of nanorefrigerants in a cascaded vapor compression refrigeration cycle

It is vital, following the Kyoto Protocol, to find environmentally benign and energy-efficient refrigerants, consequently boosting the coefficient of performance (COP). Refrigeration systems are used extensively in the industrial, home, and commercial sectors for cooling, heating, food preservation, and cryogenic purposes. Researchers have successfully employed the application of nanoparticles in cooling systems to achieve improved enhancement, reliability, and efficiency of refrigeration systems because of their higher heat transfer and thermophysical capabilities. The function of numerous variables, however, makes the experimental technique appear to be costly and time-consuming to carry out. This study was, therefore, designed to numerically simulate the performance assessment of a nanoparticle-enhanced Cascaded Vapor Compression Refrigeration Cycle (CVCRC). The focus of this paper is on four distinct SiO2 nanoparticle nanorefrigerants and their pure fluids: two HFCs as well as two fourth-generation refrigerants (HFOs), namely; R12, R134a, R1234yf, and R-1234ze (E). The results show that adding nanoparticles to the pure refrigerant improves COP, and the highest values were achieved with the R1234ze(E)/SiO2 mixture. Increasing the mass concentration of the nanoparticles leads to an increase in the refrigeration effect, an increase in COP, and a reduction in compressor work. Although R125 had the lowest compressor work of 47.12 kW when SiO2 nanoparticles are introduced, however, is not suitable for refrigeration because of its high GWP values. R1234ze has the second-lowest compressor work of 59.58 kW with the addition of SiO2, it is consequently more energy efficient and can be used in its place as it has a GWP of 6, among other benefits.