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This research involves an experimental study of vapour compression refrigeration system (VCRS) with hybrid-nanofluids zeotropic blends of (23%-R32/25%-R125/52%-R134a) in the ratio of (0.03 - 0.15 %.Vol.) with elven samples as thus: 001, 010, 100, 011, 111, 211, 121, 112, 221, 212 and 122 gram). A morphology characterization test was conducted using scanning electron microscope (SEM) and X-ray Diffraction (XRD) amongst the selected ratios using compressor work efficiency, power consummation rate and Coefficient of performance (COP) as the core enhancement parameters. The most favorable blend produced the optimum COP in three different fraction ratios (011, 111 and112). The outcome indicated that thermo-physical and vapor compression properties of hybrid-nanofluids zeotropic (011) zero gram-TiO2, 7.5g-Al2O3/CuO; (112) 3.75 g-TiO2/Al2O3, 7.5 g-/CuO and (111) 5.0g-TiO2/Al2O3/CuO produced the best optimum performance of 3.1%, 1.41% and 1.21% respectively. The COP was found to be highest at (011) blend by about 3.1% at refrigerant temperature of -7 oC. The maximum compressor power coefficient, volumetric cooling capacity and TEGWI were found to increase by 13.51%, 5.78 % and 1.06 kg/sec CO2. The study also revealed that nanoparticles mixed in the base fluid increased the heat transfer coefficient even with a smaller particle portion of 0.003%, with optimum improvement of 0.0075 Vol % application. The calculated values of exergy destruction in each component at various % fractions are presented in Appendix I. Outcome of the study confirmed that hybrid-nanofluids zeotropic blend is energy efficient and environmentally friendly with good characteristics healthier than CFCs and HCFCs, and can offer healthier compressor/refrigerator working fluid substitute to be adopted in VCRS and air conditioning operations. [ABSTRACT FROM AUTHOR]

Cooling refrigeration systems ingest prime energy and contribute to universal negative impact due to ecologically unfavorable working fluids used. Hence, the quest to improve the performance of Vapour Compression Refrigeration System (VCRS) with more efficient and eco-friendly refrigerant such as nanoparticles becomes imperative. In this study, performance analysis of hybrid nanofluids-zeotropic mixtures in a VCRS were experimentally investigated to determine the best operating optimum performance using exergy based approach. To achieve this, varying concentrated mixtures were selected using ternary graph. The results revealed that all the designated ratios of the mixed refrigerant with different fractions achieved good performance improvement with optimum values obtained at (011) zero gram of TiO2, 7.5g-Al2O3/CuO. All the selected hybrid mixtures led to an improved outcome in terms of Coefficient of Performance (COP), less power consumption and high performance exergetic efficiency, with COP values ranging from 0.31% to 3.10% and exergetic efficiency from 0.32 to 1.43%. The value for thermal conductivity, dynamic viscosity, density and specific heat were found to be highest (0.0958 W/m.K; 0.00164 W/m.K; 686.82 kg/m³ and 359.82 kJ/kg.K) at the same concentration of zero grams TiO2 in the mixture. Comparison made from the performance characteristics curve (with global parameters) indicated that maximum power coefficient and cooling capacity for the various concentrations were found at (001) 7.5g-TiO2, zero grams Al2O3/CuO equal to 2.2 kW, and the minimum value at concentration of 5 was 0.61% at (111) 5g-TiO2/Al2O3/CuO, and 0.87% for (121). An increase was observed in the maximum power coefficient, cooling capacity and COP increased by 13.51%, 5.78% and 10.33%. It was also observed that hybrid nanofluid-zeotropic refrigerant worked seamlessly with VRCS, making it a sustainable, green and clean as well as eco-friendly alternative with near-zero to zero negative effects on public health safety and environment. [ABSTRACT FROM AUTHOR]