This review study examines flow boiling heat transfer in micro-fin tubes using mixed and pure refrigerants with zero ozone-depleting potential (ODP) and minimal global warming potential (GWP). This investigation focuses on the extraordinary relationship between heat transfer coefficients (HTCs) and vapor quality. Since the introduction of micro-fin heat exchanger tubes over 30 years ago, refrigerant-based cooling has improved significantly. Air conditioning and refrigeration companies are replacing widely used refrigerants, with substantial global warming impacts. When space, weight, or efficiency are limited, micro-fin heat exchangers with improved dependability are preferred. This review article discusses flow boiling concepts. The researchers used several refrigerants under different testing conditions and with varying micro-fin tube parameters. Micro-fin tubes are promising for improved heat transfer techniques. This tube increases the heat transfer area, fluid disturbance, flow speed, and direction owing to centrifugal force and HTC. As the focus shifts to improving heat transfer, pressure drop, mean vapor quality, and practical devices, this subject will grow more intriguing. A radical shift will reduce equipment size for certain traditional heat transfer systems and bring new products using micro-scale technologies. This suggested review effort helps comprehend saturation flow boiling through micro-fin tubes and find the right correlation for a given application. This domain’s challenges and future relevance are also discussed.

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The flow boiling heat transfer performance of R22 and R407c, in a microfin tube with a helix angle of 22° and an apex angle of 48°, was evaluated in a study. The study is aimed at investigating the impact of heat flux, mass flux, saturation temperature, and vapor quality on the heat transfer coefficient during flow boiling. Two different saturation temperatures, 293.15 K and 313.15 K, were used in the experiments, with heat fluxes ranging from 25 to 85 kW.m-2 and mass fluxes ranging from 150 to 350 kg.m-2.s-1. To validate the experimental data, the results were compared with existing correlations for microfin tubes. The calculated error margin among all correlations with the experimental dataset, which ±15% and ±30%, was also matched by 85% and 95% of the datasets, respectively. Findings reveal that at lower saturation temperatures, the average heat transfer coefficients augmented with increasing mass flux. The study also found that R22 has a higher heat transfer coefficient than R407c at low saturation temperatures due to its stronger thermal conductivity and lower viscosity.