INFLUENCE OF MAGNETIZATION ON HEAT TRANSFER COEFFICIENT OF CONDENSER IN R404A REFRIGERANT-BASED VAPOR COMPRESSION REFRIGERATION SYSTEM

Enhancing the thermal performance of vapor compression refrigeration systems is crucial for developing energy-efficient and environmentally friendly cooling technologies. The present study investigates the application of magnetic field exposure to augment the condensation heat transfer coefficient in a refrigeration system operating with R404A refrigerant. The liquid line of the condenser having an inner diameter of 0.838 cm was subjected to magnetic treatment using two configurations: magnetic pairs and Halbach arrays with field strengths of 300 mT and 720 mT, respectively. Experiments were conducted under varying numbers of magnetizers (one to four), mean dryness fractions (0.5-0.6), and saturation temperatures (45°C and 50°C). Results show that the heat transfer coefficient is significantly influenced by magnetic configuration, saturation temperature, and mean dryness fraction. The effect of magnetic treatment was observed to be more significant at lower saturation temperatures and higher mean dryness fractions. Halbach arrays generally offer greater enhancement than magnetic pairs. However, this improvement was limited to a specific number of magnetizers in both configurations, beyond which the heat transfer coefficient deteriorated. For the current work, the limiting number of magnetizers was determined to be two for magnetic pairs and one for Halbach array. Under optimal conditions, the heat transfer coefficient is increased by 18.06% for Halbach arrays and by 9% for magnetic pairs. Additionally, CO<sub>2</sub> emissions were found to be lower with Halbach arrays compared to magnetic pairs. Emissions ranged from 2.56% to 4.24% for Halbach arrays and from 1.07% to 2.97% for magnetic pairs, across the use of one to four magnetizers.