Small-diameter heat exchangers for air conditioning can reduce cost and refrigerant charge

which is of great significance for realizing energy savings and emission reduction. In this study

the plate fins of a 5 mm single-row air-conditioning condenser are optimized to replace a 7 mm single-row air-conditioning condenser. The optimization variables are tube spacing

fin width

and fin spacing

and the objectives are to maximize heat transfer and minimize air-side pressure drop and cost. The Taguchi method was selected for the experimental design and single-objective optimization

and the grey relational analysis and comprehensive performance index method were used for multi-objective optimization. The final optimum tube spacing

fin width

and fin spacing were 16.0 mm

16 mm

and 1.4 mm

respectively. The heat transfer was the same as that of the 7 mm tube condenser. The pressure drop was reduced by 35%

and the cost was reduced by 26%

validating the effective replacement of the 7 mm condenser.