Evolutionary optimization of heat exchanger circuitries for the advancement of next-generation refrigerants

This study presents an assessment technique based on the evolutionary optimization of heat exchanger circuitries for the performance evaluation of next-generation refrigerants. A novel evolutionary algorithm is developed to handle the implementation of genetic operators with unrestrained number and location of splitting and merging nodes, while ensuring the circuitry feasibility. The circuitry optimization is conducted for a finned-tube evaporator with 36 tubes under given cooling capacity, degree of superheat, and heat source boundary conditions representative of air conditioning applications. The thermodynamic interrelations between minimum entropy generation and maximum COP are discussed, identifying optimal configurations of the heat exchanger that maximize the performance of each refrigerant. It is shown that low-GWP zeotropic mixtures with temperature glide exhibit the largest benefit from the developed circuitry optimization procedure and may achieve performance comparable to R32 and higher than R410A by approaching a Lorenz cycle operation.