Development of a Plate Heat Exchanger Design Tool and Heat Transfer Analysis Considering Temperature Glide characteristics of Zeotropic Mixtures

As environmental concerns and demands for energy efficiency grow, zeotropic refrigerant mixtures made from low-GWP refrigerants like R-290 and R-744 are gaining attention for their thermodynamic benefits. A key characteristic of these mixtures is the temperature glide during phase change, which can either enhance or hinder the performance of heat exchangers, depending on how well it aligns with the heat source temperature profile. This study developed and validated a numerical simulation tool to analyze the heat transfer performance of a plate heat exchanger while considering the effects of temperature glide. Experimental validation indicated errors below 8% for both the condenser and evaporator. Among the tested mixtures, R-290/R-744 at an 80/20 weight percent ratio demonstrated the best thermal performance, whereas higher fractions of R-1234yf in R-744/R-1234yf resulted in excessive glide and thermal mismatching. The findings suggest that careful selection of refrigerant mixtures can enhance effectiveness and lay the groundwork for optimizing eco-friendly refrigeration systems, with potential applications in heat pump design, energy-efficient HVAC systems, and refrigerant leakage diagnostics.