Investigating Transport Properties of Environmentally Friendly Azeotropic Binary Blends Based on Evaporation in Auto-Cascade Refrigeration

The exploration of performance and prediction of environmentally friendly refrigerant physical properties represents a critical endeavor.Equilibrium molecular dynamics simulations were employed to investigate the density and transport properties of propane and ethane at ultra-low temperatures under evaporative pressure conditions.The results of the density simulation of the evaporation conditions of the blends proved the validity of the simulation method.Under identical temperature and pressure conditions, increasing the proportion of R170 in the refrigerant blends leads to a density decrease while the temperature range in which the gas-liquid phase transition occurs is lower.The analysis of simulated results pertaining to viscosity, thermal conductivity, and self-diffusion coefficient reveals heightened deviation levels within the phase transition temperature zone.This increase in deviation attributed to intensified molecular activity.In terms of uncovering the physical mechanism of gas-liquid phase transition, the work illustrates the macroscopic phenomenon of the intensified existing disorder during phase transitions at the molecular level.Molecular dynamics simulations analyzing the thermophysical properties of refrigerant blends from a microscopic point of view can deepen the comprehension of the thermal optimization of refrigeration processes.