Improved thermohydraulic numerical model of a heat exchanger for air-to-refrigerant systems

• Thermohydraulic unsteady numerical model of fin-and-tube heat exchanger.
• Unsteady behaviors corresponding to the input conditions and elapsed time.
• Improved governing equations of two-phase fluid flow.
• Experimental validation of the thermohydraulic mathematical model.

This paper reports on a numerical model derived to predict the transient thermohydraulic behavior of the air and refrigerant in a heat exchanger for refrigerant systems. The purpose of this study is to improve the numerical model of the fin-and-tube heat exchanger for air conditioners. The equations of mass, energy, and momentum were completely separated for vapor and liquid in a two-phase thermal fluid flow. The model was validated by analyzing experimental data based on the temperature and pressure of the refrigerant. The numerical results of superheating, temperature, and pressure distributions in each zone in the fin-and-tube structure were estimated using the input variables. The maximum errors in temperature difference and pressure were within 5 °C and 4%, respectively.