Simulation and experimental study of heat pump air-side heat transfer

Abstract

A simulation model is developed for the air side of a heat pump dryer which defines the smallest heat exchange unit between fins and air, focusing on the heat exchange between them. A self-constructed test bench was designed to control the temperature and humidity inlet of the heat pump and minimize the impact of environmental factors. The study examined the impact of diverse inlet conditions on heat pump heat transfer performance via a test bench. The experimental results were compared to the simulation outcomes to verify the precision of the model, which recorded a 3.31% outlet temperature deviation. Furthermore, the analysis discovered that the link between the outlet temperature and the inlet air volume of the heat pump demonstrates distinct stage features. When the airflow is below 170 m3/h or above 230 m3/h, the temperature of the heat pump outlet remains almost constant. However, when the airflow falls between 170 m3/h and 230 m3/h, the heat pump outlet temperature becomes dependent on the heat pump’s operational power. The simulation of the unit model under constant temperature boundary conditions and constant heat flow boundary conditions models the variation of outlet temperature and airflow. This model facilitates the thermal design of the heat pump system, particularly for the examination of heat transfer properties under varying inlet conditions. Furthermore, it ensures the validation of the effectiveness of numerical simulation methods in evaluating and enhancing air-side heat transfer in heat pumps for different engineering applications.