Simulation Study of a Dual-temperature Display Cabinet with Condensing Heat Recovery

Among all cold chain equipment, the energy consumption of an open refrigerated display case is usually high, especially the dual-temperature display cabinet, which provides simultaneous heating and cooling and consumes even more electricity. The condensing heat can be used for heating and therefore will lead to significant energy savings for the dual-temperature display cabinet. This paper simulates a dual-temperature display cabinet with condensing heat recovery. Employing COP and effective heating power as the indices, the optimization direction of each component in the refrigeration system is determined, and its performance is compared with the baseline cabinet with an electric heater. The simulation results of the baseline cabinet are validated by experimental results, and the energy-saving potential of the new system is studied. Simulation results suggest that the dual-temperature display cabinet with condensation heat recovery has significant energy-saving advantages. The key is the air volumetric flowrate of the condenser. It is recommended to install a variable-speed fan, which can produce optimal air volumes of 0.018 m3/s, 0.03 m3/s, 0.045 m3/s, and 0.095 m3/s at ambient temperatures of 15 ℃, 20 ℃, 25 ℃, and 32 °C, respectively. When the condenser air flow rate is kept at 0.06 m3/s, the cabinet has a decent energy-saving potential when the ambient temperature is high. The best energy savings is achieved when the ambient temperature is 25 ℃, with a reduction in power consumption of 52%.