The effect of refrigerant circuitry on the performance of a freezer with a tube-on-sheet evaporator

Abstract

In this work, the effect of flow circuitry on the performance of a household freezer with a tube-on-sheet evaporator is investigated. The evaporator used in the freezer is a tube-on-sheet type where the tubes are bent and attached underneath the shelves, as in the serpentine heat exchanger. The evaporator is composed of six shelves that are located inside the cabin with a particular distance between each. Four different refrigerant circuitries are modeled to identify the one that provides a homogeneous temperature distribution while consuming less energy, and experiments are conducted by switching the refrigerants flow route between the shelves. The uniform temperature distribution at around the target temperature and the energy consumption of the entire system while achieving this target are monitored as the major performance measures of the investigation. The tests are conducted according to IEC 62552:2015, standard clause 8. The experiments found that the change of the flow circuitry has a crucial impact on the temperature distribution’s uniformity and energy consumption. The type in which the refrigerant circuitry between the shelves is 2-1-6-5-4-3 has the best performance in terms of temperature distribution and energy consumption.