Theoretical and experimental study on a frost-free refrigerated display cabinet.

We propose a frost-free refrigerated display cabinet (RDC) that mainly comprises a compressor, a low-temperature evaporator and two desiccant-coated heat exchangers (DCHEs). One of the DCHEs works as a mid-temperature evaporator, in which the return air is dehumidified due to the desiccant adsorption process. The dry air leaving the DCHE is cooled by the low-temperature evaporator and supplied to the display cabinet. Meanwhile, another DCHE works as a condenser, in which the desiccant is regenerated using condensation heat that would otherwise be ejected into the ambient air in conventional RDCs. Calculation was conducted for a forced draft, open-type frost-free RDC, with cabin volume of 67L and cabin temperature of 2~8°C and the results show daily electricity consumption of 10.4 MJ, 70% of which is due to the compressor.