Improvement of a thermoelectric and vapour compression hybrid refrigerator

This paper presents the improvement in the performance of a domestic hybrid refrigerator that combines vapour compression technology for the cooler and freezer compartments, and thermoelectric technology for a new compartment. The heat emitted by the Peltier modules is discharged into the freezer compartment, forming a cascade refrigeration system. This configuration leads to a significant improvement in the coefficient of operation. Thus, the electric power consumption of the modules and the refrigerator decrease by 95 % and 20 % respectively, with respect to those attained with a cascade refrigeration system connected with the cooler compartment. The optimization process is based on a computational model that simulates the behaviour of the whole refrigerator. Two prototypes have been built and tested. Experimental results indicate that the temperature of the new compartment is easily set up at any value between 0 and -4 ºC, the oscillation of this temperature is always lower than 0.4 ºC, and the electric power consumption is low enough to include this hybrid refrigerator into energy efficiency class A, according European rules and regulations.