A New Control System of a Household Refrigerator-Freezer

This paper will present the structure of the new system, the control scheme and its performance test results.In this new system, the damper in the conventional refrigerator is replaced by an additional cooling fan Thus, it uses two cooling fans: one (F-fan) is to provide cooled air for freezing compartment (F-compartment) and the other (R-fan) is for refrigerating compartment (R-compartment), respectively.The F-fan and the R-fan are controlled independently by thermo-sensors installed in the F and R-compartments.Experimental results show improved performance of the new refrigerator over the conventional refrigerator.Among them is the lower fluctuation of the R-compartment temperature, which has a significant effect in lowering the refrigerating temperature and storing foods fresh longer.It can quickly response to the load change in the R-compartment The air-defrosting by the use of the R-fan was proved to be an efficient method in saving the energy consumption during the defrosting cycle.1. Smaller temperature fluctuation and lower average temperature in the R-compartment which have significant effect in improving food freshness 2. Faster refrigerating speed and quick response to the load change in the R-compartment 3. Energy saving by the use of the air-defrosting and maintaining the R-compartment cool during the defrosting cycle.