Experimental investigation of a miniature-scale refrigeration system for electronics cooling

A miniature-scale refrigeration system suitable for electronics cooling applications was developed and experimentally investigated. A detailed review of the literature on refrigeration systems and system simulation models for application to electronics cooling is also provided. Experimental results obtained with the prototype system demonstrate its feasibility for use in cooling compact electronic devices. The cooling capacity of the system investigated varied from 121 to 268W, with a COP of 2.8 to 4.7, at pressure ratios of 1.9 to 3.2. The effectiveness of the condenser ranged from 52% to 77%, while a thermal resistance of 0.60 and 0.77 °C-cm²/W was achieved at the evaporator. The evaporator-heat spreader thermal resistance is defined as the ratio of the temperature difference between the chip surface and the refrigerant evaporator to the evaporator heat transfer rate. The overall system thermal resistance, defined as the ratio of the temperature difference between the chip surface and the condenser air inlet, is of 0.04 to 0.18 °C-cm²/W. An overall second-law efficiency ranging from 33% and 52% was obtained, using a commercially available small-scale compressor. The measured overall isentropic efficiency was between 25% and 60%.