Liquid-Flooded Ericsson Cycle Cooler: Part 2 – Experimental Results

An experimental test program was conducted on a novel Ericsson cycle heat pump. The concept uses liquid flooding of the compressor and expander to approach isothermal compression and expansion processes. Open drive automotive scrolls were used in the experimental system. Numerous experiments were run at various conditions using nitrogen as the refrigerant and alkyl-benzene oil as the flooding liquid. Volumetric cooling capacities of over 110 kJ/m 3 were measured, and second law efficiencies of approximately 3% were achieved. Similar to other gas cycles, the cycle performance is very sensitive to the adiabatic efficiencies of the rotating equipment and the performance of the off-the-shelf equipment was not sufficient to achieve good cycle efficiency. In addition, large pressure drops occurred in the system due to the instrumentation used, and the long and arduous flow paths. The scroll compressor and expander were found to perform reasonably well considering that they were not designed for the operating conditions encountered.