24 June 2014
A thermodynamically analytical model on the two-stage compression
refrigeration/heat pump system with vapor injection was derived. The optimal volume ratio of the high-pressure cylinder to the low-pressure one has been discussed under both cooling and heating conditions. Based on the above research, the prototype was developed and its experimental setup established. A comprehensive experiment for the prototype has been
conducted, and the results show that, the favorable value of the volume ratio is between 0.70 and 0.85. The value of the relative intermediate pressure between 1.1 and 1.2 is suitable for
the two-stage system; Comparing with the single-stage cycle, the discharge temperature decreases about 2.3°C~4.8°C under cooling conditions and 4.1°C~9.0°C under heating conditions.