EXPERIMENTAL STUDY ON SINGLE-REFRIGERANT CASCADE REFRIGERATION SYSTEM

摘要

High and low temperature levels are using R410A as refrigerant, and expansion of the containers and other devices do not need to set in flow single-refrigerant cascade refrigeration system. It makes system structure is more simple. The refrigerant flow can be controlled by the frequency of compressor in this refrigeration system. Study and analyze the effect of evaporation temperature incremental and high temperature compressor frequency incremental on system performance. The flow ratio decreases and COP increases with evaporation temperature increases when condensation temperature is constant in the cascade refrigeration system. The maximum flow ratio of the high temperature level decreased by 0.071% and the flow ratio of the low temperature level increased by 0.27% when the evaporation temperature increased by 1K. Meanwhile the flow ratio decreased by about 1.36%, and the interstage capacity ratio increased by 1.5%, and the COP maximum increased by 3.76%. And the interstage capacity ratio maximum decreased by 2.62% when the frequency of compressor increased by 1Hz. Through changing the frequency of compressor, the energy consumption can be reduced. And the COP can be improved and the system is more energy efficient.