PERFORMANCE TESTING AND COMPARISON OF LIQUID OVERFEED AND CASCADE CO2 SYSTEMS WITH R404A PRIMARY
A subcritical CO2 parallel compressor system was setup and tested, and energy efficiency comparisons were completed. R404A was the high-side refrigerant, and heat was rejected at controlled condensing temperatures. CO2 was the low side secondary refrigerant and heat was added from a glycol-heated evaporator. For low evaporating temperatures, tests were conducted with: 1) Pumped liquid CO2 in a liquid overfeed system and 2) Direct expansion of CO2. The direct expansion approach used a cascade refrigeration system with CO2 low side compressors and R404A high side compressors. For medium evaporating temperatures, tests were conducted only with pumped liquid overfeed, and no CO2 compressors were used. Semi-hermetic piston compressors were used for both R404A high side and cascade CO2 low side. Performance comparisons were made between these two types of CO2 systems and baseline direct expansion R404A. At high temperature ratio conditions, the cascade CO2 system was roughly 5％ more efficient than either the baseline R404A direct expansion system or pumped liquid CO2 system. At low temperature ratio conditions, the energy efficiency of the pumped liquid system was roughly equal to the R404A baseline.
B.REES C.ROHRER D.SHAPIRO J.TRACHTA
McAlpine Hussmann Limited,11-17 Walls Road, Penrose P.O. Box 12303, Penrose Auckland, New Zealand Ingersoll-Rand Climate Control Technologies 12999 St. Charles Rock Road Bridgeton, MO 63044, USA
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21（万方平台首次上网日期，不代表论文的发表时间）