CO2-DX SYSTEMS FOR MEDIUM- AND LOW-TEMPERATURE REFRIGERATION IN SUPERMARKET APPLICATIONS
This paper describes use of low-temperature (LT) and medium-temperature (MT) CO2 refrigeration systems in supermarket applications. The Linde Refrigeration Company refrigeration plant employs a cascade heat exchanger where the waste heat of the LT CO2 system is transferred to a conventional MT HFC system typically operated with R404A or R134a. The cascade arrangement limits the high-side pressure of the LT CO2 system to a maximum of 40 bars. Due to the high density of the CO2 suction gas, very small dimensions for compressors and the piping system are achieved. Excellent boiling heat transfer properties lead to higher CO2 evaporating temperatures, thereby compensating for the energy penalty imposed by the cascade heat exchanger. Based on the positive experience with LT systems, efforts were undertaken to develop a transcritical CO2 system for MT application and thus affect an all-CO2 refrigeration system. While many standard components were possible for the LT-system, original designs were needed for the MT-system due to high-side system pressures of up to 120 bars. This presented significant design challenges, particularly with regard to the compressors, gas coolers, and high-side expansion valves. Experience to date suggests that these systems are potentially viable alternatives to HFC-based supermarket refrigeration systems.
T.SIENEL O.FINCKH
Carrier Commercial Refrigeration, Lead Design Center Am Mainzer Weg 7, 55246 Mainz-Kostheim, Germany
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）