PROTOTYPE LIQUID CHILLER USING CARBON DIOXIDE AS REFRIGERANT
A 40 kW cooling capacity liquid chiller using carbon dioxide (CO2) has been designed, built and tested experimentally. The prototype had the possibility to reject heat both to air and water. Both the water chiller and the gascoolers are new designs adapted for CO2.The water cooled gas cooler was a compact multi tube-in-tube counter flow concept, whereas the air cooled gascooler was a conventional round tube in fin. The liquid chiller/evaporator was based on a tube-in-shell concept. The compressor was a semi-hermetic piston type.Experiments were conducted with varying cooling water temperatures and at steady state and cooldown situations. Measured cooling capacity at steady state conditions showed a cooling capacity of 13 to 33kW, depending of high pressure and cooling water temperature. The COP varied with high pressure and cooling water temperature. Optimum high side pressure was 70bar for cooling water temperatures below 18, whereas 80 bar above.Calculated U-value of the evaporator was 3100W/m2K. Measured values were in the range of 1100 to 1400 W/m2K. The reduction is probably due to suppressed nucleate boiling caused by oil film. The heat rejector worked well as gascooler, whereas relatively poor as condenser. This initial study shows that the CO2 liquid chiller technology is promising. However, there is room for performance improvements.
Arne Jakobsen H(a)vard Rekstad Geir Skaugen Trygve Eikevik Petter Neks(a)
SINTEF Energy Research AS N-7465 TRONHEIM, NORWAY Norwegian University of Science and Technology, Dept. Energy and Process Engineering N-7491 TRONDHEI
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）