Flow boiling of CO{sub 2} in microchannels

Conference · Sat Jul 01 04:00:00 EDT 2000

OSTI ID:20104805

Zhao, Y; Molki, M; Ohadi, M M; Dessiatoun, S V

A review of recent work on flow boiling of CO{sub 2} in microchannels indicated that the heat transfer coefficient for flow boiling in microchannels is substantially higher than that in tubes of normal size. These characteristics might suggest an extended use of CO{sub 2} in the next century. The authors present their preliminary results obtained for flow boiling of CO{sub 2} in microchannels. These preliminary experiments were conducted at mass fluxes of 250 to 700 kg/m{sup 2}{center_dot}s and heat fluxes of 8 to 25 kW/m{sup 2}. For the range of parameters tested, it was demonstrated that the heat transfer coefficient of CO{sub 2} in microchannels is almost independent of heat flux and mass flux. This might imply that the heat transfer mechanism of CO{sub 2} in microchannels depends on other parameters such as the size and the geometry of the microchannels. Furthermore, besides its excellent thermal properties and environmental advantages, CO{sub 2} offers outstanding heat transfer characteristics compared to traditional refrigerants such as R-134a.

• Research Organization: Univ. of Maryland, College Park, MD (US)
• OSTI ID: 20104805
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BOILING
CARBON DIOXIDE
FLUID FLOW
HEAT TRANSFER
REFRIGERANTS