Study of In-Tube Evaporation Heat Transfer of Carbon Dioxide

摘要

The evaporative heat transfer characteristics of carbon dioxide (CO2) were measured in a fluid-heated, 8.0 mm ID smooth stainless steel tube. The test apparatus was a concentric tube heat exchanger heated by water in the annulus with CO2 in the central tube. Data were collected for temperatures of 5 oC and 10 oC; mass fluxes of 250 kg/m2s, 500 kg/m2s, and 650 kg/m2s; and heat fluxes of 24 kW/m2 to 58 kW/m2. The average heat transfer coefficient was determined with the overall UA equation for the annular configuration. All properties were calculated using REFPROP 7.0 (Lemmon et. al. 2002). Results are presented and compared to existing correlations for the two-phase average evaporative heat transfer coefficient.