The flow and heat transfer characteristics of contact condensation in rectangular microchannels were studied experimentally. All tests were performed with water and steam. At a certain gas-liquid ratio, three flow patterns were found in the microchannel of 600 Î¼m: slug flow, annular flow and mist flow. The experimental results show that the contact condensation heat transfer process in the microchannel is affected by the channel structure and gas-liquid flow. In the experimental conditions with higher Reynolds number, due to the influence of inertia force, the Nusselt number decreases with the increase of hydraulic diameter, and increases with the increase of flow rate. However, in the same microchannel, the Nux of the fluid reaches the maximum at the entrance, and then decreases gradually along the flow direction.
Keywords Microchannel, Heat transfer, Condensation, Two-phase flow