Evaporation heat transfer from the hot water flow to the cold air flow in a horizontal and rectangular flow channel was examined. The water temperature was 35°C ∼ 65°C. The air velocity was 0.02 m/s ∼2.57 m/s. The heat transfer rate from the water flow to the air flow became large with an increase in the air velocity and the water temperature. The evaporation heat transfer was much larger than the convection heat transfer and dominant in the heat transfer. The ratio of the evaporation heat transfer rate to the total heat transfer rate was approximately 0.9 ∼ 0.7 in the present experimental conditions. It showed the slightly decreasing tendency for the air velocity. The evaporation heat transfer coefficient showed strong dependency on the air velocity in both the laminar and the turbulent flow region of the air flow. The convection heat transfer coefficient showed the same tendency for the Reynolds number of the air flow as that for the air single-phase flow in the turbulent flow region although the value was much larger than that of the single-phase flow. In the laminar flow region, the convection heat transfer coefficient was constant as in the single-phase flow when the water temperature was low, although the value itself was much larger than that of the single-phase flow. As the water temperature became high, the convection heat transfer coefficient became large and showing dependency on the Reynolds number of the air flow. As the Reynolds number of the air flow became further small, the convection heart transfer coefficient greatly decreased irrespective of the water temperature.
- Heat Transfer Division
Study on Cooling of Hot Water by Air Flow With Evaporation
- Views Icon Views
- Share Icon Share
- Search Site
Koizumi, Y, Ebihara, Y, & Murase, M. "Study on Cooling of Hot Water by Air Flow With Evaporation." Proceedings of the ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASME/JSME 2011 8th Thermal Engineering Joint Conference. Honolulu, Hawaii, USA. March 13–17, 2011. T10242. ASME. https://doi.org/10.1115/AJTEC2011-44512
Download citation file: