Turbulent Convective Heat Transfer over a Circular Tube Carrying Gas-Liquid Two Phase Flow with Phase Change

상변화를 수반하는 이상류(二相流)가 흐르는 원관 주위에서의 난류 열전달

Turbulent convective heat transfer phenomenon which occur around the evaporator section of heat pump were analyzed experimentally. For this purpose a special wind tunnel and a heat pump system were designed and fabricated. Evaporator section was installed perpendicular to air flow direction and part of the evaporator was made of a glass tube for visual observation. The velocity distribution, turbulent intensity and temperature distribution were measured by hot wire technique and thermocouples. An experimental correlation for the convective heat transfer coefficient was obtained and the result is somewhat higher than the value calculated from Hilpert equation. The difference in two equations is believed to be due to the boning effect inside the evaporator tube.