Host: The Japan Society of Mechanical Engineers
Name : International Conference on Power Engineering-2021(ICOPE-2021)
Date : October 17, 2021 - October 21, 2021
Mini-channel heat exchangers are widely applied in aerospace industry, refrigeration/heat pump systems and other fields, because of small size and good heat exchange performance. In small scale, the condensation heat transfer is less affected by gravity. Under certain conditions, the condensation heat transfer under microgravity can be regarded as the same as the condensation heat transfer under normal gravity, which can be called ‘gravity independence’. In this paper, the process of flow condensation heat transfer of R134a in a mini-channel is numerically simulated by using CFD with gravity and surface tension as body force. Under different mass fluxes, vapor qualities, tube shapes and tube diameters, the influence of gravity on heat transfer coefficient is studied. Based on the data from the simulation and previous studies, a criterion of gravity independence for flow condensation heat transfer in mini-channel is established by combining the dimensionless numbers related to gravity, surface tension and inertial force.
