Thermal characteristics and field coordination angle analysis of gas-liquid two-phase annular heat transfer in microchannels

The study of fluid heat transfer characteristics and mechanisms in microchannels is the basis of microreactor regulation, transfer strengthening and design. For the multiphase flow System in the microchannel, the flow and dispersion of each mobile phase directly affect the heat transfer characteristics of the multiphase System and determine the heat transfer efficiency of the microchannel. Numerical methods were utilized to study the heat transfer Performance of gas-liquid two-phase annular flow in cross-shaped microchannels. In the annular flow heat transfer process, the introduction of gas phase on the one hand allows the gas-liquid shear force to drive the liquid phase to increase the liquid phase flow rate. On the other hand, it increases the perturbation and thus reduces the field synergy angle. The two aspects work together to strengthen the total annular flow heat transfer Performance. Starting from the liquid film fluctuation of the annular flow, the field synergy angle is introduced to study the relationship between the liquid film fluctuation and the local heat transfer Performance of the annular flow. The local field synergy angle becomes smaller at the liquid film fluctuation, and the smaller the field synergy angle, the stronger the heat exchange between the high-velocity gas phase and the high-temperature liquid phase, so the high-velocity gas phase carries away more heat, which strengthens the total heat transfer Performance of the annular flow. Finally, a preliminary heat transfer flow chart is drawn based on the study to provide theoretical support for the temperature control and heat transfer enhancement technology inside the microreactor.