Abstract: The microchannel heat exchanger has obvious advantages in solving the problem of heat dissipation under high heat flux. In practical industrial applications, the integrated structure is usually adopted to improve the reaction efficiency, however, it is easy to affect the performance of heat transfer by uneven flow distribution in the process of reactor integration, and even leads to the phenomena of “dry steam”or“excessive liquid supply”. Therefore, the study of phase distribution characteristics in parallel microchannels has important guiding significance to improve the heat transfer efficiency. By optimizing the structure of the interrupted microchannel, a two-side-widened microchannel with transverse microcavities is proposed, the phase distribution uniformity of the new microchannel was determined by flow distribution, heat transfer characteristics, relative deviation of the two-phase distribution and pressure drop fluctuation. The results show that the structural optimization of the interrupted microchannel significantly improves the uniformity of phase distribution, and the relative deviation of gas flow in each branch pipe is less than 40%. The design of transverse microcavity makes two adjacent channels fully mixed, and the overall flow uniformity is improved by 37.5%. By widening the channel on both sides of the design, played a bubble filter, which reduce the pressure on both sides of the space and ensure the channel flow between the flow pattern and pressure consistency.

Key words: microchannel, gas-liquid two-phase flow, flow pattern, phase distribution, pressure drop