The cooling of high-power electronics urgently requires efficient and controllable heat dissipation techniques. In this work, a novel bidirectional counter-flow microchannels (CFMC) with mass flux distribution being regulated is proposed to achieve this goal. Flow boiling experiments are conducted in the CFMC and compared with traditional unidirectional parallel-flow microchannels (PFMC) by using deionized water as the working fluid. The effects of mass flux distributions on the boiling heat transfer process are experimentally investigated by changing the mass flux on one side of CFMC from 118 kg/m²·s to 370 kg/m²·s while keeping the mass flux on the other side unvaried. It is found that CFMC excels in heat transfer enhancement, as compared to traditional PFMC, the critical heat flux (CHF) can be increased by 42.9%∼53.8%. Furthermore, the average and local heat transfer coefficient (HTC) of CFMC in the convective boiling stage can be enhanced by 33.5%∼62.0% and 39.3%∼89.4%, respectively. In the nucleate boiling stage, the average enhancement of HTC for CFMC can be up to ∼170%. It should be noted that due to the shortening of the drying-out length and ensuring the wetting on one side, compared with the results under even mass flux distribution, the CHF can be further improved for CFMC with uneven mass flux distribution, but HTC has deteriorated. Surprisingly, all heat transfer enhancement results are achieved with a 53.4%∼66.7% reduction in two-phase pressure drop. Equally important, precise regulation of wall temperature distributions, heat transfer characteristics, and two-phase pressure drops can be realized by adjusting the mass fluxes on both sides. The statistical analysis of the visualization results reveals that the mass flux deployment also allows for regulating the wetting and drying times within the CFMC. This work presents essential value for optimizing the flow boiling process in microchannels and has great potential in practical applications.

大功率电子产品的散热迫切需要高效可控的散热技术。在这项工作中，提出了一种具有调节质量通量分布的新型双向逆流微通道（CFMC）来实现这一目标。在CFMC中进行流动沸腾实验，并与传统的单向平行流微通道（PFMC）进行比较，使用去离子水作为工作流体。通过将CFMC一侧的质量通量从118 kg/m ² ·s改为370 kg/m ^{2实验研究了质量通量分布对沸腾传热过程的影响}·s同时保持另一侧的质量通量不变。研究发现，CFMC在传热增强方面表现出色，与传统PFMC相比，临界热通量（CHF）可提高42.9%~53.8%。此外，CFMC在对流沸腾阶段的平均传热系数和局部传热系数（HTC）分别可以提高33.5%~62.0%和39.3%~89.4%。在核沸腾阶段，CFMC 的 HTC 平均增强可达 170%。需要注意的是，由于干燥长度的缩短和保证一侧润湿，与质量通量分布均匀的结果相比，对于质量通量分布不均匀的CFMC，CHF可以进一步提高，但HTC有恶化。令人惊讶的是，所有的传热增强结果都达到了 53.4%~66。两相压降降低 7%。同样重要的是，可以通过调节两侧的质量通量来实现壁温分布、传热特性和两相压降的精确调节。可视化结果的统计分析表明，质量通量部署还允许调节 CFMC 内的润湿和干燥时间。该工作对优化微通道中的流动沸腾过程具有重要价值，在实际应用中具有巨大潜力。可视化结果的统计分析表明，质量通量部署还允许调节 CFMC 内的润湿和干燥时间。该工作对优化微通道中的流动沸腾过程具有重要价值，在实际应用中具有巨大潜力。可视化结果的统计分析表明，质量通量部署还允许调节 CFMC 内的润湿和干燥时间。该工作对优化微通道中的流动沸腾过程具有重要价值，在实际应用中具有巨大潜力。