Abstract
Flow boiling in microchannels is a promising approach to solve the heat dissipation problems of the electronic components. In this work, two types of interconnected slot microchannels (SM) with the staggered (SSM) and in-line (ISM) arrangement of the slots (W = 300μm, H = 600μm) are fabricated. Flow boiling experiments are conducted in the SMs (W = 300μm, H = 600μm, L = 35mm) at mass fluxes of 118–370 kg/m2·s, with the deionized water being used as the working fluid. It is found that compared with plain-wall microchannels (PM), the critical heat fluxes (CHF) in ISM are increased by 24.3%∼50.0%, and 30.8∼53.1% for SSM within the test range. The comparative study with PM reveals that SMs can significantly promote the bubbly flow. Equally important, IMs increase the effective heat transfer area while facilitating the redevelopment of the liquid film. Therefore, the heat transfer coefficient (HTC) in ISM and SSM are significantly enhanced by 44.8% ∼ 60.9% and 43.7% ∼ 68.3%, respectively. Furthermore, the connection of the microchannels promotes the mixing of the fluid and enables a more uniform flow distribution in microchannels. The interconnected slots provide the lateral expansion space for bubbles, thus suppressing the reversal flow of the bubbles. Compared with ISM, SSM could break out the long slug bubbles more effectively and prevent gigantic bubbles from forming. The two-phase pressure drop in SSM could be reduced by 23% on average compared with ISM. This work is trying to provide an improved design for microchannels to enhance the flow boiling process.
