Lattice Boltzmann mesoscopic study of effects of corrosion on flow boiling heat transfer in microchannels

Abstract

The robustness of boiling heat transfer performance is crucial for the long-term applications, and it is necessary to understand the influence of corrosion on flow boiling heat transfer. In the present study, the corrosion process is first studied and the corrosion morphologies under typical reactive transport conditions and pit geometrical parameters are obtained using the corrosion lattice Boltzmann (LB) model. Then, the flow boiling heat transfer in the corroded microchannels is studied using the hybrid thermal multiphase LB model, and compared with the heat transfer performance and bubble dynamic behaviors of smooth intact microchannel. Effects of corrosion morphology, pit height, and staggered distance between pits on the flow boiling heat transfer characteristics are explored. The corrosion level plays an important role in the heat transfer performance. Although the corroded cavities with various corrosion levels can promote the bubble nucleation, the reduced heat transfer performance occurs at high corrosion level due to inefficient removal of the bubbles from the large corroded cavities. Increasing the pit height and staggered distance between pits can slow down the reduction of heat transfer performance. For the severe corroded microchannels, the heat transfer performance is deteriorated significantly due to the formation of the vapor film covered on the heating surface.