空間制限によるMEB遷移時の伝熱面気泡挙動観察

抄録

We found that the transition from nucleate boiling to microbubble emission boiling (MEB) occurs even below the critical heat flux when the boiling space is confined by placing a rod above the boiling surface. We examined this transition to MEB by focusing on the heat flux, superheat, and sound pressure together with high-speed video analyses. The following results were obtained. At the initiation of transition, the surface temperature increased rapidly while the heat flux decreased slightly. Then, the surface temperature gradually decreased with increasing heat flux. This indicates that the partial dry-out area caused by limiting the boiling space enhances the heat transfer. The high heat transfer rate in MEB may be attributed to the direct contact between the solid and liquid, along with latent heat transport.