Direct local heat flux measurement during water flow boiling in a rectangular minichannel using a MEMS heat flux sensor
Direct local heat flux measurement during water flow boiling in a rectangular minichannel using a MEMS heat flux sensor
复制标题
DOI：
10.1016/j.expthermflusci.2020.110285
复制
发表时间：
2021-02-01
影响因子：
3.2
通讯作者：
Yabuki, Tomohide
中科院分区：
文献类型：
--
作者：
Morisaki, Masanori;Minami, Shota;Yabuki, Tomohide
采用自制的多层结构MEMS热流传感器直接测量微通道内的局部热流，研究了微通道内水流沸腾的传热特性。在10 kHz的采样频率下，与沸腾行为的高速可视化同步地测量水流沸腾中的局部温度和热通量。测量结果揭示了基本的传热过程，包括薄液膜蒸发，干出的液体膜，干补丁再润湿后的瞬态热传导，和单相强制对流。薄液膜蒸发表明高的局部热通量，其远超过1 MW/m（2），并且对壁传热提供主要贡献。此外，再润湿后瞬态热传导表明高于1 MW/m（2）的高热通量。然而，它是微不足道的，在所有测试的热通量，因为它的持续时间短的整体壁传热。除了低蒸汽质量外，液相强制对流的贡献也很小。
Heat transfer characteristics of water flow boiling in a minichannel were investigated through the direct measurement of local heat flux using a fabricated MEMS heat flux sensor with a multi-layered structure. Local temperatures and heat fluxes in the water flow boiling were measured at a sampling frequency of 10 kHz in synchronism with the high-speed visualization of the boiling behavior. The measurement results revealed fundamental heat transfer processes, including thin liquid film evaporation, dry-out of the liquid film, transient heat conduction after dry patch rewetting, and single-phase forced convection. The thin liquid film evaporation indicated a high local heat flux that was well over 1 MW/m(2) and provided a dominant contribution to the wall heat transfer. Furthermore, the post-rewetting transient heat conduction indicated a high heat flux that was higher than 1 MW/m(2). However, it was insignificant in terms of the overall wall heat transfer at all the tested heat fluxes because of its short duration. The contribution of liquid-phase forced convection was also small, except at low vapor qualities.