Influence of system pressure on flow boiling in microchannels
Influence of system pressure on flow boiling in microchannels
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DOI：
10.1016/j.ijheatmasstransfer.2023.124470
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发表时间：
2023
影响因子：
5.2
通讯作者：
V. Lee;T. Karayiannis
中科院分区：
文献类型：
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作者：
V. Lee;T. Karayiannis
在平行微通道热沉（Dh= 0.48mm，44通道）中，研究了压力对HFE-7200在1.0至2.0 bar之间的流动沸腾特性的影响。质量通量和过冷度分别保持恒定在200 kg/m2 s和10 K，而热通量范围为26.1 - 160.7 kW/m2。增加系统压力会降低蒸汽密度比，从而导致压降降低，气泡产生频率增加，系统中的两相传热系数增加，尽管这在较高压力下的低沸点下可能不明显。在较高的压力下观察到较小的气泡直径，并导致流态过渡到弹状流的延迟，这是容易发生流动逆转。实验工作表明，有前途的手段来管理流动不稳定性和提高传热性能的两相微通道系统HFE-7200。
The effect of pressure on the flow boiling characteristics of HFE-7200 between 1.0 to 2.0 bar was investigated in a parallel microchannel heat sink (Dh= 0.48 mm, 44 channels). The mass flux and subcooling degree were kept constant at 200 kg/m2s and 10 K respectively, while heat flux ranged from 26.1 – 160.7 kW/m2. Increasing system pressure decreased the vapour density ratio, thus leading to reduced pressure drop, increased bubble generation frequency and two-phase heat transfer coefficients in the system, though this may not be apparent at low superheat degrees at higher pressures. Smaller bubble diameters were observed at higher pressures and resulted in a delay in flow regime transition to slug flow, which is prone to flow reversal. The experimental work showed promising means to manage flow instabilities and enhance heat transfer performance in two-phase microchannel systems for HFE-7200.