R134a condensation flow regime and pressure drop in horizontal microchannals cooled symmetrically and asymmetrically
R134a condensation flow regime and pressure drop in horizontal microchannals cooled symmetrically and asymmetrically
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对称和非对称冷却的水平微通道中的 R134a 冷凝流态和压降
DOI：
10.1016/j.ijheatmasstransfer.2017.08.003
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发表时间：
2017-12
影响因子：
5.2
通讯作者：
Li Jun Ming
中科院分区：
文献类型：
--
作者：
Wang Ji;Wang Jin;Li Jun Ming
对制冷剂R134 a在水力直径为301.6 μm、长径比为2.46、长度为50 mm的椭圆形平行微通道内的两相流态和冷凝摩擦压降进行了实验研究。研究了非对称冷却和对称冷却两种微通道冷却方式的冷却效果。对于0.1-0.9的质量和60-250 kg/（m2 s）的质量通量，记录流态和压降。R134 a的入口饱和温度为31.3 °C。实验中观察到了膜状波纹流、角部波纹流、弹状流和泡状流。绘制了流型图，并与文献中的8幅流型图进行了比较。用蒸汽韦伯数给出了两种流型判据。测量了波动-间歇流动转变的位置，并与文献中的关联式进行了比较。随着制冷剂质量流量和入口品质的增加，过渡位置向下游移动。对称冷却凝结流的转捩位置比非对称冷却凝结流的更靠上游。摩擦压降随着质量流量和干度的增加而增加。对称冷却的微通道的压降低于非对称冷却。压降数据与文献中的关联式进行了比较。
An experimental investigation was conducted for two-phase flow regimes and friction pressure drop during condensation of refrigerant R134a in oval parallel microchannels with a hydraulic diameter of 301.6 µm, an aspect ratio of 2.46 and a length of 50 mm. The effects of microchannel cooling methods, including asymmetric cooling and symmetric cooling, were studied. The flow regimes and pressure drops were recorded for qualities of 0.1–0.9 and mass flux of 60–250 kg/(m2s). The inlet saturation temperature of R134a is 31.3 °C. Film wavy flow, corner wavy flow, slug flow and bubbly flow were observed. The flow regimes were mapped and compared with 8 flow regime maps in the literature. Two flow regime criteria were given using vapor Weber number. The wavy-intermittent flow transition locations were measured and compared with the correlations in the literature. The transition location moves downstream with increasing refrigerant mass flux and inlet quality. The transition locations were more upstream for the condensation flow cooled symmetrically then that cooled asymmetrically. The friction pressure drop increases with increasing mass flux and quality. The pressure drop for microchannels with symmetric cooling is lower than asymmetric cooling. The pressure drop data was compared with the correlations in the literature.
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DOI：
10.1016/j.ijheatmasstransfer.2008.03.028
发表时间：
2008-10
影响因子：
5.2
作者：
Xiaojun Quan;P. Cheng;Huiying Wu
通讯作者：
Xiaojun Quan;P. Cheng;Huiying Wu
DOI：
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2002-06
影响因子：
5.2
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通讯作者：
Tian-yang Zhao;Q. Liao
DOI：
--
发表时间：
2007-04
期刊：
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影响因子：
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作者：
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通讯作者：
E. Lemmon;M. Huber;M. McLinden
影响因子：
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作者：
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DOI：
10.1016/j.icheatmasstransfer.2004.02.019
发表时间：
2005-01-01
影响因子：
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作者：
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通讯作者：
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