Evaporation Heat Transfer and Pressure Drop Characteristics of R32 Inside a Multiport Tube with Microfins
Evaporation Heat Transfer and Pressure Drop Characteristics of R32 Inside a Multiport Tube with Microfins
复制标题
R32微翅片多口管内蒸发传热及压降特性
DOI：
10.1142/s2010132518500177
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发表时间：
2018
影响因子：
1
通讯作者：
Shigeru Koyama
中科院分区：
文献类型：
--
作者：
Daisuke Jige;Shogo Kikuchi;Hikaru Eda;Norihiro Inoue;Shigeru Koyama
研究了R32在矩形直微翅片小通道水平多通道管内的蒸发换热和压降特性。在饱和温度为15℃、质量速度为50 ~ 400kgmt、热流密度为5 ~ 20kwt的条件下，测量了传热系数和压降。在相同的饱和温度下，在质量速度为50 ~ 400kgm、质量范围为0.1 ~ 0.9的条件下，测量了绝热两相流动时的摩擦压降。由于强迫对流的增加，传热系数随质量的增加而增加。干燥起始质量随质量速度的增大而增大。除高质量区域外，热流密度对换热系数的影响较小。在质量速度为200kgm的高质量区域和质量速度为400kgm的低质量区域，带微翅片的多通道管的换热系数均高于不带微翅片的多通道管。阐明了质量速度和微鳍对摩擦压降的影响。推测微鳍对摩擦压降的影响可以用水力直径来考虑。结果表明，摩擦压降与先前的相关关系很好地吻合。
This study investigated the evaporation heat transfer and pressure drop characteristics of R32 in a horizontal multiport tube consisting of rectangular minichannels with straight microfins. The heat transfer coefficient and pressure drop were measured for a mass velocity range of 50–400kgmsand heat flux range of 5–20kWmat a saturation temperature of 15C. The frictional pressure drop during an adiabatic two-phase flow was also measured for a mass velocity range of 50–400kgmsand quality range of 0.1–0.9 at the same saturation temperature. The heat transfer coefficient increased with an increasing quality owing to the increase in forced convection. The dryout inception quality increased with the increase in mass velocity. The effects of heat flux on the heat transfer coefficient were small, except in a high-quality region. The heat transfer coefficient in a multiport tube with microfins was higher than that in a multiport tube without microfins in a high-quality region at a mass velocity of 200kgmsand in a low-quality region at a mass velocity of 400kgms. The effects of mass velocity and microfins on the frictional pressure drop were clarified. It is suspected that the effects of a microfin on the frictional pressured drop can be considered using the hydraulic diameter. The frictional pressure drop was shown to be in good agreement with previous correlations.