An experimental study on condensation of refrigerant R134a in a multi-port extruded tube
An experimental study on condensation of refrigerant R134a in a multi-port extruded tube
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DOI：
10.1016/s0140-7007(02)00155-x
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发表时间：
2003-06
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影响因子：
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通讯作者：
S. Koyama;K. Kuwahara;K. Nakashita;Ken Yamamoto
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文献类型：
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作者：
S. Koyama;K. Kuwahara;K. Nakashita;Ken Yamamoto
本文对纯制冷剂R134a在两种长865 mm的多通道挤压管（8个通道，水力直径1.11 mm）和19个通道（水力直径0.80 mm）中的冷凝压降和传热特性进行了实验研究。通过小的压力测量端口以191 mm的间隔测量压降。在有效冷却长度为75 mm的每一个分段中，使用热流传感器测量局部传热率。发现摩擦压降的实验数据与三岛和Hibiki [trans.JMSE（B）61（1995）99]的关联式一致，而与奇泽姆和Laird [trans.ASME 80（1958）227]，Soliman等[trans.ASME，Ser.C90（1998）267]，和Haraguchi等人[Trans.JSME（B）60（1994）239]，过度预测。作为试验，还将局部传热系数的数据与Moser等人[J.Heat Transfer 120（1998）410]和Haraguchi等人[Trans.JSME（B）60（1994）245]的关联式进行了比较。高质量速度的数据与Moser等人的关联式一致，而低质量速度的颗粒则表现出不同的趋势。Haraguchi等人的相关性显示出与使用三岛和Hibiki的相关性估计其相关性中的剪切应力时的数据相似的趋势。
In the present study, the local characteristics of pressure drop and heat transfer are investigated experimentally for the condensation of pure refrigerant R134a in two kinds of 865 mm long multi-port extruded tubes having eight channels in 1.11 mm hydraulic diameter and 19 channels in 0.80 mm hydraulic diameter. The pressure drop is measured at an interval of 191 mm through small pressure measuring ports. The local heat transfer rate is measured in every subsection of 75 mm in effective cooling length using heat flux sensors. It is found that the experimental data of frictional pressure drop agree with the correlation of Mishima and Hibiki [Trans. JMSE (B) 61 (1995) 99], while the correlations of Chisholm and Laird [Trans. ASME 80 (1958) 227], Soliman et al. [Trans. ASME, Ser. C 90 (1998) 267], and Haraguchi et al. [Trans. JSME (B) 60 (1994) 239], overpredict. As a trial, the data of local heat transfer coefficient are also compared with correlations of Moser et al. [J. Heat Transfer 120 (1998) 410] and Haraguchi et al. [Trans. JSME (B) 60 (1994) 245]. The data of high mass velocity agree with the correlation of Moser et al., while those of low mass velocity show different trends. The correlation of Haraguchi et al. shows the trend similar to the data when the shear stress in their correlation is estimated using the correlation of Mishima and Hibiki.