2012 Fiscal Year Final Research Report
Effect of lubricating oil on flow boiling heat transfer of low GWPrefrigerant R-1234yf in a horizontal small-diameter tube
| Project/Area Number |
22560188
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
SAITOH Shizuo 東京大学, 大学院・工学系研究科, 助手 (60170502)
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| Co-Investigator(Renkei-kenkyūsha) |
HIHARA Eiji 東京大学, 新領域創成科学研究科, 教授 (00156613)
DAN Chaobin 東京大学, 新領域創成科学研究科, 准教授 (30401227)
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| Project Period (FY) |
2010 – 2012
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| Keywords | 低GWP冷媒 / 沸騰熱伝達 / 冷凍機油 |
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| Research Abstract |
The effects of lubricant oil on flow boiling heat transfer of low GWP refrigerant HFO-1234yf in small-diameter tubes with inner diameter of 2 and 4 mm were experimentally investigated. Experimental results showed that with increasing oil mass fraction, the local heat transfer coefficient increased at lower vapor quality due to intensified foaming phenomena. However, the heat transfer coefficient decreases monotonically with oil mass fraction in high quality region. The forming phenomena and flow patterns at different mass flux and heat flux were illustrated by the visual observation. With increasing oil mass fraction, pressure drop was larger from 1.7 to 4.8 times than that for oil free.
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