| 摘要: |
| 针对CO2作为制冷剂在微细通道内流动沸腾换热进行了实验与理论研究，采用红外成像观测与换热系数实验研究定量与定性的分析了热流密度：2~35 kW/m2，饱和温度：﹣10 ℃ ~15 ℃工况时，内径为1 mm、2 mm圆管内的换热系数。实验结果表明：热流密度的增加强化了微细通道内工质核态沸腾换热，使换热系数得到显著提高；换热系数随饱和温度非单调变化，饱和温度较高时，越接近CO2临界温度其换热系数随饱和温度升高而增加，当饱和温度在低温工况时换热系数则随其降低而增加，换热过程中发生干涸干度随饱和温度升高而单调降低。 |
| 关键词: 微细通道 换热系数 热流密度 饱和温度 干涸 |
| DOI： |
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| 基金项目: |
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| Characteristics of Heat Transfer for CO2 Flow Boiling in Mini-channel |
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Jiang Linlin1, Liu Jianhua1, Ye Fangping2, Zhang Liang1, Ding Yang1, Wu Hao1
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| (1.Refrigeration Technology Institute, University of Shanghai for Science and Technology;2.Zhejiang Xinjin Air Conditioning Equipment Co. , Ltd.) |
| Abstract: |
| The experimental and theoretical researches have been carried out to get the flow boiling heat transfer characteristics of CO2 as a refrigerant in horizontal mini-channel. Based on infrared thermal imaging tests and experimental study on heat transfer coefficients, the heat transfer coefficients of refrigerant are analyzed qualitatively and quantitatively in follow conditions: Heat flux: 2-35 kW/m2,Saturation temperature: ﹣10 ℃-15 ℃, mini-channel inner diameter:1mm or 2 mm. Primary conclusions can be drawn from the results of experiments: The increase of heat flux enhances the nucleate boiling heat transfer of refrigerant inside mini-channel, which leads to the remarkable increase of heat transfer coefficient; the heat transfer coefficient doesn’t always monotonely vary with the saturation temperature: when the saturation temperature is high and even close to the critical temperature of CO2, the heat transfer coefficient rises with the increase of saturation temperature; when the saturation temperature is low, the heat transfer coefficient rises with the decline of saturation temperature. Besides, during the heat transfer process, the dryout quality monotonely falls with the rise of saturation temperature. |
| Key words: mini-channel heat transfer coefficient heat flux saturation temperature dryout |
