CAJ | 학술논문

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。
침대 CO2작위제랭제재미세통도내류동비등환열진행료실험여이론연구,채용홍외성상관측여환열계수실험연구정량여정성적분석료열류밀도；2~35 kW∕m2,포화온도；_10~15℃공황시,내경위1 mm﹑2 mm 원관내적환열계수。실험결과표명；열류밀도적증가강화료미세통도내공질핵태비등환열,사환열계수득도현저제고；환열계수수포화온도비단조변화,포화온도교고시,월접근 CO2림계온도기환열계수수포화온도승고이증가,당포화온도재저온공황시환열계수칙수기강저이증가,환열과정중발생간학간도수포화온도승고이단조강저。
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 ,satura_tion temperature; _10 _15 ℃, mini_channel inner diameter;1mm or 2 mm.Primary conclusions can be drawn from the results of experi_ments; The increase of heat flux enhances the nucleate boiling heat transfer of refrigerant inside mini_channel, which leads to the remarka_ble 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 tempera_ture.Besides, during the heat transfer process, the dryout quality monotonely falls with the rise of saturation temperature.