摘要
实验研究了制冷剂/润滑油混合物在泡沫金属加热表面核态池沸腾的换热特性,分析了润滑油浓度和泡沫金属结构对池沸腾换热特性的影响。实验使用3种结构参数的泡沫金属作为加热表面,其参数分别为10ppi/90%孔隙率、10ppi/95%孔隙率和30ppi/98%孔隙率,厚度均为5mm。实验使用的制冷剂为R113,润滑油为VG68,润滑油浓度为0～5%。实验结果表明:泡沫金属的存在极大提高了制冷剂/油混合物的池沸腾传热系数,最多提高1.6倍;润滑油的存在恶化制冷剂在泡沫金属加热表面池沸腾的换热特性,传热系数最多降低15%;相比平加热面,润滑油对泡沫金属加热表面池沸腾换热恶化的程度低。基于混合物性,开发了制冷剂/油混合物在泡沫金属加热表面池沸腾换热关联式,预测值与95%的实验数据偏差在±10%之内。
The influence of concentration of lubrication oil and structure of metal foam on the nucleate pool boiling heat transfer characteristics of refrigerant/oil mixture on metal foam covers was investigated experimentally.Three copper foams,10 ppi/90% porosity,10 ppi/95% porosity and 30 ppi / 98% porosity with the thickness of 5 mm,were used in this study.The refrigerant is R113 and the oil is VG68 with concentrations from 0 to 5%.The experimental results indicate that the pool boiling heat transfer coefficient on copper covers is larger than that on flat heated surface,with a maximum increase of 1.6 times under the experimental conditions.The presence of oil deteriorates the pool boiling heat transfer on copper foam covers,decreased by 15% or less under the experimental conditions.The deterioration of oil on nucleate pool boiling heat transfer is less on copper foam covers than on a flat heated surface.A correlation for predicting the nucleate pool boiling heat transfer coefficient of refrigerant/oil mixture on metal foam covers is developed,and it agrees with 95% of the experimental data within a deviation of ±10%.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2011年第2期329-335,共7页
CIESC Journal
基金
国家自然科学基金项目(50906048)
中国博士后科学基金项目(20090460618)~~
