摘要
实验研究了环保制冷工质R410A-润滑油混合物在5 mm小管径内螺纹强化管内流动沸腾的摩擦压降特性.实验结果表明,对于纯制冷剂R410A,摩擦压降随着干度的增大先增大后减小,峰值出现在干度为0.7～0.8左右;R410A-油混合物的摩擦压降随油平均质量分数、干度和质流密度的增大而增大,当油平均质量分数从0增长到5%时,在干度为0.9的高干度工况下,摩擦压降最大可增加120%.R410A-油混合物在5 mm强化管内流动沸腾的摩擦压降与7 mm强化管的相比约增大10%～30%;用已有的7 mm强化管的压降关联式预测5 mm强化管的压降时,误差为±40%.以R410A-油混合物在7和5 mm强化管内摩擦压降的实验值为基础,建立了基于混合物物性的R410A-油混合物在不同管径强化管内的摩擦压降关联式.该关联式的预测值与95%的实验值误差在±20%以内.
An experimental study of flow resistance characteristics of R410A-oil mixture during evaporation inside a 5 mm internally spiral grooved enhanced tube was performed.The test results show that the frictional pressured drop of R410A initially increases with vapor quality and then decreases,presenting a local maximum in the vapor quality range between 0.7 and 0.8;the frictional pressure drop of R410A-oil mixture increases with increasing nominal oil concentration,vapor quality and mass flux;the presence of oil enhances frictional pressure drop maximum by 120% as the oil concentration increases from 0 to 5% at a vapor quality of 0.9.The frictional pressure drop of R410A-oil mixture in 5 mm enhanced tube is about 10% to 30% higher than that in 7 mm enhanced tube.The deviations of the prediction of existing correlation for 7 mm enhanced tube to the pressure drop characteristics of R410A-oil mixture in 5 mm enhanced tube are within ±40%.Based on the experimental data of R410A-oil mixture in 7 mm and 5 mm enhanced tubes,a new correlation of frictional pressure drop was developed by considering the mixture properties,which agreed with 95% of the experimental data within the deviation of ±20%.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2010年第10期1317-1321,共5页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金(50906048)
中国博士后科学基金(20090460618)资助项目
关键词
R410A
油
强化管
小管径
压降
关联式
R410A
oil
enhanced tube
small tube
pressure drop
correlation
