作　　者： ; ; ; ;

机构地区： 清华大学机械工程学院热科学与动力工程教育部重点实验室

出　　处： 《工程热物理学报》 2008年第1期124-126,共3页

摘　　要： 对添加有TiO_2纳米颗粒的制冷剂R11在外径为22.4mm紫铜管外的池沸腾换热特性进行了实验研究。池沸腾饱和温度为35℃和40℃,纳米颗粒悬浮液的浓度为0.01g/l和0.05g/l。对铜管圆周上、下、前,后四个部位的局部换热情况进行了测量和可视化观察以及相应的粗糙度检测分析。结果发现,纳米颗粒的添加基本使管上部粗糙度降低,传热弱化,而使下部粗糙度增加,传热强化。就整体换热而言,40℃的强化换热效果好于30℃,0.01g/l的强化换热效果好于0.05g/l。 The pool boiling heat transfer characteristics of refrigerant Rll with TiO2 nano-particles on a horizontal tube of 22.4 mm OD was investigated experimentally. The saturation temperature was set to be 35℃ and 40℃, respectively, and the concentration of the nano-particle suspensions was taken to be 0.01 g/1 and 0.05 g/l, respectively. The heat transfer characteristics at four different positions （up, down, front, back） around the tube was measured and observed. The surface roughness at the four positions was measured before and after the test. The results suggested that addition of nano-particles acted to reduce the roughness of the upper part and deteriorate the heat transfer at that part while it worked to increase the roughness of the bottom part and improve the heat transfer at that part. From the viewpoint of overall heat transfer performance, better heat transfer enhancing effect was observed at 40℃ than at 35℃, and so was for 0.01 g/1 than for 0.05 g/1.

关 键 词： 制冷剂 纳米颗粒 池沸腾 强化传热

领　　域： [动力工程及工程热物理] [动力工程及工程热物理]