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传热和压力降的测定是在三个螺旋形内翅片管(外径12.7～15.9毫米,片数30～32,片高0.5～0.6毫米)中,在蒸发的情况下进行的,F_(22)在其中呈二相流动。并将所测的数据同装有星状插入物的光管和不装有星状插入物的光管作了比较。在相同的加热长度试验区(0.8和2.44米)内,冷剂量的变化为0.2和0.7和质量流速范围为65,000～270,000克/秒·米~2,比较的结果是:(1)内翅片管的传热系数比光管的传热系数增长36～760％并随着质量流速的增加而增加。更密致些的翅状螺旋片传热的效果更好。(2)带有星状插入物的光管的传热系数增长40～370％,但是随着质量流速降低而降低。(3)内翅片管的压力降比光管的压力降增加10～290％。当光管装上星状插入物时则为300～2000％。提高内翅片管特性的因素包括对横截面流通面只有很小影响的低翅片和密致的螺旋片。该密致的螺旋片增加了单位管长的边缘转角长度,使得气泡成核。
The heat transfer and the pressure drop were measured in three spiral inner finned tubes (outer diameter 12.7-15.9 mm, number of slices 30-32, height 0.5-0.6 mm) under evaporation, F_ ( 22) in which two-phase flow. The measured data were compared with those with star-shaped inserts and those with no star-shaped inserts. Within the same heating length test zone (0.8 and 2.44 m), the change in the refrigerant amount was 0.2 and 0.7 and the mass flow rate was in the range of 65,000 to 270,000 g / sm ~ 2. The results of the comparison were: (1) The heat transfer coefficient of the tube is 36 to 760% higher than the heat transfer coefficient of the light tube and increases with the mass flow rate. More dense fin-shaped spiral heat transfer better. (2) The heat transfer coefficient of a light pipe with a star-shaped insert increases by 40 to 370%, but decreases as the mass flow rate decreases. (3) The pressure drop of the inner finned tube is 10 to 290% higher than the pressure drop of the optical tube. When the light pipe mounted star insert is 300 ~ 2000%. Factors that improve the characteristics of the inner finned tube include low fins and dense flights that have only a small effect on the cross-section flow surface. The dense spiral sheet increases the edge turn length per unit tube length, allowing nucleation of bubbles.