R22在水平双侧强化管外的凝结换热  

Condensation heat transfer of R22 outside horizontal doubly-enhanced tubes

作　　者：张定才[1] 刘启斌[1] 陶文铨[1] 何雅玲[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《化工学报》2005年第10期1865-1868,共4页CIESC Journal

基　　金：国家重点基础研究基金项目(G2000026303);国家自然科学基金项目(50323001).~~

摘　　要：An experimental study on R22 film condensation on single horizontal tubes(one smooth tube and two doubly enhanced ones) was conducted at the saturation temperatures of 32℃, 35℃ and 38℃ respectively. A modified Wi lson plot was used to obtain the water-side and vapor-side heat transfer coeff icients. The results indicated that the experimental condensation heat transfer coefficients agreed with the Nusselt theory with ±10%. The water side heat tr ansfer coefficients of tube No.1 and tube No.2 were 2.78 and 2.99 times of t hat of smooth tube, respectively. At the same heat flux the condensation heat t ransfer coefficients of tube No.1 and tube No.2 were 8.2—18.0 times and 8. 1—12.4 times of the smooth tube, respectively. Thermal resistance analysis sh owed that the relative percentage of vapor-side thermal resistance increased wi th water velocity. When the thermal resistance values of the two sides were equ al, the water velocity of tube No.1 was 1.25 m·s-1(Re=2.41×104) and that of No.2 was 0.82 m·s-1(Re=1.54×104).For all cases, th e wall thermal resistance was less than 4 percentage. The reasons accounting fo r the superiority of tube No.1 were analyzed.An experimental study on R22 film condensation on single horizontal tubes （one smooth tube and two doubly enhanced ones） was conducted at the saturation temperatures of 32℃, 35℃ and 38℃ respectively. A modified Wilson plot was used to obtain the water-side and vapor-side heat transfer coefficients. The results indicated that the experimental condensation heat transfer coefficients agreed with the Nusselt theory with ±10%. The water side heat transfer coefficients of tube No. 1 and tube No. 2 were 2.78 and 2.99 times of that of smooth tube, respectively. At the same heat flux the condensation heat transfer coefficients of tube No. 1 and tube No. 2 were 8.2-18.0 times and 8.1-12.4 times of the smooth tube, respectively. Thermal resistance analysis showed that the relative percentage of vapor-side thermal resistance increased with water velocity. When the-thermal resistance values of the two sides were equal, the water velocity of tube No. 1 was 1.25 m · s^-1 （Re= 2.41 × 10^4 ） and that of No. 2 was 0.82 m · s^-1 （Re=l. 54 × 10^4）. For all cases, the wall thermal resistance was less than 4 percentage. The reasons accounting for the superiority of tube No. 1 were analyzed.

关 键 词：强化管 膜状凝结 传热特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]