Abstract: To study the steam cooling in thick-wall ribbed channel, a conjugate calculation model was established on the basis of experiment data. The influence of the wall thickness on the flow and heat transfer characteristics of thick-wall ribbed channel with 3D heat conduction effect was investigated. The flow and heat transfer performance of steam in thick-wall ribbed channel for rib height-to-hydraulic diameter ratio (e/D) ranging from 0.047 to 0.188 and rib angle-attack ranging from 30° to 90° was also analyzed. Then, the relationship of Nu with wall thickness, e/D and rib angle was developed. The results show that the influence of the wall thickness on the flow and heat transfer performance of the ribbed channel is small, and the heat transfer coefficients of the channel decrease with the increase in the wall thickness. When e/D is 0.141 and 0.047, the comprehensive performance factor of the thick-wall ribbed channel reaches it maximum and minimum, respectively. When the Nu on the rib walls is not considered, the comprehensive performance factor of 60° thick-wall channel is the highest. When the average Nu is obtained from the whole walls, the comprehensive performance factor of 45° thick-wall ribbed channel is the highest.

Key words: power machinery engineering, ribbed channel, steam cooling, 3D heat conduction, conjugate calculation