Abstract: Using the application experiences of direct air cooling project of domestic large thermal power project and domestication technical research results for reference, combining with the characteristics of stiffened cylindrical shell structure, a design method of material and geometric nonlinear finite element numerical assist computation was put forward, and the design method was compared and analyzed in depth. The method was adopted in the exhaust duck design of a large ACC project, the structure characteristics in whole combined operation conditions were analyzed, and the structure design optimization of the ACC duck system of large thermal power project was realized.

Key words: direct air cooling, exhaust duct, cylindrical shell, analysis and design, finite element method