Taking the cross flow path of superheater with pitted tubes as the research object

three-dimensional numerical simulation was performed to investigate the heat transfer and resistance characteristics of the flue gas side of the pitted tubes. The results show that

the added pits on external wall of the pitted tubes and the proper arrangement of tubes improve the flue gas convection and scour effect

damage the gas flow boundary layer

and reduce the area of heat flow deterioration region. Compared with the smooth tubes

at flue gas side of the aligned pitted tubes and staggered tubes

the Nusselt number(Nu) increases by 8%～63% and 12%～48%

and the overall heat transfer performance evaluation criterion(C_(PEC)) is 1.05～1.5 and 1.07～1.28. Taking Nu

f and C_(PEC) at the flue gas side as the objective functions

a group of optimal parameters are obtained. The optimal parameters of in-line bank are 2.1 for transversal pitch and 1.75 for longitudinal pitch under the condition of Nu=42.63

C_(PEC)=1.24 while the optimal parameters of staggered bank are 2.55 for transversal pitch and 2.5 for longitudinal pitch under the condition of Nu=47.02

C_(PEC)=1.31. The criterion formula of heat transfer at flue gas side of the aligned and staggered pitted tubes are obtained respectively by the method of multiple linear regression. The research results of this paper can provide references for the engineering application of pitted tubes.