Abstract: In order to solve the problems of the severe high-temperature corrosion and de-oxidation atmosphere that cannot be effectively reduced by combustion adjustment at the sidewalls of one 600-MW supercritical opposed firing boiler, the schemes for improving the combustion system to prevent high-temperature corrosion on the sidewalls such as installing air ports along the sidewalls and burner innovations are proposed. The numerical simulation results show that installing air ports along the sidewalls is most effective, which makes the oxidizing atmosphere be formed near the sidewalls. Practical operation after the modification demonstrates that the testing results are consistent with those of the numerical simulation; the atmosphere at the sidewalls is greatly improved and the major running parameters of the boiler meet the designed requirements. The modification can ensure the boiler operation and can be a reference for high-temperature corrosion prevention.

Key words: high-temperature corrosion, opposed firing, numerical simulation, retrofit