Root cause analysis and remedial renovation of one 350MW boiler made by Mitsubishi

摘要

When the fuel of two boilers in one Power Plant was changed to SHENHUA coal, a serial of problems were appeared, such as a lower temperature of the main steam, a larger deviation of the reheat steam temperature and a higher temperature of the flue gas, etc. Through a deep theoretical analysis, it was found that the insufficiency of heat exchange surfaces of superheaters was the main reason caused these problems. After adding heat delivery surface and changing normal Secondary Air burner AA to horizontally tilting OFA burner, all of these problems were solved.