On March 19, 2013, news came from Guangdong Guohua Yuedian Taishan Power Generation Co. that the No. 1 unit of Taishan Power Plant had been smoothly running for 15 days since startup after cleaning of the boiler body and superheater. All indicators, including steam quality and superheater wall temperature, were normal. This means the superheater chemical cleaning project undertaken by Xian Thermal Power Research Institute has achieved full success and that a major technical breakthrough has been made by domestic enterprise by addressing the oxidation coat issues of superheater of high-parameter and large-capacity generating units.
Taishan Power Plant organized technical personnel to evaluate project completion immediately after the cleaning. Specialized testing on 1460 superheater tubes at the division wall, rear panel, and end stage that have been cleaned showed no blockage in any tube. The average descaling rate of the superheater is 94.0%, and the average corrosion of different materials is 0.14g/ (m2.h) ～1.22 g/(m2.h), which are in full compliance with the limits defined in Thermal Power Plant Boiler Chemical Cleaning Guidelines (DL/T 794-2012).
Removal of superheater oxidation coat by means of chemical cleaning not only avoids tube explosion accidents caused by chipped oxidation coat, but also increases the life cycle of the superheater tubes by 60000h. Besides, it improves the operation efficiency of the boiler, prevents the washout of steam turbine blades (thus avoiding reduced efficiency of the steam turbine), and reduces repair workload, resulting in great economic benefits due to energy conservation and lower consumption during safe production and high-efficiency operation.