Research On Excess Reheater System Temperature Of Zhangjiakou 1025t/h Power Plant Boiler

Excess temperature tube failure was happened in the reheater system of the 1025t/h boiler of Zhangjiakou power plant. Checks of thermal calculations with four different unit loads are performed, and the results are coincided to the results provided by the boiler manufacturer. Wall temperature calculations are also carried out based on these checking calculations; the results indicate that the most dangerous point of each reheater's tube panel is in section of #1 tube bottom elbow. The point coincides with the actual excess temperature tube failure of the reheater. The FLUENT software is applied to simulate different furnance combustion conditions. The results show that the main causation of excess temperature is the serious residual rotation of medium rehearter over outlet of furnace. When second wind resected 15 degrees, the residual rotation disappeared and the aerodynamic field in furnace was stable. According to the above analyses, three retrofit scheduals of the reheater are suggested.