The structure and layout of flue gas system of coal-fired units not only determine the resistance of the smoke wind system, but also affect the operation state of related equipment. Due to the unreasonable flue structure between induced draft fan and desulfurization tower in a 2×1060 MW unit, one of the two parallel induced draft fans oscillated badly, affected the reliability and economy of the unit. A numerical simulation of the flow field of this part of the flue gas was carried out by the software of fluid dynamics. The problems existing in the flue gas were analyzed, and the optimum plan was proposed to reform the flue in combination with the field conditions. After technological transformation, the flue resistance of this part decreases to 300 Pa, parallel deviation is less than 3%, and the vibration detection value of the fan is reduced from more than 4.6 mm/s to 2.5 mm/s. This creates huge economic benefits for power plants.
