Research On Anti-erosion Of Low-temperature Heating Surface In 1000MW Ultra-supercritical Tower Type Boiler With CFD

It is of great significance to operate safely and economicly in the boiler for a power plant, and one of the effective methods to reduce exhaust gas temperature and increase energy recovery is to add heating surface in the tail of the flue resulting in the change of flue gas flow field, then so called ‘smoke corridor’ appears between heating surface and flue wall where stack gas velocity increases resulting in serious damage of the heating surface. Meanwhile, the strong vibration of heating surface caused by the flow in the tail flue will damage the facilitiy and reduce its service life. So, it is necessary to analyze both the causes of ‘smoke corridor’ to find out corresponding prevention measures and the flow field in the flue system according to the intrinsic characteristics and acoustic properties of the flue to find out what causes the vibration and then make the corresponding improving plan.In this paper, the author analyzed the flue field in the tail of the flue of a certain power plant with the help of CFD, through which a solution—installing appropriate orifice plate and ‘false tube’ to make the flue field more uniform and reduce the heating surface’s damage—could be designed because we can find where is the most damaged part. In addition, the author also analyzed the influence of steam blowing on the tube with and without the shock baffles. In order to prevent serious damage, he advised that the first row of the tube arrangement which is neareat to shock baffle should be installed with protection tiles and so are the first three rows of the other tubes. Through the theoretical calculation, a conclusion that the distance of the shock baffles increases with the decrease of running load is obtained. So, the best shock baffles’ distance apears when the running load comes to the highest, it is 4.8m corresponding to the first-stage reheater and 5.083 m corresponding to the economizer.