Analysis of cfb boiler water-cooled wall wear main causes

       With the increasingly strict domestic environmental protection policy, circulating fluidized bed boilers have been widely promoted and applied in China. Now the major thermal power plants, whether the newly installed boilers, or the old boiler transformation, will be used circulating fluidized bed boiler. The main advantage of circulating fluidized bed boiler is environmental protection, energy-saving lights, the main drawback is the boiler wear problem, circulating fluidized bed boiler wear problem has been plagued by major thermal power plants. How to prevent and solve the circulating fluidized bed boiler wear problems occur, is of great significance to thermal power plants.

　　The main wear of circulating fluidized bed boilers is water-cooled wall tube wear, water-cooled wall tube wear mainly occurs in the circulating fluidized bed boiler furnace part of the injection and water-cooled wall tube transition area tube wall, the furnace around the corner area tube wall, irregular area of the tube wall.

　　Wear causes mainly with the wind speed, particle concentration, particle size particle shape and collision angle with the heating surface, as well as the unevenness of the flow field and other closely related research shows that the wear and wind speed 3 to 4 times (the value of the size and the nature of the ash particles, concentration and particle size is proportional.

　　The main form of wear is erosion wear. One is the impact angle between the particles and the surface of the water-cooled wall tube is small, or even close to parallel, the particles on the surface of the water-cooled wall tube similar to grinding, after a certain period of time, the surface will produce wear, that is, scouring wear another is the impact angle of the particles relative to the surface of the water-cooled wall tube is large, some close to the vertical impact, so that the surface produces a small plastic deformation or microscopic cracks, a large number of particles in the furnace repeatedly under the impact, plastic deformation The layer of plastic deformation gradually falls off and forms the wear, that is, impact wear.

　　According to practical experience, the characteristics of circulating fluidized bed boilers have decided that the water-cooled wall heating surface wear is bound to exist. Although the characteristics of circulating fluidized bed boilers cannot be changed, with the in-depth research on wear, the anti-wear technology of circulating fluidized bed boilers has become more and more mature. Reasonable analysis of the boiler wear problem, according to the practical situation to choose the appropriate anti-wear method to completely cure the boiler wear problem.