Experimental study of ash wear of heat exchange surfaces of the boiler

Highlights: • The value of the reduction in wear was obtained for transversely washed tube bundles. • The distribution of wear along the length of the pipe tube air heater is obtained. • An equation of motion of a spherical particle for Re < 1000 is obtained. • Upward movement in the convective shafts significantly reduce ash wear. Annotation. Based on comparative experiments, the value of the reduction in wear was obtained for transversely washed tube bundles with different geometries, as well as for pipes and tube boards of tubular air heaters. The dependence of the wear of tube bundles and the distribution of wear along a number of relative steps is established. The dependence of the amount of wear reduction on the diameter of the pipes is established. The distribution of wear along the length of the pipe tube air heater with an upward movement is obtained. An equation of motion of a spherical particle in a dimensional and dimensionless form that describes its motion in the range Re < 1000 is obtained. Based on this equation, the probability curves of the inertial collision of particles with the surface of a single cylinder during upward and downward movements and the product of the calculated estimate of the amount of wear reduction when changing the direction of movement of the flue gas are obtained. Based on the results of experimental studies, the design of the convective surface of the heating surface with uniform wear of all rows of pipes is proposed. It is shown that the organization of upward movement in the convective shafts of boilers can significantly reduce ash wear. The obtained results allow us to choose the optimal geometric dimensions of the tube bundles from the point of view of minimal wear.