A waste heat exchanger fly ash particle deposition model with dynamic mesh and random function method

Abstract

The fly ash particle deposition in the heat recovery process of the heat exchanger is an urgent issue that must be addressed. In this work, the particle deposition model is improved using the dynamic mesh technology and random function method. We simulated and predicted the fouling morphology and particle size distribution of the fly ash layer using the deposition characteristics of particles of various sizes. The results indicated that when dynamic mesh technology is adopted, the tube wall's boundary will be deformed geometrically with the deposition of particles, allowing the changes in the fouling morphology to be expressed more effectively. Under this study conditions, the particle deposition mass on the windward and leeward sides of the tube increased initially and then decreased with the particle size increased. When particles of different sizes are mixed, the first layer of particles accelerates the deposition of subsequent particles, and the first layer of particles is generally composed of particles of small size.