A novel structure with rhombus heat transfer surface used in the waste heat boiler was researched. Numerical simulation and experimental investigation were conducted to obtain characteristics of ash distribution and deposition. A deposition model was built to predict the stick

rebound and shedding of an ash particle

and the simulation results were compared with traditional staggered and aligned tubes arrangement. The results indicated that the rhombic surface showed obvious advantages in the heat transfer and ash deposition. The deposits were mainly concentrated on the upper left side. Particle deposited on windward side due to the inertial impaction and on leeward side because of pipe wall vortex. The deposition amount of windward side was higher than that of the leeward side. The deposition increased firstly and then decreased with the increase of the particle size under the same velocity. When the gas velocity was 3 m·s-1 and particle diameter was 5 μm

the ash particle deposition rate was up to 9.49%. For particles of the same size

the deposition rate decreased gradually with increasing velocity.