[Objective] Ash deposition on the heating surfaces of waste incineration boilers increases thermal resistance, weakens heat transfer, raises flue gas temperature, and reduces boiler operating efficiency. Powerful wave ash cleaning can generate high-intensity pressure waves and gas disturbance through rapid combustion of a combustible gas-air mixture, showing potential advantages over conventional acoustic soot blowing, steam soot blowing, and mechanical rapping. However, the ash fragmentation process under powerful wave action and the influence of outlet working pressure on cleaning performance remain insufficiently understood. This study investigates the dynamic ash removal process and pressure-dependent cleaning effect of a powerful wave ash cleaner in a waste incineration boiler, aiming to provide a basis for engineering application and parameter optimization. 

[Methods] A numerical model of the powerful wave ash cleaning process was established by combining the cohesive zone model with the coupled Eulerian-Lagrangian method. The gas domain was described using the Eulerian formulation, while the water-wall tube and ash deposit layer were described using the Lagrangian formulation, so as to simulate the transient fluid-solid interaction between the cleaning gas and the ash layer. Cohesive elements were embedded in the ash deposit, and the damage ratio of cohesive elements was used to characterize ash fragmentation. Four outlet working pressures, 25, 30, 35, and 40 MPa, were selected to compare the evolution of ash damage. Field tests were also conducted on a waste incineration boiler, in which the flue gas temperature at the inlet of the three-pass superheater and the main steam flow rate were collected. A normalized heat-transfer recovery index was introduced to reduce the influence of load fluctuation. 

[Results] The simulation results show that the damage degree of the ash deposit layer increases with increasing outlet working pressure, whereas the initial time of ash damage is only slightly affected by pressure. The field test results further verified this trend. When the outlet working pressure increased from 30 MPa to 35 MPa, corresponding to a pressure increase of 16.67%, the flue gas temperature drop at the left inlet of the three-pass superheater increased from 24.20℃ to 26.85℃, improving by about 11%. Meanwhile, the normalized heat-transfer recovery index increased from 0.53℃·h/t to 0.55℃·h/t, with a relative increase of about 3.8%. 

[Conclusions] The proposed model can reasonably describe the damage evolution of ash deposits during powerful wave ash cleaning. Both simulation and field test results indicate that the powerful wave ash cleaner has favorable cleaning performance, and its ash removal effect is positively correlated with outlet working pressure.