STUDY ON NUMERICAL DIFFUSION IN NUMERICAL SIMULATION OF FLOW CHARACTERISTIC IN COMPLICATED TANGENTIALLY FIRED BOILER

摘要

The effect of offset angles of mid-secondary air nozzles on gas flow field in tangentially fired boiler with the FLUENT package was numerically studied and the effect of numerical diffusion near the burner areas on gas flow field in the furnace was investigated. To reduce the influence of numerical diffusion, some measures were taken by evaluating the nature of numerical diffusion, such as changing the type of grid, the grid size and the order of the discretization scheme. Compared with experimental data, an appropriate method was adopted to solve the numerical diffusion. It can provide research basis of air-dynamic field of tangentially fired boiler.