Computer modelling of particle gasflow in fluidized bed combustion boilers
Thermohydraulic computer codes are used to describe the flow of coal and ash particles in flue gases of fluidised bed combustion boilers. Two codes investigated, FLUENT and PHOENICS, both suffer from the problem of numerical diffusion in the solution of algebraic equations although the second order differencing scheme of the former code is effective in suppressing this. The code PARTRACK is based on a discrete (Monte Carlo simulation) method as particle trajectory model, making the particle flow calculations independent of the flow field calculations. Using body fitted coordinates made it difficult to set up the problem. Using rectangular coordinates, the calculations fail to show recirculation zones downstream of the flaps, which are found in experiments. Laminar calculations with a constant, low value for the viscosity give a distinct improvement. The application of PARTRACK to the case of an AFBC-internal givesencouraging agreement between particle calculations and actual measurements.
Bibliographic Reference: EUR 12472 EN (1990) 119 pp., MF, ECU 8
Record Number: 199010153 / Last updated on: 1994-12-01
Original language: en
Available languages: en