Estimates of turbulence mechanisms in circulating fluidized bed combustors
Artikel i vetenskaplig tidskrift, 1998

Estimates of the characteristic time scales (particle relaxation time, eddy-particle interaction time, interparticle collision time), and the energy dissipation mechanisms are performed together with a turbulent kinetic energy budget, for a simple equilibrium shear flow with conditions similar to those of a circulating fluidized bed (CFB) combustor. Based on dimensional analysis, the influence of five parameters is investigated: the Eulerian integral length scale in the gas phase, the gas-particle density ratio, the mean velocity gradient, the particle diameter, and the particle volume fraction. The results show significant differences between particles of Geldart groups A and B regarding response to gas phase turbulence, transition from dense to dilute suspensions, pressure and temperature dependence, and also energy dissipation mechanisms.

Fluidized beds

Gas-solid flow

Circulating beds

Combustors

Turbulence

Författare

Eric Peirano

Institutionen för energiomvandling

G. Palchonok

Filip Johnsson

Institutionen för energiomvandling

Bo G Leckner

Institutionen för energiomvandling

Powder Technology

0032-5910 (ISSN)

Vol. 96 2 90-105

Ämneskategorier

Maskinteknik

DOI

10.1016/S0032-5910(97)03362-7