Afprøvning og verifikation af laserbaserede metoder i kulstøvfyret kedel

The project is the first in Denmark, where laser techniques are used in diagnostics of a semi scale pulverized coal combustor. The light scattering of spherical absorbing particles have been studied theoretically. Back, forward and off-axis scattered detector signals, Doppler bursts, have been calculated based on Mie scattering.

The experimental furnace used 1.2 m in diameter and 4.5 m long. The maximum input power is 1.5 MW. In the reported laser measurements the power was set to 490 kW. The furnace have been specially designed for laser measurements with measuring ports for detection of the forward scattered light. Heat transport to the 11 sections of the furnace, temperatures, gas composition, air and coal flows where logged on computer.

Local axial and tangential mean and RMS velocities were measured throughout the furnace with a laser Doppler anemometer (LDA) for an isothermal and a coal combustion case. Laser Doppler measurements were problematic in the center of the first 300 mm of the coal flame, the hard zone of the near burner field, because of the high coal concentrations. (author) 2 tabs., 51 ills., 33 refs..