Numerical computation of corona space charge and V-I characteristic in DC electrostatic precipitators

The distribution of the corona space-charge density and the V-I characteristic of a DC precipitator, neglecting the presence of fly ash, are calculated by a numerical procedure based on the finite-element method, which imposes Kaptzov's assumption on the emitter surfaces. The ion charge density, the electric potential, and the electric field distributions are evaluated with reference to a real wide-duct electrostatic precipitator installed for testing purposes in the slipstream of the flue-gas duct of a 35 MWe coal boiler. The V-I characteristic, obtained by means of the mathematical procedure described, is compared with the experimentally obtained one. The satisfactory agreement guarantees the reliability of the mathematical model. The model will be implemented by considering the induced effect of the dust present in the flue gas, the back corona, and the dynamic corona originating from the application of pulsed-voltage energization to the electrostatic precipitators.<
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