Distribution of Gas Concentration in a Furnace of Large-Scale CFB Boiler

摘要

In the curent paper an analysis of the distribution of: O{sub}2, CO, NO and SO{sub}2 concentration in the furnace of a large-scale circulating fluidized bed (CFB) boiler has been presented. The research was carried out in the furnace of a 670 MW{sub}t CFB boiler. The furnace was equipped with 25 measurement holes. In order to measure the local gas concentrations inside the combustion chamber gas suction probes were used. The measured gas concentration profiles indicate an oxygen-depleted wall region with a thickness of about 0.5 m. Significant differences are observed between gas concentrations near the front wall and those near the rear wall: O{sub}2 and NO are lower and CO is higher near the front wall than near the rear wall. It can be concluded that these effects are related to the fuel dispersion: near the rear wall the lateral ash flow transports fuel deeper into the combustion chamber and thus avoids the formation of plumes.