The effect of thermal and flow conditions in the combustion chamber of the 670 MW boiler on the emission of gaseous pollutants

An analysis of the effect of thermal and flow conditions in the combustion chamber of the circulating fluid-ized-bed (CFB) boiler on the gaseous pollutant emission was undertaken in the study. The tests were carried out on a 670 MW boiler operating in the power ebgineering industry. On the basis of the obtained test results it was found that the optimization of primary and secondary air distribution, as well as fuel distribution, allowed the following pollutant reductions: CO by 52%, SO2 by 40% and NO by 6% in relation to the standart operation conditions of the boiler under investigation. The test results demonstrated that increasing the number of repetitions of bed material particle circulation between the combustion chamber and the recycling system resulted in an equalization of temperature distribution along the combustion chamber height and elongated the time of residence of sorbent particles in the CFB system. Ultimately, the test results showed the following pollutant reductions: CO by 71%, SO2 by 41% and NOx by 19% with the number of particle circulation repetitions increased from 28 to 60 for the boiler analyzed.