Experimental study on the combustion and emission characteristics of thermal release-assisted load increase in a circulating fluidized bed

To address the challenges posed by the intermittency and fluctuation of renewable energy sources on the power grid, coal power will serve as a flexible resource, ensuring stability and security. In this paper, in response to the problems of large thermal inertia and low load change rate encountered during the load increase process in circulating fluidized bed (CFB), an experimental study on the combustion and emission characteristics of thermal release-assisted load increase process was carried out. The experimental results indicate that the thermal release significantly affects combustion efficiency, NO_x emission, and the rate of load increase. Compared to conventional load increase, when the load is raised from 50% and 30% to 100%, the combustion efficiency improves by 0.9% and 0.4%, respectively. NO_x emissions increase by 23% with no change observed in the latter case, while CO emissions decrease by 56% and 36%, respectively. Additionally, the load increase rate rises by 48% and 37%. As the discharge material temperature increases, the NO_x emissions first decrease and then increase, CO emissions decrease, combustion efficiency improves, and the rate of load increase is enhanced. At discharge temperatures of 650 ℃, 750 ℃, and 850 ℃, the load increase rate increased by 23%, 31%, and 48%, respectively.