Experimental Study on the Effect of Bed Material Amount and Fuel Particle Size on Load Change of Circulating Fluidized Bed

The large-scale integration of new energy generation has put forward higher requirements for the peak-shaving capability of thermal power. The circulating fluidized bed (CFB) depends on the advantages of a wide load adjustment range and low cost of pollutant control to become a good peak shaving power supply. However, the large delay and inertia caused by its unique combustion mode make it very difficult to change the load quickly. To further understand the factors that affect the load change of CFB, and explore the method of increasing CFB load change rate, the load change experiment on the combustion side was carried out in the 0.1 MW CFB experiment platform. The influence law of bed material amount and fuel particle size on load change of CFB combustion side was revealed for the first time. The results indicated that the increase of bed material amount was beneficial to improve the load change rate on the combustion side of CFB and reduce the carbon content of fly ash, but had no obvious effect on NO x emission. When the bed height at rest increased from 200 mm to 400 mm, the load change rate of the CFB combustion side load from 50% to 75% increased from 0.78%/min to 1.14%/min, and the carbon content of fly ash at 75% load decreased from 26.6% to 24.9%. In addition, the reduction of fuel particle size positively improved the load change rate on the combustion side of the CFB and reduced NO x emission but had a negative effect on reducing the carbon content of fly ash. When the fuel particle size decreased from 0–1 mm to 0–0.12 mm, the load change rate of CFB combustion side load from 50% to 75% increased from 0.78%/min to 1.09%/min, and the NO x emission and carbon content of fly ash at 75% load decreased from 349.5 mg/m 3 to 194.1 mg/m 3 and increased from 26.6% to 31.8%, respectively.