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Indexed by:会议论文

Date of Publication:2007-01-01

Included Journals:CPCI-S

Page Number:315-321

Key Words:micronized coal; NOx reduction; numerical simulation; full-scale

Abstract:Three dimensional numerical simulation of micronized coal reburning in full-scale tangentially fire boiler was conducted by using CFD method. Bituminous coal was chosen as reburn fuel to study the effects of reburn zone length, the height of reburn nozzles, the stoichiometry ratio in reburn zone, the reburn fuel fraction and the reburn coal fineness on NOx emissions. The results indicated that when the relative height of reburn nozzles was about 0.210 and the stoichiometry ratio was between 0.8 and 0.9 in rebum zone, the NOx reduction efficiency reached the largest value. NOx reduction efficiency increased with reburn zone length and rebum fuel fraction. The optimum reburn fuel fraction is 20%. NOx reduction efficiency increased with the reduction of rebum coal particle size. The optimum particle size of reburning fuel is 20 mu m. Compared with conventional coal reburning, micronized coal reburning is superior. This technology not only has less influence on combustion efficiency but also has higher NOx reduction efficiency.