MILD Combustion under Different Premixing Patterns and Characteristics   of the Reaction Regime

doi:10.1021/ef402357t

CORC > 北京大学 > 工学院

	MILD Combustion under Different Premixing Patterns and Characteristics of the Reaction Regime
	Li, P. ; Wang, F. ; Mi, J. ; Dally, B. B. ; Mei, Z.
刊名	energy and fuels
	2014
关键词	COLORLESS DISTRIBUTED COMBUSTION LABORATORY-SCALE FURNACE RADIANT-HEAT TRANSFER FINITE-VOLUME METHOD HIGH-TEMPERATURE AIR OXY-FUEL COMBUSTION HOT-COFLOW FLAMES PULVERIZED COAL OPERATIONAL CHARACTERISTICS THERMAL INTENSITY
DOI	10.1021/ef402357t
英文摘要	Through experiment and numerical modeling, this study investigated the establishment of moderate or intense low-oxygen dilution (MILD) combustion in a laboratory-scale furnace when fuel and air are fully premixed (FP), partially premixed (PP), or non-premixed (NP). Experiments were carried out at firing rates from 7.5 to 15 kW and equivalence ratios (Phi) ranging from 0.5 to 1. The furnace thermal fields and exhaust NOx emissions for the three mixing patterns were compared. Validated computational fluid dynamics was used to aid in better understanding the flow and compositional structures in the furnace. Natural gas was used as the fuel. The eddy dissipation concept (EDC) model and the GRI-Mech 3.0 mechanism were used. Additional chemical kinetics calculations were also performed to examine reaction pathways under the MILD combustion regime. Moreover, the characteristics of the reaction regime of MILD combustion were examined and are discussed in detail. Estimation of the initial jet momentum rate (I) showed that J(FP) > J(NP) > J(PP), and consistently the recirculating rate of internal flue gas (K-v) was found to be in the order K-v,K- FP > K-v,K-NP > K-v,K- PP. Correspondingly, the highest values of both furnace temperature and NOx emission were experimentally measured in the PP case, while the lowest values were found in the FP case. The measured NOx emission was negligibly low for the FP case. Numerical results revealed that in all the three cases of firing natural gas (FP, PP, NP), more than 80% of the total NOx formation results from the N2O intermediate route while other NOx mechanisms are unimportant. As Phi is increased from 0.5 to 1.0, both the measured and simulated NOx emissions in the three cases initially increase and then decrease. Moreover, for Phi > 0.9, the NOx-reburning reaction becomes significant and the resulting reduction of NOx is notable. The rates of both turbulent mixing and chemical reaction were found to play a significant role in the structure and establishment of MILD combustion, with estimated Damkohler numbers in the range Da = 0.01-5.35.; Energy & Fuels; Engineering, Chemical; SCI(E); EI; 4; ARTICLE; jcmi@coe.pku.edu.cn; 3; 2211-2226; 28
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/154316]
专题	工学院
推荐引用方式 GB/T 7714	Li, P.,Wang, F.,Mi, J.,et al. MILD Combustion under Different Premixing Patterns and Characteristics of the Reaction Regime[J]. energy and fuels,2014.
APA	Li, P.,Wang, F.,Mi, J.,Dally, B. B.,&Mei, Z..(2014).MILD Combustion under Different Premixing Patterns and Characteristics of the Reaction Regime.energy and fuels.
MLA	Li, P.,et al."MILD Combustion under Different Premixing Patterns and Characteristics of the Reaction Regime".energy and fuels (2014).