ZHU Xinyang;ZHANG Liqi;LUO Junwei;WANG Wenzhe;YANG Wenhai;

• 1:Wuhan Wuguo Energy Engineering Co.
• 2:Ltd.
• 3:State Key Laboratory of Coal Combustion
• 4:Huazhong University of Science and Technology

Abstract：

Due to the fact that water vapor has specific gasification reaction with coke and can reduce the burning rate,air blending water vapor is expected to be a mean of promoting the coal MILD combustion.Based on the pilot-scale furnace of IFRF,the effects of different O_2 and H_2O concentrations on the air-MILD combustion of pulverized coal was investigated by numerical simulation.The results show that increasing the H_2O concentration at different oxygen concentration will make the furnace temperature distribution more uniform,and the proportion of gasification reaction with coke is improved.It is beneficial to the realization of MILD and make thermal-NO decreased from 798×10-6 to 121×10-6 at most.With the increase of O_2 concentration,the peak temperature and whole temperature of the furnace increase obviously.The higher furnace temperature can promote the formation of thermal-NO and the gasification reaction,and thus inhibit the fuel-NO.

Key Words： water vapor;MILD combustion;gasification reaction;NO emission

Abstract:

Keywords:

Foundation: 国家重点研发计划政府专项资助项目(2016YFE0102500)

Authors: ZHU Xinyang;ZHANG Liqi;LUO Junwei;WANG Wenzhe;YANG Wenhai;

DOI: 10.13226/j.issn.1006-6772.2018.03.013

References：

• [1]李鹏飞,米建春,DALLY B B,等.MILD燃烧的最新进展和发展趋势[J].中国科学:技术科学,2011,41(2):135-149.LI Pengfei,MI Jianchun,DALLY B B,et al.The latest developments and trends of MILD combustion[J].Science China:Technological Sciences,2011,41(2):135-149.
• [2]TSUJI H,GUPTA A K,HASEGAWA T,et al.High temperature air combustion:From energy conservation to pollution reduction[M].Boca Raton:CRC Press,2002.
• [3]KIGA T,YOSHIKAWA K,SAKAI M,et al.Characteristics of pulverized coal combustion in high-temperature preheated air[J].Journal of Propulsion and Power,2000,16(4):601-605.
• [4]WNNING J.Flameless oxidation to reduce thermal NO-formation[J].Progress in Energy and Combustion Science,1997,23(1):81-94.
• [5]SUDA T,TAKAFUJI M,HIRATA T,et al.A study of combustion behavior of pulverized coal in high-temperature air[J].Proceedings of the Combustion Institute,2002,29(1):503-509.
• [6]MEI Z,LI P,WANG F,et al.Influences of reactant injection velocities on moderate or intense low-oxygen dilution coal combustion[J].Energy&Fuels,2013,28(1):369-384.
• [7]SAHA M,DALLY B B,MEDWELL P R,et al.Moderate or intense low oxygen dilution(MILD)combustion characteristics of pulverized coal in a self-recuperative furnace[J].Energy&Fuels,2014,28(9):6046-6057.
• [8]YI B,ZHANG L,HUANG F,et al.Effect of H2O on the combustion characteristics of pulverized coal in O2/CO2atmosphere[J].Applied Energy,2014,132(11):349-357.
• [9]张振,王涛,冯太,等.水蒸气及氧气复合气氛对活性半焦孔隙结构演化的影响[J].燃烧科学与技术,2015,21(4):318-323.ZHANG Zhen,WANG Tao,FENG Tai,et al.Influence of steam and oxygen on pore structure evolution of active semi-char[J].Journal of Combustion Science and Technology,2015,21(4):318-323.
• [10]丁继伟,张立麒,夏佐君,等.富氧气氛下水蒸气气化对煤焦燃烧的影响[J].热能动力工程,2017,32(1):63-69.DING Jiwei,ZHANG Lilin,XIA Zuojun,et al.Effects of steam gasification on coal char combustion under oxy-fuel combustion atmosphere[J].Journal of Engineering for Thermal Energy and Power,2017,32(1):63-69.
• [11]ZOU C,ZHANG L,CAO S,et al.A study of combustion characteristics of pulverized coal in O2/H2O atmosphere[J].Fuel,2014,115:312-320.
• [12]WEBER R,SMART J P,KAMP W V.On the(MILD)combustion of gaseous,liquid,and solid fuels in high temperature preheated air[J].Proceedings of the Combustion Institute,2005,30(2):2623-2629.
• [13]SMOOT L D,PRATT D T.Pulverized-coal combustion and gasification:Theory and applications for continuous flow processes[M].New York:Plenum Press,1979:95-100.
• [14]HOWARD J B,WILLIAMS G C,FINE D H.Kinetics of carbon monoxide oxidation in postflame gases[J].Symposium on Combustion,1973,14(1):975-986.
• [15]HAUTMAN D J,DRYER F L,SCHUG K P,et al.A multiple-step overall kinetic mechanism for the oxidation of hydrocarbons[J].Combustion Science and Technology,1981,25(5/6):219-235.
• [16]JONES W P,LINDSTEDT R P.Global reaction schemes for hydrocarbon combustion[J].Combustion and Flame,1988,73(3):233-249.
• [17]FIELD M A.Measurements of the effect of rank on combustion rates of pulverized coal[J].Combustion and Flame,1970,14(2):237-248.
• [18]SCHAFFEL N,MANCINI M,SZLE A,et al.Mathematical modeling of MILD combustion of pulverized coal[J].Combustion and Flame,2009,156(9):1771-1784.
• [19]WEBER R.Combustion of natural gas,oil and coal with air preheated to temperatures in excess of 1 000℃[C]//17th International Symposium on Combustion Processes.Poznan:Poznan University of Technology,2001:24-27.
• [20]VASCELLARI M,CAU G.Influence of turbulence-chemical interaction on CFD pulverized coal MILD combustion modeling[J].Fuel,2011,101:90-101.
• [21]ORSINO S,TAMURA M,STABAT P,et al.Excess enthalpy combustion of coal[R].[S.N.]:IFRF,2000.