Premium
A dimensionless factor characterizing the ignition of pulverized coal flow: Analytical model, experimental verification, and application
Author(s) -
Zhou Qulan,
Zhao Qinxin,
Li Na,
Chen Xi,
Xu Tongmo,
Hui Shien
Publication year - 2009
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.1465
Subject(s) - pulverized coal fired boiler , combustor , ignition system , coal , dimensionless quantity , flow (mathematics) , flue gas , mechanics , combustion , engineering , physics , waste management , thermodynamics , chemistry , organic chemistry
An analytical model describing the ignition process of pulverized coal is proposed, and a dimensionless condition number ( N com ) is obtained to describe the comprehensive effect of factors governing the ignition of pulverized coal flow, such as the initial temperature of flow, the sectional heat load of the furnace, and the flux of primary air, secondary air and recirculation flue gas. An optimized concentration of pulverized coal flow is derived explicitly, upon which the earliest ignition of pulverized coal flow is possible. The model is verified in a hot furnace experiment, where it is shown that the derived criterion ( N com ) can be used for different kinds of coal and different types of burner. For given coal and sectional heat load of furnace, when the value of N com increases, the condition of ignition is improved and both unburned carbon and NO x emission are reduced. The employment of N com in the optimization of burner operating conditions is demonstrated through two applications. In practice, the criterion N com can be used to guide the selection of the concentration and type of pulverized coal, as well as the choice of burner and desired aerodynamic field, so as to achieve an optimized performance. Copyright © 2008 John Wiley & Sons, Ltd.