In the present paper, a multifluid model of two-phase flows with pulverized-coal combustion, based on a continuum-trajectory model with reacting particle phase, is developed and employed to simulate the 3-D turbulent ...In the present paper, a multifluid model of two-phase flows with pulverized-coal combustion, based on a continuum-trajectory model with reacting particle phase, is developed and employed to simulate the 3-D turbulent two-phase hows and combustion in a new type of pulverized-coal combustor with one primary-air jet placed along the wall of the combustor. The results show that: (1) this continuum-trajectory model with reacting particle phase can be used in practical engineering to qualitatively predict the flame stability, concentrations of gas species, possibilities of slag formation and soot deposition, etc.; (2) large recirculation zones can be created in the combustor, which is favorable to the ignition and flame stabilization.展开更多
The mechanisms of flame stabilization and low NO_x emission features of an eccentric jet pulverized coal com- bustor were studied through numerical modelling and experimental investigation.The results show that the fo...The mechanisms of flame stabilization and low NO_x emission features of an eccentric jet pulverized coal com- bustor were studied through numerical modelling and experimental investigation.The results show that the formation of the unique flowfield structure is closely related to the interaction among combustor configuration, the primary jet and the control jet;and that certain rules should be followed in order to obtain the optimum condition for flame stabilization.The distributions of temperature and concentrations of NO,O_2,CO and CO_2 inside the combustor were experimentally measured.The effects of structural and operational parameters on combustion and NO formation were studied.It was found that reduction of primary air,suitable use of control jet and reasonable uptilt angle of the primary jet all contributed to the reduction of NO_x at the combustor exit. A new hypothesis,that reasonable separation of oxygen and fuel within the fuel-rich zone is beneficial to further reduction of NO_x emission,is given.The study showed that good compatibility existed between the capability of flame stabilization and low NO_x emission for this type of combustor.展开更多
基金Sponsored by the National Key Projects of Fundamental Research of China.
文摘In the present paper, a multifluid model of two-phase flows with pulverized-coal combustion, based on a continuum-trajectory model with reacting particle phase, is developed and employed to simulate the 3-D turbulent two-phase hows and combustion in a new type of pulverized-coal combustor with one primary-air jet placed along the wall of the combustor. The results show that: (1) this continuum-trajectory model with reacting particle phase can be used in practical engineering to qualitatively predict the flame stability, concentrations of gas species, possibilities of slag formation and soot deposition, etc.; (2) large recirculation zones can be created in the combustor, which is favorable to the ignition and flame stabilization.
基金This project was supported by the National Natural Science Foundation of China
文摘The mechanisms of flame stabilization and low NO_x emission features of an eccentric jet pulverized coal com- bustor were studied through numerical modelling and experimental investigation.The results show that the formation of the unique flowfield structure is closely related to the interaction among combustor configuration, the primary jet and the control jet;and that certain rules should be followed in order to obtain the optimum condition for flame stabilization.The distributions of temperature and concentrations of NO,O_2,CO and CO_2 inside the combustor were experimentally measured.The effects of structural and operational parameters on combustion and NO formation were studied.It was found that reduction of primary air,suitable use of control jet and reasonable uptilt angle of the primary jet all contributed to the reduction of NO_x at the combustor exit. A new hypothesis,that reasonable separation of oxygen and fuel within the fuel-rich zone is beneficial to further reduction of NO_x emission,is given.The study showed that good compatibility existed between the capability of flame stabilization and low NO_x emission for this type of combustor.
