In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burn...In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.展开更多
In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler...In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small.展开更多
The present paper describes the numerical investigation for a newly developed pulverized coal rich/lean burner used in the utility boilers. The mechanism of the rich/lean separation process of the pulverized coal are ...The present paper describes the numerical investigation for a newly developed pulverized coal rich/lean burner used in the utility boilers. The mechanism of the rich/lean separation process of the pulverized coal are analyzed and the effect of the height of the baffle body and the different particle sizes on the separation efficiency are considered. It is concluded that the burner is applicable in industry.展开更多
基金supported by the National Natural Science Foundation of China(Grant No. 51906075)Key Research and Development Program of Department of Science and Technology of Jiangxi Province(Grant No. 20223BBG74009)Science and Technology Innovation Project for Carbon Peak and Carbon Neutrality of Jiangxi Carbon Neutralization Research Center(Grant No. 2022JXST01)。
文摘In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.
基金This work was supported by National Key Research and Development Program of China(Grant No.2017YF C0212500).
文摘In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small.
文摘The present paper describes the numerical investigation for a newly developed pulverized coal rich/lean burner used in the utility boilers. The mechanism of the rich/lean separation process of the pulverized coal are analyzed and the effect of the height of the baffle body and the different particle sizes on the separation efficiency are considered. It is concluded that the burner is applicable in industry.
