B164 2D Simultaneous Measurement of the Combustion Reaction Zone and the Pulverized Coal Particles in a Turbulent Pulverized Coal Combustion Flame

2005 ◽  
Vol 2005 (0) ◽  
pp. 91-92
Author(s):  
Seung-Min HWANG ◽  
Ryoichi KUROSE ◽  
Fumiteru AKAMATSU ◽  
Hirofumi TSUJI ◽  
Hiromi SHIRAI
Author(s):  
M. J. Chernetsky ◽  
A. A. Dekterev

To fully understand the processes of heat-and-mass transfer on the laboratory-scale and full-scale coal boilers, computer models are needed to develop, which can predict flow fields, heat transfer and the combustion of the coal particles with reasonable accuracy. In the work reported here, a comprehensive model for pulverized coal combustion has been presented. Attention has been given to the char burnout submodel, NOx formation sub-model and accurate calculation of the temperature of the particles. The model predictions have been compared with the experimental measurements of the laboratory-scale pulverized-coal combustion burner.


Author(s):  
Hiroaki Watanabe ◽  
Kenji Tanno ◽  
Ryoichi Kurose ◽  
Satoru Komori

Large-eddy simulation (LES) is applied to a pulverized coal combustion field in a combustion test furnace with a practical advanced low NOx burner called CI-α burner, and its validity is investigated by comparing with the experiment. The motion of coal particles is calculated by the Lagrangian method with a parcel model. In the coal combustion modeling, three chemical processes are considered, namely devolatilization, char combustion and gaseous combustion. The direct closure SSFRRM (scale similarity filtered reaction rate model) is used as a turbulent combustion model. The results show that a swirling recirculation flow is formed in the central region close to the burner and its size and strength dynamically change with time. The predicted distributions of gaseous temperature and oxygen are in general agreement with the experiment.


2005 ◽  
Vol 127 (12) ◽  
pp. 1322-1333 ◽  
Author(s):  
S. K. Som ◽  
S. S. Mondal ◽  
S. K. Dash

A theoretical model of exergy balance, based on availability transfer and flow availability, in the process of pulverized coal combustion in a tubular air-coal combustor has been developed to evaluate the total thermodynamic irreversibility and second law efficiency of the process at various operating conditions. The velocity, temperature, and concentration fields required for the evaluation of flow availability have been computed numerically from a two-phase separated flow model on a Eulerian-Lagrangian frame in the process of combustion of pulverized coal particles in air. The total thermodynamic irreversibility in the process has been determined from the difference in the flow availability at the inlet and outlet of the combustor. A comparative picture of the variations of combustion efficiency and second law efficiency at different operating conditions, such as inlet pressure and temperature of air, total air flow rate and inlet air swirl, initial mean particle diameter, and length of the combustor, has been provided to shed light on the trade-off between the effectiveness of combustion and the lost work in the process of pulverized coal combustion in a tubular combustor.


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