A particle-tracking image pyrometer for characterizing ignition of pulverized coal particles

2022 ◽  
Vol 225 ◽  
pp. 107065
Author(s):  
Qianyun Chen ◽  
Dingyi Qin ◽  
Jing Li ◽  
Zhaohui Liu
Keyword(s):  
Particle Tracking ◽  
Pulverized Coal ◽  
Coal Particles

Numerical Simulation on Improving NOx Reduction Efficiency of SNCR by Regulating the 3-D Temperature Field in a Furnace

2013 ◽  
Vol 807-809 ◽  
pp. 1505-1513 ◽  
Author(s):  
Amir A.B. Musa ◽  
Xiong Wei Zeng ◽  
Qing Yan Fang ◽  
Huai Chun Zhou
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Removal Efficiency ◽  
Pulverized Coal ◽  
Measuring System ◽  
Optimum Temperature ◽  
Utility Boiler ◽  
Coal Particles ◽  
Injection Zone ◽  
Reduction Efficiency

The optimum temperature within the reagent injection zone is between 900 and 1150°C for the NOX reduction by SNCR (selective non-catalytic reduction) in coal-fired utility boiler furnaces. As the load and the fuel property changes, the temperature within the reagent injection zone will bias from the optimum range, which will reduces significantly the de-NOX efficiency, and consequently the applicability of SNCR technology. An idea to improve the NOX reduction efficiency of SNCR by regulating the 3-D temperature field in a furnace is proposed in this paper. In order to study the new method, Computational fluid dynamics (CFD) model of a 200 MW multi-fuel tangentially fired boiler have been developed using Fluent 6.3.26 to investigate the three-fuel combustion system of coal, blast furnace gas (BFG), and coke oven gas (COG) with an eddy-dissipation model for simulating the gas-phase combustion, and to examine the NOX reduction by SNCR using urea-water solution. The current CFD models have been validated by the experimental data obtained from the boiler for case study. The results show that, with the improved coal and air feed method, average residence time of coal particles increases 0.3s, burnout degree of pulverized coal increases 2%, the average temperature at the furnace nose decreases 61K from 1496K to 1435K, the NO emission at the exit (without SNCR) decreases 58 ppm from 528 to 470 ppm, the SNCR NO removal efficiency increases 10% from 36.1 to 46.1%. The numerical simulation results show that this combustion adjustment method based on 3-D temperature field reconstruction measuring system in a 200 MW multi-fuel tangentially fired utility boiler co-firing pulverized coal with BFG and COG is timely and effective to maintain the temperature of reagent injection zone at optimum temperature range and high NOX removal efficiency of SNCR.

Comparison of Sieve Diameter and Stokes' Diameter Distributions for Pulverized Coal Particles

1981 ◽  
Vol 27 (1-2) ◽  
pp. 79-82 ◽  
Author(s):  
L. M. COHEN ◽  
M. R. DENISON ◽  
N. GAT ◽  
A. B. WITTE
Keyword(s):  
Pulverized Coal ◽  
Coal Particles ◽  
Diameter Distributions

Measurement & Control of Pulverized Coal Concentration in Exhaust Pneumatic Convey System

2012 ◽  
Vol 190-191 ◽  
pp. 1006-1009
Author(s):  
Xing Sen Yang ◽  
Jing Yin
Keyword(s):  
Power Plants ◽  
Fine Particles ◽  
Engineering Application ◽  
Pulverized Coal ◽  
Mixing Process ◽  
Horizontal Pipes ◽  
Controlling System ◽  
Coal Particles ◽  
Balance Analysis ◽  
Energy Balance Analysis

Pulverized coal firing boilers are widely used in power plants. Coal is pulverized into very fine particles and then mixed with primary air in horizontal pipes in the case of exhaust pneumatic convey system. The pulverized coal particles are conveyed by primary air to the burner and burn in the furnace. The concentration of pulverized coal in primary air should be well controlled to keep the safe and economic operation of the boiler. Credible measuring and controlling system is needed in engineering applications. Investigation of the mixing process shows that the pressure of primary air drops rapidly within the process, which gives the possible way to determine the pulverized coal concentration. The rapid pressure drop is mainly due to the acceleration of the pulverized coal particles. With energy balance analysis, study of the relationship between the mass flow rate of the pulverized coal and the pressure changes within the mixing process is done. The governing equation is achieved and the method of using two sections to measure the flow is proposed. The measuring and controlling system can be established according to the method. As a result, the measuring and controlling method provides a new way to meet the needs of engineering application.

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