scholarly journals Optimization of Air Distribution to Reduce NOx Emission and Unburned Carbon for the Retrofit of a 500 MWe Tangential-Firing Coal Boiler

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3281 ◽  
Author(s):  
Hyunbin Jo ◽  
Kiseop Kang ◽  
Jongkeun Park ◽  
Changkook Ryu ◽  
Hyunsoo Ahn ◽  
...  
Keyword(s):  
Negative Impact ◽  
Nox Reduction ◽  
Standard Technique ◽  
Unburned Carbon ◽  
Air Distribution ◽  
Reference Case ◽  
Design Data ◽  
Secondary Air ◽  
Coal Boiler ◽  
Air Staging

The use of separated overfire air (SOFA) has become a standard technique of air staging for NOx reduction in the coal-fired boiler and can also be applied to existing boilers by retrofit. This study was to optimize the air distribution for the proposed SOFA installation in a 500 MWe tangential-firing boiler that has 20 identical units in Korea. Using computational fluid dynamics (CFD) incorporating advanced coal combustion submodels, the reference case was established in good agreement with the design data, and different flow ratios of burner secondary air, close-coupled OFA (CCOFA), and SOFA were evaluated. Increasing the total OFA ratio effectively suppressed NO formation within the burner zone but had a negative impact on the boiler performance. With moderate air staging, NO reduction became active between the CCOFA and SOFA levels and, therefore, the OFA distribution could be optimized for the overall boiler performance. For total OFA ratios of 25% and 30% with respective burner zone stoichiometric ratios of 0.847 and 0.791, increasing the SOFA ratio to 15% and 20%, respectively, was ideal for decreasing the unburned carbon release and ash slagging as well as NO emission. Too high or low SOFA ratios rapidly increased the unburned carbon because of inefficient mixing between the strong air jets and char particles. Based on these ideal cases, the actual air distribution can be adjusted depending on the coal properties such as the ash slagging propensity.

Effects of secondary air distribution in primary combustion zone on combustion and NO emissions of a large-scale down-fired boiler with air staging

Energy ◽  
2018 ◽  
Vol 165 ◽  
pp. 399-410 ◽  
Author(s):  
Qingxiang Wang ◽  
Zhichao Chen ◽  
Jiaquan Wang ◽  
Lingyan Zeng ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Combustion Zone ◽  
Large Scale ◽  
Air Distribution ◽  
Scale Down ◽  
Secondary Air ◽  
Air Staging ◽  
No Emissions

Research of Cold Test in 170t/h Tangentially Fired Boiler

2012 ◽  
Vol 516-517 ◽  
pp. 180-186
Author(s):  
Yu Hua Xiang ◽  
Jia Yuan Zhang ◽  
Xiao Hui Zhang
Keyword(s):  
Cold Test ◽  
Air Distribution ◽  
Stable Operation ◽  
Test Results ◽  
Air Velocity ◽  
Pulverized Coal Boiler ◽  
Width Direction ◽  
Aerodynamic Field ◽  
Secondary Air ◽  
Coal Boiler

The characteristics of the WGZ170/9.8-3 pulverized coal boiler were obtained based on cold test，Including the air velocity distribution in tangential firing boiler and the relation between air distribution with opening of each secondary air dampe，The test results had determined that the baffle of blower at around 40% and two parallel draft fan about 45% were relatively appropriate. and the air distribution and opening of each secondary air dampe and balancing the distribution of primary air and second air along the width direction of the boiler hearth were confirmed through test，and the aerodynamic field inside the boiler was investigated based on the tie-floating test．and good aerodynamic field can be obtained after distributing the primary air and second air reasonably，which guarantee the ignition and stable operation of the boiler．

TO THE QUESTION OF THE IMPACT OF CLIMATE CHANGE ON THE ECOLOGICAL STATE OF ARTIFICIAL PLANTATIONS OF PITSUNDSKAYA PINE IN THE SEASIDE AREA OF GELENDZHIK

2017 ◽  
Author(s):  
Elizaveta Derevenets ◽  
Elizaveta Derevenets
Keyword(s):  
Negative Impact ◽  
Standard Technique ◽  
Negative Influence ◽  
Exhaust Gases ◽  
The Road ◽  
Industrial Enterprises ◽  
Federal Highway ◽  
On The Road ◽  
The Impact ◽  
The City

Gelendzhik is the resort town, there aren't a lot of industrial enterprises here. The main pollutant is transport. The work purpose is the assessment of a condition of the artificial landings of a pine located along the Federal highway "Don" and landings, which is nearly the sea coast. Researches were conducted to a standard technique of the General vital state (A. S. Bogolyubov). The assessment of a condition of pines was carried out during 6 years: from 2010 to 2015. For carrying out research we used 6 experimental grounds on the Markotkhsky spine and 2 control grounds within the town. We investigated 24 trees on each platform, middle age of the trees were 30 - 40 years. Results. 1. The condition of trees in the pine forests located in immediate proximity with the Federal highway "Don" (No. 1, 2, 3) is unsatisfactory. As even weak influences of the majority of atmospheric gaseous pollutants (sulphurous gas, nitrogen oxides, etc.) give effect of a necrosis and hloroz of pine needles, the condition of pines is connected with technogenic pollution. So near the Federal highway "Don" the air environment is strongly polluted by exhaust gases. Information of 2012 confirm that negative influence of the route on Markotkh's vegetation decreases at reduction of load of the route. 2. On the sites located above on a slope (No. 4,5,6) thanks to remoteness and the wind mode intensity of influence of pollutants is lower and a condition of pines the quite satisfactory. 3. Trees on the sites located near the sea (No. 7,8) are in a good shape. Small deterioration of a state is noted in very droughty years. Conclusion. Results of six years' research show that the condition of the plantings which are in close proximity with the road worsens. It is explained by increase in intensity of the movement on the road, especially during a resort season. Gelendzhik is the city with a good ecological shape, but the damage to environment is already caused. If not to take measures, we can lose a unique part of the nature in the future, recreate it will be impossible. Measures of reduction of negative impact of exhaust gases were offered. Results of researches are transferred to ecological department of the City administration of Gelendzhik.

TO THE QUESTION OF THE IMPACT OF CLIMATE CHANGE ON THE ECOLOGICAL STATE OF ARTIFICIAL PLANTATIONS OF PITSUNDSKAYA PINE IN THE SEASIDE AREA OF GELENDZHIK

2017 ◽  
Author(s):  
Elizaveta Derevenets ◽  
Elizaveta Derevenets
Keyword(s):  
Negative Impact ◽  
Standard Technique ◽  
Negative Influence ◽  
Exhaust Gases ◽  
The Road ◽  
Industrial Enterprises ◽  
Federal Highway ◽  
On The Road ◽  
The Impact ◽  
The City

Gelendzhik is the resort town, there aren't a lot of industrial enterprises here. The main pollutant is transport. The work purpose is the assessment of a condition of the artificial landings of a pine located along the Federal highway "Don" and landings, which is nearly the sea coast. Researches were conducted to a standard technique of the General vital state (A. S. Bogolyubov). The assessment of a condition of pines was carried out during 6 years: from 2010 to 2015. For carrying out research we used 6 experimental grounds on the Markotkhsky spine and 2 control grounds within the town. We investigated 24 trees on each platform, middle age of the trees were 30 - 40 years. Results. 1. The condition of trees in the pine forests located in immediate proximity with the Federal highway "Don" (No. 1, 2, 3) is unsatisfactory. As even weak influences of the majority of atmospheric gaseous pollutants (sulphurous gas, nitrogen oxides, etc.) give effect of a necrosis and hloroz of pine needles, the condition of pines is connected with technogenic pollution. So near the Federal highway "Don" the air environment is strongly polluted by exhaust gases. Information of 2012 confirm that negative influence of the route on Markotkh's vegetation decreases at reduction of load of the route. 2. On the sites located above on a slope (No. 4,5,6) thanks to remoteness and the wind mode intensity of influence of pollutants is lower and a condition of pines the quite satisfactory. 3. Trees on the sites located near the sea (No. 7,8) are in a good shape. Small deterioration of a state is noted in very droughty years. Conclusion. Results of six years' research show that the condition of the plantings which are in close proximity with the road worsens. It is explained by increase in intensity of the movement on the road, especially during a resort season. Gelendzhik is the city with a good ecological shape, but the damage to environment is already caused. If not to take measures, we can lose a unique part of the nature in the future, recreate it will be impossible. Measures of reduction of negative impact of exhaust gases were offered. Results of researches are transferred to ecological department of the City administration of Gelendzhik.

NOX reduction in calciner using air staging and raw meal split technology

2021 ◽  
Author(s):  
Shubham Kinekar ◽  
Shital Mone ◽  
Adnan Taqi ◽  
Pravin Mane ◽  
Bajirao Gawali ◽  
...  
Keyword(s):  
Nox Reduction ◽  
Air Staging

scholarly journals Use of Ash-and-Slag Wastes after Burning of Fine-Dispersed Coal-Washing Wastes

2018 ◽  
Vol 41 ◽  
pp. 01042
Author(s):  
Vasilii Murko ◽  
Veniamin Khyamyalyainen ◽  
Marina Baranova
Keyword(s):  
Power Plants ◽  
Building Materials ◽  
Negative Impact ◽  
Mineralogical Composition ◽  
Unburned Carbon ◽  
Crushed Rock ◽  
Low Carbon ◽  
Technological Parameters ◽  
Coal Fuel ◽  
Granulated Slag

Effective utilization of ash-and-slag waste generated by coalfired power plants can help significantly to reduce the negative impact on the environment and improve their economic performance. Studies have been made of the mineralogical composition of ash-and-slag wastes obtained after the combustion of water-coal fuel based on fine-dispersed coal-washing waste (filter cake) in a specially designed boiler with a vortex combustion system. The possibility of effective use of ash-and-slag wastes for the production of building materials, primarily mortar mixes, widely used for mining works on mine openings, laying the worked out space, etc. (high content of silicon oxide and aluminum oxide is combined with a low carbon content in other words a negligible unburned carbon loss). The optimum percentage ratio of the initial components of the filling mixture based on ash-and-slag wastes and crushed rock (granulated slag) has been established. The results of experimental tests of hardening tabs on the strength under uniaxial compression are presented. It has been established that a sample containing 18% of ash-and-slag wastes, 33% of a granulated slag and 19% of cement, corresponds to the required technological parameters for the strength and cement content.

scholarly journals Reduction of Unburned Carbon Release and NOx Emission from a Pulverized Wood Pellet Boiler Retrofitted for Fuel Switching from Coal

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5077 ◽  
Author(s):  
Jiseok Lee ◽  
Seunghan Yu ◽  
Jinje Park ◽  
Hyunbin Jo ◽  
Jongkeun Park ◽  
...  
Keyword(s):  
Power Plant ◽  
Bottom Ash ◽  
Flow Characteristics ◽  
Electricity Production ◽  
Unburned Carbon ◽  
Nox Emissions ◽  
Wood Pellet ◽  
Operating Variables ◽  
Carbon Release ◽  
Air Staging

For renewable electricity production, biomass can fully displace coal in an existing power plant with some equipment modifications. Recently, a 125 MWe power plant burning mainly anthracite in Korea was retrofitted for dedicated wood pellet combustion with a change of boiler configuration from arch firing to wall firing. However, this boiler suffers from operational problems caused by high unburned carbon (UBC) contents in the bottom ash. This study comprises an investigation of some methods to reduce the UBC release while achieving lower NOx emissions. The computational fluid dynamics approach was established and validated for typical operating data. Subsequently, it was applied to elucidate the particle combustion and flow characteristics leading to the high UBC content and to evaluate the operating variables for improving the boiler performance. It was found that the high UBC content in the bottom ash was a combined effect of the poor fuel grindability and low gas velocity in the wide burner zone originating from the arch-firing boiler. This prevented the operation with deeper air staging for lower NOx emissions. Reducing the particle size to <1.5 mm by modifying mills or pretreating the fuel using torrefaction was the only effective way of lowering the UBC and NOx emissions with deeper air staging while increasing the boiler efficiency.

scholarly journals Reduction of Major Pollutants via Air-staged Commbustion on Burner System

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Mohammad Nazri Mohd. Jaafar ◽  
Mohd Nur Hanafi Zaini
Keyword(s):  
Combustion Process ◽  
Primary Concern ◽  
Nox Emissions ◽  
Percent Reduction ◽  
Secondary Air ◽  
Secondary Zone ◽  
Combustion Processes ◽  
Different Gases ◽  
Air Staging ◽  
Co Emission

Emission from the combustion processes can cause adverse effect to the environment.  The formation of pollutants such as NOx, CO, CO2 and SOx are hazardous and harmful to the ecosystem.  The awareness about the pollution due to the combustion activities, particularly in industrial field has set off an effort to find more comprehensive and enhanced technologies to reduce these pollutants.  There are several methods that can be used to reduce the emissions of these pollutants either by combustion modifications or post combustion treatment.  In this research, the method used is the post combustion treatment, i.e. the air staging method.  By air staging techniques, some of the combustion air will be directed into the primary combustion zone, while the remaining air is directed into the secondary zone.  The function of the secondary air is to reduce the peak flame temperatures, which theoretically reduce the emissions of NOx emissions.  The primary concern for this research is to study the effectiveness of the air staging in reducing NOx, CO, SO2, and UHC emissions from the combustion process.  The results obtained showed significant reduction in all major pollutants, i.e., a 31.8 percent reduction for CO emission, 16.8 percent for NOx, 12.7 percent for SO2 and 10.3 percent for UHC.  These reductions were obtained at different equivalence ratios for different gases.

scholarly journals OPTIMIZED FUEL INJECTOR DESIGN FOR MAXIMUM IN-FURNACE NOx REDUCTION AND MINIMUM UNBURNED CARBON

10.2172/7176 ◽  
1998 ◽  
Author(s):  
A F SAROFIM ◽  
R LISAUSKAS ◽  
D RILEY ◽  
E G EDDINGS ◽  
J BROUWER ◽  
...  
Keyword(s):  
Nox Reduction ◽  
Unburned Carbon ◽  
Fuel Injector ◽  
Injector Design
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