The Large Capacity Pulverized Coal Fired Utility Boiler and the Low NOx Combustion Technology Developments in China in Response to Environmental Challenges

2011 ◽  
Author(s):  
Hao Zhou ◽  
Guiyuan Mo ◽  
Kefa Cen
Keyword(s):  
High Efficiency ◽  
Catalytic Reduction ◽  
Pulverized Coal ◽  
Large Capacity ◽  
Environmental Challenges ◽  
Utility Boiler ◽  
Integrated Technology ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Scr System

Large capacity pulverized coal fired utility boiler technology is in quick developments in China, hundreds of super critical boilers have been constructed in the last several years which can achieve high efficiency and low pollutants emissions. The different types of super critical boilers are introduced in this paper, they include the single-furnace with double fireball corner fired furnace, the wall fired furnace and the tower-type furnace. The low NOx combustion technologies have been widely used to face the environmental challenges. The low NOx technologies employed in pulverized-coal boilers consist of the combustion modification and post-combustion technology. The low NOx combustion modification technology includes the low NOx burner, close coupled over fire air (CCOFA) and separated over fire air (SOFA). The post-combustion technology consists of selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) technologies. Zhejiang University develops integrated low NOx technology, including the low NOx combustion system, SNCR system and SCR system. This integrated technology can reduce the NOx emissions to be lower than 50 mg/Nm3.

PDA research on a novel pulverized coal combustion technology for a large utility boiler

Energy ◽  
2010 ◽  
Vol 35 (5) ◽  
pp. 2141-2148 ◽  
Author(s):  
Weidong Fan ◽  
Youyi Li ◽  
Zhengchun Lin ◽  
Mingchuan Zhang
Keyword(s):  
Coal Combustion ◽  
Pulverized Coal ◽  
Pulverized Coal Combustion ◽  
Utility Boiler ◽  
Combustion Technology

scholarly journals A study on the high-efficiency mixer of the SCR system

2021 ◽  
Vol 22 ◽  
pp. 7
Author(s):  
Kai Lu ◽  
Dewen Liu ◽  
Yan Wu ◽  
Shusen Liu ◽  
Shuzhan Bai
Keyword(s):  
High Efficiency ◽  
Catalytic Reduction ◽  
Treatment System ◽  
Bench Test ◽  
Durability Test ◽  
Wall Film ◽  
Emission Regulation ◽  
Calculation Results ◽  
Analysis Engine ◽  
Scr System

A new mixer for a diesel engine after-treatment system is developed to meet the requirements of China VI emission regulation. As for the structure of the mixer, it is surrounded by spiral blades, and the center is staggered with small blades, which is conducive to the crushing of urea droplets and can make the droplets fully mixed with air, improve the conversion efficiency of nitrogen oxides (NOx) and reduce ammonia leakage. The numerical analysis, engine bench test, and vehicle road test were carried out on the after-treatment system equipped with the new mixer. The numerical calculation results show that the velocity uniformity index of the selective catalytic reduction (SCR) carrier can reach 0.98, as well as the ammonia uniformity can reach 0.95, meanwhile, the low wall film height shows excellent anti-crystallization properties. engine bench test results are consistent with numerical results. The crystallization status of the mixer after the vehicle durability test is acceptable and well performed.

The Discharge Status and Technical Analysis of NOX of Thermal Power Plant Boiler

2014 ◽  
Vol 535 ◽  
pp. 131-134 ◽  
Author(s):  
Dong Yang ◽  
Qing Wen Chen
Keyword(s):  
Power Plant ◽  
Flue Gas ◽  
Thermal Power Plant ◽  
Catalytic Reduction ◽  
Thermal Power ◽  
Combustion Technology ◽  
Discharge Status ◽  
Low Nox Combustion ◽  
Plant Boiler ◽  
Flue Gas Denitrification

NOXis one of the pollutants which will be key governanced by Government in Twelfth Five, and thermal power plant boiler is the main source of NOXin the atmospheric. Overview of the discharge status of NOXand the state-controlled status of the power plant NOXdischarge regulations with the latest standards, analysis of the current two thermal power plant NOXcontrol technology: low-NOx combustion technology and flue gas denitrification technology. Low NOx combustion technology introduces low excess air combustion technology, air staged combustion technology, flue gas recirculation technology, flue gas denitrification technology introduced four methods which is selective catalytic reduction, selective non-catalytic reduction, hybrid SNCR-SCR catalyst reduction combined metgod and wet NOXabsorption system, principle of denitration and their advantages and disadvantages of different methods are discussed. Finally a brief introduction of the difficulties of governance NOXand some necessary issues when select zhe control methods.

Selective Catalytic Reduction (SCR) System Installation and Commissioning at the Chow II Power Plant in Chowchilla, California

2003 ◽  
Author(s):  
Don Newburry ◽  
Pat Runnels ◽  
Mike Owings
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Selective Catalytic Reduction ◽  
High Efficiency ◽  
Catalytic Reduction ◽  
Industrial Applications ◽  
Urea Solution ◽  
Lean Burn ◽  
High Oxygen Content ◽  
Scr System

Lean burn, natural gas, reciprocating engines are becoming widely utilized for stationary industrial applications due to their high efficiency and low emissions. However, despite the low engine emissions, some locations still require exhaust after-treatment to meet the local emissions requirements. Due to the high oxygen content (greater than 4%) in the exhaust of lean burn engines, 3-Way (non-selective) catalysts are not suitable to reduce NOx. Selective catalytic reduction (SCR), which utilizes a consumable reductant to reduce NOx over a catalyst, is very effective at reducing NOx and is becoming an accepted technology for large, stationary engine applications. In the summer of 2001, Stewart & Stevenson installed 16 Deutz TGB632V16 natural gas fired engines for NEO Corporation at the Chow II power plant. MIRATECH SCR provided and commissioned 16 selective catalytic reduction systems for these engines using a 40% urea solution as the reductant. This paper describes the installed SCR systems and reports some of the emissions testing results and costs. With the SCR systems in place, the engines were successfully able to meet the permitted exhaust emissions requirements of 0.07 g/bhp-hr of NOx, 0.1 g/bhp-hr of CO, and 0.15 g/bhp-hr of VOC’s (volatile organic compounds) with less than 10 ppmvd of ammonia slip @ 15% O2. Additional measurements were made of formaldehyde and acrolein. Very low levels of these emissions were found after the SCR.

Cost Control of 600 MW Coal-Fired Units Denitration Based on LCA

2013 ◽  
Vol 864-867 ◽  
pp. 357-360
Author(s):  
Wen Huan Wang ◽  
Wei Guo Pan ◽  
Guo Xin Hu
Keyword(s):  
Life Cycle ◽  
Flue Gas ◽  
Life Cycle Analysis ◽  
Evaluation Method ◽  
Catalytic Reduction ◽  
Gas Concentration ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Construction Operation ◽  
The Cost

Life cycle analysis combined with technical economic evaluation method in the paper to control the cost of denitration. A simple model for denitration cost is developed. The influence of different flue gas concentration of NOx to the cost of unit denitration is analysed by life cycle analysis, includes construction, operation and decommissioning, which based on 600 MW coal-fired units. Preliminary calculations reveal that comparing with directly using the denitration technology of selective catalytic reduction (SCR), after using Air staged Low NOx Combustion Technology reduced NOx below 400mg/m3, using SCR denitration further decreased the concentration of NOx in flue gas to 100mg/m3 can save more than 44% of the general denitration cost. This can improve effectively the environmental protection and economy of the coal-fired unit.

Study of NOx Inhibition Technology Based on Water-Gas Reaction

2015 ◽  
Vol 737 ◽  
pp. 584-587
Author(s):  
Tian Hua Wu ◽  
Ren Zhang Qian
Keyword(s):  
Coal Combustion ◽  
Nox Reduction ◽  
Pulverized Coal ◽  
Peak Temperature ◽  
Emission Sources ◽  
Pulverized Coal Combustion ◽  
Staged Combustion ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Water Gas

Pulverized coal combustion is one of the main NOx emission sources. The existing low NOx combustion technology can not meet the requirements of environment conservation. In this paper, a new low NOx combustion technology, the NOx inhibition method based on water-gas reaction, is presented, in which steam is injected into the anoxic flame of pulverized coal to bring water-gas reaction and produce CO and H2 which will inhibit the production of NOx. The produced H2 is especially very active. Water-gas reaction is endothermic, which has an effect of reducing the peak temperature of the flame and is very propitious to the inhibition of thermal type NOx. As the water-gas reaction is also an interim process, the heat absorbed in it will be released when burning with oxygen so that the whole amount of heat inside the furnace is not affected. The principle of the method is proved correct by experiments and industrial scale of 420 t/h boiler tests in which the effect of NOx reduction is obvious. The technology is consistent with that of air-staged combustion.

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