Combustion and NOx emissions characteristics of a down-fired 660-MWe utility boiler retro-fitted with air-surrounding-fuel concept

Ren, Feng; Li, Zhengqi; Liu, Guangkui; Chen, Zhichao; Zhu, Qunyi

doi:10.1016/j.energy.2010.11.010

Cited by 52 publications

(20 citation statements)

References 14 publications

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“… Heating process of coal/air flows. A thermocouple device (K‐type, nickel chromium–nickel silicon, 6‐mm diameter, 8‐m length) with a measuring range of 0–1300°C and a measuring error of 1°C was used to obtain the gas temperature under the fuel‐rich and fuel‐lean coal/air flow nozzles (where the measuring locations are shown in Fig. d).…”

Section: Methodscontrasting

confidence: 88%

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging

Song

Zeng

Liu

et al. 2017

Asia-Pacific J Chem Eng

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Effects of adjusting the inner-secondary-air damper opening among 100%, 70%, and 50% on the flow, combustion, and NO x emissions of a 600-MW e down-fired boiler incorporating multiple-injection and multiple-staging technology were investigated. Both 1 : 20-scale aerodynamic tests and industrial experiments were conducted. The smallscale tests showed that symmetric flow patterns formed in all cases, and the velocities of boundary and outer secondary air decayed more quickly than the velocity of inner secondary air. As the inner-secondary-air damper opening decreased from 100% to 50%, the average dimensionless depth of downward airflow reduced from 0.830 to 0.788 while the horizontal velocity in the recirculation zone increased. Industrial experiments demonstrated that, as the inner-secondary-air damper opening decreased from 100% to 50%, the heating rate of fuel-rich coal/air flow increased from 572 to 687°C/m, the corresponding ignition distance shortened from 1.36 to 1.11 m, and the hopper near-wall temperature decreased by approximately 50°C. Carbon in fly ash decreased from 7.31% to 6.93%, and NO x emissions rose from 343 to 371 ppm at 6% O 2 . The boiler efficiency improved from 89.78% to 89.92%. An inner-secondary-air damper opening of 70% is more reasonable than 50% and 100% considering the ignition distance, carbon in fly ash, and NO x emissions. Figure 7. Horizontal velocity distributions along the vertical section X/X 0 = À0.322 in (a) Section I and (b) Section II.

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Section: Methodscontrasting

confidence: 88%

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging

Song

Zeng

Liu

et al. 2017

Asia-Pacific J Chem Eng

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“…Errors of the thermocouple's measurement (i.e., the extent of the measured values deviating from the “true” temperatures) are less than 8% . More detailed introductions about the industrial‐size measurement methods and apparatus can be found in literature …”

Section: Methodsmentioning

confidence: 99%

“…However, it is found that four kinds of down‐fired boilers are all suffered from various problems in practical operations, such as late ignition, poor combustion stability, heavy slagging, poor burnout, asymmetric combustion, especially for high NO x emissions . For down‐fired boilers with split burner, various solutions were developed to deal with these problems, such as burning pulverized coals to improve ignition and combustion stability, positioning fuel‐lean coal/air flow nozzle far from the furnace central part to weaken slagging, inclining downward wall‐air jets below furnace arches to prolong coal residence times for higher burnout, and performing comprehensive combustion retrofits to reduce NO x emissions …”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Zeng

Liu

et al. 2019

Asia-Pacific J Chem Eng

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Numerical simulations are carried out to investigate the influence of burner nozzle–organization–mode (N–O–M) on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler. Three typical N–O–Ms respectively designed with Mitsui Babcock Energy Limited (MBEL), fuel‐lean coal/air flow down‐setting (FD), and multi‐injection multistaging combustion (MIMSC) technology are studied, plus industrial‐size measurements on the original MBEL boiler. Vertical velocity attenuation index (η) and maximum dimensionless penetrating depth (γ) are introduced to estimate the transfer effect and penetrating capacity of pulverized coal/air flow. Results uncover that under the N–O–M based on MBEL technology, flow field and temperature field are deflective. η is 9.257. Under N–O–Ms based on FD and MIMSC technology, flow field and temperature field present obvious symmetry. η respectively are 4.365 and 2.921. γ are correspondingly about 0.8 and 1.36. Carbon content in fly ash and NOx emissions at furnace outlet are lowest (5.77% and 735.21 mg/m3 (O2 = 6%)) under the N–O–M with MIMSC technology. The bigger the η is, the worse penetrating characteristics of coal/air flow is, resulting in poor burnout of pulverized coal. Therefore, MIMSC technology is recommended for the boiler improvement, and η should be taken into account in the design of new down‐fired boiler N–O–Ms.

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“…These measures optimise fuel and air distribution to suppress NO x formation and they can be very useful and cost effective [3]. Combustion control technology is one of the most cost-effective measures in NO x emissions reduction [4]. Although effective in terms of emission reduction, these measures could reduce thermal power plan efficiency due to increase of auxiliary power consumption.…”

Section: Introductionmentioning

confidence: 99%

Improvement of existing coal fired thermal power plants performance by control systems modifications

Mikulandrić¹,

Lončar²,

Cvetinović³

et al. 2013

Energy

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This paper presents possibilities of implementation of advanced combustion control concepts in selected Western Balkan thermal power plant, and particularly those based on artificial intelligence as part of primary measures for nitrogen oxide reduction in order to optimise combustion and to increase plant efficiency. Both considered goals comply with environmental quality standards prescribed in large combustion plant directive. Due to specific characterisation of Western Balkan power sector these goals should be reached by low cost and easily implementable solution. Advanced self-learning controller has been developed and the effects of advanced control concept on combustion process have been analysed using artificial neural-network based parameter prediction model.

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Combustion and NOx emissions characteristics of a down-fired 660-MWe utility boiler retro-fitted with air-surrounding-fuel concept

Cited by 52 publications

References 14 publications

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Improvement of existing coal fired thermal power plants performance by control systems modifications

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Combustion and NOx emissions characteristics of a down-fired 660-MWe utility boiler retro-fitted with air-surrounding-fuel concept

Cited by 52 publications

References 14 publications

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MWe down‐fired boiler incorporating multiple‐injection and multiple‐staging

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MWe down‐fired boiler incorporating multiple‐injection and multiple‐staging

Numerical investigation on the influence of nozzle–organization–mode of split burner on flow field distribution and combustion characteristics of a 300‐MWe subcritical down‐fired boiler

Improvement of existing coal fired thermal power plants performance by control systems modifications

Contact Info

Product

Resources

About

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging

Effects of the inner‐secondary‐air damper opening on flow and combustion in a 600‐MW_e down‐fired boiler incorporating multiple‐injection and multiple‐staging