The influence of air distribution on gas-fired coal preheating method for NO emissions reduction

Liu, Changchun; Suo, Hui; Pan, Su; Wang, Denghui; Shang, Tong; Liang, Ling

doi:10.1016/j.fuel.2014.08.068

Cited by 37 publications

(12 citation statements)

References 18 publications

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“…The results showed that the secondary air is more favorable for the high temperature area of the flame to move towards the nozzle, so the flame becomes shorter. Similar results were obtained in the study of air distribution in a propane burner (Liu et al, 2015). A number of experiments have shown that a reasonable combination of primary air and secondary air has a very positive effect on the flame temperature in the furnace (Wu et al, 2016).…”

Section: Introductionsupporting

confidence: 82%

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Xie

Cui

Qiu

et al. 2020

JAFM

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It is a difficult scientific problem of applied fluid mechanics that the flame is too long and does not match the furnace chamber in a small restricted heating space. This paper aims to investigate the effect of the air quantity distribution ratio on the flame height of a flue gas self-circulation burner. In order to obtain a better combustion emission effect and a shorter flame height, a burner head structure with a small flue gas selfcirculation was designed. Numerical simulation was employed to investigate the effect of the different distributions of central air, swirling air and secondary air on flame height. The periodic boundary condition model was adopted and the numerical model was compared and validated by experiment. Correlation analysis was used to determine the influence of the air inlet ratio of each part on the flame height and recirculating flue gas ratio (RFGR). The results show that the influence of different air quantity distributions on flame length is very significant. A reasonable central air ratio is a necessary condition for the good combustion of this flue gas self-circulation burner. Secondary air can effectively increase the RFGR, and flame height was significantly shorter with the increase of RFGR, but when it increased to more than 12%, the flame length was basically no longer shortened. On the premise of stable combustion, when the ratio of central air, swirling air and secondary air are respectively 25%, 35% and 40%, the shortest flame length is achieved. This work reveals an influence mechanism of the flame height of a small burner with a flue gas circulation structure. These results can provide theoretical support and an engineering design basis for the short flame problem in a small restricted space.

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Section: Introductionsupporting

confidence: 82%

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Xie

Cui

Qiu

et al. 2020

JAFM

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“…Common denitration technologies include denitration during combustion and denitration after combustion. Denitration in combustion mainly includes air staged combustion, fuel staged combustion, and moderate or intense low oxygen dilution (MILD) combustion et al However, a large number of literature survey results indicate that the lowest NO x emission level that can be achieved during coal combustion with these technologies is between 100 and 400 mg/m 3 (@ 6% O 2 ) 5–11 . Postcombustion denitration mainly includes selective noncatalytic reduction technology (SNCR), selective catalytic reduction technology (SCR), or SCNR + SCR.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on ultra‐low NO_x emissions from pulverized coal preheating combustion

Zhang

Zhu

Lyu

et al. 2020

Asia-Pacific J Chem Eng

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Realizing ultra‐low NOx emissions during coal combustion is currently a development trend and technical bottleneck of coal combustion technology. To further exploit the low‐nitrogen potentialities in preheating combustion technology, the preheating characteristics, combustion characteristics, and NOx emission characteristics of pulverized coal, after changing operating parameters such as the air equivalence ratio of circulating fluidized bed, preheating temperature, combustion temperature, and air equivalence ratio in the reduction zone, are explored. The experimental results show that changing the operating parameters has a great impact on the composition of high‐temperature coal gas, the particle size, apparent morphology, and specific surface area of the high‐temperature preheated char after preheating. Properly adjusting the operating parameters can effectively reduce NOx emissions. Based on the explored principle, experiments were designed, and the goal of reducing the initial NOx emissions from coal combustion to less than 50 mg/m3 (the average emissions were 46 mg/m3 [@ 6% O2]) was successfully achieved. The research of this paper provides the most basic experimental guidance and theoretical support for achieving ultra‐low NOx emissions during the engineering pulverized coal combustion.

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“…With this technology, Zhou et al achieved ultralow NO x emissions (<50 mg/m 3 at 6% O 2 ) in a pilot-scale test rig . The All-Russian Thermal Engineering Institute developed a novel gas-fired coal preheating technology (GFCP) and showed its ability on NO x reduction compared to conventional PC combustion. , Liu et al conducted in-depth research on the technology and gained a vast amount of useful conclusions. − …”

Section: Introductionmentioning

confidence: 99%

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

et al. 2019

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As a novel technology, coal preheating technology has been proved to be effective on NO x reduction by previous experiments. However, the role of some components of the fuel is still not clear in the preheating process and combustion process. To clarify the effects of volatile and carbon on NO x formation and reduction, three fuels with different volatile contents were used, and the experiments were launched in a bench-scale coal preheating combustion test apparatus. Results showed that the self-preheating burner was widely adaptable to the fuels and the fuels could be stably preheated to be above 860 °C. The coal gas mainly containing the combustible components of CO, H2, and CH4 was generated in the self-preheating burner, accompanying with the high-temperature coal char. Due to the high contents of carbon and volatiles, more combustible components in coal gas could be yielded by the bituminous coal after being preheated. Most of the volatile matters and carbon were released into the coal gas, and the volatile-N was mainly converted into N2. Because of the reduction of CO and carbon in char, the NO x conversion rates were low enough of the bituminous coal and the semicoke, while the NO x conversion rate of the coal gasification fly ash was a little high for its low carbon content.

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The influence of air distribution on gas-fired coal preheating method for NO emissions reduction

Cited by 37 publications

References 18 publications

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Experimental study on ultra‐low NO_x emissions from pulverized coal preheating combustion

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

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The influence of air distribution on gas-fired coal preheating method for NO emissions reduction

Cited by 37 publications

References 18 publications

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Effect of Air Quantity Distribution Ratio on Flame Height of Flue Gas Self-Circulation Burner

Experimental study on ultra‐low NOx emissions from pulverized coal preheating combustion

Experimental Research on Combustion Characteristics and NOx Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

Contact Info

Product

Resources

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Experimental study on ultra‐low NO_x emissions from pulverized coal preheating combustion

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner