Effect of inner and outer secondary air ratios on ignition, C and N conversion process of pulverized coal in swirl burner under sub-stoichiometric ratio

Chen, Zhichao; Qiao, Yulong; Guan, Shuo; Wang, Zhenwang; Zheng, Yufeng; Zeng, Lingyan; Li, Zhengqi

doi:10.1016/j.energy.2021.122423

Cited by 9 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Wang et al proposed a combustion technology, which modifies the axes of the inner and outer secondary air boxes of a swirl burner to reduce NOx emissions. A thermal test was carried out while mixing the inner and outer optimized secondary air to reduce the NOx emission of a swirl burner . Further, the multistaging combustion technology with multi-injection was carried out in a 600 MWe boiler .…”

Section: Introductionmentioning

confidence: 99%

“…A thermal test was carried out while mixing the inner and outer optimized secondary air to reduce the NOx emission of a swirl burner. 20 Further, the multistaging combustion technology with multi-injection was carried out in a 600 MWe boiler. 21 Air staging combustion is a promising technology that reduces NOx emissions and unburned carbon or char conversion in a pulverized biomass boiler.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Optimization on Char Conversion and NOx Emission under Various Operating Conditions in a Retrofit Biomass Boiler

et al. 2023

View full text Add to dashboard Cite

Retrofitting retirement or existing fossil boiler with biomass is an important method of curbing electricity shortage and lowering the cost of modern power plants. However, the use of biomass combustion is hampered by operational problems, such as the resulting high unburned carbon, amount of bottom ash, and nitrogen oxide (NOx) release. In this study, we investigated the burning of pulverized biomass in a retrofitting boiler power plant using computational fluid dynamics of commercial software fluent ANSYS to determine the optimal combustion conditions. The objective of this study was to investigate a 125 MWe pulverized biomass boiler that was retrofitted from an anthracite down-fired boiler. The air distribution, including the influence of the secondary air ratio and the location of the burner standby, was evaluated. Key factors such as biomass ash mass at the hopper, char conversion, and high zone temperature relating to NOx formation/reduction were calculated. The adjustment of the secondary air ratio from 30 to 50% of the total air and the mass ash at the hopper significantly decreased to a low value at 247 kg/h and a high value of char conversion at 97.33% in case R (SA40%). The standard deviation temperature was 240 K at the BNR B−A level for case R, which was significantly lower than in other cases. This implies that the best mixing of air and biomass occurs in case R at 40%. Comparative analysis of the burner standby conditions showed that the NOx emission was similar at the boiler outlet (approximately 94−116 ppm). Burner A on standby, with a secondary air ratio of 40%, was used as the optimal case with the highest value of char conversion at 98.43%, the lowest bottom ash release of 204 kg/h, and a low-NOx emission of 106 ppm.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%