Article
Thermodynamics
Yanyu Qiao, Song Li, Xinjing Jing, Zhichao Chen, Subo Fan, Zhengqi Li
Summary: This study investigates the combustion characteristics of a retrofitted wall-fired boiler using anthracite as fuel. The results show that stable combustion of anthracite can be achieved at different loads. By adjusting the excess air coefficient and combustion system parameters, combustion efficiency can be improved and pollutant emissions reduced.
Article
Energy & Fuels
Xin Zhang, Zhichao Chen, Mingdi Zhang, Lingyan Zeng, Zhengqi Li
Summary: When burning coal for electricity generation under low load conditions, bituminous coal exhibits better combustion stability compared to anthracite, with shorter ignition distance, higher furnace temperature, and lower NOx emissions at the furnace exit.
Article
Thermodynamics
Xin Zhang, Zhichao Chen, Liankai Li, Lingyan Zeng, Zhengqi Li
Summary: The study found that without over-fire air, a down-fired boiler can still achieve air-staging combustion when burning bituminous coal, leading to different combustion performance under different coal varieties.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Thermodynamics
Wei Zhang, Jianjun Pei, Zhujun Zhu, Zefu Ye, Changfu You
Summary: This study proposes the use of wall air injection technology in an opposed wall-fired utility boiler to alleviate problems of high temperature corrosion and slagging. Numerical simulations show that injecting wall air reduces gas velocity and temperature near the side wall, improves coal combustion stability, and decreases CO and NO concentrations in the flue gas.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Thermodynamics
Dafu Ma, Shouyu Zhang, Xiang He, Jian Zhang, Xian Ding
Summary: To achieve carbon peaking and carbon neutrality in China, coal-fired units need to respond in real-time to intermittent renewable energy sources. However, operating under ultra-low loads leads to unstable combustion and high NOX emissions. The study found that combustion stability improves as the load decreases, but the low-NOX combustion system's effectiveness weakens.
Article
Energy & Fuels
Xin Zhang, Zhichao Chen, Guangfei Jiang, Lingyan Zeng, Zhengqi Li
Summary: The effects of central secondary air on the combustion characteristics of a down-fired boiler were studied through experiments. The results showed that reducing the supply of central secondary air can delay the ignition of the coal/air flow, allowing for a higher proportion of blending with bituminous coal.
Article
Energy & Fuels
Lun Ma, Anli Zhou, Qingyan Fang, Cheng Zhang, Yuan Li, Xinping Zhao, Rui Mao, Liming Ren
Summary: A comprehensive study was conducted on the combustion characteristics, slagging potential, and NOx emissions of cofiring coal slime and anthracite in a 600MW down-fired utility boiler. The results showed that there are combustion interactions between the two fuels, with the inhibitive effect being greater than the promotive effect when the blending ratio of coal slime is above 5%. The addition of coal slime effectively improves the ash fusion temperature of blended samples.
JOURNAL OF ENERGY ENGINEERING
(2023)
Article
Energy & Fuels
He Du, Zhengqi Li, Zheng Liu, Mingdi Zhang, Chunchao Huang, Guangfei Jiang, Zhichao Chen, Jian Song, Fan Fang, Jianjun Su, Haibing Liu
Summary: A novel low-load stable combustion technology was proposed in this study, which involves arranging the oil secondary air flow parallel to the fuel-rich coal/air flow for pulverized coal combustion during boiler operation. Industrial measurements demonstrated the stable operation of the boiler at low loads without oil support, achieving high efficiency and low NOx emissions.
Article
Thermodynamics
Caixia Bian, Junlin Huang, Rongyue Sun
Summary: In order to meet ultralow NOx emission standard, a 600 MWe tangentially-fired lignite boiler was retrofitted using air-staged combustion technology. Numerical simulations were conducted to study and compare the combustion and NOx emission characteristics of the original and retrofitted boiler. Different over-fired air ratios were tested in optimization simulations. Results showed that the retrofit reduced NOx emission by approximately 40%. An over-fired air ratio of 20% was found to be the most economical case, while a ratio of 25% was the most environmentally friendly. The results provide valuable insights for the retrofit and practical operation of similar lignite-fired boilers.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Viet Thieu Trinh, Seung-Mo Kim, Kang-Min Kim, Byoung-Hwa Lee, Tae-Yong Jeong, Ju-Seong Son, Jong-Man Kim, Chung-Hwan Jeon
Summary: A comprehensive 3D numerical simulation was conducted to analyze the combustion and NOx emission behavior in a biomass boiler. The study focused on the effect of biomass particle size and active burner location on combustion efficiency. The results showed that volatile burnout rate was higher than that of char burnout, the burner throat had the highest temperature range, and thermal NOx emission rate was higher than that of total NOx. The position of the active burner significantly impacted char conversion, and particles below 665μm could be entrained upward to achieve high conversion rates.
Article
Thermodynamics
Woojin Lee, Kwonwoo Jang, Woojoo Han, Kang Y. Huh
Summary: The study constructs ROMs for a 500 MWe pulverized coal boiler using POD, Kriging, and RBFN, reproducing the 3D distribution of reacting scalars with small errors. Through parallel computation of the ROM, it can replicate scalar fields at any unexplored operation condition within a few seconds.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Environmental Sciences
Jiafei Qiao
Summary: In this study, a high-precision online real-time prediction model of boiler outlet NOx concentration was established based on an improved long short-term memory network (ILSTM). By analyzing the change rates of feature quantities, the model can predict the boiler outlet NOx concentration 22 seconds ahead of measurement with an accuracy of 96%.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Chemical
Yaojie Tu, Jianlan Li, Dongfeng Chang, Bo Hu
Summary: The study shows that the location of biomass injection affects combustion and NOX formation characteristics, with the lowest NO emission observed when biomass is injected into the highest layer.
ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Energy & Fuels
Yu Jiang, Byoung-Hwa Lee, Dong-Hun Oh, Chung-Hwan Jeon
Summary: The study analyzed and optimized different operating parameters for stable combustion and low pollutant emissions of a pulverized coal boiler under half-load conditions using numerical simulation. The results showed that the arrangement of the middle burner group was more effective in reducing NOX emissions and maintaining a higher coal burnout rate. A 5% close-coupled overfire air and 15% separated overfire air ratio were preferred for optimal combustion stability and emissions control.
Article
Chemistry, Physical
Tiantian Wang, Hai Zhang, Yang Zhang, Hongjian Wang, Junfu Lyu, Guangxi Yue
Summary: Hydrogen-enriched natural gas (HENG) is a promising low-carbon fuel for the industry. This study evaluates the thermal and emission performances of a large-scale industrial steam boiler fueled with HENG and proposes different operation scenarios. The results show that the trade-off between thermal efficiency and NOx emission should be carefully considered when applying HENG to industrial steam boilers.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)