Numerical Simulation of Lean Coal Combustion Based on Staged Plasma Ignition

doi:10.12141/j.issn.1000-565X.250214

Abstract

Abstract:

Improving coal adaptability of plasma ignition systems is of significant importance for assisting power plants in energy conservation, emission reduction, and achieving the dual-carbon goals. To address issues such as unstable combustion and flameout encountered during the operation of existing staged plasma burners when igniting lean coal with low volatile content, this study employs a numerical simulation approach. First, a three-dimensional mesh model of the staged plasma burner is established, incorporating the Realizable k-ε turbulence model, the P1 radiation model, and a pulverized coal combustion model with Two-competing-rates model for volatile matter release and kinetics/diffusion-limited model for char combustion. Subsequently, mesh independence verification is conducted by comparing temperature parameter differences among models with low, medium, and high mesh densities to ensure the reliability of the selected mesh. Following this, the control variable method is applied to sequentially investigate the effects of three critical operational parameters—plasma power, primary air velocity, and pulverized coal concentration—on lean coal combustion process within the staged plasma burner. Finally, the operational parameters of the plasma burner are optimized to resolve ignition and combustion issues associated with lean coal. The results demonstrate that plasma power is the key factor affecting lean coal ignition. To achieve stable ignition and combustion of lean coal in the plasma burners, the plasma power should not be less than 150 kW. Primary air velocity affects the combustion temperature during the initial ignition stage, with an optimal range identified between 22 to 25 m/s. Pulverized coal concentration is a crucial factor for successful lean coal ignition; maintaining a relatively high concentration is necessary to ensure stable ignition and combustion, with a recommended concentration not lower than 0.3 kg/kg. This research provides direct and important theoretical guidance and a practical basis for power plants to optimize the operational strategies of existing plasma burners, safely and economically utilize lean coal, reduce fuel costs, and lower carbon emissions. It holds positive implications for promoting fuel flexibility and facilitating the green, low-carbon transformation of coal-fired power plants.

Key words: pulverized coal combustion, plasma ignition, lean coal, numerical simulation

CLC Number:

TK229.6

LIU Dingping, WU Chaochao, PAN Shuhuan. Numerical Simulation of Lean Coal Combustion Based on Staged Plasma Ignition[J]. Journal of South China University of Technology(Natural Science Edition), 2026, 54(3): 1-9.

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References 23

[1]	龚泽儒，王晓娜，邹鹏，等．新型等离子体点火技术在火电灵活性中的应用分析［J］．锅炉技术，2024，55（1）：50-54.
	GONG Zeru， WANG Xiaona， ZOU Peng， et al ．Application analysis of new plasma ignition technology in thermal power flexibility［J］．Boiler Technology，2024， 55（1）： 50-54.
[2]	李明，邹鹏，李冰冰，等．660 MW高水分褐煤机组等离子体点火技术应用［J］．洁净煤技术，2024，30（9）：52-59．
	LI Ming， ZOU Peng， LI Bingbing， et al ．Application of plasma ignition technology in 660 MW high moisture lignite unit［J］．Clean Coal Technology， 2024，30（9）：52-59.
[3]	王志浩，赵星海，辛国华，等．富氧气氛下煤粉锅炉等离子冷风直接点火特性的数值模拟［J］．热力发电，2013，42（11）：69-75.
	WANG Zhihao， ZHAO Xinghai， XIN Guohua， et al ．Numerical simulation on direct ignition characteristics with plasma and cold air in pulverized coal boilers in oxygen-enriched atmosphere ［J］．Thermal Power Gene-ration， 2013， 42（11）： 69-75.
[4]	MESSERLE V E， KARPENKO E I， USTIMENKO A B ．Plasma assisted power coal combustion in the furnace of utility boiler：numerical modeling and full-scale test［J］．Fuel，2014，126：294-300.
[5]	卢洪波，黄静伟，刘畅，等．等离子点火炉内燃烧数值模拟［J］．科学技术与工程，2016，16（10）：145-150.
	LU Hong-bo， HUANG Jing-wei， LIU Chang，et al ．Numerical simulation of plasma ignition in boiler［J］．Science Technology and Engineering，2016，16（10）：145-150.
[6]	朱兴营，陈峰，徐荣田，等．大功率可调节等离子点火实验研究与工业应用［J］．热能动力工程，2015，30（5）：808-812，831-832．
	ZHU Xing-ying， CHEN Feng， XU Rong-tian， et al ．Experimental study of high power controllable plasma ignition and its application in industries［J］．Journal of Engineering for Thermal Energy and Power，2015，30（5）：808-812，831-832．
[7]	张成锐，邹鹏，牛涛，等．高水分低热值褐煤等离子体点火试验研究［J］．热力发电，2020，49（12）：71-77．
	ZHANG Chengrui， ZOU Peng， NIU Tao， et al ．Experimental study on plasma ignition technology of lignite with high moisture and low calorific value ［J］．Thermal Power Generation， 2020， 49（12）： 71-77．
[8]	胡卓飞，董中俊，宋继坤，等．不同煤粉浓度下大功率等离子点火过程的数值模拟［J］．工业炉，2024，46（3）：7-11.
	HU Zhuofei， DONG Zhongjun， SONG Jikun， et al ．Numerical simulation on high-power plasma ignition process under different pulverized coal concentrations［J］．Industrial Furnace， 2024， 46（3）： 7-11.
[9]	ASKAROVA А， GEORGIEV A， BOLEGENOVA S，et al. Highly efficient plasma technology for ignition and thermochemical preparation of high-ash fuel in various power boilers in Kazakhstan［J］．Energy，2025，322：135677/1-23.
[10]	MESSERLE V E， USTIMENKO A B ．Thermodynamic and kinetic modeling and experiment on plasma ignition of pulverized high-ash coal［J］．Applications in Energy and Combustion Science， 2024， 17：100248/1-8．
[11]	闫高程．交流等离子点火方法在600MW贫煤机组的应用［J］．燃烧科学与技术，2020，26（4）：316-324．
	YAN Gaocheng ．AC plasma ignition method in 600　MW lean coal unit ［J］．Journal of Combustion Science and Technology，2020，26（4）：316-324．
[12]	IBRAHIMOGLU B， CUCEN A， YILMAZOGLU M ．Z，Numerical modeling of a downdraft plasma gasification reactor ［J］．International Journal of Hydrogen Energy，2017，42（4）：2583-2591．
[13]	IBRAHIMOGLU B， YILMAZOGLU M ．Z，Numerical modeling of a downdraft plasma coal gasifier with plasma reactions［J］．International Journal of Hydrogen Energy，2020，45（5）：3532-3548．
[14]	王铁健，闫文刚，程海鹰，等．煤粉燃烧火焰特征影响因素的分析研究［J］．工程热物理学报，2024，45（12）：3906-3914.
	WANG Tiejian， YAN Wengang， CHENG Haiying，et al ．Analysis and study on the influencing factors of flame characteristics in pulverized coal combustion ［J］．Journal of Engineering Thermophysics， 2024，45（12）： 3906-3914.
[15]	张建国．等离子体点火及助燃的数值模拟与实验研究［D］．哈尔滨：哈尔滨工程大学，2018.
[16]	程海鹰，李旋，张勇．骨料烘干煤粉燃烧器数值模拟及配风参数优化［J］．机械工程学报，2024，60（20）：289-299．
	CHENG Haiying， LI Xuan， ZHANG Yong ．Numerical simulation and air distribution parameters optimization for pulverized coal burner of aggregate drying ［J］．Journal of Mechanical Engineering， 2024， 60（20）：289-299．
[17]	YAO G J， LIU Z D， TANG H， et al ．Prediction of reduction products in the preheating process［J］．Thermal Science，2023，27（5B）：4021-4034．
[18]	刘长春，惠世恩，马砺，等．考虑碳烟还原NO反应的煤粉燃烧仿真模型［J］．燃烧科学与技术，2017，23（4）：372-377．
	LIU Changchun， HUI Shien， MA Li， et al ．Numerical simulation model of pulverized coal combustion considering NO reduction by soot ［J］．Journal of Combustion Science and Technology，2017，23（4）：372-377．
[19]	张小桃，张程俞，刘昊明，等．660　MW燃煤锅炉掺烧再燃气燃烧数值模拟［J］．洁净煤技术，2022，28（3）：72-81．
	ZHANG Xiaotao， ZHANG Chengyu， LIU Haoming，et al ．Numerical simulation on combustion of re-burning gas co-firing in a 660 MW coal-fired boiler ［J］．Clean Coal Technology，2022，28（3）： 72-81．
[20]	任德军，陈刚，张寅，等．1　000　MW超超临界双切圆混煤燃烧锅炉还原性气氛数值模拟［J］．动力工程学报，2023，43（1）：14-23．
	REN Dejun， CHEN Gang， ZHANG Yin，et al ．Numerical simulation on reducing atmosphere for a 1 000 MW ultra-supercritical double tangential circular mixed coal combustion boiler ［J］．Journal of Power Engineering， 2023， 43（1）： 14-23．
[21]	TANG H， YAO G J， WANG Z B，et al ．Study on low-load combustion characteristics of a 600 MW power plant boiler with self-sustaining internal combustion burners［J］．Applied Thermal Engineering，2025，267：125859/1-13．
[22]	朱兴营，陈峰，周法，等．低挥发分煤种大功率等离子点火试验研究［J］．电力科技与环保，2016，32（5）：22-25.
	ZHU Xingying， CHEN Feng， ZHOU Fa， et al ．Experimental investigation on high-power plasma ignition for low volatile coal［J］．Electric Power Technology and Environmental Protection， 2016， 32（5）：22-25.
[23]	许开龙，俞伟伟，吴玉新，等．一次风速度对煤颗粒群着火特性影响的实验研究［J］．燃烧科学与技术，2014，20（4）：313-318．
	XU Kailong， YU Weiwei， WU Yuxin， et al ．Experimental study on effects of primary flow velocity on ignition of coal particles ［J］．Journal of Combustion Science and Technology， 2014， 20（4）： 313-318．

工业分析					元素含量/%						低位发热量/（MJ·kg^-1）
V_ar/%	F_C，ar/%	A_ar/%	M_ar/%		C	H	O	N	S		低位发热量/（MJ·kg^-1）
14.29	55.41	22.06	8.24		61.49	2.55	3.82	1.09	1.05		22.39