Numerical Simulation on Characteristics of Coaxial Dual-Chamber Plasma Generator

doi:10.12141/j.issn.1000-565X.250040

Abstract

Abstract:

To reveal the distribution characteristics of the arc-plasma and the behavior of the flow field and further analyze the relationship between external parameters and arc behavior, this study conducts a numerical simulation of a coaxial dual-chamber plasma generator based on Magneto Hydro Dynamics (MHD) theory. The research investigates the correlations among arc voltage, cathode spot distribution, and airflow parameters with the axisymmetric model by incorporating coupled calculations of the flow field and electromagnetic field. The simulation results indicate that arc voltage is relatively insensitive to radial airflow; within the studied parameter range, fluctuations in radial airflow pressure have a maximum impact of only 4.2% on arc voltage. In contrast, arc voltage exhibits a strong positive correlation with axial airflow velocity, and a fitted correlation equation has been obtained. Temperature and velocity distribution analyses show that the maximum nozzle temperature exceeds 3 500 K, ensuring sufficient ignition capability for low-quality coal and stable combustion performance. Moreover, the results confirm that, under proper airflow configuration, the coaxial dual-chamber structure enables plasma igniters to achieve both high power and extended electrode lifespan. It reveals the anti-ablation mechanism of this structure, namely, the alternating sweeping effect of the two gas flows—the axial flow primarily controls the output power, while the radial flow regulates the arc root position through periodic fluctuations, thereby preventing single-point erosion and extending the electrode lifespan. Furthermore, the study further identifies the balance point between the two gas flows through optimized design experiments, providing theoretical support for future research on the long-term durability of plasma generators.

Key words: plasma generator, numerical simulation, Magneto Hydro Dynamics (MHD), anti-ablation mechanism, coaxial dual-chamber

CLC Number:

TK227.7

LIU Dingping, PAN Shuhuan, WU Chaochao. Numerical Simulation on Characteristics of Coaxial Dual-Chamber Plasma Generator[J]. Journal of South China University of Technology(Natural Science Edition), 2026, 54(1): 10-18.

Figures/Tables 13

Fig.1

Fig.2

Table 1

Table 2

Boundary conditions"

计算域	T	$v i$	$φ$	$A r$
AB	300 K	$v i$	耦合	耦合
IH	300 K	$v i$	耦合	耦合
CD/BC
AJ	绝热	0	定电流密度	耦合
FG	绝热	0	0	耦合
FED/JI/HG	绝热	0	耦合	耦合

Table 2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

References 18

[1]	吴迪，陈安会，陈柯旭，等．新形势下煤电灵活调峰和稳定供热的挑战和应对措施［J］．煤炭经济研究，2024，44（11）：104-112.
	WU Di， CHEN Anhui， CHEN Kexu，et al ．Challenges and counter measures for flexible peak regulation and stable heat supply of coal power under new circumstances［J］．Coal Economic Research，2024，44（11）：104-112.
[2]	陈佳，宋飞，窦荣．650　MW超临界机组锅炉出力受限原因分析及应对探讨［J］．中国设备工程，2024（22）：189-191.
	CHEN Jia， SONG Fei， DOU Rong ．Analysis of the output limitation causes of a 650 MW supercritical unit boiler and countermeasure discussions ［J］．China Plant Engineering，2024（22）：189-191.
[3]	郭为，林邦春，吕智嘉．燃煤电厂锅炉微油点火与等离子点火技术对比［J］．中国设备工程，2019（20）：161-163.
	GUO Wei， LIN Bangchun， Zhijia LÜ ．Comparison of micro-oil ignition and plasma ignition technology in coal-fired power plant boilers［J］．China Plant Engineering，2019（20）：161-163.
[4]	黄炽煌，陈敏生，廖晓春．非接触式等离子点火起弧及稳弧特性差分析［J］．中国高新技术企业，2014（17）：59-60.
	HUANG Chihuang， CHEN Minsheng， LIAO Xiaochun ．Analysis of arc initiation and instability issues in non-contact plasma ignition［J］．China High-Tech Enterprises，2014（17）：59-60.
[5]	冯培峰，王林，刘晓莎．等离子点火装置配套改造与效益分析［J］．华电技术，2018，40（3）：24-26，78.
	FENG Peifeng， WANG Lin， LIU Xiaosha ．Transformation and benefit analysis of plasma ignition device［J］．Huadian Technology，2018，40（3）：24-26，78.
[6]	徐荣田，张海龙，汤忆，等．等离子点火系统非转移弧特性研究及在1 000 MW机组锅炉的应用［J］．中国设备工程，2019（10）：156-158.
	XU Rongtian， ZHANG Hailong， TANG Yi，et al ．Study on the characteristics of non-transferred arc plasma ignition system and its application in a 1 000 MW unit boiler［J］．China Plant Engineering，2019（10）：156-158.
[7]	邵林芳，王春林，段周朝，等．提高锅炉等离子体火炬燃弧稳定性的参数调整方法研究［J］．电力学报，2023，38（3）：238-246.
	SHAO Linfang， WANG Chunlin， DUAN Zhouchao，et al ．Parameter adjustment method of plasma torch used in boiler for improving arc burning stability［J］．Journal of Electric Power，2023，38（3）：238-246.
[8]	SCOTT D A， KOVITYA P， HADDAD G N ．Temperatures in the plume of a DC plasma torch［J］．Journal of Applied Physics，1989，66（11）：5232-5239.
[9]	MURPHY A B， MCALLISTER T ．Modeling of the phy-sics and chemistry of thermal plasma waste destruction［J］．Physics of Plasmas，2001，8（5）：2565-2571.
[10]	LI H P， CHEN X ．Three-dimensional modelling of the flow and heat transfer in a laminar non-transferred arc plasma torch［J］．Chinese Physics，2002，11（1）：44-49.
[11]	TRELLES J P ．Finite element modeling of flow instabilities in arc plasma torches［D］．Minnesota：University of Minnesota，2007.
[12]	PENG YI， HUANG H J， PAN W X ．Effects of Lorentz force on flow fields of free burning arc and wall stabilized non-transferred arc［J］．High Power Laser and Particle Beams，2013，25（1）：52-56.
[13]	GONZALEZ J J， FRETON P， GLEIZES A ．Comparisons between two-and three-dimensional models：gas injection and arc attachment［J］．Journal of Physics D：Applied Physics，2002，35（24）：3181-3191.
[14]	于婷婷．连续弧等离子点火器喷嘴电弧数值模拟分析［D］．哈尔滨：哈尔滨工程大学，2014.
[15]	周前红．直流电弧等离子体炬的数值模拟［D］．上海：复旦大学，2010.
[16]	LOWKE J J ．Simple theory of free-burning arcs［J］．Journal of Physics D：Applied Physics，1979，12（11）：1873-1894.
[17]	黄卫星，武劭恂，司徒达志，等．直流电弧等离子炬温度场-电场分布特性数值模拟［J］．工程科学与技术，2020，52（5）：236-241.
	HUANG Weixing， WU Shaoxun， SITU Dazhi，et al ．Numerical simulation of the temperature-electrical field characteristics in DC arc plasma torches ［J］．Advanced Engineering Sciences，2020，52（5）：236-241.
[18]	刘燕燕．等离子点火发生器多物理场的数值研究［D］．哈尔滨：哈尔滨工程大学，2014.

网格数量	最高温度/K	最大速度/（m∙s^-1）	出口温度/K	出口速度/（m∙s^-1）	最大弧压/V
8 076	4 490.8	453.2	2 983.7	292.4	398.9
9 678	5 327.3	559.5	3 558.3	336.8	565.2
12 044	5 410.6	571.4	3 594.4	370.1	595.4
14 606	5 951.7	579.1	3 729.6	382.6	599.0