Noninvasive Detection and Quantitative Characterization of Flashback in a Bluff-Body-Stabilized Flame Under Acoustic Excitation by Electrical Capacitance Tomography

被引:0
|
作者
Chang, Liuyong [1 ,2 ]
Hu, Die [3 ]
Zhang, Chenglin [1 ,2 ]
Li, Guangze [1 ,2 ]
Cui, Boxuan [4 ]
机构
[1] Beihang Univ, Inst Int Innovat, Hangzhou 311115, Peoples R China
[2] Beihang Univ, Zhongfa Aviat Inst, Hangzhou 311115, Peoples R China
[3] China Acad Space Technol, Beijing Inst Space Mech & Elect, Beijing 100094, Peoples R China
[4] Beihang Univ, Sch Energy & Power Engn, Beijing 100191, Peoples R China
基金
中国国家自然科学基金;
关键词
Fires; Sensors; Electrodes; Permittivity; Electron tubes; Capacitance; Image reconstruction; Acoustic excitation; bluff-body-stabilized flame; electrical capacitance tomography (ECT); flashback index (FI); permittivity; BOUNDARY-LAYER FLASHBACK; INDUCED VORTEX BREAKDOWN; LARGE-EDDY SIMULATION; TEMPERATURE; FIELD;
D O I
10.1109/JSEN.2024.3370694
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
Flame flashback poses a significant threat to combustors, necessitating the development of reliable detection methods. However, detecting flashback is challenging due to its occurrence within the premixing tube. In this study, we employed an electrical capacitance tomography (ECT) system, capable of nonintrusively reconstructing the permittivity distribution in opaque tubes, to address this challenge. A bluff-body stabilized combustor under acoustic excitation was utilized to generate controllable flashback. To reconstruct the permittivity within the annular flashback region of the combustor, the conventional Calderon-based reconstruction method was modified by compensating the scattering transform in the central area. The revised Calderon method was compared with original methods to validate its applicability in reconstructing the permittivity distribution in annular zones with a circular sensor. Reconstructed images of flashback flames demonstrated that the effectiveness of the ECT system in detecting flashback occurrences, with a distinct increase in permittivity corresponding to the intensification of flame flashback. To quantitatively characterize the flashback intensity, a flame flashback index (FI) was proposed based on the above findings. This index's distribution across various frequencies ( f(s) ) and sound pressure levels (SPLs) was analyzed to investigate the effects of sound parameters on flashback. The results revealed several significant insights: 1) the existence of both a flashback boundary and an extinction boundary; 2) the nonlinear dependence of SPL on f(s) at the flashback boundary; and 3) a monotonous increase in the flame FI for f(s) < 110 Hz, followed by an initial increase and subsequent decrease for f(s) > 110 Hz as SPL increases. The effective detection and characterization of flashback hold great significance for the secure operation of combustors.
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页码:13354 / 13363
页数:10
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