High-Frequency Ignition System Based on Corona Discharge

Bohne, Steffen; Rixecker, Georg; Brichzin, Volker; Becker, Michael

doi:10.1007/s38313-014-0007-1

Cited by 11 publications

(2 citation statements)

References 2 publications

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“…Typically, advanced ignition systems attempt to overcome the ignition limit by increasing either their output energy (e.g., dual-coil ignition [10,11], Controlled Electronic Ignition [12]) or the effectiveness of the spark-to-gas energy transfer (e.g. microwave-assisted spark ignition [13,14], corona ignition [15,16,17], nanosecond-pulsed transient-plasma ignition [18,19], breakdown ignition [4], laser ignition [20]). On the other hand, these systems attempt to overcome the partial-burn limit by some combination of increasing the flame-propagation rate (e.g., microwave-assisted ignition [21,22]) or reducing the flame-travel distance within the cylinder (multi-plug ignition [23], high-frequency corona ignition [24,25,17]).…”

Section: Ignition Limitsmentioning

confidence: 99%

Infrared Borescopic Evaluation of High-Energy and Long-Duration Ignition Systems for Lean/Dilute Combustion in Heavy-Duty Natural-Gas Engines

Mazacioglu¹,

Groß²,

Kern³

et al. 2018

SAE Technical Paper Series

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N atural gas (NG) is attractive for heavy-duty (HD) engines for reasons of cost stability, emissions, and fuel security. NG cannot be reliably compressionignited, but conventional gasoline ignition systems are not optimized for NG and are challenged to ignite mixtures that are lean or diluted with exhaust-gas recirculation (EGR). NG ignition is particularly challenging in large-bore engines, where completing combustion in the available time is more difficult. Using two high-speed infrared (IR) cameras with borescopic access to one cylinder of an HD NG engine, the effect of ignition system on the early flame-kernel development and cycle-to-cycle variability (CCV) was investigated. Imaging in the IR yielded strong signals from water emission lines, which located the flame front and burned-gas regions and obviated image intensifiers. A 9.7-liter, six-cylinder engine was modified to enable exhaust-gas recirculation and to provide optical access. Three ignition technologies were studied: a conventional system delivering 65 mJ of energy to each spark, a high-energy conventional system delivering 140 mJ, and a Bosch Controlled Electronic Ignition (CEI) system. CEI uses electronics to extend the ignition event, yielding sparks up to 5 ms in duration with up to 300 mJ of energy. Air/fuel equivalence ratios, λ, as high as 1.6 (with minimum EGR) and EGR fractions as high as 23% (stoichiometric) were tested; ignition delay, engine-out emissions, fuel consumption and image-derived parameters were compared. In most lean or dilute cases, the 140-mJ system yielded the lowest CCV. The imagery provided information about the early stages of ignition and combustion, where pressure measurements are not reliable. Image-based metrics also revealed that early flame kernels located further from the head yielded better combustion, showing that borescopic IR imaging can provide guidance for future engine design. INFRARED BORESCOPIC EVALUATION OF HIGH-ENERGY AND LONG-DURATION IGNITION SYSTEMS

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Section: Ignition Limitsmentioning

confidence: 99%

Infrared Borescopic Evaluation of High-Energy and Long-Duration Ignition Systems for Lean/Dilute Combustion in Heavy-Duty Natural-Gas Engines

Mazacioglu¹,

Groß²,

Kern³

et al. 2018

SAE Technical Paper Series

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“…An overview of possible alternative ignition systems is given by Lackner, 4 Feßler 5 and Das and Thynell. 6 Electrodes-based alternative systems, namely, high-frequency ignition systems 7,8 or modulated capacitive discharge ignition technology, 9 may extend the ignition limits but material durability is in any case the major challenge for less total costs of ownership.…”

Section: Introductionmentioning

confidence: 99%

Pulse train ignition with passively Q-switched laser spark plugs

Lorenz

Bärwinkel

Stäglich

et al. 2015

International Journal of Engine Research

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Leaner burning and downsizing are two concepts pursued by engine developers to reduce fuel consumption and emissions. Both approaches lead to increasing challenges concerning ignition, as these concepts are typically associated with an increase in flow velocity and degree of turbulence as well as raised pressure at the moment of ignition. In this context, the use of miniaturized passively Q-switched laser spark plugs with pulse train ignition is considered as a promising alternative to conventional spark plugs.However, the application of these passively Q-switched laser spark plugs inevitably leads to the question of optimum pulse train parameters. For a better understanding, this study deals with improved flame formation by passively Qswitched laser pulse train ignition under engine-like conditions. The entire ignition process is investigated with a special focus on interactions of consecutive pulses. Therefore, three methods are combined: energy transfer measurements from laser pulse to plasma with high temporal and spatial resolution show the breakdown process depending on different pressures and fluid mixtures. The temperature decrease in the induced plasma is analyzed with measurement strategies for temporal high-resolved plasma spectroscopy especially adapted to passively Q-switched lasers. In combination with high-speed schlieren measurements, the changing local ignition conditions during pulse train ignition are demonstrated. The experiments show how consecutive pulses interact and contribute to the ignition in case of a gas flow. The used prototypes of laser spark plugs are provided by Robert Bosch GmbH.

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