Observation on the Ignition Delay Time of Cool and Thermal Flame of n-heptane/alcohol Blended Fuel at Low Temperature Combustion Regime

Abstract In this study, the auto ignition with low limit temperature of syngas has been numerically investigated using a 2-D numerical analysis. Previous study showed that auto ignition was observed at above 860 K in co-flow jet experiments using syngas and dry air. However, the auto ignition at this low temperature range could not be predicted with existing chemical mechanisms. Inconsistency of the auto ignition temperature between the experimental and numerical results is thought to be due to the inaccuracy of the chemical kinetic mechanism. The prediction of ignition delay time and sensitivity analysis for each chemical kinetic mechanism were performed to verify the reasons of the inconsistency between the experimental and numerical results. The results which were calculated using the various mechanisms showed significantly differences in the ignition delay time. In this study, we intend to analyze the reason of discrepancy to predict the auto ignition with low pressure and low temperature region of syngas and to improve the chemical kinetic mechanism. A sensitive analysis has been done to investigate the reaction steps which affected the ignition delay time significantly, and the reaction rate of the selected reaction step was modified. Through the modified chemical kinetic mechanism, we could identify the auto ignition in the low temperature region from the 2-D numerical results. Then CEMA (Chemical Explosive Mode Analysis) was used to validate the 2-D numerical analysis with modified chemical kinetic mechanism. From the validation, the calculated λexp, EI, and PI showed reasonable results, so we expect that the modified chemical kinetic mechanism can be used in various low temperature region.

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Low-temperature auto-ignition characteristics of NH3/diesel binary fuel: Ignition delay time measurement and kinetic analysis

Fuel ◽

10.1016/j.fuel.2020.118761 ◽

2020 ◽

Vol 281 ◽

pp. 118761 ◽

Cited By ~ 1

Author(s):

Yuan Feng ◽

Jizhen Zhu ◽

Yebing Mao ◽

Mohsin Raza ◽

Yong Qian ◽

...

Keyword(s):

Low Temperature ◽

Kinetic Analysis ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

Time Measurement ◽

Auto Ignition ◽

Ignition Characteristics

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Distributed Low Temperature Combustion: Fundamental Understanding of Combustion Regime Transitions

10.21236/ad1019756 ◽

2016 ◽

Author(s):

Peter Lindstedt ◽

F. Hampp ◽

P. Kraus ◽

P. Simatos

Keyword(s):

Low Temperature ◽

Combustion Regime ◽

Low Temperature Combustion ◽

Fundamental Understanding ◽

Temperature Combustion ◽

Regime Transitions

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Ignition Characteristics of Diesel and Canola Biodiesel Sprays in the Low-Temperature Combustion Regime

Energy & Fuels ◽

10.1021/ef2005332 ◽

2011 ◽

Vol 25 (7) ◽

pp. 2896-2908 ◽

Cited By ~ 16

Author(s):

Casey M. Allen ◽

Elisa Toulson ◽

David L. S. Hung ◽

Harold Schock ◽

Dennis Miller ◽

...

Keyword(s):

Low Temperature ◽

Combustion Regime ◽

Low Temperature Combustion ◽

Temperature Combustion ◽

Ignition Characteristics

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An Experimental Investigation on the Effect of Post-Injection Strategies on Combustion and Emissions in the Low-Temperature Diesel Combustion Regime

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2180812 ◽

2005 ◽

Vol 129 (1) ◽

pp. 279-286 ◽

Cited By ~ 36

Author(s):

Hanho Yun ◽

Rolf D. Reitz

Keyword(s):

Low Temperature ◽

Soot Formation ◽

Combustion Regime ◽

Nox Emissions ◽

Diesel Combustion ◽

Low Temperature Combustion ◽

Post Injection ◽

Temperature Combustion ◽

Soot Emissions ◽

Injection Strategies

In order to meet future emissions regulations, new combustion concepts are being developed. Among them, the development of low-temperature diesel combustion systems has received considerable attention. Low NOx emissions are achieved through minimization of peak temperatures during the combustion process. Concurrently, soot formation is inhibited due to a combination of low combustion temperatures and extensive fuel-air premixing. In this study, the effect of late-cycle mixing enhancement by post-injection strategies on combustion and engine-out emissions in the low-temperature (low soot and NOx emissions) combustion regime was experimentally investigated. The baseline operating condition considered for low-temperature combustion was 1500rpm, 3bar IMEP with 50% EGR rate, and extension to high loads was considered by means of post injection. Post-injection strategies gave very favorable emission results in the low-temperature combustion regime at all loads tested in this study. Since post injection leads to late-cycle mixing improvement, further reductions in soot emissions were achieved without deteriorating the NOx emissions. With smaller fuel injected amounts for the second pulse, better soot emissions were found. However, the determination of the dwell between the injections was found to be very important for the emissions.

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Experimental and Kinetic Modeling of Kerosene-Type Fuels at Gas Turbine Operating Conditions

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2436575 ◽

2006 ◽

Vol 129 (3) ◽

pp. 655-663 ◽

Cited By ~ 32

Author(s):

P. Gokulakrishnan ◽

G. Gaines ◽

J. Currano ◽

M. S. Klassen ◽

R. J. Roby

Keyword(s):

Low Temperature ◽

Gas Turbine ◽

Ignition Delay ◽

Delay Time ◽

Equivalence Ratio ◽

Ignition Delay Time ◽

Flow Reactor ◽

Fuel Oil ◽

Stirred Reactor ◽

Lean Conditions

Experimental and kinetic modeling of kerosene-type fuels is reported in the present work with special emphasis on the low-temperature oxidation phenomenon relevant to gas turbine premixing conditions. Experiments were performed in an atmospheric pressure, tubular flow reactor to measure ignition delay time of kerosene (fuel–oil No. 1) in order to study the premature autoignition of liquid fuels at gas turbine premixing conditions. The experimental results indicate that the ignition delay time decreases exponentially with the equivalence ratio at fuel-lean conditions. However, for very high equivalence ratios (>2), the ignition delay time approaches an asymptotic value. Equivalence ratio fluctuations in the premixer can create conditions conducive for autoignition of fuel in the premixer, as the gas turbines generally operate under lean conditions during premixed prevaporized combustion. Ignition delay time measurements of stoichiometric fuel–oil No. 1∕air mixture at 1 atm were comparable with that of kerosene type Jet-A fuel available in the literature. A detailed kerosene mechanism with approximately 1400 reactions of 550 species is developed using a surrogate mixture of n-decane, n-propylcyclohexane, n-propylbenzene, and decene to represent the major chemical constituents of kerosene, namely n-alkanes, cyclo-alkanes, aromatics, and olefins, respectively. As the major portion of kerosene-type fuels consists of alkanes, which are relatively more reactive at low temperatures, a detailed kinetic mechanism is developed for n-decane oxidation including low temperature reaction kinetics. With the objective of achieving a more comprehensive kinetic model for n-decane, the mechanism is validated against target data for a wide range of experimental conditions available in the literature. The data include shock tube ignition delay time measurements, jet-stirred reactor reactivity profiles, and plug-flow reactor species time–history profiles. The kerosene model predictions agree fairly well with the ignition delay time measurements obtained in the present work as well as the data available in the literature for Jet A. The kerosene model was able to reproduce the low-temperature preignition reactivity profile of JP-8 obtained in a flow reactor at 12 atm. Also, the kerosene mechanism predicts the species reactivity profiles of Jet A-1 obtained in a jet-stirred reactor fairly well.

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