Study on the Combustion Chemical Reaction of Biodiesel Fuel for the Improvement of Compression Ignition Combustion Performance

2017 ◽  
Author(s):  
Young Chan Lim ◽  
Hyun Kyu Suh
Keyword(s):  
Chemical Reaction ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Combustion Temperature ◽  
Numerical Study ◽  
Constant Volume ◽  
Biodiesel Fuel ◽  
Compression Ignition ◽  
Combustion Performance ◽  
Compression Ignition Combustion

Numerical study on the combustion chemical reaction of biodiesel fuel for the improvement of compression ignition combustion performance was studied in this work. The constant volume closed homogeneous reactor model was applied, at the same time, analysis conditions were set to 700∼900K of ambient temperature, and 15atm of ambient pressure. Also, the equivalence ratio was changed from 0.5 to 1.4 under the various mixing ratio, respectively. The results of analysis were compared in terms of ignition delay, combustion temperature, combustion pressure, NOx and CO emissions. Also, the total mass and the mass densities of the reactants were compared in the constant volume chamber. It was revealed that the value of ignition delay became shorter and combustion temperature and pressure were increased under the rich combustion conditions (Φ > 1.0). Furthermore, the CO emission was decreased under the lean combustion conditions (1.0 > Φ). Maximum value of NOx emission was observed when the equivalence ratio was 0.8 condition since the nitrogen and oxygen chemical reactions became actively than other cases.

Ozone-Assisted Combustion—Part I: Literature Review and Kinetic Study Using Detailed n-Heptane Kinetic Mechanism

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Christopher Depcik ◽  
Michael Mangus ◽  
Colter Ragone
Keyword(s):  
Ignition Delay ◽  
Equivalence Ratio ◽  
Atomic Oxygen ◽  
Direct Injection ◽  
Kinetic Mechanism ◽  
Combustion Model ◽  
Ozone Decomposition ◽  
Compression Ignition ◽  
Review Of The Literature ◽  
Compression Ignition Engine

In this first paper, the authors undertake a review of the literature in the field of ozone-assisted combustion in order to summarize literature findings. The use of a detailed n-heptane combustion model including ozone kinetics helps analyze these earlier results and leads into experimentation within the authors' laboratory using a single-cylinder, direct-injection compression ignition engine, briefly discussed here and in more depth in a following paper. The literature and kinetic modeling outcomes indicate that the addition of ozone leads to a decrease in ignition delay, both in comparison to no added ozone and with a decreasing equivalence ratio. This ignition delay decrease as the mixture leans is counter to the traditional increase in ignition delay with decreasing equivalence ratio. Moreover, the inclusion of ozone results in slightly higher temperatures in the cylinder due to ozone decomposition, augmented production of nitrogen oxides, and reduction in particulate matter through radial atomic oxygen chemistry. Of additional importance, acetylene levels decrease but carbon monoxide emissions are found to both increase and decrease as a function of equivalence ratio. This work illustrates that, beyond a certain level of assistance (approximately 20 ppm for the compression ratio of the authors' engine), adding more ozone has a negligible influence on combustion and emissions. This occurs because the introduction of O3 into the intake causes a temperature-limited equilibrium set of reactions via the atomic oxygen radical produced.

A Numerical Investigation on the Effect of Hydrogen and Syngas Addition on the Ignition of JP-8 Surrogates

2012 ◽  
Author(s):  
Thomas Helma ◽  
S. K. Aggarwal
Keyword(s):  
Numerical Investigation ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Numerical Study ◽  
Flame Structure ◽  
Flame Temperature ◽  
Kinetic Mechanism ◽  
Smoke Point ◽  
Temperature Profiles ◽  
Two Component

A numerical study is carried out investigating the effect of hydrogen and syngas addition on the ignition of two JP-8 surrogates, a two-component surrogate and a six-component surrogate. This six-component surrogate has previously been found to accurately simulate the smoke point, volatility, flame temperature profiles, and extinction limits of JP-8, while the two component surrogates has been shown to reproduce the flame structure predicted with the six-component surrogate. CHEMKIN 10101 is used to simulate ignition in a closed homogenous reactor under adiabatic and isobaric conditions. The parameters include temperature ranging from 850–1250 K, pressure of 20 atm, and equivalence ratio ϕ = 1.0. The CRECK-0810 kinetic mechanism, involving 341 species and 9173 reactions, is used to model the ignition chemistry. For the conditions studied, the addition of H2 or syngas in small quantities has no effect on the ignition behavior of either the surrogates or their individual components. Addition of H2 or syngas in larger quantities increases and decreases the ignition delay at low and high temperatures, respectively. For the conditions investigated, the ignition behavior of both the surrogates is predominantly determined by the ignition chemistry of n-dodecane.

Study of Assisted Compression Ignition in a Direct Injected Natural Gas Engine

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Ivan M. Gogolev ◽  
James S. Wallace
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Direct Injection ◽  
Air Entrainment ◽  
Source Analysis ◽  
Compression Ignition ◽  
Glow Plug ◽  
Injection Duration ◽  
Intake Pressure

Natural gas direct injection (DI) and glow plug ignition assist technologies were implemented in a single-cylinder, compression-ignition optical research engine. Initial experiments studied the effects of injector and glow plug shield geometry on ignition quality. Injector and shield geometric effects were found to be significant, with only two of 20 tested geometric combinations resulting in reproducible ignition. Of the two successful combinations, the combination with 0 deg injector angle and 60 deg shield angle was found to result in shorter ignition delay and was selected for further testing. Further experiments explored the effects of the overall equivalence ratio (controlled by injection duration) and intake pressure on ignition delay and combustion performance. Ignition delay was measured to be in the range of 1.6–2.0 ms. Equivalence ratio was found to have little to no effect on the ignition delay. Higher intake pressure was shown to increase ignition delay due to the effect of swirl momentum on fuel jet development, air entrainment, and jet deflection away from optimal contact with the glow plug ignition source. Analysis of combustion was carried out by examination of the rate of heat release (ROHR) profiles. ROHR profiles were consistent with two distinct modes of combustion: premixed mode at all test conditions, and a mixing-controlled mode that only appeared at higher equivalence ratios following premixed combustion.

Sign in / Sign up

Export Citation Format

Share Document