scholarly journals Effect of Hydrogen Addition and Equivalence Ratio on Tumble Motion of Direct Ignition Engine

2017 ◽  
Vol 11 (46) ◽  
pp. 1-14
Author(s):  
Nhad K. Frhan ◽  
Azwan Bin Sapit ◽  
◽  
Keyword(s):  
Equivalence Ratio ◽  
Hydrogen Addition ◽  
Direct Ignition

scholarly journals Effect of Hydrogen Addition and Equivalence Ratio on Swirl Motion of Direct Ignition Engine

2017 ◽  
Vol 11 (46) ◽  
pp. 1-9
Author(s):  
Nihad K. Frhan ◽  
Azwan Bin Sapit ◽  
◽  
Keyword(s):  
Equivalence Ratio ◽  
Hydrogen Addition ◽  
Direct Ignition

Experimental Study of Operation Stability of a Spark Ignition Engine Fueled With Coal Bed Gas

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Lei Chen ◽  
Peng Song ◽  
Wuqiang Long ◽  
Liyan Feng ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Equivalence Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Coal Bed ◽  
Stable Operation ◽  
Volumetric Fraction ◽  
Lean Burn ◽  
Gas Engine ◽  
Hydrogen Addition ◽  
Operation Stability

Experimental research has been carried out on a single cylinder naturally aspirated spark ignition engine which was modified to operate with coal-bed gas fuel to investigate the method of improving operation stability and lean burn limit. Varied fuel composition with methane concentration 30–100% and CO2 volumetric fraction 0–0.7 was employed to simulate coal-bed methane (CBM) and coal mined methane (CMM), respectively. Hydrogen was then employed to improve operational stability and lean burn limit. The results show that a stable operation range of the engine was obtained under most of the fuel compositions even if up to CO2 volumetric fraction = 0.6 was employed. Besides lean burn limit, the unstable operation with COVIMEP > 10% only appears at lean burn limit as well as CO2 volumetric fraction = 0.7 at each equivalence ratio. The lean burn limit of coal-bed gas has been significantly enlarged from the equivalence ratio equals to 0.6–0.4 by hydrogen addition. Stable operation with COVIMEP < 5% at the equivalence ratio equals to 0.4 has also been obtained at some high hydrogen concentration conditions. Hydrogen addition induced the reduction of both carbon monoxide (CO) and total hydrocarbon (THC) emissions at all equivalence ratio conditions, especially at the equivalence ratio equals to 0.4 and 0.6. CO2 addition improves NOx emission significantly; however, high CO2 volumetric fraction will lead to unstable operation, which results in deteriorated CO and THC emissions. Hydrogen addition has benefits of improving operation stability and enlarging lean burn limit of coal-bed gas engine, which has practical significance to improve the application of coal-bed gas engine technology.

Flame Speeds in Fuel Sprays With Hydrogen Addition

1989 ◽  
Vol 111 (1) ◽  
pp. 84-89 ◽  
Author(s):  
G. A. Richards ◽  
P. E. Sojka ◽  
A. H. Lefebvre
Keyword(s):  
Hydrogen Concentration ◽  
Combustion Zone ◽  
Equivalence Ratio ◽  
Drop Size ◽  
Hydrogen Addition ◽  
Fuel Sprays ◽  
Controlling Effect ◽  
Burning Rates

The influence of hydrogen addition on the burning rates of kerosine sprays in air is studied experimentally. Flame speeds are measured as a function of fuel drop size, equivalence ratio, and hydrogen concentration. The results obtained show that evaporation rates have a controlling effect on flame speeds over wide ranges of mean drop size. They also demonstrate that the burning rates of liquid kerosine-air mixtures are augmented appreciably by the addition of small quantities of hydrogen to the air flowing into the combustion zone.

scholarly journals Numerical analysis of lean premixed combustor fueled by propane-hydrogen mixture

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2599-2608 ◽  
Author(s):  
Mustafa Mahjoub ◽  
Aleksandar Milivojevic ◽  
Vuk Adzic ◽  
Marija Zivkovic ◽  
Vasko Fotev ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Equivalence Ratio ◽  
Reaction Rates ◽  
The Other ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Swirl Number ◽  
Micro Gas Turbine ◽  
Hydrogen Addition ◽  
Hydrogen Mixture

A numerical investigation of combustion of propane-hydrogen mixture in a swirl premixed micro gas turbine combustor is presented. The effects of hydrogen addition into propane on temperature distribution in the combustor, reaction rates of propane and hydrogen and NOx emissions for different equivalence ratios and swirl numbers are given. The propane-hydrogen mixture of 90/10% by volume was assumed. The numerical results and measurements of NOx emissions for pure propane are compared. Excellent agreements are found for all equivalence ratios and swirl numbers, except for the highest swirl number (1.13). It is found that the addition of hydrogen into propane increases NOx emission. On the other hand, the increase of swirl number and the decrease of equivalence ratio decrease the NOx emissions.

PROPAGATION OF THE BURNING WAVE IN A PULSED DETONATION COMBUSTOR OPERATING ON MIXTURES OF HEPTANE AND JET A-1 WITH AIR AND OXYGEN AT [O2/AIR] < 1

2020 ◽  
Author(s):  
M. S. ASSAD ◽  
◽  
O. G. PENYAZKOV ◽  
I. I. CHERNUHO ◽  
K. ALHUSSAN ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Combustion Wave ◽  
Equivalence Ratio ◽  
Pressure Sensors ◽  
Jet Fuel ◽  
Propagation Time ◽  
Burning Wave ◽  
Pulsed Detonation ◽  
Combustion Wave Propagation ◽  
Fuel Jet

This work is devoted to the study of the dynamics of combustion wave propagation in oxygen-enriched mixtures of n-heptane with air and jet fuel "Jet A-1" in a small-size pulsed detonation combustor (PDC) with a diameter of 20 mm and a length less than 1 m. Experiments are carried out after the PDC reaches a stationary thermal regime when changing the equivalence ratio (ϕ = 0.73-1.89) and the oxygen-to-air ratio ([O2/air] = 0.15-0.60). The velocity of the combustion wave is determined by measuring the propagation time of the flame front between adjacent pressure sensors that form measurement segements along the PDC.

Effect of nitrogen and hydrogen addition on performance and emissions in reactivity controlled compression ignition

Fuel ◽  
2021 ◽  
Vol 292 ◽  
pp. 120330
Author(s):  
Sohayb Bahrami ◽  
Kamran Poorghasemi ◽  
Hamit Solmaz ◽  
Alper Calam ◽  
Duygu İpci
Keyword(s):  
Compression Ignition ◽  
Reactivity Controlled Compression Ignition ◽  
Hydrogen Addition ◽  
Performance And Emissions

Reaction kinetics of hydrogen addition to methyl 5-decenoate

Fuel ◽  
2021 ◽  
Vol 295 ◽  
pp. 120608
Author(s):  
Yage Gao ◽  
Xiaoqing You
Keyword(s):  
Reaction Kinetics ◽  
Hydrogen Addition ◽  
Kinetics Of

scholarly journals Interaction of equivalence ratio fluctuations and flow fluctuations in acoustically forced swirl flames

2021 ◽  
pp. 175682772110155
Author(s):  
Vincent Kather ◽  
Finn Lückoff ◽  
Christian O. Paschereit ◽  
Kilian Oberleithner
Keyword(s):  
Equivalence Ratio ◽  
Transfer Functions ◽  
Transport Model ◽  
Mode Conversion ◽  
Fuel Injector ◽  
One Dimensional ◽  
Flow Fluctuations ◽  
Non Linear ◽  
Non Local ◽  
Acoustic Forcing

The generation and turbulent transport of temporal equivalence ratio fluctuations in a swirl combustor are experimentally investigated and compared to a one-dimensional transport model. These fluctuations are generated by acoustic perturbations at the fuel injector and play a crucial role in the feedback loop leading to thermoacoustic instabilities. The focus of this investigation lies on the interplay between fuel fluctuations and coherent vortical structures that are both affected by the acoustic forcing. To this end, optical diagnostics are applied inside the mixing duct and in the combustion chamber, housing a turbulent swirl flame. The flame was acoustically perturbed to obtain phase-averaged spatially resolved flow and equivalence ratio fluctuations, which allow the determination of flux-based local and global mixing transfer functions. Measurements show that the mode-conversion model that predicts the generation of equivalence ratio fluctuations at the injector holds for linear acoustic forcing amplitudes, but it fails for non-linear amplitudes. The global (radially integrated) transport of fuel fluctuations from the injector to the flame is reasonably well approximated by a one-dimensional transport model with an effective diffusivity that accounts for turbulent diffusion and dispersion. This approach however, fails to recover critical details of the mixing transfer function, which is caused by non-local interaction of flow and fuel fluctuations. This effect becomes even more pronounced for non-linear forcing amplitudes where strong coherent fluctuations induce a non-trivial frequency dependence of the mixing process. The mechanisms resolved in this study suggest that non-local interference of fuel fluctuations and coherent flow fluctuations is significant for the transport of global equivalence ratio fluctuations at linear acoustic amplitudes and crucial for non-linear amplitudes. To improve future predictions and facilitate a satisfactory modelling, a non-local, two-dimensional approach is necessary.

scholarly journals Emission Characteristics for Swirl Methane–Air Premixed Flames with Ammonia Addition

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 662
Author(s):  
Joanna Jójka ◽  
Rafał Ślefarski
Keyword(s):  
Equivalence Ratio ◽  
Combustion Process ◽  
Great Influence ◽  
Emission Characteristics ◽  
Firing Rates ◽  
Numerical Tests ◽  
Ammonia Addition ◽  
Swirl Flame ◽  
Reactor Network ◽  
No Emissions

This paper details the experimental and numerical analysis of a combustion process for atmospheric swirl burners using methane with added ammonia as fuel. The research was carried out for lean methane–air mixtures, which were doped with ammonia up to 5% and preheated up to 473 K. A flow with internal recirculation was induced by burners with different outflow angles from swirling blades, 30° and 50°, where tested equivalence ratio was 0.71. The NO and CO distribution profiles on specified axial positions of the combustor and the overall emission levels at the combustor outlet were measured and compared to a modelled outcome. The highest values of the NO emissions were collected for 5% NH3 and 50° (1950 ppmv), while a reduction to 1585 ppmv was observed at 30°. The doubling of the firing rates from 15 kW up to 30 kW did not have any great influence on the overall emissions. The emission trend lines were not proportional to the raising share of the ammonia in the fuel. 3D numerical tests and a kinetic study with a reactor network showed that the NO outlet concentration for swirl flame depended on the recirculation ratio, residence time, wall temperature, and the mechanism used. Those parameters need to be carefully defined in order to get highly accurate NO predictions—both for 3D simulations and simplified reactor-based models.

In situ biomethanation: Inoculum origin influences acetate consumption rate during hydrogen addition

2021 ◽  
Vol 14 ◽  
pp. 100656
Author(s):  
Nathalia Thygesen Vechi ◽  
Laura Mia Agneessens ◽  
Anders Feilberg ◽  
Lars Ditlev Mørck Ottosen ◽  
Michael Vedel Wegener Kofoed
Keyword(s):  
Consumption Rate ◽  
Hydrogen Addition
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