scholarly journals A Review on Combustion Characteristics of Ammonia as a Carbon-Free Fuel

2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Li ◽  
Shini Lai ◽  
Danan Chen ◽  
Rongjun Wu ◽  
Noriyuki Kobayashi ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Burning Velocity ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Pollutant Emissions ◽  
Attractive Alternative ◽  
Laminar Burning Velocity ◽  
Numerical Studies ◽  
Combustion Properties ◽  
And Storage

A comprehensive review of combustion characteristics of ammonia (NH3) as a carbon free fuel is presented. NH3 is an attractive alternative fuel candidate to reduce the consumption of fossil fuel and the emission of CO2, soot, and hydrocarbon pollutants, due to its comparable combustion properties, productivities from renewable sources, and storage and transportation by current commercial infrastructure. However, the combustion properties of NH3 are quite different from conventional hydrocarbon fuels, which highlight the specific difficulties during the application of NH3. Therefore, this paper presents comparative experimental and numerical studies of the application of NH3 as a fuel during combustion process, including the combustion properties of laminar burning velocity, flame structures, pollutant emissions for the application of NH3 as a carbon free fuel. This paper presents the burning velocity and pollutant emissions of NH3 alone and mixtures with other fuels to improve the combustion properties. The aim of this paper is to review and describe the suitability of NH3 as a fuel, including the combustion and emission characteristics of NH3 during its combustion process.

scholarly journals The Effect of Hydrogen Addition on Low-Temperature Combustion of Light Hydrocarbons and Alcohols

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3808
Author(s):  
Fekadu Mosisa Wako ◽  
Gianmaria Pio ◽  
Ernesto Salzano
Keyword(s):  
Experimental Data ◽  
Burning Velocity ◽  
Engine Performance ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Laminar Burning Velocity ◽  
Nox Formation ◽  
Hydrogen Addition ◽  
Temperature Combustion ◽  
Fuel Mixtures

Hydrogen is largely considered as an attractive additive fuel for hydrocarbons and alcohol-fueled engines. Nevertheless, a complete understanding of the interactions between blended fuel mechanisms under oxidative conditions at low initial temperature is still lacking. This study is devoted to the numerical investigation of the laminar burning velocity of hydrogen–hydrocarbon and hydrogen–alcohol fuels under several compositions. Estimations were compared with experimental data reported in the current literature. Additionally, the effects of hydrogen addition on engine performance, NOX, and other pollutant emissions of the mentioned fuels have been thermodynamically analyzed. From the study, it has been observed that the laminar burning velocity of the fuel mixtures increased with increasing hydrogen fractions and the peak value shifted to richer conditions. Besides, hydrogen fraction was found to increase the adiabatic flame temperatures eventually favoring the NOX formation for all fuel blends except the acetylene–hydrogen–air mixture where hydrogen showed a reverse effect. Besides, hydrogen is also found to improve the engine performances and helps to surge thermal efficiency, improve the combustion rate, and lessen other pollutant emissions such as CO, CO2, and unburned hydrocarbons. The model predicted well and in good agreement with the experimental data reported in the recent literature.

scholarly journals Evaluation of the combustion characteristics of isolated droplets of Jet A blended with ethanol and butanol

2017 ◽  
Author(s):  
Javier Ballester ◽  
Álvaro Muelas ◽  
Pilar Remacha
Keyword(s):  
Gas Turbines ◽  
Alternative Fuels ◽  
Droplet Diameter ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
The Other ◽  
Combustion Properties ◽  
Alcohol Mixtures ◽  
Free Falling ◽  
Scarce Data

In light of the potential of ethanol and butanol as alternative fuels for blending with conventional kerosene in gasturbine engines, experimental data regarding the burning characteristics of these blends are required in order tobetter understand their combustion process. In this study, free-falling droplets of Jet A, ethanol, butanol and theirmixtures (20% alcohol in Jet A by volume) were examined in a combustion chamber which providesrepresentative conditions of real flames, both in terms of temperature and oxygen availability. Results show thatthe evolution of droplet diameter for Jet A and its blends with both alcohols are very similar, regardless of theobvious compositional differences. On the other hand, sooting behaviors are found to be quite different, with aclear reduction in the sooting propensity of the Jet A/alcohol mixtures when compared to neat kerosene. Theseresults are consistent with previous studies in gas turbines, suggesting that such blends are viable alternativefuels with similar combustion characteristics to Jet A, but with much less propensity to produce soot. Moreover,this study provides new results on the combustion properties of Jet A/ethanol and Jet A/butanol mixtures, forwhich very scarce data exist in the open literature.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4990

scholarly journals Turbulent burning velocity in combustion chamber of SI engine fueled with compressed biogas

2015 ◽  
Vol 37 (3) ◽  
pp. 205-216
Author(s):  
Bui Van Ga ◽  
Nguyen Van Dong ◽  
Bui Van Hung
Keyword(s):  
Combustion Chamber ◽  
Burning Velocity ◽  
Combustion Process ◽  
Chemical Properties ◽  
Spark Ignition Engines ◽  
Laminar Burning Velocity ◽  
Physico Chemical ◽  
Combustion Simulation ◽  
Velocity Coefficient ◽  
Turbulent Burning Velocity

Turbulent burning velocity is the most important parameter in analyzing pre-mixed combustion simulation of spark ignition engines. It depends on the laminar burning velocity and turbulence intensity in the combustion chamber. The first term can be predicted if one knows fuel composition, physico chemical properties of the fluid. The second term strongly depends on the geometry of the combustion chamber and fluid movement during the combustion process. One cannot suggest a general expression for different cases of engine. Thus, for accuracy modeling, one should determine turbulent burning velocity in the combustion chamber of each case of engine individually. In this study, the turbulent burning velocity is defined by a linear function of laminar burning velocity in which the proportional constant is defined as the turbulent burning velocity coefficient. This coefficient was obtained by analyzing the numerical simulation results and experimental data and this is applied to a concrete case of a Honda Wave motorcycle engine combustion chamber that fueled with compressed biogas. The results showed that the turbulent burning velocity coefficient in this case is around 1.3 when the average engine revolutions is in the range of 3000 rpm to 6000 rpm with biogas containing 80% Methane. We can then predict the effects of different parameters on the performance of the engine fueled with compressed biogas by simulation.

scholarly journals Evaluation of the possibility of the sewage sludge gasification gas use as a fuel

2016 ◽  
Vol 23 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Sebastian Werle ◽  
Mariusz Dudziak
Keyword(s):  
Sewage Sludge ◽  
Gas Turbines ◽  
Burning Velocity ◽  
Combustion Process ◽  
Laminar Burning Velocity ◽  
Gas Combustion ◽  
Reducing Atmosphere ◽  
Gasification Process ◽  
Gas Utilization ◽  
Dioxins And Furans

Abstract Biomass is one of the major sources of energy that is estimated to contribute between 10% and 14% of the world’s energy supply. Over the past several years, many societies have established policy targets to increase their production of renewable energy from biomass. The thermo-chemical utilization of biomass includes 4 technologies: the most popular combustion and co-firing, and unconventional: pyrolysis and gasification. Gasification is considered to be the perspective technology because has many advantages in comparison to traditional process of combustion: (1) limited emission of the SO2, NOx, oxides of the heavy metals and no risk of the dioxins and furans emission due to reducing atmosphere in the gasification reactor, (2) volume of the gasification gas is smaller in comparison to flue gases from combustion due to the reducing atmosphere, (3) gasification process produce gas which is potential gaseous fuel in power engineering (engines, gas turbines and boilers) and chemistry. Unfortunately, composition of the gasification gas is always described as a variable. Moreover, it depends on the conditions of the process and quality of the base fuel. For this reason, the use of gasification gas can’t be very easy. For this reason, the knowledge of the basic properties of the gas is very important. Laminar burning velocity is assumed as an important quantity for in the process of the design equipment for the gas utilization. The numerical and experimental results of the laminar burning velocity of sewage sludge gasification gases were presented. Experimental Bunsen burner method was used. Cosilab 3© software for numerical analysis was used. GRI-Mech 3.0 mechanism of gas oxidation was implemented. As a result of the work, the set of the parameters where the sewage sludge gasification gas combustion process is stable with effective heat release, were presented.

Experimental Investigation of Combustion Behavior of Biodiesel-Water Emulsion

2019 ◽  
Author(s):  
Gurjap Singh ◽  
Nicholas Hentges ◽  
Damion Johnson ◽  
Albert Ratner
Keyword(s):  
Fuel Economy ◽  
High Speed ◽  
Combustion Process ◽  
Ccd Camera ◽  
The United States ◽  
Attractive Alternative ◽  
Compression Ignition Engine ◽  
Water Emulsion ◽  
Combustion Behavior ◽  
Combustion Properties

Abstract Biodiesel has proved to be an attractive alternative fuel for the compression-ignition engine, with its blends of regular petrodiesel being sold at virtually every gas station in the United States. Researchers have explored many of its combustion properties and sought to modify them in the interest of better fuel economy, specific fuel combustion, and lower emissions. The emulsification of biodiesel with water in order to promote microexplosions during the combustion process is one such fuel modification method. Microexplosions fragment the fuel droplet into many smaller droplets, which promote homogeneous combustion, and can result in smoother power output and better fuel economy. Present research analyzes the droplet combustion properties of soy biodiesel with 10% water and 0.1% POLYOX™ polymer. A sub-millimeter droplet is suspended on three 16μm silicon carbide wires and ignited using hot wire loops. The combustion process is recorded at 1000 frames/second by a high-speed CCD camera. Combustion behavior of the emulsified fuel is then analyzed by post-processing the resulting high-speed images. Results show several microexplosion events. Combustion trends are plotted, and combustion rates are determined. Burning rate for the emulsion was found to be very close to that of base fuel, with 2.1% decrease noted. It is hoped that present research will spark further interest in the fuel behavior modification of biodiesel.

Prediction of Ultra-Lean SI Engine Performance by QD-Combustion Model With an Improved Laminar Flame Speed

2020 ◽  
Author(s):  
Ratnak Sok ◽  
Jin Kusaka ◽  
Kyohei Yamaguchi
Keyword(s):  
Gasoline Engine ◽  
Laminar Flame ◽  
Burning Velocity ◽  
Turbulent Flame ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Flame Speed ◽  
Combustion Model ◽  
Lean Mixture ◽  
Turbulent Flame Speed

Abstract A quasi-dimensional (QD) simulation model is a preferred method to predict combustion in the gasoline engines with reliable results and shorter calculation time compared with multi-dimensional simulation. The combustion phenomena in spark ignition (SI) engines are highly turbulent, and at initial stage of the combustion process, turbulent flame speed highly depends on laminar burning velocity SL. A major parameter of the QD combustion model is an accurate prediction of the SL, which is unstable under low engine speed and ultra-lean mixture. This work investigates the applicability of the combustion model for evaluating the combustion characteristics of a high-tumble port gasoline engine operated under ultra-lean mixture (equivalence ratio up to ϕ = 0.5) which is out of the range of currently available SL functions initially developed for a single component fuel. In this study, the SL correlation is improved for a gasoline surrogate fuel (5 components). Predicted SL data from the conventional and improved functions are compared with experimental SL data taken from a constant-volume chamber under micro-gravity condition. The SL measurements are done at reference conditions at temperature of 300K, pressure of 0.1MPaa, and at elevated conditions whose temperature = 360K, pressure = 0.1, 0.3, and 0.5 MPaa. Results show that the conventional SL model over-predicts flame speeds under all conditions. Moreover, the model predicts negative SL at very lean (ϕ ≤ 0.3) and rich (ϕ ≥ 1.9) mixture while the revised SL is well validated with the measured data. The improved SL formula is then incorporated into the QD combustion model by a user-defined function in GT-Power simulation. The engine experimental data are taken at 1000 RPM and 2000 RPM under engine load IMEPn = 0.4–0.8 MPa (with 0.1 increment) and ϕ ranges are up to 0.5. The results shows that the simulated engine performances and combustion characteristics are well validated with the experiments within 6% accuracy by using the QD combustion model coupled with the improved SL. A sensitivity analysis of the model is also in good agreement with the experiments under cyclic variation (averaged cycle, high IMEP or stable cycle, and low IMEP or unstable cycle).

Combustion Behavior of Jet A Droplets and its Blends With Butanol

2017 ◽  
Author(s):  
Álvaro Muelas ◽  
Pilar Remacha ◽  
Adrián Martínez ◽  
Javier Ballester
Keyword(s):  
Alternative Fuels ◽  
Droplet Diameter ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Promising Alternative ◽  
Combustion Properties ◽  
Droplet Sizes ◽  
Burning Rates ◽  
Petroleum Fuels ◽  
Scarce Data

In light of the potential of butanol as an alternative fuel for blending with petroleum fuels such as gasoline, diesel or Jet A, experimental data regarding the burning characteristics of these blends are required in order to better understand their combustion process. In this study, freely-falling droplets of butanol, Jet A, and their mixtures (10, 20 and 50% butanol by volume) were examined in a combustion chamber which provides representative conditions of real flames, both in terms of temperature and oxygen availability. The combustion characteristics reported here include evolution of droplet sizes, burning rates, soot measurements, and the occurrence of microexplosions and soot shells. Results show that the evolution of droplet diameter for butanol, Jet A and their blends are very similar, regardless of the obvious compositional differences. Sooting behaviors are found to be quite different, with a clear reduction in the sooting propensity as the butanol content in the fuel increases. These results are consistent with a previous study in a gas turbine showing similar performance among Jet A and its blends with butanol, suggesting that such mixtures are promising alternative fuels with very similar combustion characteristics to Jet A, but with much less propensity to soot. Moreover, this study provides new results on the combustion properties of Jet A/butanol blends, for which very scarce data exist in the open literature.

Fundamental Combustion Characteristics of Lean and Stoichiometric Hydrogen Laminar Premixed Flames Diluted With Nitrogen or Carbon Dioxide

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Hong-Meng Li ◽  
Guo-Xiu Li ◽  
Zuo-Yu Sun ◽  
Zi-Hang Zhou ◽  
Yuan Li ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Equivalence Ratio ◽  
Burning Velocity ◽  
Flame Temperature ◽  
Premixed Flames ◽  
Combustion Characteristics ◽  
Inert Gas ◽  
Chemical Effect ◽  
Laminar Burning Velocity ◽  
Suppression Effect

In this work, the laminar combustion characteristics of H2/N2/air (H2/CO2/air) were systematically investigated under different hydrogen ratios (40–100%) and equivalence ratios (0.4–1.0) in a closed combustion vessel using the spherical expanding flame method associated with Schlieren technology. The unstretched laminar burning velocities were compared with data from previous study, and the result indicates that excellent agreements are obtained. Numerical simulations were also conducted using GRI3.0 and USC II mechanisms to compare with the present experimental results. The Markstein length for H2/inert gas can be decreased by decreasing the equivalence ratio and hydrogen ratio. The results indicate that the H2/inert gas premixed flames tend to be more unstable with the decrease of equivalence ratio and hydrogen ratio. For H2/N2 mixture, the suppression effect on laminar burning velocity is caused by modified specific heat of mixtures and decreased heat release, which result in a decreased flame temperature. For H2/CO2 mixture, the carbon dioxide has stronger dilution effect than nitrogen in reducing laminar burning velocity owing to both thermal effect and chemical effect.

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