Measurements of Laminar Flame Speeds of Alternative Gaseous Fuel Mixtures

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Ahmed S. Ibrahim ◽  
Samer F. Ahmed

Global warming and the ever increasing emission levels of combustion engines have forced the engine manufacturers to look for alternative fuels for high engine performance and low emissions. Gaseous fuel mixtures such as biogas, syngas, and liquefied petroleum gas (LPG) are new alternative fuels that have great potential to be used with combustion engines. In the present work, laminar flame speeds (SL) of alternative fuel mixtures, mainly LPG (60% butane, 20% isobutane, and 20% propane) and methane have been studies using the tube method at ambient conditions. In addition, the effect of adding other fuels and gases such as hydrogen, oxygen, carbon dioxide, and nitrogen on SL has also been investigated. The results show that any change in the fuel mixture composition directly affects SL. Measurements of SL of CH4/LPG–air mixtures have found to be about 56 cm/s at ø = 1.1 with 60% LPG in the mixture, which is higher than SL of both pure fuels at the same ø. Moreover, the addition of H2 and O2 to the fuel mixtures increases SL notably, while the addition of CO2/N2 mixture to the fuel mixture, to simulate the EGR effect, decreases SL of CH4/LPG–air mixtures.

Author(s):  
Brian Hollon ◽  
Erlendur Steinthorsson ◽  
Adel Mansour ◽  
Vincent McDonell ◽  
Howard Lee

This paper discusses the development and testing of a full-scale micro-mixing lean-premix injector for hydrogen and syngas fuels that demonstrated ultra-low emissions and stable operation without flashback for high-hydrogen fuels at representative full-scale operating conditions. The injector was fabricated using Macrolamination technology, which is a process by which injectors are manufactured from bonded layers. The injector utilizes sixteen micro-mixing cups for effective and rapid mixing of fuel and air in a compact package. The full scale injector is rated at 1.3 MWth when operating on natural gas at 12.4 bar (180 psi) combustor pressure. The injector operated without flash back on fuel mixtures ranging from 100% natural gas to 100% hydrogen and emissions were shown to be insensitive to operating pressure. Ultra-low NOx emissions of 3 ppm were achieved at a flame temperature of 1750 K (2690 °F) using a fuel mixture containing 50% hydrogen and 50% natural gas by volume with 40% nitrogen dilution added to the fuel stream. NOx emissions of 1.5 ppm were demonstrated at a flame temperature over 1680 K (2564 °F) using the same fuel mixture with only 10% nitrogen dilution, and NOx emissions of 3.5 ppm were demonstrated at a flame temperature of 1730 K (2650 °F) with only 10% carbon dioxide dilution. Finally, using 100% hydrogen with 30% carbon dioxide dilution, 3.6 ppm NOx emissions were demonstrated at a flame temperature over 1600 K (2420 °F). Superior operability was achieved with the injector operating at temperatures below 1470 K (2186 °F) on a fuel mixture containing 87% hydrogen and 13% natural gas. The tests validated the micro-mixing fuel injector technology and the injectors show great promise for use in future gas turbine engines operating on hydrogen, syngas or other fuel mixtures of various compositions.


1998 ◽  
Vol 120 (1) ◽  
pp. 232-236 ◽  
Author(s):  
R. L. Evans ◽  
J. Blaszczyk

The work presented in this paper compares the performance and emissions of the UBC “Squish-Jet” fast-burn combustion chamber with a baseline bowl-in-piston (BIP) chamber. It was found that the increased turbulence generated in the fastburn combustion chambers resulted in 5 to 10 percent faster burning of the air–fuel mixture compared to a conventional BIP chamber. The faster burning was particularly noticeable when operating with lean air–fuel mixtures. The study was conducted at a 1.7 mm clearance height and 10.2:1 compression ratio. Measurements were made over a range of air–fuel ratios from stoichiometric to the lean limit. At each operating point all engine performance parameters, and emissions of nitrogen oxides, unburned hydrocarbons, and carbon monoxide were recorded. At selected operating points a record of cylinder pressure was obtained and analyzed off-line to determine mass-burn rate in the combustion chamber. Two piston designs were tested at wide-open throttle conditions and 2000 rpm to determine the influence of piston geometry on the performance and emissions parameters. The UBC squish-jet combustion chamber design demonstrates significantly better performance parameters and lower emission levels than the conventional BIP design. Mass-burn fraction calculations showed a significant reduction in the time to burn the first 10 percent of the charge, which takes approximately half of the time to burn from 10 to 90 percent of the charge.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5318
Author(s):  
Imantas Lipskis ◽  
Saugirdas Pukalskas ◽  
Paweł Droździel ◽  
Dalibor Barta ◽  
Vidas Žuraulis ◽  
...  

The article describes a compression-ignition engine working with a dual-fuel system installed in diesel locomotive TEP70 BS. The model of the locomotive engine has been created applying AVL BOOST and Diesel RK software and engine performance simulations. Combustion characteristics have been identified employing the mixtures of different fuels. The paper compares ecological (CO2, NOx, PM) and energy (in-cylinder pressure, temperature and the rate of heat release (ROHR)) indicators of a diesel and fuel mixtures-driven locomotive. The performed simulation has shown that different fuel proportions increased methane content and decreased diesel content in the fuel mixture, as well as causing higher in-cylinder pressure and ROHR; however, in-cylinder temperature dropped. CO2, NOx and PM emissions decrease in all cases thus raising methane and reducing diesel content in the fuel mixture.


2017 ◽  
Vol 2 (5) ◽  
pp. 20
Author(s):  
Jafaar A. Kadhem ◽  
Khalid Sadiq Reza ◽  
Wahab K. Ahmed

The Iraq air is polluted highly by pollutants emitted from automobiles and trucks as well as power stations. This pollution resource is well known it is the burning of oil and natural gas. Iraq has been subjected to a series of wars and economic blockade for more than 40 continuing years. The war and blockade conditions have affected all the country's infrastructure causing huge deterioration in the services provided to Iraqi citizens. The Iraqi refineries as well have been subjected to major destruction and reconstruction several times. Unfortunately, the reconstruction in Iraq conditions was not in appropriate level, and for that reason we find the Iraqi gasoline and diesel are one of the worst fuels in the world. All reports demonstrated that the Iraqi gasoline contains high levels of sulfur (500ppm), as well as high levels of lead compounds to increase octane. The Iraqi diesel contains sulfur up to 1 to 2.5% of its weight which makes it the worst globally.In Iraq there are many alternative fuels that generate better engine performance and emit lower exhaust pollutants while improving fuel consumption. This paper reviews some of the Iraqi experimental work during the past ten years and the available results about using gaseous fuels such as natural gas, liquefied petroleum gas and hydrogen. In addition, the study focus on the use of some additives to gasoline and diesel, such as alcohols and biofuels to reduce the effects of sulfur associated with these types of fuel. The Iraqi research works have found many solutions and alternative methods of operation to eliminate the various engines emitted pollutants. The role has now come to the decision makers to legislate the laws and decisions necessary to switch to new types of alternative fuels.


2012 ◽  
Vol 148 (1) ◽  
pp. 40-47
Author(s):  
Stanisław SZWAJA ◽  
Wojciech TUTAK ◽  
Karol GRAB-ROGALIŃSKI ◽  
Arkadiusz JAMROZIK ◽  
Arkadiusz KOCISZEWSKI

Results from tests conducted in several RTD centers lead to conclusion that biogas as a potential fuel for the internal combustion (IC) spark ignited (SI) engine features with its satisfactory combustion predisposition causing smooth engine run without accidental misfiring or knock events. This good predisposition is obtained due to carbon dioxide (CO2) content in the biogas. On the other hand, carbon dioxide as incombustible gas contribute to decrease in the brake power of the biogas fueled engine. To analyze mutual CO2 and CH4 content on biogas burning the combustion parameters as follows: adiabatic combustion temperature, laminar flame speed and ignition delay of biogas with various methane content were determined and presented in the paper. Additionally, these parameters for pure methane were also included in order to make comparison between each other. As computed, ignition delay, which has is strongly correlated with knock resistance, can change several times with temperature increase, but does not change remarkably with increase in methane content. Adiabatic combustion temperature does not also ought to influence on engine performance or increase in engine cooling and exhaust losses due to its insignificant changes. The largest change was observed in laminar flame speed, that can influence on development of the first premixed combustion phase.


2019 ◽  
Vol 4 (8) ◽  
pp. 80-84
Author(s):  
Van Quy Nguyen ◽  
Huu Cuong Le

To cope with the depletion of fossil fuels and the threat of exhaust pollution from internal combustion engines, research finds alternative fuels. Step by step to completely replace fossil fuels that will be exhausted in the future and environmentally friendly due to internal combustion engines is an urgent and important issue. Diversify fuel sources used for internal combustion engines and environmentally friendly when using Jatropha - Diesel fuel mixture. The paper focuses on studying the ability to use biodiesel derived from Jatropha seeds with the volume ratios of 5%, 10% and 15% on experimental engines. Thereby, it will analyze and evaluate the technical features and pollution levels of engines compared to pure fuels. Experimental study assessing the effect of Jatropha - Diesel mixing ratio on the emission formation compared with emissions in Vikyno EV2600 engines.


1989 ◽  
Vol 111 (2) ◽  
pp. 100-103
Author(s):  
I. Wierzba ◽  
G. A. Karim

The behavior of the lean and rich flammability limits of various fuel mixture combinations involving propane, n-butane, propylene and ethylene, which feature prominently in a variety of industrial and natural fuel gases such as liquefied petroleum gases (LPGs), was examined. It was found that the lean limits of such mixtures can be predicted well by using Le Chatelier’s Rule. This rule can also predict the rich flammability limits of propane-n-butane mixtures. However, its application to calculate the rich limits of mixtures such as propane-propylene, propane-ethylene, butane-ethylene, propylene-ethylene mixtures carries a significant error with certain mixtures composition. The effect of the dilution of such fuel mixtures with nitrogen or carbon dioxide was also investigated and a predictive procedure is described.


Author(s):  
Jeffrey D. Munzar ◽  
Bradley M. Denman ◽  
Rodrigo Jiménez ◽  
Ahmed Zia ◽  
Jeffrey M. Bergthorson

An understanding of the fundamental combustion properties of alternative fuels is essential for their adoption as replacements for non-renewable sources. In this study, three different biojet fuel mixtures are directly compared to conventional Jet A-1 on the basis of laminar flame speed and vapor pressure. The biofuel is derived from camelina oil and hydrotreated to ensure consistent elemental composition with conventional aviation fuel, yielding a bioderived synthetic paraffinic kerosene (Bio-SPK). Two considered blends are biofuel and Jet A-1 mixtures, while the third is a 90% Bio-SPK mixture with 10% aromatic additives. Premixed flame speed measurements are conducted at an unburned temperature of 400K and atmospheric pressure using a jet-wall stagnation flame apparatus. Since the laminar flame speed cannot be studied experimentally, a strained (or reference) flame speed is used as the basis for the initial comparison. Only by using an appropriate surrogate fuel were the reference flame speed measurements extrapolated to zero flame strain, accomplished using a direct comparison of simulations to experiments. This method has been previously shown to yield results consistent with non-linear extrapolations. Vapor pressure measurements of the biojet blends are also made from 25 to 200°C using an isoteniscope. Finally, the biojet blends are compared to the Jet A-1 benchmark on the basis of laminar flame speed at different equivalence ratios, as well as on the basis of vapor pressure over a wide temperature range, and the suitability of a binary laminar flame speed surrogate for these biojet fuels is discussed.


Author(s):  
Hui Xu ◽  
Leon A. LaPointe ◽  
Robin J. Bremmer

Gaseous fueled spark ignited (SI) engines are often developed using pipeline quality natural gas as the fuel. However, natural gas engines are occasionally expected by customers to accommodate different fuel compositions when deployed in the field. Depending on the source or production processing of the fuel and the ambient conditions, gaseous fuels can have different levels of heavy hydrocarbons and/or significant levels of diluents when compared to natural gas. In recent years, there are increasing interests in using synthesis gas (syngas) from renewable sources in gaseous fueled spark ignition engines. This work investigated syngas compositions from different production processes and describes a methodology to predict engine performance using syngas. Syngas composition variations can provide different laminar flame speeds (LFS), which can result in changes in combustion burn rate, heat release rate and knock likelihood, if the engine combustion process is not optimized appropriately. It is challenging to obtain LFS data at the high pressure and temperature conditions that are characteristic of the piston engine combustion process. It has proven to be effective to employ a chemical kinetics solver using an appropriate chemical kinetics mechanism to obtain LFS values under piston engine combustion conditions. Alternative chemical kinetics mechanisms were investigated to identify one which best characterized combustion performance relative to detailed rig and engine measurements. With this appropriate chemical kinetics mechanism, LFS results are now used to guide natural gas engine combustion tuning when using syngas as a fuel. Engine performance is predicted in terms of NOx emissions and knock likelihood using the in-house developed methodology.


Author(s):  
S. F. Levko ◽  
B. V. Dolishnii ◽  
В. М. Melnyk

Currently, the disposal and recycling of the alcohol industry products creates a number of difficulties due to the lack of well-established recycling lines in Ukraine. Since 1998, eight enterprises of the state-owned concern Ukrspirt have been converted to produce high-octane oxygen-containing additives (CFCs) for ethanol-based fuels to organize the processing of waste from the alcohol industry. During this time, they produced 28.2 thousand tonnes of CALs, but CALA enterprises face great difficulties in selling their products, as they are new and expensive. The influence of fusel oil additives on commodity fuels on the main physical and technical indicators of the obtained alternative fuels is considered in the paper. According to the results of studies of octane number, we have established the optimal compositions of fuel mixtures of fusel oils with gasoline A-80 can contain up to 10% of the latter. For mixtures of fusel oils with diesel fuel by cetane number, their optimum content in diesel fuel is from 4 to 10% by volume. But, according to the trends of the development of diesel engines, the compression ratio increases, which allows the use of diesel fuel with higher cetane number, and therefore it is possible to raise the content of fusel oils in diesel fuel to 12%. According to the results of studies of the environmental performance of the ZIL-130 engine when fusel oils are added to commercial gasoline in an amount of 2 to 10% vol. the CO content in ICE exhaust gases decreases by 9.3%, fuel consumption increases by 6.5%, hydrocarbons by 10.2% and nitrogen oxide by 16.9%. As a result of increasing the content of fusel oils in diesel from 0 to 6%, there is an increase in mass flow rate of fuel to 6.1%, an increase in the concentration of hydrocarbons to 10% and nitrogen oxides by 1.9% in the exhaust gases of the engine D21A1. Thus, as we see today, along with traditional fuels for internal combustion engines, it is possible to use their alternative substitutes quite efficiently both in their pure form and in mixtures with them. There are all prerequisites for this in Ukraine and the region, the only question is the financing of these projects.


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