scholarly journals Воспламенение топливной смеси с помощью многоточечного импульсного искрового разряда при различных начальных условиях

2021 ◽  
Vol 91 (9) ◽  
pp. 1339
Author(s):  
П.В. Булат ◽  
К.Н. Волков ◽  
Л.П. Грачев ◽  
И.И. Есаков ◽  
П.Б. Лавров
Keyword(s):  
Fuel Mixture ◽  
Initial Mixture ◽  
Combustion Products ◽  
Combustible Mixture ◽  
Physical Experiment ◽  
Practical Applications ◽  
Spark Discharges ◽  
Rate Of Combustion ◽  
Fuel Mixtures ◽  
Concentration Limits

The development of efficient and reliable systems for the ignition of air/fuel mixtures is of interest for many practical applications associated with the use of combustion devices. To increase the total surface of the flame, ensure the reliability of ignition, increase the rate of combustion in the volume of the chamber and the completeness of combustion of the combustible mixture, multi-point ignition of the air/fuel mixture using several pulsed spark discharges is used. A comparison of the characteristics of combustion products in the working chamber when using different numbers of igniting spark discharges is made based on the data of a physical experiment. Measurements are carried out at various ignition points of the mixture, initial mixture pressures, and air/fuel ratios. The values of the air/fuel ratio used in the experiment are in the range, the boundaries of which are the lower and upper concentration limits of the ignition of the propane-air mixture.

scholarly journals SOOT FORMATION WHILE OPERATING A DIESEL POWER UNIT

2019 ◽  
Vol 14 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Иосиф Аладашвили ◽  
Iosif Aladashvili ◽  
Ольга Макарова ◽  
Ol'ga Makarova ◽  
Фанис Яруллин ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Environmental Performance ◽  
Soot Formation ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Fuel Mixture ◽  
Combustion Products ◽  
Combustible Mixture ◽  
Working Fluid ◽  
Oxides Of Nitrogen

The article presents the technical, economic and environmental problems that arise during the operation of power units of any kind. Harmful components that poison the environment during the operation of diesel power units are a combination of different chemical compounds. Oxides of nitrogen, carbon monoxide and various unburned hydrocarbons are abundantly present in the exhaust gases of power units, but in our opinion soot is the most insidious, and it also takes up almost 50% of all diesel engine poisonous substances. The purpose of this work is to improve the technical, economic and environmental performance of the internal combustion engine, by feeding an additional air mixture into the cylinders. Possible ways to solve the above-mentioned problem are proposed, namely, one of the variants of charge turbulence by supplying additional air to the lower part of the cylinder liner at the end of the filling stroke and at the beginning of compression. The essence of this process is as follows: a jet of additional air creates kinetic energy of the main charge and simultaneously lowers the temperature inside the cylinder to the allowed values, thereby providing a favorable atmosphere for oxidizing the combustible mixture and helps reduce toxic components of combustion products, including soot. As a result of the foregoing, it should be concluded that the additional portion of air introduced into the cylinder contributes to an increase in the kinetic energy of the working fluid, and this in turn is the guarantor of the maximum burn-out of the air-fuel mixture. In addition, it presents the results of experiments in the form of graphs and on the basis of these data a comparative analysis was conducted and certain conclusions were made on the positive dynamics of technical, economic and environmental performance of power units.

STUDYING THE PROCESS OF HEATING OF A PIPE BILLET DURING GAS FORMING

2021 ◽  
pp. 156-161
Author(s):  
А.Ю. Боташев ◽  
Р.А. Байрамуков ◽  
Н.У. Бисилов ◽  
Р.С. Малсугенов
Keyword(s):  
Heat Transfer ◽  
Heat Balance ◽  
Heating Temperature ◽  
Fuel Mixture ◽  
Combustion Products ◽  
New Device ◽  
Combustible Gas ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Propane Butane

Разработана и представлена схема нового устройства, осуществляющего штамповку деталей с нагревом трубной заготовки воздействием продуктов сгорания газообразной топливной смеси. В качестве топливной смеси может использоваться горючий газ - смесь воздуха с метаном или с пропан-бутаном. Представлены результаты исследования процесса нагрева трубной заготовки воздействием продуктов сгорания. Исследование проведено на базе уравнений конвективного теплообмена, теплового баланса и термодинамики. Получена зависимость для определения температуры нагрева трубной заготовки. Установлено, что температура заготовки зависит от материала и геометрических размеров заготовки, а также давления топливной смеси. Данное устройство обеспечивает нагрев до интервала горячей обработки стальных трубных заготовок диаметром более 150 мм при толщине стенки до 1,2…1,5 мм, а при диаметре более 300 мм - толщиной до 2,0…2,5 мм. Для нагрева трубных заготовок из цветных металлов и сплавов (например, алюминия и меди) требуется меньшее давление топливной смеси, чем для стали, благодаря этому обеспечивается нагрев заготовок значительно большей толщины, в частности, заготовок из алюминия толщиной до 6 мм We developed a diagram of a new device for stamping parts by heating a pipe billet by the action of combustion products of a gaseous fuel mixture. A combustible gas can be used as a fuel mixture - a mixture of air with methane or with propane-butane. We present the results of a study of the process of heating a pipe billet by the action of combustion products. We carried out the study on the basis of the equations of convective heat transfer, heat balance and thermodynamics. We obtained the dependence for determining the heating temperature of the pipe billet. We found that the temperature of the workpiece depends on the material and geometric dimensions of the workpiece, as well as the pressure of the fuel mixture. This device provides heating to the hot working interval of steel pipe billets with a diameter of more than 150 mm with a wall thickness of up to 1.2 ... 1.5 mm, and with a diameter of more than 300 mm - with a thickness of up to 2.0 ... 2.5 mm. To heat tubular billets made of non-ferrous metals and alloys (for example, aluminum and copper), a lower pressure of the fuel mixture is required than for steel, due to this, billets of a much greater thickness are heated, in particular, billets made of aluminum with a thickness of up to 6 mm

SPECTRAL DIAGNOSTICS OF THE HYDROCARBON FUEL COMBUSTION PROCESS

2021 ◽  
pp. 12-17
Author(s):  
M. A. Vaganov
Keyword(s):  
Combustion Process ◽  
Hydrocarbon Fuel ◽  
Combustion Products ◽  
Combustible Mixture ◽  
Fuel Combustion ◽  
Propane Combustion ◽  
Gaseous Hydrocarbon ◽  
Spectral Bands ◽  
Air Supply ◽  
Spectral Diagnostics

It is proposed to use the methods of applied optical spectroscopy to solve the problem of control and diagnostics of gaseous hydrocarbon fuel combustion in this work. The results of an experimental study of spectroscopic informative parameters characterizing the propane combustion process are presented for three modes: combustion of pure propane without air supply, stoichiometric combustion and combustion with a change in the amount of supplied air relative to stoichiometric combustion. As a result of the experiment, it was found that the most intense bands in the emission spectrum of the flame arising from the combustion of propane correspond to the spectral bands of radicals of combustion products: OH, CH, and C2. While the intensities of various systems of bands in the flame spectrum depend significantly on the composition of the combustible mixture.

Ultra-Low Emission Hydrogen/Syngas Combustion With a 1.3 MW Injector Using a Micro-Mixing Lean-Premix System

2011 ◽  
Author(s):  
Brian Hollon ◽  
Erlendur Steinthorsson ◽  
Adel Mansour ◽  
Vincent McDonell ◽  
Howard Lee
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Flame Temperature ◽  
Fuel Mixture ◽  
Full Scale ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Nitrogen Dilution ◽  
Fuel Mixtures

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.

Characterization of Spray Formed by Diesel-Water Mixture Jet Injected Into an Air Crossflow

2017 ◽  
Author(s):  
Jinkwan Song ◽  
Jong Guen Lee
Keyword(s):  
Diesel Fuel ◽  
Drop Size ◽  
Pure Water ◽  
Fuel Mixture ◽  
Water Mixture ◽  
Fuel Injector ◽  
Spray Characteristics ◽  
Two Fluids ◽  
Mixing Ratios ◽  
Fuel Mixtures

Using a mixture of water and diesel fuel is considered a way to reduce gas emissions including NOx and COx in the gas turbine. This paper presents experimental results on spray characteristics of the water-diesel fuel mixture in an air crossflow. A plain-orifice type injector of 0.508 mm in diameter is employed in the research. Pure water, pure diesel fuel, and water-diesel fuel mixtures with different mixing ratios are used to compare their spray characteristics. In order to observe spray behaviors in different breakup regimes, Weber numbers for water of 30 and 125 are chosen as the operating condition and the corresponding Weber numbers for diesel fuel at the same conditions are 92 and 382, respectively. Momentum flux ratios are 10 and 20. A tee connection and a subsequent static mixer are employed at upstream of fuel injector to mix two liquids. Phase Doppler Particle Analyzer (PDPA) measurement is performed to measure droplet distributions and mean drop size at various mixture ratios, and planar laser induced fluorescence (PLIF) technique with dyeing either diesel or water is used to look into the primary breakup process. PDPA data show that the spray characteristics of water-diesel fuel mixtures such as mean drop size and number density distribution can be predicted from the measured drop size distribution of pure fluids by weighting those quantities by mass fraction of each fluid, indicating that the water and diesel are injected alternately without significant mixing between the two fluids. A short transition of liquid flow from water-to-diesel or diesel-to-water produces small fraction of relatively bigger droplets.

Development and Testing of a FuelFlex Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications With Variable Hydrogen Methane Mixtures

2019 ◽  
Author(s):  
H. H.-W. Funke ◽  
N. Beckmann ◽  
S. Abanteriba
Keyword(s):  
Gas Turbine ◽  
Experimental Studies ◽  
Fuel Mixture ◽  
Combustion Efficiency ◽  
Pollutant Emission ◽  
Pure Hydrogen ◽  
Negative Effects ◽  
Low Emission ◽  
Combustion Properties ◽  
Fuel Mixtures

Abstract The negative effects on the earth’s climate make the reduction of the potent greenhouse gases carbon-dioxide (CO2) and nitrogen oxides (NOx) an imperative of the combustion research. Hydrogen based gas turbine systems are in the focus of the energy producing industry, due to their potential to eliminate CO2 emissions completely as combustion product, if the fuel is produced from renewable and sustainable energy sources. Due to the difference in the physical properties of hydrogen-rich fuel mixtures compared to common gas turbine fuels, well established combustion systems cannot be directly applied for Dry Low NOx (DLN) hydrogen combustion. The paper presents initial test data of a recently designed low emission Micromix combustor adapted to flexible fuel operation with variable fuel mixtures of hydrogen and methane. Based on previous studies, targeting low emission combustion of pure hydrogen and dual fuel operation with hydrogen and syngas (H2/CO 90/10 vol.%), a FuelFlex Micromix combustor for variable hydrogen methane mixtures has been developed. For facilitating the experimental low pressure testing the combustion chamber test rig is adapted for flexible fuel operation. A computer-controlled gas mixing facility is designed and installed to continuously provide accurate and homogeneous hydrogen methane fuel mixtures to the combustor. An evaluation of all major error sources has been conducted. In the presented experimental studies, the integration-optimized FuelFlex Micromix combustor geometry is tested at atmospheric pressure with hydrogen methane fuel mixtures ranging from 57 vol.% to 100 vol.% hydrogen in the fuel. For evaluating the combustion characteristics, the results of experimental exhaust gas analyses are applied. Despite the design compromise, that takes into account the significantly different fuel and combustion properties of the applied fuels, the initial results confirm promising operating behaviour, combustion efficiency and pollutant emission levels for flexible fuel operation. The investigated combustor module exceeds 99.4% combustion efficiency for hydrogen contents of 80–100% in the fuel mixture and shows NOx emissions less than 4 ppm corrected to 15 vol.% O2 at the design point.

Experimental Investigation of the Performance of a Micro Gas Turbine Fueled With Mixtures of Natural Gas and Biogas

2013 ◽  
Author(s):  
Homam Nikpey ◽  
Mohsen Assadi ◽  
Peter Breuhaus
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Emissions ◽  
Fuel Mixture ◽  
Combined Heat And Power ◽  
Test Rig ◽  
Heating Value ◽  
Micro Gas Turbine ◽  
Fuel Mixtures ◽  
The Impact

Previously published studies have addressed modifications to the engines when operating with biogas, i.e. a low heating value (LHV) fuel. This study focuses on mapping out the possible biogas share in a fuel mixture of biogas and natural gas in micro combined heat and power (CHP) installations without any engine modifications. This contributes to a reduction in CO2 emissions from existing CHP installations and makes it possible to avoid a costly upgrade of biogas to the natural gas quality as well as engine modifications. Moreover, this approach allows the use of natural gas as a “fallback” solution in the case of eventual variations of the biogas composition and or shortage of biogas, providing improved availability. In this study, the performance of a commercial 100kW micro gas turbine (MGT) is experimentally evaluated when fed by varying mixtures of natural gas and biogas. The MGT is equipped with additional instrumentation, and a gas mixing station is used to supply the demanded fuel mixtures from zero biogas to maximum possible level by diluting natural gas with CO2. A typical biogas composition with 0.6 CH4 and 0.4 CO2 (in mole fraction) was used as reference, and corresponding biogas content in the supplied mixtures was computed. The performance changes due to increased biogas share were studied and compared with the purely natural gas fired engine. This paper presents the test rig setup used for the experimental activities and reports results, demonstrating the impact of burning a mixture of biogas and natural gas on the performance of the MGT. Comparing with when only natural gas was fired in the engine, the electrical efficiency was almost unchanged and no significant changes in operating parameters were observed. It was also shown that burning a mixture of natural gas and biogas contributes to a significant reduction in CO2 emissions from the plant.

Measurements of Laminar Flame Speeds of Alternative Gaseous Fuel Mixtures

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Ahmed S. Ibrahim ◽  
Samer F. Ahmed
Keyword(s):  
Carbon Dioxide ◽  
Alternative Fuels ◽  
Laminar Flame ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Gaseous Fuel ◽  
Combustion Engines ◽  
Liquefied Petroleum Gas ◽  
Ambient Conditions ◽  
Fuel Mixtures

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.

Optimizing the Quantity of Diesel Fuel Injection by Using 25HHOCNG Gas Fuel Mixture

2015 ◽  
Vol 14 ◽  
pp. 36-45 ◽  
Author(s):  
Hüseyi̇n Turan Arat ◽  
Mustafa Kaan Baltacioğlu ◽  
Mustafa Özcanli ◽  
Kadir Aydın
Keyword(s):  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Injection Technique ◽  
Fuel Pump ◽  
Pump Plunger ◽  
Fuel Mixtures ◽  
Diesel Fuel Injection

Injection behaviors of internal combustion engines are very substantial fact that provides developments to future strategies about optimizing the engine and fuel parameters. During the combustion process, pilot diesel injection technique is more preferable option while using alternative gas fuels in a diesel engine. In this experimental study, a 3.6 L commercial, four stroke, four cylinders and mechanical fuel pump non-modified diesel test engine operated with hydroxy (HHO) and compressed natural gas (CNG) fuel mixtures under 25% and 75% (vol/vol), respectively. Diesel fuel injection quantities were reduced with the help of steeping motor devices which mounted on mechanical fuel pump plunger pin. Sensitive removes of steeping motor, plunger pin twisted clockwise 360°, 720° and 1080°, respectively. Comparisons of engine performance and exhaust emissions were explained briefly and illustrated via graphs. As a result, 720° clockwise twisted pin is the optimum point for experimental fuel pump plunger while using 25HHOCNG fuel mixtures.

Fast-Burn Combustion Chamber Design for Natural Gas Engines

1998 ◽  
Vol 120 (1) ◽  
pp. 232-236 ◽  
Author(s):  
R. L. Evans ◽  
J. Blaszczyk
Keyword(s):  
Combustion Chamber ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Performance Parameters ◽  
Combustion Chambers ◽  
Natural Gas Engines ◽  
Chamber Design ◽  
Performance And Emissions ◽  
Unburned Hydrocarbons ◽  
Fuel Mixtures

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.

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