An Investigation of a Cause of Backfire and Its Control Due to Crevice Volumes in a Hydrogen Fueled Engine

2000 ◽  
Vol 123 (1) ◽  
pp. 204-210 ◽  
Author(s):  
J. T. Lee ◽  
Y. Y. Kim ◽  
C. W. Lee ◽  
J. A. Caton
Keyword(s):  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Ring Groove ◽  
Fundamental Study ◽  
Fuel Supply ◽  
Spark Plug

To understand the occurrence of backfire in hydrogen fueled engines using an external (inducted) fuel supply, a fundamental study was completed using a modified experimental engine. A relation was found between the crevice volume in the combustion chamber and the occurrence of backfire. The results showed that the crevice around the spark plug electrode was not a major cause of backfire, but the combustion state of the mixture in the piston top land crevice, second land, and ring groove did have a direct affect on backfire occurrence. By increasing the top land crevice volume and the amount of blow-by gas, the equivalence ratio before backfire occurred was extended.

scholarly journals Моделювання якісного складу паливно-повітряної суміші у факельному запальнику камер згоряння ГТД

2021 ◽  
pp. 39-47
Author(s):  
Юрій Іванович Торба ◽  
Дмитро Вікторович Павленко ◽  
Віталій Вікторович Манжос
Keyword(s):  
Numerical Model ◽  
Combustion Chamber ◽  
Operating Conditions ◽  
Main Task ◽  
Qualitative Composition ◽  
Engine Operation ◽  
Fuel Supply ◽  
Excess Air ◽  
Spark Plug ◽  
Torch Igniter

The qualitative composition of the fuel-air mixture, which is formed in the torch igniter of the combustion chamber of the gas turbine engine (GTE), determines the efficiency and reliability of their work. The main task of the study is to determine the qualitative composition of the fuel-air mixture near the electric spark plug of the GTE torch igniter depending on its geometric features and engine operation condition. The composition of the mixture was evaluated using analytical, experimental, and numerical methods. According to the analytical model, a significant over-enrichment of the fuel-air mixture in the igniter housing was established and confirmed experimentally. A numerical model was used to determine the fields of mass concentration of fuel particles in the fuel-air mixture in the torch igniter housing, considering the peculiarities of airflow and fuel supply for different combinations of GTE design features and operating conditions. The influence of geometric parameters of the housing and external factors was investigated using the numerical model of stationary combustion of fuel-air mixture, which was prepared in the torch igniter housing of GTE combustion chamber by evaporation and spraying of aviation kerosene particles in the air stream. The implementation of a small-factor experiment allowed to establish the degree of influence of each factor under study and their interaction on the excess air coefficient. The correlation coefficient between the coefficient of excess air near the spark plug and the average flame temperature is set. Given the absence of serial designs of controller torch ignites, it is proposed to use a pulsed fuel supply to control the quality of the fuel-air mixture. Further ways of research to increase the reliability of ignition of both the torch igniter from the electric spark plug and the combustion chamber of GTE from the flame is outlined.

scholarly journals Analysis of Product and Temperature of Biogas Combustion in Various Air Biogas Equivalence Ratio and Methane Content

2018 ◽  
Vol 18 (2) ◽  
pp. 211
Author(s):  
Arini Wresta ◽  
Aep Saepudin
Keyword(s):  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Methane Content ◽  
Combustion Reaction ◽  
Combustion Characteristic ◽  
Inert Material ◽  
Complete Combustion ◽  
Combustion Gases ◽  
Degraded Material ◽  
Higher Temperature

Biogas resulted from anaerobic digestion of organic compounds have various methane content depend on the type of the degraded material. The methane content of biogas is range between 40–80% that influence the heating value and combustion characteristic of that biogas. The higher methane content can be obtained through upgrading biogas by removing CO2 and other trace components like H2S, NH3, and water vapor. This research was a simulation of product composition and temperature of biogas combustion in various methane content and air biogas equivalence ratio. Biogas combustion was done in combustion chamber at constant pressure of 1 atm. Biogas and air enter into combustion chamber at temperature approximately of 30 °C as the common ambient temperature in Indonesia. The input air was designed higher than stoichiometric need in order to reach complete combustion. Combustion reaction between methane and O2 then carried out in the combustion chamber to produce CO2 and H2O. The product gases consisting of CO2, H2O, N2, and excess O2, bring heat from combustion reaction and exit from combustion chamber at the higher temperature. The analysis was done for methane content range between 20 and 100% with air biogas equivalence ratio from 1 until 3. The simulation result showed that for V m3 biogas, the combustion gases could reach 0.12271 until 1.26798V gmol with temperature above 700 °C until above 1900 °C. More than 50% component in the combustion gases is N2 as inert material from input air to combustion chamber.

Simulation of Pollutant Emissions in a Small-Sized Combustion Chamber With a Gas Fuel for Various Regime Modes

2019 ◽  
Author(s):  
Nikita I. Gurakov ◽  
Ivan A. Zubrilin ◽  
Ivan V. Chechet ◽  
Vladislav M. Anisimov ◽  
Sergey S. Matveev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Products ◽  
Pollutant Emissions ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Combustion Processes

Abstract The study shows the results of the emission simulation in a small-sized combustion chamber. The influence of temperature and equivalence ratio on CO and CxHy in the combustion chamber was investigated. Experiments and calculations were carried out for the following modes: temperature at the inlet of the combustion chamber Tinlet = 323 ... 523 K; equivalence ratio φ = 0.2 ... 0.33; normalized flow rate at the inlet of the combustion chamber λ = 0.1 ... 0.3. The simulation of combustion of natural gas was carried out. The studies were conducted using CFD software and experimental methods. Measurements of the combustion products composition were carried out by the method of sampling collection and subsequent chromatographic analysis. The flow and combustion processes were simulated in a three-dimensional steady formulation using the Reynolds-averaged Novier-Stokes equations (RANS) and in a transient formulation using the Large Eddy Simulation (LES) method. The combustion processes were simulated by Flamelet Generated Manifold model in conjunction with the probability density function method (PDF). In addition to the above methods, the method of the reactor network model (RNM) was used to simulate the emission. As a result, a comparison of the calculated and experimental data of concentrations values of combustion products and emissions indices averaged over the combustion chamber outlet was conducted. According to the results of the calculated-experimental study obtained: - the simulated concentrations values of the main combustion products such as CO2 and H2O qualitatively and quantitatively coincide with the experimental data (the discrepancy is less than 5%) for all three approaches — RANS, LES, RNM; - when modeling CO emissions, the discrepancy between the calculated emission indices obtained by the RANS and LES methods is greatly underestimated relative to the experimental data, whereas the values calculated by the RNM method deviate from the experiment by less than 10%; - mass concentration values of unburned hydrocarbons obtained by the RANS method are overestimated relative to the experimental values, while using the LES with RNM methods, the discrepancy does not exceed 10%.

THE OXIDATION, IGNITION, AND DETONATION OF FUEL VAPORS AND GASES: XV. THE CONCENTRATION OF FINELY DIVIDED CARBON IN TOWN GAS-AIR MIXTURES REQUIRED TO INDUCE SEVERE KNOCKING COMBUSTION

1950 ◽  
Vol 28f (6) ◽  
pp. 177-188
Author(s):  
R. O. King ◽  
E. J. Durand ◽  
A. B. Allan
Keyword(s):  
Combustion Chamber ◽  
Volume Ratio ◽  
Lubricating Oil ◽  
Carbon Deposit ◽  
Gaseous Fuels ◽  
Measured Rate ◽  
Spark Plug ◽  
Crank Angle

When using gaseous fuels for the C.F.R. engine, the lubricating oil decomposed to finely divided carbon when the gas was hydrogen and optimum spark advance nearly zero. When town gas was used, optimum spark advance varied from 85 to 15 degrees of crank angle, according to mixture strength, and the lubricant yielded carbon of the hard adherent graphitic variety. When using an L head engine having a combustion chamber with a large surface-to-volume ratio and with the spark plug so placed that optimum spark advance for town gas was approximately half that required with the C.F.R. engine, no appreciable carbon deposit of any variety was obtained. Conditions were therefore such that knocking combustion observed on adding finely divided carbon to the gas–air mixture was not caused to any appreciable degree by carbon derived from the lubricant. It was then found on adding carbon, as graphite dust, at a measured rate to the entering mixture, that approximately 0.3 mgm. in the end gas caused a knock intensity of the degree required to reduce brake horsepower by from 10 to 14%.

Modifications to Quasi-Dimensional Burning Model of Spark Ignition Engines

2009 ◽  
Author(s):  
M. R. Modarres Razavi ◽  
A. Hosseini ◽  
M. Dehnavi
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Numerical Solution ◽  
Taylor Expansion ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
Algebraic Functions ◽  
Spark Plug ◽  
Burning Model

The way in which position of spark plug affects combustion in a spark ignition engine can be analyzed by using two-zone burning model. The purpose of this paper is to extract correlations to simulate the geometric interaction between the propagating flame and the general cylindrical combustion chamber. Eight different cases were recognized. Appropriate equations to calculate the flame area (Af), the burned and the unburned volume (Vb & Vu) and the heat transfer areas related to the burned and unburned regions were derived and presented for each case using Taylor expansion in order to replace numerical solution with trigonometric algebraic functions.

scholarly journals Analisa posisi derajat tonjolan magnet (trigger magnet) pada konsumsi bahan bakar

2018 ◽  
Vol 1 (1) ◽  
pp. 42
Author(s):  
Fatkur Rhohman ◽  
Susdi Subandriyo ◽  
Hesti Istiqlaliyah
Keyword(s):  
Combustion Chamber ◽  
Electric Current ◽  
High Voltage ◽  
Rotation Rate ◽  
Combustion Process ◽  
Engine Performance ◽  
Ignition System ◽  
Spark Plug ◽  
Significant Difference ◽  
Independent Variable

In automotive, many various modifications are made to improve engine performance. One that is done is to maximize the combustion that occurs in the combustion chamber. By maximizing the ignition system in the combustion process, it is expected to enlarge sparks from spark plugs. One of the components affecting the combustion process is Magnet, serves to generate electricity that will become a high voltage electric current and allow the occurrence of spark jumps on the spark plug. In this study, the independent variable is the modified tregger magnet which is reversed 0.50, to 9.50 and 90. in general there is no significant difference. Fcount value for result on magnetic trigger type = 3.00 <F (0.05; 2.24) = 3.40 (rejected H0) means reversing the 90 and 9.50 magnetic triggers does not significantly influence. In addition, Fcount for 6000, 7000, 8000 rpm engine yield = 1.00 <F (0.05; 2.24) = 3.40 (Rejected H0) means the engine's rotation rate has no significant effect. So there is no effect of fuel consumption on the modified magnetic trigger, nor at rpm 6000, rpm 7000 and rpm 8000.

scholarly journals Experimental study on combustion of CH4/NH3 fuel blends in an industrial furnace operated in flameless conditions

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3625-3635
Author(s):  
Rafal Slefarski ◽  
Pawel Czyzewski ◽  
Michal Golebiewski
Keyword(s):  
Experimental Study ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Molar Fraction ◽  
Combustion Process ◽  
Steel Production ◽  
Methane Combustion ◽  
Efficient Technology ◽  
Flameless Combustion ◽  
Fuel Blends

This paper presents the results of an experimental study on the combustion process of methane mixed with NH3 in flameless mode. At a time of striving for CO2-free power, NH3 became a potential energy storage carrier fuel from renewable sources. Flameless combustion features low emissions and is a very efficient technology used in the power sector, as well as steel production, ceramics, etc. Industrial furnaces were tested in the context of pure methane combustion with an addition of NH3, up to 5%. Flameless combustion conditions were achieved with a regenerative gas burner system (high regenerative system). The burner consists of four ceramic regenerators allowing for continuous preheating of air, even up to 50 K lower than the temperature of the combustion chamber wall. Constant power of the introduced fuel was kept at 150 kW and the fuel-air equivalence ratio ranged from 0.75 to 0.95. The results have shown a growth of molar fraction of NO in flue gases when NH3 content in the fuel rose. The increase is more significant for the tests with a higher amount of oxygen in the combustion chamber (a lower fuel-air equivalence ratio). An addition of 5% of NH3 into the fuel caused an emission of NO at the levels of 113 ppmv and 462 ppmv (calculated to O2 = 0%), respectively for low and high fuel-air equivalence ratios.

scholarly journals Effect of Using Power Air Screw And Cyclone On Air – Fuel Equivalence Ratio And Monoxide Carbon Gas Emissions In Four Stroke Gasoline Engines

Tibuana ◽  
2021 ◽  
Vol 4 (01) ◽  
pp. 49-54
Author(s):  
Syamsul Arifin
Keyword(s):  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Fuel Mixture ◽  
Petrol Engine ◽  
Gas Emissions ◽  
Gasoline Engines ◽  
The Third

The experience is observed for fourstrokes petrol engine for revolution 1000 rpm - 4000 rpm, with used of power air screw oncarburator and cyclone on outlet intakemanifold. Air – fuel mixture have passed ofcyclone to combustion chamber to becometurbulent flow and homogen. Then theexperience of step by step used power screwand cyclone. The first investigation on standarcondition, the second put of power air screwon carburator, the third put of cyclone on outletintake manifold, the fourth put of combinationof power air screw and cyclone. It wasobserving for increasing air – fuel equivalenceratio and reduction of exhaust COconcentration. Actually, used combination ofpower air screw and cyclone are resulted ofcarbon monoxide concentration drop ofenough significant for 2500 rpm and 4000 rpm,respectively 51% and 67%. The carbonmonoxide least concentration is 1,14% oncondition 4000 rpm.

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