An Experimental Study of Cyclic Variations in a Lean Burn Natural Gas Fuelled Spark Ignition Engine

2003 ◽  
Author(s):  
A. Ramesh ◽  
Mohand Tazerout ◽  
Olivier Le Corre
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Pressure Rise ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
High Rate ◽  
Lean Burn ◽  
Complete Combustion ◽  
Average Value ◽  
Indicated Mean Effective Pressure

This work deals with the nature of cycle by cycle variations in a single cylinder, lean burn, natural gas fuelled spark ignition engine operated at a constant speed of 1500 rev/min under variable equivalence ratio, fixed throttle conditions. Cycle by cycle variations in important parameters like indicated mean effective pressure (IMEP), peak pressure, rate of pressure rise and heat release characteristics were studied. At the lean misfire limit there was a drastic increase in combustion duration. With mixtures leaner than the lean limit, good cycles generally followed poor cycles. However, the vice versa was not true. Cycles that had a high initial heat release rate lead to more complete combustion. A high rate of pressure rise led to a high IMEP. The IMEP of cycles versus their frequency of occurrence was symmetric about the average value when the combustion was good.

Optical analysis of flame inception and propagation in a lean-burn natural-gas spark-ignition engine with a bowl-in-piston geometry

2019 ◽  
Vol 21 (9) ◽  
pp. 1584-1596 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Flame Propagation ◽  
Diesel Engines ◽  
Pressure Rise ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Expansion Velocity ◽  
Cylinder Pressure ◽  
Lean Burn ◽  
Piston Bowl

Heavy-duty diesel engines can convert to lean-burn natural-gas spark-ignition operation through the addition of a gas injector in the intake manifold and of a spark plug in place of the diesel injector to initiate and control combustion. However, the combustion phenomena in such converted engines usually consist of two distinct stages: a fast-burning stage inside the piston bowl followed by a slow-burning stage inside the squish area. This study used flame luminosity data and in-cylinder pressure measurements to analyze flame propagation inside a bowl-in-piston geometry. The experimental results showed a low coefficient of variation and standard deviation of peak cylinder pressure, moderate rate of pressure rise, and no knocking for the lean-burn (equivalence ratio 0.66), low-speed (900 r/min), and medium-load (6.6 bar IMEP) operating condition. Flame inception had a strong effect on the flame expansion velocity, which increased fast once the flame kernel established, but it reduced near the bowl edge and the entrance of the narrow squish region. However, the burn inside the bowl was very fast. In addition, the long duration of burn inside the squish indicated a much lower flame propagation speed for the outside-the-bowl combustion, which contributed to a long decreasing tail in the apparent heat release rate. Furthermore, cycles with fast flame inception and fast burn inside the bowl had a similar end of combustion with cycles with delayed flame inception and then a retarded burn inside the bowl, which indicated that the combustion inside the squish region determined the combustion duration. Overall, the results suggested that the spark event, the flame development inside the piston bowl, and the start of the second combustion stage affected the phasing and duration of the two combustion stages, which (subsequently) can affect engine efficiency and emissions of diesel engines converted to a lean-burn natural-gas spark-ignition operation.

Hydrogen Blended Natural Gas Operation of a Heavy Duty Turbocharged Lean Burn Spark Ignition Engine

2004 ◽  
Author(s):  
S. R. Munshi ◽  
C. Nedelcu ◽  
J. Harris ◽  
T. Edwards ◽  
J. Williams ◽  
...  
Keyword(s):  
Natural Gas ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Heavy Duty ◽  
Lean Burn

Lean Burn Natural Gas Spark Ignition Engine - An Overview

2003 ◽  
Author(s):  
A. Manivannan ◽  
P. Tamil Porai ◽  
S. Chandrasekaran ◽  
R. Ramprabhu
Keyword(s):  
Natural Gas ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn

Laser Spark Ignition: Laser Development and Engine Testing

2004 ◽  
Author(s):  
Michael H. McMillian ◽  
Steven D. Woodruff ◽  
Steven W. Richardson ◽  
Dustin L. McIntyre
Keyword(s):  
Natural Gas ◽  
Laser System ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Engine Operation ◽  
Natural Gas Engines ◽  
Laser Spark ◽  
Engine Testing ◽  
Laser Spark Ignition

Evermore demanding market and legislative pressures require stationary lean-burn natural gas engines to operate at higher efficiencies and reduced levels of emissions. Higher in-cylinder pressures and leaner air/fuel ratios are required in order to meet these demands. Contemporary ignition systems, more specifically spark plug performance and durability, suffer as a result of the increase in spark energy required to maintain suitable engine operation under these conditions. This paper presents a discussion of the need for an improved ignition source for advanced stationary natural gas engines and introduces laser spark ignition as a potential solution to that need. Recent laser spark ignition engine testing with natural gas fuel including NOx mapping is discussed. A prototype laser system in constructed and tested and the results are discussed and solutions provided for improving the laser system output pulse energy and pulse characteristics.

Lean Burn Performance of a Natural Gas Fuelled, Port Injected, Spark Ignition Engine

2012 ◽  
Author(s):  
Payman Abbasi Atibeh ◽  
Peter A. Dennis ◽  
Pedro J. Orbaiz ◽  
Michael J. Brear ◽  
Harry C. Watson
Keyword(s):  
Natural Gas ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn

An experimental study the impact of the hydrogen enrichment on cycle-to-cycle variations of the large bore and lean burn natural gas spark-ignition engine

Fuel ◽  
2020 ◽  
Vol 282 ◽  
pp. 118868 ◽  
Author(s):  
Xiongbo Duan ◽  
Banglin Deng ◽  
Yiqun Liu ◽  
Shunzhang Zou ◽  
Jingping Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Hydrogen Enrichment ◽  
The Impact

Effect of Hydrogen Addition on Combustion Characteristics of a Spark Ignition Engine Fueled With Low Heat Value Gas

2011 ◽  
Vol 197-198 ◽  
pp. 688-691
Author(s):  
Zhung Qing Hu ◽  
Xin Zhang
Keyword(s):  
Spark Ignition ◽  
Combustion Characteristics ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Hydrogen Addition ◽  
Indicated Mean Effective Pressure ◽  
Excess Air ◽  
Heat Value ◽  
Hc Emissions ◽  
Engine Power

An experimental investigation on the effect of hydrogen fraction on the combustion characteristics of a spark ignition engine fueled with low heat value gas-hydrogen blends was studied. The results show that engine indicated thermal efficiency, indicated mean effective pressure and maximum combustion pressure are increased with the increase of hydrogen fraction in the blends. And hydrogen addition shows remarkable influence on engine power and emissions. At the same excess air ratio, HC emissions decrease, CO and NOxemissions increase with the increase of hydrogen fraction in the blends. And engine power is influenced by both hydrogen fraction and heat value in low heat value gas-hydrogen blends combining. Hydrogen significant extends the lean burn limit of combustion of low heat value gas.

Experimental Examination of Prechamber Heat Release in a Large Bore Natural Gas Engine

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Daniel B. Olsen ◽  
Allan T. Kirkpatrick
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Equivalence Ratio ◽  
Dynamic Pressure ◽  
Pressure Rise ◽  
Main Chamber ◽  
Lean Burn ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Common Solution

A common solution in reducing NOx emissions to meet new emission regulations has been lean burn combustion. However, with very lean air∕fuel (A∕F) ratios, both carbon monoxide and hydrocarbon emissions become unacceptably high due to the spark misfiring and combustion instabilities. In order to mitigate this, a prechamber ignition system is often used to stabilize combustion at very lean A∕F ratios. In this paper, the heat release in a retrofit prechamber system installed on a large bore natural gas engine is examined. The heat release analysis is based on dynamic pressure measurements both in the main chamber and prechamber. The Woschni correlation is utilized to model heat transfer. Based on heat release modeling and test data analysis, the following observations are made. Main chamber heat release rates are much more rapid for prechamber ignition compared to spark ignition. During combustion in the prechamber, much of the fuel flows into the main chamber unreacted. About 52% of the mass in the prechamber, at ignition, flows into the main chamber during prechamber combustion. Prechamber total heat release, pressure rise, and maximum jet velocity all increase with increasing prechamber equivalence ratio. Prechamber combustion duration and coefficient of variation of peak pressure are minimized at a prechamber equivalence ratio of about 1.09.

The impact of gasoline and synthesized ethanol blends on the emissions of a spark ignition engine

2014 ◽  
Vol 11 (4) ◽  
pp. 391-396 ◽  
Author(s):  
Laminu Kuburi ◽  
David Obada ◽  
Ibraheem Samotu ◽  
M. Jeremiah ◽  
Zainab Kashim
Keyword(s):  
Alternative Fuels ◽  
Combustion Products ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Complete Combustion ◽  
Ethanol Addition ◽  
Hc Emissions ◽  
Ethanol Blends ◽  
The Impact

Considering pollution problems and the energy crisis today, investigations have been concentrated on lowering the concentration of toxic components in combustion products and decreasing fossil fuel consumption by using renewable alternative fuels. In this work, the effect of ethanol addition to gasoline on the exhaust emissions of a spark ignition engine at various speeds was established. Ethanol was extracted from groundnut seeds using fermentation method. Gasoline was blended with 20 - 80% of the extracted ethanol in an interval of 20%. Results of the engine test indicated that using ethanol-gasoline blended fuels decreased carbon monoxide (CO) and hydrocarbon (HC) emissions as a result of the lean- burn effects caused by the ethanol, and the carbon dioxide (CO2) emission increased because of a near complete combustion. Finally, the results showed that blending ethanol in a proportion of 40% with gasoline can be used as a supplementary fuel in modern spark ignition engines as it is expected that the engine performs at its optimum in terms of air toxic pollutants reduction, by virtue of that mix.

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