A Theoretical Investigation On the Performance and Combustion Parameters in an SI Engine Fueled with Different Shale Gas Mixtures

2020 ◽  
Author(s):  
HABIB GÜRBÜZ ◽  
Serife KÖSE
Keyword(s):  
Shale Gas ◽  
Engine Performance ◽  
Good Alternative ◽  
Combustion Efficiency ◽  
Experimental Results ◽  
Combustion Model ◽  
Si Engine ◽  
Combustion Duration ◽  
Si Engines ◽  
Temperature And Pressure

Abstract In this paper, a theoretical analysis of in-cylinder combustion and indicated engine parameters by using a zero-dimensional, single-zone combustion model presented, in a SI engine operated with shale gas-1(86% CH4, 14% C2H6), shale gas-2 (81% CH4, 10% C2H6, 9% N2), shale gas-3 (58% CH4, 20% C2H6, 12% C3H8, 10% CO2), methane and LPG (30% C3H8, 70% C4H10). The technical characteristics and experimental results (i.e. engine speed, throttle position, intake air temperature and pressure, combustion duration and combustion efficiency) of a single-cylinder SI engine operated with LPG was processed for developing of theoretical combustion model. Also, the results of the theoretical combustion model by LPG fuel and the experimental results by LPG operated SI engine are compared and provided to the validation of the theoretical model. The results showed that the shale gas-1 has the potential to be a good alternative fuel for SI engines soon with an average engine performance of 6.4% lower than LPG in the range of ?=0.83-1.2. Also, methane has an average engine performance of 8.5% lower than LPG. However, shale gas-2 and shale gas-3 caused an average 21% decline at the engine performance.

The Lean Mixture Operational Limits of a Spark Ignition Engine When Operated on Fuel Mixtures

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Lean Mixture ◽  
Si Engines ◽  
Unstable Combustion ◽  
Fuel Mixtures ◽  
Traditional Approaches ◽  
Combustion Processes

The operation of spark ignition (SI) engines on lean mixtures is attractive, in principle, since it can provide improved fuel economy, reduced tendency to knock, and extremely low NOx emissions. However, the associated flame propagation rates become degraded significantly and drop sharply as the operating mixture is made increasingly leaner. Consequently, there exist distinct operational lean mixture limits beyond which satisfactory engine performance cannot be maintained due to the resulting prolonged and unstable combustion processes. This paper presents experimental data obtained in a single cylinder, variable compression ratio, SI engine when operated in turn on methane, hydrogen, carbon monoxide, gasoline, iso-octane, and some of their binary mixtures. A quantitative approach for determining the operational limits of SI engines is proposed. The lean limits thus derived are compared and validated against the corresponding experimental results obtained using more traditional approaches. On this basis, the dependence of the values of the lean mixture operational limits on the composition of the fuel mixtures is investigated and discussed. The operational limit for throttled operation with methane as the fuel is also established.

Performance enhancement using different nitromethane blends in a small two-stroke engine

2021 ◽  
pp. 1-33
Author(s):  
Raviteja Sammeta ◽  
Ramakrishna PA ◽  
Asvathanarayanan Ramesh
Keyword(s):  
Performance Enhancement ◽  
Combustion Efficiency ◽  
Si Engine ◽  
Fuel Blend ◽  
Emission Analysis ◽  
Marginal Value ◽  
Lower Heating Value ◽  
Si Engines ◽  
Hc Emissions ◽  
Alternate Fuels

Abstract Nitromethane being immiscible in gasoline, is often added to methanol to enhance the engine power output. But with the use of methanol as the base fuel, the brake specific fuel consumption (BSFC) of the SI engine often doubles due to its lower heating value. To constrain this increase to a marginal value, a tri-component fuel blend consisting of nitromethane-alcohol-gasoline was prepared and observed to be stable. Methanol, ethanol, and butanol were the chosen alcohols for the tests due to their popularity as alternate fuels for SI engines. Tests on a small (35cc) two-stroke SI engine revealed that the torque produced with the use of tri-component blends was comparable to nitromethane-methanol blend and was on an average 1.35 times higher than gasoline. However, the BSFC with the nitromethane-butanol-gasoline blend was 50% lower than nitromethane-methanol blend and was only 14% higher than gasoline. The emission analysis showed lower HC emissions with the tri-component blends proving the improved combustion efficiency due to better mixing of the fuel-air mixture. Combustion analysis showed the increased heat release rate with nitromethane addition due to its higher flame speeds.

Optimization of combustion and performance parameters by intake-charge conditions in a small-scale air-cooled hydrogen fuelled SI engine suitable for use in piston-prop aircraft

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Habib Gürbüz
Keyword(s):  
Air Temperature ◽  
Alternative Fuels ◽  
Engine Performance ◽  
Wide Area ◽  
Injection Timing ◽  
Performance Parameters ◽  
Si Engine ◽  
Road Vehicles ◽  
Content Type ◽  
Si Engines

Purpose Spark ignition (SI) engines are used in a wide area in the transportation industry, from road vehicles to piston-prop aircraft. On the other hand, the decrease in reserves of fossil fuels used in SI engines and the increase in greenhouse gas emissions makes the use of alternative fuels inevitable. In this paper, optimization of in-cylinder combustion and engine performance parameters by intake-charge conditions [i.e. intake-air temperature, injection timing and exhaust gas recirculation (EGR)] in a hydrogen (H2)-fueled small SI engine is performed. Design/methodology/approach Experimental studies were performed at a 1,600 rpm engine speed of a single-cylinder, air-cooled engine having a stroke volume of 476.5 cm3, maximum output power of 13 HP and torque of 25 Nm. The hydrogen-fueled SI engine was operated by a lean air-fuel mixture (ϕ = 0.6) under wide-open throttle (WOT) conditions. Findings The findings of the paper show that improvements can be achieved in in-cylinder combustion, indicated engine performance, exhaust NOx emissions with optimum intake-air temperature, the start of H2 injection and the ERG rate. Practical Implications It has been determined that a 32°C intake-air temperature, 395°C (bTDC) start of H2 injection, and 5%–10% EGR rates are the most suitable values for the examined hydrogen fueled SI engine. Originality Value Hydrogen is a usable alternative fuel for SI engines used in a wide area from road vehicles to piston-prop aircraft engines. However, a number of problems remain that limit hydrogen fueled SI engines to some extent, such as backfire, a decrease of engine power, and high NOx emissions. Therefore, it is appropriate to examine the effects of intake-charge conditions on in-cylinder combustion, engine performance, and NOx emissions parameters in a hydrogen fuelled SI engine.

Modeling of NOx Emissions Using a Super-Extended Zel’dovich Mechanism

2003 ◽  
Author(s):  
Huateng Yang ◽  
Sundar R. Krishnan ◽  
Kalyan K. Srinivasan ◽  
K. Clark Midkiff
Keyword(s):  
Diesel Engine ◽  
Reaction Scheme ◽  
Combustion Model ◽  
Nox Emissions ◽  
Si Engine ◽  
Nox Formation ◽  
Natural Gas Engines ◽  
Lean Combustion ◽  
Temperature And Pressure ◽  
The Difference

A kinetic model for NOx production has been developed to predict NOx emissions. The reaction scheme is a modified super-extended Zel’dovich mechanism (SEZM), which includes 43 reactions and 20 species instead of just the three reactions typically used in the extended Zel’dovich mechanism. The NOx emissions predicted by both mechanisms are compared using two separate models. First, a theoretical investigation of the two mechanisms is made for an SI engine using prescribed temperature and pressure histories. Then each of the two mechanisms is combined with a phenomenological combustion model for a single-cylinder Caterpillar 3400 series diesel engine to calculate the NOx emissions. The predictions from both mechanisms are compared with experimental results. It is shown that the SEZM can predict NOx emissions more accurately than the extended Zel’dovich mechanism. Results show that the SEZM increases the predicted NOx by about 25 percent. The difference between the two models is more pronounced for lean combustion, in which NO2 and NH play an important role in the NOx formation. In addition, the effects of several parameters on diesel engine NOx production are investigated. The super-extended Zel’dovich mechanism for NOx formation is expected to be more appropriate for lean combustion, such as in diesel or natural gas engines and other engines that typically operate at lean conditions.

Simulation of Fuel Droplet Gasification in SI Engines

1984 ◽  
Vol 106 (4) ◽  
pp. 849-853 ◽  
Author(s):  
X. Q. Liu ◽  
C. H. Wang ◽  
C. K. Law
Keyword(s):  
Upper Bounds ◽  
Fuel Droplet ◽  
Gas Temperature ◽  
Lower And Upper Bounds ◽  
Si Engine ◽  
Initial Size ◽  
Compression Stroke ◽  
Gasification Rate ◽  
Si Engines ◽  
Temperature And Pressure

The heating and gasification of a fuel droplet during the intake and compression strokes of an SI engine are modeled. Results show that the simultaneous increases in the gas temperature and pressure during compression tend to have compensatory effects on the droplet gasification rate such that it remains somewhat insensitive to changes in the cylinder environment. Generalized results are presented allowing for the assessment of the lower and upper bounds in the initial size of the droplet that can achieve complete gasification prior to the end of the compression stroke.

Performance improvement of turbocharged SI engine by post-oxidation enhancement in exhaust gas in-homogeneity

2020 ◽  
pp. 146808742096087 ◽  
Author(s):  
Madan Kumar ◽  
Salaar Moeeni ◽  
Tatsuya Kuboyama ◽  
Yasuo Moriyoshi
Keyword(s):  
Performance Improvement ◽  
Experimental Validation ◽  
Engine Performance ◽  
Simulation Models ◽  
Experimental Results ◽  
Exhaust Gas ◽  
Exhaust Manifold ◽  
Si Engine ◽  
Exhaust Port ◽  
Design And Implementation

In this research, the improvement of mixing and pulsation in exhaust manifold with a design and implementation of bypass adapter at exhaust port were deeply investigated. This in-turn can improve the post-oxidation phenomena and hence emissions and engine performance could be enhanced. This research investigation includes 1-D, 3-D simulations and experimental validation on a 4-cylinder turbocharged spark ignition (SI) engine. Firstly, the 1-D and 3-D simulation models were developed and calibrated with the experimental results. Then, the simulations were used for the detailed investigation of mixing and pulsation in exhaust manifold with and without bypass adapter. Thereafter, experimental test for the post-oxidation were conducted with and without consideration of the bypass adapter and results were compared. From the simulation and experimental results, it was proven that by using bypass adapter at the exhaust port, the mixing of exhaust gas species was observed to be significantly improved to some extent. Also, the unbalance between exhaust port and turbocharger upstream gas species were reduced. This also reduced the exhaust gas pulsation. By the improvement of mixing between scavenged O2 and unburned gas species, the post-oxidation reaction was also noted to have improved and consequently the emissions and turbo-speed were found to be better that led to an improved IMEP and thermal efficiency of the engine.

scholarly journals Parametric Optimization in SI Engine Fuelled With Gasoline-Ethanol Blends Using Response Surface Methodology

2019 ◽  
Vol 8 (6) ◽  
pp. 2336-2345 ◽  
Keyword(s):  
Fossil Fuels ◽  
Engine Performance ◽  
Loading Conditions ◽  
Si Engine ◽  
Constant Loading ◽  
Octane Rating ◽  
Si Engines ◽  
Ethanol Blends ◽  
Ethanol Ethanol ◽  
The Given

Alcohols are a unit gaining attention everywhere in the world has an alternate to gasolene. Among alcoholic alternative combustible fuels such as Biogas, Hydrogen, Methanol, Biodiesel and Ethanol, Ethanol is the best-listed alternative renewable and neat fuel for Spark Ignition (SI) engines as blends in various fractions boosts the oxygen content, leads to promising minimum emissions as compared to non-blended fossil fuels. Non-oxygenated gasoline-ethanol blends were prepared, with 5% to 35 % ethanol to boost the Octane rating. Iso-octane is also added in to the blends as an additive (3% to 5%). The results from the engine test for the prepared blends at constant loading conditions are analyzed and optimized by RSM and DoE. It was found that at E30 blend with 5% Iso-octane additive found minimum BSFC and higher BTE. The emission characteristics like CO, CO2, HC, and NO2 are quite low for the given maximum constant loading conditions (9kg) with setted Compression Ratio (9) and at rated speed. The perceptions produced using the test that E30 blends and 5% of additive Iso-Octane have come about better engine performance' and least 'emitants' when contrasted with other tested blends.

Engine Capability Prediction for Spark Ignited Engine Fueled With Syngas

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Hui Xu ◽  
Leon A. LaPointe
Keyword(s):  
Natural Gas ◽  
Solid Waste ◽  
Combustion Engine ◽  
Flame Temperature ◽  
Engine Performance ◽  
Nox Emissions ◽  
Si Engine ◽  
Lean Burn ◽  
Gaseous Fuels ◽  
Combustion Duration

Abstract There are increasing interests in converting solid waste or lignocellulosic biomass into gaseous fuels and using reciprocating internal combustion engine to generate electricity. A widely used technique is gasification. Gasification is a process where the solid fuel and air are introduced to a partial oxidation environment, and generate combustible gaseous called synthesis gas or syngas. Converting solid waste into gaseous fuel can reduce landfill and create income for process owners. However, it can be very challenging to use syngas on a gaseous fueled spark ignited (SI) engine, such as a natural gas (NG) engine. NG engines are typically developed with pipeline quality natural gas (PQNG). NG engines can operate at lean burn spark ignited (LBSI), or stoichiometric with exhaust gas recirculation (EGR) spark ignited (SESI) conditions. This work discusses the LBSI engine condition. NG engines can perform very differently when fueled with nonstandard gaseous fuels such as syngas without appropriate tuning. It is necessary to evaluate engine performance in terms of combustion duration, relative knock propensity, and NOx emissions for such applications. Due to constraints in time and resources it is often not feasible to test such fuel blends in the laboratory. An analytical method is needed to predict engine performance in a timely manner. This study investigated the possibility of using syngas on an SI engine developed with PQNG. Engine performance was predicted using in house developed models and PQNG as the reference fuel. Laminar flame speed (LFS), adiabatic flame temperature (AFT), and auto-ignition interval (AI) are used to predict combustion duration, engine out NOx and engine knock propensity relative to NG at the target lambda values. Single cylinder research engine data obtained under lean burn conditions fueled with PQNG was selected as the baseline. LFS, AFT, and AI of syngas were computed at reference conditions. Lambda of operation was predicted for syngas to provide the same burn rate as NG at the reference lambda value for NG. Analysis shows that, using syngas at the selected lambda, the engine can have less engine out NOx emissions and less knock propensity relative to NG at the same speed and load. Modifications to fuel system components may be required to avoid engine derate.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

Sign in / Sign up

Export Citation Format

Share Document