scholarly journals CFD Performance Analysis of a Spark Ignition Engine Fueled by Landfill Gas

2014 ◽  
Vol 7 (1) ◽  
pp. 26-33
Author(s):  
Daniel Swain ◽  
S.O. Bade Shrestha

Landfill gas (LFG) that is generated in an anaerobic environment in landfills and consists primarily of methane and carbondioxide with small amount of nitrogen and other non-methane gases, could be collected and used to produce energy either by extracting methane or using the landfill gas directly in an internal combustion engine or a gas turbine. It amounts to be a net-negative greenhouse gas emission process. Carbondioxide component of LFG dilutes the fuel and absorbs some of the heat of combustion, causing reduced flame temperature that decreases NOx emissions and also suppresses knock. A model was developed and validated with the experimental data available in literature, using the computation fluid dynamic (CFD) code, KIVA-4. Various engine performance parameters at various operating conditions were evaluated and the benefits of methane purification and or direct use of LFG as a fuel in the engine scenarios were compared. It was found that landfill gas used directly at higher compression ratios can be used for pure methane fuel with higher fuel efficiency than can be achieved using pure methane fuel only.

Author(s):  
Abazar Shamekhi ◽  
Nima Khatibzadeh ◽  
Amir H. Shamekhi

Nowadays, increased attention has been focused on internal combustion engine fuels. Regarding environmental effects of internal combustion engines particularly as pollutant sources and depletion of fossil fuel resources, compressed natural gas (CNG) has been introduced as an effective alternative to gasoline and diesel fuel in many applications. A high research octane number allows combustion at higher compression ratios without knocking and good emission characteristics of HC and CO are major benefits of CNG as an engine fuel. In this paper, CNG as an alternative fuel in a spark ignition engine has been considered. Engine performance and exhaust emissions have been experimentally studied for CNG and gasoline in a wide range of the engine operating conditions.


2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.


Author(s):  
B. B. Sahoo ◽  
U. K. Saha ◽  
N. Sahoo ◽  
P. Prusty

The fuel efficiency of a modern diesel engine has decreased due to the recent revisions to emission standards. For an engine fuel economy, the engine speed is to be optimum for an exact throttle opening (TO) position. This work presents an analysis of throttle opening variation impact on a multi-cylinder, direct injection diesel engine with the aid of Second Law of thermodynamics. For this purpose, the engine is run for different throttle openings with several load and speed variations. At a steady engine loading condition, variation in the throttle openings has resulted in different engine speeds. The Second Law analysis, also called ‘Exergy’ analysis, is performed for these different engine speeds at their throttle positions. The Second Law analysis includes brake work, coolant heat transfer, exhaust losses, exergy efficiency, and airfuel ratio. The availability analysis is performed for 70%, 80%, and 90% loads of engine maximum power condition with 50%, 75%, and 100% TO variations. The data are recorded using a computerized engine test unit. Results indicate that the optimum engine operating conditions for 70%, 80% and 90% engine loads are 2000 rpm at 50% TO, 2300 rpm at 75% TO and 3250 rpm at 100% TO respectively.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Mateos Kassa ◽  
Carrie Hall ◽  
Michael Pamminger ◽  
Thomas Wallner

Abstract One of the main factors limiting the efficiency of spark-ignited (SI) engines is the occurrence of engine knock. In high temperature and high pressure in-cylinder conditions, the fuel–air mixture auto-ignites creating pressure shock waves in the cylinder. Knock can significantly damage the engine and hinder its performance; as such, conservative knock control strategies are generally implemented which avoid such operating conditions at the cost of lower thermal efficiencies. Significant improvements in the performance of conventional knock controllers are possible if the properties of the knock process are better characterized and exploited in knock controller designs. One of the methods undertaken to better characterize knocking instances is to employ a probabilistic approach, in which the likelihood of knock is derived from the statistical distribution of knock intensity (KI). In this paper, it is shown that KI values at a fixed operating point for single fuel and dual fuel engines are accurately described using a mixed lognormal distribution. The fitting accuracy is compared against those for a randomly generated mixed-lognormally distributed dataset, and shown to exceed a 95% accuracy threshold for almost all of the operating points tested. Additionally, this paper discusses a stochastic knock control approach that leverages the mixed lognormal distribution to adjust spark timing based on KI measurements. This more informed knock control strategy would allow for improvements in engine performance and fuel efficiency by minimizing knock occurrences.


2015 ◽  
Vol 138 (2) ◽  
Author(s):  
N. Morris ◽  
R. Rahmani ◽  
H. Rahnejat ◽  
P. D. King ◽  
S. Howell-Smith

Minimization of parasitic losses in the internal combustion (IC) engine is essential for improved fuel efficiency and reduced emissions. Surface texturing has emerged as a method palliating these losses in instances where thin lubricant films lead to mixed or boundary regimes of lubrication. Such thin films are prevalent in contact of compression ring to cylinder liner at piston motion reversals because of momentary cessation of entraining motion. The paper provides combined solution of Reynolds equation, boundary interactions, and a gas flow model to predict the tribological conditions, particularly at piston reversals. This model is then validated against measurements using a floating liner for determination of in situ friction of an engine under motored condition. Very good agreement is obtained. The validated model is then used to ascertain the effect of surface texturing of the liner surface during reversals. Therefore, the paper is a combined study of numerical predictions and the effect of surface texturing. The predictions show that some marginal gains in engine performance can be expected with laser textured chevron features of shallow depth under certain operating conditions.


2019 ◽  
Vol 179 (4) ◽  
pp. 86-92
Author(s):  
Mieczysław DZIUBIŃSKI ◽  
Ewa SIEMIONEK ◽  
Artur DROZD ◽  
Michał ŚCIRKA ◽  
Adam KISZCZAK ◽  
...  

The article discusses the impact of ignition system damage on the emission of toxic subcategories in a spark-ignition internal combustion engine. The aim of the work was to develop an analytical model of ignition system diagnostics, test performance and comparative analysis of the results of simulations and experiments. The model developed allows to analyse the basic parameters of the ignition system affecting the content of toxic substances in the exhaust. Experimental tests were carried out using the MAHA MGT5 exhaust gas analyser for four different combustion engines fueled with petrol at various operating conditions. During the tests, the content of toxic substances in the exhaust gas of a properly working engine and the engine working with damage to the ignition system were registered. The tests will be used to assess the impact of the damage of the spark-ignition engine on the emission of individual components of toxic fumes.


2019 ◽  
Vol 8 (3) ◽  
pp. 5496-5498

Methanol (CH3OH) and ethanol (C2H5OH) have came to limelight now-a-days because of their property of less polluting emittants and thought of as extremely economical due to its swish operative capacity. Low particulate level and soot free emission can also be obtained due to presence of oxygen in these fuels. We can obtain a considerable fuel efficiency and sound mileage if we double the carbon in ethanol which contains more energy. The structure is more similar to iso-butanol. Iso-butanol is unique in alcoholic fuels due to its equatorial affinity for water. The worldwide energy policy also aims to reduce greenhouse gas emissions occurred due to traditional fuels and thus developing renewable energy became an important part of this policy. Now-a-days transport sector has decreased its reliance on oil which generally contributes to hazardous environmental impact and to achieve this some alternative transport fuels such as biofuels, hydrogen and natural gas emerged up as a helping hand. Blending methanol into diesel and gasoline permits the mixture to possess an entire combustion with the presence of oxygen which increases its combustion efficiency and reduces greenhouse gas emission. Gasohol- a blend of gasoline and 10%methanol is available at plenty of petrol service stations as a regular automobile fuel within the United States. Brazil has successfully implemented and used methanol in terms of spark ignition engine operations as a fuel. Methanol has emerged up as a sustainable fuel for IC engines in past few decades because of its characteristics of soot free burning and higher efficiencies at less cost. The European Union decided to set 10% requirement of renewable energy in transport sector which is to be compiled with by 2020. In 2010, the transport sector utilized 4.70% of renewable energy out of which 91% was covered by biofuels. This paper discusses significance of methanol as a fuel for IC engines and its applicability in various sectors


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6473
Author(s):  
Stanislaw Szwaja ◽  
Michal Gruca ◽  
Michal Pyrc ◽  
Romualdas Juknelevičius

Investigation of a new type of fuel for the internal combustion engine, which can be successfully used in both the power generation and the automotive industries, is presented in this article. The proposed fuel is a blend of 75% n-butanol and 25% glycerol. The engine tests conducted with this glycerol–butanol blend were focused on the performance, combustion thermodynamics, and exhaust emissions of a spark-ignition engine. A comparative analysis was performed to find potential similarities and differences in the engine fueled with gasoline 95 and the proposed glycerol–butanol blend. As measured, CO exhaust emissions increased, NOx emissions decreased, and UHC emissions were unchanged for the glycerol–butanol blend when compared to the test with sole gasoline. As regards the engine performance and combustion progress, no significant differences were observed. Exhaust temperature remarkably decreased by 3.4%, which contributed to an increase in the indicated mean effective pressure by approximately 4% compared to gasoline 95. To summarize, the proposed glycerol–butanol blend can be directly used as a replacement for gasoline in internal combustion spark-ignition engines.


2021 ◽  
Vol 18 (1) ◽  
pp. 12-29
Author(s):  
V. N. Kuznetsova ◽  
R. V. Romanenko

Introduction. The use of an electromechanical transmission in the design of a tracked vehicle allows an increase in the complex indicator of mobility, an increase in the range, fuel efficiency, maximum speed, a decrease in acceleration time, etc. The improvement of these indicators is achieved mainly due to the different performance characteristics of the internal combustion engine and the energy characteristics of electrical machines. The latter fact makes it possible to ensure the operation of the power plant of the tracked vehicle in such a way as to avoid unfavorable operating modes of both the internal combustion engine and the elements of the electromechanical transmission (a generator, a traction electric motor, an energy storage) from the point of view of energy efficiency, and to realize the high efficiency of the entire system.Research methods. To improve the mobility and implement a rational strategy for electromechanical transmission control, it is necessary to have an idea of the effective modes of operation of the main elements of the power plant. As a way to solve this problem it is proposed to study the energy characteristics of the main elements of an electromechanical transmission using the developed mathematical model for various modes of movement of a tracked vehicle.Results. Modeling the motion of a tracked vehicle with an electromechanical transmission makes it possible, in addition to determining the transmission parameters, to formulate preliminary requirements for its characteristics.Discussion and conclusion. To solve these problems, it is necessary to simulate the process of movement of a tracked vehicle, taking into account the initial data that are adequate to real operating conditions.


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