scholarly journals Study of dynamic and ecological properties of automotive bi-fuel engine

Author(s):  
Zdzisław Chłopek ◽  
Jakub Lasocki ◽  
Hubert Sar

AbstractGaseous fuels are increasingly used to power internal combustion engines. Spark-ignition engines are fuelled with liquefied petroleum gas. Engines powered by gaseous fuels are characterized by good ecological properties due to the emission of pollutants. The paper presents the results of empirical tests of two passenger cars with spark-ignition engines powered alternatively: with gasoline and LPG fuel. The engines were equipped with fifth generation LPG fuelling systems. The tests were performed on a chassis dynamometer in tests used in approval procedures in Europe (NEDC test) and in the United States of America (FTP-75 test). These tests were the basis for determining the average specific distance emission of pollutants (carbon monoxide, hydrocarbons, nitrogen oxides and carbon dioxide) during the tests. The engines were also tested in the conditions of the external speed characteristics while accelerating the car in third gear. It was found that the type of fuelling the engines with both fuels has little influence on the dynamic properties of the engine due to the effective power. The tests clearly showed a decrease in specific distance emission of carbon monoxide and carbon dioxide. The relative reduction in specific distance emission of carbon monoxide was in the order of (45–65)%, and carbon dioxide—about 10%. For hydrocarbons, there was an increase in specific distance emission of hydrocarbons for the fuelling of engines with LPG, while for hydrocarbons, there was a large difference in the value of the relative specific distance emission difference for both tests. (The relative difference was from 25 to 175%.) Specific distance emission of nitrogen oxides turned out to be significantly higher when running engines with LPG. The reason for this is leaning of the fuel mixture at high rotational speed during acceleration of the car, which may result from insufficient conversion efficiency of engine control algorithms in the LPG fuel mode.

2020 ◽  

<p>Air pollutant emissions and fuel consumption of vehicles equipped with internal combustion engines are highly susceptible to the conditions of engine operation. The purpose of this research was to investigate the correlation between the emissions of individual pollutants (carbon monoxide, hydrocarbons, nitrogen oxides, and carbon dioxide), the fuel consumption and various dynamic conditions of the operation of an engine. The empirical data was obtained by testing of passenger car with a spark-ignition engine on a chassis dynamometer in 12 various driving tests, both type-approval and special. The results indicate, that the strongest correlation exists between the emissions of carbon dioxide and hydrocarbons and between the fuel consumption and the emissions of hydrocarbons and carbon dioxide. The weakest correlation was found to be between the emissions of carbon monoxide and nitrogen oxides. The average value of vehicle velocity proved to be suitable zero-dimensional characteristic of the dynamic driving conditions. The correlation between the emission of hydrocarbons and the average vehicle velocity can be assessed as the strongest, while between the emission of nitrogen oxides and the average vehicle velocity – the weakest.</p>


1.It may be taken as an axiom of electrical ignition that the closer its conditions resemble those in the explosion wave front the more readily will it occur. These conditions are high temperature and pressure, and in the case of hydrocarbons combustion to carbon monoxide. They are also characteristic of condenser discharge sparks, for in the first place the surface of a platinum pole to which condenser discharge has been made becomes pitted to a remarkable extent, greater than when large currents are broken by separation of the poles. The sparks have therefore a high temperature. That they give rise to high gas pressure is clear from the intensity of the sound of a single spark discharge, and finally it will be shown that combustion to carbon monoxide rather than to carbon dioxide is peculiar in certain cases to ignition by capacity sparks. In addition to these the sparks are of very short duration, are oscillatory in character, and start with ionisation or breakdown of the gas between the poles. The belief that all visible sparks will ignite explosive mixtures no doubt arose from observations of the activity of condenser discharge in this respect, but while in certain cases, especially in the ignition of hydrogen, the least is in every case a well marked limit to their igniting power, and as the percentage of gas limits of inflammability are approached they require to be large. 2. The Paraffins—Ethane, Propane, and Butane .—The gases used in the present work were from the same stocks as those used for break-spark ignition. The results obtained from them are given in fig. 1. They have two interesting features; their minimum igniting current is the same in every case, in this resembling their ignition by continuous current break-sparks, but they have the parabolic form characteristic of alternating current break-spark ignition. Ethane has, however, a minimum at 7∙7 per cent., the point of combustion to carbon monoxide, the others, as before, midway between this and combustion to carbon dioxide. There is, however, on the higher side of the ethane and propane curves—the supply of butane gave out before this could be examined fully—a step or increase in difficulty of ignition corresponding to mixtures midway between four and five atoms of oxygen to one molecule of ethane, and between six and seven to one of propane. This point was thought to be some failure in the quality of the gas, but when it appeared in both, and to a still greater extent in methane, it was more fully examined. Condenser-spark ignition has therefore some of the features of both continuous and low frequency alternating current break-spark ignition, but it has a characteristic type of its own.


2016 ◽  
Vol 18 (7) ◽  
pp. 717-731 ◽  
Author(s):  
David K Marsh ◽  
Alexander K Voice

In this work, a simple methodology was implemented to predict the onset of knock in spark-ignition engines and quantify the benefits of two practical knock mitigation strategies: cooled exhaust gas recirculation and syngas blending. Based on the results of this study, both cooled exhaust gas recirculation and the presence of syngas constituents in the end-gas substantially improved the knock-limited compression ratio of the engine. At constant load, 25% exhaust gas recirculation increased the knock-limited compression ratio from 9.0 to 10.8:1 (0.07 compression ratio per 1% exhaust gas recirculation) due to lower end-gas temperature and reactant (fuel and oxygen) concentrations. At exhaust gas recirculation rates above 43%, higher intake temperature outweighed the benefits of lower end-gas reactant concentration. At constant intake temperature, cooled exhaust gas recirculation was significantly more effective at all exhaust gas recirculation rates (0.10 compression ratio per 1% exhaust gas recirculation), and no diminishing returns or optimum was observed. Both hydrogen and carbon monoxide were also predicted to improve knock by reducing end-gas reactivity, likely through the conversion of high-reactivity hydroxy-radicals to less reactive peroxy-radicals. Hydrogen increased the knock-limited compression ratio by 1.1 per volume percent added at constant energy content. Carbon monoxide was less effective, increasing the knock-limited compression ratio by 0.38 per volume percent added. Combining 25% cooled exhaust gas recirculation with reformate produced from rich combustion at an equivalence ratio of 1.3 resulted in a predicted increase in the knock-limited compression ratio of 3.5, which agreed well with the published experimental engine data. The results show the extent to which syngas blending and cooled exhaust gas recirculation each contribute separately to knock mitigation and demonstrate that both can be effective knock mitigation strategies. Together, these solutions have the potential to increase the compression ratio and efficiency of spark-ignition engines.


2013 ◽  
Author(s):  
Jorge Duarte Forero ◽  
German Amador Diaz ◽  
Fabio Blanco Castillo ◽  
Lesme Corredor Martinez ◽  
Ricardo Vasquez Padilla

In this paper, a mathematical model is performed in order to analyze the effect of the methane number (MN) on knock tendency when spark ignition internal combustion engine operate with gaseous fuels produced from different thermochemical processes. The model was validated with experimental data reported in literature and the results were satisfactory. A general correlation for estimating the autoignition time of gaseous fuels in function of cylinder temperature, and pressure, equivalence ratio and methane number of the fuel was carried out. Livengood and Wu correlation is used to predict autoignition in function of the crank angle. This criterium is a way to predict the autoignition tendency of a fuel/air mixture under engine conditions and consider the ignition delay. A chemical equilibrium model which considers 98 chemical species was used in this research in order to simulate the combustion of the gaseous fuels at differents engine operating conditions. The effect of spark advance, equivalence ratio, methane number (MN), charge (inlet pressure) and inlet temperature (manifold temperature) on engine knocking is evaluated. This work, explore the feasibility of using syngas with low methane number as fuel for commercial internal combustion engines.


2017 ◽  
Vol 9 (2) ◽  
pp. 168781401668884 ◽  
Author(s):  
Yu Li ◽  
Jinke Gong ◽  
Wenhua Yuan ◽  
Jun Fu ◽  
Bin Zhang ◽  
...  

Ethanol is known as the most widely used alternative fuel for spark-ignition engines. Compared to it, butanol has proved to be a very promising renewable fuel in recent years for desirable properties. The conjoint analysis on combustion, performance, and emissions characteristics of a port fuel injection spark-ignition engine fueled with butanol–gasoline blends was carried out. In comparison with butanol–gasoline blends with various butanol ratio (0–60 vol% referred as G100~B60) and conventional alcohol alternative fuels (methanol, ethanol, and butanol)–gasoline blends, it shows that B30 performs well in engine performance and emissions, including brake thermal efficiency, brake-specific fuel consumption, carbon monoxide, unburned hydrocarbons, and nitrogen oxides. Then, B30 was compared with G100 under various equivalence ratios ( Φ = 0.83–1.25) and engine loads (3 and 5-bar brake mean effective pressure). In summary, B30 presents an advanced combustion phasing, which leads to a 0.3%–2.8% lower brake thermal efficiency than G100 as the engine was running at the spark timing of gasoline’s maximum brake torque (MBT). Therefore, the sparking timing should be postponed when fueled with butanol–gasoline blends. For emissions, the lower carbon monoxide (2.3%–8.7%), unburned hydrocarbons (12.4%–27.5%), and nitrogen oxides (2.8%–19.6%) were shown for B30 compared with G100. Therefore, butanol could be a good alternative fuel to gasoline for its potential to improve combustion efficiency and reduce pollutant emissions.


Author(s):  
Guillaume Brecq ◽  
Camal Rahmouni ◽  
Abdellilah Taouri ◽  
Mohand Tazerout ◽  
Olivier Le Corre

Experimental investigations on the knock rating of gaseous fuels were carried out on a single cylinder SI engine of Lister-Petter make. The Service Methane Number (SMN) of different gas compositions is measured and then compared to the standard Methane Number (MN), calculated by the AVL software. Effects of engine parameters, by mean of the Methane Number Requirement (MNR) are also highlighted. A linear correlation, between the SMN and the MN, has been obtained with a maximum absolute deviation lower than 2 MN units. A prediction correlation giving the MNR from engine parameters has finally been deduced from experimental data with a good accuracy (mean absolute deviation of 0.5 MNR unit).


Author(s):  
Amirreza Talaiekhozani ◽  
Ali Mohammad Amani ◽  
Zeinab Eskandari ◽  
Reza Sanaye

Introduction: Although many studies on Isfahan’s air pollution have been done, there is no report about the effects of cigarette consumption in Isfahan. The aims of this study were (a) to find the amount of nitrogen oxides, hydrocarbons, carbon monoxide and carbon dioxide emitted by cigarette consumption in Isfahan; and (b) to model the distribution of such pollutants in Isfahan’s atmosphere. Materials and methods: Based on the literature, it is assumed that 15% of Isfahan’s people consume cigarettes and each smoker on average smokes 1,147 cigarettes per year. Based on these assumptions, the 249,000 smokers living in Isfahan consume 285,000,000 cigarettes per year. The amount of pollutant emissions was calculated by existing emission factors for cigarette consumption. Finally, the distribution of the emitted pollutants from cigarette consumption in Isfahan’s atmosphere was modeled using AERMOD. Results: The results illustrated that each year, 2.85 kg nitrogen oxides, 2.85 kg hydrocarbons, 37.05 kg carbon monoxide and 142.5 kg carbon dioxide are emitted into Isfahan’s atmosphere from residents’ smoking. The modeling of pollutants’ dispersion in Isfahan’s atmosphere showed that only some of these pollutants result from cigarette consumption. Conclusion: This study demonstrated that the amount of pollutants emitted by cigarette consumption was negligible compared to the other pollutant sources in Isfahan.


2020 ◽  
Vol 183 (4) ◽  
pp. 11-14
Author(s):  
Małgorzata Mrozik

The aim of the article is to present the environmental effects of changes in material composition in selected internal combustion engines used in passenger cars using LCA analysis. The levels of energy consumption and emissions of pollutants related to material inputs occurring at the stage of engine production have been determined. The simplified LCA model presented in the paper shows the energy consumption and total CO2 and SO2 emissions on the basis of the mass of materials from which the engine is made. The research results presented in the paper give a picture of a modern passenger car engine on the basis of wear and the degree of recovery of materials used for its construction.


Sign in / Sign up

Export Citation Format

Share Document