An Experimental and Numerical Investigation of Spark Ignition Engine Operation on H2, CO, CH4, and Their Mixtures

Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi

The knock and combustion characteristics of CO, H2, CH4, and their mixtures were determined experimentally in a variable compression ratio spark ignition (SI) cooperative fuel research (CFR) engine. The significant effects of gaseous fuel mixtures containing H2 in enhancing the combustion and oxidation process of CH4 were examined. The unique combustion characteristics of CO in dry air and its distinct performance in mixtures with H-containing fuels were investigated. The addition of a simulated synthesis gas (2H2+CO) to CH4 was found to enhance the combustion process of the resulting mixture and lowers its knock resistance. The effectiveness of such an addition is slightly weaker than that of a comparable H2 addition but much stronger than that with CO addition only. A predictive model with detailed kinetic chemistry was used successfully to simulate SI engine operation fuelled with CH4, H2, CO, and their mixtures. The predicted engine performance and knock limits of CH4, H2, CO, and their mixtures agree well with experimental data with the exception around pure CO operation in dry air with the presence of small amounts of CH4 or H2. A remedial approach to improve the prediction of the knock limits of fuel mixtures containing mainly CO with a small amount of H-containing fuels such as H2 and CH4 was proposed and discussed.

Author(s):  
Jerald A. Caton

Abstract A thermodynamic cycle simulation was developed for a spark-ignition engine which included the use of multiple zones for the combustion process. This simulation was used to complete analyses for a commercial, spark-ignition V-8 engine operating at a part load condition. Specifically, the engine possessed a compression ratio of 8.1:1, and had a bore and stroke of 101.6 and 88.4 mm, respectively. A part load operating condition at 1400 rpm with an equivalence ratio of 1.0 was examined. Results were obtained for overall engine performance, for detailed in-cylinder events, and for the thermodynamics of the individual processes. In particular, the characteristics of the engine operation with respect to the combustion process were examined. Implications of the multiple zones formulation for the combustion process are described.


2021 ◽  
Vol 11 (4) ◽  
pp. 1441
Author(s):  
Farhad Salek ◽  
Meisam Babaie ◽  
Amin Shakeri ◽  
Seyed Vahid Hosseini ◽  
Timothy Bodisco ◽  
...  

This study aims to investigate the effect of the port injection of ammonia on performance, knock and NOx emission across a range of engine speeds in a gasoline/ethanol dual-fuel engine. An experimentally validated numerical model of a naturally aspirated spark-ignition (SI) engine was developed in AVL BOOST for the purpose of this investigation. The vibe two zone combustion model, which is widely used for the mathematical modeling of spark-ignition engines is employed for the numerical analysis of the combustion process. A significant reduction of ~50% in NOx emissions was observed across the engine speed range. However, the port injection of ammonia imposed some negative impacts on engine equivalent BSFC, CO and HC emissions, increasing these parameters by 3%, 30% and 21%, respectively, at the 10% ammonia injection ratio. Additionally, the minimum octane number of primary fuel required to prevent knock was reduced by up to 3.6% by adding ammonia between 5 and 10%. All in all, the injection of ammonia inside a bio-fueled engine could make it robust and produce less NOx, while having some undesirable effects on BSFC, CO and HC emissions.


2018 ◽  
Vol 244 ◽  
pp. 03001
Author(s):  
Donatas Kriaučiūnas ◽  
Saugirdas Pukalskas ◽  
Alfredas Rimkus

Numerical simulations of Nissan Qashqai HR16DE engine with increased compression ratio from 10,7:1 to 13,5:1 was carried out using AVL BOOST software. Modelled engine work cycles while engine works with biogas (BG) and hydrogen (H2) mixtures. For biogas used mixture of 35 % carbon dioxide (CO2) and 65 % methane (CH4). Three mixtures of biogas with added 5 %, 10 % and 15 % H2 was made. The simulation of engine work cycles was performed at fully opened throttle and changing engine crankshaft rotation speeds: ne1 = 1500, ne2 = 3000, ne3 = 4500, ne4 = 6000 rpm. Simulation results demonstrated what adding hydrogen to biogas increase in-cylinder temperature and nitrogen oxides (NOx) concentration because of higher mixtures lower heating values (LHV) and better combustion process. Other emissions of carbon monoxide (CO) and hydrocarbons (HC) decreased while adding hydrogen due to the fact that hydrogen is carbon-free fuel.


2010 ◽  
pp. 42-49 ◽  
Author(s):  
Md Ehsan

Petrol engines can run on natural gas, with little modification. The combustion characteristics of naturalgas is different from that of petrol, which eventually affects the engine performance. The performance of atypical automotive engine was studied running on natural gas, firstly at a constant speed for various loadsand then at a constant load for a range of speeds and results were compared with performance using petrol.Variation of the spark advance, consisting of centrifugal and vacuum advance mechanisms, wasinvestigated. Results showed some reduction in power and slight fall of efficiency and higher exhausttemperature, for natural gas. The air-fuel ratio for optimum performance was higher for gas than for petrol.This variation in spark requirement is mainly due to the slower speed of flame propagation for natural gas.For both the cases, the best power spark advance for natural gas was found to have higher values thanpetrol. This issue needs to be addressed during retrofitting petrol engines for running on natural gas.Journal of Chemical Engineering Vol.ChE 24 2006 42-49


Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi

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.


2021 ◽  
Vol 14 (2) ◽  
pp. 125-129
Author(s):  
Gatot Setyono ◽  
Navik Kholili

Ethanol is an alternative fuel to replace fossil fuels. Ethanol's high octane value can substitute for power in spark-ignition engines (SI). Gasoline mixed with ethanol will reduce the calorific value generated and intensify the combustion process in the combustion chamber. Through the engine performance test, we can find out the increase in the performance of the SI engine. Several essential variables can improve engine performance, such as gasoline-ethanol variations, iridium spark plugs, and hydroxy gas generators (HHO). This research uses an experimental method by utilizing gasoline (octane-92)-ethanol variations (35%, 45%, and 55% v/v) with the intake of hydroxy gas during the combustion process. The SI automatic transmission engine has a capacity of 124.8 cubic centimeters (one cylinder-four stroke), a compression ratio of 11/1, fuel injection, and iridium spark plugs. Engine performance test using chassis dyno test with engine speed variations of 4000-9000 rpm. This study resulted in optimal performance on a 55% increase in gasoline-ethanol mixture with an intensify in output-power, pressure, and thermal efficiency at an engine-speed of 8000 rpm. It is contrary to the specific fuel consumption has decreased.


Author(s):  
By R. C. Teasel ◽  
R. D. Miller

The increasing use of spark ignition engines throughout the world has confronted the engine designer with new problems such as air pollution, world-wide temperature extremes, as well as legislative, economic, and human considerations. To meet these situations and improve the competitive position of the spark ignition engine requires considerable research and development effort. This paper reports on work conducted by Champion Spark Plug Company in attempting to evaluate the potential contribution that ignition system and spark plug designs can make towards improving spark ignition engine operation. Almost all the work reported here covers investigations in current large displacement United States passenger car engines. The three main characteristics of the overall ignition systems that are investigated are (1) the available output voltage characteristics of the ignition systems; (2) the effect of the ignition system spark discharge characteristics on engine performance; and (3) the effect of several spark plug design features on engine performance. This investigation shows that the inter-relationship of the ignition system spark discharge characteristics and the spark plug design requires that the overall evaluation must consider the dependence of both items. It also suggests that significant improvements can result in other United States and European engines, through the careful evaluation of ignition system and spark plug designs. The results of this work indicate that a fast rise time, short arc duration system results in reduced spark plug gap growth and better resistance to spark plug fouling. However, the arc duration must not be shorter than a minimum value, or a loss in engine performance may result. High output systems are desirable as they provide a higher voltage reserve to provide longer spark plug life, but the higher voltages that occur with the larger spark plug gaps can stress other ignition system components. The spark plug designs which incorporate a projection of the spark plug gap result in better performance in the engines tested, and possibly even reduce exhaust emissions. Certainly other features which engine manufacturers must consider, which are not discussed in detail here, are costs, durability, and maintenance of the new systems. At least one other important related problem is that of interference.


Author(s):  
C D Rakopoulos ◽  
C N Michos ◽  
E G Giakoumis

Although a first-law analysis can show the improvement that hydrogen addition impacts on the performance of a biogas-fuelled spark-ignition (SI) engine, additional benefits can be revealed when the second law of thermodynamics is brought into perspective. It is theoretically expected that hydrogen enrichment in biogas can increase the second-law efficiency of engine operation by reducing the combustion-generated irreversibilities, because of the fundamental differences in the mechanism of entropy generation between hydrogen and traditional hydrocarbon combustion. In this study, an experimentally validated closed-cycle simulation code, incorporating a quasi-dimensional multi-zone combustion model that is based on the combination of turbulent entrainment theory and flame stretch concepts for the prediction of burning rates, is further extended to include second-law analysis for the purpose of quantifying the respective improvements. The analysis is applied for a single-cylinder homogeneous charge SI engine, fuelled with biogas—hydrogen blends, with up to 15 vol% hydrogen in the fuel mixture, when operated at 1500r/min, wide-open throttle, fuel-to-air equivalence ratio of 0.9, and ignition timing of 20° crank angle before top dead centre. Among the major findings derived from the second-law balance during the closed part of the engine cycle is the increase in the second-law efficiency from 40.85 per cent to 42.41 per cent with hydrogen addition, accompanied by a simultaneous decrease in the combustion irreversibilities from 18.25 per cent to 17.18 per cent of the total availability of the charge at inlet valve closing. It is also illustrated how both the increase in the combustion temperatures and the decrease in the combustion duration with increasing hydrogen content result in a reduction in the combustion irreversibilities. The degree of thermodynamic perfection of the combustion process from the second-law point of view is quantified by using two (differently defined) combustion exergetic efficiencies, whose maximum values during the combustion process increase with hydrogen enrichment from 49.70 per cent to 53.45 per cent and from 86.01 per cent to 87.33 per cent, respectively.


Author(s):  
Gustavo Fontana ◽  
Enzo Galloni ◽  
Elio Jannelli

Abstract Combustion models, used in spark-ignition engine modeling, are reviewed. Different approaches for representing the main combustion features are reported. Limitations in simulating such a complex phenomenon as turbulent combustion in engines are highlighted as well. In order to compare different combustion models, the multidimensional program KIVA-3V has been used. The behavior of an actual spark-ignition engine has been investigated. In particular, simulation results, using simple chemical kinetics and mixing-controlled models, are compared. The results obtained, compared to measured data, confirm that different combustion models can lead to a satisfactory prediction of engine performances. But, in many cases, these models require experimental data for determining the model characteristic constants. A hybrid combustion model is proposed. It is able to provide a good reproduction of engine combustion process and, in particular, the model seems to be less sensitive to the engine operation. The computation results are compared to the measured data.


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