Jatin H. Vaghela et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 6, Issue No. 1, 027 - 030
Investigation of performance and emissions of 2- stroke Single Cylinder SI Engine operating on Alcohol–Gasoline fuel blends using 4-spark plugs A new kind of ignition Jatin H. Vaghela
Abstract—In this study, the effects of ethanol–gasoline
Research Scholar, S.V. National Institute of Technology, Surat, Gujarat.
liquids and have several physical and chemical properties similar to those of gasoline and diesel fuels. Also one of method is new concept of ignition Four Spark – ignition, in a combustion chamber improves the rate of combustion in a simple but novel way. The cylinder head is equipped with four spark plugs, instead of the conventional single spark plug shown in figure. The spark is generated simultaneously at four different locations in the combustion chamber. The Air-Fuel mixture gets ignited simultaneously such that, there are four flame fronts created and therefore significant reduction in flame travel for complete combustion in the chamber. The rate of combustion improves considerably which also leads to a fast rate of pressure rise. The obvious outcome of such phenomena is to improve the emissions and also efficiency of the engine. Indeed, when Henry Ford designed his first automobile (Model T), it was built to run on both gasoline and pure ethanol. However, in the past, ethanol was not given expectancy due to its insufficient production and high price. Ethanol can be produced from biomass such as sugar cane, sugar beet, wood, corn, and other grain. The production of ethanol from biomass sources involves fermentation and distillation of crop. Ethanol is biodegradable and will evaporate quickly. Methanol can be produced from natural gas, gasification of coal or biomass. However, coal is not preferred as a feedstock because conversion process is complex and costly than using other feedstock in commercial methanol production. Both methanol and ethanol have much higher octane number than gasoline. This allows to alcohol engines to have much higher compression ratios, and so
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(E5, E10) & methanol–gasoline (M5, M10) fuel blends and 4-spark plugs ignition are investigated on 2- stroke single cylinder SI engine for analysing the performance and combustion characteristics. The tests were performed using an electric dynamometer while running the engine at constant speed of 3000 rpm and at four different engine load conditions (0.5, 1, 1.5 2 kW). The results obtained from the use of alcohol– gasoline fuel blends with 4-spark plugs are compared to those of single conventional SI engine. The results indicated that when all four spark plugs and alcohol– gasoline fuel blends were used, the brake specific fuel consumption (BSFC) and exhaust emission are decreased. Exhaust gases namely, carbon dioxides (CO2), carbon monoxide (CO) and total unburned hydrocarbons (HC) are measured using multi exhaust gas analyser. Performance and exhausts emissions are compared with conventional gasoline engine with all working 4-spark plugs, using alcohol-gasoline fuel blends. This ignition system shows significant improvement for exhaust emission and also fuel consumptions at different load conditions.
Akshay A. Pujara
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Indus Institute of Technology & Engineering Automobile Department Ahmedabad-Gujarat, India jatinvaghela13@yahoo.co.in
Keywords- 4- spark plugs, Alcohol gasoline blend, emission & performance measurement, 2- stroke engine
The uses of automobiles are increasing day by day and in Ahmedabad alone more than 500 vehicles undergo R.T.O clearance everyday. Increasing global concern due to air pollution has generated much interest in the environmental friendly alternative fuels. Alternative fuels for IC engines are also becoming important because of diminishing gasoline reserves and increasing air pollution. Methanol and ethanol are good candidates as alternative fuels since they are
ISSN: 2230-7818
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Jatin H. Vaghela et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 6, Issue No. 1, 027 - 030
increasing thermal efficiency. Nevertheless, a significant disadvantage of methanol and ethanol relative to gasoline is that they have lower energy content and high production cost. Many additives can be added to gasoline to enhance the combustion efficiency and engine performance. The addition of high octane oxygenated fuel to gasoline is very important. MODIFICATIONS
Air consumption was measured using a sharp edged orifice plate manometer. Fuel consumption was determined by measuring burette used for a period of time on a scale with a precision of 1cc. Two different digital thermocouples monitored the temperatures of engine exhaust and room. The concentrations of exhaust emission (CO, HC, and CO2) were measured by multi exhaust gas analyzer. The schematic diagram of the experimental setup is shown in figure 2. The tests were carried out under steady-state conditions. Four different loads (0.5–2 kW with an increment of 0.5 kW) at constant 3000 rpm engine speeds were selected for the performance tests. The fuel properties of pure alcohols were obtained from the manufacture companies and literature. All tests were compared with single conventional single park plug engine. To prevent the confusion about the engine and vehicle performance characteristics, the engine torque outputs obtained in the experiments are shown in figures.
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methanol + 90% unleaded gasoline). The tests were conducted on engine, which has a single-cylinder, two stroke, and carburetor system 4SI engine (modified with four spark plugs in single cylinder), placed on a electric dynamometer. Engine specifications are shown in figure.
ENGINE SPECIFICATIONS
TABLE I.
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Fig. 1 Ignition Circuit Diagram of and modified head
Bajaj engine
Engine type Bore 70mm Stroke
Four stroke, Single cylinder air cooled engine 70mm 90mm
Cubic capacity Rated power Rated speed Fuel
100 cc 5.2 kW 6500 rpm Gasoline
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Here, the timing of ignition of spark for single and four plugs is not altered. It remains at the same time which was originally designed for the two stroke scooter engine. The modification carried in cylinder head includes simultaneous spark by one out of four selected spark plugs, removal of magneto, as originally available with the engine and replaced by four ignition coils (one for each spark plug). The contact breaker of the original magneto system was used for ignition. Electrical supply was provided by 12 volts parallel connected battery. The ignition circuit with four numbers of simultaneous sparks is shown in figure 1. Simultaneous four sparks is provided by discharging capacitor through sparkplug where high voltage is generated at tip of the plug which provides spark in the combustion chamber.
Engine make and model
II.
FUELS AND METHODS
Unleaded gasoline was blended with ethanol and methanol to prepare four different blends on a volume basis. These are E5 (5% ethanol + 95% unleaded gasoline), E10 (10% ethanol + 90% unleaded gasoline), M5 (5% methanol + 95% unleaded gasoline), and M10 (10%
ISSN: 2230-7818
Fig. 2 Experiment setup
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Jatin H. Vaghela et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 6, Issue No. 1, 027 - 030
30.00
Convetional engine E5
25.00 20.00 15.00
E 10
10.00 5.00
M5
0.00
4
8
12
16
Load in kg
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A. BSFC The comparison of BSFC for test fuels with four spark plugs is shown in figure 3. At the engine speed of 3000 rpm, BSFC for E5, E10, M5 and M10 increased by 2.8%, 3.6%, 0.6% and 3.3%, respectively, compared to those of unleaded gasoline conventional spark plug ignition. As seen in the figure 3, at the engine speed of 3000 rpm, BSFC for gasoline at the engine powers of 1.5 kW is lower than that of E5, E10, M5 and M10. However, the maximum BSFC was obtained at the 2 kW in the gasoline test. Indeed, these upward trends in BSFC with the use of E5, E10, M5 and M10 are normal due to the lower energy content of the alcohols. The heat of evaporation of ethanol is higher than that gasoline, both on a mass basis and on a volume basis. This means that the engine needs a lower fuel amount of ethanol or methanol to produce the same wheel power in a gasoline fueled engine. Thus, use of ethanol–gasoline or methanol– gasoline fuel blends resulted a slightly decreasing in the fuel consumption compared to the use of unleaded gasoline conventional ignition system.
vaporization of the fuel also continues in the compression stroke when the latent heat of vaporization increases. Since the fuel absorbs heat from the cylinder during the vaporization, the necessity work for compressing the air–fuel mixture decreases and this situation increases the thermal efficiency.
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RESULTS AND DISCUSSION
BRAKE THERMEL EFFICIENCY
III.
Convetional engine E5
BSFC
0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00
E 10
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M5
4.00 8.00 12.00 16.00
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Load in kg
Figure 3. EBSFC graph
B. Brake thermal efficiency As shown in Fig. 4, brake thermal efficiency increased with the increasing load. The main reason for this situation is the decrease in BSFC. At the engine speed of 3000rpm, the increases in thermal efficiencies of E5, E10, M5 and M10 are 1.9%, 2.5%, 1.8% and 4.7%, respectively, compared to unleaded gasoline conventional ignition system. There is a reduction of 0.8% in the thermal efficiency for E5 when compared to unleaded gasoline. This is because E10, M5 and M10 fuel blends have more oxygen rate than E5, the combustion becomes better and so the thermal efficiency increases. Moreover, the
ISSN: 2230-7818
Figure 4. Brake Thermal Efficiency graph
C. Emissions analysis Each emission content is measured for neat gasoline fuel and blends with E5, E10, M5 and M10, at the four loads (20%, 40% and 60% of the full load) at constant engine speed of 3000 rpm. Fig. 5 shows the carbon monoxide (CO) exhaust emissions for the neat gasoline fuel and the various percentages of the ethanol and methanol in its blends. One can observe that the CO emitted by the E5/gasoline fuel blends is either equal or lower than that for the corresponding neat gasoline fuel case, with the reduction being E10 and M10 in the blend with gasoline file bland case. Conclusively, the emitted CO follows the same behavior as the emitted soot by the engine, a fact collectively attributed to the same physical and chemical mechanisms affecting almost in the same way, at least qualitatively, the net formation of these emissions. Fig. 8 shows the total unburned hydrocarbons (HC) exhaust emissions for the neat gasoline fuel and the various percentages of the E5, E10, M5, and M10 in its blends with gasoline fuel. One can observe that the HC emitted by the E10 /gasoline fuel blends are higher than those for the corresponding neat gasoline fuel case.
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Jatin H. Vaghela et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 6, Issue No. 1, 027 - 030
Convetion al engine E5
4000
HC ppm
3000 E 10
2000
M5
1000
0.5
1.0 1.5 Load in KW
2.0
Bludszuweit; J. Holzapfel; H. Schmidt; N. Kruemmling: M 10 Prediction of the Hydrogen Flame in Combustion chambers of different shapes, ASME, 1997 [2] Bludszuweit; P. Pittermann; A. Stanev: Investigations into Emission Characteristics of Large Two-Stroke Cross-Head Engines Running on Heavy Fuel, Proceedings 22nd CIMAC International Congress on Combustion Engines, Copenhagen, 18-21 May 1998 [3] Energy and Environmental Analysis, “Benefits and Cost of Convetional Potential Tier 2 Emission Reduction Technologies”, Final Report, November 1997, Docket A-2000-01, Document IIengine A-01. E5 [4] G.Jain, S.Kabra, J.P.Subrahmanyam,”Experimental investigations on a dual ignition gasoline engine”.Dept. of E 10 mechanical engineering, IT, New Delhi. [5] H.B. Mathur, M.K. Gajendra Babu and M5 K.S.Reddi”Athermodymanic simulation model for methanol fueled spark ignition”SAE Paper No.830333. [6] Heywood, J., “Internal Combustion Engine Fundamentals,” M 10 McGraw-Hill, Inc., New York, 1988, pp.829-836, Docket A-2000-01, Document IV-A-110. [7] Lu T., Ju Y., Law C. K., “Complex CSP for Chemistry Reduction and Analysis,” Combustion and Flame, Vol.126, 2001,pp. 1445, 1455. [8] Pulkrabek, Engineering Fundamentals of the Internal Combustion Engine First Edition, 1997 [9] Stone, Introduction to Internal Combustion Engines Second Convetional Edition, 1992 engine [10] Quader, A.A.” lean combustion and misfire limit in spark E5 ignition engine”, SAE [11] Mukesh saxena “Studies of combustion parameters in a two stroke engine with selective exhaust gas recirculation” E 10 Indian institute of gasolineeum, Dehradun. [12] Houghton-Alico D (1982), Alcohol fuels production and M5 potential.
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Figure 5. HC graph
2.50 2.00 1.50 1.00 0.50 0.00 0.5
1.0
1.5
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CO in %
REFERENCE [1]
0
2.0
Load in KW Figure 6. CO graph
6.80
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6.60
CO2 in %
emission decreased because of the improvement of the combustion due to 4-spark plugs effect. Unburned HC is a product of incomplete combustion which is related to A/F ratio. It also reduces due to new arrangement of spark plugs in cylinder head for multi ignition.
6.40 6.20 6.00 5.80
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5.60
0.5
1.0
1.5
2.0
M 10
Load in KW
Figure 7. CO2 graph
IV.
CONCLUSION
Adding ethanol to gasoline will lead to a leaner better combustion. It was experimentally investigated that adding ethanol and methanol to the blends led to an increase in the engine brake thermal efficiency and decreases BSFC. The lean combustion improves the completeness of combustion and therefore the CO emission is expected to be decreased. The oxygen enrichment generated from ethanol increased the oxygen ratio in the charge and lead to lean combustion. The CO2
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