3n13 ijaet0313424 revised

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963

EFFECT OF INJECTION TIMING AND INJECTION PRESSURE ON A SINGLE CYLINDER DIESEL ENGINE FOR BETTER PERFORMANCE AND EMISSION CHARACTERISTICS FOR JATROPA BIO DIESEL IN SINGLE AND DUAL FUEL MODE WITH CNG Meyyappan Venkatesan Assistant Professor, Mechanical Engineering, Ethiopian Institute of Technology [EIT – M], Mekelle University, Ethiopia

ABSTRACT In the present investigation test were carried out to examine the performance and emissions of a direct injection diesel engine blended with Jatropa bio-diesel prepared with methanol to get jatropa oil methyl ester (JOME) .

Experiments are conducted with JOME single and dual fuel mode with compressed natural gas (CNG) in a single cylinder 4 stroke diesel engine. Performance parameters such as brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), emissions such as CO, UBHC, smoke density and NOx are determined at three injection pressures of 180, 200 and 220 bar and two injection timings 27 obtdc and 31obtdc. Parameters are compared with base line data of diesel fuel. It was found through experiments that CNG - JOME can be used as fuel with better performance at 220 bar pressure and advanced injection timing of 31 obtdc. The harmful pollutants such as UBHC, CO and NOx are reduced in jatropa oil methyl ester with CNG in single and dual fuel mode compared to diesel fuel.

KEYWORDS: Jatropa oil methyl ester - performance – emission characteristics - dual fuel mode – CNG.

I.

INTRODUCTION

Motor vehicles contribute significantly to the air pollutions problems. Therefore use of alternative fuels can help in the promotion of environmental protection. Increased consumption of conventional based fuel gives way for the exploration of several alternative fuels. Important requirement of automotive fuels such as high energy density safety in usage and handling, conveniences in transportation, storage and cost but not the least environmental acceptability make bio-diesel especially jatropa oil a vegetable oil derived fuel and among the gaseous fuels Compressed natural Gas as the strongest contenders to replace the petroleum derived fuels.

Major problems associated with direct use of vegetable oils are their viscosity, volatility and heating value. Excessive carbon deposits and thickening of lubricating oil are the problems associated with direct use of straight vegetable oils. Properties can be improved by preparing esters of jatropa with methanol to form jatropa oil methyl ester (JOME).

Among the various alternative fuels bio-diesel is one of the most promising liquid fuels for CI engines. Gaseous fuels such as compressed natural gas (CNG), biogas, hydrogen, liquefied petroleum gas have been tried. Gaseous fuels are promising because they are less polluting for environment.

They form premixture very easily. Taking into consideration the availability and development in India regarding bio-diesel and CNG the present work has concentrated on utilization of JOME bio-diesel and CNG as alternative fuel in CI engine.

21

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963 Notations used: BSFC: Brake specific fuel consumption BTE: Brake thermal efficiency BSEC: Brake specific energy consumption UBHC: Un burnt hydrocarbon CO: Carbon monoxide NOx: Nitric oxides

II.

PROCEDURE

Engine Test Engine running tests were conducted on Kirloskar make, single cylinder,4-stroke-cycle, constant speed (1500 rpm) vertical, water cooled, direct injection, 5hp (3.7 kW), bore 100 mm and stroke 110mm, compression ratio 20:1 diesel engine. Tests were conducted at different loads, with diesel oil, transesterified oil (JOME) CNG-Diesel and CNG-JOME for comparative study. The experimental setup of the engine is shown in figure 1a. An eddy current dynamometer was used for load measurement. The engine speed was sensed and indicated by an inductive pick up sensor facing marks on flywheel with digital meter output. Chromel-alumel thermocouple was used for exhaust gas temperature measurement. Figure 1b shows AVL make smoke meter used for smoke measurement.

Carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitrous oxide (NOx) were measured by MRU air emission monitoring systems shown in figure 1c.Fuel consumption is measured by a burette with two sensors placed apart two markings to measure 20cc accurately.

Make

Table – 1 Specification of the engine Kirloskar, single cylinder

Type

direct injection, water cooled

Bore X Stroke (mm)

100 X 110

Compression ratio

20:1

Rated power

5hp (3.7 kW),

Rates speed

constant speed (1500 rpm)

Start of injection

180 bar

Table – 2 Range of operating parameter tried in the present testing % Load

20% 40% 60% 80% and 100%

Speed

constant speed (1500 rpm)

Compression ratio

20:1

Injection Timing obTDC

27 o bTDC and 31 o bTDC

Injection Pressure

180bar, 200bar and 220 bar

Table.3 Properties of Biodiesel compared with neat diesel Properties Diesel Jatropha BioDiesel (Methyl Ester) Cetane No. Density(kg/m 3 ) Viscosity (cSt) Calorific value (MJ/kg) Flash point (°C)

22

48 – 56 821 3.52 43 48

23 / 51 920 75,7 39,628 340

57 892 5.402 39.15 156

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963

a. Engine Set up

b. Smoke meter

c. Exhaust Gas analyzer Figure 1- Equipment used in Conducting Tests

2.1 Test Procedure Engine tests were conducted at 27° btdc and 310 btdc injection timings and injection pressures of 180bar, 200bar and 220 bar respectively. Engine was started on neat diesel and warmed up till cooling water temperature was stabilized. Fuel consumption, exhaust temperature, exhaust emissions such as UBHC, NOX, CO2, CO and exhaust gas opacity were measured and recorded for different loads.

Similar procedure was repeated for CNG-diesel for constant flow rate of CNG of 0.4kg per hour at constant speed of 1500rpm.Since a governor is used in the engine to regulate the flow rate of diesel to keep the engine speed constant, natural gas flow rate is maintained constant. Tests were repeated for 20%, 40%, 60%and 80% loading conditions. Three readings were taken for each load and average value is used for calculations.

III.

RESULTS AND DISCUSSIONS

3.1 Engine performance Brake Specific fuel consumption (BSFC)

Fig 2 – BSFC VS BP AT 180 BAR 27O BTDC

23

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963

Fig 3 - BSFC VS BP AT 200 BAR 27O BTDC

bsfc(Kg/Kw-hr)

BSFC VS Brake Power for 220 bar pressure 27O BTDC

1 0.8 0.6 0.4 0.2 0

DIESEL CNG-DIESEL

0.92

1.83

2.75 3.675

Brake Power (Kw)

Fig 4 - BSFC VS BP AT 220 BAR 27O BTDC

Figure 2, 3 and 4 shows variation of brake specific fuel consumption with brake power curves for diesel and CNG-Diesel operation of the engine at 27 deg btdc and 180bar, 200bar and 220bar injection pressures respectively. BSFC of diesel at standard injection pressure of 180 bar and injection timing of 27 deg btdc is 0.61Kg/Kw-hr at low loads of operation. At higher loads of operation BSFC is 0.30Kg/Kw-hr. The values for CNG-Diesel for low load and higher loads are 0.83 and 0.32Kg/Kwhr For CNG-Diesel at all the three injection pressures at low loads it is 0.83Kg/Kw-hr with very little variations and it is nearly equal to that of diesel at higher loads. This is because of better mixing and atomization of fuel at higher injection pressures.

BSFC VS Brake Power for 180 bar pressure 31O BTDC

0.6

DIESEL

0.4 0.2 0

CNG-DIESEL

hr)

bsfc(Kg/Kw-hr)

0.8

0.92

1.83

2.75 3.675

Brake Power (Kw)

Fig 5 - BSFC VS BP AT 180 BAR 31O BTD

24

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 BSFC VS Brake Power for 200 bar pressure 31O BTDC

bsfc(Kg/Kw-hr)

0.8 0.6

DIESEL

0.4 hr)

CNG-DIESEL

0.2 0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 6 - BSFC VS BP AT 200 BAR 31O BTDC

BSFC VS Brake Power for 220 bar pressure 31O BTDC

0.6

DIESEL

0.4

CNG-DIESEL

hr)

bsfc(Kg/Kw-hr)

0.8

0.2 0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 7 - BSFC VS BP AT 220 BAR 31O BTDC

Figure 5,6 and 7 shows variation of brake specific fuel consumption with brake power curves for diesel and CNG-Diesel operation of the engine at 31 deg btdc and 180bar,200bar and 220bar injection pressures respectively For CNG-Diesel operation at low loads of operation for all injection pressures is 10%. At higher loads it is 27.8%, 27.75% and 28.74% at 180bar, 200bar and 220bar pressures respectively. An increase of 1%in efficiency at higher pressures of 200bar and 220bar.Advancing the injection timing improves the BTE due to longer time available for proper mixing and combustion

BTE(%)

BTE VS Brake Power for 180 bar pressure 27O BTDC

30 25 20 15 10 5 0

DIESEL CNG-DIESEL

0.92

1.83

2.75 3.675

Brake Power (Kw)

Fig 8 - BTE VS BP AT 180 BAR 27O BTDC

25

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 BTE Vs Brake Power for 200 bar pressure 27O BTDC

BTE(%)

30 20

DIESEL CNG-DIESEL

10 0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 9 - BTE VS BP AT 200 BAR 27O BTDC BTE VS Brake Power for 220 bar pressure 27O BTDC

BTE(%)

30 20

DIESEL

10

CNG-DIESEL

0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 10 - BTE VS BP AT 220 BAR 27O BTDC

Figure 8, 9 and 10 shows variation of brake thermal efficiency with brake power curves for diesel and CNG-Diesel operation of the engine at 27 deg btdc and 180bar,200bar and 220bar injection pressures respectively BTE for diesel baseline at 180bar pressure 27 deg btdc is 13.75% and 28% t low and high loads of operation respectively. For CNG-Diesel it is almost equal to 10% at all injection pressures and at high loads it is 25.93%, 2.28% and 26.92% respectively at 180bar 200bar and 220bar pressures.

At higher pressures efficiency approaches to that of diesel due to better mixing and combustion of fuel

BTE(%)

BTE VS Brake Pow er for 180 bar pressure 31 deg btdc 30 25 20 15 10 5 0

DIESEL CNG-DIESEL

0.92

1.83

2.75

3.675

Brake Pow er(Kw )

Fig 11 - BTE VS BP AT 180 BAR 31O BTDC

26

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 BTE VS Brake Power for 200 bar pressure 31O BTDC

40 BTE(%)

30 DIESEL

20

CNG-DIESEL

10 0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 12 - BTE VS BP AT 200 BAR 31O BTDC

BTE VS Brake Power for 220 bar 31O BTDC

BTE(%)

40 30 DIESEL

20

CNG-DIESEL

10 0 0.92

1.83

2.75

3.675

Brake Power (Kw)

Fig 13- BTE VS BP AT 220 BAR 31O BTDC

Figure 11, 12 and 13 shows variation of brake thermal efficiency with brake power curves for diesel and CNG-Diesel operation of the engine at 31 deg btdc and 180bar, 200bar and 220bar injection pressures respectively. BSFC of CNG-Diesel at 180 bar pressure and 31 deg btdc is 0.70Kg/Kw-hr at low loads of operation and at higher loads it is 0.25 Kg/Kw-hr.At higher loads of operation for 200bar and 220 bar pressures it is 0.24 Kg/Kw-hr and 0.26 Kg/Kw-hr respectively. A very low bsfc of 0.24 Kg/Kw-hr is achieved at 200 bar pressure and 31 deg btdc. Advancing the injection timing improves the bsfc due to better mixing and combustion process.

27

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963 3.2. EMISSIONS Un Burnt Hydro Carbons UBHC VS Brake Power 180bar 31O BTDC

400 350 300 250 DIESEL

200

CNG-DIESEL

150 100 50 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 14 - UBHC VS BP AT 180 BAR 31O BTDC

UBHC VS Brake Power for 200 bar 31O BTDC 400 350 300 250 200 150

DIESEL

100

CNG-DIESEL

50 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 15 - UBHC VS BP AT 200 BAR 31O BTDC

28

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 UBHC VS Brake Power for 220 bar 31O BTDC

350 300 250 200

DIESEL

150

CNG-DIESEL

100 50 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 16 - UBHC VS BP AT 220 BAR 31O BTDC

Figure 14, 15 and 16 shows variation of unburnt hydrocarbons with brake power curves for diesel and CNG-diesel operation of the engine at 31 deg btdc and 180bar,200bar and 220bar injection pressures respectively. A very high value of nearly 320ppm is obtained at all pressures at low loads for CNG-diesel operation when compared to very low value of 7ppm for diesel operation indicating incomplete combustion due to improper mixing of liquid and gaseous fuels. It is nearly 65 ppm at higher loads of operation at all the three pressures due to better mixing and combustion CO VS Brake Power 180 bar 31O BTDC 0.25 0.2 0.15

DIESEL CNG-DIESEL

0.1 0.05 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 17 - CO VS BP AT 180 BAR 31O BTDC

29

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 CO VS Brake Power for 200 bar 31O BTDC

0.3 0.25 0.2 DIESEL

0.15

CNG-DIESEL

0.1 0.05 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 18 - CO VS BP AT 200 BAR 31O BTDC CO VS Brake Power for 220bar 31O BTDC

0.25 0.2 0.15

DIESEL CNG-DIESEL

0.1 0.05 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw) Fig19 - CO VS BP AT 220 BAR 31O BTDC

Figure 17, 18 and 19 shows variation of carbon monoxide with brake power curves for diesel and CNG-Diesel operation of the engine at 31 deg btdc and 180bar, 200bar and 220bar injection pressures respectively. The values are nearly 0.15% atlow loads of operation at all the three pressures and 0.22 at higher loads. The values for diesel are 0.01 at low loads and 0.07 at higher loads of operation.

30

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963 Smoke Density VS Brake Power 180bar 31O BTDC 80 70 60 50

DIESEL

40

CNG-DIESEL

30 20 10 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 20 - SMOKE DENSITY VS BP AT 180 BAR 31O BTDC

Smoke Density VS Brake Power for 200bar 31O BTDC

120 100 80

DIESEL

60

CNG-DIESEL

40 20 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 21 - SMOKE DENSITY VS BP AT 200 BAR 31O BTDC Smoke Density VS Brake Power for 220 bar 31O BTDC

80 70 60 50 40 30

DIESEL CNG-DIESEL

20 10 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 22 - SMOKE DENSITY VS BP AT 220 BAR 31O BTDC

Figure 20, 21 and 22 shows variation of smoke density with brake power curves for diesel and CNGDiesel operation of the engine at 31 deg btdc and 180bar,200bar and 220bar injection pressures respectively. The values 2 to 30ppm at low loads and 55 to 97 at higher load at three pressures when compared to 1to 71 for diesel from low load to high loads indicating higher temperatures of running with CNG-diesel.

31

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963 NOx VS Brake Power 180 bar 31O BTDC 180 160 140 120 100 80

DIESEL CNG-DIESEL

60 40 20 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw)

Fig 23 - Nox VS BP AT 180 BAR 31O BTDC NOx vs Brake Power for 200 bar 31O BTDC

160 140 120 100

DIESEL

80

CNG-DIESEL

60 40 20 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw) Fig 24 - Nox VS BP AT 200 BAR 31O BTDC NOx VS Brake Power for 220bar 31O BTDC

160 140 120 100

DIESEL

80

CNG-DIESEL

60 40 20 0 0

0.92

1.83

2.75

3.68

Brake Power (Kw) Fig 25 - Nox VS BP AT 220 BAR 31O BTDC

32

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ©IJAET ISSN: 2231-1963 Figure 23, 24 and 25 shows variation of oxides of nitrogen with brake power curves for diesel and CNG-Diesel operation of the engine at 31 deg btdc and 180bar,200bar and 220bar injection pressures respectively. At low loads it approaches to that of diesel with 22ppm and at higher loads it is 140ppm at all loads of operation due to higher temperatures of operation.

IV.

CONCLUSION

In this investigation the diesel engine have been set to run at compression ratio 20:1, advanced injection timing 31°bTDC and injector pressure 220bar to arrive at the optimum for jatropa oil methyl esters (JOME). In CNG-JOME dual fuel operation of the engine at 31 deg btdc, BSFC of 0.87 Kg/Kw-hr, 0.74 Kg/Kw-hr and 0.76 Kg/Kw-hr were obtained at low loads of operation at 180bar, 200bar and 220bar pressures. At higher loads the values are 0.29Kg/Kw-hr,0.26Kg/Kw-hr and 0.27Kg/Kw-hr for 180bar, 200bar and 220bar injection pressures respectively. BSFC at higher loads is even less than diesel operation at all pressures with advanced injection timings due to slow flame velocities and clean burning.

The values for CNG-Diesel (single fuel) for low load and higher loads are 0.83 and 0.32Kg/Kw-hr For CNG-Diesel at all the three injection pressures at low loads it is 0.83Kg/Kw-hr with very little variations and it is nearly equal to that of diesel at higher loads. This is because of better mixing and atomization of fuel at higher injection pressures. An increase in Brake thermal efficiency of 1.28% is obtained at higher loads when compared to base line diesel operation due to the advancement in injection timing. At low loads the UBHC is high and it reduces at high load conditions. Pressure variation does not have any effect on NOx and CO emissions but higher pressure causes higher value of smoke density.

Finally it can be concluded that CNG - JOME dual fuel mode could be used as alternative fuel for operating CI engine at compression ratio of 20:1, higher injector operating pressure of 220 bar and advanced injection timing of 31ºbTDC for optimum engine performance and lower emissions.

REFERENCES [1]. Agarawal.A.K. & Das.L.M. “Biodiesel development and characterization for use as a fuel in compression ignition engines”, pp. 440-447, Transactions of ASME, Vol.123, April 2001.

[2]. Avinash kumar Agarwal and Deepak Agarwal (2007) “Performance and emission characteristics of Jatropha oil (preheated and blends) in a direct injection compression ignition engine”Elsevier –Applied Thermal Engineering 2314-2323.

[3]. G.H. Abd Alla, H.A. Soliman, O.A. Badr, M.F. Abd Rabbo,“effect of pilot fuel quantity on the performance of a dual fuel engine” pp269-277,Energy Conversion and Management, Vol 43, 2002.

[4]. Karim G.A.(1983) “The dual fuel engine of compression ignition type –prospects, problems and solutions –A review” SAE Paper NO 831073, P3569.

[5]. Karim G.A. An Examination of some Measures for Improving the Performance Gas fuelled diesel engines at light load SAE Paper No912366,1991, p966.

[6]. Lakshminarayanarao G. and K.Rajagopal(2007) “Combustion Analysis of Diesel engine Fueled with jatropha oil methyl esters – Diesel blends ”Int Journal of Green Energy 2007.

[7]. Liu.Z and Karim.G.A. ”The Ignition delay period in dual fuel engines.”SAE Paper No 950466, 1995, p356.

[8]. Nwafor O.M.I “ Effect of Advanced Injection Timing on the performance of natural gas in Diesel Engine” Sadhana,Vol 25,part 1,2000,p11..Nwafor O.M.I,” Emission characteristics of Diesel engine operating on Rapeseed methyl ester”,Rewnewable Energy,vol.29,pp.119-129,2004.

[9]. Papagiannakis R.G. and Houtalas D.T. “Combustion and exhaust emission characteristics of dual fuel compression ignition engine operated with pilot diesel fuel and natural gas.” Energy and management 45, 2004, P2971 [10]. Sahoo P.K. and L.M.Das “(2009) Combustion analysis of jatropha, Karanja and Polanga based biodiesel as fuel in a diesel engine”Elsevier-Fuel 994-999.

[11]. Experimental investigation of performance and emission characteristics of oxygenated compounds in a DI diesel engine using split injection method “Indian Journal of Engineering and Material Science P.No 251-255 Vol17 (4) Aug 2010.

33

Vol. 6, Issue 1, pp. 21-34

International Journal of Advances in Engineering & Technology, Mar. 2013. ŠIJAET ISSN: 2231-1963

AUTHOR PROFILE: M. Venkatesan received the Ph. D Award from the International University of Contemporary Studies, Washington DC in 2009, Masters in Thermal Engineering (2001) and Bachelor Degree in Mechanical Engineering (1997) from University of Madras. He is currently working as Assistant Professor in Mekelle University – Ethiopia and he has also served as Vice Principal (Academics) in PMR Engineering College, Chennai, TamilNadu, India. He has more than 14+ years of experience in Teaching, Research and Administration at National and International Levels. His fields of interests are various, viz., Alternative fuels, Heat Transfer, Aeronautics, Design, and Supply chain Management. He has more than 10 publications to his credit both in National and International Journals and conferences and has authored 5 books on Engineering viz., Engineering Mechanics, Aero Engineering Thermodynamics, Fluid Mechanics and Fluid Machinery, Engineering Graphics and Workshop Practice as per Anna University Chennai regulation. He has dedicated his whole soul and life to research and education and he has been serving as Editorial Board Member, Advisory Board Member and Editor-in-Chief for International Journals.

34

Vol. 6, Issue 1, pp. 21-34