The Effect of Load and the Methanol Percentage in the Blended Fuels on the Performance of Four Stroke Single Cylinder Water Cooled Diesel Engine

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 6, June 2014)

510

The Effect of Load and the Methanol Percentage in the Blended

Fuels on the Performance of Four Stroke Single Cylinder Water

Cooled Diesel Engine

T. Singha

1

, S. Sakhari

2

, T. Sarkar

3

, P. Das

4

, A. Dutta

5

1,2,3,4,5Department of Mechanical Engineering, Hooghly Engineering and Technology College, Vivekananda Road, Pipulpati,

Hooghly, PIN- 712103, West Bengal, India. Abstract— Experimentation about alternative fuels started

mostly after the oil crisis of 1980’s to 1990’s after the World War II. In order to reduce the use of petroleum product which are limited in nature, the idea of alternative fuels was developed. In this paper an attempt has been made to investigate the engine performance in a four stroke single cylinder water cooled diesel engine using pure diesel and methanol-diesel blended fuel. During the investigation the ratios of methanol: diesel was taken 6:94, 12:88 and 18:82 respectively by volume. The different loads considered during the analysis were 0 kg, 7 kg, 10.4kg, and 12.6 kg respectively. From the experimental study it has been revealed that for a constant break power, the consumption of fuel and friction power increases with the increase in percentage of methanol. Similarly, for a constant load the air fuel ratio and mechanical efficiency decreases with the increase in percentage of methanol. Whereas, break thermal efficiency and indicated thermal efficiency increases with the increase in percentage of methanol. In conclusion, among the different fuel blends, the blends containing 12% methanol concentration is the most suited for the CI engine due to its acceptable engine performance.

Keywords—engine performance, methanol-diesel blended fuel, ratio of methanol.

I. INTRODUCTION

The improvement of civilization and technology improve the transport which becomes an essential part of our life. As a result, the vehicles are increasing day by day. But the major problem is the energy sources of those vehicles which are mainly fossils fuels are limited and decreasing gradually. To fix this problem and decrease the consumption of fossils fuels, the idea of mixing blending of fuels and alternative fuels comes out.

Methanol, an oxidizing atom with a chemical formula CH3OH can be used as alternative fuel in case of diesel

engine. A lot of research had been done on the prospect of methanol as an alternative fuel.

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Results indicated that brake specific fuel consumption and nitrogen oxide emissions increased while brake thermal efficiency, carbon-monoxide and hydrocarbons decreased relative to single diesel fuel operation with increasing amount of methanol in the fuel mixture. Methanol diesel blended fuel burns more fully than that of diesel fuel which means 10% to 25% fuel saving In addition it is also eco-friendly and can reduce exhaust emissions by 40 to 80%. Xing-Cai et al [4] examined the Methanol-Diesel blend in 2004. The Cetane number improver of different percentages such as 0%, 0.2%, 0.4% was used in the fuel blends during experiments in high speed diesel engine to check engine performance. They observed an increase in Brake Specific Fuel Consumption (BSFC) and thermal efficiency, and a significant decrease in exhaust emissions; the combustion characteristics of Ethanol–Diesel blend fuel at large load are recommenced to conventional diesel oil, although variation remains at smaller load. In 2008 Jikar et al [5] carried out a comprehensive research on methanol as an alternative fuel. In this study, the diesel engine was tested using methanol blended with diesel at certain mixing ratio of 10:90, 20:80 and 30:70 of methanol to diesel respectively. Experimental results showed that the output power and torque for diesel fuel was lower compared to methanol-diesel blended fuel at any ratio. The best mixing ratio that produced the lowest Exhaust temperature was at 10% of Methanol in 90% of Diesel fuel. The exhaust temperature for diesel fuel was higher compared to any mixing of the blended fuel. The brake specific fuel consumption for the three mixing ratios was not varying significantly but the lowest was for 30% Methanol and 70% Diesel. The specific fuel consumption for diesel fuel was much lower compared to any mixing ratio. It was noticed that brake thermal efficiency was thus improved in almost all operation conditions with the methanol and diesel blended fuels. From the performance review of literature, it is observed that there exists a void as far as the study on the analysis of performance in a diesel engine with respect to load and different percentages of blended fuels are concerned. Therefore, in this paper an endeavour has been made to study the performance in a diesel engine with respect to various loads and percentages of blended fuels and suitable alternative of diesel.

II. MATHEMATICAL FORMULATION

The calorific value of pure diesel and different percentages of blended fuels have been assessed on the basis of experiment, which has been performed by the help of bomb calorimeter. The result has depicted on the TABLE I.

TABLE I

Blended Fuel Calorific Value (kJ/kg)

Pure diesel 42528.16

6:94 methanol: diesel 34264.42

12:88 methanol: diesel 33254.55

18:82methanol: diesel 30797.81

The mathematical formulation has given below [6].

Brake power (B.P) = 2πNT/ (60×1000) kW

Where,

N = speed in rpm,

T = torque in N-m

Fuel Consumption (F.C) =10×0.78×3600/tf×1000 kg/ hr.

Where,

tf = time for 10ml fuel in Sec.

In the graph BP plotted in the X-axis and FC in the Y- axis. From this Willian’s line was obtained and frictional power (FP) was found. For graph result refer FIGURE I.

Indicated power = (B.P + F.P) kW

Air consumption (ma) = Ca × A0 × Pa ×360 ×√2× g× h× a

Where,

AO = Area of orifice

Ca = Co-efficient of Discharge

Air fuel ratio = Air consumption / Fuel consumption

Heat equivalent to B.P (Q1) = B.P ×3600 kW

Heat equivalent to I.P (Q2) = I.P ×3600 kW

Mechanical Efficiency = %

Brake Thermal Efficiency (B.T.E) = %

Where,

Q1 = Heat equivalent to B.P

QS = Calorific value of a certain mixture

Indicated Thermal Efficiency (I.T.E) = %

Where,

Q2 = Heat equivalent to I.P

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International Journal of Emerging Technology and Advanced Engineering

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512 TABLE II F uel L o a d F uel Co ns um ptio n B re a k po wer (B .P ) F rict io n P o wer ( F .P ) Ind ica ted P o wer ( I. P ) Pu re d iesel

0 0.369 0 2.4 2.4

7 0.555 1.714 2.4 4.12

10.4 0.655 2.49 2.4 4.89

12.6 0.748 2.945 2.4 5.34

6 :9 4 m eth an o l: d iesel

0 0.39 0 2.7 2.7

7 0.6006 1.704 2.7 4.404

10.4 0.658 2.48 2.7 5.18

12.6 0.743 3.03 2.7 5.73

1 2 :8 8 m eth an o l: d iesel

0 0.452 0 3.0 3.0

7 0.668 1.704 3.0 4.704

10.4 0.755 2.49 3.0 5.49

12.6 0.855 2.96 3.0 5.96

1 8 :8 2 m eth an o l: d iesel

0 0.432 0 3.25 3.25

7 0.7335 1.705 3.25 4.95

10.4 0.741 2.515 3.25 5.76

12.6 0.769 3.026 3.25 6.27

TABLE III F uel L o a d Air fuel ra tio M ec ha nica l E ff icien cy B re a k T herma l E ff iciency Ind ica ted therma l E ff iciency Pu re d iesel

0 72.55 0 0 20.32

7 47.86 41.6 14.52 34.87

10.4 39.8 47.97 21.07 43.93

12.6 34.16 55.15 24.93 45.2

6 :9 4 m eth an o l: d iesel

0 69.33 0 0 28.36

7 44.22 38.69 17.9 46.27

10.4 38.84 47.8 26.05 54.42

12.6 35.42 52.8 31.83 60.2

1 2 :8 8 m eth an o l: d iesel

0 61.05 0 0 32.47

7 40.66 36.22 18.45 50.92

10.4 35.06 45.35 26.95 59.43

12.6 31.75 49.66 32.04 62.52

1 8 :8 2 m eth an o l: d iesel

0 53.09 0 0 37.98

7 36.2 34.37 19.9 57.89

10.4 35.83 43.62 29.4 67.38

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III. RESULT AND DISCUSSIONS

In this study, the effect of load and the methanol percentage in the blended fuels on the performance of a single cylinder four stroke diesel engine has been carried out. All the calculations during analysis have been performed on the basis of experimented result. The points on the graph shows the experimented results, on the basis of experimented results the extrapolation of the line has been made. Due to the knocking in the experimented engine the lines have been slightly overlapped. The intension of this study is to compare the performance of pure diesel and different type of blended fuel and also find out the most suitable blended mixture with acceptable engine performance in the experimented engine. The different load considered during the analysis is 0 kg, 7 kg, 10.4 kg, and 12.6 kg respectively.

A. The Effect of Change in Break Power (B.P) on Fuel Consumption (F.C)

Figure I

Table IV

From the FIGURE I, at a particular type of fuel, fuel consumption (FC) increases with the increase in load. Again at a particular load, fuel consumption increases with the decrease in methanol percentage in the blended fuel. The friction power (FP) can be obtained by extending brake power (BP) line on the negative y axis. This method is known as Willian’s line method.

B. The Effect of Load on Air –Fuel Ratio

Figure II

Table V

Methanol has an oxygenated atom with chemical formulae CH3OH. Due to the presence of oxygen in its

atomic structure, it exhibits a remarkable property of utilizing less amount of oxygen for combustion. Thus when it is used in blended proportion with diesel, it reduces the air-fuel ratio i.e. the stiochiometric ratio for combustion to take place.

At a particular load, the air-fuel ratio gradually increases with the decrease in percentage of methanol in the mixture. The air-fuel ratio is highest in case of pure diesel. Again at a particular mixture, air-fuel ratio decreases with the increase in load.

Variable Constant

1. Load

2. Methanol-

Diesel percentages

1. Water Flow rate

2. Ambient Temperature

3. Atmospheric pressure

Variable Constant

1. Load

2. Methanol-

Diesel percentages

1. Water Flow rate

2. Ambient Temperature

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International Journal of Emerging Technology and Advanced Engineering

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514 C. The Effect of Load on Mechanical Efficiency

Figure III

Table VI

Due to low calorific value, the mechanical efficiency of methanol is quite lower than that of diesel.

In the FIGURE III, change of mechanical efficiency with change in load and the different percentage of methanol in the blended mixture has shown. At a particular load, mechanical efficiency of the engine increases with the decrease in methanol percentage of the fuel. Similarly at a particular mixture, the mechanical efficiency increases with the increase in load.

D. The Effect of Load on Break Thermal Efficiency (B.T.E)

Figure IV

Table VII

Break thermal efficiency depends on the value of heat equivalent to B.P (Q1) of a certain load and calorific value

of a certain mixture (QS).

In the FIGURE IV, with the increase in load the B.P increases for a particular mixture. As B.P increases Q1 also

increases and so is the B.T.E. Similarly at a particular load, break thermal efficiency increase with the decrease in percentage of methanol in the mixture.

Variable Constant

1. Load

2. Methanol-

Diesel percentages

1. Water Flow rate

2. Ambient Temperature

3. Atmospheric pressure

Variable Constant

1. Load

2. Methanol-

Diesel percentages

1. Water Flow rate

2. Ambient Temperature

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International Journal of Emerging Technology and Advanced Engineering

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515 E. The Effect of Change in Load on Indicated Thermal

Efficiency (I.T.E)

Figure V

Table VIII

At a particular load, the I.T.E increases with the increase in percentage of methanol in the blended fuel. Again at a particular fuel, indicated thermal efficiency increases with the increase in load.

IV. CONCLUSION

The study in this paper presents the effect of load and the methanol percentage in the blended fuels on the performance of a single cylinder four stroke diesel engine. i.e. Fuel Consumption, Air –Fuel Ratio, Mechanical Efficiency, Break Thermal Efficiency and Indicated Thermal Efficiency for pure diesel and various ratios of blended fuels at different loads have been assessed. The results of these analyses provide the following conclusions.

1. The friction power is directly proportional to the percentage of methanol blended in the mixture when load is fixed. F.P. is lowest for the pure diesel and maximum for 18:82 methanol: diesel blended fuel.

2. At a particular load, the air-fuel ratio increases with the decrease in percentage of methanol in the mixture. The air-fuel ratio is highest in case of pure diesel. Again at a particular mixture, air-fuel ratio decreases with the increase in load.

3. At a particular load, mechanical efficiency of the engine increases with the decrease in methanol percentage of the fuel. Similarly at a particular mixture, the mechanical efficiency increases with the increase in load.

4. The break thermal efficiency increases with the increase of the percentage of methanol blended in the mixture at a constant load. Again, at a particular type of fuel, break thermal efficiency increases with the increase in load.

5. At a particular type of fuel, with the increment of load the indicated thermal efficiency also increases. Again, at a particular load the indicated thermal efficiency increases with the increase in percentage of methanol blend in the fuel.

The points on the graph shows the experimented results, on the basis of experimented results the extrapolation of the line has been made. Due to the knocking in the experimented engine the lines have been slightly overlapped. The slope of performance graph in case of pure diesel and 12: 88 methanol: diesel blended fuel are quite similar, that is why it may be concluded that, the aforesaid blended fuel could be the best possible alternative of pure diesel for the experimented engine.

Acknowledgement

The support of all the faculty members of Mechanical Engineering Department specially Mr. Uttam Kumar Samanta, Mr. Goutam Banerjee and Mr. Shantabrata Pal of Hooghly Engineering and Technology College, Hooghly, West Bengal, India, for providing help to conduct the experiment, the authors is acknowledged.

Nomenclature

C.V. = Calorific Value in kJ/kg. N = speed in rpm.

rpm = revolution per minute. tf = time for 10ml fuel in Sec.

AO = Area of orifice.

Ca = Co-efficient of Discharge.

T = torque in N-m. B.P = Brake Power in kW. F.P = Friction Power in kW. I.P = Indicated power in kW.

Variable Constant

1. Load

2. Methanol-

Diesel percentages

1. Water Flow rate

2. Ambient Temperature

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ma = Air consumption in kg/ hr.

Q1 = Heat equivalent to B.P kJ.

Q2 = Heat equivalent to I.P kJ.

QS = Calorific value of a certain mixture in kJ.

F.C = Fuel Consumption in kg/hr.

REFERENCES

[1] Hansen, C., Zhang, Q., and Lyne, P.W.L. 2005. Ethanol–Diesel Fuel Blends––A Review. Bioresource Technology, Vol. 96, pp. 277–285.

[2] Sayin, Ozsezen, A. N., and Canakci, M. 2010. The Influence of Operating Parameters on Performance and Emissions of CI Diesel Engine Using Methanol-Blended-Diesel Fuel. Fuel Vol. 89, pp. 1407-1414.

[3] Can, H., Murat, C., Ibrahim, Ö., Yakup, İ., Adnan, P., and Salman, M. S. 2008. Performance Characteristics of a Low Heat Rejection Diesel Engine Operating With Biodiesel. Renewable Energy, Vol. 33, pp. 1709-1715.

[4] Xing-cai, L. , Jian-guang,Y., Wu-gao, Z., and Zhen, H. 2004. Effect Of Cetane Number Improver On Heat Release Rate And Emissions Of High Speed Diesel Engine Fueled With Ethanol– Diesel Blend Fuel. Fuel, Vol. 83, pp. 2013–2020.

Figure

TABLE II TABLE III

TABLE II

TABLE III p.3
Figure II Table V

Figure II

Table V p.4
Table IV Methanol has an oxygenated atom with chemical Figure I 3OH. Due to the presence of oxygen in its formulae CHatomic structure, it exhibits a remarkable property of

Table IV

Methanol has an oxygenated atom with chemical Figure I 3OH. Due to the presence of oxygen in its formulae CHatomic structure, it exhibits a remarkable property of p.4
Figure III Table VI Figure IV

Figure III

Table VI Figure IV p.5
Table VI Table VIIVariable  Constant Variable

Table VI

Table VIIVariable Constant Variable p.5
Table VIII Figure V The points on the graph shows the experimented results, on the basis of experimented results the extrapolation of the line has been made

Table VIII

Figure V The points on the graph shows the experimented results, on the basis of experimented results the extrapolation of the line has been made p.6

References

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