Effect of Tangential Groove Piston on Diesel Engine with Jatropha Methyl Ester Ravindra R. Dhanfule 1, Prof. H. S. Farkade 2, Jitendra S. Pahbhai 3 1,3 M. Tech. Student, 2 Assistant Professor, Dept. of Mechanical Engineering Govt. College of Engineering, Amravati, MH, India Abstract The major part of all energy consumed worldwide comes from fossil sources. However these sources are limited and will be exhausted by the near future. Vegetable oils have become more attractive because of its environmental benefits. Vegetable oils are a renewable and potentially inexhaustible source of energy with an energetic content close to diesel fuel. The major problem associated with the use of pure vegetable oils as fuels for diesel engines are caused by high fuel viscosity in compression ignition engine. These problems can be minimized by the process of transesterification. In the present work experiments are conducted on D I diesel engine with tangential grooved piston, using jatropha methyl ester blends. The effect of tangential grooves on piston crown on the performance parameters in terms of Brake Specific Fuel Consumption (BSFC) and Brake Thermal Efficiency (BTE) for different engine loads and different blending ratios like B20, B40 and B60 are studied. Keywords Diesel engine, Jatropha methyl ester blends, Performance parameters, Tangential groove piston, I. INTRODUCTION The increasing industrialization, agricultural applications and motorization of the world has led to a steep rise for the demand of petroleum products. Petroleum based fuels are obtained from limited reserves. Therefore rising crude oil prices and the increasing concerns for environment problems [1]. The major part of all energy consumed worldwide comes from fossil sources (petroleum, coal and natural gas). However these sources are limited and will be exhausted by the near future. Thus looking for alternative sources of new and renewable energy, Alternative new and renewable fuels have the potential to solve many of the current social problems and concerns, from air pollution and global warming to other environmental improvements and sustainability issues [2]. Vegetable oils hold good promise as alternative fuel for diesel engines. They are biodegradable and renewable fuels [3]. Certain edible oils such as palm, sunflower, rapeseed and cottonseed and some of the non-edible oils such as Karanja (Pongamia pinnata), mahua (Madhuca Indica), castor, neem (Azadiracta indica), rice bran, linseed, jatropha (Jatropha curcas) etc. were tested to their performance in diesel engine. Since straight vegetable oils are not suitable as fuels for diesel engines, they have to be modified to bring their combustion related properties closer to diesel. This fuel modification is mainly aimed at reducing the viscosity to eliminate flow or atomization related problem [4]. A number of vegetable oils like rapeseed oil, neem oil, palm oil, karanji oil, coconut oil, cottonseed oil, jatropha oil, etc., were tested to evaluate their performance in diesel engines. Among these, jatropha oil was found as the most suitable for diesel. 90 C preheating is sufficient to bring physical and chemical properties of neat jatropha oil close to diesel for safe operation of fuel without any engine modification [5]. It is well known that in DI diesel engines swirl motion is needed for proper mixing of fuel and air. Moreover, the efficiency of diesel engines can be improved by increasing the burn rate of fuel air mixture. This can be achieved in two ways; one by designing the combustion chamber in order to reduce contact between the flame and the chamber surface, and two by providing the intake system so as to impart a swirl motion to the incoming air [7]. R.V. Ravikrishna studied the effect of swirl by re-entrant piston bowl geometry using Computational Fluid Dynamics (CFD) simulations. This re-entrant chamber produces the higher turbulence in the chamber [8]. V.V Prathiba investigated that by cutting grooves on the piston crown will affect the swirl for better mixing and hence reduction in brake specific fuel consumption (BSFC) and smoke [9]. C.V. Subba Reddy reported that Combustion chamber geometry have significance influence on the engine performance, the combustion chamber with the four tangential grooves on the piston crown will effect on air flow motion in the piston bowl hence there will be improvement in combustion efficiency which is due to formation of homogeneous mixture of fuel with air and greater turbulence in the cylinder [6]. The combustion efficiency in the combustion chamber depends on the formation of homogeneous mixture of fuel with air. The formation of homogenous mixture depends on the amount of turbulence created in the combustion chamber. 184
As the piston approaches the TDC, the part of compressed air enters the bowl through the tangential grooves and forms a swirl ring in the combustion bowl which increases combustion efficiency due to better evaporation and mixing of fuel with air better efficiency is obtained [6,10]. A. Transesterification Biodiesel is produced from the triaglycerol containing material by means of a transesterification reaction [11]. Transesterification is otherwise known as alcohol-sis. It is the reaction off at or oil with an alcohol to form esters and glycerin. A catalyst is used to improve their action rate and yield [1]. The formation of methyl esters by transesterification of vegetable oil requires raw oil (Jatropha oil), 15% of methanol and 5%of KOH on mass basis. However, transesterification is an equilibrium reaction in which excess alcohol is required to derive the reaction with an alcohol in presence of a catalyst to produce methyl esters. Glycerol was produced as a byproduct of transesterification reaction. The mixture was stirred continuously and then allowed to settle under gravity in a separating funnel. Two distinct layers form after gravity settling for 24 hrs. The upper layer was of Jatropha methyl esters and lower was of glycerol. The lower layer was separated out. The separated Jatropha methyl ester was mixed with some warm water (around 10% volume of ester) to remove the catalyst present in ester and allowed to settle under gravity for another 24 hrs. The catalyst got dissolved in water, which was separated and removed the moisture. The Jatropha methyl ester was then blended with mineral diesel in various concentrations for preparing biodiesel blends to be used in CI engine for conducting various engine tests [12,13,14]. The tangential groove depth is 2 mm and width is 6.5 mm. The various properties of the above biodiesel are presented in Table I. TABLE I PROPERTIES OF FUEL Properties Jatrpha oil Diesel Density (kg/m 3 ) Calorific Value (kj/kg) Viscosity @400C(cSt) Cetan Number Flash Point ( o C) 862 830 39230 43000 4.8 2.75 51 45 135 74 IV. EXPERIMENTAL SETUP II. OBJECTIVE OF THE STUDY The present study is to investigate the effect of tangential grooves piston on diesel engine fuelled with jatropha methyl ester blends at 170 bar injection pressure for which the diesel engine delivers better efficiency and there by the suitable replacement for diesel oil. To achieve the better efficiency, the following experiments are carried out as explained below. Figure 1. Block Diagram of the Experimental Setup III. MATERIAL AND METHODOLOGY In the present study, four tangential grooves were produced on a piston of 80 mm diameter and their performance compared with without tangential groove piston by using jatropha methyl ester blends. Figure 2. Tangential Groove Piston 185
A Kirloskar make single cylinder four stroke, naturally aspirated, direct injection, air-cooled diesel engine test rig of 3.72 kw (5BHP) with 1500 RPM, is directly coupled to a rope brake dynamometer. The fuel flow rate measured by burette and stop watch, exhaust gas temperatures measured by thermocouple and digital display, loads are applied by rope brake dynamometer at constant rpm 1500 which is measured by contact type tachometer and at constant fuel injection pressure 170 bar. Calculations are done for torque, brake power, brake specific fuel consumption, brake thermal efficiency. The fuels used are diesel, B20, B40, B60.Their result compared. Blends are used in following composition. A. Brake Thermal Efficiency V. RESULTS AND DISCUSSION with BLE-5 and BLE-1 is shown in figure 3. It was observed that brake thermal efficiencies of BLE-5 were found to be higher at all load levels than BLE-1. The percentage increase in brake thermal efficiencies are 3.82 for 3.35kW, 4.28 for 2.875kW and 2.68 for 2.39kW. 2.875 kw. BLE-5 is found to have the maximum thermal efficiency of 33.40% at a brake power of 3.35 kw while for BLE-1 it is 32.17%. TABLE II BLEND RATIO Sr. no. Blends Jatropha methyl ester (%) Diesel (%) 1 0BD 00 100 2 20BD 20 80 3 40BD 40 60 4 60BD 60 40 Experiments are conducted on D.I. diesel engine with following configurations. 1. BLE-1: Base line engine with diesel fuel. 2. BLE-2: Base line engine with 20BD 3. BLE-3: Base line engine with 40BD. 4. BLE-4: Base line engine with 60BD. 5. BLE-5: Base line engine with tangential grooves size diesel. 6. BLE-6: Base line engine with tangential grooves size 20BD. 7. BLE-7: Base line engine with tangential grooves size 40BD. 8. BLE-8: Base line engine with tangential grooves size 60BD. The steady state engine performance testing was carried out with diesel fuel and its blends. Figure 3. Variation of Brake Thermal Efficiency with Brake Power for BLE-1 and BLE-5 with BLE-6 and BLE-2 is shown in figure 4. It was observed that brake thermal efficiencies of BLE-6 were found to be higher at all load levels than BLE-2. The percentage increase in brake thermal efficiencies are 4.08 for 3.35kW, 3.78 for 2.875kW and 1.83 for 2.39kW. 3.35 kw. BLE-6 is found to have the maximum thermal efficiency of 32.60% at a brake power of 3.35 kw while for BLE-2 it is 31.32%. Figure 4. Variation of Brake Thermal Efficiency with Brake Power for BLE-2 and BLE-6 186
with BLE-7 and BLE-3 is shown in figure 5. It was observed that brake thermal efficiencies of BLE-7 were found to be higher at all load levels than BLE-3. The percentage increase in brake thermal efficiencies are 5.98 for 3.35kW, 3.79 for 2.875kW and 5.12 for 2.39kW. 3.35 kw. BLE-7 is found to have the maximum thermal efficiency of 31.69% at a brake power of 3.35 kw while for BLE-3 it is 29.90%. B. Brake Specific Fuel consumption Figure 5. Variation of Brake Thermal Efficiency with Brake Power for BLE-3 and BLE-7 with BLE-8 and BLE-4 is shown in figure 6. It was observed that brake thermal efficiencies of BLE-8 were found to be higher at all load levels than BLE-4. The percentage increase in brake thermal efficiencies are 5.34 for 3.35kW, 4.34 for 2.875kW and 2.77 for 2.39kW. 3.35 kw. BLE-8 is found to have the maximum thermal efficiency of 30.16% at a brake power of 3.35 kw while for BLE-4 it is 28.63%. Figure 7. Variation of Brake Specific Fuel Consumption with Brake Power for BLE-1 and BLE-5 BLE-1 and BLE-5 at different loads is shown on figure 7. It was observed that brake specific fuel consumptions of BLE- 5 were found to be lower at all load levels than BLE-1. The percentage decrease in brake specific fuel consumptions are 3.68 for 3.35kW, 4.09 for 2.875kW and 2.59 for 2.39kW. Maximum decrease in brake specific fuel consumption occurred at 2.875 kw. BLE-5 is found to have the minimum brake specific fuel consumption of 0.2506 kg/kw-hr at a brake power of 3.35 kw while for BLE-1 it is 0.2602 kg/kw-hr. BLE-2 and BLE-6 at different loads is shown on figure 8. It was observed that brake specific fuel consumptions of BLE- 6 were found to be lower at all load levels than BLE-2. The percentage decrease in brake specific fuel consumptions are 3.39 for 3.35kW, 3.63 for 2.875kW and 3.65 for 2.39kW. Maximum decrease in brake specific fuel consumption occurred at 2.39 kw. BLE-6 is found to have the minimum brake specific fuel consumption of 0.2613 kg/kw-hr at a brake power of 3.35 kw while for BLE-2 it is 0.2720 kg/kw-hr. Figure 6. Variation of Brake Thermal Efficiency with Brake Power for BLE-4 and BLE-8 187
Figure 8. Variation of Brake Specific Fuel Consumption with Brake Power for BLE-2 and BLE-6 BLE-3 and BLE-7 at different loads is shown on figure 9. It was observed that brake specific fuel consumptions of BLE- 7 were found to be lower at all load levels than BLE-3. The percentage decrease in brake specific fuel consumptions are 5.67 for 3.35kW, 3.63 for 2.875kW and 4.89 for 2.39kW. Maximum decrease in brake specific fuel consumption occurred at 3.35 kw. BLE-7 is found to have the minimum brake specific fuel consumption of 0.2737 kg/kw-hr at a brake power of 3.35 kw while for BLE-3 it is 0.2901 kg/kw-hr. Figure 10. Variation of Brake Specific Fuel Consumption with Brake Power for BLE-4 and BLE-8 BLE-4 and BLE-8 at different loads is shown on figure 10. It was observed that brake specific fuel consumptions of BLE-8 were found to be lower at all load levels than BLE-4. The percentage decrease in brake specific fuel consumptions are 5.08 for 3.35kW, 4.16 for 2.875kW and 2.59 for 2.39kW. Maximum decrease in brake specific fuel consumption occurred at 3.35 kw. BLE-8 is found to have the minimum brake specific fuel consumption of 0.2929 kg/kw-hr at a brake power of 3.35 kw while for BLE-4 it is 0.3086 kg/kw-hr. C. Exhaust Gas Temperature The variation of the exhaust gas temperature of BLE-5 and BLE-1 at different loads is shown on figure 11. It was observed that exhaust gas temperatures of BLE-5 were found to be higher at all load levels than BLE-1. The percentage increase in exhaust gas temperatures are 2.94 for 3.35kW, 2.78 for 2.875kW and 2.20 for 2.39kW. Maximum increase in exhaust gas temperature occurred at 3.35 kw. BLE-5 is found to have the maximum exhaust gas temperature of 280 o C at brake power of 3.35 kw while for BLE-1 it is 272 o C. Figure 9. Variation of Brake Specific Fuel Consumption with Brake Power for BLE-3 and BLE-7 188
The percentage increase in exhaust gas temperatures are 3.18 for 3.35kW, 2.29 for 2.875kW and 2.96 for 2.39kW. Maximum increase in exhaust gas temperature occurred at 3.35 kw. BLE-7 is found to have the maximum exhaust gas temperature of 292 o C at brake power of 3.35 kw while for BLE-3 it is 283 o C. Figure 11. Variation of Exhaust Gas Temperature with Brake Power for BLE-1 and BLE-5 Figure 13. Variation of Exhaust Gas Temperature with Brake Power for BLE-3 and BLE-7 Figure 12. Variation of Exhaust Gas Temperature with Brake Power for BLE-2 and BLE-6 The variation of the exhaust gas temperature of BLE-6 and BLE-2 at different loads is shown on figure 12. It was observed that exhaust gas temperatures of BLE-6 were found to be higher at all load levels than BLE-2. The percentage increase in exhaust gas temperatures are 2.11 for 3.35kW, 2.73 for 2.875kW and 2.15 for 2.39kW. Maximum increase in exhaust gas temperature occurred at 2.875 kw. BLE-6 is found to have the maximum exhaust gas temperature of 284 o C at brake power of 3.35 kw while for BLE-2 it is 278 o C. The variation of the exhaust gas temperature of BLE-7 and BLE-3 at different loads is shown on figure 13. It was observed that exhaust gas temperatures of BLE-7 were found to be higher at all load levels than BLE-3. Figure 14. Variation of Exhaust Gas Temperature with Brake Power for BLE-4 and BLE-8 The variation of the exhaust gas temperature of BLE-8 and BLE-4 at different loads is shown on figure 14. It was observed that exhaust gas temperatures of BLE-8 were found to be higher at all load levels than BLE-4. The percentage increase in exhaust gas temperatures are 2.74 for 3.35kW, 2.62 for 2.875kW and 2.89 for 2.39kW. Maximum increase in exhaust gas temperature occurred at 2.39 kw. BLE-8 is found to have the maximum exhaust gas temperature of 299 o C at brake power of 3.35 kw while for BLE-4 it is 291 o C. 189
VI. CONCLUSIONS The brake thermal efficiency of diesel engine increased for tangential groove piston for all fuels (diesel, B20, B40, B60). This is due to the swirling motion of air in combustion chamber. The brake specific fuel consumption of diesel engine decreased for tangential groove piston for all fuels (diesel, B20, B40, B60). Brake thermal efficiencies for BLE-6 and BLE-7 closer to BLE-1 and greater than BLE-2 and BLE-3. Maximum percentage increase in brake thermal efficiency occurred for BLE-7 than BLE-3 is 5.98. Maximum percentage decrease in brake specific fuel consumption occurred for BLE-7 than BLE-3 is 5.67. The exhaust gas temperatures are increased for tangential groove piston for all fuels (diesel, B20, B40, B60). It is concluded that jatropha methyl ester with the base line engine with tangential grooves proved to be another option for diesel. REFERENCES [1] Sagar P.Kadu, R.H. Sarda, Use of vegetable oils by transesterification method as C.I. engines fuels: A Technical Review, JERS, vol.2, issue 3, 2011, 19-26. [2] Ram Prakash, S. P. Pandey, S. Chatterji, performance analysis of C.I.engine using jatropha Oil and their esters., IJAET, vol.2, issue 2, 2011, 186-191. [3] M. Nematullah Nasim, Ravindra Babu Yarasu and Jehad Yamin, Simulation of CI engine powered by neat vegetable oil under variable fuel inlet temperature, Indian Journal of Science and Technology, vol. 3 no. 4, Apr. 2010, 387-392. [4] P. P. Sonune, H. S. Farkade, Performance and emissions of CI engine fuelled with preheated vegetable oil and its blends A Review, IJEIT, vol. 2, Issue 3, September 2012, 123-128. [5] M. Nematullah Nasim, Ravindra Babu Yarasu and R. H. Sarda, Experimental investigation on compression ignition engine powered by preheated neat jatropha oil, Journal of Petroleum Technology and Alternative Fuels, vol. 4(7), July 2013, 119-114. [6] C.V. Subba Reddy, K. Hemachandra Reddy, C. Eswar Reddy, Effect of tangential grooves on piston crown of diesel engine with preheated cotton seed oil., International Journal of Emerging Research in Management &Technology, vol. 2, issue 4, April 2013, 6-12. [7] C.V. Subba Reddy, K. Hemachandra Reddy, C. Eswar Reddy, Effect of tangential grooves on piston crown of D.I. diesel engine with retarded injection timing., IJERD, vol.5, issue 10, January 2013, 01-06. [8] B.V.V.S.U. Prasad, C.S. Sharma, T.N.C. Anand, R.V. Ravikrishna, High swirl-inducing piston bowls in small diesel engines for emission reduction, Applied Energy 88, 2011, 2355 2367. [9] V. V. Prathibha Bharathi and G. Prasanthi, Influence of in cylinder air swirl on diesel engine performance and emission, International Journal of Applied Engineering and Technology, vol. 1, October- December 2011, 113-118. [10] C.V. Subba Reddy, K. Hemachandra Reddy, C. Eswar Reddy, effect of tangential grooves on piston crown of D.I. diesel engine with blends of cotton seed oil methyl easter., IJRRAS,vol. 13, issue 1, Octomber 2012. [11] Darunde Dhiraj S., Prof. Deshmukh Mangesh M., Biodiesel production from animal fats and its impact on the diesel engine with ethanol-diesel blends: A Review, International Journal of Emerging Technology and Advanced Engineering, ISSN 2250-2459, vol. 2, issue 10, October 2012, 179-185. [12] D. Agrawal, L. Kumar, A. K. Agrawal, Performance evaluation of vegetable oil fuelled CI engine., Renewable Energy, June 2007. [13] M. A. Fangrui, M. A. hanna, Biodiesel Production:Areview., Biosource Technology, vol.70,1999, 1-15. [14] Mukesh A. Mane, Karanja oil as an alternative fuel for direct injection CI engine- A Review, International Journal of Science and Research, vol. 2, issue 10, October 2013, 203-206. 190