INTERNATIONAL JOURNAL OF ADVANCED RESEARCH IN ENGINEERING AND TECHNOLOGY (IJARET) International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN ISSN 0976-6480 (Print) ISSN 0976-6499 (Online) Volume 4, Issue 3, April 2013, pp. 26-32 IAEME: www.iaeme.com/ijaret.asp Journal Impact Factor (2013): 5.8376 (Calculated by GISI) www.jifactor.com IJARET I A E M E PERFORMANCE CHARACTERISTICS FOR THE USE OF BLENDED SAFFLOWER OIL IN DIESEL ENGINE A. Swarna Kumari 1*, Ch.Penchalayya 2, A.V. Sita Rama Raju 3, D.Vinay Kumar 4 1,2 Department of Mechanical Engineering, J. N. T. U. Kakinada, A.P, India 3 Department of Mechanical Engineering J. N. T. U. Hyderabad, A.P, India 4 Department of Mechanical Engineering, N.I.T.Warangal, AP, India ABSTRACT Looking for an alternative source of energy has gained vital importance in present scenario keeping in view the threat of exhaustion of fossil fuels in the future. Vegetable oils are a renewable and potentially inexhaustible source of energy with an energy content close to diesel fuel. In recent years, vegetable oils and bio-diesels have become more attractive as an alternative fuel for diesel engine because of its environmental benefits and it is made from renewable resources. Among different types of alternate fuels available, vegetable oils and their blends have come across the world as an alternative fuel. This paper presents the results of investigations carried out in studying the fuel properties of safflower oil and its blends with diesel from 20% to 100% by volume and running diesel engine with these fuels. The considered parameters are specific fuel consumption, brake specific fuel consumption, brake thermal efficiency, volumetric efficiency, air fuel ratio, emissions and smoke opacity evaluate single cylinder diesel engine running with the mentioned fuels. The increase in brake thermal efficiency and reduction in emissions made the blend of safflower oil, in particular suitable alternative fuel for diesel and can control air pollution. Key words: Alternative fuels, safflower diesel blends, diesel engine performance, emissions. INTRODUCTION Using straight vegetable oils in diesel engines is not an invention, Rudolf first used peanut oil as a fuel in his newly developed CI engine. Speaking to Engineering Society at St. Louis, Missouri, in 1912, said, the use of vegetable oils for engine fuels may seem insignificant today, but such oils may become in course of time as important as petroleum and the coal tar products of the present times. engines are the major source of transportation [1]. There is need to search the alternate fuel for the present diesel fuel. Due to depletion of fossil fuels and increasing exhaust emissions, nowadays the focus is on renewable energy fuels i.e., vegetable oils as an alternative to petroleum fuels and also its emissions are less as compared to existing diesel fuel. The use of pure vegetable oils causes failure in the fuel system and in components of the diesel engine due to its considerably high viscosity [2,3]. In order to cope with these problems, the viscosity of 26
vegetable oil can be decreased by heating the oil, blending with diesel fuel and esterification. Several investigators [4-7] conducted experiments with different edible and non-edible vegetable oils and diesel blends and literature suggests that vegetable oils can be substituted for diesel fuel if viscosity is reduced by blending it with diesel fuel. Most of the esterified oils tried in diesel engines was soybean, sunflower, rapeseed, palm oil and safflower oil. Though the mentioned oils are edible, because of their wide availability, reliability they were used as fuels. In the present investigation straight vegetable oil, safflower oil has been taken for study to substitute for diesel fuel. MATERIAL AND METHOD Engine tests were conducted on a single cylinder, four stroke diesel engines. Table 1: Fuel properties of different blends and diesel Property Density (kg/m 3 ) @ 28 o C Calorific Value(kJ/kg) Kinematic Viscosity (cst) @28 o C Make Type Rated output Table 2: Specifications of the engine setup (Preheate d raw oil) 832 841 852 863 874 876 43626 41345 39641 38448 37419 36325 2-4.5 3.28 4.14 5.18 6.24 28.34 Kirloskar oil engines Ltd.India Single cylinder DI, NA CI engine 3.68 kw Engine speed 1500 rpm Injection timing & pressure 23 0 CA BTDC & 220 kg/cm 2 Loading device Water Brake dynamometer Stroke 110 mm Bore 80 mm Compression ratio 16.5:1 EXPERIMENTAL METHODOLOGY The experimental setup consists of a single-cylinder, four-stroke, water cooled, vertical,, direct injection, naturally aspirated Kirloskar diesel engine connected to a water brake dynamometer for loading the engine. The specifications of the engine are given in Table 2. The engine was always running at its rated speed. The operating pressure of the nozzle was set at the rated value of 220 kg/cm 2.The governor of the engine was used to control the engine speed. Cooling of the engine was accomplished by supplying water through the water jackets on the engine block and cylinder head. The engine is coupled with eddy current dynamometer. 27
Smoke emissions were measured using NETEL smoke meter in HSU (Model No.NPM-SM- 111B). In the present work the fuel considered for investigation is Safflower oil. The fuel blends were prepared using an emulsifier to mix safflower and diesel at molar level and the investigation is to find the suitability of diesel engine with the prepared fuels at fuel injector opening pressure of 220 kg/cm 2. The following blends of safflower oil and diesel are prepared on volume basis. The instrument used for measuring volumes of each oil is measuring flask of capacity 1000ml. Oils are measured according to the blend ratios and taken into the emulsifier. Oils were measured according to the blend ratios and taken into the emulsifier (Fig2). For complete mixing of oils varies with the blend and the least time among them was for blend and more time for the blend for mixing. Table 1shows fuel properties of different blends and diesel. The engine was started with diesel fuel and warmed for 15 minutes and the experimental tests were conducted at no load, 20%, 40%, 60%, 80% and100% of maximum load for all fuels at 1500rpm (rated speed). All tests were repeated three times and the results were averaged. RESULTS AND DISCUSSION Fig 2: Emulsifier for the blend preparation The results concerning the performance and smoke opacity of the safflower diesel blends in comparison with the diesel are presented and discussed here. Fuel Consumption (kg/hr) 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 Fig 3:Variation of fuel consumption with respect to load 28
Fig.3 shows the variation of fuel consumption with load for Safflower oil and its blends with diesel. The blend with minimum fuel consumed by the engine is with 1.44 kg/hr and with diesel it is 1.576 kg/hr at higher loads because of better combustion. BSFC Vs Load @ 220 bar BSFC (kg/kw hr) 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 Fig 4: Variation of brake specific fuel consumption with respect to load Brake specific fuel consumption (BSFC) is a measure of volumetric fuel consumption for any fuel. From fig 4, the fuel, shows minimum brake specific fuel consumption, i.e., 0.391 kg/kwhr and with diesel 0.428 kg/kwhr at maximum load. It is also seen that at 80% loading shows less brake fuel consumption than diesel. This is mainly due to combined effects of fuel density, viscosity and heating value of blends. Brake Thermal Efficiency Vs Load @ 220 bar 25 Brake Thermal Efficiency (%) 20 15 10 5 0 120 Fig 5: Variation of brake thermal efficiency with respect to load The thermal efficiency is the ratio of the brake power obtained from the engine to the fuel energy supplied to the engine. Because the vegetable oil has a higher combustion efficiency due to its oxygen content, it improves the combustion when used in the blend. Consequently the thermal efficiency of the engine using the blend has increased, as shown in Fig.5. Brake thermal efficiency is an indication of the performance of the engine. With the safflower diesel blends, the diesel engine is performing better than that of diesel. The brake thermal efficiency of the engine is maximum with blend at maximum load, 23.3% were as with diesel it is 19.3%, with a rise of 4.0% thermal 29
efficiency. The combined effects of higher oxygen content and improved spray characteristics [9] may result in a higher burning rate of the blend over the diesel and pure safflower oil at higher loads contributing to the observed increase in thermal efficiency Volumetric Efficiency Vs Load @ 220 bar 85 Volumetric Efficiency (%) 80 75 70 65 60 Fig6:Variation of volumetric efficiency with respect to load The above figure shows the Comparison of Volumetric efficiency with load. The volumetric efficiency of the engine is more with than and diesel. 70 Air Fuel Ratio Vs Load @ 220 bar Air Fuel Ratio 60 50 40 30 20 10 0 Fig 7: Variation of Air Fuel Ratio with respect to load Figure 7 shows a comparison of Air Fuel Ratio with load. It is observed that with blend the air fuel mixture taken by the engine is more than that of diesel at full load which mean that the engine was run with lean mixture. It is 16.9 with and15.6 with diesel. 30
Smoke Opacity Vs Load @ 220 bar 100 80 60 B 40 20 0 Fig 8: Variation of smoke opacity with respect to load The formation of smoke primarily results from the incomplete burning of the hydrocarbon fuel and the partially reacted carbon content in the liquid fuel [10]. The results of smoke opacity were depicted in Fig. 8.The smoke opacity increased with the increase of the engine load as shown in Fig 8. The formation of smoke strongly depends on the engine load. As the load increases, more fuel is injected, and this increases smoke formation [11]. It is seen that with fuel smoke opacity is lower than that of diesel at all the loads i.e., from no load to full load. The engine can run with as the smoke opacity of the engine with is lower than diesel fuel at all the loads except 40% loading. Safflower oil in its pure form can be used as fuel at higher loading (60% - 100%) without any increase in smoke opacity. CONCLUSIONS From the experiments conducted with the safflower oil diesel blends the following conclusions can be made: The engine was run without any problem and requires no modification in engine hardware. The blend is the best fuel with minimum fuel consumption and minimum brake specific fuel consumption at higher loads. The blend is the best fuel with 4.0 % higher brake thermal efficiency (19.3% to 23.3%) than that of diesel fuel at full load. The blend had a better volumetric efficiency than diesel. The blend had a higher air fuel ratio than diesel at higher loading. Smoke opacity of the engine is minimized with the fuel and pure safflower oil can be used as fuel at higher loads (60-100%) without any increase in smoke opacity. Safflower oil and its blends can be used as an alternative fuel in the future. From the above, it is concluded that, fuel is the best substitution for diesel fuel because it gives better performance and less smoke as compared to that of diesel fuel. 31
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