American International Journal of Research in Science, Technology, Engineering & Mathematics Available online at http://www.iasir.net ISSN (Print): 2328-3491, ISSN (Online): 2328-3580, ISSN (CD-ROM): 2328-3629 AIJRSTEM is a refereed, indexed, peer-reviewed, multidisciplinary and open access journal published by International Association of Scientific Innovation and Research (IASIR), USA (An Association Unifying the Sciences, Engineering, and Applied Research) Effect of Injection Pressure on Performance of CIDI Engine Fuelled with Jatropha Curcas Biodiesel Sirivella Vijaya Bhaskar* #, G.Satish Babu* *Department of Mechanical Engineering, JNTUH University, Hyderabad. TS, India Abstract: In this work, the objective is to investigate the effect of variation of fuel injection pressure on the performance characteristics such as Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), Brake Specific Energy Consumption (BSEC) and Exhaust Gas Temperature (EGT) of compression ignition direct injection (CIDI) engine when fuelled with Jatropha Curcas Oil Methyl Ester (JCOME). The experimental results of a single cylinder, four-stroke, water cooled diesel engine fuelled with different blends (B20J, B40J, B60J and B100J) of JCOME at different fuel injection pressures have shown that neat biodiesel has lower BTE, higher BSFC, BSEC and moderately higher EGT at all tested injection pressures. The biodiesel percentage in blend is affecting inversely proportional to performance characteristics. The performance characteristics are optimal at fuel injection pressure of 220 bar and it can be treated as optimum injection pressure with reference to performance parameters. I. Introduction In the past few decades, the production of biodiesel from the vegetable oils has gained momentum due to rapid inflation of fossil fuel reserves, volatile crude oil prices, and hazardous environmental pollution. Many researchers have identified that neat vegetable oil or its diesel blends can be used in diesel engine as fuel without any engine modifications for all blend ratios. But it is not desirable for long period operations which raised critical problems such as piston ring sticking, injector coking, and thickening of the lubricating oil in the diesel engine [1-3]. This is because of high viscosity, density and low volatility of biodiesel. The previous studies have revealed that heating of biodiesel feedstock, blending oil with diesel and transesterification are some of the methods used to reduce viscosity and to improve its engine performance. The biodiesel, produced through transesterification process with lower alcohols such as ethanol, methanol as fuel resolves all mentioned issues. Currently, many nations are encouraging the blend of biodiesel as alternative to petro-diesel to promote rural employment and economic growth, to develop a long term replacement renewable fuel, to minimize the dependency on the petroleum imports and to increase the energy security [4]. The past research was primarily focused on evaluation of engine characteristics without any changes in the engine parameters to identify the suitable alternative fuel. Recent studies on IC engines revealed that engine operational and design parameters such as load, biodiesel blend percentage, compression ratio, injection timings and injection pressure has significant effect individually or groups of parameters on the engine performance and emission properties. Murthy et.al were conducted experiments using vegetable oil as fuel in a conventional diesel engine, which showed the deterioration in the performance, while low heat rejection (LHR) engines demonstrated improved performance, when compared to diesel operation on conventional diesel engine [5]. Naga Raja et.al., were investigated the performance of palm oil fuelled engine, which increased with the heating of oil. The exhaust emissions of palm oil were slightly higher than that of diesel fuel. They noticed that carbon deposits, fuel filtering problems, lubricating oil dilution were still evident even after its heating to 80 0 C [6]. Shankar et al. were used Coconut oil as fuel and compared its results with diesel fuel. The effect of injection pressure on the performance and emission characteristics of biodiesel blends of B20, B30 and B100 at four different injection pressures from 160 to 180 bar with 20 bar increments were studied experimentally. From the investigations it was found that 200 bar was the optimum injection pressure with B20 and B30 blends, which resulted in better performance and emission characteristics with biodiesel blends as fuel [7]. İsmet Çelikten et.al have carried-out experiments with methyl esters of rapeseed and soybean oils in a diesel engine to evaluate the performance and emissions of engine and compared with diesel fuel. The tests were conducted at different injection pressures such as 200 bar, 300 bar, 350 bar with each of these fuel in order to evaluate the engine performance. Results revealed that the performance and emission values of rapeseed oil and soybean oil methyl esters were found to be nearly the same with those of diesel fuels when injection pressure was increased to 300 bar [8]. Raheman et.al were performed tests to evaluate the performance of Ricardo E6 engine using biodiesel obtained from Mahua oil (B100) and its blend with high speed diesel (HSD) at varying compression ratio (CR), injection timing (IT) and engine loading (L) has been investigated. The brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT) AIJRSTEM 16-206; 2016, AIJRSTEM All Rights Reserved Page 14
increased, whereas brake thermal efficiency (BTE) decreased with increase in the proportion of biodiesel in the blends at all compression ratios (18:1 20:1) and injection timings (35 45 before TDC) tested. However, a reverse trend for these parameters was observed with increase in the CR and advancement of IT. The BSFC of B100 and its blends with high speed diesel reduced, whereas BTE and EGT increased with the increase in loading for the range of CR and injection timing tested [9]. Avinash Kumar Agarwal et al. were conducted the performance and emissions characteristics of single cylinder diesel engine with diesel and blends of Jatropha oil at different loads and confirmed that the thermal efficiency was lower for Jatropha oil blends and BSFC and EGT were higher than that of diesel fuel. However the emissions from the engine with biodiesel were much lower than that of diesel [10]. The present research work is aimed to evaluate the effect of injection pressure on performance characteristics in terms of Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), Brake Specific Energy Consumption (BSEC) and Exhaust Gas Temperature (EGT) of a single cylinder diesel engine using jatropha curcas oil methyl ester (JCOME) as fuel. II. Materials and Methods The jatropha curcas oil used in this study was collected from a local vendor and transesterification process was carried-out to reduce the viscosity of the oil and to prepare the jatropha curcas biodiesel. In the transesterification process, the carbonyl carbon of the starting ester (RCOOR) undergoes nucleophilic attack by the arriving alkoxide (R2O ) to give a tetrahedral intermediate, which either reverts to the starting material, or proceeds to the transesterified product (RCOOR2). The various species exist in equilibrium, and the product distribution depends on the relative energies of the reactant and product. Figure 1 Transesterification Reaction. The fuel properties of diesel fuel and JCOME are shown in Table I. Table I: Diesel Fuel and Jatropha Curcas Biodiesel Properties. ASTM Fuel Property Unit Diesel JCOME Standards Kinematic Viscosity @ 40 0 C CST D445 3.52 5.4 Flash Point 0 C D93 49 169 Density @ 30 0 C kg/m 3 D1298 830 872 Calorific Value kj/kg D4868 42850 38500 Cetane Number -- D613 50 53 Ash % by mass D1119 0.01 0.03 III. Experimental Setup The experimental set-up which was used for the present study consists of a single cylinder water cooled and fourstroke diesel engine of 3.7 KW power as shown in Figure 2. An eddy current dynamometer of water cooling was used as loading unit. The instrumentation attached to the test rig measures the air consumption, fuel consumption, in cylinder pressure, crank angle, cooling water flow rate, exhaust gas temperature. A separate gas analyser was used which was coupled to the computerized test rig to measure the emissions. The lubricating oil, fuel and ambient temperatures are measured by thermocouples.the computed values are recorded by considering the error analysis of the respective devices. The specifications of the engine are given below in Table II. Table II: Engine Specifications Type Details Bore & Stroke Rated Power Kirloskar, AV1 Single cylinder, Direct injection, 4-Stroke, Water cooled engine 80 110 mm 3.7 KW at 1500 rpm Compression Ratio 16.5 :1 Rated Injection Pressure 200 bars AIJRSTEM 16-206; 2016, AIJRSTEM All Rights Reserved Page 15
Figure 2 Experimental Setup. Nomenclature: 2: Outlet engine Jacket Water Temperature ( 0 C); 3: Inlet water temperature ( 0 C); 4 & 6: Exhaust Gas Temperature before and after Calorimeter ( 0 C); 12: Pressure Transducer IV. Results and Analysis A. Brake Thermal Efficiency (BTE) Figure 3 shows the variation of brake thermal efficiency with injection pressure at constant engine speed of 1500 rpm. As shown in graph, increase of BTE was observed from 200 bar to 220 bar of injection pressure and decreased afterwards. The highest BTE was noticed at fuel injection pressure of 220 bar and can be considered as optimum injection pressure. The reduction of BTE was observed with the increase of biodiesel percentage in the blend. Figure 3 Injection Pressure vs. BTE for different blends of Jatropha Biodiesel 34 33 32 31 B20J B40J B60J B100J 30 BTE (%) 29 28 27 26 25 24 B. Brake Specific Fuel Consumption (BSFC) Figure 4 shows variation of BSFC at different fuel injection pressures. The higher BSFC observed at rated injection pressure of 200 bar. The graph clearly indicated that the BSFC has decreased initially and then raised like U curve. The low BSFC was noticed at 220 bar of injection pressure. As the biodiesel content percentage increases in the blend, the BSFC also increased. AIJRSTEM 16-206; 2016, AIJRSTEM All Rights Reserved Page 16
Figure 4 Injection Pressure vs. BSFC for different blends of Jatropha Biodiesel 0.36 B20R B40R B60R B100R BSFC (kg/kw-h) 0.32 0.28 C. Brake Specific Energy Consumption (BSEC) Brake specific energy consumption (BSEC) can be defined as the energy required producing a unit power in unit time. Figure 5 illustrates the variation of BSEC with injection pressure for different blends of jatropha biodiesel. The BSEC of the engine with neat jatropha biodiesel at all engine loads is higher and B20 biodiesel was lower when compared with all blends. This is because of the lower calorific value of biodiesel. For addition of 20% biodiesel content in the blend increasing the brake specific energy consumption (BSEC). Figure 5 Injection Pressure vs. BSEC for different blends of Jatropha Biodiesel 14 B20R B40R B60R B100R BSEC (MJ/kW-h) 13 12 11 D. Exhaust Gas Temperature (EGT) The exhaust gas temperature (EGT) reflects the utilization of energy by the engine, which in turn represents the engine s thermal efficiency. Figure 6 shows the variation of EGT with the injection pressure for different blends of jatropha biodiesel. B20 blend has lowest and jatropha biodiesel in its neat form has highest EGT when compared with all blends. EGT initially decreased from 200 bar to 220 bar and then increased, but 220 bar has lowest exhaust temperature. As biodiesel content in the blend increases, the EGT has increased. AIJRSTEM 16-206; 2016, AIJRSTEM All Rights Reserved Page 17
Figure 6 Injection Pressure vs. EGT for different blends of Jatropha Biodiesel 350 340 B20J B40J B60J B100J 330 EGT (0C) 320 310 300 290 V. Conclusions The fuel injection pressure is one of the significant engine parameters that affect the performance characteristics of diesel engine. The present test results of single cylinder, 4-stroke, water cooled diesel engine fuelled with different blends (BR20, BR40, BR60 and BR100) of jatropha curcas biodiesel at fuel injection pressures of 200 bar, 210 bar, 220 bar, 230 bar and 240 bar at full load condition revealed that BR20 blend has highest brake thermal efficiency (BTE), lowest BSFC, BSEC and EGT when compared with all blends of biodiesel. The optimum engine performance characteristics were found at 220 bar of injection pressures. The results have also revealed that the BTE has decreased and the BSFC, BSEC and EGT increased with the increase of biodiesel percentage of JCOME in the blend. References [1] Ziejewski M, Goettler H, Pratt GL. Comparative analysis of the long-term performance of a diesel engine on vegetable oil based alternative fuels. Society of Automotive Engineers Paper No. 860301. SAE, Warrendale, PA, 1986. [2] Schlick ML, Hanna MA, Schinstock JL. Soybean and sunflower oil performance in a diesel engine. Transactions of the ASAE 1988; vol.31(5), pp.1345 9. [3] Graboski MS, McCormick RL. Combustion of fat and vegetable oil derived fuels in diesel engines. Progress in Energy and Combustion Science 1998; vol. 24,pp.125 64. [4] Moser BR. Biodiesel production, properties, and feedstocks. In Vitro Cell Dev Pl 2009, pp.45:229 66. [5] P. V. K. Murthy, M.V.S. Murali Krishna, Performance, Emissions and Combustion Characteristics of Mohr Oil in Crude and Biodiesel Form in High Grade Low Heat Rejection Diesel Engine Int. Journal of Engineering Research and Applications 2248-9622, vol. 3 (6), 2013, pp.215-227. [6] C. Naga Raja, Dr.B.S.P. Kumar,Dr.K. Raja Gopal, Study of emission characteristics of a palm oil fuelled 5 hp diesel engine, International Conference On IC Engines(Iconice),Dec 6-9,2007,pp.192-196. [7] Shankar K.S, Vijay Desai, Mohanan P, The Effect Of Injection Pressure On The Performance And Emission Charactersticks Of A Biodiesel Fueled Dorect Injection Sngle Cylinder 4-S Diesel Engine, International Conference On IC Engines(ICONICE),Dec 6-9, 2007, pp.27-33. [8] İsmet Çelikten, Atilla Koca and Mehmet Ali Arslan, Comparison of performance and emissions of diesel fuel, rapeseed and soybean oil methyl esters injected at different pressures, Renewable Energy,vol.35 ( 4), Dec. 2009, pp. 814-820. [9] H. Raheman, S.V. Ghadge, Performance of diesel engine with biodiesel at varying compression ratio and ignition timing, Fuel, vol. 87 (12), September 2008, pp. 2659-2666. [10] Avinash Kumar Agarwal, Atul Dhar, Performance, Emission and Combustion Characteristics of Jatropha Oil Blends in a Direct Injection CI Engine, SAE Tech papers, 2009-01-0947, 2009. AIJRSTEM 16-206; 2016, AIJRSTEM All Rights Reserved Page 18