Performance analysis of a single cylinder diesel engine using cotton seed oil.

Basha, M. Shameer ; Reddy, B.G. Krishna ; Reddy, K. Vijaya Kumar 等

Introduction

With the rapid development of automobile engines and fast depletion of fossil fuels, the discrepancy between demand foe and supply of energy has become and increasingly acute problem. Among the many different types of alternative fuels, vegetable oils and their esters come across as good choices. They are renewable, as the carbon released by the burning of vegetable oils is used when the oil crops undergo photosynthesis.

China is rich in cotton seed and research using cotton seed oil as diesel engine fuel has been intensively and widely studied here. From a technological point of view the fuel property of cotton seed oil seems to meet the fundamental requirements of diesel engine. It has been observed that by using cotton seed oil as there is unnecessary change in engine structure. There are differences between properties of the cotton seed oil and diesel oil, for the smooth engine performance optimum oil mixture.

An extended experimental study is conducted to evaluate and compare the use of various diesel fuel supplements at blend ratio's varying from 25/75v/v to 75/25v/v by C.D. Rakpoulus et al [1]. An extended experimental study is conducted to evaluate and compare the use of various diesel fuel supplements at blend ratio's varying from 10/90v/v to 20/80v/v by C.D. Rakpoulus et al [1]. The researchers mainly concentrated on the emission characteristics. Georgios Fontaras et al [3] studied the performance of a Euro3-compliant diesel passenger car using 10/90v/v cotton seed oil and diesel blend which showed promising results. The higher blends of the cotton seed oil/diesel and palm oil/diesel are mostly considered not viable alternatives for diesel, in the emission point of view.

Y.D. Wang et al [2] carried out a series of experiments on different vegetable oil blends varying in 25%, 50% and 75% proportions and at different load conditions varying between no load to full load i.e. 0%, 25%, 50%, 75%, 100% loads. The effect of variation of injection pressure on the performance of the C.I engine using different blends i.e. 25/75v/v, 50/50v/v, 75/25v/v 100/0 v/v, of cotton seed oil/diesel oil, palm oil/diesel oil are generally neglected in the literature. In the present research work, the effect of variation of injection pressure, using different blends of cotton seed oildiesel, with and without preheating are studied.

Experimental Procedure

The engine is started by hand cranking and with the help of the decompression lever. The rack in the fuel pump is adjusted to run the engine at rated speed of 1500 rpm. (At no load). Cooling water supply valve is opened, and the water flow is adjusted such that the outlet temperature of water is around 50[degrees] to 60[degrees]C. When the engine runs steadily without fluctuations in the speed, time taken for 25cc of fuel consumption is noted down.

The exhaust gas temperature is also measured. Load is applied on the dynamometer by opening the water inlet valve. When load is applied, the speed falls. The engine speed is brought back to the rated speed (of 1500 rpm) by adjusting the fuel supply. Once again, the time taken for 25cc of fuel consumption and exhaust gas temperatures are noted down. Now the engine is loaded in steps from zero loads to rated load.

In all these cases, the engine speed is maintained constant at rated speed by adjusting the fuel supply. Smoke density is also measured at no load, half load and rated load conditions. Constant speed performance is conducted at different injection pressure of diesel, cotton seed oil and blends of cotton seed oil- diesel. At each of this condition, energy balance heat converted into work and heat carried away by exhaust gases are calculated.

Results and discussions

The analysis of the experimental data obtained to characterize the fuel propertied of cotton seed oil and cotton seed oil-diesel blends. The performance of the engine with these fuels is also analyzed.

Figure (a) shows that the SFC of Cotton seed oil is around 8 to 9% greater than the corresponding SFC with diesel. This can be attributed to the lower value of calorific value of cotton seed oil compared to diesel.

Figure (b) shows the comparison of S.F.C. at three different injection pressures of 200 kg/[cm.sup.2], 225 kg/[cm.sup.2] and 250 kg/[cm.sup.2]. S.F.C. is minimum at 225 kg/[cm.sup.2]. With increase in the fuel injection pressure, the droplet size, no doubt decreases, but the velocity is so high, that it goes and hits the cylinder walls

Figure (c) shows the comparison of SFC vs. BKW at three different injection pressures of 200, 225, 250kg/[cm.sup.2]. From the figure it can be observed that the SFC is minimum at 225 kg/[cm.sup.2]. This can be explained that the increase in fuel injection pressures depends on the droplet size. This is also supported by the higher exhaust gas temperature and higher smoke levels as shown in Figures (d) and (e).

It can be seen from the figure (f) there is a 4-6% decrease in the S.F.C with preheating. This is because of the improved spray characteristics.

It is observed that for 50%-50% Cotton seed oil--diesel blend, the brake thermal efficiency is almost identical with that of pure diesel operating throughout the range of power output. However, for the 75%-25% Cotton seed oil -diesel blend, the thermal efficiency is 4-5% less. This can be attributed to the poor spray characteristics.

[FIGURE (a) OMITTED]

[FIGURE (b) OMITTED]

[FIGURE (c) OMITTED]

[FIGURE (d) OMITTED]

[FIGURE (e) OMITTED]

[FIGURE (f) OMITTED]

Conclusions

Test result shows 25% cotton seed oil and 75% diesel oil was suitable for it to be used as diesel fuel. The main factor influencing the specific fuel consumption or thermal efficiency is good at fuel injection pressure at 225Kgf.Heat losses in the engine are reduced with the usage of cotton seed oil because exhaust gas temperatures are lower when compared to diesel. Hence brake thermal efficiency of cotton seed oil is higher.

References

[1] C.D. Rakopoulos, K.A. Antonopoulos, D.C. Rakopoulos, "Development and application of multi-zone model for combustion and pollutants formation in direct injection diesel engine running with vegetable oil or its bio-diesel," Internal Combustion Engines Laboratory, Thermal Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou St., Zografou Campus, 15780 Athens, Greece. SCIENCE DIRECTS, Energy Conversion and Management 48 (2007) pg 1881-1901.

[2] Y.D. Wang a,*, T. Al-Shemmeri b, P. Eames a, J. McMullan a, N. Hewitt a, Y. Huang a, S. Rezvani a, "An experimental investigation of the performance and gaseous exhaust emissions of a diesel engine using blends of a vegetable oil"

(a) Centre for Sustainable Technologies, School of Built Environment, University of Ulster, Shore Road, Newtownabbey, Antrim BT37 0QB, United Kingdom

(b) Faculty of Computing, Engineering and Technology, Staffordshire University, Stafford ST18 0DF, United Kingdom. SCIENCE DIRECT, Applied Thermal Engineering 26 (2006) 1684-1691

[3] Georgios Fontaras, Zissis Samaras Georgios Miltsios,"Experimental Evaluation of Cottonseed Oil-Diesel Blends as Automotive Fuels via Vehicle and Engine Measurements". 1 Aristotle University Thessaloniki, 2 Aristotle University Thessaloniki, 3 Technological Educational Institutes of Serres, SAE Technical Papers, Document Number: 2007-24-0126

[4] C.D. Rakopoulos *, K.A. Antonopoulos, D.C. Rakopoulos, D.T. Hountalas, E.G. Giakoumis, "Comparative performance and emissions study of a direct injection Diesel engine using blends of Diesel fuel with vegetable oils or bio-diesels of various origins," Internal Combustion Engines Laboratory, Thermal Engineering Department, School of Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 15780 Athens, Greece. SCIENC EDIRECT, Energy Conversion and Management 47 (2006) pg 3272-3287.

[5] I.H. Inan A. Kubas, O. Gaytancioglu, M.O. Azabagaoglu, G. Unakitan,[4] " The Structure and Fundamental Problems of Vegetable Oil Industry in Turkey," Trakya University, Tekirdag Faculty of Agriculture, Department of Agricultural Economics Tekirdag. Tekirdag Ziraat Fakultesi Dergisi Inan et al., 2006 3(1) Journal of Tekirdag Agricultural Faculty

[6] B.K. Barnwal, P. Sharma "Prospects of biodiesel production from vegetable oils in India," Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee 247667, Uttaranchal, India. SCIENCE DIRECT, Renewable and Sustainable Energy Reviews and Management 9 (2005) pg 363-378.

(1) M. Shameer Basha, (2) B.G. Krishna Reddy, (3) K. Vijaya Kumar Reddy, (4) P. Ravi Kumar and (5) B. Sudheer Prem Kumar

(1) 9-4-86/136, 1st Floor, Salarjung Colony, Mehdipatnam Hyderbad 500008, Andhra Pradesh

(2) 17-1-389/1/203, Prasanth Nagar, Saida Bad, Hyderabad 500058, Andhrapradesh

(3) Professor In Mechanical Department, Jntuce, Jntu Kukutpally, Hyderbad500085, Andhra Pradesh

(4) Associate Professor, Nit, Warangal 506004, Andhra Pradesh

(5)Assoc.Professor In Mechanical Department, Jntuce, Jntu Hyderbad500085, Andhra Pradesh