The effect of Turbocharger on the performance and exhaust emission of diesel engine run on Biodiesel fuel

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May, 2016
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Biodiesels have been used as renewable alternative fuels for the compression ignition (C.I.) engine. The use of biodiesel fuel in the CI engine leads to substantial reduction in hydrocarbon (HC) and carbon monoxide (CO) emissions. However, the C.I. engine run on petroleum diesel fuel has higher break power and thermal efficiency than when run on biodiesel fuel. A turbocharger is one of the accessories added to the C.I. engine to improve the engine’s performance, efficiency and power. In this work, a palm kernel oil biodiesel fuel (B100) of Ghanaian origin is used to study the performance and exhaust emissions of a C.I. engine fitted with a turbocharger. The experiments were conducted in the automotive engineering laboratory of the Department of Automotive Engineering of the Koforidua Polytechnic where a 4-cylinder VW C.I. engine is dedicated to run on biodiesel and petroleum diesel fuels. The VW engine has a rated power of 55 kW, rated speed 4200 rpm and engine cylinder bore of 79.5 mm x 95.5 mm as well as compression ratio of 22.5 and turbocharger capacity of 0.7 bars. The brake power of the C.I engine, when run on biodiesel fuel, naturally aspirator, recorded 40 kW while recording 50 kW with turbocharger connected respectively at 2200 rpm. In terms of torque, the engine, while running on biodiesel fuel at a speed of 1600 rpm, recorded maximum torque of 195 Nm with natural aspiration and 240 Nm with the turbocharger. For brake specific fuel consumption (BSFC), the C.I engine, when run on biodiesel fuel, recorded 320 g/kWh with natural aspiration and 250 g/kWh with the turbocharger. The C.I engine, while running at engine speed of 1600 rpm with the biodiesel fuel recorded 29% with natural aspiration and 36% with turbocharger. The engine, while running at a speed of 1200 rpm, with biofuel, naturally aspirator, recorded CO emissions of 2600 ppm while recording 1700 ppm with the biodiesel fuel and turbocharger (BF–TU) connected. The engine, when run on biodiesel fuel, naturally aspirator, at a speed of 1200 rpm, recorded NOX emissions of 1275 ppm while with the turbocharger connected recorded 1425 ppm.
A Thesis submitted to The School of Graduate Studies Kwame Nkrumah University of Science and Technology, Kumasi, Ghana In partial fulfillment of the requirements for the Degree of Master of Science in Mechanical Engineering Department of Mechanical Engineering College of Engineering,