الفهرس | Only 14 pages are availabe for public view |
Abstract In the present time, the human is facing two essential problems regarding engine fuels. These problems are the depletion and the environmental pollution of the fossil oil. Vegetable oils after some chemical treatments may be used as an alternative to solve partially these problems, since these oils are renewable and environmental friendly. The extracted biofuel from vegetable oils is considered as a renewable alternative diesel engine fuel. The present work aims to study the engine behavior when using Waste Vegetable Oils (WVOS). For this purpose, five blends[B5, B10, B20, B30 and B40] of Waste Palm Kernel Oil (WPKO) and three blends [B20, B30 and B40] of Waste Sunflower Oil (WSFO) with Diesel Fuel (DF) are prepared and used as a fuel in a direct injection diesel engine. Because of the great effect of the fuel viscosity on atomization process and combustion, the WPKO and WSFO are preheated to approach diesel fuel viscosity. For this purpose the effect of temperature on the viscosity of WPKO and WSFO is addressed. The current study proves that, using fuel blends (B5-WPKO, B10-WPKO and B20-WPKO) lead to an increase in the Brake Thermal Efficiency (BTE) and decrease in Brake Specific Fuel Consumption (BSFC) compared with that of DF at different loads. B30-WSFO blend contributes to increase the BTE compared with that of DF and no significant change is noticed in BSFC. When heating blends, the BTE increases and BSFC decreases compared with that at normal conditions. Smoke density percentages during each of the WVO blends operations were greater than that of DF. When heating blends, the smoke density decreases compared with that at normal conditions. Moreover, the present study reveals that, WVOS can be used as an alternative fuel in diesel engine without any major modifications. A mathematical model is developed to simulate the engine behavior when running with WSFO blends as biofuel. The model is used as a tool to predict the engine performance at wide range of fuel blends. The result show fair agreement with experimental data. |