THEORETICAL INVESTIGATION OF THE EFFECTS OF ETHANOL-DIESEL FUEL BLENDS ON DIESEL ENGINE PERFORMANCE CHARACTERISTICS AND COMBUSTION

Öz

In the presented study, the effects of the using of ethanol-diesel fuel blends on the engine performance characteristics such as brake specific fuel consumption (BSFC), brake effective power, brake effective efficiency and exhaust emissions have been investigated theoretically in different direct-injection (DI) diesel engines by using a multi-zone thermodynamic model. The results indicate that as ethanol percentage in the mixture increases, BSFC reduces and brake effective efficiency improves significantly and brake effective power increases slightly. On the other hand, equivalence ratio decreases and ignition delay increases for ethanol blends and combustion duration indicates generally a decreasing tendency. The concentrations of nitric oxide (NO), carbon monoxide (CO) and hydrogen (H2) increase at low ethanol ratios because of increment of cylinder temperatures. But at high ethanol ratios they decrease because of decrement of cylinder temperatures. In the presented study, cost analysis has also been performed by using semi empirical relation given by Durgun. It was determined that ethanol blends are not economic for these engines because cost of ethanol is higher than diesel fuel in Turkey as well as in many of the other countries and decrease ratio of brake specific fuel consumption is low

Anahtar Kelimeler

• Ethanol blends, combustion model, cost analysis, exhaust emissions