Yuhua Bi

Performance and Emission Characteristics of Diesel Engine Fueled with Ethanol-Diesel Blends in Different Altitude Regions

In order to investigate the effects ethanol-diesel blends and altitude on the emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel engine fueled with pure diesel (as prototype) and ethanol-diesel blends (E10, E15, E20 and E30) under different atmospheric pressures (81kPa, 90kPa and 100kPa). The experimental results indicate that all the parameters of emissions during 90~100kPa are superior to those of 81~90kPa. At 81kPa, both HC and CO emissions rise greatly with the increasing engine speeds and loads and addition of ethanol, while at 90kPa and 100kPa the effects of engine speeds and loads and usage of ethanol on HC and CO emissions are slightest. The changes of atmospheric pressure and mix proportion of ethanol have no obvious effect on NOx emissions and NOx emissions of ethanol-diesel blends have a slight drop in a small scale compared with prototype under most engine conditions.

Emission Characteristics of Diesel Engine Fueled with Ethanol-diesel Blends in Different Altitude Regions

In order to investigate the effects ethanol-diesel blends and altitude on the emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel engine fueled with pure diesel (as prototype) and ethanol-diesel blends (E10, E15, E20 and E30) under different atmospheric pressures (81kPa, 90kPa and 100kPa). The experimental results indicate that all the parameters of emissions during 90~100kPa are superior to those of 81~90kPa. At 81kPa, both HC and CO emissions rise greatly with the increasing engine speeds and loads and addition of ethanol, while at 90kPa and 100kPa the effects of engine speeds and loads and usage of ethanol on HC and CO emissions are slightest. The changes of atmospheric pressure and mix proportion of ethanol have no obvious effect on NOx emissions and NOx emissions of ethanol-diesel blends have a slight drop in a small scale compared with prototype under most engine conditions.

Power recovery of a variable nozzle turbocharged diesel engine at high altitude by response surface methodology and sequential quadratic programming

Based on a review of the research methods about diesel engine performance recovery at high altitude and an experimental investigation, by optimizing variable nozzle turbocharger (VNT) and fuel supply system calibration parameters a novel method is proposed to enhance the performance of a turbocharged diesel engine at high altitude. At an altitude of 1920 m, four calibration parameters deeply affecting performance of the diesel engine were selected at the rated power condition, that is, injection quantity, injection timing, injection pressure, and VNT nozzle opening. In order to reduce thermal load of the diesel engine running in the plateau environment, reasonable coded levels of Design of Experiments (DoE) factors were chosen, and an experimental design matrix was selected based on the Box–Behnken design. The interaction effects of the four calibration parameters on engine performance were investigated using the response surface methodology. Power recovery optimization was carried out by means of sequential quadratic programming under a minimum smoke limit and durability constraints. The results show that this performance optimization method can effectively recover engine performance at high altitude. Moreover, it can, to an extent, alleviate the problems such as deterioration of fuel consumption and high thermal load induced by the rise in elevation. With optimized calibration parameters, the rated power of the diesel engine at an altitude of 1920 m proved to be recovered to that at sea level, and there was an increase of brake specific fuel consumption by less than 3% compared with that in the plain area, which met the performance and durability requirements for general turbocharged internal combustion engines at altitudes lower than 2000 m.

Performance of Diesel Engine Fueled with Ethanol-diesel Blends in Different Altitude Regions

In order to investigate the effects ethanol-diesel blends and altitude on the performance of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel engine fueled with pure diesel (as prototype) and ethanol-diesel blends (E10, E15, E20 and E30) under different atmospheric pressures (81kPa, 90kPa and 100kPa). The experimental results indicate that the equivalent brake-specific fuel consumption (BSFC) of ethanol-diesel blends are better than that of diesel under different atmospheric pressures and that the equivalent BSFC gets great improvement with the rise of atmospheric pressure when the atmospheric pressure is lower than 90kPa. When the atmospheric pressure declines below 90kPa, the ethanol-diesel blends have a remarkable effect on the drop of soot emission. Contrarily, in the case that the atmospheric pressure is over 90kPa, the influence weakens. Nevertheless, smoke emissions decrease obviously with the increasing percentage of ethanol in blends.