非直喷式增压柴油机燃用生物柴油的性能与排放特性

研究了非直喷式增压柴油机燃用柴油一生物柴油混合燃料的性能和排放特性。未对原机作任何调整和改动，研究了不同生物柴油掺混比例的混合燃料对功率、油耗、烟度和NOx排放的影响。结果表明：非直喷式柴油机燃用生物柴油后柴油机功率略有下降，油耗有所上升，烟度大幅下降，NOx排放增加明显。油耗、烟度和NOx的变化均与生物柴油掺混比例呈线性关系，合适的生物柴油掺混比例即可以保持柴油机的性能，又可有效地降低碳烟排放，且不引起NOx排放的显著变化。对于该增压柴油机，掺混生物柴油对外特性下的排放影响最大，影响最小的为标定转速下的负荷特性。不论是全负荷还是部分负荷，燃用生物柴油时低速下的烟度降低和NOx上升幅度均比高速时大，而同转速下高负荷时烟度降低和NOx上升更为明显。

Performance and Emissions of IDI Turbocharged Diesel Engines Fuelled with Biodiesel Fuels

Biodiesel fuels derived from vegetable oils or animal fats have been evaluated as substitutes for conventional diesel fuels. In this study, the biodiesel fuels produced from soybean oil were operated on an IDI turbocharged, high-speed diesel engine. The effects of biodiesel on performance and emissions of the engines are evaluated. Neat biodiesel, three diesel/biodiesel blends, and the baseline diesel were tested without engine modification. The results show that engine performances of neat biodiesel and the blends are similar to those of diesel fuel, but high fuel consumption is presented. Smoke decreases remarkably with slight increase in NOx. The variations in fuel consumption, smoke and NOx emissions present linear relationship with biodiesel blended ratio. For turbocharged diesel engines with biodiesel fuels, the variations in smoke and NOx emissions at low engine speed are higher than those at high engine speed. At the same engine speed, the variations in smoke and NOx emissions at high engine loads are higher than those at low engine loads.