活塞式航空发动机燃用生物航煤与RP-3燃料的适用性对比

以大豆油为原料,经催化裂解、精馏、芳构化和加氢过程制备生物航煤,并分析了其组成及理化性能;进一步采用活塞式航空发动机进行发动机台架试验,对比分析了生物航煤与RP-3燃料的燃用适用性。研究结果表明：生物航煤的基本组成为直链烷烃74.54%、环烷烃13.04%、芳香烃10.31%、醚类1.07%和非α-链烯烃1.04%;生物航煤的热值较高(44.4 MJ/kg),冰点低(-48 ℃),但黏度较高(2.11 mm²/s)。与RP-3燃料相比,生物航煤具有更低的启动温度;温升速度(相差4 ℃之内)、油耗(相差小于0.02 g/s)与RP-3燃料接近,当发动机转速超过4 200 r/min时,过量空气系数波动较大(0.8~1.2),燃烧状态恶化。台架试验后发动机拆解检查发现,燃用生物航煤后出现结焦积炭现象,这是由于该批次生物航煤黏度较大(>2 mm²/s),对雾化效率、燃烧充分程度等发动机工作性能产生影响。

Comparative Study on Applicability of Bio Aviation Kerosene for Piston Aero Engine and RP-3 Fuel

Bio aviation kerosene was prepared from soybean oil by catalytic cracking, distillation, aromatization and hydrogenation, and its composition and physicochemical properties were analyzed. A piston aero-engine was used to start the bench test, and the applicabilities of bio aviation kerosene and RP-3 fuel were compared and analyzed. The results showed that the basic components of bio aviation kerosene were straight-chain alkanes 74.54%, naphthenes 13.04%, aromatic hydrocarbons 10.31%, ethers 1.07% and non-alpha-chain olefins 1.04%. The calorific value of bio aviation kerosene was high(44.4 MJ/kg), freezing point was low(-48 ℃), but its viscosity was high(2.11 mm²/s). Compared with RP-3 fuel, bio aviation kerosene had lower start-up temperature; temperature rise rate(within 4 ℃ difference), fuel consumption(less than 0.02 g/s difference) were close to those of RP-3 fuel, the excess air coefficient fluctuated greatly(0.8-1.2) when engine speed exceeded 4 200 r/min, and those of combustion state deteriorated; engine disassembly inspection after bench test showed that coking occured after burning bio aviation kerosene. The phenomenon of carbon deposition was due to the high viscosity(>2 mm²/s) of bio aviation kerosene in this batch, which had an impact on the working performance of engines such as atomization efficiency and combustion adequacy.