Effect of diesel and gasoline blending fuel coordinate with in-cylinder charge conditions on efficient and clean combustion based heavy-duty diesel engine

摘要

High-octane fuel (such as gasoline) does not easily self-ignite, which is conducive to the formation of homogeneous mixture. However, gasoline compression ignition (GCI) under low load is difficult, and some problems arise, such as rough combustion under high load, which limit the application of high-octane fuel in the compression ignition (CI) combustion. The synergistic effect of the fuel characteristics and boundary conditions represents the key for achieving efficient and clean combustion. In this study, based on a modified single-cylinder engine, fuels with different reactivity (diesel G0, gasoline and diesel blended fuel G50, and gasoline G100) are studied under different loads. In the test, the engine operates at 1300 rpm, and the loads were 6, 10, and 15 bars gross indicated mean effective pressure (IMEPg) respectively. Meanwhile, the injection mode of the three fuels was direct injection with one injector. The results indicate that in-cylinder charge conditions of the engine largely vary under different loads. Under a low load (IMEPg: 6 bar), the in-cylinder temperature and pressure are low, and the gross indicated thermal efficiency (ITEg) of the high-reactivity fuels (G0 and G50) are higher. Under a medium load (IMEPg: 10 bar), high ITEg (52.1%) and low emission can be achieved using a G50 fuel. Under a high load, higher charging pressure and temperature lead to the high ITEg of the G100 fuel (fuel reactivity is the lowest), which reaches up to 53.1%.