Spraying and combustion characteristics of Fischer-Tropsch diesel/ethanol/ n-pentanol blends in constant volume combustion chamber

Spray characteristics and combustion characteristics of diesel, Fischer-Tropsch diesel and Fischer-Tropsch diesel/ ethanol/n-pentanol blends were investigated based on a constant volume combustion chamber (CVCC) system. The test fuels were D100 (diesel), FT100 (Fischer-Tropsch diesel) and FT60E20P20 (20 % ethanol, 20 % npentanol and 60 % Fischer-Tropsch diesel, by vol). The tests were conducted at different ambient temperatures and ambient pressures. The test results show that FT60E20P20 has better atomization and evaporation than D100 and FT100. The fuel viscosity has greater influence on the spray tip distance (STP) of fuel than the fuel density. The fuel boiling point has greater influence on the spray cone angle (SCA) of the fuel than the fuel viscosity. The STP, SCA and spray area (SPA) of the fuel decrease with increasing ambient temperature. The STP and SPA of the fuel decrease with increasing ambient pressure, but the SCA increases with increasing ambient pressure. Blending ethanol and n-pentanol in Fischer-Tropsch diesel can effectively reduce soot emissions. The FT60E20P20 has a longer ignition delay and FLOL under combustion conditions. The FT60E20P20 has the lowest INFL and average flame temperature compared to the D100 and FT100. In addition, higher ambient temperatures and ambient pressures can promote soot emissions.