Realization of low-temperature premixed combustion with diesel TR combustion system

To clarify the ability of TR (Three-rapidity) combustion system for reducing emissions and realizing low-temperature premixed combustion, a series of tests were carried out in a modified 135 single-cylinder diesel engine, including lowering compression ratio, using diesel-ethanol blend and delaying injection timing. The results show that the decrease of compression ratio results in ignition delay, the increase in maximum rate of heat release and maximum cylinder pressure, the decrease in maximum mean gas temperature and NO_x. However, at the medium and high loads the combustion rate would decrease and the brake specific fuel consumption would increase. Compared to diesel combustion, ethanol-diesel combustion prolongs ignition delay period and remarkably lowers the exhaust smoke. The maximum cylinder pressure, maximum gas temperature, maximum heat release rate and combustion rate will be decreased somewhat under low load, while under medium and high loads, a higher heat release rate and quicker combustion rate present with little decrease of NO_x. In addition, delaying of fuel delivery advance angle from 15° CA BTDC to 13° CA BTDC leads to little variation in smoke at all.