An analysis of the flame temperature field and soot concentration field of diesel ignition injection natural gas
In response to the problem that the flame temperature field and carbon soot concentration field of diesel-ignited high-pressure direct-injection natural gas are still unclear.On a constant-volume combustion bomb platform,a high-pressure direct injection(HPDI)natural gas coaxial injector was used to study the distribution characteris-tics of flame temperature and soot KL value after HPDI natural gas combustion under different diesel/gas injection pressures and diesel/gas injection intervals using a high-speed color camera and the dual-color method.This study provides a basic reference for the fuel injection strategy of HPDI natural gas engines and for related research on re-ducing soot formation.The results show that the flame average temperature and soot average KL value decrease with the increase in the diesel/gas injection pressure after high-pressure natural gas is ignited.Thus,the diesel/gas in-jection pressure should be increased to reduce the soot KL value.When the diesel/gas injection interval is 0.8 ms,the average temperature of the high-pressure natural gas jet flame is the highest at up to 2 318 K.When the injec-tion interval is 0.4 ms,the average temperature of the flame is the lowest at 2 148 K at most.At the same moment,the average KL value of soot at a 0.8 ms diesel/air injection interval is increased by 112.8%at most compared with that at 0.4 ms and increased by 49.02%at most compared with that at a 1.2 ms injection interval.The experimen-tal results show that,to reduce the soot formation level during high-pressure directly injected natural gas combus-tion,the injection interval should be set before the end of diesel injection.
high-pressure direct injectiondouble-color methodconstant-volume bombnatural gassootflame temperatureinjection pressureinjection interval
万方数据
维普
