Experimental Study On The Combustion Of Diesel/PODE3-4/N-amyl Alcohol Mixed Fuel

The alternative fuels of diesel fuel have been the focus of attention,and the diesel/PODE_3-4 hybrid fuel has been widely studied at home and abroad in recent years.PODE_3-4 plays significant role in reducing Soot.However,NOx will be increased because of the high temperature and high oxygen content of PODE_3-4 in the combustion process.The adding of n-amyl alcohol with low cetane number and high oxygen,form a mixed fuel diesel/PODE_3-4/n-amyl alcohol,which prolong the ignition delay period and reduce the temperature in the cylinder.Combined with exhaust gas recycling?EGR?,NOx emission can be reduced on the basis of diesel/PODE_3-4.Based on this principle,three fuels(pure diesel,marked as D100;diesel blended volume 20%PODE_3-4,marked as DP20;DP20 blended volume is 20%of the n-amyl alcohol,marked as DPPt20)will be combustion tested in this paper,to study the combustion and emission characteristics by changing the injection pressure,pre-injection strategy,EGR rate and load.The test results show that:?1?with the injection pressure increasing,the peak of average pressure in cylinder and the heat release rate of the three fuels have increased,Soot emissions has decreased and NOx emissions has increased,The peak of the state of aggregation particle number concentration has decreased,the total particles number concentration and mass concentration have decreased;Under the same injection pressure,Soot emissions D100>DP20>DPPt20,NOx emissions DP20>DPPt20>D100,the total particules mass concentration D100>DP20>DPPt20.?2?By using pre-injection strategy,the maximum pressure rise rate of three fuels has decreased,the Soot and NOx emission has decreased,CO and HC emissions have increased;The peak of the nuclear particles concentration has decreased,and the peak of the state of aggregation particles number concentration has increased;With the pre-injection interval increasing,the total particles number concentration has increased,and the total particles mass concentration has decreased;With the pre-injection rate increasing,the total particles number concentration has decreased,and the total particles mass concentration has increased.?3?With the EGR rate increasing,the combustion temperature and the peak of average pressure in cylinder and the heat release rate of the three fuels have decreased;Soot emissions D100>DP20>DPPt20,NOx emissions DP20>DPPt20>D100;The peak of the nuclear particles concentration has decreased,and the state of aggregation particles number concentration has increased,the total particles number concentration and mass concentration have increased.?4?When BMEP was 0.4MPa and 0.8MPa,the peak of average pressure in cylinder and the heat release rate DPPt20>DP20>D100;When BMEP was 1.2MPa,the peak of average pressure in cylinder and the heat release rate DPPt20>DP20>D100;When BMEP was 1.6MPa,the peak of average pressure in cylinder and the heat release rate D100>DP20>DPPt20;With BMEP increasing,the maximum pressure rise rate of three fuels has increased,Soot emissions D100>DP20>DPPt20,NOx emissions DP20>DPPt20>D100;With BMEP increasing,the peak of the nuclear particles concentration of three fuels has decreased,the total particles number concentration and mass concentration of three fuels have decreased.