Experimental Study On Combustion And Emission Characteristics Of Water-containing N-Butanol/Diesel Fuel

Energy crisis and environmental pollution make alternative fuels a hot research topic in the field of internal combustion engines.Burning of 5%,10%and 20% shared volume of water-containing n-butanol(BW5,BW10 and BW20,where BW5 represents 5% shared volume of water-containing n-butanol with 95% pure diesel)with pure diesel in a turbocharged,4-cylinder,common rail diesel engine is reported.Compared with pure diesel,BW5 and BW10 can increase the NOx emission and decrease the particulate matter emissions,and BW20 can decrease the NOx and particulate matter emission simultaneously.To further decrease NOx emission,Exhaust gas recirculation is experimentally investigated at the brake mean effective pressure of 0.56 MPa and 0.98 MPa.The research results of this article are as follows:(1)With the increase of water-containing n-butanol,the density of the mixed fuels is not much different,heating value,freezing point and cold filter point gradually decrease,and the oxygen content gradually increases.The kinematic viscosity of BW5 is lowest.(2)The peak cylinder pressure,peak heat release rate and peak cylinder temperature in the main injection show different conditions.In most cases,the peak cylinder pressure,peak heat release rate and peak cylinder temperature in the main injection of BW10 is highest.Because high latent heat of vaporization has more obvious inhibitory effect on combustion at high load,the peak cylinder pressure,peak heat release rate and peak cylinder temperature in the main injection of BW20 is lower than that of pure diesel.(3)Compared with pure diesel,the HC emissions of BW5 and BW10 decrease,and the HC emission of BW20 increases in the most cases.The NOx emissions of BW5 and BW10 increase,and the NOx emission of BW20 decreases at all roads.The total number concentration of particulate matter are decreased to varying degrees in most cases,and the decrease in BW10 was the most significant.(4)With the increase of the EGR rate,the ignition delay period and combustion duration of the four fuels are prolonged due to the thermal and dilution effects of EGR,while the peak cylinder pressure,peak heat release rate and peak cylinder temperature in the main injection gradually decrease.(5)At the brake mean effective pressure of 0.56 MPa and 0.98 MPa,the NOx emissions gradually decrease with the increase of EGR rate.At the brake mean effective pressure of0.56 MPa,the total number concentration of particulate matter emissions of BW10 and BW20 first decrease and then increase with the increase of EGR rate.At the brake mean effective pressure of 0.98 MPa,the total number concentration of particulate matter emissions of four fuels significantly increase.At the medium load,EGR can decrease NOx and particulate matter emissions at small EGR rate.At the high load,although EGR can decrease NOx emissions,it can cause a significant increase in particulate matter emissions.