Experimental Study On HCCI Combustion And Emissions Of N-butanol/Diesel Blend

With the rapid development of auto industry, there are a lot of automobiles in our country.Automobiles bring people convenience while the environmental pollution, the automobileindustry yielded and the shortage of energy are progressively turned into serious. Therefore,energy-saving and exhaust emission reduction for internal combustion engines become moreand more vital. Homogeneous Charge Compression Ignition (HCCI) is new kind ofcombustion mode, which integrates the advantages of traditional gasoline and diesel engineswith high thermal efficiency and ultra-low NOx and PM emissions, in addition, using fuel iswidely, thus are paid highly attentions in the automotive and engine field.This paper conducted in-depth study about combustion and emission characteristics testof HCCI engine with n-butanol/diesel blend. Firstly, it discusses the modification process ofHCCI engine which builds up a HCCI testing platform based on alteration of a CT2100dieselengine, including the design of fuel supplied system, design of intake and exhaust system.Secondly, it discusses in detail about the test equipment and the methods of measurement usedin the test. Finally, the effects of fuel property on the combustion and emission characteristicsof homogeneous charge compression ignition at various fuel mixture ratio, intake airtemperature and are made. Test conditions: intake air temperatures are from120℃to160℃, is3.0,2.5and2.0, fuel mixture ratios are B50, B70, B80and B90.The results show that the intake air temperature impacts greatly, with the increase ofintake air temperature, the in-cylinder pressure, pressure rise rate and instantaneous heatrelease rate are increased, start combustion timing and main combustion timing are bothadvanced, cycle to cycle variation of peak pressure is gradually reduced, the combustionstability becomes better. With the increase of intake air temperature, the emissions of CO andHC (B50and B90) are both decreased, there is an optimum temperature for less CO and HC(B70) emissions. With the increase of, the in-cylinder pressure, pressure rise rate andinstantaneous heat release rate are decreased, start combustion timing and main combustiontiming are both delayed, the emissions of CO and HC are both increased. With the increase of , the combustion duration and combustion stability have different trendsWhen the issmall, the in-cylinder pressure, pressure rise rate and instantaneous heat release rate increasewith the increase of n-butanol ratio. When the is large, the in-cylinder pressure, pressurerise rate and instantaneous heat release rate increase first and then decrease with the increaseof n-butanol ratio, start combustion timing and main combustion timing are both advanced,the combustion duration is shortened gradually.