Combustion Process Analysis in a DISI Engine Fuelled with N-Butanol through UV-VIS Emission Spectroscopy

Abstract

Abstract-In this paper, the study on the effects of n-butanol on the combustion process in a DISI engine has been conducted.Experiments were performed on a direct injection SI engine operated on gasoline and butanol, with combined analysis of in-cylinder pressure traces, exhaust emissions and optical data. The optically accessible power unit was fitted with a commercial head and a high pressure wall guided injection system working at 100 bar. The engine speed was set at 2000 rev/min as a representative value for mid-road load automotive use. Different spark timings were tested. All trials were performed at close to stoichiometric air-fuel ratio.UV-visible natural emission spectroscopy was applied to investigate the formation and the evolution of the main compounds characterizing the spark ignition and combustion process. Pollutant measurements (HC, CO and NOx) at undiluted exhaust, for gasoline and butanol, were correlated with pressure related data and optical results.Index Terms-Spark ignition engines, direct injection, butanol, optical investigations.

Experimental Investigation of Methane Direct Injection with Stratified Charge Combustion in Optical SI Single Cylinder Engine

“…N 2 * can emit weakly at ~316 nm and ~337 nm due to C 3 Π→B 3 Π (0, 1) and (0, 0) transitions. In addition, N 2 + emission can be characterized due to transitions in the 330-435 nm range [36,37,38]. However, it has been noted that the emissions of N 2 * and N 2 + can be very unstable [38,39].…”

“…In addition, N 2 + emission can be characterized due to transitions in the 330-435 nm range [36,37,38]. However, it has been noted that the emissions of N 2 * and N 2 + can be very unstable [38,39]. During combustion, chemical reactions in the flame generate excited species (OH*, CH*, C 2 * and CO 2 *), which are the main chemiluminescent emitters in hydrocarbon flames.…”

“…methane) thermal decomposition causes chain initiation where pool of OH* (also O* and H*) radicals develops [42]. OH* appears during flame kernel (also appears during the spark discharge) due to A-X transition at vibrational band (0, 0) at 306 nm and at 309 nm wavelength [36,38,43]. The OH* radical is formed in the primary combustion zone via the chemical reaction shown in Table 2.…”

Theoretical Study of the Effects of Spark Timing on the Performance and Emissions of a Light-Duty Spark Ignited Engine Running under Either Gasoline or Ethanol or Butanol Fuel Operating Modes

“…A review of ethanol/gasoline blends impact on performance and emissions of a spark-ignited engine is given in [8][9][10][11][12][13][14][15][16]. In [17][18][19][20][21][22][23][24][25][26] results are given concerning the use of butanol, either blended with gasoline or as a neat fuel, in a spark-ignited engine. By observing these results, it can generally be concluded that the increase in alcohol content in the blend with gasoline, could have a significant impact on engine performance and efficiency only at high alcohol concentrations, if the air-fuel ratio is to be maintained within the same range of values as for the gasoline operation.…”

“…Specifically, many of the theoretical and experimental studies evaluating the potential of alcohols are based on ethanol [8][9][10][11][12][13][14][15][16], while other studies have been performed on butanol-fueled engines [17][18][19][20][21], or on assessing n-butanol as a blending agent with gasoline [22][23][24][25][26]. Ethanol can be used as a neat fuel in spark-ignited engines or blended up to 40% with diesel fuel for use in compression-ignition (CI) engines [8][9][10][11][12][13][14][15][16].…”