| OCR Text |
Show Much of the contradiction and inconsistency in these results is undoubtedly due to the close interrelationships and dependencies of various fuel properties and may also result from difficulties in isolating the various physical and chemical combustion phenomena in these systems. For example, with increase in carbon number, the specific gravity, cetane number, and boiling point of n-paraffinic fuels increase. Similarly, the volatility of paraffinic fuels can be increased either by decreasing molecular weight or by increasing branching. With aromatic compounds, the interrelationships are even more complex. In addition, the physical processes of mixing, droplet formation, etc. are also affected by changes in fuel properties. In the present study, a premixed prevaporized, one dimentional flat flame burner was used to eliminate most of these complicating phenomena and focus exclusively on the chemical properties of fuels. The fuels used were paraffins, isoparaffins, and aromatics. Samples were collected in the flame and post flame zones along the burner axis and were analyzed for oxygenated aromatics using the Diesel Odor Analysis System (DOAS) method followed by Gas Chromatography/Mass Spectrometry (GC/MS) analysis and identification. Experimental Facility A premixed, prevaporized, one dimensional flat flame burner test facility was used to conduct the present study. A schematic of this facility is shown in Figure 1. This facility consists of a fuel evaporator in an electric oven, the burner itself in a second oven, and a gas sampling system. During operation, the fuel is atomized by high pressure inert gas and the fuel vapor inert gas mixture is heated to a temperature slightly higher than the boiling point of the fuel. In the present study, only fuels with boiling points less |
