The emission rate of PMS was calculated from the mass weighed with a microbalance. Table 4 states the experimental conditions, in which the engine speed and load are kept constant at 2200 rpm and 75 % of continuous rated output while the mixing ratio has been changed from 10 to 20 and 30 vol.%. The experiments were carried out without preheating the fuel oil, under atmospheric temperature (about 25 ℃).
Fig. 5: Experimental Schematic Diagram
Fig. 6: Pressure Diagram
4 .EXPERIMENTAL RESULTS AND DISCUSSIONS
Figure 6 shows the combustion pressure diagram. Along with the increase of WPD mixing ratio, although exhaust gas temperature does not change the maximum combustion pressure decreases and the combustion retards. Figure 7 indicates the change in ignition lag and exhaust gas temperature. Figures 8 and 9 show the change in the concentration of components of the exhaust gas. Regardless of the change in the WPD ratio CO, CO2, O2 concentration is stable around 700 ppm, 8 % , and 10.5 % respectively. However, as the WPD mixing ratio increases NO* concentration gradually increase 19 % from 1180 to 1400 ppm due to the rise in combustion temperature. NO2 concentration however remains remarkably low at about 100 ppm. Moreover, SO2 concentration decreases 17% from 882 ppm to 735 ppm probably due to the reduced amount of the heavy fuel oil. As shown in figures 10 and 11, along with the increase in WPD ratio PM, SOF, DS as well as UV absorbency by SOF decrease significantly as a result of the decrease in SOF concentration. In order to evaluate sulfide and nitrate fraction brought about by the exhaust gas, the gas was bubbled in a water bubbling pot and the water's pH concentration was measured and converst into the equivalent amount of sulfuric acid diluted in the same amount of water. Figures 12 and 13 show the tendency increasing towards pH concentration and consequently the de-crease in the equivalent emitted sulfuric acid in the exhaust gas as the WPD ratio decreases due to the decline in SO2. In the present paper, the emission of metals and non-metals was also inspected. Figure 14 and 15 show the qualitative as well as quantitative metal and non-metal emissions from the exhaust gas. As shown in the figures, S, Si, Al, Mg and V were found and the emission rates range from 0.013 to 1.34 mg/m3N.
