| OCR Text |
Show Orimulsion Ml 0.833 1.00 Equivalence ratio 1.20 Figure 2: Baseline emissions of nitric oxide from the fuels investigated at three equivalence ratios 250-r Orimulsion Ml 0.833 1.00 Equivalence ratio 1.20 Figure 3: Baseline emissions of nitrogen dioxide from the fuels investigated at three equivalence 300" 250^ _ 200- E 150- 0. 1 Q. ' gioo. 50- 0- I *. - •- --•- \ -*r- \ - J- - Orimulsion Ml M -GI r -G2 ' • 1 0.833 1.00 Equivalence ratio 1.20 Figure 4: Baseline emissions of oxides of nitrogen from the fuels investigated at three equivalence ratios 1. Fuel-lean conditions (q> = 0. 833) The maximum values of NO emissions were measured from Orimulsion (269.2 ppm-wet), followed by those from the heavy gas oils, fuels M1, G 2 and G1. Orimulsion was the only fuel able to produce significant amounts of N 0 2 (33.5 ppm-wet). This fuel is characterised by its high water content (30 % ) , which may play a role in the formation of amounts of N 0 2 at fuel-lean conditions. As a result, high emissions of NOx were observed at fuel-lean conditions, almost solely due to the formation of N O , with Orimulsion and fuel M1 yielding the largest concentrations. 2. Stoichiometric conditions (q> = 1.00) Significant emissions of NO and N 0 2 were found in these conditions from fuels M1, G 2 and G1. Emissions of nitric oxide were less compared with those at fuel-lean conditions, whereas those of nitrogen dioxide were greater. Maximum readings of N 0 2 were obtained from fuel G1 (68.3 ppm-wet), whereas fuel M1 produced intermediate values (35.6 ppm-wet) and fuel G2 gave the lowest readings (31.4 ppm-wet). Whilst considerable differences exist in the N O x emissions from these three fuels at fuel-lean and -rich conditions, the values measured at stoichiometric conditions were comparable (97.7 ppm-wet for fuel M1, 91.1 ppm-wet for fuel G1 and 80.3 ppm-wet for fuel G2). This can be seen in Figure 4. In addition, the emissions 8 |
