| OCR Text |
Show is considered a soot precursor; both predictions are lower than the soot emissions predicted (and measured) with pure toluene. In fact, the soot level predicted by using only methylethylnaphthalene as a soot precursor is lower than that predicted for No. 2 fuel oil. This result is in agreement with the observation jaade in tests on an 8Cf-hp firetube boiler (Ref. 13) that the Bacharach smoke number o"f No. 2 fuel oil is higher than that of SRC-II MD. A possible explanation for this observation is that the presence of the hydroxyl functional group is the phenolic part of SRC-II MD probably impedes the condensation polymerization process thought to be crucial in soot formation. Based on this possible explanation, methylethylphenol is an unlikely soot precursor. CONCLUDING REMARKS The research described in this paper deals with the overall problem of synthetic fuel characterization and the key area of characterization of the chemical kinetics of synthetic (and conventional) fuel combustion processes. Results of the tests carried out to investigate the overall fuel characterization problem show that those fuel properties involved directly in the spray formation and vaporization process and those which are directly involved in the combustion process are the most critical. That is, determination of those properties is of considerable importance to the evaluation of the use of a given fuel in a specific application. In the second part of this paper, the development and application of a quasiglobal chemical kinetics model for synthetic fuel combustion has been described. This approach provides a realistic method for incorporating all of the necessary details of the kinetics of the combustion process in a combustion performance calculation. It has been demonstrated to be accurate for neat fuels and fuel blends, and examination of its accuracy in predicting the combustion of complex hydrocarbon fuels, as represented by No. 2 fuel oil and SRC-II MD awaits the availability of sufficient data. Results of these fuels obtained to date are both plausible and in accord with available observations. By.combining models of the spray vaporization process with the quasiglobal chemical kinetics formulation described here it is possible to develop a generalized spray combustion model. One such approach has been developed and is -described in Ref. 3. While space limitations do not permit reviewing the spray flame model in the present paper, the results shown in Ref. 3 indicate that the combination of spray vaporization models and the quasiglobal kinetics formulation provides a powerful tool for the parametric examination of the use of fuels of different properties in a given type of burner. 1.2.30 |
