OCR Text |
Show burner aerodynamics. In extreme cases, fouling and corrosion processes can result in localized burnout of the burner lining and subsequent failure. All of these interactions between physical properties and industrial burner operation were considered in detail in the work reported in Ref. 1. In this work, the fuel property - combustion characteristic relationships were studied through the use of empirical correlating expressions and theoretical combustion process analyses, in order to develop a ranking of the importance of the accurate knowledge of a given fuel property to the determination of the fuel's combustion characteristics. The results of this work are summarized in Table 1. Each physical or chemical property has been ranked in Table 1 with respect to the combustion characteristic or indicator shown in the column heading. In establishing this ranking, only primary interactions have been included. Thus, for example, the heat of combustion and heat of vaporization of a fuel affects the droplet vaporization and burning process directly. Through the droplet vaporization phenomenon, these properties also affect ignition and flame stabi1izatoin, but this "secondary" interaction has been ignored in the summary given in Table 1. Hence, those physical and chemical properties that possess "strong" (S) or "moderate" (M) summary rankings as shown in the last column of Table 1, are properties that affect the majority of the combustion characteristics listed. However, through secondary interactions such as outlined above, certain of the apparently less important fuel properties indicated in Table 1 can become of key importance also, particularly for specific combustion processes. Inspection of Table 1 shows that the chemical composition of the fuel, including hydrocarbon type and elemental and species analyses, and the chemical kinetic rates that define the consumption of the fuel are key chemical properties that impact the majority of the combustion characteristics and indicators. Fuel composition is central to determination of the effects of the various chemical kinetic phenomena that control the completion of combustion, sooting, and emissions characteristics. It is also central to the determination of flame temperature and laminar gas phase flame speed, as well as important in the assessment of ignition and flame stabilization phenomena. Fuel composition plays a major role in thermal and oxidative stability characterization, as well as in estimation of fouling and corrosion tendencies. Finally, techniques for the estimation of fuel properties, where specific data do not exist, depend heavily on knowledge of the fuel composition. Knowledge of the chemical kinetic rates that apply,to the fuel consumption process is crucially important to any detailed assessment of the effects of the use of an 1.2.5 |