Fuels energy content

The servo voltage is a function of mass-flow rate. Axial-flow angular-momentum meters are sometimes used in measuring jet engine fuel flow as the fuel energy content correlates much mote closely with mass than volume. 

The quality of the product is of primary importance in developing a recycling technology converting plastics into fuels by pyrolysis. Today the characterization of a liquid fuel from any sources is obviously based on the qualification methods and standards of fuels from mineral oil. The properties of the pyrolysis-derived fuels from plastics are expected to be similar to conventional fuels (energy content, viscosity, density, octane and cetane number, flash-point, etc.). However, in addition to the familiar ranking values it is necessary to know more about the chemical composition of the plastic pyrolysis oil, because of the peculiarities as follows ... 

TABLE 9. Fuel Energy Content of Various Rendered Fats and Oils (11). 

Fuel Energy Content Btu/Lb Ash Carbon Hydrogen Nitrogen Oxygen Sulfur... 

RESOURCE MATERIALS W ENERGY CONTENT RESOURCE FUELS ENERGY CONTENT... 

The heat of combustion (ASTM D-240, ASTM D-1405, ASTM D-2382, ASTM D-3338, ASTM D-4529, ASTM D-4809, ASTM D-6446, IP 12) is a direct measure of fuel energy content and is determined as the quantity of heat liberated by the combustion of a unit quantity of fuel with oxygen in a standard bomb calorimeter. This fuel property affects the economics of engine performance, and the specified minimum value is a compromise between the conflicting requirements of maximum fuel availability and good fuel consumption characteristics. 

Fuel thermomechanical models consist of a code for normal operation, which predicts the initial fuel conditions before an accident (strain, fuel-to-sheath heat transfer coefficient, gas release, initial temperatures, etc.), and a transient thermomechanical code for accidents. The latter includes submodels for fuel failure mechanisms due to fuel sheath strain, beryllium braze penetration, sheath embrittlement due to oxidation, athermal strain and excessive fuel energy content. Because of the need to predict the dose for each accident, the models must be able to estimate the percentage of fuel that fails in an accident (if any), and the release of fission products to the channel. 

In the first years of gasohol use some starting and driveabiUty problems were reported (19). Not all vehicles experienced these problems, however, and better fuel economy was often indicated even though the energy content of the fuel was reduced. Gasohol was exempted from the federal excise tax amounting to a 0.16/L ( 0.60/gal) subsidy. Without this subsidy, ethanol would be too expensive for use even as a fuel additive. 

Chemical Composition. Chemical compositional data iaclude proximate and ultimate analyses, measures of aromaticity and reactivity, elemental composition of ash, and trace metal compositions of fuel and ash. All of these characteristics impact the combustion processes associated with wastes as fuels. Table 4 presents an analysis of a variety of wood-waste fuels these energy sources have modest energy contents. 

Fig. 5. Fuel economy vs energy content for various fuels. Each data poiat represents the average of twenty 1989 vehicles. To convert MJ/L to Btu/gal,...

Assumes deUvered electricity has one-third of the energy content of the fuel used to produce it ie, 1 Joule of electrical supply to an industrial user represents 3 Joules of fuel consumed. 

The energy content of fossil fuels in commonly measured quantities is as follows. ... 

It is clear from Table 27.1 that the energy content of the car itself - that is of the steel, rubber, glass and of the manufacturing process itself - is small less than one-tenth of that required to move the car. This means that there is little point in trying to save energy here indeed (as we shall see) it may pay to use more energy to make the car (using, for instance, aluminium instead of steel) if this reduces the fuel consumption. 

Fuel lower heating value. In many plants on-line fuel analyzers have been introduced to not only monitor the turbine performance but to also calculate the fuel payments, which are usually based on the energy content of the fuel. 

Vehicle fuel economy is normally measured in miles per gallon. At any given instant, it depends on the energy content of a gallon of fuel (Qf), the vehicle velocity (V.,) and power required (P,-5q), the thermal efficiency with which the engine converts fuel energy into useful output work (rj,.), and the mechanical efficiency with which the driveline delivers that work to the vehicle wheels (r j). Specifically,... 

Coal competes primarily in the market for low-cost boiler fuels. Coal is also characterized by a relatively low energy content per unit of weight (at best two-thirds chat of residual oil). Consequently, low-cost... 

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