Fuel mass-flow rate

Turbulent jet flames have zf D, so we can neglect D in Equation (10.51). The fuel mass flow rate is given by... 

A typical heat balance for Run LSF 34 on No. 6 oil is given in Table V. The calculated efficiencies are also given in the table. Heat input terms consist of the input heat from the fuel, the fuel sensible heat, and the makeup water sensible heat. The heat available from combustion of the fuel is calculated from the measured volumetric flow rate, the measured fuel heating value, and the measured fuel density at the nozzle temperature. The fuel sensible heat contains the fuel mass flow rate, the measured temperature at the nozzle, a reference temperature, and an estimated specific heat for the oil of 0.480 Btu/lb°F. The specific heat was taken from graphical information in the ASME Power Test Code. Similarly, the water sensible heat calculation contains a tabular value... 

FIGURE 17 Sooting tendency of some hydrocarbon fuels plotted as the log of the reciprocal of the fuel mass flow rate at the smoke height versus the reciprocal of the calculated adiabatic flame temperature. 

The test rig is equipped with a feedstock hopper suitable to low-bulk-density biofuels and the biomass is fed continuously into the sand bed of the reactor via an injector screw which can feed fuel either into the bottom of the bed or to about 1 meter above the air distributor. The maximum fuel mass flow rate is 90 kg/h. The feeding system consists of two screw feeders in series separated by a rotary valve. The second screw has a higher feeding rate thus it will remain almost empty and therefore is not likely to be blocked by pyrolysis products. Steam can be added to the primary air as a gasification agent. 

The results are usually outlined in the diagrams as NO, emissions of the combustion reactor related to 6 % O2 in the flue gas over the fuel mass flow rate of the pyrolysis process. The higher the fuel mass flow rate of the pyrolysis process the more pyrolysis gas and thus rebum fuel is injected into the combustion. Directly related to the flow rate of the pyrolysis gas into the combustion is the air ratio in the reduction zone of the combustion reactor. The outline of the NO, emissions over the air ratio describes the rebum efficiency of the injected gas, whereas the outline over the fuel mass flow rate gives information on the biomass ratio on the overall process. 

Figure 8 Relation between the air ratio in the reduction zone and fuel mass flow rate... 

Three carbonaceous materials were employed in the experiments i) commercial (Degussa) amorphous carbon black (CB-330) with specific surface area (s.s.a.) of 82 m /g (BET) and apparent density of 375 kg/m ii) Diesel Soot (DS), collected at the exhaust of a Lombardini, single cylinder, D.I., 325 cm displacement, 18 1 compression ratio Diesel engine, operated at an air/fuel mass flow ratio of about 20. The BET s.s.a. of fi esh soot was 90 m /g and the apparent density 375 kg/m iii) soot (BS) generated by an heating gas-oil burner. The fuel mass flow rate fed to the burner was 1.6 kg/h while the air/fuel mass flow rate ratio was 18 and, correspondingly, the soot concentration in the exhaust gas was about 1000 ppm. 

Smoke point of a turbulent flame is defined as the critical fuel mass flow rate (CFMFR) beyond which the flame does not smoke. Goh [88] studied the effects of nitrogen dilution on the smoke point characteristics of propylene diffusion flames in crossflow. Figure 29.20 shows the variation of diluent mass flow rate with fuel... 

Fuel mass flow rate Excess air Heat loss Flue gas temperature Hue gas mass flow rate... 

Fuel mass flow rate Flue gas temperature Excess air Flue gas mass flow rate Heat loss... 

The smoke point is another measure of the tendency of a fuel to produce smoke and this quantity, like SEA, is related to the chemical composition and structure of the fuel. The smoke point is defined as the minimum fuel mass flow rate at which smoke first escapes from the tip of a laminar diffusion flame (see Fig. 2), ie, the residence time of the smoke in the combustion zone becomes too short to effect complete oxidation. The results of the smoke point test are qualitatively similar to the SEA data in Table 15 with respect to chemical structure and smokeforming tendency. In particular, it is found that the smoke-forming tendency, as determined by smoke point measurements, is lowest for oxygenated fuels (alcohols, aldehydes, esters, ethers) and increases through the series alkanes, branched alkanes, alkenes, and aromatics. 

The rest of the specifications needed to simulate the gas turbine are the compression ratio (fixed at 20 kPa in this example), the ratio of air to fuel (fixed at 53.888 in this example), and the fuel mass flow rate. At this moment, we do not know how much fuel... 

The VHP steam flow calculated depends on the fuel mass flow rate specified in the gas turbine. Note, however, that independent of the flow, the pressure, and temperature (and composition pure water) are the VHP header conditions. So we will take advantage of this fact and create a new stream that is an exact copy of the VHP steam stream except the mass flow that will not be specified. We call it VHP header. ... 

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