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Show 14 Jordan Loftus ScD. Texaco Inc - August 24. 1989 The recirculation flow, Wr , is taken proportional to its value at rc and the ratio of the areas for recirculation: Wr,z - Wr,c [Ar,z /Ar,cl Eq. 17 . which is equivalent to a constant recirculation velocity for a constant flue gas density. 4. Plug Flo~ When jet fills the burner volume domain, then no recirculation can occur. When the flow reaches the opposite individual surface zones, the flow quantities become sources to be dissipated to the flue gas exit. 5. Dissipation Flow Each surface zone having a source flow, Wj' either from a burner jet or from flue gases from an adjacent gas space is discharged to all surface zones m specified as exits (Figure 11) by As the flow proceeds from j to m, it is divided vectorial into its XYZ components. After completing all sources, the flows are summed over the 3 by 4 by 8 mesh but flow in opposite direction are summed separately . D. Energy Balances 18 There is one non-linear energy balance equation for each of the 48 gas volume zones and one for each refractory or partial refractory surface zone. Each cell of the energy balance matrix (Figure 11) is computed for the current estimated value of the unknown refractory surface or gas volume temperatures for the ith column. The gas zone temperature is then updated by NewtonRaphson method and refractory temperatures, by Gauss-Seidel procedure by solving jth row energy balances. For gas zone Uk", the energy entering (non-diagonal terms) includes: a. One way radiative fluxes from all other zones (gas, refractory and sink) one by one to gas zone Uk", b. One way convective heat fluxes from contiguous surface zone(s) to gas zone Uk" equal to the sum of the forced 18. Hottel, H.C. and A.F. Sarofim, "Radiative Transfer", HcGraw-Hill (1967), paragraph 11.4 Total Energy Balances. |