Within turbine blade rows, particularly for cascades of high deflection angle, cross-channel gradients of steam properties may be appreciable. To determine the effects on spontaneous condensation of gradients of super...Within turbine blade rows, particularly for cascades of high deflection angle, cross-channel gradients of steam properties may be appreciable. To determine the effects on spontaneous condensation of gradients of supersaturation normal to streamlines, the conservation equations can be incorporated in a two dimensional calculation procedure. With the help of program FORTRAN 90 a developed computational program of calculations is accomplished, whose results are communicated to the pressure and Mach number distribution, direction of flow and streamlines in the field and the drops distribution in the outlet of the stator blade mesh. The procedure contains a program section, which avoids difficulties in the strongly curved profile of the leading and trailing edge by a developed computational mesh construction.展开更多
The combustion products of fuels containing the elements C, H, O, N and S are calculated. The methodology is based on the equations obtained in the stoichiometric balance of atoms. The adiabatic flame temperature is d...The combustion products of fuels containing the elements C, H, O, N and S are calculated. The methodology is based on the equations obtained in the stoichiometric balance of atoms. The adiabatic flame temperature is determined considering that the pressure of the boiler furnace remains constant. The scope of this work is limited to the analysis of natural gas (methane) with molecular formula CH4. The methodology can, however, be employed for the calculation of combustion products of a great variety of hydrocarbons under the established restrictions.In the development of the methodology two cases are contemplated: Φ ≤ 1 (lean and stoichiometric mixture) and Φ > 1 (rich mixture). In the first case it is considered that when the combustion is complete, the combustion products are O2, H2O, CO2, N2, SO2, and the solution follows directly. When the combustion is incomplete, however, the products H, O, N, H2, OH, CO, NO, O2, H2O, CO2, N2 and SO2 can be generated, according to Stephen R. Turns, (2000). When bal-ances of atoms are performed, four conservation equations are obtained, one for each of the C, O, H and N elements. An additional restriction requires that the sum of the molar fractions of the products equals one mol. Finally, seven equilibrium constants, corresponding to the seven chemical reactions of combustion, are introduced. All this provides a system of four nonlinear equations which is solved with the Newton-Raphson method.展开更多
文摘Within turbine blade rows, particularly for cascades of high deflection angle, cross-channel gradients of steam properties may be appreciable. To determine the effects on spontaneous condensation of gradients of supersaturation normal to streamlines, the conservation equations can be incorporated in a two dimensional calculation procedure. With the help of program FORTRAN 90 a developed computational program of calculations is accomplished, whose results are communicated to the pressure and Mach number distribution, direction of flow and streamlines in the field and the drops distribution in the outlet of the stator blade mesh. The procedure contains a program section, which avoids difficulties in the strongly curved profile of the leading and trailing edge by a developed computational mesh construction.
文摘The combustion products of fuels containing the elements C, H, O, N and S are calculated. The methodology is based on the equations obtained in the stoichiometric balance of atoms. The adiabatic flame temperature is determined considering that the pressure of the boiler furnace remains constant. The scope of this work is limited to the analysis of natural gas (methane) with molecular formula CH4. The methodology can, however, be employed for the calculation of combustion products of a great variety of hydrocarbons under the established restrictions.In the development of the methodology two cases are contemplated: Φ ≤ 1 (lean and stoichiometric mixture) and Φ > 1 (rich mixture). In the first case it is considered that when the combustion is complete, the combustion products are O2, H2O, CO2, N2, SO2, and the solution follows directly. When the combustion is incomplete, however, the products H, O, N, H2, OH, CO, NO, O2, H2O, CO2, N2 and SO2 can be generated, according to Stephen R. Turns, (2000). When bal-ances of atoms are performed, four conservation equations are obtained, one for each of the C, O, H and N elements. An additional restriction requires that the sum of the molar fractions of the products equals one mol. Finally, seven equilibrium constants, corresponding to the seven chemical reactions of combustion, are introduced. All this provides a system of four nonlinear equations which is solved with the Newton-Raphson method.
