OPTIMIZATION OF PARAMETERS OF A HYDRO-STEAM TURBINE

Consideration has been given to the specifi c features of the work process of a hydro-steam turbine operating on the principle of Segner′s wheel. A method has been suggested for the organization of entry into the turbine channels that ensures minimum hydraulic losses. It has been shown that losses due to the friction of the rotor wheel rotating in a steam-water medium have a number of specifi c features that do not allow their reliable calculation assessment at present. At the same time, some maximum estimates have shown that these losses can be quite signifi cant in the turbine′s total energy balance and force one to pay serious attention to the aerodynamic properties of the periphery zone of the turbine rotor wheel. It has been established that the diversion of the nozzle axes′ direction from the direction of the circumferential velocity of motion of the center of the nozzles' outlet cross section with a view to preventing structure elements from getting into their jets results in a drop of the turbine capacity, which brings about the need for seeking a compromise solution in selecting the angle of this deviation. The calculation assessment of the optimum ratio of the circumferential velocity of motion of the nozzle outlet section to its fi ctitious velocity corresponding to the available heat drop in a hydro-steam turbine has shown that it lies within 0.32–0.37, depending on the nozzle velocity coeffi cient, and the fl at pattern of the said dependence provides certain freedom to the designer in selecting the turbine design dimensions.
Consideration has been given to the specifi c features of the work process of a hydro-steam turbine operating on the principle of Segner′s wheel. A method has been suggested for the organization of entry into the turbine channels that ensures minimum hydraulic losses. It has been shown that losses due to the friction of the rotor wheel rotating in a steam-water medium have a number of specifi c features that do not allow their reliable calculation assessment at present. At the same time, some maximum estimates have shown that these losses can be quite signifi cant in the turbine′s total energy balance and force one to pay serious attention to the aerodynamic properties of the periphery zone of the turbine rotor wheel. It has been established that the diversion of the nozzle axes′ direction from the direction of the circumferential velocity of motion of the center of the nozzles' outlet cross section with a view to preventing structure elements from getting into their jets results in a drop of the turbine capacity, which brings about the need for seeking a compromise solution in selecting the angle of this deviation. The calculation assessment of the optimum ratio of the circumferential velocity of motion of the nozzle outlet section to its fi ctitious velocity corresponding to the available heat drop in a hydro-steam turbine has shown that it lies within 0.32–0.37, depending on the nozzle velocity coeffi cient, and the fl at pattern of the said dependence provides certain freedom to the designer in selecting the turbine design dimensions.
Author:  B. A. Shifrin, O. O. Mil′man, V. B. Perov, A. S. Goldin
Keywords:  hydro-steam turbine, boiling-up, water–steam mixture, reactive force, nozzle, underheating, dryness, low-temperature heat
Page:  1285