Patent · US Expired

Rotor-stress preestimating turbine control system

US4228359A · kind A · utility

20Cited by
5References
29Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 28, 1978
Grant dateOct 14, 1980
Priority date
Expiry dateJul 28, 1998

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF01D19/02
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

The present stress in the turbine rotor is estimated at each control period, from the steam temperature and pressure at the turbine inlet. In addition, the future turbine inlet steam temperature or pressure is preestimated once every n.sub.T control cycles, for a given speed or load changing rate, making use of data concerning the changing rate of the turbine steam inlet temperature or pressure in relation with the change of the speed or load, which has been obtained by a learning of the past turbine operating condition. This future steam temperature or pressure at the turbine inlet is used as a factor for preestimating the future stress expected to be caused in the turbine rotor. The preestimation of the rotor stress is performed for a plurality of assumed speed or load changing rates. The turbine is controlled at the maximum speed increase-rate or load changing rate which would not cause the future stress preestimated over a given preestimation time to exceed a limit stress. An observation of the present stress is made at each control period to check whether the limit stress is not exceeded by the present stress.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.