GB360763A - Improvements in and relating to methods for automatically starting steam turbines - Google Patents

Abstract

360,763. Steam turbines. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.- (Assignees of Allgemeine Elektricitats-Ges. ; 2, Friedrich Karl-Ufer, Berlin. ) Feb. 3, 1931, No. 3456. Convention date, Feb. 3, 1930. [Class 110 (iii).] In starting a steam turbine the actuation of a primary member automatically or manually sets into operation a series of starting operations in dependence on the physical conditions occurring with the setting into operation of steam turbine plants. In the arrangement shown, the primary member consists of a switch 2 which is thrown over when the voltage in the system to which the generator driven by the turbine 13 is to be connected falls below a predetermined value. This causes an auxiliary prime mover 3a to be started up to set into operation the condensate pump 3b, the cooling water pump 3c, and the pump 3d for the jet apparatus 4 of the condenser 5. When a predetermined vacuum has been created an automatic device 6 attached to the condenser causes a valve 7 in the steam line to open so that steam is supplied to a turbine driving an auxiliary oil pump 8. This pump feeds the main bearings, and when the outflow from all of the bearings, as measured by devices 9 reaches a predetermined amount, a valve 10 is actuated to pass pressure oil to the servomotor 11 of the main stop valve 12. The turbine is thereby started up, and when the shaft begins to turn a contact g on its end acts to open a valve 15 which passes steam to seal the outer stuffing-boxes. The main oil pump 16 now comes into operation to supply the oil pipe lines. It delivers at a pressure greater than that of the auxiliary oil pump 8 and causes a non-return valve 17 to close, whereupon the valve is closed and the auxiliary oil pump is shut down. At the same time the speed governor 19 takes over the control of the regulating valves 18. Means may be provided for preventing excessive supply of steam during the preliminary heating up of the rotor and casing. These means depend upon the movement over contacts of a pivoted lever which follows the differential movement of the rotor and casing due to expansion. A pressure responsive device connected to the condenser may act upon the pilot valve of the servomotor 11 in order to limit the supply of steam upon increase of the condenser vacuum. The same result may be secured by the use of a motor-driven cam, and the actuation of this cam may be associated with the heating-up control referred to above. The whole operation may be controlled by a contact drum, and a pressure responsive device actuated by the oil may be provided to cut out the control.