Patent GB-924439-A (GB)
Title: Hydraulic turbine driven alternator power unit
IPC: F03B15/00
Filed: 1959-07-06
Abstract: 924,439. Hydraulic turbines. ETABLISSEMENTS NEYRPIC. (Ateliers Neyret-Beylier et Piccard-Pictet). July 6, 1959 [July 8, 1958], No. 23198/59. Class 110 (3). A hydro-electric power unit comprises an hydraulic turbine driving an alternator, the turbine having adjustable pitch rotor blades also adjustable pitch guide blades, also a governor for normally varying the pitch of the blades in response to rotational speed of the rotor. Cam means are provided for co-ordinating movement of the rotor blades and guide blades upon actuation of the governor, there being an over-riding device responsive to zero load condition of the alternator for over-riding normal regulation by the governor device and for imparting to all the blades pre-determined positions. A sluice valve is also provided in the draught tube downstream of the turbine rotor, the valve being responsive to the zero load condition of the alternator whereby it is fully open when the load is normal and partially closed when the load falls to zero. The turbine shown is of the Kaplan type and comprises a rotor 1 with angularly adjustable blades 2, an inlet nozzle assembly 15 with angularly adjustable guide blades, and a draught tube 21 having a sluice valve 20 therein. The rotor blades 2 are adjustable by a piston device to which pressure fluid may be supplied from a distributer 7 through pipes 5, 6. The guide blades are movable by a servo device 14 which is supplied with pressure fluid from a distributer 18 through pipes 16, 17. The sluice valve 20 is operated by a servo device 22 which is supplied with pressure fluid from a servo piston device 25 through pipes 23, 24. The distributors 7, 18 and 25 are supplied with pressure fluid from a tank C which in turn is supplied by a pump P. The alternator A feeds line L and lines 1 1 , 1 2  are connected thereto so that when the turboalternator is operating normally, the solenoids 27, 26a are energized, whereby the detent 28 is held in the full-line position shown against the tension of a spring, and the piston-rod 26 and piston are held in the full-line position shown against the compression of spring 26b, the piston then blocking the flow of fluid to the ducts 23, 24. Following a fall in the electrical load the solenoids become de-energized. The piston rod 26 is therefore moved to the right by action of the spring 26b and pressure fluid flows through the duct 23 and effects a closing movement of the valve 20, the closing movement ceasing when the cam 30 on the valve rod engages the piston-rod 26, thereby moving the piston-rod 26 back to the neutral position shown. The detent 28a is simultaneously moved to the left consequent upon de-energization of the solenoid 27, this movement acting through linkages to move the rotor blades 2 and inlet guide blades from the full-line positions shown to the dotted line positions. When the electrical output commences to increase, the solenoids 27, 26a are again energized, resulting in re-opening of the sluice valve 20, the inlet guide blades and adjustment of the rotor blades. The pitch of the rotor blades 2 and of the guide blades 15 is normally controlled by the governor 19.