Abstract: When the trigonometric function of the phase lag of the hydraulic excitation of the runner vanes, which varies in accordance with the combination of the number of runner vanes and the number of guide vanes of a high head pump/turbine, is denoted by cos(.theta..sub.R n), the thickness of the crown along a circle of a diameter at a mid point of the diameter of the outermost periphery of the runner is denoted by t.sub.MC, the thickness of the band is denoted by t.sub.MB, the mean thickness of the crown at the outer peripheral portion of the runner is denoted by t.sub.C, the mean thickness of the band is denoted by t.sub.B, and the rigidity ratio of the crown and band to the runner vane is denoted by K.sub.R taking the rigidity of the runner vane as a reference, the moment coefficient C.sub.MO which is a function of cos(.theta..sub.R N) and the rigidity ratio K.sub.R is selected to be less than 0.5 in accordance with the value of cos(.theta..sub.R n), and relations t.sub.C /t.sub.MC .ltoreq.1 and t.sub. B /t.sub.

Abstract: A method for operating pumps in a pumping-up power plant having a single speed reversible pump-turbine and a booster pump, the booster pump being provided in a branch pipe which is provided in parallel with a portion of a draft tunnel between the pump-turbine and a lower reservoir, is disclosed. The method includes the steps of, closing guide vanes of the pump-turbine, opening the portion of the draft tunnel which runs in parallel with the branch pipe, closing the branch pipe, then starting the pump-turbine in air as a pump, and starting the booster pump.

Abstract: A multi-stage hydraulic machine comprises a rotatable shaft, a plurality of runners fixed to the shaft and arranged from a highest-pressure stage to a lowest-pressure stage, runner chambers which, respectively, house the runners, a return channel for connecting adjacent ones of the runner chambers with each other, movable wicket gates provided at least in the highest-pressure stage and capable of moving between a position in which the movable wicket gates block the channel and a position in which the movable wicket gates open the channel, a casing connected to the highest-pressure stage, and an inlet valve disposed between the casing and a penstock.

Abstract: A multistage hydraulic machine such as a pump/turbine having at least three pressure stages in which the highest and lowest pressure stages are provided with movable guide vanes the degree of opening of which are variable, and the other intermediate pressure stages are provided with stationary guide vanes the degree of opening of which are not variable. The movable and stationary guide vanes are simultaneously or independently controlled in accordance with a change of an operational condition at the time of steady operation in a manner such that the degree of opening of the movable guide vanes of the lowest pressure stage becomes relatively larger or smaller than that of the stationary guide vanes in a high flow-rate range or in a low flow-rate range, respectively, while maintaining the degree of opening of the movable guide vanes of the lowest pressure stage to be equal to or smaller than that of the highest pressure stage.

Abstract: In a multistage hydraulic machine of the type having a main shaft supporting a plurality of runners ranging from a highest pressure stage to a lowest pressure stage, at least one set of adjustable wicket gates provided for the highest pressure stage runner, a draft tube connected to a lower end of the lowest pressure stage runner, and devices for supplying and exhausting compressed air into and out of the pressure stages upon closure of the wicket gates, there is provided an air exhausting device including an air exhausting passage opening in a runner-cone portion of the lowest pressure stage runner.

Abstract: A multi-stage hydraulic machine comprises a rotatable shaft; a plurality of runners fixed to the shaft and arranged from a highest-pressure stage to a lowest-pressure stage; runner chambers in which are respectively housing the runners; a return channel for connecting adjacent ones of said runner chambers with each other; movable wicket gates provided at least in the highest-pressure stage and capable of moving between a position in which the movable wicket gates block the channel and a position in which the movable wicket gates open the channel; and a casing connected to the highest-pressure stage. In a control method for the hydraulic machine, the wicket gates are closed and highly pressurized water is fed through a feed pipe in an outer circumferential portion of the runner chamber of the highest-pressure stage defined inside of the movable wicket gates, said water sequentially reaching the lower pressure stages through the return channels.

Abstract: In a pumping-up hydroelectric power plant comprising a single speed main pump/turbine and a booster pump operable in series in a pumping operation between an upper reservoir and a lower reservoir, a water head shared by said booster pump is varied depending on a variation in the static head between the two reservoirs for maintaining the operation of the main pump/turbine always in a maximum efficiency range.

Abstract: A method for operating pumps in a pumping-up power plant having a single speed reversible pump turbine and a booster pump, the booster pump being provided in a branch pipe which is provided in parallel with a portion of a draft tunnel between the pump turbine and a lower reservoir, is disclosed. The method includes the steps of initiating the closing of a first inlet valve at the discharge side of the pump turbine, disconnecting the pump turbine and the booster pump simultaneously from an outer electric power system to which the pump turbine and the booster pump are connected, after an opening of the first inlet valve is closed to a predetermined value, and then closing the first inlet valve completely.

Abstract: In a pumping up hydroelectric power plant including a main pump/turbine and a booster pump operable in series during the pumping operation of the main pump/turbine, time constants K.sub.1 and K.sub.2 for the pump/turbine and the booster pump, and average torques y.sub.1 and y.sub.2 for the same two machines are selected to satisfy relations(K.sub.1 /K.sub.2)(y.sub.2 /y.sub.1).apprxeq.1.0and0.71.ltoreq.K.sub.2 /K.sub.1 .ltoreq.1.42.

Abstract: A method for operating pumps in a pumping-up power plant having a single speed reversible pump turbine and a booster pump, the booster pump being provided in a branch pipe which is provided in parallel with a portion of a draft tunnel between the pump turbine and a lower reservoir, is disclosed. The method for operating the pumps comprises the steps of, closing an inlet valve at the discharge side of the pump turbine, closing a portion of the draft tunnel which is in parallel with the branch pipe, opening the branch pipe, starting the pump turbine in air as a pump, starting exhaustion of the air remaining inside the pump turbine when the rotation speed thereof reaches a predetermined value, starting the booster pump after the exhaustion is started, and opening the inlet valve at the discharge side of the pump turbine after the rotation speed of the booster pump reaches a predetermined value.

Abstract: In a Francis type pump turbine, for the purpose of switching the operation of a synchronous dynamoelectric machine from synchronous condenser operation wherein compressed air is admitted into a runner chamber to force down water level therein so as to cause a runner to rotate in air, to a synchronous generator operation, the air is released from the runner chamber and an inlet valve and guide vanes are completely or nearly completely closed. Then the inlet valve and guide vanes are gradually opened until a predetermined degree of opening is reached while maintaining the degree of opening of the guide vanes to be larger than that of the inlet valve. After the predetermined degree of opening, both the inlet valve and the guide vanes are gradually opened. But at this time the degree of opening of the inlet valve is maintained to be larger than that of the guide vanes. To switch from the generator operation to the condenser operation the same characteristic curves are traced in the opposite direction.

Abstract: A method of controlling a two-stage hydraulic pump-turbine, rotating at a constant speed under a steady condition, in which high and low pressure stages are connected through a return passage. The variable degrees of openings of movable guide vanes of the high and low pressure stages are equally controlled to the same extent when the hydraulic pump-turbine operates as a pump and independently controlled to the different extents when the pump-turbine operates as a turbine in accordance with a change of an operational condition such as water level or load at a time of the steady operation.

Abstract: Disclosed are a method of pumping up electric power generation and an apparatus therefor which comprises a single-speed reversible pump-turbine and a booster pump, hydraulically coupling and driving the pump-turbine in series with the booster pump to perform pumping with the sum of respective pump total heads of the pump-turbine and the booster pump, and generating electric power by an average turbine net head affecting the pump-turbine without employing the booster pump, the ratio of the average pump total head to the average turbine net head of the pump-turbine being selected at the range from 0.82 to 1.0 and the ratio of average pump total head of the booster to the average turbine net head being selected at the range of from 0.23 to 0.05.

Abstract: Disclosed is a multistage hydraulic machine system which comprises a multistage hydraulic pump/pump-turbine including a highest-pressure stage having movable guide vanes with variable opening of water path arranged round a runner and a lower-pressure stage or stages having fixed guide vanes with fixed opening of water path arranged round a runner or runners, and a control unit for controlling the operation of the multistage hydraulic pump/pump-turbine, whereby the opening of the movable guide vanes is controlled by the control unit so that such opening is larger than that of the fixed guide vanes for a large-flow normal operation of the pump/pump-turbine and smaller for a small-flow normal operation.

Abstract: In a method of controlling guide vanes of a multistage hydraulic machine including a plurality of stages interconnected by return passages of the type wherein under an abnormal condition which occurs when the operation of a water wheel or a pump is stopped or when the load of the water wheel is interrupted or the input of the pump is interrupted due to a fault of the machine, the guide vanes are closed such that the degree of opening of the guide vanes of a higher pressure stage is maintained to be always equal to or smaller than the degree of opening of the guide vanes of a lower pressure stage, the guide vanes of the lower pressure stage are not completely closed and maintains a predetermined small degree of opening when the guide vanes of the higher pressure stage are completely closed.

Abstract: In a casing of a hydraulic machine of the type comprising a stay ring including a pair of opposing annular plates and a plurality of stay vanes fixed therebetween to form stay vane flow passages between the stay vanes, and a spiral case disposed on the radially outside of the stay ring, the stay vane passages and the spiral case are proportioned such that the ratio n of the area 2.pi. R.sub.o B of a circle encircling the outer periphery of the stay vanes and the cross-sectional area .pi. R.sub.s.sup.2 of the flow passage in the spiral case is from 1.9 to 2.5, and that the ratio (R-R.sub.o) /R.sub.s =l is larger than 0.75 where R.sub.s represents the radius of the cross-section of the flow passage in the spiral case taken along a plane containing the axis of the shaft of the hydraulic machine and intersecting at right angles with the axis of an inlet to the spiral case, R the distance between the axis of the shaft and the center of the flow passage in the spiral case, R.sub.

Abstract: A multistage hydraulic machine is provided with an outer backchamber, an inner backchamber and a sidechamber around the runners of each stage.A piping having a control valve is provided between the outer back chamber in the highest pressure-stage and the sidechamber in the lowest pressure-stage.Moreover, the outer backchamber is connected to the sidechamber for the runners of the high-pressure-stage.