US2010555A

US2010555A - Hydraulically reversible pumpturbine

Info

Publication number: US2010555A
Application number: US540136A
Authority: US
Inventors: Moody Lewis Ferry
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-05-26
Filing date: 1931-05-26
Publication date: 1935-08-06
Anticipated expiration: 1952-08-06

Description

Aug. 6, 1935. F. MOODY 2,010,555 HYDRAULICALLY REVERSIBLE PUMP 'TURBINE Filed May 2. 1931 3 Sheets-Sheet l F. MOODY HYDRAULIGALLY REVERSIBLE PUMP TURBINE Filed May 26. 1951 I5 Sheets-Sheet 2 Aug. 6 1935. 1.. F. MOODY 2,010,555 r HYDRAULICALLY REVERSIBLE PUMP TURBINE v Filed May 26,- 1931 5 Shepts-She'et s cLosmg o' PEnmq' Patented Aug. 6, 1935 UNITED f STATES PATENT OFFICE HYDRAULICALLY REVERSIBLE PUMP- TURBINE This invention relates generally to hydraulic machines and more particularly to hydraulically reversible pump-turbines especially of the type having uni-directional rotation for both pump and turbine operations.

The reversibly operable pump-turbine is particularly adapted to use in hydraulic power-accumulation systems, in which during offepeak periods of load demand the machine may pump Water into the pond or reservoir by utilizing current supplied by other stations in the system; and may utilize the water so stored to carry peak loads by operating the machine as a turbine and thus supply current to the system.

In attempting to use a single machine for both pump and turbine operations it is readily appreciated that the design of the flow passages,

runner blades, guide vanes or flow control mechanism must be adapted to operate with flow in either direction. However, it is difficult to have a machine of this type which will function with the same degree of efficiency for both the turbine and pump operations as could be obtained with a pump or turbine alone. It is very desirable to have a single machine for performing both functions, providing a reasonably good efficiency may be obtained, because the cost of one unit for performing both functions is materially less than the cost of two separate units each performing only one function, due not only to the costs of the units themselvesbut ofthe powerhouse structure and conduits required. The use of only one unit will require less space in the power house and will reduce not only the initial cost of installation but also maintenance and depreciation charges. It is therefore seen that an efiicient reversible pump-turbine is most desirable.

A further feature which is desirable in the reversible pump-turbine and relating more to the operation of theequipment has to do with maintaining a constant direction of revolution of the rotor for pump and turbine operations. With this constant direction of revolution the unit may be changed from pump to turbine operation or vice versa without shutting down the unit and reversing its rotation which would involve, in each case of an alternating current system, resynchronizing the unit to the system. To reverse the direction of revolution would require an appreciable period of time on the part of the operating personnel in the power plant.

My invention involves a reversible pump-turbine having uni-directionalrotation, the reversal of hydraulic action being accomplished by reversing the angle of inclination of bgth the runner blades and adjustable guide vanes or wicket gates, while at the same time maintaining proper passage formation through the runner and guide vanes so as to be suited not only to good efiiciency 5 but also for eliminating or reducing cavitation tendencies to a minimum; it being understood that cavitation may be a vital factor in a machine of this type unless relatively favorable flow velocities are maintained. This is especially true in a unit of the high specific speed type wherein the runner blades are relatively few in number, for instance, preferably not more than six and as low as two or three in number and wherein the blades are relatively flat in the direction of flow thereover and also have normally a relatively small angle of inclination with respect to a plane normal to the axis of runner rotation. For relatively high head plants of 50 feet or more it is desirable that the blades have 20 an actual area at least equal to the areaof the runner passage taken on a plane normal to the runner axis, although the blade area may decrease as the head decreases.

It is an object of my invention to provide an improved arrangement in a reversible pumpturbine of the type having uni-directional rotation at all times. A further object is to provide in such a type of turbine, and especially of high specific speed, means whereby the runner blades may have their angle of inclination adjustably reversed and whereby at the same time the angle of the wicket gates may also be reversed thus permitting the unit to be operated either as a.

further and more specific object is to provide during turbine operation means for adjusting both the runner blades and the wicket gates automatically in response to changes in load and to superimpose on such automatic adjustment means whereby the runner blades and adjustable guide vanes may be reversed for pump operation through a manual control. A still further object is to have the adjustable guide vanes adapted to pass each other in either direction of the movement thereof, thereby providing an arrangement which requires minimum movement of the guide vanes in changing the machine from one operation to the other. 50

Another object is to provide an improved governor control between the runner blades and adjustable guide vanes.

Other objects and advantages will be readily apparent to those skilled in the art from the following description of the accompanying drawings in which:

Fig. 1 is a vertical sectional view of a machine or unit showing a generator-motor and the hydraulic element;

Fig. 2 is a partial plan view showing diagrammatically the dimensional relations of the adjustable guide vanes to permit reversal thereof, the gate operating links and shifting ring also being shown;

Fig. 3 is a partial elevational view showing diagrammatically a four-bladed runner;

Fig. 4 is a diagrammatic view showing adjustable runner blades of the type adapted to pass each other in their closed position so they may be reversed; a

Fig. 4a is a modification showing runner blades of such length that they cannot pass each other in their closed position but must be reversed with? the one portion of the blade remaining at all times below the center line of the axis of adjustment;

Fig. 5 is a horizontal section taken substantially on the" line 55' of Fig. 1;

Fig. 6 is a diagrammatic view of the automatic and manual control equipment; and

Fig. 7 is an enlarged view of the pilot valve for controlling the adjustment of the runner blades after the wicket gates have been initially adjusted in response to load variations of the turbine operation.

From the foregoing discussion it is seen that if the runner blades of an adjustable blade propeller turbine are made so as to be not only adjustable for varying angles during turbine operation but .also reversible in angular'inclination then they can be suited for pump operation without changing the direction of rotation of the runner. At the same time the guide vanes must also be re- Versible in inclination, by providing additional travel of the operating mechanism, as is also the case with the actuating mechanism for the runner blades. As will be seen from the disclosure herein, it is preferable that both the guide vanes and runner blades should have a length just small enough to allow them to pass each other in their closed positions so they may be reversed. It isalso preferable to have a casing of the concentric type, that is, one having a double spiral, thereby being suitable for fairly eificient regain of velocity head for the pump operation and also of good form for use as the turbine casing.

As a result it will be possible in su h a'machine to have continuous adjustment from turbine operation, through zero output, to operation as a.

. tions between their angular positions.

' One specific form of structure illustrating the foregoing principles and operation comprises a vertical unit of the high specific spedpropeller type having a so-called concentric intake I of the double spiral type as shown in Fig. 5. During turbine operation fiuidflows radially inwardly from around the entire circumference of the unit, past water is discharged to the tailwater through outlet -8.

, The guide vanes 2 are of the usual type wherein each vane is rotatable about its own axis and actuated by a shifting ring 9 connected to the guide vanes by connecting links 10 and gate arms II.

The shifting ring is operated preferably through the usual type of fluid actuated piston and cylinder type of servo-motor l2, the piston rod M of which is connected to the shifting ring. Any, usual type of speed governor diagrammatically indicated at G is employed so as to control the supply and discharge of actuating fluid to the gate operating motor I2 automatically in accordance with speed variations of the unit from.

. normal.

As the turbine speed varies it is desirable to adjust the angle of inclination of both the runner blades and guide vanes and to do this a follow-up' mechanism is connected to the piston rod of the gate operating motor so that during or sometimes after movement of the gates the runner blades will be adjusted to a corresponding position. This follow-up mechanism includes a link l3 pivotally connected at one end to the piston rod I A and at its other end to one arm of a bell-crank IS, the other arm thereof being connected through a link I 6, bell-crank l1, link Hi to a pivotal cam l9.

Link I6 is also connected through links and levers 20 to operate as a restoring mechanism for the speed governor pilot valve. The contour of cam I 9 is such that upon movement of the gates a certain predetermined movement will be 'imparted to a pilot valve 2| as by links and levers 22 and 23. As the pilot valve H is moved say downwardly, Fig. 7, fluid pressure is admitted from liquid pressure supply passage 3i through the pilot valve and passage 25 to an upper chamber 26 formed in a stationary casing mounted upon the top of the motor-generator 21. .Pressure fluid flows from the chamber 26 downwardly through a pipe 27 to the under side, Fig. 1, of piston 28, this piston being connected through an axially reciprocal rod29 to the runner blades 31.].

The runner blades are rotatably adjustable in the runner hub and are connected to the actuating rod 29 as by cranks and links such as shown in my copending application, Serial No. 631,985. As

the particular details of the blade operating connections within the hub do not specifically enter into my improved combination it will sumce-to state that the dimensions of these connections are such that the inclination of the runner blades may be reversed by movement of piston 28 and rod 29 to near their upper extreme position. "-"If the load or speed change on the turbine is such as to move the adjustable guide vanesin the opposite direction pilot valve 2| will also be oppositely moved, thereby permitting discharge of fluid from the under side of piston 28 through pipe 2?, chamber 26 and passage 25 to a discharge chamber 24% and fluid pre'ssure will be admitted from supply inlet 3! through pilot valve 2|, passage 32, also chamber .33 and pipe Bd'lzconnected to the top side of the cylinder 35, thereby moving piston 28 downwardly and adjusting the runner blades accordingly.

To eiiect restoring action on pilot valve 2| a rod 35' is connected to piston 28 and extends upwardly through a suitable packing gland and is connected to a slidably guided .block 36 to which the floating lever 23 is pivotally connected. From this it is seenthat as the piston 28 moves upwardly or downwardly it will restore pilot valve 2| to its neutral position and thus hold the runner blades in their adjusted position.

To change the unit from turbine operation to ,pump operation with a minimum of effort and loss of time, I have brought into cooperating relation with the control equipment, means whereby the wicket gates and runner blades may be adjusted for giving zero output notwithstanding that the speed governor would under normal turbine operation tend to readjust the blades and adjustable guide vanes. Any suitable means may be used to accomplish this. As shownin Fig. 6 a hand control valve diagrammatically shown at 3B is adapted when thrown in one position by a handle 39 to place the unit solely under control of governor i3 and to open valves 40 and M, thereby permitting supply of actuating fluid through either pipe 42 or 43 to the opening or closing sides of the usual piston and cylinder servo-motors l2. The operating ends of the motorcylinders are cross connected so that one piston moves out as the other moves in, this being necessary where two motors 12 are connected to the shifting ring 9 as shown in Fig. 6. Accumulator tank, pump and sump tank are also shown. When changing from turbine to pump operation, handle 39 is thrown to a neutral position, thereby connecting supply pipe 44 to pipe 45 which supplies closing fluid pressure to valves 40 and 4i, thereby closing pipes 42 and 43 to eliminate control by governor I3. In order to move the pistons of motors l2 to their other extreme ends and thus reverse the inclination of the runner blades and adjustable guide vanes, handle 39 is moved from its neutral position so as to connect supply pipe 44 with say pipe 46 and when the pistons have been sufliciently moved the hand control may be returned to neutral, thus holding the gates and runner blades in their newly adjusted pump position. It will be understood that it is only necessary to adjust gate operating motors l2 because the runner blades will be controlled automatically through the pilot valve 2| upon movement of the gate operating motors. Inasmuch as a pump usually operates under a relatively constant load or head, automatic adjustment of the runner blades and guide vanes is not so essential as in turbine operation, and hence if desired the pump operation may be kept entirely under manual control.

The adjustment for pump operation may also be efiected through manual adjustment of the governor, through the use of its load limit device, by which the effect of the flyballs is removed. The guide vanes are then controlled through the governor pilot 'valve and restoring mechanism.

The operation so far described is for use with runner blades of the type shown in Fig. 4 wherein the dimensions are such that the blades may pass each other through zero position. If the blades are of the type shown in Fig. 4a wherein they cannot pass each other through the zero position, they are reversed by being rotated through their completely open position, this merely requiring a reverse operation of the gate operating motors l2 in a manner similar to that be changed with respect to a meridian plane from to (d) Fig.v 4 and 4a. This is what is referred to as reversal, which does not mean turning 180 or necessarily making the angles a and b equal, or c and at equal, since in general these angles will be somewhat different in numer ical value for turbine and pump operation. Usually the vanes and blades will be at a lessinclina-y tion to the meridian plane, and therefore at a greater angle to the tangential direction, for turbine than for pump operation, in order to limit the quantity of flow and the power required from the electric motor when driving the hydraulic element as a pump and thereby to avoid overloading the motor during pumping. During either pump or turbine operation it will be noted from Figs. 4 and-4a that the blades are in overlapped relation withrespect to each other in that aline drawn from a radial edge of one blade at right angles to the flow lines between the blades will intersect the body of the adjacent blade. sult, a definite flow guiding passage is provided between the adjacent blades and this is accom plished during either pump or turbine operation.

It will of course be understood that various changes may be made in the arrangement and construction of parts without departing from the spir t of the invention asset forth in the appended claims.

1. A hydraulic pump-turbine having uni-directional rotaton for both pumpand turbine oper ations, comprising, a runner having unitary blades adjustable'past each other in closed p0 sition to one direction of inclination for pump operation and in the opposite direction for turbine operation and said blades having an actual area at least equal to substantially the area of the runner passage taken on a plane normal to the runner axis, said blades in their operative position for either pump or turbine operation being in overlapped relation with respect to each other in that a line drawn from the radial edge of a blade at right angles to the flow lines between the blades will intersect the body of the adjacent blade whereby a definite flow guiding passage is formed between said blades, a passage leading to and from said runner, adjustable guide As a revanes disposed in the portion of said passage which normally constitutes the inlet during turbine operation, and means for reversing the direction of inclination of said guide vanesin accordance with pump or turbine operation.

2. A hydraulic pump-turbine having uni-directional rotation for both pump and turbine operations, comprising, in combination, a runner provided with unitary blades adjustable past each other in their closed position so as to be inclined in one direction for pump operation and in the opposite direction for turbine operation and said blades having an actual area at least equal to substantially the area of the runner passage taken on a plane normal to the runner axis, said .blades in their operative position for either pump or turbine operation being in overlapped relation with respect to each other in that a line drawn from the radial edge of a blade at right angles to the flow lines between the blades will intersect the body of the adjacent blade whereby a definite flow guiding passage is formed between said blades, guide vanes, passages leading to the guide vanes and from said runner, said guide vanes being disposed in the portion of said passages normally constituting the inlet during turbine operation-and adjustable past each other through closed position so as to be inclined in one direction for turbine operation and in an opposite direction for pump operation, a passage leading during turbine operation to said guide vanes, said latter passage and said other passages beingsymmetrical in a plane normal to the runner axis about a center line through said axis, and being formed to provide gradual enlargement of flow sections in proceeding away from the pump-turbine.

1 3. A hydraulic pump-turbine having uni-directional rotation for both pump and turbine operations, comprising, in combination, a runner having blades adjustable past each other in closed position to opposite directions of inclination, a passage leading to and from said runner, guide vanes adjustable to opposite directions of inclination, governing mechanism for simultaneously adjusting said runner blades and guide vanes during turbine operation, means whereby'the direction of inclination of the runner blades and guide vanes may be reversed to permit pumping without reversing the direction of runner rotation, and means whereby during pump operation said governing mechanism is disconnected from control by its governor while still effecting simultaneous adjustment between said guide vanes and runner blades under hand control.

4. A hydraulic pump-turbine having unidirectional rotation for both pump and turbine operations, comprising, in combination, a runner having blades adjustable past each other in closed position to opposite directions of inclination, a passage leading to and from said runner, guide vanes adjustable to opposite directions of inclination, governing mechanism for simultaneously adjusting said runner blades and guide vanes during turbine operation, including means for relatively quickly adjusting the guide vanes and for more slowly adjusting the runner blades in response to adjustment of the guide vanes and means whereby the direction of inclination of the runner blades and guide vanes may be reversed to permit pumping without reversing the direction of runner rotation, said means including a fluid actuated motor for adjusting the runner blades.

5. A hydraulic pump-turbine having unidirectional rotation for both pu mp and turbine operations, comprising, in combination, a runner having blades adjustable to opposite directions of inclination, a passage leading to and from said runner, guide vanes adjustable to opposite directions of inclination, governing mechanism for simultaneously adjusting said runner blades and guide vanes during turbine operation,

and means whereby the direction of inclination of the runner blades and guide vanes may be reversed to permit pumping without reversing the direction of runner rotation, said means including a hand control valve mechanism adapted to disconnect the governor control and reverse the inclination of the runner blades and guide vanes while still providing simultaneous adjustment of said blades and vanes.

6. A rotary hydraulic machine adapted for reversal of the direction of flow therethrough and to have uni-directional rotation for both turbine and pump operations, including a series of rotatably adjustable guide vanes and a runner i, having blades rotatably adjustable past each other in closed position and rotatable with respect to the runner hub, operating mechanism to effect said adjustment, said guide vanesbeing adjustable so that their angle of inclination with respect .to a plane containing the runner axis may be changed from a positive to a negative angle, said runner blades also being adjustable so that their angle of inclination with respect to a. plane containing the runner axis may be changed from a positive to a negative angle, the travel of said operating mechanism being so disposed that said angles are difierent for turbine operation from those for pump operation whereby the passages between successive guide vanes and runner blades are wider for turbine than for pump operation.

'7. A rotary hydraulic machine adapted for reversal of the direction of flow therethrough and to have uni-directional rotation for both turbine and pump operations, including a series of rotatably adjustable guide vanes and a runner having blades rotatably adjustable past each other in closed position and rotatable with respect to the runner, operating mechanism to efiect said adjustment mechanism for adjusting said blades so that their angle of inclination with respect to a plane containing the runner axis may be changed from a positive to a negative angle, and mechanism for also adjusting said runner blades so that their angle of inclination with respect to a plane containing the runner axis may be changed from a positive to a negative angle, the travel of said operating mechanism being so disposed that said angles are different for turbine operation from those for pump operation whereby the passages between successive guide vanes and runner blades are wider for turbine than for pump operation.

LEWIS FERRY MoobY.

CERTIFICATE or CORRECTlON.

Patent No. 2,010,555. I Auguste, 19.35.

LEWIS FERRY MOODY.

It is hereby certified that error appears in the printedspecificationof the above numbered patent requiring correction as follows: Page 4, second column, line 45, claim '7, "after "adjustment" insert a comma; and that the said Letters Patent should 'be read with this correction therein that the "same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of. April, A. D. 1936.

Leslie Frazer (Seal) Acting Commissioner of Patents.