US2671635A

US2671635A - Reversible pump-turbine

Info

Publication number: US2671635A
Application number: US164240A
Authority: US
Inventors: Richard B Willi
Original assignee: Baldwin Lima Hamilton Corp
Current assignee: Baldwin Lima Hamilton Corp
Priority date: 1950-05-25
Filing date: 1950-05-25
Publication date: 1954-03-09
Anticipated expiration: 1971-03-09

Description

March 9, '1954 R. B. WILLI REVERSIBLE PUMP-TURBINE Filed May 25 2 Sheets-Sheet l I l- R H mm f m M I R R. B. WILLI REVERSIBLE PUMP-TURBINE March 9, 1954 2 Sheets-Sheet 2 Tiled May 25, 1950 INVENTOR RICHARD B WILLI A T TORNEY Patented Mar. 9, 1954 REVERSIBLE PUMP-TURBINE Richard B. Willi, Norristown, Pa., assignor to Baldwin-Lima-Hamilton Corporation, a corporation of Pennsylvania Application May 25, 1950, Serial No. 164,240

Claims. 1

This invention relates generally to reversible pump-turbines and it is an object of my invention to provide an improved unit whose best efflciency occurs at the same speed for either pump or turbine operation.

As is well-known, pump storage apparatus has been used to pump water into an elevated reservoir duringofi-peak loads of a power system and then such stored wateris utilized to drive a hydraulic turbine to supply electric current back to the system during peak load demands. These installations have generally employed separate turbine and pump units whereby the turbine remains idle while the pump is operating and vice versa. In such installations, there is not only the cost of the two units but also the additional space requared for such units. To overcome these difficulties various arrangements have heretofore been proposed for combining both the pump and turbine operations in a single machine, but this involves the well-known problem of operating the unit at different speeds for the pump and turbine operations, thus increasing the cost of the pump motor which functions as a generator during turbine operation, and also involves other diificulties incident thereto.

In the combination or elements comprising my present invention, I have provided an improved runner that may be effectively used in a single reversible pump-turbine unit adapted to operate at a single speed at best efficiency for either pump or turbin operation.

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

Fig. 1 is a transverse section through the runner and a portion of the casing structure employing my improved runner;

Fig. 2 is a section taken generally on the line 2-! of Fig. 1 showing a runner blade converted to turbine operation;

Fig. 3 is an enlarged plan view of a link type of operating mechanism for convertin a runner blade from turbine to pump operation or vice versa and taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary horizontal section taken substantially on the line 4-4 of Fig. lshowing the relationship of a series of the runner blades when in their pump position;

Fig. 5 is a fragmentary plan view of a series of operated devices for a plurality of blades and of a type such as shown in Fig. 3

Fig. 6 is a partial plan view of a modified form of gear operating mechanism for the blades;

Fig. 7 is a modified form of runner blade;

Fig. 8 is a perspective of one of the conversion blades; and

Fig. 9 is an enlarged vertical section of one of the runner blades.

In the particular embodiment of the invention disclosed in Fig. 1, I have shown a pump-turbine unit in a Francis type setting which includes a spiral casing l, a radial annular passage 2 in which a series of adjustable guide vanes 3 are mounted, a runner generally indicated at 4, and a draft tube 5 or other suitable axial flow passage. The runner, as is customary, is mounted on a shaft 6 suitably journalled in a head cover 7. When the unit operates as a turbine the water flows from casing I through passage 2 and the runner into passage 5 and when operating as a pump the water flows in the reverse direction.

To permit the turbine runner to have its best eificiency at the same speed whether operating as a pump or as a turbine, I have provided runner blade sections 8 with hinged blade sections 9 suitably journalled at In and H at their upper and lower ends in the runner walls 12 and I3, the blade sections 8 being fixed with respect to these two walls. The hinged blade sections are shown more particularly in Fig. 2 as forming a continuation of the outer edge l4 of the fixed blade sections 8. The sections 8 also are suitably recessed as at l5 to receive the hinged blades 9 when folded back against blade 8 in which position the two blades present a substantially continuous surface that will insure substantially uniform fluid flow. The joints between these blade sections may be fitted with any desired degree of clearance as may be required.

To adjust the movable blade sections simultaneously, individual operating mechanism is employed consisting of having the blade shafts l0 provided with a pair of links it and I1 operated by a piston and cylinder l 8 whose supply and exhaust of operating fluid may be suitably controlled through pipes l9 and 20 connected to a control valve (not shown), common to all servomotors, for moving the servo-motor l8 in either of opposite directions. There is one servo-motor for each hinged blade, althugh, as shown in Fig. 6, a single operating mechanism common to all of the hinged blades comprises a ring gear 2| engaging a quadrant gear 22 secured to the shaft III of each of the hinged blades. The ring gear can be operated by a single servo-motor such as l 8 or in any other manner desired.

In the modification shown in Fig. 7, the hinged blade sections 23 are disposed between the outer ends of the other blade sections 24 which are fixed with respect to the runner walls. The hinged sections are folded back to their dotted line positions 25 when the unit operates as a turbine and are extended to their full line position when operating as a pump. In the same manner the hinged blade sections 9 of Fig. 1 are extended for pump operation and are folded back for turbine operation. In both forms of the invention it is seen that by swinging the pivotal blades through 180 the blades have maximum and minimum radial positions lying in a common plane substantially parallel to the runner axis so that the effective length of the runner blading in the direction in which water flows over the blades is increased or decreased so as to provide either a maximum or minimum diameter runner respectively for pump or turbine operation in opposite directions of rotation but at the same speed. Also in both forms the pivotal axes of the movable blades are offset from the center line thereof but these axes are substantially parallel to the fixed blades at the outer edges thereof.

Thus it is seen that I have provided an extremely simple, yet highly effective, compact and economical arrangement for converting from turbine to pump operation or vice versa in a single unit. The single runner, with its two selective diameters, permits best efliciency, at the same speed, regardless of whether the unit operates as a pump or as a turbine.

It will, of course, be understood by those skilled in the art that various changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. A hydraulic reversible pump-turbine unit comprising, incombination, a runner rotatable in one direction for turbine operation and in the opposite direction for pump operation, means forming passages leadin to and from said runner, said runner having radially extending fixed blades terminating in outer edges, radially extending movable blade sections, means carried by said runner for pivotally supporting said movable blades about axes substantially parallel to the fixed blades at the outer edges thereof, the pivotal axes being offset from the center line of the movable blades, and operating mechanism for swinging said pivotal blades through substantially 180 from maximum to minimum radial positions lying in a common plane substantially parallel to the runner axis so as to increase or decrease the effective length of the runner blading in the direction in which the hydraulic fluid flows over the blades thereby either to provide a maximum runner diameter for determining the operation of the runner as a pump in one direction of its rotation at substantially a given speed or to provide 4 a minimum runner diameter for determining the operation of the runner as a turbine when rotated in the opposite direction at said given speed.

2. The combination set forth in claim 1 further characterized in that the movable blade sections are hinged adjacent to the outer edges of the fixed runner blades.

3. The combination set forth in claim 1 further characterized in that the movable blade sections are hinged adjacent to the outer edges of the fixed runner blades which are provided with a recess into which the movable section may be disposed.

4. The combination set forth in claim 1 further characterized in that the movable blade sections are spaced between the outer edges of adjacent fixed blades.

5. A hydraulic reversible pump-turbine of the Francis type having a spiral casing with a radial flow passage, means forming an axial flow passage, adjustable guide vanes, means for supporting the same in said radial flow passage, a Francis type runner, means for supporting the runner between said radial and axial flow passages, said runner having fixed and hinged blade sections, means carried by said runner for pivotally supporting said hinged blades about axes offset from the center line of the hinged blades, and operating mechanism for swinging said hinged blades through substantially 180 from maximum to minimum radial positions lying in a common plane substantially parallel to the runner axis so as to increase or decrease the effective runner blading in the direction in which the hydraulic fluid flows over the blades thereby either to provide a maximum runner diameter for determining the operation of the runner as a pump in one direction of its rotation at substantially a given speed or to provide a minimum runner diameter for determining the operation of the runner as a turbine when rotated in the opposite direction at said given speed.

RICHARD B. WILLL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,611,341 Deriaz Dec. 21, 1926 1,627,294 Nydqvist May 3, 1927 1,664,895 Nydqvist Apr. 3, 1928 1,837,568 Moody Dec. 22, 1931 2,028,368 White Jan. 21, 1938 FOREIGN PATENTS Number Country Date 250,234 Great Britain July 1, 1926 821,862 France Sept. 6, 1937