US1552074A

US1552074A - Hydraulic turbine

Info

Publication number: US1552074A
Application number: US407084A
Authority: US
Inventors: Moody Lewis Ferry
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-08-31
Filing date: 1920-08-31
Publication date: 1925-09-01
Anticipated expiration: 1942-09-01

Description

Sept. 1, 1925. 1,552,074

L. F. MOQDY HYDRAULIC TURBINE I Filed Aug. 31. 1920 2 Straits-Sheet 1 Swam -to:

Sept. 1, .1925. 1,552,074

HYDRAULIC TURBINE Filed Aug. 31. 1920 2 Shoots-Shae. 2

Patented Sept. 1, 1925. v

umrab STATES.

PATENT oral-c LEWIS runny zloom'r, or r'nrnannnrnm, PmmsYnvANra;

' mnaumc momma Application filed August 31, 1920. Serial No. 467,094.

To all whom it may concern:

Be it known that I, LEWIS FERRY MOODY, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvan1a,-have invented certain new and useful Improvements in Hydraulic Turbines, of which the following is a specification. 4 p

This invention relates to hydraulic turbines and the chief object of the invention is to provide a'turbine of simple and rugged construction having a small number of moving parts and adapted particularlyforuse under low and moderate heads.

A furtherobject of the invention is to provide a runner of relatively sim 1e blade formation and particularly adapte for high I drical portion 7 fittin T in which,

speeds. 1

Further objects of the invention "in providing a turbine adapted to develop increased power particularl 'during times of reduced head or increase demand will appearin the following specification taken 1n connection with the accompanying drawing Fig. 1 1s a vertical sectional view of a turbine illustrating one embodiment of the invention,

Fig. 2 is a similar view'of a'modification, and i i Fig. 3 is a plan view of the in Fig. 2. v

In the embodiment of the invention shown in the drawing a turbine of the vertical runner shown shaft type has an intake passage 1 for instance of volute form adapted to impart a whirl to the inflow and draft tube 2 pref erably of the spreading'type adapted to reconvert the velocity head of boththe whirling, and axial components of'velocity into effective pressure head in the discharge. vane ring 3 in the intake has 'its' vanes 1nclined. from the radial in direction of the flow to, the turbine runner 4. Between the vane ring 3 and runner 4 intervenes the of these holes 13 being shown on t .tributo'r plate.

able for turbines under low heads, A larly in small sizes where simplicity and vane ring 3 and carries an annular piston portion 9 sliding in the space between the cylindrical walls 10 and 11 set in the foundation, the formerforming the top end of the draft tube and the latter supporting the vane ring 3.

In order to raise the plunger, pressureeither penstock'pressure or .a higher pressure-.-wou1d be admitted to the'space belowthe lower flange v9 of the plungerby a pipe 12 from control or governor 15on the power l'iouse floor above. A restoring'rod connection 16 to the governing means is also provided and this pipe and rod may pass through a hollow vane or bafie 3 as shown;

This would overbalance the pressure on the top of the plunger which would be reducedby the velocity head of the water entering the turbine, and the plunger would move upward. To lower the plunger, theps ace 'below the lower plunger flange woul be connected to the exhaust. The weight of the plungerinaddition to the pressure on its upper curved face would then move .the plunger-downward. There would be a slight displacement' of water as-the plun ris lowered due to the volume of the dra tube wall enteringthis hollow space. To provide for this displacement of water small holes would communicate with this space from the entrance. side of the plungn'one e ri ht hand side of .Fig. 1 near the lower 's- A corresponding cavity 14 would be left in the speed ring to communicate with this hole when the plunger is at the extreme lower limit of its stroke. The resulting arrangement is ver -simple and has few parts, so that it would be very suitarticucheapness are important.

The controlling means 15 may represent either a hand control or. an automatic governor. When a governor is used, the action will be as follows: Upon overspeedingof the turbine runnerthe governor will act to admit pressure through pipe 12'to raise the plunger and'shut 03 the guide vane orifices of the vane ring 3 and restrict the-inflow at the'same time movingthe surfaces of transi-.

tion space 5 closer together to accommodate the restricted new. Upon underspeeding the pressure will be exhausted-from pipe 1 'vane orifices and simultaneously enlarge the 1 space a'is is space 5. 'Thusin effect the intake passage.

'ortransition space 5 itself expands and contracts to control the flow and plunger 6 always'maintains smoothly rounded surfaces. uide the flow to the-runner. avoiding the to eddies and losses that would beset u if a sharp ed ed cylindrical gate were'use Where esirable as for instance where flood conditions are likely to provide a'surlus supply of water the plunger gate may e arranged to be lowered as indicated in dotted lines d and provide for overgating. The plunger .can then be opened so far that a free passage 7) isprovided outside of the runner, roducing ejector action in the draft tube an lowering the back pressure therein under high tail water conditions.

The modified construction shown in' Fig. 2 has an annular plunger of relatively less thickness between its

cylinders

7 and 8. The inner ring 10 is separate from the draft tube linin 10 and the outer ring 11 has its upper en flan ed over' at 11'. The outer cylinder 8 of t e plunger carries the separate piston ring 9' of greater diameter than the cylinderso that in addition to the space 8 below the piston for closing pressure the above the piston for 0 ening pressure.

Pipes

12 and 12 respective y connect the spaces 8 and s'with the governor 15 so that upon drop'in the load pressure is ex- V annular plunger is accurate s to raise the plunger hausted romjspace s and admitted to space ate and upon increase in load pressure is ex h and admitted to space a to lower the plunger gate. The control means of this invention is sim le in form and easily and compactly assem led within the turbine speed ring. The y guided by a number of circular surfaces and "is moved simply by fluid ressure evenly distributed eration of the plunger.

bility of arranging the .pl

" above or below t e. piston portion 9. Upon removal of the cover plate call the movable. parts are accessible from above and are read- 11y removable for inspection and repair. By making the plunger annular the surface exposedto the flow of the water can be properly rounded to give smooth flow lines for the water and to allow the water streams to continue in contact with the surface at all points. This latter condition cannot be obtained withcylinder, gates such as have been din the rior-art. The radial thickness 0 the annu ar plunger provides space for piston surfaces and for the fluid pressure op- A particular advanta obtainable with the method of this invention is also the y ir 80, that in the normal full gate position it will still be a moderate distanceabove thelower distribw. tor plate or curb plate! ,By opening the austed. from space 8 plunger still further as indicated in dotted lines (1, Figs. 1 and 2 it can "be designed; to leave a clear spacebetween the plunger and the tips ofthe runner vanes so that water -will be freely bypassed around the runner and will be capa le of producing ejector action in the draft tube. By this arran ement this ejector action can be produced y 7 simply overgating the turbine, and this pro vision will be of great value in plants sub-' ject to flood conditions during which the tail water rises to an abnormal height'and thus reduces the effective head by increasing theback pressure on the turbine. At such times there is a surplus of water available and efiiciency 'is of no consequence, the problembeing to discharge the surplus water and to maintain the turbine powerif possible.

-Another advantage of this arrangement is that a steady bearing 20 can be placed close to the runner, the head cover 0 being rigidly supported by the vane ring 3, without the necessity of allowing a space within the head cover for the operation of the plunger. The plunger does not interfere with either the de sign of the head cover or the arrangement of the main shaft and bearings, and can be used with runners of greatly varying type, for example, it can be used with an inward flow, inward diagonal, 'mixed'or axial flow runner, or even with anoutward diagonal -flo'w runner. When used withan outward flow runner the arrangement may be altered so that the plunger closes the outflow space of the runner rather than the inflow space as shown in the specific embodiment in the drawings. v

In Figs. 2 and 3. a form of runner is shown, 'particula'rl' adapted for extremely high specific spec and suited for. turbines operatm under low and moderate heads such as e turbines shown in Figs. 1 and 2 either'with the lunger gate or with other forms of contro ling gates or movable guide vanes. The special orm of-runner R consists of one having unshrouded blades B arranged either for axial orfdiagonal flow. It 1s a characteristic of the operation of the runner blades when rotating at high velocity compared gates such aswicket to the head that since each portion of. the

water stream should for the attainment of high efliciency exert substantially the same turning moment of torque upon the runner, the. force or reaction of the water upon the blades. As a result of this relation the inortions of the runner blades must nermost deflect t e water through a considerably 1:0 runner blades must be much greater in'the greater angle than theoutermost portions. 7 L

It is found that in runners designed for very high rotational speeds the portions of-theblades at or near theouter tips are required to deflect the water only. to every slight extent. In order that the innermost 'portion of the blade may deflect the water through av considerable angle relative to the runner while the tip" runner blade with a considerable width .w

is therefore formed in the neighborhood of the hub and this width is reduced as the outer tips 21 are ap reached as at w.

Although in 'the plan view the width of the blade appears to increase slightly from the hub toward the middle portion of the blade,

- nevertheless this apparent increase vis more than offset by the narrowing of the blade as viewed in rofile, so that the actual width of the bla e gradually decreases from the hub outward. The length of the vane sec- .tion which must be traversed by the. water.

is therefore reduced to a low value in the ner su cient at all points to provide the necesg sary deflectionflof the direction of flow rela tively to the runner. jBy thus forming the runner so that the length of surface tra'-.

versed by the water will be no more than is necessary at each'point the amount of surface friction between the vane and the water is reduced. Thus at the outermost portions of the blades where the relative velocity between the blades and water is high, the

' width w of the surface is reduced and high friction losses avoided.

' In special cases where extremel high speeds are desired with the permissi le sac-' rifice ofa small or moderate amount of chiciencv the width of the blade 'is brought to zero before reaching the surrounding walls of the conduit or chamber inwhlch therunner is placed; that is therunner is constructed so'that the width w of the blade diminishes rapidly as the walls of the run-- ner chamber are approached and. the inflow and outflow ed es of the blade come together to form the runner tips 21 at a point a small distance e within the confining walls of the space in which the runner operates,

leaving a clear annular space surrounding the tips of the runner within the walls 0 the runner chamber.

. The annular clearances between the runner tips 21 and the boundary surface Sof the space will serve to'by-pass'water freely around the runner from. the @runner en- 'trancaf to the draft tubef This bypassed .waterflwhile not acting dir ectlyyupon the -.ru1mer vanes will produceejector action in I the draft tube serving to accelerate the flow 1 through the runner and to ipgtwer on the turbine. This same ejector ction is performed to a, 'limitudextent in high speed .iszheretofore (level aged in which a wide space is leftbetween e runn er vanes which a portion of the flowcanpaj'n freely with httle or" I ortions deflect the water through only as ight angle, thehborhood of the outer tips 21, but is,

no deflection and practically no direct action on the wheel vanes; Instead of'providing this space between the vanes, or in addition thereto, this invention provides an annular s ace surrounding the tips of the vanes, If t e velocityhead of the discharge from the runner is regained in a well formed draft tube, preferably of the spreading type, a large part of the energy of the yassed' flow; may 'be made available for re ucing the back ressure on the runner, and the energy of t is water will by no means be completely lost, but a considerable ortion of it made efiective in increasing t 'e power of the runner. The object of the modification so .just described is therefore to effect, econf i siderable increase in the power of the run? ner at the exgense of a small-or moderate sacrifice in je ciency. When a runner of this design is used in combination w-ith 'the annular plun r gate, of this invention an opening of t e gate beyond the normal full-gate position will provide an increase in the width of the annular by-pass pening' around the runner, and -b thus, "over gating 'the turbine an additional increase in ower will be provided for use during periods of reduced head on the plant, as

during times of floodor freshet, or other emergency mal supp rifice of e ciency.

I claim:

1.- Ina hydraulic turbine the combination with a radial inflowguide means," of a run-- ner,-,and a movableannular plunger forming a guiding surface for the flow curving from said dial axial irection adjacent said runner and adapted to regulate said flow.

2. In a hydraulic turbine the combination with a runner having-inflow: guide means and a dischar e, of coaxial .cylinders 'oined at one end to orm a hollow annular p unger providing a guiding. surface between said guide means and said discharge and movable to vary'the flow through said runner.

3. In a hydraulic turbine, the combination with an intake'passage and discharge pas-.

sage, of=a runner between said passages, co-

conditions requiring an abnorof power at a considerable sacguide means to a substantially axial cylinders joined at one end to form a" a 'hollow annular plunger surrounding saidysressure operated means surrounding said raft tube for moving said lunger. a 5. In a hydraulic turbine 5m combination with a runner offa draft tube receiving the I gradually from the radial to the axial direction and-extended into said draft tube.

6. In a hydraulic turbine, "means forcontrolling the flow therethrough comprising I an annular plunger surrounding the turbine runner and having rounded surfaces guiding the flow'from asubstantially radial direction to a substantially axial direction at said runner. y

7. 'In a hydraulic turbine means for controlling, the flow therethrough comprising an annular plunger moving across the blade edges of the turbine runnerand having rounded surfaces guiding the flow from a substantially radial direction to a substantially axial direction'at said runner.

8. In a hydraulic turbine the combination with a runner, of intake an discharge passages-therefor, a movable annular plunger forming the guiding surface of both of said] passages adjacentsaid runner, and means for moving said plunger.

- '9. In a' hydraulic turbine the combination with a runner, of intake and discharge passages therefor, a movable annular plunger forming the guiding surface of one of said passages adjacent said runner, and means for moving said plunger comprising fluid pressure 0 erated means. j 1 10. In'a ydraul'c turbine the combinatlon with a runner, of intake and discharge pas sages therefor, a movable annular plunger forming the guiding surface of one of said passages adjacent said runner, and means for moving said plunger'comprising fluid pressure operated means surrounding said discharge passage. r

11. In .a hydraulic-turbine the combination with a runner .and shaft, of a; bearing for said shaft in close proximity to said runner, intake and discharge passages for the'fiow through said runner, and an annular plunger ate movable to surround said runner and caring and control the flow through said turbine.-

12. In a hydraulic turbine the combination with a runner having a vertical shaft, of a bearing for said shaft in close roximity to said runner, and water guid ng surface surrounding said bearing, and an annular plunger gate surrounding said runner and movable upward toward said water guidin surface. to restrict the flow through the tur ine.

13. In a hydraulic turbine the combination with a runnerhaving, a shaft, of a bearing for said shaft adjacent said runner,- intake and discharge passa es for the flow through said runner, a he cover supporting said bearing and a speed ring supporting said head cover and positionedin said intake passage, the portionmfsaid intake the runner is adjustable.

blades, of walls forming a chamber in which passage between the speed ring andrunner forming a vane-free transition space.

14. In a hydraulic turbine the combination with a runner, of a draft tube therefor having walls a portion of' which adjacent 15. In a hydraulic turbine the combination with a runner,.of a draft tube therefor having walls. a portion of'which adjacent the runner is adjustable to control the flow therethrough. v

16. In a hydraulic turbine the combination with a runner,'of a draft tube therefor comprising an adjustable portion adjacent the runner surrounding the runner and controlling the flow therethrough. v

17. 'In'a hydraulic turbine the combination with a runner, of a draft tube therefor comprising an adjustable portion adjacent the runner, and movable to by-pass a portion of the inflow around the runner.

I 18. In a hydraulic turbine the combination with arunner having unshrouded said runner rotates and spaced "from the outermost diameter of the runner a distance providing an opening between the runner.

and said wall adapted to freely bypass water.

around the runner and produce an ejector g action to accelerate the flow through said runner.

19. In a-hydraulic turbine a water conduit'bounded by walls formed as'surfaces of revolution, an unshrouded runner rotating within said conduit said runner bein smaller than the surrounding conduit andleavin a clear annular opening between the tips of the runner blades and the bounding conduit wall so as to freely bypass water around said runner from the runner entrance to the dischar' passage.

20. In a rotary hy raulic machine a runner having unshrouded blades, the width of which measured in the direction of flow progressively decreases toward the outer tips of said blades and diminishes to zero at said P 21. In a rotary hydraulic machine a runher having unshrouded blades, the width. of which measured inlth'e direction of flow continuously decreases toward the outer ti s of-said blades and diminishesto zero at sa d p 4 t,

22. In a hydraulic turbine a runner of substantially axial flow type, and means for controlling the flow therethrough compris- -.ing an annular plunger moving relatively v to the turbine runner and having rounded surfaces guiding the flow to said runner.

1 23. In a rotar hydraulic machine the 2 combination wit ,a runner having vunshrouded blades, .of surrounding walls forming a chamber in which said runner rotates and spaced from the outermost diameter of said runner a distance at least ten per cent .of the radial distance between the runner hub and said wall soas .to leave a clear annular space for by-passi-ng water around the fiow passes axially of a surrounding wallforming a chamber in which said runner ro- 'tates, and means for. moving said wall axially to regulate the flow to said runner.

26. In a hydraulic turbine the combine tion with a runner to which the entering flow passes axially, of surrounding walls forming a chamber in which the runner rotates, rounded entrance walls merging with said surrounding walls and means for moving said walls to regulate the flow through said runner.

27.-In a-hydraulic turbine'the combination with a runner, of inwardly directed guiding means for the entrance flow, atransition space between said guiding means and said runner, awall surrounding said runner and forming a chamber in which said runner rotates, and means for -moving said wall axially to regulatethe flow to said runner.

- 28. 'In a hydraulic turbine the combination with a runner, of inwardly directed guiding means for the entrance flow, a transition space between said guiding means and said runner and extendingfrom a radial toward an axial direction, a circular wall in said transition space, and having its inner diameter greater than the diameter of the runner, and means for moving said wall axially to regulate the flow to said runner.

29. Apparatus for regulating the flow through a hydraulic turbine comprising.

relatively axially movable surfaces of the entrance space within .the inflow guiding means and surrounding the runner so' as to leave a by-pass betweenthe runner and said surface. A

30. Apparatus for. regulating the flow through a 'ydraulic turbine having a substantially axial flow runner comprising means directingthe flow inwardlyinto an entrance space 'in advance of the turbine runner, means discharging the flow from said runner into an axially directed passage, and means for regulating the flow through said turbine by movement of the surface of said entrance space which is .onthe discharge (guiding p p the flowfrom said. inwardly directe intake side thereof.

31. In a hydraulic machine a runner having unshrouded blades of curved outline, the width-of which measured in .the direction of flow continuously decreases. on gradually curving lines toward the outer tips of said blades so that the blade edges merge to gether at said tips.

32. Ina h draulic turbine the combination with a runner, of guide vanes directing the flow inwardlytoward the axis of said runner. and a transition space from the discharge end of the guide wines to the entrance to the runner. the lower wall .of said transition space being movable and curvingfrom the radial toward the axial direction.

33. In a hydraulic turbine the combination with a runner having vanes extending diagonally with respect'to a plane normal to the runner axis, of guide vanes directing the flow inwardly toward the axis of said charge end of the guide vanes to-the en- "trance to the runner, the lower wall of said transitionspace being movable and curving from the radialtoward the axial direction. 34. In a hydraulic turbine the combination with a runner, of walls forming a conduit movable to bypass a portion of the flow around the runner.

35. In a hydraulic turbine the combination with a vertical shaft runner, of walls forming a conduit for the flow to .said runner and comprising an inwardly directed guiding surface adjacent .the runner tips. movrunner, and a transition space from the dis- 7 for'the flow to said runner and comprising a guiding surface adjacent the runner tips able to bypass a portion of the flow around,-

the runner. 36. In a hydraulic turbine the combination with a runner having a shaft, of a bearing .for said shaft adjacent said runner, intake and discharge passages for the flow throughsaid runner, .a head cover supporting said bearing and a speed ring sup head cover and positioned in s i intake passage, the portion of said intaiepassage between the speed ring and runner forming a vane-free transition space, ahdan axially I movable gate in said transition space. v

37. In a hydraulic turbine the combination with fixed guide vanes adapted to impart a whirl to the entering flow of a'bearing for the turbine shaft and a casing surrounding s'aid bearingsupported by. said vanes, said bearing casing -having an outer orting SfildI wall turning from an axial direction to a diagonal inward direction in smooth curves continuous w1th the runner hub. I

38. In a hydraulic turbm thecombination with an unshrouded propeller type runner receiving the flow in a nearl axial direction, of an intake passage gui in .the flow inwardly and with a Whlll aroun the axis,

ieans forming a transition space to said runner, and an axially movable'gate having its inner diameter greater than the diameter of said runner and movable across said transition space to control the flow.

Y 39. In a hydraulic turbine a runner through which fluid is adapted to flow in an axial direction, means forming a passage communicating with said runner and comprising radial and axial flow portions connected by a transition space at least one side of which is bounded by a surface curving gradually from a radial direction toward an axial direction, and means for moving said bounding surface of said transition.

space to expand or contract said space for controlling the flow through said runner.

40. In a hydraulic turbine a runner through which fluid is adapted to flow in an axial d irection,,a conduit for passing the .of said transition space being bounded by a surface of revolution curving gradually from a radial direction toward an axial direction, and means for moving said bounding surface of said transition space to expand or contract said space forcontrolling the. flow through said runner.

I 'LEWIS FERRY MOODY.