US2813696A - Oil storage and cooling apparatus in hydraulic turbines - Google Patents

Description

Nov. 19, 1957 P. F. DANEL 2,813,696

OIL STORAGE AND COOLING APPARATUS IN HYDRAULIC TURBINES Filed Sept. 9, 1953 2 Sheets-Sheet 1 PIERRE F. DANEL Nov. 19, 1957 P. F. DANEL 2,813,696

OIL STORAGE AND COOLING APPARATUS IN HYDRAULIC TURBINES 2 Sheets-Sheet 2 20 39' A Ar A.

INVENTORQ PIERRE F. DANEL HTTORNEY United States Patent OIL STORAGE AND COOLING APPARATUS IN HYDRAULIC TURBINES Pierre Frangois Dane], Grenoble, France, assignor to Etablissemenis Neyrpic, Grenoble, France, a corporation of France Application September 9, 1953, Serial No. 379,247 Claims priority, application France September 9, 1952 11 Claims. (Cl. 253-148) According to certain proposals which mark an important development in the construction of vertical hydroelectric units and principally in Kaplan turbines, the height of the unit may be considerably reduced by the fact that the stator of the alternator may be disposed immediately above the distributor which carries the wickets for distributing the water to the turbine runner. This squat construction make its possible to eliminate the conventional turbine shaft and to substitute for it a rotor body which is completely hollow and of large diameter.

These constructions have been made the subject of the application for patent in France of September 5, 1952, and in the corresponding United States application Serial No. 383,815, filed September 4, 1953, Ro-tatable Assembly in a Vertical Hydraulic Turbo-Generator, now Patent No. 2,767,328, issued October 16, 1956, in which applications and patent are described the characteristics and the advantages of such arrangements.

The present invention has for an object apparatus for storing and circulating and cooling the oil used in vertical hydraulic turbines, especially those of the Kaplan type, which apparatus forms a part of the constructive arrangements referred to above and having various advantages which are disclosed hereinafter.

It is known that actual turbines use at present two kinds of oil of different fluidity and quality, on the one hand, an oil serving as lubricant for the lower guide bearing of the unit and for the thrust bearing which supports the rotating assembly and, on the other hand, an oil serving as operating fluid for a servo-motor which controls the position of the blades of the runner.

It has been proposed heretofore to use as a reservoir for the lubricating oil the annular space between the shaft of the turbine and the fixed support the exterior wall of which guides and directs toward the runner of the turbine the stream of Water entering into the distributor and which carries the thrust bearing at a low point of the unit. When, however, this unit has a shaft, as is the case with constructions heretofore, the annular space in question is of large size, the thrust bearing is distant from the fixed wall and the guide bearing still more so. Thus, the lubrication of the members necessitates a complicated device and the mass of oil which is only in contact at the external part of large diameter with this wall cooled by water is poorly cooled.

According to the invention the narrow space between the fixed supporting wall .and the wall of the hollow body of the rotor is put to advantage for arranging two distinct superposed oil baths or reservoirs, the upper one for lubricating the thrust bearing, the lower one for lubrieating the guide bearing in which the neck of the hollow body of the rotor turns, each with a suitable device to insure circulation of the oil with systematic cooling.

The bath of oil for the thrust bearing, limited exteriorly by the stationary supporting wall :and interiorly 'by the annular support for the thrust bearing and a cylindrical internal partition extending upwardly therefrom and somewhat spaced from the elements of the thrust bearing, is divided into two annular concentric chambers by a depending partition extending about the elements of the thrust bearing and slightly spaced from them. This depending partition defines with the internal wall an annular lubricating flue containing the thrust bearing and communicating with the exterior part below the bottom of the depending partition and by openings through this depending partition.

The oil is put in circulation by thermosiphon action in the flue and passes to the exterior through the openings in the depending partition and returns in a closed circuit to the base of the flue after being cooled by contact with the cool supporting wall.

The guide bearing is supported at the center of its height by a flange carried by a prolongation of the wall supporting the rotating parts and defining an annular basin below the flange and with a bottom and an internal fixed partition surrounding the neck of the rotating body. Tubes extend through this wall prolongation and communicate with a narrow annular reservoir or cooler the external wall of which is an extension of the supporting wall, this reservoir communicating at the upper part by means of return passages for the oil with the space above the flange for the guide bearing, the basin and cooling reservoir containing an oil bath the level of which is intermediate the length of the lower portion of the guide bearing.

The oil moving up the guide bearing leaves this bearing heated at its upper portion and discharges into the upper portion of the cooling reservoir and then is cooled during its descent therein before returning to the guide bearing by means of the closed circuit formed by the communicating tubes.

In accordance with the invention, also, the interior space of the neck of the hollow rotating body has for its end walls the upper cover of the servo-motor cylinder which operates the turbine blades and a plate at the upper part of the neck, this hollow enclosed space constituting an oil reservoir for the servo-motor, the oil distributor for this servo-motor being supported by this plate and being connected for its supply of oil with a circulating pump also supported on this plate, the distributor being connected for discharge of the oil to the reservoir after serving to operate the distributor.

In alignment with the external wall of the annular cooler reservoir carried in the fixed support, a guide wall of the water passage carried by the rotor defines about the body of the rotor an annular cooling receptacle or flue for cooling the servo-motor oil, this receptacle encircling the cylinder of the servo-motor which forms the other wall thereof. This receptacle contains a tube which extends through the upper part thereof into the bottom of the oil reservoir within the hollow body and which extends also downwardly and terminates near the bottom of the receptacle in a filter. This tube is connected to the pump as the suction pipe for the pump.

The advantages of this arrangement are that the distributor of the servo-motor may be placed within the body of the rotor immediately adjacent the servo-motor which it operates. This eliminates the necessity for long tubing and assures continuous cooling of the oil due to the forced circulation of the pump, this oil being decantered in the flue or receptacle and being filtered before returning to the pump.

The invention will be described in an embodiment thereof employing a Kaplan type turbine as illustratedin the accompanying drawings wherein:

Fig. l is a vertical view, partly in section, of a vertical Kaplan type turbo-generat or'u'nit.

""Fig. 2 isa-vertical section to an enlarged scale showing in greater detail the features of the invention embodied in the turbo-generator unit illustrated in Fig. 1.

Referring now to Fig. 1, an annular foundation supports the distributor which comprises the wickets 11 and the stay vanes 12. The stator 13 of the generator is supported on the upper cover 14 of the stay vane ring, to which is affixed the support 15 for the rotating elements of the turbo-generator unit. The support 15 has the general shape of a hollow truncated cone and its wall and the deflecting wall 15a progressively direct the flow of water downwardly to the turbine runner 20. The thrust bearing 16 and the lower guide bearing 17 of the hollow rotating assembly are supported by the support 15 within the hollow space thereof. The neck 18 of the hollow rotating assembly turns within the lower guide bearing and the hollow rotating assembly designated generally at 19 having a relatively large diameter connects the turbine runner 20 to the rotor 21 of the generator which is provided with a trunnion 22 rotating in upper guide bearing 23.

It may be seen in Fig. 1 that within the upper part of the distributor the flowing water touches the support 15 at the level of the thrust bearing and thereafter descends toward the turbine. Thus the support 15 and the wall of the rotating assembly aligned therewith are constantly cooled by the flowing water.

The hollow rotating assembly 19 is made up of a number of superadjacent hollow members or ferrules provided with flanges and connected together one resting on the other and rotating concentrically with respect to the vertical axis of the hollow rotating assembly.

As shown in Fig. 2 the upper hollow member or ferrule 24 carries the movable element 25 of the thrust bearing. The stationary element of the thrust bearing rests on the annular ring 27 which is supported by a shoulder inwardly projecting from the wall 28 of the stationary support 15 (Fig. l) which supports the rotating assembly. An annular space which extends about the thrust hearing is defined exteriorly by the wall 28 and interiorly at the lower portion thereof by the ring 27, the upper portion of this space being defined interiorly by the cylindrical wall 31 which extends upwardly from a bottom wall 30 supported on the annular ring 27 to a height above the surface of the movable element 25 of the thrust bearing bearing onthe stationary element 26 thereof. The element 26 is provided with openings 29 providing communication between the space exterior to the thrust bearing and the space interior thereto. The wall 31 is somewhat spaced from the thrust bearing to provide for circulation of the oil therebetween.

A partition 32 concentric with the axis of rotation and likewise spaced somewhat from the thrust bearing exteriorly thereof depends from an upper wall 33 resting on an inner projection from the wall 28. The partition 32 extends downwardly to the lower part of the stationary thrust bearing element 26 and is provided with holes 34 to a height above the surface of the movable element 25 of the thrust bearing bearing on the stationary element 26. Anannular wall also extends upwardly above the wall 32 and cooperates with a cylindrical deflector wall 35 disposed exteriorly thereto. The partitions 31 and 32 define an annular lubricating line or passage 36 about the thrust bearing which communicates at the lower portion thereof with the annular basin or reservoir 37 formed by wall 28, ring 27 and wall 31 and which contains the bath of oil up to the general level of the holes 34.

The heat developed by friction in the thrust bearing 25, 26 is'absorbed by the oil which flows upwardly in the flue 36. This oil and oil from between the bearing surfaces then passes through the holes 34-due to the etfect of centrifugal force which is developed in the body of the oil by friction of the rotating element 25 of the thrust hearing. The oil then passes downwardly to the basin 37 and is cooled bycontact with the fixed wall 28 which, as above indicated, is cooled by the Water flowing to the turbine runner. The oil then returns in the circuit to the flue 36 for again lubricating and cooling the thrust bearing.

The hollow rotating assembly is suspended from the ferrule 24 which carries the rotatable thrust bearing element 25. ,Such suspension is accomplished by the intermediate ferrule 38 of truncated conical form. The circumferential wall 39 of the neck is connected to the lower internal flanged end of the ferrule 38 and is provided with a bottom 40 which constitutes the upper head of the cylinder 41 of the servo-motor which operates the adjustable blades of the runner of the turbine.

The wall 39 also carries at its upper portion exteriorly thereof the bearing ring 42 which is the rotatable element of the guide bearing. The stationary element of this bearing is provided by the element 43 in bearing relation to the element 42 and is supported in the annular ring 44 of this hearing. The annular ring 44 carries an outwardly projecting flange 45. bearing on an inwardly projecting flange carried by an extension 46 of the fixed wall28 which thus supports the stationary members of the lower guide hearing. The extension 46 terminates at this lower end in a stufiing box 47 supported by the fixed extension wall 46 and engaging a sleeve carried by the circumferential wall 39 of the neck exteriorly thereof. 7

An annular basin or reservoir 48 within the annular extension wall 46 is provided by a bottom wall 49 supported on the fixed extension 46 and connected to an inwardly disposed vertical cylindrical partition 50 extending about the wall 39 exteriorly thereto and within the lower part of the downwardly extending portion of the ring 42 which constitutes the rotatable element of the guide bearing and which engages the bearing surface of the stationary guide bearing element 43.

Below the wall 28 and exteriorly with respect to the extension 46 thereof a narrow annular cooling reservoir 51 is suspended. This reservoir has relatively thin cylindrical walls and forms a heat exchanger for cooling the oil heated in contact with the guide bearing. The exterior wall of this cooling reservoir provides a portion of the guide surface for the water flowing to the turbine runner. Tubes 52 provide communication between the lower portion of the annular cooling reservoir and the lower portion of the basin48. Oblique holes 53 also are provided through the extension wall 46 connecting the upper part of the cooling reservoir with an annular space 54 formed between the wall 28 with its extension 46 and the guide bearing 44, 45.

The cooling reservoir 51 and the basin 48, together with the tubes 52, constitute communicating vessels which contain oil at a level about half way up the lower portion of the guide bearing. The oil which moves upwardly in the guide bearing and is heated therein flows therefrom into the space 54 from which it passes through the holes 53 into the upper part of the cooling reservoir. The oil moves downwardly in this reservoir and is cooled therein and returns through the tubes 52 to the basin 48 for further cooling of the bearing.

As shown in Fig. 2 a cylindrical casing wall 55 carried by the rotor abuts at its lower end the hub 56 of the runner of the turbine and at its upper end is connected to an annular head 57 disposed at a slight distance from the bottom of the cooling reservoir 51 so as to be rotatable relative thereto. The head 57 is tightly connected to the lower end of the neck of the rotatable assembly. The casing wall 55 extending about the cylindrical wall 41 of the servo-motor forms therewith an annular oil cooling receptacle. Openings 58 are provided through the wall of the neck 39 to provide communication between the upper part of the receptacle 55 and the basin 59 formed within the hollow neck 39 above the head 40.

This basin together with the receptacle provided he- '-tween 'the* casing-wal1"55 and the wall 41 form a resetbearing and the voir for the oil for the servo-motor. The top of the space of the basin 59 is closed by a plate 60' which carries the body 61 of an oil distributor disposed on the axis of the rotating assembly. The distributor may be of conventional type having a vertically sliding member 62 controlled by an axially disposed rod 63 and connected to the piston rod 64 of the piston 65 of the servo-motor for insuring delivery of oil to one or the other spaces at either side of the piston. The outlet of the oil from the distributor is connected by pipe 66 to the reservoir 59. The inlet to the distributor is connected to a pump 67 carried by the plate 60 and drawing the oil through the pipe 68 which extends from a filter 69 disposed at the bottom of the cooling receptacle 55.

The oil discharged from the distributor 61 to the basin 59 through the pipe 66 flows by gravity and by centrifugal force into the receptacle 55 and then flows downwardly therein and is cooled before reaching the filter 69 from which it is again pumped by the pump 67 to the distributor 66. Thus, only oil which has been cooled and filtered is delivered to the distributor.

It will be apparent from the above description that the apparatus provides for each member which requires oil a separate reservoir, that is, a bath of oil for the thrust guide bearing and a reservoir of oil for the servo-motor, assuring in each case movement of the oil in a closed circuit concomitantly with cooling and decantation or filtering of the oil. It is to be further noted that at the speed at which the rotatable assembly rotates decantation by gravity is combined with centrifugal decantation, the impurities thus collecting adjacent the bottom of the cooling wall of the cooling reservoir or cooling receptacle. Moreover, centrifugal force aids the circulation. There are secured in this manner the optimum conditions for refreshing the oil which again is put in service in its circuit.

It is to be noted further that the constructions which have been described utilize simple means and that pipes and connections which are relatively delicate members are reduced to a minimum. In particular, the pump of the servo-motor is placed at the level of the distributor and within the hollow rotating body, the large diameter of which makes it possible to provide an oil reservoir of sufficient capacity directly above the cylinder of the servo-motor.

While the invention has been described in a single embodiment thereof modification of the structures may be made within the scope of the invention which provides for the storage and circulation of lubricating oil and of oil or other fluid for operating auxiliary control devices such as the servo-motor, as well as for cooling and purifying the oil thus utilized.

I claim:

1. A vertical hydraulic turbine unit comprising a runner rotatable on a vertical axis, a stationary supporting structure of said turbine unit, an annular wall supported on said structure and extending about said axis and defining at the side of said wall outwardly of said axis an annular flow passage for conducting hydraulic fluid to flow along said wall to said runner for driving said runner, a bearing disposed inwardly of said wall with respect to said axis and having an annular stationary element supported by said wall and having an annular element rotatable on said vertical axis and engaging said stationary element in bearing relation thereto, a rotatable member connected to said runner and to said annular rotatable bearing element for supporting on said wall said runner and said vmember by said rotatable bearing element bearing on said stationary bearing element for rotation of said runner and said rotatable member and said rotatable bearing element together on said vertical axis, said annular rotatable bearing element being disposed outwardly with respect to said axis in spaced re1ation to said rotatable member to provide therebetween an annular space extending about said axis inwardly of said rotatable bearing element and outwardly of said rotatable member, an annular reservoir wall extending about said axis and disposed in said annular space inwardly of said annular rotatable bearing element and connected to said flow passage wall to define therewith an oil reservoir, said annular reservoir wall and said flow passage wall extending from a level below said bearing to a level above a given portion of the engaging bearing surfaces of said two annular bearing elements, and means including a part of said flow passage wall and said annular reservoir wall for effecting circulation of said oil within said reservoir upwardly adjacent said annular reservoir wall towards said bearing surfaces of said bearing elements and from said bearing surfaces to the upper part of said oil reservoir adjacent said flow passage wall and downwardly in contact with said fiow passage wall for cooling the oil by the hydraulic fluid flowing along said flow passage at the opposite side of said flow passage wall from said reservoir and return flow of said cooled oil towards said annular reservoir wall.

2. A vertical hydraulic turbine unit as defined in claim 1, which comprises a baffle partition supported by said stationary structure between said annular reservoir wall and said fiow passage wall, said baffle partition extending downwardly below at least a part of the bearing surface of said bearing and into the oil contained in said reservoir, said baflie partition being provided with holes therethrough for passage therethrough of oil from said bearing toward said flow passage wall.

3. A vertical hydraulic turbine unit as defined in claim 1 in which said bearing constitutes a thrust bearing, said annular rotatable element of said bearing being carried by said rotatable member and being disposed above and supported by said annular stationary element of said bearing in thrust bearing relation thereto.

4. A vertical hydraulic turbine unit as defined in claim 1 in which said bearing of said turbine unit constitutes a guide bearing, the annular stationary element of said bearing being supported by said flow passage wall outwardly of said annular rotatable element of said bearing and in bearing relation thereto upon a cylindrical surface about said axis, said annular reservoir Wall-extending upwardly between said rotatable member and a downwardly extending portion of said annular rotatable element of said bearing.

5. A vertical hydraulic turbine unit comprising a runner rotatable on a vertical axis, a stationary supporting structure of said turbine unit, an annular wall supported on said structure and extending about said axis and defining at the side of said wall outwardly from said axis an annular flow passage for conducting hydraulic fluid to flow along said wall to said runner for driving said runner, a bearing disposed inwardly of said wall with respect to said axis and having an annular stationary element supported by said wall and having an annular element rotatable on said vertical axis and engaging said stationary element in bearing relation thereto, a rotatable member connected to said runner and to said annular rotatable bearing element for supporting on said wall said runner and said member by said rotatable bearing element bearing on said stationary bearing element for rotation of said runner and said rotatable member and said rotatable bearing element together on said vertical axis, said annular rotatable bearing element being disposed outwardly with respect to said axis in spaced relation to said rotatable member to provide therebetween an annular space extending about said axis inwardly of said rotatable bearing element and outwardly of said rotatable member, an annular reservoir wall extending about said axis and disposed in said annular space inwardly of said annular rotatable bearing element and connected'to said flow passage wall to define therewith an oil reservoir said annularreservoir wall. and said flow passage'wall extending from a-level below said bearing to a level above a given portion of the engagg bearing surfaces of said two annular bearing elements, a partition disposed between said flow passage wall and 'said annular reservoir wall and dividing said reservoir into an annular cooling chamber disposed between said partition and said flow passage wall andan annular bearing chamber disposed inwardly of said cooling chamber toward said axis, and means connecting said chambers forefiiecting flow of hot oil to said cooling chamber adjacent the upper part thereof and into contact with said flow passage wall and flow of said oil-downwardly along said flow passage wall for cooling the oil by the hydraulic fluid flowing in contact with said flow passage wall at the opposite side thereof from said cooling chamber and return of the cooled oil from saidcooling chamber to said bearing chamber for flow to said elements of said bearing.

6. A vertical hydraulic turbine unit as defined in claim 5 in which said partition is provided with an opening communicating therethrough between said chambers above said oil level to provide for flow of oil overflowing from said bearing surfaces to the upper part of said coolingchamber.

7. A vertical hydraulic turbine unit comprising a runner rotatable on a vertical axis, a stationary supporting structure of said turbine'unit, a bearing supported by said stationary structure and having a bearing element rotatable on said vertical axis of said runner, a hollow member providing a peripheral wall extending about said vertical axis and connected to said runner and to said rotatable bearing element for supporting said hollow "member and said runner by said bearing for rotation of said hollow member and said bearing element together with said runner on said vertical axis, annular reservoir walls extending about said axis and disposed respectively outwardly and inwardly of said bearing with respect to said axis and providing an oil reservoir, said annular walls extending from the level below said bearing to a level above a given portion of the bearing surface of said hearing so as to maintain the oil level in said reservoir at least to cover said portion of said surface of said bearing, said peripheral wall of said hollow wall member being connected to the cylinder wall of a servomotor disposed concentric with said axis of rotation, the upper head of said cylinder forming the bottom wall of and cooperating with said peripheral wall of said hollow member to provide a reservoir for fluid for operating said servo-motor, said hollow member carrying a cover plate disposed above said fluid reservoir and transverse to said axis of rotation of said runner and closing a space within said hollow member, a piston rod connected to the piston within the cylinder of said servomotor and extending upwardly through said cylinder head and through said hollow member coaxially with said axis tacle, the outer surface of said casing forming at least a part of the surface of a passage conveying hydraulic fluid to said runner for efiecting rotation of said runner,

the annular space within said casing being connected at the upper portion thereof by an opening through the wall of said hollow member to the space within said member for flow of oil from said hollow space to said :arlnular space within said casing, and means for withdrawing oil adjacent the bottom of said annular space withinsaidjcasing and delivering theoil ,to-said .means foroperating said piston rod, and, piston of said servomotor.

9. Avertical. hydraulic turbine unit as defined in claim 8, in which .said means for-withdrawing said oil from saidreceptacle comprisesla pipewextending from the lower portionof said receptacle'ptov a pump carried by said plate covering said hollow? space within saidmember, said pump being connected tolsaid meansfor operating said piston rod and piston for delivering oil thereto for operating said piston, :and a pipe connection from said operating means to said-space within: said hollow member for returning oil thereto.

10. A vertical hydraulic ,tu'rbineunit as defined in claim 1 in which said rotatable member connected to said runner and to said annular rotatable bearing element provides a peripheral wall extending about said axis and about ahollow space within said, peripheral wall, said peripheralwall of said rotatable member being disposed adjacent and in'inwardly spaced relation to said wall defining said flow passageto form therewith an annular oil confining space about said, axis, said annular rotatable element of said. bearing being supported on said peripheral wall of said hollow rotatable member outwardly thereof and in said. annular oil confining space.

11. A vertical hydraulicxturbine unit'comprising a runner rotatable on a vertical .axis, a stationary supporting structure on said turbine unit,- an annular wall supported on said structure-and extending about said axis and desfining at, the side of said wall outwardly from said axis an annular flow .passage for conducting hydraulic fluid to flow along "said wall to said runner for driving said runner, a bearing disposed inwardly ofsaid flow passage wall with respect to the said-axis and having a stationary element'supported by said structure. and having an element rotatable on'said vertical axis and engaging said stationary'element in bearing'relation thereto, a trotatable member connected to said runner and to said'rotatable bearingelement for supporting. on said structure said runner and said rotatable member by said rotatable bearing element bearingon said stationary bearing elementfor rotation of said runner and said rotatable member and said rotatablebearingelement together on said vertical axis; said: rotatable bearing element being disposed-outwardly with respect tosaid axis in spaced relation to said rotatable member to provide therebetween a space extending about said axis inwardly of said rotatable bearing elementand outwardly ofsaid rotatable member, an inner reservoir wall extending about said axis and disposed in said spaceinwardly of said rotatable bearing element andconnected to said flow passage wall to define therewith 'a reservoir for oil, said inner reservoir wall and'said flow passage wall extending from a level below said bearing to a level above a given portion of the engaging bearing surface of said two bearing elements, andmeans including a part of said flow passage wall and said innerwreservoir wall foreffecting circulation of said oil within said :reservoir upwardly adjacent said inner reservoir'wall toward said bearing surfaces of said bearing'elements and from said bearing surfaces to the upper part of said oil reservoir adjacent said flow passage'wall and downwardly in contact with said flow passage wall for cooling the oil by the hydraulic fluid flowing along said flow passage-at the opposite side of said flow .passage wall from said reservoir and return flow of said cooled oil toward said inner reservoir wall.

References Cited in'the file of this patent TED STATES PATENTS 1,117,504 'Kingsbury Nov. 17, 1914 1,265,334 i Howarth May 7, 1918 1,898,023 1 'Smyser Feb; 21, 1933 1,934,628 Powell j 'Nov. 7, 1933 2,073,044 Andrews Mar. 9,1937 2,077,883 -zHand Apr. 20,,1937

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