US2079060A - Means for maintaining a constant flow of water in the tailrace of a hydraulic turbine installation - Google Patents

Description

May 4, 1937. A. YOUNG 2,079,060

MEANS FOR MAINTAINING A CONSTANT FLOW OF WATER IN THE TAILRACE OF A HYDRAULIC TURBINE INSTALLATION Filed Sept. 22, i956 5 Sheets-Sheet 1 Fig. 1.

TAILRACE.

INVENTOR ARTHUR YOUNG ATTORNEY A. YOUNG MEANS FOR MAINTAINING A CONSTANT FLOW OF WATER IN THE TAILRACE OF A HYDRAULIC TURBINE INSTALLATION Flled Sept 22, 1936 5 Sheets-Sheet 2' INVENTOR ARTHUR YOUNG- ATTORNEY y 4, 1937. A. YOUNG 2,079,060

' MEANS FOR MAINTAINING A CONSTANT FLOW OF WATER IN THE TAILRACE OF -A HYDRAULIC TURBINE INSTALLATION Filed Sept. 22, 1936 5 Sheets-Sheet 5 Fig.4. 2

INVQNTOR ARTHUR YOUNG ATTORNEY A. YOUNG May 4, 1937.

MEANS FOR MAINTAINING A CONSTANT FLOW OF WATER IN THE TAILRACE OF A HYDRAULIC TURBINE INSTALLATION 5 Sheets-Sheet 4.

Filed Sept. 22, 1936 INVENTOR ARTHUR YOUNG BY M Q. QIMQM ATTORNEY May 4, 1937. A. YOUNG ,0 MEANS FOR MAINTAINING A CONSTANT FLOW OF WATER IN THE TAILRACE OF A HYDRAULIC TURBINE INSTALLATION Filed Sept. 22, 1936 5 Sheets-Sheet 5 INVENTOR ARTHUR YOUN- Patented May 4, 1937 UNITED STATES A PATENT O-FFl FLOW OF WATER IN THE TAILRACE OF A HYDRAULIC TURBINE INSTALLATION Arthur Young, York, Pa., assignor to' S.'Morgan Smith Company, York, Pa., a corporation of Pennsylvania Application September 22, 1936, Serial No. 101,928

3 Claims.

This invention relates to hydraulic machines, and more particularly to an improvement in hydraulic turbine installations.

An object of the, invention is to provide an improved'hydraulic turbine installation having means for maintaining a constant flow of water in the tailrace.

Another object ofthe invention is to provide an improved hydraulic turbine installation in which there are means for by-passing water around the turbine so that a predetermined quantity of water can. flow to the tailrace at a constant rate under constant or variable heads.

Another object of the invention is to' provide 1 an improved hydraulic turbine installation in which there are means for delivering a predetermined quantity of water to the tailrace when the discharge of water through the turbine varies above or below normal due to an increase or decrease in. load on the turbine.

Another object of the invention is to provide an improved hydraulic turbine installation of the character mentioned, which is simple in construction, and reliable and exact in function under all conditions of service.

The invention also comprises certain new and useful improvements in the construction, arrangement and combination of the several parts of which it is composed, as will be hereinafter more fully described'and claimed.

In the accompanying drawings:-

Figure 1 is a vertical view partly in section and partly in elevation of a hydraulic turbine installation embodying the present invention;

Fig. 2 is a horiz'ontalsection'taken on the line 2-2 of Fig. 1;

Fig. 3 is a horizontal section taken on the line 3-3 of Fig. 1;

Fig. 4 is an enlarged vertical section. of the turbine and parts associated therewith;

Fig. 5 is a horizontal section taken on the line 5-5 of Fig. 4, the parts being shown in the position in. which the water by-passes the runner of the turbine; and

Fig. 6 is a View similar to Fig. 5, showing the parts in closed position.

Referring to the drawings, wherein the turblue is shown connected to an electricgenerator for the purpose of operating the same, the complete generating unit may comprise a hydraulic turbine ii, an electric generator 12, and, a governor mechanism l3. 1 I V I As is well known in the art, the governor i3 is adapted to automatically control'the operation of theturbina'so that the turbine will operate at a substantially uniform speed, irrespective of the variations of the load.

shown in Fig. 1, the complete generating unit'may be contained within a suitable structure, preferablyiormed from concrete or other suitable masonry material. This structure includes an upper portion M, in which is disposed the generator II and governor M, an intermediate portionyl5 in which is disposed the hydraulic turbine H, and a lower portion it which is disposed beneath the hydraulic turbine H. The portion I5 of the structure may be tubular in form as shown in Fig. 3, and such portion is separated from the lower structure It by a horizontally disposed wall 'll which constitutes means for supporting'the turbine ILas will be hereinafter more fully described.

The turbine ii is adapted to be submerged in water within the chamber formed by'the intermediate structure 15, and connected to said chamber is one endof a suitable pipe 18 through which water'is'conducted from a suitable source of supply, as is customary in installations of this type.

As shown in Fig. 4,'the turbine H has a runner I9 which is mounted on the lower end of a shaft 20.

The shaft 20 extends upwardly in the setting and is connected to the generator shaft 2| in the usual manner (see Fig. 1).

The turbine casing comprises an upper or crown plate 23, and a lower or curb plate 24. The space between the plates 23 and 2d constitutes an annular inlet for the water delivered to the runner I9, and inorder to control the amount of water delivered to the runner iii, wicket gates 22 aredisposed between said plates. As is customary, the wicket gates 22 are adapted to be rotated simultaneously into different angular positions.

For the purpose of operating the wicket gates 22, there is a gate shifting ring 28 which encircles the periphery of the curb plate 2t and which is supported by said curb plate. The gate shifting ring 28 is operatively connected to the wicket gates 22 in the customary manner whereby rotation of said ring effects rotation of said wicket gates to increase or decrease the areaof the. spaces between said gates and thereby enlarge or reduce the vsize of the annular inlet through which the water flows. It will be understoodthat the wicket gates 22 can be so positioned as to entirely close the annular inlet and thereby 'cut off the flow of water to the runner 1:9, as is well known in the art.

For the purpose of operating the gate shifting ring 28, said ring has connected thereto, the ends of two operating rods 29 and 30 (see Figs. 3 and 5). The other ends of the rods 29 and 30 are pivotally connected to a lever. 3| fixed to the lower end of a shaft 32.

The upper end of shaft 32 is operatively connected by links 33 to the governor 3 in the usual manner, whereby operation of the governor rotates the shaft 32, and the movement of said shaft in turn is transmitted to the gate shifting ring 28, so as to effect operation of the Wicket gates 22.

Beneath the curb plate 24 there is the usual draft tube 25 through which the water flows after it leaves the runner. The draft tube 25 terminates within the tailrace at the lower part of the structure i6.

The construction and operation of the parts thus far described is well known in the art, and therefore needs no further amplification.

Referring now to Fig. 4, the horizontal wall |1 heretofore referred to, has mounted thereon a stationary orifice ring 36 which is interposed between the wall l1 and the curb plate 24 of the turbine casing.

The orifice ring 36 comprises an upper annular portion or band 31 and a lower annular portion or band 38. The portions 31 and 38 are held in spaced relation by means of a plurality of vertical vanes or ribs 39 which are uniformly spaced apart around said upper and lower portions of the orifice ring 36 so as to provide a series of passages or openings 46, the purpose of which will be hereinafter more fully described. If so desired, the portions 31, 38 and. 39 of the ring 36 may be cast integrally.

The inner surface of the upper portion 31 of the orifice ring 36 is formed as a continuation of the draft tube 25, and the curb plate 24 rests on the top of said upper portion 31.

The lower portion 38 of the orifice ring 36 is formed with an outwardly extending flanged portion 4| and an inner downwardly extending flanged portion 42.

The diameter of the flanged portion 42 is greater than the diameter of the draft tube 25 whereby an annular space is provided around the exterior of the draft tube.

Surrounding the draft tube 25 and extending downwardly from the flange 42 to the bottom of the draft tube, is another tube 43.

The tubes 25 and 43 are retained in spaced relation by means of spacers 44.

The contours of the openings 39 are such that said openings are, in vertical section, narrower at their lower ends than at their upper outer ends and the lower ends of said openings register with the space between the two tubes 25 and. 43.

Surrounding the stationary orifice ring 36 is a rotatable orifice ring 46, comprising an upper annular portion or band 41, a lower annular portion or band 48, and a plurality of vertical vanes or ribs 49 disposed between said bands 41 and 48. The vanes 49 are uniformly spaced apart around the ring 46 and, as shown in Fig. 5, said vanes register with the vanes 39 of the stationary orifice ring 36 when the parts are in one position, so that the spaces or openings between the vanes 49 will aline with the openings 46 in the stationary orifice ring 36. If so desired, the portions 41, 48 and 49 of the rotatable orifice ring 46 may be cast integrally.

The lower portion 48 of the rotatable orifice ring 46 is supported by the flange 4| of the stationary orifice ring 36, and in order to reduce friction as much as possible, a suitable bearing 5| may be interposed between the flange 4| and the bottom portion 48 of the ring 46, as shown in Fig. 4.

For the purpose of operating the rotatable orifice ring 46, said ring has connected thereto, the ends of two operating rods 53 and 54 (see Figs. 4, 5 and 6). The other ends of the rods 53 and 54 are pivotally connected to a lever 55 fixed to the lower end of a shaft 56.

As shown in Figs. 2 and 3, shaft 56 parallels shaft 32 heretofore referred to, and said shafts are operatively connected to each other so that when the governor l3 actuates shaft 32, the shaft 56 will also be actuated. Therefore, when the wicket gates 22 are operated by the gate shifting ring 28 as the result of rotation of shaft 32 by the governor I3, the orifice ring 46 will also be actuated by the simultaneous rotation of shaft 56.

Extending outwardly from shaft 56 is an arm 51, and extending outwardly from shaft 32 is an arm 58.

Pivotally connected to arm 58, by a pin 59, is one end of a link 60. The other end of link 66 is pivotally connected, by a pin 6|, to a block 62 slidably mounted in an elongated slot 63 formed in the arm 51.

A screw 64 mounted in the arm 51 axially of the slot 63 extends through the block 62. The outer end of the screw 64 carries a hand wheel 65.

The construction of the parts is such, that by operating the hand wheel 65, the end of the link which is pivotally connected to the arm 51 can be adjusted so that the distance between the center of shaft 56 and the center of pivot pin 6! can be shifted in order to effect rotation of the shaft 56 through such an are that when the wicket gate operating shaft 32 is turned through a predetermined arc, the orifice ring 46 will also be moved a distance to effect a corresponding registration of the vanes 49 and openings 56 of orifice ring 46 with the openings 46 and vanes 39, respectively, of the stationary orifice ring 36.

It should be here noted that the connection between the two shafts 32 and 56 is such, that when shaft 32 is rotated in one direction by the governor l3, the shaft 56 will be rotated in the opposite direction (see arrows in Fig. 5). That is to say, when the orifice rings 36 and 46 are in the position shown in Fig. 5, in which position the openings 40 of ring 36 register fully with the openings 50 of ring 46, the wicket gates 22 will be in closed position thereby preventing the flow of water to the runner |9. In such position water will flow through the openings in the orifice ring and into space between the tubes 25 and 43 heretofore referred to, thereby bypassing the turbine.

On the other hand, as shown in Fig. 6, when the outer orifice ring 46 has been rotated to the position in which the vanes 49 overlap the openings 40 in the inner orifice ring 36, the wicket gates 22 will be in fully open position, in which water flows only through the turbine.

Therefore, it will be understood that when the wicket gates 22 are partly opened, the orifice rings will also be so positioned that the openings therethrough will be partly open, and consequently water will flow downwardly through draft tube 25 and also downwardly through the space between the draft tube 25 and the outer tube 43.

In this way, no matter what may be the position of the wicket gates 22, the outer orifice ring 46 will be so positioned as to permit flow of water to the tailrace, and since the size of the opening through the orifice ring varies according to the size of the opening through the wicket gates, obviously a constant flow of water will be delivered to the tailrace of the turbine.

It is well known in the art that for a change of head above or'below normal, the discharge of water through the turbine varies approximately in the ratio of the square root of the normal to the new head. Hence, in the cases when the head exceeds the normal head and with the wicket gates closed and the turbine shut down, an excess of the desired amount of water will bypass the turbine. Also, in the case of the head being below normal, and with the wicket gates closed and the turbine shut down, the discharge through the orifice ring will be below the desired amount. Therefore when such conditions occur, the relative positions of the arms 51 and 58 and link Bil can be shifted by operating the hand wheel 65 so that the relative position of the outer orifice ring 46 will be adjusted to permit the desired amount of water to bypass the turbine, and at the same time allow the governor l3 to make a full stroke.

Having thus described my invention what I claim is 1. The combination with a hydraulic turbine having a runner, wicket gates movable into various positions for controlling the fiow of water to the runner, a governor and mechanism operated thereby for operating the wicket gates, and a draft tube for carrying ofi the water flowing through the runner, of a second tube encircling the draft tube, an orifice ring comprising a stationary portion and a movable portion for controlling the fiow of water through said second tube, and means actuated by said governor for operating said movable portion of the orifice ring to control the flow of water through the second tube according to the relative positions of the wicket gates, whereby when said wicket gates are closed and all fiow of water to the runner cut off the orifice ring will be'wide open, when the wicket gates are in wide open position the orifice will also be partly opened so that water will flow ring will be closed thereby cutting off the flow of water through the second tube, and when the wicket gates are partly opened the orifice ring simultaneously through both the draft tube and the second tube, thereby maintaining constant the amount of water delivered to the tailrace of i said water chamber and separated therefrom by a wall, a second tube coextensive with said draft tube for connecting the chamber with the tailrace for also delivering water to the tailrace, and variable means for controlling the flow of water from said chamber to said second tube so that a uniform quantity of water is delivered to the tailrace irrespective of the amount of water fiowing through the turbine and its draft tube.

3. A hydraulic turbine installation comprising a runner, wicket gates movable into various positions for controlling the fiow of water to the runner, a governor and mechanism operated. thereby for operating the wicket gates, a draft tube for carrying off the water flowing through the runner, a second tube encircling the draft tube and substantially coextensive therewith, an orifice ring comprising a stationary portion and a movable portion for controlling the flow of water through said second tube, and means actuated by said governor for operating said movable portion of the orifice ring to control the flow of water through the second tube according to the relative positions of the Wicket gates, whereby when said wicket gates are closed and all flow of water to the runner cut off, the orifice ring will be wide open to permit free flow of water only through the space between said tubes, when the wicket gates are wide open the orifice ring will be closed thereby cutting off the flow of water through the space between the two tubes and permitting the water to flow only through the draft tube, and when the wicket gates are partly opened the orifice ring will also be partly opened so that water will flow simultaneously through both the draft tube and the space between said tubes, thereby maintaining constant the amount of water delivered to the tailrace of the turbine installation irrespective of the position of the wicket gates.

ARTHUR YOUNG.

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