US2442019A - Turbine construction - Google Patents

Description

May 25, 1948. J. L. RAY 2,442,019

TURBINE CONSTRUCTION Filed June 11, 1943 EL 0 W50 COMAESSOR gatented May 25, 1948 TURBINE CONSTRUCTION James L. Ray, Elm Grove, Wis., assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application June 11, 1943, Serial No. 490,433

17 Claims.

This invention relates generally to turbines and more particularly to multistage elastic fluid turbines embodying a bypass for conducting a portion of the motive fluid directly to an intermediate stage.

In this invention, it has heretofore been proposed to increase the rate of flow'and thereby the load output of high pressure elastic fluid turbines by employing a nozzle plate having openings therethrough for directing motive fluid to the first row of moving blades, a plurality of nozzle chests or chambers for conducting motive fluid to separate sections of the nozzle plate, passages for conducting motive fluid from one or more of the nozzle chests or chambers directly to the diaphragm of the second stage, and valves severally controlling the admission of motive fluid to each nozzle chest or chamber. However, this known construction is not entirely satisfactorily in that the maximum flow rate for the first stage cannot be attained without first bypassing motive fluid to the second stage and in that such a construction is limited for use in partial admission machines.

It is therefore the primary object of this invention to provide an improved elastic fluid turbine bypass construction embodying internally disposed passages and valves operable to control the quantity of motive fluid delivered to an intermediate stage independently of the flow rate to the first stage.

Another object of this invention is to provide an improved elastic fluid turbine bypass construction embodying an arrangement of internally disposed passages and valves applicable to full admission machines.

Still another object of this invention is to provide an improved valve actuating and control means for elastic fluid turbine bypass constructions embodying internally disposed passages and valves.

In accordance with this invention, the above stated objects may be accomplished in whole or in part by a multistage turbine construction embodying one or more of the following features or modifications thereof a first stage nozzle structure having first stage and bypass openings therethrough arranged for conducting motive fluid directly to the first stage and directly to an intermediate stage, respectively, valve means positioned adjacent and operable to control the flow of motive fluid through said bypass openings independently of the flow of motive fluid through the first stage openings; and means operable from the exterior of the turbine casing for actuating said valve means to selectively open and close said bypass openings.

The invention accordingly consists of the various details of construction, combinations of elements, and arrangements of parts as is more fully set forth in the appended claims and in the detailed description, reference being had to the' accompanying drawing, in which:

Fig. l is a partial longitudinal section through a gas turbine structure embodying the invention;

Fig. 2 is an enlarged view of a portion of the outer nozzle ring and valve carrying elements shown in Fig. 1;

Fig. 3 is a partial section taken on line III-III of Fig. 2; and

Fig. 4 is a partial section taken on line IV--IV of Fig. 1.

Referring to drawing and particularly to Fig. 1, it is seen that the invention may be applied to a multistage axial flow gas turbine comprising an overhung rotor I having a coaxial shaft portion 2 rotatably supported on a conventional bearing structure 3 and a casing 4 enclosing said rotor.

The rotor I includes a low pressure disk I carrying a plurality of blade rows 8, an intermediate pressure disk 9 carrying a single blade row II, and a high pressure disk I2 carrying a single blade row l3, said disks being welded or otherwise secured together and to the shaft portion 2 in the coaxial rotor forming relation shown.

The exhaust end of casing 4 includes an annular exhaust portion 6 which embodies an annular seal ring carrying portion l4 surrounding the shaft 2 and an annular low pressure stationary blade mounting member l6 carrying a pluralityof blade rows ll disposed in coacting flow directing relation to the rows of moving blades 8 carried by rotor disk I. The intermediate portion of casing 4 mounts an annular hollow diaphragm disk l6 which is disposed between the moving blade rows ii and i3 and has fluid directing passages l9 extending therethrough adapted to receive the motive fluid issuing from blade row 53 and direct same toward blade row ii. The inlet portion of casing 4 includes a full admission first stage nozzle structure 2i and an insulated conduit portion 22 surrounding and forming with said nozzle structure a motive fluid confining inlet chamber 23. Nozzle structure 2i comprises nozzle passage forming vane elements 24 disposed between an outer ring element 26 carried by the casing 4 and an inner annular hollow disk member 21 mounted on the inner ends of coaxial fluid conducting tubes 28 and 29 in spaced opposed relation to the inlet side of rotor disk l2.

Hollow disk member 21 has an annular series of openings 3| therethrough arranged to direct a ,cooiitig fluid against; the outer blade carrying portion oi rotor disk l2 and the tubes 23 and 29 extend through the conduit portion 22 and terminate exteriorly thereof in connections placing said tubes in communication with a suitable source of cooling fluid which for purposes of illustration may comprise a cooler 32 and a, blower 33; the arrangement being such that the blower delivers cool air to the tube 29 from which it enters the hollow portion of nozzle disk 21 and flows therefrom through the openings 3| against the outer portion of rotor disk l2 and into the space 34 provided between nozzle disk 21 and rotor disk l2 and then returns through inner tube 28 to the cooler 32 and the inlet side of blower 33 for recirculation in the manner just described. In this connection, the pressure of the cooling air in'the space 34 should be sufllcient to prevent the motive fluid issuing from the nozzle passages defined by vane elements 24 from entering said space. In order to increase the cooling action of the air discharged from the openings 3| in nozzle disk 21, the opposed portion of rotor disk l2 may be provided with fins or corrugations 36 as shown.

Outer ring element 2| has an annular series of bypass openings 31 therethrough arranged for conducting motive fluid from inlet chamber 23 directly to an intermediate stage, in this case, directly to the space 33 immediately adjacent the inlet side of diaphragm l8, and the flow of motive fluid through said bypass openings is controlled by a valve means (see Figs. 2 and 3) comprising a valve 39 for each opening 31 and actuating -means including a ring-shaped element 4| on which each valve is mounted for movement relative to each other and relative to said element by means of a pair of pins 42 which arecarried by said element and extend through openings 43 of larger diameter provided in each valve, a series of circumferentially spaced shoes 44 mounted on said element for limited pivotal movement relative thereto by means of pins 46, and a similar shoe 41 mounted in a like manner on the mid-portion of each valve 39 with the opposite ends of each shoe 41 in engagement with the opposed ends of a pair of adjacent shoes 44 on element 4|. In other words, each shoe 44 carried by ring-shaped element 4| has its opposite ends in engagement at all times with the opposed endsv of the shoes carried by a pair of adjacent valves 39. The portions of the shoes 44 and 41 which are in engagement with surface portions of the element 4| and valves 39 are curved in order to facilitate the limited degree of pivotal movement hereinbefore specified and it should now be obvious that the shoes 44 and 41 may pivot slightly relative to each other and relative to the valves and ring element mounting same and, that since the valves 39 are also mounted for movement relative to each other and relative to ring element 4|, a movement of said ring-shaped element toward the nozzle ring element 26 simultaneously efiects an independent and positive seating of each valve to close its respective bypass opening. Consequently, this construction will efiect a complete closure of the bypass openings irrespective Ring-shaped element 4| is supported by struts 43 carried by a tubular element-49 which spacedly surrounds tube 29 and has its inner end mounted for reciprocation on a coaxial support 5| which is in turn supported in part by nomle disk 21 through the medium of pin mounted blocks 52 disposed between pairs of parallel guides 53 (see Fig. 4) and in part by the outer ring element 29 through the medium of struts 54. The outer end of tubular element 49 terminates exteriorly oi the conduit portion 22 of easing 4 in an annular piston portion 55 enclosed in a cylinder 51 provided with-axially spaced ports 53 and 59 connected by means of a four-way valve BI and pipes 62, 63, 64 and 66 with a suitable source of fluid under pressure, such as the compressor 51, and with the atmosphere; the. arrangement being such that when the valve 5| is in one position, fluid under pressure enters one end of cylinder 51 through port 58 and the opposite end of cylinder 51 is placed in communication with the atmosphere through port 59 and pipes 64 and 63 and that when said valve is in its other position, fluid under pressure enters cylinder 51 through the port 59 and the opposite end of-the cylinder is placed in communication with the atmosphere through port 58 and pipes 62 and 63. With the parts in the position shown, valves 39 completely close the bypass openings 31 and all that is necessary in order to increase the flow capacity of the turbine is to move the handle of valve 6| to the right which admits fluid under pressure through port 53, thus causing tubular element from bypass openings 31, thereby permitting motive fluid to flow from inlet chamber 23 directly of the relative expansion and contraction of into the space 33 immediately adjacent the inlet side of diaphragm l3. When it is desired to again close the bypass openings, the handle of valve 6| is moved to the position shown.

The space between fluid conducting tube 29 and tubular member 49 is preferably. wholly or partially filled with insulation 58, as shown. In addition, it is desirable to form the outer ring element 26 of nozzle structure 2| with a series of cooling fluid conducting passages 59 which extend through the wall portions 1| separating the passages 31 and discharge into the motive fluid confining chamber 23 adjacentthe inlet ends of the nozzle passages formed by vane elements 24; the cooling fluid being supplied to said passages from a suitable source (not shown) by means of a conduit 12. Furthermore, it is also desirable to cool both the diaphragm l8 and the opposed portion of rotor disk |2 by introducing a cool.- ing fluid into the hollow interior 13 thereof and directing same through openings 14 against the outer corrugated surface portion 15 of disk l2. Cooling fluid may be readily introduced into diaphragm l8 through a suitable connection with a source of fluid (not shown). 7

The construction hereinbefore described provides a durable and compact arrangement of internally disposed bypass openings, valves controlling same and valve actuating mechanism operable from the exterior of the turbine to control the quantity of motive fluid flowing through the bypass openings independently of the flow of motive fluid through the first stage nozzle openings. The invention is applicable to elastic fluid turbines generally and although it is of particular advantage for use in high temperature gas turbines, it should be understood that it is not desired to limit the invention to the exact details or construction and operation herein shown and described as various modifications within the scope of the appended claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure having first stage and bypass openings therethrough arranged to conduct motive fluid from said inlet chamber to the first row of moving blades and to an intermediate stage, respectively, a valve mounting and actuating mechanism supported within said inlet chamber and adjacent said bypass openings for movement relative to said nozzle structure, said mechanism including valves disposed in controllable relation with respect to said bypass openings and actuating parts operative substantially simultaneously to severally, positively seat said valves in passage closing relation in response to an actuation of one of said parts, and means, extending through and operable from the exterior of said casing for controlling the movement of said one part.

2. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure having an annular series of bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage, a ring-shaped element mounted within said inlet chamber adjacent said bypass openings for movement relative to said nozzle structure, valve means carried by said ringshaped element in controlling relation with respect to said bypass openings, an actuator supported by a central portion of said nozzle structure for movement relative thereto and operatively connected with said ring-shaped element, and means rendering said actuator operable from the exterior of said casing for controlling the movement of said ring-shaped element,

3. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure having an annular series of bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage, a coaxial ring-shaped element mounted within said inlet chamber adjacent said bypass openings for movement axially toward and away from said nozzle structure, valve means carried by said ring-shaped element in controlling relation with respect to said bypass openings and operatively connected with said ring-shaped element, an actuator supported by a central portion of said nozzle structure for movement relative thereto, and means rendering said actuator operable from the exterior of said casing for controlling the axial movement of said ring-shaped element.

4. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure including an outer ring element having an annular series of bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage diaphragm structure and an inner disk member, a coaxial ring-shaped element carried by said nozzle structure for movement axially toward and away from said by-pass openings, valve means mounted on said ring-shaped element for movement therewith and for limited movement relative thereto, said valve means being disposed in controlling relation with respect to said bypass openings, a member united with a central portion of said inner disk and projecting coaxially therefrom to a point exterior of said casing, an actuator movably mounted on said member, and operatively connected with said ring-shaped element, and means operable from the exterior of said casing for controlling the axial movement of said ring-shaped element.

5. In combination in a turbine including an overhung rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure including an outer ring element having bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage and an inner hollow disk member disposed in spaced opposed relation to the adjacent end of said rotor, means including openings in said hollow disk member effective to cause a cooling fluid to flow through said disk member and through the space provided between said member and the adjacent end of said rotor, a coaxial ring-shaped element mounted on said nozzle structure for movement axially toward and away from said nozzle structure, valve means carried by said ring-shaped element in controlling relation with respect to said bypass openings, an actuator movably supported by said hollow disk member and operatively connected with said ring-shaped element, and means ren dering said actuator operable from the exterior of said casing for axially moving said ring-shaped element to selectively open or close said bypass openings.

6. In combination in a turbine including an overhung rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure including an outer ring element having bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage and an inner hollow disk member disposed in spaced opposed relation to the adjacent end of said rotor, means including openings in said hollow disk member and fluid conductors extending through said inlet chamber effective to cause a cooling fluid to flow through said disk member and through the space provided between said member and the adjacent end of said rotor, a tubular member surrounding said fluid conductors, means mounting said tubular member for reciprocation toward and away from said nozzle structure, a coaxial ringshaped element carried by said tubular member for movement therewith, valve means carried by said ring-shaped element in controlling relation with respect to said bypass openings, and means exterior of said inlet chamber for reciprocating said tubular member to selectively open or close said bypass openings.

7. In combination in a turbine including an overhung rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure including an outer ring element having bypass openings therethrou'gh arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage and an inner hollow disk member disposed in spaced opposed relation to the adjacent end of said rotor, means including openings in said hollow disk member and fluid conductors extending through said inlet chamber efiective to cause a cooling fluid to flow through said disk member and through the space provided between said member and the adjacent end of said rotor, a tubular member surrounding sai-d fluid conductors, means mounting said tubular member for reciprocation toward and away from said nozzle structure, said tubular member terminating exterior of said inlet chamber in a piston portion enclosed in a cylinder provided with fluid admission and discharge openings, a coaxial ring-shaped element carried. by said tubular member for movement therewith, valve means carried by said ring-shaped element in controlling relation with respect to said bypass openings, and means controllably connecting said cylinder with a source of fluid under pressure for efiecting a movement of said tubular member in a selected direction and a corresponding bypass opening or closing movement of said valve means.

8. In combination in a turbine including an overhung rotor and a casing enclosing said rotor, a full admission nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure including an outer ring element having bypass openings therethrough arranged to conduct motive fluid from said inlet chamber directly to an intermediate stage and an inner hollow disk member disposed in spaced opposed relation to the adjacent end of said rotor, means including openings in said hollow disk member and a pair of coaxial fluid conducting tubes effective to cause a cooling fluid to flow through said disk member and through the space provided between said member and the adjacent end of said rotor, a tubular member spacedly surrounding said pair of fluid conducting tubes, means mounting said tubular member for reciprocation axially toward and away from said nozzle structure, said tubular member terminating exterior of said inlet chamber in an annular piston portion enclosed in a cylinder provided with fluid admission and discharge openings, a coaxial ring-shaped element carried by said tubular member for movement therewith, valve means disposed in controlling relation to said bypass openings and operatively connected with said ring-shaped element for actuation thereby, and means controllably connecting said cylinder with a source of fluid under pressure for eflecting a movement of said tubular member in a selected directionland a p n in byp s p ning or closing movement of said valve means.

9. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of flrst-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure and extending away therefrom in a noncoaxial direction with respect to the axis of said rotor, a valve supporting member mounted within said conductor and adjacent said bypas-s openings for movement relative to said nozzle structure, valves carried by said member in controllable relation with respect to said bypass openings, a reciprocable actuator extending through a wall portion of said conductor in coaxial relation with respect to said nozzle structure, and means connecting said member with the adjacent end portion of said actuator.

10. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of flrst-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure and extending away therefrom in a noncoaxial direction with respect to the axis of said rotor, a valve supporting member mounted within said conductor and adjacent said bypass openings for movement relative to said nozzle structure, valves carried by said member in controllable relation with respect to said bypass openings, an elongated member united with a central portion of said nozzle structure and projecting coaxially therefrom and through a wall portion of said conductor, an actuator reciprocably mounted on said elongated member and extending-from a point adjacent said valve supporting member to a point exterior of said conductor, and means connecting said member with the adjacent end portion of said actuator.

11. In combination in a turbine including a multistage rotor' and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of first-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure, a valve mounting and actuating mechanism supported within said conductor and adjacent said bypass openings for movement relative to said nozzle structure, said mechanism including valves disposed in controllable relation with respect to said bypass openings and valve actuating parts operative substantially simultaneously to severally, positively seat said valves in passage closing position in response to an actuation of one of said parts, and means operable from the exterior of said conductor for actuating said one part to selectively open or close said bypass openings.

12. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having inner and outer annular series of first stage and flrst-stage-bypass openings extending therethrough, a motive fiuid conductor enclosing said nozzle structure and extending away therefrom in a noncoaxlal direction with respect to the axis of said rotor, an annular valve supporting member mounted within said conductor and adjacent said bypass openings for coaxial movement relative to said nozzle structure, valves carried by said member in controllable relation with respect to said bypass openings, a reciprocable actuator extending through a wall portion of said conductor in coaxial relation with respect to said nozzle structure and valve supporting member, and means connecting said member with the adjacent end portion of said actuator.

13. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of first-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure, a valve mounting and actuating mechanism disposed within said conductor and supported by a central portion of said nozzle structure for movement coaxially toward and away from same, said mechanism including a valve disposed in controllable relation with respect to said bypass openings and anactuating part operative to substantially simultaneously move all said valves, and means operable from the exterior of said conductor for actuating said part to selectively open or close said bypass openings.

14. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of flrst-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure, a valve mounting and actuating mechanism disposed within said conductor and operatively supported for movement coaxially toward and away from said nozzle structure, said mechanism including valves disposed in controllable relation with respect to said bypass openings and an actuating part operative to substantially simultaneously move all of said valves, and means operable from the exterior of said conductor for actuating said part to selectively open or close said bypass openings.

15. In combination in a turbine including a multistage rotor and a casing enclosing the rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor and having a plurality of first stage and of first-stage-bypass openings extending therethrough, a motive fluid conductor enclosing said nozzle structure and extending away therefrom in a noncoaxial direction with respect to the axis of said rotor. said nozzle structure including a hollow central portion and a coolin fluid conductor extending coaxially therefrom and through a wall portion of said motive fluid conductor, a valve supporting member mounted within said conductor and adjacent said bypass openings for movement relative to said nozzle structure, valves carried by said member in controllable relation with respect to said bypass openings, a tubular actuator surrounding said cooling fluid conductor and reciprocable relative thereto, and means operatively connecting said valve supporting member with the adjacent end portion of said actuator.

16. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a nozzle structure disposed in spaced 0pposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chambensaidnozzle structure having first stage and bypass openings therethrough arranged to conduct motive fluid from said inlet chamber to the first row of moving blades and to an intermediate stage, respectively, a valve actuating mechanism supported within said inlet chamber and adjacent said bypass openings for movement relative to said nozzle structure, valves carried by said mechanism in controllable relation to said bypass openings, and means extending through and operable from the exterior of said casing for controlling the movement of said valve actuating mechanism.

17. In combination in a turbine including a multistage rotor and a casing enclosing said rotor, a nozzle structure disposed in spaced opposed relation with respect to the first stage end of said rotor, means surrounding and forming with said nozzle structure a motive fluid confining inlet chamber, said nozzle structure having first stage and bypass openings therethrough arranged toconduct motive fluid from said inlet chamber to the first row'of moving blades and to an intermediate stage, respectively, a valve actuating mechanism disposed within said inlet chamber adjacent said bypass openings and carried by said nozzle structure for movement relative thereto, valves carried by said mechanism in controllable relation to said bypass openings, and means extending through and operable from th exterior of said casing for controlling the movement of said valve actuating mechanism.

JAMES L. RAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 750,880 Schulz Apr. 21, 1903 760,003 Lindmark May 17, 1904 1,012,813 Chaleil -1 Dec. 29, 1911 1,190,074 Alqulst July 4, 1916 1,234,687 Patitz July 24, 1917 1,621,435 Rosch Mar. 15, 1927 1,987,631 Noack Jan. 15, 1935 2,081,149 Meininghaus May 25, 1937 2,131,047 Holzwartn Sept. 27, 1938 2,207,762 Schmidt July 16, 1940 Re.13,772 Junssr a" July 1914

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