US3677658A - Split casting steam chest, nozzle chamber and casing assembly for turbines - Google Patents

Split casting steam chest, nozzle chamber and casing assembly for turbines Download PDF

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Publication number
US3677658A
US3677658A US95997A US3677658DA US3677658A US 3677658 A US3677658 A US 3677658A US 95997 A US95997 A US 95997A US 3677658D A US3677658D A US 3677658DA US 3677658 A US3677658 A US 3677658A
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US
United States
Prior art keywords
nozzle chamber
opening
casing
steam chest
steam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US95997A
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English (en)
Inventor
Philip A Dinenno Jr
Joseph S Bonk
Kenneth C Conrad
Rodney S Moore
Harry E Lochman
Daniel D Torello
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CBS Corp
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Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
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Publication of US3677658A publication Critical patent/US3677658A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D17/00—Regulating or controlling by varying flow
    • F01D17/10—Final actuators
    • F01D17/12—Final actuators arranged in stator parts
    • F01D17/18—Final actuators arranged in stator parts varying effective number of nozzles or guide conduits, e.g. sequentially operable valves for steam turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D9/00—Stators
    • F01D9/02—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles
    • F01D9/04—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector
    • F01D9/047—Nozzle boxes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D9/00—Stators
    • F01D9/06—Fluid supply conduits to nozzles or the like

Definitions

  • ABSTRACT In an elastic fluid turbine, an improved construction of the casing, the steam chest and the nozzle chamber which permits free expansion of parts subject to thermal transients at reduced cost and higher assurance of quality. This is accomplished by casting the nozzle chamber, the upper and lowe halves of the outer casing and at least a portion of the steam chest as separate pieces and then bolting them together. ln cases where a high pressure nozzle chamber is employed, this also is cast separate from the lower casing half and fitted into an opening in that part. Forming the assembly from a number of parts in this manner considerably reduces the problems encountered in casting complex shapes which are costly and difficult to fabricate.
  • the steam chest is provided with governor-controlled valves that are sequentially movable to open and close a plurality of flow paths between the steam chest and passageways formed in the nozzle chamber.
  • governor-controlled valves that are sequentially movable to open and close a plurality of flow paths between the steam chest and passageways formed in the nozzle chamber.
  • the steam is usually taken from the main turbine-generator unit at the crossover pipe line of the low pressure turbine.
  • the steam at this point varies in pressure downwardly from about 180 pounds per square inch, 650 F, and will support pumping power from 100 percent to about 40 percent main unit load.
  • a secondary source of higher pressure steam must be available to the drive turbine or the system will collapse.
  • This secondary source is usually from the cold reheat pipe line where the pressure varies downwardly from about 600 pounds per square inch, 750 F, or from the main boiler leads at a pressure in the range of about 2,400 to 3,500 pounds per square inch at 1,00? F.
  • Crossover steam is always admitted to the low pressure connection on the aforesaid steam chest.
  • Cold reheat steam, pressure reduced and desuperheated if required is either manifolded externally and connected to this same low pressure connection or to a separate high pressure inlet connection.
  • main boiler steam is selected as the secondary steam source, it is always connected to a separate high pressure inlet connection.
  • the low pressure nozzle chamber which is connected to the aforesaid valves through the steam chest is designed symmetrically about the turbine axis to assure even stress levels throughout.
  • the low pressure nozzle chamber is inserted into a slot in the turbine casing such that its outside wall forms a wall of the turbine itself.
  • the low pressure nozzle chamber connects to the turbine casing near the steam chest and is free to expand radially in the nozzle arch under rapidly varying temperatures within the individual nozzle chambers (from load changes) or with changing low pressure inlet temperatures (from steam source switching).
  • a steam turbine inlet cylinder casing construction of the double-wall type wherein the steam chest, nozzle chambers and casing cover are cast in separate pieces and then bolted together.
  • the assembly consists of a casing formed from upper and lower generally semicylindrical parts secured together by means of bolts or other suitable fastening means.
  • An opening is provided in the upper wall of the upper casing part; and this opening receives a self-contained nozzle chamber including an annular array of nozzle groups and a cavernous body extending through the opening for conducting elastic fluid from the exterior to the interior of the casing.
  • the cavernous body is spaced from the wall of the casing parts to permit relative thermal expansion and construction between the two; while means, preferably bolts, secure the top of the nozzle chamber to the periphery of the opening in the upper part.
  • the steam chest is cast as a separate part and bolted to the upper end of the upper casing half; while in another embodiment the steam chest side walls are formed integrally with the nozzle chamber. In this latter case, the cover is bolted onto the open top of the steam chest.
  • FIG. 1 is a transverse cross-sectional view of a steam turbine having an inlet casing and associated nozzle assembly constructed in accordance with the teachings of the invention
  • FIG. 2 is a cross-sectional view taken substantially along line II-Il of FIG. 1;
  • FIG. 3 is a cross-sectional view of another embodiment of the invention.
  • FIG. 4 is a cross-sectional view taken substantially along line IV-IV ofFIG. 3.
  • FIGS. 1 and 2 there is shown an axial flow steam turbine having a cylinder or casing 10, which casing is formed about a horizontal axis and includes an upper half 12 and a lower half 14 bolted together by means of bolts 15 passing through flanges l6.
  • a low pressure nozzle chamber 20 Extending through an opening 18 (FIG. 2) in the upper casing part 12 is a low pressure nozzle chamber 20.
  • the low pressure nozzle chamber 20 is provided with an upper peripheral flange 22 which is bolted by means of bolts 24 to a cooperating peripheral flange around the opening 18 on upper casing part 12.
  • a flange 26 Also bolted to a flange 26 projecting outwardly from around the opening 18 is a separately cast steam chest 28 pro vided with openings 30 and 32 for the admission of steam from a suitable source, not shown.
  • valve seats 36 In the upper wall of the low pressure nozzle chamber 20 is a plurality of openings 34 which receive valve seats 36.
  • Each valve seat 36 is provided with a valve member 38 carried by a vertically movable, horizontal lift bar 40, only the valves on the left side of the assembly, the valve seats 36 and the lift bar 40 being shown in full lines in FIG. 1.
  • the valve members 38 can slide within openings within the lift bar 40 and are provided with stop nuts 42 which, when engaged by the lift bar 40, will cause their associated valves to be unseated from their valve seats 36. Note that the valve member 38 closest to the center of the assembly will become unseated first, followed by successive unseating or opening of the remaining valve members until the outermost valve member is unseated.
  • the arrangement of the right of center of FIG. 1 is identical to that to the left shown in full lines.
  • each of the passageways 44 terminates at a nozzle vane assembly 46 which directs steam through rotatable blades 48 and stationary blades 50 carried on the turbine rotor 52 and the casing 26, respectively.
  • the passageways 44 are formed between radially spaced walls 54 extending between the front and back walls of the low pressure nozzle chamber 20.
  • steam will be introduced into some of the passageways 44 and not others, giving rise to uneven thermal expansion forces.
  • the arrangement shown permits portions of the walls 54 to elongate, due to thermal expansion, in a direction transverse to the rotor axis without imposing forces on other parts of the assembly.
  • the outer wall of the nozzle chamber 20 is spaced from the casing 10, giving rise to a double wall construction. This permits relatively free expansion and contraction of the walls 54 of the nozzle chamber 20 without undue thermal stresses occasioned by the fact that the outer surface of the casing is exposed to ambient temperatures.
  • the lower casing part 14 is provided with an opening 56.
  • a plate 58 Bolted to the periphery of this opening is a plate 58 having a central opening within which is welded or cast the neck portion of a high pressure nozzle chamber 60.
  • the high pressure nozzle chamber 60 will be connected to the main boiler or to cold reheat steam as a secondary source through an intervening control and stop valve (not shown). In certain cases, it may not be necessary to employ the high pressure nozzle chamber 60, in which case the opening 56 will simply be closed by a plate, similar to plate 58 but without the high pressure nozzle chamber.
  • the use of the high pressure nozzle chamber 60 provides the necessary flexibility required with high temperature steam admission and uses the same first row blading 48 used by the low pressure nozzle chamber 20.
  • the low pressure nozzle chamber covers approximately 270 of the periphery of the rotor structure; while the high pressure nozzle assembly 60 covers the remaining 90, thus providing for maximum flow capacity from the design.
  • this high pressure nozzle chamber 60 without plate 58 was welded directly to the periphery of a much smaller opening in base casing 14; however, this requires expensive X-ray quality chromium-molybdenum base castings.
  • the bolted-on design permits the use of carbon steel material for the base casting without X-ray inspection.
  • the nozzle chamber 60 is formed from a chromium-molybdenum steel.
  • a double wall inlet nozzle assembly is provided formed from four separate castings.
  • the low pressure nozzle chamber 20 is a relatively small casting that can be poured in a horizontal position, improving metal feed at changes in section and minimizing cracks at these points. All external surfaces are accessible to facilitate inspection and repair.
  • the use of a separately cast steam chest requires no boring or turning operations and need only be assembled at the final assembly stage. Boring operations involve the upper casing part 12, the lower casing part 14 and the nozzle chambers 20 and 60 only.
  • FIGS. 3 and 4 Another embodiment of the invention is shown in FIGS. 3 and 4.
  • This embodiment is similar to that of FIGS. 1 and 2, and, accordingly, elements in FIGS. 3 and 4 which correspond to those of FIGS. 1 and 2 are identified by like reference numerals.
  • the side walls 28A and 28B of the steam chest 28 are cast integrally with the low pressure nozzle chamber 20.
  • the upper ends of the walls 28A and 28B are provided with flanges 62 to which is bolted a covering plate 64.
  • the chief advantage of the embodiment of FIGS. 3 and 4 over that of FIGS. 1 and 2 is that internal nozzle chamber bolting is not required. However, larger boring mills must be used to machine the castings shown in FIGS. 3 and 4.
  • An elastic fluid turbine comprising a casing formed from upper and lower generally semicylindrical parts secured together, an opening in the top wall of said upper part, a selfcontained nozzle chamber including an annular array of nozzle groups and a cavernous body extending through said opening for conducting elastic fluid from the exterior to the interior of the casing, said cavernous body being spaced from the walls of said casing parts to permit relative thermal expansion and contraction between the two, means securing the top of said body to the periphery of the opening in said upper part, a steam chest covering said top of the body and housing valve means for admitting steam under pressure to said nozzle chamber, means defining an opening in the bottom of said lower casing part, and a separately cast high pressure nozzle chamber inserted into and sealed within said opening.
  • cavernous body defines passageways leading to nozzles, openings in the ends of said passageways opposite said nozzles, and valve means carried within said steam chest for controlling the admission of steam into said passageways through said openings.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
US95997A 1970-12-08 1970-12-08 Split casting steam chest, nozzle chamber and casing assembly for turbines Expired - Lifetime US3677658A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US9599770A 1970-12-08 1970-12-08

Publications (1)

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US3677658A true US3677658A (en) 1972-07-18

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US95997A Expired - Lifetime US3677658A (en) 1970-12-08 1970-12-08 Split casting steam chest, nozzle chamber and casing assembly for turbines

Country Status (7)

Country Link
US (1) US3677658A (de)
JP (1) JPS5013413B1 (de)
CH (1) CH545415A (de)
DE (1) DE2158163A1 (de)
FR (1) FR2117437A5 (de)
GB (1) GB1303015A (de)
IT (1) IT943749B (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4936002A (en) * 1989-04-03 1990-06-26 Westinghouse Electric Corp. Method of modifying integral steam chest steam turbines
WO1999058819A1 (en) * 1998-05-14 1999-11-18 Dresser-Rand Company A method for fabricating a turbine inlet casing and the turbine inlet casing
US6099246A (en) * 1998-01-27 2000-08-08 Siemens Aktiengesellschaft Admission section of a turbine casing
AT410698B (de) * 2000-11-27 2003-06-25 Otto Ing Blank Abgasturbolader
US20050072157A1 (en) * 2003-10-06 2005-04-07 Masaki Takahashi Steam turbine
RU2445466C2 (ru) * 2006-09-06 2012-03-20 Дженерал Электрик Компани Сопловая коробка паровой турбины, а также паровая турбина
US20190234230A1 (en) * 2018-01-30 2019-08-01 Mitsubishi Heavy Industries Compressor Corporation Valve device for turbine, turbine, and method for producing valve device and turbine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5544818U (de) * 1978-09-14 1980-03-24

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH95102A (de) * 1921-03-24 1922-06-01 Escher Wyss Maschf Ag Turbine für elastische Treibmittel, mit mindestens einem innerhalb des Turbinengehäuses angeordneten Einführungsring für das Treibmittel.
GB197873A (en) * 1922-07-18 1923-05-24 Westinghouse Electric & Mfg Co Improvements relating to elastic fluid turbines
FR724286A (fr) * 1930-10-13 1932-04-25 Perfectionnements aux turbines
FR48244E (fr) * 1937-03-10 1937-11-23 Perfectionnements aux turbines

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH95102A (de) * 1921-03-24 1922-06-01 Escher Wyss Maschf Ag Turbine für elastische Treibmittel, mit mindestens einem innerhalb des Turbinengehäuses angeordneten Einführungsring für das Treibmittel.
GB197873A (en) * 1922-07-18 1923-05-24 Westinghouse Electric & Mfg Co Improvements relating to elastic fluid turbines
FR724286A (fr) * 1930-10-13 1932-04-25 Perfectionnements aux turbines
FR48244E (fr) * 1937-03-10 1937-11-23 Perfectionnements aux turbines

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4936002A (en) * 1989-04-03 1990-06-26 Westinghouse Electric Corp. Method of modifying integral steam chest steam turbines
US6099246A (en) * 1998-01-27 2000-08-08 Siemens Aktiengesellschaft Admission section of a turbine casing
WO1999058819A1 (en) * 1998-05-14 1999-11-18 Dresser-Rand Company A method for fabricating a turbine inlet casing and the turbine inlet casing
US6071073A (en) * 1998-05-14 2000-06-06 Dresser-Rand Company Method of fabricating a turbine inlet casing and the turbine inlet casing
AT410698B (de) * 2000-11-27 2003-06-25 Otto Ing Blank Abgasturbolader
US20050072157A1 (en) * 2003-10-06 2005-04-07 Masaki Takahashi Steam turbine
US7065968B2 (en) * 2003-10-06 2006-06-27 Hitachi, Ltd. Steam turbine
US20060201155A1 (en) * 2003-10-06 2006-09-14 Hitachi, Ltd. Steam turbine
RU2445466C2 (ru) * 2006-09-06 2012-03-20 Дженерал Электрик Компани Сопловая коробка паровой турбины, а также паровая турбина
US20190234230A1 (en) * 2018-01-30 2019-08-01 Mitsubishi Heavy Industries Compressor Corporation Valve device for turbine, turbine, and method for producing valve device and turbine
US10808566B2 (en) * 2018-01-30 2020-10-20 Mitsubishi Heavy Industries Compressor Corporation Valve device for turbine, turbine, and method for producing valve device and turbine

Also Published As

Publication number Publication date
CH545415A (de) 1973-12-15
IT943749B (it) 1973-04-10
FR2117437A5 (de) 1972-07-21
GB1303015A (de) 1973-01-17
JPS5013413B1 (de) 1975-05-20
DE2158163A1 (de) 1972-07-06

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