US3306575A - Steam turbines - Google Patents

Steam turbines Download PDF

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Publication number
US3306575A
US3306575A US435506A US43550665A US3306575A US 3306575 A US3306575 A US 3306575A US 435506 A US435506 A US 435506A US 43550665 A US43550665 A US 43550665A US 3306575 A US3306575 A US 3306575A
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US
United States
Prior art keywords
steam
blades
blade
guide
rotor
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
US435506A
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English (en)
Inventor
Frankel Adolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Associated Electrical Industries Ltd
Original Assignee
Associated Electrical Industries Ltd
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 Associated Electrical Industries Ltd filed Critical Associated Electrical Industries Ltd
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Publication of US3306575A publication Critical patent/US3306575A/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/32—Collecting of condensation water; Drainage ; Removing solid particles
    • 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
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/18—Hollow blades, i.e. blades with cooling or heating channels or cavities; Heating, heat-insulating or cooling means on blades
    • 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
    • F01D9/041—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector using blades
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K7/00—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating
    • F01K7/16—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type
    • F01K7/22—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type the turbines having inter-stage steam heating
    • F01K7/226—Inter-stage steam injection

Definitions

  • An object of the present invention is the provision of an improved steam turbine in which erosion in the later rotor stages is at least reduced.
  • a steam turbine provided with circumferential rows of blades mounted on a rotor and with circumferential rows of guide blades mounted in a fixed casing and arranged respectively intermediate pairs of circumferential rows of blades on the rotor, is also provided with means by which steam can be discharged from port means in the trailing edges of at least the guide blades in the final circumferential row of guide blades and substantially in the direction of the main steam flow past the blades.
  • FIGURE 1 is a sectional side elevation of one guide blade of a steam turbine and of an adjacent rotor blade;
  • FIGURE 2 is a sectional plan view of the guide blade, taken on the line II-II of FIGURE 1;
  • FIGURE 3 is a sectional plan view, drawn to a larger scale than FIGURE 2, of a trailing end or tip of the guide blade shown in FIGURE 2;
  • FIGURE 4 is a sectional plan view, similar to FIGURE 3, but showing a modified construction.
  • a steam turbine guide blade diaphragm 1 includes an inner ring 3 and an outer ring 5 between which extends a multiplicity of fixed guide blades 7.
  • the rotor 9 carries a plurality of bladed stages, each consisting of a circumferential row of rotor blades, and the drawings show one of the blades 15 of the last bladed stage.
  • the guide blade 7, and in fact each guide blade of this circumferential row of guide blades, is hollow, being formed from a bent strip of material, and the trailing edge 7B of the blade forms a nozzle 17.
  • the hollow interior of guide blade 7, and those of the other guide blades in the same circumferential row are in communication with a steam manifold 19 formed in the outer ring 5.
  • the internal cross-section of this nozzle 17 can be divergent, as shown in FIGURE 3, or convergent, as shown in FIGURE 4. It will be seen that the guide blade 7 is curved in transverse cross-section, If desired the trailing edge of the blade can be thinned down by cutting it back from the outside, as shown by the dashed line in FIGURE 4. Although this thinning is shown only on the concave surface of the blade form, it can be applied to both sides or to either side of the blade.
  • the steam manifold 19 is connected by passages, indicated diagrammatically by a pipe 21, to a source of steam which is at a higher pressure than the steam in the region of the guide blade 7 during normal working of the turbine.
  • a suitable source. of this steam could be a bleed point from a higher pressure stage of the turbine.
  • the'steam can enter each blade individually, so that the-collecting manifold is not necessary. If an entrance port 8 is provided in each hollow blade at or near the leading edges, and at a radial position at which the total pressure at the leading edge of the guide blade 7 is highest, this can help to achieve a steam velocity from slot 17 very similar to the main steam velocity.
  • the 3 steam jet injects momentum into the wake leaving the trailing edge of the blade; it entrains the water coming off the trailing edge, and helps both to break it up into relatively small drops and to accelerate it to a velocity of the same order as the velocity of the main stream of steam. If this acceleration is achieved, even approximately, the relative impact velocity of the water on the rotor blades is very considerably reduced, resulting in great reduction of erosion damage, even if the drops are still fairly large in size.
  • the thickness of the steam jet is of the same order of magnitude as the thickness of the side edges of the nozzle 17, and all these dimensions are small compared with the axial distance between the trailing edge of the stator guide blade 7 and the leading edge of the rotor blade, and very much smaller still compared with the distance the steam has to travel obliquely, due to its leaving angle, before it reaches the leading edge of the rotor blade.
  • stator blades of the type illustrated Will generally operate at about the critical pressure ratio, the pressure ratio of the expansion of steam through this nozzle 17 is likely to be higher than critical.
  • the static pressure in the throat of the nozzle 17 will be higher than the mean static pressure in the surrounding steam, and the resulting expansion of width of the steam jet after it has left the nozzle 17, which is a well known effect in super sonic jets, will aid the momentum transfer and the acceleration and the break-up of the water drops or film.
  • the performance of the stator guide blade can be improved by shaping the inside of the guide blade in such a way as to provide a smooth acceleration of steam flowing towards the nozzle 17.
  • FIGURE 4 shows such an arrangement.
  • Suitable rounding off, or tapering (as shown by the dashed line in FIGURE 4) of the outside Wall of the trailing edge of the guide blade, to thin down the trailing edge at the slot to bring the water coming oh" the blade surfaces as near to the trailing edge as possible, may also be advantageous.
  • This tapering can also be applied to the other side of the nozzle. Further, both inside and outside of the nozzle can be tapered off in this manner.
  • the blade metal can be heated well above the saturation temperature of the steam surrounding it in the main steam flow passages. This will result in partial evaporation of the water collecting on theblade surfaces, and also in a temperature gradient in the main steam flow surrounding the blade, reducing the flow of microscopic water drops towards the blade surface, due to thermal diffusivity effects.
  • This heating effeet can be improved by adding partitions, ribs or baflles inside the guide blades so that the steam passing through the blade of the nozzle 17 follows an extended path.
  • the discharge of steam should take place over at least the radially outer end of the trailing edge of the guide blade and can, if desired, take place over the whole length of the trailing edge.
  • a steam turbine comprising:
  • each guide blade is provided with a steam discharge port extending inwardly from a radially outer end of the blade.
  • each guide blade in the circumferential row includes further inlet port means connected to the port means at the trailing edge and effective to receive steam flowing through the turbine and discharge it through the port means at the trailing edge, whereby to increase the quantity of steam discharged from the port means in the trailing edge.
  • a steam turbine according to claim 1 wherein the radially outer ends of the circumferential row of guide blades are secured to an outer ring of a diaphragm attached to the turbine'casing and the outer ring includes a steam manifold connected to a suitable steam supply source and effective simultaneously to supply steam to the port means in each of the blades in the circumferential row.
  • a steam turbine comprising;
  • a fixed casing including circumferential rows of guide blades respectively arranged intermediate pairs of circumferential rows of rotor blades, each of the guide blades in at least the final circumferential row of guide blades being hollow and comprising two appropriately shaped metal sheets respectively forming opposite faces of the blade,
  • port means comprise a slot like nozzle extending inwardly from a radially outer end of the guide blade.
  • each guide blade in the circumferential row includes further inlet port means connected to the port means at the trailing edge and effective to receive steam flowing through the turbine and discharge it through the port means at the trailing edge, whereby to increase the quantity of steam discharged from the port means in the trailing edge.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
US435506A 1964-03-05 1965-02-26 Steam turbines Expired - Lifetime US3306575A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB938964 1964-03-05

Publications (1)

Publication Number Publication Date
US3306575A true US3306575A (en) 1967-02-28

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Family Applications (1)

Application Number Title Priority Date Filing Date
US435506A Expired - Lifetime US3306575A (en) 1964-03-05 1965-02-26 Steam turbines

Country Status (5)

Country Link
US (1) US3306575A (de)
CH (1) CH434300A (de)
DE (1) DE1426788A1 (de)
FR (1) FR1426543A (de)
SE (1) SE305220B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4425077A (en) 1981-08-11 1984-01-10 Westinghouse Electric Corp. Turbine disc environment control system
US5167123A (en) * 1992-01-13 1992-12-01 Brandon Ronald E Flow condensing diffusers for saturated vapor applications
US6233937B1 (en) 2000-09-20 2001-05-22 Siemens Westinghouse Power Corporation Cooling spray application to a turbine and exhaust region of a steam turbine
US20070274824A1 (en) * 2006-05-23 2007-11-29 General Electric Company Airfoil and method for moisture removal and steam injection
US20150139812A1 (en) * 2013-11-21 2015-05-21 Mitsubishi Hitachi Power Systems, Ltd. Steam Turbine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19640298A1 (de) * 1996-09-30 1998-04-09 Siemens Ag Dampfturbine, Verfahren zur Kühlung einer Dampfturbine im Ventilationsbetrieb sowie Verfahren zur Kondensationsminderung bei einer Dampfturbine im Leistungsbetrieb

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1864352A (en) * 1930-01-02 1932-06-21 Gen Electric Means for avoiding damage through moisture in the low pressure part of steam turbines
US2149510A (en) * 1934-01-29 1939-03-07 Cem Comp Electro Mec Method and means for preventing deterioration of turbo-machines
FR1115125A (fr) * 1954-11-26 1956-04-19 Rateau Soc Perfectionnement aux turbines à vapeur
US3002725A (en) * 1957-02-07 1961-10-03 Ljungberg Klas Wilhelm Moisture absorbing means in radial flow turbines
US3123283A (en) * 1962-12-07 1964-03-03 Anti-icing valve means

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1864352A (en) * 1930-01-02 1932-06-21 Gen Electric Means for avoiding damage through moisture in the low pressure part of steam turbines
US2149510A (en) * 1934-01-29 1939-03-07 Cem Comp Electro Mec Method and means for preventing deterioration of turbo-machines
FR1115125A (fr) * 1954-11-26 1956-04-19 Rateau Soc Perfectionnement aux turbines à vapeur
US3002725A (en) * 1957-02-07 1961-10-03 Ljungberg Klas Wilhelm Moisture absorbing means in radial flow turbines
US3123283A (en) * 1962-12-07 1964-03-03 Anti-icing valve means

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4425077A (en) 1981-08-11 1984-01-10 Westinghouse Electric Corp. Turbine disc environment control system
US5167123A (en) * 1992-01-13 1992-12-01 Brandon Ronald E Flow condensing diffusers for saturated vapor applications
US6233937B1 (en) 2000-09-20 2001-05-22 Siemens Westinghouse Power Corporation Cooling spray application to a turbine and exhaust region of a steam turbine
US20070274824A1 (en) * 2006-05-23 2007-11-29 General Electric Company Airfoil and method for moisture removal and steam injection
US7422415B2 (en) * 2006-05-23 2008-09-09 General Electric Company Airfoil and method for moisture removal and steam injection
CN101078355B (zh) * 2006-05-23 2011-10-05 通用电气公司 用于除水分及蒸汽注入的翼面和方法
US20150139812A1 (en) * 2013-11-21 2015-05-21 Mitsubishi Hitachi Power Systems, Ltd. Steam Turbine
US10145248B2 (en) * 2013-11-21 2018-12-04 Mitsubishi Hitachi Power Systems, Ltd. Steam turbine
US10794196B2 (en) * 2013-11-21 2020-10-06 Mitsubishi Hitachi Power Systems, Ltd. Steam turbine
US11203941B2 (en) * 2013-11-21 2021-12-21 Mitsubishi Power, Ltd. Steam turbine

Also Published As

Publication number Publication date
SE305220B (de) 1968-10-21
DE1426788A1 (de) 1969-02-20
CH434300A (de) 1967-04-30
FR1426543A (fr) 1966-01-28

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