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
  • F01D25/08—Cooling; Heating; Heat-insulation
  • F01D25/14—Casings modified therefor
  • F01D25/145—Thermally insulated casings
• • 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
  • F01D25/24—Casings; Casing parts, e.g. diaphragms, casing fastenings
  • F01D25/26—Double casings; Measures against temperature strain in casings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/20—Heat transfer, e.g. cooling
  • F05D2260/231—Preventing heat transfer

Definitions

• the invention relates to a device for heat insulation between housing parts of a steam turbine, in particular between an inner housing and an outer housing of a steam turbine with a spiral inflow.
• An inflow casing of a steam turbine with a spiral inflow is e.g. known from DE 36 17 537 AI.
• German supplement 1055549 specifies an insert which is arranged in the region of a dividing flange of an outer turbine housing between the outer turbine housing and a claw of the inner turbine housing resting on the outer turbine housing.
• the insert is a pressure plate that has holes through which the supporting cross-sections are limited.
• the determination of the pressure plate is based explicitly on the fact that when there is a bridging of a clearance in the cold state between the claw of the inner housing and the flange of the outer housing, as a result of strong thermal expansions, no inadmissible stresses occur in the flange of the outer housing. This is achieved through the bores, which ensure a plastic deformation of the pressure plate and thus a reduction in the stress input into the flange of the outer housing.
• Swiss patents 665450 and 666 937 a steam turbine with a spiral inflow is specified.
• components that are not specified in more detail are arranged between the outer housing and an inner housing.
• the invention is based on the object of specifying a particularly suitable device for heat insulation between housing parts of a steam turbine, in particular for the inflow housing of a steam turbine with a spiral inflow.
• the insert element is used to transmit power between the housing parts of the steam turbine, at least in the event that steam is applied to the steam turbine. It is also possible that the insert element additionally or alternatively consists of a material which has a higher strength than the respective material of the housing parts at a temperature which is higher than the room temperature. This is particularly important in the case of steam turbines which are exposed to high pressures and temperatures above 500 °, in particular above 550 to 650 ° C.
• the invention is based on the consideration that within a shim element also used to align housing parts to one another, material reduction up to the value of the permissible compressive stress or surface tension is possible, since the permissible compressive stress within the shim element is several times higher than that permissible surface pressure from the insert element to the housing part.
• the insert element prevents an inadmissibly high heat transfer from the inner casing to the outer casing.
• the temperature differences between the inner housing and the outer housing can be around 200 to 300 K.
• the insert element preferably has cross-sectional openings and / or cavities.
• Such cross-section-reducing openings can be made subsequently in the insert element, for example by drilling, milling, laser beam treatment and other suitable methods.
• the insert element can be made in one piece or in several pieces.
• the openings or cavities mentioned can pass through Depressions, slots, troughs or the like can be formed in parts of the insert element which are to be connected to one another.
• each part preferably has depressions, in particular grooves, which form channels which are separate from one another when the parts are joined together by webs. Steam or a similar cooling medium for cooling the insert element can flow through such channels.
• the expediently cuboidal insert element has a number of through holes arranged next to one another.
• the through bores advantageously run parallel to the opposite contact surfaces of the insert element and preferably transversely to its longitudinal direction.
• the through holes can thus be flowed through to cool the insert element, for. B. by means of an additional cooling medium or solely by convection. This is also ensured if the through holes run in the longitudinal direction of the insert element. This is e.g. then appropriate if due to the
• The, in particular drilled, insert element is particularly suitable for use in a spiral housing with two torque supports arranged opposite one another, which are expediently formed from mutually opposing supporting claws of an outer housing and an inner housing.
• the claws are molded on the inside of the outer housing or on the outside of the inner housing.
• the insert element can advantageously also be used as a feather key or an insert to align the housing parts with one another.
• FIG. 1 shows in cross section an inflow housing of a steam turbine in a spiral construction with two torque supports provided with shim elements
• FIG. 2 shows a detail II from FIG. 1 on an enlarged scale with an insert element arranged between two claws
• FIG. 3 shows a drilled insert element in perspective view
• the inflow housing 1 according to FIG. 1 of a steam turbine 2 with a spiral inflow has two flow channels 3a and 3b, each encompassing around a half of a turbine blade arrangement, each of which has an inlet 4 and 5, respectively.
• the inflow housing 1 is constructed from an inner housing 6 forming the flow channels 3a, 3b and an outer housing 7 concentrically surrounding it.
• the inner housing 6 and the outer housing 7 are each composed of an upper housing part 6a, 7a and a lower housing part 6b, 7b, which are screwed together along the same parting line 8 by means of flange connections 9 and 10, respectively.
• the inner housing 6 is supported in relation to the outer housing 7 by means of two torque supports 12 which lie opposite one another transversely to the joint 8 and are provided with insert elements 11.
• FIG. 2 shows such a torque arm 12 with support claws 13 and 14 integrally molded onto the inner housing 6 on the outside and with support claws 13 and 14 formed on the inside of the outer housing 7.
• 14 form a support for the inner housing 6 with respect to the fixedly fixed outer housing 7, so that a torque acting on the inner housing 6 during operation of the steam turbine 2 is introduced via the outer housing 7 into a turbine fixation (not shown).
• a support area 15 is provided between the support claws 13 and 14, which are at a distance from one another, in which the insert element 11 shown in FIG. 3 is arranged.
• the insert element 11 is a cuboid body made of preferably heat-resistant steel, e.g. made of high-alloy chrome-molybdenum-vanadium of the alloy X22CrMoV121.
• a steam turbine 2 designed for a steam temperature of 560 to 580 ° C. and a steam pressure of 180 bar (fresh steam state) with a total electrical output of 350 MW
• Length L of the insert body 11 about 240 mm.
• the width B is approximately 50 mm and the height H is approximately 100 mm.
• the insert element 11 has two opposing support surfaces 16, 17 which, when used in the support region 15, bear against the corresponding support surfaces of the claws 13 and 14, respectively.
• the insert element 11 further has two opposite end faces 18, 19, of which the end face 18 is visible in FIG. 2.
• the insert element 11 also has opposite longitudinal surfaces, of which only the upper longitudinal surface 20 is visible in FIG. 3.
• the insert element 1 has six through bores 21 as bore openings which, in the exemplary embodiment, run parallel to the bearing surfaces 16, 17 and transversely to the longitudinal direction, that is to say passing through the throughflow surfaces 20.
• the through bores 21 By arranging the through bores 21 in this way, a flow running along the flow line 23 can be established in the intermediate space 22 between the inner housing 6 and the outer housing 7 (FIG. 2).
• the through holes gen 21 also run parallel to the longitudinal surface 20 and thereby penetrate the end faces 18,19.
• the web width d1 between adjacent through bores 21 is approximately 10 mm, while the web width d2 in the edge region is in each case approximately 5 mm.
• the dimensions L, W, H for an insert element 11 made of chrome-molybdenum-vanadium with the alloy X22CrMoV121 are dimensioned for a permissible surface pressure of 65 N / mm 2 .
• a compressive stress of 300 to 400 N / mm 2 is then permissible within the material body, ie within the insert element 11.
• the number of through bores 21 and their bore diameter d3 and the web widths dl, d2 are therefore dimensioned such that the remaining cross section in the intermediate webs 24 between the through bores 21 and in the two edge webs 25 is used up to the permissible compressive stress.
• the insert element 11 also serves to align the inner housing 6 with the outer housing 7, in particular to compensate for a play occurring as a result of manufacturing tolerances in the support area 15 between the two claws 13 and 14.
• an insert element 11 composed of two sub-elements 31 and 32 is shown in a perspective view.
• the insert element 11 corresponds after the assembly of the two sub-elements 31 and 32 in terms of its construction to the insert element 11 already described in FIG. 3.
• the sub-elements 31 and 32 each have groove-shaped depressions with a semicircular cross section, so that when the partial elements 31 and 32 are assembled, channels with a circular cross section and a diameter D3 are formed analogously to the through holes 21.
• each partial element 31 and 32 it is also possible, additionally or alternatively, to introduce hemispherical or similar depressions into each partial element 31 and 32, through which cavities, for example in the form of spheres, are formed when the partial elements 31 and 32 are assembled.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Engine Equipment That Uses Special Cycles (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7828022

Family Applications (1)

Country Status (9)

Families Citing this family (10)

Family Cites Families (19)

• 1998
  • 1998-04-21 CN CNB988043319A patent/CN1268834C/zh not_active Expired - Fee Related
  • 1998-04-21 EP EP98931958A patent/EP0979347B1/fr not_active Expired - Lifetime
  • 1998-04-21 WO PCT/DE1998/001104 patent/WO1998049427A1/fr not_active Ceased
  • 1998-04-21 AT AT98931958T patent/ATE219817T1/de not_active IP Right Cessation
  • 1998-04-21 DE DE59804590T patent/DE59804590D1/de not_active Expired - Lifetime
  • 1998-04-21 KR KR19997009939A patent/KR20010012125A/ko not_active Withdrawn
  • 1998-04-21 JP JP54648498A patent/JP4046774B2/ja not_active Expired - Fee Related
  • 1998-04-21 PL PL98336486A patent/PL336486A1/xx unknown
• 1999
  • 1999-10-28 US US09/428,579 patent/US6171053B1/en not_active Expired - Lifetime

Non-Patent Citations (1)

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