Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B33/00—Features common to bolt and nut
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
  • F16B35/04—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws with specially-shaped head or shaft in order to fix the bolt on or in an object
  • F16B35/041—Specially-shaped shafts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/0275—Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores

Definitions

• the invention relates to a screw having a lower and an upper end for connecting a first component to a second component, wherein the screw comprises a cavity ent ⁇ long their longitudinal direction. Furthermore, the invention relates to a screw having a lower and an upper end for connecting a first component and a second component, wherein the screw comprises a bore.
• Screw connections are used in many areas of mechanical engineering. Especially in the construction of turbomachinery screw play a particularly important role, since the pressures and forces are high, at comparatively high temperatures ⁇ .
• turbomachinery Hydraulic turbines, steam and gas turbines, wind turbines, centrifugal pumps and centrifugal compressors as well as propellers are summarized under the collective term turbomachinery. All these machines have in common that they serve the purpose of extracting energy from a fluid in order to drive another machine or, conversely, to supply energy to a fluid in order to increase its pressure.
• the steam valves used in steam turbine construction are often designed with screw connections, which are also exposed to high thermal loads.
• screws for screw which are made of ferritic screw materials. Because the material properties As the strength of ferritic materials change with increasing temperature, these materials are only used up to an upper limit temperature.
• expansion sleeves are generally required due to the unfavorable thermal expansion behavior.
• the design of the expansion sleeves requires the exact knowledge of the local temperature conditions of the screw. It is an object of the invention to provide a screw that can be used at high thermal loads.
• the object is achieved by a screw having a lower and an upper end for connecting a first component to a second component, wherein the screw comprises a cavity ent ⁇ long their longitudinal direction.
• the cavity may have at the lower end a bottom for forming a cup-like cavity, wherein the cavity for filling with a medium is formed.
• Can be the cavity may also be continuous, so that a registered with a medium-filled, special pipe ⁇ inserted.
• the invention exploits the effect of the heat pipe principle.
• the heat pipe principle is thermodynamically based on the evaporation of a medium at the hot end and the condensation of the medium at a cold end within an elongated ⁇ formed cavity. Even at low temperature differences between the ends of the self-contained cavity relatively large amounts of heat are conducted.
• the principle of the heat pipe is the following: At the warmer end of the pipe, the liquid vaporizes and absorbs heat of vaporization. On cool ⁇ ren end it condenses and gives off the heat of vaporization.
• the principle is also applicable to horizontal arrangement. In this case, the wall should be formed with capillaries. Due to the capillary action of the inner wall, the condensate flows back to the warmer end of the pipe. Due to the high enthalpy of enthalpy of heat, heat pipes allow heat transfer on the order of magnitude better than, for example, steel.
• a screw in a thermally stressed environment usually has a temperature gradient.
• the lower end may be colder than the upper end.
• the heat of the warmer unte ⁇ Ren end is passed to the cooler upper end and rank ⁇ leads there.
• This heat transfer from the lower to the upper end cools the screw as a whole.
• the screw can therefore be used at higher temperatures, since the heat transferred to the screw at the lower end can be dissipated quickly at the upper end.
• the cavity is designed as a bore.
• the principle of the heat pipe is valid in cavities which are not formed as a pipe, ie with a circular cross section. If the cross section of the heat pipe assumes triangular, quadrangular or a similar geo ⁇ metric shape, these heat pipes thus formed have the same physical effect as heat pipes with a circular cross section.
• a bore is comparatively easy to carry out with respect to a triangular, quadrangular or similar cross-section. Thereby one obtains the advantage that the screw can be carried out with a tion as Boh ⁇ cavity executed inexpensively.
• the screws used in the prior art already have a defined bore when used as expansion screws.
• a part of the wall of the cavity protrudes beyond the upper end.
• the effect is achieved that the heat absorbed by the lower hot ⁇ end end can be passed into a particularly easy ⁇ ble range of the heat pipe.
• This cooling need not be active, the cooling can be done solely by the geometric distance to the hot components due to the difference in temperature to the environment. If, so to speak, a part of the wall of the cavity protrudes beyond the upper end, then this part undergoes a different, clotting ⁇ gere temperature than the rest of the heat pipe, whereby a better cooling effect can be achieved.
• the wall which projects beyond the upper end at least as long as the part located in the screw of the wall. It has been found that this geometric configuration, in which the protruding from the screw part is at least as long as the part located in the screw, a particularly effective cooling effect.
• the object is also achieved by a screw having a lower and an upper end for connecting a first component to a second component, wherein the screw comprises a Boh ⁇ tion, wherein in the bore a heat pipe is arranged, wherein the heat pipe for filling with a Medium is formed.
• OF INVENTION ⁇ dung is presented according to a screw, wherein the heat Rohr can be disposed in a bore of the screw.
• the cooling effect is based on the same physical principle as described above.
• the trained with a heat pipe in the bore screw is relatively easier to manufacture. This reduces costs.
• the screw comprises in this embodiment at least two Be ⁇ constituent parts. On the one hand this would be a ver with a bore ⁇ provided screw and a heat pipe inserted into the bore ⁇ leads is.
• the heat pipe can in this case made of the same material as the screw are made, but it is also different surface materials for the heat pipe and the screw is ⁇ be set.
• liquid sodium or liquid potassium is used as the medium.
• Liquid sodium or potassium liquid is therefore a geeig ⁇ neter candidate for this temperature range.
• FIG. 1 is a perspective view of a steam valve for a steam turbine
• Figure 2 is a plan view of the steam valve of Figure 1
• Figure 3 is a sectional view of a screw
• Figure 4 is a sectional view of a screw in an alternative embodiment
• Figure 5 is a sectional view of a screw in an alternative embodiment.
• a steam valve 1 is shown in a perspective view.
• Essential features of the steam valve 1 is the inflow region 3, where steam flows in at very high temperatures. This vapor is passed through channels not shown in FIG. 1 to the outflow region 2.
• the steam valve 1 is designed substantially cylindrical and comprises a first component 4 and a second component 5.
• the second component 5 is designed as a lid.
• the first component 4 is cylindrical.
• the first component 4 is connected by means of screws 6 with the second component 5. Since, in steam turbine construction in particular, the steam valves 1 are subjected to water vapor having very high pressures, a plurality of screws 6 are provided for connecting the first component to the second component 5 in order to withstand the high forces.
• the invention is not limited to the connection of a first component 4 and a second component 5 of a steam valve.
• the first component 4 or the second component 5 could also be the upper part and the lower part of an inner casing of a steam turbine.
• the first component 4 and the second component 5 could also be designed as outer casings of a steam turbine.
• FIG. 2 shows a plan view of the steam valve according to FIG.
• the lid 5 as an embodiment of the second component is circular and comprises several Holes into which the screws 6 are inserted.
• threads are arranged which are formed in alignment with the holes.
• the screw 6 connects the first building ⁇ part 4 with the second component 5.
• the screw 6 is provided in its longitudinal direction 7 with a cavity 8.
• the screw 6 has an upper end 9 and a lower end 10.
• the cavity 8 has at the lower end 10 a bottom 11 for forming a cup-like cavity 8.
• the cup-like hollow ⁇ space 8 is formed for filling with a medium 12th
• a part of the wall 13 of the cavity 8 projects beyond the upper end.
• the wall 13 may be formed as a sleeve which is designed so that the space above the upper end 9 of the screw is executed closed.
• the cavity 8 may be designed as a bore. Other embodiments such. B. a triangular or a quadrangular cross section are possible.
• the wall 13 of the cavity 8 may be equipped with capillaries 26 along the length, with the result that thedeme ⁇ dium is also promoted in non-vertical position to the floor. 11
• the wall 13, which projects beyond the upper end 9, may be as long as the screw 6 located in the part of the wall 14, but also longer or shorter.
• the cavity 8 is executed closed.
• the screw 6 may be formed as a threaded rod 16 and with a located at the upper end 9 nut 17.
• the second component 5 comprises a bore 18.
• a further bore 19 is arranged with a thread in alignment with the bore 18 in the second component.
• the medium 12 located in the cavity 8 may be, for example, liquid sodium or liquid potassium.
• the lower part 10 of the screw heats up, which causes the medium 12 to become so hot that it vaporizes and re-precipitates and condenses on the wall 13 at the top. This heat is dissipated, which is led away from the environment or another external cooling medium.
• An insulation 15 for thermal insulation of the component can additionally be arranged around the screw 6.
• the tube must be at least so long that the wall 13 is located with the end of the tube to be cooled outside the insulation.
• materials from lower grade classes of materials can be used for the screw.
• high-chromium steels at ⁇ place of nickel-based alloys eg X19CrMoNbVNll-l instead Nimonic.
• X19CrMoNbVNll-l instead Nimonic.
• less expensive and more readily available 1% chromium steels can be used instead of high chrome steels (eg 21CrMoV5-7 instead of X19CrMoNbVNll-l).
• the length of the screw has 150 to 800 mm and has a thread according to DIN between M56 and M180.
• FIG. 4 shows an alternative embodiment of the screw 6.
• the difference between the screw 6 shown in FIG. 4 and the screw 6 shown in FIG. 3 is that the bottom 11 at the lower end 10 of the screw is formed by a cup-shaped sleeve 22.
• the cavity 8 is characterized as a continuous bore from the upper end 9 bis executed to the lower end 10 of the screw 6.
• the sleeve 22 with the cup-like bottom 11 is welded, riveted or soldered at the lower end 10 of the screw. ⁇ training opportunities other Verbin are conceivable.
• the operation and the remaining components of the screw are identical to those in Figure 3. Therefore, reference is made to the explanation of Figure 3 at this point.
• FIG. 5 shows a further alternative embodiment of the screw 6.
• the screw 6 is formed such ⁇ that a closed heat pipe 23 in a bore 24 which has a slightly larger diameter than the diameter of the heat pipe 23, is arranged.
• the heat pipe 23 is longer than the threaded rod 16 and protrudes beyond the upper end 9 and the lower end 10.
• the heat pipe 23 does not necessarily have to protrude at the lower end 10.
• the heat pipe can be flush with the threaded rod 16 at the lower end 10.
• the hole does not have to be continuous, but can go to the lower end 10. Otherwise, the operation of the screw 6 is almost identical to the operation of the screw 6 as in Figures 3 and 4 be ⁇ written . Therefore, reference is made to the explanations to the figures 3 and 4 at this point.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Connection Of Plates (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Closures For Containers (AREA)
• Lubricants (AREA)
• Materials For Medical Uses (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

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Families Citing this family (8)

Citations (2)

Family Cites Families (14)

• 2006
  • 2006-02-02 EP EP06002174A patent/EP1816357A1/de not_active Withdrawn
• 2007
  • 2007-01-15 US US12/223,489 patent/US20090035092A1/en not_active Abandoned
  • 2007-01-15 CN CNA2007800040628A patent/CN101379306A/zh active Pending
  • 2007-01-15 WO PCT/EP2007/050349 patent/WO2007088098A1/de not_active Ceased
  • 2007-01-15 PL PL07703865T patent/PL1979632T3/pl unknown
  • 2007-01-15 AT AT07703865T patent/ATE528520T1/de active
  • 2007-01-15 JP JP2008552766A patent/JP5154449B2/ja not_active Expired - Fee Related
  • 2007-01-15 EP EP07703865A patent/EP1979632B1/de not_active Not-in-force

Patent Citations (2)

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