Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/58—Cooling; Heating; Diminishing heat transfer
  • F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
  • F04D29/584—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps cooling or heating the machine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/10—Centrifugal pumps for compressing or evacuating
  • F04D17/12—Multi-stage pumps
  • F04D17/122—Multi-stage pumps the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors
  • F04D17/125—Multi-stage pumps the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors the casing being vertically split
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/002—Details, component parts, or accessories especially adapted for elastic fluid pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/08—Sealings
  • F04D29/10—Shaft sealings
  • F04D29/12—Shaft sealings using sealing-rings
  • F04D29/122—Shaft sealings using sealing-rings especially adapted for elastic fluid pumps
  • F04D29/124—Shaft sealings using sealing-rings especially adapted for elastic fluid pumps with special means for adducting cooling or sealing fluid
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/58—Cooling; Heating; Diminishing heat transfer
  • F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
  • F04D29/5853—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps heat insulation or conduction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/60—Mounting; Assembling; Disassembling
  • F04D29/62—Mounting; Assembling; Disassembling of radial or helico-centrifugal pumps
  • F04D29/624—Mounting; Assembling; Disassembling of radial or helico-centrifugal pumps especially adapted for elastic fluid pumps
• • 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
  • F05D2210/00—Working fluids
  • F05D2210/10—Kind or type
  • F05D2210/12—Kind or type gaseous, i.e. compressible
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S415/00—Rotary kinetic fluid motors or pumps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S417/00—Pumps

Definitions

• Exemplary embodiments relate generally to compressors and, more specifically, to the provision of thermal barriers for ensuring the smooth operation of a compressor over a wide temperature range.
• a compressor is a machine which increases the pressure of a compressible fluid, e.g., a gas, through the use of mechanical energy.
• Compressors are used in a number of different applications and in a large number of industrial processes, including power generation, natural gas liquification and other processes.
• compressors used in such processes and process plants are the so-called centrifugal compressors, in which the mechanical energy operates on gas input to the compressor by way of centrifugal acceleration, for example, by rotating a centrifugal impeller.
• Centrifugal compressors can be fitted with a single impeller, i.e., a single stage configuration, or with a plurality of impellers in series, in which case they are frequently referred to as multistage compressors.
• Each of the stages of a centrifugal compressor typically includes an inlet conduit for gas to be compressed, an impeller which is capable of providing kinetic energy to the input gas and a diffuser which converts the kinetic energy of the gas leaving the impeller into pressure energy.
• a multistage compressor 100 is illustrated in Figure 1.
• the 100 includes a shaft 120 and a plurality of impellers 130.
• the shaft 120 and impellers 130 are included in a rotor assembly that is supported through bearings 190 and 190' and sealed to the outside through sealings 180 and 180'.
• the multistage centrifugal compressor operates to take an input process gas from an inlet duct 160, to increase the process gas pressure through operation of the rotor assembly, and to subsequently expel the process gas through an outlet duct 170 at an output pressure which is higher than its input pressure.
• the process gas may, for example, be any one of carbon dioxide, hydrogen sulfide, butane, methane, ethane, propane, liquefied natural gas, or a combination thereof.
• the sealings 180 and 180' are provided to prevent the process gas from flowing through to the bearings.
• Each of the impellers 130 increases the pressure of the process gas.
• Each of the impellers 130 may be considered to be one stage of the multistage compressor 100. Additional stages, therefore, result in an increase in the ratio of output pressure to input pressure.
• Compressors in oil and gas industries and power plants are operated with different gas temperatures.
• the temperature varies from cryogenic to very high temperature.
• the internal surfaces in boiled off gas application (BOG) compressors are subjected to cryogenic temperature while the outer surfaces of the compressor are exposed to atmospheric temperature. Due to the cryogenic temperature, thermal contraction occurs in the components. The contraction is not uniform due to variation in temperature on different parts. The non-uniform contraction reduces clearance and/or creates interference between the adjacent components and affects performance of the compressors.
• BOG boiled off gas application
• the differential thermal contraction between the sealings 180 and 180' in general, mechanical seals or dry gas seal type or DGS
• the end head 140 and 140' which could also include heated seal carrier
• the bearings 190 and 190' and the shaft 120 creates interference between them and affects normal operation of the compressor.
• dry gas seals 180 and 180' are encapsulated in heated seal carriers 140 and 140' that also act as thermal shields.
• Systems and methods according to these exemplary embodiments provide radial and axial thermal barriers to minimize thermal tension and stress on a mechanical seal and an end head by introducing a thermal barrier around the mechanical seal to ensure smooth operation of the BOG compressor.
• a compressor end head for providing a thermal barrier near a mechanical seal includes an inner end head and an outer end head.
• the outer end head includes an opening in the center for enclosing the inner end head, an outlet and grooves along side surfaces radially adjacent the opening.
• the inner head has an opening in the center, an inlet, grooves in the opening for enclosing an end portion of a compressor shaft and a flow path along an outer surface.
• a compressor end head for providing a thermal barrier near a mechanical seal includes an inner end head and an outer end head.
• the inner head includes an opening in the center, an inlet, grooves in the opening for enclosing an end portion of a compressor shaft.
• the outer end head includes an opening in a center for enclosing the inner end head, an outlet, grooves along side surfaces radially adjacent the opening, an inlet chamber connected to the inlet, an outlet chamber connected to the outlet and axial channels connecting the inlet chamber and the outlet chamber.
• a compressor includes a shaft, a plurality of impellers, a plurality of seals, an inner end head and an outer end head adjacent the seals.
• the outer end head includes an opening in the center for enclosing the inner end head, an outlet and grooves along side surfaces radially adjacent the opening.
• the inner head has an opening in the center, an inlet, grooves in the opening for enclosing an end portion of a compressor shaft and a flow path along an outer surface.
• FIG. 1 illustrates a multistage compressor
• FIG. 2 illustrates a dry gas seal end head according to exemplary embodiments
• FIGS. 3 and 4 illustrate a cut view of a dry gas seal end head according to exemplary embodiments
• FIGS. 5 and 6 illustrate inner and outer sides of an outer end head according to exemplary embodiments
• FIG. 7 illustrates a cut view of an outer end head according to exemplary embodiments
• FIGS. 8 and 9 illustrate internal and external cut views of an inner end head according to exemplary embodiments
• FIG. 10 illustrates an oil flow path in an inner end head according to exemplary embodiments
• FIG. 11 illustrates an oil flow path in an end head according to exemplary embodiments
• FIGS. 12 and 13 illustrate a cut view of a dry gas seal end head according to exemplary embodiments
• FIG. 14 illustrates a cut view of an outer end head according to exemplary embodiments.
• FIGS. 15 and 16 illustrate a cut view of an inner end head according to exemplary embodiments. DETAILED DESCRIPTION
• interference between a mechanical seal and an end head is prevented by providing axial thermal barriers around the mechanical seal to ensure smooth operation of a BOG compressor.
• the mechanical seal (such as sealings 180 and
• 180' of FIG. 1 may include a dry gas seal encapsulated in a heated seal carrier as is known.
• the dry gas seal closes the compressor to seal the compressor from the outside.
• end head 200 may includes an inner end head 210 and an outer end head 220. Each or both of the end heads 210 and 220 may be circular or may be some other shape but are illustrated as being circular in exemplary embodiments. End head 200 may be formed by, for example, welding the inner end head and outer end heads 210 and 220 in some embodiments.
• Outer end head 220 may include a circular opening 221 in the center within which inner end head 210 may be is circumferentially enclosed or fitted (as illustrated in FIG. 2).
• outer end head 220 includes a hot oil outlet 224 on an inner side surface 222.
• Outer end head 220 also includes a circular groove 225 surrounding the circular opening 221 where the inner end head 210 may be welded with the outer end head 220 to form the circumferential enclosure.
• Inner end head 210 may include grooves 225 along both side surfaces (i.e. inner side surface and outer side surfaces).
• Inner end head 210 includes a hot oil inlet 213.
• Cut section views of the outer and inner surfaces of inner end head 210 are illustrated in FIGS. 8 and 9.
• Inner end head 210 includes a circular opening 21 1 in the center.
• inner end head 210 includes a plurality of grooves 212 within the opening for facilitating the placement and sealing of the end portion of a compressor shaft.
• the diameter of inner end head 210 may be approximately equal to the diameter of circular opening 221 of outer end head 220 in order to facilitate the enclosure of inner end head 210 within outer end head 220.
• inner end head 210 may also includes an oil flow path 214 along an outer surface.
• Flow path 214 may be a helical flow path.
• Flow path 214 along the outer surface may be formed between the grooves 212 which are on the inner surface of inner end head. That is, the helical path 214 on the outer surface may correspond to the raised portion of the inner surface of the inner end head between the grooves 212 (path 214 may be positioned on the outer surface corresponding to the raised portions between grooves 212 on the inner surface of the inner end head 210).
• flow path 214 may correspond to the grooves 212.
• End head 200 of FIGS. 3 and 4 illustrates a helical flow path 214 and hot oil or gas outlet 224.
• hot oil or gas entering inlet 213 of inner end head 210 flows through helical flow path 214 to outlet 224 of outer end head 220.
• the outer surface of inner end head 210 may includes the helical flow path 214 as described above and illustrated in FIG. 10.
• the flow path may be similar to a spiral path providing an axial thermal barrier as illustrated in FIG. 1 1.
• the flow path as described herein provides a thermal barrier between the end head and DGS.
• an additional thermal barrier may also be provided.
• a hot oil/gas chamber 223 proximate the outer side surface of outer end head 220 reduces the thermal differential further.
• oil in helical flow path 214 flows into chamber 223 and to outlet 224.
• a light interference fit may be made between the inner end head 210 and the outer end head 220 in some embodiments.
• the inner and outer end heads can also be bolted to the compressor housing in some embodiments.
• the helical flow path may be substituted with straight holes in the outer end head to provide heating to the inner end head so that inner end head and the dry gas seal can be maintained at required temperature to avoid interference between the dry gas seal and end head when the compressor handles or processes gas at cryogenic temperatures.
• an end head 300 includes inner end head
• Inner end head 310 includes a hot oil inlet 313.
• Outer end head 320 includes hot oil outlet 324 and groove 325 for facilitating welding of inner end head 310 to outer end head 320.
• Outer end head also includes an inlet gas or oil chamber 326 and an outlet gas or oil chamber 327.
• Chamber 326 is provided near the inner head hot oil inlet 313 for receiving the oil from inlet 313.
• a plurality of passages 328 in the outer end head 320 (illustrated in FIG. 14) facilitates oil flow from inlet chamber 326 to outlet chamber 327.
• Outlet chamber 327 is connected to oil outlet 324.
• Chambers 326 and 327 may be connected with each other via straight holes 328 in outer end head 320 in order to facilitate uniform hot oil flow along the axis of the inner end head 310.
• Inner end head 310 may be in the form as illustrated in FIGS. 15 and
• Inner end head 310 may also facilitate oil flow along its outer surface 315 from inlet 313 to outlet 324 of outer end head 320. Inner end head 310 may provide a labyrinth seal.
• inner side surface of an outer end head (or the inner end head) as used herein may refer to the side of the end head that is facing an impeller (i.e. between an impeller and end of the shaft).
• outer side surface as used herein may refer to the side of the end head that is on a side not facing an impeller (i.e. side of the end head that faces toward the outside of the casing).
• the outer surface of the outer end head is adjacent the mechanical seal.
• the mechanical seal may be a dry gas seal (DGS).
• DVS dry gas seal
• the inlet, the outlet, the chamber (of FIG. 7) and the flow path may be for hot oil or gas.
• the inlet chamber 326 and the outlet chamber 327 provide a radial thermal barrier.
• Channels or passages 328 may be axial channels and provide an axial thermal barrier.
• a heating system provides a radial and axial thermal barrier.
• the thermal barrier reduces heat transfer between inlet and the zone surrounding the DGS leading to a smooth operation of the BOG compressor.
• the optimized flow path provides gradual change in temperature in radial and axial directions around the DGS and also reduces internal thermal stress.
• the heating system according to exemplary embodiments prevents interference between DGS and the end head.
• the system is simple and compact. The system also prevents interference and provides smooth operation of the BOG compressor at cryogenic temperatures.
• Exemplary embodiments as described provide an axial thermal barrier or an axial and a radial thermal barrier for handling temperature gradients in boiled off gas applications.
• the end head may be bolted to the compressor.
• the inner and outer heads may also be interference fitted to form the end head.

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• 2009
  • 2009-12-07 IT ITCO2009A000061A patent/IT1396519B1/it active
• 2010
  • 2010-12-03 BR BR112012013798A patent/BR112012013798A2/pt not_active IP Right Cessation
  • 2010-12-03 US US13/514,388 patent/US9631637B2/en active Active
  • 2010-12-03 AU AU2010330096A patent/AU2010330096B2/en not_active Ceased
  • 2010-12-03 IN IN5004DEN2012 patent/IN2012DN05004A/en unknown
  • 2010-12-03 WO PCT/EP2010/068845 patent/WO2011069909A1/en active Application Filing
  • 2010-12-03 MX MX2012006569A patent/MX2012006569A/es active IP Right Grant
  • 2010-12-03 KR KR1020127017490A patent/KR20120120191A/ko not_active Application Discontinuation
  • 2010-12-03 JP JP2012542469A patent/JP5903384B2/ja active Active
  • 2010-12-03 CA CA2783667A patent/CA2783667A1/en not_active Abandoned
  • 2010-12-03 RU RU2012124946/06A patent/RU2552658C2/ru active
  • 2010-12-03 CN CN201080063295.7A patent/CN102741555B/zh active Active
  • 2010-12-03 EP EP10788063.5A patent/EP2510241B1/en active Active

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