US3469126A - Liquid-cooled turbo-generator - Google Patents

Liquid-cooled turbo-generator Download PDF

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Publication number
US3469126A
US3469126A US588910A US3469126DA US3469126A US 3469126 A US3469126 A US 3469126A US 588910 A US588910 A US 588910A US 3469126D A US3469126D A US 3469126DA US 3469126 A US3469126 A US 3469126A
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rotor
turbo
cylinder
generator
stator
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Expired - Lifetime
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US588910A
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Eugen Wiedemann
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BBC Brown Boveri AG Germany
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Bbc Brown Boveri & Cie
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K9/00—Arrangements for cooling or ventilating
    • H02K9/19—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
    • H02K9/197—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K9/00—Arrangements for cooling or ventilating

Definitions

  • a turbo-generator includes a hollow cylinder of insulating material interposed between the rotor and stator elements.
  • the insulating cylinder is spaced radially from the surface of the rotor to establish a running space in which the pressure is reduced to reduce the rotor surface friction losses, and the inner surface of the insulating cylinder is lined with a helical pipe extending between the opposite ends of the rotor for circulation of a liquid coolant in order to remove heat from the space resulting from rotor surface friction and eddy current losses.
  • This invention relates to turbo-generator machine construction and more particularly to an improved arrangement for effecting cooling of machines of the type.
  • a certain disadvantage of the above-mentioned design consists in that practically no heat is removed through the air gap between rotor and stator. Consequently the eddy current losses resulting on the rotor surface bring about an undue increase of the temperature within the air gap cylinder. To prevent this, the heat can be removed through cooling pipes installed in the vicinity of the surface of the rotor iron. This, however, is a measure which meets with structural difficulties and is not efficient enough in the case of a very large machine.
  • the principal object of this invention now is to provide an improved turbo-generator structure with directly cooled stator and rotor windings and a rotor space separated from the stator space by an insulation air gap cylinder, where the temperature within the air gap cylinder is maintained at a permissible value in a simple manner.
  • this is achieved in that at the inner side of the air gap cylinder cooling pipes are arranged through which a cooling liquid, in particular water, circulates.
  • FIG. 1 is a view in longitudinal central section through a turbo-generator provided with squarely configured cooling pipes at the inner side of the insulation cylinder provided in the air gap between the liquid cooled rotor and stator elements;
  • FIG. 2 is a fragmentary view in section showing the arrangement of the square cooling pipes in the vicinity of one end of the turbo-generator, the view being drawn to a larger scale for a better showing of the structural details;
  • FIG. 3 is a fragmentary view in section showing a circular configuration for the cooling pipes, also drawn to larger scale for detailing;
  • FIG. 4 is a fragmentary view in section showing an "ice elongated rectangular configuration for the cooling pipes, also drawn to larger scale;
  • FIG. 5 is a fragmentary view in section showing still another configuration for the cooling pipes, this being a modified rectangular cross section, one side of which has a semi-circular configuration.
  • FIGS. 1 and 2 where for the sake of simplicity only the parts required for comprehension of the invention are shown, 1 denotes the liquid cooled stator and 2 the liquid cooled rotor of the turbogenerator. Between the stator 1 and the rotor 2, an insulation air gap cylinder 3 is inserted, which hermetically separates the rotor space from the stator space.
  • cylinder 3 On the inner side of cylinder 3, which can be made of any suitable insulating material, for instance a synthetic resin, cooling pipes are arranged which extend helically along the cylinder surface and can be partially embedded therein. For example, several pipes arranged in parallel can be used to establish a multiple helix.
  • FIG. 1 illustrates a double helix of two pipes 4 and 4.
  • the cooling pipes are made of a metal of low electric conductivity, e.g. non-magnetic steel.
  • cooling pipes are arranged in a multiple helix, these can be manifolded at opposite ends of the in sulating air gap cylinder 3.
  • the feed-in ends of the dual helical pipes 4, 4 are manifolded into an annular, distribution chamber 5 at one end of cylinder 3 and to which an inlet pipe 5' is connected to supply the liquid coolant.
  • the discharge ends of the pipes 4, 4 at the opposite end of the insulation cylinder 3 are manifolded into another annular, collection chamber 6 at that end from which the liquid coolant is removed by a pipe 6'.
  • the liquid coolant which gains heat by flowing through the helical pipe system 4, 4 can be re-cooled after removal and then recycled through the pipes.
  • FIGS. 3, 4 and 5 show other suitable cross-sectional configurations for the piping used in conjunction with the inner wall of the annular insulating air gap cylinder 3.
  • the piping 4a is seen to be of circular cross-section; in FIG. 4, the piping 4b has an elongated rectangular cross-section; and in FIG. 5, the piping 4c has a modified rectangular cross-section, three of the sides of the pipe being straight and the fourth side being a semicircle.
  • Cooling of the stator and rotor elements of the turbogenerator is accomplished by conventional constructions.
  • the stator winding 7 is compoosed of hollow conductors, for example, through which a liquid coolant such as water is circulated, the water being admitted to the conductors through an inlet pipe 8 and removed for re-cooling and re-oirculation by means of an outlet pipe 9.
  • Cooling of the rotor element is likewise effected by circulating a fluid coolant such as water in heat-transfer relation with the rotor conductors, the conductors being tubular for example for passage of the coolant therethrough. The details for the rotor cooling have not been included.
  • cooling water is introduced to one end of tthe tubular rotor windings through a duct arrangement including a central bore in the rotor shaft 10 and is removed at the same shaft end from the other end of the windings by means including an annular channel concentric with the feed-in bore.
  • the rotor space 11 inside the air gap cylinder 3 is connected to a vacuum pump VP, which produces there the required negative pressure or vacuum.
  • the friction losses of the rotor, as well as a part of the eddy current losses resulting on the rotor surface are removed in simple manner through the cooling pipes in the stationary insulation air gap cylinder.
  • the cooling pipes thus arranged not only protect the air gap cylinder, which consists of a synthetic insulation resin, against excessive temperatures but also serve to mechanically reinforce it against the higher external pressure and also assure a better stablity as to form.
  • zero voltage is induced in all pipes, so that at the beginning and end they can be connected metallically to a common water chamber for each.
  • a turbo-generator structure comprising a stator element, a rotor element spaced radially inward from said stator element to establish an annular gap therebetween, a hollow cylinder of insulating material interposed in said annular gap and which extends between the opposite ends of said rotor and stator elements, said hollow cylinder being spaced radially from the surface of said rotor to establish therebetween a running space for said rotor, means establishing a reduced pressure condition in said space to decrease surface friction losses, pipe means applied to the inner surface of said hollow cylinder, and means for circulating a liquid coolant through said pipe means thereby to effect removal of heat from said space resulting from rotor surface friction and eddy current losses.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Motor Or Generator Cooling System (AREA)

Description

Sept. 23, 1969 I E. WIEDMANN 3,469,126
LIQUID COOLED TURBO-GENERATOR Filed oct. 24, 1966 2 Sheets-Sheet 1 INVENTOR.
Eugen WIecLemwnn WEB/V575 United States Patent 3,469,126 LIQUID-COOLED TURBO-GENERATOR Eugen Wiedemann, Baden, Switzerland, assignor to Aktiengesellschaft Brown, Boveri & Cie., Baden, Switzerland, a joint-stock company Filed Oct. 24, 1966, Ser. No. 588,910 Claims priority, application Switzerland, Oct. 29, 1965, 14,991/ 65 Int. Cl. H02k 9/20 US. Cl. 31054 9 Claims ABSTRACT OF THE DISCLOSURE A turbo-generator includes a hollow cylinder of insulating material interposed between the rotor and stator elements. The insulating cylinder is spaced radially from the surface of the rotor to establish a running space in which the pressure is reduced to reduce the rotor surface friction losses, and the inner surface of the insulating cylinder is lined with a helical pipe extending between the opposite ends of the rotor for circulation of a liquid coolant in order to remove heat from the space resulting from rotor surface friction and eddy current losses.
This invention relates to turbo-generator machine construction and more particularly to an improved arrangement for effecting cooling of machines of the type.
It is known practice in turbo-generators to separate the rotor space from the stator space by insertion of an insulation air gap cylinder between the rotor and stator to allow the rotor to run within the air gap cylinder in air or other gas at greatly reduced pressure. In this way the surface friction losses can be reduced and the efficiency of the machine improved.
A certain disadvantage of the above-mentioned design, however, consists in that practically no heat is removed through the air gap between rotor and stator. Consequently the eddy current losses resulting on the rotor surface bring about an undue increase of the temperature within the air gap cylinder. To prevent this, the heat can be removed through cooling pipes installed in the vicinity of the surface of the rotor iron. This, however, is a measure which meets with structural difficulties and is not efficient enough in the case of a very large machine.
The principal object of this invention now is to provide an improved turbo-generator structure with directly cooled stator and rotor windings and a rotor space separated from the stator space by an insulation air gap cylinder, where the temperature within the air gap cylinder is maintained at a permissible value in a simple manner. According to the invention, this is achieved in that at the inner side of the air gap cylinder cooling pipes are arranged through which a cooling liquid, in particular water, circulates.
The invention will be now explained in more detail in relation to the accompanying drawings wherein:
FIG. 1 is a view in longitudinal central section through a turbo-generator provided with squarely configured cooling pipes at the inner side of the insulation cylinder provided in the air gap between the liquid cooled rotor and stator elements;
FIG. 2 is a fragmentary view in section showing the arrangement of the square cooling pipes in the vicinity of one end of the turbo-generator, the view being drawn to a larger scale for a better showing of the structural details;
FIG. 3 is a fragmentary view in section showing a circular configuration for the cooling pipes, also drawn to larger scale for detailing;
FIG. 4 is a fragmentary view in section showing an "ice elongated rectangular configuration for the cooling pipes, also drawn to larger scale; and
FIG. 5 is a fragmentary view in section showing still another configuration for the cooling pipes, this being a modified rectangular cross section, one side of which has a semi-circular configuration.
With reference now to FIGS. 1 and 2, where for the sake of simplicity only the parts required for comprehension of the invention are shown, 1 denotes the liquid cooled stator and 2 the liquid cooled rotor of the turbogenerator. Between the stator 1 and the rotor 2, an insulation air gap cylinder 3 is inserted, which hermetically separates the rotor space from the stator space. On the inner side of cylinder 3, which can be made of any suitable insulating material, for instance a synthetic resin, cooling pipes are arranged which extend helically along the cylinder surface and can be partially embedded therein. For example, several pipes arranged in parallel can be used to establish a multiple helix.
FIG. 1 illustrates a double helix of two pipes 4 and 4. To keep the eddy current losses as low as possible, the cooling pipes are made of a metal of low electric conductivity, e.g. non-magnetic steel.
Where the cooling pipes are arranged in a multiple helix, these can be manifolded at opposite ends of the in sulating air gap cylinder 3. Thus, as illustrated in FIG. 1, the feed-in ends of the dual helical pipes 4, 4 are manifolded into an annular, distribution chamber 5 at one end of cylinder 3 and to which an inlet pipe 5' is connected to supply the liquid coolant. Similarly, the discharge ends of the pipes 4, 4 at the opposite end of the insulation cylinder 3 are manifolded into another annular, collection chamber 6 at that end from which the liquid coolant is removed by a pipe 6'. If desired, the liquid coolant which gains heat by flowing through the helical pipe system 4, 4 can be re-cooled after removal and then recycled through the pipes.
FIGS. 3, 4 and 5 show other suitable cross-sectional configurations for the piping used in conjunction with the inner wall of the annular insulating air gap cylinder 3. Thus, in FIG. 3, the piping 4a is seen to be of circular cross-section; in FIG. 4, the piping 4b has an elongated rectangular cross-section; and in FIG. 5, the piping 4c has a modified rectangular cross-section, three of the sides of the pipe being straight and the fourth side being a semicircle.
Cooling of the stator and rotor elements of the turbogenerator is accomplished by conventional constructions. The stator winding 7 is compoosed of hollow conductors, for example, through which a liquid coolant such as water is circulated, the water being admitted to the conductors through an inlet pipe 8 and removed for re-cooling and re-oirculation by means of an outlet pipe 9. Cooling of the rotor element is likewise effected by circulating a fluid coolant such as water in heat-transfer relation with the rotor conductors, the conductors being tubular for example for passage of the coolant therethrough. The details for the rotor cooling have not been included. However the cooling water is introduced to one end of tthe tubular rotor windings through a duct arrangement including a central bore in the rotor shaft 10 and is removed at the same shaft end from the other end of the windings by means including an annular channel concentric with the feed-in bore. Further details of one suitable arrangement for cooling the rotor conductors are disclosed in my copending application Ser. No. 539,058, filed Mar. 31, 1966.
The rotor space 11 inside the air gap cylinder 3 is connected to a vacuum pump VP, which produces there the required negative pressure or vacuum.
With the described arrangement, the friction losses of the rotor, as well as a part of the eddy current losses resulting on the rotor surface are removed in simple manner through the cooling pipes in the stationary insulation air gap cylinder. At the same time there result the additional advantages that the cooling pipes thus arranged not only protect the air gap cylinder, which consists of a synthetic insulation resin, against excessive temperatures but also serve to mechanically reinforce it against the higher external pressure and also assure a better stablity as to form. Furthermore, by using a helical arrangement of the cooling pipes with a coil of 360 or a multiple thereof zero voltage is induced in all pipes, so that at the beginning and end they can be connected metallically to a common water chamber for each.
I claim:
1. In a turbo-generator structure the combination comprising a stator element, a rotor element spaced radially inward from said stator element to establish an annular gap therebetween, a hollow cylinder of insulating material interposed in said annular gap and which extends between the opposite ends of said rotor and stator elements, said hollow cylinder being spaced radially from the surface of said rotor to establish therebetween a running space for said rotor, means establishing a reduced pressure condition in said space to decrease surface friction losses, pipe means applied to the inner surface of said hollow cylinder, and means for circulating a liquid coolant through said pipe means thereby to effect removal of heat from said space resulting from rotor surface friction and eddy current losses.
2. A turbo-generator structure as defined in claim 1 wherein said pipe means applied to the inner surface of said hollow cylinder extend from one end of said cylinder to the other in the form of a helix.
3. A turbo-generator structure as defined in claim 2 wherein said pipe means are arranged as multiple helices.
4. A turbo-generator structure as defined in claim 1 wherein said pipe means consist of non-magnetic metal having a low electrical conductivity.
5. A turbo-generator structure as defined in claim 1 wherein said pipe means is partially embedded in the inner surface portion of said hollow cylinder.
6. A turbo-generator structure as defined in claim 1 wherein said hollow cylinder is made from a synthetic resin and said pipe means is partially embedded in the inner surface portion thereof.
7. A turbo-generator structure as defined in claim 1 wherein said pipe means is constituted as a helix extending between opposite ends of said hollow cylinder and is made from a non-magnetc metal having a 10w electrical conductivity, said hollow cylinder being made from a synthetic resin and said helical pipe means being partially embedded in the inner surface thereof.
8. A turbo-generator structure as defined in claim 7 and wherein in-flow and out-flow manifolds are provided at the opposite ends of said hollow cylinder and connected to the corresponding ends of said helical pipe means.
9. A turbo-generator structure as defined in claim 1 wherein said helical cooling pipe is arranged with a coil of 360 or a multiple thereof.
References Cited UNITED STATES PATENTS 1,382,878 6/1921 Alexanderson 310-54 1,494,715 5/1924 Schroeder "310-54 2,929,943 3/1960 Richardson 31o 54 3,249,775 5/1966 Baylac 310-54 FOREIGN PATENTS 1,068,803 11/1959 Germany.
ORIS L. RADER, Primary Examiner A. G. COLLINS, Assistant Examiner
US588910A 1965-10-29 1966-10-24 Liquid-cooled turbo-generator Expired - Lifetime US3469126A (en)

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CH1499165A CH428919A (en) 1965-10-29 1965-10-29 Turbo generator with directly cooled windings

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963950A (en) * 1973-10-17 1976-06-15 Hitachi, Ltd. Stator of rotary electric machine
US5144177A (en) * 1988-10-12 1992-09-01 Ksb Aktiengesellschaft Canned motor pump with heat exchanger in rotor chamber
EP1205020A4 (en) * 1999-08-16 2003-08-27 American Superconductor Corp Water cooled stator winding of an electric motor
US20040130223A1 (en) * 2001-01-25 2004-07-08 Detlef Nimz Cooling of stator by corrugated hose in an electric machine
US20070176509A1 (en) * 2006-01-30 2007-08-02 Kalsi Swarn S Stator coil assembly
US20070200440A1 (en) * 1999-08-16 2007-08-30 American Superconductor Corporation Thermally-conductive stator support structure
CN104852523A (en) * 2015-06-03 2015-08-19 博深工具股份有限公司 Series machine water-cooling structure
CN106100206A (en) * 2016-08-28 2016-11-09 福建亚南电机有限公司 A kind of high-power density permanent magnetic synchronizes water-cooled outer rotor medium frequency electric generating machine

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU629601A1 (en) * 1976-11-30 1978-10-25 Специальное Конструкторское Бюро "Энергохиммаш" Electric machine with cryogenic cooling
US5808386A (en) * 1997-02-03 1998-09-15 Willyoung; David M. Low stress liquid cooled generator armature winding
RU2231195C1 (en) * 2002-10-09 2004-06-20 Научно-производственное объединение "ЭЛСИБ" Открытое акционерное общество Cooling system of electric machine
EP2073348A1 (en) 2007-12-20 2009-06-24 SycoTec GmbH & Co. KG Electromotor with connected interior cooling

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1382878A (en) * 1918-11-26 1921-06-28 Gen Electric Cooling dynamo-electric machines
US1494715A (en) * 1921-03-11 1924-05-20 Schroeder Giulio Cooling of electrical apparatus
DE1068803B (en) * 1958-01-28 1959-11-12
US2929943A (en) * 1956-01-11 1960-03-22 Parsons C A & Co Ltd Dynamo-electric machine cooling structure
US3249775A (en) * 1961-11-30 1966-05-03 Baylac Marcel Liquid-circulation cooling device for the rotors of high-power turbo-alternators rotating at high speed

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1382878A (en) * 1918-11-26 1921-06-28 Gen Electric Cooling dynamo-electric machines
US1494715A (en) * 1921-03-11 1924-05-20 Schroeder Giulio Cooling of electrical apparatus
US2929943A (en) * 1956-01-11 1960-03-22 Parsons C A & Co Ltd Dynamo-electric machine cooling structure
DE1068803B (en) * 1958-01-28 1959-11-12
US3249775A (en) * 1961-11-30 1966-05-03 Baylac Marcel Liquid-circulation cooling device for the rotors of high-power turbo-alternators rotating at high speed

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963950A (en) * 1973-10-17 1976-06-15 Hitachi, Ltd. Stator of rotary electric machine
US5144177A (en) * 1988-10-12 1992-09-01 Ksb Aktiengesellschaft Canned motor pump with heat exchanger in rotor chamber
US7589441B2 (en) 1999-08-16 2009-09-15 American Superconductor Corporation Circumferentially wound cooling tube structure for cooling a stator
US20070200440A1 (en) * 1999-08-16 2007-08-30 American Superconductor Corporation Thermally-conductive stator support structure
US20080143200A1 (en) * 1999-08-16 2008-06-19 American Superconductor Corporation Thermally-conductive stator support structure
US7423356B2 (en) 1999-08-16 2008-09-09 American Superconductor Corporation Thermally-conductive stator support structure
EP1205020A4 (en) * 1999-08-16 2003-08-27 American Superconductor Corp Water cooled stator winding of an electric motor
US20040130223A1 (en) * 2001-01-25 2004-07-08 Detlef Nimz Cooling of stator by corrugated hose in an electric machine
US6822352B2 (en) * 2001-01-25 2004-11-23 Baumüller Nürnberg GmbH Cooling of stator by corrugated hose in an electric machine
US20070176509A1 (en) * 2006-01-30 2007-08-02 Kalsi Swarn S Stator coil assembly
US7619345B2 (en) 2006-01-30 2009-11-17 American Superconductor Corporation Stator coil assembly
CN104852523A (en) * 2015-06-03 2015-08-19 博深工具股份有限公司 Series machine water-cooling structure
CN104852523B (en) * 2015-06-03 2017-04-19 博深工具股份有限公司 Series machine cooling structure
CN106100206A (en) * 2016-08-28 2016-11-09 福建亚南电机有限公司 A kind of high-power density permanent magnetic synchronizes water-cooled outer rotor medium frequency electric generating machine

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DE1488433C3 (en) 1973-10-18
CH428919A (en) 1967-01-31
DE1488433B2 (en) 1971-01-07
DE1488433A1 (en) 1969-04-24
GB1093862A (en) 1967-12-06

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