US2707243A - Inner-cooled generators with singledirection ventilation - Google Patents

Inner-cooled generators with singledirection ventilation Download PDF

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Publication number
US2707243A
US2707243A US394602A US39460253A US2707243A US 2707243 A US2707243 A US 2707243A US 394602 A US394602 A US 394602A US 39460253 A US39460253 A US 39460253A US 2707243 A US2707243 A US 2707243A
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stator
gas
winding
cooling
core
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US394602A
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Rene A Baudry
Paul R Heller
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CBS Corp
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Westinghouse Electric Corp
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Priority to BE532988D priority Critical patent/BE532988A/xx
Priority claimed from US389349A external-priority patent/US2707242A/en
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Priority to JP681557A priority patent/JPS326815B1/ja
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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
    • H02K9/14—Arrangements for cooling or ventilating wherein gaseous cooling medium circulates between the machine casing and a surrounding mantle
    • H02K9/18—Arrangements for cooling or ventilating wherein gaseous cooling medium circulates between the machine casing and a surrounding mantle wherein the external part of the closed circuit comprises a heat exchanger structurally associated with the machine casing

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  • Our invention relates to inner-cooled hydrogen-cooled turbine-generators, or other dynamoelectric machines, in which the heat generated in the stator and rotor windings is directly withdrawn from the Winding conductors, through inner-cooling ducts which are disposed in good thermal relation to the winding-conductors.
  • stator-core cooling which has been used for several decades in turbine generators, that is, since long before the introduction of inner-cool mg.
  • the conventional method of cooling the statorcores of machines having such large length-to-diameter ratios as are prevalent in turbine-generators has been to provide the stator-core with a large number of radial ventilating-spaces, which are disposed between small bunches of stator-core laminations, and these radial ventilating-spaces have been surrounded with a plurality of peripheral annular ventilating-zones, which have been alternately intake-zones and outlet-zones.
  • the cooling-gas which was at first air, but which has been hydrogen since along about 1930, was introduced into the radial ventilating-passages in a zigzag path, which forced the gas first radially inwardly, to the air gap, then radially outwardly in the next group of core-passages to the adjacent outlet-zone surrounding the statorcore, then to the next adjacent inlet-zone surrounding the stator-core, and radially inwardly through those statorcore passages to the air gap, and so on.
  • This used the air gap, so far as the stator-core ventilation was con cerned, only as a means for transferring the coolant from one group of radial inlet-passages to the next adjacent group of radial outlet-passages of the stator-core.
  • the arrangement also commingled the hot gas, which was discharged from the rotor-member into the air gap, with the stator-core cooling-gas, thus considerably increasing the hottest-point temperature of the stator core.
  • stator-core cooling-method is not at all desirable in these machines.
  • the inner-cooling ducts of the stator and rotor windings successfully dissipate all of the copper losses or conductor-heat, into the coolant which flows through these inner-cooling ducts. Consequently, the heat which is to be removed from the stator and rotor cores is only the relatively small amount of heat which is produced by hysteresis and eddy currents within these structures.
  • the rotor-core heat is adequately withdrawn by the coolant which inner-cools the rotor-windings. This leaves, therefore, only the statorcore heat-losses, due to hysteresis and eddy currents, which can be withdrawn by relatively small quantities of coolant.
  • the air gap of our inner-cooled generator sufficiently large to serve as a hot-gas collecting-chamber and as an axial duct for a substantial portion of the ventilating-gas of the machine.
  • all of the gas which is used for cooling the stator-core passes radially inwardly through the radial core-ventilating passages, and discharges, as hot gas, into the air gap; and substantially all of the rotor-cooling gas, for cooling both the innercooled rotor-windings and the rotor-core, also discharges into the air gap, which thus acts as a hot-gas collecting chamber.
  • the gas is then drawn from one end of the air gap by a special multistage axial blower, and is thence blown through the coolers; and from the coolers, the cooled gas is led into the inner-cooling ducts of the stator and rotor windings, and into the core-cooling passages of the stator core.
  • This arrangement results in the simplest and most efficient utilization of the machine-space, it provides a more efficient blower-system which is capable of producing higher compression-ratios and of supplying lowertemperature gas to the windings, and it permits a frameconstruction which is more suited to operation with the higher gas-pressures which are now preferred in innercooled turbine-generators.
  • Figure l is a side-elevational view, the top half being in longitudinal section, showing a hydrogen-cooled turbine-generator embodying our invention in a form in which we use only a single pair of vertical coolers, disposed at only one end of the machine, and suitable for all except perhaps the very highest ratings of future machines which are larger than any machines thus far sold;
  • Figs. 2, 3, 4 and 5 are successive transverse sections on the section-planes indicated, in Fig. l, by the lines lI-ll, Ill-Ill, IV-IV and VV, respectively;
  • Fig. 6 is a partial horizontal sectional view, on the section-plane indicated at VIVI in Fig. 1;
  • Figs. 7 and 8 are respectively vertical and horizontal longitudinal sections of an alternative machine-design in which the vertical coolers must be used at both ends of the machine, in order to meet the required ratings;
  • Figs. 9 and 10 are respectively vertical and horizontal longitudinal sections of a generator using a series-blower system, as distinguished from the parallel-blower system which is shown in Figs. 7 and 8;
  • Figs. 12 and 14 are respectively vertical and horizontal longitudinal sectional views of a machine in which the stator-core is cooled by axially disposed cooling-openings, instead of radially disposed cooling-passages, and in which a dilferent disposition or arrangement of the coolers is provided;
  • Figs. 11 and 13 are transverse sectional views on the sections-planes indicated at XI-XI, XIII-XIII in Figs. 12 and 14.
  • Fig. 1 shows a turbine generator, which is illustrative of a dynamoelectric machine having a stator member 15 and a rotor member 16, separated by an air gap 17.
  • the stator member 15 includes a substantially gas-tight machine-enclosing housing, which comprises an outer cylindrical frame-shell or core-surrounding housing-portion 18, and two brackets 19 and 20, enclosing the respective ends of the outer frame-shell.
  • the housing is filled with a gaseous filling, which is preferably hydrogen, at a gaspressure which is adapted, at times, to be at least as high as 30 pounds per square inch, gauge, which may be regarded as a minimum pressure, as somewhat higher gaspressures are contemplated. While hydrogen is preferred, it is possible to use other gases having a molecular weight lower than nitrogen, the low molecular weight being desirable in order to keep down the windage-losses resulting from the rotation of the motor member 16 within the gas.
  • the stator member 15 also comprises a cylindrical stator-core 21, having a plurality of winding-receiving stator-slots 22.
  • the stator member also comprises an inner-cooled stator winding 23 having coil-sides lying within the winding-receiving slots 22, and coil-ends lying beyond the respective ends of the stator-core 21.
  • This stator winding 23 is an inner-cooled winding, having cooling-ducts 24 which are in good thermal relation to the stator-conductors, for substantially directly cooling said stator-conductors.
  • the stator-winding cooling-ducts 24 have inlet-openings 2411 at one end of the winding, and outlet openings 24b at the other end.
  • a recirculating stator-winding cooling-system is necessarily provided, for recirculating a stator-winding coolingfluid in said inner-cooling stator-winding ducts 24, said recirculating cooling-system including a means for cooling the stator-winding cooling-fluid.
  • stator-inlets 24a are open to an endspace 24' within the machine, at one end of the machine, while the duct'outlets 24b are open to another end-space 34" within the machine at the other end of the machine, thus cooling the stator winding 23 with the gas which is enclosed within the machine-housing, said gas being cooled by the subsequently described coolers.
  • the stator winding 23 is usualy a polyphase winding, and in the large machine-sizes to which our present invention is particularly applicable, the stator Winding 23 is provided with ground insulation 25 which is good for 10,000 volts, or higher.
  • the stator-core 21 is also provided with a plurality of core-ventilating stator-ducts, which may be either radially disposed ducts or spaces 26, as shown in Figs. 1 to 10, or axially disposed ducts or holes as shown in Figs. 11 to 14.
  • the rotor member 16 has a cylindrical rotor core 28, which has a plurality of axially extending winding-receiving slots 29, and an inner-cooled rotor winding having cooling-ducts 31 in good thermal relation to the rotor-conductors for substantially directly cooling said rotor-conductors.
  • the rotorwinding cooling-ducts 31 have inlet-openings or means, 32, at the respective ends of the rotor winding, and outletopenings 33 at a plurality of intermediate discharge-points within the winding-receiving rotor-slots, these dischargepoints being commonly grouped together near the center of the rotor-core, and being connected to the air gap 17 by a plurality of radially extending rotor ducts or holes 34 which discharge the rotor-cooling gas to the rotorperiphery.
  • the rotor windings 30 are insulated for a voltage which is considerably lower than the stator windings 23, so as to require a much thinner rotorinsulation, which is too thin to be shown on the scale to which our drawings are drawn.
  • the rotor core 28 is carried by a rotor shaft 35, which is supported by a pair of bearing housings 36 near the respective frame-brackets 19 and 20. Associated with the bearing-housings 36, are suitable gland-seal members 37 for maintaining gas-tight joints around the respective shaft-ends.
  • One end of the shaft is connected to a coupling 38, whereby the machine may be connected to a turbine or other prime mover; while the other end of the shaft carries two slip rings 39 for exciting the rotor winding 30, which serves as the field-winding for the machine.
  • the air gap 17 has a single gap-length of the order of from three and one half to five inches, more or less, so that the air gap is sufiiciently large to act as a hot-gas collecting-chamber and as an axial duct for a substantial portion of the ventilating-gas of the machine, as will be evident from the subsequent explanations.
  • this gas-moving means comprises a single evacuating blower 41, carried by the rotor member at one end of the rotor core, and directed so as to evacuate hot gas from that end of the air gap 17, and also from the stator endspace 24" in which the stator-winding duct-outlets 24b discharge.
  • the blower 41 includes a supporting-means of such nature that it provides one or more axially extending under-blower passages 42, extending axially underneath the blower 41.
  • the blower 41 is preferably a multistage blower, which is capable of developing a considerable blower-pressure for rapidly moving the hot gases in an axial direction.
  • the heatexchanging means comprises a pair of vertical coolers 44 and 45.
  • coolers are located axially between the stator-winding duct-outlets 24b and the housing-bracket 20 at that end of the machine, as shown in Fig. 1.
  • the blower 41 is disposed underneath, or within the axial confines of, the stator-winding end-turns which have the duct-outlets 24b, so that the blower 41 discharges the hot gas axially toward the portion of the housing which is occupied by the pair of coolers 44 and 45.
  • the two vertical coolers 44 and 45 are located radially between the bearing housing 36 and the outer frame-shell 18, as shown in Fig.
  • Each of the coolers 44 and 45 comprises a plurality of substantially straight, vertical, liquid-cooled, finned pipes, each end of each cooler terminating in a cooler-head 47.
  • the outer frame-shell 18 is provided with cooler-accommodating perforations 48, having pressure-resistant reinforcing means 51, which are secured to the frame-shell around each perforation 48.
  • the top and bottom coolerheads 47 of each cooler 44 and 45 are hermetically but removably secured to their own reinforcing-means 51, so that each cooler can be lifted vertically out of the machine, after disconnecting its two cooler-heads 47.
  • the water-connections, for circulating water or other coolant through the cooler-pipes, are preferably provided at the lower cooler-head 47, as shown in Figs. 2 and 3.
  • the endwinding space 24" into which the stator-winding duct-outlets 24b discharge is confined by an outer cylindrical or arcuate partition 53, a fiat transverse plate or disc 54 which extends vertically between the two coolers 44 and 45 on the sides thereof closest to the stator end-windings, and the shroud 55 of the blower 41.
  • the transverse plate or disc 54 is provided with a central hole 54a which is more or less hermetically joined to the outer periphery of the blowershroud 55.
  • This curved transverse plate or disc 57 has a central hole 57a which is substantially hermetically sealed to the large end of the funnel-like member 56, so as to provide a separation between the hot gas which is flowing to the right and left between the two vertical coolers 44 and 45, and cold gas which flows radially inwardly in the flat end-space 57b between the curved plate 57 and the bracket 20, and then axially inwardly through the funnel-like member 56, into the under-blower passages 42, to ventilate that end of the rotor-windings, as will be subsequently described.
  • the cold gas which is delivered from the coolers 44 and 45, is used for the inner-cooling of the rotor winding 30, the inner-cooling of the stator winding 23, and the cooling of the stator-core 21.
  • these functions are accomplished by a structure in which some of the cold gas is led into both ends of the rotor winding 30, some to the inlets 24a of the stator winding 23, and some to the outer peripheries of the radial cooling-ducts 26 of the stator core.
  • An essential feature of this construction is the provision of an axially extending, peripherally disposed, through duct-means, such as a duct 58 (Fig. 1), to provide an axial communication from one end of the machine to the other.
  • the through-duct 58 is illustrated as being in the space between the outer periphery of the stator core and the outer frame-shell 18.
  • the stator member is provided, as is well known, with a plurality of axially spaced frame-rings 61 to 64, extending inwardly from the outer cylindrical frame-shell 18 in the axial length which is occupied by the stator core 21.
  • the frame-ring 61 is secured to one end of the cylindrical or arcuate partition 53, which surrounds the hot-gas discharge-end space 24" of the stator-winding ventilation.
  • the space 53a outside of this cylindrical or arcuate partition 53 is filled with cooled gas which is delivered by the two coolers 44 and 45.
  • the cool-gas space 53a which is outside of the cylindrical or arcuate partition 53 is also in communication with the radial space 57b between the curved transverse plate 57 and the housing-bracket 20; and hence some of the cooled gas is supplied to the rotor-winding inlet-openings 32 at this end of the machine.
  • the cold-gas end-space 24 is nearly altogether, or substantially, closed off from the end of the air gap 17, at that end of the machine, by means of a stationary cylindrical bafile-member 69 (Fig. 1), which has a small clearance with that end of the rotor member 16, so as to limit, or substantially stop, the escape of cool gas directly from the end-space 24' into that end of the air gap 17, as described in our Patent No. 2,626,365, granted January 20, 1953.
  • the through-duct 58 is provided with lateral openings 70 for discharging the cooled gas into the annular spaces 70 between the successive frame-rings 61 to 64, these annular spaces 70 being disposed between the outer periphery of the stator-core 21 and the outer cylindrical frame-shell 18. Since the radial stator-core coolingspaces 26 are in communication with these annular framering spaces 70, the cooled gas is thus led radially inwardly, through all of these radial cooling-spaces or ducts 26 of the stator core, thereby cooling the stator core, and discharging the heated core-cooling gas into the air gap 17.
  • a suitable resistance to the flow of this core-cooling gas is provided by a proper restriction of the size of the openings 70 in the through-duct 58, so as to properly control the division of the gas-flow, so that each part receives the quantity of gas which is required to cool the same.
  • the cool-gas space 53a which is outside of the cylindrical or arcuate partition 53 may contain a fifth framering 71, which is provided with a plurality of openings 72 therethrough, as shown in Fig. 4, so that the entire space outside of this cylindrical or arcuate partition 53 is in effect a single space 53a, all portions of which are in communication with each other.
  • the blower 41 exhausts the hot gases from the air gap 17, and from the stator-winding outlet-end 24" in the space inside of the cylindrical or arcuate partition 53.
  • the blower delivers this hot gas, in two streams, so that it spreads to the right and to the left and flows laterally through the two vertical coolers 44 and 45, respectively.
  • the gas which is discharged from the coolers 44 and 45 is cold or cooled gas, which appears in the space 53a outside of the cylindrical or arcuate partition 53. A part of this gas flows into the side edges of the flat end-space 57b between the curved transverse plate or disc 57 and the housing-bracket 20, and it flows radially inwardly through this space. As shown in the vertical sectional view, Fig. 1, this gas then flows axially through the funnel-like duct or partition 56, so that it passes through the under-blower passages 42 and enters the rotor-winding inlet-openings 32 at that end of the machine.
  • the portion of the cool gas which flows all the way through the through-duct 58 is discharged into the coolair end-space 24', where most of it divides between the stator-winding duct-inlets 24a and the rotor-winding inletopenings 32 at that end of the machine.
  • a very small portion of the cool gas in this end-space 24' is admitted to that end of the air gap 17, by means of the baffle 69. In some machines, however, this baffie 69 may block substantially all gas-flow into that end of the air gap.
  • the inner-cooling gas for the stator-windings 23 in Fig. 1, enters the inlets 24a from the end-space 24', and it passes all the way through the stator-winding coolingducts 24 from that end of the machine to the other end of the machine, where it is discharged, as hot gas, through the outlets 24b, into the space 24" inside of the cylindrical or arcuate partition 53, where it merges with the hot gas which is being delivered from the air gap 17. This merged hot gas is then picked up by the blower 41, and the recirculating process is continued.
  • a small portion of this rotor-winding cooling-gas may be bypassed directly into the air gap 17, immediately after having cooled the end-winding portions of the rotor winding 30, as shown by the small openings 73 in Fig. l.
  • the major portion of the rotorwinding cooling-gas flows axially through the rotor-winding inner-cooling ducts 31, from both ends, towards the center of the rotor core 28, at which point the heated gas is discharged to the air gap 17 through the dischargeopenings 33 of the inner-cooling ducts 31 and through the radial rotor-ducts 34.
  • our invention uses a large air gap 17, to receive the bulk of the coolant from the stator-core cooling-vents 24 and from the rotor-winding discharge-ducts 34, discharging this hot gas axially to a high-pressure, multistage axial blower 41 which is located at one end of the rotor member.
  • the high-pressure gas is then blown through suitable coolers, and the cooled high-pressure gas is then distributed to the various inlet-openings for cooling the inner-cooled rotor-windings 30, the inner-cooled statorwindings 23, and the stator-core 21.
  • This arrangement greatly simplifies the amount of battling which is necessary to properly conduct and distribute the coolant.
  • our evacuating high-pressure blower avoids the introduction of even the small temperature-rise which is produced by the compression of the hydrogen in the blower, because this compressed hydrogen is passed first through the cooler of coolers, before being passed on into the ventilating passages of the machine.
  • Figs. 7 and 8 show a form of embodiment of the invention, in a parallel-blower system which is useful where coolers must be used at both ends of the machine, either in order to meet the required ratings, either because of cooler-limitations or ventilation-characteristics, or in order to make two ditferent blower-pressures available, one for the inner-cooled windings 23 and 30, and the other for the stator core 21, as described and claimed in a copending application of Kilgore, Baudry and Heller, Serial No. 394,622, filed November 27, 1953.
  • the pair of vertical coolers 44 which are located at the machine-end which is bounded by the bracket 21), is duplicated by another pair of vertical coolers 74 at the machine-end which is bounded by the bracket 19.
  • This second pair of coolers, 74 may be of the same description as the first pair, 44, except that the second coolers may sometimes be somewhat smaller.
  • the second pair of coolers, 74 use the same kind of bathing or partition-members as the first pair of coolers, 44, as shown at 54', 55, 56 and 57', these parts corresponding to the correspondingly numbered unprimed parts at the other end of the machine.
  • FIGs. 7 and 8 the air-gap baffie 69 of Figs. 1 to 6 is omitted, and is replaced by a second exhaust-blower 76, which is disposed to exhaust some of the hot gases out of that end of the air gap 17.
  • This second blower 76 develops a much lower blower-pressure than the firstdescribed multistage blower 41.
  • this second blower 76 is shown as a single-stage blower. Otherwise, the second blower 76 is of the same description as the first blower 41, and
  • the rotor-member In order to segregate the suction-side of the second blower 76 from the high-pressure cool-gas end-space 24 which services the inner-cooled windings 23 and 30, the rotor-member is provided with a cylindrical baffle 77 which is secured to the periphery of the stator core 21 at that end of the machine, and which extends close to the blower-shroud 55 which surrounds the blower 76.
  • the cool-gas discharge-sides of the second pair of vertical coolers, 74 are partitioned off from the high-pressure cool-gas end-space 24 by transversely disposed vertical barrier-plates 78.
  • barrier-plates 78 As a consequence of the addition of these barrier-plates 78 as shown in Fig. 8, it is necessary to provide a communication-means between the highpressure coolgas end-space 24' and the under-blower passages 42 at that end of the machine, by a means which is shown in the vertical sectional view, Fig.
  • this means including a plurality of ducts 79 between the plates 54 and 57', so that some of the high-pressure cooled gas is diverted or discharged from the end-space 24' which services the stator-winding duct-inlets 24a, and this highpressure cooled gas is delivered through the ducts 79 to the flat end-space 57b between the curved transverse plate or disc 57' and the housing-bracket 19, being thence delivered to the large end of the funnel-like member 56, and thence delivered to the under-blower passages 42 under the blower 76, to service that end of the innercooled rotor-windings 30.
  • the stator-frame has six frame-rings 81 to 86, instead of the four frame-rings 61 to 64 of Figs. 1 to 6. These six frame-rings 81 to 86 are axially spaced from each other, within the axial length which is occupied by the stator core 21, the frame-rings 81 and 86 being more or less hermetically sealed with respect to the respective ends of the stator core. As in Figs. 1 to 6, these six framerings 81 to 86 are traversed by a through-duct 88, as shown in Fig. 7. This through-duct 88 carries the highpressure cool gas, from the space 53a outside of the cylindrical or arcuate partition 53, to the end-space 24 which surrounds the stator-winding duct-inlets 24a.
  • the through-duct 88 of Fig. 7 is imperforate along its sidewalls, so that it does not deliver any gas to the annular spaces 70" between successive frame-rings 81 to 86.
  • These annular spaces 70" between successive framerings 81 to 86, as shown in Fig. 8, are in communication with each other, through openings 82 to 85' in the intermediate frame-rings 82 to 85, and the whole group of these annular spaces 70 is placed in communication with the output-sides of the low-pressure coolers 74, by means of ducts 89 (Fig. 8), extending from the barrierpiates 78 to the frame-ring 86.
  • the hot gas from the discharge-end space 24" of the stator windings 23, and from the same end of the air gap 17, is compressed to a high blower-pressure by the multistage exhaust-blower 41, and is delivered through the pair of coolers 44 to the high-pressure cool-gas space 53a which is outside of the cylindrical or arcuate partition 53 at that end of the machine.
  • This high-pressure cool-gas space 53a is in communication with the rotor-winding inlet-openings 32 at that end of the machine, through the inwardly curved portion of the transverse plate or disc 57, as shown in Figs. 7 and 8; this air passing radially inwardly between this curved plate 57 and the housing-bracket 20, to the funnel-like member 56.
  • the high-pressure cool-gas end-space 53a which is fed by the discharge-sides of the coolers 44, is plaeed in communication with the high-pressure cool-gas end-space 24' at the other end of the machine, as shown by the throughduct 88 in Fig. 7.
  • This high-pressure cool-gas endspace 24' encloses the stator-winding duct-inlets 24a, so as to feed gas into these inlets. It is also in communication with the rotor-winding inlet-openings 32 at that end of the machine, through the ducts 79 and the flat endspace 57b between the curved plate 57' and the housingbracket 19. It will be noted that this high-pressure cool gas, for inner-cooling both the stator and rotor windings 23 and 30, is kept separate from the cool gas which ventilates the stator-core 21.
  • the stator-core ventilation in Figs. 7 and 8, is obtained from the single-stage exhaust-blower 76, which draws the necessary quantity of hot gas out of that end of the air gap 17, and compresses it to a much lower blower-pressure than is obtained in the multistage blower 41.
  • This compressed hot gas from the single-stage blower 76 is delivered through the second pair of vertical coolers, 74, and the discharge-sides of these coolers are placed in communication, by the ducts 89 in Fig.
  • annular spaces 70" between the successive frame-rings 81 to 86 these annular spaces 70" being in communication with the outer peripheries of all of the radial stator-core ventilating-spaces 2.6, which dis charge their hot gases into the air gap, after cooling the stator core 21.
  • the necessary low pressuredifferential which is needed to provide the relatively small amount of stator-core cooling, which is necessary, is obtained from a low-pressure blower 76, thus avoiding the expense of first compressing that quantity of gas to the same high pressure-differential which is needed for the inner-cooling of the windings, and then throttling it down to the pressure-differential which is needed by the stator-core cooling-spaces 26.
  • a series-blower system such as is shown in Figs. 9 and 10, is suitable for those turbine-generators in which a gas-d1scharge from only one end of the air gap is practicable, and where the savings in the blower-power requirements will justify the slight additional complication wltilrch is required by using two blowers in series with each ot er.
  • FIGs. 9 and 10 we show two blowers 91 and 91', one at each end of the rotor-core. Both of the blowers 91 and 91', in Figs. 9 and 10, are shown as single-stage blowers, because, as will subsequently appear, the two blowers are connected in series with each other, for producing the pressure-differential which is needed for the inner-cooling of the stator and rotor windings 23 and 30, whereas the stator-core cooling is obtained from the pressure-differential which is created by the blower 91 alone, as will subsequently appear.
  • the blower 91 is an exhaust-blower, for evacuating gas out of that end of the air gap and also from the chamber 24" which receives the gas from the stator-winding ductoutlets 24b, as was the case with the multistage blower 41 in Figs. 1 to 8.
  • This blower 91 is provided with the previously described under-blower passages 42, and it delivers its hot gas to a single pair of vertical coolers 44 and 45, with the same bathe or partition-arrangement which has already been described for the end of the machine which is bounded by the frame-bracket in Figs. 1 to 8
  • the frame-ring perforations 92', 93 and 94 also put the first cool-gas zone 53a into communication with the annular frame-ring spaces 70 which are in communication with the outer peripheral ends of all of the radial ventilating-spaces 26 of the stator-core 21.
  • the second blower 91 blows the gas axially inwardly toward the stator and rotor cores 21 and 28.
  • This blower 91 receives gas, on its intake side, through a passageway 98 which is in communication with the outer cool-gas zone 96 which surrounds the cylindrical or arcuate partition 97.
  • the blower 91 adds its blower-pressure to that of the first mentioned blower 91, thus creating a combined pressure-differential which blows the cooling gas into a high-pressure inner cool-gas zone 99, which is in communication with the stator-winding duct-inlets 24a and with the rotorwinding inlet-openings 32 at that end of the machine.
  • the air gap 17, at this end of the machine, that is, adjacent to the inner cool-gas zone 99, is blocked, or nearly blocked, by a suitable annular or cylindrical baffle 100, such as is described and claimed in our Patent No. 2,626,365.
  • the cylindrical or arcuate partition 97 which constitutes the outer boundary of the high-pressure cool-gas zone 99, is provided with an out let-opening 101, which is connected, through a throughduct 102, to the curved transverse plate or disc 57, thus transmitting the high-pressure cooling-gas to the flat endspace 57b between this plate or disc 57 and the framebracket 20, at the same end of the machine at which the coolers 44 and 45 are located, thus delivering the gas, through the funnel-like member 56 and the under-blower passages 42, to the rotor-winding inlet-openings 32 at that end of the machine.
  • the through-duct 102 is illustrated in Fig.
  • the first blower 91 receives all of the hot gas, and delivers it through the two vertical coolers 44 and 45 to the first cool-gas zone 53a at a pressure which is suitable for forcing the necessary amount of cooling-gas through the radial ventilating-ducts 26 of the stator core 21, these stator-ducts discharging their heated gases into the air gap 17.
  • the statorwinding ducts 24 discharge their heated gas into the hotgas zone 24" which is in communication with the inlet side of the first blower 41.
  • the heated rotor-winding cooling-gas is discharged through the discharge-openings 10 34 of the rotor-core, into the air gap 17, from which it is drawn to the intake side of the blower 41.
  • the machine of Figs. ll to 14 has an inner cylindrical frame-shell 103, which is disposed inside of the outer cylindrical frame-shell 18, in spaced relation thereto.
  • the outlet end of the blower 41 discharges into a passageway 104 which terminates in the inner cylindrical frame-shell 103 at a place which is close to, but spaced from, the end-bracket 20 of the housing.
  • the hot gas which is discharged through the openings 105, spreads out longitudinally through the entire lengths of the spaces 106 and 106, which are bounded radially by the inner and outer frame-shells 103 and 18, and which are bounded laterally by the two top coolers 107 (for the space 106), and by the two bottom coolers 107 (for the space 106), respectively.
  • the hot gases leave the hot-gas spaces 106 and 106' at the top and bottom of the machine, respectively, and pass eircumferentially through the adjacent coolers 107, leaving these coolers as cold or cooled gas, which is collected in cool-gas spaces 118 and 118, which are located on the same horizontal level as the rotor member 16 of the machine, being bounded radially by the inner and outer shells 103 and 118, and being bounded circumferentially by the right-hand pair of coolers 196 (for the space 113) and by the left-hand pair of coolers (not shown, for the space 118').
  • the cool gas in the spaces 118 and 118' spreads out axially throughout the entire length of the machine, with in these spaces, through openings 118 in the seven frame-rings 111 to 117, these openings 113 being placed just over and under the horizontal axis, as shown in Figs. 11 and 13. From the cool-gas spaces 118 and 118, the pressurized cool gas is distributed radially inwardly, at several points along the lengths of these spaces, as will be subsequently described.
  • stator-core ventilating-system which is shown in Figs. 12 and 14.
  • the stator core 21 is ventilated by means of a plurality of axially or longitudinally extending core-ventilating holes or passages 120, which extend all the way through the length of the stator core 21 from one end to the other end thereof.
  • the cooling gas may flow uninterruptedly all the way through the entire axial length of each of these axial core-passages 120; but if the machine is very long, it may be desirable, as shown in Figs.
  • radial ventilating spaces 121 and 122 which are provided at spaced intermediate points in the stator core 21.
  • These radial vent-spaces are closed at their inner, or air-gap, ends, as shown at 123; and they are open at their outer peripheries, the radial space 121 eing in communication with a peripheral annular space 121', which is just underneath the space between the two frame-rings 113 and 114, while the radial core-ventilating space 122 is in communication with a peripheral annular space 122 which is just underneath the space between the two frame-rings 115 and 116. The purposes of these spaces will soon be apparent.
  • the inner frame'shell 103 is provided with certain openings which are disposed on about the same horizontal level as the rotor member 16.
  • the inner frame-shell 103 is provided with an opening or openings 124, which discharge some of the cool gas radially inwardly mto the flat end-space 124' close to the bracket 20, said gas thence flowing axially inwardly through the underblower passages 42 to the rotor-winding inlet-openings 32 at that end of the machine.
  • the inner frame-shell 103 is provided with one or more openings 125 (Fig.
  • the inner frame-shell 103 is provided with three other openings 127, 123 and 129, at about the same horizontal level as the rotor member 16, as shown in Fig. 14.
  • the opening 127, in the inner shell 103 communicates with the previously described peripheral annular space 121, which feeds cool gas radially inwardly into the radial ventilating space 121 of the stator core, and from this point the cool gas flows, in two opposite directions, into the two adjacent portions of the axial core-passages 120.
  • the opening 128, in the inner shell 103 is in communication with the other previously described peripheral annular space 122, but it is shut off from communication with the annular space between the two framerings 115 and 116, by means of a short radially disposed duct 128', which extends from the opening 128 into communication with a closed end of an axially disposed duct 130, which extends through the frame-rings 115, 114, 113 and 112, terminating before it reaches the frame-ring 111.
  • This terminal end of the axial duct 130 is also closed, and is in communication with a short radial duct 129, which is in communication with the opening 129 in the inner frame-shell 103, this opening 129 discharging into the hot-gas space 24" which is in communication with the intake side of the blower 41.
  • the cool gas in the coolgas spaces 118 and 118 is discharged in three ,different paths, at the horizontally disposed openings 124, 125 and 127.
  • the opening 124 delivers cool gas to the left-hand end of the rotor-windings 30.
  • the opening 127 delivers cool gas to the intermediate point 121 in the length of the axially extending stator-core ventilatingopenings 120.
  • the opening 125 delivers cool gas to the cool-gas end-space 126 at the right-hand end of the machine, and from this space, three streams of cool gas are delivered, respectively, to the stator-winding duct-inlets 24a, the rotor-winding inlet-openings 32 at that end of the machine, and the stator-core axial-openings 120 at that end of the machine.
  • the inner-cooling statorwinding ducts 24 discharge into the hot-gas space 24" at the left-hand end of the machine.
  • the rotor-winding inner-cooling ducts discharge through the centrally disposed discharge-openings 34 and thence into the air gap 17, which is in turn in communication with the hot-gas space 24" at the left-hand end of the machine.
  • the stator-core axial-openings receive cool gas at two points, as described, and discharge their heated gas into the hot-gas space 24" at the left-hand end of the machine.
  • stator-core ventilating-openings 120 in Figs. 11-14, can be quite small in size, and small in number, for a combination of reasons, including the small amount of heat which remains to be extracted from the stator-core after the stator-winding heat-losses have been removed by inner-cooling, the avoidance of the introduction of hot air-gap gases into the statorcore vents, and the high hydrogen-pressure and the high blower-pressure which are needed for the inner-cooling of the stator and rotor windings.
  • stator-core may be appreciably reduced, by using axial core-vents instead of the usual radial vents.
  • a dynamoelectric machine having a stator member and a rotor member separated by an air gap; (a) said stator member having a cylindrical stator core having a plurality of axially extending winding-receiving statorslots, and a stator winding having coil-sides lying within the winding-receiving stator-slots; (b) said rotor memher having a cylindrical rotor core having a plurality of axially extending winding-receiving rotor-slots, and an inner-cooled rotor winding having coil-sides lying within the Winding-receiving rotor-slots, said rotor winding having rotor-winding cooling-ducts in good thermal relation to the rotor-conductors for substantially directly cooling sa1d rotor-conductors, said rotor-winding cooling-ducts having inlet-openings at the respective ends of the rotor winding and having outlet-openings at
  • gaseous filling of item being a gas having a molecular weight lower than nitrogen, at a gas-pressure which is adapted, at times, to be at least as high as 30 pounds per square inch, gauge.
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator-winding cooling-ducts having outlet-openings at one end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which also causes a plurality of streams of stator-winding ventilating-gas to flow through the stator-winding cooling-ducts of item (an), said gas-circulation guiding-means also including: a means for guiding some of the cooled gas from the heat-exchanging means (f) to the inlet-openings of item (zza); and a means for returning hot gas from the outlet-openings of item (ml) to the suction side of the blower (e).
  • stator winding being an inner-cooled winding having stator-Winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an inner-cooled winding having stator-Winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator- Winding cooling-ducts having outlet-openings at the blower-end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which also causes a plurality of streams of stator-winding ventilating-gas to flow through the stator-winding cooling-ducts of item (an); said gas-circulation guiding-means also including: a means for guiding some of said cooled gas to the inletopenings of item (an) at the said other end of the machine; and a means for returning hot gas from the outlet-openings of item (aa) to the suction side of the blower (e).
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator-winding cooling-ducts having outlet-openings at one end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which also causes a plurality of streams of stator-winding ventilating-gas to ilow through the stator-winding cooling-ducts of item ((111), said gas-circulation guiding-means also including: a means for guiding some of the cooled gas from the heat-exchanging means (1) to the inlet-openings of item (an); and a means for returning hot gas from the outlet-openings of item (an) of the suction side of the blower (e).
  • stator winding being an innercooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an innercooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator-winding cooling-ducts having outlet-openings at the blower-end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which alsocauses a plurality of streams of stator-winding ventilating-gas to flow through the stator-winding cooling-ducts of item (fill), said gas-circulation guiding means also including: a means for guiding some of said cooled gas to the inletopenings of item (aa) at the said other end of the machine; and a means for returning hot gas from the outlet-openings of item (on) to the suction side of the blower (e).
  • stator winding being an inner-cooled Winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator-winding cooling-ducts having outlet-opening at one end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which also causes a plurality of streams of statorwinding ventilating-gas to flow through the stator-winding cooling-ducts of item (an), said gas-circulation guiding-means also including: a means for guiding some of the cooled gas from the heat-exchanging means (f) to the inlet-openings of item (aa); and a means for returning hot gas from the outlet-openings of item (aa) to the suction side of the blower (e).
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors; and (h) a recirculating stator-winding cooling-system comprising: a means for recirculating a stator-winding cooling-fluid in said stator-winding cooling-ducts; and a means for cooling said stator-winding cooling-fluid.
  • stator winding being an inner-cooled winding having stator-winding cooling-ducts in good thermal relation to the stator-conductors for substantially directly cooling said stator-conductors, said stator-winding cooling-ducts having outlet-openings at the blower-end of the machine and inlet-openings at the other end of the machine; and (gg) the gas-circulation guiding-means (g) being a means which also causes a plurality of streams of stator-winding ventilating-gas to flow through the statorwinding cooling-ducts of item (aa), said gas-circulation guiding-means also including: a means for guiding some of said cooled gas to the inlet-openings of item (aa) at the said other end of the machine; and a means for returning hot gas from the outlet-openings of item (aa) to the suction side of the blower (6).

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Motor Or Generator Cooling System (AREA)
US394602A 1953-10-30 1953-11-27 Inner-cooled generators with singledirection ventilation Expired - Lifetime US2707243A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE532988D BE532988A (fr) 1953-10-30
US394602A US2707243A (en) 1953-10-30 1953-11-27 Inner-cooled generators with singledirection ventilation
JP681557A JPS326815B1 (fr) 1953-11-27 1957-11-27

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US389349A US2707242A (en) 1953-10-30 1953-10-30 Inner-cooled generators with vertical coolers
US394602A US2707243A (en) 1953-10-30 1953-11-27 Inner-cooled generators with singledirection ventilation

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1059097B (de) * 1957-03-28 1959-06-11 Westinghouse Electric Corp Gaskuehlung fuer elektrische Wechselstromgeneratoren, insbesondere Turbogenerator
DE1067519B (de) * 1955-06-14 1959-10-22 Vickers Electrical Co Ltd Haupt- und Nebenkuehlanlage fuer dynamoelektrische Maschinen mit Kuehlmittelkanaelen in den Statorleitern
FR2353985A1 (fr) * 1976-06-01 1977-12-30 Gen Electric Machine dynamo-electrique a refroidissement perfectionne
US4100439A (en) * 1975-04-01 1978-07-11 Kraftwerk Union Aktiengesellschaft Apparatus for cooling the end zones of the lamination stacks of electric machines
US4163163A (en) * 1976-04-06 1979-07-31 Filippov Iosif F Non-salient pole synchronous electric generator
US4383190A (en) * 1979-08-30 1983-05-10 Khutoretsky Garri M Non-reversible electrical machine with gas cooling
US5785114A (en) * 1996-02-23 1998-07-28 Westinghouse Electric Corporation Integral hydrogen cooler assembly for electric generators
US20040070291A1 (en) * 2002-10-11 2004-04-15 Siemens Westinghouse Power Corporation Dynamoelectric machine with arcuate heat exchanger and related methods
US20180183301A1 (en) * 2015-06-16 2018-06-28 Siemens Aktiengesellschaft Electrical Machine and Method for Cooling the Electrical Machine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2185728A (en) * 1937-11-01 1940-01-02 Allis Louis Co Dynamo-electric machine
GB518207A (en) * 1937-09-25 1940-02-20 Hermes Patentverwertungs Gmbh Improvements in or relating to dynamo-electric machines
US2573670A (en) * 1949-08-12 1951-10-30 Westinghouse Electric Corp Insulation of generator windings
US2663808A (en) * 1952-06-20 1953-12-22 Allis Chalmers Mfg Co Dynamoelectric machine having a ventilation shield in the air gap

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB518207A (en) * 1937-09-25 1940-02-20 Hermes Patentverwertungs Gmbh Improvements in or relating to dynamo-electric machines
US2185728A (en) * 1937-11-01 1940-01-02 Allis Louis Co Dynamo-electric machine
US2573670A (en) * 1949-08-12 1951-10-30 Westinghouse Electric Corp Insulation of generator windings
US2663808A (en) * 1952-06-20 1953-12-22 Allis Chalmers Mfg Co Dynamoelectric machine having a ventilation shield in the air gap

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1067519B (de) * 1955-06-14 1959-10-22 Vickers Electrical Co Ltd Haupt- und Nebenkuehlanlage fuer dynamoelektrische Maschinen mit Kuehlmittelkanaelen in den Statorleitern
DE1059097B (de) * 1957-03-28 1959-06-11 Westinghouse Electric Corp Gaskuehlung fuer elektrische Wechselstromgeneratoren, insbesondere Turbogenerator
US4100439A (en) * 1975-04-01 1978-07-11 Kraftwerk Union Aktiengesellschaft Apparatus for cooling the end zones of the lamination stacks of electric machines
US4163163A (en) * 1976-04-06 1979-07-31 Filippov Iosif F Non-salient pole synchronous electric generator
FR2353985A1 (fr) * 1976-06-01 1977-12-30 Gen Electric Machine dynamo-electrique a refroidissement perfectionne
US4383190A (en) * 1979-08-30 1983-05-10 Khutoretsky Garri M Non-reversible electrical machine with gas cooling
US5785114A (en) * 1996-02-23 1998-07-28 Westinghouse Electric Corporation Integral hydrogen cooler assembly for electric generators
US20040070291A1 (en) * 2002-10-11 2004-04-15 Siemens Westinghouse Power Corporation Dynamoelectric machine with arcuate heat exchanger and related methods
US7247959B2 (en) 2002-10-11 2007-07-24 Siemens Power Generation, Inc. Dynamoelectric machine with arcuate heat exchanger and related methods
US20180183301A1 (en) * 2015-06-16 2018-06-28 Siemens Aktiengesellschaft Electrical Machine and Method for Cooling the Electrical Machine
US10720814B2 (en) * 2015-06-16 2020-07-21 Siemens Aktiengesellschaft Electrical machine and method for cooling the electrical machine

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