CN103227521B - Hollow rotor motor and systems comprising the same - Google Patents

Abstract

The present invention relates to hollow rotor motors and systems including hollow rotor motors. In one or more embodiments, the present invention provides electric motors and related systems that include: (a) a motor housing; and (b) a hollow rotor configured to rotate within a stator housed within the motor housing, and Driven by a stator; wherein the motor housing is characterized by a maximum cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the flow channel has a minimum The cross-sectional area is at least 25% of the maximum cross-sectional area of the motor housing, and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, the flow channel, and the fluid outlet Configured to allow fluid to pass from the fluid inlet to the fluid outlet through the flow channel.

Description

Hollow rotor motors and systems including hollow rotor motors

This application claims priority to US Provisional Application Serial No. 61/592,191 filed January 30, 2012, which is hereby incorporated by reference in its entirety.

Statement Regarding Federally Funded Research and Development

One or more aspects of the invention described herein were developed under the United States Department of Energy's cooperative agreement DE-EE0002752 entitled "High Temperature High Volume Lift for Enhanced Geothermal Systems." Accordingly, the Government has certain rights in this invention.

technical field

The present invention relates to hollow rotor motors and systems including hollow rotor motors.

Background technique

In one aspect, the present invention provides advanced motor technology particularly useful in well fluid lift systems. A major challenge is to provide a well fluid lift system that can withstand the extreme pressures and temperatures of thermal energy recovery wells while providing sufficient life to meet the needs of the enhanced geothermal systems (EGS) industry for many years to come. Currently, there are few, if any, viable well fluid lift systems capable of extended operation in geothermal wells of the type required to provide large amounts of geothermal energy for human use.

Contents of the invention

In one embodiment, the present invention provides an electric motor comprising: a motor housing; and a hollow rotor configured to rotate within and driven by a stator accommodated in the motor housing; wherein the motor housing characterized by the maximum cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel, the flow channel is characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is the maximum cross-sectional area of the motor housing At least 25% of the area, and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, flow channel, and fluid outlet configured to allow fluid to pass from the fluid inlet through the flow channel to fluid outlet.

In another embodiment, the present invention provides an electric fluid pump comprising: (a) an electric motor comprising: (i) a motor housing; and (ii) a hollow rotor configured to Rotates within a stator within the housing and is driven by the stator; wherein the motor housing is characterized by the largest cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel characterized by the smallest cross-sectional area of the flow channel , wherein the minimum cross-sectional area of the flow channel is at least 25% of the maximum cross-sectional area of the motor housing, and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid The inlet, flow channel and fluid outlet are configured to allow fluid to pass from the fluid inlet to the fluid outlet through the flow channel; (b) a transition section configured to couple the hollow rotor to a drive shaft of a pumping device to be powered by the motor (c) one or more suction ports defined by the transition coupling, the first end portion, or both the transition coupling and the first end portion; the suction ports are in fluid communication with the flow passage of the hollow rotor; and ( d) A pumping device comprising a fluid inlet and one or more impellers secured to a drive shaft powered by an electric motor.

In yet another embodiment, the present invention provides a machine for generating electrical power comprising: (a) an electrical generator comprising: (i) an electrical generator housing; and (ii) a hollow magnetic rotor configured to rotate within a stator housed within a generator housing; wherein the generator housing is characterized by the maximum cross-sectional area of the generator housing, and wherein the hollow magnetic rotor defines a flow channel characterized by the flow channel's a minimum cross-sectional area, wherein the minimum cross-sectional area of the flow channel is at least 25% of the maximum cross-sectional area of the generator housing, and wherein the hollow magnetic rotor has a first end portion defining a fluid inlet, and a fluid outlet defining a The second end portion; the fluid inlet, the flow channel, and the fluid outlet are configured to allow fluid to pass through the flow channel from the fluid inlet to the fluid outlet; (b) a transition section configured to couple the hollow magnetic rotor to a and (c) one or more suction ports defined by the transition coupling, the first end portion, or both the transition coupling and the first end portion; the suction port is connected to the hollow magnetic rotor The flow passages of the invention are in fluid communication; wherein the turbine device includes one or more impellers fixed to the drive shaft.

In yet another embodiment, the present invention provides an electric fluid pump that is an electric submersible pump (ESP) optimized for operation in a wellbore.

Description of drawings

These and other features, aspects and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like symbols represent like parts throughout the several views, in which:

Figure 1 illustrates one or more embodiments of the invention;

Figure 2 illustrates one or more embodiments of the invention;

Figure 3 illustrates one or more embodiments of the invention;

Figure 4 illustrates one or more embodiments of the invention;

Figure 5 illustrates one or more embodiments of the invention;

Figure 6 illustrates one or more embodiments of the invention;

Figure 6A shows an enlarged end view of a radial bearing of the present invention; Figure 7 shows one or more embodiments of the present invention;

Figure 8 illustrates one or more embodiments of the invention;

Figure 9 illustrates one or more embodiments of the invention;

Figure 10 illustrates one or more embodiments of the invention;

Figure 11 illustrates one or more embodiments of the invention; and

Figure 12 illustrates one or more embodiments of the invention.

Parts list:

100 hollow rotor electric motor

10 Motor housing

12 Maximum diameter of motor housing

14 Clearance (between stator and rotor)

15 Seal leak paths

16 Rotary seal section

17 Fixed sealing part

18 Seal bellows

19 Seal installation part

20 hollow rotor

21 Dielectric fluid

22 Minimum inner diameter of hollow rotor

24 First end part of the hollow rotor

25 Flow channel defined by hollow rotor

26 Second end part of the hollow rotor

27 Fluid inlet (defined by either hollow rotor or pump)

29 Fluid outlet defined by hollow rotor

30 stator

40 Transition section

41 Connecting piece with transmission shaft 50

42 Connecting piece with the hollow rotor 20

50 Driveshaft (also first driveshaft) of a device powered by a motor

51 Direction of rotation of the first transmission shaft

52 Second drive shaft

53 Direction of rotation of the second transmission shaft (opposite to direction 51)

54 Planetary gearbox configured to rotate drive shaft 52 in a direction opposite to that of drive shaft 50

60 Suction port

70 Fluid Flow Direction

80 Seal (face seal)

90 Pipe to receive output from motor

100 hollow rotor electric motor

200 pumps

210 pump housing (casing)

215 Bearing support strut

251 drive shaft support bearing

252 Thrust bearing

253 diffuser

257 impeller

258 Second set of impellers

300 electric fluid pump including motor 100 and pump 200

900 Electric motor (motor/generator)

910 Motor housing (housing)

920 Hollow Magnetic Rotor

957 Turbine Blades

960 egress port

1000 Turbo

1010 turbine housing

1027 Turbine Fluid Outlet

1028 Turbine Fluid Inlet

1105 rotor shaft

1110 Permanent magnet attached to rotor shaft

1115 Magnet Retaining Ring

1120 Hollow Magnetic Rotor

1200 Geothermal wells and heat extraction systems 1200

1205 Geothermal field

1210 Energy Recovery Unit

1215 Geothermal production wellhead

1220 Geothermal production wells

1225 power supply cable

1230 hot water

1235 cold water

1240 energy

1250 Geothermal injection well.

detailed description

As mentioned, in one embodiment, the present invention provides an electric motor comprising: a motor housing; and a hollow rotor configured to rotate within and driven by a stator housed within the motor housing ; wherein the motor housing is characterized by a maximum cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is At least 25% of the maximum cross-sectional area of the motor housing, and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, flow channel, and fluid outlet are configured to allow fluid Transmitted from the fluid inlet to the fluid outlet through the flow channel.

A variety of motor topologies are available including surface mount permanent magnet, internal permanent magnet, induction, wound field, synchronous reluctance and switched reluctance topologies. In one or more embodiments, the motor is a surface mounted permanent magnet type.

In one or more embodiments, the present invention provides an electric motor characterized in that the minimum cross-sectional area of the flow channel is 25% to about 75% of the maximum cross-sectional area of the motor housing.

In one or more embodiments, the present invention provides an electric motor characterized in that the minimum cross-sectional area of the flow channel is 30% to about 55% of the maximum cross-sectional area of the motor housing.

In one or more embodiments, the present invention provides an electric motor further comprising: a transition section (sometimes referred to herein as a transition coupling) configured to couple the hollow rotor to a drive shaft of a device powered by the motor and one or more suction ports defined by the transition coupling, the first end portion, or both the transition coupling and the first end portion; the suction ports being in fluid communication with the flow passage of the hollow rotor. In one or more embodiments, the transition section is a coupling that may be integral or separate from either the hollow rotor or the drive shaft of the device.

In one or more embodiments, the transition coupling defines one or more suction ports. In another embodiment, the first end portion defines one or more intake ports. In yet another embodiment, both the transition coupling and the first end portion each define at least one suction port. In yet another embodiment, only the transition coupling defines one or more suction ports.

In one or more embodiments, the electric motor further includes a dielectric fluid, sometimes referred to herein as a dielectric coolant fluid. In one or more embodiments, a dielectric fluid filled gap separates the outer surface of the hollow rotor from the stator. Suitable dielectric coolant fluids include silicone oils, aromatics such as biphenyls, diphenyl ethers, fluorinated polyethers, silicate fluids, perfluorocarbons, alkanes and polyalphaolefins.

In another embodiment, a gas fluid filled gap separates the outer surface of the hollow rotor from the stator. In one embodiment, the gas within the gap may be air. In another embodiment, the gas within the gap may be a relatively noble gas such as helium or argon. In one embodiment, the gas in the gap is nitrogen.

In one or more embodiments, the present invention provides motors that include encapsulated stators, such as those described in U.S. Patent 7,847,454, U.S. Divisional Application No. 12/904,523, and U.S. Patent Application Nos. 12/915,604 and 12/940,524, which are incorporated by reference And it is incorporated in this article in its entirety.

As mentioned, in one or more embodiments, the present invention provides an electric fluid pump comprising: (a) an electric motor comprising: (i) a motor housing; and (ii) a hollow rotor , which is configured to rotate within and is driven by a stator housed within a motor housing; wherein the motor housing is characterized by the largest cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel, the flow channel is characterized by In the minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is at least 25% of the maximum cross-sectional area of the motor housing, and wherein the hollow rotor has a first end portion defining a fluid inlet, and defining a fluid the second end portion of the outlet; the fluid inlet, the flow channel, and the fluid outlet are configured to allow fluid to pass through the flow channel from the fluid inlet to the fluid outlet; (b) a transition section configured to couple the hollow rotor to the motor-powered on the drive shaft of the pumping device; (c) one or more suction ports defined by the transition coupling, the first end portion, or both the transition coupling and the first end portion; flow between the suction port and the hollow rotor the channel is in fluid communication; and (d) a pumping device comprising a fluid inlet and one or more impellers secured to a drive shaft powered by an electric motor.

In one or more embodiments, the electric fluid pump provided by the present invention includes a first set of impellers mounted on a first drive shaft, and a second set of impellers mounted on a second drive shaft, the first drive shaft and a second drive shaft configured to be driven by the hollow rotor, the first and second drive shafts configured to rotate in opposite directions.

In one or more embodiments, the present invention provides an electric fluid pump comprising a pumping device housing (also referred to as a pump housing) defining a fluid inlet and housing a pump section comprising a One or more impellers on a drive shaft powered by a motor. In one or more embodiments, the electric fluid pump includes a stationary diffuser mounted to an inner surface of the pumping device housing.

In yet another embodiment, the present invention provides a machine for generating electrical power comprising: (a) an electrical generator comprising: (i) an electrical generator housing; and (ii) a hollow magnetic rotor configured to Rotates within a stator housed within a generator housing; wherein the generator housing is characterized by the largest cross-sectional area of the generator housing, and wherein the hollow magnetic rotor defines a flow channel characterized by a minimum of the flow channel cross-sectional area, wherein the minimum cross-sectional area of the flow channel is at least 25% of the maximum cross-sectional area of the generator housing, and wherein the hollow magnetic rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet Two end portions; a fluid inlet, a flow channel, and a fluid outlet configured to allow fluid to pass through the flow channel from the fluid inlet to the fluid outlet; (b) a transition section configured to couple the hollow magnetic rotor to a motor configured to drive the hollow magnetic rotor and (c) one or more outlet ports defined by the transition coupling, the first end portion, or both the transition coupling and the first end portion; the suction port and the hollow magnetic rotor The flow channels are in fluid communication; wherein the turbine arrangement includes one or more impellers secured to the drive shaft.

In one or more embodiments, the present invention provides a machine for generating electrical power further comprising a turbine device housing defining one or more fluid outlets. In one or more embodiments, the present invention provides a machine for generating electrical power further comprising a turbine device housing defining one or more fluid inlets.

In one or more embodiments, the present invention provides a machine for generating electrical power further comprising a pressurized dielectric fluid in the gap separating the outer surface of the hollow rotor from the stator.

In one or more embodiments, the present invention provides a machine for generating electrical power that includes an encapsulated stator.

Referring now to the accompanying drawings, FIG. 1 shows a large-diameter electric motor 100 provided by the present invention. The motor includes a motor housing 10 and a hollow rotor 20 disposed inside the motor. The hollow rotor 20 is configured to rotate within and be driven by a stator 30 housed within a motor housing. A gap 14 separates the outer surface of the hollow rotor from the stator. Gap 14 is sometimes referred to herein as an air gap, but in one or more embodiments may be filled with a dielectric coolant fluid, air, or another fluid. The hollow rotor 20 defines a flow channel 25 characterized by a minimum cross-sectional area 22 . Similarly, the motor housing 10 is characterized by a maximum cross-sectional area 12 . In one or more embodiments, both the flow channel 25 and the motor housing 10 are cylindrical in shape and are characterized by a single flow channel cross-sectional area and a single motor housing cross-sectional area. In such a case, the cross-sectional area of the flow channel 25 is at least 25% of the cross-sectional area of the motor housing 10 . In the illustrated embodiment, the hollow rotor 20 has a first end portion 24 defining a fluid inlet 27 . The hollow rotor 20 further defines a second end portion 26 defining a fluid outlet 29 . Fluid inlet 27, flow channel 25, and fluid outlet 29 are in fluid communication such that fluid (eg, liquid) entering the hollow rotor through the fluid inlet can pass through the flow channel and exit the fluid outlet.

Referring now to FIG. 2 , there is shown a large diameter electric motor 100 provided by the present invention, the motor including a transition coupling 40 (sometimes referred to herein as a transition section) configured to couple the hollow rotor 20 to the On the drive shaft 50 of a power supply device (not shown). In the embodiment shown, the suction port 60 allows fluid to pass into the flow channel 25 as suggested by the flow direction arrow 70 . In one or more embodiments, the transition coupling 40 is separate from the hollow rotor and drive shaft 50 and coupled to each of the hollow rotor and drive shaft 50 , such as by friction joints, shrink fit, threads, or combinations thereof. In one or more embodiments, the transition coupling is integral with the hollow rotor and coupled to drive shaft 50 . In one or more embodiments, the transition coupling is integral to the drive shaft of the motor powered device and is coupled to the hollow rotor. In one or more embodiments, the suction port 60 is characterized by one or more cross-sectional areas, and the sum of these cross-sectional areas of the suction port is substantially equal to or greater than the smallest cross-sectional area of the flow channel 25 .

Referring now to FIG. 3 , there is shown a large diameter electric motor 100 provided by the present invention. In the embodiment shown, the motor is coupled to a drive shaft 50 of a pump configured to pump fluid into and through the flow passage 25 . In one or more embodiments, fluid may be pushed axially along drive shaft 50 toward and through suction port 60 by a series of impellers (not shown). Seal 80 prevents this working fluid from entering the motor and contacting internal motor components, such as the stator. In one or more embodiments, the motor is filled with a pressurized dielectric fluid that is at a greater pressure than the environment external to the motor. In one or more embodiments, the pressurized dielectric fluid leaks out from the interior of the motor as a means of preventing working fluid from being drawn into the interior of the motor. Seal 80 is typically of the face seal type. In one or more embodiments, seal 80 includes a stationary seal member secured within the motor housing, and a movable seal member attached to the hollow rotor, the stationary and movable seal members confining the pressurized dielectric fluid A leak path through which flow can flow. In the illustrated embodiment, the transition coupling 40 is shown integral with the drive shaft 50 and defines a suction port 60 . In the illustrated embodiment, the transition coupling 40 defines a suction port 60, and the first end portion ( FIG. 1 ) of the hollow rotor lacks a suction port.

Referring now to FIG. 4 , there is shown a large diameter electric motor 100 provided by the present invention. In the illustrated embodiment, the transition coupling 40 is shown integral with the hollow rotor 20 . It should be noted that in this or any other embodiment, the transition coupling 40 is not considered in determining the minimum cross-sectional area of the flow passage. In the embodiment shown, the motor is configured to power a drive shaft 50 of a pump section (not shown) that acts on and moves the working fluid (not shown) axially along the drive shaft 50 , as indicated by directional arrow 70 . Working fluid enters the flow channel 25 through the suction port 60 . In the illustrated embodiment, the first end portion ( FIG. 1 ) of the hollow rotor 20 defines a suction port 60 and the transition coupling 40 lacks a suction port.

Reference is now made to FIG. 5 , which illustrates an electric fluid pump in accordance with one or more embodiments of the present invention. The electric fluid pump includes a large diameter electric motor 100 configured to power a pump 200 . In the embodiment shown, only a portion of the pump 200 is visible. Pump 200 includes pump housing 210 and impeller 257 attached to drive shaft 50 coupled to hollow rotor 20 of large diameter electric motor 100 by transition coupling 40 . In the illustrated embodiment, the transition coupling 40 is a separate component joined to both the drive shaft 50 and the hollow rotor 20 (ie, not integral with either the drive shaft 50 or the hollow rotor 20). Transition coupling 40 defines a suction port 60 and hollow rotor 20 does not define a suction port. Electric motor 100 includes a motor housing 10 which, in the embodiment shown, is joined to pump housing 210 at the fluid inlet end of the hollow rotor and to conduit 90 at the outlet end of the hollow rotor. In one or more embodiments, conduit 90 is configured to receive fluid propelled by pump 200 through flow channel 25 of hollow rotor 20 , as indicated by fluid direction arrow 70 .

Reference is now made to FIG. 6 , which illustrates an electric fluid pump in accordance with one or more embodiments of the present invention. The electric fluid pump includes a large diameter electric motor 100 configured to power the pump 200 . In the embodiment shown, only a portion of the motor 100 is visible. Pump 200 includes pump housing 210 and impeller 257 attached to drive shaft 50 coupled to hollow rotor 20 of large diameter electric motor 100 by transition coupling 40 . In the illustrated embodiment, the transition coupling 40 is a separate component joined to both the drive shaft 50 and the hollow rotor 20 (ie, not integral with either the drive shaft 50 or the hollow rotor 20). The pump 200 also includes a stationary diffuser 253 and a thrust bearing 252 . A thrust bearing 252 (sometimes referred to herein as a thrust washer) is positioned between the stationary diffuser and the rotating impeller. In the illustrated embodiment, the drive shaft 50 is shown supported by radial bearings 251 , which are shown in an enlarged end view in FIG. 6A , where the radial bearings 251 are supported by support struts 215 . While only a single radial support bearing is depicted in FIG. 6, multiple radial bearings are typically included in the large diameter electric motors, electric fluid pumps, and machines for generating electrical power provided by the present invention.

Reference is now made to FIG. 7 , which illustrates a transition coupling 40 in accordance with one or more embodiments of the present invention. In the embodiment shown, the transition coupling is a single separate component configured to be coupled to the drive shaft (50) via a first coupling 41 and configured to be coupled to the hollow rotor (20) via a second coupling 42 superior. The transition coupling defines a plurality of suction ports 60 . In the illustrated embodiment, transition coupling 40 may be coupled to each of drive shaft 50 and hollow rotor 20 by, for example, a friction joint, a shrink fit joint, or a combination thereof.

Reference is now made to FIG. 8 , which illustrates a transition section 40 that is integral with and forms a part of hollow rotor 20 , in accordance with one or more embodiments of the present invention. The transition section 40 includes a first coupling piece configured to be coupled to a drive shaft of a device configured to be driven by the hollow rotor 20 . Although both the first coupling 41 and the suction port 60 are integral with and form part of the hollow rotor 20 , the transition section 40 is not considered when calculating the minimum cross-sectional area 22 of the flow channel 25 .

Reference is now made to FIG. 9 , which illustrates a machine for generating electrical power in accordance with one or more embodiments of the present invention. In the embodiment shown, the machine includes a generator 900 including a generator housing 910 and a hollow magnetic rotor 920 configured to rotate within a stator 30 housed within the generator housing. The generator housing 910 is characterized by a maximum cross-sectional area. The hollow magnetic rotor defines a flow channel 25 that extends the length of the hollow magnetic rotor and is characterized by a minimum cross-sectional area that is at least 25% of the maximum cross-sectional area of the generator housing. The hollow magnetic rotor has a first end portion 24 defining a fluid outlet 29 and a second end portion 26 defining a fluid inlet 27 . The fluid inlet, flow channel and fluid outlet are in fluid communication such that fluid entering flow channel 25 through fluid inlet 27 may pass through flow channel 25 and exit the hollow magnetic rotor through fluid outlet 29 . It can be said that the fluid inlet, the flow channel and the fluid outlet are configured to allow fluid to pass through the flow channel from the fluid inlet to the fluid outlet. The machine for generating electrical power includes a transition section 40 configured to couple a hollow magnetic rotor to a propeller shaft of a turbine arrangement configured to drive the hollow magnetic rotor. In the illustrated embodiment, the transition section 40 is shown defining an outlet port 960 configured to allow fluid to be communicated from the flow channel and fluid outlet of the hollow magnetic rotor. Transition section 40 is coupled to drive shaft 50 of turbine 1000 (sometimes referred to herein as a turbine arrangement). In the illustrated embodiment, turbine 1000 includes turbine blades 957 and a turbine housing 1010 .

In one or more embodiments, during operation, the machine for generating electrical power shown in Figure 9 generates electricity as follows. Fluid flowing under pressure enters the hollow magnetic rotor through fluid inlet 27 and flows through flow channel 25 as indicated by directional arrow 70 . Fluid passes into the transition section and exits into the cavity defined by the generator housing 910 and the turbine housing 1010 . Fluid flowing under pressure encounters turbine blades 957 during its passage through the turbine. Energy from the fluid is transferred to the turbine blades, causing the blades and drive shaft 50 to rotate. Rotation of drive shaft 50 in turn rotates hollow magnetic rotor 920 adjacent stator 30 and thereby generates electrical power. A portion of the energy it contains has been transferred to the fluid of the turbine which is then sent out of the turbine 1000 through the turbine fluid outlet 1027 .

In one or more embodiments, the turbine housing defines one or more fluid inlets 1028 . These may be used when the machine used to generate electrical power operates in a confined space such as a pipe or wellbore or other conduit in which a portion of the fluid flowing under pressure is allowed to flow along the outer surface of the generator housing 910. for useful. For example fluid flowing under pressure may encounter a fluid inlet 27 end of a machine for generating electrical power disposed within the duct such that a gap exists between the outer surface of the generator housing and the inner wall of the duct. A first portion of the fluid flowing under pressure is passed into the flow channel 25, while a second portion of the fluid is passed along the outer surface of the generator housing. The second portion then encounters the outer surface of the turbine casing defining fluid inlet 1028 . Some or all of the second portion of fluid enters the turbine and contacts the turbine blades, and a portion of the energy contained in the second portion of fluid is transferred to the turbine. In one or more embodiments, the turbine casing is configured to partially or completely block the fluid passage between the outer surface of the turbine casing and the inner wall of the duct.

Those of ordinary skill in the art will appreciate the close relationship between one or more embodiments of the machine for generating electrical power provided by the present invention and one or more embodiments of the electric fluid pump provided by the present invention. Thus, simply reversing the direction of fluid flow and electrical current can convert a power consuming electric fluid pump into an electrical power generating machine. In the context of geothermal production wells, for example, the electric fluid pump provided by the present invention and provided in the geothermal production well can pump hot water from the geothermal field to the thermal energy extraction facility at the surface.

Reference is now made to FIG. 10 , which illustrates an electric fluid pump 300 in accordance with one or more embodiments of the present invention. The pump includes a hollow rotor electric motor (not shown) provided by the present invention, and a pumping section 200 including a first set of impellers 257 mounted on a first drive shaft 50 configured to rotate in direction 51, and a second set of impellers 258 mounted on a second drive shaft 52 configured to rotate in direction 53, said first and second drive shafts being configured to be driven by a hollow rotor, said first and second The drive shafts are configured to rotate in opposite directions through the planetary gearbox 54 .

Reference is now made to FIG. 11 , which illustrates a seal 80 within a hollow rotor electric motor in accordance with one or more embodiments of the present invention. The figure shows a portion of a hollow magnetic rotor 1120 having a rotor shaft 1105 that defines the flow channel 25 . Permanent magnets 1110 are attached to the outer surface of rotor shaft 1105 by magnet retaining ring 1115 . In the embodiment shown, the motor includes a pressurized dielectric fluid 21 that contacts the stator 30 and fills the gap 14 between the outer surface of the hollow rotor magnetic rotor 1120 and the stator 30 . Seal 80 prevents working fluid (not shown) from being drawn into the interior of motor 100 . The seal 80 includes a rotating portion 16 that is fixed to an outer surface of a hollow rotor magnetic rotor 1120 and that rotates with the hollow rotor magnetic rotor 1120 . The seal 80 also includes a fixed seal portion 17, a seal bellows 18, and a seal mount 19 attached to an inactive surface of the motor (in the embodiment shown, to the motor housing). formula part. The seal 80 defines a sealed leak path 15 through which a small amount of pressurized dielectric fluid 21 can flow, thereby preventing working fluid from being sucked into the internal portion of the motor.

Reference is now made to FIG. 12 , which illustrates a geothermal well and thermal energy extraction system 1200 in accordance with one or more embodiments of the present invention. In the illustrated embodiment, an electric fluid pump 300 provided by the present invention and comprising a hollow rotor electric motor 100 and a pump section 200 is disposed within a geothermal production well 1220 . Hot water 1230 is supplied to production well 1220 from geothermal field 1205 . In one embodiment, the hot water 1230 is at a temperature of 300°C and a pressure of 300 bar. Hot water from geothermal field 1205 enters geothermal production well 1220 and is pushed to the surface by electric fluid pump 300 powered by cable 1225 . At the surface, energy is extracted 1240 from hot water in an energy recovery unit 1210 coupled to a production well 1220 at a wellhead 1215 . As will be understood by those of ordinary skill in the art, various methods may be employed, including generating steam and driving electric turbines. In one embodiment, the energy recovery unit comprises an organic Rankine cycle. Cooling water 1235 produced by removing energy from hot water 1230 is returned to geothermal field 1205 through injection well 1250 , where cooling water 1235 absorbs heat from the field to produce hot water 1230 .

As mentioned, in one embodiment, the present invention provides an electric motor comprising: a motor housing; and a hollow rotor configured to rotate within and driven by a stator housed within the motor housing ; wherein the motor housing is characterized by a maximum cross-sectional area of the motor housing, and wherein the hollow rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is At least 25% of the maximum cross-sectional area of the motor housing, and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, flow channel, and fluid outlet are configured to allow fluid Transmitted from the fluid inlet to the fluid outlet through the flow channel.

Such motors can be used in a wide variety of applications. For example, the motors provided by the present invention may be used in situations where, during operation, the motor is disposed within a confined space, such as a pipe, ship hold or wellbore. In one embodiment, the present invention provides a motor for use in an in-line pump capable of moving fluid at a higher rate than conventional in-line pumps. It is believed that the motors provided by the present invention and pumping systems comprising these motors will be useful in a wide variety of applications such as in-line pumps in high flow rate airborne firefighting systems, compact high flow rate shipboard emergency water pumps, etc. In-line high-flow fluid transfer pumps in chemical manufacturing and distribution, in-line high-flow fluid transfer pumps in petroleum refining and distribution, and in-line pumps capable of maintaining sterile environments required in medical and food applications Type high flow fluid transfer pump.

As mentioned, in one embodiment, the present invention provides an electric fluid pump, which is an electric submersible pump (ESP) optimized for operation in a wellbore and comprising at least one hollow rotor motor provided by the present invention . In one or more embodiments of the invention, the ESP includes one or more electric motors configured for one or more pumping sections. In one embodiment, an electric submersible pump (ESP) is optimized for operation in a geothermal wellbore having a bore diameter of approximately 10.625 inches. In one such embodiment, the ESP is configured to utilize approximately 5.0 MW of power, which is a 300°C working fluid (water, with 2% or less gas share) the required amount. In such an embodiment, the ESP can be run to gain benefit at a pump/motor speed of approximately 3150 RPM in order to balance system efficiency and pump stage boost with motor thermal concerns. In one or more embodiments, the present invention provides an ESP comprising approximately 126 impeller/diffuser stages having a total length of approximately 19 meters, and a hollow rotor electric motor section having a length of approximately 16 meters, which makes the ESP The combined total length of the motor and pumping section is about 35 meters. The overall length of the ESP provided by the present invention is typically slightly longer than the sum of the motor and pumping section lengths due to the presence of additional structural features along the ESP pump-motor axis, such as guard sections (discussed herein) . The overall length of the ESP provided by the present invention can vary widely, but in geothermal production well applications, the length of such an ESP will typically fall in the range between 30 and 50 meters. A Design of Experiments analysis using Computational Fluid Dynamics (CFD) performed by the inventors revealed that pump efficiencies as high as 78% can be achieved at flow rates of 80 kg/sec with an ESP according to one or more embodiments of the present invention. In one aspect, the present invention provides an ESP that includes an induction motor. In an alternative embodiment, the present invention provides an ESP comprising a permanent magnet motor. During operation, water propelled by the ESP impeller/diffuser stages is primarily conveyed into and through the holes (sometimes referred to herein as flow channels) of the hollow rotor. In one or more embodiments, the present invention provides an ESP comprising a modular motor that has been optimized for power density and divided into 8-10 segments with a total motor length of approximately 16 meters. High temperature testing of various motor isolation materials and high temperature, high pressure evaluation of candidate dielectric coolant fluids have been performed and suitable candidate motor isolation materials and dielectric coolant fluids have been identified. These include, for example, motor isolation materials disclosed in U.S. Patent Application Nos. 12/968437 and 13/093306, which are incorporated herein by reference in their entirety, as well as dielectric fluids known in the art, such as perfluorinated Polyether. With the combination of thermal management using circulating dielectric oil and the use of inorganic solid motor isolation materials, peak motor temperatures of <330°C were achievable and acceptable. In one or more embodiments, the present invention provides an ESP that includes a high pressure high temperature dielectric fluid flow loop. As will be understood by those of ordinary skill in the art, the use of pressurized dielectric fluid within the motor portion of the ESP requires the use of one or more seals to isolate the dielectric fluid from the process fluid.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims Inside.

Claims (10)

1. An electric motor comprising: (a) the motor housing; and (b) a hollow rotor configured to rotate within and driven by a stator contained within said motor housing; wherein said motor housing is characterized by a maximum cross-sectional area of said motor housing, and wherein the hollow rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is a maximum cross-sectional area of the motor housing 25% to 75% of , and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, the flow channel, and the fluid outlet are configured to Fluid is permitted to pass from the fluid inlet to the fluid outlet through the flow channel. 2. The electric motor according to claim 1, further comprising: a transition section configured to couple the hollow rotor to a drive shaft of a device to be powered by the motor; and a transition coupling, the first end portion, or the transition coupling and the One or more suction ports defined by both first end portions; the suction ports being in fluid communication with the flow passage of the hollow rotor. 3. Electric motor according to claim 2, characterized in that the transition section is provided as an integral or separate coupling with the hollow rotor or the drive shaft of the device. 4. The electric motor of claim 2, wherein the suction port is characterized by one or more cross-sectional areas, and wherein the sum of the cross-sectional areas of the suction ports is substantially equal to or greater than the The minimum cross-sectional area of the flow channel. 5. The electric motor of claim 4, wherein the transition coupling defines one or more suction ports. 6. The electric motor of claim 1, further comprising a pressurized dielectric fluid. 7. The electric motor of claim 1 wherein a dielectric fluid filled gap separates the outer surface of the hollow rotor from the stator. 8. An electric fluid pump comprising: (a) Electric motors, which include: (i) the motor housing; and (ii) a hollow rotor configured to rotate within and driven by a stator contained within said motor housing; wherein said motor housing is characterized by a maximum cross-sectional area of said motor housing, and wherein the hollow rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is a maximum cross-sectional area of the motor housing 25% to 75% of , and wherein the hollow rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, the flow channel, and the fluid outlet are configured to allowing fluid to pass through the flow channel from the fluid inlet to the fluid outlet; (b) a transition section configured to couple said hollow rotor to a drive shaft of a pumping device to be powered by said motor; (c) one or more suction ports defined by a transition coupling, said first end portion, or both said transition coupling and said first end portion; flow between said suction port and said hollow rotor the channels are in fluid communication; and (d) A pumping device comprising a fluid inlet and one or more impellers secured to a drive shaft powered by said electric motor. 9. The electric fluid pump according to claim 8, characterized in that it comprises a first set of impellers mounted on the first drive shaft, and a second set of impellers mounted on the second drive shaft, the first drive A shaft and a second drive shaft are configured to be driven by the hollow rotor, and the first and second drive shafts are configured to rotate in opposite directions. 10. A machine for generating electrical power comprising: (a) Generators, which include: (i) generator casings; and (ii) a hollow magnetic rotor configured to rotate within a stator contained within said generator housing; wherein said generator housing is characterized by a maximum cross-sectional area of said generator housing, and wherein, The hollow magnetic rotor defines a flow channel characterized by a minimum cross-sectional area of the flow channel, wherein the minimum cross-sectional area of the flow channel is 50% of the maximum cross-sectional area of the generator housing 25% to 75%, and wherein the hollow magnetic rotor has a first end portion defining a fluid inlet, and a second end portion defining a fluid outlet; the fluid inlet, the flow channel, and the fluid outlet are configured to allowing fluid to pass through the flow channel from the fluid inlet to the fluid outlet; (b) a transition section configured to couple the hollow magnetic rotor to a propeller shaft of a turbine device configured to drive the hollow magnetic rotor; and (c) one or more outlet ports defined by a transition coupling, said first end portion, or both said transition coupling and said first end portion; the flow channels are in fluid communication; Wherein said turbine arrangement comprises one or more impellers fixed to said drive shaft.