JP2015061978A - Cryogenic temperature liquid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryogenic temperature liquid pump capable of efficiently transferring liquid gas and having a highly reliable structure that is simple and that does not take maintenance time and labor.SOLUTION: A cryogenic temperature liquid pump 1 for transferring a liquid at a temperature equal to or lower than a temperature at which a superconductive line experiences superconducting transition, includes: a cylindrical outer pipe element 2 having openings on both ends, respectively; a stator device 4 provided along an inner circumference of the outer pipe element 2, and including a field coil 3 around which a superconductive line is wound; a cylindrical rotor 5 coaxially fitted into the outer pipe element 2 with a play, including a magnetic force generator 11 generating a magnetic force, and rotating around an axis of the outer pipe element 2 by an interaction between the magnetic force generated by the magnetic force generator 11 and a magnetic force generated by the field coil 3 of the stator device 4; and an impeller 6 provided on an inner circumference of the rotor 5, transmitting a torque of the rotor 5 to the liquid in the rotor 5, and flowing the liquid from one opening to the other opening of the outer pipe element 2.

Description

  The present invention relates to a cryogenic liquid pump for transferring a cryogenic liquefied gas (cryogenic liquid) such as liquefied natural gas, liquid nitrogen, liquid hydrogen, and liquid helium without leaking completely.

Conventionally, it is a submerged pump as a pump that transfers liquefied natural gas (LNG), liquid nitrogen, liquid hydrogen, and liquid helium in a liquid state, such as a cryogenic liquefied gas (cryogenic liquid) with a boiling point of about 100K (Kelvin) or less There are two types of pumps: mold pumps and canned pumps.
The submerged pump is a pump of a type in which the pump and the motor are integrated into a storage pod, and is mainly used for a ground-installed LNG pump. The canned pump is a type of pump in which the entire motor is not immersed in liquefied gas, but the stator and liquefied gas are isolated by a stator can on the inner peripheral side of the stator, and only the rotor is immersed in liquefied gas.

Patent Document 1 discloses a submerged pump among these two types of pumps.
The submerged pump disclosed in Patent Document 1 includes a casing main body having a bottomed cylindrical inner tub that houses a pump main body therein and a bottomed cylindrical outer tub that covers the periphery of the inner tub. A lid member that closes the upper opening of the casing body, a discharge pipe that extends through the lid member from the discharge port of the pump body, and an intake that penetrates the outer tank and communicates with the inner tank In a submerged pump comprising a pipe and having a heat insulating layer formed between the inner tub and the outer tub, the upper edge of the outer tub is fixed to the outer periphery of the lower surface of the flange provided on the outer periphery of the upper end of the inner tub. A planting bolt for fixing the lid member is planted on the upper surface of the flange on the inner peripheral side of the outer tank fixing portion, and the planted bolt is inserted into a bolt hole provided in the flange portion on the outer periphery of the lid member. Nut the protruding stud It is characterized in that the removably attached to the lid member at the top of the inner tub to wear.

Patent document 2 is disclosing the canned pump which is another kind of pump.
The low-temperature liquefied gas pump disclosed in Patent Document 2 is attached to a pump main body that transports low-temperature liquefied gas by rotationally driving a lower impeller provided at a lower part of a rotating shaft that extends vertically, and an upper part of the pump main body The rotor is fixed to the rotating shaft, and a canned motor in which a stator can is inserted so as to surround the rotor and the rotating shaft with a gap on the inner peripheral side of the stator, and above the stator can, the rotating shaft It includes an upper impeller provided at an upper portion and an injection pipe for injecting a low-temperature liquefied gas boosted by the upper impeller to the discharge side of the pump main body.

Patent Document 3 discloses a hybrid pump of a type different from the submerged pump and the canned pump.
The hybrid pump disclosed in Patent Document 3 includes a pipe through which a liquid can flow, an impeller that is rotatably supported in the pipe, and a rotor that is fixed to the impeller and is rotatable together. And a stator coil device installed outside the pipe, and the impeller is driven to rotate by electromagnetic interaction between the rotor and the stator coil device.

Japanese Patent No. 47474857 (Japanese Patent Laid-Open No. 2006-161737) Japanese Patent Laid-Open No. 8-200294 Japanese Patent Laid-Open No. 5-71492

As described above, the submerged pump disclosed in Patent Document 1 and the canned pump disclosed in Patent Document 2 are mainstream as pumps for transferring a cryogenic liquefied gas (cryogenic liquid). However, both pumps have problems that are desired to be solved.
In the submerged pump, since the motor is in the liquefied gas, the heat generated by the motor is added to the liquefied gas and vaporizes the liquefied gas. Therefore, if the vaporized liquefied gas is discharged into the atmosphere, there is a problem that the liquefied gas is wasted. If a pipe for returning the vaporized liquefied gas to the suction port side of the pump is provided separately, the submerged The problem arises that the structure of the mold pump is complicated.

In the can pump, the liquefied gas itself to be transferred is used as a canned motor circulation flow for cooling the motor and lubricating the bearing portion. Therefore, the canned pump that needs to return the liquefied gas used as the circulated flow of the canned motor to the suction port side of the pump has a problem that the structure is unsuitable for improving the transfer efficiency of the liquefied gas.
Further, since the flow rate of the canned motor circulating flow changes depending on the discharge flow rate of the can pump, there is a problem that the cooling capacity of the motor and the lubrication conditions of the bearing portion change during the operation of the can pump. Furthermore, since the can pump uses liquefied gas for cooling the motor, the heat generated by the motor is added to the liquefied gas to vaporize the liquefied gas, and the transfer efficiency of the liquefied gas is reduced.

Both the above-mentioned submerged pumps and canned pumps require piping for discharging the liquefied gas vaporized by the heat generated by the motor or returning it to the suction port side of the pump, resulting in a complicated pump structure. have.
Moreover, the hybrid pump of patent document 3 is a pump which has a structure different from a submerged type pump and a canned pump, and is equipped with the stator coil apparatus outside piping. Accordingly, the portion where the stator coil device is provided has a shape that is greatly enlarged compared to the diameter of the pipe, so that it can be said that this hybrid pump is difficult to handle and has a configuration for selecting an installation location. Further, this hybrid pump is more difficult to handle because the complicated structure of the stator coil device is exposed to the outside of the enlarged pipe. In addition, although not disclosed in Patent Document 3, it is considered that a cooling mechanism for cooling the stator coil device of the hybrid pump is necessary, so that the hybrid pump becomes more complicated and more difficult to handle. There's a problem.

  Accordingly, an object of the present invention is to provide a cryogenic liquid pump having a highly reliable structure that can efficiently transfer liquefied gas and does not require maintenance work. .

In order to achieve the above-described object, the present invention takes the following technical means.
A cryogenic liquid pump according to the present invention is a cryogenic liquid pump for transferring a liquid having a temperature equal to or lower than a temperature at which a superconducting wire undergoes superconducting transition, and includes a cylindrical outer tube body having openings at both ends, A stator device provided along the inner periphery and having a field coil around which the superconducting wire is wound, and a magnetic force generator that generates a magnetic force and is loosely fitted so as to be coaxial with the outer tube body. A cylindrical inner tube that rotates about the axis of the outer tube by the interaction between the magnetic force generated by the magnetic force generator and the magnetic force generated by the field coil of the stator device; A rotational force transmitting means that is provided around the circumference and transmits the rotational force of the inner tube to the liquid in the inner tube, and causes the liquid to flow from one opening side to the other opening side of the outer tube; It is characterized by providing.

Here, the rotational force transmitting means is constituted by a blade plate which is a plate-like member arranged so as to be spiral along the axial center of the outer tube body on the inner periphery of the inner tube body. Good.
A magnetic bearing for holding the inner tube at a predetermined position in the outer tube by a magnetic force, wherein the magnetic bearing is configured by a superconducting coil around which the superconducting wire is wound to magnetize the inner tube; It is good to leave.

The outer tube body may include an inner diameter expanding portion formed by enlarging an inner diameter on the inner periphery of the outer tube body, and the stator device may be disposed in the inner diameter expanding portion.
Furthermore, the magnetic force generator provided in the inner tube body may be a permanent magnet.
Alternatively, the magnetic force generator provided in the inner tube body may be an oxide superconductor.
Here, the liquid may be liquid nitrogen, liquid oxygen, liquid hydrogen, liquid neon, or liquid helium.

The field coil of the stator device may be in direct contact with the liquid.
Preferably, the field coil is disposed along the inner peripheral surface of the outer tubular body so that the magnetic axis of the field coil is parallel to the axis of the outer tubular body, The generator may be attached to the inner tube so that the magnetic axis of the magnetic generator is parallel to the axis of the outer tube.

  Preferably, the field coil is disposed on an inner peripheral surface of the outer tubular body so that a magnetic axis of the field coil is perpendicular to an axis of the outer tubular body, and the magnetic generator is The magnetic generator may be attached to the inner tube so that the magnetic axis thereof is perpendicular to the axis of the outer tube.

  According to the cryogenic liquid pump of the present invention, it is possible to realize a cryogenic liquid pump having a highly reliable structure that can efficiently transfer liquefied gas and does not require maintenance work.

It is a figure which shows the cross-sectional structure of the cryogenic liquid pump by embodiment of this invention. It is a figure which shows another cross-sectional structure of the cryogenic liquid pump by 1st Embodiment. It is a figure which shows the cross-sectional structure which looked at the cryogenic liquid pump of the modification of 1st Embodiment from the same direction as FIG. It is a figure which shows the cross-sectional structure of the cryogenic liquid pump of 2nd Embodiment.

“First Embodiment”
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a cross-sectional configuration of a cryogenic liquid pump 1 according to a first embodiment of the present invention. The cryogenic liquid pump 1 according to the first embodiment is a cryogenic liquefied gas having a boiling point of about 100 K (Kelvin) or less, such as liquefied natural gas (LNG), liquid nitrogen, liquid oxygen, liquid hydrogen, liquid neon, and liquid helium. This is a pump for transferring (cryogenic liquid) in a liquid state. FIG. 1 shows a cross section of a cryogenic liquid pump 1 having a tubular external shape when cut by a plane passing through the axis of the tubular cryogenic liquid pump 1.

FIG. 2 is a diagram showing another cross-sectional configuration of the cryogenic liquid pump 1 according to the first embodiment. FIG. 2 is a cross-sectional view of the tubular cryogenic liquid pump 1 shown in FIG. 1 taken along the line AA, and shows a section taken along a plane perpendicular to the axis of the cryogenic liquid pump 1.
The cryogenic liquid pump 1 transports a cryogenic liquid having a boiling point at a temperature at which the superconducting wire is superconductingly transitioned, such as about 100 K (Kelvin) or less as described above.

  A cryogenic liquid pump 1 includes a tubular (tubular) outer tube body 2 having openings at both ends, a stator device 4 having a field coil 3, and a tubular inner tube that rotates about an axis C of the outer tube body 2. Tube 5, rotational force transmitting means 6 for causing cryogenic liquid to flow from one opening side of outer tube 2 to the other opening, and magnetism for holding inner tube 5 at a predetermined position in outer tube 2. A bearing 7 is provided. The stator device 4, the inner tube 5 (hereinafter referred to as the rotor 5), the rotational force transmission means 6 (hereinafter referred to as the impeller 6), and the magnetic bearing 7 are provided in the tube (in the cylinder) of the outer tube 2.

  Referring to FIGS. 1 and 2, the outer tube body 2 is a tubular (tubular) member having openings at both ends as described above, and is formed of a steel pipe such as stainless steel, for example. Specifically, it has two tubular (cylindrical) steel pipes having different diameters, and a large-diameter steel pipe having a large diameter is surrounded around a small-diameter pipe 2a which is a steel pipe having a small diameter among these two steel pipes. The diameter tube 2b surrounds and covers it. The large-diameter pipe 2b and the small-diameter pipe 2a are provided so as to maintain a distance so as not to contact each other. It is done.

  Around the openings formed at both ends of the small-diameter pipe 2a, flanges (not shown) extending in a direction perpendicular to the axis of the small-diameter pipe 2a are formed, and both ends of the large-diameter pipe 2b are welded or the like Is connected to the flange of the small-diameter pipe 2a. That is, the outer tube body 2 is configured by integrating a small diameter tube 2a, a flange formed around the opening of the small diameter tube 2a, and a large diameter tube 2b connected to the flange.

Accordingly, the outer tube body 2 has a space (vacuum heat insulating layer) 8 in which the space between the large diameter tube 2b and the small diameter tube 2a is sealed by the flange and held in vacuum. The vacuum heat insulating layer 8 is a space for insulating the inside of the small diameter tube 2 a and the outside of the large diameter tube 2 b, that is, the inside and outside of the outer tube 2, from the outside of the outer tube 2. This prevents heat from entering the cryogenic liquid flowing in the outer tube 2.
As shown in FIG. 1, the outer tube body 2 having the above-described configuration includes an inner diameter expansion portion 9 formed by enlarging the inner circumference diameter (inner diameter) in the outer tube body 2 in the vicinity of the center of the entire length. Have. As shown in FIG. 1, the inner diameter expanding portion 9 is a depression formed by the large diameter tube 2 b and the small diameter tube 2 a being recessed toward the outside of the tube when viewed from the inside of the outer tube body 2. The inner diameter expanding portion 9 is formed to have a predetermined length along the axis of the outer tube body 2, and a stator device 4 and a rotor 5 described later are provided in the inner diameter expanding portion 9.

The outer tube body 2 having the stator device 4 and the rotor 5 is connected and incorporated into a pipe for transferring a cryogenic liquid by flanges provided at both ends thereof.
The stator device 4 includes a field coil 3 around which a superconducting wire is wound, an iron yoke 10 that is an iron core for concentrating magnetic lines generated by the field coil 3, and a magnetic bearing 7 that holds a rotor 5 described later by magnetic force. Have.

The field coil 3 is obtained by winding an oxide superconducting wire so that the coil has a winding diameter slightly shorter than the length of the inner diameter expansion portion 9 along the axis of the outer tube 2. The field coil 3 is arranged along the inner peripheral surface of the inner diameter expanding portion 9 so that the longitudinal direction of the winding diameter of the field coil 3 is substantially parallel to the axial direction of the outer tube body 2. The
As shown in FIG. 2, in the first embodiment, six field coils 3 having the above-described configuration and arrangement are used, and these six field coils 3 are substantially equal along the circumferential direction of the inner diameter expansion portion 9. Place at intervals.

Here, a high-temperature superconducting wire called Bi (bismuth) system is used for the oxide superconducting wire forming the field coil 3. Since this bismuth-based high-temperature superconducting wire is characterized by being in a superconducting state at a temperature of about 100K or less, the field coil 3 configured using this high-temperature superconducting wire is transferred through the outer tube 2. Transitions to a superconducting state by a cryogenic liquid.
Here, with reference to FIG. 2, the iron yoke 10 is provided in each of the opening of the six field coils 3 arrange | positioned along the internal peripheral surface of the internal diameter expansion part 9 as mentioned above. The iron yoke 10 is disposed in the opening of each of the two adjacent field coils 3 and has a predetermined length along the longitudinal direction of the winding diameter and a height that penetrates the opening of the field coil 3 substantially perpendicularly. Part 10a. Further, the iron yoke 10 has two field cores 10a separately disposed in the openings of two adjacent field coils 3 by connection portions 10b made of the same material as the core portion 10a. It connects between the coil 3 and the internal peripheral surface of the internal diameter expansion part 9. FIG.

  In other words, the iron yoke 10 includes two iron core portions 10a penetrating the opening of the field coil 3 substantially vertically along the longitudinal direction of the winding diameter at the openings of two adjacent field coils 3, and the two The two cores 10a are made to match the curved surface of the inner peripheral surface of the inner diameter expanding portion 9 between the field coil 3 and the inner peripheral surface of the inner diameter expanding portion 9. It is comprised with the connection part 10b which is a curved plate-shaped member.

  The cross-sectional view of FIG. 1 shows a cross-section of the connecting portion 10b of the iron yoke 10 cut along a plane passing through the axis of the cryogenic liquid pump 1, and the connecting portion slightly shorter than the field coil 3 is shown. 10 b is provided between the field coil 3 and the inner peripheral surface of the inner diameter expanding portion 9. 2 shows a cross section of the iron yoke 10 cut along a plane perpendicular to the axial center of the cryogenic liquid pump 1, and shows two field coils 3 and an inner diameter expansion portion. 9 between the inner peripheral surfaces of 9 and the opening of the field coil 3 from both ends of the connecting portion 10b spanned from the opening of one field coil 3 to the opening of the other field coil 3. 10a is provided.

  When the above-described configuration is viewed from another viewpoint with reference to FIG. 2, it can be described as follows. That is, the field coil 3 is disposed on each of the two iron core portions 10a of the iron yoke 10 arranged along the inner peripheral surface of the inner diameter expanding portion 9 so as to surround each iron core portion 10a. In this way, when one iron yoke 10 and two field coils 3 constitute one set of superconducting magnetic field generation units, the three sets of superconducting magnetic field generation units are arranged along the inner peripheral surface of the inner diameter expansion unit 9. Has been placed.

Further, referring to FIG. 1, a rotor 5 described later is provided at both ends of the inner diameter expansion portion 9 in the axial direction of the outer tube body 2, and a magnetic force is applied to the inner diameter expansion portion 9 which is a predetermined position in the outer tube body 2. Is provided with a magnetic bearing 7 that is rotatably held in a non-contact manner.
The magnetic bearing 7 holds the rotor 5 in a non-contact manner using magnetism (attraction force) generated by an electromagnet, and its configuration is well known, but the magnetic bearing 7 according to this embodiment is the same as the field coil 3. Magnetism (attraction force) is generated by the superconducting coil around which the superconducting wire is wound, and the rotor 5 is held.

  The stator device 4 having the above-described field coil 3, iron yoke 10, and magnetic bearing 7 has a magnetic field toward the end surface of the field coil 3 that faces the axis of the outer tube 2 and the axis C of the outer tube 2. The inner diameter expansion portion so that the end surface of the superconducting coil of the bearing 7 is in a state of being flush with the inner peripheral surface of the small diameter tube 2 a adjacent to the inner diameter expansion portion 9 of the outer tube 2. 9 is arranged. Then, when the impregnating resin R is injected into the inner diameter expansion portion 9, the injected impregnating resin R flows between the members of the field coil 3, the iron yoke 10, and the magnetic bearing 7, and It also flows between the inner diameter expansion portions 9. As the impregnated resin R that has flowed in is solidified, the field coil 3, the iron yoke 10, and the magnetic bearing 7 are fixed and integrated in the inner diameter expansion portion 9.

  At this time, the impregnating resin R is injected to such an extent that it does not cover the end face of the field coil 3 facing the axis of the outer tube 2 and the receiving surface of the magnetic bearing 7 facing the rotor 5. As described above, the inner diameter (inner diameter) of the stator device 4 formed by the end face of the field coil 3, the receiving face of the magnetic bearing 7 and the surface of the impregnating resin R in the inner diameter expanding portion 9 is the same as that of the small diameter pipe 2 a. It is greater than or equal to the inner diameter of the portion adjacent to the inner diameter expansion portion 9.

  An epoxy resin is used as the impregnating resin R for integrating the members constituting the stator device 4. In general, an epoxy resin is a thermosetting resin and has a strong adhesive force. In addition, an epoxy resin in which a modifier for improving characteristics is mixed as various fillers is commercially available. In this embodiment, an epoxy resin mixed with aluminum powder as a filler is used for the purpose of improving thermal conductivity characteristics. Used. It is known that this epoxy resin has a thermal shrinkage close to that of metal and does not crack at low temperatures.

Since the stator device 4 is arranged in the inner diameter expansion portion 9 as described above, when the cryogenic liquid flows into the small diameter tube 2a of the outer tube body 2, the field coil 3 of the stator device 4 and the superconducting coil of the magnetic bearing 7 are used. Is directly contacted with the flowing cryogenic liquid and cooled.
Referring to FIGS. 1 and 2, the inner tube body (rotor) 5 is a tubular (tubular) member having openings at both ends, and is made of, for example, stainless steel like the outer tube body 2. ing. As shown in FIG. 1, the total length along the axial direction of the tubular (tubular) rotor 5 is equal to or greater than the distance between the two magnetic bearings 7, 7 of the stator device 4, and as shown in FIG. The outer diameter (outer diameter) of the rotor 5 is less than the inner diameter of the stator device 4 disposed in the inner diameter expansion portion 9.

The rotor 5 has a magnetic force generator 11 that generates magnetic force on the outer peripheral surface thereof, and has a permanent magnet in the present embodiment. The magnetic force generator 11 is long and curved along the circumferential direction of the outer peripheral surface of the rotor 5, and a plurality of magnetic force generators so as to surround the outer periphery of the rotor 5 at a plurality of positions in the axial direction of the rotor 5. 11 is provided.
In the present embodiment, as shown in FIG. 1, six magnetic force generators 11 are provided so as to surround the outer periphery of the rotor 5 at each of the six positions in the axial direction of the rotor 5 as shown in FIG. 2. ing. Therefore, in the rotor 5, the six magnetic force generators 11 are linearly aligned along the circumferential direction of the outer peripheral surface of the rotor 5, and the six magnetic force generators 11 are linearly aligned along the axial direction of the rotor 5. A plurality of magnetic force generators 11 are provided so as to be aligned.

The permanent magnet that is the magnetic force generator 11 according to the present embodiment is preferably a magnet that generates as much magnetic force as possible. Here, a neodymium sintered permanent magnet made of Nd—Fe—B is used. The polarities of the plurality of magnetic force generators 11 provided in the rotor 5 are such that when the rotor 5 is arranged on the inner peripheral side of the stator device 4, the arranged rotor 5 is supported by the magnetic bearing 7 and the outer tube body. PM that is loosely fitted so as to be coaxial with the rotor 2 and that the supported rotor 5 rotates about the axis C of the outer tube 2 by interaction with the magnetic force generated by the field coil 3 of the stator device 4. It is determined to constitute a motor. Here, the PM motor is a well-known PM (Permanent Magnet).
) Motor or PMSM (Permanent Magnet Synchronous Motor) motor.

  On the inner peripheral surface of the rotor 5, a blade that is a plate-like member continuously provided in a spiral shape along the axial direction of the rotor 5 as a thread of a female screw as the rotational force transmitting means 6. (Impeller) is provided. The rotational force transmitting means 6 may be constituted by a plurality of blade plates (impellers) that are intermittently disposed in a spiral shape along the axial direction of the rotor 5. Hereinafter, the rotational force transmitting means 6 is represented as an impeller 6.

  The impeller 6 provided on the inner periphery (inner peripheral surface) of the rotor 5 is provided so as to protrude from the inner peripheral surface of the rotor 5, and the height from the inner peripheral surface of the rotor 5 along the protruding direction. Is, for example, less than half of the inner diameter of the rotor 5. Accordingly, the impeller 6 forms a space around the axial center of the rotor 5 over the entire length of the rotor 5. Since this space is a space that is not affected by the impeller 6, the space can be seen from one opening of the rotor 5 to the other opening without being blocked by the impeller 6.

When the rotor 5 having the impeller 6 having such a configuration is disposed on the inner peripheral side of the stator device 4 and rotates, the impeller 6 transmits the rotational force of the rotor 5 to the cryogenic liquid in the rotor 5. Is caused to flow from one opening side of the outer tube body 2 to the other opening side.
Again, by arranging the rotor 5 having the above-described impeller 6 on the inner peripheral side of the stator device 4, the arranged rotor 5 is supported by the magnetic bearing 7 so as to be coaxial with the outer tubular body 2. The fitted cryogenic liquid pump 1 is configured. Although not shown, the stator device 4 is connected to an AC power supply device, and by supplying power from the AC power supply device to the stator device 4, the rotor 5 has an axial center of the outer tubular body 2 in accordance with a known PM motor principle. Rotate around C.

  Since the impeller 6 serving as a rotational force transmitting means rotates integrally with the rotor 5, the rotational force of the rotor 5 is transmitted to the cryogenic liquid via the impeller 6, and the cryogenic liquid is one opening side of the outer tubular body 2 ( It flows from the suction port) to the other opening side (discharge port). At this time, since the current value and frequency of the alternating current flowing from the AC power supply device to the stator device 4 can be easily changed by thyristor control, the rotor 5 (cryogenic liquid pump is changed by changing these current value and frequency. The rotational speed of 1) can be freely controlled.

  According to the cryogenic liquid pump 1 of the present embodiment having the above-described configuration, since the superconducting wire is used for the motor (particularly the stator device 4) that generates the driving force for transferring the cryogenic liquid, the electric resistance of the motor is reduced. It becomes zero and the motor hardly generates heat. Accordingly, the cryogenic liquid pump 1 of the present embodiment can greatly reduce the amount of cryogenic liquid consumed for cooling the motor as compared with the conventional pump, and thus greatly improve pump efficiency. Can do.

  Also, the superconducting state of the superconducting wire used in the motor is a phenomenon that is realized at a constant temperature or lower, such as about 100 K (Kelvin) or lower, and generally a dedicated cooling system is required to cool the motor. Become. However, in the cryogenic liquid pump 1 of the present embodiment, the superconducting wire used in the motor is cooled to a certain temperature or less, such as about 100 K (Kelvin) or less, by the cryogenic liquid being transferred. The system becomes unnecessary.

  Furthermore, in the configuration of the cryogenic liquid pump 1 of the present embodiment, the motor hardly generates heat, so that the cryogenic liquid is hardly vaporized depending on the heat of the motor. Therefore, in the conventional pump, piping for discharging the vaporized cryogenic liquid is indispensable, but in the cryogenic liquid pump 1 of the present embodiment, the gasified cryogenic liquid is discharged. Piping is not required. As a result, the structure of the cryogenic liquid pump 1 can be simplified, and the number of parts required for manufacturing the pump can be reduced.

Finally, in the cryogenic liquid pump 1 of the present embodiment, the rotor 5 is supported by using the magnetic bearing 7 formed of a coil of superconducting wire without using a mechanical bearing. The device 4 is completely non-contact and does not use worn parts. Therefore, there are few failures due to mechanical wear or the like, and regular maintenance can be substantially omitted.
"Modification of the first embodiment"
FIG. 3 shows a cross-sectional structure of a cryogenic liquid pump 1 according to a modification of the first embodiment.

In the first embodiment described above, an example in which the iron yoke 10 is disposed inside the outer tube body 2 as shown in FIG. However, the iron yoke 10 may be disposed outside the outer tube 2 as shown in FIG.
That is, the iron yoke 10 of this modification has an annular portion 10 c having an annular shape whose diameter is larger than the outer diameter of the outer tube body 2. The annular portion 10c is formed in an annular shape with a metal capable of forming a magnetic path therein, such as iron, and the outer circumferential surface of the outer tubular body 2 while keeping a certain distance from the outer circumferential surface of the outer tubular body 2. It is deployed along. A connecting portion 10d is formed between the annular portion 10c and the outer tubular body 2 so as to connect the two along the radial direction. A plurality of the connecting portions 10d are provided in the circumferential direction corresponding to the installation locations in the circumferential direction of the field coil 3. In the example of FIG. 3, six field coils 3 are arranged at substantially equal intervals in the circumferential direction, so that the annular portion 10 c and the outer tubular body 2 are connected via six connecting portions 10 d. It is supposed to be.

As shown in the above-described modification, if the iron yoke 10 formed by the annular portion 10c and the connecting portion 10d is disposed on the outer peripheral side of the outer tube body 2, the iron yoke 10 is disposed away from the field coil 3. Therefore, there is an advantage that the work of impregnating the field coil 3 with the impregnating resin is simplified. That is, in the example of FIG. 2 in which the iron yoke 10 penetrates the field coil 3, the iron yoke 10 may become an obstacle and the resin impregnation may not be sufficiently performed, and the impregnation operation becomes difficult. In the modified example in which only the field coil 3 is impregnated, the impregnation operation is extremely easy.
“Second Embodiment”
Next, the cryogenic liquid pump 1 of the second embodiment will be described with reference to FIG.

As shown in FIG. 4, the cryogenic liquid pump 1 according to the second embodiment includes the field coil 3 and the magnetic force generator 11 as in the first embodiment. The direction is different from that of the first embodiment.
That is, in the first embodiment shown in FIGS. 1 and 2, the field coil 3 has a magnetic axis of the field coil 3 (an axis connecting the N pole and the S pole of the field coil 3, a magnetic pole). It was attached to the inner peripheral surface of the outer tube body 2 so as to face the direction, and the magnetic force generator 11 made of a permanent magnet was also attached so that the magnetic axis of the magnetic force generator 11 was directed in the radial direction. In other words, in the first embodiment, the field coil 3 is attached to the inner peripheral surface of the outer tubular body 2 such that the magnetic axis of the field coil 3 is perpendicular to the axis of the outer tubular body 2. The magnetic generator 11 is attached to the inner tube 5 so that the magnetic axis of the magnetic generator 11 is perpendicular to the axis of the outer tube 2.

On the other hand, in the second embodiment shown in FIG. 4, the field coil 3 has a superconducting wire connected to the outer tube 2 so that the magnetic axis of the field coil 3 is parallel to the axis of the outer tube 2. The magnetic generator 11 is formed so as to be along the inner peripheral surface of the inner tube 5, and the inner tube 5 is arranged such that the magnetic axis of the magnet generator 11 is parallel to the axis of the outer tube 2. It has been attached to.
Specifically, the field coil 3 of the second embodiment is formed by winding a superconducting wire in the circumferential direction along the inner peripheral surface of the outer tube body 2, and each field coil formed by winding. The cross-sectional shape of 3 is a cross-sectional shape that protrudes in the form of a flange inward from the inner peripheral surface. On the other hand, the magnetic generators 11 of the second embodiment are attached upright from the outer peripheral surface of the inner tubular body 5 toward the radially outer side, and a plurality of magnetic generators 11 are arranged at regular intervals in the axial direction. The field coil 3 and the magnetic force generator 11 are arranged such that the above-described field coil 3 is sandwiched between the magnetic generators 11 adjacent to each other with an interval in the axial direction.

In such a cryogenic liquid pump 1 of the second embodiment, the distance between the field coil 3 and the magnetic generator 11 can be made shorter than that of the first embodiment. A strong driving force can be generated by effectively using the magnetic field 3 and the pump efficiency is also improved.
Each embodiment disclosed this time should be considered as illustrative in all points and not restrictive. In particular, in each embodiment disclosed this time, matters that are not explicitly disclosed, for example, operating conditions and operating conditions, various parameters, dimensions, weights, volumes, etc. of the constituents are within the range normally practiced by those skilled in the art. It does not deviate and employs a value that can be easily assumed by those skilled in the art.

  For example, as the magnetic force generator 11 provided in the rotor (inner tube body) 5, an oxide superconductor may be used instead of the permanent magnet. As is well known, an oxide superconductor has a characteristic of having a strong pinning effect of capturing magnetic flux lines. Because of this feature, the oxide superconductor exhibits the same function as a permanent magnet when provided in the rotor (inner tube) as the magnetic force generator 11, so the rotor 5 provided with the oxide superconductor is also It rotates on the same principle as the rotor 5 provided with the permanent magnet.

Further, the shape and size of the field coil 3 can be arbitrarily selected according to the shape and size of the rotor 5.
Furthermore, in the above-described embodiment, the stator device 4 is provided in the inner diameter expansion portion 9 formed in the outer tube body 2, but the inner diameter of the outer tube body 2 having a uniform inner diameter in which the inner diameter expansion portion 9 is not provided. The stator device 4 and the rotor 5 may be provided. In that case, the inner diameter of the outer tube body 2 is reduced only by the portion where the stator device 4 is provided, but the outer tube body 2 having a uniform outer diameter can be realized because there is no inner diameter expanding portion 9. In the case of such a cryogenic liquid pump 1 having an outer tube body 2 having a uniform outer diameter, when connecting to the piping for transferring the cryogenic liquid, interference with the piping around the connecting portion is avoided. The cryogenic liquid pump 1 that can be avoided and has a high degree of freedom in installation can be obtained.

DESCRIPTION OF SYMBOLS 1 Cryogenic liquid pump 2 Outer tube 2a Small diameter tube 2b Large diameter tube 3 Field coil 4 Stator device 5 Inner tube (rotor)
6 Rotational force transmission means (impeller)
DESCRIPTION OF SYMBOLS 7 Magnetic bearing 8 Vacuum heat insulation layer 9 Inner diameter expansion part 10 Iron yoke 10a Iron core part 10b Connection part 10c Annular part 10d Connection part 11 Magnetic force generator C Shaft center R Impregnation resin

Claims (10)

A cryogenic liquid pump that transports liquid below the temperature at which the superconducting wire undergoes superconducting transition,
A cylindrical outer tube having openings at both ends;
A stator device having a field coil provided along the inner periphery of the outer tubular body and wound with the superconducting wire;
It has a magnetic force generator that is loosely fitted to the outer tubular body so as to be coaxial, and generates a magnetic force, and by the interaction between the magnetic force generated by the magnetic force generator and the magnetic force generated by the field coil of the stator device A cylindrical inner tube that rotates about the axis of the outer tube;
Provided on the inner periphery of the inner tube and transmitting the rotational force of the inner tube to the liquid in the inner tube to cause the liquid to flow from one opening side to the other opening side of the outer tube. A cryogenic liquid pump comprising: a rotational force transmitting means;   The rotational force transmitting means is composed of a blade plate which is a plate-like member arranged so as to be spiral along the axis of the outer tube at the inner periphery of the inner tube. The cryogenic liquid pump according to claim 1. A magnetic bearing for holding the inner tube in a predetermined position in the outer tube by a magnetic force;
3. The cryogenic liquid pump according to claim 1, wherein the magnetic bearing generates magnetism for holding the inner tube by a superconducting coil around which the superconducting wire is wound. 4. The outer tube has an inner diameter expansion portion formed by enlarging the inner diameter on the inner circumference of the outer tube;
The cryogenic liquid pump according to claim 1, wherein the stator device is disposed in the inner diameter expansion portion.   The cryogenic liquid pump according to any one of claims 1 to 4, wherein the magnetic force generator provided in the inner tube body is a permanent magnet.   5. The cryogenic liquid pump according to claim 1, wherein the magnetic force generator provided in the inner tube is an oxide superconductor.   The cryogenic liquid pump according to claim 1, wherein the liquid is liquid nitrogen, liquid oxygen, liquid hydrogen, liquid neon, or liquid helium.   The cryogenic liquid pump according to claim 1, wherein a field coil of the stator device is in direct contact with the liquid. The field coil is arranged along the inner peripheral surface of the outer tube so that the magnetic axis of the field coil is parallel to the axis of the outer tube,
The said magnetic generator is attached to the said inner tube so that the magnetic axis of the said magnetic generator may become parallel to the axial center of the said outer tube, The any one of Claims 1-8 characterized by the above-mentioned. The cryogenic liquid pump described in 1. The field coil is disposed on the inner peripheral surface of the outer tube so that the magnetic axis of the field coil is perpendicular to the axis of the outer tube,
The said magnetic generator is attached to the said inner tube so that the magnetic axis of the said magnetic generator may become perpendicular to the axial center of the said outer tube, The any one of Claims 1-8 characterized by the above-mentioned. The cryogenic liquid pump described in 1.