JP2002017071A - High-speed rotary motor and cooling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool the heat generation of a rotor and a stator effectively during high-speed rotation by making a high-speed rotating motor relatively simple with its constitution as it is. SOLUTION: This high-speed rotary motor 12 comprises the rotor 15 rotating at high speed in the stator 16, and a single-stage impeller 13 or a double-stage impeller 14 attached to the end of a rotating shaft 17 in the rotor 15. The stator 16 is provided with an injection opening 19 feeding cooling air to the rotor 15 and a nozzle 20 formed in the injection opening 19, and feeding fine water droplets are injected with the cooling air into a clearance between the rotor 15 and the stator 16, thus cooling the rotor 15 and the stator 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed rotating electric motor, and more particularly to a high-speed rotating electric motor capable of effectively cooling a rotor and a stator that generate heat at high speed during high-speed rotation, and a method of cooling the same. is there.

[0002]

2. Description of the Related Art A turbo compressor is suitable for increasing the capacity and reducing the size of a turbo compressor or a screw compressor, and is easily oil-free. For this reason, the turbo compressor is widely used as a general-purpose compressor for a factory air source, a source air for air separation, a process-related air source, and the like.

A conventional two-stage turbo compressor is a single-shaft, two-stage gear drive compressor, as shown in the block diagram of FIG. 2, and includes a motor 1, a gear intensifier 2, and a coaxial two-stage compressor 3. It becomes. In the coaxial two-stage compressor 3, a one-stage impeller 5 and a two-stage impeller 6 are coaxially provided at both ends of a rotating shaft 4, respectively.
(At least 100,000 min ^-1 ).

In the above-described conventional two-stage turbo compressor, the coaxial two-stage compressor 3 for compressing gas can be downsized, but the motor 1 and the gearbox 2 are large, so that the overall size is quite large. Was. Therefore, as shown in FIG. 3, some compressors (hereinafter, referred to as "one-shaft, two-stage high-speed rotary electric motor") in which the gearbox 2 is omitted have been proposed. This single-shaft, two-stage high-speed rotating motor has impellers 5 and 6 at both ends of the rotor shaft of the high-speed rotating motor without a gear speed increaser.

[0005] The high-speed rotating motor described above generates a large amount of heat because it rotates at a high speed, and it is necessary to install a cooling device.
Further, as such a cooling device, forced air cooling by a fan directly connected to a rotor shaft or supply of cooling air from the outside has conventionally been generally used.

[0006]

However, when a fan is directly connected to the rotor shaft, the length of the rotor shaft becomes longer,
There is a problem that it is difficult to support the rotation of the high-speed rotor shaft reaching tens of thousands of min ^-1 . Further, when cooling air is supplied by another system from the outside, a power source of another system, a fan driving device, and the like are required, and there is a problem that the device is complicated.

In the case of a single-shaft, two-stage high-speed motor, the gap between the rotor 7 and the stator 8 of the high-speed motor is narrow. There is a problem that a certain rotor 7 and stator 8 cannot be cooled effectively.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a high-speed rotating electric motor capable of effectively cooling the heat generated by the rotor and the stator during high-speed rotation with a relatively simple structure while maintaining the configuration of the high-speed rotating electric motor, and its cooling. It is to provide a method.

[0009]

According to the high speed rotary electric motor of the present invention, the rotor (15) rotating at high speed in the stator (16) and the end of the rotor shaft (17) of the rotor (15) are provided. A high-speed rotary electric motor (12) including a one-stage impeller (13) or a two-stage impeller (14) attached to a portion, wherein the stator (16) is directed toward the rotor (15). An injection port (19) for supplying provided cooling air;
A nozzle (20) provided in the injection port (19) for supplying water droplets, wherein the rotor (15) and the stator (1) are provided.
By spraying fine water droplets together with the cooling air into the gap between the rotor (15) and the stator (16).
And a high-speed rotating electric motor characterized by being configured to cool.

According to the high-speed rotating motor of the present invention,
Rotor (15) rotating at high speed in stator (16)
A high-speed rotating motor (12) having
5) The one-stage impeller (13) or the two-stage impeller (14) attached to the end of the rotor shaft (17), and the gas compressed by the one-stage impeller (13) is intercooled and guided to the two-stage impeller. An intermediate cooling device, wherein the stator (16) includes:
An injection port (19) provided toward the rotor (15) for supplying the cooling air from the intercooler;
A nozzle (20) provided in the injection port (19) for supplying water droplets, wherein the rotor (15) and the stator (1) are provided.
By spraying fine water droplets together with the cooling air into the gap between the rotor (15) and the stator (16).
And a high-speed rotating electric motor characterized by being configured to cool. By providing the injection port (19) substantially at the center of the stator (16), the rotor (15) and the stator (16) can be cooled uniformly.

In the structure of the present invention, a mixture of fine water droplets from the nozzle (20) is injected into the cooling air from the injection port (19) toward the rotor (15), and the latent heat of evaporation is used. The motor rotor (15) and stator (1
The rotor (15) and the stator (16) are sprayed into the gap of 6).
And the rotor shaft (17) can be cooled. The energy required for evaporating water is large and the energy taken from the surroundings as latent heat of evaporation is much larger than air cooling, so that the rotor (15) and the stator (16) can be effectively cooled.

Further, an injection port (1) for supplying cooling air from an intercooler such as an intercooler or an aftercooler.
9) and an external supply device is provided for the water sprayed from the nozzle (20) provided in the injection port (19) by using the drain (condensed water) of the intercooler and the aftercooler. Eliminates the need. Further, the condensed water has no contaminants, which leads to an increase in the life of the apparatus.

According to the cooling method of the present invention, the gas compressed by the one-stage impeller (13) is intercooled by the intercooler and led to the two-stage impeller (14), where it is recompressed to obtain a high compression ratio. A high-speed rotary motor (12) for obtaining the intermediately cooled compressed gas together with fine water droplets.
5) and the space between the stator (16) and the rotor (1).
5) A method for cooling a high-speed rotating electric motor, comprising cooling the stator and the stator (16).

In the method of the present invention, the high-speed rotating motor (1
When the compressed gas intermediate-cooled in step 2) is injected from the injection port (19), the latent heat of evaporation is injected by injecting the water into the rotor (15) with the fine water droplets mixed therein from the nozzle (20). Utilizing the motor rotor (15)
Is injected into the gap between the rotor and the stator (16), and the rotor shaft (17)
The rotor (15) and the stator (16) can be effectively cooled.

Further, when the compressed gas is injected from the injection port 19 so as to cause adiabatic expansion of the compressed gas, the temperature can be further lowered.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a high-speed rotating electric motor according to the present invention. As shown in the figure, the high-speed electric compressor 11 is a single-shaft, two-stage high-speed rotary motor, and includes a high-speed rotary motor 12, a one-stage impeller 13, and a two-stage impeller 1.
4 and 4.

The high-speed electric compressor 11 is preferably a polyphase induction motor, and includes a rotor 15 rotating around an axis and a stator 16 surrounding the rotor. The center shaft (rotor shaft 17) of the rotor 15 extends through both sides (left and right in this figure) of the electric motor, and is rotatably supported by two radial bearings 18.

The stator 16 comprises, for example, a stator core and a stator winding housed in a stator frame (not shown). As the stator core, for example, a thin plate laminated in the axial direction is used to reduce iron loss. The winding of the stator 16 is
It is housed in a groove in the iron core and is connected to a polyphase power supply to create a rotating magnetic field.

The rotor 15 includes, for example, a laminated core (rotor core) and a rotor winding (not shown). The rotor winding is housed in a groove in the iron core. The rotor is preferably a cage rotor, but may be a wound rotor. In the case of a cage rotor, one copper rod is placed in each rotor slot, and both ends of the copper rod are shorted with an end ring.
Connect with.

With the configuration described above, the stator 16 receives AC power from the polyphase power supply to generate a rotating magnetic field, and generates an induced current in the secondary winding of the rotor 15 through an air gap by an induction action. A rotating force (Fleming's left rule) is generated by the current and the magnetic flux of the rotating magnetic field, and the rotor 15 can be rotated in the same direction as the rotating magnetic field. In this case, the rotating speed of the rotating magnetic field is increased by using a high-frequency power source, so that the rotor 15, that is, the rotor shaft 17 is rotated at a high speed (for example,
(10,000 min ^-1 or more).

The present invention is not limited to a polyphase induction motor, and a high-speed rotating motor other than a polyphase induction motor, for example, a DC motor may be used.

In the present invention, the single-stage impellers 13 and 2
The stage impeller 14 is provided with a rotor shaft 17 of the high-speed rotating motor 12.
Are attached to both ends. A diffuser and a scroll casing are provided around the one-stage impeller 13 and the two-stage impeller 14.

An injection port 19 is provided at a substantially intermediate position of the stator 16 of the high-speed rotating motor 12 thus configured so as to extend from the periphery of the stator 16 toward the central axis. The injection port 19 supplies cooling air from the outside from the rotor 15 toward the rotor shaft 11 to cool the rotor 15 and the stator 16. Particularly, in the present invention, a nozzle 20 for supplying a water droplet is provided in the injection port 19.

The nozzle 20 sprays a mixture of fine water droplets into the cooling air from the injection port 19 toward the rotor 15, that is, the fine water droplets together with the cooling air and the rotor 15 and the stator 16 of the electric motor. By injecting into the gap of
The rotor 15, the stator 16, and the rotor shaft 17 can be effectively cooled using the latent heat of evaporation. As in the related art, not only the cooled air is simply jetted toward the rotor 15 and the stator 16, but the fine water droplets from the nozzle 20 require a large amount of energy to evaporate the water and take away from the surroundings as latent heat of evaporation. The energy is very large compared to air cooling. Therefore, these fine water droplets are effectively
5 and the stator 16 can be cooled.

The water sprayed from the nozzle 20 may be, for example, water condensed by an intercooler or aftercooler (not shown), which will be described later, in addition to water supplied from the outside. In particular, since this condensed water has no contaminants, it can also contribute to extending the life of the electric motor.

An intermediate cooling device (not shown)
Is an intercooler that cools the gas passing through the inside with external cooling medium cooling water, cooling air, etc., and a one-stage impeller 13.
It is also possible to cool by using a configuration in which a pipeline configured to guide the gas compressed by the intercooler to the intercooler and a pipeline configured to guide the compressed gas cooled by the intercooler to the suction port of the two-stage impeller 14 are used.

With this intermediate cooling device, the one-stage impeller 1
The gas compressed in step 3 is led through a diffuser and a scroll casing to an intercooler, where it is intermediately cooled and led to a two-stage impeller 14, where it is recompressed and has a high compression ratio (eg, 8 or more in a general-purpose compressor) Is to be obtained. The pressure of the gas compressed by the single-stage impeller 13 is 0.3 to
0.4 MPa, and the temperature after the intermediate cooling is about 40 ° C. or less.

In the cooling method of the present invention using the high-speed rotary motor 12 having the above-described configuration, the compressed gas intermediate-cooled by the intercooler is connected to the rotor 15 and the stator of the motor 12 through the injection port 19 opened in the stator 16. The fuel is injected into the gap 16 to cool the rotor shaft 17, the rotor 15 and the stator 16.
Further, it is preferable that the compressed gas is adiabatically expanded at the time of injection from the injection port 19 to further lower the temperature. In addition, injection port 1
In 9, the adiabatic expansion may be performed by passing through the gap between the rotor 15 and the stator 16 while maintaining the pressure without adiabatic expansion, and then opening to the atmosphere.

It should be noted that the present invention is not limited to the embodiment relating to the single-shaft two-stage compressor as described above, but can be embodied in a single-shaft one-stage compressor, and various modifications can be made without departing from the spirit of the present invention. Of course, it can be changed.

[0030]

As described above, the high-speed rotating electric motor and the cooling method of the present invention mix fine water droplets in cooling air,
The ambient temperature can be reduced by utilizing the latent heat of vaporization of water. In particular, the energy required for evaporating water is large, and the energy taken from the surroundings as latent heat of evaporation is much larger than air cooling, so that the rotor, the stator, and the rotor shaft can be effectively cooled.

Furthermore, by using the drain (condensed water) of the intercooler and aftercooler as the water to be sprayed, it is not necessary to provide an external supply device, and the condensed water has no contaminants. Therefore, the present invention has excellent effects such as prolonging the life of the device.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a high-speed rotation motor of the present invention.

FIG. 2 is a configuration diagram of a conventional two-stage turbo compressor.

FIG. 3 is a schematic view of a conventional high-speed rotating electric motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 High-speed electric compressor 12 High-speed rotary electric motor 13 1-stage impeller 14 2-stage impeller 15 Rotor 16 Stator 17 Rotor shaft 18 Radial bearing 19 Injection port 20 Nozzle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshio Takahashi 3-2-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Takeshi Kuwata 3-2-2 Toyosu, Koto-ku, Tokyo No. 16 Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Soningu 3-2-16 Toyosu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries, Ltd. Tokyo Engineering Center F-term (reference) 3H033 AA02 BB03 BB06 BB17 CC01 CC05 DD13 EE03 3H035 AA01 AA05 AA06 5H609 BB02 BB15 PP02 PP07 QQ03 QQ04 QQ20 RR07 RR12 RR37 RR43 RR48 RR69 RR73

Claims (5)

[Claims] A rotor (15) rotating at a high speed in a stator (16), and a rotor shaft (1) of the rotor (15).
One-stage impeller (13) or 2 attached to the end of 7)
High-speed electric motor (1) having a stage impeller (14).
2), wherein the stator (16) is provided with the rotor (1).
Injector (1) for supplying cooling air provided toward
9), and a nozzle (20) provided in the injection port (19) for supplying a water droplet, wherein the rotor (15) and the stator (1) are provided.
By spraying fine water droplets together with the cooling air into the gap between the rotor (15) and the stator (16).
A high-speed rotating electric motor, characterized in that the motor is cooled. 2. A high-speed rotating motor (12) having a rotor (15) rotating at high speed within a stator (16);
A one-stage impeller (13) or a two-stage impeller (14) attached to the end of the rotor shaft (17) of the rotor (15).
And an intermediate cooling device that intermediately cools the gas compressed by the one-stage impeller (13) and guides the gas to the two-stage impeller, wherein the stator (16) is provided toward the rotor (15). An injection port (19) for supplying the cooling air from the intermediate cooling device; and a nozzle (20) provided in the injection port (19) for supplying water droplets. The rotor (15) and the stator (16) are configured to be cooled by jetting fine water droplets together with the cooling air into a gap between the rotor (15) and the stator (16). High speed rotating electric motor. 3. The injection port (19) is connected to the stator (1).
3. The high-speed rotating electric motor according to claim 1, wherein said high-speed rotating electric motor is provided at a substantially central portion of the motor. 4. A high-speed rotary electric motor (12), in which a gas compressed by a single-stage impeller (13) is intercooled by an intercooler and led to a two-stage impeller (14), where it is recompressed to obtain a high compression ratio. And cooling the rotor (15) and the stator (16) by injecting the intermediate-cooled compressed gas together with fine water droplets into the gap between the rotor (15) and the stator (16). Characteristic cooling method of high-speed rotating motor. 5. The method for cooling a high-speed rotary electric motor according to claim 4, wherein the compressed gas is injected such that the compressed gas is adiabatically expanded at the time of injection from the injection port (19).