EP4589154A1

EP4589154A1 - Compressor

Info

Publication number: EP4589154A1
Application number: EP24753380.5A
Authority: EP
Inventors: Ryuuta Tanaka
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 2023-02-08
Filing date: 2024-02-07
Publication date: 2025-07-23
Also published as: CN120051637A; US20250237221A1; JPWO2024166937A1; WO2024166937A1

Abstract

A compressor includes a rotating shaft, an impeller configured to be attached to the rotating shaft and compress a supplied fluid, a turbine configured to be attached to the rotating shaft, a first flow path forming member configured to form a first flow path guiding a part of the fluid compressed by the impeller to the turbine, and a second flow path forming member configured to form a second flow path guiding the fluid after acting on the turbine to a fluid intake port of the impeller.

Description

Technical Field

The present disclosure relates to a compressor that compresses a fluid by a driving force of an electric motor.

Background Art

For example, Patent Literatures 1 to 3 disclose a compressor that compresses a fluid. Such a compressor is provided with a circulation flow path for returning a part of the fluid discharged from an outlet of a scroll flow path to a fluid intake port of an impeller. As a result, in this compressor, the flow rate of the fluid flowing through an aerodynamic element (the impeller and the scroll flow path) is increased to avoid surging and the like. In addition, there is a compressor that drives an impeller by an electric motor to compress a fluid.

Citation List

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Publication No. 2008-531975
Patent Literature 2: Japanese Unexamined Patent Publication No. 2010-174806
Patent Literature 3: Japanese Unexamined Patent Publication No. 2021-532300

Summary of Invention

Technical Problem

In the compressor using the electric motor, when the flow rate of the fluid flowing through the aerodynamic element is increased using the circulation flow path described above, the power of the electric motor also increases by the increased fluid. As a result, it is considered that compressor efficiency is reduced in the compressor.
Therefore, the present disclosure describes a compressor capable of increasing a flow rate of a fluid flowing through an aerodynamic element while suppressing a decrease in compressor efficiency.

Solution to Problem

One aspect of the present disclosure is a compressor compressing a fluid by a driving force of an electric motor, the compressor including: a rotating shaft configured to be driven by the electric motor; an impeller configured to be attached to the rotating shaft and compress the fluid supplied; a turbine configured to be attached to the rotating shaft; a first flow path forming member configured to form a first flow path guiding a part of the fluid compressed by the impeller to the turbine; and a second flow path forming member configured to form a second flow path guiding the fluid after acting on the turbine to a fluid intake port of the impeller.

Advantageous Effects of Invention

According to one aspect of the present disclosure, it is possible to increase the flow rate of the fluid flowing through the aerodynamic element while suppressing a decrease in compressor efficiency.

Brief Description of Drawings

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a compressor according to an embodiment.
FIG. 2 is a block diagram of a valve control device of the compressor.
FIG. 3 is a cross-sectional view illustrating a schematic configuration of a compressor according to a modification.

Description of Embodiments

One aspect of the present disclosure is a compressor compressing a fluid by a driving force of an electric motor, the compressor including: a rotating shaft configured to be driven by the electric motor; an impeller configured to be attached to the rotating shaft and compress the fluid supplied; a turbine configured to be attached to the rotating shaft; a first flow path forming member configured to form a first flow path guiding a part of the fluid compressed by the impeller to the turbine; and a second flow path forming member configured to form a second flow path guiding the fluid after acting on the turbine to a fluid intake port of the impeller.
Since this compressor is provided with the first flow path and the second flow path, the flow rate of the fluid flowing through an aerodynamic element can be increased. In addition, a part of the fluid compressed by the impeller is guided to the turbine by the first flow path. As a result, in this compressor, the turbine can be driven by the fluid returned to the aerodynamic element in order to increase the flow rate. When the turbine is driven by the fluid, the impeller attached to the rotating shaft is also driven. That is, in this compressor, an increase in the power of the electric motor can be suppressed by recovering a part of the power corresponding to the increase in the flow rate of the fluid flowing through the aerodynamic element. As a result, the compressor can increase the flow rate of the fluid flowing through the aerodynamic element while suppressing a decrease in compressor efficiency.
In the compressor described above, the electric motor may be disposed in the second flow path. In this case, the compressor can cool the electric motor with the fluid flowing through the second flow path. As a result, the compressor can suppress heat generation of the electric motor and further suppress a decrease in compressor efficiency.
The compressor described above may further include: a valve configured to be provided in the first flow path forming member and adjust a flow rate of the fluid flowing in the first flow path; a temperature acquisition unit configured to acquire a motor temperature of the electric motor; and a valve control unit configured to control the valve based on the motor temperature acquired, and the valve control unit may control the valve such that when the motor temperature is high, the flow rate of the fluid flowing in the first flow path increases as compared with that when the motor temperature is low. In this case, the compressor can more appropriately suppress the heat generation of the electric motor according to the motor temperature.
The compressor described above may further include a third flow path forming member configured to form a third flow path guiding the fluid supplied from outside to the fluid intake port of the impeller, the electric motor may be disposed in the third flow path, and a downstream end of the second flow path may be connected to the third flow path at a position between the electric motor and the fluid intake port. In this case, the fluid flowing through the second flow path is not affected by the heat of the electric motor. That is, the fluid acting on the turbine is supplied to the impeller without being heated by the heat of the electric motor. As a result, the compressor can supply a fluid at a lower temperature to the impeller, and compression efficiency can be improved.
Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that in the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description will be omitted.
As illustrated in FIG. 1, a compressor 10 is, for example, a series two-stage compressor. The compressor 10 compresses a fluid supplied from the outside with a driving force of an electric motor 4. The compressor 10 includes a first impeller 1, a second impeller 2, a turbine 3, the electric motor 4, a rotating shaft 5, a housing 6, a return pipe 7, a valve 8, and a control unit 9 (see FIG. 2).
The first impeller 1, the second impeller 2, the turbine 3, and the electric motor 4 are accommodated in the housing 6. Note that the housing 6 may include a plurality of components.
The first impeller (impeller) 1 and the second impeller 2 are attached to one end of the rotating shaft 5. The first impeller 1 and the second impeller 2 rotate integrally with the rotating shaft 5. For example, the first impeller 1 and the second impeller 2 are disposed such that the back surfaces thereof face each other with a predetermined interval. The first impeller 1 is disposed coaxially with the second impeller 2. The first impeller 1 is located between the second impeller 2 and the electric motor 4 on the rotating shaft 5. The first impeller 1 and the second impeller 2 each compress the supplied fluid.
Around the first impeller 1, a first fluid intake port (fluid intake port) H11 and a first scroll flow path H12 are formed in the housing 6. The first fluid intake port H11 is open on a rotation axis of the rotating shaft 5. The first fluid intake port H11 introduces the fluid into the first impeller 1. The first scroll flow path H12 extends in a circumferential direction around the rotation axis of the rotating shaft 5 around the first impeller 1. The first impeller 1 rotates to suck the fluid from the first fluid intake port H11 and send the fluid to the first scroll flow path H12. The fluid sucked from the first fluid intake port H11 is compressed by passing through the first impeller 1 and the first scroll flow path H12.
Around the second impeller 2, a second fluid intake port H21 and a second scroll flow path H22 are formed in the housing 6. The second fluid intake port H21 is open on the rotation axis of the rotating shaft 5. The second fluid intake port H21 introduces the fluid into the second impeller 2. The second scroll flow path H22 extends in the circumferential direction around the rotation axis of the rotating shaft 5 around the second impeller 2. The second impeller 2 rotates to suck the fluid from the second fluid intake port H21. The second impeller 2 sends the sucked fluid to the second scroll flow path H22. The fluid sucked from the second fluid intake port H21 is compressed by passing through the second impeller 2 and the second scroll flow path H22.
In the present embodiment, a discharge port of the first scroll flow path H12 on the first impeller 1 side and the second fluid intake port H21 on the second impeller 2 side are connected to each other by a coupling flow path L10. The coupling flow path L10 is formed by the housing 6. The first impeller 1 and the first scroll flow path H12 constitute a compression stage on a low-pressure side that sucks and compresses a fluid. The second impeller 2 and the second scroll flow path H22 constitute a compression stage on a high-pressure side that further compresses the fluid compressed by the compression stage on the low-pressure side.
The turbine 3 is attached to the other end of the rotating shaft 5. The turbine 3 rotates integrally with the rotating shaft 5. The turbine 3 is provided coaxially with the first impeller 1 and the second impeller 2. Around the turbine 3, a turbine outlet H31 and a turbine scroll flow path H32 are provided in the housing 6. The turbine outlet H31 is open on the rotation axis of the rotating shaft 5. The fluid after acting on the turbine 3 flows out from the turbine outlet H31. The turbine scroll flow path H32 extends in the circumferential direction around the rotation axis of the rotating shaft 5 in a circumferential direction of the turbine 3. A return flow path (first flow path) L1 to be described later is connected to the turbine scroll flow path H32. The turbine scroll flow path H32 guides the fluid introduced from the return flow path L1 to the turbine 3. The fluid guided to the turbine 3 rotates the turbine 3.
The electric motor 4 rotates the rotating shaft 5. That is, the rotating shaft 5 is driven (rotationally driven) by the electric motor 4. The electric motor 4 is disposed between the first impeller 1 and the turbine 3 on the rotating shaft 5.
Next, details of fluid flow paths provided in the compressor 10 will be described. Around the rotating shaft 5 between the first impeller 1 and the turbine 3, a supply flow path (second flow path) L2 is formed in the housing (second flow path forming member) 6. The supply flow path L2 extends along an extending direction of the rotating shaft 5. The electric motor 4 and the rotating shaft 5 are disposed in the supply flow path L2. An end of the supply flow path L2 on the turbine 3 side is connected to the turbine outlet H31. An end of the supply flow path L2 on the first impeller 1 side is connected to the first fluid intake port H11.
In the housing 6, an introduction flow path L3 through which the fluid supplied from the outside of the compressor 10 passes is formed. A downstream end of the introduction flow path L3 is connected to the supply flow path L2 at a position (position between the electric motor 4 and the turbine outlet H31) on the upstream side of the electric motor 4. As a result, the fluid supplied from the outside to the compressor 10 via the introduction flow path L3 and the fluid after acting on the turbine 3 are guided to the first fluid intake port H11 of the first impeller 1 by the supply flow path L2.
Note that the electric motor 4 is disposed in the supply flow path L2 as described above. That is, the fluid flowing in the supply flow path L2 comes into contact with the electric motor 4. Therefore, the compressor 10 can cool the electric motor 4 with the fluid flowing through the supply flow path L2. Note that the entire electric motor 4 may not be disposed in the supply flow path L2. At least a part or some components of the electric motor 4 may be disposed in the supply flow path L2. In addition, disposing the electric motor 4 in the supply flow path L2 includes exposing at least a part of the electric motor 4 in the supply flow path L2.
A discharge flow path L4 is formed in the housing 6. The discharge flow path L4 is connected to the second scroll flow path H22. As a result, the fluid compressed by the first impeller 1 and the second impeller 2 is discharged to the outside (outside the housing 6) via the discharge flow path L4. The fluid discharged from the discharge flow path L4 is supplied to a supply destination of the fluid.
The return flow path L1 is connected to the discharge flow path L4 so as to be branched from the discharge flow path L4. That is, one end of the return flow path L1 is connected to the discharge flow path L4. The other end of the return flow path L1 is connected to the turbine scroll flow path H32. In the present embodiment, the return flow path L1 is formed by the return pipe (first flow path forming member) 7 and the housing (first flow path forming member) 6 forming a flow path in the vicinity of the turbine scroll flow path H32.
A part of the fluid flowing through the discharge flow path L4 is guided to the turbine scroll flow path H32 via the return flow path L1, and further guided from the turbine scroll flow path H32 to the turbine 3. As described above, the return flow path L1 guides a part of the fluid compressed by the first impeller 1 and the second impeller 2 to the turbine 3. The fluid guided to the turbine 3 rotates the turbine 3. As a result, the rotating shaft 5 rotates together with the turbine 3.
The valve 8 adjusts the flow rate of the fluid flowing through the return flow path L1. In the present embodiment, the valve 8 is provided in the return pipe 7 forming the return flow path L1.
As illustrated in FIG. 2, the control unit 9 controls the valve 8 (controls the valve opening). The control unit 9 includes, for example, an electronic control unit including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like.
The control unit 9 functionally includes a temperature acquisition unit 91 and a valve control unit 92. The temperature acquisition unit 91 acquires a motor temperature of the electric motor 4. Here, the "motor temperature" may be the temperature of the electric motor 4 actually measured, or may be the temperature of the electric motor 4 estimated from another value. For example, the temperature acquisition unit 91 may acquire, as the motor temperature, the temperature (measurement result) of the electric motor 4 measured by a non-contact type temperature sensor or the like. For example, the temperature of the fluid in the vicinity of the first fluid intake port H11 to which the supply flow path L2 is connected is related to the temperature of the electric motor 4. Therefore, the temperature acquisition unit 91 acquires the temperature of the fluid in the vicinity of the first fluid intake port H11 measured by a temperature sensor or the like. Then, the temperature acquisition unit 91 may estimate the temperature of the electric motor 4 based on the acquired temperature and acquire the estimated temperature as the motor temperature. As described above, the temperature acquisition unit 91 may acquire the motor temperature based on the temperature of a portion related to the temperature of the electric motor 4.
The valve control unit 92 controls the valve opening of the valve 8 based on the motor temperature acquired by the temperature acquisition unit 91. More specifically, the valve control unit 92 controls the valve 8 such that when the motor temperature is high, the flow rate of the fluid flowing in the return flow path L1 increases as compared with that when the motor temperature is low.
As described above, since the return flow path L1 and the supply flow path L2 are provided, the compressor 10 can increase the flow rate of the fluid flowing through an aerodynamic element K configured by the first impeller 1, the first scroll flow path H12, the second impeller 2, and the second scroll flow path H22. In addition, a part of the fluid compressed by the first impeller 1 and the second impeller 2 is guided to the turbine 3 by the return flow path L1. As a result, in this compressor 10, the turbine 3 can be driven by the fluid returned to the aerodynamic element K in order to increase the flow rate. When the turbine 3 is driven by the fluid, the first impeller 1 and the second impeller 2 attached to the rotating shaft 5 are also driven. That is, the compressor 10 can suppress an increase in the power of the electric motor 4 by recovering, with the turbine 3, a part of the power corresponding to an increase in the flow rate of the fluid flowing through the aerodynamic element K. As a result, the compressor 10 can increase the flow rate of the fluid flowing through the aerodynamic element K while suppressing a decrease in compressor efficiency.
The electric motor 4 is disposed in the supply flow path L2. In this case, the compressor 10 can cool the electric motor 4 with the fluid flowing through the supply flow path L2. As a result, the compressor 10 can suppress heat generation of the electric motor 4 and further suppress a decrease in compressor efficiency.
The valve control unit 92 controls the valve 8 such that when the motor temperature is high, the flow rate of the fluid flowing in the return flow path L1 increases. That is, when the motor temperature is high, the flow rate of the fluid flowing through the supply flow path L2 increases as compared with that when the motor temperature is low. In this case, the compressor 10 can more appropriately suppress the heat generation of the electric motor 4 according to the motor temperature.
Next, a modification of the flow path that guides the fluid after acting on the turbine 3 to the first fluid intake port H11 of the first impeller 1 will be described. As illustrated in FIG. 3, in the housing (second flow path forming member, third flow path forming member) 6 of a compressor 10A according to the present modification, a first supply flow path (second flow path) L5 and a second supply flow path (third flow path) L6 are formed instead of the supply flow path L2 of the compressor 10 according to the embodiment.
One end of the second supply flow path L6 is connected to the introduction flow path (third flow path) L3. The other end of the second supply flow path L6 is connected to the first fluid intake port H11 of the first impeller 1. The introduction flow path L3 and the second supply flow path L6 guide a fluid supplied from the outside of the compressor 10A to the first fluid intake port H11 of the first impeller 1. In the present modification, the electric motor 4 is disposed in the second supply flow path L6.
One end (an upstream end in a fluid flow direction) of the first supply flow path L5 is connected to the turbine outlet H31. The other end (a downstream end in the fluid flow direction) of the first supply flow path L5 is connected to the second supply flow path L6 at a position between the electric motor 4 and the first fluid intake port H11. The first supply flow path L5 guides the fluid after acting on the turbine 3 to the first fluid intake port H11 of the first impeller 1 via the second supply flow path L6.
As described above, in the compressor 10A according to the present modification, the downstream end of the first supply flow path L5 is connected to the second supply flow path L6 at the position between the electric motor 4 and the first fluid intake port H11 of the first impeller 1. In this case, the fluid flowing through the first supply flow path L5 is not affected by the heat of the electric motor 4. That is, the fluid acting on the turbine 3 is supplied to the first impeller 1 without being heated by the heat of the electric motor 4. As a result, the compressor 10A can supply a fluid at a lower temperature to the first impeller 1, and compression efficiency can be improved.
Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment. For example, the compressors 10 and 10A are not limited to that including a total of two impellers of the first impeller 1 and the second impeller 2. The compressors 10 and 10A may be configured to include one or three or more impellers.
In addition, in the compressors 10 and 10A, a part of the return flow path L1 is formed by the return pipe 7. The return flow path L1 is not limited thereto, and the return flow path L1 may be formed in the housing (first flow path forming member) 6 without using the return pipe 7.

Reference Signs List

1 First impeller (impeller)
3 Turbine
4 Electric motor
5 Rotating shaft
6 Housing (first flow path forming member, second flow path forming member, third flow path forming member)
7 Return pipe (first flow path forming member)
8 Valve
10, 10A Compressor
91 Temperature acquisition unit
92 Valve control unit
H11 First fluid intake port (fluid intake port)
L1 Return flow path (first flow path)
L2 Supply flow path (second flow path)
L3 Introduction flow path (third flow path)
L5 First supply flow path (second flow path)
L6 Second supply flow path (third flow path)

Claims

A compressor compressing a fluid by a driving force of an electric motor, the compressor comprising:
a rotating shaft configured to be driven by the electric motor;

an impeller configured to be attached to the rotating shaft and compress the fluid supplied;

a turbine configured to be attached to the rotating shaft;

a first flow path forming member configured to form a first flow path guiding a part of the fluid compressed by the impeller to the turbine; and

a second flow path forming member configured to form a second flow path guiding the fluid after acting on the turbine to a fluid intake port of the impeller.
The compressor according to claim 1, wherein the electric motor is disposed in the second flow path.
The compressor according to claim 2, further comprising:
a valve configured to be provided in the first flow path forming member and adjust a flow rate of the fluid flowing in the first flow path;

a temperature acquisition unit configured to acquire a motor temperature of the electric motor; and

a valve control unit configured to control the valve based on the motor temperature acquired, wherein

the valve control unit controls the valve such that when the motor temperature is high, the flow rate of the fluid flowing in the first flow path increases as compared with the flow rate when the motor temperature is low.
The compressor according to claim 1, further comprising
a third flow path forming member configured to form a third flow path guiding the fluid supplied from outside to the fluid intake port of the impeller, wherein

the electric motor is disposed in the third flow path, and

a downstream end of the second flow path is connected to the third flow path at a position between the electric motor and the fluid intake port.