JP2626253B2 - Turbo compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo compressor used in a refrigerator of an air conditioner and the like.

[0002]

2. Description of the Related Art The basic structure of a turbo compressor conventionally used in a refrigerator such as an air conditioner is shown in FIG.
Is shown in In this turbo compressor, a refrigerant gas evaporated by heat absorption from the outside in an evaporator (not shown) is guided through a pipe 1, and the refrigerant gas is sucked from an intake nozzle 2 to be compressed, and the compressed high-temperature and high-pressure refrigerant is compressed. The gas is supplied from the outlet 3 to a condenser (not shown).

In the gear chamber 5 of the housing 4, a speed increasing device 6 interlocked with a motor (not shown) is arranged, and the impeller 7 is rotated by the speed increasing device 6. Thus, the refrigerant gas sucked in while adjusting the flow rate from the intake nozzle 2 by the guide vanes 8 is introduced into the vortex chamber 10 through the diffuser 9 facing the outlet of the impeller 7.
In this way, velocity energy is given to the sucked refrigerant gas by centrifugal force, and compression of the refrigerant gas is achieved by converting this velocity energy into pressure energy.

The gear chamber 5 and a portion of the pipe 1 near the intake nozzle 2 are connected by a pressure equalizing pipe 11. As a result, the refrigerant gas dissolved in the lubricating oil enters the gear chamber 5, and the refrigerant gas evaporated in the gear chamber 5 is guided to the space near the low-pressure intake nozzle 2, and the refrigerant gas is thus discharged. Collected. Reference numeral 12 denotes a labyrinth, which suppresses leakage of compressed refrigerant gas from the high-pressure space 13 in which the impeller 7 is accommodated, while allowing rotation of the impeller 7.

[0005]

In the turbo compressor as described above, for example, between the suction portion 14 of the impeller 7 and the suction vane 15 for guiding the refrigerant gas from the intake nozzle 2 to the impeller 7, There is a gap 16 of about 10 mm. Therefore, the refrigerant gas guided from the high-pressure space 13 through the labyrinth 12 to the relatively low-pressure space 18 in the housing 11 flows toward the rotation axis direction of the impeller 7 through the gap 16. .
Therefore, the flow direction of the refrigerant gas flowing from the gap 16 is substantially perpendicular to the flow direction of the refrigerant gas supplied from the intake nozzle 2 to the impeller 7 via the suction vanes 15. For this reason, in the vicinity of the suction portion 14 of the impeller 7, the flow of the refrigerant gas becomes unstable due to the collision between the refrigerant gas from the intake nozzle 2 and the refrigerant gas from the gap 16, and the impeller efficiency deteriorates.

[0006] Such a problem is particularly remarkable at a low load, and the separation of the impeller 7 on the shroud 17 side is accelerated due to the disturbance of the flow of the refrigerant gas from the gap 16. There is a problem that a backflow as shown below is caused, which further impairs the impeller efficiency. Then, an object of the present invention is to solve the above-mentioned technical problems, and to provide a turbo compressor capable of improving the impeller efficiency by improving the flow of the fluid guided to the impeller.

[0007]

According to a first aspect of the present invention, there is provided a turbo compressor, wherein a suction portion of an impeller is opposed to an end of a suction pipe member for sucking a fluid to be compressed. in the shroud-side portions of the slats turbo compressor which has overhang to the suction unit, said Lee
A speed increasing device that applies torque to the rotating shaft of the impeller was installed.
It has a gear chamber, and in the middle of the suction pipe member,
A suction amount adjusting vane for adjusting the suction amount.
The gear is located downstream of the adjustment vane and between the end of the suction portion of the impeller and the end of the suction pipe member.
Via a route that bypasses the space containing the impeller from the room
Te fluid flowing into the suction portion of the impeller, to form a fluid supply passage for introducing substantially parallel to the flow direction of the fluid from the suction pipe member, immediately before the fluid supply path, the shroud-side portion of the slat It is characterized by having an opening at the end.

Further, the turbo compressor according to claim 2, wherein the pressure
An impeller at the end of the suction pipe member for sucking the fluid to be compressed
Of the impeller blades
Turbo compressor with ridge side projecting to the suction section
In the tip portion of the suction portion of the impeller and the suction
Between the end of the pipe member and the outside of the suction pipe member,
The fluid flowing into the suction portion of the impeller is supplied to the suction pipe member.
Fluid supply path that is introduced almost parallel to the direction of fluid flow from
And the fluid supply passage is provided with a shroud of the blade.
It opens right before the side part, and in the middle of the above suction pipe member
Is a suction volume adjustment vane for adjusting the suction volume of fluid.
Provided in the middle of the suction pipe member and
From the upstream side, a fluid is guided to the outside of the suction pipe member,
It is characterized by having a path for guiding a fluid to the fluid supply path . Further, the turbo compressor according to claim 3 is the claim
2, a rotational force is applied to the rotating shaft of the impeller.
It has a gear chamber in which a speed-increasing device is arranged.
And a path for guiding the fluid to the fluid supply path .

[0009]

According to the above construction, the fluid guided from the outside of the suction pipe member to the suction portion of the impeller via the fluid supply path is:
The fluid is guided substantially parallel to the flow direction of the fluid from the suction pipe member. Therefore, the fluid from the suction pipe member and the fluid flowing from outside do not collide in the vicinity of the suction portion of the impeller, and the flow of the fluid in the vicinity thereof is rectified.
Further, the turbo compressor of the present invention has a blade of the impeller (29).
Attach the shroud (29B) side of the root plate to the suction section (28).
It is the type of
Is inclined near the blades of the suction part, where backflow and peeling are likely to occur.
In the direction. In contrast, in the present invention, the fluid supply path
From the blade to the position immediately before the shroud side of the blade
The body regulates the fluid flowing from the suction pipe member into the suction section.
As a result, the above-mentioned backflow and separation can be prevented.
Can be prevented.

Further, impeller from relatively high pressure above gear chamber
The low-pressure space of the suction portion of the impeller through a passage that bypasses the space containing the error, since the flow body is guided, to strengthen rectification of the fluid flow in the suction portion near the impeller at low load Can be stabilized.

Furthermore, with the configuration according to claim 2, the fluid of the suction pipe member, a relatively space of the suction portion near the low pressure impeller, is guided through the upper Kikei path and the fluid supply passage. Therefore, even by this configuration can be achieved the same effect as in claim 1. In particular, the present invention, since the front and rear intake amount adjustment vanes are communicated through the upper Kikei path and the fluid supply channel, performing an operation described below. That is, at the time of the partial load, the suction amount adjustment vane closes, and the differential pressure increases before and after the suction amount adjustment vane. This pressure difference is the larger the more partial load, fluid is additionally supplied to the shroud side portion of the vane through the upper Kikei path and the fluid supply channel the pressure difference as a driving force. Therefore, as the suction amount adjusting vane moves toward the throttle side, the amount of fluid supplied from the fluid supply path increases, and as a result, the backflow at the suction portion of the impeller increases as the partial load, which normally causes backflow or separation, increases. The prevention effect increases. Further, claim 3
With the described configuration, the fluid rectification function is enhanced,
The flow near the suction part of the impeller during loading is reduced.
Can be normalized.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 2 is a sectional view showing the overall configuration of the turbo compressor of the present invention. This turbo compressor is used in a refrigerator of an air conditioner and the like. A high-temperature refrigerant gas vaporized by removing latent heat from the outside by an evaporator (not shown) is led from a pipe 21 and compressed. Then, the high-temperature and high-pressure refrigerant gas is supplied from the discharge port 22 to a condenser (not shown).

The refrigerant gas from the pipe 21 is supplied to an intake nozzle 23
Is sucked into the housing 25 while adjusting the flow rate by the guide vane 24 as a suction amount adjusting vane ,
Through the suction vane 26, the air is supplied to an impeller 28 in which an intake unit 28 is arranged so as to face an end 27 of the suction vane 26. The pipe 21, the intake nozzle 23
And a suction pipe member including the suction vane 26.

When the impeller 29 is driven to rotate at a high speed, the refrigerant gas sucked from the suction part 28 is given a centrifugal force when passing through the passage between the hub 29A and the shroud 29B, and is swirled through the diffuser 30. It is led to the chamber 31.
In this manner, velocity energy is given to the sucked refrigerant gas by centrifugal force, and compression of the refrigerant gas is achieved by converting this velocity energy into pressure energy.

The rotating shaft 32 of the impeller 29 is provided with a rotational force from a speed increasing device 34 disposed in a gear chamber 33 at the center of the housing 25. The speed increasing device 34 is linked to a motor (not shown), and increases the speed of rotation of the motor and transmits the rotation to the rotating shaft 32. The gear chamber 33 and a portion of the pipe 21 near the intake nozzle 23 are connected by a pressure equalizing pipe 35, which melts into the lubricating oil, enters the gear chamber 33, and evaporates the refrigerant gas evaporated in the gear chamber 33. The refrigerant gas is guided to the vicinity of the intake nozzle 23 which has a relatively low pressure to recover the refrigerant gas. In a normal operation state, the lubricating oil temperature is 5
The temperature becomes about 0 ° C., and a pressure difference of about 50 to 100 mmHg is generated between the gear chamber 33 and the pipe 21 due to the evaporation of the refrigerant gas at this temperature.

FIG. 1 is an enlarged cross-sectional view showing the configuration near the suction vane 26. As shown in FIG. The distal end portion 41 of the suction portion 28 of the impeller 29 is formed in a tapered shape such that the diameter gradually decreases toward the flow direction 42 of the refrigerant gas from the intake nozzle 23. The end portion 27 of the suction vane 26 facing the tip end portion 41 of the impeller 29 is formed in a tapered shape such that the diameter decreases toward the flow direction 42. In this manner, the distal end portion 41 of the impeller 29 and the end portion 27 of the suction vane 26, each of which is formed in a tapered shape, form a refrigerant gas supply passage 43 which is an annular fluid supply passage. The refrigerant gas supply path 43 is a path (for example, a passage width of 4 mm) whose cross section is inclined at a small angle with respect to the flow direction 42, and the refrigerant gas from the space 44 in the housing 25 is indicated by an arrow 51. The shroud 29B of the impeller 28 is substantially parallel to the flow direction 42.
Into the space near the entrance.

The refrigerant gas from the high-pressure space 46 containing the impeller 29 enters the space 44 via a labyrinth 45 provided between the shroud 29B of the impeller 44 and the housing 25. Furthermore, this space 4
The gear chamber 33 is connected to a pressure equalizing pipe 35 via a pipe 47 which is connected to the pressure equalizing pipe 35 and forms a first path together with the pressure equalizing pipe 35.
The refrigerant gas in the middle of being collected in the pipe 21 is guided from the pipe.

The pipe 47 and the pressure equalizing pipe 35 are respectively
Solenoid valves 49 and 50 that are opened and closed by control means (not shown)
Is provided. The solenoid valve 49 is controlled to be open when the load is low, and is closed during the remaining period.
The solenoid valve 49 may be open at the time of normal load, but is preferably closed at least at startup. This is because the space 44 is rapidly depressurized at the time of startup, so that the refrigerant dissolved in the lubricating oil in the gear chamber 33 evaporates rapidly, flashes, and is flushed with the lubricating oil through the equalizing pipe 35 and the pipe 47. This is because there is a risk of flowing into the space 44. If such a situation occurs, the oil stored in an oil tank (not shown) is unnecessarily consumed, which is not preferable.

The solenoid valve 50 is closed at least at startup and opened after a certain period of time in order to reduce the load at startup and to smoothly start up the apparatus. According to the turbo compressor of the present embodiment having such a configuration, the tip 4 of the suction portion 28 of the impeller 29
1 through the refrigerant gas supply passage 43 formed by the end portion 27 of the suction vane 26, the refrigerant gas from the space 44 flows in the refrigerant gas flow direction 42 from the intake nozzle 23.
Are guided to the impeller 29 almost in parallel. Therefore,
Collision between the flow of the refrigerant gas guided from the suction nozzle 23 via the suction vanes 26 and the flow of the refrigerant gas from the space 44 is prevented, and the flow of the refrigerant gas near the suction portion 28 of the impeller 29 is rectified. Be transformed into This allows
Even at a low load, the suction part 2 of the impeller 29
8, the flow of the refrigerant gas is not disturbed in the space on the shroud 29B side, and separation and backflow of the flow can be effectively suppressed.

Further, in this embodiment, when the load is low, the electromagnetic valve 49 is opened, and the refrigerant gas is supplied from the gear chamber 34 to the space 44 for supplying the refrigerant gas to the refrigerant gas supply passage 43 together with the refrigerant gas via the labyrinth 45. Since the refrigerant gas is also guided, the rectifying action described above at the time of low load is increased, and the turbulence of the flow at the time of low load is more effectively suppressed.

Thus, the suction portion 28 of the impeller 29
, The flow of the refrigerant gas in the vicinity of can be maintained stably even at a low load, so that the refrigerant gas is efficiently supplied to the impeller 29 to improve the impeller efficiency and, consequently, the compression efficiency of the turbo compressor. Can be improved. In the above embodiment, the solenoid valve 50 is not always necessary, and the valve may be provided only in the pipe 47 without providing the valve in the equalizing pipe 35.
By closing the electromagnetic valve 49 provided in the pipe 47 at least at the time of startup, the lubricating oil in the gear chamber 33 is prevented from being guided to the pressure equalizing pipe 35 together with the refrigerant gas.

Further, the connection between the gear chamber 33 and the pipe 21 is not always necessary, and as shown in FIG.
1 connects the gear chamber 33 and the space 44 to each other.
May be provided in the middle of the process. Further, in the configuration shown in FIGS. 1 and 3, neither the solenoid valve 47 nor the solenoid valve 50 may be provided, and in this case, the space 4 for the lubricating oil from the gear chamber 33 at the time of startup.
There is a problem that the refrigerant gas flows into the fuel cell 4 and a problem that starting is difficult, but the flow of the refrigerant gas at a low load is kept stable.

FIG. 4 is a sectional view showing the structure of another embodiment of the present invention. In FIG. 4, portions corresponding to the respective portions shown in FIG. 1 are denoted by the same reference numerals.
In the present embodiment, a pipe 52 is provided which forms a second path for guiding the refrigerant gas flowing through a portion of the pipe 21 near the intake nozzle 23 to the outside of the pipe 21 and supplying it to the space 44. An electromagnetic valve 53 is provided in the middle of the pipe 52,
The control unit (not shown) is set to an open state at a low load. Although the solenoid valve 53 may be kept open even under normal load, it is preferable that the solenoid valve 53 be closed during a predetermined time at the time of startup in order to smoothly start up the apparatus.

The pressure of the pipe 21 in the vicinity of the suction nozzle 23 is higher than the pressure of the space in the vicinity of the suction part 28 of the impeller 29 by about 20 to 100 mmHg. Therefore, the refrigerant gas flowing through the pipe 21 is guided to the space 44 via the pipe 52, and is supplied from the refrigerant gas supply passage 43 to the suction portion 28 of the impeller 29 together with the refrigerant gas flowing into the space 44 via the labyrinth 45. Is done.

With such a configuration, the operation and effect described in connection with the first embodiment can be obviously achieved.
In the configuration of the present embodiment, the solenoid valve 53 provided in the middle of the pipe 52 is not always necessary, and the configuration in which the solenoid valve 53 is not provided can stably maintain the flow of the refrigerant gas at a low load. .

The present invention is not limited to the above embodiment. For example, in each of the above embodiments, the pipe 4
The refrigerant gas from the gear chamber 33 or the pipe 21 is led to the space 44 through the spaces 7, 51 and 52, but neither of the pipes 47 or 48 may be provided. Also, for example, in the configuration of FIG.
The pipe 52 shown in FIG. 4 may be provided at the same time. Further, in the above-described first embodiment, the first path is formed by a part of the pressure equalizing pipe 35 and the pipe 47, but the pipe connecting the gear chamber 33 and the space 44 separately from the pressure equalizing pipe 35. May be provided. Various other design changes can be made without departing from the scope of the present invention.

[0027]

As described above, according to the turbo compressor of the present invention, the flow of fluid in the suction section of the impeller can be stabilized even at a low load.
By improving the impeller efficiency, the compression efficiency can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a configuration of a main part of a turbo compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the overall configuration of the turbo compressor.

FIG. 3 is a sectional view showing a configuration of a modification of the above embodiment.

FIG. 4 is an enlarged sectional view showing a configuration of a main part of a turbo compressor according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a configuration of a conventional turbo compressor.

[Explanation of symbols]

 21 Pipe 23 Intake Nozzle 25 Housing 26 Suction Vane 27 End 28 Suction Port 29 Impeller 32 Rotating Shaft 33 Gear Chamber 34 Speed Intensifier 35 Equalizing Tube 41 Tip 42 Flow Direction 43 Refrigerant Gas Supply Path (Fluid Supply Path) 45 Labyrinth 47 Piping (first path) 51 Piping (first path) 52 Piping (second path)

Claims (3)

(57) [Claims] A suction pipe member for sucking a fluid to be compressed;
The suction portion (28) of the impeller (29) faces the end (27) of the impeller (23, 26), and the shroud (29B) of the impeller blades of the impeller (29)
In a turbo compressor having a side portion protruding to the suction portion (28) , a speed increase that applies a rotational force to the rotation shaft (32) of the impeller (29)
It has a gear chamber (33) in which a device (34) is arranged, and regulates the fluid suction amount in the middle of the suction pipe members ( 21, 23, 26).
A suction amount adjusting vane (24) for adjusting the suction amount , and a tip (41) of a suction portion (28) of the impeller (29) downstream of the suction amount adjusting vane (24) and the suction port. Between the gear chamber (33) and the end (27) of the pipe member (21, 23, 26).
Route (35, bypassing) the space (46) containing the impeller (29)
The fluid flowing into the suction portion (28) of the impeller (29) through the suction pipe member (21, 23, 26) through the suction pipe member (21, 23, 26) is introduced substantially in parallel to the flow direction (42) of the fluid from the suction pipe member (21, 23, 26). A fluid supply path (43) is formed, and the fluid supply path (43) is a shroud (29B) for the blade.
A turbo compressor characterized by being open immediately before a side portion. 2. A suction pipe member for sucking a fluid to be compressed.
(23, 26) with the suction part (28) of the impeller (29) facing the end (27)
And shroud (29B) of impeller blades of impeller (29)
Turbo compressor with side part protruding to the suction part (28)
In the tip portion (41) and the suction of the suction portion of the impeller (29) (28)
Between the inlet pipe member (21, 23, 26) and the end (27),
From the outside of the material (21, 23, 26), the suction part (2
8), the fluid flowing into the suction pipe member (21, 23, 26)
The fluid supply passage (4) is introduced almost parallel to the fluid flow direction (42).
3), and the fluid supply path (43) is provided with a shroud (29B) of the blade.
It is open just before the side part, and in the middle of the suction pipe member (21, 23, 26), the fluid suction amount is
A suction amount adjusting vane (24) for adjustment is provided, and in the middle of the suction pipe member (21 , 23, 26), the vane (2
From the upstream side of 4) to the outside of the suction pipe members (21, 23, 26).
A path (5) for guiding the body and guiding the fluid to the fluid supply path (43).
A turbo compressor comprising 2) . 3. A rotating force is applied to a rotating shaft (32) of the impeller (29).
A gear chamber (33) provided with a speed-increasing device (34) for providing the fluid supply path (43)
Characterized in that it has a path (35, 47, 51) leading to
2. The turbo compressor according to 2.