JPH04224299A - Turbo compressor - Google Patents

Abstract

PURPOSE:To increase efficiency by making the direction of fluid flowing from the outside of a suction tube member to the suction part of an impeller through an area between the top end of the suction part of the impeller and the end of a suction tube member in parallel roughly with a flow of fluid in the suction tube member to straighten the flow. CONSTITUTION:Both a top end 41 of a suction part 28 of an impeller 29 and a top end 27 of a suction vane 26 (suction tube member) are tapered to make a flow (arrow) 51 of refrigerant gas flowing in through a refrigerant gas feeding passage 43 between these both ends in parallel roughly with a flow (arrow) 42 in the suction wane 26. Thus collision of flow near these ends is not produced to give straight and stable flow, whereby impeller efficiency and compressive efficiency are increased.

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.

0002

[Prior Art] The basic configuration of a turbo compressor conventionally used in refrigerators such as air conditioners is shown in Figure 5.
is shown. In this turbo compressor, refrigerant gas evaporated by heat absorption from the outside in an evaporator (not shown) is guided through a pipe 1, and this refrigerant gas is sucked in through an intake nozzle 2 and compressed. Gas is supplied from the outlet 3 to a condenser (not shown).

[0003] A speed increasing device 6 which is interlocked with a motor (not shown) is disposed within the gear chamber 5 of the housing 4, and the impeller 7 is rotated by the speed increasing device 6. Thereby, the refrigerant gas sucked in from the intake nozzle 2 while adjusting the flow rate with the guide vane 8 is introduced into the vortex chamber 10 via the diffuser 9 facing the outlet of the impeller 7. In this way, velocity energy is imparted to the sucked refrigerant gas by centrifugal force, and compression of the refrigerant gas is achieved by converting this velocity energy into pressure energy.

[0004] The gear chamber 5 and a portion of the piping 1 near the intake nozzle 2 are connected by a pressure equalizing pipe 11. As a result, the refrigerant gas that dissolves in the lubricating oil and enters the gear chamber 5 and evaporates in the gear chamber 5 is guided to the space near the intake nozzle 2 where the pressure is low, and in this way, the refrigerant gas is It will be collected. Note that 12 is a labyrinth, which allows the impeller 7 to rotate while suppressing leakage of compressed refrigerant gas from the high-pressure space 13 in which the impeller 7 is accommodated.

[0005]

[Problems to be Solved by the Invention] In the above-mentioned turbo compressor, there is a space between the suction part 14 of the impeller 7 and the suction vane 15 for guiding refrigerant gas from the intake nozzle 2 to the impeller 7, for example. A gap 16 of about 10 mm is created. Therefore, the refrigerant gas guided from the high-pressure space 13 to the relatively low-pressure space 18 in the housing 11 via the labyrinth 12 flows in the direction of the rotation axis of the impeller 7 via the gap 16. . Therefore, the flow direction of the refrigerant gas flowing in from the gap 16 is approximately perpendicular to the flow direction of the refrigerant gas supplied from the intake nozzle 2 to the impeller 7 via the suction vane 15. Therefore, in the vicinity of the suction portion 14 of the impeller 7, the refrigerant gas from the intake nozzle 2 and the refrigerant gas from the gap 16 collide, making the flow of the refrigerant gas unstable and impairing the impeller efficiency.

[0006] Such a problem is particularly noticeable at low loads, and the disturbance of the flow caused by the refrigerant gas from the above-mentioned gap 16 accelerates the separation of the impeller 7 on the shroud 17 side, which is indicated by reference numeral A1 in FIG. There was a problem in that the impeller efficiency was further deteriorated due to the occurrence of backflow as shown in the figure. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a turbo compressor that solves the above-mentioned technical problems, improves the flow of fluid guided to the impeller, and improves impeller efficiency.

[0007]

[Means for Solving the Problems] A turbo compressor according to claim 1 for achieving the above object is a turbo compressor in which a suction portion of an impeller is opposed to an end of a suction pipe member that sucks fluid to be compressed. In the compressor, between the tip of the suction part of the impeller and the end of the suction pipe member, fluid flowing from the outside of the suction pipe member into the suction part of the impeller is transferred from the suction pipe member. The present invention is characterized in that a fluid supply path is formed to introduce the fluid substantially parallel to the flow direction of the fluid.

The turbo compressor according to a second aspect of the present invention includes a housing that houses the impeller and a speed increasing device that applies rotational force to the rotating shaft of the impeller, and the speed increasing device is disposed within the housing. The present invention is characterized in that it includes a first path that guides the fluid that has entered the gear chamber to the fluid supply path. Furthermore, the turbo compressor according to a third aspect of the present invention is characterized in that a second path is provided for guiding fluid to the outside of the suction pipe member from the middle of the suction pipe member and guiding the fluid to the fluid supply path. shall be.

[0009]

According to the above structure, the fluid introduced from the outside of the suction pipe member through the fluid supply path to the suction portion of the impeller 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 in from the outside do not collide in the vicinity of the suction portion of the impeller, and the flow of fluid in this vicinity is rectified.

[0010] Furthermore, with the configuration according to claim 2, fluid is introduced from the relatively high-pressure gear chamber to the low-pressure space of the suction portion of the impeller via the first path and the fluid supply path. Become. Therefore, since the flow rate of the fluid guided to the fluid supply path increases, the rectifying effect described above is strengthened, and the flow near the suction portion of the impeller can be stabilized during low load.

Furthermore, with the configuration according to claim 3, the fluid in the suction pipe member is guided to a space near the suction portion of the impeller having a relatively low pressure via the second path and the fluid supply path. . Therefore, with this configuration as well, the same effect as in the case of claim 2 can be achieved.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will be explained in detail below with reference to the accompanying drawings showing examples. FIG. 2 is a sectional view showing the overall configuration of the turbo compressor of the present invention. This turbo compressor is used in refrigerators of air conditioners, etc. High-temperature refrigerant gas, which has been vaporized by removing latent heat from the outside in an evaporator (not shown), is led from a pipe 21, and the refrigerant gas is compressed. The high-temperature, high-pressure refrigerant gas is then supplied from the discharge port 22 to a condenser (not shown).

The refrigerant gas from the pipe 21 is passed through the intake nozzle 23
The air is sucked into the housing 25 while adjusting the flow rate by the guide vane 24, and is supplied via the suction vane 26 to the impeller 29 in which the suction part 28 is disposed opposite the end 27 of the suction vane 26. The pipe 21, the intake nozzle 23 and the suction vane 2
6, the suction pipe member is constituted.

When the impeller 29 is driven to rotate at a high speed, the refrigerant gas sucked in from the intake section 28 is subjected to centrifugal force as it passes through the passage between the hub 29A and the shroud 29B, and is sent through the diffuser 30 into a vortex. You will be led to room 31. In this way, velocity energy is imparted to the sucked refrigerant gas by centrifugal force, and this velocity energy is converted into pressure energy, thereby achieving compression of the refrigerant gas.

The rotating shaft 32 of the impeller 29 is applied with rotational force from a speed increasing device 34 disposed within a gear chamber 33 in the center of the housing 25. The speed increasing device 34 is linked to a motor (not shown), increases the speed of rotation of the motor, and transmits the speed up to the rotating shaft 32. A pressure equalizing pipe 35 connects the gear chamber 33 and a portion of the pipe 21 near the intake nozzle 23, and prevents the refrigerant gas from dissolving into the lubricating oil, entering the gear chamber 33, and evaporating within the gear chamber 33. The refrigerant gas is recovered by guiding it to the vicinity of the intake nozzle 23 where the pressure is relatively low. In addition, under normal operating conditions, the temperature of the lubricating oil is 5.
The temperature is about 0°C, and due to the evaporation of the refrigerant gas at this temperature, there is a pressure of 50 to 100 mmHg between the gear chamber 33 and the pipe 21.
There is a pressure difference of some degree.

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

Refrigerant gas from a high-pressure space 46 housing the impeller 29 enters the space 44 through a labyrinth 45 provided between the shroud 29B of the impeller 44 and the housing 25. Furthermore, this space 4
4, the gear chamber 33 is connected to the pressure equalizing pipe 35 through a pipe 47 that forms a first path together with the pressure equalizing pipe 35.
A refrigerant gas that is being recovered from the pipe 21 is guided.

The piping 47 and the pressure equalizing pipe 35 are each provided with:
Solenoid valves 49, 50 whose opening and closing are controlled by control means not shown
is provided. The solenoid valve 49 is controlled to be open during low load, and closed during the remaining period. Although this electromagnetic valve 49 may be kept open during normal load, it is preferably kept closed at least during startup. This is because at startup, the pressure in the space 44 is rapidly reduced, so the refrigerant dissolved in the lubricating oil in the gear chamber 33 rapidly evaporates, flashes, and flows together with the lubricating oil through the pressure equalizing pipe 35 and piping 47. This is because there is a possibility that it may flow into the space 44. If such a situation occurs, the oil stored in the oil tank (not shown) will be wasted, which is not preferable.

Further, in order to reduce the load at startup and smoothly start up the device, the solenoid valve 50 is closed at least at startup, and then opened after a certain period of time. According to the turbo compressor of this embodiment having such a configuration, the tip portion 4 of the suction portion 28 of the impeller 29
1 and the end 27 of the suction vane 26 , the refrigerant gas from the space 44 flows in the flow direction 42 of the refrigerant gas from the intake nozzle 23 .
It is guided to the impeller 29 almost parallel to . therefore,
Collision between the flow of refrigerant gas led from the intake nozzle 23 via the suction vane 26 and the flow of refrigerant gas from the space 44 is prevented, and the flow of refrigerant gas near the suction portion 28 of the impeller 29 is rectified. be converted into This results in
Even under low load, the suction section 2 of the impeller 29
The flow of refrigerant gas is not disturbed in the space on the shroud 29B side of No. 8, and flow separation and backflow can be effectively suppressed.

Furthermore, in this embodiment, when the load is low, the solenoid valve 49 is opened, and the refrigerant gas is supplied from the gear chamber 34 through the labyrinth 45 to the space 44 that supplies refrigerant gas to the refrigerant gas supply path 43. Since the refrigerant gas is also guided, the above-mentioned rectifying effect is increased during low loads, thereby more effectively suppressing flow turbulence during low loads.

In this way, the suction portion 28 of the impeller 29
Since the flow of refrigerant gas in the vicinity of the turbo compressor can be kept stable even under low load, refrigerant gas can be efficiently supplied to the impeller 29, improving impeller efficiency and, in turn, improving the compression efficiency of the turbo compressor. You will be able to improve your In the above embodiment, the electromagnetic valve 50 is not necessarily required, and the equal pipe 35 may not be provided with a valve, and only the pipe 47 may be provided with a valve. If the electromagnetic valve 49 provided in the pipe 47 is closed at least during 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.

Furthermore, the gear chamber 33 and the pipe 21 do not necessarily need to be connected; as shown in FIG.
1 connects the gear chamber 33 and the space 44, and the piping 51
A solenoid valve 49 may be disposed in the middle. Furthermore, in the configurations shown in FIGS. 1 and 3, neither of the solenoid valves 47 and 50 may be provided, and in this case, the space 4 for lubricating oil from the gear chamber 33 at the time of startup.
Although there are problems with the flow of refrigerant gas into the refrigerant 4 and difficulty in starting the refrigerant gas, the flow of refrigerant gas is kept stable during low loads.

FIG. 4 is a sectional view showing the structure of another embodiment of the present invention. In FIG. 4, parts corresponding to those shown in FIG. 1 described above are given the same reference numerals. In this embodiment, a pipe 52 is provided that 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 . Further, a solenoid valve 53 is disposed in the middle of the pipe 52,
It is opened at low load by a control means (not shown). Although this solenoid valve 53 may be kept open even under normal load, in order to smoothly start up the device, it is preferable to keep it closed at a predetermined time during startup.

The pressure in a portion of the pipe 21 near the intake nozzle 23 is higher than the pressure in the space near the suction portion 28 of the impeller 29 by about 20 to 100 mmHg. Therefore, the refrigerant gas flowing in the pipe 21 is guided to the space 44 via the pipe 52, and is guided to the space 44 via the labyrinth 45.
Together with the refrigerant gas flowing into the refrigerant gas 4 , the refrigerant gas is supplied from the refrigerant gas supply path 43 to the suction portion 28 of the impeller 29 .

[0025] Even with such a configuration, the effects described in connection with the above-mentioned first embodiment can be clearly achieved. Note that in the configuration of this embodiment, the solenoid valve 53 provided in the middle of the pipe 52 is not necessarily required, and a configuration without the solenoid valve 53 can also maintain a stable flow of refrigerant gas during low load. .

Note that the present invention is not limited to the above embodiments. For example, in each of the above embodiments, the piping 4
Although the refrigerant gas from the gear chamber 33 or the pipe 21 is introduced into the space 44 through the pipes 7, 51 and 52, it is not necessary to provide either of these pipes 47, 48. For example, in the configuration of FIG. 1, together with the piping 47,
The piping 52 shown in FIG. 4 may be provided at the same time. Furthermore, in the first embodiment described above, the first path is formed by a part of the pressure equalizing pipe 35 and the piping 47;
A pipe connecting the gear chamber 33 and the space 44 may be provided separately from the pressure equalizing pipe 35. Various other design changes can be made without changing the gist of the present invention.

[0027]

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

[Brief explanation of the drawing]

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

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

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

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

FIG. 5 is a sectional view showing the configuration of a conventional turbo compressor.

[Explanation of symbols]

21 Pipe 23 Intake nozzle 25 Housing 26 Suction vane 27 End part 28 Suction part 29 Impeller 32 Rotating shaft 33 Gear chamber 34 Speed increaser 35 Pressure equalizing pipe 41 Tip part 42 Flow direction 43 Refrigerant gas supply path (fluid supply path) 45 Labyrinth 47 Piping (first route) 51 Piping (first route) 52 Piping (second route)

Claims (3)

[Claims] Claim 1: A suction pipe member (2) for suctioning fluid to be compressed.
1, 23, 26) at the end (27) of the impeller (29)
In a turbo compressor in which the suction parts (28) of
The tip (4) of the suction part (28) of the impeller (29)
1) and the ends (
27), the suction pipe member (21, 23, 26)
The fluid flowing into the suction part (28) of the impeller (29) from the outside of the suction pipe member (21, 23, 26)
A turbo compressor characterized in that a fluid supply path (43) is formed to introduce fluid approximately parallel to the flow direction (42) of the fluid. 2. A housing (25) that accommodates the impeller (29) and a speed increasing device (34) that applies rotational force to the rotation shaft (32) of the impeller (29), the housing (25) having a It is characterized by comprising a first path (35, 47; 51) that guides the fluid that has entered the gear chamber (33) in which the speed increaser (34) is arranged to the fluid supply path (43). The turbo compressor according to claim 1. 3. Directing fluid from the middle of the suction pipe member (21, 23, 26) to the outside of the suction pipe member (21, 23, 26), and guiding this fluid to the fluid supply path (43). Claim 1 characterized in that it comprises a second path (52).
Or the turbo compressor according to 2.