CN214273971U - Centrifugal compressor and volute thereof - Google Patents

Abstract

The utility model provides a centrifugal compressor and spiral case thereof. The flow channel defined by the volute comprises a volute flow channel and an air outlet flow channel which are connected, and the air outlet flow channel is integrally linear and is used for discharging air flow; and the inner wall of the flow channel of the volute protrudes to form at least one flow guide part which is positioned at the connecting part of the volute flow channel and the air outlet flow channel and is used for rectifying and dredging the airflow flowing to the air outlet flow channel. The utility model discloses do benefit to and realize that centrifugal compressor is miniaturized, and can keep high efficiency.

Description

Centrifugal compressor and volute thereof

Technical Field

The utility model relates to a compressor technical field, in particular to centrifugal compressor and spiral case thereof.

Background

The centrifugal compressor has the remarkable advantages of energy conservation, high efficiency, stable operation and long service life. However, in the refrigeration field, the centrifugal compressor is suitable for large-flow and low-pressure-ratio working occasions, and the efficient low-flow and high-pressure-ratio operation is difficult to realize. Therefore, the centrifugal compressor is applied to a large-cooling-capacity water chilling unit. Medium and small-sized refrigeration systems are increasingly using screw compressors, scroll compressors (such as small central air conditioners including multi-split air conditioners) and rolling rotor compressors. These types of compressors, however, operate far less efficiently than centrifugal compressors. Most of these compressors are lubricated with lubricating oil. The problems that the lubricating oil is accumulated in the heat exchanger, the oil is disadvantageously returned to the compressor, the lubrication of related compression parts is poor, the heat exchange resistance of the heat exchanger is increased and the like are easily caused.

Therefore, how to solve various problems caused by the miniaturization of the centrifugal compressor can make the centrifugal compressor applied to small and medium-sized refrigeration systems to replace screw compressors, scroll compressors and even rolling rotor compressors, so that the energy efficiency of the refrigeration systems is higher, and the refrigeration industry is influenced profoundly.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a centrifugal compressor and spiral case thereof to solve or solve the above-mentioned problem that prior art exists at least partially.

The utility model aims at providing a centrifugal compressor and spiral case thereof can keep high efficiency on realizing miniaturized basis.

On one hand, the utility model provides a volute for a centrifugal compressor, wherein a flow passage limited by the volute comprises a volute flow passage and an air outlet flow passage which are connected, and the air outlet flow passage is integrally linear and is used for discharging air flow; and the inner wall of the flow channel of the volute protrudes to form at least one flow guide part which is positioned at the connecting part of the volute flow channel and the air outlet flow channel and is used for rectifying and dredging the airflow flowing to the air outlet flow channel.

Optionally, each flow guiding portion is a long strip whose length direction is parallel to the length direction of the air outlet flow channel.

Optionally, both ends of each flow guide part in the axial direction of the volute are connected to the inner wall of the volute to divide the flow passage into a plurality of sub-passages isolated from each other.

Optionally, the number of the at least one flow guide part is multiple, and the multiple flow guide parts are arranged at intervals along the width direction of the volute flow channel outlet.

Optionally, the interval between each adjacent flow guide part is gradually reduced in the direction from the inner ring to the outer ring of the volute flow channel.

Optionally, the spacing between each adjacent flow guide is equal.

Optionally, along the airflow flowing direction, the outlet flow channel gradually transits from a flat shape matched with the volute flow channel to a cylindrical shape.

Optionally, the volute defines a flow path that includes an inlet flow passage for an inlet airflow, the inlet flow passage extending in an axial direction of the volute and connected to the volute flow passage.

On the other hand, the utility model provides a centrifugal compressor, including the spiral case, its spiral case is as above arbitrary spiral case.

Optionally, the centrifugal compressor comprises: a housing; the motor is arranged in the shell; and at least one compression unit, each compression unit comprises a volute and a centrifugal impeller, the volute is arranged in the machine shell, the centrifugal impeller is arranged in the volute, and the centrifugal impeller is configured to rotate under the driving of a motor so as to compress airflow entering the volute and is arranged to the volute flow channel.

The utility model discloses after considering high-pressure draught to get into the snail runner, because the velocity of flow is very fast, the mach number is great leads to centrifugal force great, makes the air current gather to the radial outside region of snail runner, leads to the flow field inhomogeneous, takes place to whirl, arouses great energy loss. The utility model discloses an alleviate above-mentioned adverse effect, make the flow channel inner wall protrusion of spiral case form the water conservancy diversion portion of at least one very much, it is located the snail runner and the runner portion of meeting of giving vent to anger to reduce the velocity of flow and carry out the rectification and dredge to the air current to the runner of giving vent to anger, make it get into the runner of giving vent to anger more evenly, so that the flow field is more even, avoid the spiral to move, improve the complete machine efficiency of compressor.

Further, the utility model discloses an among centrifugal compressor and spiral case thereof, make a plurality of water conservancy diversion portions along the width direction interval arrangement of snail runner export, and in the direction from snail runner inner circle to outer lane, the interval between each adjacent water conservancy diversion portion reduces gradually to carry out the bigger rectification of intensity to the regional air current in the great footpath outside that is influenced by centrifugal force, carry out the rectification that intensity is little a little to the regional air current in the relatively less footpath inside that is influenced by centrifugal force, make the whole even degree of air current everywhere higher.

Further, the utility model discloses a centrifugal compressor compares in traditional centrifugal compressor, can omit the diffuser, with centrifugal impeller direct mount in the spiral case to avoid the great diffusion loss that causes of the degree of rotation of air current in the diffuser, make compressor complete machine efficiency promote, also make centrifugal compressor's structure compacter simultaneously. Therefore, this configuration is advantageous for achieving a compact centrifugal compressor, and is suitable for application to a small central air conditioner such as a small chiller or a multi-split air conditioner, while maintaining high efficiency.

Furthermore, the centrifugal compressor of the utility model can adopt a radial magnetic suspension bearing and an axial magnetic suspension bearing, and the magnetic suspension bearing is an oilless bearing, so that lubricating oil is not needed to be added in the centrifugal compressor, thereby thoroughly avoiding the oil return problem of the compressor of a medium and small refrigeration system (the traditional screw compressor, the scroll compressor and the rolling rotor compressor which are usually adopted are basically lubricated with oil), and improving the heat exchange efficiency of the heat exchanger; and the mechanical abrasion is small, the energy consumption is low, the noise is small, the stability of the whole machine is enhanced, and the service life is longer.

Further, the utility model discloses a centrifugal compressor makes the snail runner that the spiral case was injectd be the platykurtic that thickness direction is on a parallel with centrifugal impeller axis direction, and the snail runner of platykurtic makes the whole flattening of spiral case, does benefit to and realizes the compressor miniaturization. More importantly, the air outlet flow channel is gradually transited from a flat shape to a cylindrical shape from the joint of the air outlet flow channel and the volute flow channel to the outlet of the volute. Therefore, the air flow enters the cylindrical and wide air outlet flow channel from the thin and flat volute flow channel, and the excellent diffusion effect can be achieved. And because the air outlet flow channel gradually transits from the flat shape to the cylindrical shape from the joint of the air outlet flow channel and the volute flow channel to the outlet of the volute, the transition is smooth, the unnecessary resistance loss of the air flow is reduced, and meanwhile, the cylindrical shape is also suitable for being connected with a downstream pipeline.

Further, the utility model discloses recognize, directly will lead to air current mach number to increase, the air current centrifugal effect is big to the spiral case exhaust by centrifugal impeller, make the air current gather to the radial outside, lead to the flow field inhomogeneous, arouse great flow loss. For eliminate or alleviate above-mentioned adverse effect at least, the utility model discloses make the thickness of snail runner be greater than centrifugal impeller's exit width very much for the air current gets into the snail runner back diffusion deceleration of spiral case, makes its mach number descend, and centrifugal effect reduces, finally makes the flow field homogeneity of spiral case export show the increase, has finally promoted centrifugal compressor's efficiency.

Further, the utility model discloses a centrifugal impeller is strong back bend formula closed impeller to make centrifugal impeller do work to the air current more turn into the static pressure and promote, turn into speed increase still less. Because the absolute airflow angle of the outlet of the strong backward-bending centrifugal impeller is larger, if the traditional diffuser is adopted, the airflow rotation degree is larger, and the diffusion loss is larger. The utility model adopts the above-mentioned special design's spiral case lug connection centrifugal impeller, can effectively avoid this problem. Therefore, the utility model discloses set up water conservancy diversion portion in the spiral case synthetically, centrifugal impeller direct mount carries out special design to the spiral case runner in the spiral case to and adopt strong back bend formula centrifugal impeller these improvements to combine together, not only obtained each item institutional advancement's beneficial effect, but also avoided respective adverse effect, make centrifugal compressor's overall efficiency higher, the structure is compacter moreover, does benefit to and realizes its miniaturization.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1 is a flow path schematic diagram of a volute of a first embodiment of the present invention;

fig. 2 is a flow path schematic diagram of a volute of a second embodiment of the present invention;

fig. 3 is a schematic view of the overall structure of the centrifugal compressor according to an embodiment of the present invention;

fig. 4 is a schematic sectional view of the centrifugal compressor shown in fig. 3 taken along the axial direction of the centrifugal impeller;

FIG. 5 is an enlarged view at A of FIG. 4;

FIG. 6 is a schematic diagram of the structure of one of the compression units of FIG. 3;

FIG. 7 is another angular schematic view of the compression unit shown in FIG. 6;

FIG. 8 is an exploded schematic view of the compression unit shown in FIG. 6;

FIG. 9 is a schematic structural view of a centrifugal impeller in the compression unit shown in FIG. 8;

FIG. 10 is a blade profile schematic of the centrifugal impeller of FIG. 9;

FIG. 11 is an exploded schematic view of the centrifugal impeller of FIG. 9;

fig. 12 is a schematic structural view of the second impeller body in fig. 11.

Detailed Description

A centrifugal compressor and a scroll casing 100 thereof according to an embodiment of the present invention will be described with reference to fig. 1 to 12. In the partial figures, the x-axis represents the axial direction of the centrifugal impeller 200, and also the axial direction of the motor 40 and its stator 41 and rotor 42; the direction of airflow is indicated by the solid arrows.

Fig. 1 is a flow path diagram of a scroll casing 100 according to a first embodiment of the present invention. As shown in fig. 1, the flow path defined by the volute 100 of the embodiment of the present invention includes a volute flow path 102 and an outlet flow path 103 connected to each other. The spiral flow passage 102 is formed in a spiral shape, and the outlet flow passage 103 is formed in a linear shape as a whole to discharge airflow. That is, the gas flow is pressurized by the centrifugal impeller, and the high-pressure gas flow is discharged toward the scroll flow path 102, then enters the outlet flow path 103, and finally is discharged from the outlet flow path 103. As shown in fig. 1, the approximate boundary between the spiral flow channel 102 and the outlet flow channel 103 is the line C. At least one flow guiding portion 106 is formed on the inner wall of the flow channel of the volute 100, and is located at a connecting portion of the volute 102 and the air outlet flow channel 103, and is used for rectifying and guiding the air flow flowing to the air outlet flow channel 103. The connection part of the spiral flow passage 102 and the outlet flow passage 103 comprises an outlet area of the spiral flow passage 102 and an inlet area of the outlet flow passage 103. In short, the flow guiding portion 106 is to rectify and channel the airflow that will flow into or just flow into the air outlet flow channel 103.

The inventor recognizes that after the high-pressure airflow enters the volute flow channel 102, the centrifugal force is large due to the high flow speed and the high mach number, so that the airflow is accumulated to the radial outer side area of the volute flow channel 102, the flow field is uneven, the vortex motion occurs, and the large energy loss is caused. The embodiment of the utility model provides a for alleviate above-mentioned adverse effect, make the protruding water conservancy diversion portion 106 that forms at least one of runner inner wall of spiral case 100 especially, it is located spiral case runner 102 and the runner 103 portion of meeting of giving vent to anger to reduce the velocity of flow and carry out the rectification and dredge to the air current to the runner 103 of giving vent to anger, make it get into the runner 103 of giving vent to anger more evenly, so that the flow field is more even, avoids the spiral movement, improves the complete machine efficiency of compressor.

In some embodiments, as shown in fig. 1, each of the flow guiding portions 106 may be an elongated shape with a length direction parallel to the length direction of the air outlet flow channel 103. Of course, the inlet end of the flow guide portion 106 may be bent to conform to the spiral shape of the spiral flow channel 102. Both ends of each flow guide 106 in the axial direction of the scroll casing 100 (the direction perpendicular to the paper surface of fig. 1, that is, the axial direction of the centrifugal impeller 200) are connected to the inner wall of the scroll casing 100 to divide the flow passage into a plurality of sub-passages 1061 isolated from each other. The number of the flow guiding portions 106 may be multiple, and the multiple flow guiding portions 106 are arranged at intervals along the width direction of the outlet of the volute 102, as shown in fig. 1. This allows the air flow to enter the outlet flow path 103 from all over the width direction. The junction of the flow guide 106 and the inner wall of the volute 100 may be rounded to reduce airflow losses.

Fig. 2 is a flow path diagram of a volute 100 according to a second embodiment of the present invention.

In some embodiments, the spacing between each adjacent flow guide 106 may be made equal, as in fig. 1. However, as shown in fig. 2, it is preferable that the interval between each adjacent guide part 106 is gradually reduced in a direction from the inner ring (s1) to the outer ring (s2) of the scroll flow path 102, that is, the width of the sub-passage 1061 is gradually reduced. This structure can rectify the airflow in the radially outer region (region adjacent to the outer ring s2) which is greatly affected by the centrifugal force with a higher intensity, and rectify the airflow in the radially inner region (region adjacent to the inner ring s1) which is relatively less affected by the centrifugal force with a lower intensity, thereby making the airflow more uniform throughout.

In some embodiments, the volute 102 can be flat with the thickness direction parallel to the axial direction of the volute 100, i.e., the flow cross-section can be an elongated rectangle. Along the flowing direction of the air flow, the air outlet flow passage 103 gradually changes from a flat shape matched with the volute flow passage 102 into a cylindrical shape. For example, in fig. 1, the volute flow passage 102 (the portion below the line C) is flat, and gradually changes from flat to cylindrical from the portion above the line C. The flat volute flow channel 102 enables the whole volute 100 to be flat, and is beneficial to reducing the axial size of the centrifugal compressor and realizing the miniaturization of the compressor. More importantly, because the outlet flow channel gradually changes from the flat shape to the cylindrical shape, the air flow can have a very good diffusion effect in the process of entering the cylindrical and wide outlet flow channel 103 from the thin and flat volute flow channel 102. Moreover, because the air outlet flow passage 103 gradually changes from a flat shape to a cylindrical shape, the transition is very smooth, unnecessary resistance loss of the air flow is reduced, and meanwhile, the cylindrical shape is also suitable for being connected with a downstream pipeline.

The embodiment of the utility model provides an on the other hand still provides a centrifugal compressor. The volute of the centrifugal compressor is the volute 100 of any one of the above embodiments.

Fig. 3 is a schematic view of the overall structure of the centrifugal compressor according to an embodiment of the present invention; fig. 4 is a schematic sectional view of the centrifugal compressor shown in fig. 3 taken along the axial direction of the centrifugal impeller 200; fig. 5 is an enlarged view of fig. 4 at a.

As shown in fig. 3 to 5, a centrifugal compressor according to an embodiment of the present invention may generally include a casing 10, a motor 40, and at least one compression unit 20, 30.

The cabinet 10 defines an accommodation space, and the motor 40 is installed in the cabinet 10. The motor 40 includes a stator 41 and a rotor 42, the stator 41 is fixed to the housing 10, and the rotor 42 is rotatable relative to the stator 41. The number of the compression units 20, 30 may be one or more. For example, the centrifugal compressor may be of a single-stage compression type, and only one compression unit may be provided. The centrifugal compressor may be of a multistage compression type in which a plurality of compression units 20 and 30 are provided. Each compression unit 20, 30 includes a volute 100 mounted to the casing 10 and a centrifugal impeller 200 disposed within the volute 100. The centrifugal impeller 200 is configured to rotate under the drive of the motor 40 to compress the airflow entering the volute 100 and discharge it through the outlet of the volute 100.

In a conventional centrifugal compressor, a diffuser is basically disposed downstream of a centrifugal impeller at each stage, the centrifugal impeller discharges an air flow into the diffuser, and the air flow is diffused by the diffuser and then enters a volute.

The utility model discloses a centrifugal compressor compares in traditional centrifugal compressor, has left out the diffuser, with centrifugal impeller 200 direct mount in spiral case 100 to avoid the great diffusion loss that causes of the rotation degree in the diffuser of air current, make centrifugal compressor's complete machine efficiency can promote, and also make centrifugal compressor's structure compacter. Therefore, this structure is advantageous for the miniaturization of the centrifugal compressor and for the application to a small central air conditioner such as a small chiller or a multi-split air conditioner while maintaining high efficiency.

In some embodiments, such as shown in fig. 3 and 4, the centrifugal compressor may be of the two-stage compression type, with two compression units. It can be seen that one of the two compression units 20, 30 is necessarily a low pressure stage, and the other is a high pressure stage, as shown in fig. 3 and 4, the compression unit 20 on the left side of the drawing is a low pressure stage, and the compression unit 30 on the right side is a high pressure stage. The outlet of the volute 100 of the compression unit 20 of the low pressure stage communicates with the inlet of the volute 100 of the compression unit 30 of the high pressure stage through a connection pipe 90. Specifically, an inlet end of the connection pipe 90 is provided with a flange 91 to be connected with a flange 130 of an outlet of the volute 100 of the compression unit 20 of the low pressure stage, and an outlet end of the connection pipe 90 is provided with a flange 92 to be connected with the volute 100 of the compression unit 30 of the high pressure stage. It is preferable that the compression unit 20 of the low pressure stage and the compression unit 20 of the high pressure stage are respectively located at both axial sides of the motor 40, so that the centrifugal impellers 200 of the two compression units 20, 30 are respectively directly connected to the motor 40, and it is advantageous to partially cancel the axial forces of the two centrifugal impellers 200.

In some embodiments, the centrifugal compressor further comprises at least one radial magnetic bearing 60 and/or at least one axial magnetic bearing 80 mounted within the casing 10 to support the rotor 42 of the motor 40. As shown in fig. 4, the centrifugal compressor comprises two radial magnetic bearings 60 to support the rotor 42 in the radial direction. The centrifugal compressor further comprises an axial magnetic bearing 80 to counteract the axial force generated by the movement of the centrifugal impeller 200 on the rotor 42. The magnetic suspension bearing is made by adopting a magnetic suspension principle and is an oilless bearing. Therefore, lubricating oil does not need to be added into the centrifugal compressor, so that the oil return problem of the compressor of a small and medium-sized refrigeration system is thoroughly solved (the conventional screw compressor, the scroll compressor and the rolling rotor compressor which are usually adopted are basically lubricated by oil), and the heat exchange efficiency of the heat exchanger is improved. And the magnetic suspension bearing is adopted, so that the centrifugal compressor has the advantages of small mechanical wear, low energy consumption, small noise, enhanced stability and longer service life.

Further, as shown in fig. 5, on the basis of the magnetic suspension bearing, a common radial bearing 70 may be further disposed at an axial end of the rotor 42 to support the end of the rotor 42 in an important manner, so that the end is more stable and the operational reliability of the centrifugal compressor is improved.

Fig. 6 is a schematic view of a structure of one compressing unit 20 of fig. 3; FIG. 7 is another angular schematic view of the compression unit 20 of FIG. 6; fig. 8 is an exploded schematic view of the compression unit 20 shown in fig. 6.

In the embodiment of the present invention, the airflow enters the flow channel defined by the volute 100 from the inlet of the volute 100, then enters the centrifugal impeller 200 in the flow channel of the volute 100, and finally flows out from the outlet of the volute 100 to enter the next-stage compression unit 30 or the discharge compressor.

In some embodiments, as shown in fig. 6-8, the flow path defined by the volute 100 also includes an intake flow path 101 for the intake airflow. The intake runner 101 extends in the axial direction of the scroll casing 100 and is connected to the scroll runner 102. I.e. the volute flow path is divided into three sections. The inlet of inlet flow path 101 forms the inlet of volute 100 as described herein, and the outlet of outlet flow path 103 forms the outlet of volute 100.

In some embodiments, as shown in FIG. 4, the intake runner 101 may include a tapered section 1011 with a gradually decreasing cross-section in the direction of airflow to improve the efficiency of air induction. Specifically, the tapered section 1011 may be made in the shape of a truncated cone as a whole, with a generatrix in the shape of an arc with a concave side facing the central axis direction of the intake runner 101. Further, the generatrix of the tapered section 1011 may be a straight line or a combination of various shapes. The intake runner 101 may be tapered as a whole, or may be a tapered section in a partial section, and a straight section in a partial section, whose cross section does not change with the change in the axial position.

In some embodiments, as shown in fig. 8, the volute 100 may be a split structure including a volute body 110 and a cover plate 120 that are split along the axial direction of the inlet flow channel 101. The volute body 110 defines the aforementioned inlet flow passage 101, a first half of the volute flow passage 102 and an outlet flow passage 103, wherein the volute flow passage 102 is open to one side of the cover plate 120. The cover plate 120 covers an axial side of the volute body 110 to cover an open side of a first half of the volute 102 and define a second half of the volute 102, the first half of the volute 102 and the second half of the volute 102 opposing each other to form the completed volute 102. The rotation shaft 214 of the centrifugal impeller 200 is connected to the rotor 42 of the motor 40 through the center hole of the cover plate 120.

In the present embodiment, the volute casing 100 is provided as a separate structure, and the volute casing body 110 and the cover plate 120 are separately machined to form the inlet flow passage 101, the volute flow passage 102 and the outlet flow passage 103 by machining. Compared with the existing integrally cast volute, in the embodiment, the surfaces of the inlet flow channel 101, the volute flow channel 102 and the outlet flow channel 103 are smoother, the uniformity of an internal flow field can be better met, the flow loss caused by the fact that the surfaces of the flow channels are too rough is reduced, and the operating efficiency of the centrifugal compressor is improved.

Further, as shown in fig. 5, two planes in the thickness direction of the volute flow channel 102 and the circumferential volute side face can be transited by a fillet (R angle in fig. 5) so as to increase the strength of the volute, relieve the local stress concentration, eliminate the corner vortex and ensure the uniformity of the flow field. The size of R can be selected based on the thickness of the volute 102. The split configuration of the volute 100 facilitates the machining of the aforementioned rounded corners.

Fig. 9 is a schematic structural view of the centrifugal impeller 200 in the compression unit 20 shown in fig. 8; fig. 10 is a blade profile schematic of the centrifugal impeller 200 shown in fig. 9.

In some embodiments, the thickness of the volute 102 is made greater than the outlet width of the centrifugal impeller 200. The thickness of the volute 102 refers to the dimension of the volute in the axial direction (x-axis) of the centrifugal impeller 200, and the outlet width B of the centrifugal impeller 200 refers to the dimension of the outlet 202 of the centrifugal impeller 200 in the axial direction of the centrifugal impeller 200, and is specifically marked in fig. 9. Specifically, the inventors have confirmed through a plurality of experiments that the optimum effect can be obtained by setting the ratio of the thickness of the scroll flow passage 102 to the outlet width of the centrifugal impeller 200 to 1.5 to 2.

The inventors have recognized that exhausting centrifugal impeller 200 directly to volute 100 results in an increased mach number of the airflow, a large centrifugal effect of the airflow that accumulates radially outward, resulting in an uneven flow field, resulting in large flow losses. In order to eliminate or at least alleviate the above adverse effect, the embodiment of the present invention particularly makes the thickness of the volute 102 be greater than the outlet width B of the centrifugal impeller 200, so that the pressure expansion and speed reduction speed of the airflow entering (the volute 102 of) the volute 100 is reduced, the mach number of the airflow is reduced, the centrifugal effect is reduced, the uniformity of the flow field at the outlet of the volute 100 is increased significantly, and the efficiency of the compressor is improved.

In some embodiments, centrifugal impeller 200 is a strong back-curved shrouded impeller. As shown in fig. 10, the centrifugal impeller 200 has a plurality of blades 203 arranged along the circumferential direction thereof, a flow channel 212 is formed between every two adjacent blades 203, and the airflow enters the radially inner side of each flow channel 212 through the inlet 201 of the centrifugal impeller 200, and is rotated by the centrifugal impeller 200, so that the airflow flows to the radially outer side of each flow channel in each flow channel, so as to flow out of the centrifugal impeller 200 to the volute flow channel 102 of the volute 100. During which each vane 203 applies work to the airflow to raise the pressure of the airflow. Fig. 10 illustrates the rotation direction of the centrifugal impeller 200 by an arrow. Each blade 203 of the centrifugal impeller 200 has a backward-curved structure, and the tip (end adjacent to the radially outer edge of the centrifugal impeller 200) of each blade is bent backward compared to the remaining section, so that each blade of the centrifugal impeller 200 has a strong backward-curved structure, as shown in fig. 10.

The embodiment of the utility model provides a make centrifugal impeller 200 be strong back curved formula to make centrifugal impeller 200 turn into the static pressure promotion to the air current does work more, turn into speed increase still less. Because the absolute airflow angle of the outlet of the strong backward-bending centrifugal impeller is larger, if a traditional diffuser form is adopted, the airflow rotation degree is larger, and the diffusion loss is larger. The embodiment of the present invention adopts the above-mentioned specially designed volute 100 to directly connect with the centrifugal impeller 200, which can effectively avoid this problem. It can be seen that the various improvements of the embodiments of the present invention are not isolated from each other, but function in combination. Specifically, the embodiment of the utility model provides a synthetically ground centrifugal impeller 200 direct mount carries out special design in spiral case 100 runner to and adopt strong back bend formula centrifugal impeller 200 these improvements to combine together, not only obtained each item institutional advancement's beneficial effect, but also greatly avoided respective unfavorable influence, make centrifugal compressor holistic efficiency higher, the structure is compacter moreover, does benefit to and realizes the miniaturization.

Fig. 11 is an exploded schematic view of the centrifugal impeller 200 shown in fig. 9; fig. 12 is a schematic structural view of the second impeller body 220 in fig. 11.

In some embodiments, as shown in fig. 10-12, the centrifugal impeller 200 may be split. Specifically, the centrifugal impeller 200 includes a first impeller body 210 and a second impeller body 220, wherein the first impeller body 210 and the second impeller body 220 are both disc-shaped and are in butt joint, and blade halves are formed on opposite surfaces of the first impeller body 210 and the second impeller body 220, and the blade halves are connected to form a complete blade 203.

The first impeller body 210 and the second impeller body 220 may be coupled and fastened by a plurality of fasteners, such as rivets 230. One or more positioning grooves 2113 can be formed on the first impeller body 210, the same number of positioning protrusions 2214 are formed on the second impeller body 220, and each positioning protrusion 2214 is clamped into one positioning groove 2113, so that the position between the first impeller body 210 and the second impeller body 220 is more stable, the alignment between the blade halves is more accurate, and the performance of the centrifugal impeller 200 is prevented from being influenced by the misalignment of the blades 203.

The first impeller body 210 is provided with a rotation shaft 214 having a mounting hole 215 formed at the center thereof so as to be coupled to the rotor 42 by a screw 300. The second impeller body 220 is provided with an inlet 201 for the centrifugal impeller 200. The traditional centrifugal impeller is of an integrally cast type, and the surface precision of the traditional centrifugal impeller is not ideal, so that the compression efficiency and the adverse noise of the traditional centrifugal impeller are influenced. Especially for a closed impeller, the blades are inside, and the precision of the blade surface is more difficult to guarantee. In the present embodiment, the centrifugal impeller 200 is configured as a split type as described above, so that the two impeller bodies are separately manufactured, and the blades of each impeller body are exposed to the outside to process the surfaces of the impeller bodies, so that the impeller bodies are smoother.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been shown and described in detail herein, many other variations and modifications can be made, consistent with the principles of the invention, which are directly determined or derived from the disclosure herein, without departing from the spirit and scope of the invention. Accordingly, the scope of the present invention should be understood and interpreted to cover all such other variations or modifications.

Claims (10)

1. A volute for a centrifugal compressor, wherein,

the flow channel defined by the volute comprises a volute flow channel and an air outlet flow channel which are connected, and the air outlet flow channel is integrally linear and is used for discharging air flow; and is

The volute is characterized in that at least one flow guide part is formed by protruding the inner wall of the flow channel of the volute, is positioned at the connecting part of the volute flow channel and the air outlet flow channel and is used for rectifying and dredging the air flow flowing to the air outlet flow channel.

2. The spiral casing of claim 1,

each flow guide part is a long strip with the length direction parallel to the length direction of the air outlet flow channel.

3. The spiral casing of claim 1,

both ends of each flow guide part in the axial direction of the volute are connected to the inner wall of the volute so as to divide the flow channel into a plurality of sub-channels which are isolated from each other.

4. The spiral casing of claim 1,

the number of the at least one flow guide part is multiple, and the flow guide parts are arranged at intervals along the width direction of the volute flow channel outlet.

5. The spiral casing of claim 4,

and the interval between every two adjacent flow guide parts is gradually reduced in the direction from the inner ring to the outer ring of the volute flow channel.

6. The spiral casing of claim 4,

the intervals between every two adjacent flow guide parts are equal.

7. The spiral casing of claim 1,

the volute flow channel is flat with the thickness direction parallel to the axial direction of the volute; and is

Along the airflow flowing direction, the air outlet flow channel gradually transits from a flat shape matched with the volute flow channel to a cylinder shape.

8. The spiral casing of claim 1,

the volute defines a flow passage that includes an inlet flow passage for an inlet airflow, the inlet flow passage extending in an axial direction of the volute and connected to the volute flow passage.

9. A centrifugal compressor comprising a volute, wherein the volute is as claimed in any one of claims 1 to 8.

10. The centrifugal compressor of claim 9, comprising:

a housing;

the motor is arranged in the shell; and

at least one compression unit, each compression unit including a volute and a centrifugal impeller, the volute being mounted to the housing, the centrifugal impeller being mounted within the volute, the centrifugal impeller being configured to rotate under the drive of the motor to compress an airflow entering the volute and discharge the airflow toward the volute.

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