CN214273969U - Centrifugal compressor and volute thereof - Google Patents

Abstract

The utility model provides a centrifugal compressor and spiral case thereof. The volute comprises a volute body and an end cover, the end cover is detachably attached to one side end face of the volute body, and the center of the end cover is provided with a mounting hole for mounting a centrifugal impeller; and the end surface of the end cover opposite to the volute body jointly defines a volute flow channel surrounding the periphery of the mounting hole, the volute body is further defined with an air inlet flow channel and an air outlet flow channel, the air inlet flow channel extends along the axial direction of the volute body and is used for being opposite to the inlet of the centrifugal impeller, and the air outlet flow channel is communicated with the outlet of the volute flow channel and is used for discharging airflow compressed by the centrifugal impeller. The utility model discloses make the inside surface precision of spiral case runner higher.

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 spiral case convenient to carry out finish machining to the inside surface of runner.

In one aspect, the present invention provides a volute for a centrifugal compressor, which includes:

a volute body; and

the end cover is detachably attached to one side end face of the volute body, and the center of the end cover is provided with a mounting hole for mounting a centrifugal impeller; and is

The end face of the end cover opposite to the volute body jointly defines a volute flow channel surrounding the periphery of the mounting hole, the volute body is further defined with an air inlet flow channel and an air outlet flow channel, the air inlet flow channel extends along the axial direction of the volute body and is used for being opposite to the inlet of the centrifugal impeller, and the air outlet flow channel is communicated with the outlet of the volute flow channel and is used for discharging airflow compressed by the centrifugal impeller.

Optionally, one side end face of the volute body is recessed inwards to form a concave cavity, and the end cover is integrally embedded in the concave cavity.

Optionally, the cavity is circular and the end cap is disk-shaped.

Optionally, a volute runner groove is formed in each end face, where the volute body and the end cover are attached to each other, and the two volute runner grooves are connected and spliced to form a volute runner.

Optionally, one of the end cover and the volute body is provided with a volute flow channel groove, and the end face of the other end cover covers the flow channel groove to define a volute flow channel.

Optionally, the volute runner channel opens onto the end cap.

Optionally, the volute flow channel is flat with the thickness direction parallel to the axial direction of the volute; and along the air flow flowing direction, the air outlet flow channel gradually transits from a flat shape matched with the volute flow channel to a cylinder shape.

Optionally, the end cover is fastened to the volute body by a screw connection.

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

Optionally, the centrifugal compressor further 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 a spiral case is for dividing the body structure to solve the current difficult problem that carries out surface machining in the inside runner surface of integrative casting formula spiral case. The utility model discloses the snail runner that makes the spiral case is injectd by dismantling continuous spiral case body and end cover to when making spiral case body and end cover respectively, carry out surface finishing to the internal surface of snail runner and handle and to contained angle department radius angle, make its surface more smooth, so that inside flow field distributes more evenly, reduce because of the too rough flow loss who brings of runner surface, promote centrifugal compressor's operating efficiency, in order to do benefit to centrifugal compressor's miniaturization.

And, the utility model discloses make the spiral case form by spiral case body and end cover combination, make the more complicated inlet channel of three-dimensional configuration, give vent to anger the runner and inject by the spiral case body, make the end cover structure very simple regular (for example can be discoid), neither influence showing (so that the finish machining) of spiral flow internal surface, on the other hand has also made things convenient for the finish machining operation of end cover. In addition, the structure enables the air inlet flow passage and the air outlet flow passage to form through holes, and finish machining is very convenient to carry out.

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.

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:

figure 1 is an exploded schematic view of a volute of one embodiment of the present invention;

FIG. 2 is another exploded schematic view of the volute of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the volute of FIG. 1;

FIG. 4 is a schematic exploded view of the volute of FIG. 3;

figure 5 is a schematic cross-sectional view of a volute of another embodiment of the present invention;

FIG. 6 is a schematic exploded view of the volute of FIG. 5;

fig. 7 is a schematic view of the overall structure of the centrifugal compressor according to an embodiment of the present invention;

fig. 8 is a schematic sectional view of the centrifugal compressor shown in fig. 7 taken along the axial direction of the centrifugal impeller;

FIG. 9 is an enlarged view at A of FIG. 8;

FIG. 10 is a schematic view of the construction of the centrifugal impeller in the compression unit shown in FIG. 8;

FIG. 11 is a blade profile schematic view of the centrifugal impeller of FIG. 10;

FIG. 12 is an exploded schematic view of the centrifugal impeller of FIG. 10;

fig. 13 is a schematic structural view of the second impeller body in fig. 12.

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 13. The axial directions of the volute 100 and the centrifugal impeller 200, as well as the axial directions of the motor 40 and its stator 41 and rotor 42, are indicated by the x-axis in the partial figures; the direction of airflow is indicated by the solid arrows.

Fig. 1 is an exploded schematic view of a volute 100 according to an embodiment of the present invention; FIG. 2 is another exploded schematic view of the volute 100 of FIG. 1; FIG. 3 is a schematic cross-sectional view of the volute 100 of FIG. 1; figure 4 is a schematic exploded view of the volute 100 shown in figure 3.

As shown in fig. 1-4, a volute 100 of embodiments of the present invention may generally include a volute body 110 and an end cover 120. The end cover 120 is detachably attached to one side end surface of the volute body 110. A mounting hole 121 for mounting a centrifugal impeller is formed in the center of the end cover 120. The end cover 120 and the opposing end face of the volute body 110 together define a volute flow channel 102 around the periphery of the mounting hole 121. Furthermore, the method is simple. The volute body 110 itself also defines an inlet flow channel 101 and an outlet flow channel 103, the inlet flow channel 101 extending in an axial direction of the volute body 110 for opposing the inlet of the centrifugal impeller 200, the outlet flow channel 103 communicating with the outlet of the volute flow channel 102 for discharging the air flow compressed by the centrifugal impeller 200.

In the prior art, the volute is usually cast integrally, and the surface of an internal flow channel is not easy to process in the processing process, so that the surface roughness of the volute is higher, and a flow field near the surface of the flow channel is influenced, thereby influencing the efficiency of the centrifugal compressor. The embodiment of the present invention solves the problem by designing the spiral case 100 as a split structure.

The embodiment of the utility model provides a snail flow channel 102 that makes spiral case 100 is injectd by dismantling continuous spiral case body 110 and end cover 120 to when making spiral case body 110 and end cover 120 respectively, carry out surface finishing to snail flow channel 102's internal surface and handle and to contained angle department fillet, make its surface more smooth, make inside flow field distribution more even, reduce because of the too rough flow loss who brings of flow channel surface, promote centrifugal compressor's operating efficiency, in order to do benefit to centrifugal compressor's miniaturization. Moreover, the inlet flow channel 101 and the outlet flow channel 103 with complex three-dimensional configurations are both defined by the volute body 110, so that the shape of the end cover 120 is very simple and regular (for example, the end cover can be disc-shaped), the exposure of the inner surface of the volute flow channel 102 is not affected (for finish machining), and on the other hand, the finish machining operation of the end cover 120 is also facilitated. Moreover, the structure also enables the air inlet flow passage 101 and the air outlet flow passage 103 to form through holes, and is very convenient for finish machining.

For example, the volute body blank may be first manufactured by casting. The surfaces of the end cover 120 and the volute body 110 which are jointed are finely ground, so that the surfaces are smooth enough, the installation precision is improved, the surfaces of the end cover and the volute body are jointed more tightly, and the air flow leakage is reduced. Also, the surface of the volute flow channel 102 is also finished to be sufficiently smooth.

As shown in fig. 1 to 4, one side end surface of the scroll body 110 may be recessed inward to form a cavity 111, and the end cover 120 is integrally embedded in the cavity 111. For example, the cavity 111 may be circular and the cap 120 may be disk-shaped. The end cover 120 and the volute body 110 may be fastened by a screw connection. Further, the location of the end cap 120 can also be located by using the pins and the pin holes, so that the installation position is more accurate.

Figure 5 is a schematic cross-sectional view of a volute 100 of another embodiment of the present invention; figure 6 is a schematic exploded view of the volute 100 shown in figure 5.

In some embodiments, as shown in fig. 1 to 4, the end surfaces of the volute body 110 and the end cover 120, which are attached to each other, are respectively provided with a volute channel 1021, 1022, and the two volute channels 1021, 1022 are connected and spliced to form the volute channel 102.

In other embodiments, one of the end cover 120 and the volute body 110 may be provided with a volute channel, and the end surface of the other may cover the volute channel 102 to define the volute channel. For example, as shown in fig. 5 and 6, the volute runner 1022 opens on the end cap 120. Thus, a volute runner groove can be omitted, and the processing technology is simplified.

In some embodiments, as shown in fig. 1 to 6, the volute flow channel 102 may be flat with the thickness direction parallel to the axial direction of the volute 100, that is, the flow cross section may 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. The flat volute flow channel 102 enables the whole volute 100 to be flat, so that the axial size of the centrifugal compressor is reduced, and the compressor is miniaturized. More importantly, because the outlet flow channel 103 gradually changes from flat to cylindrical, the gas flow can have a very good diffusion effect in the process of entering the cylindrical and widely opened outlet flow channel 103 from the thinner 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. 7 is a schematic view of the overall structure of the centrifugal compressor according to an embodiment of the present invention; fig. 8 is a schematic sectional view of the centrifugal compressor shown in fig. 7, taken along the axial direction of the centrifugal impeller 200; fig. 9 is an enlarged view of fig. 8 at a.

As shown in fig. 7 to 9, 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.

A conventional centrifugal compressor basically has a diffuser disposed downstream of a centrifugal impeller of each stage, and the centrifugal impeller discharges an air flow into the diffuser, and the air flow is diffused by the diffuser and then enters the scroll casing 100.

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. 7 and 8, 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. 7 and 8, 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. 8, the centrifugal compressor includes two radial magnetic bearings 60 to support the rotor 42 in a 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. 9, 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.

Further, as shown in fig. 9, two planes in the thickness direction of the volute flow channel 102 and the circumferential volute side face may be transited by a fillet (R angle in fig. 9) so as to increase the volute strength, 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. 10 is a schematic structural view of a centrifugal impeller 200 in the compression unit 20 shown in fig. 8; fig. 11 is a blade profile schematic of the centrifugal impeller 200 shown in fig. 10.

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. 10. 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. 11, 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, and flows 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. 11 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. 11.

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. 12 is an exploded schematic view of the centrifugal impeller 200 shown in FIG. 10; fig. 12 is a schematic structural view of the second impeller body 220 in fig. 12.

In some embodiments, as shown in fig. 11-13, 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 use in a centrifugal compressor, comprising:

a volute body; and

the end cover is detachably attached to one side end face of the volute body, and the center of the end cover is provided with a mounting hole for mounting a centrifugal impeller; and is

The end cover and the opposite end surface of the volute body jointly define a volute flow channel surrounding the periphery of the mounting hole, the volute body further defines an inlet flow channel and an outlet flow channel, the inlet flow channel extends along the axial direction of the volute body and is used for being opposite to the inlet of the centrifugal impeller, and the outlet flow channel is communicated with the outlet of the volute flow channel and is used for discharging airflow compressed by the centrifugal impeller.

2. The spiral casing of claim 1,

the end face of one side of the volute body is inwards recessed to form a concave cavity, and the end cover is integrally embedded and fixed in the concave cavity.

3. The spiral casing of claim 2,

the concave cavity is circular, and the end cover is disc-shaped.

4. The spiral casing of claim 1,

the end faces of the volute body and the end cover, which are mutually attached, are respectively provided with a volute flow channel groove, and the two volute flow channel grooves are connected and spliced into the volute flow channel.

5. The spiral casing of claim 1,

one of the end cover and the volute body is provided with a volute runner groove, and the end surface of the other end cover covers the volute runner groove to limit the volute runner.

6. The spiral casing of claim 5,

the volute runner groove is arranged on the end cover.

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 end cover is connected and fastened with the volute body through screws.

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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