CN112762733A

CN112762733A - Heat exchanger

Info

Publication number: CN112762733A
Application number: CN202110114157.7A
Authority: CN
Inventors: 王凯; 吴迎文; 杨瑞琦; 王鹏恩; 马腾飞
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-05-07

Abstract

The invention provides a heat exchanger. The heat exchanger includes: a first liquid passing pipe; the second liquid passing pipeline is provided with a plurality of first liquid passing holes which are arranged at intervals along the length direction of the second liquid passing pipeline; the connecting structure is arranged on the second liquid passing pipeline and is provided with a communicating cavity; the connecting structures are multiple, the connecting structures and the first liquid passing holes are arranged in a one-to-one correspondence mode, and each first liquid passing hole is communicated with the communicating cavity of the corresponding connecting structure; two ends of the flat pipe are respectively communicated with the first liquid passing pipeline and the communicating cavity; and the plurality of fins are arranged on the flat pipes at intervals along the extension direction of the flat pipes. The invention effectively solves the problem that the operation performance of the heat exchanger is influenced because the inner diameter of the liquid passing pipeline is larger than the width of the flat pipe in the prior art.

Description

Heat exchanger

Technical Field

The invention relates to the technical field of heat exchange equipment, in particular to a heat exchanger.

Background

At present, the inner diameter of a liquid passing pipeline of a traditional micro-channel heat exchanger is larger than the width of a flat pipe so as to assemble the liquid passing pipeline and the flat pipe together. However, the above arrangement increases the internal space of the liquid passing pipe, reduces the flow rate of the refrigerant in the liquid passing pipe, causes uneven liquid separation of the refrigerant entering the flat tube, reduces the operation performance of the heat exchanger, and also requires a large amount of refrigerant to be injected into the liquid passing pipe.

Disclosure of Invention

The invention mainly aims to provide a heat exchanger to solve the problem that the operation performance of the heat exchanger is influenced because the inner diameter of a liquid passing pipeline is larger than the width of a flat pipe in the prior art.

In order to achieve the above object, the present invention provides a heat exchanger comprising: a first liquid passing pipe; the second liquid passing pipeline is provided with a plurality of first liquid passing holes which are arranged at intervals along the length direction of the second liquid passing pipeline; the connecting structure is arranged on the second liquid passing pipeline and is provided with a communicating cavity; the connecting structures are multiple, the connecting structures and the first liquid passing holes are arranged in a one-to-one correspondence mode, and each first liquid passing hole is communicated with the communicating cavity of the corresponding connecting structure; two ends of the flat pipe are respectively communicated with the first liquid passing pipeline and the communicating cavity; and the plurality of fins are arranged on the flat pipes at intervals along the extension direction of the flat pipes.

Furthermore, the connecting structure is also provided with a first mounting hole and a second mounting hole, the second liquid passing pipeline is arranged in the first mounting hole in a penetrating mode, the open end of the flat pipe is arranged in the second mounting hole in a penetrating mode, and the second mounting hole is communicated with the communicating cavity.

Further, the first mounting hole extends along the radial direction of the connecting structure and penetrates through the connecting structure; the second mounting hole extends along the length direction of the connecting structure, and the length direction of the connecting structure is consistent with the width direction of the flat pipe.

Further, the length of the second mounting hole is smaller than the length of the connecting structure.

Further, the connection structure includes: the tubular body is provided with a communication cavity, and the first mounting hole and the second mounting hole are both arranged on the tubular body; a first blocking piece arranged on the first end of the tubular body for blocking the first end; a second closure member disposed on the second end of the tubular body for closing off the second end.

Furthermore, the second mounting hole is a waist-shaped hole or a rectangular hole, and the second mounting hole is matched with the outer surface of the flat pipe.

Further, the first liquid passing hole is coaxially arranged with the tubular body.

Further, first shutoff piece includes first shutoff board and first flanging structure, and first shutoff board sets up in the tubulose body and laminates the setting mutually with the inner peripheral surface of tubulose body, and first flanging structure sets up on the face that second shutoff piece was kept away from to first shutoff board.

Further, the second shutoff piece includes second shutoff board and second flanging structure, and the setting of second shutoff board just is laminated mutually with the inner peripheral surface of tubulose body in the tubulose body, and second flanging structure sets up on the face of first shutoff piece is kept away from at second shutoff board.

Further, the connecting structure is bonded with the second liquid passing pipeline, or clamped, or connected through a fastener.

Furthermore, a plurality of spacers are arranged in the second liquid passing pipeline, the inner cavity of the second liquid passing pipeline is divided into a plurality of sub-cavities by the plurality of spacers, and the sub-cavities are mutually and independently arranged; the second liquid passing pipeline is also provided with a plurality of second liquid passing holes, the plurality of second liquid passing holes are arranged in one-to-one correspondence with the plurality of sub-cavities, each second liquid passing hole is communicated with the corresponding sub-cavity, and the second liquid passing holes are communicated with the first liquid passing holes through the sub-cavities.

By applying the technical scheme of the invention, the second liquid passing pipeline is communicated with the flat pipe through the connecting structure, so that the inner diameter of the second liquid passing pipeline is not limited by the condition that the inner diameter of the second liquid passing pipeline is necessarily larger than the width of the flat pipe any more, the inner diameter of the second liquid passing pipeline can be smaller than or equal to the width of the flat pipe, the inner space of the second liquid passing pipeline is reduced, the flow velocity of a refrigerant in the second liquid passing pipeline is increased, the heat exchange efficiency of the heat exchanger is further improved, the problem that the operating performance of the heat exchanger is influenced because the inner diameter of the liquid passing pipeline is larger than the width of the flat pipe in the prior art is solved, and the. Meanwhile, the arrangement can reduce the refrigerant filling amount in the second liquid passing pipeline, so that the overall weight of the heat exchanger is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows a schematic perspective view of an embodiment of a heat exchanger according to the present invention;

FIG. 2 shows an enlarged schematic view at A of the heat exchanger of FIG. 1;

FIG. 3 shows the refrigerant flow direction in the heat exchanger of FIG. 1 as a condenser;

FIG. 4 shows the refrigerant flow direction in the heat exchanger of FIG. 1 when used as an evaporator;

FIG. 5 shows a partial perspective view of the heat exchanger of FIG. 1; and

fig. 6 shows a sectional view of a connection structure of the heat exchanger in fig. 5.

Wherein the figures include the following reference numerals:

10. a first liquid passing pipe; 20. a second liquid passing pipe; 21. a first liquid passing hole; 22. a spacer; 23. a second liquid passing hole; 30. a connecting structure; 31. a communicating cavity; 32. a first mounting hole; 33. a second mounting hole; 34. a tubular body; 35. a first blocking member; 351. a first plugging plate; 352. a first flanging structure; 36. a second blocking member; 361. a second plugging plate; 362. a second flanging structure; 40. flat tubes; 50. and a fin.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, unless stated to the contrary, use of the directional terms "upper and lower" are generally directed to the orientation shown in the drawings, or to the vertical, or gravitational direction; likewise, for ease of understanding and description, "left and right" are generally to the left and right as shown in the drawings; "inner and outer" refer to the inner and outer relative to the profile of the respective member itself, but the above directional terms are not intended to limit the present invention.

In order to solve among the prior art because the internal diameter of crossing the liquid pipeline is greater than the width of flat pipe and influences the problem of heat exchanger operating performance, this application provides a heat exchanger.

As shown in fig. 1 to 6, the heat exchanger includes a first liquid flowing pipeline 10, a second liquid flowing pipeline 20, a connecting structure 30, a flat pipe 40 and a plurality of fins 50. The second liquid passing pipe 20 has a plurality of first liquid passing holes 21 spaced along the length direction of the second liquid passing pipe 20. The connecting structure 30 is arranged on the second liquid passing pipeline 20, and the connecting structure 30 is provided with a communication cavity 31; the number of the connecting structures 30 is plural, the plural connecting structures 30 are provided in one-to-one correspondence with the plural first liquid passing holes 21, and each first liquid passing hole 21 communicates with the communicating chamber 31 of the corresponding connecting structure 30. Two ends of the flat pipe 40 are respectively communicated with the first liquid passing pipeline 10 and the communication cavity 31. The plurality of fins 50 are provided at intervals on the flat tubes 40 in the extending direction of the flat tubes 40.

By applying the technical scheme of the invention, the second liquid passing pipeline 20 is communicated with the flat pipe 40 through the connecting structure 30, so that the inner diameter of the second liquid passing pipeline 20 is not limited by the condition that the inner diameter is necessarily larger than the width of the flat pipe 40, the inner diameter of the second liquid passing pipeline 20 can be smaller than or equal to the width of the flat pipe 40, the inner space of the second liquid passing pipeline 20 is reduced, the flow velocity of a refrigerant in the second liquid passing pipeline 20 is increased, the heat exchange efficiency of the heat exchanger is further improved, the problem that the operation performance of the heat exchanger is influenced because the inner diameter of the liquid passing pipeline is larger than the width of the flat pipe in the prior art is solved, and the operation performance of the heat exchanger is improved. Meanwhile, the above arrangement can reduce the refrigerant charge amount in the second liquid passing pipe 20, thereby reducing the overall weight of the heat exchanger.

In this embodiment, when the heat exchanger is used as an evaporator, the gas-liquid stratification of the refrigerants in the first liquid passing pipeline 10 and the second liquid passing pipeline 20 can be slowed down, so that the refrigerant liquid distribution entering the flat pipe 40 is more uniform, and the operation performance of the heat exchanger is improved.

In this embodiment, the refrigerant in the second liquid passing pipeline 20 enters the connecting structure 30 corresponding to the refrigerant through the first liquid passing hole 21, and enters the flat tube 40 through the communicating cavity 31, and the refrigerant entering the flat tube 40 exchanges heat with the environment where the heat exchanger is located through the fins 50, so as to realize refrigeration or heating of the heat exchanger.

In this embodiment, the flat tubes 40 are plural, the flat tubes 40 are arranged at intervals along a preset direction, and the preset direction is a direction from the first liquid passing pipe 10 to the second liquid passing pipe 20.

As shown in fig. 6, the connecting structure 30 further has a first mounting hole 32 and a second mounting hole 33, the second liquid passing pipe 20 is inserted into the first mounting hole 32, the open end of the flat pipe 40 is inserted into the second mounting hole 33, and the second mounting hole 33 is communicated with the communicating cavity 31. Thus, the connection structure 30 and the second liquid passing pipe 20 are easier and simpler to disassemble and assemble due to the arrangement, and the disassembling and assembling difficulty of the connection structure and the second liquid passing pipe is reduced. Simultaneously, above-mentioned setting ensures that the refrigerant that gets into in the intercommunication chamber 31 can get into to flat pipe 40 in through second mounting hole 33, and then has promoted the flow smoothness nature of refrigerant in the heat exchanger, ensures that the heat exchanger can normal operating.

In this embodiment, the first mounting holes 32 and the second mounting holes 33 are spaced apart from each other to prevent the second liquid passing pipe 20 and the flat pipe 40 from being structurally interfered with each other and affecting the assembly and disassembly of the heat exchanger.

As shown in fig. 5 and 6, the first mounting hole 32 extends in a radial direction of the connection structure 30 and penetrates the connection structure 30. The second mounting hole 33 extends along the length direction of the connection structure 30, and the length direction of the connection structure 30 is consistent with the width direction of the flat tube 40. Thus, the arrangement is such that the plurality of connection structures 30 are arranged at intervals along the length direction of the second liquid passing pipe 20, and further the plurality of flat pipes 40 are arranged at intervals along the length direction of the second liquid passing pipe 20 and the first liquid passing pipe 10.

In the present embodiment, the length of the second mounting hole 33 is smaller than the length of the connection structure 30. Like this, above-mentioned setting ensures that flat pipe 40 can install on connection structure 30, and then has promoted the structural reliability of heat exchanger. Meanwhile, the arrangement improves the structural strength of the connecting structure 30, and further prolongs the service life of the heat exchanger.

As shown in fig. 6, the connecting structure 30 includes a tubular body 34, a first blocking piece 35 and a second blocking piece 36. Wherein the tubular body 34 has the communication chamber 31, and the first mounting hole 32 and the second mounting hole 33 are both provided on the tubular body 34. A first closure member 35 is provided on a first end of the tubular body 34 for closing off the first end. A second closure piece 36 is arranged on the second end of the tubular body 34 for closing off the second end. Thus, on one hand, the connection structure 30 is simpler in structure and easy to process and implement; on the other hand, the air tightness of the connecting structure 30 is improved, and the refrigerant waste caused by the refrigerant leakage phenomenon on the connecting structure 30 is prevented.

Specifically, the communication chamber 31 is an inner cavity of the tubular body 34, the first mounting hole 32 communicates with the communication chamber 31, and the second mounting hole 33 is provided on a tube wall of the tubular body 34. The open end of the flat pipe 40 extends into the second mounting hole 33 and is connected with the tubular body 34, so that the assembly of the flat pipe 40 and the second liquid passing pipe 20 is realized, and the inner diameter of the second liquid passing pipe 20 is not limited by the width of the flat pipe 40.

Optionally, the first blocking element 35 is made of aluminum and has a coating on its surface, and the first blocking element 35 is welded to the tubular body 34. Like this, above-mentioned setting makes the structure of first shutoff piece 35 simpler, and easy processing, realization have reduced the processing cost of heat exchanger.

Optionally, the second blocking element 36 is made of aluminum and has a coating on its surface, and the second blocking element 36 is welded to the tubular body 34. . Thus, the second plugging piece 36 is simpler in structure, easy to process and realize, and the processing cost of the heat exchanger is reduced.

Optionally, the second mounting hole 33 is a waist-shaped hole or a rectangular hole, and the second mounting hole 33 is adapted to the outer surface of the flat tube 40. Thus, on one hand, the arrangement makes the structure of the second mounting hole 33 simpler, and the second mounting hole is easy to process and implement, so that the processing cost of the second mounting hole 33 is reduced. Simultaneously, above-mentioned setting makes flat pipe 40 fasten more with the assembly of second mounting hole 33, has promoted the structural stability of heat exchanger.

In this embodiment, the second mounting hole 33 is a kidney-shaped hole, so that the structure of the connecting structure 30 is simpler and is easy to process and implement. Meanwhile, the arrangement avoids sharp edges generated on the flat pipes 40 from cutting or scratching workers.

In the present embodiment, the first liquid passing hole 21 is provided coaxially with the tubular body 34. Thus, the arrangement ensures that the refrigerant discharged from the first liquid passing hole 21 uniformly flows into the tubular body 34 on one hand, so as to reduce the impact force of the refrigerant on the connecting structure 30, avoid noise and vibration in the heat exchanger and improve the use experience of users.

As shown in fig. 6, the first blocking member 35 includes a first blocking plate 351 and a first flanging structure 352, the first blocking plate 351 is disposed in the tubular body 34 and is attached to the inner circumferential surface of the tubular body 34, and the first flanging structure 352 is disposed on the surface of the first blocking plate 351 away from the second blocking member 36. In this way, the first blocking plate 351 is mounted inside the tubular body 34 for blocking the first open end of the tubular body 34. When the first plugging member 35 needs to be detached from the tubular body 34 or the first plugging member 35 needs to be installed in the tubular body 34, the worker can operate the first flanging structure 352 to detach the first plugging member 35 from the tubular body 34 or install the first plugging member 35 into the tubular body 34, so that the worker can detach and install the first plugging member 35 more easily and conveniently, and the difficulty in detaching and installing the first plugging member 35 is reduced.

In this embodiment, the first flange structure 352 is annular and is disposed coaxially with the tubular body 34.

As shown in fig. 6, the second blocking member 36 includes a second blocking plate 361 and a second flanging structure 362, the second blocking plate 361 is disposed in the tubular body 34 and is attached to the inner circumferential surface of the tubular body 34, and the second flanging structure 362 is disposed on the surface of the second blocking plate 361 away from the first blocking member 35. In this way, the second blocking plate 361 is mounted inside the tubular body 34 for blocking the second open end of the tubular body 34. When the second blocking plate 361 needs to be detached from the tubular body 34 or the second blocking plate 361 needs to be installed in the tubular body 34, the worker can operate the second flanging structure 362 to detach the second blocking piece 36 from the tubular body 34 or install the second blocking piece 36 into the tubular body 34, so that the worker can detach and install the second blocking piece 36 more easily and conveniently, and the difficulty in detaching and installing the second blocking piece is reduced.

In this embodiment, the second flange structure 362 is annular and is disposed coaxially with the tubular body 34.

Optionally, the connecting structure 30 is bonded to the second liquid passing pipe 20, or clamped, or connected by a fastener. Thus, the connection structure 30 and the second liquid passing pipe 20 are easier and simpler to disassemble and assemble due to the arrangement, and the disassembling and assembling difficulty between the connection structure and the second liquid passing pipe is reduced.

As shown in fig. 2, a plurality of spacers 22 are disposed in the second liquid passing pipe 20, and the plurality of spacers 22 divide the inner cavity of the second liquid passing pipe 20 into a plurality of sub-cavities, and the sub-cavities are disposed independently of each other. The second liquid passing pipeline 20 is further provided with a plurality of second liquid passing holes 23, the plurality of second liquid passing holes 23 are arranged in one-to-one correspondence with the plurality of sub-cavities, each second liquid passing hole 23 is communicated with the corresponding sub-cavity, and the second liquid passing holes 23 are communicated with the first liquid passing holes 21 through the sub-cavities. Like this, the refrigerant passes through liquid hole 23 through a plurality of seconds and gets into in a plurality of sub-chambeies, and the refrigerant that gets into in the sub-chamber loops through first liquid hole 21, intercommunication chamber 31 and the entering of second mounting hole 33 entering to flat pipe 40 in to realize the smooth and easy flow of refrigerant.

Specifically, the second liquid passing pipe 20 is divided into M (M ≧ 1) sub-chambers by a plurality of spacers 22, each sub-chamber including N (N ≧ 1) connection structures 30. The second liquid passing pipe 20 is provided with a plurality of first liquid passing holes 21, and the first liquid passing holes 21 and the plurality of connecting structures 30 are arranged in a one-to-one correspondence manner. Thus, when the heat exchanger is used as an evaporator, the refrigerant is divided into M paths and enters each sub-cavity of the second liquid passing pipe 20 through the plurality of second liquid passing holes 23. Because the internal diameter of second liquid passing pipeline 20 is less, the refrigerant gets into sub-cavity after, can get into sub-upper portion of cavity from sub-cavity's bottom with very fast speed, through first liquid hole 21 gets into every connection structure 30 respectively, later through flat pipe 40 outflow, gets into first liquid passing pipeline 10 at last, accomplishes the heat transfer process in the heat exchanger.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

the second is crossed the liquid pipeline and is passed through connection structure and flat tub of intercommunication, then the internal diameter that the second crossed the liquid pipeline no longer receives the condition restriction that must be greater than the width of flat tub, the internal diameter that the second crossed the liquid pipeline can be less than or equal to the width of flat tub, in order to reduce the internal space that the second crossed the liquid pipeline, the velocity of flow of refrigerant in the second crossed the liquid pipeline has been increased, and then the heat exchange efficiency of heat exchanger has been promoted, the problem of influencing heat exchanger operating performance because the internal diameter that crosses the liquid pipeline is greater than the width of flat tub among the prior art has been solved, the operating performance of heat exchanger has been promoted. Meanwhile, the arrangement can reduce the refrigerant filling amount in the second liquid passing pipeline, so that the overall weight of the heat exchanger is reduced.

It is to be understood that the above-described embodiments are only a few, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat exchanger, comprising:

a first liquid conduit (10);

a second liquid passing pipe (20) having a plurality of first liquid passing holes (21) arranged at intervals along the length direction of the second liquid passing pipe (20);

a connecting structure (30) arranged on the second liquid passing pipeline (20), wherein the connecting structure (30) is provided with a communication cavity (31); the number of the connecting structures (30) is multiple, the connecting structures (30) and the first liquid passing holes (21) are arranged in a one-to-one correspondence mode, and each first liquid passing hole (21) is communicated with a communication cavity (31) of the corresponding connecting structure (30);

the two ends of the flat pipe (40) are respectively communicated with the first liquid passing pipeline (10) and the communication cavity (31);

the fin structure comprises a plurality of fins (50), wherein the fins (50) are arranged on the flat tubes (40) at intervals along the extension direction of the flat tubes (40).

2. The heat exchanger according to claim 1, wherein the connecting structure (30) further has a first mounting hole (32) and a second mounting hole (33), the second liquid passing pipe (20) is arranged in the first mounting hole (32) in a penetrating manner, the open end of the flat pipe (40) is arranged in the second mounting hole (33) in a penetrating manner, and the second mounting hole (33) is communicated with the communication cavity (31).

3. The heat exchanger according to claim 2, wherein the first mounting hole (32) extends in a radial direction of the connection structure (30) and penetrates the connection structure (30); the second mounting hole (33) extends along the length direction of the connecting structure (30), and the length direction of the connecting structure (30) is consistent with the width direction of the flat pipe (40).

4. The heat exchanger according to claim 2, wherein the length of the second mounting hole (33) is smaller than the length of the connection structure (30).

5. The heat exchanger according to claim 2, wherein the connection structure (30) comprises:

a tubular body (34), the tubular body (34) having the communication chamber (31), the first mounting hole (32) and the second mounting hole (33) both being provided on the tubular body (34);

a first closure piece (35), said first closure piece (35) being provided on a first end of said tubular body (34) for closing off said first end;

a second closure piece (36), the second closure piece (36) being arranged on a second end of the tubular body (34) for closing off the second end.

6. The heat exchanger according to claim 2, wherein the second mounting hole (33) is a kidney-shaped hole or a rectangular hole, and the second mounting hole (33) is adapted to the outer surface of the flat tube (40).

7. The heat exchanger according to claim 5, characterized in that the first through liquid hole (21) is arranged coaxially to the tubular body (34).

8. The heat exchanger according to claim 5, characterized in that the first obturating member (35) comprises a first obturating plate (351) and a first flanging structure (352), the first obturating plate (351) being arranged inside the tubular body (34) and being arranged in abutment with the inner circumferential surface of the tubular body (34), the first flanging structure (352) being arranged on the face of the first obturating plate (351) remote from the second obturating member (36).

9. The heat exchanger according to claim 5, wherein the second blocking piece (36) comprises a second blocking plate (361) and a second flanging structure (362), the second blocking plate (361) is arranged in the tubular body (34) and is attached to the inner circumferential surface of the tubular body (34), and the second flanging structure (362) is arranged on the surface of the second blocking plate (361) away from the first blocking piece (35).

10. The heat exchanger according to claim 1, characterized in that the connecting structure (30) is bonded to the second flow duct (20), or snapped in, or connected by fasteners.

11. The heat exchanger according to claim 1, characterized in that a plurality of spacers (22) are arranged in the second liquid passing pipe (20), the spacers (22) divide the inner cavity of the second liquid passing pipe (20) into a plurality of sub-cavities, and the sub-cavities are arranged independently; the second liquid passing pipeline (20) is further provided with a plurality of second liquid passing holes (23), the second liquid passing holes (23) are arranged in one-to-one correspondence with the sub-cavities, each second liquid passing hole (23) is communicated with the corresponding sub-cavity, and the second liquid passing holes (23) are communicated with the first liquid passing holes (21) through the sub-cavities.