Heat Exchanger

Abstract

A heat exchanger, including at least one flat pipe, each flat pipe is provided with a refrigerant cavity, an inlet, an outlet and two through holes, the inlet and the outlet are located at two ends of the refrigerant cavity, respectively, and both the inlet and the outlet communicate with the refrigerant cavity; the two through holes are respectively located at two ends of the refrigerant cavity, and the two through holes do not communicate with the refrigerant cavity. The flat pipe is provided with the inlet, the outlet and two through holes, when the plurality of flat pipes are matched with liquid collecting pipes (liquid inlet pipes or liquid outlet pipes) of the heat exchanger, different flat pipes can choose to use the inlets or outlets to communicate with the liquid collecting pipes, and the through holes are able to be used to avoid the liquid collecting pipes.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present disclosure is a national stage application of International Patent Application No. PCT/CN2020/138147, which is filed on Dec. 21, 2020. The present disclosure claims priority to Patent Application No. 202010125842.5, filed to the China National Intellectual Property Administration on Feb. 27, 2020 and entitled “Heat Exchanger”.

TECHNICAL FIELD

The disclosure relates to the technical field of heat exchangers, in particular to a heat exchanger.

BACKGROUND

In an art known to inventors, a micro-channel heat exchanger for double compressors is disclosed, which includes flat pipe groups and liquid collecting pipes, the flat pipe groups are distributed in parallel along an axial direction of the liquid collecting pipes, the liquid collecting pipes include a first liquid collecting pipe disposed at left ends of the flat pipe groups and a second liquid collecting pipe disposed at right ends of the flat pipe groups, an isolating assembly for separating an inner cavity of each liquid collecting pipe into an upper part inner cavity and a lower part inner cavity is disposed in the each liquid collecting pipe, counting backwards from a front end of each liquid collecting pipe, a left end of the odd-numbered flat pipe group communicates with the upper part inner cavity of the first liquid collecting pipe, a right end of the odd-numbered flat pipe group communicates with the lower part inner cavity of the second liquid collecting pipe, a left end of the even-numbered flat pipe group communicates with the lower part inner cavity of the first liquid collecting pipe, and a right end of the even-numbered flat pipe group communicates with the upper part inner cavity of the second liquid collecting pipe. According to the technical solution, when one compressor is started, the fin part of the heat exchanger can still be in complete contact with another flow path for heat exchange, then a heat exchange area of the heat exchanger is utilized to the maximum extent, energy such as wind energy and electric energy is reasonably utilized, the heat exchange efficiency is improved, and a purpose of saving energy is achieved. However, for the heat exchanger, due to the limitation of the structures such as the flat pipes, in order to realize double flow paths, the complex structures such as the isolating assembly need to be disposed, so that the problems that the structure is complex and the manufacturing and assembly are inconvenient exist.

SUMMARY

The disclosure provides a heat exchanger, for solving the problem that the double-flow-path heat exchanger in the art known to inventors is complex in structure and inconvenient to manufacture and assemble.

In order to solve the above problem, the disclosure provides a heat exchanger, which includes at least one flat pipe, each flat pipe is provided with a refrigerant cavity, an inlet, an outlet and two through holes, where the inlet and the outlet are located at two ends of the refrigerant cavity, respectively, and both the inlet and the outlet communicate with the refrigerant cavity; and the two through holes are respectively located at two ends of the refrigerant cavity, and the two through holes do not communicate with the refrigerant cavity.

In some embodiments, a plurality of flat pipes are provided, the plurality of flat pipes include first flat pipes and second flat pipes which are alternately distributed, the heat exchanger further includes a first liquid inlet pipe, a second liquid inlet pipe, a first liquid outlet pipe and a second liquid outlet pipe, a first inlet of each first flat pipe communicates with the first liquid inlet pipe, a first outlet of the each first flat pipe communicates with the first liquid outlet pipe, a second inlet of each second flat pipe communicates with the second liquid inlet pipe, and a second outlet of the each second flat pipe communicates with the second liquid outlet pipe; two through holes of the first flat pipe are a first through hole and a second through hole respectively, two through holes of the second flat pipe are a third through hole and a fourth through hole respectively, the first through hole is disposed corresponding to the second outlet, the second through hole is disposed corresponding the second inlet, the third through hole is disposed corresponding to the first inlet, the fourth through hole is disposed corresponding to the first outlet, the first through hole communicates with the second liquid outlet pipe, the second through hole communicates with the second liquid inlet pipe, the third through hole communicates with the first liquid inlet pipe, and the fourth through hole communicates with the first liquid outlet pipe.

In some embodiments, the first liquid inlet pipe and the second liquid outlet pipe are located at one end of the each first flat pipe, and the first liquid outlet pipe and the second liquid inlet pipe are located at the other end of the each first flat pipe.

In some embodiments, the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe are distributed along a length direction of the first flat pipe, or the first liquid inlet pipe and the second liquid outlet pipe are distributed along a width direction of the first flat pipe, and the first liquid outlet pipe and the second liquid inlet pipe are distributed along the width direction of the first flat pipe.

In some embodiments, each flat pipe includes two heat exchange plates which are connected together in a sealed manner, and the two heat exchange plates are symmetrically disposed relative to a preset symmetry plane.

In some embodiments, each heat exchange plate includes a plate body, a welding edge disposed at a periphery of the plate body, and a first convex surface and a second convex surface disposed at two ends of the plate body at intervals, and the welding edge, the first convex surface and the second convex surface are all located on a same side of the plate body; an area between the plate bodies of the two heat exchange plates forms the refrigerant cavity, welding edges of the two heat exchange plates are welded together, the first convex surfaces of the two heat exchange plates are welded together, and the second convex surfaces of the two heat exchange plates are welded together; the inlet and the outlet are respectively located at two ends of the plate body, and the two through holes are respectively located on the first convex surface and the second convex surface.

In some embodiments, the inlet, one of the two through holes, the outlet and the other of the two through holes are distributed along a length direction of the heat exchange plate; or, the inlet and one of the two through holes are distributed along a width direction of the heat exchange plate, and the outlet and the other of the two through holes are distributed along the width direction of the heat exchange plate.

In some embodiments, the first liquid inlet pipe includes a plurality of pipe sections which communicate in sequence, one end of each pipe section is connected with the first flat pipe in a sealed manner, and the other end of the each pipe section is connected with the second flat pipe in a sealed manner.

In some embodiments, the each pipe section includes a pipe body and a first ring body and a second ring body respectively disposed at two ends of the pipe body, the first ring body is welded with an outer wall of the first flat pipe, and the second ring body is welded with an outer wall of the second flat pipe.

In some embodiments, the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe have the same structure.

By adoption of the technical solution of some embodiments in the disclosure, the heat exchanger is provided, which includes the flat pipes, each flat pipe is provided with the refrigerant cavity, the inlet, the outlet, and two through holes, where the inlet and the outlet are located at two ends of the refrigerant cavity, respectively, and both the inlet and the outlet communicate with the refrigerant cavity; and the two through holes are respectively located at two ends of the refrigerant cavity, and the two through holes do not communicate with the refrigerant cavity. By adoption of the technical solution of the disclosure, since the flat pipe is provided with the inlet, the outlet and two through holes, when the plurality of flat pipes are matched with the liquid collecting pipes (the liquid inlet pipes or the liquid outlet pipes) of the heat exchanger, different flat pipes can choose to use the inlets or outlets to communicate with the liquid collecting pipes, and the through holes can be used to avoid the liquid collecting pipes, so that different parts in the heat exchanger are convenient to arrange and assemble, thus realizing double flow paths. Compared with the art known to inventors, there is no need to dispose complex structures such as the isolating assembly, thus the structure of the heat exchanger is simplified, and the manufacturing and assembling are facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings, which form a part hereof, serve to provide a further understanding of the disclosure, and illustrative embodiments of the disclosure and descriptions thereof serve to explain the disclosure and are not to be construed as unduly limiting the disclosure. In the drawings:

FIG. 1 illustrates a schematic structure diagram of a heat exchanger provided by embodiment 1 of the disclosure.

FIG. 2 illustrates an exploded diagram of the heat exchanger in FIG. 1.

FIG. 3 illustrates an enlarged partial diagram of the heat exchanger in FIG. 1.

FIG. 4 illustrates a schematic structure diagram of a first flat pipe in FIG. 1.

FIG. 5 illustrates an enlarged partial diagram of the left end of the first flat pipe in FIG. 4.

FIG. 6 illustrates an enlarged partial diagram of the right end the first flat pipe in FIG. 4.

FIG. 7 illustrates a schematic structure diagram of a heat exchanger provided by embodiment 2 of the disclosure.

FIG. 8 illustrates an exploded diagram of the heat exchanger in FIG. 7.

FIG. 9 illustrates a cross-sectional diagram of the heat exchanger in FIG. 7 at position A-A.

FIG. 10 illustrates a cross-sectional diagram of the heat exchanger in FIG. 7 at position B-B.

FIG. 11 illustrates a schematic structure diagram of the first flat pipe in FIG. 7.

FIG. 12 illustrates a cross-sectional diagram of a left end of the first flat pipe in FIG. 11.

FIG. 13 illustrates a cross-sectional diagram of a right end of the first flat pipe in FIG. 11.

Where, the above-mentioned figures include the following reference numerals:

11. First liquid inlet pipe; 12. Second liquid inlet pipe; 13. First liquid outlet pipe; 14. Second liquid outlet pipe; 15. Pipe section; 20. First flat pipe; 21. First inlet; 22. First outlet; 23. First through hole; 24. Second through hole; 25. Heat exchange plate; 26. Plate body; 27. Welding edge; 28. First convex surface; 29. Second convex surface; 30. Second flat pipe; 31. Second inlet; 32. Second outlet; 33. Third through hole; 34. Fourth through hole; and 40. Fin.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A clear and complete description on the technical solutions in the embodiments of the disclosure will be given below, in combination with the drawings in the embodiments of the disclosure. Obviously, the above-described embodiments are only some, but not all, embodiments of the disclosure. The following description for at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the disclosure without creative efforts shall fall within the protection scope of the disclosure.

A shown in the figures, the embodiments of the disclosure provide a heat exchanger, which includes at least one flat pipe, each flat pipe is provided with a refrigerant cavity, an inlet, an outlet and two through holes, where the inlet and the outlet are located at two ends of the refrigerant cavity, respectively, and both the inlet and the outlet communicate with the refrigerant cavity; the two through holes are respectively located at two ends of the refrigerant cavity, and the two through holes do not communicate with the refrigerant cavity. By adoption of the technical solution of the disclosure, since the flat pipe is provided with the inlet, the outlet and two through holes, when the plurality of flat pipes are matched with liquid collecting pipes (the liquid inlet pipes or liquid outlet pipes) of the heat exchanger, different flat pipes can choose to use the inlets or outlets to communicate with the liquid collecting pipes, and the through holes is able to be used to avoid the liquid collecting pipes, so that different parts in the heat exchanger are convenient to arrange and assemble, thus realizing double flow paths. Compared with an art known to inventors, there is no need to dispose complex structures such as the isolating assembly, thus the structure of the heat exchanger is simplified, and the manufacturing and assembling are facilitated.

In the embodiment, a plurality of flat pipes are available, the plurality of flat pipes include first flat pipes 20 and second flat pipes 30 which are alternately distributed, the heat exchanger further includes a first liquid inlet pipe 11, a second liquid inlet pipe 12, a first liquid outlet pipe 13 and a second liquid outlet pipe 14, a first inlet 21 of each first flat pipe 20 communicates with the first liquid inlet pipe 11, a first outlet 22 of the each first flat pipe 20 communicates with the first liquid outlet pipe 13, a second inlet 31 of each second flat pipe 30 communicates with the second liquid inlet pipe 12, and a second outlet 32 of the each second flat pipe 30 communicates with the second liquid outlet pipe 14; two through holes of first flat pipe 20 are a first through hole 23 and a second through hole 24 respectively, two through holes of the second flat pipe 30 are a third through hole 33 and a fourth through hole 34 respectively, the first through hole 23 is disposed corresponding to the second outlet 32, the second through hole 24 is disposed corresponding the second inlet 31, the third through hole 33 is disposed corresponding to the first inlet 21, the fourth through hole 34 is disposed corresponding to the first outlet 22, the first through hole 23 communicates with the second liquid outlet pipe 14, the second through hole 24 communicates with the second liquid inlet pipe 12, the third through hole 33 communicates with the first liquid inlet pipe 11, and the fourth through hole 34 communicates with the first liquid outlet pipe 13.

In the technical solution, the first inlet 21 of the first flat pipe 20 is the inlet of the flat pipe, and the first outlet 22 of the first flat pipe 20 is the outlet of the flat pipe. The second inlet 31 of the second flat pipe 30 is the inlet of the flat pipe, and the second outlet 32 of the second flat pipe 30 is the outlet of the flat pipe. By adoption of the technical solution, double flow paths can be realized by the cooperation of the first liquid inlet pipe 11, the second liquid inlet pipe 12, the first liquid outlet pipe 13 and the second liquid outlet pipe 14 with a plurality of first flat pipes 20 and a plurality of second flat pipes 30 which are alternately disposed. Compared with the art known to inventors, there is no need to dispose complex structures such as the isolating assembly, thus the structure of the heat exchanger is simplified, and the manufacturing and assembling are facilitated.

In some embodiments, the plurality of first flat pipes 20 and the plurality of second flat pipes 30 are alternately disposed, that is, there is one second flat pipe 30 between two adjacent first flat pipes 20 and one first flat pipe 20 between two adjacent second flat pipes 30. In some embodiments, fins 40 are disposed between adjacent first flat pipe 20 and second flat pipes 30, so that the heat exchange area is increased. According to the technical solution, the heat exchanger has two flow paths, during use, each flow path corresponds to one compressor, therefore, when one compressor is started, one flow path is closed, a fin part of the heat exchanger can still be in complete contact with the other flow path for heat exchange, so that the heat exchange area of the heat exchanger is utilized to the maximum extent, energy such as wind energy and electric energy is reasonably utilized, the heat exchange efficiency is improved, and the purpose of saving energy is achieved.

In some embodiments, the first flat pipe 20 and the second flat pipe 30 have the same structure, and the first flat pipe 20 and the second flat pipe 30 are installed interchangeably. Therefore, only one flat pipe needs to be manufactured, which is beneficial for reducing the manufacturing cost, and meanwhile, the assembly is convenient. During assembly, the first flat pipe 20 can be assembled to the position of the second flat pipe 30 by rotating 180 degrees, or the second flat pipe 30 can be assembled to the position of the first flat pipe 20 by rotating 180 degrees.

In some embodiments, the first liquid inlet pipe 11 and the second liquid outlet pipe 14 are located at one end of the first flat pipe 20, and the first liquid outlet pipe 13 and the second liquid inlet pipe 12 are located the other end of the first flat pipe 20. Through the above arrangement, the condensation in the two flow paths flows reversely, which is beneficial for improving the heat exchange uniformity at different positions.

In some embodiments, the first liquid inlet pipe 11, the second liquid inlet pipe 12, the first liquid outlet pipe 13 and the second liquid outlet pipe 14 are distributed along a length direction of the first flat pipe 20. In embodiment 2, the first liquid inlet pipe 11 and the second liquid outlet pipe 14 are distributed along a width direction of the first flat pipe 20, and the first liquid outlet pipe 13 and the second liquid inlet pipe 12 are distributed along the width direction of first flat pipe 20. The above two arrangement manners are different and can achieve the same heat exchange effect.

In some embodiments, the flat pipe (the first flat pipe 20 or the second flat pipe 30) includes two heat exchange plates 25 which are connected together in a sealed manner, and the two heat exchange plates 25 are symmetrically disposed relative to a preset symmetry plane, which is beneficial for processing. In some embodiments, the first flat pipe 20 is stamped and formed into heat exchange plates by a composite aluminum plate, and the two heat exchange plates are mirror-overlapped to form the first flat pipe 20, which is then brazed into a whole, belonging to the category of stamping and forming of flat pipes. The second flat pipe 30 can also be processed in this way.

In some embodiments, each heat exchange plate 25 includes a plate body 26, a welding edge 27 disposed at a periphery of the plate body 26, and a first convex surface 28 and a second convex surface 29 disposed at two ends of the plate body 26 at intervals, and the welding edge 27, the first convex surface 28 and the second convex surface 29 are all located on the same side of the plate body 26; an area between the plate bodies 26 of the two heat exchange plates 25 forms the refrigerant cavity, welding edges 27 of the two heat exchange plates 25 are welded together, the first convex surfaces 28 of the two heat exchange plates 25 are welded together, and the second convex surfaces 29 of the two heat exchange plates 25 are welded together; the first inlet 21 and the first outlet 22 are respectively located at two ends of the plate body 26, the first through hole 23 is located on the first convex surface 28, and the second through hole 24 is located on the second convex surface 29. In this way, it is convenient to process the inlet, the outlet and each through hole, meanwhile, a communication between the through hole and the refrigerant cavity is avoided, thus avoiding the communication between the two flow paths.

Taking the first flat pipe 20 as an example, in embodiment 1, the first inlet 21, the first through hole 23, the first outlet 22 and the second through hole 24 are distributed along a length direction of the heat exchange plate 25. In embodiment 2, the first inlet 21 and the first through hole 23 are distributed along a width direction of heat exchange pipe 25, and the first outlet 22 and the second through hole 24 are distributed along the width direction of heat exchange plate 25.

In some embodiments, the first liquid inlet pipe 11 includes a plurality of pipe sections 15 which communicate in sequence, one end of each pipe section 15 is connected with the first flat pipe 20 in a sealed manner, and the other end of the each pipe section 15 is connected with the second flat pipe 30 in a sealed manner. Through above arrangement, the connection of the first liquid inlet pipe 11 with a plurality of first flat pipes 20 and a plurality of second flat pipes 30 is facilitated.

Specifically, each pipe section 15 includes a pipe body and a first ring body and a second ring body respectively disposed at two ends of the pipe body, the first ring body is welded with an outer wall of the first flat pipe 20, and the second ring body is welded with an outer wall of the second flat pipe 30. Through above arrangement, welding is facilitated, and the connection strength and sealing effect are improved.

In some embodiments, the first liquid inlet pipe 11, the second liquid inlet pipe 12, the first liquid outlet pipe 13 and the second liquid outlet pipe 14 have the same structure. In this way, the number of parts of the heat exchanger can be reduced, processing and assembly are facilitated, and the manufacturing cost can be reduced.

By adoption of the technical solution, the heat exchanger includes the first liquid inlet pipe 11, the second liquid inlet pipe 12, the first liquid outlet pipe 13, the second liquid outlet pipe 14, the first flat pipe 20 and the second flat pipe 30, two ends of the first flat pipe 20 are respectively provided with a first inlet 21 and a first outlet 22 which communicate with the refrigerant cavity in the first flat pipe 20, two ends of the second flat pipe 30 are respectively provided with the second inlet 31 and the second outlet 32 both communicating with the refrigerant cavity in the second flat pipe 30, a plurality of first flat pipes 20 and a plurality of second flat pipes 30 are available, the plurality of first flat pipes 20 and the plurality of second flat pipes 30 are alternately distributed, the first inlet 21 of each first flat pipe 20 communicates with the first liquid inlet pipe 11, the first outlet 22 of each first flat pipe 20 communicates with the first liquid outlet pipe 13, the second inlet 31 of each second flat pipe 30 communicates with the second liquid inlet 12, and the second outlet 32 of each second flat pipe 30 communicates with the second liquid outlet pipe 14. By adoption of the technical solution, a double flow path is realized by the cooperation of the first liquid inlet pipe 11, the second liquid inlet pipe 12, the first liquid outlet pipe 13 and the second liquid outlet pipe 14 with a plurality of first flat pipes 20 and a plurality of second flat pipes 30 which are alternately disposed. Compared with the art known to inventors, there is no need to dispose complex structures such as the isolating assembly, thus the structure of the heat exchanger is simplified, and the manufacturing and assembling are facilitated. In addition, the first flat pipe 20 and the second flat pipe 30 can be interchanged, which is beneficial for processing and assembly.

The foregoing is merely some embodiments of the disclosure and is not intended to limit the disclosure, and various modifications and variations of the disclosure may be available for those skilled in the art. Any modifications, equivalents, improvements, etc., made within the spirit and principles of the disclosure are intended to be included within the scope of the disclosure.

Claims

1. A heat exchanger, comprising at least one flat pipe, each flat pipe is provided with a refrigerant cavity, an inlet, an outlet and two through holes, wherein the inlet and the outlet are located at two ends of the refrigerant cavity respectively, and both the inlet and the outlet communicate with the refrigerant cavity; and the two through holes are respectively located at two ends of the refrigerant cavity, and the two through holes do not communicate with the refrigerant cavity.

2. The heat exchanger as claimed in claim 1, wherein a plurality of flat pipes are provided, the plurality of flat pipes comprise first flat pipes and second flat pipes which are alternately distributed, the heat exchanger further comprises a first liquid inlet pipe, a second liquid inlet pipe, a first liquid outlet pipe and a second liquid outlet pipe, a first inlet of each first flat pipe communicates with the first liquid inlet pipe, a first outlet of the each first flat pipe communicates with the first liquid outlet pipe, a second inlet of each second flat pipe communicates with the second liquid inlet pipe, and a second outlet of the each second flat pipe communicates with the second liquid outlet pipe; two through holes of the first flat pipe are a first through hole and second through hole respectively, two through holes of the second flat pipe are a third through hole and a fourth through hole respectively, the first through hole corresponds to the second outlet, the second through hole corresponds to the second inlet, the third through hole is disposed corresponding to the first inlet, the fourth through hole is disposed corresponding to the first outlet, the first through hole communicates with the second liquid outlet pipe, the second through hole communicates with the second liquid inlet pipe, the third through hole communicates with the first liquid inlet pipe, and the fourth through hole communicates with the first liquid outlet pipe.

3. The heat exchanger as claimed in claim 2, wherein the first liquid inlet pipe and the second liquid outlet pipe are located at one end of the each first flat pipe, and the first liquid outlet pipe and the second liquid inlet pipe are located at the other end of the each first flat pipe.

4. The heat exchanger as claimed in claim 2, wherein the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe are distributed along a length direction of the first flat pipe; or the first liquid inlet pipe and the second liquid outlet pipe are distributed along a width direction of the first flat pipe, and the first liquid outlet pipe and the second liquid inlet pipe are distributed along the width direction of the first flat pipe.

5. The heat exchanger as claimed in claim 1, wherein each flat pipe comprises two heat exchange plates which are connected together in a sealed manner, and the two heat exchange plates are symmetrically disposed relative to a preset symmetry plane.

6. The heat exchanger as claimed in claim 5, wherein each heat exchange plate comprises a plate body, a welding edge disposed at a periphery of the plate body, and a first convex surface and a second convex surface disposed at two ends of the plate body at intervals, and the welding edge, the first convex surface and the second convex surface are all located on a same side of the plate body; an area between plate bodies of the two heat exchange plates forms the refrigerant cavity, welding edges of the two heat exchange plates are welded together, first convex surfaces of the two heat exchange plates are welded together, and second convex surfaces of the two heat exchange plates are welded together; the inlet and the outlet are respectively located at two ends of the plate body, and the two through holes are respectively located on the first convex surface and the second convex surface.

7. The heat exchanger as claimed in claim 6, wherein the inlet, one of the two through holes, the outlet and the other of the two through holes are distributed along a length direction of the heat exchange plate; or, the inlet and one of the two through holes are distributed along a width direction of the heat exchange plate, and the outlet and the other of the two through holes are distributed along the width direction of the heat exchange plate.

8. The heat exchanger as claimed in claim 2, wherein the first liquid inlet pipe comprises a plurality of pipe sections which communicate in sequence, one end of each pipe section is connected with the first flat pipe in a sealed manner, and the other end of the each pipe section is connected with the second flat pipe in a sealed manner.

9. The heat exchanger as claimed in claim 8, wherein the each pipe section comprises a pipe body and a first ring body and a second ring body respectively disposed at two ends of the pipe body, the first ring body is welded with an outer wall of the first flat pipe, and the second ring body is welded with an outer wall of the second flat pipe.

10. The heat exchanger as claimed in claim 8, wherein the first liquid inlet pipe, the second liquid inlet pipe, the first liquid outlet pipe and the second liquid outlet pipe have the same structure.