WO2023138465A1

WO2023138465A1 - Pipeline for air-conditioning system

Info

Publication number: WO2023138465A1
Application number: PCT/CN2023/071868
Authority: WO
Inventors: 单宇宽; 段宇建; 刘海波
Original assignee: 浙江盾安人工环境股份有限公司
Priority date: 2022-01-20
Filing date: 2023-01-12
Publication date: 2023-07-27

Abstract

A pipeline for an air-conditioning system. The pipeline for an air-conditioning system comprises a first pipe (100) and a second pipe (200), wherein the second pipe (200) is configured to be a split structure and comprises a plurality of pipe bodies; the plurality of pipe bodies are configured to be a first pipe body (210) and at least one second pipe body (220); and the first pipe body (210) is connected to the first pipe (100) by furnace brazing, and the second pipe body (220) is connected to an end of the first pipe body (210) away from the first pipe (100) by soldering.

Description

Pipeline for an air conditioning system

related application

This application claims the priority of the Chinese patent application filed on January 20, 2022 with the application number 202220158839.8 and the title of the invention as “a pipeline for air-conditioning system”, and the priority of the Chinese patent application with the application number 202210065987.X and the title of the invention as “a pipeline for air-conditioning system” filed on January 20, 2022, the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the technical field of air conditioning systems, in particular to a pipeline for an air conditioning system.

Background technique

In the air-conditioning system of the related art, the connection of various pipeline components is realized through the air-conditioning pipeline. The air-conditioning pipeline mainly includes the main body of the pipeline and other branch pipes connected to the air-conditioning components. Due to the large volume of the main body of the pipeline and the relatively complicated shape of the branch pipes, the overall volume of the air-conditioning pipeline is large, and the assembly between the main pipeline and the branch pipes is difficult. Moreover, the main body of the pipeline takes up a large space, and it is difficult to realize welding in the furnace. The welding efficiency is low and the welding effect is poor.

Contents of the invention

According to various embodiments of the present application, a pipeline for an air conditioning system with better assembly and welding effects is provided.

A pipeline for an air-conditioning system, comprising: a first pipe piece and a second pipe piece. The second pipe is configured as a split structure and includes a plurality of pipe sections configured as a first pipe body and at least one section of a second pipe body. Wherein, one end of the first pipe body is connected to the first pipe member by furnace welding, and the other end of the first pipe body away from the first pipe member is connected to the second pipe body by welding.

In one of the embodiments, soldering is used between the first pipe member and the first pipe body. In one embodiment, the first pipe body and the second pipe body are welded by self-fusion welding or soldering. In one embodiment, self-flux welding or solder welding is used between two adjacent second pipe bodies.

In one of the embodiments, the first pipe body and the second pipe body are firstly connected by plug-in connection, and then welded.

In one embodiment, one of the first pipe body and the second pipe body is provided with an insertion portion, and the other is provided with a socket portion, and the insertion portion is inserted into the socket portion and welded.

In one of the embodiments, a limiting structure is provided between the insertion part and the socket part to limit the insertion length between the first pipe body and the second pipe body.

In one embodiment, the one of the first pipe body and the second pipe body provided with the insertion part further includes a first body part and a first connection part, the first body part is connected to the insertion part through the first connection part, the diameter of the insertion part is smaller than the diameter of the first body part, and when the insertion part is inserted into the socket part, the first connection part stops the socket part to form the position-limiting structure.

In one of the embodiments, one of the first pipe body and the second pipe body provided with the socket part further includes a second body part and a second connection part, the second body part is connected to the socket part through the second connection part, the diameter of the socket part is larger than the diameter of the second body part, and when the insertion part is inserted into the socket part, the second connection part stops the insertion part to form the position-limiting structure.

In one embodiment, the central axis of the welding torch nozzle is defined as l, the central axis of the socket is defined as b, and the angle between the central axis l and the central axis b of the socket is defined as α, and the α needs to satisfy the following relationship: 10°≤α≤60°.

In one embodiment, the heat distribution ratio of the insertion part and the socket part when welding is 5:5-6:4.

In one of the embodiments, the one of the first pipe body and the second pipe body provided with the insertion part further includes a first body part, a first stopper protrusion is provided between the first body part and the insertion part, the first stopper protrusion protrudes outward along the radial direction of the first body part, and the first stopper protrusion stops the socket part to form the stopper structure.

In one of the embodiments, the one of the first pipe body and the second pipe body provided with the socket part further includes a second body part, a second stopper protrusion is provided between the second body part and the socket part, the second stopper protrusion protrudes inward along the radial direction of the second body part, and the second stopper protrusion stops the insertion part to form the stopper structure.

In one of the embodiments, the diameter of the second pipe is defined as d, and the d satisfies the following relationship: d≤30mm; the The weld gap between the first pipe body and the second pipe body is defined as δ, and the δ satisfies the following relationship: δ≤0.05mm; the wall thickness of the second pipe is defined as t, and the t satisfies the following relationship: t≤1.5mm; after the first pipe is connected to the second pipe by plugging, the concentricity deviation between the first pipe and the second pipe is less than or equal to 0.15mm; %.

In one of the embodiments, the first pipe body and the second pipe body are welded after being connected in a butt joint manner.

In one of the embodiments, the first pipe includes copper pipe, steel pipe or aluminum pipe. In one of the embodiments, the second pipe includes copper pipe, steel pipe or aluminum pipe.

In one embodiment, the first pipe body and the second pipe body are connected by a butt joint method, and then welded, or connected by a plug-in method, and then welded. In one embodiment, two adjacent second pipe bodies are connected by a butt joint method, and then welded, or connected by a plug-in method, and then welded.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the present application will be apparent from the description, drawings and claims.

Description of drawings

In order to better describe and illustrate embodiments and/or examples of the inventions disclosed herein, reference may be made to one or more of the accompanying drawings. Additional details or examples used to describe the drawings should not be considered limitations on the scope of any of the disclosed inventions, the presently described embodiments and/or examples, and the best mode of these inventions currently understood.

Fig. 1 is a partial cross-sectional structural schematic diagram of a pipeline for an air-conditioning system provided by the present application.

Fig. 2 is an exploded schematic diagram of a partial cross-sectional view of the air-conditioning system pipeline provided by the present application.

Fig. 3 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 4 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 5 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 6 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 7 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 8 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Fig. 9 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

FIG. 10 is a partially enlarged schematic diagram of part A in FIG. 9 .

Fig. 11 is a schematic diagram of the assembly of the first pipe body and the second pipe body in one embodiment of the present application.

Reference numerals: 100, first pipe fitting; 200, second pipe fitting; 210, first pipe body; 211, first body part; 212, insertion part; 213, first connecting part; 214, first limit protrusion; 220, second pipe body; 221, second body part; d, the diameter of the second pipe fitting; δ, the weld gap of the second pipe body; t, the wall thickness of the second pipe fitting.

Detailed ways

In order to make the above-mentioned purpose, features and advantages of the present application more obvious and understandable, the specific implementation manners of the present application will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, the present application can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

It should be noted that when a component is referred to as being “fixed on” or “set on” another component, it may be directly on the other component or there may also be an intervening component. When a component is said to be "connected" to another component, it may be directly connected to the other component or there may be intervening components at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of the present application are for the purpose of illustration only, and do not represent the only embodiment.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In this application, unless otherwise clearly specified and limited, the first feature on the second feature "on", "under" may be the first feature directly In contact with a second feature, or in contact between a first feature and a second feature indirectly through an intermediary. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or it just means that the first feature is higher in level than the second feature. "Below", "beneath" and "under" the first feature may mean that the first feature is directly below or obliquely below the second feature, or it just means that the level of the first feature is smaller than that of the second feature.

Unless otherwise defined, all technical and scientific terms used in the description of the present application have the same meaning as commonly understood by those skilled in the technical field of the present application. The terms used in the description of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The term "and/or" used in the specification of the present application includes any and all combinations of one or more related listed items.

The pipeline for the air-conditioning system of the present application will be further described in detail below in conjunction with the drawings and specific embodiments.

A pipeline for an air-conditioning system is used in the air-conditioning system to realize communication between various air-conditioning components. The pipeline generally includes a pipeline body and a branch, and the branch is reserved by the pipeline body for connection with the air-conditioning component. When the existing pipeline is processed, welding in the overall furnace is generally used. However, due to the large volume of the main pipeline itself and the complicated shape of the branch pipes, the overall volume of the air-conditioning pipeline is large, and the assembly between the main pipeline and the branch pipes is difficult. It takes up a lot of space, and it is difficult to achieve welding in the furnace, and the welding effect is poor.

In order to overcome the problems in the prior art, referring to Fig. 1 and Fig. 2, according to an embodiment of the present application, the pipeline includes a first pipe 100 and a second pipe 200, the second pipe 200 forms the main body of the pipeline, and the first pipe 100 forms a branch connected to the air conditioning element. The second pipe part 200 is set as a split structure and includes a multi-section pipe body, and the multi-section pipe body is configured as a first pipe body 210 and at least one section of a second pipe body 220; wherein, the first pipe body 210 is connected to the first pipe part 100 by furnace welding, and the second pipe body 220 is connected to the end of the first pipe body 210 away from the first pipe part 100 by welding.

In this embodiment, after the second pipe body 200 is divided into the first pipe body 210 and at least one section of the second pipe body 220, the length and volume of each pipe body become smaller, and only the first pipe body 210 and the first pipe body 100 need to be welded in the furnace, while the other pipe bodies may not be welded in the furnace. Since the first pipe body 210 is connected to the first pipe body 100, the volume is small and the space occupied is small, so it is easy to realize welding in the furnace, improve the welding efficiency, and improve the welding effect.

In this embodiment, the pipeline sub-modules are welded separately, and then welded and connected to form a whole pipeline, which makes it easier to realize automatic installation. At the same time, since the lengths of the first pipe fitting 100, the first pipe body 210 and the second pipe body 220 are shorter after being segmented, it is easier to assemble adjacent pipe fittings or pipe bodies, and the concentricity after assembly is also higher, thereby improving assembly efficiency and assembly effect.

The first pipe part 100 and the second pipe part 200 generally adopt metal pipes, the first pipe part 100 can be copper pipe, steel pipe or aluminum pipe; the second pipe part 200 can also be copper pipe, steel pipe or aluminum pipe. In some embodiments, the first pipe 100 is a copper pipe. In some embodiments, the first pipe member 100 adopts phosphorus-deoxidized copper tube (TP2) or copper tube (T2). In some embodiments, the second pipe member 200 is a steel pipe. In some embodiments, the second pipe member 200 is a stainless steel pipe or a carbon steel pipe. In some embodiments, the second pipe member 200 is a stainless steel pipe, usually made of stainless steel such as SUS304, SUS304L or SUS430L, SUS316, SUS316L.

Between the first pipe member 100 and the first pipe body 210 , between the first pipe body 210 and the second pipe body 220 , and between two adjacent second pipe bodies 220 are connected and assembled first, and then welded.

The connection between the first pipe member 100 and the first pipe body 210, between the first pipe body 210 and the second pipe body 220, and between two adjacent second pipe bodies 220 can be a butt connection or a plug connection. In some embodiments, the above connection method is a plug connection. The welding method is self-fluxing welding or solder welding, such as argon arc welding, laser welding, gas shielded welding, flame brazing, high frequency welding and other welding methods. In some embodiments, solder welding is used between the first pipe member 100 and the first pipe body 210 . In some embodiments, self-fusion welding is used between the first pipe body 210 and the second pipe body 220 , and between two adjacent second pipe bodies 220 . That is to say, the assembly form between the first pipe body 210 and the second pipe body 220 and between two adjacent second pipe bodies 220 is plug connection first and then self-fusion welding.

For the convenience of description, the assembly method between the first tube body 210 and the second tube body 220 will be described below as an example.

As shown in FIGS. 3-9 , the first pipe body 210 includes a first body portion 211 and an insertion portion 212, and the second pipe body 220 includes a second body portion 221 and a socket portion 222. The inner diameter of the socket portion 222 is greater than the outer diameter of the insertion portion 212, so that the insertion portion 212 can be inserted into the socket portion 222 to form a weld and weld at the weld.

In order to control the insertion length between the first tube body 210 and the second tube body 220 , a limiting structure is provided between the insertion part 212 and the socket part 222 .

Of course, in other embodiments, the insertion part 212 can also be provided on the second tube body 220 , and the socket part 222 can be provided on the first tube body 210 .

In order to realize position limitation, as shown in FIG. 3 , according to an embodiment of the present application, the first pipe body 210 also includes a first connecting portion 213, the first body portion 211 is connected to the insertion portion 212 through the first connection portion 213, and the diameter of the insertion portion 212 is smaller than the diameter of the first body portion 211, that is, the distance from the first connection portion 213 to the central axis of the first pipe body 210 gradually decreases from the first body portion 211 to the direction of the insertion portion 212; for the convenience of processing, the diameter of the socket portion 222 Then it has the same diameter as the second body part 221 and is integrally formed. When the insertion portion 212 is inserted into the socket portion 222 , the first connecting portion 213 stops the socket portion 222 to form the above-mentioned limiting structure. That is, the first pipe body 210 is provided with a constriction structure, the second pipe body 220 is a straight cylinder structure, and a constriction limiting structure is formed between the first pipe body 210 and the second pipe body 220 .

Of course, in other embodiments, the constriction structure can also be provided on the second tube body 220, and the first tube body 210 is a straight cylinder structure.

As shown in Figure 4, according to another embodiment of the present application, the second pipe body 220 also includes a second connecting portion 223, the second body portion 221 is connected to the socket portion 222 through the second connecting portion 223, the diameter of the socket portion 222 is greater than the diameter of the second body portion 221, that is, the distance between the second connecting portion 223 and the central axis of the second pipe body 220 gradually increases from the second body portion 221 to the direction of the socket portion 222; 211 have the same diameter and are integrally formed. When the inserting portion 212 is inserted into the socket portion 222 , the second connecting portion 223 stops the inserting portion 212 to form the aforementioned limiting structure. That is, the second pipe body 220 is provided with a flaring structure, the first pipe body 210 is a straight cylinder structure, and a flaring limiting structure is formed between the first pipe body 210 and the second pipe body 220 .

When the first pipe body 210 and the second pipe body 220 are assembled and welded using the above-mentioned flaring limiting structure, the heat generated by the flame ejected from the torch nozzle extends along the axis of the torch nozzle and points to the insertion portion 212, thereby forming a heat-affected zone at the insertion portion 212. As the included angle between the central axis l of the welding gun nozzle and the central axis b of the socket part 222 gradually expands, the welding torch nozzle is more and more facing the side wall of the insertion part 212, and the possibility of leaking due to penetration of the insertion part 212 gradually increases. Therefore, in order to ensure a good welding effect and prevent the insertion part 212 from being welded through, in this embodiment, by controlling the rotation angle of the welding torch, the angle α between the extension line of the central axis l of the welding torch nozzle and the central axis b of the socket part satisfies, 10° ≤α≤60°.

Of course, in other welding methods, the position requirements between the welding torch nozzle and the pipe body also need to meet the above conditions, and will not be repeated here.

During the welding process, in order to ensure the welding effect, the base metal that needs to be melted by the socket part 222 is more, that is, the outer socket part 222 near the welding source needs to occupy more heat than the internal insertion part 212, and the tungsten needle of the welding torch is more biased towards the socket part 222, away from the weld seam ring, and the weld shape is uniform and full. In this embodiment, the heat distribution ratio between the insertion part 212 and the socket part 222 is 5:5-6:4; in some embodiments, the heat distribution ratio between the insertion part 212 and the socket part 222 is 6:4.

Of course, in other embodiments, the flaring structure can also be provided on the first tube body 210, and the second tube body 220 is a straight cylinder structure.

Of course, in other embodiments, one of the first tube body 210 and the second tube body 220 may be provided with a flaring structure, and the other may be provided with a constriction structure, thereby forming a double limiting structure.

As shown in FIGS. 5 and 7 , according to another embodiment of the present application, the first pipe body 210 and the second pipe body 220 adopt a direct insertion method, that is, the first body portion 211 and the insertion portion 212 have the same diameter and are integrally formed, and the second body portion 221 and the socket portion 222 have the same diameter and are integrally formed. There is a first stop protrusion 214 between the first body portion 211 and the insertion portion 212. The protrusion 214 stops the socket portion 222 to form a limiting structure. As shown in FIG. 5 , the first limiting protrusion 214 may be an annular protrusion, and as shown in FIG. 7 , the first limiting protrusion 214 may also be a plurality of protrusions arranged at intervals. In one embodiment, the plurality of protrusions are uniformly distributed along the circumferential direction of the first body portion 211 , so that the stop force is uniformly distributed along the circumferential direction and avoid stress concentration.

Of course, as shown in FIGS. 6 and 8 , in other embodiments, a second position-limiting protrusion 224 may also be provided between the second body portion 221 and the socket portion 222 , and the second position-limiting protrusion 224 protrudes inward along the radial direction of the second body portion 221 , and the second position-limiting protrusion 224 stops the insertion portion 212 to form a position-limiting structure. As shown in FIG. 6 , the second limiting protrusion may be an annular protrusion, and as shown in FIG. 8 , the second limiting protrusion may also be a plurality of protrusions arranged at intervals. In one embodiment, the plurality of protrusions are uniformly distributed along the circumferential direction of the second body portion 221 , so that the stop force is uniformly distributed along the circumferential direction and avoid stress concentration.

Certainly, in other embodiments, as shown in FIG. 9 and FIG. 10 , the first tube body 210 and the second tube body 220 can also be directly welded after in-line plugging to a proper position without setting a limiting structure.

Certainly, the above-mentioned assembling method is also applicable between two adjacent second tube bodies 220 .

Certainly, the above-mentioned assembling method is also applicable between the first pipe member 100 and the first pipe body 210 .

In this embodiment, the diameter of the second pipe member 200 is defined as d, where d≤30mm; the weld gap between the first pipe body 210 and the second pipe body 220 is defined as δ, where δ≤0.05mm; the wall thickness of the second pipe member 200 is defined as t, where t≤1.5mm; using the above-mentioned plug-in connection method, the concentricity between the first pipe body 210 and the second pipe body 220 is better, and the concentricity deviation between the first pipe body 210 and the second pipe body 220 small value less than or equal to 0.15mm; the heat-affected zone of pipe welding is within 5mm near the weld, and assuming that the wall thickness of the heat-affected zone after welding is uniform, the reduction in the wall thickness t of the second pipe fitting 200 in this application is: The shrinkage of the wall thickness t is less than 0.1, that is, the shrinkage of the wall thickness t is small, so that the strength of the weld is relatively high.

Of course, in other embodiments, as shown in FIG. 11 , the first pipe body 210 and the second pipe body 220 are firstly connected by butt joints, and then welded.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of this application should be based on the appended claims.

Claims

A pipeline for an air-conditioning system, characterized in that the pipeline for an air-conditioning system comprises:

first pipe;

The second pipe is configured as a split structure and includes a plurality of sections of pipe, and the plurality of sections of pipe are configured as a first pipe and at least one section of second pipe;

Wherein, one end of the first pipe body is connected to the first pipe member by furnace welding, and the other end of the first pipe body away from the first pipe member is connected to the second pipe body by welding.
The pipeline for an air-conditioning system according to claim 1, wherein solder welding is used between the first pipe member and the first pipe body; or self-flux welding or solder welding is used between the first pipe body and the second pipe body; or self-flux welding or solder welding is used between two adjacent second pipe bodies.
The pipeline for an air-conditioning system according to claim 1 or 2, characterized in that the first pipe body and the second pipe body are first connected by means of plug-in connections, and then welded.
The pipeline for an air conditioning system according to claim 3, wherein one of the first pipe body and the second pipe body is provided with an insertion portion, and the other is provided with a socket portion, and the insertion portion is inserted into the socket portion and welded.
The pipeline for an air-conditioning system according to claim 4, wherein a limiting structure is provided between the insertion part and the socket part to limit the insertion length between the first pipe body and the second pipe body.
The pipeline for an air-conditioning system according to claim 5, wherein one of the first pipe body and the second pipe body provided with the insertion part further includes a first body part and a first connection part, the first body part is connected to the insertion part through the first connection part, the diameter of the insertion part is smaller than the diameter of the first body part, and when the insertion part is inserted into the socket part, the first connection part blocks the socket part to form the limiting structure.
The pipeline for an air-conditioning system according to claim 5, wherein one of the first pipe body and the second pipe body provided with the socket portion further includes a second body portion and a second connecting portion, the second body portion is connected to the socket portion through the second connection portion, the diameter of the socket portion is larger than the diameter of the second body portion, and when the insertion portion is inserted into the socket portion, the second connection portion blocks the insertion portion to form the limiting structure.
The pipeline for an air-conditioning system according to any one of claims 4-7, wherein the central axis of the welding torch nozzle is defined as l, the central axis of the socket part is defined as b, and the angle between the central axis l of the welding torch nozzle and the central axis b of the socket part is defined as α, and the α needs to satisfy the following relationship: 10°≤α≤60°.
The pipeline for an air-conditioning system according to any one of claims 4-7, characterized in that the heat distribution ratio between the insertion part and the socket part when welding is 5:5-6:4.
The pipeline for an air-conditioning system according to claim 5, wherein the one of the first pipe body and the second pipe body provided with the insertion part further includes a first body part, a first stopper protrusion is provided between the first body part and the insertion part, the first stopper protrusion protrudes outward along the radial direction of the first body part, and the first stopper protrusion stops the socket part to form the stopper structure.
The pipeline for an air-conditioning system according to claim 5, wherein one of the first pipe body and the second pipe body provided with the socket portion further includes a second body portion, a second position-limiting protrusion is provided between the second body portion and the socket portion, the second position-limiting protrusion protrudes inward along the radial direction of the second body portion, and the second position-limiting protrusion stops the insertion portion to form the position-limiting structure.
The pipeline for an air-conditioning system according to claim 3, wherein the diameter of the second pipe is defined as d, and d satisfies the following relationship: d≤30mm; the weld gap between the first pipe and the second pipe is defined as δ, and δ satisfies the following relationship: δ≤0.05mm; the wall thickness of the second pipe is defined as t, and t satisfies the following relationship: t≤1.5mm; The concentricity deviation value of the body is less than or equal to 0.15mm; after the first pipe body and the second pipe body are welded, the wall thickness t of the second pipe part is reduced by less than or equal to 1%.
The pipeline for an air-conditioning system according to claim 1 or 2, characterized in that, the first pipe body and the second pipe body are first connected by a butt joint method, and then welded.
The pipeline for an air-conditioning system according to claim 1, wherein the first pipe piece includes a copper pipe, a steel pipe or an aluminum pipe; or, the second pipe piece includes a copper pipe, a steel pipe or an aluminum pipe.
The pipeline for an air-conditioning system according to claim 1, wherein the first pipe body and the second pipe body are connected in a butt-joint manner, and then welded, or connected in a plug-in manner, and then welded;

Two adjacent second pipe bodies are connected by butt joints, and then welded, or connected by plugging, and then welded.