New branch pipe and refrigeration equipment

Abstract

The present invention provides a new type of branch pipe, which includes a main pipe, a first branch pipe and a second branch pipe, the second branch pipe includes an extruded portion and an extension portion welded to the extruded portion, the extruded portion and the first branch pipe extend on both sides of the main pipe respectively, the extruded portion, the main pipe and the first branch pipe are integrally molded and communicate with each other through a communication area, and the first branch pipe and the second branch pipe have the same number of arc-shaped bends. the axial lines of the first branch pipe and the extruded portion adjacent to the communication region intersect with the axial line of the main pipe adjacent to the communication region at a reference point to form two angles, the two angles constituting bending angles of the first branch pipe and the extruded portion, the bending angles being 40°≦β≦160° and the two angles being greater than 10°; the difference in vertical height between the end faces of the ends of the two branch pipes being △H≦53mm; the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance of the ends of the two branch pipes and the outer diameter of the first branch pipe adjacent to the communication region, and the offset amount of the basic size being △B≦44.5mm.

Description

[Technical field]

[0001] The present invention relates to the field of refrigeration system components, and in particular to a new type of manifold and refrigeration device. [Background technology]

[0002] A multi-air conditioner (heat pump) system is a direct evaporative air conditioning system formed by connecting one or more outdoor units and multiple indoor units with a specified piping at a construction site. In a multi-air conditioner (heat pump) unit, in order to distribute the refrigerant in the piping, it is necessary to connect them with a branch pipe that has a dedicated dividing or merging function. A branch pipe is similar to a three-way pipe, but differs from a three-way pipe component in that, firstly, the length of the three connection ends of a three-way pipe is very short, and the ratio of the length of each connection end to its outer diameter is less than twice, so it is easy to extrude, but the three connection ends are all very short, so when directly welding with the piping of a multi-air conditioner (heat pump) system, the transfer of heat easily causes secondary melting of the welded seam, which causes leakage. In addition, the port sizes of the three connection ends of a three-way pipe are all fixed, so it cannot be connected to multiple sizes of piping in an air conditioner system. Branch pipes, as an important connection part of a multi-air conditioner (heat pump) system, not only have three long connection ends, but also have multiple ports of different specification sizes at each end, meeting the connection needs of piping of different specifications for air conditioners of different power.

[0003] The conventional branch pipe structure is one three-way pipe and three extension pipes welded together (as shown in FIG. 1), so there are three weld seams 101, 102, 103. Due to the three extension pipes welded to the three-way parts, such a branch pipe has too many weld seams, which increases the risk of leakage, wastes copper material, and increases manufacturing costs. In order to reduce the weld seams of the branch pipe, a branch pipe structure with two weld seams has been proposed, as shown in FIG. 2, in which a connecting opening 102' is opened on the side wall of the collecting pipe in the structure, one branch pipe is connected to the end 101' of the collecting pipe, and the other branch pipe is connected to the connecting opening 102' on the side wall of the collecting pipe. Compared with the structure in FIG. 1, the number of weld seams in FIG. 2 is reduced by one, but not only is it difficult for the branch pipe in the structure to be welded to the connecting opening on the side wall of the collecting pipe, but the welded part is also prone to leakage, and the branch pipe is also prone to falling off after welding.

[0004] In order to solve the problem of many leakage complaints of commercially available branch pipes with three welded seams as the main body of a three-way pipe, the applicant has proposed a branch pipe that is integrally molded after extruding the pipe body in patent CN208282360U (shown in FIG. 3). The branch pipe of this structure is an integral structure, and its length is sufficient to meet the pipe connection requirements of a multi-air conditioner (heat pump) system, so that the entire product has fewer welded seams, a simple structure, and high safety performance. However, it has been found that the branch pipe of this structure has the problem that the refrigerant branching is uneven during actual installation and use, and the pressure drop between the main pipe and the branch pipe is too large, which not only reduces the refrigeration power of the indoor unit, but also affects the energy efficiency ratio of the system. Therefore, as a connecting pipe member for realizing the branching or merging of the refrigerant in the piping, the branch pipe is required to meet the pressure resistance requirements of the system, be easy to install, and have multiple requirements such as the branching of the branch pipe as uniform as possible and low flow resistance. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE PRESENT DISCLOSURE In order to overcome the drawbacks of the prior art, the present invention provides a new branch pipe and refrigeration device that has excellent flow distribution uniformity between two branch pipes and reduces inlet and outlet pressures. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a new type of branch pipe, comprising a main pipe, a first branch pipe and a second branch pipe, the second branch pipe comprising an extrusion portion and an extension portion welded to the extrusion portion, the extrusion portion and the first branch pipe respectively extending to both sides of the main pipe, the extrusion portion, the main pipe and the first branch pipe being integrally molded and communicating with each other through a communication region, the length of the main pipe is at least twice the outer diameter of the first branch pipe at a location adjacent to the communication region, the length of at least one of the two branch pipes is more than four times the outer diameter of the first branch pipe at a location adjacent to the communication region, the first branch pipe and the second branch pipe have the same number of arcuate bends, the axial lines of the first branch pipe and the extruded portion adjacent to the communication region intersect with the axial line of the main pipe adjacent to the communication region at a reference point, and respectively form two angles, which constitute bending angles of the first branch pipe and the extruded portion, the bending angles being 40°≦β≦160°, and both angles being 10° or more; the difference in vertical height between the end faces of the terminals of the two branch pipes being △H≦53mm; the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance between the terminals of the two branch pipes, and the outer diameter of the first branch pipe adjacent to the communication region, and the offset amount of the basic size being △B≦44.5mm; the length of the main pipe refers to the vertical distance from the end face of the main pipe to the cross section at which the reference point is located, and the length of the branch pipe refers to the vertical distance from the end face of the terminal of the branch pipe to the cross section at which the reference point is located.

[0007] According to one embodiment of the present invention, the basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance between the ends of the two branch pipes, respectively, and is positively correlated with the outer diameter of the first branch pipe adjacent to the communication region.

[0008] According to one embodiment of the present invention, the basic size B of the length of one branch pipe satisfies the following relationship with the outer diameter D of the first branch pipe at a portion adjacent to the communication region, the bending angle β, and the center distance L of the ends of the two branch pipes:

number

[0009] According to one embodiment of the present invention, the pressure drop differential coefficient K satisfies 1.2≦K≦1.55.

[0010] According to one embodiment of the present invention, the offset amount ΔB of the base size is positively correlated with the outer diameter of the first branch pipe adjacent to the communication region, and is negatively correlated with the center distance between the ends of the two branches.

[0011] According to one embodiment of the present invention, the offset amount ΔB of the basic size satisfies the following relationship:

number

[0012] According to one embodiment of the present invention, the maximum and minimum values ​​of the bending angle β formed between the first branch pipe and the extrusion portion are respectively correlated with the outer diameter D of the first branch pipe at a portion adjacent to the communication region and the center distance L of the ends of the two branch pipes,

number

[0013] According to one embodiment of the present invention, the vertical height difference ΔH between the end faces of the ends of the two branch pipes is correlated with the ratio of the outer diameter D of the portion of the first branch pipe adjacent to the communication area to the center distance L of the ends of the two branch pipes, and the vertical height difference ΔH between the end faces of the two branch pipes satisfies the following:

[0014]

number

[0015] According to one embodiment of the present invention, the main pipe, the first branch pipe and the second branch pipe are all copper pipes; Or, the main pipe, the first branch pipe and the second branch pipe are all made of stainless steel pipes, and the extensions are made of copper pipes, and the new branch pipe further includes a main pipe connection part welded to the main pipe and made of copper material, and a first branch pipe connection part welded to an end of the first branch pipe and made of copper material; Alternatively, the main pipe, the first branch pipe and the second branch pipe are all stainless steel pipes, and the new branch pipe further includes a main pipe connection portion welded to the main pipe and made of copper material, a first branch pipe connection portion welded to the first branch pipe and made of copper material, and a second branch pipe connection portion welded to an extension portion of the second branch pipe and made of copper material.

[0016] According to one embodiment of the present invention, the perpendicular distance between the axial line of the end of the first branch pipe and the axial line of the portion adjacent to the communication region of the main pipe is 1.3D≦L1≦4D, where D is the outer diameter of the portion adjacent to the communication region of the first branch pipe.

[0017] In another aspect, the present invention further provides a new type of branch pipe, comprising a main pipe, a first branch pipe and a second branch pipe. The main pipe comprises a main pipe joint portion and a main pipe body welded together. The first branch pipe is connected to the main pipe joint portion and extends to one side of the main pipe joint portion. The second branch pipe comprises an extrusion portion and an extension portion welded to the extrusion portion, the extrusion portion is connected to the main pipe joint portion and extends to the other side of the main pipe joint portion, the extrusion portion, the first branch pipe and the main pipe joint portion are integrally molded and communicate with each other via a communication region. The length of the main pipe is at least twice the outer diameter of the portion adjacent to the communication region of the first branch pipe, and the length of at least one of the two branches is more than four times the outer diameter of the portion adjacent to the communication region of the first branch pipe. The first branch pipe and the second branch pipe have the same number of arc-shaped bends. The axial lines of the portions adjacent to the communication regions of the first branch pipe and the extrusion section intersect with the axial line of the portion adjacent to the communication region of the main pipe joint section at a reference point and form two angles, and the two angles constitute bending angles of the first branch pipe and the extrusion section, and the bending angles are 40°≦β≦16 0°, and both angles are 10° or more; the difference in vertical height between the end faces of the two branch pipes is △H≦53mm; the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance between the ends of the two branch pipes, and the outer diameter of the first branch pipe at a point adjacent to the communication area, and the offset amount of the basic size is △B≦44.5mm; the length of the main pipe refers to the vertical distance from the end face of the main pipe body to the cross section on which the reference point is located, and the length of the branch pipe refers to the vertical distance from the end face of the branch pipe terminal to the cross section on which the reference point is located.

[0018] According to one embodiment of the present invention, the basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance of the ends of the two branch pipes, and is positively correlated with the outer diameter of the first branch pipe at a portion adjacent to the communication region, and the basic size B satisfies the following:

number

[0019] In another aspect, the present invention further provides a new type of branch pipe, comprising a main pipe, a first branch pipe and a second branch pipe, the second branch pipe comprising an extrusion section and an extension section welded to the extrusion section, the extrusion section and the first branch pipe respectively extend to both sides of the main pipe, the extrusion section, the main pipe and the first branch pipe are integrally molded and communicate with each other through a communication region, the included angle between an axial line of an end of the extension section and an axial line of the main pipe adjacent to the communication region is 80°≦θ≦100°, the main pipe has a length of at least two times the outer diameter of the first branch pipe adjacent to the communication region, and the first branch pipe has a length of more than four times the outer diameter of the first branch pipe adjacent to the communication region, the first branch pipe and the second branch pipe have the same number of arcuate bends, the arcuate bends of the second branch pipe are located in the extension section, the axial lines of the first branch pipe and the extrusion section adjacent to the communication region intersect with the axial line of the main pipe adjacent to the communication region at a reference point and form two angles, the two angles constituting bending angles of the first branch pipe and the extrusion section, the bending angles being 40°≦β≦160°, and the two angles being 10° or more, The basic size B of the length is negatively correlated with the bending angle and the lateral distance between the axial line of the first branch pipe and the extended end of the arc-shaped bent portion of the extended section, and is positively correlated with the outer diameter of the first branch pipe at a point adjacent to the communication region, the offset amount of the basic size △B≦44.5 mm, the length of the main pipe refers to the vertical distance from the end face of the main pipe to the cross section on which the reference point is located, and the length of the first branch pipe refers to the vertical distance from the end face of the terminal end of the first branch pipe to the cross section on which the reference point is located.

[0020] In another aspect, the present invention further provides a refrigeration device, comprising the new manifold described above. Effect of the Invention

[0021] From the above, the new branch pipe of the present invention controls the difference in local resistance loss between the two branches by introducing the number of circular bends, the angle, and the offset amount of the relative length basic size of the branch pipe based on the bending angle between the two branches, and further reduces the influence of the friction resistance difference between the two branches by controlling the difference in vertical height between the end faces of the ends, and further realizes the control of the flow distribution uniformity of the two branches. Regarding the pressure drop between the inflow and the outflow, the outer diameter of the part close to the communication area of ​​the first branch pipe, the bending angle, and the center distance of the ends of the two branches are precisely controlled, so that the two branches meet the installation requirements and the resistance loss of the entire product meets the pressure drop requirements of the system. By precisely setting multiple parameters between the two branches of the new branch pipe of the present invention, the product not only has excellent flow distribution uniformity, but also greatly reduces the pressure drop between the inflow and the outflow, thereby improving the energy efficiency ratio of the multi-air conditioner (heat pump) system.

[0022] In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments of the present invention will be described in detail below in conjunction with the drawings. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of a conventional branch pipe structure. [Diagram 2] FIG. 1 is a schematic diagram of a conventional branch pipe structure. [Diagram 3] FIG. 1 is a schematic diagram of a conventional branch pipe structure. [Figure 4] FIG. 2 is a structural schematic diagram of a new branch pipe according to a first embodiment of the present invention. [Diagram 5] 5 is a schematic diagram of the structure after the main pipe, the first branch pipe, and the extruded portion in FIG. 4 are integrally molded. FIG. [Figure 6] FIG. 4 is a structural schematic diagram of a new branch pipe according to another embodiment of the present invention. [Figure 7] This is a schematic diagram of a structure in which the basic size changes with the angle α1. [Figure 8] FIG. 2 is a structural schematic diagram of a thermal insulation jacket attached. [Figure 9] FIG. 4 is a structural schematic diagram of a new branch pipe according to another embodiment of the present invention. [Figure 10] FIG. 4 is a structural schematic diagram of a new branch pipe according to another embodiment of the present invention. [Figure 11] FIG. 6 is a structural schematic diagram of a new branch pipe according to a second embodiment of the present invention. [Figure 12] FIG. 11 is a structural schematic diagram of a new branch pipe according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In order to improve the uniformity of the flow between the two branches of a conventional branch pipe, this is currently mainly achieved by controlling the angle distribution between the two branches, but it has been demonstrated that it is difficult to achieve uniform flow between the two branches even if they are symmetrically distributed. In addition, based on the restriction of energy loss in the pipes due to the refrigeration energy efficiency ratio of a multi-air conditioner (heat pump) unit, the branch pipe, as a main connecting pipe, needs to consider the total energy loss when the refrigerant passes through the branch pipe during design. However, the influence of this index is not taken into account during the design of conventional branch pipes.

[0025] In order to consider the uniformity of the flow distribution between the two branches of the branch pipe and the total energy loss when the refrigerant flows through the branch pipe, this embodiment provides a new type of branch pipe. As shown in Fig. 4, the new type of branch pipe includes a main pipe 1, a first branch pipe 2, and a second branch pipe 3, the second branch pipe 3 includes an extrusion portion 31 and an extension portion 32 welded to the extrusion portion 31, the extrusion portion 31 and the first branch pipe 2 extend to both sides of the main pipe 1, the extrusion portion 31, the main pipe 1, and the first branch pipe 2 are integrally molded and communicate with each other through a communication region 100, the length Ha of the main pipe 1 is more than twice the outer diameter D of the first branch pipe 2 at a portion adjacent to the communication region, the length of at least one of the two branches is more than four times the outer diameter D of the first branch pipe 2 at a portion adjacent to the communication region, and the first branch pipe 2 and the second branch pipe 3 have the same number of arc-shaped bends Re.

[0026] The axial lines of the first branch pipe 2 and the extruded portion 31 adjacent to the communication region 100 intersect with the axial line of the main pipe 1 adjacent to the communication region 100 at a reference point O to form two angles α1 and α2, respectively. The two angles constitute a bending angle β of the first branch pipe 2 and the extruded portion 31. The bending angles are 40°≦β≦160°, and both angles are 10° or more, the difference in vertical height between the end faces of the ends of the two branch pipes is △H≦53mm, the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance of the ends of the two branch pipes, and the outer diameter of the first branch pipe adjacent to the communication region, and the offset amount of the basic size is △B≦44.5mm. In the new branch pipe of this embodiment, the direction in which the refrigerant flows out of the two branch pipes is approximately parallel to the direction in which the refrigerant flows into the main pipe 1, and the length Ha of the main pipe 1 refers to the vertical distance from the end face of the main pipe to the cross section where the reference point O is located, and the lengths Hb and Hc of the two branch pipes refer to the vertical distance from the end faces of the ends of the branch pipes to the cross section where the reference point is located.

[0027] Specifically, in this embodiment, after determining the basic size B of one branch pipe (which may be the first branch pipe or the second branch pipe) based on the outer diameter D of the part adjacent to the communication region of the first branch pipe, the bending angle β, and the center distance L of the ends of the two branch pipes, the length of the branch pipe can vary within the range of B to B + △B or B - △B to B, and the length range of the other branch pipe can be determined based on the vertical height difference △H between the end faces of the ends of the two branch pipes.

[0028] The flow distribution uniformity refers to the uniformity of the outflow flow rate of the two branches. When the inner diameters of the two branches are approximately the same, based on the relationship Q=V*S (Q is the flow rate, V is the flow velocity of the refrigerant, and S is the cross-sectional area of ​​the pipe), the flow rate balance between the two branches is embodied in the form of the refrigerant flow velocity, that is, the relationship between the flow velocity Vb of the first branch 1 and the flow velocity Vc of the second branch. During the refrigerant transport process, the change in the refrigerant flow velocity is correlated with the resistance in the pipe, which includes friction resistance that characterizes the blocking action in the fluid, and local resistance that characterizes the turbulent disturbance. Therefore, in order to improve the flow distribution uniformity between the two branches, it is necessary to study the resistance loss of the two branches and make them as close as possible. As for the total energy loss during the flow of the refrigerant, this energy loss is also due to the refrigerant eliminating the friction resistance and local resistance loss, which is expressed as the drop difference (also called pressure drop) between the flow velocity Va at the end of the main pipe and the flow velocities Vb and Vc of the two branches.

[0029] From this analysis, when the flow velocity Va at the main pipe end is determined, the uniformity of the flow between the two branches and the total energy loss of the refrigerant flowing through the new branch pipe can both be realized by the refrigerant flow velocities Vb and Vc of the two branches, and the change in the refrigerant flow velocity in each branch pipe is mainly affected by the local resistance loss and friction resistance loss of the branch pipe. Therefore, the structure of the new branch pipe in this example will be described in detail below from the two perspectives of resistance loss.

[0030] Regarding the local resistance loss, since the first branch pipe 2 and the extrusion portion 31 extend to both sides of the main pipe 1, respectively, the bending angle β formed between them will cause local loss. In addition, since the axial lines of the first branch pipe 2 and the second branch pipe 3 are both parallel to the axial line of the main pipe 1 at a location close to the communication region 100, both of the two branches have an arc-shaped bend Re, and the mass point in the refrigerant at the arc-shaped bend Re is affected by centrifugal force to generate a vortex, which causes local loss. When the number of arc-shaped bends in the two branches is different, for example, one branch pipe has one arc-shaped bend and the other has two or more arc-shaped bends, the local turbulence between the arc-shaped bends will interfere with each other and generate even larger resistance, which not only worsens the uniformity of the divided flow but also seriously affects the pressure drop difference of the branch pipes. Based on this initial analysis, in order to make the local resistances of the two branches close to each other and minimize the effect of the local resistance on the pressure drop difference, the number of arcuate bends Re of the two branches is one. However, the present invention is not limited thereto. In another embodiment, when it is necessary to install two or more arcuate bends in one branch based on the installation requirements, the same number of arcuate bends are installed in the other branch to match the flow distribution uniformity, and the adjacent arcuate bends are spaced apart by a certain distance to minimize the mutual disturbance between them.

[0031] After determining the number of circular arc bends Re, in order to find the relationship between the bending angle β between the two diversion branch pipes and the diversion uniformity, the inventor has conducted a large number of tests to study the change in flow rate of the two branches of the new branch pipe of various specifications when the bending angle β changes. For the determined bending angle β, the two angles α1 and α2 are not necessarily equal, but under the same conditions, the diversion uniformity is optimal when the two angles are equal (the study described later also proves that the effect of the change in the two angles on the diversion uniformity is small within the upper and lower critical angle ranges, but the diversion uniformity is still optimal when α1=α2). Therefore, in order to simplify the research object, in the test in Table 1, the two angles are assumed to be equal, and the length Hb of the first branch pipe 2 under the conditions is defined as the basic size B to study the effect of the bending angle β on the diversion uniformity, which is represented by Hb(B) in Table 1. However, the present invention is not limited to the actual length of the first branch being necessarily the base size, and in fact, the actual length of the first branch is based on the base size and has an offset of ΔB, or in other embodiments, the length of the second branch can be determined based on the base size B and the offset ΔB, and then the length of the first branch can be determined based on ΔH.

[0032] The test conditions are as follows: In an indoor environment of 18°C, the test specimen is placed horizontally, the working pressure is set to 2.2Mpa, the corresponding test measuring device is installed on the two branch pipes to measure the refrigerant flow velocity, the refrigerant with a flow velocity of Va=5.13036m / s and model number R410A flows in from the end of the main pipe 1, and after 30 minutes of stable operation under the operating conditions, data is collected four times at equal time intervals for the refrigerant flow velocity at the outlet ends of the two branches, and the arithmetic average value of the four collected data is the test measurement value under the operating conditions. Based on the recorded refrigerant flow velocity Vb of the first branch pipe 2 and the refrigerant flow velocity Vc of the second branch pipe 3, the flow velocity difference rate △V=(Vb-Vc) / Vb between the two branches and the reduction ratio ΔV=max(Vb / Va,Vc / Va) of the flow velocity of the two branches relative to the flow velocity at the end of the main pipe are calculated.

[0033] Select test pieces. Select six test groups based on the outer diameter D of the first branch 2 at a location adjacent to the communication region 100, form multiple sub-test groups within each test group based on the center distance between the ends of two branches, and further form multiple test pieces within each sub-test group based on the bending angle β between the two branches.

[0034] The outer diameter D in the first test group is 9.52 mm, and the center distances L in the five sub-test groups included are 46 mm, 51 mm, 56 mm, 61 mm, and 66 mm, and each sub-test group is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0035] The outer diameter D in the second test group is 15.88 mm, and the center distances L in the five sub-test groups included are 52 mm, 57 mm, 62 mm, 67 mm, and 72 mm, and each sub-test group is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0036] The outer diameter D in the third test group is 25 mm, and the center distances L in the four sub-test groups included are 67 mm, 77 mm, 87 mm, and 97 mm, and within each sub-test group, it is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0037] The outer diameter D in the fourth test group is 38 mm, and the center distances L in the four sub-test groups included are 85 mm, 95 mm, 105 mm, and 115 mm, and within each sub-test group, it is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0038] The outer diameter D in the fifth test group is 44 mm, and the center distances L in the four sub-test groups included are 100 mm, 110 mm, 120 mm, 130 mm, and 140 mm. Within each sub-test group, it is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0039] The outer diameter D in the 6th test group is 54 mm, and the center distances L in the five sub-test groups included are 150 mm, 165 mm, 180 mm, 195 mm, and 210 mm. Within each sub-test group, it is divided into 24 test groups based on the bending angle β between the two branch pipes.

[0040] The above six test groups are tested and the relevant data are recorded to form Table 1. After analyzing the data in Table 1, it is found that when the angle is within 40°≦β≦160° and the difference in vertical height between the end faces of the two branch pipes is △H≦52mm, the flow velocity difference rate △V between the two branch pipes is excellent. When the conventional branch pipe shown in Figure 3 is tested under the same conditions, its uniformity is optimally only 40% (as shown in Table 5), that is, when the angle is within 40°≦β≦160° and the difference in vertical height between the end faces of the two branch pipes is △H≦52mm, the flow distribution uniformity of the new branch pipe according to this embodiment is much better than that of the conventional branch pipe.

[0041] Further analysis of the data on which the flow distribution uniformity meets the requirements reveals that the size Hb of the first branch pipe 2 (i.e., basic size B) is correlated with the drop ratio δV of the flow velocity of the two branches to the flow velocity of the main pipe end. Specifically, when the drop ratio δV of the flow velocity of the two branches to the flow velocity of the main pipe end meets a critical value (the critical value is δV=80% in Table 1), the basic size B (i.e., the maximum basic size that meets the drop ratio δV) becomes smaller as the bending angle β and the center distance L of the ends of the two branches increase, and becomes larger as the outer diameter D of the first branch pipe 2 adjacent to the communication region 100 increases, that is, the basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance L of the ends of the two branches, and is positively correlated with the outer diameter of the first branch pipe adjacent to the communication region.

[0042] Specifically, when the outer diameter D and the center distance L are determined, the larger the bending angle β, the smaller the basic size B that meets the critical value of the drop ratio δV. In other words, when the bending angle β is increased, the basic size B of the new branch pipe needs to be controlled to reduce the friction resistance loss, so that the drop ratio δV of the flow velocity of the two branch pipes to the flow velocity of the main pipe end is within the critical value to meet the requirement. In the air conditioning system, the critical value of the drop ratio δV of the flow velocity of the two branch pipes to the flow velocity of the main pipe end is usually specified by the air conditioner manufacturer, and the basic size B is limited by the processing of the circular bend of the branch pipe and the assembly of the branch pipe and the external pipe, so that it also needs to meet a certain length requirement. For example, when an air conditioner manufacturer requires that the drop ratio ΔV of the new branch pipe is less than 20% and the basic size B is greater than 120mm, in the sub-test group (the first sub-test group in the first test group in Table 1) with D=9.52mm and L=46mm, when β=105° and 115°, the flow distribution uniformity of the two branches is excellent and the flow velocity difference rate ΔV≦15%. In this case, the maximum basic size Hb(B) of the two branches cannot simultaneously meet the drop ratio ΔV critical value requirement and the length requirement of 120mm, so under this condition, β is selected to be 100° at most. When β=100°, the basic size that meets the drop ratio ΔV critical value is 123.8mm, that is, when the basic size of the new branch pipe varies between 120mm and 123.8mm, not only is the flow distribution uniformity excellent, but the length of the basic size and the drop ratio ΔV can also meet the requirements of the air conditioner manufacturer.

[0043] When the outer diameter D and bending angle β of the portion adjacent to the communication region 100 of the first branch pipe 2 are determined, the center-to-center distance L between the ends of the two branch pipes increases, and the refrigerant flow distance from the arc-shaped bent portion Re of the two branch pipes to the reference point increases, and in order to compensate for the resistance loss due to the increase in distance, it is also necessary to control the basic size to satisfy the requirement of the reduction ratio ΔV. As shown in the first sub-test group and the second sub-test group in the first test group in Table 1, when D=9.52 mm and β=45°, if the center-to-center distance L between the ends of the two branch pipes increases from 46 mm to 51 mm, the basic size that satisfies the critical value of the reduction ratio ΔV needs to be adjusted from 151.42 mm to 149.06 mm.

[0044] Conversely, when the center distance L and the bending angle β of the ends of the two branches are determined, if the outer diameter D of the first branch 2 at a location adjacent to the communication region 100 is increased, the flow resistance of the refrigerant is reduced, and the resistance of the entire branch pipe is reduced. Therefore, the basic size B that satisfies the critical value of the reduction ratio ΔV can be increased, that is, the adjustment range of the basic size becomes wider. As shown in the fourth and fifth sub-test groups in the first test group in Table 1, when L=67 mm and β=50°, and the outer diameter D of the first branch 2 at a location adjacent to the communication region 100 is increased from 15.88 mm to 25 mm, the basic size that satisfies the critical value of the reduction ratio ΔV can be increased from 149.95 mm to 180.45 mm. When an air conditioner manufacturer requires the basic size of the branch pipe to be larger than 120 mm, the basic size can be adjusted between 120 mm and 180.45 mm according to other needs, including manufacturing process needs and external pipe connection needs, such as the length of the expansion / contraction opening or the installation insertion depth needs.

[0045] From the analysis of the above test data, it is only given in advance that there exists a certain change law between the basic size B, the outer diameter D of the first branch 2 adjacent to the communication region 100, the center distance L of the ends of the two branches, and the bending angle β between the two branches, but no specific relationship is given to accurately guide the design of the new branch. Therefore, the inventor further analyzes and fits the test data of the test sample (data shown in gray in Table 1) in which 40°≦β≦160° in Table 1 and the flow velocity difference rate ΔV and the drop ratio δV can both meet the set requirements, thereby obtaining the relationship between the basic size B, the outer diameter D of the first branch 2 adjacent to the communication region 100, the center distance L of the ends of the two branches, and the bending angle β between the two branches, and the four satisfy the following formula:

number

[0046] Furthermore, the bending angle β of the test sample that meets the requirements of the flow velocity difference rate ΔV and the drop ratio ΔV in Table 1 was further analyzed. As a result, it was found that the maximum and minimum values ​​of the bending angle β were both correlated with the outer diameter D of the first branch pipe 2 at a location close to the communication region 100 and the center distance L of the ends of the two branches. After analyzing and fitting the data, the following formula was obtained:

number

[0047] Similarly, an analysis of the vertical height difference ΔH between the end faces of the two branch pipes of the test specimen that meets the requirements of the flow velocity difference rate ΔV and the drop ratio δV in Table 1 reveals that the vertical height difference ΔH between the end faces of the two branch pipes is correlated with the ratio of the outer diameter D of the point adjacent to the communication area of ​​the first branch pipe to the center distance L of the ends of the two branch pipes, and that the vertical height difference ΔH between the end faces of the two branch pipes satisfies the following formula:

[0048]

number

[0049] Table 3 is an error table between the theoretical base size (theoretical value B) calculated by formula 1 and the test value B (Hb) of the tested base size. The test value B (Hb) is derived from the test data Hb (B) in Table 1, and the theoretical value Hb is the value of the base size calculated based on formula 1. After analyzing the data in Table 3, it can be seen that the theoretical value B and the test value B (Hb) are very close, and the error between the two is within 1 mm. In addition, formula 4 is verified, and the test value △H is derived from △H in Table 1, and the average value of the test value △H of multiple samples in each sub-test group and the theoretical value △H calculated by formula 4 are very close, and the data in Table 2 shows that both the fitted formulas 1 and 4 are very accurate.

[0050] The test in Table 1 is obtained when the two angles α1 and α2 formed by the axial lines of the first branch pipe 2 and the extrusion section 31 at the points adjacent to the communication region 100 and the axial line adjacent to the communication region of the main pipe 1 are equal (β=α1+α2). However, in the actual manufacturing process, differences between the two angles will inevitably occur due to process deviations or installation requirements of air conditioner manufacturers. For this reason, based on the above test, the ratio of the two angles of each sample is changed to observe the effects of the change in angle on the flow distribution uniformity and pressure drop difference, and the relevant data is recorded to form Table 2. According to the test data in Table 2, it can be determined whether any angle is greater than the lower limit critical angle α min , the flow velocity of the branch pipe corresponding to the angle increases rapidly, seriously reducing the uniformity of the flow distribution between the two branches. However, when the angle is within the upper critical angle α max When the angle is in the range of 0.01 to 0.5, the transition bend angle between the branch pipe and the main pipe corresponding to the angle is large and the radius of curvature is small, resulting in large local losses. Similarly, the arc-shaped bend of the branch pipe also has a large angle and a small radius of curvature, resulting in a rapid increase in local losses. The two local inhibitions are located at the upper limit critical angle α max It is shown that the flow velocity of the branch pipe at the position 1 is rapidly decreased, the uniformity of the flow distribution between the two branches is seriously decreased, and the pressure drop difference across the pipe is large (i.e., the energy loss is seriously increased). After analyzing the angle data of all samples, the lower critical angle α min is close to 10°, and its upper critical angle α max It can be seen that the angle is close to 80°.

[0051] In the actual production process, it is difficult to perform direct measurement of angles on the three-dimensional structure of the tube member, so other means such as projection or dissection must be used for accurate measurement, and more importantly, it is difficult to analyze the change in angle and find the law when analyzing the data. Therefore, it is desirable to convert the angle to distance when analyzing the data. In this embodiment, in order to facilitate the study, in Table 1, the length Hb of the first branch tube 2 when α1=α2 is defined as the basic size B, and based on this, the situation in which the basic size B changes with its corresponding angle is studied.

[0052] Further analysis of the pipe member structure shown in Figure 4 reveals that as the angle changes, the projection distance from the circular arc bend Re of the first branch pipe 2 to the cross section where the reference point O is located changes, and the change in the projection distance is also shown in the overall length of the basic size B. As shown in Figure 7, when the angle is α1, the corresponding basic size is B1, and when the angle decreases from α1 to α11, the basic size increases from B1 to B11. Based on this change law, when α1 changes from the bisecting angle to the lower critical angle α min When the height of the basic size gradually increases, the lower limit critical angle α min Maximum value B max and α1 is the upper critical angle α max When the height of the basic size gradually decreases, the upper limit critical angle α max At the minimum value B min The offset amount of the basic size B is △B=1 / 2(B max -B min During the test, in order to make the angle 80°, select the test pieces that meet the requirements of △V and δV in the sub-test group of Table 1, and study the change range of the basic size when the angle changes at the upper critical angle and the lower critical angle, and record the relevant data to form Table 2.

[0053] In Table 2, β is the bending angle between two branches, α1 is the angle of the first branch, α2 is the angle of the second branch, and B(Hb) is the basic size after the basic size changes with the angle α1 of the first branch. Take the sub-test group with D=9.52mm and L=46mm as an example, B min When α1=80°, the basic size is 124.8 mm, and B max When α1=10°, the basic size is 177.4 mm, so ΔB=1 / 2(177.4-124.8)=26.3 mm. In this manner, the offset amount ΔB of the basic size of each sub-test group can be calculated.

[0054] After analyzing the data of all the sub-test groups in Table 2, it is found that the offset amount ΔB of the basic size B is positively correlated with the outer diameter D of the first branch 2 at a point close to the communication region 100, and is negatively correlated with the center distance L of the ends of the two branches. The offset amount ΔB of the basic size obtained after fitting and calculating all the data satisfies the following relationship:

number

[0055] Table 4 is a table of errors between the theoretical value ΔB of the offset of the basic size calculated by Equation 5 and the test value ΔB tested in Table 2. The test value ΔB is derived from ΔB in Table 2, and the theoretical value ΔB is calculated by Equation 5. Table 4 shows that the theoretical value ΔB and the test value ΔB of all the sub-test groups are very close to each other, and the error between the two is very small and within 1 mm, which indicates that the accuracy of Equation 5 is high.

[0056] When designing the branch pipe, the selection range of the bending angle β is determined based on the outer diameter D of the part close to the communication area of ​​the first branch pipe 2 and the center distance L of the ends of the two branches pipes according to formulas 2 and 3 to meet the requirement of the uniformity of the flow distribution. After determining a specific bending angle β within the selection range of the bending angle β, the basic size B of one branch pipe is determined based on formula 1 and the pressure drop difference coefficient K, which is correlated with the drop ratio δV of the flow velocity of the two branches pipes to the flow velocity of the main pipe end specified by the air conditioning process manufacturer, which is calculated in advance, to meet the requirement of the drop ratio δV. After obtaining the basic size B, the actual length range of the branch pipe is determined based on the offset amount △B of the basic size calculated by formula 5, and the actual length of the other branch pipe is determined based on the vertical height difference △H between the end faces of the ends of the two branches pipes. By controlling the bending angle β, the basic size B, the offset amount △B of the basic size, and the difference in vertical height △H between the end faces of the two branch pipes, the new branch pipe of this embodiment satisfies the flow uniformity and can reduce the total energy loss of the refrigerant during flow by properly taking into account the pressure drop difference.

[0057] In this embodiment, the vertical distance between the axial line of the end of the first branch pipe 2 and the axial line of the portion adjacent to the communication region of the main pipe 1 is 1.3D≦L1≦3.5D, where D is the outer diameter of the portion adjacent to the communication region 100 of the first branch pipe 2. As shown in Fig. 8, with this installation, the first thermal insulation jacket 51 fitted from the main pipe 1 can extend well beyond the communication region 100 toward the first branch pipe 2 and can further be adjacent to the second thermal insulation jacket 52 fitted from the first branch pipe 2, and the third thermal insulation jacket 53 is fitted from the second branch pipe 3 and is adjacent to the communication region 100, as specifically shown in Fig. 8.

[0058] In this embodiment, the axial lines of the ends of the first branch pipe 2 and the second branch pipe 3 are both parallel to the axial line of the main pipe 1 at a location adjacent to the communication region. However, the present invention is not limited to this. In other embodiments, the axial line of only one of the two branch pipes at the end may be parallel to the axial line of the main pipe at a location adjacent to the communication region, and the axial line of the other branch pipe at the end may intersect with the axial line of the main pipe at a small acute angle. Alternatively, the axial lines of the ends of the two branch pipes both intersect with the axial line of the main pipe at a small acute angle.

[0059] In this embodiment, the outer diameter of the main pipe 1 at a portion adjacent to the communication region 100 is approximately equal to the outer diameter D at a portion adjacent to the communication region of the first branch pipe 2. However, the present invention is not limited thereto. In another embodiment, as shown in Fig. 6, the outer diameter D1 at a portion adjacent to the communication region 100 of the main pipe 1 may be larger than the outer diameter D at a portion adjacent to the communication region of the first branch pipe 2 after the flaring process.

[0060] In this embodiment, the main pipe 1, the first branch pipe 2, and the second branch pipe 3 are all copper pipes. However, the present invention is not limited thereto. In another embodiment, as shown in Fig. 9, the main pipe 1, the first branch pipe 2, and the extrusion portion 31 of the second branch pipe are stainless steel pipes, and the extension portion 32 of the second branch pipe is a copper pipe. The new branch pipe further includes a main pipe connection portion 41 welded to the main pipe 1 and made of a copper material, and a first branch pipe connection portion 42 welded to the end of the first branch pipe 2 and made of a copper material.

[0061] Or, in another embodiment, as shown in FIG. 10 , the main pipe 1, the first branch pipe 2 and the second branch pipe 3 are all stainless steel pipes, and the new branch pipe further includes a main pipe connection portion 41 welded to the main pipe 1 and made of copper material, a first branch pipe connection portion 42 welded to the end of the first branch pipe 2 and made of copper material, and a second branch pipe connection portion 43 welded to the extension portion 32 of the second branch pipe and made of copper material.

[0062] Accordingly, this embodiment further provides a refrigeration device including the above-mentioned new branch pipe.

[0063] Example 2 This embodiment is almost the same as the first embodiment and its variations, except that the main pipe 1 includes a main pipe joint portion 11 and a main pipe body 12, as shown in FIG.

[0064] Specifically, the new branch pipe includes a main pipe 1, a first branch pipe 2, and a second branch pipe 3. The main pipe 1 includes a main pipe joint portion 11 and a main pipe body 12 which are welded to each other. The first branch pipe 2 is connected to the main pipe joint portion 11 and extends to one side of the main pipe joint portion 11. The second branch pipe 3 includes an extruded portion 31 and an extension portion 32 which is welded to the extruded portion 31, and the extruded portion 31 is connected to the main pipe joint portion 11 and extends to the other side of the main pipe joint portion 11. The extruded portion 31, the first branch pipe 2, and the main pipe joint portion 11 are integrally molded and communicate with each other via a communication region 100. The length Ha of the main pipe 1 is at least twice the outer diameter of the first branch pipe 2 at a point adjacent to the communication region, the length of at least one of the two branch pipes is more than four times the outer diameter D of the first branch pipe at a point adjacent to the communication region, and the first branch pipe 2 and the second branch pipe 3 have the same number of arc-shaped bends.

[0065] the axial lines of the first branch pipe 2 and the extruded portion 31 adjacent to the communication region 100 intersect with the axial line of the main pipe coupling portion adjacent to the communication region 100 at reference point O to form two angles, which constitute bending angles of the first branch pipe and the extruded portion, with the bending angles being 40°≦β≦160° and both angles being 10° or more; the difference in vertical height between the end faces of the terminals of the two branch pipes being △H≦53mm; the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance of the terminals of the two branch pipes and the outer diameter of the first branch pipe adjacent to the communication region, and the offset amount of the basic size is △B≦44.5mm; the length H of the main pipe refers to the vertical distance from the end face of the main pipe body to the cross section at which the reference point O is located, and the length of the branch pipe refers to the vertical distance from the end face of the terminal of the branch pipe to the cross section at which the reference point is located.

[0066] In this embodiment, the basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance between the ends of the two branch pipes, and is positively correlated with the outer diameter of the first branch pipe at a point adjacent to the communication region. The basic size B satisfies the following:

number

[0067] In the new branch pipe of this embodiment, the main pipe body 12 and the main pipe joint part 11 are connected separately, so that the diameter of the main pipe body 12 can be made different from that of the main pipe joint part 11, for example, by selecting a main pipe body 12 with a larger diameter, the new branch pipe can be better connected to the external pipeline. However, the bending angle β, the range of the two angles, the difference in vertical height ΔH between the end faces of the ends of the two branch pipes, the basic size B and the offset amount ΔB of the basic size are determined in the same manner as in the first embodiment, and detailed explanations are omitted in this invention.

[0068] Example 3 This embodiment is almost the same as embodiment 1 and its variations. The difference is that, as shown in FIG. 12, the included angle between the axial line of the end of the extension 32 of the second branch pipe and the axial line of the portion adjacent to the communication region 100 of the main pipe 1 is 80°≦θ≦100°. With this arrangement, the direction of the refrigerant flowing out of the extension 32 of the second branch pipe is approximately perpendicular to the direction of the refrigerant flowing into the end of the main pipe, thereby realizing the distribution of refrigerant in different directions.

[0069] Specifically, the new branch pipe includes a main pipe 1, a first branch pipe 2, and a second branch pipe 3, the second branch pipe 3 includes an extruded section 31 and an extension section 32 welded to the extruded section 31, the extruded section 31 and the first branch pipe 2 extend to both sides of the main pipe, the extruded section 31, the main pipe 1, and the first branch pipe 2 are integrally molded and communicate with each other through a communication region 100, and the included angle between the axial line of the end of the extension section 32 and the axial line of the main pipe 1 at a portion adjacent to the communication region is 80°≦θ≦100°. The length of the main pipe 1 is at least twice the outer diameter D of the portion adjacent to the communication region of the first branch pipe 2, and the length of the first branch pipe 2 is more than four times the outer diameter D of the portion adjacent to the communication region of the first branch pipe.

[0070] The first branch pipe 2 and the second branch pipe 3 have the same number of arc-shaped bends Re, and the arc-shaped bends Re of the second branch pipe 3 are located in the extension section 32. The axial lines of the first branch pipe 2 and the extrusion section 31 adjacent to the communication region intersect with the axial line adjacent to the communication region of the main pipe 1 at reference point O to form two angles, and the two angles constitute a bending angle β of the first branch pipe and the extrusion section, with the bending angle being 40°≦β≦160°, and both of the two angles being 10° or more. The basic size B of the length of first branch pipe 2 is negatively correlated with the bending angle and the lateral distance L' between the axial line of the first branch pipe and extended end M of arcuate bent portion Re of extension portion 32, and is positively correlated with the outer diameter D of first branch pipe 2 at a point adjacent to the communication region, the offset amount of the basic size is △B≦44.5 mm, the length Ha of the main pipe refers to the vertical distance from the end face of the main pipe 1 to the cross section where reference point O is located, and the length Hb of first branch pipe 2 refers to the vertical distance from the end face of the terminal of first branch pipe 2 to the cross section where reference point O is located. The extended end M of arcuate bent portion Re of extension portion 32 refers to the end of arcuate bent portion Re away from extrusion portion 31.

[0071] The determination of the bending angle β, the range of the two angles, the difference in vertical height ΔH between the end faces of the ends of the two branch pipes, the basic size B and the offset amount ΔB of the basic size are the same as in Example 1, and detailed explanations are omitted in this invention.

[0072] From the above, the new branch pipe of the present invention controls the difference in local resistance loss between the two branches by introducing the number of circular bends, the angle, and the offset amount of the relative length basic size of the branch pipe based on the bending angle between the two branches, and further reduces the influence of the friction resistance difference between the two branches by controlling the difference in vertical height between the end faces of the ends, and further realizes the control of the flow distribution uniformity of the two branches. Regarding the pressure drop between the inflow and the outflow, the outer diameter of the part close to the communication area of ​​the first branch pipe, the bending angle, and the center distance of the ends of the two branches are precisely controlled, so that the two branches meet the installation requirements and the resistance loss of the entire product meets the pressure drop requirements of the system. By precisely setting multiple parameters between the two branches of the new branch pipe of the present invention, the product not only has excellent flow distribution uniformity, but also greatly reduces the pressure drop between the inflow and the outflow, thereby improving the energy efficiency ratio of the multi-air conditioner (heat pump) system.

[0073] The present invention has been disclosed above through preferred embodiments, but these are not intended to limit the present invention, and those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention, therefore, the protection scope of the present invention should be in accordance with the scope claimed by the claims.

[0074] In the table below: D is the outer diameter of the first branch pipe at a portion adjacent to the communication region, and is expressed in mm. L is the center distance between the ends of the two branch pipes, its unit is mm, β is the bending angle between two branches, its unit is °; Va is the flow velocity of the refrigerant at the end of the main pipe, and its unit is m / s. Vb is the flow velocity of the refrigerant in the first branch pipe, and its unit is m / s. Hb(B) is the length of the first branch in mm; Vc is the flow velocity of the refrigerant in the second branch pipe, and its unit is m / s. Hc is the length of the second branch, in mm. △V is the difference in the flow velocity of the refrigerant between the two branches. △H is the difference in vertical height between the end faces of the two branch pipes, and its unit is mm. δV is the ratio of the flow velocity drop in the two branch pipes to the flow velocity at the end of the main pipe, △B is the offset amount of the basic size, the unit is mm, The units of the test value B (Hb), the theoretical value B, the test value ΔH, the theoretical value ΔH, the test value ΔB and the theoretical value ΔB are all mm.

[0075] [Table 1] JPEG2025500002000013.jpg118170JPEG2025500002000014.jpg118170JPEG2025500002000015.jpg118170JPEG2025500002000016.jpg118170JPEG2025500002000017.jpg123170JPEG2025500002000018.jpg118170JPEG2025500002000019.jpg118170JPEG2025500002000020.jpg118170JPEG2025500002000021.jpg118170JPEG2025500002000022.jpg127170JPEG2025500002000023.jpg122170JPEG2025500002000024.jpg123170JPEG2025500002000025.jpg127170JPEG2025500002000026.jpg127170JPEG2025500002000027.jpg127170JPEG2025500002000028.jpg127170JPEG2025500002000029.jpg126170JPEG2025500002000030.jpg144170JPEG2025500002000031.jpg139170JPEG2025500002000032.jpg140170JPEG2025500002000033.jpg139170JPEG2025500002000034.jpg135170JPEG2025500002000035.jpg144170JPEG2025500002000036.jpg139170JPEG2025500002000037.jpg140170JPEG2025500002000038.jpg140170JPEG2025500002000039.jpg140170

[0076]

Table 2

[0077]

Table 3

[0078]

Table 4

[0079]

Table 5

Claims

1. a first branch pipe and a second branch pipe; the second branch pipe includes an extruded portion and an extension portion welded to the extruded portion, the extruded portion and the first branch pipe extend on both sides of the main pipe, the extruded portion, the main pipe and the first branch pipe are integrally molded and communicate with each other through a communication region; the length of the main pipe is at least twice the outer diameter of the first branch pipe at a location adjacent to the communication region, the length of at least one of the two branch pipes is more than four times the outer diameter of the first branch pipe at a location adjacent to the communication region, and the first branch pipe and the second branch pipe have the same number of arcuate bends; a bending angle between the end faces of the terminals of the two branch pipes is 40°≦β≦160°, and each of the two angles is 10° or more; a difference in vertical height between the end faces of the terminals of the two branch pipes is ΔH≦53 mm; a basic size B of the length of one branch pipe is correlated with the bending angle, the center distance between the terminals of the two branch pipes, and the outer diameter of the terminals of the first branch pipe is adjacent to the communication region, and an offset amount of the basic size is ΔB≦44.5 mm; the length of the main pipe refers to the vertical distance from the end face of the main pipe to the cross section at which the reference point is located, and the length of the branch pipe refers to the vertical distance from the end face of the terminal of the branch pipe to the cross section at which the reference point is located.

2. The new branch pipe as claimed in claim 1, characterized in that the basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance of the ends of the two branch pipes, respectively, and is positively correlated with the outer diameter of the portion adjacent to the communication region of the first branch pipe.

3. The basic size B of the length of one branch pipe satisfies the following relationship with the outer diameter D of the first branch pipe at a portion adjacent to the communication region, the bending angle β, and the center distance L of the ends of the two branch pipes, [0010] The new branch pipe as claimed in claim 1, characterized in that K is a pressure drop difference coefficient related to the critical value δV of the drop ratio of the flow velocity of the two branch pipes to the flow velocity at the main pipe end specified by the air conditioner manufacturer, and g is the gravitational acceleration.

4. 4. The new branch pipe according to claim 3, wherein the pressure drop difference coefficient K satisfies 1.2≦K≦1.

55.

5. The new branch pipe as described in claim 1, characterized in that the offset amount ΔB of the basic size is positively correlated with the outer diameter of the portion adjacent to the communication region of the first branch pipe, and is negatively correlated with the center distance between the ends of the two branch pipes.

6. The offset amount ΔB of the basic size satisfies the following relationship: [0025] The new branch pipe according to claim 5, characterized in that D is the outer diameter of the first branch pipe adjacent to the communication region, and L is the center distance between the ends of the two branches.

7. the maximum and minimum values ​​of the bending angle β formed between the first branch pipe and the extrusion portion are both correlated with the outer diameter D of the first branch pipe at a location adjacent to the communication region and the center distance L of the ends of the two branch pipes, [0030] β ｍｉｎ is the lower threshold of the bending angle β, and β ｍａｘ The new branch pipe according to claim 1, characterized in that: β is the upper threshold value of the bending angle β, and g is the gravitational acceleration.

8. The difference in vertical height ΔH between the end faces of the two branch pipes is correlated with the ratio of the outer diameter D of the portion of the first branch pipe adjacent to the communication region to the center distance L of the ends of the two branch pipes, and the difference in vertical height ΔH between the end faces of the two branch pipes is [0045] The new branch pipe according to claim 1, characterized in that it satisfies the above.

9. The new branch pipe as claimed in claim 1, characterized in that the number of circular arc-shaped bends of the first branch pipe and the second branch pipe is one each, and at least one of the axial lines of the ends of the two branch pipes is parallel to the axial line of the main pipe at a location adjacent to the communication region.

10. The main pipe, the first branch pipe and the second branch pipe are all copper pipes, Alternatively, the main pipe, the first branch pipe and the second branch pipe are all made of stainless steel pipes, and the extensions are made of copper pipes, and the new branch pipe further includes a main pipe connection part welded to the main pipe and made of copper material, and a first branch pipe connection part welded to an end of the first branch pipe and made of copper material; Alternatively, the new branch pipe as described in claim 1, wherein the main pipe, the first branch pipe and the second branch pipe are all stainless steel pipes, and the new branch pipe further includes a main pipe connection portion welded to the main pipe and made of copper material, a first branch pipe connection portion welded to the first branch pipe and made of copper material, and a second branch pipe connection portion welded to an extension portion of the second branch pipe and made of copper material.

11. The new branch pipe as claimed in claim 1, characterized in that the perpendicular distance between the axial line of the end of the first branch pipe and the axial line of the portion adjacent to the communication region of the main pipe is 1.3D≦L1≦4D, where D is the outer diameter of the portion adjacent to the communication region of the first branch pipe.

12. A new branch pipe, A main pipe including a main pipe joint portion and a main pipe body which are welded together; a first branch pipe connected to the main pipe joint portion and extending to one side of the main pipe joint portion; a second branch pipe including an extruded portion and an extension portion welded to the extruded portion, the extruded portion being connected to the main pipe joint portion and extending to the other side of the main pipe joint portion, the extruded portion, the first branch pipe and the main pipe joint portion being integrally molded, and the second branch pipe being in communication with each other via a communication region; the length of the main pipe is at least twice the outer diameter of the portion adjacent to the communication region of the first branch pipe, the length of at least one of the two branch pipes is more than four times the outer diameter of the portion adjacent to the communication region of the first branch pipe, the first branch pipe and the second branch pipe have the same number of arc-shaped bends, and the axial lines of the first branch pipe and the extruded portion adjacent to the communication region intersect with the axial line of the main pipe coupling portion adjacent to the communication region at a reference point and form two angles, the two angles constituting bending angles of the first branch pipe and the extruded portion, the bending angles being 40°≦β≦160°, the difference in vertical height between the end faces of the terminals of the two branch pipes is ΔH≦53 mm; the basic size B of the length of one branch pipe is correlated with the bending angle, the center distance between the terminals of the two branch pipes, and the outer diameter of the part adjacent to the communication area of ​​the first branch pipe, and the offset amount of the basic size is ΔB≦44.5 mm; the length of the main pipe refers to the vertical distance from the end face of the main pipe body to the cross section on which the reference point is located, and the length of the branch pipe refers to the vertical distance from the end face of the terminal of the branch pipe to the cross section on which the reference point is located.

13. The basic size B of the length of one branch pipe is negatively correlated with the bending angle and the center distance of the ends of the two branch pipes, and is positively correlated with the outer diameter of the first branch pipe at a point adjacent to the communication region, and the basic size B satisfies the following: [0050] The new branch pipe as claimed in claim 12, characterized in that D is an outer diameter of the first branch pipe at a portion adjacent to the communication region, β is a bending angle, L is a center distance between the ends of the two branch pipes, K is a pressure drop difference coefficient related to a critical value δV of the flow velocity drop ratio of the two branch pipes to the flow velocity at the main pipe end specified by an air conditioner manufacturer, and g is the acceleration of gravity.

14. A new-type branch pipe, comprising a main pipe, a first branch pipe and a second branch pipe, the second branch pipe comprising an extrusion portion and an extension portion welded to the extrusion portion, the extrusion portion and the first branch pipe respectively extending to both sides of the main pipe, the extrusion portion, the main pipe and the first branch pipe being integrally molded and communicating with each other through a communication region, the included angle between an axial line of an end of the extension portion and an axial line of the main pipe adjacent to the communication region is 80°≦θ≦100°, the main pipe has a length at least twice the outer diameter of the first branch pipe adjacent to the communication region, and the first branch pipe has a length more than four times the outer diameter of the first branch pipe adjacent to the communication region, the first branch pipe and the second branch pipe have the same number of arcuate bends, the arcuate bends of the second branch pipe are located in the extension section, the axial lines of the first branch pipe and the extrusion section adjacent to the communication region intersect with the axial line of the main pipe adjacent to the communication region at a reference point to form two angles, the two angles being bending angles of the first branch pipe and the extrusion section, the bending angles being 40°≦β≦160°, and both of the two angles being 10° or more; the size B is negatively correlated with the bending angle and the lateral distance between the axial line of the first branch pipe and the extended end of the arc-shaped bent portion of the extended portion, and is positively correlated with the outer diameter of the first branch pipe at a point adjacent to the communication region; the offset amount of the basic size ΔB≦44.5 mm; the length of the main pipe refers to the vertical distance from the end face of the main pipe to the cross section on which the reference point is located, and the length of the first branch pipe refers to the vertical distance from the end face of the terminal of the first branch pipe to the cross section on which the reference point is located.

15. A refrigeration system comprising the new branch pipe according to any one of claims 1 to 14.

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