Dispensing head assembly and air conditioner

Abstract

The present invention provides a liquid distributor head assembly and an air conditioner, wherein the liquid distributor head assembly includes a liquid distributor head body and a plurality of branch pipes. A plurality of branch pipe holes are formed on the liquid outlet end of the liquid distributor head body. The plurality of branch pipes are respectively welded and connected to the plurality of branch pipe holes on the liquid distributor head body, and each branch pipe includes a connecting pipe sequentially distributed along the flow direction of the refrigerant in the branch pipe, a speed increasing pipe section with an inner diameter reduced relative to the connecting pipe, and a branch pipe, and the branch pipe includes an assembled straight section welded and connected to an external heat exchanger assembly. Among them, the inner diameter d3 of the assembled straight section is greater than the inner diameter d2 at the downstream end of the speed increasing pipe section, and the inner diameter difference △d32 between the two satisfies 0.1mm≤△d32≤1.8mm.

Description

Technical Field

[0001] The invention relates to the technical field of refrigerant distribution, and in particular to a liquid dispensing head assembly and an air conditioner. Background Art

[0002] In a compression refrigeration system, the splitter head is a flow dividing element connected between the expansion valve and the heat exchanger assembly. The two-phase refrigerant flows into the splitter head after being throttled by the expansion valve, and is mixed in the splitter head body before being distributed to each branch of the heat exchanger assembly through multiple branch pipes. The design of the branch pipe structure in the existing splitter head mainly considers its welding assembly with the branch in the heat exchanger assembly, but few people have studied the impact of the branch pipe structure on the performance of the splitter head. After conducting extensive research on the existing splitter heads, the inventors found that the uneven distribution of the refrigerant is not only affected by the flow channel structure in the splitter head, but also by the inlet connecting pipe and outlet branch of the splitter head.

[0003] In the existing liquid distributor, in order to achieve welding assembly, the diameter of the outlet branch pipe needs to be set larger so that it can match the branch pipe diameter in the heat exchanger assembly. However, the larger the inner diameter of the branch pipe, the larger the expansion space it provides for the refrigerant; when the mass flow rate of the refrigerant inlet is small, the excessive expansion space in the branch pipe will cause the refrigerant to expand excessively, and the liquid refrigerant will partially vaporize before it can enter the heat exchanger assembly. The volume fraction of the gas-phase refrigerant in the branch pipe increases, and the gas-phase refrigerant will occupy the flow channel in the branch pipe, making it difficult for the liquid-phase refrigerant to enter the branch pipe; at the same time, the random movement of the gas-phase refrigerant will also be transmitted upstream and affect the uniformity of the refrigerant distribution at the inlet of the branch pipe. In addition, the premature vaporization of the liquid-phase refrigerant will also increase the dryness of the refrigerant entering the heat exchanger assembly and directly affect the cooling capacity of the heat exchanger. Furthermore, the increase in the diameter of the branch pipe will also reduce the flow rate of the refrigerant in each flow path of the heat exchanger assembly. The reduction in the refrigerant flow rate in the branch pipe will affect the flow state of the upstream refrigerant, reduce the refrigerant flow rate in the liquid separation head (even the inlet connecting pipe), aggravate the gas-liquid two-phase separation and deteriorate the flow separation performance. In addition, the reduction in the refrigerant flow rate in the branch pipe will also affect the heat transfer temperature difference and irreversible loss of the heat exchanger assembly, thereby reducing the energy efficiency of the heat exchanger assembly.

[0004] Therefore, in addition to considering the welding and assembly between the outlet branch pipe of the liquid separation head and the rear heat exchanger assembly, the design of the outlet branch pipe of the liquid separation head also needs to consider its impact on the liquid separation performance. Summary of the invention

[0005] In order to overcome at least one disadvantage of the prior art, the present invention provides a liquid dispensing head assembly and an air conditioner.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a liquid separator head assembly, which includes a liquid separator head body and a plurality of branch pipes. A plurality of branch pipe holes are formed on the liquid outlet end of the liquid separator head body. The plurality of branch pipes are respectively welded to the plurality of branch pipe holes on the liquid separator head body, and each branch pipe includes a connecting pipe distributed in sequence along the flow direction of the refrigerant in the branch pipe, a speed increasing pipe section with an inner diameter reduced relative to the connecting pipe, and a branch pipe, and the branch pipe includes an assembled straight section welded to an external heat exchanger assembly. Among them, the inner diameter d3 of the assembled straight section is greater than the inner diameter d2 at the downstream end of the speed increasing pipe section, and the inner diameter difference △d32 between the two satisfies 0.1mm≤△d32≤1.8mm.

[0007] According to an embodiment of the present invention, each branch pipe further comprises a bushing welded inside the assembly straight section, and the inner diameter of the bushing is the inner diameter of the assembly straight section;

[0008] The bushing is an integral circular pipe; or, the bushing is formed by one or more curved liner plates which are circumferentially spliced ​​and then welded.

[0009] According to an embodiment of the present invention, the difference between the inner diameter d1 at the downstream end of the connecting pipe and the inner diameter d2 at the downstream end of the speed increasing pipe section satisfies: 0.1 mm ≤ △ d12 ≤ 3.5 mm.

[0010] According to an embodiment of the present invention, the connecting pipe is a constant diameter pipe having an inner diameter and a wall thickness that remain substantially constant along its extended length, and the inner diameter d1 at the downstream end of the connecting pipe is less than or equal to the inner diameter d3 of the assembly straight section.

[0011] According to an embodiment of the present invention, the branch pipe further comprises a transition pipe section located upstream of the assembly straight section, and the inner diameter of the transition pipe section is substantially close to the inner diameter of the downstream end of the speed increasing pipe section.

[0012] According to one embodiment of the present invention, the length of the branch pipe is 60mm~200mm, the length L1 of the assembly straight section is 3mm~30mm, and the length of the branch pipe refers to the length of the refrigerant flow path from the upstream end to the downstream end of the branch pipe.

[0013] According to one embodiment of the present invention, the liquid dispensing head assembly further comprises a liquid inlet pipe arranged at the liquid inlet end of the liquid dispensing head body, the liquid inlet pipe comprising a liquid inlet pipe main body section having a substantially constant inner diameter and wall thickness and a liquid inlet pipe connecting section connected to the liquid dispensing head body; when the outer diameter D0 of the liquid inlet pipe main body section is less than or equal to 13 mm, the inner diameter d2 at the downstream end of the speed increasing pipe section is less than or equal to 4.3 mm;

[0014] When the outer diameter D0 of the main section of the liquid inlet pipe is greater than 13 mm, the inner diameter d2 of the downstream end of the speed increasing pipe section is less than or equal to 5.3 mm. According to one embodiment of the present invention, a reflecting pipe section is formed on the connecting pipe, which is bent and extended to one side relative to the center line of the branch pipe hole, and the axis at the upstream end of the reflecting pipe section and the axis at the downstream end thereof intersect to form an angle θ and 90°≤θ≤175°;

[0015] Alternatively, the connecting pipe is a straight pipe.

[0016] According to one embodiment of the present invention, the upstream end of the branch pipe is internally sleeve-welded to the downstream end of the connecting pipe, and the sleeve connection between the two forms a speed-increasing pipe section;

[0017] Alternatively, the speed increasing pipe section is integrally formed with the connecting pipe and has a tapered structure whose inner diameter gradually decreases along the flow direction of the refrigerant, and the upstream end of the branch pipe is sleeve-connected to the downstream end of the speed increasing pipe section;

[0018] Alternatively, the speed increasing pipe section is integrally formed upstream of the assembly straight section of the branch pipe, and its inner diameter gradually decreases along the refrigerant flow direction, and the upstream end of the speed increasing pipe section is welded to the downstream end of the connecting pipe.

[0019] According to an embodiment of the present invention, the branch pipe further includes an extension pipe welded between the connecting pipe and the branch pipe, and both the extension pipe and the connecting pipe are stainless steel pipe fittings.

[0020] According to an embodiment of the present invention, the connecting pipe, the speed increasing pipe section and the branch pipe are all copper pipes and the three are integrally formed;

[0021] Alternatively, the connecting pipe is a stainless steel pipe fitting, the branch pipe is a copper pipe fitting or an aluminum pipe fitting, and the branch pipe is connected to the connecting pipe by welding.

[0022] According to an embodiment of the present invention, the liquid dispensing head assembly further comprises a plurality of branch pipe heat insulation sleeves, each of which is jacketed on a corresponding branch pipe or a branch pipe on the corresponding branch pipe.

[0023] The present invention also provides another liquid separator head assembly, which includes a liquid separator head body and a plurality of branch pipes. A plurality of branch pipe holes are formed on the liquid outlet end of the liquid separator head body. The plurality of branch pipes are respectively welded to the plurality of branch pipe holes on the liquid separator head body, and each branch pipe includes a connecting pipe and a branch pipe sequentially distributed along the flow direction of the refrigerant in the branch pipe. The connecting pipe is an equal-diameter pipe fitting whose inner diameter and wall thickness remain basically unchanged along its extended length, and the branch pipe includes an assembly straight section welded to an external heat exchanger assembly. Among them, the inner diameter d3 of the assembly straight section is greater than the inner diameter d1' of the connecting pipe, and the inner diameter difference △d31' between the two satisfies 0.1mm≤△d31'≤1.8mm.

[0024] On the other hand, the present invention further provides an air conditioner, which includes any of the above-mentioned liquid dispensing head components.

[0025] In summary, in the liquid separation head assembly provided by the present invention, the branch pipes are provided including connecting pipes, speed increasing pipe sections and branch pipes with different inner diameters. The branch pipes with larger inner diameters increase the refrigerant flow rate distributed into each branch pipe and reduce the refrigerant distribution resistance, while the speed increasing pipe section increases the refrigerant flow rate by reducing the flow channel cross section, and the assembly straight section on the branch pipe whose inner diameter is larger than the inner diameter at the downstream end of the speed increasing pipe section is used for welding and assembling the rear end heat exchanger assembly. On this basis, by controlling the inner diameter difference △d32 at the downstream end of the assembly straight section and the speed increasing pipe section, the volume change rate of the refrigerant in the assembly straight section after the speed increase is constrained, and the vaporization degree of the liquid refrigerant in the assembly straight section is controlled to avoid the liquid refrigerant from vaporizing prematurely before entering the heat exchanger assembly, ensuring that multiple branch pipes can provide the rear end heat exchanger with a large amount of liquid refrigerant and reduce heat exchange losses. Furthermore, the control of the vaporization degree of the refrigerant in the branch pipe can also weaken the influence of the random movement of the gas phase refrigerant in the branch pipe on the uniformity of the upstream liquid separation, thereby improving the liquid separation performance. In addition, the setting of the inner diameter difference △d32 also realizes the precise control of the refrigerant flow rate in the branch pipe, avoiding the refrigerant flow rate in the branch pipe being too low and affecting the uniformity of liquid separation of the upstream refrigerant. At the same time, the control of the refrigerant flow rate can also reduce the irreversible heat transfer loss to greatly improve the performance of the heat exchanger.

[0026] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shown is a schematic structural diagram of a liquid dispensing head assembly provided in Embodiment 1 of the present invention.

[0028] Figure 2 Shown Figure 1 Schematic diagram of the structure of the middle branch pipe.

[0029] Figure 3 Shown Figure 2 A magnified schematic diagram of center A.

[0030] Figure 4 Shown Figure 1 A magnified schematic diagram of point B in the middle.

[0031] Figure 5 Shown Figure 1 Schematic diagram of the structure of the middle bushing.

[0032] Figure 6 and Figure 7 Shown is a schematic structural diagram of a bushing in a liquid dispensing head assembly provided in another embodiment of the present invention.

[0033] Figure 8 and Fig. 9 Shown is a schematic structural diagram of a branch pipe in a liquid dispensing head assembly provided in another embodiment of the present invention.

[0034] Fig.10 Shown Figure 1 Schematic diagram of the structure after adding a branch pipe insulation sleeve to the middle branch pipe.

[0035] Figures 11 to 18 Shown is a schematic structural diagram of a liquid dispensing head assembly provided in another embodiment of the present invention.

[0036] Fig.19 The figure is a schematic diagram of the structure of the branch pipe in the liquid dispensing head assembly provided in the second embodiment of the present invention.

[0037] Figure 20 to Figure 25 Shown is a schematic structural diagram of a branch pipe in a liquid dispensing head assembly provided in another embodiment of the present invention.

[0038] Fig.26 Shown is a schematic structural diagram of a liquid dispensing head assembly provided in Embodiment 3 of the present invention.

[0039] Fig. 27 Shown Fig.26 Schematic diagram of the structure of the middle branch pipe. DETAILED DESCRIPTION

[0040] In this application, downstream or upstream is divided based on the flow direction of the refrigerant. Generally, the refrigerant flows from upstream to downstream, and the area located downstream receives the refrigerant from upstream. In refrigeration equipment, the liquid distributor is generally installed vertically or tilted, and the liquid inlet end of the liquid distributor is located below the liquid outlet end along the direction of gravity. The inertial force of the refrigerant in the liquid distributor overcomes gravity and flows in the direction opposite to gravity; at this time, the upstream and downstream are still divided according to the flow direction of the refrigerant.

[0041] Embodiment 1

[0042] In the existing liquid distributor, the structural design of the outlet branch pipe mainly considers its welding and matching with the branch of the rear heat exchanger assembly, while few people have studied the influence of the branch pipe structure on the refrigerant evaporation degree, liquid distribution performance and refrigerant flow rate. In fact, the branch pipe structure not only affects the evaporation degree and refrigerant flow rate of the refrigerant before entering the heat exchanger, but also directly affects the performance of the rear heat exchanger assembly; at the same time, it also affects the liquid distribution uniformity of the two-phase refrigerant in the upstream liquid distributor body, and indirectly affects the performance of the rear heat exchanger assembly.

[0043] In view of this, the present embodiment provides a liquid dispensing head assembly whose branch pipe structure can take into account welding assembly, heat exchange loss and liquid dispensing uniformity. Figure 1 , Figure 2 , Figure 3 as well as Figure 4As shown, the liquid separator head assembly provided in this embodiment includes a liquid separator head body 1 and a plurality of branch pipes 2. A plurality of branch pipe holes 11 are formed on the liquid outlet end of the liquid separator head body 1. The plurality of branch pipes 2 are respectively welded to the plurality of branch pipe holes 11 on the liquid separator head body 1, and each branch pipe 2 includes a connecting pipe 21 sequentially distributed along the flow direction of the refrigerant in the branch pipe, a speed increasing pipe section 22 with an inner diameter reduced relative to the connecting pipe, and a branch pipe 23, and the branch pipe 23 includes an assembly straight section 232 welded to the external heat exchanger assembly. Among them, the inner diameter d3 of the assembly straight section 232 is greater than the inner diameter d2 at the downstream end of the speed increasing pipe section 22, and the inner diameter difference △d32 between the two satisfies 0.1mm≤△d32≤1.8mm.

[0044] In the liquid dispensing head assembly provided in this embodiment, the connecting pipe 21 with a larger inner diameter increases the refrigerant distribution flow channel at the entrance of the branch pipe 2, increases the refrigerant flow rate distributed into the branch pipe 2 and reduces the pressure loss of the refrigerant distribution. In order to compensate for the problem of reduced refrigerant flow rate caused by the increase in the inner diameter of the connecting pipe 21, the speed increasing pipe section 22 reduces the pressure and speeds up the refrigerant by reducing the inner diameter, reduces the heat transfer temperature difference and irreversible loss to improve the heat exchange performance of the refrigerant. Furthermore, in order to be welded and assembled with the rear-end heat exchanger assembly, the branch pipe 2 is provided to further include a branch pipe 23 located downstream of the speed increasing pipe section 22, and an assembly straight section 232 with an inner diameter d3 greater than the inner diameter d2 at the downstream end of the speed increasing pipe section 22 is formed on the branch pipe 23 to match the branch pipe diameter of the rear-end heat exchanger assembly. Specifically, the assembly straight section 232 is welded to the branch of the heat exchanger assembly, and the outer diameter of the assembly straight section 232 is substantially close to the inner diameter of the branch of the heat exchanger assembly.

[0045] However, the increase in the inner diameter of the assembly straight section 232 will inevitably cause the refrigerant volume to expand, and the expansion of the refrigerant volume will be accompanied by the vaporization of part of the liquid refrigerant, which will affect the flow of liquid refrigerant entering the evaporator assembly and cause the average evaporation temperature of the evaporator assembly to be too low; when the condensation temperature remains unchanged, the reduction in evaporation temperature will increase the pressure ratio of the compressor and cause the compressor power to increase. In addition, the premature vaporization of part of the liquid refrigerant will also increase the volume fraction of the gas phase refrigerant in the branch pipe 2, thereby affecting the uniformity of liquid separation. In order to study the effect of the inner diameter of the assembly straight section 232 on the uniformity of liquid separation, a CFD (computational fluid dynamics) simulation was performed. Figure 1 The dispensing head assembly shown is used for dispensing uniformity analysis. Figure 1 In the figure, the connecting pipe 21 is a constant diameter pipe whose inner diameter and wall thickness remain basically unchanged along with its extended length. The inner diameter d1 at the downstream end of the connecting pipe 21 is less than or equal to the inner diameter d3 of the assembled straight section 232. The upstream end of the branch pipe 23 is welded to the downstream end of the connecting pipe 21, and the sleeve connection between the two forms a speed increasing pipe section 22.

[0046] The existing heat exchanger component branches usually have two specifications, one is Ø7.0mm*0.35mm (i.e., the outer diameter is 7mm, the wall thickness is 0.35mm, and the inner diameter is 6.3mm); the other is Ø5.0mm*0.35mm (i.e., the outer diameter is 5mm, the wall thickness is 0.35mm, and the inner diameter is 4.3mm). Two test groups were designed to match the two different heat exchanger component branches. Each test group was divided into five sub-test groups according to the specifications of the liquid inlet pipe and the corresponding d2, and each sub-test group formed six test samples according to different d3 and △d32.

[0047] In the first test group, the specification of the branch of the rear heat exchanger assembly is Ø7.0mm*0.35mm, that is, its inner diameter is 6.3mm. When welding and assembling the branch pipe 23 and the branch of the rear heat exchanger assembly, considering that the socket connection between the two requires an assembly gap of about 0.2mm, the outer diameter D3 of the assembly straight section 232 on the branch pipe 23 is set to 6.1mm. On this basis, considering the wall thickness required for the pressure resistance of the assembly straight section 232 (the minimum wall thickness can be 0.2mm), the maximum inner diameter d3 of the assembly straight section 232 can be adjusted to 5.7mm. Similarly, in the second test group, since the specification of the branch of the rear heat exchanger assembly is Ø5.0mm*0.35mm, that is, its inner diameter is 4.3mm. Considering that the assembly straight section 232 and the branch of the rear heat exchanger assembly require an assembly gap of about 0.2mm when socketing, the outer diameter D3 of the assembly straight section 232 on the branch pipe 23 is set to 4.1mm. Similarly, taking into account the wall thickness required for the pressure resistance of the assembly straight section 232 (the minimum wall thickness can be 0.2 mm), the inner diameter d3 of the assembly straight section 232 can be adjusted to a maximum of 3.7 mm.

[0048] In this embodiment, the liquid inlet pipe 3 includes a liquid inlet pipe main section 31 with a substantially constant inner diameter and wall thickness and a liquid inlet pipe connecting section 32 connected to the liquid dispensing head body 1. When dividing the sub-test groups, the liquid inlet pipe main section 31 is divided according to the outer diameter D0. Specifically, the first test group includes five sub-test groups with outer diameters D0 of 6.35 mm, 9.52 mm, 12.7 mm, 16 mm and 22 mm for the liquid inlet pipe main section 31. In each sub-test group, based on the given inner diameter d2 of the downstream end of the speed increasing pipe section, the inner diameter of the assembly straight section 232 is adjusted to form six test samples, a total of 30 test samples; 30 test samples are formed in the second test group in the same manner.

[0049] CFD simulation analysis was performed on the above 60 test samples:

[0050] The software used for CFD simulation analysis is ANSYS software, and its condition settings are as follows:

[0051] Turbulence model: Realizable k-ε model;

[0052] Network parameters: Tetrahedral unstructured grid is used;

[0053] Working conditions: The working fluid is R410A refrigerant, the wall boundary is an adiabatic boundary, the inlet dryness is 0.2, and the installation condition is vertical installation;

[0054] Inlet boundary conditions:

[0055]

[0056] The data of 60 test samples in two test groups are summarized to form Table 1. In Table 1, STD is the evaluation index, which is the mean square deviation of the refrigerant mass flow rate at each branch outlet, and its expression is as follows:

[0057]

[0058] in, is the average refrigerant mass flow rate of all branch outlets, x j is the outlet refrigerant mass flow rate of the jth branch pipe, and n is the number of branches.

[0059] Analysis of the data in Table 1 shows that: as the inner diameter d3 of the assembly straight section increases, the STD gradually increases, that is, the liquid separation uniformity gradually deteriorates. At the same time, it is also found that: when the inner diameter d3 of the assembly straight section exceeds a critical value, the STD increases sharply, that is, the liquid separation uniformity deteriorates sharply, but the critical value is not the same in different sub-test groups. As mentioned above, the cause of the deterioration of liquid separation uniformity is most likely the excessive expansion of the refrigerant in the assembly straight section 232 after the increase in speed. Therefore, the relationship between the mean square deviation STD and the inner diameter difference △d32 (d3-d2) characterizing the liquid separation uniformity in Table 1 is further analyzed. It is found that: when △d32 is less than or equal to 1.8mm, the liquid separation uniformity is relatively excellent and the rate of change of STD with the inner diameter difference △d32 is less than 12%; when △d32 is greater than 1.8mm, STD is extremely sensitive to the change of the inner diameter difference △d32, and its rate of change with the inner diameter difference △d32 will exceed 20%.

[0060] Therefore, on the basis of satisfying that the outer diameter D3 of the assembly straight section 232 can be welded and assembled with the rear-end heat exchanger assembly, it is necessary to control the inner diameter difference △d32 at the downstream end of the assembly straight section 232 and the speed increasing pipe section 22 to avoid excessive expansion of the refrigerant to curb the vaporization degree of the refrigerant. The control of the vaporization degree of the refrigerant realizes the control of the volume fraction of the gaseous refrigerant in the branch pipe, weakens the influence of the random movement of the gas phase refrigerant on the uniformity of the refrigerant distribution at the inlet of the branch pipe 2 and the crowding of the distribution channel, thereby improving the uniformity of liquid separation. Furthermore, the control of the vaporization degree of the refrigerant in the assembly straight section 232 can also effectively reduce the heat exchange loss during the liquid separation process, increase the content of liquid refrigerant entering the heat exchanger assembly to improve the heat exchange performance. At the same time, the setting of the inner diameter difference △d32 also effectively controls the flow rate of the refrigerant entering the assembly straight section 232, avoids the problem of too low refrigerant flow rate in the branch pipe affecting the refrigerant flow rate in the upstream liquid separation head body and then causing the problem of gas-liquid two-phase separation, further improves the uniformity of liquid separation while reducing the heat transfer temperature difference and irreversible loss to improve the performance of the heat exchanger. Specifically, 0.1 mm ≤ Δd32 ≤ 1.8 mm, such as 0.2 mm, 0.5 mm, 0.8 mm, 1.1 mm, 1.4 mm and 1.6 mm. However, the present invention is not limited to this. In other embodiments, Δd32 may be set to other values ​​within the range of 0.1 mm to 1.8 mm.

[0061] In the liquid dispensing head assembly provided in the present embodiment, the speed increase of the refrigerant by the speed increasing pipe section 22 can also partially offset the speed reduction effect of the refrigerant after entering the assembly straight section 232, ensuring that the refrigerant flow rate in the assembly straight section 232 meets the design requirements of the rear-end heat exchanger assembly. However, for the evaporator assembly, it is necessary to avoid excessive pressure drop. This is because the pressure inside the evaporator assembly is low and the gas density is small, resulting in a large volume flow rate under the same mass flow rate, and the acceleration pressure drop and friction pressure drop will have a superposition effect, which will not only easily cause the total pressure drop of the evaporator assembly to be large, but also the temperature drop corresponding to the same pressure drop under low pressure is large, that is, the corresponding irreversible loss is large. In view of this, if Figure 4 As shown, in this embodiment, the difference between the inner diameter d1 at the downstream end of the connecting pipe 21 and the inner diameter d2 at the downstream end of the speed increasing pipe section 22 satisfies: 0.1mm≤△d12≤3.5mm. The inner diameter difference △d12 accurately controls the throttling degree of the speed increasing pipe section 22 on the refrigerant, avoids excessive throttling of the speed increasing pipe section 22 and causes a sharp increase in the refrigerant pressure loss, and comprehensively controls the irreversible loss of the heat exchanger component from the two aspects of flow rate and pressure drop to improve the energy efficiency of the refrigeration system.

[0062] In this embodiment, the inner diameter difference Δd12 is set to 0.5 mm. However, the present invention is not limited to this. In other examples, the inner diameter difference Δd12 can also be set to other values ​​within 0.1 mm ≤ Δd12 ≤ 3.5 mm, such as 0.2 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm and 3 mm. Figure 1As shown, the liquid-dispensing head assembly also includes a liquid inlet pipe 3 arranged at the liquid inlet end of the liquid-dispensing head body 1. Preferably, when the outer diameter D0 of the liquid inlet pipe main section 31 with substantially constant inner diameter and wall thickness on the liquid inlet pipe 3 is less than or equal to 13 mm (such as 6.35 mm, 9.52 mm or 12.7 mm), the inner diameter d2 at the downstream end of the speed-increasing pipe section 22 is set to be less than or equal to 4.3 mm. When the outer diameter D0 of the liquid inlet pipe main section 31 is greater than 13 mm (such as 16 mm, 19 mm, 22 mm or 28 mm, etc.), the inner diameter d2 at the downstream end of the speed-increasing pipe section 22 may be less than or equal to 5.3 mm. However, the present invention does not impose any limitation on this.

[0063] In the liquid separation head assembly provided in this embodiment, the outer diameter D3 of the assembly straight section 232 realizes the assembly connection between the branch pipe 2 and the rear-end heat exchanger assembly branch, and the inner diameter difference △d32 related to the inner diameter d3 of the assembly straight section realizes the effective control of the liquid separation uniformity and the heat exchange loss during the liquid separation process, and the inner diameter difference △d12 realizes the control of the refrigerant flow rate and pressure drop in the branch pipe; that is, while meeting the system assembly requirements, the effects of liquid separation uniformity, heat exchange loss, heat transfer temperature difference and irreversible loss are taken into account to comprehensively improve the performance of the rear-end heat exchange assembly.

[0064] Specifically, the inner diameter difference Δd32 can be adjusted to meet 0.1 mm ≤ Δd32 ≤ 1.8 mm by adjusting the wall thickness of the assembly straight section 232. However, the branch pipe 23 is likely to be a non-standard custom part, which will increase the production cost and production efficiency of the liquid separation head assembly to a certain extent. Figure 3 and Figure 5 As shown, each branch pipe 2 also includes a bushing 24 welded inside the assembly straight section 232, and the inner diameter of the bushing 24 is the inner diameter of the assembly straight section 232; that is, the inner diameter of the assembly straight section 232 is reduced by adding the bushing 24 so that the inner diameter difference Δd32 meets the requirements. The adjustment of the inner diameter of the assembly straight section 232 based on the bushing 24 is not only flexible and convenient but also low in cost.

[0065] Furthermore, the present embodiment also provides a bushing 24 formed by a curved and rolled arc lining plate 241 which is circumferentially spliced ​​and then welded. Specifically, the curved and rolled arc lining plate has a circumferential butt weld 240 (the butt weld 240 can be formed by self-fluxing welding), and the arc lining plate 241 is pre-fixed by welding to form a tubular bushing 24, and the bushing 24 is lined with the assembly straight section 232 and integrally welded to the assembly straight section 232 by furnace brazing. However, the present invention does not impose any limitation on this. In other embodiments, when the bushing and the assembly straight section are both made of copper material, the two can also be welded by flame brazing. Similarly, the present invention does not impose any limitation on the number of arc lining plates constituting the bushing 24. In other embodiments, when the required wall thickness of the bushing 24 is thicker, the bushing 24 may also include a plurality of (such as two, three or more than four) curved liner plates 241 that are bent and rolled, and the plurality of curved liner plates 241 are spliced ​​circumferentially and pre-fixed butt welds 240 are formed between adjacent curved liner plates 241, such as Figure 6 As shown. Decomposing the inner liner 24 into a plurality of arc-shaped liner plates 241 can further reduce the processing difficulty of the liner 24, especially when the wall thickness of the liner 24 is thick, the bending and rolling after decomposition will be easier to shape. However, the present invention is not limited to this. In other embodiments, the liner 24 can also be set as an integral circular pipe formed by cutting a hollow pipe material, such as Figure 7 shown.

[0066] Although this embodiment is described by adding a bushing 24 to adjust the inner diameter difference △d32 as an example, the present invention does not impose any limitation on this. In other embodiments, when the outer diameter D3 of the assembly straight section 232 is small, such as when the branch of the connected rear heat exchanger assembly is Ø5.0mm*0.35mm, or when the inner diameter d2 of the downstream end of the speed increasing pipe section 22 is large, if the inner diameter of the assembly straight section 232 itself is sufficient to make the inner diameter difference △d32 satisfy: 0.1mm≤△d32≤1.8mm, then no bushing is required.

[0067] In this embodiment, the branch pipe 23 further includes a transition pipe section 231 located upstream of the assembly straight section 232, the inner diameter of the transition pipe section 231 is substantially close to the inner diameter d1 at the downstream end of the speed increasing pipe section 22, and the transition pipe section 231 provides a maintenance length for the refrigerant after the speed increasing pipe section 22 is accelerated to stabilize the refrigerant flow pattern after the speed increasing pipe section 22 is accelerated. However, the present invention does not make any limitation to this.

[0068] Although the present embodiment takes the pipe 21 as an example of a pipe of equal diameter whose inner diameter and wall thickness remain substantially constant along its extended length, the present invention does not make any limitation thereto. In other embodiments, the pipe 21 may also be a conical pipe whose inner diameter gradually decreases along the flow direction of the refrigerant (e.g., Figure 8As shown), this arrangement can enlarge the refrigerant flow channel at the branch pipe hole 11, thereby increasing the refrigerant flow distributed into the branch pipe 2 and reducing the refrigerant distribution resistance.

[0069] In the liquid-dispensing head assembly provided in this embodiment, the liquid-dispensing head body 1 and the connecting pipe 21 are made of low-cost and high-pressure-resistant stainless steel materials. In order to facilitate the connection with the copper branch of the rear-end heat exchanger assembly, the branch pipe 23 is set as a copper pipe. Further, due to the limitation of the installation space in the refrigeration equipment, the multiple branch pipes 2 on the liquid-dispensing head body inevitably need to be bent to insert into the multiple copper branches of the rear-end heat exchanger assembly, and the high hardness of the stainless steel material makes the connecting pipe 21 difficult to bend. Therefore, the branch pipe 23 made of copper material is set in this embodiment to have a certain length. Based on the lower hardness and high ductility of the copper material (compared with the stainless steel material), the branch pipe 23 can be bent when welding and assembling the branch pipe 2 so that the assembly straight section 232 can be inserted into the corresponding copper branch of the rear-end heat exchanger assembly. Specifically, the length of the copper branch pipe 23 is set to 60mm~200mm, and the length of the branch pipe 23 refers to the length of the refrigerant flow path from the upstream end to the downstream end of the branch pipe 23. Preferably, the length of the branch pipe 23 can be set to 80 mm, 100 mm, 120 mm, 150 mm, 170 mm, and 190 mm. However, the present invention is not limited to this. In other embodiments, the length of the branch pipe can also be set to other values ​​within 60 mm to 200 mm.

[0070] Although the present embodiment is described by taking the connecting pipe 21 as a stainless steel pipe, the branch pipe 23 as a copper pipe, and the sleeve connection of the two forming the speed increasing pipe section 22 as an example, the present invention does not make any limitation to this. In other embodiments, the connecting pipe, the speed increasing pipe section and the branch pipe can all be copper pipe fittings and the three can be formed in one piece. Alternatively, when the branch of the rear end heat exchanger assembly is an aluminum pipe, the branch pipe can also be an aluminum pipe.

[0071] In this embodiment, the length L1 of the assembly straight section is 8 mm. However, the present invention does not impose any limitation on this. In other embodiments, the length L1 of the assembly straight section may be set to other values ​​within the range of 3 mm to 30 mm, such as 5 mm, 10 mm, 15 mm, 20 mm, and 25 mm.

[0072] Fig. 9 FIG. 2 is a schematic diagram of the structure of a branch pipe 2 provided in another embodiment of the present invention. Fig. 9 In the embodiment, the branch pipe 2 also includes an extension pipe 25, which can increase the length of the branch pipe 2 so that it can be used in refrigeration equipment with a larger internal space; preferably, the extension pipe 25 can be set as a stainless steel pipe. In this structure, the sleeve connection between the extension pipe 25 and the connecting pipe 21 forms a speed-increasing pipe section 22, and the extension pipe 25 is an equal-diameter pipe with an inner diameter substantially close to the inner diameter d2 of the downstream end of the speed-increasing pipe section 22; that is, in Fig. 9 The inner diameter of the transition pipe section 231 on the middle branch pipe 23 and the inner diameter of the extension pipe 25 are both substantially close to the inner diameter d2 of the downstream end of the speed-increasing pipe section 22. However, the present invention does not impose any limitation on this. In other embodiments, the extension pipe may be provided as a pipe of equal diameter with an inner diameter substantially close to the inner diameter d1 of the downstream end of the connecting pipe, and the sleeve connection between the extension pipe and the branch pipe forms the speed-increasing pipe section. Alternatively, in other embodiments, the speed-increasing pipe section may be provided as an inner diameter reduction structure formed on the extension pipe.

[0073] In this embodiment, if Figure 2 As shown, a reflection pipe section 211 is formed on the connecting pipe 21, which is bent and extended to one side relative to the center line of the branch pipe hole 11. The axis at the upstream end of the reflection pipe section 211 and the axis at the downstream end of the reflection pipe section 211 intersect to form an angle θ and 90°≤θ≤175°. The setting of the reflection pipe section 211 makes the speed increasing pipe section 22 no longer coaxial with the center line of the branch pipe hole 11. When there is a pressure wave downstream and oscillates upstream, the reflection pipe section 211 reflects and absorbs part of the pressure wave and changes the propagation direction of the remaining pressure wave to make it decay rapidly, effectively avoiding the influence of the downstream pressure wave on the upstream branch pipe hole 11 to further improve the distribution performance. However, the present invention does not make any limitation to this. In other embodiments, there is no need to set a reflection pipe section on the connecting pipe. In this case, the connecting pipe is a straight pipe.

[0074] As mentioned above, when the refrigerant has not entered the heat exchanger assembly, it is necessary to suppress the vaporization of the liquid refrigerant as much as possible to improve the uniformity of liquid separation and heat exchange performance; however, during the distribution process, the refrigerant will inevitably exchange heat through the wall of the branch pipe and cause part of the liquid refrigerant to vaporize. The thermal conductivity of copper material is 383 W / (m•k), while the thermal conductivity of stainless steel material is only 16 W / (m•k), that is, the thermal conductivity of stainless steel material is only 1 / 24 of that of copper material. Based on the excellent thermal insulation performance of stainless steel material, in this embodiment, setting the connecting pipe 21 (connecting pipe 21 and extension pipe 25) as a stainless steel pipe can further reduce the degree of vaporization of the refrigerant in the branch pipe, reduce heat exchange losses and improve liquid separation uniformity. On this basis, if Fig.10 As shown, the liquid dispensing head assembly in this embodiment also includes a plurality of branch pipe insulation sleeves 4, and each branch pipe insulation sleeve 4 is jacketed on the copper branch pipe 23. The branch pipe insulation sleeve 4 isolates the heat conduction between the wall of the copper branch pipe 23 with high thermal conductivity and the external air, reduces the heat exchange to weaken the vaporization degree of the refrigerant in the copper branch pipe 23. In addition, the branch pipe insulation sleeve 4 can also protect the wall of the copper branch pipe 23 with lower hardness to prevent it from being bumped or bruised. However, the present invention does not make any limitation to this. In other embodiments, each branch pipe insulation sleeve can also be arranged to be jacketed on the entire branch pipe, that is, the branch pipe insulation sleeve covers the connecting pipe and the branch pipe.

[0075] like Figure 1As shown, the liquid-dispensing head assembly provided in this embodiment is a structure integrating reflection and mixing. A partition 5 is arranged in the liquid-dispensing head body 1. A concave cavity 501 with an opening toward the liquid inlet hole is formed on the partition 5 in the area opposite to the liquid inlet pipe 3, and the partition 5 at the concave cavity 501 protrudes and extends toward the side where the branch pipe hole 11 is located. The partition 5 divides the inner cavity of the liquid-dispensing head body into a reflection mixing area 1031 near the liquid inlet end and including the concave cavity 501 and a mixing distribution area 1032 near the liquid outlet end. A plurality of partition holes 51 are formed on the partition 5, which are distributed in an annular manner around the axis of the liquid-dispensing head body 1 and connect the reflection mixing area 1031 and the mixing distribution area 1032. The plurality of partition holes 51 are configured to correspond to the plurality of branch pipe holes 11 one by one, and when projected along the axial direction of the liquid-dispensing head body 1, the plurality of partition holes 51 are located at the periphery of the liquid outlet end of the liquid inlet pipe 3. However, the present invention does not impose any limitation on the structure of the liquid-dispensing head body. The branch pipe structure provided in this embodiment is also applicable to other structures of the liquid dispensing head body, such as Figures 11 to 18 shown. Figures 11 to 18 The branch pipe heat insulation sleeve is not provided in the liquid dispensing head assembly shown in the figure. However, the present invention does not make any limitation to this. In other embodiments, Figures 11 to 18 Add branch pipe insulation sleeve on the basis of.

[0076] exist Fig.11 In the embodiment, a two-stage jet reflection and mixing component 6 is provided in the liquid-dispensing head body 1, and the two-stage jet reflection and mixing component 6 includes a primary reflection and mixing plate 61, a secondary jet orifice plate 62 and a secondary reflection and mixing plate 63 which are sequentially distributed in the inner cavity of the liquid-dispensing head body 1 along the flow direction of the refrigerant. Among them, the primary reflection and mixing plate 61 is arranged relative to the liquid inlet pipe 3 to reflect and mix the refrigerant jetted into the liquid inlet pipe 3, and a plurality of flow holes 611 are formed on the primary reflection and mixing plate 61. The secondary jet orifice plate 62 and the primary reflection and mixing plate 61 are arranged to form a jet cavity 602, and a secondary jet hole 621 is formed on the secondary jet orifice plate 62. The refrigerant reflected and mixed by the primary reflection and mixing plate 61 is collected in the jet cavity 602 through the flow hole 611 and jetted to the secondary reflection and mixing plate 63 through the secondary jet hole 621. The secondary reflection mixing plate 63 is arranged opposite to the secondary jet hole 621 and has a plurality of guide holes 631 having the same number as the branch pipe holes 11. Each guide hole 631 is substantially coaxial with the corresponding branch pipe hole 11. The secondary reflection mixing plate 63 reflects and mixes the refrigerant injected by the secondary jet hole 621, and then distributes it to the plurality of branch pipe holes 11 through the guide holes 631. Specifically, Fig.11 In the embodiment, the first-stage reflection mixing plate 61 is convexly extended toward the side where the second-stage jet orifice plate 62 is located at the position opposite to the liquid inlet pipe 3 to form a first-stage reflection cavity 610 with an opening toward the liquid outlet end of the liquid inlet pipe 3, and a second-stage reflection cavity 630 is formed on the second-stage reflection mixing plate 63. However, the present invention does not make any limitation to this.

[0077] Fig.12 and Fig.11 The structure is basically the same, the difference is: Fig.12 The liquid dispensing head body shown in the figure also includes a chamber partition plate 64 located on the downstream side of the primary reflective mixing plate 61, and the chamber partition plate 64 divides the jet chamber 602 into an upstream chamber 6021 and a downstream chamber 6022. The upstream chamber 6021 is an annular chamber surrounding the primary reflective concave cavity 610, and the downstream chamber 6022 is connected to the secondary jet hole 621. The chamber partition plate 64 is formed with partition plate through holes that are staggered with the multiple flow holes 611 (due to the viewing angle, Fig.12 not shown).

[0078] exist Fig.13 In the embodiment, a flat partition plate 5' and a conical flow channel forming member 7 are formed in the liquid dispensing head body 1; a plurality of partition plate holes 51 are formed on the flat partition plate 5'.

[0079] Fig.14 and Fig.13 The structure is basically the same, the difference is: Fig.14 In the embodiment, the flow channel forming member 7 is a spacer having a substantially constant cross section along its extending direction.

[0080] exist Fig.15 In the embodiment, only the flow channel forming member 7 is formed in the liquid dispensing head body 1 , but at this time a Venturi tube section is formed on the liquid inlet pipe 3 , and the throat 310 of the Venturi tube section accelerates the refrigerant and then jets it into the flow channel forming member 7 .

[0081] and Figures 16 to 18 In the figure, the liquid dispensing head body 1 is the body structure of the existing liquid dispensing head; wherein, Fig.16 The middle liquid separation head body 1 is an existing socket-type structure; Fig.17 The center liquid separation head body 1 is an existing brass Venturi structure; Fig.18 The liquid-separating head body 1 is a reflective structure. The present invention will not enumerate the specific structure of the liquid-separating head body one by one. Other liquid-separating head body structures that can improve the uniformity of liquid separation can be combined with the branch pipe provided in this embodiment to form a high-performance liquid-separating head assembly with high liquid separation uniformity and low heat exchange loss. Similarly, the present invention does not make any limitation on the structure of the liquid inlet pipe 3, which can be any one of an equal-diameter pipe with basically the same inner diameter, a venturi tube, a throttling orifice tube or a perforated plate structure.

[0082] On the other hand, this embodiment also provides an air conditioner including the above-mentioned liquid dispensing head assembly.

[0083] Embodiment 2

[0084] This embodiment is basically the same as the first embodiment and its variations, except that the speed increasing pipe section on the branch pipe 2 is formed in a different manner.

[0085] In this embodiment, if Fig.19As shown, the upstream end of the branch pipe 23 is connected to the downstream end of the connecting pipe 21 through an outer sleeve, and a speed increasing pipe section 22 with a gradually decreasing inner diameter is formed downstream of the sleeve connection of the branch pipe 23, and a transition pipe section 231 is formed downstream of the speed increasing pipe section 22. However, the present invention does not make any limitation to this. In other embodiments, the upstream end of the branch pipe 23 may be welded to the downstream end of the connecting pipe 21 through an inner sleeve; in this case, the speed increasing pipe section 22 is still a structure with a gradually decreasing inner diameter located downstream of the sleeve connection of the branch pipe 23, such as Fig. 20 shown.

[0086] Fig.21 , Fig. 22 as well as Fig.23 A schematic structural diagram of a branch pipe provided in another embodiment of the present invention. Fig.21 In the embodiment, the connecting pipe 21, the speed increasing pipe section 22 and the branch pipe 23 are integrally formed; Fig. 22 In the embodiment, the connecting pipe 21 and the speed increasing pipe section 22 are integrally formed, and the branch pipe 23 is welded to the end of the speed increasing pipe section 22 . Fig.23 In the embodiment, the connecting pipe 21 is a straight pipe, and the speed increasing pipe section 22 is directly formed at the sleeve connection between the connecting pipe 21 and the branch pipe 23. Further, with respect to the structure of the speed increasing pipe section 22, in other embodiments, the speed increasing pipe section 22 may include a tapered section and a straight section located downstream of the tapered section and having a certain length L22, and the inner diameter of the straight section is close to the inner diameter at the downstream end of the tapered section and remains substantially unchanged within the length L22, such as Fig.24 As shown; in this structure, the connecting pipe 21 is a straight pipe. Alternatively, an orifice plate 26 is added at the expanded connection of the connecting pipe 21 or the branch pipe 23, and the refrigerant speed is increased by using the through hole 261 on the orifice plate 26; in this case, the pipe section where the orifice plate 26 is located is the speed increasing pipe section 22, as shown in FIG. Fig.25 shown.

[0087] exist Figures 19 to 25 In the structure of , the branch pipes do not include extension pipes. However, the present invention does not make any limitation to this. In other embodiments, Figures 19 to 25 Add extension pipes to the branch pipe structure to extend the length of the branch pipe to match the refrigeration equipment with larger installation space.

[0088] Embodiment 3

[0089] This embodiment is basically the same as the first embodiment and its variations, except that: in the liquid separation head assembly provided in this embodiment, no speed increasing pipe section is formed on the branch pipe 2.

[0090] As described in the first embodiment, the purpose of setting the speed increasing pipe section 22 is to increase the flow rate of the refrigerant in the branch pipe to increase the heat transfer coefficient of the rear heat exchanger assembly and reduce the heat transfer temperature difference and irreversible loss. However, when the flow rate and pressure drop in the connecting pipe 21 are sufficient to meet the design requirements of the rear heat exchanger assembly, the speed increasing pipe section may not be required on the branch pipe 2.

[0091] In view of this, this embodiment provides another liquid dispensing head assembly, such as Fig.26 and Fig. 27 As shown, it includes a liquid separator body 1 and a plurality of branch pipes 2. A plurality of branch pipe holes 11 are formed on the liquid outlet end of the liquid separator body 1. The plurality of branch pipes 2 are respectively welded to the plurality of branch pipe holes 11 on the liquid separator body 1, and each branch pipe 2 includes a connecting pipe 21 and a branch pipe 23 sequentially distributed along the flow direction of the refrigerant in the branch pipe. The connecting pipe 21 is an equal-diameter pipe fitting whose inner diameter and wall thickness remain basically unchanged along its extended length, and the branch pipe 23 includes an assembly straight section 232 welded to an external heat exchanger assembly. Among them, the inner diameter d3 of the assembly straight section 232 is greater than the inner diameter d1' of the connecting pipe 21, and the inner diameter difference △d31' between the two satisfies 0.1mm≤△d31'≤1.8mm.

[0092] Similarly, in order to avoid the problem of premature vaporization of part of the liquid refrigerant due to excessive expansion of the refrigerant in the assembly straight section 232, thereby worsening the uniformity of liquid separation and the energy efficiency of the rear-end heat exchanger components, it is still necessary to control the inner diameter difference △d31' between the assembly straight section 232 and the connecting pipe 21 to control the volume change rate of the refrigerant entering the assembly straight section 232.

[0093] As for the adjustment of the inner diameter of the assembly straight section 232, similar to the first embodiment, when the outer diameter D3 of the assembly straight section meets the assembly requirements of the rear heat exchanger assembly branch, the wall thickness of the assembly straight section can be adjusted so that its inner diameter d3 meets the requirements of the inner diameter difference △d31'. Alternatively, the adjustment can be made by adding a bushing, which can be an integral circular pipe or formed by at least one curved and rolled arc liner plate that is circumferentially spliced ​​and then welded.

[0094] In this embodiment, the branch pipe 23 further includes a transition pipe section 231 located upstream of the assembly straight section 232 . The inner diameter of the transition pipe section 231 is substantially close to the inner diameter d1 ′ of the connecting pipe 21 .

[0095] In this embodiment, the length of the branch pipe 23 is 60 mm to 200 mm, the length L1 of the assembly straight section is 3 mm to 30 mm, and the length of the branch pipe refers to the length of the refrigerant flow path from the upstream end to the downstream end of the branch pipe.

[0096] In this embodiment, the connecting pipe 21 is a curved pipe having a reflective pipe section 211. However, the present invention is not limited to this. In other embodiments, the connecting pipe 21 may also be a straight pipe.

[0097] In addition, in other embodiments, a branch pipe heat insulation sleeve can be added on the basis of the liquid dispensing head assembly provided in this embodiment to further curb the vaporization degree of the liquid refrigerant in the branch pipe 2, and each branch pipe heat insulation sleeve is covered with a corresponding branch pipe or a branch pipe on the corresponding branch pipe. In other embodiments, an extension pipe can be added between the connecting pipe and the branch pipe to extend the length of the branch pipe to match the refrigeration equipment with a larger installation space.

[0098] In summary, in the liquid separation head assembly provided by the present invention, the branch pipes are provided including connecting pipes, speed increasing pipe sections and branch pipes with different inner diameters. The branch pipes with larger inner diameters increase the refrigerant flow rate distributed into each branch pipe and reduce the refrigerant distribution resistance, while the speed increasing pipe section increases the refrigerant flow rate by reducing the flow channel cross section, and the assembly straight section on the branch pipe whose inner diameter is larger than the inner diameter at the downstream end of the speed increasing pipe section is used for welding and assembling the rear end heat exchanger assembly. On this basis, by controlling the inner diameter difference △d32 at the downstream end of the assembly straight section and the speed increasing pipe section, the volume change rate of the refrigerant in the assembly straight section after the speed increase is constrained, and the vaporization degree of the liquid refrigerant in the assembly straight section is controlled to avoid the liquid refrigerant from vaporizing prematurely before entering the heat exchanger assembly, ensuring that multiple branch pipes can provide the rear end heat exchanger with a large amount of liquid refrigerant and reduce heat exchange losses. Furthermore, the control of the vaporization degree of the refrigerant in the branch pipe can also weaken the influence of the random movement of the gas phase refrigerant in the branch pipe on the uniformity of the upstream liquid separation, thereby improving the liquid separation performance. In addition, the setting of the inner diameter difference △d32 also realizes the precise control of the refrigerant flow rate in the branch pipe, avoiding the refrigerant flow rate in the branch pipe being too low and affecting the uniformity of liquid separation of the upstream refrigerant. At the same time, the control of the refrigerant flow rate can also reduce the irreversible heat transfer loss to greatly improve the performance of the heat exchanger.

[0099] In the following data table: the units of the outer diameter D0 of the main section of the liquid inlet pipe, the inner diameter d2 of the downstream end of the speed increasing pipe section, the inner diameter d3 of the assembly straight section and the inner diameter difference △d32 are all mm; the unit of the mean square deviation STD of the refrigerant mass flow rate is g / s; the STD increase rate refers to: the increase in the STD corresponding to the current inner diameter difference △d32 relative to the STD corresponding to the previous inner diameter difference △d32.

[0100] Table 1

[0101] .

[0102] Although the present invention has been disclosed as above by the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection required by the claims.

Claims

1. A liquid dispensing head assembly, characterized in that: include: The liquid dispensing head body has a plurality of branch pipe holes formed on the liquid outlet end thereof; Multiple branch pipes are respectively welded to multiple branch pipe holes on the liquid distributor head body, each branch pipe includes a connecting pipe distributed in sequence along the flow direction of the refrigerant in the branch pipe, a speed increasing pipe section with a smaller inner diameter than the connecting pipe, and a branch pipe, and the branch pipe includes an assembly straight section welded to an external heat exchanger assembly; Among them, the inner diameter d3 of the assembly straight section is larger than the inner diameter d2 at the downstream end of the speed increasing pipe section, and the inner diameter difference △d32 between the two satisfies 0.1mm≤△d32≤1.8mm; the difference between the inner diameter d1 at the downstream end of the connecting pipe and the inner diameter d2 at the downstream end of the speed increasing pipe section satisfies: 0.1mm≤△d12≤3.5mm; the outer diameter of the assembly straight section meets the branch assembly requirements of the rear end heat exchanger assembly, and each branch pipe also includes a bushing welded inside the assembly straight section, and the inner diameter of the bushing is the inner diameter of the assembly straight section; the bushing is an integral circular pipe fitting; or, the bushing is formed by one or more curved and rolled arc-shaped lining plates that are circumferentially spliced ​​and then welded.

2. The liquid dispensing head assembly according to claim 1, characterized in that: The connecting pipe is a pipe of equal diameter, the inner diameter and wall thickness of which remain substantially unchanged along its extended length. The inner diameter d1 at the downstream end of the connecting pipe is less than or equal to the inner diameter d3 of the assembly straight section.

3. The liquid dispensing head assembly according to claim 1, characterized in that: The branch pipe also includes a transition pipe section located upstream of the assembly straight section, and the inner diameter of the transition pipe section is substantially close to the inner diameter of the downstream end of the speed increasing pipe section.

4. The liquid dispensing head assembly according to claim 1, characterized in that: The length of the branch pipe is 60 mm to 200 mm, the length L1 of the assembly straight section is 3 mm to 30 mm, and the length of the branch pipe refers to the length of the refrigerant flow path from the upstream end to the downstream end of the branch pipe.

5. The liquid dispensing head assembly according to claim 1, characterized in that: The liquid dispensing head assembly further includes a liquid inlet pipe disposed at the liquid inlet end of the liquid dispensing head body, the liquid inlet pipe including a liquid inlet pipe main body section having a substantially constant inner diameter and wall thickness and a liquid inlet pipe connecting section connected to the liquid dispensing head body; when the outer diameter D0 of the liquid inlet pipe main body section is less than or equal to 13 mm, the inner diameter d2 at the downstream end of the speed increasing pipe section is less than or equal to 4.3 mm; When the outer diameter D0 of the main section of the liquid inlet pipe is greater than 13 mm, the inner diameter d2 of the downstream end of the speed increasing pipe section is less than or equal to 5.3 mm.

6. The liquid dispensing head assembly according to claim 1, characterized in that: The connecting pipe is formed with a reflecting pipe section that bends and extends toward one side relative to the center line of the branch pipe hole, and the axis at the upstream end of the reflecting pipe section and the axis at the downstream end thereof intersect to form an angle θ and 90°≤θ≤175°; Alternatively, the connecting pipe is a straight pipe.

7. The liquid dispensing head assembly according to claim 1, characterized in that: The upstream end of the branch pipe is internally sleeve-welded to the downstream end of the connecting pipe, and the sleeve connection between the two forms a speed-increasing pipe section; Alternatively, the speed-increasing pipe section is integrally formed with the connecting pipe and has a tapered structure whose inner diameter gradually decreases along the flow direction of the refrigerant, and the upstream end of the branch pipe is sleeve-connected to the downstream end of the speed-increasing pipe section; Alternatively, the speed increasing pipe section is integrally formed upstream of the assembly straight section of the branch pipe, and its inner diameter gradually decreases along the refrigerant flow direction, and the upstream end of the speed increasing pipe section is welded to the downstream end of the connecting pipe.

8. The liquid dispensing head assembly according to claim 1, characterized in that: The branch pipe also includes an extension pipe welded between the connecting pipe and the branch pipe, and both the extension pipe and the connecting pipe are stainless steel pipe fittings.

9. The liquid dispensing head assembly according to claim 1, characterized in that: The connecting pipe, the speed increasing pipe section and the branch pipe are all copper pipe fittings and the three are integrally formed; Alternatively, the connecting pipe is a stainless steel pipe, the branch pipe is a copper pipe or an aluminum pipe, and the branch pipe is connected to the connecting pipe by welding.

10. The liquid dispensing head assembly according to claim 1, characterized in that: The liquid dispensing head assembly further comprises a plurality of branch pipe heat insulation sleeves, each of which is jacketed on a corresponding branch pipe or a branch pipe on the corresponding branch pipe.

11. A liquid dispensing head assembly, characterized in that: include: The liquid dispensing head body has a plurality of branch pipe holes formed on the liquid outlet end thereof; A plurality of branch pipes are respectively welded to a plurality of branch pipe holes on the liquid distributor head body, each branch pipe comprises a connecting pipe and a branch pipe sequentially distributed along the flow direction of the refrigerant in the branch pipe, the connecting pipe is a pipe of equal diameter whose inner diameter and wall thickness are substantially constant along its extended length, and the branch pipe comprises an assembled straight section welded to an external heat exchanger assembly; Among them, the inner diameter d3 of the assembly straight section is larger than the inner diameter d1' of the connecting pipe, and the inner diameter difference △d31' between the two satisfies 0.1mm≤△d31'≤1.8mm; the outer diameter of the assembly straight section meets the branch assembly requirements of the rear-end heat exchanger assembly, and each branch pipe also includes a bushing welded inside the assembly straight section, and the inner diameter of the bushing is the inner diameter of the assembly straight section; the bushing is an integral circular pipe fitting; or, the bushing is formed by one or more curved and rolled arc-shaped lining plates that are circumferentially spliced ​​and then welded.

12. An air conditioner, characterized in that: A liquid dispensing head assembly comprising any one of claims 1 to 11.

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