CN113587250A

CN113587250A - Air conditioner

Info

Publication number: CN113587250A
Application number: CN202110845573.4A
Authority: CN
Inventors: 赵东方; 李晓宇; 石丽华; 曹法立; 刘晓蕾
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2021-07-26
Filing date: 2021-07-26
Publication date: 2021-11-02

Abstract

The invention provides an air conditioner, which can solve the problem that in the prior art, a gas-liquid two-phase refrigerant of the air conditioner is easy to generate gas-liquid phase separation in a collecting pipe of a multi-flat-pipe parallel flow heat exchanger, so that the refrigerant is unevenly distributed. The air conditioner comprises a multi-flat-tube parallel flow heat exchanger, the multi-flat-tube parallel flow heat exchanger comprises a plurality of flat tubes and a flow divider used for uniformly distributing gas-liquid two-phase refrigerants into the flat tubes, the flow divider comprises a flow divider main body, a refrigerant inlet and a plurality of refrigerant outlets, a flat flow channel is formed in the flow divider main body, the refrigerant inlet is communicated with the flat flow channel, the plurality of refrigerant outlets are communicated with the flat flow channel, and the plurality of refrigerant outlets are distributed along the extending direction of the flat flow channel. The invention can evenly distribute the gas-liquid two-phase refrigerant into a plurality of flat tubes by arranging the flow divider, thereby improving the performance of the micro-channel heat exchanger.

Description

Air conditioner

Technical Field

The invention relates to the technical field of air conditioners, in particular to an air conditioner.

Background

In order to reduce the production cost of the air-conditioning heat exchanger, part of manufacturers already start to produce all-aluminum heat exchangers, and compared with the traditional finned tube heat exchanger, the cost of the heat exchanger materials can be reduced by 40% because copper tubes are not used. The micro-channel parallel flow heat exchanger is a common all-aluminum heat exchanger, a plurality of flat pipes are arranged in the vertical direction of the heat exchanger, the flat pipes are directly connected through collecting pipes, fins are arranged among the flat pipes and used for reinforcing heat exchange with air, and the common micro-channel heat exchanger is shown in figure 1 and comprises a collecting pipe 1, flat pipes 2 and fins 3.

Because commercial air conditioner's heat exchanger is very big, highly generally surpass 800mm, through statistics, the interval between the flat pipe is many between 10~18mm, and flat pipe quantity in vertical direction often surpasss 60, and whether the refrigerant can evenly be distributed between these flat pipes becomes the bottleneck problem that restricts microchannel heat exchanger performance.

As is well known, when a heat exchanger is used as an evaporator, a refrigerant entering the heat exchanger is a throttled gas-liquid two-phase fluid with a certain dryness (dryness: the mass fraction of the gas-phase fluid in the gas-liquid two-phase refrigerant), the two-phase fluid can undergo gas-liquid phase separation due to the influence of gravity when the flow rate is slowed, if the gas-liquid phase separation occurs in a section of collecting pipe, most of the liquid in the refrigerant flowing into a plurality of flat pipes at the lower part of the collecting pipe is even pure liquid, and most of the gas flowing into a plurality of flat pipes at the upper part is even pure gas, and the performance of the heat exchanger is rapidly reduced due to the uneven distribution.

To solve this problem, heat exchanger manufacturers often make articles inside the collector, for example by adding baffles or by using more complex structures. The flat pipes are separated by the partition plates, for example, 6 flat pipes are in one group, the effect is better only under the condition of full load and large flow, and when the compressor is in partial load, the rotating speed of the compressor is extremely low, the flow rate of the refrigerant is also very low, the phase separation condition is serious, and the effect of uniform shunting cannot be achieved. Some of the devices use very complicated structures, and the fluid is rotated through the complicated structural design, so that the probability of gas-liquid phase separation is reduced, the structural design and the manufacturing process are very difficult, and the phase separation phenomenon still exists even when the flow is small.

From the above analysis, it is known that there are two conditions, one is a flow rate and the other is a space, for the gas-liquid phase separation of a fluid having a certain dryness. The higher the flow rate and the smaller the flow space, the more difficult the phase separation occurs; the lower the flow rate and the larger the space, the more phase separation occurs.

Disclosure of Invention

The invention provides an air conditioner, which can solve the problem that in the prior art, a gas-liquid two-phase refrigerant of the air conditioner is easy to generate gas-liquid phase separation in a collecting pipe of a multi-flat-pipe parallel flow heat exchanger, so that the refrigerant is unevenly distributed.

In some embodiments of the present application, an air conditioner is provided, including many flat pipe parallel flow heat exchangers, its characterized in that, many flat pipe parallel flow heat exchangers include a plurality of flat pipes and are used for evenly distributing the two-phase refrigerant of gas-liquid to a plurality of shunt in the flat pipe, the shunt includes:

the flow divider comprises a flow divider main body, a plurality of flow channels and a plurality of connecting pipes, wherein a flat flow channel is formed in the flow divider main body and extends along the arrangement direction of the flat pipes;

a refrigerant inlet provided in the flow divider main body and communicating with the flat flow channel on one side surface in the thickness direction of the flat flow channel;

the refrigerant outlets are long-strip-shaped flat openings and are arranged on the flow divider main body and communicated with the flat flow channel on the other side face of the flat flow channel in the thickness direction, and the refrigerant outlets are distributed along the extending direction of the flat flow channel.

In the air conditioner, the multi-flat-tube parallel flow heat exchanger comprises the flow divider used for uniformly distributing the gas-liquid two-phase refrigerant to the flat tubes, the flow divider has simple structure, does not need to be internally provided with a partition plate for dividing a flow path, when gas-liquid two-phase refrigerant fluid flowing at high speed flows into the flat flow channel from the refrigerant inlet, because the flat flow channel is a very flat and thin space, the gas-liquid two-phase refrigerant fluid can be quickly spread when contacting one side surface of the flat flow channel in the thickness direction, and can keep higher flow velocity, the influence of gravity can be greatly inhibited due to higher flow velocity, the gas-liquid two-phase refrigerant has no chance of gas-liquid phase separation, the refrigerant fluid flow distribution flowing around the refrigerant inlet is almost equal; meanwhile, the flat flow channel is flat and thin, so that the gas-liquid two-phase refrigerant basically has no space for phase separation, and the uniform flow distribution effect is further improved.

In some embodiments of the present application, the thickness a of the flat flow channel ranges from 1 mm to 3mm, the width b ranges from 10 mm to 22mm, and the length h ranges from 50 mm to 100mm, so that the flat flow channel forms a flat and thin space.

In some embodiments of the present application, the refrigerant outlet has an inner profile length m ranging from 10 to 22mm and an inner profile width n ranging from 1.5 to 3 mm.

In some embodiments of the present application, the refrigerant outlet has an inner contour width direction parallel to the extending direction of the flat flow channel, the refrigerant outlet is staggered from the refrigerant inlet, and the refrigerant outlet is correspondingly disposed at both ends of the extending direction of the flat flow channel.

In some embodiments of the present application, the refrigerant inlet is directly opposite to the center of the flat flow channel, and the plurality of refrigerant outlets are arranged at equal intervals along the extending direction of the flat flow channel.

In some embodiments of the present application, a side of the flat flow channel, which is communicated with the refrigerant inlet, is a first side of the flat flow channel in a thickness direction, and another side of the flat flow channel, which is communicated with the refrigerant outlet, is a second side of the flat flow channel in the thickness direction; along the extending direction of the flat flow channel, the first side surface in the thickness direction is composed of a first sub-side surface positioned on one side of the refrigerant inlet and a second sub-side surface positioned on the other side of the refrigerant inlet, and the first sub-side surface and the second sub-side surface are inclined towards the side where the refrigerant inlet is positioned.

In some embodiments of the present application, the first sub-side and the second sub-side are each inclined at an angle of 0.7 ° -2 °.

In some embodiments of the present application, an axis of the refrigerant inlet and an axis of the refrigerant outlet are perpendicular to the thickness direction second side surface.

In some embodiments of the present application, an arc-shaped recess is formed on the thickness direction second side face at a position opposite to the refrigerant inlet.

In some embodiments of the present application, the refrigerant outlet is in rounded transition with the flat flow channel.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a perspective view of a prior art microchannel heat exchanger;

FIG. 2 is a system schematic of a prior art air conditioner;

FIG. 3 is a schematic diagram of a prior art dual-row heat exchanger configuration;

FIG. 4 is a perspective view of a heat exchanger in a first embodiment of the air conditioner of the present invention;

FIG. 5 is an enlarged view of section I of FIG. 4;

FIG. 6 is a schematic diagram of a heat exchanger with fins and flat tubes according to a first embodiment of the air conditioner of the present invention;

FIG. 7 is a perspective view of a heat exchanger splitter according to one embodiment of the air conditioner of the present invention;

FIG. 8 is an exploded view of FIG. 7;

FIG. 9 is an A-direction elevation view of FIG. 7;

FIG. 10 is a cross-sectional view B-B of FIG. 9;

FIG. 11 is a front view in the direction of C of FIG. 9;

FIG. 12 is a cross-sectional view D-D of FIG. 11;

fig. 13 is a perspective view of a flat tube row-spanning connecting member in the air conditioner according to the first embodiment of the present invention;

FIG. 14 is a cross-sectional view of a heat exchanger splitter in a second embodiment of the air conditioner of the present invention;

FIG. 15 is an enlarged view of section E of FIG. 14;

FIG. 16 is a perspective view of an end cap of a second air splitter according to an embodiment of the present invention;

FIG. 17 is a front view F of FIG. 16;

FIG. 18 is a sectional view taken along line G-G of FIG. 17;

FIG. 19 is an enlarged view of section H of FIG. 18;

fig. 20 is a schematic view showing the flow direction of the two-phase gas-liquid refrigerant fluid in the flow divider according to the second embodiment of the air conditioner of the present invention.

Reference numerals in fig. 1 to 2:

1-collecting pipe; 2-flat tube; 3-a fin; 4-a compressor; 5-outdoor heat exchanger; 6-a throttling mechanism; 7-indoor side heat exchanger; a 8-four-way valve;

reference numerals in fig. 3:

1-a first header; 2-a second header; 3-a third header; 4-a fourth header; 5-a fin; 6-outer flat discharge pipes; 7-inner flat discharge pipes;

reference numerals in fig. 4 to 20:

10-multiple flat tube parallel flow heat exchanger;

100-flat tube; 110-a first end; 120-a second end; 130-a bending part; 140-an upper horizontal section; 150-lower horizontal section;

200-a shunt; 210-a shunt body; 211-flat flow channel; 211A-a thickness direction first side; 211a 1-first sub-side; 211a 2-second sub-side; 211B-a thickness direction second side; 212-end cap portion; 213-a body portion; 214-annular positioning groove; 220-a refrigerant inlet; 230-a refrigerant outlet; 240-arc shaped recess;

300-a fin;

400-a connector; 410-a housing; 420-flat connected flow channel; 421-inlet/outlet;

500-a gas collecting pipe;

600-main gas tube assembly; 610-main air pipe; 611-a connection end; 620-bronchus;

700-a liquid tube assembly; 710-main liquid pipe; 720-shunting head; 730-Branch liquid tube.

Detailed Description

The technical scheme of the invention is clearly and completely described in the following with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The air conditioner performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the air that has been conditioned and heat-exchanged.

The compressor compresses a refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a cooling effect by heat-exchanging with a material to be cooled using latent heat of evaporation of a refrigerant. The air conditioner can adjust the temperature of the indoor space throughout the cycle.

An outdoor unit (outdoor unit) of an air conditioner refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, an indoor unit (indoor unit) of an air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.

The indoor heat exchanger and the outdoor heat exchanger serve as a condenser or an evaporator. When the indoor heat exchanger is used as a condenser, the air conditioner is used as a heater in a heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner is used as a cooler in a cooling mode.

Fig. 2 is a schematic diagram of the system of the air conditioner, when in refrigeration operation, the refrigerant is compressed by the compressor 4, and becomes a high-temperature and high-pressure superheated gas, and the gas is discharged into the outdoor heat exchanger 5 for condensation, because the refrigerant is superheated gas, there is generally no problem of flow division, and the refrigerant can generally be distributed more uniformly at the inlet of the outdoor heat exchanger 5; the refrigerant is cooled to be supercooled liquid in the outdoor heat exchanger 5, enters the throttling mechanism 6, is throttled to be low-temperature and low-pressure two-phase refrigerant, flows into the indoor heat exchanger 7 to be evaporated and absorb heat, is evaporated to be superheated gas in the indoor heat exchanger 7, and returns to the suction end of the compressor 1 to complete a cycle.

During heating operation, high-temperature and high-pressure refrigerant gas is directly discharged into the indoor side heat exchanger 7 for heating after passing through the four-way valve 8, after being cooled into supercooled liquid in the indoor side heat exchanger 7, the refrigerant gas is throttled into low-temperature and low-pressure gas-liquid two-phase refrigerant by the throttling mechanism 6, the two-phase refrigerant enters the outdoor side heat exchanger 5 for evaporation and heat absorption, and because the phenomenon of uneven distribution caused by phase separation exists when two-phase flow is in a large space or the flow rate is reduced, a liquid separation mechanism needs to be arranged at a liquid side inlet of the outdoor side heat exchanger 5, so that the refrigerant flow entering each heat exchange tube (flat tube in the application) of the outdoor side heat exchanger 5 is basically consistent, and the maximum effect of the heat exchanger is exerted.

Therefore, one of the technical objects of the present invention is to provide an air conditioner capable of uniformly distributing a gas-liquid two-phase refrigerant entering each flat tube of an outdoor heat exchanger.

Example one

Referring to fig. 4 to 6, the air conditioner of the present embodiment includes a multi-flat-tube parallel flow heat exchanger 10, where the multi-flat-tube parallel flow heat exchanger 10 includes a plurality of flat tubes 100 and a flow divider 200 for uniformly distributing a gas-liquid two-phase refrigerant to the plurality of flat tubes 100, and certainly further includes a fin 300.

The flat tubes 100 are arranged at intervals up and down along the height direction of the multi-flat-tube parallel flow heat exchanger 10, and the distance between every two adjacent flat tubes 100 is 10-18 mm. A plurality of microchannels for circulating refrigerants are formed in the flat tube 100, the flat tube 100 is arranged in the fin 300 in a penetrating mode, the flowing direction of air flowing through the fin 300 is perpendicular to the flowing direction of the refrigerants flowing through the flat tube 100, heat/cold energy released by the refrigerants in the flat tube 100 is taken away through heat dissipation of the fin 300 and air flow, and heat exchange with air is enhanced.

The flat tube 100 is made of porous micro-channel aluminum alloy, and the fin 100 is made of aluminum alloy with a brazing composite layer on the surface, so that the flat tube is light in weight and high in heat exchange efficiency.

Referring to fig. 7 to 12, the flow divider 200 specifically includes a flow divider body 210, a refrigerant inlet 220, and a plurality of refrigerant outlets 230.

A flat flow channel 211 is formed in the diverter main body 210, so that the diverter main body 210 is of a hollow structure, the flow channel space thickness of the flat flow channel 211 is small and thin, as shown in fig. 10, a dimension a is the thickness of the flat flow channel 220, and the flat flow channel 211 extends along the arrangement direction of the flat tubes 100, that is, in this embodiment, along the height direction, that is, the up-down direction, of the multi-flat-tube parallel flow heat exchanger 10, as shown in fig. 10, the vertical direction. In this embodiment, the flow divider main body 210 is a thin rectangular shape, the length direction of the flow divider main body is the same as the extending direction of the flat flow channel 220, for manufacturing convenience, the flow divider main body 210 is further divided into an end cover part 212 and a main body part 213, the refrigerant inlet 220 is formed on the end cover part 212, the refrigerant outlet 230 is formed on the main body part 213, a shallow groove is formed inside the main body part 213, and meanwhile, an annular positioning groove 214 matched with the end cover part 212 is provided, the end cover part 212 is fittingly embedded in the annular positioning groove 214 and is fixed with the main body part 213 in a sealing manner, and the outer surface of the end cover part 212 after installation is flush with the corresponding side surface of the main body part 213 to jointly enclose the flat flow channel 211 inside.

The refrigerant inlet 220 is provided on the flow divider main body 210 and communicates with the flat flow channel 220 on one side surface in the thickness direction of the flat flow channel 220, as shown in fig. 10, the dimension a is the thickness of the flat flow channel 220, and the direction of the dimension a is the thickness direction of the flat flow channel 220, and at the same time, as viewed from fig. 10, the refrigerant inlet 220 is located on the left side surface of the flat flow channel 211 and communicates with the flat flow channel 211. The refrigerant inlet 220 is embodied as an inlet pipe formed at the end cover portion 212, and the throttled gas-liquid two-phase refrigerant fluid with a certain dryness is connected to the refrigerant inlet 220 through a capillary tube of the liquid tube assembly 700.

The plurality of refrigerant outlets 230 are used to be connected to the plurality of flat tubes 100 in a one-to-one correspondence, so that the gas-liquid two-phase refrigerant fluid uniformly distributed by the flow divider 200 flows into the corresponding flat tubes 100. The refrigerant outlet 230 is a long flat opening to be connected to the flat tube 100, and is provided on the flow divider body 210 and communicated with the flat flow channel 211 on the other side surface in the thickness direction of the flat flow channel 211, and the plurality of refrigerant outlets 230 are arranged along the extending direction of the flat flow channel 211. The refrigerant outlet 230 is specifically a short flat microchannel tube exposed outside the splitter body 210 so as to be fittingly connected to the flat tube 100, and the refrigerant outlet 230 is located on the right side of the flat flow channel 211 and communicates with the flat flow channel 211 as viewed in fig. 10.

The air conditioner of the application, the shunt 200 of the multi-flat-tube parallel flow heat exchanger 10 can be to the principle of gas-liquid two-phase refrigerant fluid uniform distribution: the gas-liquid two-phase refrigerant fluid flowing at a high speed flows into the flat flow channel 211 from the refrigerant inlet 220, and because the flat flow channel 211 is a flat thin-layer space, the gas-liquid two-phase refrigerant fluid can be quickly spread when contacting one side surface (the right side surface of the flat flow channel 211 in fig. 10) in the thickness direction of the flat flow channel 211 and then uniformly flows into each refrigerant outlet 230, the flow direction of the fluid is as shown by arrows in fig. 10, because the space of the flat flow channel 211 is thin, the fluid can still keep a high flow speed after spreading, the high flow speed can greatly inhibit the influence of gravity, so that the gas-liquid two-phase refrigerant has no chance of gas-liquid phase separation, and the flow distribution of the refrigerant fluid flowing around by taking the refrigerant inlet 220 as the center is almost equal; meanwhile, because the flat flow channel 211 is flat and thin, the gas-liquid two-phase refrigerant basically has no space for phase separation, and the effect of uniform flow distribution is further improved.

In addition, the shunt 200 does not need to be internally provided with a partition plate to divide a flow path, and has the advantages of simple structure, low cost and convenience in processing.

In this embodiment, as shown in fig. 10 and 12, the thickness a of the flat flow channel 211 ranges from 1 mm to 3mm, the width b ranges from 10 mm to 22mm, and the length h ranges from 50 mm to 100mm, so that the flat flow channel forms a flat and thin space.

In this embodiment, the length m of the inner contour (i.e., the contour corresponding to the inner diameter) of the refrigerant outlet 230 is in the range of 10-22mm, and the width n of the inner contour is in the range of 1.5-3 mm.

As shown in fig. 7, 8, and 10 to 12, the inner width direction of refrigerant outlet 230 is parallel to the extending direction of flat flow channel 211, i.e. the inner width n of refrigerant outlet 230 is parallel to the length h direction of flat flow channel 211, so that a plurality of refrigerant outlets 230 are arranged along the extending direction of flat flow channel 211, and the length and volume of flow divider 200 are reduced as much as possible without changing the number of flat tubes 100. In addition, the refrigerant outlet 230 and the refrigerant inlet 220 are arranged in a staggered manner, so that the refrigerant flowing at a high speed is prevented from directly entering the refrigerant outlet 230 directly opposite to the refrigerant inlet 220 after entering the flat flow channel 211 from the refrigerant inlet 220, the uniform spreading of the refrigerant is influenced, and meanwhile, the refrigerant outlet 230 is correspondingly arranged at both ends of the flat flow channel 211 in the extending direction, so that fluid flowing dead angles are prevented from existing at both ends of the flat flow channel 211 in the extending direction.

In the present embodiment, the refrigerant inlet 220 faces the center of the flat flow channel 211, specifically, is located at the center of the flow divider body 210, and the plurality of refrigerant outlets 230 are arranged at equal intervals along the extending direction of the flat flow channel 211. Therefore, on one hand, the flow divider 210 is symmetrical in structure, the fool-proof design is realized, and on the other hand, the uniform fluid distribution is further facilitated.

Because the multi-flat-tube parallel flow heat exchanger 10 of the commercial air conditioner is usually large in size, the height is generally over 800mm, and the distance between adjacent flat tubes 100 in the vertical direction is more than 10-18mm, the number of the flat tubes 100 in the vertical direction is often over 60, and for the embodiment with the large number of the flat tubes 100, a plurality of flow dividers 200 are correspondingly arranged, each flow divider 200 has 4 or 6 refrigerant outlets 230, namely 4 or 6 flat tubes 100 are combined with one flow divider 200, so that deformation and assembly errors caused by the fact that all the flat tubes 100 are connected to one flow divider 200 can be avoided as much as possible, the larger the deformation is, the more the assembly is not facilitated, and the more leakage is caused.

In order to improve the heat exchange efficiency, some air conditioners may employ a plurality of rows of heat exchangers, such as a double-row heat exchanger or a three-row heat exchanger, that is, two rows or three rows of flat tubes are correspondingly arranged along the air flow direction, and each row is provided with a plurality of flat tubes at intervals from top to bottom, which is described by taking a prior art double-row heat exchanger as an example as shown in fig. 3. As shown in fig. 3, for a double-row heat exchanger, the double-row heat exchanger generally includes four collecting pipes, that is, a first collecting pipe 1 and a second collecting pipe 2 which are located at an outer row, and a third collecting pipe 3 and a fourth collecting pipe 4 which are located at an inner row, the first collecting pipe 1 and the second collecting pipe 2 are respectively communicated with two ends of an outer row flat pipe 6, the third collecting pipe 3 and the fourth collecting pipe 4 are respectively communicated with two ends of an inner row flat pipe 7, and the outer row flat pipe 6 and the inner row flat pipe 7 are connected into a whole by a same group of fins 5 to enhance heat exchange with air.

For a dual-row heat exchanger, there must be cross-row flow during refrigerant operation. For example, during heating operation, a refrigerant flows into one flow path of the outer heat exchanger (for example, 6 outer flat discharge pipes 6) through the first collecting pipe 1, reaches the second collecting pipe 2, flows out of the second collecting pipe 2 again, and has two flow modes after flowing out of the second collecting pipe 2 according to different flow paths:

one is that the refrigerant flows upwards or downwards and still flows outwards, returns to the first collecting pipe 1 and then enters the fourth collecting pipe 4, and the flowing mode in the fourth collecting pipe 4 is the same as that of the first collecting pipe 1;

another way is to flow from the second header 2 to the third header 3, where a cross-row connection is required.

Because the all-aluminum heat exchanger generally welds in the tunnel furnace, the multirow heat exchanger of this kind of current many pressure manifolds can lead to the solder joint numerous, for example, flat pipe quantity is 60, then double heat exchanger only the solder joint between pressure manifold and the flat pipe just reaches 272, welding process in the stove has proposed higher requirement simultaneously, if there is the connecting pipe between the row of striding, the connecting pipe can not be installed before the welding in the tunnel furnace, need bend again after the welding completion in the tunnel furnace, the manual welding of connecting pipe is carried out again after bending, required labour is long, and probably influence welding quality.

In order to solve the above technical problems of the multi-row heat exchanger (multi-row flat tube parallel flow heat exchanger) in the prior art, as shown in fig. 5 and fig. 6, the multi-flat tube parallel flow heat exchanger 10 in this embodiment further includes a connector 400 and a heat collecting tube 500, and the flat tube 100 is bent into a U shape, and includes an upper horizontal segment 140, a lower horizontal segment 150, and a bent portion 130, the bent portion 130 is located on the same side of the upper horizontal segment 140 and the lower horizontal segment 150 and is connected to the upper horizontal segment 140 and the lower horizontal segment 150, a free end of the upper horizontal segment 140 is a first end 110 of the flat tube 100, and a free end of the lower horizontal segment 150 is a second end 120 of the flat tube 100; the first end 110 of each flat tube 100 in the innermost row is connected to the flow divider 200 through the refrigerant outlet 230, and the second end 120 is connected to the second end 120 of the flat tube 100 in the adjacent outer row through a connector 400, so that the connector 400 realizes the cross-row flow of the refrigerant between the two rows of heat exchangers, the first end 110 of the flat tube 100 in the outermost row is the refrigerant inlet end thereof, the second end 120 thereof is the refrigerant outlet end thereof, the second end 120 of the flat tube 100 in the inner row is the refrigerant inlet end thereof, the first end 110 thereof is the refrigerant outlet end thereof, and the first end 110 of the flat tube 100 in the inner row is connected to a gas collecting tube 500.

Then to double heat exchanger, need 4 pressure manifold among the prior art, and many flat pipe parallel flow heat exchanger 10 in this embodiment, because flat pipe 100 is the U-shaped, then only need set up

shunt

200 and 1 gas collecting pipe 500, can realize the intercommunication of interior outer heat exchanger and the even distribution of gas-liquid two-phase refrigerant, the heat exchanger structure has been simplified greatly, and gas collecting pipe 500 is located the heat exchanger gas side, also need not to utilize the baffle to divide the flow path in gas collecting pipe 500 inside, adopt a siphunculus can, the solder joint that this kind of design compared with traditional design reduces half.

Specifically, as shown in fig. 5 and 13, the connector 400 includes a housing 410 and a flat communication channel 420 formed in the housing 410, the flat communication channel 420 having a plurality of inlet/outlet ports 421 penetrating through the housing 410, wherein one inlet/outlet port 421 communicates with the second end 120 of the flat tube 100 in the outermost row, and the other inlet/outlet ports 421 communicate with the second end 120 of the flat tube 100 in the inner row, and the cross-sectional dimension of the flat communication channel 420 is adapted to the cross-sectional dimension of the flat tube 100 so as to facilitate the sealed communication therebetween; in order to prevent the connector 400 from deforming due to insufficient pressure bearing caused by over-high pressure of the refrigeration system, the reinforcing ribs 430 are arranged in the flat communication flow passage 420 in the embodiment to play a supporting role. For the dual-row heat exchanger in this embodiment, the flat communication channel 420 has two inlet/outlet ports 421.

For the gas collecting pipe 500, which is a collecting pipe after all refrigerants finally flow out from the heat exchange flat pipes 100, when the air collecting pipe 500 performs refrigeration operation, the gas collecting pipe 500 is communicated with the compressor to exhaust, and high-temperature and high-pressure exhaust is evenly distributed to each flat pipe 100 from the gas collecting pipe 500, because the flow divider 200 is arranged in the embodiment to ensure that the flow path refrigerants of each flat pipe 100 are distributed very uniformly, the gas collecting pipe 500 can be a through pipe with two closed ends and directly communicated with the inside, a connecting port correspondingly connected with the first ends 110 of the flat pipes 100 in the inner row is arranged on the pipe body, and a partition plate is not needed to be used in the gas collecting pipe 500 to partition the flow path, so that the structure and the manufacturing process are simplified.

Because the gas collecting pipe 500 runs through the whole heat exchanger in the height direction and is limited by the frame structure of the heat exchanger, usually, no extra space exists to directly connect the gas collecting pipe 500 with the refrigeration system, and in order to connect the gas collecting pipe 500 with the refrigeration system, the multi-flat-pipe parallel flow heat exchanger 10 in the embodiment further comprises a main gas pipe assembly 600 as a transition connecting pipe between the refrigeration system and the gas side of the whole heat exchanger.

Specifically, the main air tube assembly 600 includes a main air tube 610 and a plurality of branch air tubes 620 each directly connected to the main air tube 610, the plurality of branch air tubes 620 are disposed along an extending direction of the main air tube 610, that is, the extending direction of the gas collecting tube 500 and the height direction of the heat exchanger are arranged at intervals and are all connected to the gas collecting tube 500, one end of the main air tube 610 is closed, and the other end is a connection end 611 for connecting to a refrigeration system, thereby connecting the gas collecting tube 500 to the refrigeration system.

When the multi-flat-tube parallel flow heat exchanger 10 of the air conditioner is large in size and high in height, which results in a large number of the flat tubes 100, a plurality of the shunts 200 are usually provided, and each of the shunts 200 has 4 or 6 refrigerant outlets 230, that is, the shunts are combined with 4 or 6 flat tubes 100, so as to avoid deformation and assembly errors caused by connecting all the flat tubes 100 to one shunt 200 as much as possible. Also limited by the heat exchanger frame structure, there is also a problem that there is no extra space to directly connect the plurality of shunts 200 to the refrigeration system, and to solve this problem, the multi-flat-tube parallel flow heat exchanger 10 in this embodiment further includes a liquid tube assembly 700 as a transitional connection tube group between the refrigeration system and the liquid side of the whole heat exchanger.

Specifically, the liquid pipe assembly 700 includes a main liquid pipe 710, a branch pipe 720 and a plurality of branch pipes 730, the main liquid pipe 710 has one end communicated with the throttling mechanism and the other end connected with the branch pipe 720, the inlet ends of the branch pipes 730 are all connected to the branch pipe 720, and the outlet ends of the branch pipes 730 are connected with the flow divider 200 in a one-to-one correspondence, specifically connected to the refrigerant inlet 220 of the flow divider 200.

In summary, in the air conditioner of the present embodiment, during heating operation, the refrigerant is throttled by the throttling mechanism from the refrigeration system to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, the two-phase refrigerant enters the liquid pipe assembly 700, and because the cross-sectional area of the flow path in the branch pipe 730 is small, phase separation is difficult to occur, so it is considered that the two-phase refrigerant can be uniformly distributed to each branch pipe 730, the branch pipe 730 is connected to the flow divider 200, the two-phase refrigerant is uniformly distributed to each flat pipe 100 in the outer row in the flow divider 200, the refrigerant flows from the flow dividing side (the side defining the heat exchanger configuration flow divider 200 is called the flow dividing side, and the side where the bending portion 130 of the flat pipe 100 is located is the tail side) to the tail side in the flat pipe 100 in the outer row, and flows again to the flow dividing side through the bending portion 130 in the tail side, and then flows into the flat pipe 100 in the inner row through the connector 400, and returns again through the bending portion 130, and finally flows into the gas collecting pipe 500, and then flows into the suction end of the compressor of the refrigeration system through the main gas pipe assembly 600, thereby completing a heating process. As the refrigerant begins to flow from the first end (i.e., the inlet end) of the outer flat tube 100, it begins to absorb heat, and as the flow progresses, the refrigerant gradually vaporizes and increases in quality, and is generally heated to a superheated gas at the outlet of the main tube assembly 600.

During the cooling operation, the high-temperature and high-pressure compressor exhaust firstly exhausts the main gas pipe assembly 600, because the gas state is adopted, the pressure distribution is uniform, the refrigerant can be uniformly distributed in each branch gas pipe 620 and then uniformly distributed in the gas collecting pipe 500, the refrigerant state is unchanged in the gas collecting pipe 500, and the refrigerant is also high-temperature and high-pressure superheated gas, so the refrigerant can be easily distributed in each flat pipe 100, at the moment, the refrigerant can flow once according to the reverse process of the heating operation, exchanges heat with the outside air, and is gradually cooled into supercooled liquid (the liquid pipe assembly 700) by the air, and because the refrigerant distributed in the cooling operation is high-temperature and high-pressure gas, the problem of difficult refrigerant distribution is rarely involved.

Example two

Referring to fig. 14 to 20, in the present embodiment, for convenience of description, a side surface of the flat flow channel 211 communicating with the refrigerant inlet 220 is defined as a first side surface 211A in the thickness direction of the flat flow channel 211, and the other side surface communicating with the refrigerant outlet 230 is defined as a second side surface 211B in the thickness direction of the flat flow channel 211.

Unlike the first embodiment, in the present embodiment, the thickness direction first side surface 211A is formed by the first sub-side surface 211A1 located on one side of the refrigerant inlet 220 and the second sub-side surface 211A2 located on the other side of the refrigerant inlet 220 in the extending direction of the flat flow channel 211, and both the first sub-side surface 211A1 and the second sub-side surface 211A2 are inclined toward the side of the refrigerant inlet 220.

The reason for this is that when the gas-liquid two-phase refrigerant fluid flowing at high speed flows in through the refrigerant inlet 220 and hits the second side 211B of the flat flow channel 211 in the thickness direction, the fluid turns 90 ° and flows in a flat manner around, which may cause a large pressure loss, thereby causing flash of the refrigerant at this location, and further aggravating the pressure loss after increasing the gas phase ratio, which may adversely affect the improvement of the refrigeration performance, therefore in this embodiment, the first sub-side 211A1 and the second sub-side 211A2 of the first side 211A in the thickness direction of the flat flow channel 211 are both inclined toward the side of the refrigerant inlet 220, so that the cross section of the flat flow channel 211 changes, and when the fluid turns to flow upward or downward, the area of the flow cross section increases continuously to balance the increase of the path resistance in the flow direction, so that the refrigerant outlets 230 at both ends of the extension direction of the flat flow channel 211 may be distributed to the same size as the refrigerant outlets 230 near the refrigerant inlet 220 A refrigerant.

Since the end cap portion 212 is simple in structure, the variable cross-section flat flow channel in this embodiment is formed by the end cap portion 212, that is, the main body portion 213 is kept unchanged in structure, the shallow groove is equal in thickness a2, the end cap portion 212 is not hollowed at the center, the edge portion is hollowed out to have a thickness a1-a2, and the transition is gradually inclined from the center to the edge, so that the variable cross-section flat flow channel 211 is formed after the variable cross-section flat flow channel is matched with the main body portion 213, as shown in fig. 14 to 19 in particular, so that the structural complexity of the main body portion 213 is avoided from increasing, and the processing and the assembly are facilitated.

Thus, as shown in fig. 14 and 15, after assembly, the thickness of the thinnest part of the flat flow channel 211 is a2, the thickness of the widest part is a1, the total extension length of the flat flow channel 211 is h, the inclination angles of the first sub-side 211a1 and the second sub-side 211a2 are equal and are both α, so that the relationship α =2(a1-a2)/h exists, wherein the angle α is preferably 0.7 ° -2 °.

For further convenience of processing, in the present embodiment, both the axis of the refrigerant inlet 220 and the axis of the refrigerant outlet 230 are perpendicular to the thickness direction second side 211B, i.e., the thickness direction second side 211B is maintained as a vertical plane.

Further, referring to fig. 20 in combination with fig. 14, an arc-shaped recess 240 is formed in the thickness direction second side surface 211B at a position opposite to the refrigerant inlet 220. Specifically, the vertical cross-section of arc depressed part 240 is one section of a circle, the chord length is D, place radius of circle is R, the existence of this arc depressed part 240 makes the more even scattering of the fluid of high-speed incoming flow, simultaneously, sunken curved surface compares with the plane, the curved surface can carry out more effective buffering to the incoming flow under the same speed, be favorable to reducing loss of pressure, be favorable to making fluid shakeout rapidly simultaneously, the existence of camber makes the fluid turn tortuous flow in flat runner 211, as shown in fig. 20, be favorable to fluidic mixing more, further reduce the possibility that takes place gas-liquid phase separation.

In order to reduce the flow resistance caused by the vortex inside the flat tube 100, as shown in fig. 14, 15 and 20, the communication part between the refrigerant outlet 230 and the flat flow channel 211 is in a fillet transition, that is, a fillet is arranged at the inlet end of the refrigerant outlet 230, and the fillet radius r ranges from 0.5 mm to 2 mm.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides an air conditioner, includes many flat pipe parallel flow heat exchangers, its characterized in that, many flat pipe parallel flow heat exchangers include a plurality of flat pipes and be used for with gas-liquid two-phase refrigerant evenly distributed to a plurality of shunt in the flat pipe, the shunt includes:

2. The air conditioner according to claim 1,

the thickness a of the flat flow channel ranges from 1 mm to 3mm, the width b ranges from 10 mm to 22mm, and the length h ranges from 50 mm to 100 mm.

3. The air conditioner according to claim 2,

the length m of the inner contour of the refrigerant outlet ranges from 10 mm to 22mm, and the width n of the inner contour ranges from 1.5 mm to 3 mm.

4. The air conditioner according to claim 1,

the width direction of the inner contour of the refrigerant outlet is parallel to the extending direction of the flat flow channel, the refrigerant outlet and the refrigerant inlet are arranged in a staggered mode, and the two ends of the extending direction of the flat flow channel are correspondingly provided with the refrigerant outlet.

5. The air conditioner according to claim 4,

the refrigerant inlet is opposite to the center of the flat flow channel, and the plurality of refrigerant outlets are arranged at equal intervals along the extension direction of the flat flow channel.

6. The air conditioner according to claim 1,

the side surface of the flat flow channel, which is communicated with the refrigerant inlet, is a first side surface of the flat flow channel in the thickness direction, and the other side surface of the flat flow channel, which is communicated with the refrigerant outlet, is a second side surface of the flat flow channel in the thickness direction;

along the extending direction of the flat flow channel, the first side surface in the thickness direction is composed of a first sub-side surface positioned on one side of the refrigerant inlet and a second sub-side surface positioned on the other side of the refrigerant inlet, and the first sub-side surface and the second sub-side surface are inclined towards the side where the refrigerant inlet is positioned.

7. The air conditioner according to claim 6,

the inclination angles of the first sub-side surface and the second sub-side surface are both 0.7-2 degrees.

8. The air conditioner according to claim 6,

an axis of the refrigerant inlet and an axis of the refrigerant outlet are both perpendicular to the thickness direction second side surface.

9. The air conditioner according to claim 6,

an arc-shaped recess is formed on the thickness direction second side surface at a position opposite to the refrigerant inlet.

10. The air conditioner according to claim 1,

and the communication part of the refrigerant outlet and the flat flow passage is in fillet transition.