WO2018176283A1

WO2018176283A1 - Air conditioner

Info

Publication number: WO2018176283A1
Application number: PCT/CN2017/078651
Authority: WO
Inventors: 杨俊�; 雷华翘
Original assignee: 广东美的制冷设备有限公司; 美的集团股份有限公司
Priority date: 2017-03-29
Filing date: 2017-03-29
Publication date: 2018-10-04

Abstract

Disclosed is an air conditioner (100) comprising: a compressor (1); a diversion component (2), the diversion component (2) having first to fourth valve ports (C-F); an indoor heat exchanger (3), a first end of the indoor heat exchanger (3) being connected to the third valve port (E); an outdoor heat exchanger (4), a first end of the outdoor heat exchanger (4) being connected to the second valve port (D); and a capillary component (6), the capillary component (6) comprising a first capillary, a second capillary (63) and a transition tube (62), wherein a first end of a first capillary (61) is connected to a second end of the indoor heat exchanger (3), a first end of the second capillary (63) is connected to a second end of the outdoor heat exchanger (4), and the transition tube (62) is connected between the first capillary (61) and the second capillary (63).

Description

Air conditioner

Technical field

The invention relates to the field of heat exchange technology, and in particular to an air conditioner.

Background technique

Air conditioners using R290 as a refrigerant, especially heat pump air conditioners, are limited by the amount of charge, and the total capacity of the same section is much smaller than that of air conditioners using other refrigerants. In order to meet the cooling capacity and energy efficiency requirements, such air conditioners must use large displacement compressors and large-area heat exchangers.

When such an air conditioner uses a capillary as a throttling device, when the defrosting is turned into the heating mode, since the temperature at the capillary is lower than the pour point temperature of the lubricating oil of R290 for a long time, the lubricating oil may generate a flocculent flow, in severe cases. Even the capillary is blocked, causing malfunction of the air conditioner, and the reliability of the air conditioner is low.

Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an air conditioner that can prevent the first capillary and the second capillary of the capillary assembly from being clogged, improve the reliability of use of the air conditioner, and reduce the failure rate of the air conditioner.

According to the air conditioner of the embodiment of the invention, the air conditioner uses R290 as a refrigerant, the air conditioner includes: a compressor having an exhaust port and a return air port; a reversing assembly having the reversing assembly a first valve port to a fourth valve port, the first valve port being in communication with one of the second valve port and the third valve port, the fourth valve port and the second valve port and the third valve port The other one of the valve ports is in communication, the first valve port is connected to the exhaust port, the fourth valve port is connected to the air return port; the indoor heat exchanger, the first end of the indoor heat exchanger Connected to the third valve port; an outdoor heat exchanger, the first end of the outdoor heat exchanger is connected to the second valve port; and the capillary assembly includes a first capillary tube, a second capillary tube and a transition a first end of the first capillary is connected to a second end of the indoor heat exchanger, and a first end of the second capillary is connected to a second end of the outdoor heat exchanger a transition tube connected between the second end of the first capillary and the second end of the second capillary; wherein an inner diameter of the transition tube is larger than an inner diameter of the first capillary and the second capillary, The length of the first capillary is not less than the length of the second capillary.

An air conditioner according to an embodiment of the present invention, by causing a capillary assembly to include a first capillary, a second capillary, and a transition tube while making an inner diameter of the transition tube larger than an inner diameter of the first capillary and the second capillary, and making the length of the first capillary not It is smaller than the length of the second capillary tube, so that when the air conditioner defrosting mode ends and is turned into the heating mode, after the refrigerant flows out from the indoor heat exchanger, it is beneficial to ensure that the oil temperature of the lubricating oil in the refrigerant is higher than the pour point thereof. The temperature can avoid the blockage of the first capillary tube and the second capillary tube, reduce the failure rate of the air conditioner, improve the reliability of the use of the air conditioner, and prolong the service life of the air conditioner.

According to some embodiments of the invention, the length of the first capillary is greater than the length of the second capillary.

According to some embodiments of the invention, the length of the first capillary is L, L satisfies: L ≤ 700 mm.

According to some embodiments of the invention, the transition duct is horizontally disposed.

According to some embodiments of the present invention, the inner diameter of the transition tube is d1, the inner diameter of the first capillary tube and the second capillary tube is d2, and the d1 and the d2 satisfy: d1 ≥ 4 mm, d2 ≤ 2.1 mm .

According to some embodiments of the invention, the first capillary, the transition tube and the second capillary are in one piece.

Optionally, the transition tube is a copper tube.

Optionally, the reversing component is a four-way valve.

According to some embodiments of the invention, the air conditioner further includes a reservoir, the reservoir being connected in series between the air return port and the fourth valve port.

The additional aspects and advantages of the invention will be set forth in part in the description which follows.

DRAWINGS

The above and/or additional aspects and advantages of the present invention are described in the following description in conjunction with the accompanying drawings Will become obvious and easy to understand, where:

1 is a schematic view of an air conditioner in accordance with some embodiments of the present invention;

2 is a schematic view of an air conditioner in accordance with further embodiments of the present invention.

Reference mark:

Air conditioner 100;

Compressor 1; housing 11; exhaust port A; return port B; oil pool 12;

Reversing assembly 2; first valve port C; second valve port D; third valve port E; fourth valve port F;

Indoor heat exchanger 3; outdoor heat exchanger 4; heat exchange member 5;

Capillary assembly 6; first capillary 61; transition tube 62; second capillary 63.

detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative of the invention and are not to be construed as limiting.

In the description of the present invention, it is to be understood that the terms "length", "upper", "lower", "left", "right", "horizontal", "top", "bottom", "inside", "outside" The orientation or positional relationship of the "radial" or the like is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience of describing the present invention and the simplified description, and does not indicate or imply that the device or component referred to must have a specific The orientation, construction and operation in a particular orientation are not to be construed as limiting the invention. Furthermore, features defining "first" and "second" may include one or more of the features, either explicitly or implicitly. In the description of the present invention, it should be noted that the terms "connected" and "connected" are to be understood broadly, and may be, for example, a fixed connection, a detachable connection, or an integral, unless otherwise explicitly defined and defined. Ground connection; it can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium, which can be the internal connection of two components. For those skilled in the art, the above terms can be understood in the specific case. The specific meaning of the invention.

An air conditioner 100 according to an embodiment of the present invention may be described below with reference to FIGS. 1-2. The air conditioner 100 may use R290 as a refrigerant, and the air conditioner 100 may be used to adjust an indoor temperature, for example, the air conditioner 100 may be used to heat an indoor environment. Or cooling. Alternatively, the air conditioner 100 may be a heat pump air conditioner, for example, the air conditioner 100 is a heat pump inverter air conditioner.

As shown in FIGS. 1-2, an air conditioner 100 according to an embodiment of the present invention may include a compressor 1, a reversing assembly 2, an indoor heat exchanger 3, an outdoor heat exchanger 4, and a capillary assembly 6.

Specifically, as shown in FIG. 1 to FIG. 2, the compressor 1 includes a housing 11 and a compression mechanism (not shown). The compression mechanism includes a main bearing, a sub-bearing, a crankshaft, a cylinder, and the like, and the compression mechanism is disposed in the housing 1. The casing 11 has an oil pool 12 therein. The oil pool 12 has lubricating oil. When the compression mechanism is in operation, the lubricating oil can lubricate the compression mechanism, thereby improving the reliability of the compression mechanism.

Alternatively, compressor 1 is a low back pressure compressor.

The casing 11 has an exhaust port A and a return air port B, and the heat-exchanged refrigerant can be returned to the compressor through the air return port B, and the refrigerant can be discharged from the exhaust port A after being compressed by the cylinder of the compressor 1.

Here, it can be understood that since the lubricating oil acts to lubricate the operation of the compression mechanism, the refrigerant discharged from the exhaust port A is inevitably mixed with a small amount of lubricating oil. Therefore, the refrigerant herein refers to A refrigerant mixed with a small amount of lubricating oil.

The reversing assembly 2 has a first valve port C to a fourth valve port F, wherein the first valve port C is in communication with one of the second valve port D and the third valve port E, and the fourth valve port F and the The other of the two valve ports D and the third valve port E is in communication communication. In other words, when the first valve port C communicates with the second valve port D, the fourth valve port F communicates with the third valve port E, and when the first valve port C communicates with the third valve port E, the fourth valve port F It is in communication with the second valve port D.

The first port C is connected to the exhaust port A, and the fourth port F is connected to the return port B, thereby connecting the reversing unit 2 to the refrigerant circuit of the air conditioner 100 to facilitate the circulation of the refrigerant.

Preferably, the reversing assembly 2 is a four-way valve. When the reversing assembly 2 is de-energized, the first valve port C is in communication with the second valve port D, and the fourth valve port F is in communication with the third valve port E. When the component 2 is energized, the first valve port C is in communication with the third valve port E, and the fourth valve port F is in communication with the second valve port D. The specific structure and working principle of the four-way valve are well known to those skilled in the art and will not be described in detail herein. However, it will be understood that the reversing assembly 2 can also be formed as other components as long as it has the first to fourth valve ports C to F and can be reversed.

Since the first valve port C of the reversing assembly 2 is reversibly communicated with one of the second valve port D and the third valve port E, the fourth valve port F and the second valve port D and the third valve port E are Another commutation communication is implemented to achieve commutation, which allows the air conditioner 100 to switch between the cooling mode and the heating mode, thereby realizing the cooling function and the heating function of the air conditioner 100.

The first end of the indoor heat exchanger 3 (for example, the left end shown in Figures 1 and 2) is connected to the third valve port E, the first end of the outdoor heat exchanger 4 (for example, shown in Figures 1 and 2) The left end of the outlet is connected to the second valve port D, thereby connecting the indoor heat exchanger 3 and the outdoor heat exchanger 4 in the refrigerant flow path.

The capillary assembly 6 includes a first capillary 61, a second capillary 63, and a transition tube 62, a first end of the first capillary 61 (eg, the lower end shown in FIG. 2) and a second end of the indoor heat exchanger 3 (eg, The right end shown in Figure 2 is connected, the first end of the second capillary 63 (e.g., the upper end shown in Figure 2) and the second end of the outdoor heat exchanger 4 (e.g., the right end shown in Figure 2) Connected, the transition tube 62 is connected between the second end of the first capillary 61 (such as the upper end shown in FIG. 2) and the second end of the second capillary 63 (for example, the lower end shown in FIG. 2), first The capillary 61 and the second capillary 63 are capable of throttling and depressurizing the refrigerant flowing therethrough.

Specifically, as shown in FIG. 1 and FIG. 2, when the air conditioner 100 is in the cooling mode or the defrosting mode, the first port C of the reversing assembly 2 is in communication with the second port D, and the third port E is The fourth valve port F is connected, and the high temperature and high pressure refrigerant compressed by the compressor 1 can flow through the exhaust port A to the first valve port C of the reversing assembly 2, and then the refrigerant passes through the second valve port of the reversing assembly 2. D enters the outdoor heat exchanger 4 and exchanges energy with the external environment in the outdoor heat exchanger 4, and the refrigerant flowing out of the outdoor heat exchanger 4 sequentially flows through the second capillary 63, the transition tube 62, and the first capillary. After entering 61, the indoor heat exchanger 3 is introduced to absorb the heat in the room, and the ambient temperature in the room is lowered. The refrigerant flowing out of the indoor heat exchanger 3 passes through the third valve port E and the fourth valve port F, and passes through the compressor 1 The return port B returns to the compressor 1 to form a system Cold cycle, so as to reciprocate.

As shown in FIG. 1 and FIG. 2, when the air conditioner 100 is in the heating mode, the first valve port C of the reversing assembly 2 is in communication with the third valve port E and the fourth valve port F is in communication with the second valve port D. The high-temperature high-pressure refrigerant compressed by the cylinder of the compressor 1 is discharged from the exhaust port A, then flows through the first port C and the third port E to the indoor heat exchanger 3, and is in the indoor heat exchanger 3 The medium and the indoor environment exchange heat, and the refrigerant after heat exchange with the indoor heat exchanger 3 sequentially flows through the first capillary 61, the transition tube 62 and the second capillary 63, and then enters the outdoor heat exchanger 4, and the refrigerant is exchanged outdoors. The heat exchanger 4 exchanges heat with the outdoor environment, and the refrigerant exchanged with the outdoor heat exchanger 4 flows through the second valve port D and the fourth valve port F, and returns to the compressor through the return port B of the compressor 1. 1. In this way, the heating cycle of the air conditioner 100 is formed.

Specifically, the inner diameter of the transition duct 62 is larger than the inner diameters of the first capillary 61 and the second capillary 63, that is, the inner diameter of the transition duct 62 is larger than the inner diameter of the first capillary 61 and the inner diameter of the transition duct 62 is larger than the inner diameter of the second capillary 63. . For example, the inner diameters of the first capillary 61 and the second capillary 63 are the same, and the inner diameter of the transition tube 62 is larger than the inner diameters of the first capillary 61 and the second capillary 63.

The length of the first capillary 61 is not less than the length of the second capillary 63. That is, the length of the second capillary 63 is not greater than the length of the first capillary 61. For example, the length of the first capillary 61 is greater than the length of the second capillary 63. As another example, the length of the first capillary 61 is equal to the length of the second capillary 63.

Specifically, the inventors found in actual research that the temperature characteristic of the refrigerant in the capillary region is that during the process from the refrigerant entering the capillary to flowing out of the capillary, the temperature of the refrigerant is substantially unchanged first, when the refrigerant is in the capillary. After the internal flow distance reaches a certain distance, the temperature of the refrigerant begins to decrease rapidly (ie, steeply).

An air conditioner according to an embodiment of the present invention replaces one capillary in the related art by using the capillary assembly 6, such that the lengths of the first capillary 61 and the second capillary 63 are both smaller than the length of the one capillary, thereby being 100 in the air conditioner When the frost mode is turned into the heating mode, the refrigerant flows from the first capillary 61 to the transition tube 62, which is advantageous for ensuring that the temperature of the refrigerant in the first capillary 61 is substantially constant, which is advantageous for ensuring refrigeration. The agent enters the transition tube 62 before its temperature drops sharply, so that the temperature of the lubricating oil in the refrigerant is lower than the pour point temperature of the lubricating oil to a certain extent. A floc flow is produced.

To the contrary, even if the temperature of the refrigerant drops steeply in the first capillary 61, the lubricating oil in the refrigerant generates a floc flow in the first capillary 61, since the inner diameter of the transition tube 62 is larger than the first capillary 61 and the second The inner diameter of the capillary 63 is large, so that the floc flow can also flow into the transition tube 62 relatively easily and temporarily stored in the transition tube 62, and since the transition tube 62 does not have the effect of throttling and depressurizing the refrigerant or throttling The effect of the pressure is small (for example, the transition tube 62 is a non-capillary tube), so the temperature of the refrigerant in the transition tube 62 is slightly increased, which helps the temperature of the lubricating oil in the transition tube 62 to rise, thereby making the temperature of the lubricating oil higher than At the pour point temperature, the refrigerant in the transition duct 62 also reduces the risk of the lubricating oil clogging the second capillary 63 as it flows from the transition duct 62 to the second capillary 63.

Further, since the length of the second capillary 63 is not greater than the length of the first capillary 61, the length of the second capillary 63 can be shortened without affecting the throttling and depressurization of the refrigerant, which is advantageous in avoiding refrigerant The lubricating oil generates a floc flow in the second capillary 63, thereby further preventing the second capillary 63 from being clogged.

In short, the air conditioner 100 according to an embodiment of the present invention, by making the capillary assembly 6 include the first capillary 61, the second capillary 63, and the transition tube 62 while making the inner diameter of the transition tube 62 larger than the first capillary 61 and the second The inner diameter of the capillary 63 is such that the length of the first capillary 61 is not less than the length of the second capillary 63, so that after the defrosting mode of the air conditioner 100 ends to the heating mode, after the refrigerant flows out of the indoor heat exchanger 3, It is advantageous to ensure that the oil temperature of the lubricating oil in the refrigerant is higher than the pour point temperature, thereby preventing the first capillary 61 and the second capillary 63 from being clogged, reducing the failure rate of the air conditioner 100, and improving the reliability of the air conditioner 100. Extend the service life of the air conditioner 100.

Preferably, the length of the first capillary 61 is greater than the length of the second capillary 63. Thereby, the length of the second capillary 63 is further limited, the flow distance of the refrigerant in the second capillary 63 is shortened, and the lubricating oil in the refrigerant occludes the second capillary when the defrosting mode of the air conditioner 100 is turned into the heating mode is further reduced. 63 risk.

In order to further prevent the lubricating oil in the refrigerant from clogging the first capillary 61 when the defrosting mode of the air conditioner 100 ends to the heating mode, the length L of the first capillary 61 can be limited to L ≤ 700 mm. Can It is understood that when the length L of the first capillary 61 satisfies: L ≤ 700 mm, the length of the second capillary 63 is also less than or equal to 700 mm and the length of the second capillary 63 is not greater than the length of the first capillary 61. For example, when the length of the first capillary 61 is 690 mm, the length of the second capillary 63 may be 650 mm, 600 mm, or 620 mm or the like. For another example, when the length of the first capillary 61 is 650 mm, the length of the second capillary 63 may be 550 mm, 580 mm or 630 mm. Therefore, it is advantageous to further avoid a phenomenon in which the temperature of the refrigerant drops sharply in the first capillary 61 or the second capillary 63 when the defrosting mode of the air conditioner 100 ends to turn into the heating mode, thereby further preventing the lubricating oil from being formed into a floc flow. .

In some further embodiments of the invention, the transition duct 62 is horizontally disposed. By making the transition duct 62 horizontally disposed, the flow velocity of the refrigerant in the transition duct 62 can be greatly reduced, thereby prolonging the circulation time of the refrigerant in the transition duct 62, which is advantageous for further lubrication of the lubricant in the transition duct 62. The temperature is raised to prevent the flocc flow from clogging the second capillary 63 when the defrosting mode of the air conditioner 100 is turned to the heating mode. Of course, the present invention is not limited thereto, and the transition duct 62 may also be disposed obliquely. For example, the angle between the extending direction of the transition duct 62 and the horizontal plane is α, and α satisfies: 0° < α ≤ 90°, for example, α is 15 °, 20°, 30°, 60° or 45°.

According to some examples of the invention, the inner diameter of the transition duct 62 is d1, and the inner diameters of the first capillary 61 and the second capillary 63 are d2, and d1 and d2 satisfy: d1 ≥ 4 mm, d2 ≤ 2.1 mm. Thus, when the defrosting mode of the air conditioner 100 ends to the heating mode, it is advantageous to further prevent the generation of the floc flow in the first capillary 61 and the second capillary 63, thereby further avoiding the first capillary 61 and the second capillary 63. It is blocked, thereby further reducing the failure rate of the air conditioner 100, improving the reliability of the use of the air conditioner 100, and extending the service life of the air conditioner 100.

Alternatively, d1 ≥ 5.5 mm and d2 ≤ 2.0 mm. Further, d1 ≥ 6 mm and d2 ≤ 1.5 mm. More preferably, d1 ≥ 6 mm, d2 ≤ 1.0 mm.

Alternatively, the first capillary 61, the transition tube 62, and the second capillary 63 are a single piece. Thereby, not only the structure is simple, the production process for the capillary assembly 6 can be simplified, the production cost can be reduced, and the installation process of the capillary assembly 6 in the air conditioner 100 can be simplified.

Preferably, the transition tube 62 is a copper tube. Therefore, it is beneficial to improve the heat exchange efficiency between the copper pipe and the surrounding environment. Thereby the risk of the oil temperature of the lubricating oil at the transition duct 62 being lower than the pour point temperature is further reduced.

Specifically, the cylinder has an exhaust passage and an intake passage, and the intake passage is connected to the return port B. The heat exchanged refrigerant can be returned from the return port B and the intake passage to the cylinder of the compressor 1, and the refrigerant is in the cylinder. After being compressed, a high temperature and high pressure refrigerant can be formed, and the compressor 1 is discharged through the exhaust passage and the exhaust port A in sequence.

As shown in FIG. 1, the air conditioner 100 further includes a heat exchange member 5, and two ends of the heat exchange member 5 are respectively connected to the exhaust port A and the exhaust passage, and the heat exchange member 5 is at least partially immersed in the lubricating oil in the oil pool 12. Therefore, the refrigerant compressed by the cylinder may first flow to the heat exchange member 5 after being discharged from the exhaust passage, and the refrigerant exchanges heat with the lubricating oil in the oil pool 12 in the heat exchange member 5 to heat the lubricating oil, and then The refrigerant discharges the compressor 1 from the exhaust port A.

Thus, regardless of the operating mode of the air conditioner 100, the refrigerant discharged from the exhaust passage of the cylinder first flows through the heat exchange member 5, so that the refrigerant in the heat exchange member 5 can perform the lubricating oil in the oil pool 12. Heating, thereby increasing the oil temperature of the lubricating oil in the oil pool 12, so that when the defrosting mode of the air conditioner 100 ends and changes to the heating mode, the refrigerant flows out of the indoor heat exchanger 3 and flows through the capillary assembly 6 When the capillary 61 and the second capillary 63 are used, it is further ensured that the oil temperature of the lubricating oil mixed in the refrigerant is not lower than the pour point temperature, so that the first capillary 61 and the second capillary 63 can be further prevented from being clogged, further reducing the air conditioner. The failure rate of 100 improves the reliability of the use of the air conditioner 100 and prolongs the service life of the air conditioner 100.

According to the air conditioner 100 of the embodiment of the present invention, the oil in the oil pool 12 is heated by the exhaust of the cylinder, thereby increasing the oil temperature of the lubricating oil, so that the defrosting mode of the air conditioner 100 is turned into the heating mode. When the refrigerant flows out of the indoor heat exchanger 3 and flows through the first capillary 61 and the second capillary 63, it is further ensured that the oil temperature of the lubricating oil mixed in the refrigerant is not lower than the pour point temperature, thereby further The first capillary 61 and the second capillary 63 are prevented from being clogged, the failure rate of the air conditioner 100 is further reduced, the reliability of the use of the air conditioner 100 is improved, and the service life of the air conditioner 100 is prolonged.

Alternatively, the heat exchange member 5 is a heat exchange tube, for example, the heat exchange member 5 is a coil tube, or a flat tube or the like. Of course, it can be understood that the heat exchange member 5 can also be formed into other structures, for example, the heat exchange member 5 is a heat exchanger, as long as The heat exchange member 5 can flow a refrigerant and can realize heat exchange between the refrigerant and the lubricating oil.

Preferably, the heat exchange tube is a copper tube, whereby the heat exchange tube has good thermal conductivity and high heat exchange efficiency.

According to some embodiments of the invention, the air conditioner 100 further includes a reservoir (not shown) that is connected in series between the return port B and the fourth port F. Thereby, the refrigerant after the heat exchange flows out from the fourth valve port F to the accumulator, and the liquid refrigerant flowing into the refrigerant in the accumulator can be stored in the accumulator, and the gaseous refrigerant can pass through The return port B is returned to the compressor 1, which not only facilitates adjustment of the refrigerant flow rate in the refrigerant flow path, but also prevents the compressor 1 from generating a liquid hit phenomenon.

In the description of the present specification, the description of the terms "some embodiments", "example", or "some examples" and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in the present invention. At least one embodiment or example. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined.

Although the embodiments of the present invention have been shown and described, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the invention. The embodiments are subject to variations, modifications, substitutions and variations.

Claims

An air conditioner using R290 as a refrigerant, wherein the air conditioner comprises:

a compressor having an exhaust port and a return air port;

a reversing assembly having a first valve port to a fourth valve port, the first valve port being in communication with one of a second valve port and a third valve port, the fourth valve port being The other of the second valve port and the third valve port is in communication, the first valve port is connected to the exhaust port, and the fourth valve port is connected to the air return port;

An indoor heat exchanger, the first end of the indoor heat exchanger is connected to the third valve port;

An outdoor heat exchanger, the first end of the outdoor heat exchanger being connected to the second valve port;

a capillary assembly comprising a first capillary, a second capillary, and a transition tube, the first end of the first capillary being coupled to the second end of the indoor heat exchanger, the first end of the second capillary Connected to the second end of the outdoor heat exchanger, the transition tube is connected between the second end of the first capillary and the second end of the second capillary;

Wherein the inner diameter of the transition tube is larger than the inner diameters of the first capillary tube and the second capillary tube, and the length of the first capillary tube is not less than the length of the second capillary tube.
The air conditioner according to claim 1, wherein the length of the first capillary is larger than the length of the second capillary.
The air conditioner according to any one of claims 1 to 2, wherein the first capillary has a length L and L satisfies: L ≤ 700 mm.
The air conditioner according to any one of claims 1 to 3, wherein the transition duct is horizontally disposed.
The air conditioner according to any one of claims 1 to 4, wherein an inner diameter of the transition tube is d1, and an inner diameter of the first capillary tube and the second capillary tube is d2, the d1 and the Said d2 Satisfied: d1 ≥ 4mm, d2 ≤ 2.1mm.
The air conditioner according to any one of claims 1 to 5, wherein the first capillary tube, the transition tube, and the second capillary tube are integrally formed.
The air conditioner according to any one of claims 1 to 4, wherein the transition tube is a copper tube.
The air conditioner according to any one of claims 1 to 7, wherein the reversing assembly is a four-way valve.
The air conditioner according to any one of claims 1 to 8, further comprising a reservoir, the reservoir being connected in series between the air return port and the fourth valve port.