Air conditioning system

Abstract

The present application relates to air conditioning technical field, especially a kind of air conditioning system, including heat exchanger and indoor heat exchange unit, heat exchanger includes gas collector, heat exchange tube, liquid collector and supercooling tube, heat exchange tube is vertically arranged, the upper end of heat exchange tube is communicated with gas collector, the lower end of heat exchange tube is communicated with liquid collector, supercooling tube is sleeved on the outside of liquid collector, and supercooling tube is surrounded with liquid collector and is set out heat exchange chamber, supercooling tube is equipped with first pipe opening and second pipe opening communicated with heat exchange chamber, first pipe opening is suitable for heat exchange chamber input refrigerant, second pipe opening is suitable for heat exchange chamber output refrigerant, liquid collector is equipped with connecting pipe, connecting pipe is arranged in supercooling tube and is communicated with liquid collector, connecting pipe is also communicated with indoor heat exchange unit, connecting pipe and indoor heat exchange unit are communicated with the pipeline, and branch pipeline is also communicated with the pipeline, branch pipeline is communicated with first pipe opening, and branch pipeline is equipped with first expansion valve. Avoid the problem that drainage difficulty caused by icing seriously influence microchannel heat exchanger heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more particularly to an air conditioning system. Background Technology

[0002] The stacked microchannel heat exchanger boasts high heat exchange efficiency. When used as a heat pump evaporator, the flat tubes need to be placed vertically or at an angle to ensure that the condensate drains naturally by gravity. The stacked microchannel structure features microchannel manifolds at the top and bottom, with a liquid distribution manifold at the bottom and a gas collection manifold at the top. However, the subcooling section and the microchannel heat exchanger are in surface contact, resulting in poor heat exchange performance. Furthermore, in low outdoor temperatures, the bottom of the heat exchanger is prone to icing, affecting drainage and heat exchange. Moreover, the subcooling section and the microchannel heat exchanger are separate components, leading to higher costs. Summary of the Invention

[0003] This invention provides an air conditioning system to address one of the shortcomings of the prior art. In heating mode, the subcooling pipe can further raise the temperature at the bottom of the heat exchanger where the liquid collection pipe is located, preventing water vapor in the air from condensing and freezing at the bottom of the heat exchanger in a low-temperature environment. This avoids drainage difficulties caused by icing, and the problem that the ice layer gradually increases over time, seriously affecting the heat exchange efficiency of the microchannel heat exchanger.

[0004] The present invention provides an air conditioning system, including a heat exchanger and an indoor heat exchange unit. The heat exchanger includes a gas collecting pipe, a heat exchange tube, a liquid collecting pipe, and a subcooling pipe. The heat exchange tube is arranged vertically, with its upper end communicating with the gas collecting pipe and its lower end communicating with the liquid collecting pipe. The subcooling pipe is sleeved on the outside of the liquid collecting pipe, and a heat exchange cavity is formed between the subcooling pipe and the liquid collecting pipe. The subcooling pipe has a first port and a second port that communicate with the heat exchange cavity. The first port is suitable for inputting refrigerant into the heat exchange cavity, and the second port is suitable for outputting refrigerant from the heat exchange cavity. The liquid collecting pipe is provided with a connecting pipe, which passes through the subcooling pipe and is connected to the liquid collecting pipe. The connecting pipe is also connected to the indoor heat exchange unit. A branch pipe is also connected to the connecting pipe and the indoor heat exchange unit. The branch pipe is connected to the first pipe opening and is provided with a first expansion valve.

[0005] According to an air conditioning system provided by the present invention, a liquid pipe shut-off valve is provided on the pipe connecting the connecting pipe to the indoor heat exchange unit, and a liquid receiver is also provided on the pipe between the connecting pipe and the liquid pipe shut-off valve. A branch pipe is connected to the pipe connecting the liquid receiver and the liquid pipe shut-off valve. When the volume of the heat exchanger of the outdoor unit of the air conditioning system is smaller than the volume of the heat exchanger of the indoor unit, a small amount of refrigerant can easily cause high pressure in the heat exchanger during cooling mode, but insufficient refrigerant can easily occur during heating mode, resulting in poor heat exchange performance. To solve this problem, a liquid receiver needs to be added to achieve refrigerant balance.

[0006] According to an air conditioning system provided by the present invention, a second expansion valve is provided on the pipeline connecting the connecting pipe and the liquid receiver. The second expansion valve can reduce the pressure of the high-pressure liquid refrigerant, turning it into a low-pressure liquid refrigerant. Furthermore, by adjusting the opening of the second expansion valve, the flow rate of refrigerant entering or leaving the liquid receiver pipe is ensured to be appropriate, avoiding excessive or insufficient flow. Since the second expansion valve can control the flow rate of refrigerant entering the liquid receiver pipe, it can also control the subcooling of the refrigerant entering the heat exchanger tube, ensuring that the refrigerant is at an appropriate temperature before entering the heat exchanger.

[0007] An air conditioning system according to the present invention further includes a gas-liquid separator, wherein the second pipe port is connected to the inlet of the gas-liquid separator. After the refrigerant in the heat exchange chamber of the subcooling pipe exchanges heat with the refrigerant in the liquid collection pipe, it is discharged into the gas-liquid separator to ensure the refrigerant balance of the air conditioning system.

[0008] According to an air conditioning system provided by the present invention, the subcooling pipe is provided with a through hole, and the heat exchange pipe passes through the through hole to communicate with the liquid collection pipe inserted therein. The subcooling pipe is provided with a through hole for connection with the heat exchange pipe, which maximizes the area of ​​the subcooling pipe surrounding the liquid collection pipe, ensuring the sealing of the heat exchange chamber and the heat exchange area with the liquid collection pipe.

[0009] According to an air conditioning system provided by the present invention, a side plate is provided around the heat exchange tube between the air collecting pipe and the liquid collecting pipe. The side plate enhances the rigidity and structural stability of the entire heat exchanger, prevents deformation during transportation and installation, and protects the internal heat exchange tube from external physical damage. The design of the side plate can guide air to be evenly distributed across the entire surface of the heat exchanger, improving the heat exchange efficiency between air and refrigerant.

[0010] According to an air conditioning system provided by the present invention, a first temperature sensor is provided at the first pipe opening and a second temperature sensor is provided at the second pipe opening.

[0011] According to an air conditioning system provided by the present invention, the heat exchange tube is a microchannel flat tube, and the surface of the microchannel flat tube is provided with fins. The microchannel flat tube contains many tiny channels, which increase the contact area between the refrigerant and the fins, thereby improving the heat exchange efficiency.

[0012] An air conditioning system according to the present invention further includes a compressor and a four-way valve, the four-way valve being adapted to switch between a cooling state and a heating state; In the refrigeration state, the compressor, the gas collecting pipe, the connecting pipe, the liquid receiver, the indoor heat exchange unit, and the gas-liquid separator are connected in sequence to form a refrigeration circuit, wherein the liquid receiver and the liquid distributor are also connected by a cold pipe to form a branch. In the heating state, the compressor, the indoor heat exchange unit, the connecting pipe, the gas collecting pipe, and the gas-liquid separator are connected in sequence to form a heating circuit, wherein the liquid receiver and the liquid distributor are also connected by a cold pipe to form a branch.

[0013] The heat exchanger of this invention can solve the problem of ice formation at the bottom of the stacked microchannel evaporator, and also solve the problem of refrigerant imbalance during cooling and heating in microchannel heat exchangers. By setting a subcooling pipe outside the liquid collecting pipe, a large contact area between the liquid collecting pipe and the subcooling pipe is ensured, thereby effectively solving the problem of ice formation at the bottom of the heat exchanger when used as an evaporator.

[0014] According to an air conditioning system provided by the present invention, the indoor heat exchange unit includes multiple indoor heat exchangers connected in parallel. Each indoor heat exchanger can be controlled independently, adjusting the temperature according to the actual needs of its respective room or area. Users can individually turn on or off the air conditioning in a specific room as needed, achieving zoned control and improving energy efficiency. The parallel indoor heat exchangers can evenly distribute the total load of the system, avoiding overload of individual heat exchangers. The air conditioning system can dynamically adjust the refrigerant flow according to the load of each room, ensuring that each heat exchanger operates under optimal conditions.

[0015] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The air conditioning system of this invention mainly consists of a heat exchanger and an indoor heat exchange unit. The heat exchanger mainly consists of a gas collecting pipe, a heat exchange tube, a liquid collecting pipe, and a subcooling pipe. The heat exchange tube is vertically arranged, with its upper end inserted into the gas collecting pipe and its lower end inserted into the liquid collecting pipe. The refrigerant exchanges heat with the external environment or other media inside the heat exchange tube to achieve the effect of cooling or heating. The gas collecting pipe is located at the top of the heat exchanger and is connected to the upper end of the heat exchange tube. It can collect the gaseous refrigerant formed after heat exchange through the heat exchange tube. The liquid collecting pipe is located at the bottom of the heat exchanger and is connected to the lower end of the heat exchange tube. Under the influence of gravity, the liquid refrigerant can automatically flow downward along the direction of the heat exchange tube into the liquid collecting pipe. Therefore, the liquid collecting pipe can collect the liquid refrigerant formed after condensation through the heat exchange tube.

[0016] The subcooling tube is sleeved on the outside of the liquid collecting tube, and a closed heat exchange chamber is formed between the inner wall of the subcooling tube and the outer wall of the liquid collecting tube. The subcooling tube is provided with a first port and a second port. The refrigerant enters the heat exchange chamber through the first port of the subcooling tube, exchanges heat with the liquid refrigerant in the liquid collecting tube, and then flows out from the second port of the subcooling tube.

[0017] By installing a subcooling pipe around the outside of the collecting pipe, the subcooling pipe completely encloses the collecting pipe, forming a closed heat exchange cavity. This effectively increases the contact area between the refrigerant and the collecting pipe within the heat exchange cavity, improving heat exchange efficiency and ensuring efficient system operation. Simultaneously, in heating mode, the subcooling pipe further raises the temperature at the bottom of the heat exchanger where the collecting pipe is located, preventing moisture in the air from condensing and freezing at the bottom of the heat exchanger in a low-temperature environment. This avoids drainage difficulties caused by icing, and prevents the ice layer from gradually increasing in height over time, which severely affects the heat exchange efficiency of the microchannel heat exchanger.

[0018] In existing heat exchangers, the subcooling section and the heat exchanger are usually two separate components, which occupy a large amount of space, have complex piping connections, and have high assembly costs. However, this invention integrates the subcooling pipe and the liquid collection pipe into one unit, which effectively reduces the floor space, simplifies the device composition and piping connections, and reduces costs.

[0019] The connecting pipe is the first connecting pipe. One end of the first connecting pipe is connected to the liquid collecting pipe, and the other end passes through the subcooling pipe and is connected to the first pipe opening through a pipeline. The liquid collecting pipe is connected to the first pipe opening of the heat exchange chamber through the first connecting pipe and the pipeline. In the cooling state, the refrigerant in the liquid collecting pipe flows out of the first connecting pipe into the pipeline and is divided into two paths. One path enters the indoor heat exchange unit, and the other path enters the heat exchange chamber of the subcooling pipe through the first pipe opening via a branch pipe. In the heating state, the refrigerant in the indoor heat exchange unit enters the pipeline and is divided into two paths. One path directly enters the liquid collecting pipe through the first connecting pipe, and the other path enters the heat exchange chamber of the subcooling pipe through the first pipe opening via a branch pipe. Regardless of whether it is in the cooling or heating state, the refrigerant in the heat exchange chamber is discharged from the second pipe opening.

[0020] In cooling mode, the gaseous refrigerant in the gas collector pipe enters the heat exchange pipe. After exchanging heat with the external environment or medium through the heat exchange pipe, it cools into liquid refrigerant and enters the liquid collector pipe. A portion of the refrigerant in the liquid collector pipe enters the indoor heat exchange unit. Before entering the indoor heat exchange unit, a portion of the refrigerant is also transported through a branch pipe into the heat exchange chamber of the subcooling pipe. At this time, the refrigerant in the liquid collector pipe exchanges heat with the refrigerant in the heat exchange chamber. After completing secondary cooling, the refrigerant in the heat exchange chamber flows to the downstream heat exchange unit through the second pipe port. By adjusting the opening of the first expansion valve on the branch pipe, the refrigerant flow rate into the subcooling pipe and the indoor heat exchange unit is adjusted, ensuring that the air conditioning system operates at its optimal cooling point.

[0021] In heating mode, part of the liquid refrigerant entering the indoor heat exchanger unit enters the liquid collector through the first connecting pipe, and the other part enters the heat exchange chamber of the subcooling pipe through the branch pipe and then the first inlet. At this time, the refrigerant in the liquid collector exchanges heat with the refrigerant in the heat exchange chamber. After the refrigerant in the liquid collector is heated, it enters the heat exchanger and exchanges heat with the external environment or medium through the heat exchanger, becoming gaseous refrigerant that enters the gas collector. The flow rate of refrigerant entering the subcooling pipe and the liquid collector is controlled by adjusting the opening of the first expansion valve on the branch pipe. When the heat exchanger acts as an evaporator to extract heat from the environment, the first expansion valve is closed, so the temperature of the liquid collector is low and does not affect the heat obtained by the evaporator. When ice forms at the bottom of the heat exchanger, affecting drainage, the opening of the first expansion valve can be adjusted to allow the high-temperature, high-pressure refrigerant to heat the liquid collector, preventing ice from forming at the bottom of the heat exchanger, solving the drainage problem, and improving the heat exchange efficiency of the heat exchanger.

[0022] The liquid collecting pipe and the subcooling pipe are designed in an inner and outer nested manner. At the same time, the heat exchange refrigerant in the liquid collecting pipe and the subcooling pipe is supplied and diverted through the liquid pipe shut-off valve and branch pipes. This ensures that the refrigerant in the liquid collecting pipe and the subcooling pipe is the internal refrigerant of the system, without the need to add new media for heat exchange. The liquid collecting pipe and the subcooling pipe are effectively combined, and the cooling and heating capacity of the refrigerant in the heat exchanger is fully utilized in the cooling and heating process to achieve subcooling and heating effects, further simplifying the composition of the device and the pipeline connection relationship.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the heat exchanger provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the air conditioning system provided in an embodiment of the present invention.

[0026] Figure label: 100. Gas collecting pipe; 110. Second connecting pipe; 200, heat exchange tube; 210, side plate; 220, fins; 300. Liquid collecting pipe; 310. First connecting pipe; 400, Subcooling tube; 410, Heat exchange chamber; 420, First tube opening; 430, Second tube opening; 510. First expansion valve; 520. Second expansion valve; 600. Liquid shut-off valve; 610. Branch line; 620. Liquid reservoir; 700, Indoor heat exchange unit; 800, Compressor; 900, Gas-liquid separator; 1000, Four-way valve. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0030] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] like Figure 1 As shown, the air conditioning system provided in this embodiment of the invention includes a heat exchanger and an indoor heat exchange unit 700. The heat exchanger includes a gas collecting pipe 100, a heat exchange pipe 200, a liquid collecting pipe 300, and a subcooling pipe 400. The heat exchange pipe 200 is vertically arranged, with its upper end connected to the gas collecting pipe 100 and its lower end connected to the liquid collecting pipe 300. The subcooling pipe 400 is sleeved on the outside of the liquid collecting pipe 300, and a heat exchange cavity 410 is formed between the subcooling pipe 400 and the liquid collecting pipe 300. The subcooling pipe 400 is connected to the heat exchange cavity 410. The first port 420 and the second port 430 are connected. The first port 420 is suitable for inputting refrigerant into the heat exchange chamber 410, and the second port 430 is suitable for outputting refrigerant into the heat exchange chamber 410. The liquid collection pipe 300 is provided with a connecting pipe, which passes through the subcooling pipe 400 and is connected to the liquid collection pipe 300. The connecting pipe is also connected to the indoor heat exchange unit 700. The connecting pipe is connected to the indoor heat exchange unit 700 and is also connected to a branch pipe 610. The branch pipe 610 is connected to the first port 420 and is provided with a first expansion valve 510.

[0033] The air conditioning system of this invention mainly consists of a heat exchanger and an indoor heat exchange unit 700. The heat exchanger mainly consists of a gas collecting pipe 100, a heat exchange tube 200, a liquid collecting pipe 300, and a subcooling pipe 400. The heat exchange tube 200 is vertically arranged, with its upper end inserted into the gas collecting pipe 100 and its lower end inserted into the liquid collecting pipe 300. The refrigerant exchanges heat with the external environment or other media in the heat exchange tube 200 to achieve the effect of cooling or heating. The gas collecting pipe 100 is located at the top of the heat exchanger and is connected to the upper end of the heat exchange tube 200. It can collect the gaseous refrigerant formed after heat exchange in the heat exchange tube 200. The liquid collecting pipe 300 is located at the bottom of the heat exchanger and is connected to the lower end of the heat exchange tube 200. Under the influence of gravity, the liquid refrigerant can automatically flow downward along the direction of the heat exchange tube 200 into the liquid collecting pipe 300. Therefore, the liquid collecting pipe 300 can collect the liquid refrigerant formed after condensation in the heat exchange tube 200.

[0034] A subcooling pipe 400 is sleeved on the outside of the liquid collecting pipe 300. A closed heat exchange chamber 410 is formed between the inner wall of the subcooling pipe 400 and the outer wall of the liquid collecting pipe 300. The subcooling pipe 400 is provided with a first port 420 and a second port 430. The refrigerant enters the heat exchange chamber 410 through the first port 420 of the subcooling pipe 400, exchanges heat with the liquid refrigerant in the liquid collecting pipe 300, and then flows out from the second port 430 of the subcooling pipe 400.

[0035] By installing a subcooling pipe 400 around the outside of the collecting pipe 300, the subcooling pipe 400 completely encloses the collecting pipe 300, forming a closed heat exchange cavity 410. This effectively increases the contact area between the refrigerant and the collecting pipe 300 in the heat exchange cavity 410, improving heat exchange efficiency and ensuring efficient system operation. Simultaneously, in heating mode, the subcooling pipe 400 further raises the temperature at the bottom of the heat exchanger where the collecting pipe 300 is located, preventing water vapor in the air from condensing and freezing at the bottom of the heat exchanger in a low-temperature environment. This avoids drainage difficulties caused by icing, and prevents the ice layer from gradually increasing in height over time, which seriously affects the heat exchange efficiency of the microchannel heat exchanger.

[0036] In existing heat exchangers, the subcooling section and the heat exchanger are usually two separate components, which occupy a large amount of space, have complex piping connections, and have high assembly costs. However, this invention integrates the subcooling pipe 400 and the liquid collecting pipe 300 into one unit, which effectively reduces the floor space, simplifies the device composition and piping connections, and reduces costs.

[0037] The connecting pipe is a first connecting pipe 310. One end of the first connecting pipe 310 is connected to the liquid collecting pipe 300, and the other end passes through the subcooling pipe 400 and is connected to the first pipe port 420 through a pipeline. The liquid collecting pipe 300 and the first pipe port 420 of the heat exchange chamber 410 are connected through the first connecting pipe 310 and the pipeline. In the cooling state, the refrigerant in the liquid collecting pipe 300 flows out of the first connecting pipe 310 and is divided into two paths after entering the pipeline. One path enters the indoor heat exchange unit 700, and the other path enters the heat exchange chamber 410 of the subcooling pipe 400 through the first pipe port 420 via the branch pipe 610. In heating mode, the refrigerant in the indoor heat exchange unit 700 enters the pipeline and is divided into two paths. One path goes directly from the first connecting pipe 310 into the liquid collection pipe 300, and the other path enters the heat exchange chamber 410 of the subcooling pipe 400 through the branch pipe 610 from the first pipe port 420. Regardless of whether it is in cooling or heating mode, the refrigerant in the heat exchange chamber 410 is discharged from the second pipe port 430.

[0038] In cooling mode, the gaseous refrigerant in the gas collector pipe 100 enters the heat exchange pipe 200. After exchanging heat with the external environment or medium through the heat exchange pipe 200, it is cooled into liquid refrigerant and enters the liquid collector pipe 300. A portion of the refrigerant in the liquid collector pipe 300 enters the indoor heat exchange unit 700. Before entering the indoor heat exchange unit 700, a portion of the refrigerant is also transported through the branch pipe 610 into the heat exchange chamber 410 of the subcooling pipe 400. At this time, the refrigerant in the liquid collector pipe 300 exchanges heat with the refrigerant in the heat exchange chamber 410. After completing secondary cooling, the refrigerant in the heat exchange chamber 410 flows to the downstream heat exchange unit through the second pipe port 430. By adjusting the opening of the first expansion valve 510 on the branch pipe 610, the refrigerant flow rate into the subcooling pipe 400 and the indoor heat exchange unit 700 is adjusted, so that the air conditioning system operates at the optimal cooling point.

[0039] In heating mode, part of the liquid refrigerant entering the indoor heat exchanger unit 700 enters the liquid collection pipe 300 through the first connecting pipe 310, and the other part enters the heat exchange chamber 410 of the subcooling pipe 400 through the branch pipe 610 into the first pipe port 420. At this time, the refrigerant in the liquid collection pipe 300 exchanges heat with the refrigerant in the heat exchange chamber 410. After the refrigerant in the liquid collection pipe 300 is heated, it enters the heat exchange pipe 200. After exchanging heat with the external environment or medium through the heat exchange pipe 200, it is heated into gaseous refrigerant and enters the gas collection pipe 100. By adjusting the opening of the first expansion valve 510 on the branch pipe 610, the flow rate of refrigerant entering the subcooling pipe 400 and the liquid collecting pipe 300 is controlled. When the heat exchanger acts as an evaporator to extract heat from the environment, the first expansion valve 510 is closed, so the temperature of the liquid collecting pipe 300 is low and does not affect the heat obtained by the evaporator. When ice forms at the bottom of the heat exchanger, affecting drainage, the opening of the first expansion valve 510 can be adjusted to allow the high-temperature and high-pressure refrigerant to heat the liquid collecting pipe 300, so that the bottom of the heat exchanger will not freeze, thus solving the drainage problem and improving the heat exchange efficiency of the heat exchange tube 200.

[0040] The liquid collecting pipe 300 and the subcooling pipe 400 are designed to be nested inside and outside. At the same time, the heat exchange refrigerant of the liquid collecting pipe 300 and the subcooling pipe 400 is supplied and diverted through the liquid pipe shut-off valve 600 and the branch pipe 610. This makes the refrigerant in the liquid collecting pipe 300 and the subcooling pipe 400 the internal refrigerant of the system. There is no need to add new media for heat exchange. The liquid collecting pipe 300 and the subcooling pipe 400 are effectively combined. During the cooling and heating process, the cold and heat capacity of the refrigerant in the heat exchanger is fully utilized to achieve the subcooling and heating effects, and further simplifies the composition of the device and the connection of the pipeline.

[0041] According to one embodiment of the present invention, a liquid pipe shut-off valve 600 is provided on the pipe connecting the connecting pipe to the indoor heat exchange unit 700, and a liquid receiver 620 is also provided on the pipe between the connecting pipe and the liquid pipe shut-off valve 600. A branch pipe 610 is connected to the pipe connecting the liquid receiver 620 and the liquid pipe shut-off valve 600. In this embodiment, when the volume of the heat exchanger of the outdoor unit of the air conditioning system is smaller than the volume of the heat exchanger of the indoor heat exchange unit 700, a small amount of refrigerant can easily cause high pressure in the heat exchanger during cooling mode, but insufficient refrigerant is easily caused during heating mode, resulting in poor heat exchange effect. To solve this problem, a liquid receiver 620 needs to be added to achieve refrigerant balance.

[0042] In this embodiment, the connecting pipe is a first connecting pipe 310. A liquid receiver 620 is installed on the pipe connecting the first connecting pipe 310 and the liquid pipe shut-off valve 600. That is, the first connecting pipe 310 is connected to the first liquid inlet of the liquid receiver 620, and the second liquid inlet of the liquid receiver 620 is connected to the liquid pipe shut-off valve 600. In the cooling state, the refrigerant flowing out of the liquid collector 300 first enters the liquid receiver 620, and the refrigerant flowing out of the liquid receiver 620 is then diverted through the branch pipe 610. In the heating state, the refrigerant flowing out of the liquid pipe shut-off valve 600 is first diverted through the branch pipe 610 and then enters the liquid receiver 620. The refrigerant flowing out of the liquid receiver 620 then enters the liquid collector 300 through the first connecting pipe 310.

[0043] In this embodiment, the liquid reservoir 620 may be a high-pressure liquid reservoir 620.

[0044] According to one embodiment of the present invention, a second expansion valve 520 is provided on the pipeline connecting the connecting pipe and the liquid receiver 620. In this embodiment, the connecting pipe is a first connecting pipe 310. In the cooling state, the refrigerant in the liquid collector 300 flows into the pipeline through the first connecting pipe 310, passes through the second expansion valve 520 on the pipeline, and then enters the liquid receiver 620. In the heating state, the refrigerant in the liquid receiver 620 flows into the first connecting pipe 310 after passing through the second expansion valve 520 on the pipeline, and then enters the liquid collector 300.

[0045] The second expansion valve 520 can reduce the pressure of high-pressure liquid refrigerant, turning it into low-pressure liquid refrigerant. Furthermore, by adjusting the opening of the second expansion valve 520, it ensures that the refrigerant flow rate into or out of the liquid collector 300 is appropriate, avoiding excessive or insufficient flow. Since the second expansion valve 520 can control the refrigerant flow rate into the liquid collector 300, it can also control the subcooling of the refrigerant entering the heat exchange tube 200, ensuring that the refrigerant is at an appropriate temperature before entering the heat exchanger. By precisely controlling the refrigerant flow rate into the heat exchanger, the second expansion valve 520 can prevent icing problems caused by excessively low temperatures at the bottom of the heat exchanger. By adjusting the refrigerant flow rate, the second expansion valve 520 ensures that the refrigerant in the system remains balanced when switching between cooling and heating modes, avoiding system performance degradation due to uneven refrigerant distribution. It also helps maintain pressure balance in the system, reducing system instability caused by pressure fluctuations.

[0046] According to one embodiment of the present invention, the air conditioning system further includes a gas-liquid separator 900, and a second port 430 is connected to the inlet of the gas-liquid separator 900. In this embodiment, after the refrigerant in the heat exchange chamber 410 of the subcooling pipe 400 exchanges heat with the refrigerant in the liquid collection pipe 300, it is discharged into the gas-liquid separator 900, ensuring the refrigerant balance of the air conditioning system.

[0047] According to one embodiment of the present invention, the subcooling pipe 400 is provided with a through hole, through which the heat exchange pipe 200 passes to communicate with the liquid collecting pipe 300. In this embodiment, the subcooling pipe 400 is provided with a through hole, the size and distribution of which are adapted to the heat exchange pipe 200. Each heat exchange pipe 200 corresponds to one through hole, and the lower end of the heat exchange pipe 200 passes through the through hole to enter the liquid collecting pipe 300. The subcooling pipe 400 is provided with a through hole for connection with the heat exchange pipe 200, maximizing the area of ​​the subcooling pipe 400 surrounding the liquid collecting pipe 300, ensuring the sealing of the heat exchange chamber 410 and the heat exchange area with the liquid collecting pipe 300.

[0048] According to one embodiment of the present invention, the second port 430 of the subcooling pipe 400 is connected to the liquid line shut-off valve 600. In this embodiment, the second port 430 of the subcooling pipe 400 is connected to the downstream unit via a pipeline, and the liquid line shut-off valve 600 is installed on the pipeline.

[0049] The refrigerant flow rate through the piping can be controlled by the liquid line shut-off valve 600, ensuring efficient system operation under various conditions. During system maintenance or component replacement, closing the liquid line shut-off valve 600 can isolate a portion of the system to prevent refrigerant leakage. After system installation or repair, pressure testing can be performed by closing the liquid line shut-off valve 600 to check the system's sealing. In case of system malfunction, closing the liquid line shut-off valve 600 can isolate the faulty section, helping to quickly locate the problem.

[0050] According to one embodiment of the present invention, a side plate 210 is provided around the heat exchange tube 200 between the gas collecting pipe 100 and the liquid collecting pipe 300. In this embodiment, the top of the heat exchanger is the gas collecting pipe 100, the bottom of the heat exchanger is the liquid collecting pipe 300, and the middle part of the heat exchanger is the heat exchange tube 200. The side plate 210 is provided around the outside of all the heat exchange tubes 200, and the side plate 210 is located between the gas collecting pipe 100 and the liquid collecting pipe 300.

[0051] The side plate 210 enhances the rigidity and structural stability of the entire heat exchanger, preventing deformation during transportation and installation. It also protects the internal heat exchange tubes 200 from external physical damage. The design of the side plate 210 guides air to be evenly distributed across the entire heat exchanger surface, improving the heat exchange efficiency between air and refrigerant. A well-designed side plate 210 reduces turbulence in airflow, lowers wind resistance, and improves the overall performance of the system. The side plate 210 is removable, facilitating the disassembly and maintenance of internal components when needed.

[0052] The side plate 210 is typically made of high-strength metal materials (such as aluminum alloy), possessing good corrosion resistance and mechanical strength. The side plate 210 is securely connected to the heat exchange tube 200, gas collecting pipe 100, and liquid collecting pipe 300 via welding, bolting, or other fixing methods, ensuring the structural stability of the entire heat exchanger. Sealing gaskets or sealant are typically used at the connection points between the side plate 210 and the gas collecting pipe 100 and liquid collecting pipe 300 to ensure a tight seal. The side plate 210 may be designed with guide channels or guide plates to guide airflow along a predetermined path, reducing turbulence and wind resistance.

[0053] According to one embodiment of the present invention, a first temperature sensor is provided at the first pipe port 420, and a second temperature sensor is provided at the second pipe port 430. The first and second temperature sensors can monitor the refrigerant temperature entering and exiting the subcooling pipe 400 in real time, so that during the cooling or heating process, the opening of the first expansion valve 510 can be adjusted according to the detected refrigerant temperature to ensure the heat exchange effect between the subcooling pipe 400 and the liquid collecting pipe 500, as well as the refrigerant flow and pressure balance of the air conditioning system.

[0054] According to one embodiment of the present invention, the heat exchange tube 200 is a microchannel flat tube, and the surface of the microchannel flat tube is provided with fins 220. In this embodiment, the heat exchange tube 200 is a microchannel flat tube, thereby forming a stacked microchannel heat exchanger. Fins 220 are provided on both sides of the microchannel flat tube, and the microchannel flat tube and the fins 220 are combined to form an external heat exchange structure.

[0055] Microchannel flat tubes contain numerous tiny channels that increase the contact area between the refrigerant and the fins 220, thereby improving heat exchange efficiency. The thinner walls of microchannel flat tubes reduce thermal resistance, making heat transfer more efficient. The design of microchannel flat tubes significantly reduces the size and weight of the heat exchanger, making them suitable for applications with limited space. Microchannel flat tubes are typically manufactured using lightweight materials such as aluminum alloys, further reducing the weight of the heat exchanger.

[0056] The multiple channels inside the microchannel flat tube ensure that the refrigerant is evenly distributed inside the heat exchanger, avoiding local overheating or undercooling. The multi-channel design helps optimize the refrigerant flow field, reduce flow resistance, and improve the overall performance of the system.

[0057] The fins 220 significantly increase the heat exchange area between air and refrigerant by increasing the surface area, thereby improving heat exchange efficiency. The design of the fins 220 is typically optimized for fluid dynamics and heat transfer to ensure efficient heat transfer as air passes through them, reducing turbulence, lowering wind resistance, and improving overall system performance. The fins 220 can guide air to be evenly distributed across the entire heat exchanger surface, avoiding a decrease in heat exchange efficiency caused by uneven local airflow.

[0058] According to one embodiment of the present invention, the air conditioning system further includes a compressor 800 and a four-way valve 1000. The four-way valve 1000 is adapted to switch between a cooling state and a heating state. In the cooling state, the compressor 800, the gas collection pipe 100, the connecting pipe, the liquid receiver 620, the indoor heat exchange unit 700, and the gas-liquid separator 900 are sequentially connected to form a cooling circuit. The liquid receiver 620 and the liquid distributor are also connected by a cold pipe 400 to form a branch. In the heating state, the compressor 800, the indoor heat exchange unit 700, the connecting pipe, the gas collection pipe 100, and the gas-liquid separator 900 are sequentially connected to form a heating circuit. The liquid receiver 620 and the liquid distributor are also connected by a cold pipe 400 to form a branch.

[0059] In this embodiment, the air conditioning system mainly consists of a heat exchanger, an indoor heat exchange unit 700, a compressor 800, a gas-liquid separator 900, and a four-way valve 1000. By changing the port connection of the four-way valve 1000, the air conditioning system can switch between cooling and heating states.

[0060] In the air conditioning system of this embodiment, the gas collection pipe 100 is connected to a second connecting pipe 110, and the second connecting pipe 110 is connected to the air conditioning system at one end as a heat exchanger, while the second port 430 on the subcooling pipe 400 is connected to the air conditioning system at the other end as a heat exchanger. This provides a suitable refrigerant for the cooling and heating processes of the air conditioner.

[0061] The heat exchanger of this invention can solve the problem of ice formation at the bottom of the stacked microchannel evaporator, and also solve the problem of refrigerant imbalance during cooling and heating in the microchannel heat exchanger. By setting a subcooling pipe 400 outside the liquid collecting pipe 300, a large contact area between the liquid collecting pipe 300 and the subcooling pipe 400 is ensured, thereby effectively solving the problem of ice formation at the bottom of the heat exchanger when used as an evaporator.

[0062] In cooling mode, the refrigerant is pressurized and discharged from the compressor 800. After entering the gas collecting pipe 100 through the second connecting pipe 110, it is distributed to each microchannel flat tube. After heat exchange and cooling with the outside environment in the microchannel flat tube, the refrigerant enters the liquid collecting pipe 300. After passing through the first connecting pipe 310 and the second expansion valve 520 of the liquid collecting pipe 300, it enters the liquid receiver 620 through the first liquid inlet. Then, it is divided into two paths from the second liquid inlet of the liquid receiver 620. One path passes through the liquid pipe shut-off valve 600 and enters... The refrigerant enters the indoor heat exchanger unit 700, and after heat exchange in the indoor heat exchanger unit 700, it enters the gas-liquid separator 900. After gas-liquid separation, it returns to the compressor 800. Another path goes through the first expansion valve 510 of the branch pipe 610, and through the first pipe port 420 into the heat exchange chamber 410 of the subcooling pipe 400. At this time, the refrigerant in the subcooling pipe 400 exchanges heat with the refrigerant in the liquid collection pipe 300, and then is discharged into the gas-liquid separator 900 through the second pipe port 430. After gas-liquid separation, it returns to the compressor 800.

[0063] In heating mode, the refrigerant is pressurized in the compressor 800 and discharged to the indoor heat exchange unit 700. The refrigerant flows out of the liquid pipe shut-off valve 600 from the indoor heat exchange unit 700 and then splits into two paths. One path enters the liquid receiver 620 through the second liquid inlet. After passing through the first liquid inlet and the second expansion valve 520 of the liquid receiver 620, it enters the liquid collector 300 through the first connecting pipe 310. After passing through the liquid collector 300, it is distributed to the microchannel flat tube. After exchanging heat with the outside in the microchannel flat tube and being heated, the refrigerant enters the gas collector 100. After passing through the second connecting pipe 110 of the gas collector 100, it enters the gas-liquid separator 900. After gas-liquid separation, it returns to the compressor 800. Another route is through branch pipe 610, then through the first expansion valve 510, and into the heat exchange chamber 410 of subcooling pipe 400 through the first pipe port 420. At this time, the high temperature and high pressure refrigerant in subcooling pipe 400 heats the liquid collection pipe 300. Then the refrigerant enters the gas-liquid separator 900 through the second pipe port 430. After gas-liquid separation, it returns to compressor 800.

[0064] When the volume of the heat exchanger in the outdoor unit of an air conditioning system is smaller than that in the indoor unit, a small amount of refrigerant can easily cause high pressure in the microchannel heat exchanger during cooling. However, insufficient refrigerant during heating results in poor heat exchange performance. To solve this problem, a high-pressure liquid receiver 620 needs to be added to the system to achieve refrigerant balance.

[0065] According to one embodiment of the present invention, an indoor heat exchange unit 700 includes a plurality of indoor heat exchangers connected in parallel. In this embodiment, the indoor heat exchange unit 700 is composed of a plurality of indoor heat exchangers connected in parallel, with one end of the parallel connection being a port of a four-way valve 1000, and the other end being a pipeline connected to a liquid pipe shut-off valve 600. The indoor heat exchangers may be finned heat exchangers 220.

[0066] Each indoor heat exchanger can be controlled independently, adjusting the temperature according to the actual needs of its respective room or area. Users can turn the air conditioning on or off in a specific room as needed, achieving zoned control and improving energy efficiency. Parallel indoor heat exchangers can evenly distribute the total system load, preventing overload of individual exchangers. The air conditioning system can dynamically adjust the refrigerant flow based on the load of each room, ensuring that each heat exchanger operates at its optimal condition. Each indoor heat exchanger can be locally optimized according to actual needs, improving the overall energy efficiency of the system. Through zoned control, unnecessary energy consumption is avoided, further enhancing the system's energy utilization efficiency.

[0067] Users can adjust the temperature of each room according to their personal preferences and needs, improving the comfort of living or working. Independent control avoids temperature differences between different rooms, ensuring that each room reaches its ideal temperature. Even if one indoor heat exchanger fails, the others can continue to operate, ensuring the overall reliability of the system. The parallel design makes maintenance and repair more convenient, allowing for repairs to be performed on a heat exchanger without affecting other rooms.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An air conditioning system, characterized in that, It includes a heat exchanger and an indoor heat exchange unit (700). The heat exchanger includes a gas collecting pipe (100), a heat exchange tube (200), a liquid collecting pipe (300), and a subcooling pipe (400). The heat exchange tube (200) is arranged vertically. The upper end of the heat exchange tube (200) is connected to the gas collecting pipe (100), and the lower end of the heat exchange tube (200) is connected to the liquid collecting pipe (300). The subcooling pipe (400) is sleeved on the outside of the liquid collecting pipe (300), and a heat exchange cavity (410) is formed between the subcooling pipe (400) and the liquid collecting pipe (300). The subcooling pipe (400) is provided with a first port (420) and a second port (430) communicating with the heat exchange cavity (410). The first port (420) is suitable for inputting refrigerant into the heat exchange cavity (410), and the second port (430) is suitable for outputting refrigerant into the heat exchange cavity (410). The liquid collection pipe (300) is provided with a connecting pipe, which passes through the subcooling pipe (400) and is connected to the liquid collection pipe (300). The connecting pipe is also connected to the indoor heat exchange unit (700). A branch pipe (610) is also connected to the pipe connecting the connecting pipe to the indoor heat exchange unit (700). The branch pipe (610) is connected to the first pipe port (420). The branch pipe (610) is provided with a first expansion valve (510).

2. The air conditioning system according to claim 1, characterized in that, A liquid pipe shut-off valve (600) is provided on the pipe connecting the connecting pipe to the indoor heat exchange unit (700). A liquid reservoir (620) is also provided on the pipe between the connecting pipe and the liquid pipe shut-off valve (600). The branch pipe (610) is connected to the pipe connecting the liquid reservoir (620) and the liquid pipe shut-off valve (600).

3. The air conditioning system according to claim 2, characterized in that, A second expansion valve (520) is provided on the pipeline that connects the connecting pipe to the liquid reservoir (620).

4. The air conditioning system according to claim 1, characterized in that, It also includes a gas-liquid separator (900), with the second port (430) connected to the inlet of the gas-liquid separator (900).

5. The air conditioning system according to claim 1, characterized in that, The subcooling tube (400) is provided with a through hole, and the heat exchange tube (200) passes through the through hole to communicate with the liquid collection tube (300).

6. The air conditioning system according to any one of claims 1 to 5, characterized in that, A side plate (210) is provided around the outside of the heat exchange tube (200) between the gas collecting tube (100) and the liquid collecting tube (300).

7. The air conditioning system according to any one of claims 1 to 5, characterized in that, A first temperature sensor is provided at the first pipe opening (420), and a second temperature sensor is provided at the second pipe opening (430).

8. The air conditioning system according to any one of claims 1 to 7, characterized in that, The heat exchange tube (200) is a microchannel flat tube, and the surface of the microchannel flat tube is provided with fins (220).

9. The air conditioning system according to claim 8, characterized in that, It also includes a compressor (800) and a four-way valve (1000) adapted to switch between cooling and heating modes; In the refrigeration state, the compressor (800), the gas collecting pipe (100), the connecting pipe, the liquid receiver (620), the indoor heat exchange unit (700), and the gas-liquid separator (900) are connected in sequence to form a refrigeration circuit. The liquid receiver (620) and the liquid separator are also connected by a cold pipe (400) to form a branch. In the heating state, the compressor (800), the indoor heat exchange unit (700), the connecting pipe, the gas collecting pipe (100) and the gas-liquid separator (900) are connected in sequence to form a heating circuit, wherein the liquid receiver (620) and the liquid distributor are also connected by a cold pipe (400) to form a branch.

10. The air conditioning system according to claim 9, characterized in that, The indoor heat exchange unit (700) includes multiple indoor heat exchangers connected in parallel.

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