Heat exchanger, heat exchange system and air conditioner

Abstract

The utility model relates to the technical field of air conditioners, in particular to a heat exchanger, a heat exchange system and an air conditioner, the heat exchanger comprises at least one heat exchange tube group, each heat exchange tube group comprises a first tube body and a second tube body, the first tube body is communicated with the second tube body, a refrigerant is changed from a gas state to a liquid state in the process of flowing from the first tube body to the second tube body, and the refrigerant flows from the first tube body to the second tube body. The pipe diameter of the first pipe body is larger than that of the second pipe body, and the ratio of the length of the first pipe body to the length of the second pipe body is 1 / 2-1 / 1. By optimizing the pipe diameter of the heat exchange pipe of the heat exchanger, the pipe diameter is gradually reduced according to the direction that a refrigerant is changed from a gas state to a liquid state, the heat exchange efficiency of the heat exchanger is improved, meanwhile, the cost can be reduced, and the length of the second pipe body is properly prolonged and controlled within a certain range; the heat exchange duration and the heat exchange path of the refrigerant from the gas-liquid phase to the liquid state can be effectively prolonged, and sufficient heat exchange is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, and in particular to a heat exchanger, a heat exchange system and an air conditioner. Background Art

[0002] At present, in the design of heat exchangers, the inner diameter of the copper tube is fixed. Because the refrigerant exchanges heat with the outside world during the flow process, the state of the refrigerant will continue to change. For example, in the refrigeration condenser, the high-temperature and high-pressure gaseous refrigerant gradually becomes a liquid at room temperature and high pressure after heat release, and the volume is constantly shrinking. The volume of the refrigerant is reduced, but the diameter of the heat exchange tube is fixed. In some copper tubes in the middle of the condenser, there is not much condensed refrigerant liquid inside, which will accumulate in the middle and lower parts of the copper tubes. The top part of the copper tubes does not contact the refrigerant, and the heat exchange efficiency decreases. Utility Model Content

[0003] The utility model provides a heat exchanger, a heat exchange system and an air conditioner, which are used to solve one of the defects in the prior art. By optimizing the diameter of the heat exchange tube of the heat exchanger, the diameter of the tube is gradually reduced according to the direction in which the refrigerant changes from gas to liquid, which conforms to the law of the change of the refrigerant in the heat exchanger, thereby improving the heat exchange efficiency of the heat exchanger and reducing the cost at the same time.

[0004] The utility model provides a heat exchanger, comprising at least one heat exchange tube group, each of the heat exchange tube groups comprising a first tube body and a second tube body, the first tube body being connected to the second tube body, the refrigerant changes from gas to liquid during the process of flowing from the first tube body to the second tube body, the tube diameter of the first tube body is larger than the tube diameter of the second tube body, and the ratio of the length of the first tube body to the length of the second tube body is 1 / 2 to 1 / 1.

[0005] According to a heat exchanger provided by the utility model, the first tube body is bent to form at least one first tube row, the second tube body is bent to form at least one second tube row, and the first tube row and the second tube row are arranged in parallel and stacked with each other. In the design of a heat exchanger, it is difficult to change the diameter of the heat exchange tube in production, and even if it can be achieved, the cost is relatively high. Therefore, the utility model enables the first tube body and the second tube body to form at least two rows of tubes respectively, and tubes of different diameters can be independently configured and manufactured, so that it is easier to change the diameter and easy to achieve.

[0006] According to a heat exchanger provided by the utility model, the heat exchange tube group further includes a reducer tube body, and the first tube body and the second tube body are connected through the reducer tube body. The reducer tube body is independent of the first tube body and the second tube body, which is more convenient for the design and manufacture of the heat exchange tube. At the same time, for the structure in which the first tube body and the second tube body are arranged in the form of a tube row, the reducer tube body can also be more conducive to the connection between the first tube body and the second tube body, and adapt to the spatial position.

[0007] According to a heat exchanger provided by the utility model, the heat exchanger further includes a liquid collector, and the second tube bodies of the plurality of heat exchange tube groups are all connected to the liquid collector. The liquid collector is connected to the second tube openings of the second tube bodies of the three heat exchange tube groups, and the refrigerant becomes liquid in the second tube body and then flows out, and the refrigerant of all the heat exchange tube groups is discharged into the liquid collector, or flows into the second tube body of each heat exchange tube group through the liquid collector.

[0008] According to a heat exchanger provided by the utility model, the heat exchanger further includes an air supply pipe, and the first tube bodies of the plurality of heat exchange tube groups are all connected to the air supply pipe. The air supply pipe is connected to the first pipe openings of the first tube bodies of the three heat exchange tube groups, and the refrigerant is supplied to the first tube body of each heat exchange tube group through the air supply pipe, or after being converted into gaseous state in the first tube body, the refrigerant of all heat exchange tube groups is discharged into the air supply pipe.

[0009] According to a heat exchanger provided by the utility model, in the cooling state, the refrigerants in the first tube body and the second tube body flow from top to bottom, and in the heating state, the refrigerants in the first tube body and the second tube body flow from bottom to top. The flow direction of the refrigerant in the heat exchanger is always maintained so that the liquid refrigerant is below the gaseous refrigerant, and the liquid refrigerant is always kept downward and the gaseous refrigerant is always kept upward on the refrigerant flow path, further improving the heat exchange effect.

[0010] According to a heat exchanger provided by the utility model, the diameter of the first tube body and the diameter of the second tube body range from 5 mm to 19.05 mm. The diameter selection of the tube body is easy to obtain.

[0011] According to a heat exchanger provided by the utility model, the outer wall of the first tube body and the outer wall of the second tube body are both provided with fins. The outer walls of the first tube body and the second tube body are both provided with fins to increase the heat exchange area of ​​the heat exchange tube and improve the heat exchange effect of the heat exchanger.

[0012] The utility model also provides a heat exchange system, comprising a compressor, an evaporator and the heat exchanger as described above, wherein the compressor is connected to a first tube body of the heat exchanger, and the second tube body of the heat exchanger is connected to the evaporator.

[0013] The utility model also provides an air conditioner, comprising the heat exchange system as described above.

[0014] The heat exchanger of the utility model provided by the utility model embodiment of the utility model includes at least one heat exchange tube group, each heat exchange tube group is composed of a first tube body and a second tube body, the first tube body has a first tube opening and a second tube opening, the second tube body also has a first tube opening and a second tube opening, the second tube opening of the first tube body is connected to the first tube opening of the second tube body, and the tube diameter of the first tube body is larger than the tube diameter of the second tube body.

[0015] During the flow of the refrigerant, the high-temperature and high-pressure gaseous refrigerant is in the first tube body, and the low-temperature and high-pressure gas-liquid two-phase refrigerant is in the second tube body. By optimizing the diameters of the first tube body and the second tube body, the refrigerants in different states in each heat exchange tube group flow and exchange heat in tube bodies of different diameters, ensuring that all tubes in the heat exchange tube group are efficiently exchanging heat. This solves the problem that ordinary heat exchangers with the same diameter of heat exchange tubes will reduce the heat exchange efficiency and waste costs due to changes in the volume of the refrigerant. The variable diameter heat exchanger provided by the utility model optimizes the diameter of the heat exchange tube of the heat exchanger, and the diameter is gradually reduced in the direction of the refrigerant changing from gas to liquid, which conforms to the law of the change of the refrigerant in the heat exchanger, improves the heat exchange efficiency of the heat exchanger, and reduces costs at the same time. The heat exchanger of the utility model can select different diameter combinations for the first tube body and the second tube body according to different models, which not only meets the requirements of improving the heat exchange efficiency, but also reduces costs.

[0016] The ratio of the length of the first tube body to the length of the second tube body is 1 / 2 to 1 / 1, that is, in the flow path where the refrigerant releases heat from gas to liquid, the length of the second tube body in the entire refrigerant flow path accounts for 1 / 2 to 2 / 3. The refrigerant first passes through the first tube body and then the second tube body. In the first tube body, the refrigerant mostly releases heat in the gaseous state, and part of the gaseous state changes to liquid state, that is, during the flow process of the second tube body, the refrigerant is mostly gas-liquid two-phase, and then further releases heat to liquid state. Therefore, in order to ensure that the refrigerant heat exchange is more thorough and the heat of the refrigerant can be more fully utilized, the length of the second tube body is appropriately extended, but the second tube body cannot be too long, and the overcooling of the refrigerant is likely to affect the heat exchange efficiency. Therefore, the refrigerant flow path in the gas-liquid two-phase state is lengthened and controlled within a certain range, which can effectively increase the heat exchange time and heat exchange path of the refrigerant from the gas-liquid two-phase to the liquid state, and achieve sufficient heat exchange. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is one of the structural schematic diagrams of the heat exchanger provided in the embodiment of the utility model;

[0019] Figure 2 This is the second structural schematic diagram of the heat exchanger provided by the embodiment of the utility model;

[0020] Figure 3 It is a height ratio diagram of the internal refrigerant of the first tube body and the second tube body of the heat exchanger provided by the embodiment of the utility model.

[0021] Reference numerals:

[0022] 100, heat exchange tube group; 110, first tube body; 111, first tube row; 120, second tube body; 121, second tube row; 130, variable diameter tube body;

[0023] 200. Liquid collector; 300. Air supply pipe; 400. Fin. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] In cooling mode, the refrigerant in the heat exchanger changes from a high-temperature and high-pressure gas to a low-temperature and high-pressure liquid in the condenser through heat exchange with the air, and finally collects at the bottom of the heat exchanger. The volume of the refrigerant is gradually decreasing. In heating mode, the refrigerant in the heat exchanger changes from a low-temperature and high-pressure liquid to a high-temperature and high-pressure gas in the condenser through heat exchange with the air, and finally is discharged from the heat exchanger. The volume of the refrigerant is gradually increasing. The outer diameter of the heat exchange tube has not changed, and the theoretical heat exchange area is unchanged, but in actual applications, the effective heat exchange area of ​​the heat exchange tube is calculated by the wetted circumference inside the heat exchange tube, not the cross-sectional circumference of the heat exchange tube. Therefore, the volume of the refrigerant inside the condenser is gradually decreasing or increasing, and the effective heat exchange area at the corresponding position of the heat exchange tube should also be decreasing or increasing.

[0026] like Figure 1 and Figure 2 As shown, the heat exchanger provided by the embodiment of the utility model includes at least one heat exchange tube group 100, each heat exchange tube group 100 includes a first tube body 110 and a second tube body 120, the first tube body 110 is connected to the second tube body 120, and the refrigerant changes from gas to liquid during the process of flowing from the first tube body 110 to the second tube body 120. The diameter of the first tube body 110 is larger than the diameter of the second tube body 120, and the ratio of the length of the first tube body 110 to the length of the second tube body 120 is 1 / 2 to 1 / 1.

[0027] The heat exchanger of the embodiment of the utility model includes at least one heat exchange tube group 100, each heat exchange tube group 100 is composed of a first tube body 110 and a second tube body 120, the first tube body 110 has a first tube opening and a second tube opening, the second tube body 120 also has a first tube opening and a second tube opening, the second tube opening of the first tube body 110 is connected to the first tube opening of the second tube body 120, and the tube diameter of the first tube body 110 is larger than the tube diameter of the second tube body 120.

[0028] During the flow of the refrigerant, the high-temperature and high-pressure gaseous refrigerant is in the first tube body 110, and the low-temperature and high-pressure gas-liquid two-phase refrigerant is in the second tube body 120. By optimizing the diameters of the first tube body 110 and the second tube body 120, the refrigerants in different states in each heat exchange tube group 100 flow and exchange heat in tube bodies with different diameters, ensuring that all tube bodies of the heat exchange tube group 100 are efficiently exchanging heat. This solves the problem that the heat exchanger with the same diameter of the heat exchange tube will reduce the heat exchange efficiency and waste costs due to the change of the refrigerant volume in the ordinary heat exchanger. The variable-diameter heat exchanger provided by the utility model optimizes the diameter of the heat exchange tube of the heat exchanger, and the diameter is gradually reduced in the direction of the refrigerant changing from gas to liquid, which conforms to the law of the change of the refrigerant in the heat exchanger, improves the heat exchange efficiency of the heat exchanger, and reduces the cost at the same time. The heat exchanger of the utility model can select different diameter combinations for the first tube body 110 and the second tube body 120 according to different models, which not only meets the requirement of improving the heat exchange efficiency, but also reduces the cost.

[0029] In the heat exchanger of this embodiment, the heat exchange capacity of each heat exchange tube group 100 can be calculated by the formula Q=K×A×ΔT, where Q is the heat exchange capacity; K is the heat transfer coefficient, which is related to the material, wall thickness and flow velocity in the tube; A is the heat exchange area, which is related to the wetted perimeter; the heat transfer temperature difference on both sides of ΔT is generally calculated by the logarithmic mean temperature difference, which is related to the arrangement of the heat exchange tubes (sequential arrangement, cross arrangement), the upstream and downstream flow of the refrigerant. In this embodiment, the materials are the same, and the main factors are the wall thickness, the flow velocity in the tube and the wetted perimeter. In the design of the heat exchanger, the smaller the tube diameter and the thinner the wall thickness, the higher the K value; the smaller the tube diameter and the faster the flow velocity, the higher the K value; the smaller the tube diameter, the more the wetted perimeter is equivalent to the cross-sectional perimeter.

[0030] According to the above reasoning, in the design of the heat exchanger, it is more reasonable to have a larger pipe diameter in the front part and a smaller pipe diameter in the middle and rear part on the flow path where the refrigerant changes from gas to liquid. This means that the corresponding reduction in the pipe diameter in the middle and rear part of the heat exchanger does not make the heat exchange effect worse. In some applications, it can improve the heat exchange efficiency. Therefore, after analysis and calculation, the heat exchange effect of the combined heat exchanger scheme with gradually decreasing pipe diameter on the flow path where the refrigerant changes from gas to liquid is higher than that of the fixed large pipe diameter scheme, and the material cost is lower, which is in line with the trend of efficient design and cost reduction.

[0031] The ratio of the length of the first tube body 110 to the length of the second tube body 120 is 1 / 2 to 1 / 1, that is, in the flow path where the refrigerant releases heat from gas to liquid, the length of the second tube body 120 on the entire refrigerant flow path accounts for 1 / 2 to 2 / 3. The refrigerant first passes through the first tube body 110 and then the second tube body 120. In the first tube body 110, the refrigerant mostly flows in gaseous state and releases heat, and part of the gaseous state changes to liquid state, that is, during the flow process of the second tube body 120, the refrigerant is mostly gas-liquid two-phase, and further releases heat to liquid state. Therefore, in order to ensure that the refrigerant heat exchange is more thorough and the heat of the refrigerant can be more fully utilized, the length of the second tube body 120 is appropriately extended, but the second tube body 120 cannot be too long, and the overcooling of the refrigerant is likely to affect the heat exchange efficiency. Therefore, the refrigerant flow path in the gas-liquid two-phase state is lengthened and controlled within a certain range, which can effectively increase the heat exchange time and heat exchange path of the refrigerant from the gas-liquid two-phase to the liquid state, and achieve sufficient heat exchange.

[0032] According to an embodiment provided by the utility model, the first tube body 110 is bent to form at least one first tube row 111, the second tube body 120 is bent to form at least one second tube row 121, and the first tube row 111 and the second tube row 121 are arranged in parallel with each other. In this embodiment, each heat exchange tube group 100 is composed of two tube rows parallel to each other, one is the first tube row 111 formed by bending the first tube body 110, and the other is the second tube row 121 formed by bending the second tube body 120. The first tube row 111 and the second tube row 121 are arranged opposite to each other and in parallel, and the external air flows from the first tube row 111 to the second tube row 121 under the action of the fan.

[0033] In the design of a heat exchanger, it is difficult to change the diameter of the heat exchange tube in production. Even if it can be achieved, the cost is relatively high. Therefore, the utility model makes the first tube body 110 and the second tube body 120 form at least two rows of tubes respectively, and the tube bodies of different diameters can be independently configured and manufactured, so that it is easier to change the tube diameter and easy to achieve.

[0034] In this embodiment, there is one first tube row 111 and one second tube row 121, that is, all heat exchange tube groups 100 form a heat exchanger with two tube rows. In other embodiments, the number of first tube rows 111 and second tube rows 121 can be set according to actual needs.

[0035] According to an embodiment provided by the utility model, the heat exchange tube group 100 further includes a reducer tube body 130, and the first tube body 110 and the second tube body 120 are connected through the reducer tube body 130. In this embodiment, in each heat exchange tube group 100, the second tube opening of the first tube body 110 is connected to the first tube opening of the second tube body 120 through the reducer tube body 130, and the diameter of the reducer tube body 130 can be gradually changed between the diameters of the first tube body 110 and the second tube body 120, or the diameter of the reducer tube body 130 can be the same as the diameter of the first tube body 110, and the position connected to the first tube opening of the second tube diameter is designed to be narrowed, or the diameter of the reducer tube body 130 can be the same as the diameter of the second tube body 120, and the position connected to the second tube opening of the first tube diameter is designed to be expanded.

[0036] The reducer tube body 130 is independent of the first tube body 110 and the second tube body 120, which is more convenient for designing and manufacturing the heat exchange tube. At the same time, for the structure in which the first tube body 110 and the second tube body 120 are arranged in a tube row form, the reducer tube body 130 can also facilitate the connection between the first tube body 110 and the second tube body 120 and adapt to the spatial position.

[0037] According to an embodiment provided by the utility model, the heat exchanger further includes a liquid collector 200, and the second tube bodies 120 of the plurality of heat exchange tube groups 100 are all connected to the liquid collector 200. In this embodiment, there are three heat exchanger groups, which are arranged sequentially from top to bottom and are divided into upper, middle and lower heat exchanger groups, and the length of the heat exchange tubes of each heat exchanger group is basically the same. The liquid collector 200 is connected to the second tube openings of the second tube bodies 120 of the three heat exchange tube groups 100, and the refrigerant flows out after becoming liquid in the second tube body 120. The refrigerant of all heat exchange tube groups 100 is discharged into the liquid collector 200, or flows into the second tube body 120 of each heat exchange tube group 100 through the liquid collector 200.

[0038] According to an embodiment provided by the utility model, the heat exchanger further includes an air supply pipe 300, and the first tube bodies 110 of the plurality of heat exchange tube groups 100 are all connected to the air supply pipe 300. In this embodiment, there are three heat exchanger groups, which are arranged sequentially from top to bottom and are divided into upper, middle and lower heat exchanger groups, and the length of the heat exchange tubes of each heat exchanger group is basically the same. The air supply pipe 300 is connected to the first pipe openings of the first tube bodies 110 of the three heat exchange tube groups 100, and the refrigerant is delivered to the first tube bodies 110 of each heat exchange tube group 100 through the air supply pipe 300, or after becoming gaseous in the first tube body 110, the refrigerant of all heat exchange tube groups 100 is discharged into the air supply pipe 300.

[0039] According to an embodiment provided by the utility model, in the cooling state, the refrigerant in the first tube body 110 and the second tube body 120 flows from top to bottom, and in the heating state, the refrigerant in the first tube body 110 and the second tube body 120 flows from bottom to top. In this embodiment, the upper and lower directions are the directions from the high position to the low position in the vertical direction. The first pipe opening of the first tube body 110 is located above the second pipe opening of the device, and the first pipe opening of the second tube body 120 is located above its second pipe opening. In the cooling state, the high-temperature gaseous refrigerant enters the first tube body 110 from the first pipe port of the first tube body 110, flows into the second tube body 120 from the first tube body 110, and after heat exchange, the low-temperature liquid refrigerant flows out from the second pipe port of the second tube body 120. In the heating state, the low-temperature liquid refrigerant enters the second tube body 120 from the second pipe port of the second tube body 120, flows into the first tube body 110 from the second tube body 120, and after heat exchange, the high-temperature gaseous refrigerant flows out from the first pipe port of the first tube body 110.

[0040] The flow direction of the refrigerant in the heat exchanger is always maintained so that the liquid refrigerant is located below the gaseous refrigerant, and the liquid refrigerant always flows downward and the gaseous refrigerant flows upward in the refrigerant flow path, further improving the heat exchange effect.

[0041] According to an embodiment provided by the utility model, the diameter of the first tube body 110 and the diameter of the second tube body 120 range from 5mm to 19.05mm. In this embodiment, the selection of the first tube body 110 and the second tube body 120 may include copper tubes of sizes such as Φ19.05, Φ15.88, Φ12.7, Φ9.52, Φ7.94, Φ7, Φ6, Φ5, etc. In this embodiment, the heat exchanger uses a 9.52mm large-diameter copper tube in the high-temperature and high-pressure gaseous refrigerant section, and a 7mm small-diameter copper tube in the low-temperature and high-pressure gas-liquid two-phase refrigerant section. The diameter selection of the tube body is easy to obtain.

[0042] When a heat exchange tube group 100 is in cooling mode, the refrigerant gradually changes from gas to liquid. In the rear section, in a 9.52 mm copper tube with the same diameter, the height of the liquid is less than half of the diameter of the tube. Figure 3 As shown:

[0043] If the refrigerant is in a 9.52mm diameter copper tube and its height is halfway, the following calculation is equivalent to the 7mm diameter copper tube being full of liquid.

[0044] The cross-sectional area of ​​the half-height of the 9.52 mm diameter tube is S = π × r × r / 2 = 3.14 × 4.76 × 4.76 = 35.6;

[0045] The cross-sectional area of ​​the full liquid height of a 7mm diameter tube is S = π × r × r = 3.14 × 3.5 × 3.5 = 38.4;

[0046] Can be used for wetted perimeter calculation for efficient heat transfer,

[0047] The wetted perimeter of half the height of a 9.52 mm diameter tube is L = π × d / 2 = 3.14 × 9.52 / 2 = 14.9 mm;

[0048] The wetted circumference of the full liquid height of a 7mm diameter tube is L = π × d / 2 = 3.14 × 7 = 21.98mm.

[0049] After comparative analysis, the wetted perimeter L of the 7mm diameter tube is longer than that of the 9.52mm diameter tube in the middle and rear sections, and the corresponding effective heat exchange area is larger.

[0050] Similarly, when in heating mode, the heat exchanger complies with the characteristics of heat transfer, can efficiently exchange heat and reduce the cost of the entire machine.

[0051] According to an embodiment provided by the utility model, the outer wall of the first tube body 110 and the outer wall of the second tube body 120 are both provided with fins 400. In this embodiment, the outer walls of the first tube body 110 and the second tube body 120 are both provided with fins 400 to increase the heat exchange area of ​​the heat exchange tube and improve the heat exchange effect of the heat exchanger.

[0052] The heat exchange system provided by the present invention is described below. The heat exchange system described below and the heat exchanger described above can be referred to each other.

[0053] The embodiment of the utility model further provides a heat exchange system, including a compressor, an evaporator and a heat exchanger as in the above embodiment, wherein the compressor is connected to a first tube body 110 of the heat exchanger, and the second tube body 120 of the heat exchanger is connected to the evaporator.

[0054] In the heat exchange system of the embodiment of the utility model, when the heat exchange system is in cooling mode, the refrigerant is divided into multiple paths to flow to multiple heat exchange tube groups 100. The refrigerant is compressed by the compressor into a high-temperature and high-pressure gas, enters the heat exchanger from the inlet, first passes through the first tube body 110 with a large diameter, gradually becomes a low-temperature and high-pressure liquid, and then passes through the variable diameter tube body 130 to flow to the second tube body 120 with a small diameter, and then is completely collected by the liquid collector 200, throttled and reduced in pressure by the throttling element, flows to the evaporator to evaporate and become a low-temperature and low-pressure gas, and then is compressed by the compressor into a high-temperature and high-pressure gas, forming a cycle.

[0055] When the heat exchange system is in heating mode, the same heat exchanger has the refrigerant flowing in the opposite direction. The low-temperature and low-pressure liquid coming from the evaporator is divided into multiple paths in the liquid collector 200. The front section first flows through the second tube body 120 with a small diameter. The liquid flows in the tube, which has a small volume and a fast flow rate, and is suitable for the second tube body 120 with a small diameter. Then it passes through the variable diameter tube body 130 and flows to the first tube body 110 with a large diameter. At this time, the liquid in the tube body evaporates and becomes gas. Most of the liquid flowing in the tube is gas-liquid two-phase, and finally all becomes gas. The volume gradually increases, and it is just right to flow in the first tube body 110 with a large diameter. Finally, the low-temperature and low-pressure gas is sucked into the compressor, compressed into high-temperature and high-pressure gas, and discharged into the evaporator for heat exchange, becoming low-temperature and low-pressure liquid, completing a heating cycle.

[0056] The air conditioner provided by the utility model is described below. The air conditioner described below and the heat exchange system described above can be referred to each other.

[0057] An embodiment of the utility model further provides an air conditioner, comprising a heat exchange system as described in the above embodiment.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A heat exchanger, characterized in that: The invention comprises at least one heat exchange tube group (100), each of the heat exchange tube groups (100) comprising a first tube body (110) and a second tube body (120), the first tube body (110) being connected to the second tube body (120), the refrigerant changing from gas to liquid during the process of flowing from the first tube body (110) to the second tube body (120), the tube diameter of the first tube body (110) being larger than the tube diameter of the second tube body (120), and the ratio of the length of the first tube body (110) to the length of the second tube body (120) being 1 / 2 to 1 / 1.

2. The heat exchanger according to claim 1, characterized in that: The first tube body (110) is bent to form at least one first tube row (111), and the second tube body (120) is bent to form at least one second tube row (121). The first tube row (111) and the second tube row (121) are stacked and arranged parallel to each other.

3. The heat exchanger according to claim 1, characterized in that: The heat exchange tube group (100) further comprises a diameter-reducing tube body (130), and the first tube body (110) and the second tube body (120) are connected via the diameter-reducing tube body (130).

4. The heat exchanger according to claim 1, characterized in that: The heat exchanger further comprises a liquid collector (200), and the second tube bodies (120) of the plurality of heat exchange tube groups (100) are all in communication with the liquid collector (200).

5. The heat exchanger according to claim 1, characterized in that: The heat exchanger further comprises an air supply pipe (300), and the first tube bodies (110) of the plurality of heat exchange tube groups (100) are all in communication with the air supply pipe (300).

6. The heat exchanger according to claim 1, characterized in that In the cooling state, the refrigerant in the first tube body (110) and the second tube body (120) flows from top to bottom, and in the heating state, the refrigerant in the first tube body (110) and the second tube body (120) flows from bottom to top.

7. The heat exchanger according to claim 1, characterized in that The diameter of the first tube body (110) and the diameter of the second tube body (120) are in the range of 5 mm to 19.05 mm.

8. The heat exchanger according to any one of claims 1 to 7, characterized in that: Fins (400) are provided on the outer wall of the first tube body (110) and the outer wall of the second tube body (120).

9. A heat exchange system, characterized in that: It comprises a compressor, an evaporator and the heat exchanger according to any one of claims 1 to 8, wherein the compressor is connected to a first tube body (110) of the heat exchanger, and the second tube body (120) of the heat exchanger is connected to the evaporator.

10. An air conditioner, characterized in that: Includes the heat exchange system as claimed in claim 9.

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