Heat exchange tube and heat exchanger with same

Abstract

The utility model discloses a heat exchange tube and a heat exchanger with the heat exchange tube, the heat exchange tube comprises a first side wall and a second side wall, the heat exchange tube also comprises a plurality of separators, one end of each separator is connected with the first side wall, the other end of each separator is connected with the second side wall, the number of the separators is multiple, and the separators are arranged on the first side wall and the second side wall respectively. The heat exchange tube comprises a plurality of separators, the separators are arranged at intervals in the width direction of the heat exchange tube, the heat exchange tube further comprises n first channels, the first channels are arranged between every two adjacent separators, the number of the first channels is n, the n first channels are arranged at intervals in the width direction of the heat exchange tube, the width of each first channel is w, and the width of each first channel is w. The height of the first channel is h, and (w * h * n) / 12.2 is larger than 0.5 and smaller than 0.6. Through the optimal design, the relation between the heat exchange area of the heat exchange tube and the inner volume of the heat exchange tube can be considered, and the product reliability is high.

Description

Technical Field

[0001] The present invention relates to the field of heat exchange technology, and in particular to a heat exchange tube and a heat exchanger having the heat exchange tube. Background Art

[0002] As users' requirements for the heat exchange performance of heat exchangers increase, heat exchange tubes, as important components of heat exchangers, have a significant impact on the heat exchange performance of heat exchangers. In related technologies, in order to improve the heat exchange capacity of heat exchangers, the heat exchange area of ​​the heat exchanger is usually increased. For heat exchange tubes, the heat exchange area of ​​the heat exchange tubes can be increased by increasing the contact area between the heat exchange tubes and the refrigerant. However, increasing the heat exchange area of ​​the heat exchange tubes will also increase the internal volume of the heat exchange tubes. How to balance the relationship between the heat exchange area and the internal volume of the heat exchange tubes has become a technical issue of concern to technicians in this field. Summary of the invention

[0003] To this end, the present invention proposes a heat exchange tube on one hand, which can take into account the relationship between the heat exchange area of ​​the heat exchange tube and the internal volume of the heat exchange tube through optimized design, and the product reliability is strong.

[0004] An embodiment of the present invention provides a heat exchange tube, which includes a plurality of partitions, which are arranged at intervals in the width direction of the heat exchange tube. The heat exchange tube also includes a plurality of first channels, wherein a first channel is provided between two adjacent partitions. There are n first channels, which are arranged at intervals in the width direction of the heat exchange tube. The width of the first channel is w, and the height of the first channel is h. The units of the width w and the height h are mm, wherein 0.5<(w*h*n) / 12.2<0.6.

[0005] In the embodiments of the present application, by setting the number of first channels of the heat exchange tube to n, the width of the first channel to w, the height of the first channel to h, and the relationship between the parameters satisfies: 0.5<(w*h*n) / 12.2<0.6, therefore, by optimizing the design, while meeting the requirements of heat exchange performance, by optimizing the number of first channels, as well as the height and width of the first channels, the relationship between the heat exchange area of ​​the heat exchange tube and the internal volume of the heat exchange tube can be taken into account, and the product reliability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic structural diagram of a heat exchange tube according to an embodiment of the present invention;

[0007] Figure 2 yes Figure 1 A cross-sectional view of the heat exchange tube in the EE direction;

[0008] Figure 3 yes Figure 1A schematic diagram of a front view of a heat exchange tube is shown;

[0009] Figure 4 is a schematic structural diagram of a heat exchanger according to an embodiment of the present invention;

[0010] Figure 5 Figure 4 An enlarged view of the D portion of the heat exchanger 1 is shown;

[0011] Figure 6 yes Figure 4 The schematic diagram of the front view of the heat exchanger shown;

[0012] Figure 7 yes Figure 4 The schematic diagram of the structure of the heat exchanger after bending is shown;

[0013] Figure 8 is a schematic structural diagram of a heat exchanger according to another embodiment of the present invention;

[0014] Fig. 9 4 is a schematic structural diagram of a heat exchanger according to another embodiment of the present invention.

[0015] Reference numerals:

[0016] Heat exchanger 100, heat exchange tube 10, first channel 101, first side wall 102, second side wall 103, third side wall 104, fourth side wall 105, partition 106, first sub-wall 1061, second sub-wall 1062, main body 107, first part 108, first tube 20, third cavity 201, fourth cavity 202, fifth cavity 203, second tube 30, sixth cavity 301, seventh cavity 302, first connecting pipe 40, second connecting pipe 50, first piece 60. DETAILED DESCRIPTION

[0017] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but cannot be understood as limiting the present invention. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element fixture referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0018] like Figure 1-3As shown, according to an embodiment of the present invention, the heat exchange tube 10 has a flat cross-sectional shape, and the heat exchange tube 10 includes a plurality of partitions 106, and the plurality of partitions 106 are arranged at intervals in the width direction of the heat exchange tube 10. The heat exchange tube 10 divides the inner cavity of the heat exchange tube 10 into n first channels 101 by the plurality of partitions 106, and the n first channels 101 are arranged at intervals in the width direction of the heat exchange tube 10, and there is a first channel 101 between two adjacent partitions 106. It should be noted that, as shown in FIG. Figure 1 As shown, the width direction of the heat exchange tube 10 is the AA direction shown in the figure, the length direction of the heat exchange tube 10 is the BB direction shown in the figure, and the thickness direction of the heat exchange tube 10 is the CC direction shown in the figure, that is, a plurality of first channels 101 are arranged at intervals in the AA direction of the heat exchange tube 10, and the first channels 101 can allow the refrigerant to flow inside the heat exchange tube 10 to facilitate heat exchange with the external air. The width of the first channel 101 is w, and the height of the first channel 101 is h. The units of the width w and the height h are mm, wherein 0.5<(w*h*n) / 12.2<0.6,

[0019] According to the heat exchange tube 10 of the embodiment of the present invention, by optimizing the design of the heat exchange tube 10, the parameter is set to 0.5<(w*h*n) / 12.2<0.6, which is beneficial to take into account the relationship between the internal volume of the heat exchange tube 10 and the heat exchange area of ​​the heat exchange tube 10, and the product reliability is strong.

[0020] In some embodiments, specifically, Figure 1 and Figure 2The heat exchange tube 10 shown in the figure has a first portion 108 and a main body 107, the width of the first portion 108 is smaller than the width of the main body 107, the first portions 108 are provided at both ends of the main body 107, the outer perimeter of the main body 107 is greater than the outer perimeter of the first portion 108, the partition wall includes a first sub-wall 1061 and a second sub-wall 1062, the main body 107 has a first cavity, the first portion 108 has a second cavity, the first sub-wall 1061 is located in the first cavity of the main body 107, the second sub-wall 1062 is located in the second cavity, and the plurality of second sub-walls are arranged at intervals in the width direction of the heat exchange tube 10, the thickness of at least one of the first sub-wall 1061 and the second sub-wall 1062 is t, the unit of the wall thickness t is mm, wherein 0.2<(25-2t) / (n*l)<0.9, by optimizing the design of the heat exchange tube 10, the heat exchange tube 10 is The parameter range of the second sub-wall 1062 of the heat pipe 10 is 0.2<(25-2t) / (n*l)<0.9, which is beneficial to reducing the internal volume of the heat exchange tube, improving the pressure resistance of the heat exchange tube 10, and controlling the material cost. When the parameter range of the second sub-wall 1062 of the heat exchange tube 10 is less than 0.2, it is easy to cause insufficient pressure resistance of the heat exchange tube 10. When the parameter range of the second sub-wall 1062 of the heat exchange tube 10 is greater than 0.9, the material cost of the heat exchange tube 10 will be increased. Therefore, when the wall thickness of the second sub-wall 1062 and / or the first sub-wall 1061 is within 0.2<(25-2t) / (n*l)<0.9, the relationship between the heat exchange area of ​​the heat exchange tube 10 and the internal volume of the heat exchange tube 10 can be optimized, thereby meeting multiple requirements for the heat exchange performance of the heat exchange tube 10 and the internal volume of the heat exchange tube 10.

[0021] In some embodiments, specifically, Figure 3 As shown, the cross-section of the heat exchange tube 10 is roughly an elliptical structure. The heat exchange tube 10 includes a first side wall 102 and a second side wall 103 in the thickness direction (CC direction) of the heat exchange tube 10. The heat exchange tube 10 also includes a third side wall 104 and a fourth side wall 105 in the width direction (AA direction) of the heat exchange tube 10. One end of the first side wall 102 is connected to one end of the third side wall, the other end of the third side wall is connected to one end of the second side wall 103, the other end of the second side wall 103 is connected to one end of the fourth side wall 105, and the other end of the fourth side wall is connected to the other end of the first side wall 102. The thickness of at least one of the third side wall 104 and the fourth side wall 105 is y, where the unit of the wall thickness y is mm, where 0.4<y<0.7, when the wall thickness y of the third side wall 104 and the fourth side wall 105 is in the range of 0.4 to 0.7, it is beneficial to take into account the relationship between the internal volume of the heat exchange tube 10 and the heat exchange area of ​​the heat exchange tube 10, and the product reliability is strong.

[0022] In some embodiments, specifically, Figure 3As shown, the heat exchange tube 10 is a flat tube, and the difference between the width and height of the first channel 101 of the heat exchange tube 10 is between 0.2 and 0.32, wherein the units of the heat exchange tube width w and height h are mm. Within this parameter range, it is beneficial to take into account the relationship between the internal volume of the heat exchange tube 10 and the heat exchange area of ​​the heat exchange tube 10, and the product reliability is strong.

[0023] In some embodiments, specifically, Figure 3 As shown, the height h of the first channel 101 satisfies the following condition: 0.36<h<0.6. Within this parameter range, it is beneficial to take into account the relationship between the internal volume of the heat exchange tube 10 and the heat exchange area of ​​the heat exchange tube 10, and the product reliability is strong.

[0024] In some embodiments, specifically, Figure 3 As shown, the width w of the first channel 101 satisfies the following conditions, where the unit of the width w is mm, 0.79<w<1.03. Within this parameter range, it is beneficial to take into account the relationship between the internal volume of the heat exchange tube 10 and the heat exchange area of ​​the heat exchange tube 10, and the product reliability is strong.

[0025] A heat exchanger 100 according to an embodiment of the present invention, specifically, Figure 4-Figure 8 As shown, the heat exchanger 100 includes a first tube 20 and a second tube 30, the first tube 20 includes a tube body, the tube body includes a tube wall, and the tube body has a second channel. The heat exchanger 100 also includes a plurality of heat exchange tubes 10, one end of the heat exchange tube 10 is connected to the first tube 20, and the other end of the heat exchange tube 10 is connected to the second tube 30. The plurality of heat exchange tubes 10 are arranged at intervals in the length direction of the first tube 20 or the second tube 30, and the heat exchange tube 10 includes a plurality of first channels 101, and the plurality of first channels 101 are arranged at intervals in the width direction (AA direction) of the heat exchange tube 10.

[0026] The heat exchange tube 10 includes a main body 107 and a first portion 108. In some designs, the first portion may be a necked portion, such as Figure 1 to Figure 2 In the heat exchange tube shown, both ends of the main body 107 are connected to the first part 108. When one end of the heat exchange tube 10 is connected to the first tube 20, and the other end of the heat exchange tube 10 is connected to the second tube 30, therefore, one of the two first parts 108 is located at the first tube 20, and the other first part 108 is located at the second tube 30. The provision of the first part 108 is beneficial to improving the connection strength between the heat exchange tube 10 and the first tube 20 / the second tube 30 on the one hand, and is beneficial to controlling the insertion depth of the heat exchange tube 10 into the first tube 20 / the second tube 30 on the other hand, because the size of the notch on the first tube 20 / the second tube 30 matches the size of the first part 108.

[0027] The heat exchanger 100 also includes a first connecting pipe 40 and a second connecting pipe 50. Typically, one of the first connecting pipe 40 and the second connecting pipe 50 is a refrigerant inlet pipe, and the other connecting pipe is a refrigerant outlet pipe. In some designs, the first connecting pipe 40 is connected to the first pipe 20, and the second connecting pipe 50 is connected to the first pipe 20. Alternatively, the second connecting pipe 50 may be connected to the second pipe 30, and the first connecting pipe 40 and the second pipe 30 may be connected. The two connecting pipes are arranged on the same side of the heat exchanger 100, which is beneficial to reducing packaging costs.

[0028] Specifically, Figures 4 to 8 As shown, the flow cross-sectional area of ​​the second channel is S2, and the flow cross-sectional areas of the two channels are the same. On the cross section of the heat exchange tube 10, the sum of the flow cross-sectional areas of the plurality of first channels 101 is S1, the length of the main body 107 of the heat exchange tube 10 is L, and the height of the second tube 30 is H. The units of the length L and the height H of the main body are mm, wherein 4<(S1*L*6+S2*H) / (7.33*L+12*H)<8, which is conducive to taking into account the relationship between the internal volume of the heat exchanger 100 and the heat exchange area of ​​the heat exchanger 100, and the product reliability is strong.

[0029] In some embodiments, the lengths of the first tube 20 and the second tube 30 of the heat exchanger 100 may be different. Figure 6 As shown, the lengths of the first tube 20 and the second tube 30 of the heat exchanger 100 are different, and the length of the second tube 30 is smaller than the length of the first tube 20. Therefore, in the definition 4<(S1*L*6+S2*H) / (7.33*L+12*H)<8, H is the length of the relatively shorter tube in the first tube 20 and the second tube 30. In addition, as Fig. 9 As shown, there is also a design in which the first tube 20 and the second tube 30 of the heat exchanger 100 have the same length. Therefore, since the lengths of the two tubes are the same, the length of any tube can be selected.

[0030] Specifically, Figure 4-Figure 6 As shown, the length of the first tube 20 is greater than the length of the second tube 30, and the first connecting pipe 40 is installed in the range where the first tube exceeds the length of the second tube. Therefore, compared with the usual heat exchanger, by setting the connecting pipe in the range where the first tube exceeds the length of the second tube and by connecting the connecting pipe to the tube wall of the first tube 20, it is beneficial to increase the compressive strength of the first connecting pipe and improve the corrosion resistance of the first connecting pipe.

[0031] In some embodiments, Figure 5 As shown, the radius of the second tube 30 is R. Usually, the radius of the first tube 20 is the same as the radius of the second tube 30. Therefore, when the radius of at least one of the first tube 20 and the second tube 30 satisfies, 3<π*R 2 / 12<10. When the above range is met, it is beneficial to increase the flow rate of the refrigerant on the one hand, and to improve the pressure resistance of the heat exchanger 100 on the other hand. If it is less than 3, the flow rate of the first tube 20 and the second tube 30 is too large, affecting the heat exchange performance. If it is greater than 10, the internal volume of the first tube 20 and the second tube 30 is too small, the heat exchange amount is insufficient, and the pressure resistance is insufficient.

[0032] In some embodiments, Figures 6 to 8 The heat exchanger 100 shown in FIG. 1 can be used as a condenser in some applications, such as Figure 7 As shown, the heat exchanger 100 can be used to wrap some metal tanks after being bent to heat the liquid in the metal tanks, such as water. Normally, the spacing between adjacent heat exchange tubes 10 is equal, but the distance between some adjacent heat exchange tubes 10 in some heat exchangers 100 is greater than the width of a heat exchange tube 10. The purpose is to achieve local enhanced heat exchange, save costs, and save energy.

[0033] In some embodiments, Figure 8 and Fig. 9 The heat exchanger 100 shown in the figure also includes a first piece 60, which is connected to the side wall of the heat exchange tube 10 and is used to fix the position of the heat exchange tube 10 and reduce the deviation of the heat exchange tube 10. In some designs, the first piece 60 can be foam, a rubber strip, or an aluminum plate. The first piece 60 is fixedly connected to the multiple heat exchange tubes 10 by gluing or welding, thereby improving the reliability of the heat exchanger 100.

[0034] In some embodiments, Figure 8 and Fig. 9 As shown, the first channel 101 of the first tube 20 is divided into a plurality of chambers, and the second channel of the second tube 30 is divided into a plurality of chambers. Specifically, the first tube 20 includes a third chamber 201, a fourth chamber and a fifth chamber 203, and the second tube 30 includes a sixth chamber 301 and a seventh chamber 302. The third chamber 201 is connected to the inner chamber of the first connecting tube 40, and the fifth chamber 203 is connected to the inner chamber of the second connecting tube 50. There is a fourth chamber between the third chamber 201 and the fifth chamber 203. The heat exchanger 100 includes a first connecting tube 40 and a second connecting tube 50. The first connecting tube 40 is connected to the first tube 20, and the second connecting tube 50 is connected to the first tube 20.

[0035] The multiple heat exchange tubes 10 include a first group of heat exchange tubes 10, a second group of heat exchange tubes 10, a third group of heat exchange tubes 10 and a fourth group of heat exchange tubes 10. The multiple first channels 101 of the first group of heat exchange tubes 10 connect the third cavity 201 and the sixth cavity 301, the multiple first channels 101 of the second group of heat exchange tubes 10 connect the fourth cavity and the sixth cavity 301, the multiple first channels 101 of the third group of heat exchange tubes 10 connect the fourth cavity and the seventh cavity 302, and the multiple first channels 101 of the fourth group of heat exchange tubes 10 connect the seventh cavity 302 and the fifth cavity 203.

[0036] In some embodiments, specifically, Figure 8 As shown, the heat exchanger 100 includes a plurality of heat exchange tubes 10, and the plurality of heat exchange tubes 10 can be divided into a first group of heat exchange tubes 10, a second group of heat exchange tubes 10, a third group of heat exchange tubes 10 and a fourth group of heat exchange tubes 10. The total number of the heat exchange tubes 10 in the fourth group is less than the number of the heat exchange tubes 10 in the first group because during the condensation process of the heat exchange tubes 10, the refrigerant changes from a high-temperature and high-pressure gas to a relatively low-temperature and low-pressure gas. Therefore, reducing the number of the heat exchange tubes 10 in the fourth group is beneficial to reducing the cost of the heat exchanger 100.

[0037] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0038] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A heat exchange tube, characterized in that: include: a first side wall and a second side wall, A separator, one end of the separator is connected to the first side wall, and the other end of the separator is connected to the second side wall. There are multiple separators, and the multiple separators are arranged at intervals in the width direction of the heat exchange tube. The heat exchange tube also includes a first channel, and the first channel is provided between two adjacent separators. There are n first channels, and the n first channels are arranged at intervals in the width direction of the heat exchange tube. The width of the first channel is w, and the height of the first channel is h. The units of the width w and the height h are mm, wherein 0.5<(w*h*n) / 12.2<0.

6.

2. The heat exchange tube according to claim 1, characterized in that: The heat exchange tube includes a main body and a first part, the width of the first part is smaller than the width of the main body, at least one end of the main body has the first part, the partition includes a first sub-wall and a second sub-wall, the main body has a first cavity, the first sub-wall is located in the first cavity, the first part has a second cavity, the second sub-wall is located in the second cavity, the thickness of at least one of the first sub-wall and the second sub-wall is t, the unit of thickness t is mm, wherein 0.2<(25-2t) / (n*l)<0.

9.

3. The heat exchange tube according to claim 1 or 2, characterized in that: The heat exchange tube includes a third side wall and a fourth side wall in the width direction of the heat exchange tube, one end of the first side wall is connected to one end of the third side wall, the other end of the first side wall is connected to one end of the fourth side wall, one end of the second side wall is connected to the other end of the third side wall, the other end of the second side wall is connected to the other end of the fourth side wall, and the wall thickness of at least one of the third side wall and the fourth side wall is y, and the unit of the wall thickness y is mm, wherein 0.4<y<0.

7.

4. The heat exchange tube according to claim 1 or 2, characterized in that: The heat exchange tube is a flat tube, and the heat exchange tube meets the following conditions: 0.2<wh<0.

32.

5. The heat exchange tube according to claim 1 or 2, characterized in that: The height h of the first channel satisfies the following condition: 0.36<h<0.

6.

6. The heat exchange tube according to claim 1 or 2, characterized in that: The width w of the first channel satisfies the following condition: 0.79<w<1.

03.

7. A heat exchanger, characterized in that: include: A first tube and a second tube, wherein one of the first tube and the second tube comprises a tube body, the tube body comprises a tube wall, the tube body has a second channel, and the flow cross-sectional area of ​​the second channel is S2; A heat exchange tube, wherein the heat exchange tube is the heat exchange tube according to any one of claims 1 to 6, wherein one end of the heat exchange tube is connected to the first tube, and the other end of the heat exchange tube is connected to the second tube, wherein there are a plurality of heat exchange tubes, and the plurality of heat exchange tubes are arranged at intervals in the length direction of the first tube or the second tube, and wherein the heat exchange tube comprises a plurality of first channels, and the plurality of first channels are arranged at intervals in the width direction of the heat exchange tube, and in the cross section of the heat exchange tube, the sum of the flow cross-sectional areas of the plurality of first channels is S1; The heat exchange tube includes a main body and a first part, at least one end of the main body has the first part, the main body and the first part are connected, the first part is located in the tube body, the length of the main body is L, the height of the second tube is H, the units of the main body length L and the second tube height H are mm, wherein 4<(S1*L*6+S2*H) / (7.33*L+12*H)<8.

8. The heat exchanger according to claim 7, characterized in that The radius of at least one of the first tube and the second tube is R, and the unit of the radius R is mm, wherein 3<π*R 2 / 12<10.

9. The heat exchanger according to claim 7, characterized in that: The width of the main body of the heat exchange tube is W, and in the width direction of the heat exchange tube, the distance between at least one of the heat exchange tubes and the adjacent heat exchange tubes is greater than W.

10. The heat exchanger according to claim 7, characterized in that The first tube includes a third cavity, a fourth cavity and a fifth cavity, the second tube includes a sixth cavity and a seventh cavity, and a fourth cavity is provided between the third cavity and the fifth cavity; The multiple heat exchange tubes include a first group of heat exchange tubes, a second group of heat exchange tubes, a third group of heat exchange tubes and a fourth group of heat exchange tubes. The multiple first channels of the first group of heat exchange tubes are connected to the third chamber and the sixth chamber, the multiple first channels of the second group of heat exchange tubes are connected to the fourth chamber and the sixth chamber, the multiple first channels of the third group of heat exchange tubes are connected to the fourth chamber and the seventh chamber, and the multiple first channels of the fourth group of heat exchange tubes are connected to the seventh chamber and the fifth chamber.

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