Double-pipe heat exchanger and heat exchange system

Abstract

The utility model discloses a double-pipe heat exchanger and a heat exchange system. The double-pipe heat exchanger comprises an outer pipe; the inner pipe is arranged in the outer pipe in a penetrating mode, a first cavity in the inner pipe is used for water flowing, a second cavity between the inner pipe and the outer pipe is used for refrigerant flowing, and a plurality of first spiral protrusions which are spirally arranged in the length direction of the inner pipe are arranged on the peripheral wall of the inner pipe. A first spiral groove spirally formed in the length direction of the inner pipe is defined between every two adjacent first spiral protrusions, second spiral grooves are formed in the positions, corresponding to the first spiral protrusions, of the inner circumferential wall of the inner pipe, and second spiral protrusions are arranged at the positions, corresponding to the first spiral grooves, of the inner circumferential wall of the inner pipe. According to the double-pipe heat exchanger, the heat dissipation area of a refrigerant can be increased, the contact area and the contact length of the refrigerant and water can be increased, the heat exchange efficiency between the refrigerant and the water can be improved, and under the same heat exchange efficiency, the length of the double-pipe heat exchanger can be reduced, the cost can be reduced, and a heat exchange system can be miniaturized.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange equipment, in particular to a shell and tube heat exchanger and a heat exchange system. Background Art

[0002] In the related art, heat exchange equipment such as water-cooled outdoor units dissipate heat through plate heat exchangers or shell-and-tube heat exchangers. The shell-and-tube heat exchanger is divided into an inner layer and an outer layer. A simple shell-and-tube heat exchanger can be made by wrapping a copper tube with plastic. The inside of the copper tube is a refrigerant channel, and the space between the plastic and the copper tube is a water channel. The existing shell-and-tube heat exchanger has low heat exchange efficiency between the refrigerant and water, and requires a longer shell to achieve better heat exchange. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a shell and tube heat exchanger, wherein the shell and tube heat exchanger has high heat exchange efficiency between refrigerant and water.

[0004] The utility model also provides a heat exchange system, which includes the above-mentioned shell and tube heat exchanger.

[0005] According to the embodiment of the utility model, the shell and tube heat exchanger includes: an outer tube; an inner tube, the inner tube is inserted into the outer tube, the first cavity in the inner tube is used for water flow, and the second cavity between the inner tube and the outer tube is used for refrigerant flow, the outer circumferential wall of the inner tube is provided with a plurality of first spiral protrusions spirally arranged along the length direction of the inner tube, a first spiral groove spirally arranged along the length direction of the inner tube is defined between two adjacent first spiral protrusions, a second spiral groove is provided on the inner circumferential wall of the inner tube at a position corresponding to the first spiral protrusion, and a second spiral protrusion is provided at a position corresponding to the first spiral groove.

[0006] According to the shell and tube heat exchanger of the embodiment of the utility model, the first cavity in the inner tube is used for the flow of water, the second cavity between the inner tube and the outer tube is used for the flow of refrigerant, and a plurality of first spiral protrusions spirally arranged along the length direction of the inner tube are provided on the outer peripheral wall of the inner tube, a first spiral groove spirally arranged along the length direction of the inner tube is defined between two adjacent first spiral protrusions, a second spiral groove is provided at a position corresponding to the first spiral protrusion on the inner peripheral wall of the inner tube, and a second spiral protrusion is provided at a position corresponding to the first spiral groove, thereby increasing the heat dissipation area of ​​the refrigerant, increasing the contact area and contact length between the refrigerant and water, and improving the heat exchange efficiency between the refrigerant and water. At the same heat exchange efficiency, it is beneficial to reduce the length of the shell and tube heat exchanger, reduce the cost and miniaturize the heat exchange system.

[0007] According to some embodiments of the present invention, a plurality of spaced-apart rough structures are provided on the outer peripheral wall of the inner tube.

[0008] In some embodiments of the present invention, the rough structure is a groove and / or a protrusion formed on the outer peripheral wall of the inner tube.

[0009] In some embodiments of the present invention, the rough structure is in the shape of dots or strips.

[0010] In some embodiments of the present invention, the rough structure is strip-shaped, and the rough structure includes a first rough structure extending along the first spiral groove or the first spiral protrusion and / or includes a second rough structure arranged crosswise with the length direction of the first spiral protrusion or the first spiral groove.

[0011] According to some embodiments of the present invention, the outer tube is a circular tube, and the inner circumferential wall and the outer circumferential wall of the outer tube are both smooth wall surfaces.

[0012] According to some embodiments of the present invention, the gap between the first spiral protrusion and the inner circumferential wall of the outer tube is 0.5 mm-2 mm.

[0013] According to some embodiments of the utility model, the two ends of the inner tube in the length direction have a first inlet and a first outlet connected to the first cavity, and the two ends of the outer tube in the length direction have a second inlet and a second outlet connected to the second cavity, and the first inlet and the second inlet are respectively arranged at the two ends of the length direction of the shell and tube heat exchanger.

[0014] According to some embodiments of the present invention, the inner tube is a copper part, and the outer tube is a carbon steel part.

[0015] The heat exchange system according to the embodiment of the utility model includes the above-mentioned shell and tube heat exchanger.

[0016] According to the heat exchange system of the embodiment of the utility model, by setting the above-mentioned shell and tube heat exchanger, the first cavity in the inner tube is used for the flow of water, and the second cavity between the inner tube and the outer tube is used for the flow of refrigerant, and a plurality of first spiral protrusions spirally arranged along the length direction of the inner tube are arranged on the outer circumferential wall of the inner tube, and a first spiral groove spirally arranged along the length direction of the inner tube is defined between two adjacent first spiral protrusions, and a second spiral groove is provided on the inner circumferential wall of the inner tube at a position corresponding to the first spiral protrusion, and a second spiral protrusion is provided at a position corresponding to the first spiral groove, which can increase the heat dissipation area of ​​the refrigerant, increase the contact area and contact length between the refrigerant and water, and improve the heat exchange efficiency between the refrigerant and water. At the same heat exchange efficiency, it is beneficial to reduce the length of the shell and tube heat exchanger, reduce costs and miniaturize the heat exchange system.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a three-dimensional diagram of a shell-and-tube heat exchanger according to an embodiment of the utility model;

[0020] Figure 2 is a schematic diagram of a partial structure of a shell and tube heat exchanger according to an embodiment of the utility model;

[0021] Figure 3 yes Figure 2 A partial schematic diagram of the outer peripheral wall of the middle inner tube;

[0022] Figure 4 is a schematic diagram of a heat exchange system according to an embodiment of the utility model;

[0023] Figure 5 It is the temperature comparison of refrigerant heat exchange due to different water flow directions.

[0024] Reference numerals:

[0025] 100. Heat exchange system;

[0026] 10. Shell and tube heat exchanger;

[0027] 1. outer tube; 11. second cavity; 12. second inlet; 13. second outlet;

[0028] 2. inner tube; 21. first cavity; 22. first spiral protrusion; 23. first spiral groove; 24. second spiral protrusion; 25. second spiral groove; 26. first rough structure; 27. second rough structure; 28. first inlet; 29. ​​first outlet;

[0029] 20. Compressor; 201. Exhaust pipe; 202. High-pressure valve; 203. Capillary tube. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0031] In the description of the present utility model, it is necessary to understand that 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" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] A double-tube heat exchanger 10 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0034] like Figure 1 and Figure 2 As shown, the shell and tube heat exchanger 10 according to the embodiment of the present utility model comprises an outer tube 1 and an inner tube 2 .

[0035] Specifically, Figure 1 and Figure 2 As shown, the inner tube 2 is arranged inside the outer tube 1, and the cavity inside the inner tube 2 can be a first cavity 21. The outer peripheral wall of the inner tube 2 and the inner peripheral wall of the outer tube 1 are arranged at intervals, and the cavity defined between the outer peripheral wall of the inner tube 2 and the inner peripheral wall of the outer tube 1 can be a second cavity 11. The first cavity 21 can be used for the flow of water, and the second cavity 11 can be used for the flow of refrigerant. The first cavity 21 is designed as a water channel, and the second cavity 11 is designed as a refrigerant channel. Since the area of ​​the outer peripheral wall of the inner tube 2 is larger than the area of ​​the inner peripheral wall of the inner tube 2, compared with the first cavity designed as a refrigerant channel, it is beneficial for the gaseous refrigerant to have a larger heat dissipation surface area. At the same time, the high-temperature refrigerant can also dissipate heat with the outside world, realizing two-way heat exchange and improving the refrigerant heat dissipation efficiency.

[0036] Furthermore, if Figure 2As shown, the outer circumferential wall of the inner tube 2 is provided with a plurality of first spiral protrusions 22 spirally arranged along the length direction of the inner tube 2, and a first spiral groove 23 spirally arranged along the length direction of the inner tube 2 is defined between two adjacent first spiral protrusions 22. A second spiral groove 25 is provided on the inner circumferential wall of the inner tube 2 at a position corresponding to the first spiral protrusion 22, and a second spiral protrusion 24 is provided at a position corresponding to the first spiral groove 23.

[0037] It can be understood that the inner circumferential wall and the outer circumferential wall of the inner tube 2 have the same tendency of bulging and concaving along the radial direction of the inner tube 2. The outer circumferential wall of the inner tube 2 is a convex position, and the position of the inner circumferential wall of the inner tube 2 corresponding to the convex position of the outer circumferential wall of the inner tube 2 is a groove. The outer circumferential wall of the inner tube 2 is a groove position, and the position of the inner circumferential wall of the inner tube 2 corresponding to the groove of the outer circumferential wall of the inner tube 2 is a bulge. The wall thickness of the inner tube 2 is generally consistent.

[0038] Optionally, the inner tube 2 may be formed by providing a first spiral protrusion 22 and a first spiral groove 23 on the outer circumferential wall of the circular tube, and providing a second spiral protrusion 24 and a second spiral groove 25 on the inner circumferential wall of the circular tube.

[0039] Optionally, the wall thicknesses at any two positions of the inner tube 2 are equal.

[0040] In the present application, the spiral design of the inner tube 2 is beneficial to increase the contact area between the refrigerant and water. In addition, part of the refrigerant in the second cavity 11 flows along the first spiral groove 23. The rotating channel can lengthen the contact length between the refrigerant and water, and can improve the heat exchange efficiency between the refrigerant and water. Under the premise of the same heat exchange efficiency, the relatively smooth inner and outer walls of the round tube can reduce the length of the shell and tube heat exchanger 10, which is beneficial to reduce the cost and reduce the volume of the shell and tube heat exchanger 10, thereby facilitating the miniaturization of the heat exchange system 100 using this shell and tube heat exchanger 10.

[0041] According to the shell and tube heat exchanger 10 of the embodiment of the utility model, the first cavity 21 in the inner tube 2 is used for the flow of water, and the second cavity 11 between the inner tube 2 and the outer tube 1 is used for the flow of refrigerant, and a plurality of first spiral protrusions 22 spirally arranged along the length direction of the inner tube 2 are provided on the outer peripheral wall of the inner tube 2, and a first spiral groove 23 spirally arranged along the length direction of the inner tube 2 is defined between two adjacent first spiral protrusions 22, and a second spiral groove 25 is provided on the inner peripheral wall of the inner tube 2 at a position corresponding to the first spiral protrusion 22, and a second spiral protrusion 24 is provided at a position corresponding to the first spiral groove 23, thereby increasing the heat dissipation area of ​​the refrigerant, increasing the contact area and contact length between the refrigerant and water, and improving the heat exchange efficiency between the refrigerant and water. At the same heat exchange efficiency, it is beneficial to reduce the length of the shell and tube heat exchanger 10, reduce the cost and miniaturize the heat exchange system 100.

[0042] like Figure 2 and Figure 3As shown, a plurality of spaced rough structures are provided on the outer peripheral wall of the inner tube 2. The rough structures can make the outer peripheral wall of the inner tube 2 rougher, increase the friction of the refrigerant channel, increase the resistance of the refrigerant flow, help slow down the flow speed of the refrigerant, prolong the heat exchange time between the refrigerant and water, and improve the heat exchange efficiency.

[0043] Optionally, the rough structure is a groove and / or a protrusion formed on the outer peripheral wall of the inner tube 2. It is understandable that the rough structure may be only a groove formed on the outer peripheral wall of the inner tube 2, or the rough structure may be only a protrusion formed on the outer peripheral wall of the inner tube 2, or the rough structure may include both protrusions formed on the outer peripheral wall of the inner tube 2 and grooves formed on the outer peripheral wall of the inner tube 2. In this way, the diversity of the rough structure can be increased, and different rough structures can be set according to different heat exchange efficiencies, so that the shell-and-tube heat exchanger 10 meets the heat exchange requirements.

[0044] Optionally, the rough structure is dot-shaped or strip-shaped. For example, when the rough structure is a groove, the rough structure can be a dot-shaped groove or a strip-shaped groove, and when the rough structure is a protrusion, the rough structure can be a dot-shaped protrusion or a strip-shaped protrusion. This can increase the diversity of the rough structure, and different rough structures can be set according to different heat exchange efficiencies, so that the shell-and-tube heat exchanger 10 meets the heat exchange requirements.

[0045] In some embodiments of the present invention, the rough structure is strip-shaped, and the rough structure includes a first rough structure 26 extending along the length direction of the first spiral groove 23 or the first spiral protrusion 22 and / or includes a second rough structure 27 intersecting the length direction of the first spiral protrusion 22 or the first spiral groove 23. It can be understood that the rough structure is strip-shaped, and the rough structure may only include the first rough structure 26 extending along the length direction of the first spiral groove 23 or the first spiral protrusion 22, or the rough structure may only include the second rough structure 27 intersecting the length direction of the first spiral protrusion 22 or the first spiral groove 23, or the rough structure may include both the first rough structure 26 extending along the length direction of the first spiral groove 23 or the first spiral protrusion 22 and the second rough structure 27 intersecting the length direction of the first spiral protrusion 22 or the first spiral groove 23, wherein the first rough structure 26 and the second rough structure 27 may be intersectingly arranged to form a lattice or grid shape.

[0046] For example, in Figure 3In the example shown, a rough structure is provided on the outer peripheral wall of the inner tube 2, and the rough structure is provided on the first spiral protrusion 22. The rough structure includes both a first rough structure 26 extending along the length direction of the first spiral protrusion 22 and a second rough structure 27 arranged crosswise with the length direction of the first spiral protrusion 22. The first rough structure 26 is a plurality of structures arranged at intervals along the width direction of the first spiral protrusion 22, and the second rough structure 27 is a plurality of structures arranged at intervals along the length direction of the first spiral protrusion 22. The plurality of first rough structures 26 and the plurality of second rough structures 27 are arranged to intersect to form a grid shape.

[0047] In some embodiments of the present invention, Figure 3 As shown, the outer tube 1 is a round tube, and the inner and outer peripheral walls of the outer tube 1 are both smooth walls, thereby simplifying the structure and processing technology of the outer tube 1 and improving production efficiency.

[0048] In some embodiments of the utility model, the gap between the first spiral protrusion 22 and the inner peripheral wall of the outer tube 1 is 0.5mm-2mm. In this way, the distance between the first spiral protrusion 22 and the inner peripheral wall of the outer tube 1 can be reduced, and part of the refrigerant flows in the slit between the first spiral protrusion 22 and the inner peripheral wall of the outer tube 1 along the length direction of the shell-and-tube heat exchanger 10, which can ensure that each section of the fast-flowing refrigerant can be completely heat-exchanged, thereby improving the heat exchange efficiency.

[0049] In some embodiments of the present invention, Figure 1 As shown, the inner tube 2 has a first inlet 28 and a first outlet 29 connected to the first cavity 21 at both ends in the length direction. Water enters the first cavity 21 from the first inlet 28 and flows out from the first outlet 29, that is, water flows from the first inlet 28 to the first outlet 29. The outer tube 1 has a second inlet 12 and a second outlet 13 connected to the second cavity 11 at both ends in the length direction. The refrigerant flows into the second cavity 11 from the second inlet 12 and flows out from the second outlet 13, that is, the refrigerant flows from the second inlet 12 to the second outlet 13. Among them, the first inlet 28 and the second inlet 12 are respectively arranged at both ends in the length direction of the shell-and-tube heat exchanger 10, that is, the flow paths of the refrigerant and water are in opposite directions. For example, in Figure 1 In the example shown, the shell-and-tube heat exchanger 10 is wound in a spiral shape, the refrigerant flow path is counterclockwise, and the water flow path is clockwise, and the two are in countercurrent directions.

[0050] Reverse flow of refrigerant and water can play a greater role than unidirectional flow when the temperature difference between water and refrigerant is large. For the water-cooled outdoor unit of kitchen air conditioner, we compare the cooling capacity of air conditioner with unidirectional and reverse water flow. Figure 5 As shown, the temperature of the exhaust pipe 201 (condensation inlet temperature) can reach 90 degrees Celsius. When the condensation outlet temperature is lower, the heat exchange capacity is greater and the cooling capacity is greater.

[0051] The specific system diagram is as follows Figure 4 As shown, the compressor 20 passes the high-temperature refrigerant through the exhaust pipe 201 and then through the second inlet 12 of the casing into the second cavity 11 of the outer layer of the casing heat exchanger 10, and then comes out from the second outlet 13 of the casing, enters the capillary 203 to limit the flow, and then reaches the high-pressure valve 202; the low-temperature water enters the first cavity 21 of the inner layer of the casing heat exchanger 10 from the first inlet 28, flows in the opposite direction of the refrigerant, and is discharged from the first outlet 29. In this process, the heat of the refrigerant in the outer layer of the casing is absorbed, and the purpose of heat exchange is achieved.

[0052] Table 1

[0053]

[0054]

[0055] The test data can be exported through Table 1 Figure 5 Line chart, through Figure 5 It can be seen from the line graph that when the water flows in the same direction as the refrigerant, the middle of the casing (cold middle temperature) is lower than when they flow in the opposite direction. This is because when the two flow in the same direction, the temperature difference between the refrigerant temperature of 92℃ (exhaust temperature) at the casing inlet and the inlet water temperature of 30℃ is 62℃. The heat exchange rate will be faster in the first half of the casing, and the refrigerant temperature can drop faster; but at this time, the water temperature of the same-direction scheme has reached 52.5℃, and the temperature difference with the refrigerant temperature of 60.62℃ is very small, resulting in a very slow heat exchange rate in the second half of the casing. Finally, the refrigerant temperature at the outlet position only reaches 57.35℃ (cold outlet temperature), which is less than 2℃ different from the water temperature. The same-direction scheme only reduces the refrigerant temperature by 34.65℃.

[0056] For the solution where the water flow direction is opposite to the refrigerant flow direction, the refrigerant temperature of 92℃ (exhaust temperature) at the casing inlet has a temperature difference of 23.44℃ with the heated water temperature of 68.56℃. The refrigerant temperature at the casing outlet is 43.42℃, which has a temperature difference of 13.42℃ with the 30℃ water temperature just entering the casing. By comparing the two curves of reverse medium temperature and reverse water temperature, it can be seen that the curvatures of the two are basically the same, and a relatively uniform temperature difference is maintained during the heat exchange process. The casing is reasonably utilized and more heat can be dissipated through water. On the other hand, the curves of the same-direction medium temperature and the same-direction water temperature have a faster heat exchange in the first half of the casing, but in the second half, due to the small temperature difference between the water temperature and the coal temperature, the heat exchange is very slow and cannot reach the water temperature of the reverse solution. The water takes away less heat and the heat exchange capacity is lower. Comparing the cooling capacity of the two, it can be seen that the 2927W of the reverse solution is 530W higher than the 2396W of the same direction. This shows that under the same environmental conditions, water temperature and water flow rate, the heat exchange efficiency is higher and the cooling capacity is greater when the water flow direction is opposite to the refrigerant flow direction.

[0057] In summary, the utility model adopts a kitchen water-cooled air-conditioning system with water counterflow, combined with a twisted sleeve with an indentation, which can effectively improve the cooling capacity of the air-conditioning, make full use of water to carry away heat, shorten the sleeve length under the same capacity, reduce the volume and reduce the cost.

[0058] In some embodiments of the present invention, the inner tube 2 is a copper part, and the outer tube 1 is a carbon steel part, thereby improving the corrosion resistance of the shell-and-tube heat exchanger 10 and ensuring the heat exchange effect of the shell-and-tube heat exchanger 10 .

[0059] In some embodiments of the present invention, Figure 1 As shown, the shell and tube heat exchanger 10 is wound in a spiral shape. This can reduce the space occupied by the shell and tube heat exchanger. Figure 4 As shown, the compressor 20 is disposed in the middle space of the shell-and-tube heat exchanger 10 , which can effectively utilize the internal space of the shell-and-tube heat exchanger 10 and improve the space utilization rate of the heat exchange system 100 .

[0060] The heat exchange system 100 according to an embodiment of the present invention is described below.

[0061] like Figure 4 As shown, the heat exchange system 100 according to the embodiment of the present invention includes the above-mentioned shell and tube heat exchanger 10.

[0062] Specifically, the heat exchange system 100 may also include a compressor 20, an evaporator and other structures. The exhaust port of the compressor 20 may be connected to the second inlet 12 of the shell-and-tube heat exchanger 10. The shell-and-tube heat exchanger 10 may be used as a condenser to achieve heat dissipation and cooling of the refrigerant, and to achieve water heating to meet the user's water demand. The evaporator may be a heat exchanger for an indoor unit of an air conditioner. The evaporator evaporates and absorbs heat, and can achieve refrigeration of the indoor unit of the air conditioner. The heat exchange system 100 according to the utility model not only achieves indoor refrigeration, but also achieves hot water production, meeting the various needs of users.

[0063] According to the heat exchange system 100 of the embodiment of the utility model, by setting the above-mentioned shell and tube heat exchanger 10, the first cavity 21 in the inner tube 2 is used for the flow of water, and the second cavity 11 between the inner tube 2 and the outer tube 1 is used for the flow of refrigerant, and a plurality of first spiral protrusions 22 spirally arranged along the length direction of the inner tube 2 are arranged on the outer peripheral wall of the inner tube 2, and a first spiral groove spirally arranged along the length direction of the inner tube 2 is defined between two adjacent first spiral protrusions 22, and a second spiral groove is provided on the inner peripheral wall of the inner tube 2 at a position corresponding to the first spiral protrusion 22, and a second spiral protrusion 24 is provided at a position corresponding to the first spiral groove, which can increase the heat dissipation area of ​​the refrigerant, increase the contact area and contact length between the refrigerant and water, and improve the heat exchange efficiency between the refrigerant and water. At the same heat exchange efficiency, it is beneficial to reduce the length of the shell and tube heat exchanger 10, which is beneficial to reduce the cost and miniaturization of the heat exchange system 100.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" 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 utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A shell and tube heat exchanger, characterized in that: include: External pipe; An inner tube, wherein the inner tube is passed through the outer tube, the first cavity in the inner tube is used for water flow, the second cavity between the inner tube and the outer tube is used for refrigerant flow, the outer circumferential wall of the inner tube is provided with a plurality of first spiral protrusions spirally arranged along the length direction of the inner tube, a first spiral groove spirally arranged along the length direction of the inner tube is defined between two adjacent first spiral protrusions, a second spiral groove is provided on the inner circumferential wall of the inner tube at a position corresponding to the first spiral protrusion, and a second spiral protrusion is provided at a position corresponding to the first spiral groove.

2. The double-tube heat exchanger according to claim 1, characterized in that: A plurality of spaced-apart rough structures are arranged on the outer peripheral wall of the inner tube.

3. The double-tube heat exchanger according to claim 2, characterized in that: The rough structure is a groove and / or a protrusion formed on the outer peripheral wall of the inner tube.

4. The double-tube heat exchanger according to claim 3, characterized in that: The rough structure is in the shape of dots or stripes.

5. The double-tube heat exchanger according to claim 4, characterized in that: The rough structure is strip-shaped, and includes a first rough structure extending along the first spiral groove or the first spiral protrusion and / or includes a second rough structure arranged to cross the length direction of the first spiral protrusion or the first spiral groove.

6. The double-tube heat exchanger according to claim 1, characterized in that: The outer tube is a circular tube, and the inner circumferential wall and the outer circumferential wall of the outer tube are both smooth wall surfaces.

7. The double-tube heat exchanger according to claim 1, characterized in that: The gap between the first spiral protrusion and the inner circumferential wall of the outer tube is 0.5mm-2mm.

8. The double-tube heat exchanger according to claim 1, characterized in that: The inner tube has a first inlet and a first outlet connected to the first cavity at both ends in the length direction, and the outer tube has a second inlet and a second outlet connected to the second cavity at both ends in the length direction. The first inlet and the second inlet are respectively arranged at both ends in the length direction of the shell-and-tube heat exchanger.

9. The double-tube heat exchanger according to claim 1, characterized in that: The inner tube is a copper part, and the outer tube is a carbon steel part.

10. A heat exchange system, characterized in that: It comprises a double-tube heat exchanger according to any one of claims 1 to 9.

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