A pipe-in-pipe heat exchanger and heat pump for a heat pump overseas swimming pool machine

Abstract

The utility model relates to a pipe cover pipe heat exchanger for overseas swimming pool machine of heat pump, including outer tube and titanium screw pipe, the outer tube spiral spring shape is established, and its both ends are equipped with refrigerant import and refrigerant export respectively, titanium screw pipe is nested in the outer tube inner chamber, and its both ends are equipped with water outlet and water inlet respectively, the spiral convex rib of titanium screw pipe exists with the outer tube inner wall gap, the annular channel is formed between the outer tube inner wall and titanium screw pipe outer wall, and the refrigerant flows in the annular channel, and the refrigerant flow direction is opposite with the water flow direction in titanium screw pipe, the utility model discloses the inner tube is titanium screw pipe through the setting, to increase the contact area of refrigerant and swimming pool water, improve the heat exchange efficiency of pipe cover pipe heat exchanger, through setting the refrigerant flow direction and swimming pool water flow direction are full counterflow, to further realize the heat exchange efficiency of pipe cover pipe heat exchanger is improved significantly.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a tube-to-tube heat exchanger and a heat pump for a heat pump swimming pool machine. Background Technology

[0002] In overseas swimming pool heat pump systems, the heat exchanger, as one of the core components, plays a crucial role in transferring heat between the refrigerant side and the water side to supply heat to the user. Because swimming pool water typically contains corrosive substances such as chloride ions and salt, especially in coastal areas or seawater swimming pools, traditional copper or stainless steel heat exchangers are prone to severe corrosion, resulting in short service life and high maintenance costs.

[0003] To address the poor corrosion resistance of traditional copper or stainless steel tube-and-shell heat exchangers, existing pool heat pump heat exchangers employ a vertical design combining PVC outer tubes and titanium tube heat exchangers. (Please refer to...) Figure 1 This vertical titanium tube heat exchanger includes a cylindrical body 1, a water outlet 2, and a water inlet 3. A heat exchanger jacket 4 is located inside the cylindrical body, within which titanium coils 5 are wound. The water outlet 2 and water inlet 3 are located at the upper and lower ends of the heat exchanger jacket 4, respectively. The inlet of the titanium coil 5 is a refrigerant inlet 6, and the outlet of the titanium coil 5 is a refrigerant outlet 7. Both the refrigerant inlet 6 and the refrigerant outlet 7 extend out of the heat exchanger jacket 4 through pipe fittings. The titanium coils 5 are spirally and interwoven within the heat exchanger jacket 4. This vertical titanium tube heat exchanger can meet the basic corrosion resistance requirements for pool machine water, but it suffers from relatively low heat exchange efficiency. Utility Model Content

[0004] Based on this, one of the objectives of this utility model is to provide a tube-to-tube heat exchanger for a heat pump overseas swimming pool machine. By setting the inner tube to be a titanium threaded tube, the contact area between the refrigerant and the pool water is increased, thereby improving the heat exchange efficiency of the tube-to-tube heat exchanger. Furthermore, by setting the refrigerant flow direction and the fluid flow direction to be completely counter-current, the heat exchange efficiency of the tube-to-tube heat exchanger is significantly improved.

[0005] Another objective of this invention is to provide a heat pump equipped with the aforementioned tube-to-tube heat exchanger for an overseas swimming pool machine, which can achieve high corrosion resistance and high heat exchange efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A tube-to-tube heat exchanger for a heat pump swimming pool machine includes an outer tube and a titanium threaded tube. The outer tube is coiled into a spring shape, with a refrigerant inlet and a refrigerant outlet at its two ends. The titanium threaded tube is nested inside the outer tube, with a water outlet and a water inlet at its two ends. The spiral ribs of the titanium threaded tube have gaps with the inner wall of the outer tube, and an annular channel is formed between the inner wall of the outer tube and the outer wall of the titanium threaded tube. The refrigerant flows in the annular channel, and the liquid flows in the titanium threaded tube, with the refrigerant flow direction opposite to the liquid flow direction.

[0008] Furthermore, the tube-to-tube heat exchanger for the heat pump overseas swimming pool machine also includes a first refrigerant pipe and a second refrigerant pipe for communicating with an external refrigerant flow path, wherein the first refrigerant pipe is connected to the refrigerant inlet and the second refrigerant pipe is connected to the refrigerant outlet.

[0009] Furthermore, the diameter of the second refrigerant pipe is 60-90% of the diameter of the first refrigerant pipe.

[0010] Furthermore, the tube-to-tube heat exchanger for the heat pump overseas swimming pool machine also includes a first connector and a second connector for connecting to an external water circuit, wherein the inlet is sealed to the first connector and the outlet is sealed to the second connector.

[0011] Furthermore, the first and second connectors are titanium threaded connectors or flange connectors.

[0012] Furthermore, the tube-to-tube heat exchanger for the heat pump overseas swimming pool machine also includes a first tee assembly and a second tee assembly. The refrigerant inlet is connected to the first refrigerant pipe through the first tee assembly, the refrigerant outlet is connected to the second refrigerant pipe through the second tee assembly, the water outlet passes through the first tee assembly and is connected to the first connector, and the water inlet passes through the second tee assembly and is connected to the second connector.

[0013] Furthermore, the outer tube is a double-layer tube, with an inner layer of carbon steel, stainless steel, or titanium, and an outer layer of thermal insulation cotton.

[0014] Furthermore, the pitch and gap of the titanium threaded tube gradually decrease from the outlet to the inlet; the thread depth of the titanium threaded tube gradually increases from the outlet to the inlet.

[0015] Furthermore, a spiral band is provided inside the titanium threaded tube and / or inside the annular channel.

[0016] On the other hand, this utility model also provides a heat pump, including the above-mentioned tube-to-tube heat exchanger for heat pump overseas swimming pool machines.

[0017] The beneficial effects of this utility model are as follows:

[0018] (1) By using titanium threaded tubes as heat exchange pipelines for pool water, the corrosion resistance of the tube-to-tube heat exchanger is improved. Titanium threaded tubes have extremely strong resistance to chloride ion and salt corrosion, and are suitable for pools under various water quality conditions, including pools in coastal areas with high salt content or seawater pools, and have broad market application prospects.

[0019] (2) The threaded structure on the surface of the titanium threaded pipe can effectively increase the surface area of ​​the refrigerant and pool water, extend the flow path of the fluid and significantly enhance the turbulent flow of the fluid, thereby improving the heat transfer coefficient.

[0020] (3) By setting the outer layer of the outer tube to be insulation cotton, air is isolated to prevent air from affecting the overall heat exchange efficiency.

[0021] (4) By adopting a modular design, the tube-to-tube heat exchanger is small in size and easy to install, and each component can be replaced individually. By placing components such as the compressor in the heat pump in the middle of the tube-to-tube heat exchanger, the volume occupied by each component in the heat pump is reduced.

[0022] (5) By setting the titanium threaded pipe that is only in key contact with the pool water to be made of titanium, the rest of the structure, such as the outer pipe, is made of carbon steel and stainless steel.

[0023] (6) By adjusting the specific parameters of the titanium threaded pipe, it can meet the pressure resistance test (i.e., no leakage in 60,000 alternating tests when the refrigerant side alternating pressure reaches 4MPa; no leakage in 60,000 alternating tests when the water side alternating pressure reaches 0.5MPa, with a test frequency of 10-30 times / min), so as to ensure the flow state of the pool water and reduce the flow resistance.

[0024] (7) By setting a spiral ribbon inside the titanium threaded tube and in the annular channel between the titanium threaded tube 14 and the outer tube 12, the heat exchange efficiency can be improved by 2%-4%.

[0025] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a vertical titanium tube heat exchanger in the prior art;

[0027] Figure 2 A schematic diagram of the tube-to-tube heat exchanger for a heat pump overseas swimming pool machine provided by this utility model;

[0028] Figure 3 for Figure 2 The diagram shows the structure of the tubing assembly.

[0029] Figure 4 for Figure 3 A cross-sectional schematic diagram of the tube-casing assembly shown;

[0030] Figure 5 for Figure 2 A schematic diagram of one embodiment of the first tee assembly is shown;

[0031] Figure 6 for Figure 2 A schematic diagram of one embodiment of the first tee assembly is shown;

[0032] Figure 7 This is a schematic diagram of the flange joint structure;

[0033] Figure 8 This is a schematic diagram of the spiral ligature structure;

[0034] In the diagram: 1-Cylinder body; 2-Water outlet; 3-Water inlet; 4-Heat exchanger jacket; 5-Titanium coil; 6-Fluorine inlet; 7-Fluorine outlet;

[0035] 10-Pipe-casing assembly; 12-Outer pipe; 122-Refrigerant inlet; 124-Refrigerant outlet; 14-Titanium threaded pipe; 142-Outlet; 144-Inlet; 146-Helical rib; 148-Multi-head spiral section pipe body; 22-First tee assembly; 222-First interface; 224-Second interface; 226-Third interface; 24-Second tee assembly; 32-First refrigerant pipe; 34-Second refrigerant pipe; 36-First connector; 38-Second connector; 362-Flange body; 364-Rubber sealing ring; 366-Clamp; 368-Bolt. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] In the description of this utility model, it should be noted that the terms "upper," "lower," "bottom," "top," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, unless otherwise stated, "a plurality of" means two or more.

[0038] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] Existing heat pump pool coolers typically employ vertical titanium tube heat exchangers. In these exchangers, the water path is located in the middle of the tank. Pool water enters from the bottom of the tank, flows upwards, and exits from the top. Refrigerant piping is spirally wound around the outside of the water path. The refrigerant enters from the top of the tank, spirals downwards to the bottom, then spirals upwards again and exits from the top. The refrigerant outlet flow direction is co-current with the pool water flow, resulting in low heat exchange efficiency. Furthermore, the small contact area between the pool water and refrigerant inside the tank, and their lack of direct contact, also contributes to low heat exchange efficiency.

[0040] Based on this, the present invention provides a tube-to-tube heat exchanger for a heat pump overseas swimming pool machine. By setting the inner tube to be a titanium threaded tube, the contact area between the refrigerant and the pool water is increased, thereby improving the heat exchange efficiency of the tube-to-tube heat exchanger. Furthermore, by setting the refrigerant flow direction and the fluid flow direction to be completely counter-current, the heat exchange efficiency of the tube-to-tube heat exchanger is significantly improved.

[0041] Please see Figure 2-4 The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine provided in this embodiment includes a tube-to-tube assembly 10. The tube-to-tube assembly 10 includes an outer tube 12 and a titanium threaded tube 14. The outer tube 12 is coiled into a spring shape, and its two ends are respectively provided with a refrigerant inlet 122 and a refrigerant outlet 124. The titanium threaded tube 14 is nested in the inner cavity of the outer tube 12, and its two ends are respectively provided with a water outlet 142 and a water inlet 144. There is a gap between the spiral ribs 146 of the titanium threaded tube 14 and the inner wall of the outer tube 12, and an annular channel is formed between the inner wall of the outer tube 12 and the outer wall of the titanium threaded tube 14. The refrigerant flows in the annular channel, and the pool water flows in the titanium threaded tube 14. The refrigerant flow direction is opposite to the pool water flow direction.

[0042] Compared to existing vertical titanium tube heat exchangers, this embodiment features an outer tube 12 spiraled into a helical shape, with a titanium threaded tube housed inside. The interior of the titanium threaded tube 14 serves as a liquid (e.g., pool water) conduit, while the annular channel formed between the titanium threaded tube 14 and the outer tube 12 acts as a refrigerant conduit. This design improves the corrosion resistance of the tube-to-tube heat exchanger and increases the heat exchange area between the pool water and the refrigerant, thereby enhancing the heat exchange efficiency. Furthermore, the flow direction of the refrigerant in the outer tube 12 is opposite to that of the liquid (pool water) in the titanium threaded tube 14, further improving the heat exchange efficiency between the pool water and the refrigerant, thus further enhancing the overall heat exchange efficiency of the tube-to-tube heat exchanger.

[0043] The tube-to-tube heat exchanger also includes a first tee assembly 22 and a second tee assembly 24. The refrigerant inlet 122 and refrigerant outlet 124 of the outer tube 12 are connected to the external refrigerant flow path, i.e., the refrigerant flow path of the heat pump overseas swimming pool unit, through the first tee assembly 22 and the second tee assembly 24, respectively. The outlet 142 and inlet 144 of the titanium threaded tube 14 are connected to the external water path, i.e., the water path of the heat pump overseas swimming pool unit, through the first tee assembly 22 and the second tee assembly 24, respectively.

[0044] For example, please refer to Figure 5 The outer pipe 12 has openings at both ends serving as a refrigerant inlet 122 and a refrigerant outlet 124. The titanium threaded pipe 14 has openings at both ends protruding from the outer pipe 12, serving as a water outlet 142 and a water inlet 144, respectively. The first interface 222 of the first tee assembly 22 is sealed to the outer wall of the top end of the outer pipe 12, the second interface 224 is sealed to the outer wall of the top end of the titanium threaded pipe 14, and the third interface 226 communicates with the refrigerant inlet 122 of the outer pipe 12. The first interface of the second tee assembly 24 is sealed to the outer wall of the bottom end of the outer pipe 12, the second interface is sealed to the outer wall of the bottom end of the titanium threaded pipe 14, and the third interface communicates with the refrigerant outlet 124 of the outer pipe 12.

[0045] For example, please refer to Figure 6 The outer tube 12 has two openings that are sealed to the outer walls of the titanium threaded tube 14 at both ends. The outer walls of the outer tube 12 have refrigerant inlets 122 and refrigerant outlets 124 at both ends. The titanium threaded tube 14 protrudes from the outer tube 12 at both ends, with its openings serving as outlets 142 and inlets 144, respectively. The first port 222 and second port 224 of the first tee assembly 22 are sealed to the outer wall of the top end of the outer tube 12, and the third port 226 communicates with the refrigerant inlet 122 of the outer tube 12. The first port and second port of the second tee assembly 24 are sealed to the outer wall of the bottom end of the outer tube 12, and the third port communicates with the refrigerant outlet 124 of the outer tube 12.

[0046] Preferably, the refrigerant inlet 122 of the outer pipe 12 and the water outlet 142 of the titanium threaded pipe 14 are located at the top of the pipe-casing assembly 10, and the refrigerant outlet 124 of the outer pipe 12 and the water inlet 144 of the titanium threaded pipe 14 are located at the bottom of the pipe-casing assembly 10.

[0047] Please see Figure 2 The tube-to-tube heat exchanger also includes a first refrigerant pipe 32 for connecting to the refrigerant pipeline outlet of the heat pump overseas swimming pool unit, and a second refrigerant pipe 34 for connecting to the refrigerant pipeline inlet of the heat pump overseas swimming pool unit. The first refrigerant pipe 32 and the second refrigerant pipe 34 are respectively connected to the third interface 226 of the first tee assembly 22 and the third interface of the second tee assembly 24. Preferably, the first refrigerant pipe 32 and the second refrigerant pipe 34 are copper pipes, and are located inside the tube-to-tube assembly to reduce the space occupied by the tube-to-tube heat exchanger. The end of the first refrigerant pipe 32 away from the first tee assembly 22 and the end of the second refrigerant pipe 34 away from the second tee assembly 24 are provided with copper threaded joints.

[0048] The tube-to-tube heat exchanger also includes a first connector 36 for connecting to the water inlet (i.e., the collection tank) of the heat pump overseas swimming pool unit and a second connector 38 for connecting to the water outlet (i.e., the outlet tank) of the heat pump overseas swimming pool unit. The first connector 36 and the second connector 38 are respectively sealed to the outlet 142 and the inlet 144 of the titanium threaded tube 14. The first connector 36 and the second connector 38 are titanium threaded connectors, preferably titanium external threaded connectors, which have good connectability and temperature resistance, and are more conducive to welding to both ends of the titanium threaded tube 14. Alternatively, the first connector 36 and the second connector 38 can be flanged connectors to reduce the difficulty and cost of manufacturing the tube-to-tube heat exchanger.

[0049] Please see Figure 7 In some embodiments, the flange joint includes a flange body 362, a rubber sealing ring 364, a clamp 366, and bolts 368. The flange body 362 has a flange seat, a flange, and a socket end, with the outer diameter of the flange being larger than the outer diameter of the titanium threaded tube 14. The rubber sealing ring 364 is disposed on the side of the flange body 362 facing the titanium threaded tube 14. The clamp hook of the clamp 366 is connected to the flange of the flange body 362, and the clamp 366 is clamped to the end of the titanium threaded tube 14 by bolts 368. When connected to the end of the titanium threaded tube 14, the socket end of the flange body 362 is inserted into the inner cavity of the titanium threaded tube 14, and the rubber sealing ring 364 disposed on the flange forms a sealing surface with the end of the titanium threaded tube 14. The clamp 366 consists of two halves, which are clamped to the outer wall of the titanium threaded tube 14 by bolts 368. The clamp hook is connected to the flange flange. When the clamp 366 is tightened, the inner side of the clamp 366 is in close contact with the outer wall of the titanium threaded tube 14, and the connection is completed. This flange joint is made of corrosion-resistant material and has strong anti-detachment, leak-proof, pressure-resistant, and waterproof properties.

[0050] Preferably, the tee assembly is welded to the outer pipe 12, the titanium threaded pipe 14, the first refrigerant pipe 32, and the second refrigerant pipe 34 to ensure complete isolation of the fluids inside and outside the titanium threaded pipe 14 and to ensure that the pipeline can withstand a certain water pressure without leakage.

[0051] The outer tube 12 has a double-layer structure. The inner layer is a carbon steel layer or a stainless steel layer, which reduces the overall manufacturing cost of the tube-to-tube heat exchanger by more than 50%. The outer layer is an insulation cotton layer, which can isolate air and prevent air from affecting the heat exchange efficiency of the tube-to-tube heat exchanger. The thickness of the insulation cotton is 5-15mm, preferably 10mm, which can improve the heat exchange efficiency of the tube-to-tube heat exchanger by more than 10%.

[0052] In other embodiments, the inner layer of the outer tube 12 is made of corrosion-resistant titanium, further enhancing the corrosion resistance of the tube-to-tube heat exchanger and ensuring its applicability to a wide range of chloride ion concentrations. Furthermore, using the same material for the outer tube and the titanium threaded tube solves welding process issues between different materials, significantly reducing welding costs and standardizing the procurement of raw materials for tube-to-tube heat exchanger processing, thus providing effective support for material standardization within enterprises. In this embodiment, the pool water piping and refrigerant piping are interchangeable; that is, the titanium threaded tube 14 is connected to the refrigerant piping of the heat pump overseas pool unit, and both ends of the outer tube 12 are connected to the water piping of the heat pump overseas pool unit.

[0053] The titanium threaded tube 14 includes two ends and a multi-start helical section tube body 148 disposed between the two ends. The multi-start helical section tube body 148 has a helical angle of 30-50°, a thread depth of 2-5 mm, a thread pitch of 3-6 mm, a tube wall thickness of 0.3-0.6 mm, and a multi-start helical groove pattern with 3 to 8 thread starts. In this embodiment, the multi-start helical section tube body 148 adopts a 4-start helical groove pattern, and its cross-section is in the shape of a "quadrilateral star". (See reference...) Figure 4 The gap between the spiral rib 146 of the titanium threaded tube 14 and the inner wall of the outer tube 12 is 2-5mm, preferably 2mm, to ensure that a stable and well-shaped annular channel is formed between the two for the circulation of pool water and the flow of refrigerant.

[0054] Preferably, a stainless steel bracket is used to support and fix the outer tube 12, preventing deformation caused by the spring shape formed by the coiling of the outer tube 12. The stainless steel bracket can also fix the tube-to-tube heat exchanger inside the heat pump, facilitating maintenance and repair.

[0055] Because the refrigerant in the outer tube 12 exchanges heat with the pool water in the titanium threaded tube 14, the refrigerant changes from a high-temperature, high-pressure gaseous state to a high-temperature, high-pressure liquid state. This reduction in refrigerant volume leads to a decrease in refrigerant flow rate and a significant drop in the heat exchange efficiency of the tube-to-tube heat exchanger. The refrigerant's residence time in the outer tube 12 also increases, potentially causing localized overheating or undercooling. Therefore, in this embodiment, the diameter of the refrigerant outlet 124 of the outer tube 12 is set to 60-90% of the diameter of the refrigerant inlet 122 of the outer tube 12, and the diameter of the second refrigerant tube 34 is set to 60-90% of the diameter of the first refrigerant tube 32. This increases the pressure on the refrigerant outlet 124 side, promoting refrigerant flow in the outer tube 12.

[0056] The working principle of the tube-to-tube heat exchanger provided in this embodiment is as follows: The refrigerant of the heat pump overseas swimming pool machine is compressed into a high-temperature and high-pressure gaseous state by the compressor, and then enters the outer tube 12 through the first refrigerant pipe 32, the third interface 226 of the first tee assembly 22, and the refrigerant inlet 122 of the outer tube 12. It flows along the refrigerant flow area between the outer tube 12 and the titanium threaded tube 14, i.e., the outer annular channel. During this period, the high-temperature and high-pressure gaseous refrigerant releases heat and condenses, changing from a high-temperature and high-pressure gaseous state to a high-temperature and high-pressure liquid state, transferring heat to the pool water in the titanium threaded tube 14. The high-temperature and high-pressure liquid refrigerant enters the throttling device of the heat pump overseas swimming pool machine through the refrigerant outlet 124 of the outer tube 12, the third interface of the second tee assembly 24, and the second refrigerant pipe 34. After being throttled and depressurized by the throttling device, it becomes a low-temperature and low-pressure liquid state, and then evaporates into a gaseous state through the evaporator of the heat pump overseas swimming pool machine. It then enters the compressor for compression, completing the refrigerant cycle. The pool water from the heat pump overseas swimming pool machine enters the outlet tank, and then enters the titanium threaded pipe 14 through the inlet 144 of the second connector 38 and the titanium threaded pipe 14. During this period, the pool water absorbs the heat released by the refrigerant and rises to the required temperature. The high-temperature pool water enters the liquid collection tank of the heat pump overseas swimming pool machine through the outlet 142 of the titanium threaded pipe 14 and the first connector 36. The high-temperature pool water in the liquid collection tank enters the pool, and the low-temperature pool water in the pool is discharged from the pool and enters the outlet tank, completing the water circulation.

[0057] Because the refrigerant releases heat and undergoes changes in temperature and state when flowing within the heat exchanger, and different states of refrigerant place different requirements on the tube-and-tube assembly 10, this invention also provides an embodiment in which the pitch of the titanium threaded tube 14, the gap between the inner wall of the outer tube 12 and the spiral ribs 146 of the titanium threaded tube 14 gradually decreases from the outlet 142 at the top of the tube-and-tube assembly 10 to the inlet 144 at the bottom of the tube-and-tube assembly 10, while the thread depth of the titanium threaded tube 14 gradually increases from the outlet 142 to the inlet 144. At the inlet 144 of the titanium threaded tube 14, the synergistic effect of small pitch, large thread depth, and small gap maximizes centrifugal force disturbance, increases turbulent kinetic energy, and thus enhances heat exchange. At the outlet 142 of the titanium threaded tube 14, the synergistic effect of large pitch, small thread depth, and large gap reduces flow tortuosity, expands the flow area, and thus reduces shear stress, thereby reducing resistance and promoting pool water flow.

[0058] Please see Figure 8 To further improve the heat exchange efficiency of the shell-and-tube heat exchanger, a spiral ribbon 16 is provided inside the titanium threaded tube 14, and the diameter of the spiral ribbon 16 inside the titanium threaded tube 14 is slightly smaller than the minimum inner diameter of the titanium threaded tube 14; alternatively, at least one spiral ribbon is provided in the annular channel between the titanium threaded tube 14 and the outer tube 12. The spiral ribbon increases the turbulence intensity by inducing fluid swirl, thereby improving the heat exchange efficiency. This embodiment requires first inserting the spiral ribbon into the heat exchange tube, and then coiling the heat exchange tube to make it spiral into a spring shape.

[0059] This utility model also provides a heat pump, which includes the aforementioned tube-to-tube heat exchanger. The tube-to-tube heat exchanger in this embodiment can have the same structure and achieve the same effect as the tube-to-tube heat exchanger in the above embodiment, and will not be described again in this embodiment.

[0060] Furthermore, the heat pump includes a compressor and a chassis. The compressor is located in the middle of the tube-to-tube heat exchanger, meaning the tube-to-tube heat exchanger is coiled around the compressor in a spring shape, thereby reducing inter-tube vibration and increasing space utilization by more than 10%. The stainless steel support of the tube-to-tube heat exchanger is fixed to the chassis of the heat pump.

[0061] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0062] (1) By using titanium threaded tubes as heat exchange pipelines for pool water, the corrosion resistance of the tube-to-tube heat exchanger is improved. Titanium threaded tubes have extremely strong resistance to chloride ion and salt corrosion, and are suitable for pools under various water quality conditions, including pools in coastal areas with high salt content or seawater pools, and have broad market application prospects.

[0063] (2) The threaded structure on the surface of the titanium threaded pipe can effectively increase the surface area of ​​the refrigerant and pool water, extend the flow path of the fluid and significantly enhance the turbulent flow of the fluid, thereby improving the heat transfer coefficient.

[0064] (3) By setting the outer layer of the outer tube to be insulation cotton, air is isolated to prevent air from affecting the overall heat exchange efficiency.

[0065] (4) By adopting a modular design, the tube-to-tube heat exchanger is small in size and easy to install, and each component can be replaced individually. By placing components such as the compressor in the heat pump in the middle of the tube-to-tube heat exchanger, the volume occupied by each component in the heat pump is reduced.

[0066] (5) By setting the titanium threaded pipe that is only in key contact with the pool water to be made of titanium, the rest of the structure, such as the outer pipe, is made of carbon steel and stainless steel.

[0067] (6) By adjusting the specific parameters of the titanium threaded pipe, it can meet the pressure resistance test (i.e., no leakage in 60,000 alternating tests when the refrigerant side alternating pressure reaches 4MPa; no leakage in 60,000 alternating tests when the water side alternating pressure reaches 0.5MPa, with a test frequency of 10-30 times / min), so as to ensure the flow state of the pool water and reduce the flow resistance.

[0068] (7) By setting a spiral ribbon inside the titanium threaded tube and in the annular channel between the titanium threaded tube 14 and the outer tube 12, the heat exchange efficiency can be improved by 2%-4%.

[0069] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and this utility model also intends to include these modifications and variations.

Claims

1. A tube-to-tube heat exchanger for a heat pump overseas swimming pool machine, characterized in that, The device includes an outer tube and a titanium threaded tube. The outer tube is coiled into a spring shape, with a refrigerant inlet and a refrigerant outlet at its two ends. The titanium threaded tube is nested inside the outer tube, with a water outlet and a water inlet at its two ends. There is a gap between the spiral ribs of the titanium threaded tube and the inner wall of the outer tube, forming an annular channel between the inner wall of the outer tube and the outer wall of the titanium threaded tube. The refrigerant flows in the annular channel, and the direction of the refrigerant flow is opposite to the direction of the water flow in the titanium threaded tube.

2. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 1, characterized in that, It also includes a first refrigerant pipe and a second refrigerant pipe for connecting to an external refrigerant flow path, wherein the first refrigerant pipe is connected to the refrigerant inlet and the second refrigerant pipe is connected to the refrigerant outlet.

3. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 2, characterized in that, The diameter of the second refrigerant pipe is 60-90% of the diameter of the first refrigerant pipe.

4. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 2, characterized in that, It also includes a first connector and a second connector for connecting to an external waterway, wherein the inlet is sealed to the first connector and the outlet is sealed to the second connector.

5. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 4, characterized in that: The first and second connectors are titanium threaded connectors or flange connectors.

6. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 4, characterized in that: It also includes a first tee assembly and a second tee assembly. The refrigerant inlet is connected to the first refrigerant pipe through the first tee assembly, the refrigerant outlet is connected to the second refrigerant pipe through the second tee assembly, the water outlet passes through the first tee assembly and is connected to the first connector, and the water inlet passes through the second tee assembly and is connected to the second connector.

7. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 1, characterized in that: The outer tube is a double-layer tube, with an inner layer of carbon steel, stainless steel, or titanium, and an outer layer of thermal insulation cotton.

8. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 1, characterized in that: The pitch and gap of the titanium threaded tube gradually decrease from the outlet to the inlet; the thread depth of the titanium threaded tube gradually increases from the outlet to the inlet.

9. The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to claim 1, characterized in that: A spiral band is provided inside the titanium threaded tube and / or inside the annular channel.

10. A heat pump, characterized in that, include: The tube-to-tube heat exchanger for a heat pump overseas swimming pool machine according to any one of claims 1-9.

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