Heat exchange tube, heat exchanger and chiller

Abstract

The present application provides a heat exchange tube, a heat exchanger, and a chiller. The heat exchange tube includes a tube body (1) and external fins (2) provided on the outer peripheral wall of the tube body (1). The external fins (2) spirally extend circumferentially along the outer peripheral wall of the tube body (1) and form a spiral flow guiding groove (3). Turbulence fins for forming a baffle disturbance to the fluid are arranged on the external fins (2) and / or on the outer peripheral wall of the tube body (1). According to the heat exchange tube of the present application, the heat exchange area of the heat exchange tube can be effectively increased, and the heat exchange efficiency of the heat exchange tube can be improved.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning, and particularly relates to a heat exchange tube, a heat exchanger, and a chiller. Background Art

[0002] During the operation of a commercial chiller, the gaseous refrigerant is first condensed from a superheated gas to a saturated liquid in the condenser. At this time, if the temperature of the saturated liquid is further reduced, the refrigerant will be in a subcooled state. Increasing the subcooling degree of the refrigerant at the condenser outlet can significantly improve the refrigerating capacity and energy efficiency of the unit.

[0003] An efficient refrigerant subcooling solution known to the applicant is: a subcooling area is provided at the bottom of the condenser housing. The condensed saturated liquid passes through a small hole and throttles and flashes into a low-temperature gas-liquid two-phase mixture, and then enters the subcooling area. The cooling water in the tube exchanges heat with the flashed gaseous refrigerant through a subcooling tube, and the low-temperature gas is condensed to achieve subcooling of the refrigerant at the condenser outlet. Since the outside of the heat exchange tube in the subcooling area is phase change heat transfer, the heat transfer efficiency is higher than that of the traditional baffle non-phase change condensation structure.

[0004] Existing heat exchange tubes for subcooling usually adopt the same tooth-shaped structure as the condenser tubes, and there is room for further improvement in the heat transfer area. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this application is to provide a heat exchange tube, a heat exchanger, and a chiller that can effectively increase the heat transfer area of the heat exchange tube and improve the heat transfer efficiency of the heat exchange tube.

[0006] To solve the above problems, this application provides a heat exchange tube, including a tube body and external fins provided on the outer peripheral wall of the tube body. The external fins extend spirally along the circumferential direction on the outer peripheral wall of the tube body and form a spiral flow guiding groove. Turbulence fins for forming a baffle disturbance to the fluid are arranged on the external fins and / or the outer peripheral wall of the tube body.

[0007] Preferably, the turbulence fins include first turbulence fins and second turbulence fins. The external fins include a first flow guiding surface and a second flow guiding surface for guiding the fluid flow. The first flow guiding surface, the second flow guiding surface, and the tube body form a flow guiding groove. The first turbulence fins are arranged on the first flow guiding surface, and the second turbulence fins are arranged on the second flow guiding surface.

[0008] Preferably, the first turbulence fins located in the flow guiding groove extend towards the second flow guiding surface and form a flow passage with the second flow guiding surface. The second turbulence fins located in the flow guiding groove extend towards the first flow guiding surface and form a flow passage with the first flow guiding surface.

[0009] Preferably, the first turbulence fins and the second turbulence fins located on both sides of the flow guiding groove are arranged alternately along the extending direction of the flow guiding groove.

[0010] Preferably, the length that at least part of the first spoiler fin extends towards the second flow guiding surface is greater than the minimum width of the flow passage between the second spoiler fin and the first flow guiding surface.

[0011] Preferably, the length that the first spoiler fin extends towards the second flow guiding surface is D1, and the width of the flow passage between the second spoiler fin adjacent to the first spoiler fin and the first flow guiding surface is D2, where D1 > D2.

[0012] Preferably, the radial height of the spoiler fin is H1, and the radial height of the outer fin is H, where the range of H / H1 is 1 to 5; and / or, the height range of H1 is 0.2 mm to 3 mm.

[0013] Preferably, H / H1 = 1.

[0014] Preferably, the spiral angle α of the outer fin ranges from 0.1° to 90°.

[0015] Preferably, the width of the flow passage between the first spoiler fin and the second flow guiding surface is L1, and the distance between the adjacent first spoiler fin and the second spoiler fin after the heat exchange tube is unfolded is L2, where the range of L1 / L2 is 0.2 to 5.

[0016] Preferably, L1 / L2 = 1.

[0017] Preferably, at least one of the outer fin, the tube body, and the spoiler fin is provided with a vortex generator.

[0018] Preferably, at least one vortex generator is provided on the flow guiding surface of the outer fin, the outer peripheral wall of the tube body, and the wall surface of the spoiler fin.

[0019] Preferably, a vortex generator is provided at the position on the first flow guiding surface corresponding to the second spoiler fin; and / or, a vortex generator is provided at the position on the second flow guiding surface corresponding to the first spoiler fin.

[0020] Preferably, the vortex generator is a protrusion protruding from the surface where it is located.

[0021] Preferably, the protrusion is a cuboid, a hemisphere, a cone, or a frustum of a cone.

[0022] According to another aspect of the present application, there is provided a heat exchanger, including a heat exchange tube, and the heat exchange tube is the above-mentioned heat exchange tube.

[0023] According to another aspect of the present application, there is provided a water chiller, including the above-mentioned heat exchange tube or the above-mentioned heat exchanger.

[0024] The heat exchange tube provided by the present application includes a tube body and external fins provided on the outer peripheral wall of the tube body. The external fins extend spirally along the circumferential direction on the outer peripheral wall of the tube body and form spiral flow guiding grooves. Turbulence fins for forming a baffle disturbance to the fluid are arranged on the external fins and / or on the outer peripheral wall of the tube body. The heat exchange tube is provided with turbulence fins for forming a baffle disturbance to the fluid on the external fins and / or on the outer peripheral wall of the tube body. On the one hand, the turbulence fins can be used to increase the heat exchange area on the outer side of the heat exchange tube. On the other hand, the convective heat transfer between the fluid and the external fins can be increased. The turbulence fins can form a baffle disturbance to the fluid, so that when the fluid flows in the flow guiding grooves, the flow direction of the fluid can be changed, thereby changing the relationship between the fluid velocity field and the temperature gradient field, reducing the included angle between the fluid velocity field and the temperature gradient field, and even making them tend to be consistent, so as to effectively strengthen the convective heat transfer and improve the heat exchange efficiency of the heat exchange tube. Description of the Drawings

[0025] Figure 1 It is a three-dimensional structure diagram of the heat exchange tube according to the embodiment of the present application;

[0026] Figure 2 It is the first axonometric drawing after the heat exchange tube according to the embodiment of the present application is unfolded;

[0027] Figure 3 It is the second axonometric drawing after the heat exchange tube according to the embodiment of the present application is unfolded;

[0028] Figure 4 It is the structural schematic diagram after the heat exchange tube according to the embodiment of the present application is unfolded;

[0029] Figure 5 It is the first structural dimension drawing of the turbulence fins after the heat exchange tube according to the embodiment of the present application is unfolded;

[0030] Figure 6 It is the second structural dimension drawing of the turbulence fins after the heat exchange tube according to the embodiment of the present application is unfolded.

[0031] The reference numerals are shown as:

[0032] 1. Tube body; 2. External fins; 3. Flow guiding groove; 4. First turbulence fin; 5. Second turbulence fin; 6. First flow guiding surface; 7. Second flow guiding surface; 8. Flow passage; 9. Eddy current generator. Detailed Embodiments

[0033] With reference to Figures 1 to 6 As shown, according to the embodiment of the present application, the heat exchange tube includes a tube body 1 and external fins 2 provided on the outer peripheral wall of the tube body 1. The external fins 2 extend spirally along the circumferential direction on the outer peripheral wall of the tube body 1 and form spiral flow guiding grooves 3. Turbulence fins for forming a baffle disturbance to the fluid are arranged on the external fins 2 and / or on the outer peripheral wall of the tube body 1.

[0034] The heat exchange tubes in the conventional subcooled region usually adopt the same tube type as the condenser tubes, which is a double-sided enhanced structure inside and outside the tubes. The outer fins mainly aim to increase the heat exchange area, pierce the liquid film, enhance liquid drainage, and reduce the thermal resistance. After flashing, the gas condenses on the outer wall surface and then quickly drips along the flow guide groove. At this time, the refrigerant temperature at the condenser outlet is the condensation temperature of the gas in the flashing region. When the liquid flows through the flow guide groove, if the non-phase change convective heat transfer intensity between the liquid film and the spiral fins is increased, the refrigerant temperature can be further reduced and the subcooling degree can be improved.

[0035] When the liquid refrigerant flows through the flow guide groove between the two fins, the angle formed between the refrigerant flow velocity direction and the heat transfer direction of the outer fin side wall is basically 90°. According to the field synergy theory, reducing the angle between the fluid velocity field and the temperature gradient field until the fluid velocity field and the temperature gradient field are close to parallel can effectively enhance the convective heat transfer.

[0036] In this application, the heat exchange tube is provided with flow disturbing fins on the outer fin 2 and / or the outer peripheral wall of the tube body 1 to form a flow deflection disturbance to the fluid. On the one hand, the flow disturbing fins can be used to increase the heat exchange area on the outside of the heat exchange tube. On the other hand, the convective heat transfer between the fluid and the outer fin 2 can be increased. The flow disturbing fins can form a flow deflection disturbance to the fluid, so that when the fluid flows in the flow guide groove, the flow direction of the fluid can be changed, thereby changing the relationship between the fluid velocity field and the temperature gradient field, reducing the angle between the fluid velocity field and the temperature gradient field, and even making it tend to be parallel, thereby effectively enhancing the convective heat transfer and improving the heat exchange efficiency of the heat exchange tube.

[0037] The flow disturbing fins include a first flow disturbing fin 4 and a second flow disturbing fin 5. The outer fin 2 includes a first flow guiding surface 6 and a second flow guiding surface 7 for guiding the fluid flow. The first flow guiding surface 6, the second flow guiding surface 7 and the tube body 1 form a flow guide groove 3. The first flow disturbing fin 4 is arranged on the first flow guiding surface 6, and the second flow disturbing fin 5 is arranged on the second flow guiding surface 7.

[0038] The first flow guiding surface 6 and the second flow guiding surface 7 are two walls of the outer fin 2 for forming the flow guide groove 3. By arranging the flow disturbing fins on the two flow guiding surfaces respectively, the heat exchange area of the outer fin 2 can be further increased, the subcooling degree of the condensed liquid can be more effectively increased, and the disturbance intensity during the fluid flow can also be increased, improving the heat exchange efficiency of the fluid.

[0039] The first flow disturbing fin 4 located in the flow guide groove 3 extends towards the second flow guiding surface 7 and forms a flow passage 8 with the second flow guiding surface 7. The second flow disturbing fin 5 located in the flow guide groove 3 extends towards the first flow guiding surface 6 and forms a flow passage 8 with the first flow guiding surface 6, so that the arrangement of the flow disturbing fins does not hinder the flow direction of the fluid and does not form an axial closed structure, ensuring the continuous flow ability of the fluid and the continuous heat exchange ability of the fluid.

[0040] The first spoiler fins 4 and the second spoiler fins 5 located on both sides of the diversion channel 3 are arranged alternately along the extending direction of the diversion channel 3. The first spoiler fins 4 and the second spoiler fins 5 are arranged alternately, so that during the flow of the fluid in the diversion channel 3, the overall flow direction is the spiral extending direction of the diversion channel 3, and the local flow direction is the baffle guiding direction of the first spoiler fins 4 and the second spoiler fins 5. Thus, without changing the overall structure of the heat exchange tube, the flow path of the fluid can be increased and the heat exchange amount can be increased. In addition, the mutual cooperation of the first spoiler fins 4 and the second spoiler fins 5 makes the diversion channel 3 form an S-shaped flow path. During the process of the fluid flowing along the guiding direction of the first spoiler fins 4 or the second spoiler fins 5, the flow direction of the fluid is basically parallel to the direction of the temperature gradient field, thereby greatly strengthening the convective heat transfer effect of the outer fins 2. The above-mentioned fluid is, for example, a condensing liquid.

[0041] The length that at least part of the first spoiler fins 4 extend towards the second guide surface 7 is greater than the minimum width of the flow-through channel 8 between the second spoiler fins 5 and the first guide surface 6. In this case, only part of the length of the first spoiler fins 4 can be greater than the minimum width of the flow-through channel 8 between the second spoiler fins 5 and the first guide surface 6, or the lengths of all the first spoiler fins 4 can be greater than the minimum width of the flow-through channel 8 between the second spoiler fins 5 and the first guide surface 6, or the lengths of all the first spoiler fins 4 can be greater than the maximum width of the flow-through channel 8 between the second spoiler fins 5 and the first guide surface 6. In all these cases, the spoiler fins can make the condensing liquid form a baffle effect during the flow in the baffle channel, strengthening the convective heat transfer effect of the outer fins 2.

[0042] The condensing liquid flows in the baffle channel in the diversion channel 3. When the condensing liquid impacts the wall surface of the first spoiler fins 4 or the second spoiler fins 5 circumferentially, the velocity field of the condensing liquid is parallel to the temperature gradient field. At this time, the convective heat transfer intensity between the liquid and the outer fins 2 can be effectively increased. After the condensing liquid impacts the spoiler fins, the flow velocity direction changes to the axial direction. When contacting the circumferentially extending outer fins 2, the velocity field of the condensing liquid is parallel to the temperature gradient field. When the condensing liquid flows along the baffle channel, it will baffle several times, which can effectively increase the subcooling degree of the condensing liquid.

[0043] The length that the first spoiler fins 4 extend towards the second guide surface 7 is D1, and the width of the flow-through channel 8 between the second spoiler fins 5 adjacent to the first spoiler fins 4 and the first guide surface 6 is D2, and D1 > D2.

[0044] In one embodiment, the length that the first spoiler fin 4 extends towards the second guiding surface 7 is greater than the width of the flow-through channel 8 between the second spoiler fin 5 adjacent to the first spoiler fin 4 and the first guiding surface 6. Correspondingly, the length that the second spoiler fin 5 adjacent to the first spoiler fin 4 extends towards the first guiding surface 6 is also greater than the width of the flow-through channel 8 between the first spoiler fin 4 and the second guiding surface 7. In this way, during the fluid flow, when the fluid flows along the guiding groove 3 to the position where the first spoiler fin 4 is located, under the guiding action of the first spoiler fin 4, it passes through from the flow-through channel 8 between the first spoiler fin 4 and the second guiding surface 7, and then reaches the second spoiler fin 5. It cannot directly pass through the flow-through channel 8 between the second spoiler fin 5 and the first guiding surface 6, and can only flow under the guiding action of the second spoiler fin 5. When it reaches the flow-through channel 8 between the second spoiler fin 5 and the first guiding surface 6, it can only flow through from the flow-through channel 8 between the second spoiler fin 5 and the first guiding surface 6. Therefore, the flow deflection effect during the fluid flow is ensured, and the heat exchange efficiency during the fluid flow is improved.

[0045] In one embodiment, the radial height of the spoiler fin is H1, and the radial height of the outer fin 2 is H, where the range of H / H1 is 1 to 5.

[0046] The height range of H1 is 0.2 mm to 3 mm.

[0047] As a preferred embodiment, H / H1 = 1.

[0048] The height of the spoiler fin is less than or equal to the height of the outer fin 2. When the height of the spoiler fin is less than the height of the outer fin 2, a part of the fluid will form a flow deflection movement under the guidance of the spoiler fin, and another part of the fluid will directly flow along the guiding groove 3 through the part where the flow deflection fin is not provided. When the height of the spoiler fin is equal to the height of the outer fin 2, it can be ensured that all the fluid flowing through the guiding groove 3 can form a flow deflection movement under the action of the spoiler fin, thereby enhancing the convective heat transfer intensity of the fluid with the maximum efficiency and improving the heat exchange efficiency of the fluid.

[0049] The spiral angle α of the outer fin 2 ranges from 0.1° to 90°.

[0050] The width of the flow-through channel 8 between the first spoiler fin 4 and the second guiding surface 7 is L1, and the distance between the adjacent first spoiler fin 4 and the second spoiler fin 5 after the heat exchange tube is unfolded is L2, where the range of L1 / L2 is 0.2 to 5.

[0051] As a preferred embodiment, L1 / L2 = 1, which can ensure that the width of the flow-through channel 8 is consistent with the width of the flow channel between the first spoiler fin 4 and the second spoiler fin 5, so that the channel width during the fluid flow remains substantially constant, ensuring the stability of the fluid flow rate.

[0052] The eddy current generator 9 is provided on at least one of the outer fins 2, the tube body 1, and the spoiler fins. When the fluid flows through the eddy current generator 9, it can enhance the fluid disturbance, reduce the thickness of the fluid boundary layer, increase the convective heat transfer intensity, and increase the degree of subcooling.

[0053] At least one eddy current generator 9 is provided on the guiding surface of the outer fin 2, the outer peripheral wall of the tube body 1, and the wall surface of the spoiler fins, so that the eddy current generator 9 is provided on each surface on the fluid flow path, maximizing the enhancement of fluid disturbance and increasing the convective heat transfer intensity.

[0054] The eddy current generator 9 is provided at a position corresponding to the second spoiler fin 5 on the first guiding surface 6; and / or, the eddy current generator 9 is provided at a position corresponding to the first spoiler fin 4 on the second guiding surface 7.

[0055] During the fluid flow, due to the small width of the flow-through channel 8 and the need for the fluid to change direction at the flow-through channel 8 during the flow, setting the eddy current generator 9 on the wall surface of the flow-through channel 8 can maximize the effect of the eddy current generator 9. Even if the number of eddy current generators 9 at this position is small, it can still have an obvious fluid disturbance effect.

[0056] In this embodiment, the eddy current generator 9 is provided on the two guiding surfaces of the spoiler fins respectively, which can further strengthen the spoiler effect of the spoiler fins and improve the heat transfer effect of the fluid.

[0057] The eddy current generator 9 is a protrusion protruding from its corresponding surface.

[0058] The protrusion is a cuboid, a hemisphere, a cone, or a frustum of a cone.

[0059] According to an embodiment of the present application, the heat exchanger includes a heat exchange tube, and the heat exchange tube is the heat exchange tube described above.

[0060] According to an embodiment of the present application, the chiller includes the heat exchange tube described above or the heat exchanger described above.

[0061] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0062] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present application, several improvements and variations can also be made, and these improvements and variations should also be regarded as within the protection scope of the present application.

Claims

1. A heat exchange tube, characterized in that, It includes a tube body (1) and external fins (2) arranged on the outer peripheral wall of the tube body (1). The external fins (2) spirally extend circumferentially along the outer peripheral wall of the tube body (1) and form a spiral diversion groove (3). Turbulence fins for forming a baffle disturbance to the fluid are arranged on the external fins (2) and the outer peripheral wall of the tube body (1). The turbulence fins include a first turbulence fin (4) and a second turbulence fin (5). The external fins (2) include a first diversion surface (6) and a second diversion surface (7) for guiding the fluid flow. The first diversion surface (6), the second diversion surface (7) and the tube body (1) form the diversion groove (3). The first turbulence fin (4) is arranged on the first diversion surface (6), and the second turbulence fin (5) is arranged on the second diversion surface (7). The first turbulence fin (4) located in the diversion groove (3) extends towards the second diversion surface (7) and forms a flow-through channel (8) with the second diversion surface (7). The second turbulence fin (5) located in the diversion groove (3) extends towards the first diversion surface (6) and forms a flow-through channel (8) with the first diversion surface (6). The first turbulence fin (4) and the second turbulence fin (5) located on both sides of the diversion groove (3) are arranged alternately along the extension direction of the diversion groove (3). The length of at least part of the first turbulence fin (4) extending towards the second diversion surface (7) is greater than the minimum width of the flow-through channel (8) between the second turbulence fin (5) and the first diversion surface (6). The length of the first turbulence fin (4) extending towards the second diversion surface (7) is greater than the width of the flow-through channel (8) between the second turbulence fin (5) adjacent to the first turbulence fin (4) and the first diversion surface (6). The length of the second turbulence fin (5) adjacent to the first turbulence fin (4) extending towards the first diversion surface (6) is greater than the width of the flow-through channel (8) between the first turbulence fin (4) and the second diversion surface (7). The mutual cooperation of the first turbulence fin (4) and the second turbulence fin (5) makes the diversion groove (3) form an S-shaped flow path.

2. The heat exchange tube according to claim 1, characterized in that, The length of the first turbulence fin (4) extending towards the second diversion surface (7) is D1, and the width of the flow-through channel (8) between the second turbulence fin (5) adjacent to the first turbulence fin (4) and the first diversion surface (6) is D2, and D1 > D2.

3. The heat exchange tube according to claim 1, characterized in that, The radial height of the turbulence fin is H1, and the radial height of the external fin (2) is H, where the range of H / H1 is 1 - 5; and / or, the height range of H1 is 0.2 mm - 3 mm.

4. The heat exchange tube according to claim 3, characterized in that, H / H1 = 1.

5. The heat exchange tube according to claim 1, characterized in that, The spiral angle α of the external fin (2) ranges from 0.1° to 90°.

6. The heat exchange tube according to claim 1, characterized in that, The width of the flow passage (8) between the first spoiler fin (4) and the second flow guiding surface (7) is L1, and the distance between the adjacent first spoiler fin (4) and the second spoiler fin (5) after the heat exchange tube is unfolded is L2, where the range of L1 / L2 is 0.2 to 5.

7. The heat exchange tube according to claim 6, characterized in that, L1 / L2 = 1.

8. The heat exchange tube according to any one of claims 1 to 2, characterized in that, At least one of the outer fins (2), the tube body (1) and the spoiler fins is provided with a vortex generator (9).

9. The heat exchange tube according to claim 8, characterized in that, At least one of the vortex generators (9) is provided on the flow guiding surface of the outer fin (2), the outer peripheral wall of the tube body (1) and the wall surface of the spoiler fin.

10. The heat exchange tube according to claim 8, characterized in that, The vortex generator (9) is provided at a position corresponding to the second spoiler fin (5) on the first flow guiding surface (6); and / or, the vortex generator (9) is provided at a position corresponding to the first spoiler fin (4) on the second flow guiding surface (7).

11. The heat exchange tube according to claim 8, characterized in that, The vortex generator (9) is a protrusion protruding from its corresponding surface.

12. The heat exchange tube according to claim 11, characterized in that, The protrusion is a cuboid, a hemisphere, a cone or a frustum of a cone.

13. A heat exchanger, comprising a heat exchange tube, characterized in that, The heat exchange tube is the heat exchange tube according to any one of claims 1 to 12.

14. A chiller, characterized in that, Comprising the heat exchange tube according to any one of claims 1 to 12 or the heat exchanger according to claim 13.

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