Heat exchange device for medium-deep geothermal well

Abstract

The application relates to the geothermal utilization field and provides a heat exchange device for a middle-deep geothermal well, which comprises an outer pipe, an inner pipe and a disturbing part; a convex part and a concave part are arranged on the inner wall of the outer pipe; one end of the inner pipe penetrates into the outer pipe and communicates with the outer pipe; the disturbing part is arranged in the outer pipe and connected with the inner pipe; the disturbing part has a plurality of disturbing blades; the disturbing blades are configured to be deformable and unfolded; the number of the disturbing parts is one or more; at least one disturbing blade is used to unfold to abut against the concave part; and at least one disturbing blade of at least one disturbing part is used to semi-unfold to abut against the convex part. The application solves the problem of poor heat exchange efficiency of a traditional heat exchange structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of geothermal utilization, in particular to a heat exchange device for a middle-deep geothermal well. BACKGROUND

[0002] With the increasing demand for clean energy, the efficient development and utilization of geothermal resources have become increasingly important. Middle-deep geothermal resources contain abundant heat energy, and if they can be effectively converted into usable energy, it will be of great significance to alleviate energy pressure and reduce environmental pollution. For a long time, scientific researchers and engineering and technical personnel have been continuously exploring and improving the exploitation and utilization technology of middle-deep geothermal resources to improve the utilization efficiency and economic benefits of geothermal energy.

[0003] In the traditional heat exchange process of a middle-deep geothermal well, in order to realize heat exchange, a simple casing heat exchange structure is usually adopted. This structure generally places an inner pipe in an outer pipe, and then heat transfer is realized through fluid flow. Specifically, fluid is introduced into the outer pipe, and the fluid is heated by geothermal convection during the downward flow along the pipe. The heated fluid enters the inner pipe from the lower end of the inner pipe and is discharged by backflow through the inner pipe, and finally the heat of the heated fluid is utilized.

[0004] However, the traditional casing heat exchange structure has the problem of poor heat exchange effect, so there is a processing method in the prior art to increase the pipe length to increase the heat exchange time. However, this method will significantly increase the cost, which does not conform to the development trend. SUMMARY

[0005] In order to solve the problem of poor heat exchange efficiency of the traditional heat exchange structure, the present application provides a heat exchange device for a middle-deep geothermal well.

[0006] The heat exchange device for a middle-deep geothermal well provided by the present application adopts the following technical scheme:

[0007] A heat exchange device for a middle-deep geothermal well, comprising:

[0008] an outer pipe, provided with a protruding portion and a recessed portion on the inner wall;

[0009] an inner pipe, one end of which penetrates into the outer pipe and communicates with the outer pipe;

[0010] a disturbance member, provided in the outer pipe and connected with the inner pipe; the disturbance member has a plurality of disturbance blades; the disturbance blades are configured to be deformable and expandable; the number of the disturbance members is one or more, and at least one of the disturbance blades is used to expand to abut against the recessed portion, and at least one of the disturbance blades of the disturbance member is used to semi-expand to abut against the protruding portion.

[0011] By adopting the technical scheme, the convex part and the concave part are arranged on the inner wall of the outer pipe, the convex part and the concave part can destroy the boundary layer formed when the fluid flows along the wall of the outer pipe, thereby increasing the heat exchange efficiency; the arrangement of the disturbance vane can also disturb the fluid to increase the heat exchange efficiency; in addition, part of the disturbance vanes abut against the convex part and part of the disturbance vanes abut against the concave part, the unfolding degree can be changed according to the abutting condition, so that the disturbance effect of each disturbance vane on the water flow is not completely the same; the disturbance vane can also support the outer pipe when abutting against the convex part and the concave part.

[0012] Optionally, the disturbance vane is a memory metal piece configured to be unfolded by heat.

[0013] By adopting the technical scheme, the disturbance vane is a memory metal piece and can be unfolded by heat, when the disturbance vane is not heated, the disturbance vane is in a contracted state, which is convenient for installation; after the disturbance vane is heated, the disturbance vane can gradually unfold and abut against the convex part and the concave part, thereby producing different disturbance effects on the water flow to improve the heat exchange efficiency, and also supporting the outer pipe.

[0014] Optionally, a corrugation is arranged on the inner wall of the outer pipe, the wave crest of the corrugation constitutes the convex part, and the wave trough of the corrugation constitutes the concave part.

[0015] By adopting the technical scheme, the arrangement of the corrugation helps to increase the heat exchange area and disturb the water flow, thereby improving the heat exchange efficiency; at the same time, the disturbance vane abuts against the convex part constituted by the wave crest of the corrugation and the concave part constituted by the wave trough of the corrugation, so that the disturbance vanes have different unfolding degrees, thereby producing different disturbance effects on the water flow, and also supporting the outer pipe.

[0016] Optionally, the inner pipe and the outer pipe are coaxially arranged;

[0017] The disturbance piece is sleeved on the inner pipe, the disturbance vanes are arranged in an inclined manner relative to the axial direction of the inner pipe, and the plurality of disturbance vanes of the disturbance piece are arranged in a circumferential direction.

[0018] By adopting the technical scheme, the coaxial arrangement of the inner pipe and the outer pipe makes the water flow more uniform and stable, the disturbance piece is sleeved on the inner pipe, which is convenient for installation and positioning, the disturbance vanes are arranged in an inclined manner relative to the axial direction of the inner pipe and the plurality of disturbance vanes are arranged in a circumferential direction, so that the disturbance vanes can guide the water flow, the water flow spirally flows, and the heat exchange efficiency is improved.

[0019] Optionally, the corrugation is a sine corrugation or a sawtooth corrugation; the corrugation extends along the axial direction of the outer pipe; the number of the disturbance pieces is a plurality, and the plurality of disturbance pieces are arranged in the axial direction of the inner pipe.

[0020] By adopting the technical scheme, the sine wave and the sawtooth wave are helpful to increase the heat exchange area and have a good water flow disturbance effect; on the basis that the plurality of disturbance blades of the same disturbance member are arranged at intervals in the circumferential direction, the wave is arranged as a sine wave or a sawtooth wave, so that the plurality of disturbance blades of the same disturbance member have the same unfolding degree, the support effect on the outer tube is better, and the spiral flow of the fluid is smoother; the plurality of disturbance members arranged at intervals in the axial direction of the inner tube can make the unfolding degrees of the disturbance blades of different disturbance members not completely the same, the water flow disturbance effects are different, the water flow disturbance effect can be further improved, and the heat exchange efficiency is improved.

[0021] Optionally, the wave is a spiral wave.

[0022] By adopting the technical scheme, the spiral wave is arranged on the inner wall of the outer tube, the fluid can be disturbed, and the spiral guiding effect on the fluid is achieved, which is helpful to improve the heat exchange efficiency; in addition, on the basis that the plurality of disturbance blades of the same disturbance member are arranged at intervals in the circumferential direction, the wave is arranged as a spiral wave, so that the plurality of disturbance blades of the same disturbance member have different unfolding states, and the disturbance effect on the fluid is different even if only a single disturbance member is arranged.

[0023] Optionally, the disturbance blade is configured to change the included angle between the side away from the inner tube and the axial direction of the inner tube during the unfolding process.

[0024] By adopting the technical scheme, the included angle between the disturbance blade and the axial direction of the inner tube changes during the unfolding process of the disturbance blade, so that the inclination angle of the disturbance blade is different when the unfolding degree of the disturbance blade is different, and the disturbance effect of the disturbance blade on the water flow is also different, the water flow disturbance effect can be further improved, and the heat exchange efficiency is improved.

[0025] Optionally, the side wall of the end of the inner tube penetrating into the outer tube is provided with a water inlet hole.

[0026] By adopting the technical scheme, the fluid between the inner tube and the outer tube can enter the inner tube through the water inlet hole and the end opening of the inner tube, and the fluid can be fully disturbed when the two fluids meet, so that the heat exchange efficiency is improved.

[0027] Optionally, the inner tube is provided with a heat insulation part.

[0028] By adopting the technical scheme, the heat insulation part is arranged on the inner tube of the heat exchange device, the heat loss of the fluid inside the inner tube can be reduced, and the heat exchange efficiency is improved.

[0029] In summary, the present application has at least one of the following beneficial technical effects:

[0030] 1. By setting the protrusions and recesses on the inner wall of the outer tube, the boundary layer formed when the fluid flows along the wall of the outer tube is destroyed, and the heat exchange efficiency is increased;

[0031] 2. The disturbance vane can be unfolded and abut against the protrusions or recesses, thereby supporting the outer tube; and the disturbance vane unfolds to different degrees when abutting against the protrusions and recesses, and the disturbance effect on the water flow can be adjusted;

[0032] 3. The corrugations on the inner wall of the outer tube help to increase the heat exchange area, and also disturb the water flow, thereby realizing efficient heat exchange in a limited space. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic diagram of the three-dimensional structure of the heat exchange device for a middle-deep geothermal well provided by the present application.

[0034] Figure 2 is a sectional view of the first embodiment of the heat exchange device for a middle-deep geothermal well provided by the present application.

[0035] Figure 3 is a schematic diagram of the third embodiment of the heat exchange device for a middle-deep geothermal well provided by the present application. Figure 2 is an enlarged schematic diagram of position A in FIG. 4.

[0036] Figure 4 is a sectional view of the second embodiment of the heat exchange device for a middle-deep geothermal well provided by the present application.

[0037] Figure 5 is an enlarged schematic diagram of position B in FIG. 5. Figure 4

[0038] Figure 6 is a sectional view of the inner tube and the outer tube in the third embodiment of the heat exchange device for a middle-deep geothermal well provided by the present application.

[0039] Figure 7 is an enlarged schematic diagram of position C in FIG. 6. Figure 6

[0040] Explanation of Reference Signs:

[0041] 1. outer tube; 11. protrusion; 12. recess;

[0042] 2. inner tube; 21. water inlet hole;

[0043] 3. disturbance member; 31. disturbance vane. DETAILED DESCRIPTION

[0044] The present application is further described below in conjunction with the accompanying drawings. Figures 1 to 7 The present application is further described below in conjunction with the accompanying drawings.

[0045] As Figures 1 to 3 ​​As shown, the embodiment of the present application discloses a heat exchange device for a middle-deep geothermal well, which comprises an outer pipe 1, an inner pipe 2 and a disturbing member 3.

[0046] Specifically, one end of the inner pipe 2 penetrates into the outer pipe 1 and communicates with the outer pipe 1. In the embodiment, the inner pipe 2 and the outer pipe 1 are coaxially arranged, and specifically, both can be vertically arranged. The lower end of the inner pipe 2 penetrates into the outer pipe 1, and the opening of the lower end of the inner pipe 2 communicates with the inside of the outer pipe 1. When heat exchange is needed, fluid (for example, water) is introduced into the gap between the outer pipe 1 and the inner pipe 2. During the downward flow of the fluid, the geothermal heat can heat the fluid, and the heated fluid enters the inside of the inner pipe 2 from the lower end of the inner pipe 2 and is finally discharged from the top of the inner pipe 2. By absorbing heat and secondary utilization of the absorbed heat, the geothermal heat can be fully utilized.

[0047] The inner wall surface of the outer pipe 1 is provided with a protruding part 11 and a recessed part 12. When the fluid flows along the inner wall surface of the outer pipe 1, the protruding part 11 and the recessed part 12 can force the fluid to flow transversely, thereby disturbing the fluid, destroying the boundary layer, and thus improving the heat exchange efficiency. Specifically, corrugations can be provided on the inner wall surface of the outer pipe 1, the peaks of the corrugations constitute the protruding part 11, and the valleys of the corrugations constitute the recessed part 12. The corrugations are integrally formed with the outer pipe 1.

[0048] The disturbing member 3 is arranged in the outer pipe 1 and connected with the inner pipe 2. For example, the body of the disturbing member 3 can be annular, which is sleeved on the inner pipe 2. The disturbing member 3 has a plurality of disturbing blades 31, which can be deformed and unfolded to disturb the fluid and enhance the heat exchange. For example, the plurality of disturbing blades 31 are arranged on the body of the disturbing member 3 in a circumferential direction, and the disturbing blades 31 are made of a memory metal. In a low-temperature or even normal-temperature environment, the disturbing blades 31 are in a rolled state, thereby facilitating the installation of the disturbing blades 31 into the inside of the outer pipe 1. After installation, the disturbing blades 31 can be unfolded under the action of geothermal heat, so that the disturbing blades 31 can abut against the inner wall surface of the outer pipe 1, thereby preventing the outer pipe 1 from being decentered with the inner pipe 2 due to soil settlement or other unexpected situations.

[0049] The number of disturbance elements 3 is one or more, and at least one disturbance blade 31 can be deployed to abut against the recess 12, and at least one disturbance blade 31 of the disturbance element 3 can be partially deployed to abut against the protrusion 11. Due to the inward convex structure of the protrusion 11, it prevents the disturbance element 3 from being fully deployed. Therefore, the degree of deployment of the disturbance blade 31 abutting against the protrusion 11 is different from the degree of deployment of the disturbance blade 31 abutting against the recess 12, so that the shapes of each disturbance blade 31 are not completely the same, which can have different disturbance effects on the fluid and enhance the heat transfer efficiency. Of course, some disturbance blades 31 can also be configured to be deployed to abut against other parts of the corrugation except for the crests and troughs, so that the shape of the disturbance blades 31 is more diverse. Furthermore, since the extent of the deployment of the disturbance blades 31 mainly depends on the geothermal temperature, and the geothermal temperature varies at different underground depths, some of the disturbance blades 31 can be placed in a specific geothermal environment. Under this environment, the disturbance blades 31 can only be partially deployed, and after being partially deployed, they do not contact the inner wall of the outer pipe 1, thereby further enriching the shape of the disturbance blades 31 and enhancing the turbulence effect.

[0050] The disturbance blades 31 are inclined relative to the axis of the inner tube 2, similar to the arrangement of fan blades. By tilting the disturbance blades 31, the fluid can be guided, causing it to flow in a spiral motion, thus facilitating heat exchange. Furthermore, during the deployment process, the angle between the side of the disturbance blades 31 furthest from the inner tube 2 and the axis of the inner tube 2 changes, resulting in different inclination angles for disturbance blades 31 at different deployment degrees, which can better disturb the fluid.

[0051] like Figures 1 to 3 As shown, in some embodiments, the corrugations are sinusoidal or sawtooth corrugations, extending along the axial direction of the outer tube 1. Specifically, along the axial direction of the outer tube 1, the protrusions 11 and recesses 12 of the corrugations are arranged alternately; along the circumferential direction of the outer tube 1, the degree of protrusion (or recess) of the corrugations is the same, and at this time, both the protrusions 11 and recesses 12 of the corrugations have annular structures. When the fluid flows along the axial direction of the outer tube 1, the corrugations can continuously disturb the fluid, avoiding the formation of a boundary layer on the inner wall of the outer tube 1. When the corrugations are sinusoidal or sawtooth corrugations and extend along the axial direction of the outer tube 1, not only is the fabrication simple, but when multiple disturbance blades 31 of the disturbance element 3 are spaced apart circumferentially, the multiple disturbance blades 31 of the same disturbance element 3 have the same degree of expansion, resulting in better support for the outer tube 1 and better spiral guiding effect for the fluid. In this embodiment, there are multiple disturbance elements 3, which are spaced apart along the axial direction of the inner tube 2. The deployment degree of the disturbance blades 31 of the multiple disturbance components 3 is not exactly the same.

[0052] like Figure 1 , Figure 4 and Figure 5As shown, in some embodiments, the corrugations are sinusoidal or sawtooth corrugations, extending along the axial direction and circumferential direction of the outer tube 1. Specifically, along the axial direction of the outer tube 1, the protrusions 11 and recesses 12 of the corrugations are arranged alternately; along the circumferential direction of the outer tube 1, the protrusions 11 and recesses 12 of the corrugations are also arranged alternately. At this time, when the multiple disturbance blades 31 of the disturbance member 3 are arranged circumferentially at intervals, the degree of deployment of the multiple disturbance blades 31 of the same disturbance member 3 may be the same or not completely the same, which can be set according to actual needs. For example, one of two disturbance blades 31 of the same disturbance member 3 can be set to abut against one protrusion 11 (wave crest) of the corrugation, and the other can be set to abut against the other protrusion 11 (wave crest) of the corrugation, so that the two disturbance blades 31 have the same degree of deployment.

[0053] For example, one of the two disturbance blades 31 of the same disturbance member 3 can be deployed to abut a protrusion 11 (wave crest) of the corrugation, and the other can be deployed to abut a depression 12 (wave trough) of the corrugation, so that the two disturbance blades 31 are deployed to different degrees.

[0054] like Figure 1 , Figure 6 and Figure 7 As shown, in some embodiments, the corrugations are helical corrugations. By setting helical corrugations on the inner wall of the outer pipe 1, not only can the fluid be effectively disturbed, but it can also be guided, which helps to improve heat exchange efficiency. Furthermore, by setting the corrugations as helical corrugations on the basis of multiple disturbance blades 31 of the same disturbance element 3 being spaced circumferentially, the deployment states of the multiple disturbance blades 31 of the same disturbance element 3 are not entirely the same. Even if only a single disturbance element 3 is used, it can still have different disturbance effects on the fluid. This helps to save costs.

[0055] like Figure 3 or Figure 5 As shown, in some embodiments, a water inlet hole 21 is provided on the side wall of the end of the inner tube 2 that penetrates the outer tube 1. In this embodiment, both the inner tube 2 and the outer tube 1 are vertically arranged, and multiple water inlets 21 can be provided and evenly distributed on the lower side wall of the inner tube 2. By providing water inlets 21, the fluid between the outer tube 1 and the inner tube 2 can enter the inner tube 2 not only through the lower opening of the inner tube 2, but also through the water inlets 21. When the fluids entering the inner tube 2 from different water inlets 21 converge, they can disturb the fluid, and when the fluids entering the inner tube 2 from the water inlets 21 and the fluids entering the inner tube 2 from the end opening of the inner tube 2 converge, they can also disturb the fluid, thereby enhancing the disturbance effect and increasing the heat exchange efficiency.

[0056] In some embodiments, the inner tube 2 is provided with a heat insulation part. Since the fluid entering the gap between the outer tube 1 and the inner tube 2 has a low temperature, as the fluid flows downward, the fluid absorbs geothermal heat and gradually heats up. The fluid after absorbing heat enters the inner tube 2 from the lower end of the inner tube 2 and flows back upward. In order to avoid the heat of the backflowing fluid being absorbed by the fluid in the gap between the outer tube 1 and the inner tube 2, the inner tube 2 is provided with a heat insulation part to reduce heat loss. The structure and heat insulation mode of the heat insulation part are not limited. For example, the heat insulation part can be a low-vacuum heat insulation cavity (not shown in the figure) in the wall of the inner tube 2.

Claims

1. A heat exchange device for medium-deep geothermal wells, characterized in that, include: The outer tube (1) has a protrusion (11) and a recess (12) on its inner wall. The inner tube (2) has one end inserted into the outer tube (1) and connected to the outer tube (1); A disturbance element (3) is disposed inside the outer tube (1) and connected to the inner tube (2); the disturbance element (3) has a plurality of disturbance blades (31); the disturbance blades (31) are configured to be deformable and deployable; the number of disturbance elements (3) is one or more, at least one of the disturbance blades (31) is deployed to abut against the recess (12), and at least one of the disturbance blades (31) of the disturbance element (3) is partially deployed to abut against the protrusion (11).

2. The heat exchange device for medium-deep geothermal wells according to claim 1, characterized in that: The disturbance blade (31) is a shape memory metal component and is configured to be heat-deployable.

3. The heat exchange device for medium-deep geothermal wells according to claim 1, characterized in that: The inner wall of the outer tube (1) is provided with corrugations, the crests of the corrugations constitute the protrusions (11); the troughs of the corrugations constitute the depressions (12).

4. The heat exchange device for medium-deep geothermal wells according to claim 3, characterized in that: The inner tube (2) and the outer tube (1) are coaxially arranged; The disturbance component (3) is sleeved on the inner tube (2); the disturbance blade (31) is inclined relative to the axial direction of the inner tube (2), and the plurality of disturbance blades (31) of the disturbance component (3) are spaced apart in the circumferential direction.

5. The heat exchange device for medium-deep geothermal wells according to claim 4, characterized in that: The corrugations are sinusoidal or sawtooth corrugations; the corrugations extend along the axial direction of the outer tube (1); there are multiple disturbance elements (3), and the multiple disturbance elements (3) are spaced apart along the axial direction of the inner tube (2).

6. The heat exchange device for medium-deep geothermal wells according to claim 4, characterized in that: The ripples are spiral ripples.

7. The heat exchange device for medium-deep geothermal wells according to claim 4, characterized in that: The disturbance blade (31) is configured such that, during deployment, the angle between the side of it away from the inner tube (2) and the axial direction of the inner tube (2) changes.

8. The heat exchange device for medium-deep geothermal wells according to claim 1, characterized in that: The inner tube (2) has a water inlet hole (21) on the side wall of the end through which it enters the outer tube (1).

9. The heat exchange device for medium-deep geothermal wells according to claim 1, characterized in that: The inner tube (2) is provided with a heat insulation part.

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