Geothermal well heat exchanger head pipe

Abstract

The present application belongs to the technical field of geothermal energy utilization, and particularly relates to a geothermal well heat exchange head pipe, which comprises: a heat absorption pipe head, a transition arc surface is arranged on the heat absorption pipe head, the transition arc surface is coaxially arranged with the heat absorption pipe head, and the curve of the cross section of the transition arc surface is an Archimedes spiral structure; a second heat insulation material is laid in the transition arc surface; a heat conduction column is coaxially fixed at the center of the heat absorption pipe head; the bottom of a heat absorption outer sleeve pipe is coaxially fixed to the heat absorption pipe head, a heat insulation inner sleeve pipe is coaxially arranged in the heat absorption outer sleeve pipe, the heat conduction column extends into the inner side of the heat insulation inner sleeve pipe, and the bottom of the heat absorption outer sleeve pipe is communicated with the bottom of the heat insulation inner sleeve pipe through the transition arc surface. The device can reduce the influence of turbulent flow on the flow resistance of the heat exchange medium, thereby reducing the energy consumption of the high-pressure pump and improving the heat exchange efficiency.

Description

Technical Field

[0001] This invention belongs to the field of geothermal energy utilization technology, and particularly relates to a geothermal well heat exchange head tube. Background Technology

[0002] Currently, commonly used medium-deep geothermal wells typically employ double-layered heat exchange systems to provide heating energy for buildings. The circulating heat exchange medium flows downwards through the gap between the outer and inner casings, and then flows upwards from the center of the inner casing at the bottom of the double-layered heat exchange system. The circulating heat exchange medium releases heat and cools down through the heat source heat pump evaporator before flowing back into the double-layered heat exchange system.

[0003] As the temperature of the lower part of a geothermal well increases with depth, the circulating heat exchange medium absorbs heat energy as it flows downward through the gap between the outer and inner casings. The gradually increasing temperature of the circulating heat exchange medium at the bottom generates upward turbulence, which hinders the flow of the circulating heat exchange medium, increases the energy consumption of the circulating pump, and reduces the heat exchange efficiency of the geothermal well heat exchange device. Therefore, a geothermal well heat exchange head tube is urgently needed to solve this problem. Summary of the Invention

[0004] The purpose of this invention is to provide a geothermal well heat exchange head tube to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A geothermal well heat exchange head tube includes: a heat absorption tube head, wherein the heat absorption tube head is provided with a transition arc surface, the transition arc surface is coaxially arranged with the heat absorption tube head, and the curve of the cross section of the transition arc surface is an Archimedean spiral structure.

[0007] A second heat insulation material is laid inside the transition arc surface;

[0008] A heat-conducting column is coaxially fixed to the center of the heat-absorbing tube head;

[0009] The heat-absorbing tube head is coaxially fixed to the bottom of the heat-absorbing outer tube, and a heat-insulating inner tube is coaxially sleeved inside the heat-absorbing outer tube. The heat-conducting column extends into the inside of the heat-insulating inner tube, and the bottom of the heat-absorbing outer tube is connected to the bottom of the heat-insulating inner tube through the transition arc surface.

[0010] Preferably, a spiral heat-conducting plate is coaxially fixed to the outside of the heat-absorbing outer tube, and the spiral heat-conducting plate is used to increase the heat exchange area of ​​the heat-absorbing outer tube.

[0011] Preferably, an installation ring is coaxially fixed to the outer side of the bottom of the heat-insulating inner sleeve, and the gap between the installation ring and the inner wall of the heat-absorbing outer sleeve and the outer wall of the heat-insulating inner sleeve is matched.

[0012] The mounting ring is circumferentially fixed with several one-way valves at equal intervals. The liquid inlet of the one-way valve is connected to the inside of the heat-absorbing outer sleeve, and the liquid outlet of the one-way valve is connected to the inside of the heat-insulating inner sleeve through the transition arc surface.

[0013] Preferably, a first heat-insulating material is coaxially fixed to the inner side of the bottom of the heat-absorbing outer jacket. The top plane of the first heat-insulating material is higher than the top plane of the heat-conducting column. The first heat-insulating material and the second heat-insulating material work together to prevent heat exchange between the medium in the transition arc surface and the geothermal source.

[0014] Preferably, the heat-absorbing outer tube comprises a stainless steel outer tube, the spiral heat-conducting plate is coaxially fixed to the outside of the stainless steel outer tube, and the inside of the stainless steel outer tube is coated with a graphene inner coating.

[0015] Preferably, a heat insulation pipe is coaxially fixed to the outside of the heat insulation inner sleeve.

[0016] Preferably, the inner heat insulation sleeve is provided with a vacuum heat insulation layer, the vacuum heat insulation layer is coaxially arranged with the inner heat insulation sleeve, and the top of the vacuum heat insulation layer is connected to an exhaust port.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] In use, a geothermal well is dug, and the heat-absorbing pipe head of this device is placed at the bottom of the well. Simultaneously, the heat-absorbing pipe head is connected to the bottom of both the heat-absorbing outer casing and the inner insulation casing. The liquid inlet at the top of the heat-absorbing outer casing is connected to the liquid outlet of the high-pressure pump. The high-pressure pump injects the heat exchange medium into the outer cavity formed between the heat-absorbing outer casing and the inner insulation casing. The heat exchange medium enters the transition arc surface from the outer cavity, and then enters the inner cavity formed within the inner insulation casing from the transition arc surface. When the heat exchange medium contacts the transition arc surface, under the action of the second insulation material, the geothermal heat absorbed by the heat-absorbing pipe head does not interact with the heat exchange medium within the transition arc surface. Heat exchange occurs between the heat exchange medium and the liquid inlet of the transition arc surface, ensuring that the temperature is consistent with the temperature at the liquid outlet of the transition arc surface. This avoids turbulence caused by temperature differences. When the heat exchange medium turns through the transition arc surface and enters the inner insulation tube, the heat-conducting column inside the inner insulation tube exchanges heat with the heat exchange medium. The ground source heat absorbed by the heat absorber head is transferred to the heat exchange medium through the heat-conducting column, causing the heat exchange medium to heat up at the bottom of the spiral heat-conducting fins. Since the direction of the turbulence generated by the heating is consistent with the direction of movement of the heat exchange medium, the influence of turbulence on the flow resistance of the heat exchange medium is reduced, thereby reducing the energy consumption of the high-pressure pump and improving the heat exchange efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a cross-sectional view of the structure of the present invention;

[0022] Figure 3 For the present invention Figure 2 Enlarged view of a section at point A in the middle;

[0023] Figure 4 This is a schematic diagram of the heat-absorbing outer jacket structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0025] Figure 6 This is a cross-sectional view of the structure in Embodiment 2 of the present invention;

[0026] Among them, 1. heat-absorbing outer tube; 2. spiral heat-conducting fin; 3. heat-insulating inner tube; 4. vacuum insulation layer; 5. first insulation material; 6. mounting ring; 7. one-way valve; 8. heat-conducting column; 9. second insulation material; 10. heat-absorbing tube head; 11. transition arc surface; 12. inner tube cavity; 13. outer tube cavity; 101. stainless steel outer tube; 102. graphene inner coating; 14. spiral tube. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1:

[0030] Reference Figures 1 to 4As shown, this embodiment discloses a geothermal well heat exchange head tube, including: a heat absorption tube head 10, a transition arc surface 11 provided on the heat absorption tube head 10, the transition arc surface 11 being coaxially arranged with the heat absorption tube head 10, and the curve of the cross section of the transition arc surface 11 being an Archimedean spiral structure.

[0031] The transition arc surface 11 is lined with a second heat insulation material 9;

[0032] A heat-conducting column 8 is coaxially fixed to the center of the heat-absorbing tube head 10;

[0033] The heat-absorbing tube head 10 is coaxially fixed to the bottom of the heat-absorbing outer tube 1. The heat-absorbing outer tube 1 is coaxially fitted with the heat-insulating inner tube 3. The heat-conducting column 8 extends into the inner side of the heat-insulating inner tube 3. The bottom of the heat-absorbing outer tube 1 is connected to the bottom of the heat-insulating inner tube 3 through the transition arc surface 11.

[0034] In use, a geothermal well is dug, and the heat-absorbing pipe head 10 of this device is placed at the bottom of the geothermal well. Simultaneously, the heat-absorbing pipe head 10 is connected to the bottom of the heat-absorbing outer sleeve 1 and the bottom of the heat-insulating inner sleeve 3. The liquid inlet end of the top of the heat-absorbing outer sleeve 1 is connected to the liquid outlet end of the high-pressure pump. The heat exchange medium is injected into the outer cavity 13 formed between the heat-absorbing outer sleeve 1 and the heat-insulating inner sleeve 3 through the high-pressure pump. The heat exchange medium enters the transition arc surface 11 from the outer cavity 13, and then enters the inner cavity 12 formed inside the heat-insulating inner sleeve 3 from the transition arc surface 11. When the heat exchange medium contacts the transition arc surface 11, under the action of the second heat insulation material 9, the geothermal heat absorbed by the heat-absorbing pipe head 10 does not come into contact with the transition arc surface. Heat exchange occurs within the heat exchange medium 11, ensuring that the temperature at the inlet end of the transition arc surface 11 matches the temperature at the outlet end of the transition arc surface 11, thus avoiding turbulence caused by temperature differences. When the heat exchange medium turns through the transition arc surface 11 into the inner insulation sleeve 3, heat exchange occurs through the heat-conducting column 8 located within the inner insulation sleeve 3. This allows the ground-source heat absorbed by the heat-absorbing tube head 10 to be transferred to the heat exchange medium via the heat-conducting column 8, causing the heat exchange medium to heat up at the bottom of the spiral heat-conducting plate 2. Since the direction of the turbulence generated by the heating is consistent with the direction of movement of the heat exchange medium, the resistance of the turbulence to the flow of the heat exchange medium is reduced, thereby reducing the energy consumption of the high-pressure pump and improving the heat exchange efficiency.

[0035] The cross-section of the transition arc surface 11 has an Archimedean spiral structure, which allows the heat exchange medium to smoothly enter the inner tube 12 from the outer tube 13 without causing a large change in the flow velocity of the heat exchange medium, thus avoiding turbulence caused by sudden changes in flow velocity.

[0036] To further optimize the design, a spiral heat-conducting plate 2 is coaxially fixed to the outside of the heat-absorbing outer tube 1. The spiral heat-conducting plate 2 is used to increase the heat exchange area of ​​the heat-absorbing outer tube 1.

[0037] The spiral heat-conducting plate 2 increases the heat exchange area of ​​the heat-absorbing outer tube 1, improves the heat exchange efficiency, and facilitates rapid heat absorption and temperature rise of the heat exchange medium as it moves along the heat-absorbing outer tube 1.

[0038] The scheme is further optimized by attaching an installation ring 6 coaxially to the outer side of the bottom of the heat insulation inner sleeve 3. The gap between the installation ring 6 and the inner wall of the heat absorption outer sleeve 1 and the outer wall of the heat insulation inner sleeve 3 is matched.

[0039] A number of one-way valves 7 are fixedly connected to the mounting ring 6 at equal intervals in the circumferential direction. The liquid inlet end of the one-way valve 7 is connected to the inside of the heat-absorbing outer sleeve 1, and the liquid outlet end of the one-way valve 7 is connected to the inside of the heat-insulating inner sleeve 3 through the transition arc surface 11.

[0040] The one-way valve 7 is preferably a Tesla valve (not shown in the figure).

[0041] Furthermore, the outlet of the one-way valve 7 is connected to the inlet of a Laval tube (not shown in the figure) to further increase the flow rate of the heat exchange medium.

[0042] Under the action of the one-way valve 7, the heat exchange medium in the transition arc surface 11 cannot return to the outer tube cavity 13, but can only move towards the inner tube cavity 12, thereby avoiding bottom backflow and reducing the influence of turbulence on the flow resistance of the heat exchange medium.

[0043] The scheme is further optimized by having a first heat insulation material 5 coaxially fixed to the inner side of the bottom of the heat-absorbing outer jacket 1. The top plane of the first heat insulation material 5 is higher than the top plane of the heat-conducting column 8. The first heat insulation material 5 and the second heat insulation material 9 work together to prevent the medium in the transition arc surface 11 from exchanging heat with the geothermal source.

[0044] The installation of the first insulation material 5 and the second insulation material 9 increases the area at the bottom of the heat-absorbing outer tube 1 that is isolated from the ground source heat. In this area, the heat exchange medium does not exchange heat with the ground source heat, avoiding the generation of turbulence. The heat exchange process is concentrated at the bottom of the inner tube cavity 12, and the heat exchange medium is heated only through the heat-conducting column 8, so that the turbulence direction is consistent with the movement direction of the heat exchange medium.

[0045] Further optimization of the scheme: the heat-absorbing outer tube 1 includes a stainless steel outer tube 101, the spiral heat-conducting plate 2 is coaxially fixed to the outside of the stainless steel outer tube 101, and the inside of the stainless steel outer tube 101 is coated with a graphene inner coating 102.

[0046] Stainless steel outer tube 101 is chosen as the heat-absorbing outer jacket 1 because it has strong durability, is easy to construct and maintain, and has good thermal conductivity. Furthermore, by coating the inside of the stainless steel outer tube 101 with graphene inner coating 102, its thermal conductivity is improved, thereby improving the heat exchange efficiency with the heat exchange medium.

[0047] The design was further optimized by attaching a heat insulation pipe coaxially to the outside of the inner heat insulation sleeve 3.

[0048] Heat exchange between the outer cavity 13 and the inner cavity 12 is avoided by using an insulation pipe (not shown in the figure).

[0049] The design is further optimized by providing a vacuum insulation layer 4 inside the inner insulation sleeve 3. The vacuum insulation layer 4 is coaxially arranged with the inner insulation sleeve 3, and an exhaust port is connected to the top of the vacuum insulation layer 4.

[0050] The inner heat insulation tube 3 can be selected as a vacuum heat insulation tube. A vacuum heat insulation layer 4 is set inside the inner heat insulation tube 3. The air inside the vacuum heat insulation layer 4 is exhausted through the exhaust port (not shown in the figure) at the top of the vacuum heat insulation layer 4, so that it has a good heat insulation effect and avoids heat exchange between the outer tube cavity 13 and the inner tube cavity 12.

[0051] Example 2:

[0052] refer to Figures 5 to 6 The difference between this embodiment and embodiment 1 is that the bottom of the heat-absorbing outer sleeve 1 is a tapered structure, the bottom of the heat-absorbing outer sleeve 1 is connected to the water inlet end of the spiral tube 14, the water outlet end of the spiral tube 14 is connected to the bottom of the heat-insulating inner sleeve 3, and the heat-insulating inner sleeve 3 is installed through the bottom of the heat-absorbing outer sleeve 1.

[0053] By replacing the heat-absorbing tube head 10 with a spiral tube 14, the liquid inlet end of the spiral tube 14 is connected to the liquid outlet end at the bottom of the heat-absorbing outer tube 1, and the liquid outlet end of the spiral tube 14 is connected to the liquid inlet end at the bottom of the heat-insulating inner tube 3. This allows the heat exchange medium in the outer tube cavity 13 to enter the inner tube cavity 12 through the spiral tube 14. The spiral tube 14 has a large heat exchange area, which can rapidly raise the temperature of the heat exchange medium. At the same time, it increases the flow path of the heat exchange medium, causing the turbulent flow to turn into laminar flow, thus avoiding resistance to the flow of the heat exchange medium.

[0054] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0055] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A heat exchange head tube for a geothermal well, characterized in that, include: The heat absorption tube head (10) is provided with a transition arc surface (11), which is coaxially arranged with the heat absorption tube head (10). The curve of the cross section of the transition arc surface (11) is an Archimedean spiral. The transition arc surface (11) is lined with a second heat insulation material (9); A heat-conducting column (8) is coaxially fixed to the center of the heat-absorbing tube head (10); The heat-absorbing tube head (10) is coaxially fixed to the bottom of the heat-absorbing outer tube (1). The heat-absorbing outer tube (1) is coaxially fitted with a heat-insulating inner tube (3). The heat-conducting column (8) extends into the inner side of the heat-insulating inner tube (3). A gap is reserved between the bottom of the heat-absorbing outer tube (1) and the transition arc surface (11). The gap allows the heat-absorbing outer tube (1) to communicate with the heat-insulating inner tube (3). The heat-absorbing outer jacket (1) is coaxially fixed to the inner side of the bottom with a first heat-insulating material (5). The top plane of the first heat-insulating material (5) is higher than the top plane of the heat-conducting column (8). The first heat-insulating material (5) and the second heat-insulating material (9) work together to prevent the medium in the transition arc surface (11) from exchanging heat with the geothermal source.

2. The geothermal well heat exchanger head pipe according to claim 1, characterized in that: A spiral heat-conducting plate (2) is coaxially fixed to the outside of the heat-absorbing outer tube (1). The spiral heat-conducting plate (2) is used to increase the heat exchange area of ​​the heat-absorbing outer tube (1).

3. The geothermal well heat exchange head pipe according to claim 1, characterized in that: An installation ring (6) is coaxially fixed to the outer side of the bottom of the heat-insulating inner sleeve (3). The gap between the installation ring (6) and the inner wall of the heat-absorbing outer sleeve (1) and the outer wall of the heat-insulating inner sleeve (3) is matched. The installation ring (6) is located at the turbulent interface. The mounting ring (6) is fixed with several one-way valves (7) at equal intervals in the circumferential direction. The liquid inlet of the one-way valve (7) is connected to the inside of the heat-absorbing outer sleeve (1), and the liquid outlet of the one-way valve (7) is connected to the inside of the heat-insulating inner sleeve (3) through the interval.

4. A geothermal well heat exchange head pipe according to claim 2, characterized in that: The heat-absorbing outer tube (1) includes a stainless steel outer tube (101), the spiral heat-conducting plate (2) is coaxially fixed to the outside of the stainless steel outer tube (101), and the inside of the stainless steel outer tube (101) is coated with a graphene inner coating (102).

5. A geothermal well heat exchanger head pipe according to claim 1, characterized in that: The outer side of the inner heat insulation sleeve (3) is coaxially fixed with a heat insulation pipe.

6. A geothermal well heat exchanger head pipe according to claim 1, characterized in that: The inner heat insulation sleeve (3) is provided with a vacuum heat insulation layer (4), which is coaxially arranged with the inner heat insulation sleeve (3), and the top of the vacuum heat insulation layer (4) is connected to an exhaust port.

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