Coaxial heat exchange central tube counterweight combination device
Through the coaxial heat exchange central pipe counterweight combination device, the counterweight distribution is optimized, and the problems of central pipe elongation and thermal deformation are solved, achieving the improvement of safety and stability.
Patent Information
- Application Number
- CN202422430028.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-10-09
AI Technical Summary
The existing central pipe weight combination method increases the elongation of the central pipe, resulting in thermal deformation, affecting the safety of use.
The counterweight distribution of the coaxial heat exchange center pipe weight combination device is adopted. By connecting the screen pipe and the counterweight oil pipe at the bottom of the central pipe and connecting the second counterweight oil pipe at the top, the counterweight distribution is optimized to reduce elongation and thermal deformation.
Effectively reduce the elongation and thermal deformation of the central tube, improve the safety of use and structural stability, and reduce the risk of operating failure.
Smart Images
Figure CN223179070U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a coaxial heat exchange central pipe weight combination device, belonging to the technical field of medium-deep geothermal heat exchange. Background Technique
[0002] Medium-deep geothermal heat exchange refers to the process of installing a closed metal casing and a central pipe in a borehole with a depth of 200m to 3000m to form a downhole heat exchanger. By injecting a low-temperature medium into the annulus between the metal casing and the central pipe for heat exchange with the surrounding high-temperature rock, heat is absorbed and the temperature rises. The heated heat exchange medium is transported from inside the central pipe to the ground for utilization. As a very important part in the heat exchange process, in order to reduce the friction and wear during the lowering and installation process, water is usually filled in the wellbore in advance, and then the method of setting weights is used for lowering and installation. The conventional central pipe weight combination method usually concentrates the weight oil pipes at the bottom of the central pipe. This approach will increase the elongation rate of the pipe material, to a certain extent, affect its service life and increase the risk of failure during operation. In addition, due to the high pressure and temperature in the lower part of the wellbore, the central pipe will undergo upward thermal deformation under high temperature and high pressure conditions for a long time, thus affecting the use safety. Summary of the Invention
[0003] The utility model provides a coaxial heat exchange central pipe weight combination device, which can solve the problems that the existing central pipe weight combination method will increase the elongation rate of the central pipe and make the central pipe prone to upward thermal deformation, thus affecting the use safety.
[0004] The utility model provides a coaxial heat exchange central pipe weight combination device, and the device includes:
[0005] A first weight oil pipe, vertically arranged in the heat exchange borehole;
[0006] A screen pipe, arranged above the first weight oil pipe, and its bottom end is connected to the top end of the first weight oil pipe, and its top end is connected to the bottom end of the first central pipe; the first weight oil pipe, the screen pipe and the first central pipe are coaxially arranged; a plurality of screen holes are arranged on the pipe wall of the screen pipe;
[0007] A second weight oil pipe, coaxially arranged above the first central pipe, and its bottom end is connected to the top end of the first central pipe.
[0008] Optionally, the device further includes:
[0009] A third weight oil pipe, coaxially arranged between the screen pipe and the first central pipe, and its bottom end is connected to the top end of the screen pipe, and its top end is connected to the bottom end of the first central pipe.
[0010] Optionally, both ends of the first central pipe are respectively connected to the third counterweight oil pipe and the second counterweight oil pipe through adapter joints.
[0011] Optionally, the length of the screen pipe is greater than or equal to 2 times the length of the first counterweight oil pipe.
[0012] Optionally, the flow-through area of the screen pipe is greater than the annulus area of its corresponding cross-section.
[0013] Optionally, the screen pipe includes a first screen pipe and a second screen pipe connected to one end of the first screen pipe; the two ends of the first screen pipe and the second screen pipe away from each other are respectively connected to the first counterweight oil pipe and the third counterweight oil pipe.
[0014] Optionally, the top end of the second counterweight oil pipe is connected with a second central pipe through an adapter joint, and the second central pipe is coaxially arranged with the first central pipe.
[0015] Optionally, the second central pipe is a heat-insulating central pipe.
[0016] Optionally, the first counterweight oil pipe, the screen pipe, the first central pipe and the second counterweight oil pipe are sequentially connected through threaded couplings.
[0017] The beneficial effects that the present utility model can produce include:
[0018] By analyzing the conventional counterweight combination of the existing central pipe and combining the installation and lowering characteristics of the central pipe, the present utility model determines a new central pipe counterweight combination scheme to reduce the elongation rate of the central pipe under the action of gravity and the upward thermal deformation under high temperature and high pressure. The counterweight should be calculated according to the size of the central pipe, the comprehensive density of the pipe material and the wellbore depth, and it is advisable that the weight of the central pipe string is greater than the weight of the water displaced by the central pipe by 50 kg to 80 kg. Considering that there will be sediment at the bottom of the well during the long-term circulation of the heat exchange working medium in the wellbore, a counterweight oil pipe and a sand settling pipe (i.e., the first counterweight oil pipe) are arranged at the bottom end of the pipe string. The upper part of the first counterweight oil pipe is connected to a screen pipe made by perforating an oil pipe. The flow-through area of the screen pipe should be greater than the annulus area of its corresponding cross-section, which can improve the flow efficiency of the circulating working medium and enhance the sand control effect. The upper part of the screen pipe is connected to the third counterweight oil pipe. The upper part of the third counterweight oil pipe is connected to the first central pipe through an adapter joint. The upper part of the first central pipe is continuously connected to the second counterweight oil pipe through an adapter joint. Arranging counterweights here can, to a certain extent, inhibit the upward development of the thermal expansion of the first central pipe under the thermal temperature, which is safer than arranging all the counterweights at the bottom, and can effectively reduce the elongation rate of the first central pipe between the counterweights. Description of the Drawings
[0019] Figure 1 It is a schematic structural diagram of a coaxial heat exchange central pipe counterweight combination device provided by an embodiment of the present utility model;
[0020] Figure 2 Schematic diagram of the first counterweight oil pipe provided by an embodiment of the present utility model;
[0021] Figure 3 Schematic diagram of the first screen pipe provided by an embodiment of the present utility model;
[0022] Figure 4 Schematic diagram of the adapter provided by an embodiment of the present utility model.
[0023] Reference numerals:
[0024] 10. First counterweight oil pipe; 11. External thread of the male oil pipe joint; 12. Oil pipe body; 13. Internal thread of the female oil pipe joint; 20. First screen pipe; 30. Second screen pipe; 31. External thread of the male screen pipe joint; 32. Screen pipe body; 33. Internal thread of the female screen pipe joint; 40. Third counterweight oil pipe; 50. Adapter; 51. External thread of the joint; 52. Joint body; 53. Internal thread of the joint; 60. First central pipe; 70. Second counterweight oil pipe; 80. Second central pipe. Detailed implementation manners
[0025] The present utility model will be described in detail below in conjunction with embodiments, but the present utility model is not limited to these embodiments.
[0026] An embodiment of the present utility model provides a coaxial heat exchange central pipe counterweight combination device, as Figures 1 to 4 shown, the device includes:
[0027] The first counterweight oil pipe 10 is vertically arranged in the heat exchange drilling hole.
[0028] The screen pipe is arranged above the first counterweight oil pipe 10, and its bottom end is connected to the top end of the first counterweight oil pipe 10, and its top end is connected to the bottom end of the first central pipe 60; the first counterweight oil pipe 10, the screen pipe and the first central pipe 60 are coaxially arranged; a plurality of screen holes are arranged on the pipe wall of the screen pipe.
[0029] The second counterweight oil pipe 70 is coaxially arranged above the first central pipe 60, and its bottom end is connected to the top end of the first central pipe 60.
[0030] The first counterweight oil pipe 10, the screen pipe, the first central pipe 60 and the second counterweight oil pipe 70 are sequentially connected by thread collars.
[0031] Further, the device further includes: a third counterweight oil pipe 40, which is coaxially arranged between the screen pipe and the first central pipe 60, and its bottom end is connected to the top end of the screen pipe, and its top end is connected to the bottom end of the first central pipe 60.
[0032] In practical applications, both ends of the first central pipe 60 are respectively connected to the third counterweight oil pipe 40 and the second counterweight oil pipe 70 through the adapter 50.
[0033] The length of the above-mentioned screen pipe is greater than or equal to 2 times the length of the first counterweight oil pipe 10; and the flow-through area of the screen pipe is greater than the annulus area of its corresponding cross-section.
[0034] In the embodiment of the present utility model, the screen pipe includes a first screen pipe 20 and a second screen pipe 30 connected to one end of the first screen pipe 20; the two ends of the first screen pipe 20 and the second screen pipe 30 away from each other are respectively connected to the first counterweight oil pipe 10 and the third counterweight oil pipe 40.
[0035] The top end of the second counterweight oil pipe 70 is connected with a second central pipe 80 through the adapter 50, and the second central pipe 80 is coaxially arranged with the first central pipe 60.
[0036] Among them, the second central pipe 80 can be a heat-insulating central pipe.
[0037] Reference Figure 1 As shown, the first counterweight oil pipe 10, the first screen pipe 20, the second screen pipe 30, the third counterweight oil pipe 40, the adapter 50, the first central pipe 60, the adapter 50, the second counterweight oil pipe 70, the adapter 50, and the second central pipe 80 are sequentially connected through thread collars.
[0038] Further, the pipe bodies of the above-mentioned first counterweight oil pipe 10, first screen pipe 20, second screen pipe 30, second counterweight oil pipe 70, adapter 50, first central pipe 60, third counterweight oil pipe 40, and second central pipe 80 are all of cylindrical structures.
[0039] The present utility model does not limit the size specifications of the first counterweight oil pipe 10, first screen pipe 20, second screen pipe 30, second counterweight oil pipe 70, adapter 50, first central pipe 60, third counterweight oil pipe 40, and second central pipe 80. By way of example, the outer diameters of the first counterweight oil pipe 10, first screen pipe 20, second screen pipe 30, second counterweight oil pipe 70, and third counterweight oil pipe 40 are all 101.6 mm, and the wall thickness is 6.65 mm; the outer diameters of the first central pipe 60 and the second central pipe 80 are 116 mm, and the wall thickness is 14 mm; the outer diameter of the adapter 50 is 126 mm, and the wall thickness is 5 mm.
[0040] The above-mentioned first screen pipe 20 and second screen pipe 30 are both made by punching holes in the counterweight oil pipe. The present utility model does not limit the punching specifications on the screen pipe, and those skilled in the art can set them according to the actual situation. By way of example, the punching hole diameter on the screen pipe is 18 mm, the punching spacing is 15 cm, and the holes are arranged in a plum blossom shape.
[0041] Reference Figure 2As shown, in practical applications, the first counterweight tubing 10, the second counterweight tubing 70, and the third counterweight tubing 40 have the same structure, and each includes an external male thread 11 of the tubing, a tubing body 12, and an internal female thread 13 of the tubing. During the lowering process of the first central tube 60 and the second central tube 80, the counterweight tubing mainly overcomes the buoyancy of water to ensure the slow and steady lowering of the entire pipe string. Under the lubricating and cooling effects of water, the friction and wear of the central tube during the lowering process can be effectively reduced, and the service life of the tubing can be extended.
[0042] Reference Figure 3 As shown, the first screen pipe 20 and the second screen pipe 30 have the same structure, and each includes an external male thread 31 of the screen pipe, a screen pipe body 32, and an internal female thread 33 of the screen pipe. On the one hand, the screen pipe can isolate impurities and sediments in the circulating fluid, prevent blockage of the pipe string, and improve the purity and circulation efficiency of the circulating fluid, which helps to improve the heat exchange efficiency and efficient utilization of geothermal energy.
[0043] Reference Figure 4 As shown, the adapter 50 includes an adapter body 52 and an external adapter thread 51 and an internal adapter thread 53 provided at both ends of the adapter body 52. The main function of the adapter 50 is to connect the counterweight tubing and the central tube.
[0044] Another embodiment of the present utility model provides a coaxial heat exchange central tube counterweight combination device, which specifically includes:
[0045] 101.6mm counterweight tubing × 9.6m (i.e., the first counterweight tubing) + 101.6mm screen pipe × 9.6m × 2 pieces (i.e., the first screen pipe and the second screen pipe) + 101.6mm counterweight tubing × 9.6m (i.e., the third counterweight tubing) + 116mm central tube × 11m × 37 pieces (i.e., the first central tube) + 101.6mm counterweight tubing × 9.6m × several pieces (i.e., the second counterweight tubing) + 116mm insulated central tube × 11m × several pieces (i.e., the second central tube).
[0046] When the present utility model is in use, during the installation and construction of the coaxial heat exchange central tube, since the conventional counterweight tubing is concentrated at the bottom of the central tube, it will cause an increase in the elongation rate of the tubing, and the central tube will undergo upward thermal deformation under high temperature and high pressure conditions for a long time, thus affecting the use safety. By optimizing the positional relationship among the first counterweight tubing 10, the first screen pipe 20, the second screen pipe 30, the third counterweight tubing 40, the adapter 50, the first central tube 60, and the second counterweight tubing 70, a coaxial heat exchange central tube counterweight combination scheme is formed to achieve efficient heat exchange in medium and deep geothermal energy.
[0047] The coaxial heat exchange central tube weight combination device provided by the utility model suppresses the upward development of thermal expansion of the first central tube 60 under thermal temperature by connecting a screen pipe and a first weight oil pipe 10 to the bottom of the first central tube 60 and connecting a second weight oil pipe 70 to the top thereof. Compared with the case where all the weights are arranged at the bottom, the safety is higher, and the elongation rate of the first central tube 60 between the weights can be effectively reduced, ensuring that the first central tube 60 meets the designed service life and operates safely during the service life.
[0048] Without changing the heat exchange function, the utility model optimizes the anti-gravity elongation performance of the first central tube 60, improves the stability of the heat exchanger structure, reduces the risk of failures during operation, and to a certain extent suppresses the influence of thermal expansion of the first central tube 60 under thermal temperature, improving the overall safety of the heat exchanger compared with the case where all the weights are arranged at the bottom.
[0049] The above are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are all equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A coaxial heat exchange central tube weight combination device, characterized in that, The device includes: A first weighted oil pipe, vertically arranged in the heat exchange borehole; A screen pipe, arranged above the first weighted oil pipe, and its bottom end is connected to the top end of the first weighted oil pipe, and its top end is connected to the bottom end of a first central pipe; the first weighted oil pipe, the screen pipe and the first central pipe are coaxially arranged; a plurality of screen holes are arranged on the pipe wall of the screen pipe; A second weighted oil pipe, coaxially arranged above the first central pipe, and its bottom end is connected to the top end of the first central pipe.
2. The device according to claim 1, characterized in that, The device further includes: A third weighted oil pipe, coaxially arranged between the screen pipe and the first central pipe, and its bottom end is connected to the top end of the screen pipe, and its top end is connected to the bottom end of the first central pipe.
3. The device according to claim 2, wherein Both ends of the first central pipe are respectively connected to the third weighted oil pipe and the second weighted oil pipe through adapter joints.
4. The device according to claim 1, characterized in that The length of the screen pipe is greater than or equal to twice the length of the first weighted oil pipe.
5. The device according to claim 1, characterized in that, The flow-through area of the screen pipe is greater than the annulus area of its corresponding cross-section.
6. The device according to claim 2, wherein The screen pipe includes a first screen pipe and a second screen pipe connected to one end of the first screen pipe; the two ends of the first screen pipe and the second screen pipe away from each other are respectively connected to the first weighted oil pipe and the third weighted oil pipe.
7. The device according to claim 1, characterized in that, The top end of the second weighted oil pipe is connected to a second central pipe through an adapter joint, and the second central pipe is coaxially arranged with the first central pipe.
8. The device according to claim 7, characterized in that, The second central pipe is a heat-insulating central pipe.
9. The device according to claim 1, characterized in that, The first weighted oil pipe, the screen pipe, the first central pipe and the second weighted oil pipe are sequentially connected through threaded collars.