A new screw energy pile and a preparation method thereof

Abstract

This invention belongs to the field of energy pile technology and discloses a novel screw-type energy pile and its preparation method to solve the problems of low heat exchange efficiency and poor bearing capacity of existing energy piles. Specifically, it includes a pile cap, pile body, steel threaded screws, pile tip, and heat exchange pipe. The pile cap has an internal hole; the pile body is connected below the pile cap; the pile tip is connected to the bottom of the pile body; steel threaded screws are spirally wound around the pile body; one section of the heat exchange pipe has a spiral structure, with the spiral pipe body passing through the steel threaded screws and winding around the pile body; both ends of the heat exchange pipe protrude from the hole. When the energy pile of this invention is buried in the soil, the steel threaded screws directly contact the surrounding soil, and the heat exchange pipe inside improves the heat exchange efficiency, enabling the energy pile to efficiently extract geothermal energy. The energy pile preparation method of this invention uses a prefabrication process, resulting in lower construction costs and a shorter construction period; moreover, the pile body is cast in one piece, resulting in strong bearing capacity and reliable quality.

Description

Technical Field

[0001] This invention relates to the field of energy pile technology, and in particular to a novel screw-type energy pile and its manufacturing method. Background Technology

[0002] The use of fossil fuels is a major cause of global warming because it disrupts the natural carbon cycle. Meanwhile, because fossil fuels are non-renewable, uncontrolled consumption will lead to an energy crisis, impacting national energy security. Against this backdrop, the utilization of geothermal energy as a renewable energy source has attracted widespread attention. In the field of civil engineering, energy piles, as a typical example of geothermal energy utilization, are an emerging energy-saving and emission-reduction technology combining ground source heat pump technology with pile foundations. They have the dual functions of bearing the building load and providing energy to the building. Therefore, improving the heat exchange efficiency of energy piles while ensuring their superior load-bearing capacity is a current research focus.

[0003] Currently, the main form of energy piles is cast-in-place piles. While this type of pile can withstand high loads and has a long service life, it is costly, and the construction quality is difficult to control during on-site drilling and casting. Furthermore, it typically requires larger borehole diameters, which limits the utilization of underground space. To address this issue, precast energy piles have been explored to improve pile quality and reduce construction costs. Simultaneously, the layout of heat exchange tubes within the pile has been optimized to improve heat exchange efficiency. However, current technologies still rely on concrete for the installation of heat exchange tubes, which has relatively low thermal conductivity, resulting in low heat exchange efficiency. Moreover, the existing heat exchange tube designs are relatively simple, failing to substantially increase the heat exchange area. Additionally, existing energy piles often use multiple heat exchange tubes or larger diameter tubes within the pile to improve heat exchange efficiency, which undoubtedly reduces the pile's load-bearing capacity.

[0004] Therefore, the present invention provides a novel energy pile that is easy to manufacture, has lower cost, higher heat exchange performance, and superior load-bearing capacity. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a novel screw-type energy pile and its preparation method to solve the problems of low heat exchange efficiency and poor bearing capacity of existing energy piles.

[0006] Firstly, in order to achieve the aforementioned objectives, the technical solution adopted by this invention is as follows:

[0007] A novel screw-type energy pile includes a pile cap, a pile body, steel threaded screws, a pile tip, and a heat exchange pipe. The pile cap is a disc-shaped structure with holes inside. The pile body is connected below the pile cap and is a conical cylindrical structure with a larger diameter at the top and a smaller diameter at the bottom. The pile tip is connected to the bottom of the pile body. Steel threaded screws are spirally wound around the pile body. The heat exchange pipe is a spiral structure, with the spiral tube passing through the steel threaded screws and wound around the pile body along the steel threaded screws. Both ends of the heat exchange pipe protrude from the holes.

[0008] In this design, steel threaded rods are wound around the pile body. When the energy pile is buried in the soil, the steel threaded rods are in direct contact with the surrounding soil. The thermal conductivity of the steel threaded rods is much greater than that of the concrete pile body. The heat exchange pipes are inserted inside the steel threaded rods, which can improve the heat exchange efficiency between the heat exchange pipes and the soil, enabling the energy pile to efficiently extract geothermal energy. Furthermore, the main body of the heat exchange pipes is located inside the steel threaded rods, which reduces the space occupied inside the pile body, resulting in high concrete density inside the pile body and ensuring the load-bearing capacity of the energy pile.

[0009] Furthermore, the steel thread has an upper thread interface and a lower thread interface at both ends, and the pile body has an upper pile body interface and a lower pile body interface, which correspond to the positions of the upper thread interface and the lower thread interface, respectively; the holes include an inlet hole and an outlet hole; the inlet hole communicates with the inner cavity of the upper pile body interface; the outlet hole communicates with the inner cavity of the lower pile body interface;

[0010] The heat exchange pipe includes an inlet pipe, a spiral pipe, and an outlet pipe. The inlet pipe is installed inside the inlet hole, with one end serving as the inlet, which is located at the top of the pile cap. The other end of the inlet pipe passes through the upper interface of the pile body and connects to the inlet end of the spiral pipe. The spiral pipe is installed inside the steel structure thread, and the outlet end of the spiral pipe is connected to the outlet pipe. The outlet pipe enters the pile body from the lower interface and exits the pile cap through the outlet hole.

[0011] In this design, during heat exchange, water flows from the inlet pipe into the spiral pipe, and then from the spiral pipe into the outlet pipe. The spiral pipe is installed in the threads of the steel structure. After the water enters the spiral pipe, it undergoes sufficient heat exchange with the soil and fully absorbs geothermal energy. The water that has undergone heat exchange then flows out from the outlet pipe, which is mostly located within the concrete pile body. The concrete pile body can significantly reduce the heat loss during the process of heat energy being transferred from the outlet pipe to the heat pump unit along with the water flow. This design avoids the problem of not only improving heat exchange efficiency but also reducing energy loss.

[0012] Furthermore, the connection between the upper interface of the pile body and the upper interface of the thread, as well as the connection between the lower interface of the pile body and the lower interface of the thread, are sealed with concrete and sealant.

[0013] In this scheme, the connection between the steel structure thread and the pile body is sealed to ensure that the heat exchange pipe is in a closed environment and to prevent damage to the heat exchange pipe from factors such as gravel in the soil.

[0014] Furthermore, a steel reinforcement cage is installed inside the pile body, and steel threaded connections are made between the steel reinforcement cage and the pile body.

[0015] In this scheme, a steel cage is designed inside the pile body, which can improve the bearing capacity of the energy pile and enhance its flexural and shear resistance. At the same time, the steel cage is connected to the steel structure threaded thread, which ensures the stability of the connection between the steel structure threaded thread and the pile body and improves the overall stability of the energy pile.

[0016] Furthermore, the cross-section of the steel thread is trapezoidal, with one side of the bottom edge of the trapezoidal structure in contact with the pile body.

[0017] In this scheme, when the steel thread of the trapezoidal structure comes into contact with the soil, the top bottom and both sides of the trapezoidal structure are in contact with the soil, resulting in a larger contact area and higher heat exchange efficiency; and the connection between the trapezoidal structure and the pile body is more stable.

[0018] Secondly, based on the novel screw-type energy pile provided in the first aspect, the present invention provides a method for preparing a novel screw-type energy pile, comprising the following steps:

[0019] S1: Fabricating steel structure threads;

[0020] S2: Fabricate pile casting molds and steel cages;

[0021] S3: Fix the steel structure threaded bolts to the pile casting mold;

[0022] S4: Install a steel cage inside the pile casting mold and then cast the pile to obtain a screw-type energy pile.

[0023] In this scheme, steel threaded screws are first made when preparing energy piles, then the steel threaded screws are installed on the pile casting mold, and finally the integrated pile body is cast. After casting, the part of the steel threaded screws connected to the pile body is directly cast inside the pile body. The steel threaded screws and the pile body obtained by using this method are a whole, which improves the structural stability of the energy pile.

[0024] Furthermore, S1 includes:

[0025] S101: Make a trapezoidal outer mold and a thin-walled round tube mold, and insert the thin-walled round tube mold into the trapezoidal outer mold;

[0026] S102: Inject molten steel into the cavity between the trapezoidal outer mold and the thin-walled round tube mold;

[0027] S103: After the molten steel has initially solidified, the trapezoidal outer mold and the thin-walled round tube mold are removed to form a steel structure component with a central hole running through it. The spiral tube is then inserted into the central hole. At this point, the steel structure component is in the plastic stage.

[0028] S104: The steel structure components, together with the spiral tube, are twisted into a spiral structure to form steel structure threads by a CNC twisting machine;

[0029] S105: After the steel structure threads have completely solidified, apply anti-rust and anti-leakage materials evenly to the outer surface of the steel structure threads and the inner surface of the heat exchange tube.

[0030] In this scheme, molten steel is poured into the cavity between the trapezoidal outer mold and the thin-walled circular tube mold to obtain a hollow steel structure component, and a spiral tube is inserted inside to form steel structure threads; the good thermal conductivity of steel material is fully utilized to improve the efficiency of the energy pile in extracting geothermal energy; at the same time, the steel structure threads increase the connection stability between the energy pile and the soil.

[0031] Furthermore, S2 includes:

[0032] S201: Separately manufacture pile cap mold, pile body mold, and pile tip mold. The outer surface of the pile body mold is provided with threaded mold. The pile cap mold, pile body mold, and pile tip mold are all symmetrical parts, and the opening and closing of the two parts are controlled by bolts. Connect the pile cap mold and pile body mold with bolts. Connect the pile body mold and pile tip mold with bolts to obtain the pile casting mold.

[0033] S202: Fix several longitudinal threaded steel bars onto the model machine according to the pile body dimensions; then fix several circumferential threaded steel bars onto the model machine; finally, bind the longitudinal threaded steel bars and circumferential threaded steel bars at the junction with wire to obtain the steel cage.

[0034] In this design, the pile casting mold is designed as two symmetrical parts. After the two parts are disassembled, it is convenient to install the steel structure threads inside. Furthermore, the symmetrical design of the pile casting mold facilitates demolding after the casting is completed. During demolding, the two parts of the pile casting mold can be pulled apart to the sides to achieve demolding. This design facilitates the installation of steel structure threads, is also conducive to the assembly of the pile casting mold, and has a fast demolding efficiency.

[0035] Furthermore, S3 includes:

[0036] S301: Disassemble the pile cap mold and pile tip mold, apply release agent evenly to the inner surface of the pile body mold; and split the pile body mold into two parts;

[0037] S302: Place a portion of the pile body mold horizontally; and place the steel structure thread into the horizontally placed pile body mold, so that the thread body of the steel structure thread is embedded inside the thread mold;

[0038] S303: Fasten another part of the pile body mold to the top of the horizontally placed pile body mold, and connect the two parts of the pile body mold with bolts;

[0039] S304: Install pile tip mold.

[0040] In this solution, the pile body mold is split into two parts, the steel structure thread is placed inside, and then the two pile body mold parts are snapped together to install the steel structure thread, which is convenient to install.

[0041] Furthermore, S3 includes:

[0042] S401: Vertically set up the pile body mold with the pile tip mold installed; and pour concrete into the pile body mold through the feeder. After the concrete reaches the preset depth, hoist the steel cage into the pile body mold.

[0043] S402: Install pile cap mold;

[0044] S403: Install the heat exchange pipe; connect the inlet pipe to the end of the spiral pipe near the pile cap, and connect the outlet pipe to the end of the spiral pipe near the pile tip; and pass the inlet and outlet pipes out through the holes reserved on the upper surface of the pile cap mold respectively;

[0045] S404: Continue pouring concrete until the concrete fills the pile casting mold, and the pouring is complete;

[0046] S405: Place the cast-in-place pile body along with the pile casting mold into a centrifuge tank for centrifugation to make the concrete evenly dispersed and compacted.

[0047] S406: Allow the poured pile body to cure statically until the concrete solidifies and takes shape.

[0048] S407: Remove the pile casting mold to obtain the screw-type energy pile; and repair the screw-type energy pile.

[0049] In this scheme, concrete is first poured into the pile body mold by a feeding machine. After the concrete reaches the preset depth, the reinforcing cage is hoisted into the pile body mold. At this time, the reinforcing cage is restricted by the concrete inside the pile body mold. This not only prevents the bottom of the reinforcing cage from contacting the pile tip mold, but also keeps the reinforcing cage in the exact center of the pile body mold, preventing the reinforcing cage from being eccentric inside the pile body mold. This method can avoid the phenomenon that the reinforcing cage is not encased in concrete when the energy pile is cast.

[0050] The beneficial effects of this invention are:

[0051] This invention provides a novel screw-type energy pile where the heat exchange pipe is directly embedded in the steel threaded section on the pile surface. The expanded spiral design significantly increases the heat exchange area and improves heat exchange efficiency. Simultaneously, the thermal conductivity of steel is much higher than that of concrete. Designing the heat exchange pipe within the steel threaded section, compared to existing technologies that embed it within the concrete pile body, allows for more effective heat transfer, significantly improving the efficiency of geothermal energy extraction. The spiral design of the steel threaded section on the pile surface creates a spiral anchor as the pile penetrates the soil, enhancing its flexural and shear resistance. This allows it to withstand stronger vertical, horizontal, and complex loads, making it suitable for deep foundations and high-rise buildings, aligning with future building development trends.

[0052] The present invention provides a novel method for preparing screw-type energy piles. The method uses a prefabrication process to prepare the pile foundation structure, which is simple. The energy pile body is cast in one go, with strong bearing capacity and reliable quality. Furthermore, the method requires less equipment such as underground drilling to prepare energy piles, resulting in lower construction costs and shorter construction cycles, and has strong engineering application prospects. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of a novel screw-type energy pile structure according to the present invention;

[0054] Figure 2 This is a top view of the pile cap structure of the present invention;

[0055] Figure 3 This is a schematic diagram of the steel thread structure of the present invention;

[0056] Figure 4 This is a schematic diagram of the cross-sectional structure of the steel thread of the present invention;

[0057] Figure 5 This is a schematic diagram of the heat exchange tube structure of the present invention;

[0058] Figure 6 This is a schematic diagram of the steel cage structure of the present invention;

[0059] Figure 7 This is a schematic diagram of the pile casting mold structure of the present invention.

[0060] Figure label:

[0061] 1. Pile cap; 101. Inlet hole; 102. Outlet hole; 2. Pile body; 201. Upper end interface of pile body; 202. Lower end interface of pile body; 3. Steel thread; 301. Upper end interface of thread; 302. Lower end interface of thread; 4. Pile tip; 5. Heat exchange pipe; 501. Spiral pipe; 502. Inlet pipe; 503. Outlet pipe; 504. Inlet; 505. Outlet; 6. Reinforcing cage; 7. Pile casting mold; 701. Pile cap mold; 702. Pile body mold; 703. Thread mold; 704. Pile tip mold; Detailed Implementation

[0062] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Specific embodiments of the present invention are described below to facilitate understanding by those skilled in the art. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various modifications are obvious as long as they fall within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0063] Example 1

[0064] like Figure 1 As shown, this embodiment provides a novel screw-type energy pile. This energy pile has heat exchange pipes inserted into the steel threads on the surface of the pile body, improving the heat exchange efficiency of the energy pile; furthermore, the steel threads are wound around the pile body, enhancing the load-bearing capacity of the energy pile; specifically, it includes:

[0065] 1. Pile cap, 2. Pile body, 3. Steel thread, 4. Pile tip, and 5. Heat exchange pipe;

[0066] Among them, pile cap 1 is a disc structure, such as Figure 2 As shown, the disc-shaped structure has holes inside; the pile cap 1 is connected to the pile body 2 below, and the pile body 2 is a conical column structure with a larger diameter at the top and a smaller diameter at the bottom; the pile tip 4 is connected to the bottom of the pile body 2; steel thread 3 is spirally wrapped around the pile body 2. When the energy pile is buried in the soil, the steel thread 3 can make the connection between the energy pile and the soil more stable; one section of the heat exchange pipe 5 is a spiral structure, and the spiral pipe is inserted into the steel thread 3 and wrapped around the pile body 2 along the steel thread 3. The heat exchange pipe 5 is located inside the steel thread 3, which increases the heat exchange area; both ends of the heat exchange pipe 5 protrude from the holes.

[0067] Specifically, such as Figure 3As shown, the steel thread 3 has an upper thread interface 301 and a lower thread interface 302 at both ends, and the pile body 2 has an upper pile body interface 201 and a lower pile body interface 202, which correspond to the positions of the upper thread interface 301 and the lower thread interface 302, respectively. The holes include an inlet hole 101 and an outlet hole 102. The inlet hole 101 is connected to the inner cavity of the upper pile body interface 201, and the outlet hole 102 is connected to the inner cavity of the lower pile body interface 202.

[0068] like Figure 4 As shown, the cross-section of the steel thread 3 is a trapezoidal structure, and one side of the bottom edge of the trapezoidal structure is in contact with the pile body 2. When the steel thread 3 of the trapezoidal structure is in contact with the soil, the top bottom and both sides of the trapezoidal structure are in contact with the soil, resulting in a larger contact area and higher heat exchange efficiency. Furthermore, the connection between the trapezoidal structure and the pile body 2 is more stable.

[0069] Specifically, such as Figure 5 As shown, the heat exchange pipe 5 is installed inside the pile body 2 to exchange heat with the soil and extract geothermal energy; it includes an inlet pipe 502, a spiral pipe 501, and an outlet pipe 503; the inlet pipe 502 is installed inside the inlet hole 101, one end of the inlet pipe 502 is an inlet 504, which is located at the top of the pile cap 1; the other end of the inlet pipe 502 passes through the upper interface 201 of the pile body and connects to the inlet end of the spiral pipe 501; the spiral pipe 501 is installed inside the steel thread 3, and the inlet end and outlet end of the spiral pipe 501 are respectively from the upper interface 301 of the thread and the outlet end. The threaded end interface 302 protrudes from the threaded end; the water outlet end of the spiral tube 501 is connected to the water outlet pipe 503; the water outlet pipe 503 enters the pile body from the lower end interface 202 of the pile body and exits the pile cap 1 from the water outlet hole 102; during heat exchange, water flows from the water inlet pipe 502 into the spiral tube 501, and then from the spiral tube 501 into the water outlet pipe 503; the spiral tube 501 is set in the steel threaded end 3, and after the water enters the spiral tube 501, it undergoes heat exchange with the soil in the spiral tube 501 and absorbs geothermal energy; after absorption, it flows out from the water outlet 505 through the water outlet pipe 503.

[0070] like Figure 6 As shown, a reinforcing cage 6 is provided inside the pile body 2, and the steel threaded thread 3 is connected to the pile body 2 through the reinforcing cage 6. The design of the reinforcing cage 6 inside the pile body 2 can improve the bearing capacity of the energy pile and enhance its flexural and shear resistance. At the same time, the connection of the steel threaded thread 3 through the reinforcing cage 6 ensures the stability of the connection between the steel threaded thread 3 and the pile body 2, thereby improving the overall stability of the energy pile.

[0071] The connection between the upper interface 201 of the pile body and the upper interface 301 of the thread, as well as the connection between the lower interface 202 of the pile body and the lower interface 302 of the thread, are sealed with concrete and sealant to ensure that the heat exchange pipe 5 is in a closed environment and to prevent damage to the heat exchange pipe 5 by factors such as gravel in the soil.

[0072] The working principle of this embodiment:

[0073] The energy pile provided in this embodiment is buried in the soil when in use. The steel thread 3 around the pile body 2 is in contact with the soil, which can improve the stability of the energy pile. During heat exchange, the water first flows into the inlet pipe 502 and then into the spiral pipe 501. It flows along the spiral pipe 501 in the steel thread 3. When flowing in the steel thread 3, it absorbs the geothermal energy of the soil and carries the energy flow into the outlet pipe 503, and finally flows out from the outlet pipe 503.

[0074] Example 2

[0075] like Figure 1-7 As shown, this embodiment, based on the novel screw-type energy pile provided in Embodiment 1, provides a novel method for preparing screw-type energy piles. This method uses a prefabrication process to prepare the energy piles, eliminating the need for underground drilling and casting, resulting in lower preparation costs and higher efficiency. It includes the following steps:

[0076] S1: Fabricating steel structure threads 3; specifically including:

[0077] S101: Make a trapezoidal outer mold and a thin-walled round tube mold, and insert the thin-walled round tube mold into the trapezoidal outer mold;

[0078] S102: Inject molten steel into the cavity between the trapezoidal outer mold and the thin-walled round tube mold;

[0079] S103: After the molten steel has initially solidified, the trapezoidal outer mold and the thin-walled round tube mold are removed to form a steel structure component with a central hole running through it. The spiral tube 501 is then inserted into the central hole. At this point, the steel structure component is in the plastic stage.

[0080] S104: The steel structure components, together with the spiral tube 501, are twisted into a spiral structure to form the steel structure thread 3 by a CNC twisting machine;

[0081] S105: After the steel thread 3 has completely cooled, apply anti-rust and anti-leakage materials evenly to the outer surface of the steel thread 3 and the inner surface of the heat exchange tube 5.

[0082] In this embodiment, molten steel is poured to obtain a hollow steel structure component, and a spiral tube 501 is inserted inside to form a steel structure thread 3; the good thermal conductivity of steel material is fully utilized to improve the efficiency of the energy pile in extracting geothermal energy; at the same time, the steel structure thread 3 increases the connection stability between the energy pile and the soil.

[0083] S2: Fabricate the pile casting mold 7 and the reinforcing cage 6; as follows Figure 7 As shown, it specifically includes:

[0084] S201: Fabricate pile cap mold 701, pile body mold 702, and pile tip mold 704 respectively. The outer surface of pile body mold 702 is provided with threaded mold 703. Pile cap mold 701, pile body mold 702, and pile tip mold 704 are all symmetrical parts, and the opening and closing of the two parts are controlled by bolts. Connect pile cap mold 701 and pile body mold 702 with bolts. Connect pile body mold 702 and pile tip mold 704 with bolts to obtain pile casting mold 7.

[0085] S202: Fix several longitudinal threaded steel bars onto the model machine according to the pile body dimensions; then fix several circumferential threaded steel bars onto the model machine; finally, bind the longitudinal threaded steel bars and circumferential threaded steel bars at the junction with wire to obtain the steel cage 6.

[0086] In this embodiment, the pile casting mold 7 is designed as two symmetrical parts. After the two parts are disassembled, it is convenient to install the steel structure thread 3 in them. Furthermore, the design of the pile casting mold 7 as two symmetrical parts is conducive to demolding after the later casting is completed. When demolding, the two parts of the pile casting mold 7 can be pulled apart to both sides to achieve demolding.

[0087] S3: Fix the steel structure thread 3 to the pile casting mold 7; specifically including:

[0088] S301: Disassemble the pile cap mold 701 and the pile tip mold 704, apply a release agent evenly to the inner surface of the pile body mold 702, and then split the pile body mold 702 into two parts;

[0089] S302: Place a portion of the pile body mold 702 horizontally; and place the steel thread 3 inside the horizontally placed pile body mold 702, so that the thread body of the steel thread 3 is embedded inside the thread mold 703;

[0090] S303: Fasten another part of the pile body mold 702 onto the horizontally placed pile body mold 702, and connect the two parts of the pile body mold 702 with bolts;

[0091] S304: Installation of pile tip mold 704.

[0092] In this embodiment, the pile body mold 702 is split into two parts, the steel structure thread 3 is placed inside it, and then the two parts of the pile body mold 702 are fastened together to realize the installation of the steel structure thread 3, which is convenient.

[0093] S4: Install the reinforcing cage 6 inside the pile casting mold 7, and then cast the pile to obtain a screw-type energy pile; specifically including:

[0094] S401: Vertically set up the pile body mold 702 with the pile tip mold 704 installed; and pour concrete into the pile body mold 702 through the feeder. After the concrete reaches the preset depth, hoist the steel cage 6 into the pile body mold 702.

[0095] As a preferred embodiment, after the reinforcing cage 6 is hoisted into the pile body mold 702, reinforcing bars or wires can be welded onto the reinforcing cage 6. The reinforcing cage 6 and the steel structure thread 3 are connected by the reinforcing bars or wires, so that the reinforcing cage 6 is fixed in the center of the pile body mold 702. At the same time, the steel structure thread 3, the reinforcing cage 6 and the pile body can be connected into a whole.

[0096] S402: Install pile cap mold 701;

[0097] S403: Install heat exchange pipe 5; connect water inlet pipe 502 to the end of spiral pipe 501 near the pile cap, and connect water outlet pipe 503 to the end of spiral pipe 501 near the pile tip; and pass water inlet pipe 502 and water outlet pipe 503 through the holes reserved on the upper surface of pile cap mold 701 respectively.

[0098] As a preferred embodiment, after the water outlet pipe 503 is designed inside the pile body, it needs to be fixed to ensure that the water outlet pipe 503 is vertically fixed inside the pile body.

[0099] S404: Continue pouring concrete until the concrete fills the pile casting mold 7, and the pouring is complete;

[0100] S405: Place the cast-in-place pile body along with the pile casting mold 7 into the centrifuge tank for centrifugation to make the concrete evenly dispersed and compacted.

[0101] S406: Allow the poured pile body to cure statically until the concrete solidifies and takes shape.

[0102] S407: Remove the pile casting mold 7 to obtain the screw-type energy pile; and repair the screw-type energy pile.

[0103] In this embodiment, concrete is first poured into the pile body mold 702 by a feeding machine. After the concrete reaches the preset depth, the reinforcing cage 6 is hoisted into the pile body mold 702. At this time, the reinforcing cage 6 is restricted by the concrete inside the pile body mold 702. This not only prevents the bottom of the reinforcing cage 6 from contacting the pile tip mold 704, but also ensures that the reinforcing cage 6 is located in the exact center of the pile body mold 702, preventing the reinforcing cage 6 from being eccentric inside the pile body mold 702. This method can avoid the phenomenon that the reinforcing cage 6 is not encased in concrete when the energy pile is cast.

[0104] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention and should be understood as not limiting the scope of protection of the invention to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed herein without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of the invention.

Claims

1. A method for preparing a new screw energy pile, characterized by: The system includes a pile cap (1), a pile body (2), steel threaded screws (3), a pile tip (4), and a heat exchange pipe (5). The pile cap (1) is a disc structure with holes inside. The pile body (2) is connected to the bottom of the pile cap (1). The pile body (2) is a conical column structure with a larger diameter at the top and a smaller diameter at the bottom. The pile tip (4) is connected to the bottom of the pile body (2). The steel threaded screws (3) are spirally arranged around the pile body (2). The heat exchange pipe (5) is a spiral structure. The spiral pipe is inserted into the steel threaded screws (3) and is wound around the pile body (2) along the steel threaded screws (3), increasing the heat exchange area. Both ends of the heat exchange pipe (5) protrude from the holes. The steel thread (3) has an upper thread interface (301) and a lower thread interface (302) at both ends. The pile body (2) has an upper pile body interface (201) and a lower pile body interface (202). The upper pile body interface (201) and the lower pile body interface (202) are respectively located opposite to the upper thread interface (301) and the lower thread interface (302). The holes include an inlet hole (101) and an outlet hole (102); the inlet hole (101) is connected to the inner cavity of the upper end interface (201) of the pile body; the outlet hole (102) is connected to the inner cavity of the lower end interface (202) of the pile body. The heat exchange pipe (5) includes an inlet pipe (502), a spiral pipe (501), and an outlet pipe (503); the inlet pipe (502) is located inside the inlet hole (101), one end of the inlet pipe (502) is an inlet (504), and the inlet (504) is located at the top of the pile cap (1); the other end of the inlet pipe (502) passes through the upper interface (201) of the pile body and is connected to the inlet end of the spiral pipe (501); the spiral pipe (501) passes through the steel thread (3), and the outlet end of the spiral pipe (501) is connected to the outlet pipe (503); the outlet pipe (503) passes through the lower interface (202) of the pile body into the pile body (2) and passes through the outlet hole (102) out of the pile cap (1); The cross-section of the steel thread (3) is a trapezoidal structure, and one side of the bottom edge of the trapezoidal structure is in contact with the pile body (2); the trapezoidal structure has a larger contact area with the soil, resulting in higher heat exchange efficiency; The preparation method of the novel screw-type energy pile includes the following steps: S1: Fabricating steel structure threads (3); specifically including: S101: Fabricate a trapezoidal outer layer mold and a thin-walled round tube mold, and insert the thin-walled round tube mold into the trapezoidal outer layer mold; S102: Inject molten steel into the cavity between the trapezoidal outer mold and the thin-walled circular tube mold; S103: After the molten steel has initially solidified, the trapezoidal outer mold and the thin-walled round tube mold are removed to form a steel structure component (303) with a central hole (304) through it. The spiral tube (501) is then inserted into the central hole (304). At this time, the steel structure component (303) is in the plastic stage. S104: The steel structure component (303) together with the spiral tube (501) is twisted into a spiral structure by a CNC twisting machine to form the steel structure thread (3). S105: After the steel thread (3) has completely cooled, apply anti-rust and anti-leakage materials evenly to the outer surface of the steel thread (3) and the inner surface of the heat exchange tube (5); S2: Make pile casting mold (7) and steel cage (6); S3: Fix the steel structure thread (3) onto the pile casting mold (7); S4: Install the steel cage (6) inside the pile casting mold (7) and cast the pile to obtain a screw-type energy pile.

2. The method of manufacturing a novel screw energy pile according to claim 1, characterized in that: The connection between the upper interface (201) of the pile body and the upper interface (301) of the thread, as well as the connection between the lower interface (202) of the pile body and the lower interface (302) of the thread, are all sealed with concrete and sealant.

3. The method for preparing the novel screw-type energy pile according to claim 1, characterized in that: The pile body (2) is provided with a steel cage (6), and the steel structure thread (3) is connected to the pile body (2) through the steel cage (6).

4. The method for preparing the novel screw-type energy pile according to claim 1, characterized in that, S2 includes: S201: Construct pile cap mold (701), pile body mold (702), and pile tip mold (704) respectively. The outer surface of the pile body mold (702) is provided with threaded mold (703). The pile cap mold (701), the pile body mold (702), and the pile tip mold (704) are all two symmetrical parts, and the two parts are controlled to open and close by bolts. Connect the pile cap mold (701) and the pile body mold (702) with bolts. Connect the pile body mold (702) and the pile tip mold (704) with bolts to obtain the pile casting mold (7). S202: Fix several longitudinal threaded steel bars on the model machine according to the dimensions of the pile body (2); then fix several circumferential threaded steel bars on the model machine; finally, tie the longitudinal threaded steel bars and the circumferential threaded steel bars together with wire to obtain the steel cage (6).

5. The method for preparing the novel screw-type energy pile according to claim 4, characterized in that, S3 includes: S301: Disassemble the pile cap mold (701) and the pile tip mold (704), apply a release agent evenly to the inner surface of the pile body mold (702), and split the pile body mold (702) into two parts; S302: Place a portion of the pile body mold (702) horizontally; and place the steel thread (3) inside the horizontally placed pile body mold (702), and make the thread body of the steel thread (3) embedded inside the thread mold (703); S303: Fasten another part of the pile body mold (702) to the top of the horizontally placed pile body mold (702), and connect the two parts of the pile body mold (702) with bolts; S304: Install the pile tip mold (704).

6. The method for preparing the novel screw-type energy pile according to claim 5, characterized in that, S3 includes: S401: The pile body mold (702) with the pile tip mold (704) installed is set vertically; and concrete is poured into the pile body mold (702) by a feeder. After the concrete reaches the preset depth, the steel cage (6) is hoisted into the pile body mold (702). S402: Install the pile cap mold (701); S403: Install heat exchange pipe (5); connect the inlet pipe (502) to one end of the spiral pipe (501) near the pile cap (1), and connect the outlet pipe (503) to one end of the spiral pipe (501) near the pile tip (4); and pass the inlet pipe (502) and the outlet pipe (503) through the holes reserved on the upper surface of the pile cap mold (701) respectively; S404: Continue pouring concrete until the concrete fills the pile casting mold (7), and the pouring is completed; S405: Place the cast-in-place pile body along with the pile casting mold (7) into a centrifuge tank for centrifugation to make the concrete evenly dispersed and compacted; S406: Allow the poured pile body to cure statically until the concrete solidifies and takes shape. S407: Remove the pile casting mold (7) to obtain the screw-type energy pile; and repair the screw-type energy pile.

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