An energy pile and its embedding method

Abstract

This invention relates to an energy pile and its embedding method. The energy pile includes a PHC pipe pile, a high thermal conductivity permeable concrete core cast within the pipe pile, a reinforcing steel cage embedded in the core, and a heat exchange tube. The lower part of the PHC pipe pile has multiple radially extending through holes evenly distributed circumferentially. The reinforcing steel cage is a cylindrical steel mesh arranged coaxially with the PHC pipe pile. The heat exchange tube is fixed inside the steel mesh. The invention also relates to an embedding method using the aforementioned energy pile. In this invention, the high thermal conductivity permeable concrete core is confined within the PHC pipe pile, which plays a primary load-bearing role, preventing the high thermal conductivity permeable concrete from cracking and failing under high load conditions. Simultaneously, the multiple radially extending through holes evenly distributed circumferentially at the lower part of the PHC pipe pile ensure that after embedding, the through holes are below the groundwater level, facilitating direct energy exchange between groundwater and the high thermal conductivity permeable concrete, aluminum annular fins, and heat exchange tube, significantly improving thermal conductivity.

Description

Technical Field

[0001] This invention relates to the field of building foundation construction technology, specifically to an energy pile and its embedding method. Background Technology

[0002] With social progress and development, my country's energy demand is increasing. Reducing pollution and energy consumption is an important goal for my country to achieve sustainable development. Shallow geothermal energy, as a clean, efficient, and environmentally friendly renewable energy source, is receiving increasing attention. Energy piles, a green technology that utilizes shallow geothermal sources, involve embedding circulation pipelines within the building's pile foundation. While meeting the bearing capacity requirements of conventional pile foundations, the pile body serves as a carrier to achieve heat exchange with shallow geothermal energy. Compared to traditional drilled buried pipes, this increases the contact area between the heat exchanger and the soil, fully utilizing the high volumetric specific heat and thermal conductivity of concrete to improve heat exchange efficiency. It saves underground space and engineering costs, and its design concept aligns with the current development trend of energy conservation, emission reduction, and environmental protection, possessing excellent development prospects and promotional value.

[0003] However, traditional energy piles have low thermal conductivity concrete and cannot fully utilize the thermal convection of groundwater, making it difficult to further improve heat exchange efficiency. Therefore, energy piles made of highly thermally conductive permeable concrete greatly increase the contact area between the pile and groundwater, fully utilizing the thermal convection of groundwater and increasing heat flow. The added thermally conductive materials also improve the pile-soil heat exchange efficiency. However, because the strength and permeability of permeable concrete are contradictory, highly thermally conductive permeable concrete piles often have low mechanical strength, making it difficult to meet pile foundation bearing standards.

[0004] How to design an energy pile with high load-bearing capacity and efficient heat conduction, and prevent the high thermal conductivity permeable concrete pile from being damaged, is an urgent technical problem to be solved. Summary of the Invention

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An energy pile includes a PHC pipe pile, a high thermal conductivity permeable concrete pile core cast inside the pipe pile, a steel reinforcement cage embedded in the pile core, and a heat exchange pipe. The lower part of the PHC pipe pile has multiple radially extending through holes evenly distributed along the circumference. The steel reinforcement cage is a cylindrical steel mesh and is arranged coaxially with the PHC pipe pile. The heat exchange pipe is fixed inside the steel mesh.

[0007] Preferably, the heat exchange tube is a U-shaped heat exchange tube, and multiple aluminum annular fins are fixed on the U-shaped heat exchange tube. The heat exchange tube is fixed to the inner side of the steel mesh through the aluminum annular fins.

[0008] Preferably, the bottom of the PHC pipe pile is welded with a cross-shaped pile tip.

[0009] The above-mentioned method for embedding energy piles includes the following steps:

[0010] S1. The through holes of the PHC pipe piles are sealed with polylactic acid material;

[0011] S2. Insert the PHC pipe pile into the foundation, and hoist the U-shaped heat exchange pipe and the steel mesh together into the PHC pipe pile along the same axis;

[0012] S3. Inject high thermal conductivity permeable concrete into the PHC pipe pile;

[0013] S4. After the high thermal conductivity permeable concrete has hardened, pour in enough water to degrade the polylactic acid material and clear the pores.

[0014] The beneficial effects of this invention are:

[0015] 1. High-strength prestressed concrete pipe piles, namely PHC pipe piles, are used. They are suitable for standardized factory production, have reliable quality, and allow for a high degree of mechanized construction on site. At the same time, due to the strength of the PHC pipe piles themselves, the settlement of the structure above the PHC pipe piles can be effectively reduced, and the ultimate bearing capacity of the foundation can be greatly improved, thus making up for the shortcomings of low strength of high thermal conductivity and permeable concrete in the pile core.

[0016] 2. The high thermal conductivity permeable concrete pile core is confined within the PHC pipe pile, which plays a major load-bearing role, preventing the high thermal conductivity permeable concrete from cracking and failing under high load conditions. At the same time, multiple radially extending through holes are evenly distributed along the circumference of the lower part of the PHC pipe pile. The size of these through holes must meet the pile foundation bearing capacity specifications, ensuring that after the pile is buried, the through holes are located below the groundwater level. This facilitates the exchange of energy between groundwater and the high thermal conductivity permeable concrete, aluminum annular fins, and heat exchange tubes, significantly improving thermal conductivity.

[0017] 3. Regarding the pile embedding method, polylactic acid (PLA) material is first used to seal the through holes. After the high thermal conductivity permeable concrete filling the core of the PHC pipe pile meets the strength requirements, sufficient water is poured in. The alkaline environment generated by the cement hydration process degrades the sealing PLA material, thus clearing the through holes and forming a permeable PHC pipe pile. Together with the high thermal conductivity permeable concrete pile core, a complete permeable energy pile is formed. This method not only solves the problem of groundwater penetrating the PHC pipe pile but also prevents the injected high thermal conductivity permeable concrete from clogging the through holes, which is very ingenious. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the energy pile of the present invention.

[0019] Figure 2 A schematic diagram of the structure of an aluminum annular fin.

[0020] In the diagram: 1. Heat exchange tube, 2. PHC pipe pile, 3. Through hole, 4. Pile tip plate, 5. Pile core, 6. Reinforcing steel cage, 7. Aluminum annular fin, 8. Groundwater level, 9. Sealing plate, 10. Fin body, 11. Fixing ring plate, 12. Bolt, 13. Fixing ear plate. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. The following specific embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should also be noted that, for ease of description, only the parts related to the present invention are shown in the drawings, and not all of them.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1

[0024] An energy pile includes a PHC pipe pile 2, a high thermal conductivity permeable concrete core 5 cast inside the pipe pile, a steel reinforcement cage 6 embedded in the core, and a heat exchange pipe 1. Multiple radially extending through holes 3 are evenly distributed circumferentially at the lower part of the PHC pipe pile. The steel reinforcement cage is a cylindrical steel mesh arranged coaxially with the PHC pipe pile. The heat exchange pipe is fixed inside the steel mesh and is a U-shaped heat exchange pipe. Multiple aluminum annular fins 7 are fixed on the U-shaped heat exchange pipe. In this embodiment, the U-shaped heat exchange pipe is a PE material pipe. The aluminum annular fins include a C-shaped fixing ring plate 11, two fixing ear plates 13 integrally disposed at the opening of the fixing ring plate, and a fin body 10 horizontally disposed outside the fixing ring plate. The fixing ear plate has one or two fixing holes. When the fixing ear plate has one fixing hole, the aluminum annular fin is fixed to the U-shaped heat exchange pipe by bolts 12 passing through the fixing hole. Simultaneously, the steel reinforcement on the steel mesh is also located inside the two fixing ear plates. When the fixed ear plate has two fixing holes, the aluminum annular fins are fixed to the U-shaped heat exchange tube by bolts passing through the fixing holes. At the same time, the other fixing hole is fixed to the steel bars on the steel mesh by wire. The U-shaped heat exchange tube is fixed to the inner side of the steel mesh by the aluminum annular fins. A fixed welding method can be used. The bottom of the PHC pipe pile is welded with a cross-shaped pile tip. The cross-shaped pile tip includes a sealing plate 9 welded to the bottom of the PHC pipe pile and a pile tip plate 4 arranged in a cross shape welded and fixed to the sealing plate. The welding is CO2 shielded welding. After welding, the cross-shaped pile tip is coated with anti-corrosion asphalt. The through hole 3 is located below the groundwater level 8, which facilitates the direct energy exchange between groundwater and the high thermal conductivity permeable concrete, aluminum annular fins and heat exchange tubes through the PHC pipe pile, greatly improving the heat conduction efficiency.

[0025] Example 2

[0026] Using the energy pile embedding method in Example 1, such as Figure 1 As shown, it includes the following steps:

[0027] S1. The through hole 3 of PHC pipe pile 2 is sealed with polylactic acid material;

[0028] S2. Insert the PHC pipe pile into the foundation, and hoist the U-shaped heat exchange pipe and the steel mesh together into the PHC pipe pile along the same axis; the insertion method of the PHC pipe pile into the foundation can be the static pressure method, the method of first opening the pile hole and then inserting it, etc.

[0029] S3. Inject high thermal conductivity permeable concrete into the PHC pipe piles;

[0030] S4. After the high thermal conductivity permeable concrete has hardened, pour in enough water to degrade the polylactic acid material and clear the holes.

[0031] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Those skilled in the art should understand that it is neither necessary nor possible to exhaustively describe all possible implementations. It should be noted that various modifications or alterations can be made to the device without departing from the concept of the present invention. These all fall within the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for embedding energy piles, characterized in that: It includes PHC pipe piles, a high thermal conductivity permeable concrete pile core cast in the PHC pipe piles, a steel reinforcement cage embedded in the pile cores, and heat exchange pipes. The lower part of the PHC pipe piles has multiple radially extending through holes evenly distributed along the circumference. The steel reinforcement cage is a cylindrical steel mesh and is arranged coaxially with the PHC pipe piles. The heat exchange pipes are fixed inside the steel mesh. The heat exchange tube is a U-shaped heat exchange tube, and multiple aluminum annular fins are fixed on the U-shaped heat exchange tube. The heat exchange tube is fixed to the inner side of the steel mesh through the aluminum annular fins. The aluminum annular fin includes a C-shaped fixing ring plate, two fixing ear plates integrally disposed at the opening of the fixing ring plate, and a fin body horizontally disposed on the outside of the fixing ring plate. The bottom of the PHC pipe pile is welded with a cross-shaped pile tip; Includes the following steps: S1. The through holes of the PHC pipe piles are sealed with polylactic acid material; S2. Insert the PHC pipe pile into the foundation, and hoist the U-shaped heat exchange pipe and the steel mesh together into the PHC pipe pile along the same axis; S3. Inject high thermal conductivity permeable concrete into the PHC pipe pile; S4. After the high thermal conductivity permeable concrete has hardened, pour in enough water to degrade the polylactic acid material and clear the pores.

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