External heat exchange tube lower expansion U-shaped energy pile and construction method thereof

Abstract

The invention relates to a U-shaped energy pile with an external heat exchange tube and a lower expansion body and a construction method of the U-shaped energy pile. The U-shaped energy pile comprises a prefabricated concrete pile body, the U-shaped heat exchange tube, high-thermal-conductivity pervious concrete, crescent aluminum fins and a pile shoe at the bottom of the pile. The U-shaped heat exchange pipe is fixed outside the prefabricated concrete pile body, the high-thermal-conductivity pervious concrete is poured outside the prefabricated concrete pile body, the crescent aluminum fins are arranged outside the U-shaped heat exchange pipe, the pile shoe is arranged at the bottom of the prefabricated concrete pile body, and the U-shaped heat exchange pipe is fixed outside the prefabricated concrete pile body. The lower portion of the high-thermal-conductivity pervious concrete is subjected to mechanical reaming to form a lower expanded body and then poured. Compared with the prior art, the structure is simple, construction is convenient, design is reasonable, production is convenient, the performance of high-thermal-conductivity pervious concrete can be achieved, meanwhile, the bearing capacity of a pile body is improved, the stability is excellent, and the advantages of an energy pile and an expansion pile are integrated.

Description

Technical Field

[0001] The invention relates to the technical field of building foundation construction, and in particular to a U-shaped energy pile with an expanded lower portion of an external heat exchange tube and a construction method thereof. Background Art

[0002] With the continuous development of my country's economy and the process of industrialization, environmental problems have become increasingly prominent. Reducing the emission of polluting gases and controlling air pollution and other environmental problems have reached a point where they can no longer be delayed. In recent years, there have been cases where heat exchange tubes are buried in underground structures (piles, underground continuous walls, tunnels, etc.). The buried pipes and underground structures together form underground thermal structures. Energy piles are the most widely used type of underground thermal structures. They use the pile foundation itself to be in a certain depth and in a stratum that maintains a constant temperature all year round. The underground loop pipe system is directly implanted in the pile foundation, and together with some structures of the underground engineering, it forms an underground heat exchanger.

[0003] The concrete of the traditional energy pile has a low thermal conductivity and cannot fully utilize the thermal convection of groundwater. The energy pile made of high thermal conductivity permeable concrete greatly increases the contact area between the pile body and groundwater, and fully utilizes the thermal convection of groundwater to increase heat flow. However, high thermal conductivity permeable concrete often has low mechanical strength; the temperature difference between the upper part of the pile foundation and the outdoor is small; at the same time, the heat exchange tube is generally made of PE material, and the heat exchange efficiency is low. The current energy pile structure needs to be improved.

[0004] Patent CN202221712284.3 provides a high-efficiency heat exchange energy pile structure, including a concrete pile body, a steel frame embedded in the concrete pile body, a heat exchange tube structure, a radial heat transfer rod and an axial heat transfer rod. The radial heat transfer rod is evenly distributed in the circumference of the lower part of the concrete pile body, one end of the radial heat transfer rod is inserted into the concrete pile body and approaches or reaches the outer steel cage, and the other end of the radial heat transfer rod is inserted into the side wall soil layer of the energy pile hole. The axial heat transfer rod is evenly distributed at the bottom of the concrete pile body, one end of the axial heat transfer rod is inserted into the concrete pile body and approaches or reaches the outer steel cage, and the other end of the axial heat transfer rod is inserted into the bottom soil layer of the energy pile hole. However, the setting of the axial heat transfer rod cannot achieve the technical effect of improving the heat exchange efficiency of the aluminum crescent fin. The radial heat insulation sleeve and the axial heat insulation sleeve are set between the radial heat transfer rod and the axial heat transfer rod, which also affects the pile body prefabrication process. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a U-shaped energy pile with an external heat exchange tube at the bottom and a construction method thereof. The pile has a simple structure, convenient construction, reasonable design, and is easy to produce. It can achieve the performance of high thermal conductivity permeable concrete while also improving the bearing capacity of the pile body. It has excellent stability and integrates the respective advantages of energy piles and expanded piles.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a U-shaped energy pile with an external heat exchange tube at the bottom, comprising: a precast concrete pile body, a U-shaped heat exchange tube, high thermal conductivity permeable concrete, aluminum crescent-shaped fins, and a pile shoe at the bottom of the pile;

[0008] The U-shaped heat exchange tube is fixed outside the precast concrete pile body, the high thermal conductivity permeable concrete is cast outside the precast concrete pile body, the aluminum crescent fin is arranged outside the U-shaped heat exchange tube, the pile shoe is arranged at the bottom of the precast concrete pile body, and the lower part of the high thermal conductivity permeable concrete is cast after mechanical expansion to form a lower expanded body.

[0009] Furthermore, the mechanical expansion hole is below the groundwater level.

[0010] Furthermore, the aluminum crescent-shaped fin comprises a fin body, a fixed ring plate, and a fixed ear plate;

[0011] The aluminum crescent-shaped fin is in a concave crescent shape close to the precast concrete pile body, so that the aluminum crescent-shaped fin fits the precast concrete pile body, and the fin body is connected to the U-shaped heat exchange tube through a fixed ring plate.

[0012] Furthermore, the fin body comprises an upper fin and a lower fin, the edges of the upper fin and the lower fin are welded to a fixed ring plate and a fixed ear plate, and the two fixed ear plates are connected by bolts.

[0013] Furthermore, the U-shaped heat exchange tube is tied to the outside of the precast concrete pile body by steel wire.

[0014] Furthermore, the aluminum crescent-shaped fins are fixed to the U-shaped heat exchange tube at the lower expansion body by bolts.

[0015] Furthermore, a limiting hole is provided on the pile shoe to facilitate the positioning of the U-shaped heat exchange tube.

[0016] Furthermore, the high thermal conductivity permeable concrete has a reserved width around the upper part of the precast concrete pile body for the heat exchange tubes to be lowered.

[0017] The present invention also provides a construction method for a U-shaped energy pile with an expanded lower portion of an external heat exchange tube, comprising the following steps:

[0018] S1: Drilling or manually drilling holes on the precast concrete pile;

[0019] S2: Pour the high thermal conductivity permeable concrete below the groundwater level and perform mechanical or manual hole expansion on the lower part;

[0020] S3: pouring a solidifying material into the hole, wherein the solidifying material is a high thermal conductivity permeable concrete;

[0021] S4: Tie the U-shaped heat exchange tube to the outside of the precast concrete pile body with steel wire, and put aluminum crescent-shaped fins on the outside of the U-shaped heat exchange tube at the bottom of the precast concrete pile body at regular intervals and fix them with bolts. Before the high thermal conductivity permeable concrete poured in S3 is cured, implant the precast concrete pile body.

[0022] Furthermore, in S2, during the hole expansion construction, the angle between the hole wall of the hole diameter enlargement section and the axis of the hole is not greater than 12°.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) The U-shaped energy pile with an external heat exchange tube at the bottom expanded in the present invention does not affect the prefabrication process of the pile body and the construction period, and the U-shaped heat exchange tube is directly tied outside the prefabricated pile body.

[0025] (2) The lower part of the U-shaped energy pile with an external heat exchange tube is expanded in the present invention, and the expansion area is filled with high thermal conductivity permeable concrete. On the one hand, the thermal convection effect of groundwater is fully utilized to increase heat flow; on the other hand, the bearing capacity of the pile foundation is increased.

[0026] (3) The aluminum crescent-shaped fins of the present invention can not only fit tightly to the pile body, but also improve the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a U-shaped energy pile with an expanded lower part of an external heat exchange tube according to the present invention;

[0028] Figure 2 It is a schematic diagram of S1 in the construction method of the present invention;

[0029] Figure 3 It is a schematic diagram of S2 in the construction method of the present invention;

[0030] Figure 4 It is a schematic diagram of S3 in the construction method of the present invention;

[0031] Figure 5 It is a schematic diagram of S4 in the construction method of the present invention.

[0032] Figure numerals: 1. precast concrete pile; 2. U-shaped heat exchange tube; 3. high thermal conductivity permeable concrete; 4. aluminum crescent fin; 5. groundwater level; 6. fin body; 7. fixed ring plate; 8. fixed ear plate; 9. bolt; 10. pile shoe; 11. limit hole; 12. upper fin; 13. lower fin. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0034] Example 1

[0035] This embodiment provides a U-shaped energy pile with an external heat exchange tube bottom expansion, such as Figure 1 As shown, it includes: a precast concrete pile body 1, a U-shaped heat exchange tube 2, a high thermal conductivity permeable concrete 3, an aluminum crescent-shaped fin 4, and a pile shoe 10 at the bottom of the pile;

[0036] The U-shaped heat exchange tube 2 is fixed to the outside of the precast concrete pile body 1, the high thermal conductivity permeable concrete 3 is cast outside the precast concrete pile body 1, the aluminum crescent fin 4 is arranged outside the U-shaped heat exchange tube 2, the pile shoe 10 is arranged at the bottom of the precast concrete pile body 1, and the lower part of the high thermal conductivity permeable concrete 3 is cast after the lower expanded body is formed by mechanical expansion.

[0037] In a specific embodiment, the mechanical expansion hole is below the groundwater level 5.

[0038] In a specific embodiment, the aluminum crescent-shaped fin 4 includes a fin body 6, a fixed ring plate 7, and a fixed ear plate 8;

[0039] The aluminum crescent-shaped fin 4 is in a concave crescent shape close to the precast concrete pile body 1 so that the aluminum crescent-shaped fin 4 fits the precast concrete pile body 1 , and the fin body 6 is connected to the U-shaped heat exchange tube 2 through a fixed ring plate 7 .

[0040] In a specific embodiment, the fin body 6 includes an upper fin 12 and a lower fin 13 , the edges of the upper fin 12 and the lower fin 13 are welded to a fixing ring plate 7 and a fixing ear plate 8 , and the two fixing ear plates 8 are connected by bolts 9 .

[0041] In a specific implementation, the U-shaped heat exchange tube 2 is tied to the outside of the precast concrete pile body 1 by steel wire.

[0042] In a specific embodiment, the aluminum crescent-shaped fin 4 is fixed to the U-shaped heat exchange tube 2 at the lower expansion portion by bolts 9 .

[0043] In a specific implementation, a limiting hole 11 is provided on the pile shoe 10 to facilitate positioning of the U-shaped heat exchange tube 2 .

[0044] In a specific implementation, the high thermal conductivity permeable concrete 3 is provided around the upper part of the precast concrete pile body 1 to reserve a width for the heat exchange tube 2 to be lowered.

[0045] This embodiment also provides a construction method for a U-shaped energy pile with an expanded lower portion of an external heat exchange tube, comprising the following steps:

[0046] S1: Drilling or manually drilling holes on the precast concrete pile body 1, such as Figure 2 As shown;

[0047] S2: Pour the high thermal conductivity permeable concrete 3 below the groundwater level and perform mechanical or manual hole expansion on the lower part, such as Figure 3 As shown;

[0048] S3: Pour the solidifying material into the hole, such as Figure 4 As shown, the solidifying material is high thermal conductivity permeable concrete 3;

[0049] S4: Tie the U-shaped heat exchange tube 2 to the outside of the precast concrete pile body 1 with steel wire, and put aluminum crescent-shaped fins 4 on the outside of the U-shaped heat exchange tube 2 at the lower part of the precast concrete pile body 1 at intervals and fix them with bolts. Before the high thermal conductivity permeable concrete 3 poured in S3 is cured, implant the precast concrete pile body 1, such as Figure 5 shown.

[0050] In a specific implementation, in S2, during the hole expansion construction, the angle between the hole wall of the hole diameter enlargement section and the axis of the hole is not greater than 12°.

[0051] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0052] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A U-shaped energy pile with an external heat exchange tube bottom expansion, It is characterized in that include: Precast concrete pile body (1), U-shaped heat exchange tube (2), high thermal conductivity permeable concrete (3), aluminum crescent-shaped fins (4), and pile shoes (10) at the bottom of the pile; The U-shaped heat exchange tube (2) is fixed outside the precast concrete pile body (1), the high thermal conductivity permeable concrete (3) is cast outside the precast concrete pile body (1), the aluminum crescent-shaped fin (4) is arranged outside the U-shaped heat exchange tube (2), the pile shoe (10) is arranged at the bottom of the precast concrete pile body (1), and the high thermal conductivity permeable concrete (3) is cast after the lower part is expanded by mechanical expansion to form a lower expanded body.

2. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The mechanical expansion hole is located below the groundwater level (5).

3. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The aluminum crescent-shaped fin (4) comprises a fin body (6), a fixed ring plate (7), and a fixed ear plate (8); The aluminum crescent-shaped fin (4) is in a concave crescent shape close to the precast concrete pile body (1), so that the aluminum crescent-shaped fin (4) fits the precast concrete pile body (1), and the fin body (6) is connected to the U-shaped heat exchange tube (2) through a fixed ring plate (7).

4. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 3, It is characterized in that The fin body (6) comprises an upper fin (12) and a lower fin (13), the edges of the upper fin (12) and the lower fin (13) are welded to a fixed ring plate (7) and a fixed ear plate (8), and the two fixed ear plates (8) are connected by bolts (9).

5. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The U-shaped heat exchange tube (2) is tied to the outside of the precast concrete pile body (1) by means of steel wires.

6. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The aluminum crescent-shaped fin (4) is fixed to the U-shaped heat exchange tube (2) at the lower expansion part by means of bolts (9).

7. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The pile shoe (10) is provided with a limiting hole (11) to facilitate the positioning of the U-shaped heat exchange tube (2).

8. A U-shaped energy pile with an external heat exchange tube bottom expansion according to claim 1, It is characterized in that The high thermal conductivity permeable concrete (3) is provided around the upper part of the precast concrete pile body (1) to reserve a width for the heat exchange pipe (2) when it is lowered.

9. A construction method for a U-shaped energy pile with an expanded lower part of an external heat exchange tube. It is characterized in that The following steps are involved: S1: drilling a hole in the precast concrete pile body (1) by drilling a hole or manually drilling a hole; S2: pouring the high thermal conductivity permeable concrete (3) below the groundwater level and mechanically or manually expanding the hole at the bottom; S3: pouring a solidifying material into the hole, wherein the solidifying material is a high thermal conductivity permeable concrete (3); S4: The U-shaped heat exchange tube (2) is tied to the outside of the precast concrete pile body (1) with steel wires, and aluminum crescent-shaped fins (4) are placed on the outside of the U-shaped heat exchange tube (2) at the bottom of the precast concrete pile body (1) at intervals and fixed with bolts. Before the high thermal conductivity permeable concrete (3) poured in S3 is solidified, the precast concrete pile body (1) is implanted.

10. The construction method of a U-shaped energy pile with an expanded lower portion of an external heat exchange tube according to claim 9, It is characterized in that In S2, during the hole expansion construction, the angle between the hole wall of the hole diameter enlargement section and the hole axis is not greater than 12°.

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