Freezing device and method capable of achieving directional freezing

Abstract

A freezing device and method capable of achieving directional freezing, comprising: an inner tube with a closed lower end coaxially inserted into an outer tube with a closed lower end, a bottom through-hole being provided at the bottom of the inner tube; a top cover being fixedly mounted on the outer side of the upper end of the inner tube, the outer cylindrical surface of the top cover slidingly and sealingly fitted with the outer tube, a refrigerant interface and a thermal insulation interface being relatively connected to the top cover, and the refrigerant interface corresponding to one side of the bottom through-hole; two radial isolation assemblies being distributed at set angles on both sides of the bottom through-hole, and dividing the annular cavity into two independent sealed spaces; a method comprising: constructing a freezing hole; installing a freezing device; filling the insulating medium through the thermal insulation interface; utilizing a freezing refrigeration system to supply a cooling medium to the top interface, and then recovering the cooling medium through the refrigerant interface; and carrying out construction operations after freezing is completed. The device and method can achieve directional freezing operations under specific working conditions, can meet the freezing construction requirements of specific working conditions, and have good economic and social benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of ground freezing construction method, and in particular relates to a freezing device and method capable of realizing directional freezing. Background Art

[0002] Artificial ground freezing is a common construction method for underground projects in complex geological conditions, such as those involving weak, water-bearing formations. The principle is to insert a freezing pipe into the ground and circulate a refrigerant through the pipe, cooling the ground and freezing it. This transforms the loose, water-bearing rock and soil into frozen soil, increasing its strength and stability while effectively isolating groundwater, forming a frozen wall or frozen wall. This allows underground excavation and masonry work to proceed under the protection of the frozen wall or frozen wall. The key device in implementing artificial ground freezing is the freezing pipe. Traditional freezing pipes are simple in structure and have a single function. They typically consist of a fixed double-tube structure, with an inner pipe inserted at the center of an outer pipe to form an internal fluid circulation structure. The inner pipe is welded to the outer pipe via a cover plate, and the relative position of the two pipes remains fixed. During operation, the freezing pipe can circulate the refrigerant either from the inner pipe in and out, or from the outer pipe in and out. The ground surrounding the freezing pipe freezes evenly outward, with the freezing pipe axis as the centerline, forming a cylindrical frozen soil structure.

[0003] In some special working conditions, such as during artificial ground freezing operations near protected structures, it is often necessary to extend the frozen soil away from the protected structure during freezing, while leaving the side closer to the protected structure unfrozen. In other words, the freezing pipe freezes at certain angles along the circumference, while remaining unfrozen at other angles, thereby forming a semi-cylindrical or fan-shaped frozen body. However, existing freezing pipes cannot achieve directional freezing. Therefore, a new type of freezing pipe that can achieve this function is urgently needed. Summary of the Invention

[0004] To address the aforementioned problems of the prior art, the present invention provides a freezing device and method for directional freezing. This device features a simple structure, low manufacturing cost, high cooling efficiency, excellent durability, high reliability, and ideal energy-saving effects. It enables directional freezing operations and is easily applicable for large-scale deployment. The method features simple implementation steps and high freezing efficiency, enabling directional freezing operations under specific working conditions, meeting the freezing construction requirements of specific working conditions, and providing excellent economic and social benefits.

[0005] In order to solve the above technical problems, the present invention provides a freezing device capable of achieving directional freezing, comprising an outer tube, an inner tube, a top cover and an isolation mechanism;

[0006] The outer tube includes an outer straight tube section and an outer sealing bottom plate encapsulated at the lower end of the outer straight tube section;

[0007] The inner tube includes an inner straight tube section and an inner sealing bottom plate encapsulated at the lower end of the inner straight tube section. The inner tube is coaxially inserted into the interior of the outer tube, and the upper end of the inner straight tube section is located above the upper open end of the outer straight tube section and serves as a top interface. At the same time, a bottom through hole is opened on one side of the bottom of the inner straight tube section.

[0008] The top cover is annular, and a refrigerant hole and a grease hole are symmetrically opened on the outside of the center hole. The diameter of the center hole is adapted to the outer diameter of the inner straight pipe section, and its outer diameter is adapted to the inner diameter of the outer straight pipe section; the top cover is fixedly sleeved on the outer side of the upper end of the inner straight pipe section through the center hole, and the outer circular surface and the outer straight pipe section are slidingly sealed, and the refrigerant hole corresponds to one side of the bottom through hole; the upper end of the top cover is fixedly connected with a refrigerant interface and a thermal insulation interface at the positions corresponding to the refrigerant hole and the grease hole respectively; an annular cavity is formed between the top cover, the inner pipe and the outer pipe;

[0009] The isolation mechanism includes two radial isolation components, which are radially arranged between the inner tube and the outer tube. The radial isolation components include two strip steel plates and a sealing brush. The two strip steel plates are spaced apart at a set distance, and their inner ends are fixedly connected to the outer surface of the inner tube, their outer ends are spaced apart and matched with the outer tube, their upper ends are fixedly connected to the lower end surface of the top cover, and their lower ends extend to the bottom center of the annular cavity; a strip clamping space is formed between the two strip steel plates; the shape and size of the sealing brush are adapted to the strip clamping space, the sealing brush is inserted into the strip clamping space, and its outer end is slidingly and sealingly connected to the outer tube;

[0010] The two radial isolation components are distributed on both sides of the bottom through hole at an acute angle, a right angle, a flat angle or an obtuse angle. At the same time, the bottoms of the two radial isolation components are sealed and connected, and the annular cavity is divided into two independent sealed spaces, among which the sealed space where the bottom through hole is located serves as a freezing chamber, and the other sealed space serves as a temperature insulation chamber.

[0011] Furthermore, in order to ensure that there is always good sealing performance between the top cover and the outer tube, and between the radial isolation assembly and the outer tube during the rotation process, and at the same time, to improve the translational performance of the rotation action, a plurality of guide mechanisms are also included, and the guide mechanisms include a support column, a guide member, a spring, a ball and a guide ball; the support column is radially arranged between the inner straight tube section and the outer straight tube section, and its inner end is fixedly connected to the outer wall surface of the inner straight tube section, and its outer end is spaced apart from the outer straight tube section, and a radial slide groove is provided at the axis center of the outer end of the support column; the guide member includes a guide column and a limit ring, and the size of the guide column is adapted to the size of the radial slide groove , and is radially slidably installed in the radial slide groove. At the same time, a hemispherical cavity is opened at the center of the outer end of the guide column, and a semicircular groove is coaxially opened on the outside of the hemispherical cavity; the limiting ring is fixedly connected to the outside of the outer end of the guide column, and is limitedly matched with the outer end of the support column; the spring is installed at the inner end of the radial slide groove, and its two ends are respectively connected to the support column and the guide column; the size of the ball is adapted to the size of the semicircular groove, and multiple balls are installed in the semicircular groove in sequence; the size of the guide ball is adapted to the size of the hemispherical cavity, and it is assembled in the hemispherical cavity and is rollingly connected with multiple balls.

[0012] Furthermore, in order to automatically change the orientation of the freezing chamber, it also includes a ring gear, a stepper motor and a driving gear. The ring gear is coaxially fixedly connected to the upper end of the top cover, and its inner hole is located on the outside of the refrigerant interface and the insulation interface. The stepper motor is fixedly mounted on the outer wall surface of the upper end of the outer tube, and the driving gear is fixedly sleeved on the output shaft of the stepper motor and meshes with the ring gear.

[0013] Furthermore, in order to ensure good sealing performance between the radial isolation assembly and the inner and outer tubes during the rotation process, the inner sealing bottom plate and the outer sealing bottom plate are both in the shape of a hemispherical shell.

[0014] As a preference, the number of the guide mechanisms is four, two of which are symmetrically arranged on the outside of the upper part of the inner straight pipe section, and the other two guide mechanisms are symmetrically arranged on the outside of the lower part of the inner straight pipe section.

[0015] In the present invention, an inner tube with a closed lower end is coaxially inserted into an outer tube with a closed lower end, and a top cover is fixedly mounted on the outer side of the inner tube. At the same time, the outer circular surface of the top cover and the outer tube are slidingly and sealed together. In this way, not only a sealed annular cavity can be formed between the top cover, the inner tube and the outer tube, but also the inner tube can be rotated relative to the outer tube. In addition, the top cover and the inner tube can be removed from the inner cavity of the outer tube by directly pulling. Therefore, maintenance operations on the freezing device can be easily performed. A bottom through hole is provided at the bottom of the inner tube. At the same time, a refrigerant interface is connected to the side of the top cover corresponding to the bottom through hole, and an insulation interface is connected to the side of the top cover away from the bottom through hole. On this basis, two radial isolation components distributed at a certain angle are provided between the inner tube and the outer tube, and the annular cavity is isolated into a freezing cavity and an insulation cavity, which cleverly separates the annular space between the inner and outer tubes into independent and sealed freezing space and non-freezing space. In this way, under the premise of insulating medium in the insulation cavity, the freezing medium can be supplied to the bottom of the inner tube through the top interface, and then injected into the freezing cavity through the bottom through hole, and then flow out through the refrigerant interface, thereby realizing the circulation of the freezing medium in the freezing space, and the circulating low-temperature refrigerant can be used to quickly take away the heat in the formation by heat transfer, so that the formation can be quickly cooled and frozen, and then the directional freezing operation of the soil layer in the predetermined direction can be achieved efficiently and accurately. Since the inner tube and the top cover can be rotated relative to the outer tube, the angle of the inner tube and the top cover relative to the outer tube can be easily adjusted after installation, thereby enabling convenient adjustment of the position of the freezing chamber and convenient adjustment of the freezing direction. Since the annular cavity is isolated into two independent sealed cavities, it is beneficial to reduce the volume of the freezing chamber, thereby accelerating the circulation rate of the freezing medium, saving energy and facilitating more efficient freezing operations. For the radial isolation component, a strip clamping space is formed between the two strip steel plates, and the sealing brush is inserted into the strip clamping space. The two strip steel plates can serve as a rigid support, thereby enabling the outer end of the sealing brush to more closely slide in contact with the inner wall of the outer tube during rotation, which is beneficial to ensuring the sealing effect between the sealing brush and the outer tube. The present invention optimizes the internal structure of the freezing tube so that the flow range and position of the refrigerant along the annular direction in the freezing tube can be adjusted, thereby achieving a directional freezing operation with controllable annular position, which is beneficial to meeting diverse construction needs.

[0016] The device has a simple structure, low manufacturing cost, high refrigeration efficiency, good durability, high reliability, and ideal energy-saving effect. It can realize directional freezing operations and is easy to promote and apply on a large scale.

[0017] The present invention also provides a freezing method capable of achieving directional freezing, which uses a freezing device capable of achieving directional freezing and includes the following steps:

[0018] Step 1: Locate the freezing hole according to the design requirements and use a drilling rig to drill the hole;

[0019] Step 2: lowering a freezing device capable of achieving directional freezing into the freezing hole, and exposing the head end of the freezing device capable of achieving directional freezing to the outside of the freezing hole opening;

[0020] Step 3: Control the stepper motor to start working, and drive the gear ring to rotate the set angle through the driving gear, so that the freezing chamber is rotated to the side away from the protected building and toward the predetermined construction method, and then the inner tube is positioned;

[0021] Step 4: Prepare the insulation medium and use the filling equipment to inject the insulation medium into the insulation cavity through the insulation interface until the insulation cavity is full;

[0022] Step 5: Prepare the freezing refrigeration system and debug it. Connect the output pipe in the freezing refrigeration system to the top interface, and connect the return pipe in the freezing refrigeration system to the refrigerant interface.

[0023] Step 6: Run the freezing refrigeration system. Use the freezing refrigeration system to inject the freezing medium into the inner tube through the top interface, and then enter the freezing chamber through the bottom through-hole. Then, it flows back to the freezing refrigeration system through the refrigerant interface. The soil layer in the predetermined direction is frozen by circulating the freezing medium. When the freezing state meets the construction requirements, the freezing operation is stopped.

[0024] Step 7: Carry out construction work at the predetermined location.

[0025] As a preference, in step six, the cooling medium is brine.

[0026] Furthermore, in order to achieve a good thermal insulation effect and at the same time to have a lubricating effect while isolating, in step four, the thermal insulation medium is random grease.

[0027] The present invention has simple implementation steps and high freezing efficiency, can realize directional freezing operations under specific working conditions, can meet the freezing construction requirements of specific working conditions, and has good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a top view of an embodiment of the present invention without a top plate installed;

[0029] Figure 2 yes Figure 1 Cross-sectional view along AA direction with the top cover assembled;

[0030] Figure 3 yes Figure 1 Cross-sectional view along the BB axis with the top cover assembled;

[0031] Figure 4 It is a structural schematic diagram of the guide mechanism in the present invention;

[0032] Figure 5 It is a structural diagram of another embodiment of the present invention.

[0033] In the figure: 1. outer tube, 2. sealing brush, 3. strip steel plate, 4. inner tube, 5. guide mechanism, 6. guide ball, 7. bottom through hole, 8. top interface, 9. refrigerant interface, 10. thermal insulation interface, 11. top cover, 12. outer sealing bottom plate, 13. inner sealing bottom plate, 14. inner straight pipe section, 15. outer straight pipe section, 16. radial isolation component, 17. freezing chamber, 18. thermal insulation chamber, 19. support column, 20. radial slide groove, 21. guide part, 22. guide column, 23. limit ring, 24. hemispherical cavity, 25. spring, 26. semicircular groove, 27. ball, 28. gear ring, 29. drive gear, 30. stepper motor. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings.

[0035] like Figures 1 to 5 As shown, the present invention provides a freezing device capable of achieving directional freezing, comprising an outer tube 1, an inner tube 4, a top cover 11 and an isolation mechanism;

[0036] The outer tube 1 includes an outer straight tube section 15 and an outer sealing bottom plate 12 encapsulated at the lower end of the outer straight tube section 15;

[0037] The inner tube 4 includes an inner straight tube section 14 and an inner sealing bottom plate 13 encapsulated at the lower end of the inner straight tube section 14. The inner tube 4 is coaxially inserted into the interior of the outer tube 1, and the upper end of the inner straight tube section 14 is located above the upper open end of the outer straight tube section 15 and serves as the top interface 8. At the same time, a bottom through hole 7 is opened on one side of the bottom of the inner straight tube section 14.

[0038] As a preferred embodiment, in order to effectively improve the freezing efficiency, the inner tube 4 and the outer tube 4 are both thin-walled round steel tubes;

[0039] The top cover 11 is annular, and a refrigerant hole and a grease hole are symmetrically opened on the outside of the center hole. The diameter of the center hole is adapted to the outer diameter of the inner straight pipe section 14, and its outer diameter is adapted to the inner diameter of the outer straight pipe section 15; the top cover 11 is fixedly sleeved on the outer side of the upper end of the inner straight pipe section 14 through the center hole, and the outer circular surface and the outer straight pipe section 15 are slidingly sealed, and the refrigerant hole corresponds to one side of the bottom through hole 7; the upper end of the top cover 11 is fixedly connected to the refrigerant interface 9 and the thermal insulation interface 10 at the positions corresponding to the refrigerant hole and the grease hole respectively; an annular cavity is formed between the top cover 11, the inner tube 4 and the outer tube 1;

[0040] The isolation mechanism includes two radial isolation components 16, which are radially arranged between the inner tube 4 and the outer tube 1. The radial isolation components include two strip steel plates 3 and a sealing brush 2. The two strip steel plates 3 are distributed at a set distance, and their inner ends are fixedly connected to the outer surface of the inner tube 1, their outer ends are spaced apart and matched with the outer tube 1, their upper ends are fixedly connected to the lower end surface of the top cover 11, and their lower ends extend to the bottom center of the annular cavity; a strip clamping space is formed between the two strip steel plates 3; the shape and size of the sealing brush 2 are adapted to the strip clamping space, it is inserted into the strip clamping space, and its outer end is slidably and sealedly connected to the outer tube 1;

[0041] As a preferred embodiment, the sealing brush 2 is made of a rubber sheet;

[0042] The two radial isolation components 16 are distributed on both sides of the bottom through hole 7 at an acute angle, a right angle, a flat angle or an obtuse angle. At the same time, the bottoms of the two radial isolation components 16 are sealed and connected, and the annular cavity is divided into two independent sealed spaces, among which the sealed space where the bottom through hole 7 is located serves as a freezing chamber 17, and the other sealed space serves as a temperature insulation chamber 18.

[0043] In order to ensure that there is always good sealing performance between the top cover and the outer tube, and between the radial isolation assembly and the outer tube during the rotation process, and at the same time, to improve the translational performance of the rotation action, a plurality of guide mechanisms 5 are also included, and the guide mechanism 5 includes a support column 19, a guide member 21, a spring 25, a ball 27 and a guide ball 6; the support column 19 is radially arranged between the inner straight tube section 14 and the outer straight tube section 15, and its inner end is fixedly connected to the outer wall surface of the inner straight tube section 14, and its outer end is spaced apart from the outer straight tube section 14, and a radial groove 20 is provided at the axis center of the outer end of the support column 19; the guide member 21 includes a guide column 22 and a limit ring 23, and the size of the guide column 22 is adapted to the size of the radial groove and can be radially moved. It is slidably installed in the radial slide 20. At the same time, a hemispherical cavity 24 is opened at the center of the outer end of the guide column 22, and a semicircular groove 26 is coaxially opened on the outside of the hemispherical cavity 24; the limiting ring 23 is fixedly connected to the outside of the outer end of the guide column 22, and is limitedly matched with the outer end of the support column 19; the spring 25 is installed at the inner end of the radial slide 20, and its two ends are respectively connected to the support column 19 and the guide column 22; the size of the ball 27 is adapted to the size of the semicircular groove 26, and multiple balls 27 are installed in the semicircular groove 26 in sequence; the size of the guide ball 6 is adapted to the size of the hemispherical cavity 24, and it is assembled in the hemispherical cavity 24 and is rollingly connected with multiple balls 27.

[0044] In order to automatically change the orientation of the freezing chamber, it also includes a ring gear 28, a stepper motor 30 and a drive gear 29. The ring gear 28 is coaxially fixedly connected to the upper end of the top cover 11, and its inner hole is located on the outside of the refrigerant interface 9 and the insulation interface 10. The stepper motor 30 is fixedly mounted on the outer wall surface of the upper end of the outer tube 1, and the drive gear 29 is fixedly mounted on the output shaft of the stepper motor 30 and meshes with the ring gear 28.

[0045] In order to ensure good sealing performance between the radial isolation assembly and the inner and outer tubes during the rotation process, the inner sealing bottom plate 13 and the outer sealing bottom plate 12 are both in the shape of a hemispherical shell.

[0046] As a preference, the number of the guide mechanisms 5 is four, two of which are symmetrically arranged on the outside of the upper portion of the inner straight pipe section 14 , and the other two are symmetrically arranged on the outside of the lower portion of the inner straight pipe section 14 .

[0047] In the present invention, an inner tube with a closed lower end is coaxially inserted into an outer tube with a closed lower end, and a top cover is fixedly mounted on the outer side of the inner tube. At the same time, the outer circular surface of the top cover and the outer tube are slidingly and sealed together. In this way, not only a sealed annular cavity can be formed between the top cover, the inner tube and the outer tube, but also the inner tube can be rotated relative to the outer tube. In addition, the top cover and the inner tube can be removed from the inner cavity of the outer tube by directly pulling. Therefore, maintenance operations on the freezing device can be easily performed. A bottom through hole is provided at the bottom of the inner tube. At the same time, a refrigerant interface is connected to the side of the top cover corresponding to the bottom through hole, and an insulation interface is connected to the side of the top cover away from the bottom through hole. On this basis, two radial isolation components distributed at a certain angle are provided between the inner tube and the outer tube, and the annular cavity is isolated into a freezing cavity and an insulation cavity, which cleverly separates the annular space between the inner and outer tubes into independent and sealed freezing space and non-freezing space. In this way, under the premise of insulating medium in the insulation cavity, the freezing medium can be supplied to the bottom of the inner tube through the top interface, and then injected into the freezing cavity through the bottom through hole, and then flow out through the refrigerant interface, thereby realizing the circulation of the freezing medium in the freezing space, and the circulating low-temperature refrigerant can be used to quickly take away the heat in the formation by heat transfer, so that the formation can be quickly cooled and frozen, and then the directional freezing operation of the soil layer in the predetermined direction can be achieved efficiently and accurately. Since the inner tube and the top cover can be rotated relative to the outer tube, the angle of the inner tube and the top cover relative to the outer tube can be easily adjusted after installation, thereby enabling convenient adjustment of the position of the freezing chamber and convenient adjustment of the freezing direction. Since the annular cavity is isolated into two independent sealed cavities, it is beneficial to reduce the volume of the freezing chamber, thereby accelerating the circulation rate of the freezing medium, saving energy and facilitating more efficient freezing operations. For the radial isolation component, a strip clamping space is formed between the two strip steel plates, and the sealing brush is inserted into the strip clamping space. The two strip steel plates can serve as a rigid support, thereby enabling the outer end of the sealing brush to more closely slide in contact with the inner wall of the outer tube during rotation, which is beneficial to ensuring the sealing effect between the sealing brush and the outer tube. The present invention optimizes the internal structure of the freezing tube so that the flow range and position of the refrigerant along the annular direction in the freezing tube can be adjusted, thereby achieving a directional freezing operation with controllable annular position, which is beneficial to meeting diverse construction needs.

[0048] The device has a simple structure, low manufacturing cost, high refrigeration efficiency, good durability, high reliability, and ideal energy-saving effect. It can realize directional freezing operations and is easy to promote and apply on a large scale.

[0049] The present invention also provides a freezing method capable of achieving directional freezing, which uses a freezing device capable of achieving directional freezing and includes the following steps:

[0050] Step 1: Locate the freezing hole according to the design requirements and use a drilling rig to drill the hole;

[0051] Step 2: lowering a freezing device capable of achieving directional freezing into the freezing hole, and exposing the head end of the freezing device capable of achieving directional freezing to the outside of the freezing hole opening;

[0052] Step 3: Control the stepper motor 30 to start working, and drive the ring gear 28 to rotate the set angle through the driving gear 29, so that the freezing chamber 17 is rotated to the side away from the protected building and toward the predetermined construction method, and then the inner tube 4 is positioned;

[0053] Step 4: Prepare the insulation medium and use the filling device to inject the insulation medium into the insulation cavity 18 through the insulation interface 10 until the insulation cavity 18 is full.

[0054] Step 5: Prepare the freezing refrigeration system and debug it. Connect the output pipe in the freezing refrigeration system to the top interface 8, and connect the return pipe in the freezing refrigeration system to the refrigerant interface 9;

[0055] Step 6: Run the freezing refrigeration system. Use the freezing refrigeration system to inject the freezing medium into the inner tube 4 through the top interface 8, and then enter the freezing chamber 17 through the bottom through-hole 7. Then, it flows back to the freezing refrigeration system through the refrigerant interface 9. The soil layer in the predetermined direction is frozen by circulating the freezing medium. When the freezing state meets the construction requirements, the freezing operation is stopped.

[0056] Step 7: Carry out construction work at the predetermined location.

[0057] As a preference, in step six, the cooling medium is brine.

[0058] In order to achieve a good thermal insulation effect and at the same time to achieve a lubricating effect while insulating, in step 4, the thermal insulation medium is random grease.

[0059] The present invention has simple implementation steps and high freezing efficiency, can realize directional freezing operations under specific working conditions, can meet the freezing construction requirements of specific working conditions, and has good economic and social benefits.

Claims

1. A freezing device capable of achieving directional freezing, comprising an outer tube (1) and an inner tube (4), characterized in that: It also includes a top cover (11) and an isolation mechanism; the outer tube (1) includes an outer straight tube section (15) and an outer sealing bottom plate (12) encapsulated at the lower end of the outer straight tube section (15); the inner tube (4) includes an inner straight tube section (14) and an inner sealing bottom plate (13) encapsulated at the lower end of the inner straight tube section (14); the inner tube (4) is coaxially inserted into the interior of the outer tube (1), and the upper end of the inner straight tube section (14) is located above the upper open end of the outer straight tube section (15) and serves as a top interface (8); at the same time, a bottom through hole (7) is opened on one side of the bottom of the inner straight tube section (14); The top cover (11) is annular, and has a refrigerant hole and a grease hole symmetrically opened on the outside of the center hole. The diameter of the center hole is adapted to the outer diameter of the inner straight pipe section (14), and its outer diameter is adapted to the inner diameter of the outer straight pipe section (15); the top cover (11) is fixedly sleeved on the outer side of the upper end of the inner straight pipe section (14) through the center hole, and the outer circular surface thereof is slidably sealed with the outer straight pipe section (15), and the refrigerant hole corresponds to one side of the bottom through hole (7); the upper end of the top cover (11) is fixedly connected to a refrigerant interface (9) and a thermal insulation interface (10) at the positions corresponding to the refrigerant hole and the grease hole respectively; an annular cavity is formed between the top cover (11), the inner pipe (4) and the outer pipe (1); The isolation mechanism includes two radial isolation components (16), the radial isolation components (16) are radially arranged between the inner tube (4) and the outer tube (1), and the radial isolation components include two strip steel plates (3) and a sealing brush (2). The two strip steel plates (3) are spaced apart at a set distance, and their inner ends are fixedly connected to the outer surface of the inner tube (4), their outer ends are spaced apart from each other and matched with the outer tube (1), their upper ends are fixedly connected to the lower end surface of the top cover (11), and their lower ends extend to the bottom center of the annular cavity; a strip clamp is formed between the two strip steel plates (3). holding space; the shape and size of the sealing brush (2) are adapted to the strip-shaped holding space, the sealing brush (2) is inserted into the strip-shaped holding space, and the outer end thereof is slidingly sealed and connected to the outer tube (1); the two radial isolation components (16) are distributed on both sides of the bottom through hole (7) at an acute angle, a right angle, a flat angle, or an obtuse angle, and at the same time, the bottoms of the two radial isolation components (16) are sealed and connected, and the annular cavity is divided into two independent sealed spaces, wherein the sealed space where the bottom through hole (7) is located serves as a freezing chamber (17), and the other sealed space serves as a temperature-insulating chamber (18).

2. A freezing device capable of achieving directional freezing according to claim 1, characterized in that: The invention also includes a plurality of guide mechanisms (5), wherein the guide mechanisms (5) include a support column (19), a guide member (21), a spring (25), a ball (27) and a guide ball (6); the support column (19) is radially arranged between the inner straight pipe section (14) and the outer straight pipe section (15), and its inner end is fixedly connected to the outer wall surface of the inner straight pipe section (14), and its outer end is spaced apart from the outer straight pipe section (14), and a radial groove (20) is provided at the axis center of the outer end of the support column (19); the guide member (21) includes a guide column (22) and a limiting ring (23), and the size of the guide column (22) is adapted to the size of the radial groove and is radially slidably installed in the radial groove (20), and at the same time, the center of the outer end of the guide column (22) is fixedly connected to the outer wall surface of the inner straight pipe section (14). A hemispherical cavity (24) is provided, and a semicircular groove (26) is coaxially provided on the outer side of the hemispherical cavity (24); the limiting ring (23) is fixedly connected to the outer side of the outer end of the guide column (22) and is limitedly matched with the outer end of the support column (19); the spring (25) is installed at the inner end of the radial slide groove (20), and its two ends are respectively connected to the support column (19) and the guide column (22); the size of the ball (27) is adapted to the size of the semicircular groove (26), and a plurality of balls (27) are sequentially and adjacently installed in the semicircular groove (26); the size of the guide ball (6) is adapted to the size of the hemispherical cavity (24), and is assembled in the hemispherical cavity (24) and is rollingly connected with the plurality of balls (27).

3. A freezing device capable of achieving directional freezing according to claim 1, characterized in that: It also includes a ring gear (28), a stepper motor (30) and a driving gear (29), wherein the ring gear (28) is coaxially fixedly connected to the upper end of the top cover (11), and its inner hole is located outside the refrigerant interface (9) and the thermal insulation interface (10), and the stepper motor (30) is fixedly mounted on the outer wall surface of the upper end of the outer tube (1), and the driving gear (29) is fixedly sleeved on the output shaft of the stepper motor (30) and meshed with the ring gear (28).

4. A freezing device capable of achieving directional freezing according to claim 3, characterized in that: The inner sealing bottom plate (13) and the outer sealing bottom plate (12) are both in the shape of a hemispherical shell.

5. A freezing device capable of achieving directional freezing according to claim 2, characterized in that: The number of the guide mechanisms (5) is four, two of which are symmetrically arranged on the outside of the upper portion of the inner straight pipe section (14), and the other two guide mechanisms (5) are symmetrically arranged on the outside of the lower portion of the inner straight pipe section (14).

6. A freezing method capable of achieving directional freezing, using a freezing device capable of achieving directional freezing according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Locate the freezing hole according to the design requirements and use a drilling rig to drill the hole; Step 2: lowering a freezing device capable of achieving directional freezing into the freezing hole, and exposing the head end of the freezing device capable of achieving directional freezing to the outside of the freezing hole opening; Step 3: Control the stepper motor (30) to start working, and drive the ring gear (28) to rotate a set angle through the driving gear (29), so that the freezing chamber (17) is rotated to the side away from the protected building and toward the predetermined construction method, and then the inner tube (4) is positioned; Step 4: Prepare the insulation medium and inject the insulation medium into the insulation cavity (18) through the insulation interface (10) using a filling device until the insulation cavity (18) is filled. Step 5: Prepare the freezing refrigeration system and debug it, connect the output pipe in the freezing refrigeration system to the top interface (8), and connect the return pipe in the freezing refrigeration system to the refrigerant interface (9); Step 6: Run the freezing refrigeration system, use the freezing refrigeration system to inject the freezing medium into the inner tube (4) through the top interface (8), and then enter the freezing chamber (17) through the bottom through-hole (7), and then return to the freezing refrigeration system through the refrigerant interface (9), so as to realize the freezing operation of the soil layer in the predetermined direction by circulating the freezing medium, and stop the freezing operation when the freezing state meets the construction requirements; Step 7: Carry out construction work at the predetermined location.

7. A freezing method capable of achieving directional freezing according to claim 6, characterized in that: In step six, the freezing medium is brine.

8. A freezing method capable of achieving directional freezing according to claim 7, characterized in that: In step 4, the thermal insulation medium is random grease.

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