Freezing device and method capable of achieving directional freezing

Abstract

According to the freezing device and method capable of achieving directional freezing, an inner pipe with the lower end closed is coaxially inserted into an outer pipe with the lower end closed, and a bottom through hole is formed in the bottom of the inner pipe; the outer side of the upper end of the inner pipe is fixedly sleeved with a top cover, the outer circle face of the top cover is in sliding sealing fit with the outer pipe, the top cover is oppositely connected with a refrigerant connector and a heat insulation connector, and the refrigerant connector corresponds to one side of the bottom through hole. The two radial isolation assemblies are distributed on the two sides of the bottom through hole at a set angle and divide the annular cavity into two independent sealed spaces. The method comprises: constructing freezing holes; installing a freezing device; a thermal insulation medium is filled through the thermal insulation interface; the freezing refrigeration system is used for supplying a cooling medium to the top connector, and then the cooling medium is recycled through the refrigerant connector; and construction operation is carried out after freezing is completed. According to the device and the method, directional freezing operation under specific working conditions can be realized, freezing construction requirements under the specific working conditions can be met, and good economic benefits and social benefits are achieved.

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 engineering under complex geological conditions such as weak and water-bearing strata. Its principle is to insert a freezing pipe into the stratum, and then circulate a refrigerant into the freezing pipe to cool the stratum and freeze it, thereby turning loose water-bearing rock and soil into frozen soil to increase the strength and stability of the stratum and effectively isolate groundwater to form a frozen soil wall or frozen wall. In this way, underground engineering excavation and masonry operations can be carried out under the protection of the frozen soil wall or frozen wall. The key device for implementing the artificial ground freezing method is the freezing pipe. The structure of the traditional freezing pipe is simple and has a single function. It is usually a fixed double-layer casing structure, that is, an inner pipe is inserted into the center of the outer pipe to form an internal fluid circulation structure, wherein the inner pipe is welded to the outer pipe through a cover plate, and the relative position of the two pipes is fixed. When the freezing pipe is working, a refrigerant circulation method of inner (pipe) in outer (pipe) out or outer (pipe) in inner (pipe) out can be adopted. The stratum around the freezing pipe is uniformly frozen outward with the freezing pipe axis as the center line to form a cylindrical frozen soil structure.

[0003] In some special working conditions, such as when implementing artificial ground freezing operations near protected buildings, it is often necessary to extend the frozen soil to the side away from the protected building during freezing, while not freezing the side close to the protected building, that is, the freezing pipe achieves freezing at a certain angle along the circumference, and does not freeze at other angles, thereby forming a semi-cylindrical or fan-shaped frozen soil. However, the existing freezing pipe cannot achieve the function of directional freezing, so it is urgent to provide a new type of freezing pipe that can achieve the function of directional freezing. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a freezing device and method capable of realizing directional freezing, which has a simple structure, low manufacturing cost, high refrigeration efficiency, good durability, high reliability, and ideal energy-saving effect, and can realize directional freezing operation, and is convenient for large-scale promotion and application. The method has simple implementation steps and high freezing efficiency, which can realize directional freezing operation under specific working conditions, can meet the freezing construction requirements of specific working conditions, and has good economic and social benefits.

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

[0006] The outer tube comprises an outer straight tube section and an outer plugging 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 plugging bottom plate sealed at the lower end of the inner straight tube section. The inner tube is coaxially inserted into the inner part 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 has refrigerant holes and grease holes 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 thereof is slidably sealed with the outer straight pipe section, 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 at a set distance, and their inner ends are fixedly connected to the outer surface of the inner tube, their outer ends are spaced 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 slidably sealed and connected to the outer tube;

[0010] The two radial isolation components are distributed on both sides of the bottom through hole at acute angles, right angles, flat angles or obtuse angles. 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 is used as a freezing chamber, and the other sealed space is used 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 bearing 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 and matched with the outer straight tube section, and a radial slide groove is provided at the axial 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 outer side of the hemispherical cavity; the limit ring is fixedly connected to the outer side 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 a plurality of balls are installed in the semicircular groove adjacent to each other in sequence; the size of the guide ball is adapted to the size of the hemispherical cavity, and is assembled in the hemispherical cavity, and is rollingly connected with a plurality of 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 mounted 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 outer side of the upper portion of the inner straight pipe section, and the other two guide mechanisms are symmetrically arranged on the outer side of the lower portion 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 cylindrical surface of the top cover and the outer tube are slidingly sealed. 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 taken out from the inner cavity of the outer tube by directly pulling. Therefore, maintenance operations on the freezing device can be easily achieved. A bottom through hole is opened at the bottom of the inner tube, and at the same time, a refrigerant interface is connected to a 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 arranged between the inner tube and the outer tube, and the annular cavity is isolated into a freezing cavity and an insulation cavity, so that the annular space between the inner and outer tubes is cleverly divided into independent and sealed freezing space and non-freezing space. In this way, when the insulation medium is inserted 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 realized 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 conveniently adjusted after installation, so that the position of the freezing chamber can be conveniently adjusted, thereby realizing 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 cavity, thereby accelerating the circulation rate of the freezing medium, saving energy consumption and realizing more efficient freezing operations. For the radial isolation component, a strip clamping space is formed between two strip steel plates, and then the sealing brush is inserted into the strip clamping space, which can play a role of rigid support through the two strip steel plates, so that the outer end of the sealing brush can be more closely slidably contacted with the inner wall of the outer tube during the rotation process, which is beneficial to ensure 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 in the annular direction of the freezing tube can be adjusted, thereby realizing a directional freezing operation with controllable annular position, which is beneficial to meet diverse construction needs.

[0016] The device has a simple structure, low manufacturing cost, high refrigeration efficiency, good durability, high reliability, ideal energy-saving effect, can realize directional freezing operation, and is convenient for large-scale promotion and application.

[0017] The present invention also provides a freezing method capable of achieving directional freezing, using a freezing device capable of achieving directional freezing, comprising the following steps:

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

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

[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 rotates to the side away from the protection building and toward the predetermined construction method, and then positions the inner tube;

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

[0022] Step 5: Prepare the freezing refrigeration system and debug it, connect the output pipeline in the freezing refrigeration system to the top interface, and connect the return pipeline 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, and then return to the freezing refrigeration system through the refrigerant interface, 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;

[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 achieve a lubricating effect while providing thermal insulation, 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 under 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 when the top plate is not assembled;

[0029] Figure 2 yes Figure 1 Sectional view along AA direction when the top cover is assembled;

[0030] Figure 3 yes Figure 1 Cross-sectional view along the BB axis when the top cover is 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 schematic 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. 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. insulation chamber, 19. support column, 20. radial slide groove, 21. guide member, 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 in conjunction with 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 plugging 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 plugging bottom plate 13 encapsulated at the lower end of the inner straight tube section 14. The inner tube 4 is coaxially inserted into the inner part 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.

[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 has refrigerant holes and grease holes 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 cylindrical surface thereof is slidably sealed with the outer straight pipe section 15, and its refrigerant hole corresponds to one side of the bottom through hole 7; the upper end of the top cover 11 is fixedly connected with 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 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 spaced 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 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, in order 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 and matched with the outer straight tube section 14, and a radial groove 20 is provided at the axis 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 It is slidably installed in the radial slide groove 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 outer side of the hemispherical cavity 24; the limit 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 installed in the semicircular groove 26 adjacent to each other in sequence; 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 a plurality of 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 driving 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 installed on the outer wall surface of the upper end of the outer tube 1, and the driving 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] Preferably, the number of the guide mechanisms 5 is four, wherein two guide mechanisms 5 are symmetrically arranged on the outer side of the upper portion of the inner straight pipe section 14 , and the other two guide mechanisms 5 are symmetrically arranged on the outer side 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 cylindrical surface of the top cover and the outer tube are slidingly sealed. 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 taken out from the inner cavity of the outer tube by directly pulling. Therefore, maintenance operations on the freezing device can be easily achieved. A bottom through hole is opened at the bottom of the inner tube, and at the same time, a refrigerant interface is connected to a 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 arranged between the inner tube and the outer tube, and the annular cavity is isolated into a freezing cavity and an insulation cavity, so that the annular space between the inner and outer tubes is cleverly divided into independent and sealed freezing space and non-freezing space. In this way, when the insulation medium is inserted 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 realized 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 conveniently adjusted after installation, so that the position of the freezing chamber can be conveniently adjusted, thereby realizing 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 cavity, thereby accelerating the circulation rate of the freezing medium, saving energy consumption and realizing more efficient freezing operations. For the radial isolation component, a strip clamping space is formed between two strip steel plates, and then the sealing brush is inserted into the strip clamping space, which can play a role of rigid support through the two strip steel plates, so that the outer end of the sealing brush can be more closely slidably contacted with the inner wall of the outer tube during the rotation process, which is beneficial to ensure 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 in the annular direction of the freezing tube can be adjusted, thereby realizing a directional freezing operation with controllable annular position, which is beneficial to meet diverse construction needs.

[0048] The device has a simple structure, low manufacturing cost, high refrigeration efficiency, good durability, high reliability, ideal energy-saving effect, can realize directional freezing operation, and is convenient for large-scale promotion and application.

[0049] The present invention also provides a freezing method capable of achieving directional freezing, using a freezing device capable of achieving directional freezing, comprising the following steps:

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

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

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

[0053] Step 4: prepare a thermal insulation medium, and use a filling device to inject the thermal insulation medium into the thermal insulation cavity 18 through the thermal insulation interface 10 until the thermal insulation cavity 18 is filled;

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

[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 four, 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 under 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) sealed 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) sealed at the lower end of the inner straight tube section (14); the inner tube (4) is coaxially inserted into the inner part 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 compatible with the outer diameter of the inner straight pipe section (14), and its outer diameter is compatible with 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 cylindrical 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 with 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 tube (4) and the outer tube (1); The isolation mechanism comprises 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 comprise two strip steel plates (3) and a sealing brush (2), the two strip steel plates (3) are spaced apart by 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 from 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 sealedly 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 sealedly 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 insulation chamber (18).

2. A freezing device capable of achieving directional freezing according to claim 1, characterized in that: The invention also comprises a plurality of guide mechanisms (5), wherein the guide mechanisms (5) comprise a support column (19), a guide member (21), a spring (25), a ball bearing (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), wherein the inner end thereof is fixedly connected to the outer wall surface of the inner straight pipe section (14), the outer end thereof is spaced and matched with 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) comprises a guide column (22) and a limit ring (23), wherein the size of the guide column (22) is adapted to the size of the radial groove, and the guide column (22) 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 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 a 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 on the outside of 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 4, characterized in that: The number of the guide mechanisms (5) is four, of which two guide mechanisms (5) are symmetrically arranged on the outer side of the upper part of the inner straight pipe section (14), and the other two guide mechanisms (5) are symmetrically arranged on the outer side of the lower part 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 as claimed in 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 perform drilling operations; Step 2: lowering a freezing device capable of achieving directional freezing into the freezing hole, and making the head end of the freezing device capable of achieving directional freezing exposed outside the opening of the freezing hole; Step 3: Control the stepping motor (30) to start working, and drive the gear ring (28) to rotate a set angle through the driving gear (29), so that the freezing chamber (17) rotates to the side away from the protected building and faces the predetermined construction mode, and then positions the inner tube (4); Step 4: Prepare a thermal insulation medium, and use a filling device to inject the thermal insulation medium into the thermal insulation cavity (18) through the thermal insulation interface (10) until the thermal insulation cavity (18) is filled; Step 5: Prepare and debug the freezing refrigeration system, connect the output pipeline in the freezing refrigeration system to the top interface (8), and connect the return pipeline in the freezing refrigeration system to the refrigerant interface (9); Step 6: operate the freezing refrigeration system, use the freezing refrigeration system to inject the freezing medium into the inner tube (4) through the top interface (8), 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 cooling medium is salt water.

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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