Liquid carbon dioxide stratum freezing system based on refrigerating unit and dry ice double cold sources

Abstract

The invention discloses a refrigerating unit and dry ice double cold source-based liquid carbon dioxide stratum freezing system, which comprises a base, a heat exchange box, a liquid carbon dioxide supply device and a lifting assembly are fixed on a bottom plate, the lifting assembly is connected with a connecting frame, and the connecting frame is moved into a pit through the lifting of the lifting assembly; a rotating assembly and a telescopic assembly are connected to the connecting frame, a camera module is connected to the rotating assembly, the camera module collects rotating images of a soil wall in a pit through rotation of the rotating assembly, the telescopic assembly is connected with a drill rod and a pressure sensor, and the drill rod can be driven to be inserted into the soil wall through stretching of the telescopic assembly. The pressure sensor can collect the resistance of the drill rod entering the soil wall, a heat exchanger is arranged in the heat exchange box, the heat exchanger penetrates out of the heat exchange box to be communicated with a freezing pipe, the freezing pipe is arranged in an area needing freezing construction, the heat exchanger and refrigerants in the storage box serve as double cold sources, and secondary cooling is conducted by adding dry ice into the heat exchange box.

Description

Technical Field

[0001] The invention relates to the technical field of ground freezing, and in particular to a liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources. Background Art

[0002] Artificial ground freezing (hereinafter referred to as "freezing method") refers to a special civil engineering construction method that uses artificial refrigeration technology to turn natural soil into artificial frozen soil, thereby improving the properties of the soil to facilitate subsequent underground engineering construction. At present, among the existing freezing methods, brine freezing is the most common and widely used freezing method, followed by expensive liquid nitrogen freezing. The usual practice of brine freezing is: use a compressor to lower the temperature of the primary refrigerant and then lower the temperature of the secondary refrigerant (calcium chloride brine), and then use low-temperature brine to continuously circulate in the freezing pipe driven into the soil to lower the soil temperature, thereby gradually forming frozen soil.

[0003] This method freezes at a temperature of about -30°C, with a long total freezing period and significant frost heave, thaw and sinking effects on the soil. At the same time, the brine freezing system uses a compressor to lower the primary refrigerant temperature, which has problems such as complex system, high mechanical failure rate, high power consumption and high carbon emissions. Summary of the invention

[0004] In view of the above-mentioned technical problems existing in the existing freezing schemes, the purpose of the present invention is to provide a liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources. In the early stage of freezing, the liquid carbon dioxide inside the heat exchanger and the storage box is used as a dual cold source, and secondary cooling is performed by adding dry ice into the heat exchange box. In the later stage of freezing, when the required cooling amount is not large, the heat exchange box stops adding dry ice, and the storage box only needs to keep outputting liquid carbon dioxide to maintain the freezing effect of the soil. The overall dry ice consumption of the project is small, the power consumption is low, and the cost is controllable.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a liquid carbon dioxide stratum freezing system based on a refrigeration unit and dry ice dual cold sources, including a base, a heat exchange box fixed on the bottom plate, a liquid carbon dioxide supply device, and a lifting component, the lifting component is connected to a connecting frame, and the connecting frame is moved to a soil pit by lifting the lifting component, the connecting frame is connected to a rotating component and a telescopic component, the rotating component is connected to a camera module, and the camera module collects rotating images of the soil wall in the soil pit through the rotation of the rotating component, the telescopic component is connected to a drill rod, and a pressure sensor, the drill rod can be driven to be inserted into the soil wall through the extension and contraction of the telescopic component, and the pressure sensor can collect the resistance of the drill rod entering the soil wall;

[0006] A heat exchanger is provided in the heat exchanger box, and the heat exchanger passes through the heat exchanger box and is connected with a freezing pipe. The freezing pipe is set in the area where freezing construction is required. Refrigerant is added to the heat exchanger, and the refrigerant flows into the freezing pipe through the heat exchanger. The liquid carbon dioxide supply device is connected to the heat exchanger box, and the liquid carbon dioxide supply device continuously feeds liquid carbon dioxide into the heat exchanger box. The liquid carbon dioxide can perform a first cooling on the refrigerant in the heat exchanger. The heat exchanger box is provided with a dry ice feed port. Dry ice is added to the heat exchanger box through the dry ice feed port. The dry ice can perform a second cooling on the refrigerant in the heat exchanger. The refrigerant after the second cooling freezes the surrounding soil through the freezing pipe to complete the freezing construction in the corresponding area in the stratum.

[0007] Furthermore, it is characterized in that the lifting component is a lifting cylinder, which is connected to the base by installation, and the connecting frame is a columnar structure with a hollow interior, which is connected to the lifting shaft of the lifting component.

[0008] Furthermore, the rotating assembly includes a first motor bolted to the inside of the connecting frame, the output end of the first motor is bolted to a driving wheel, connecting rings are bolted to both sides of the connecting frame, the outer side of the connecting ring is rotatably connected to a rotating ring, the upper inner side of the rotating ring is bolted to a gear ring, two cross bars are horizontally symmetrically bolted to the surface of the connecting frame, the two cross bars are located inside the rotating ring, the top ends of the cross bars are rotatably connected to rotating rods through bearings, the rotating rods and the cross bars are vertically arranged, the top and middle parts of the rotating rods are respectively bolted to a driving gear and a driven wheel, the driving gear is meshed with the gear ring, the surfaces of the driven wheel and the driving wheel are provided with belts, and the side wall of the rotating ring is bolted to a camera module.

[0009] Furthermore, the telescopic assembly includes a second motor bolted to the connecting frame, the output end of the second motor is bolted to a driving cone wheel, and the front side of the second motor is bolted to a pressure sensor. The second motor is used as a driving source to drive the driving cone wheel to rotate, so that the pressure sensor collects torque data provided by the second motor to the driving cone wheel. Two driven cone wheels are symmetrically meshed and connected on both sides of the driving cone wheel, and the two driven cone wheels are respectively connected to a first screw rod, one end of the first screw rod is connected to the driven cone wheel, and the other end passes through the connecting frame, a bearing assembly is connected between the first screw rod and the connecting frame, and the other ends of the two first screw rods are connected to a connecting ring, and the connecting ring is sleeved on the connecting piece. The connecting ring can be passed through by the first screw rod and is connected to the first screw rod through the bearing assembly, and a drill rod is threadedly connected to the surface of the first screw rod, and a through hole for the drill rod to pass through is provided on the connecting ring.

[0010] Furthermore, the heat exchanger in the heat exchange box is a spiral heat exchanger, a refrigerant feed port and a dry ice feed port are provided on the top of the heat exchange box, and a delivery pipe is provided on the bottom. The heat exchanger is located inside the heat exchange box and its two ends are respectively connected to the refrigerant feed port and the delivery pipe, and the delivery pipe is connected to the freezing pipe. The refrigerant is added to the heat exchanger through the refrigerant feed port and flows to the freezing pipe through the delivery pipe.

[0011] Furthermore, the liquid carbon dioxide supply device includes a storage tank, in which liquid carbon dioxide is stored. The storage tank is connected to a heat exchange box through a heat exchange pipe. A pump is provided on the heat exchange pipe, and the pump can continuously pump the liquid carbon dioxide in the storage tank into the heat exchange box through the heat exchange pipe.

[0012] Furthermore, a recovery pipe is provided between the storage tank and the heat exchange box, and a pump is connected to the recovery pipe. The pump can extract the liquid carbon dioxide in the heat exchange box and the refrigerant in the freezing pipe into the storage tank after completing the work.

[0013] Furthermore, the freezing pipe includes a medium pipe, the medium pipe is connected to the delivery pipe, the end of the medium pipe connected to the delivery pipe is bolted with a sealing plug, and the outer side of the sealing plug is threadedly connected to the outer pipe;

[0014] The heat exchange box can transport the refrigerant to the medium pipe through the delivery pipe, and the sealing plug fixes the medium pipe and the outer pipe to each other;

[0015] One end of the outer tube is connected to the sealing plug, and the other end of the outer tube is conical. The medium tube is covered by the outer tube, and a cavity is formed between the outer tube and the medium tube. Some interference flow grooves are arranged in the cavity, and through grooves are arranged on the surfaces of the outer tube and the medium tube.

[0016] Furthermore, a third motor is bolted to the bottom of the inner cavity of the connecting frame, a second screw rod is bolted to the output end of the third motor, a threaded sleeve is threadedly connected to the surface of the second screw rod, and a contact plate is bolted to the bottom of the threaded sleeve.

[0017] The liquid carbon dioxide ground freezing system based on the refrigeration unit and dry ice dual cold sources provided by the present invention uses the liquid carbon dioxide in the heat exchange box and the storage box as dual cold sources in the early stage of freezing, and performs secondary cooling by adding dry ice into the heat exchange box. In the late stage of freezing, when the required cooling amount is not large, the heat exchange box stops adding dry ice, and only needs to keep the refrigeration unit turned on to maintain the freezing effect of the soil. The overall dry ice consumption of the project is small, the power consumption is low, and the cost is controllable.

[0018] In addition, the present invention provides a rotating assembly and a telescopic assembly and cooperates with a camera module and a drill rod respectively. The camera module and the drill rod can respectively collect images of the freezing condition of the soil wall and judge the firmness of the frozen soil, thereby greatly improving the practicality of the present system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 A schematic cross-sectional view of a liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources provided by the present invention;

[0021] Figure 2 A schematic diagram of a partial structure enlargement of a liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources provided by the present invention;

[0022] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0023] Figure 4 for Figure 2 A schematic diagram of the enlarged structure at B in the middle;

[0024] Figure 5 A schematic diagram of the structure of a freezing pipe in a liquid carbon dioxide stratum freezing system based on a refrigeration unit and dry ice dual cold sources provided by the present invention.

[0025] Illustration Description:

[0026] Base 100, heat exchange box 200, liquid carbon dioxide supply device 300, lifting assembly 400, connecting frame 500, rotating assembly 600, telescopic assembly 700, camera module 800, drill rod 900, pressure sensor 920, freezing pipe 1000,

[0027] Refrigerant feed port 210, spiral heat exchanger 220, dry ice feed port 230, delivery pipe 240, storage tank 310, heat exchange pipe 320, recovery pipe 330, mounting bracket 410, third motor 501, second screw rod 502, threaded sleeve 503, contact plate 504, first motor 610, driving wheel 620, connecting ring 630, rotating ring 640, gear ring 650, cross bar 660, rotating rod 670, driving gear 680, driven wheel 690, belt 691, second motor 710, driving bevel wheel 720, driven bevel wheel 730, first screw rod 740, connecting ring 750, medium pipe 1100, sealing plug 1200, outer pipe 1300, spoiler groove 1400, through groove 1500. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0029] See also Figure 1, which is a schematic structural diagram of a liquid carbon dioxide stratum freezing system based on a refrigeration unit and dry ice dual cold sources provided by the present invention.

[0030] As can be seen from the figure, the liquid carbon dioxide ground freezing system based on the dual cold sources of a refrigeration unit and dry ice provided by the present invention includes four components: a base 100, a heat exchange box 200, a liquid carbon dioxide supply device 300, and a lifting assembly 400.

[0031] The base 100 is a structural body used to carry other components.

[0032] Four components, namely, a heat exchange box 200 , a liquid carbon dioxide supply device 300 , and a lifting assembly 400 , are fixed on the bottom plate 100 .

[0033] Further, the lifting assembly 400 is connected to a connecting frame 500, and the connecting frame 500 is moved into the earth pit by lifting and lowering the lifting assembly 400. The connecting frame 500 is connected to a rotating assembly 600 and a telescopic assembly 700. The rotating assembly 600 is connected to a camera module 800, and the rotating assembly 600 is rotated so that the camera module 800 can collect rotating images of the earth wall in the earth pit. The telescopic assembly 700 is connected to a drill rod 900, and the pressure sensor 920 can drive the drill rod 900 to be inserted into the earth wall by the telescopic assembly 700, and the pressure sensor 920 can collect the resistance of the drill rod 900 entering the earth wall;

[0034] A heat exchanger 220 is provided in the heat exchange box 200. The heat exchanger 220 passes through the heat exchange box 200 and is connected to the freezing pipe 1000. The freezing pipe 100 is set in the area where freezing construction is required. By adding refrigerant into the heat exchanger 220, the refrigerant flows into the freezing pipe 1000 through the heat exchanger 220. The liquid carbon dioxide supply device 300 is connected to the heat exchange box 200. The liquid carbon dioxide supply device 300 continuously feeds liquid carbon dioxide into the heat exchange box 200. The liquid carbon dioxide can perform a first cooling of the refrigerant in the heat exchanger 220. The heat exchange box 200 is provided with a dry ice feed port 230. Dry ice is added to the heat exchange box 200 through the dry ice feed port 230. The dry ice can perform a second cooling of the refrigerant in the heat exchanger 220. The refrigerant after the second cooling freezes the surrounding soil through the freezing pipe 1000 to complete the freezing construction of the corresponding area in the formation.

[0035] Specifically, the lifting assembly 400 is preferably a lifting cylinder, and the lifting cylinder is bolted to the base 100 through a mounting frame 410;

[0036] The connecting frame 500 is a hollow columnar structure, which is connected to the lifting shaft of the lifting assembly 400;

[0037] Furthermore, if Figure 2 , Figure 3The rotating assembly 600 includes a first motor 610 bolted to the inside of the connecting frame 500, the output end of the first motor 610 is bolted to a driving wheel 620, connecting rings 630 are bolted to both sides of the connecting frame 500, the outer side of the connecting ring 630 is rotatably connected to a rotating ring 640, and a gear ring 650 is bolted to the upper part of the inner side of the rotating ring 640, two cross bars 660 are bolted to the surface of the connecting frame 500 horizontally and symmetrically, the two cross bars 660 are located inside the rotating ring 640, the top ends of the cross bars 660 are rotatably connected to a rotating rod 670 through a bearing, the rotating rod 670 is vertically arranged with the cross bars 660, the top and middle of the rotating rod 670 are bolted to a driving gear 680 and a driven wheel 690 respectively, the driving gear 680 is meshed with the gear ring 650, the surfaces of the driven wheel 690 and the driving wheel 620 are provided with belts 691, and the side wall of the rotating ring 640 is bolted to a camera module 800.

[0038] When the rotating assembly 600 with such a structure is actually used, the driving wheel 620 is driven by the first motor 610 to rotate, and the driving wheel 620 drives the driven wheel 690 to rotate through the belt 691, and the driven wheel 690 drives the rotating rod 670 fixed thereto to rotate, and the rotating rod 670 drives the driving gear 680 fixed thereon to rotate, and the driving gear 680 drives the gear ring 650 meshing therewith to rotate, and the gear ring 650 drives the rotating ring 640 to rotate around the connecting ring 630, so that the camera module 800 fixed on the rotating ring 640 rotates, and the camera module 800 rotates to shoot the soil in the pit and observe the freezing condition of the pit wall.

[0039] Furthermore, if Figure 2 , Figure 4 The telescopic assembly 700 includes a second motor 710 bolted to the connecting frame 500, the output end of the second motor 710 is bolted to a driving cone wheel 720, and the front of the second motor 710 is bolted to a pressure sensor 920. The second motor 710 is used as a driving source to drive the driving cone wheel 720 to rotate, so that the pressure sensor 920 collects torque data provided by the second motor 710 to the driving cone wheel 720, so as to determine the resistance of the drill rod 900 entering the soil.

[0040] Two driven cone wheels 730 are symmetrically meshed and connected on both sides of the driving cone wheel 720. The two driven cone wheels 730 are respectively connected to the first screw rods 740. One end of the first screw rod 740 is connected to the driven cone wheel 730, and the other end passes through the connecting frame 500. A bearing assembly is connected between the first screw rod 740 and the connecting frame 500. The other ends of the two first screw rods 740 are connected to the connecting ring 750. The connecting ring 750 is sleeved on the connecting piece 500. The connecting ring 750 can be passed through by the first screw rod 740 and is connected to the first screw rod 740 through the bearing assembly. In this way, the first screw rod 740 is respectively connected to the connecting frame 500 and the connecting ring 750 through the two bearing assemblies to realize rotation. The surface of the first screw rod 740 is threadedly connected with a drill rod 900, and the connecting ring 750 is provided with a through hole for the drill rod 900 to pass through.

[0041] In this way, the driving cone wheel 720 is driven by the second motor 710 to rotate, and the driving cone wheel 720 drives the driven cone wheel 720 meshing with it to rotate, and the second cone wheel 720 drives the first screw rod 740 to rotate, so that the drill rod 900 moves horizontally on the surface of the first screw rod 740, extends to the through hole of the connecting ring 750 through the drill bit of the drill rod 900 until it is inserted into the soil, and the resistance is analyzed and transmitted to the pressure sensor 920, so as to judge the firmness of the soil freezing.

[0042] like Figure 1 The heat exchanger 220 in the heat exchange box 200 is a spiral heat exchanger. A refrigerant feed port 210 and a dry ice feed port 230 are provided at the top of the heat exchange box 200, and a delivery pipe 240 is provided at the bottom. The heat exchanger 220 is located inside the heat exchange box 200 and its two ends are respectively connected to the refrigerant feed port 210 and the delivery pipe 240. The delivery pipe 240 is connected to the freezing pipe 1000. The refrigerant is added to the heat exchanger 220 through the refrigerant feed port 210 and flows to the freezing pipe 1000 through the delivery pipe 240.

[0043] This solution does not limit the refrigerant in the heat exchanger 220, which can be determined according to actual needs. For example, it can also be liquid carbon dioxide.

[0044] The liquid carbon dioxide supply device 300 includes a storage tank 310, in which liquid carbon dioxide is stored. The storage tank 310 is connected to the heat exchange box 200 through a heat exchange pipe 320. A pump is provided on the heat exchange pipe 320, and the liquid carbon dioxide in the storage tank 310 can be continuously pumped into the heat exchange box 200 through the heat exchange pipe 320 by the pump.

[0045] In actual use, the refrigerant is poured into the heat exchanger 220 through the refrigerant feed port 210 on the top of the heat exchange box 200, so that the refrigerant can enter the freezing pipe 1000 through the delivery pipe 240, and the refrigerant is delivered to the soil in contact with the freezing pipe 1000, so that the soil medium released therefrom is quickly frozen. A pump assembly is provided in the middle of the heat exchange pipe 320, which mainly extracts the liquid carbon dioxide in the storage tank 310 into the heat exchange box 200, so that the temperature of the refrigerant in the heat exchanger 210 in the heat exchange box 200 is consistent with that of the liquid carbon dioxide in the storage tank 310.

[0046] Furthermore, in order to improve the reliability and environmental protection of the system, a recovery pipe 330 is provided between the storage tank 310 and the heat exchange box 200. The recovery pipe 330 is connected to a pump. The pump can extract the liquid carbon dioxide in the heat exchange box 200 and the refrigerant in the freezing pipe 1000 into the storage tank 310 after completing the work, so as to avoid the refrigerant from being retained in the pipeline for a long time and facilitate the continuous use of subsequent devices.

[0047] In the initial stage of freezing, the refrigerant in the heat exchanger 220 and the liquid carbon dioxide inside the storage tank 310 serve as dual cold sources. The liquid carbon dioxide in the storage tank 310 first cools the refrigerant in the heat exchanger 220, and then the refrigerant in the heat exchanger 220 is cooled a second time by the dry ice in the heat exchange box 200. The carbon dioxide gas-liquid mixture coming out of the freezing pipe 1000 returns to the storage tank 310 for cooling.

[0048] In the later stage of freezing, when the required cooling capacity is not large, the heat exchange box 200 stops adding dry ice, and the storage tank 310 only needs to keep outputting liquid carbon dioxide to the heat exchange box 200 to maintain the freezing effect of the soil;

[0049] like Figure 5 The freezing pipe 1000 includes a medium pipe 1100, the medium pipe 1100 is connected to the delivery pipe 240, the end of the medium pipe 1100 connected to the delivery pipe 240 is bolted with a sealing plug 1200, and the outer side of the sealing plug 1200 is threadedly connected to an outer pipe 1300;

[0050] The heat exchanger 220 can transport the refrigerant to the medium pipe 1100 through the delivery pipe 240 , and the sealing plug 1200 fixes the medium pipe 1100 and the outer pipe 1300 to each other.

[0051] One end of the outer tube 1300 is connected to the sealing plug 1200, and the other end of the outer tube 1300 is conical. The medium tube 1100 is covered by the outer tube 1300, and a cavity is formed between the outer tube 1300 and the medium tube 1100. The cavity is provided with an interference flow groove 1400. The surfaces of the outer tube 1300 and the medium tube 1100 are arranged with through grooves 1500.

[0052] In practical terms, the refrigerant flows from the medium pipe 1100 through the through grooves 1500 on the surface of the medium pipe 110 , then through the spoiler grooves 1400 , and finally through the through grooves 1500 on the surface of the outer pipe 1300 into the soil.

[0053] The spoiler groove 1400 allows the carbon dioxide gas-liquid mixture to gradually rise from the bottom of the inner cavity of the outer tube when it enters the conical sealed tube bottom of the outer tube 1300 from the medium tube 1100, thereby achieving the difference in freezing circle time, thereby better controlling the staged freezing effect of the formation.

[0054] Furthermore, in order to improve the applicability of this solution, Figure 2 A third motor 501 is bolted to the bottom of the inner cavity of the connecting frame 500, and a second screw rod 502 is bolted to the output end of the third motor 501. A threaded sleeve 503 is threadedly connected to the surface of the second screw rod 502, and a resistance plate 504 is bolted to the bottom of the threaded sleeve 503. The third motor 501 is used as a driving source to drive the second screw rod 502 to rotate. When the second screw rod 502 rotates, the threaded sleeve 503 on its surface will move vertically along the second screw rod 502, so that the resistance plate 504 will telescope vertically and contact the ground.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources, characterized in that: It comprises a base, a heat exchange box, a liquid carbon dioxide supply device, and a lifting component fixed on the bottom plate, the lifting component is connected to a connecting frame, the connecting frame is moved into the earth pit by lifting and lowering the lifting component, the connecting frame is connected to a rotating component and a telescopic component, the rotating component is connected to a camera module, the rotating component is rotated to enable the camera module to collect rotating images of the earth wall in the earth pit, the telescopic component is connected to a drill rod, and a pressure sensor, the drill rod can be driven to be inserted into the earth wall by the telescopic component, and the pressure sensor can collect the resistance of the drill rod entering the earth wall; A heat exchanger is provided in the heat exchanger box, and the heat exchanger passes through the heat exchanger box and is connected with a freezing pipe. The freezing pipe is set in the area where freezing construction is required. Refrigerant is added to the heat exchanger, and the refrigerant flows into the freezing pipe through the heat exchanger. The liquid carbon dioxide supply device is connected to the heat exchanger box, and the liquid carbon dioxide supply device continuously feeds liquid carbon dioxide into the heat exchanger box. The liquid carbon dioxide can perform a first cooling on the refrigerant in the heat exchanger. The heat exchanger box is provided with a dry ice feed port. Dry ice is added to the heat exchanger box through the dry ice feed port. The dry ice can perform a second cooling on the refrigerant in the heat exchanger. The refrigerant after the second cooling freezes the surrounding soil through the freezing pipe to complete the freezing construction in the corresponding area in the stratum.

2. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1 is characterized in that: The lifting component is a lifting cylinder, which is connected to the base by installation. The connecting frame is a columnar structure with a hollow interior, which is connected to the lifting shaft of the lifting component.

3. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1 is characterized in that: The rotating assembly includes a first motor bolted to the inside of the connecting frame, the output end of the first motor is bolted to a driving wheel, connecting rings are bolted to both sides of the connecting frame, the outer side of the connecting ring is rotatably connected to a rotating ring, the upper part of the inner side of the rotating ring is bolted to a gear ring, two cross bars are bolted to the surface of the connecting frame horizontally and symmetrically, the two cross bars are located inside the rotating ring, the top ends of the cross bars are rotatably connected to rotating rods through bearings, the rotating rods and the cross bars are vertically arranged, the top and middle parts of the rotating rods are respectively bolted to a driving gear and a driven wheel, the driving gear is meshed with the gear ring, belts are arranged on the surfaces of the driven wheel and the driving wheel, and a camera module is bolted to the side wall of the rotating ring.

4. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1 is characterized in that: The telescopic assembly includes a second motor bolted to the connecting frame, a driving cone wheel bolted to the output end of the second motor, a pressure sensor bolted to the front of the second motor, and the second motor is used as a driving source to drive the driving cone wheel to rotate, so that the pressure sensor collects torque data provided by the second motor to the driving cone wheel. The two sides of the driving cone wheel are symmetrically meshed and connected to two driven cone wheels, and the two driven cone wheels are respectively connected to a first screw rod, one end of the first screw rod is connected to the driven cone wheel, and the other end passes through the connecting frame, a bearing assembly is connected between the first screw rod and the connecting frame, and the other ends of the two first screw rods are connected to a connecting ring, and the connecting ring is sleeved on the connecting piece. The connecting ring can be passed through by the first screw rod and is connected to the first screw rod through the bearing assembly, and the surface of the first screw rod is threadedly connected to a drill rod, and the connecting ring is provided with a through hole for the drill rod to pass through.

5. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1 is characterized in that: The heat exchanger in the heat exchange box is a spiral heat exchanger. A refrigerant feed port and a dry ice feed port are provided on the top of the heat exchange box, and a delivery pipe is provided on the bottom. The heat exchanger is located inside the heat exchange box and its two ends are respectively connected to the refrigerant feed port and the delivery pipe. The delivery pipe is connected to the freezing pipe. The refrigerant is added to the heat exchanger through the refrigerant feed port and flows to the freezing pipe through the delivery pipe.

6. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1 is characterized in that: The liquid carbon dioxide supply device includes a storage tank, in which liquid carbon dioxide is stored. The storage tank is connected to a heat exchange box through a heat exchange pipe. A pump is provided on the heat exchange pipe, and the pump can continuously pump the liquid carbon dioxide in the storage tank into the heat exchange box through the heat exchange pipe.

7. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 6 is characterized in that: A recovery pipe is provided between the storage tank and the heat exchange box, and a pump is connected to the recovery pipe. The pump can extract the liquid carbon dioxide in the heat exchange box and the refrigerant in the freezing pipe into the storage tank after completing the work.

8. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1, characterized in that: The freezing pipe comprises a medium pipe, the medium pipe is connected to the delivery pipe, the end of the medium pipe connected to the delivery pipe is bolted with a sealing plug, and the outer side of the sealing plug is threadedly connected to the outer pipe; The heat exchange box can transport the refrigerant to the medium pipe through the delivery pipe, and the sealing plug fixes the medium pipe and the outer pipe to each other; One end of the outer tube is connected to the sealing plug, and the other end of the outer tube is conical. The medium tube is covered by the outer tube, and a cavity is formed between the outer tube and the medium tube. Some interference flow grooves are arranged in the cavity, and through grooves are arranged on the surfaces of the outer tube and the medium tube.

9. The liquid carbon dioxide ground freezing system based on a refrigeration unit and dry ice dual cold sources according to claim 1, characterized in that: A third motor is bolted to the bottom of the inner cavity of the connecting frame, a second screw rod is bolted to the output end of the third motor, a threaded sleeve is threadedly connected to the surface of the second screw rod, and a contact plate is bolted to the bottom of the threaded sleeve.

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