Ventilation pipe cooling device suitable for underground butt joint of river bottom shield tunnel

Abstract

The utility model discloses a ventilation pipe cooling device suitable for underground butt joint of a river bottom shield tunnel. The ventilation pipe cooling device comprises an outer cooling unit, a refrigerant base station and an inner cooling unit. On the one hand, on the basis that internal airflow is smooth, cooling is achieved through cooperation of refrigerants flowing inside and outside, heat is taken away in a section-by-section reinforced mode in the airflow transmission direction to form gas cooling, the formed cooling effect reduces the freezing and thawing failure risk of the soil body, and meanwhile energy consumption and construction cost are low; on the other hand, based on the arrangement of the multiple sets of inner cooling pipelines inside, the rigidity of the pipelines is enhanced while the heat exchange capacity is improved, and in addition, in segmented blocking formed by all the sets of inner cooling pipelines, cooling of airflow is better facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel engineering, specifically relating to a ventilation pipe cooling device suitable for underground docking of shield tunnels under rivers, especially suitable for shield docking projects that use freezing to reinforce the soil in high-temperature environments. Background Technology

[0002] Currently, in shield tunnel docking projects, it is necessary to freeze and reinforce the surrounding soil of the docking area to ensure stability. In the traditional freezing reinforcement process (ground docking freezing method), holes are drilled around the predetermined docking area (usually in the soil surrounding the two tunnel sections), and vertical or horizontal freezing pipes are installed. The freezing pipes are usually arranged in a ring to form a continuous "frozen wall". At the same time, the design thickness of the frozen wall (usually 3-5 meters or more), the target temperature (usually reduced to below -10℃ or even -20℃), and the construction period requirements are calculated and determined. A freezing station is set up inside the tunnel (usually behind one of the shields) or on the surface. The low-temperature refrigerant (usually calcium chloride solution) generated by the refrigeration unit is sent into the freezing pipe through the liquid distribution ring and supply pipe. The refrigerant circulates in the freezing pipe, absorbs heat from the soil, and then flows back to the evaporator for recooling.

[0003] However, tunnel construction requires continuous ventilation to ensure air quality, cooling equipment, and the working environment for personnel. Ventilation ducts (usually large-diameter flexible ducts) continuously deliver relatively warm air (higher than the ambient soil temperature, especially when the tunnel is deep) to the vicinity of the tunnel face. Therefore, if the ventilation ducts are not cooled, the following technical drawbacks will exist:

[0004] 1) Especially under high-temperature conditions in summer, the temperature of the air entering through the ventilation ducts rises, further exacerbating temperature fluctuations in the freezing zone and potentially triggering the risk of soil freeze-thaw failure.

[0005] 2) In order to effectively cool down, coils are usually installed around the ventilation duct. The cooling of the ventilation duct is based on the refrigerant flowing inside the coil. That is, the cooling method is indirect cooling. Therefore, if the required cooling effect is to be achieved, the flow rate of the refrigerant can only be increased. That is, there are problems such as high energy consumption and increased construction costs.

[0006] Therefore, a highly efficient and energy-saving solution is urgently needed. Utility Model Content

[0007] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide an improved ventilation pipe cooling device suitable for underground docking of shield tunnels at the bottom of rivers.

[0008] To solve the above technical problems, the present invention adopts the following technical solution:

[0009] A cooling device for ventilation ducts used in underground docking of shield tunnels under rivers includes an outer cooling unit located around the ventilation duct and a refrigerant base station that circulates and supplies refrigerant to the outer cooling unit. The outer cooling unit indirectly contacts the flowing gas inside the ventilation duct to absorb heat and cool down. In particular, the cooling device also includes an inner cooling unit consisting of multiple sets of inner cooling pipes spaced apart along the length of the ventilation duct. Each set of inner cooling pipes includes multiple cooling pipes that extend from the ventilation duct and communicate with the outer cooling unit. Each pair of adjacent sets of inner cooling pipes and the corresponding portion of the outer cooling unit constitute an inner and outer cooling section. The airflow and refrigerant pass through each inner and outer cooling section in reverse order, so that the cooling capacity of each inner and outer cooling section along the airflow direction of the ventilation duct is gradually enhanced.

[0010] Preferably, multiple cooling pipes in each set of internal cooling piping are connected from the inner end. This increases the flow capacity of internal cooling, thereby further improving heat exchange performance.

[0011] In some specific implementations, multiple cooling pipes are arranged in a cross or star shape. This not only forms a relatively stable internal support, but also increases the heat exchange efficiency as the number of cooling pipes increases.

[0012] Furthermore, the center of the "+" or "X" shape is aligned with the center of the ventilation duct.

[0013] Furthermore, multiple sets of internal cooling pipes are distributed at equal intervals based on the length of the external cooling units. This makes it easier to differentiate the cooling capacity of different sections.

[0014] According to a specific embodiment or preferred aspect of this utility model, multiple sets of internal cooling pipelines are aligned and distributed. The temperature of the airflow leading to the tunnel working face (face) is changed solely based on the coordinated cooling of internal and external systems.

[0015] Alternatively, multiple sets of internal cooling pipes can be sequentially deflected and staggered along the length of the ventilation duct, and a spiral airflow can be formed by changing the airflow direction of each internal and external cooling section, flowing through each section sequentially. This not only reduces the airflow temperature leading to the tunnel face (working face), but also maintains flow stability in the curved tunnel, preventing the formation of vortices at bends that would cause heat accumulation. At the same time, the rotating airflow creates a centrifugal effect, causing hot air to move to the outside of the duct, while cold air concentrates at the center. When reaching the working face, the hot air preferentially contacts the tunnel wall rather than the core frozen area. In addition, after changing the airflow direction, the hot air at the ventilation duct outlet can be directed to non-frozen areas (such as the tunnel top or sidewalls), avoiding direct contact with the frozen wall.

[0016] According to another specific embodiment or preferred aspect of this utility model, the external cooling unit includes a spiral coil wound around the circumference of the ventilation duct, wherein a refrigerant inlet and a refrigerant outlet are formed at both ends of the spiral coil, and a refrigerant base station is connected to the refrigerant inlet and the refrigerant outlet respectively through refrigerant pipelines. The external cooling formed by the coil facilitates the layout of the required internal and external cooling sections, thereby meeting the cooling requirements.

[0017] Preferably, the external cooling unit further includes a metal tube sleeved around the circumference of the ventilation duct, with a spiral coil wound around the metal tube, and the cooling pipe of the internal cooling unit passing through the ventilation duct and the metal tube and communicating with the corresponding spiral coil. Normally, the ventilation duct is made of wear-resistant plastic cloth, which lacks rigidity and has poor thermal conductivity. Using a metal tube (made of a high thermal conductivity alloy) and fixing it with adhesive not only enhances the rigidity of the ventilation duct but also increases the thermal conductivity of the corresponding section of the ventilation duct.

[0018] Furthermore, the length of the metal pipe is set based on the distance between the air outlet of the ventilation pipe and the tunnel working face, the spiral coil is wound based on the length of the metal pipe, and multiple sets of internal cooling pipes are distributed based on the spiral coil winding length intervals.

[0019] Furthermore, the length of the metal pipe is 1.2 to 1.5 times the distance between the ventilation pipe and the tunnel working face. Under normal working conditions, the distance between the ventilation pipe and the tunnel working face is approximately 3 meters, meaning that the length of the metal pipe used is approximately 3.6 to 4.5 meters. Therefore, the layout based on the cooling length and location is designed to meet the requirements of shield tunneling docking construction for soil reinforcement using the freezing method in high-temperature environments.

[0020] Due to the implementation of the above technical solution, this utility model has the following advantages compared with the prior art:

[0021] In existing shield tunnel underground docking projects, especially under high summer temperatures, the increased air temperature entering the ventilation ducts further exacerbates temperature fluctuations in the freezing zone, potentially leading to soil freeze-thaw failure. Simultaneously, to effectively cool the ducts, coils are typically installed around their perimeter, with the cooling medium flowing inside the coils providing indirect cooling. Therefore, achieving the desired cooling effect requires increasing the refrigerant flow rate, resulting in high energy consumption and increased construction costs. This invention cleverly solves these shortcomings by comprehensively designing a ventilation duct cooling device suitable for underground docking of shield tunnels under rivers. Using this ventilation duct cooling device, based on the refrigerant flow rate... The media base station forms flowing refrigerant to the inner and outer cooling sections for collaborative cooling. Simultaneously, based on the reverse flow of airflow and refrigerant through each inner and outer cooling section, the cooling capacity gradually decreases, carrying away heat from the airflow to complete the cooling process. Therefore, this invention, on the one hand, relies on smooth internal airflow and collaborative cooling by internal and external flowing refrigerant. This not only gradually strengthens heat removal along the airflow direction to achieve gas cooling, but also reduces the risk of soil freeze-thaw failure, while having low energy consumption and low construction costs. On the other hand, the multiple sets of internal cooling pipes increase heat exchange capacity and enhance pipe rigidity. Furthermore, the segmented barriers formed by the various sets of internal cooling pipes further facilitate airflow cooling. Attached Figure Description

[0022] Figure 1 This is a front view schematic diagram of a ventilation pipe cooling device suitable for underground docking of shield tunnels under rivers, as described in Example 1.

[0023] Figure 2 for Figure 1 Front view schematic diagram of the cooling unit and ventilation ducts;

[0024] Figure 3 for Figure 2 A left-view diagram;

[0025] Figure 4 for Figure 2 Schematic diagram of the sectional view along the central AA direction;

[0026] Figure 5 for Figure 1 Schematic diagram of working principle (partial cross-section);

[0027] Figure 6 This is a left-side view of Example 2;

[0028] Figure 7 This is a left-side view of Example 3;

[0029] Wherein: 1. External cooling unit; 10. Metal pipe; 11. Spiral coil; 11a. Refrigerant inlet; 11b. Refrigerant outlet;

[0030] 2. Internal cooling unit; 20. Internal cooling piping; 200. Cooling pipe;

[0031] 3. Refrigerant base station; g. Refrigerant piping;

[0032] T, ventilation duct. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a full understanding of the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present utility model. Therefore, the present utility model is not limited to the specific embodiments disclosed below.

[0034] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Example 1

[0037] like Figures 1 to 5 As shown in the figure, the ventilation pipe cooling device applicable to the underground docking of shield tunnels under the riverbed in this embodiment includes an external cooling unit 1, an internal cooling unit 2, and a refrigerant base station 3.

[0038] Specifically, the ventilation duct T is made of wear-resistant plastic cloth, and the external cooling unit 1 includes a metal pipe 10 sleeved around the circumference of the ventilation duct T and a spiral coil 11 wound around the circumference of the metal pipe 10, wherein the two ends of the spiral coil 11 form a refrigerant inlet 11a and a refrigerant outlet 11b; the internal cooling unit 2 includes multiple sets of internal cooling pipes 20 spaced apart along the length of the ventilation duct T, wherein each pair of adjacent sets of internal cooling pipes 20 and the corresponding spiral coil 11 constitute an internal and external cooling section; the refrigerant base station 3 is connected to the refrigerant inlet 11a and the refrigerant outlet 11b respectively through the refrigerant pipe g, wherein the airflow and refrigerant pass through each internal and external cooling section in reverse order, so that the cooling capacity formed by each internal and external cooling section along the airflow direction of the ventilation duct T is gradually enhanced.

[0039] In some specific embodiments, the metal pipe 10 (made of a high thermal conductivity alloy) is fixed circumferentially to the ventilation pipe T by an adhesive. Each set of internal cooling pipes 20 includes multiple cooling pipes 200 that pass through the ventilation pipe T and the metal pipe 10 and are connected to the corresponding spiral coil 11. The internal and external cooling sections are formed between each pair of adjacent sets of internal cooling pipes 20 and the corresponding external cooling unit.

[0040] In this example, multiple cooling pipes 200 of each set of internal cooling pipes 20 are connected from the inner end. Based on the increased internal cooling flow capacity, thereby further improving heat exchange performance, the four cooling pipes are arranged in a "+" shape, with the center of the "+" aligned with the center of the ventilation duct. This not only forms a relatively stable internal support, but also, with the increase in the number of cooling pipes, the heat exchange efficiency increases. The multiple sets of internal cooling pipes 20 are based on the effective winding length of the spiral coils 11 on the metal tubes 10, distributed at equal intervals. This is more conducive to distinguishing the cooling capacity of different sections.

[0041] In some specific implementations, multiple sets of internal cooling pipes 20 are aligned and distributed (referring to the length direction of the metal pipes 10). The temperature of the airflow leading to the tunnel working face (face) is changed solely based on the coordinated cooling of the internal and external systems.

[0042] Furthermore, the length of the metal pipe 10 is determined based on the distance between the air outlet of the ventilation pipe T and the tunnel working face (distance from the tunnel face). The spiral coil 11 is wound based on the length of the metal pipe 10, and the multiple sets of internal cooling pipes 20 are distributed at intervals based on the length of the spiral coil 11. In this example, the length of the metal pipe 10 is 1.2 to 1.5 times the distance between the ventilation pipe T and the tunnel working face. Under normal working conditions, the distance between the ventilation pipe T and the tunnel working face (distance from the tunnel face) is about 3m. That is to say, the length of the metal pipe 10 used is about 3.6 to 4.5m. Therefore, the layout based on the cooling length and position is to meet the requirements of shield tunneling docking construction for soil reinforcement by freezing in high-temperature environments.

[0043] In summary, the implementation process of this embodiment is as follows:

[0044] Based on the refrigerant base station 3 providing a cooling medium (-20°C coolant) to the refrigerant inlet 11a of the spiral coil 11, the coolant flows spirally to the right and sequentially passes through multiple sets of internal cooling pipelines 20 arranged in sequence, so that each internal and external cooling section forms flowing refrigerant for internal and external collaborative cooling. At the same time, the air flowing from the right end to the left end of the ventilation pipe T reversely passes through multiple sets of internal cooling pipelines 20 in sequence, and enhanced heat exchange is carried out section by section during the air flow, so as to make full use of the characteristics of the coolant to efficiently complete the cooling, and the heat-exchanged medium is discharged from the refrigerant outlet 11b and returned to the refrigerant base station 3, and then after being processed by the refrigerant base station 3, the -20°C coolant is circulated to provide to the spiral coil 11, thereby implementing air cooling during the coolant circulation.

[0045] Embodiment 2

[0046] Combined with Figure 6 As shown, the ventilation pipe cooling device applicable to the in-situ docking of the underwater shield tunnel in this embodiment has the same structure as that in Embodiment 1. The difference is that: multiple cooling pipes 200 of each set of internal cooling pipelines 20 are connected and arranged from the inner end. Based on the increase in the internal cooling flow capacity, the heat exchange performance is further improved. The four cooling pipes are in a "rice" shape, and the center of the "rice" shape is aligned with the center of the ventilation pipe, which not only forms a relatively stable internal support, but also with the increase in the number of cooling pipes, the higher the heat exchange efficiency formed.

[0047] Embodiment 3

[0048] Combined with Figure 6 As shown, the ventilation pipe cooling device applicable to the in-situ docking of the underwater shield tunnel in this embodiment has the same structure as that in Embodiment 2. The difference is that: multiple sets of internal cooling pipelines 20 are deflected and misaligned in sequence along the length direction of the ventilation pipe, and based on the change in the air flow direction of each internal and external cooling section, a spiral air flow is formed to flow through each internal and external cooling section in sequence. It not only reduces the air flow temperature leading to the tunnel working face (heading face), but also the formed spiral air flow maintains the flow stability in the curved tunnel, avoiding the formation of eddy currents at the bend of the air flow resulting in heat accumulation. At the same time, the rotating air flow forms a centrifugal effect, making the hot air move to the outside of the pipeline, and the cold air is concentrated in the center. When reaching the heading face, the hot air preferentially contacts the tunnel wall rather than the core freezing area. In addition, after changing the air flow direction, the hot air at the outlet of the air duct can be redirected to non-freezing areas (such as the tunnel top or side wall), avoiding direct irradiation on the freezing wall.

[0049] In summary, by adopting this ventilation duct cooling device, the refrigerant base station forms a flow of refrigerant to the inner and outer cooling sections for collaborative cooling. Simultaneously, based on the reverse flow of airflow and refrigerant through each inner and outer cooling section, the cooling capacity gradually decreases, carrying away heat from the airflow to complete the cooling process. Therefore, this invention, on the one hand, is based on smooth internal airflow and collaborative cooling by the internal and external flowing refrigerant. This not only gradually strengthens heat removal along the airflow direction to form gas cooling, but also reduces the risk of soil freeze-thaw failure, while having low energy consumption and low construction costs. On the other hand, the multiple sets of internal cooling pipes increase heat exchange capacity and enhance pipe rigidity. Furthermore, the segmented isolation formed by each set of internal cooling pipes is more conducive to airflow cooling. Thirdly, the increased internal cooling flow capacity further improves heat exchange performance, and the multiple cooling pipes are distributed in a "+" or "X" shape. Not only does it form a relatively stable internal support, but the heat exchange efficiency increases with the number of cooling pipes. Fourthly, multiple sets of internal cooling pipes are distributed at equal intervals based on the length of the external cooling unit. This is more conducive to differentiating the cooling capacity of different sections. Multiple sets of internal cooling pipes are aligned and distributed. The internal and external cooling is based solely on changing the airflow temperature leading to the tunnel working face (face). Alternatively, multiple sets of internal cooling pipes can be deflected and staggered along the length of the ventilation pipe, and the airflow direction of each internal and external cooling section can be changed to form a spiral airflow that flows through each internal and external cooling section in sequence. This not only reduces the airflow temperature leading to the tunnel face, but also maintains flow stability in curved tunnels by creating a spiral airflow, preventing heat accumulation caused by vortices at bends. Simultaneously, the rotating airflow creates a centrifugal effect, causing hot air to move outwards from the duct while cold air concentrates at the center. Upon reaching the tunnel face, the hot air preferentially contacts the tunnel wall rather than the core frozen area. Furthermore, by changing the airflow direction, the hot air at the duct outlet can be redirected to non-frozen areas (such as the tunnel top or sidewalls), avoiding direct contact with the frozen wall. Fifthly, the external cooling formed by the coil facilitates the layout of the required internal and external cooling sections, thus meeting the cooling requirements. Metal pipes (made of a high thermal conductivity alloy) are used. The adhesive fixation not only enhances the rigidity of the ventilation duct but also increases the thermal conductivity of the corresponding section of the ventilation duct. Sixthly, the length of the metal pipe is determined based on the distance between the ventilation duct outlet and the tunnel face. The spiral coil is wound based on the length of the metal pipe, and multiple sets of internal cooling pipes are distributed at intervals based on the length of the spiral coil winding. The length of the metal pipe is 1.2 to 1.5 times the distance between the ventilation duct and the tunnel face. Under normal working conditions, the distance between the ventilation duct and the tunnel face (distance from the tunnel face) is approximately 3 meters. Therefore, the length of the metal pipe used is approximately 3.6 to 4.5 meters. This layout, based on the cooling length and location, meets the requirements of shield tunneling for high-temperature environment conditions requiring freezing to reinforce the soil.

[0050] The present utility model has been described in detail above, with the aim of enabling those skilled in the art to understand its contents and implement it. However, this description should not be construed as limiting the scope of protection of the present utility model. All equivalent changes or modifications made in accordance with the spirit and essence of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A cooling device for ventilation ducts used in underground docking of shield tunnels under rivers, comprising an outer cooling unit located around the periphery of the ventilation duct and a refrigerant base station that circulates and supplies a cooling medium to the outer cooling unit, wherein the outer cooling unit indirectly contacts the flowing gas inside the ventilation duct for heat absorption and cooling, characterized in that: The cooling device also includes an internal cooling unit consisting of multiple sets of internal cooling pipes spaced apart along the length of the ventilation duct. Each set of internal cooling pipes includes multiple cooling pipes that extend out of the ventilation duct and connect to the external cooling unit. Each pair of adjacent sets of internal cooling pipes and the corresponding portion of the external cooling unit constitute an internal and external cooling section. The internal and external cooling sections are sequentially passed through based on the reverse direction of the airflow and refrigerant, so that the cooling capacity formed by each internal and external cooling section along the airflow direction of the ventilation duct is gradually enhanced.

2. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 1, is characterized in that: Multiple cooling pipes in each set of internal cooling pipelines are connected from the inner end.

3. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 2, is characterized in that: Multiple cooling pipes are arranged in a cross shape or a star shape.

4. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 3, is characterized in that: The center of the "+" or "X" shaped piping is aligned with the center of the ventilation duct; and / or, multiple sets of internal cooling piping are distributed at equal intervals based on the length of the external cooling unit.

5. The ventilation duct cooling device suitable for underground docking of shield tunnels under rivers, as described in claim 1, 2, 3, or 4, is characterized in that: Multiple sets of internal cooling pipes are aligned and distributed.

6. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 1, 2, 3, or 4, is characterized in that: Multiple sets of internal cooling pipes are deflected and staggered along the length of the ventilation pipe, and the airflow direction of each internal and external cooling section is changed to form a spiral airflow that flows through each internal and external cooling section in sequence.

7. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 1, is characterized in that: The external cooling unit includes a spiral coil wound around the circumference of the ventilation duct, wherein the two ends of the spiral coil form a refrigerant inlet and a refrigerant outlet, and the refrigerant base station is connected to the refrigerant inlet and the refrigerant outlet respectively through refrigerant pipelines.

8. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 7, is characterized in that: The external cooling unit also includes a metal tube sleeved around the circumference of the ventilation duct, the spiral coil is wound around the metal tube, and the cooling tube of the internal cooling unit passes through the ventilation duct and the metal tube and is connected to the corresponding spiral coil.

9. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 8, is characterized in that: The length of the metal pipe is determined based on the distance between the air outlet of the ventilation pipe and the tunnel working face. The spiral coil is wound based on the length of the metal pipe, and the multiple sets of internal cooling pipes are distributed at intervals based on the length of the spiral coil.

10. The ventilation duct cooling device for underground docking of shield tunnels under rivers, as described in claim 9, is characterized in that: The length of the metal pipe is 1.2 to 1.5 times the distance between the ventilation pipe and the tunnel working face.

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