A heat insulation test device and method for high-geothermal-tunnel off-wall lining structure

Abstract

The application provides a kind of high geothermal tunnel off-wall lining structure heat insulation test device and method, including test box, rock mass is equipped in test box and is constructed with tunnel, and heating assembly is buried in rock mass, primary support is equipped in tunnel, and the inside of primary support is equipped with secondary lining, temperature sensor is equipped in secondary lining, secondary lining is thin-walled sheet material and has elastic deformation capacity, and the end of secondary lining is equipped with flexible sheet material in folding shape, the gap between primary support and secondary lining constitutes air heat insulation layer, since secondary lining is flexible adjustable component, then the size of air heat insulation layer can be adjusted. By changing the size of air heat insulation layer to explore the influence of different heat insulation sizes on heat insulation effect, and then the size of air heat insulation layer with optimal heat insulation effect is obtained, then the design of off-wall lining structure is optimized by experimental method, and the basis and basis for actual application process are provided, so that the inside of tunnel is in suitable working temperature.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation testing of detached lining structures, specifically to a thermal insulation testing device and method for detached lining structures in high-temperature tunnels. Background Technology

[0002] With the national need to build a strong transportation network, some tunnels will traverse high-temperature geothermal zones, resulting in extremely harsh construction environments. For example, the Sichuan-Tibet Railway traverses an exceptionally long section with high geothermal temperatures, where high-temperature rock and hot water coexist. The highest measured rock temperature reached 66℃. To address the impact of high-temperature heat damage during the later operation of these tunnels, a detached tunnel lining structure will be adopted in the project. This reduces heat transfer from the surrounding rock to the tunnel environment, thereby minimizing the heat transfer from the high rock temperature to the tunnel environment. This ensures that the operating temperature of trains remains within a normal range during the tunnel's operation, guaranteeing the long-term stability of the tunnel structure and the safety of train operation.

[0003] Publication number CN110145345B discloses a ventilation and heat dissipation support structure and its usage method for ultra-high geothermal tunnels. The structure dissipates heat from the tunnel through active heat dissipation. Since the heat source of the tunnel comes from the high geothermal surrounding rock, active ventilation and heat reduction can indeed enable the tunnel to reach a suitable temperature range. However, effective isolation of the heat source is necessary to better ensure that the temperature inside the tunnel remains at a suitable level.

[0004] Since the off-wall lining structure consists of a primary support and a secondary lining, and an air insulation layer is formed between the secondary lining and the primary support, the air insulation layer plays a crucial role in tunnel cooling. However, the existing technologies mentioned above do not involve the exploration of the air insulation layer, and therefore cannot effectively isolate the source of high ground temperature. Summary of the Invention

[0005] The purpose of this invention is to provide a thermal insulation test device and method for high-temperature tunnel detached lining structures, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A thermal insulation test device for a high-temperature tunnel detached lining structure includes a test chamber containing rock mass and a tunnel. Heating components are embedded within the rock mass. An initial support is located within the tunnel, and a secondary lining is located inside the initial support. Temperature sensors are installed inside the secondary lining.

[0008] The secondary lining is a thin-walled plate with elastic deformation capability, and the end of the secondary lining is provided with a folded flexible plate. The gap between the primary support and the secondary lining constitutes an air insulation layer. Since the secondary lining is a flexible and adjustable component, the size of the air insulation layer can be adjusted.

[0009] Preferably, the test apparatus further includes an adjustment component for adjusting the position of the secondary lining.

[0010] Preferably, the adjustment assembly includes an annular guide rail, a sliding frame, clamping rollers, and a slider. The annular guide rail is located on the side of the primary support, and the sliding frame is fitted onto the annular guide rail and can move along the annular guide rail. A slider is provided in the vertical guide rail on the sliding frame, and two clamping rollers are arranged on the slider. The two clamping rollers clamp the secondary lining. When the distance between the clamping rollers and the center point of the secondary lining changes, the distance between the secondary lining and the primary support can be adjusted by moving along the sliding frame.

[0011] Preferably, the adjusting assembly further includes a lead screw, which is rotatably mounted on the sliding frame and passes through the slider, wherein the lead screw and the slider form a threaded connection pair.

[0012] Preferably, the adjustment assembly further includes a drive assembly for driving the sliding frame to move along the annular guide rail.

[0013] Preferably, the drive assembly includes a winch and a rope, with a winch on each side of the sliding frame, and a rope wound around the power output end of the winch, the other end of which is connected to the sliding frame.

[0014] An experimental method for a thermal insulation test device for a high-temperature tunnel detached lining structure, characterized by comprising the following steps:

[0015] S1, construct rock mass and tunnel inside the test chamber and pre-embed heating components;

[0016] S2, the primary support is attached to the inner wall of the tunnel, and a secondary lining is provided inside the primary support;

[0017] S3, the temperature sensor is placed inside the secondary lining;

[0018] S4, the rock mass is heated by the heating component, and then the temperature sensor will detect the temperature inside the secondary lining;

[0019] S5, change the distance between the secondary lining and the primary support, and the size of the air insulation layer will be adjusted accordingly. Repeat S4 to record the insulation effect of different sizes of air insulation layers, and then obtain the insulation effect under the optimal state.

[0020] Preferably, step S1 specifically involves filling the test chamber with a material similar to the surrounding rock, pre-embedding the heating component in a designated position during the filling process, and then removing the surrounding rock material at the location where the tunnel needs to be opened after the surrounding rock similar material has been filled, thereby constructing the tunnel.

[0021] Preferably, S5 specifically involves the secondary lining being a flexible material with folded flexible plates at its ends. By applying external force to the secondary lining, the secondary lining can be expanded or contracted, thereby changing the distance between the secondary lining and the primary support.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention explores the impact of different insulation dimensions on the insulation effect by changing the size of the air insulation layer, thereby determining the optimal air insulation layer size. The experimental approach optimizes the design of the detached lining structure and provides a basis for practical application, ensuring that the tunnel interior is at a suitable working temperature. By exploring the influence of heat sources on the insulation effect, the optimal insulation conditions can be determined more accurately. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of the overall structure of the present invention;

[0025] Figure 2 This is a side view of the overall structure of the present invention;

[0026] Figure 3 This is a three-dimensional schematic diagram of the relevant components inside the test chamber in this invention;

[0027] Figure 4 This is a three-dimensional schematic diagram of the sliding frame in this invention.

[0028] In the diagram: 1 Test chamber, 2 Secondary lining, 3 Primary support, 4 Air insulation layer, 5 Adjustment component, 11 Heating component, 12 Temperature sensor, 21 Flexible sheet, 51 Circular guide rail, 52 Sliding frame, 53 Clamping roller, 54 Slider, 55 Lead screw, 56 Winch, 57 Rope. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example:

[0031] Please see Figures 1 to 4 The present invention provides a technical solution:

[0032] A thermal insulation test device for a high-temperature tunnel lining structure with detached walls includes a test chamber 1. The test chamber 1 contains rock mass and a tunnel. A heating component 11 is embedded within the rock mass. An initial support 3 is located within the tunnel, and a secondary lining 2 is located inside the initial support 3. A temperature sensor 12 is located inside the secondary lining 2. Wherein:

[0033] The secondary lining 2 is a thin-walled plate with elastic deformation capability. The ends of the secondary lining 2 are provided with folded flexible plates 21, preferably aluminum plates, which allow for plastic deformation under external force. The gap between the primary support 3 and the secondary lining 2 forms an air insulation layer 4. Since the secondary lining 2 is a flexible and adjustable component, the size of the air insulation layer 4 can be adjusted, allowing for the investigation of the heat insulation effect of different sized air insulation layers 4 on the heat source. (Appendix) Figure 2 The lining 2 described herein has a folded flexible plate 21 at both ends. Of course, depending on the actual use, only one end may have a folded flexible plate 21.

[0034] In a preferred embodiment, the test apparatus further includes an adjustment component 5 for adjusting the position of the secondary lining 2. In this embodiment, the adjustment component 5 primarily applies a force to the secondary lining 2 to cause it to deform, thereby changing its position. However, this method is not limited to using mechanical mechanisms to change the position of the secondary lining 2; it can also be achieved through manual intervention by applying a force to the secondary lining 2 to cause it to deform.

[0035] In a preferred embodiment, the adjusting assembly 5 includes an annular guide rail 51, a sliding frame 52, clamping rollers 53, and a slider 54. The annular guide rail 51 is located on the side of the primary support 3. Preferably, the annular guide rail 51 has the same arcuate surface as the primary support 3. The sliding frame 52 is fitted onto the annular guide rail 51 and can move along the annular guide rail 51. The slider 54 is provided in the vertical guide rail on the sliding frame 52, and two clamping rollers 53 are arranged on the slider 54. The two clamping rollers 53 clamp the secondary lining 2. When the distance between the clamping rollers 53 and the center point of the secondary lining 2 changes, the distance between the secondary lining 2 and the primary support 3 can be adjusted by moving along the sliding frame 52. In this embodiment, an external force is applied to the secondary lining 2 using a mechanical structure.

[0036] In a preferred embodiment, the adjusting assembly 5 further includes a lead screw 55, which is rotatably mounted on the sliding frame 52 and passes through the slider 54, wherein the lead screw 55 and the slider 54 form a threaded connection pair. By rotating the lead screw 55 to change the position of the slider 54, the distance between the clamping roller 53 and the center point of the secondary lining 2 changes accordingly.

[0037] In a preferred embodiment, the adjustment assembly 5 further includes a drive assembly for driving the sliding frame 52 to move along the annular guide rail 51.

[0038] In a preferred embodiment, the drive assembly includes a winch 56 and a rope 57. A winch 56 is located on each side of the sliding frame 52, and the power output end of the winch 56 is wound with the rope 57. The other end of the rope 57 is connected to the sliding frame 52. The sliding frame 52 is moved by the coordinated winding and unwinding of the two winches 56. Of course, the drive assembly is not limited to this; it can also consist of a friction plate, a friction wheel, and a motor. The friction wheel is mounted on the sliding frame 52 and driven by the motor. The friction plate has the same shape and size as the annular guide rail 51, and the friction wheel makes frictional contact with the friction plate. When the friction wheel rotates, it drives the sliding frame 52 to move.

[0039] In a preferred embodiment, the heating component 11 is an electric heating plate.

[0040] As a preferred embodiment, the test chamber 1 is equipped with an insulation layer to reduce heat exchange with the air.

[0041] As a preferred embodiment, the secondary lining 2 is coated with heat-insulating material to prevent heat from being directly transferred to the tunnel interior.

[0042] An experimental method for a thermal insulation test device for a high-temperature tunnel detached lining structure, characterized by comprising the following steps:

[0043] S1. Constructing rock mass and tunnel in test chamber 1 and pre-embedding heating component 11. Specifically, filling test chamber 1 with surrounding rock similar material, pre-embedding heating component 11 in designated position during filling process, and then removing surrounding rock material at the location where tunnel needs to be opened after filling the surrounding rock similar material, thereby constructing tunnel.

[0044] S2, the primary support 3 is attached to the inner wall of the tunnel, and a secondary lining 2 is provided inside the primary support 3; wherein the primary support 3 is anchored to the inner wall of the tunnel by anchor bolts;

[0045] S3, arrange the temperature sensor 12 inside the secondary lining 2;

[0046] S4, the rock mass is heated by the heating component 11, and then the temperature sensor 12 will detect the temperature inside the secondary lining 2;

[0047] S5, change the distance between the secondary lining 2 and the primary support 3, and the size of the air insulation layer 4 will be adjusted accordingly. Repeat S4 to record the insulation effect of different sizes of air insulation layers 4, and then obtain the insulation effect under the optimal state. Specifically, the secondary lining 2 is a flexible material and its end is provided with a folded flexible plate 21. Then, by applying external force to the secondary lining 2, the secondary lining 2 can be opened or closed, and the distance between the secondary lining 2 and the primary support 3 can be changed.

[0048] S5 describes applying external force to the secondary liner 2. This external force can be a person directly pushing or pulling the secondary liner 2 to adjust its position. Of course, manual force can adaptively adjust the shape of the secondary liner 2. Alternatively, it can be adjusted using the adjustment component 5. The specific steps of using the adjustment component 5 are as follows: adjust the position of the slider 54, which changes the distance between the clamping roller 53 and the center of the secondary liner 2. Then, the sliding frame 52 moves along the annular guide rail 51. The movement trajectory of the sliding frame 52 is from one end of the secondary liner 2 to the other end. The clamping roller 53 applies a force to the secondary liner 2. After the clamping roller 53 circles the secondary liner 2 once, it adjusts the position of the secondary liner 2, thereby changing the size of the air insulation layer 4.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A thermal insulation test device for a high-temperature tunnel lining structure with detached wall, comprising a test chamber (1), wherein the test chamber (1) contains a rock mass and a tunnel is constructed therein, a heating component (11) is embedded in the rock mass, a primary support (3) is provided in the tunnel, and a secondary lining (2) is provided on the inner side of the primary support (3), and a temperature sensor (12) is provided inside the secondary lining (2), characterized in that: The secondary lining (2) is a thin-walled plate with elastic deformation capability, and the end of the secondary lining (2) is provided with a folded flexible plate (21). The gap between the primary support (3) and the secondary lining (2) constitutes an air insulation layer (4). Since the secondary lining (2) is a flexible adjustable component, the size of the air insulation layer (4) can be adjusted. The test apparatus also includes an adjustment component (5) for adjusting the position of the secondary lining (2); The adjustment assembly (5) includes an annular guide rail (51), a sliding frame (52), a clamping roller (53), and a slider (54). The annular guide rail (51) is located on the side of the primary support (3), and the sliding frame (52) is installed on the annular guide rail (51) and can move along the annular guide rail (51). The slider (54) is provided in the vertical guide rail on the sliding frame (52), and two clamping rollers (53) are set on the slider (54). The two clamping rollers (53) clamp the secondary lining (2). When the distance between the clamping rollers (53) and the center point of the secondary lining (2) changes, the distance between the secondary lining (2) and the primary support (3) can be adjusted by moving along the sliding frame (52).

2. The heat insulation test device for high-geotemperature tunnel lining structure according to claim 1, characterized in that: The adjustment assembly (5) also includes a lead screw (55), which is rotatably mounted on the sliding frame (52) and passes through the slider (54), wherein the lead screw (55) and the slider (54) form a threaded connection pair.

3. The heat insulation test device for high-geotemperature tunnel lining structure according to claim 1, characterized in that: The adjustment assembly (5) also includes a drive assembly for driving the sliding frame (52) to move along the annular guide rail (51).

4. The thermal insulation test device for a high-temperature tunnel detached lining structure according to claim 3, characterized in that: The drive assembly includes a winch (56) and a rope (57). A winch (56) is provided on each side of the sliding frame (52), and the power output end of the winch (56) is wound with a rope (57). The other end of the rope (57) is connected to the sliding frame (52).

5. An experimental method for a heat insulation test device for a high-temperature tunnel detached lining structure according to claim 1, characterized in that, Includes the following steps: S1, construct rock mass and tunnel in test chamber (1) and pre-embed heating components (11). S2, the primary support (3) is attached to the inner wall of the tunnel, and a secondary lining (2) is provided inside the primary support (3). S3, arrange the temperature sensor (12) inside the secondary lining (2); S4, the rock mass is heated by the heating component (11), then the temperature sensor (12) will detect the temperature inside the secondary lining (2); S5, change the distance between the secondary lining (2) and the primary support (3), then the size of the air insulation layer (4) is adjusted accordingly. Repeat S4 to record the insulation effect of different sizes of air insulation layers (4), and then obtain the insulation effect under the optimal state.

6. The experimental method of the heat insulation test device for a high-temperature tunnel detached lining structure according to claim 5, characterized in that: Specifically, S1 involves filling the test chamber (1) with a material similar to the surrounding rock, pre-embedding the heating component (11) in a designated position during the filling process, and then removing the surrounding rock material at the location where the tunnel needs to be opened after the surrounding rock similar material is filled, thereby constructing the tunnel.

7. The experimental method of the heat insulation test device for a high-temperature tunnel detached lining structure according to claim 5, characterized in that: Specifically, S5 is that the secondary lining (2) is made of a flexible material and its end is provided with a folded flexible plate (21). Then, by applying external force to the secondary lining (2), the secondary lining (2) can be opened or closed, thereby changing the distance between the secondary lining (2) and the primary support (3).

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