Lateral cavern heat removal device for high-ground-temperature tunnel

Abstract

The utility model discloses a lateral cavern heat removal device for a high-ground-temperature tunnel. The lateral cavern heat removal device comprises a supporting frame body and a heat exchange pipeline. The heat exchange pipelines are arranged in the supporting frame body in a surrounding mode, and a plurality of layers of heat exchange pipelines are sequentially arranged in the height direction of the supporting frame body. The supporting frame body is arranged in the lateral cavern, and the residual space in the lateral cavern is backfilled and compacted; an inlet and an outlet of the heat exchange pipeline penetrate out of a hole of the lateral cavern and are connected with an external heat exchanger. According to the scheme, the heat removal device is preset in the tunnel construction period, so that a stable heat source can be continuously provided in the tunnel operation period.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel energy conservation and environmental protection, and in particular to a heat extraction device for a lateral cavern of a high ground temperature tunnel. Background Art

[0002] With the implementation of my country's "Strong Transportation Nation" strategy and the advancement of the Western Development, tunnel construction is extending to high-altitude areas. Since the surrounding rock temperature is positively correlated with the tunnel depth, high ground temperatures are common and may be accompanied by high-temperature groundwater activities. The geothermal energy reserves in the tunnel surrounding rock are considerable.

[0003] At present, most projects regard high geothermal heat as a kind of tunnel heat damage, and rarely pay attention to geothermal energy associated with heat damage. The main harmful effect of high geothermal temperature is in the construction stage. With the construction of lining and insulation layer and the ventilation and cooling effect in the tunnel, high geothermal temperature rarely affects the tunnel operation period.

[0004] The proportion of the construction period and operation period of a tunnel in the entire life cycle depends on the scale and complexity of the tunnel, but the operation period usually accounts for between 85% and 95%. The utilization of geothermal energy during the tunnel operation period has the characteristics of small impact and long duration.

[0005] There are many geothermal energy utilization scenarios during the tunnel operation period, such as tunnel antifreeze, ventilation equipment heating, operating facility heating, etc. Using electric energy for heating is neither economical nor in line with my country's green development concept. Therefore, for tunnels with high geothermal heat damage, it is urgent to propose a heat damage utilization method to provide a long-term, stable, low-carbon and portable heat source for the tunnel operation period. Utility Model Content

[0006] The utility model aims to solve the deficiencies of the prior art and to provide a high geothermal tunnel lateral cavern heat extraction device. The heat extraction device is preset during the tunnel construction period so that it can continuously provide a stable heat source during the tunnel operation period.

[0007] The utility model is realized by the following technical solutions:

[0008] A high ground temperature tunnel lateral cavern heat extraction device, comprising a support frame and a heat exchange pipe;

[0009] The heat exchange pipe is disposed around the support frame, and is arranged in a plurality of layers in sequence along the height direction of the support frame;

[0010] The support frame is arranged in the lateral cavern, and the remaining space in the lateral cavern is backfilled and compacted;

[0011] The inlet and outlet of the heat exchange pipe both pass through the lateral cavern opening and are connected to an external heat exchanger.

[0012] Compared with the prior art, the geothermal energy reserves in the tunnel surrounding rock are considerable, but little attention has been paid to the geothermal energy associated with heat damage. There are many geothermal energy utilization scenarios during the tunnel operation period, such as tunnel anti-freezing, ventilation equipment heating, operating facility heating, etc. The use of electric energy for heating is neither economical nor in line with my country's concept of green development. The utility model provides a high geothermal tunnel lateral cavern heat extraction device. According to this solution, a lateral cavern is opened on the inner side of the tunnel, and a heat exchange pipe is installed therein. Then, the lateral cavern is backfilled with concrete grouting to make it dense, so that heat is exchanged with the tunnel geothermal through the internal heat exchange pipe, and the heat is extracted so that it can be continuously provided during the tunnel operation period. Stable heat source; the specific plan also includes a support frame for placing and fixing heat exchange pipes. The support frame is located in the lateral cavern as a whole. The support frame is set up to facilitate the installation of heat exchange pipes. The heat exchange pipes can be bent and erected in sequence in several layers, and arranged in sequence from bottom to top to facilitate uniform heat exchange. That is, the heat pipes are laid out in layers, stacked and connected from bottom to top. The pipe spacing of each layer of heat pipes is 0.6m, and the total length of the pipeline is 380m. It is calculated that the heat exchanger system requires a water pump with a head of at least 30m to operate normally; the exchanged heat is output to the external heat exchanger through the inlet and outlet of the heat exchange pipe for storage, so as to continuously provide a stable heat source during the tunnel operation period.

[0013] In a further solution, the support frame is composed of a plurality of transverse bars, longitudinal bars and vertical bars, and the size of the support frame is matched with the size of the internal space of the lateral cavern; that is, the support frame is connected by the transverse bars, longitudinal bars and vertical bars to form a plurality of rectangular frame frames, so that the heat exchange pipes can be aligned and arranged in sequence in the transverse and longitudinal directions to facilitate uniform heat exchange; in addition, the top height of the support frame is the same as the height of the lateral cavern, and the width is also matched with the longitudinal length, that is, the support frame can be stably installed to provide sufficient installation space for the heat exchange pipes.

[0014] In a further solution, a plurality of intersections of the horizontal bars, longitudinal bars and vertical bars are provided with connectors for fixing the heat exchange pipes; wherein the connectors are preferably cable ties, which are connected by binding with the cable ties.

[0015] In a further solution, the bottom of the support frame is provided with universal wheels to facilitate the support frame to enter the lateral cave chamber.

[0016] A further solution is that the inlet and outlet of the heat exchange pipe are connected to the insulated water tank in the external heat exchanger through a connecting pipe to form a circulation loop; a water pump is provided on the circulation loop; the heat exchange pipe is selected from PERT floor heating pipes with a diameter of 40mm. The design pressure bearing capacity of this type of floor heating pipe is 0.8MPa, and the working pressure is generally between 0.15 and 0.3MPa. During grouting, the concrete fluidity is considered to be good, and a maximum pressure of 0.1MPa can be generated; the heat exchange pipes of each layer are connected, and the water pump and water tank are connected to form a circulating water loop to realize circulating heat exchange.

[0017] In a further solution, water valves are provided at the inlet and outlet ends of the heat exchange pipe.

[0018] A further solution also includes a steel template for closing the lateral cavern opening.

[0019] A further solution is that the steel template is provided with casting holes and drilled holes for the inlet and outlet of the heat exchange pipe; that is, during the installation process, the heat exchanger end pipe, sensor signal line, and grouting pipe are inserted through the drilled holes and grouting holes on the steel template, and the drilled holes are sealed with rubber gaskets and water glue, thereby ensuring the good airtightness of the heat exchange system.

[0020] A further solution also includes a reaction frame arranged on the outside of the steel formwork; the reaction frame is arranged to support the steel formwork to prevent the steel formwork from being pushed out due to excessive pressure during pouring concrete.

[0021] A further solution also includes several temperature sensors, which are respectively installed on the support frame, the lateral cavern entrance and the tunnel surrounding rock; the temperatures in the lateral cavern, the lateral cavern entrance and the tunnel surrounding rock are detected in turn by several sensors, so as to facilitate real-time monitoring of the temperature field of the cavern and the surrounding rock.

[0022] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0023] 1. The utility model provides a heat extraction device for the lateral cavern of a high geothermal tunnel. The heat extraction device is preset during the tunnel construction period so that it can continuously provide a stable heat source during the tunnel operation period.

[0024] 2. The utility model provides a heat extraction device for the lateral cavern of a high geothermal tunnel. The support frame is located as a whole in the lateral cavern. The support frame is arranged to facilitate the installation of heat exchange pipes. The heat exchange pipes can be bent and erected in several layers in sequence, and are arranged in sequence from bottom to top to facilitate uniform heat exchange. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, constitute a part of this application, and do not constitute a limitation of the embodiments of the present utility model. In the drawings:

[0026] Figure 1 A schematic diagram of the position of the lateral cavern opening of an embodiment provided by the utility model;

[0027] Figure 2 A schematic diagram of a lateral cavern opening end portion of an embodiment provided by the utility model;

[0028] Figure 3 A top view of a lateral cavern after backfilling in an embodiment provided by the utility model;

[0029] Figure 4 A side view of a lateral cavern after backfilling according to an embodiment of the utility model.

[0030] Marks and corresponding parts names in the attached drawings:

[0031] 1-support frame, 2-heat exchange pipe, 3-lateral cavern, 4-steel formwork, 5-reaction frame, 6-water valve, 7-insulated water tank, 8-water pump. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0033] Example

[0034] This embodiment provides a high ground temperature tunnel lateral chamber heat extraction device, such as Figure 1-Figure 4 As shown, it includes a support frame 1 and a heat exchange pipe 2;

[0035] The heat exchange pipe 2 is disposed around the support frame 1, and is arranged in a plurality of layers in sequence along the height direction of the support frame 1;

[0036] The support frame 1 is arranged in the lateral cavern 3, and the remaining space inside the lateral cavern 3 is backfilled and compacted;

[0037] The inlet and outlet of the heat exchange pipe 2 pass through the opening of the lateral cavern 3 and are connected to an external heat exchanger.

[0038] Compared with the prior art, the geothermal energy reserves in the tunnel surrounding rock are considerable, but little attention has been paid to the geothermal energy associated with heat damage. During the tunnel operation period, there are many geothermal energy utilization scenarios, such as tunnel antifreeze, ventilation equipment heating, operating facility heating, etc. The use of electric energy for heating is neither economical nor in line with my country's concept of green development. The utility model provides a high geothermal tunnel lateral cavern 3 heat extraction device. According to this solution, a lateral cavern 3 is opened on the inner side of the tunnel, and a heat exchange pipe 2 is installed therein, and then the lateral cavern 3 is densely filled with concrete grouting, so that heat is exchanged with the internal heat exchange pipe 2 and the tunnel geothermal, and the heat is extracted so that it can continue to provide stable heat during the tunnel operation period. heat source; in the specific scheme, it also includes a support frame 1 for placing and fixing the heat exchange pipe 2, and the support frame 1 is located as a whole in the lateral cavern 3. The support frame 1 is set, and while it is convenient to install the heat exchange pipe 2, the heat exchange pipe 2 can be bent and erected in sequence in several layers, and arranged in sequence from bottom to top, so as to facilitate uniform heat exchange, that is, the heat pipes are laid out in layers, stacked and connected from bottom to top, the pipe spacing of each layer of heat pipes is 0.6m, the total length of the pipeline is 380m, and it is calculated that the heat exchanger system requires a water pump 8 with a head of at least 30m to operate normally; the exchanged heat is output to the external heat exchanger through the inlet and outlet of the heat exchange pipe 2 for storage, so as to continuously provide a stable heat source during the tunnel operation period.

[0039] In this embodiment, the support frame 1 is composed of a plurality of transverse bars, longitudinal bars and vertical bars, and the size of the support frame 1 is adapted to the size of the internal space of the lateral cavern 3; that is, the support frame 1 is connected by transverse bars, longitudinal bars and vertical bars to form a plurality of rectangular frame frames, so that the heat exchange pipes 2 can be aligned and arranged in sequence in the transverse and longitudinal directions to facilitate uniform heat exchange; in addition, the top height of the support frame 1 is the same as the height of the lateral cavern 3, and the width and longitudinal length are also adapted, that is, the support frame 1 can be stably installed to provide sufficient installation position for the heat exchange pipes 2.

[0040] In this embodiment, a plurality of intersections of the horizontal bars, longitudinal bars and vertical bars are provided with connectors for fixing the heat exchange pipe 2; wherein the connectors are preferably cable ties, which are connected by binding with the cable ties.

[0041] In this embodiment, the bottom of the support frame 1 is provided with universal wheels, which facilitate the support frame 1 to enter the lateral cavern 3 .

[0042] In this embodiment, the inlet and outlet of the heat exchange pipe 2 are connected to the insulated water tank 7 in the external heat exchanger through a connecting pipe to form a circulation loop; a water pump 8 is provided on the circulation loop; the heat exchange pipe 2 is selected from a PERT floor heating pipe with a diameter of 40 mm. The design pressure bearing capacity of this type of floor heating pipe is 0.8 MPa, and the working pressure is generally between 0.15 and 0.3 MPa. During grouting, the concrete fluidity is considered to be good, and a maximum pressure of 0.1 MPa can be generated; the heat exchange pipes 2 of each layer are connected, and the water pump 8 and the water tank are connected to form a circulating water loop to realize circulating heat exchange.

[0043] In this embodiment, water valves 6 are provided at the inlet and outlet ends of the heat exchange pipe 2 .

[0044] In this embodiment, a steel template 4 is also included for closing the opening of the lateral cavern 3.

[0045] In this embodiment, the steel template 4 is provided with casting holes and drilled holes for the inlet and outlet of the heat exchange pipe 2; that is, during the installation process, the heat exchanger end pipe, the sensor signal line, and the grouting pipe are inserted through the drilled holes and the grouting holes on the steel template 4, and the drilled holes are sealed with rubber gaskets and water glue, thereby ensuring the good airtightness of the heat exchange system.

[0046] In this embodiment, a reaction frame 5 is further included which is arranged outside the steel formwork 4 ; the reaction frame 5 is arranged to support the steel formwork 4 to prevent excessive pressure during pouring concrete and push out the steel formwork 4 .

[0047] In this embodiment, it also includes a plurality of temperature sensors, which are respectively installed on the support frame 1, the entrance of the lateral cavern 3 and the surrounding rock of the tunnel; the temperature inside the lateral cavern 3, the entrance of the lateral cavern 3 and the surrounding rock of the tunnel is detected in turn by the plurality of sensors, so as to facilitate real-time monitoring of the temperature field of the cavern and the surrounding rock.

[0048] The specific layout of the heat exchange pipe 2 is as follows: first, a simple movable support frame 1 is made outside the hole, and each layer of the heat exchange pipe 2 is tied to the support frame 1. Figure 2 As shown, 1 section is laid out at intervals of 1m. Push the stand into the corresponding position in the heat extraction tunnel to complete the preliminary layout of the heat pipe;

[0049] After the heat exchange pipe 2 and the temperature sensor are laid out, they need to be backfilled and compacted. A steel template 4 is set at the heat extraction area to seal the hole and a reaction frame 5 is set up. The heat exchanger port template is opened and exposed. Backfilling is performed by grouting. The concrete used for grouting is required to have small shrinkage, low hydration heat and thermal conductivity greater than the thermal conductivity of the surrounding rock. The reference thermal conductivity of the surrounding rock design is 3.5W / m / K, and the grouting pressure is 0.3MPa.

[0050] The construction process of cavern backfill is as follows:

[0051] 1) Install heat pipe heat exchanger;

[0052] 2) Install grouting pipe;

[0053] 3) Set up the reaction frame 5 and support the steel mold to seal the hole, and extend the heat exchanger end pipe, sensor signal line, and grouting pipe through the drilled hole on the steel mold, and seal the drilled hole with a rubber gasket and water glue;

[0054] 4) Connect the heat pipes of each layer, and connect the water pump 8 and the water tank to form a circulating water loop, and observe whether the water volume in the water tank changes.

[0055] 5) If the heat pipe system is well sealed, continue to flow water and start grouting with a grouting height of 1m;

[0056] 6) After the upper layer of slurry has initially solidified, continue grouting with a grouting height of 1m;

[0057] 7) After the initial setting of the upper layer of slurry, grouting is performed to cap the top. This grouting is performed under pressure with a grouting pressure of 0.3 MPa. When the grouting pressure reaches 0.3 MPa and is maintained for a period of time, grouting is stopped;

[0058] 8) After removing the formwork, set an insulation layer on the end face of the opening.

[0059] Grouting backfill may face the following problems:

[0060] 1) Heat pipe is damaged by pressure;

[0061] 2) The heat pipe itself has manufacturing defects or the joints are not tightly connected;

[0062] 3) The pouring of large volumes of concrete will generate a large amount of hydration heat, and the surrounding ground temperature is relatively high, which will reduce the structural performance of the heat pipe.

[0063] In view of the above three problems, the following solutions are proposed: after the formwork is set up, the layers of the heat pipes are first connected, and the water pump 8 and the water tank are connected to form a circulating water loop. After a period of time, the water volume in the water tank is observed to see if it decreases, so as to check whether there are defects in the heat pipe system; if the heat pipe system is well sealed, the water flow in the loop continues, so that there is a certain initial internal pressure in the heat exchanger system, and grouting begins. The grouting is carried out in batches, and the next grouting is carried out after the initial setting of the previous grouting is completed. This not only reduces the grouting pressure, but also effectively replaces the heat generated by the hydration of the concrete. If the temperature of the water tank is high, the hot water in the water tank can be replaced by new water, which solves the problems of pressure damage to the heat pipe and heat of concrete hydration.

[0064] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A heat extraction device for a lateral cavern of a high geothermal tunnel, characterized in that: It comprises a support frame (1) and a heat exchange pipe (2); The heat exchange pipe (2) is arranged around the support frame (1) and is arranged in a plurality of layers in sequence along the height direction of the support frame (1); The support frame (1) is arranged in the lateral cavern (3), and the remaining space inside the lateral cavern (3) is backfilled and compacted; The inlet and outlet of the heat exchange pipe (2) both pass through the opening of the lateral cavern (3) and are connected to an external heat exchanger.

2. A high geothermal tunnel lateral chamber heat extraction device according to claim 1, characterized in that: The support frame (1) is formed by splicing a plurality of horizontal bars, longitudinal bars and vertical bars, and the size of the support frame (1) is compatible with the size of the internal space of the lateral cavern (3).

3. A high geothermal tunnel lateral chamber heat extraction device according to claim 2, characterized in that: Connectors for fixing the heat exchange pipe (2) are provided at the intersections of the plurality of horizontal bars, longitudinal bars and vertical bars.

4. A high geothermal tunnel lateral chamber heat extraction device according to claim 1, characterized in that: The bottom of the support frame (1) is provided with universal wheels.

5. The high geothermal tunnel lateral chamber heat extraction device according to claim 1, characterized in that: The inlet and outlet of the heat exchange pipe (2) are connected to the heat preservation water tank (7) in the external heat exchanger via a connecting pipe to form a circulation loop; a water pump (8) is provided on the circulation loop.

6. A high geothermal tunnel lateral chamber heat extraction device according to claim 5, characterized in that: The inlet and outlet ends of the heat exchange pipe (2) are both provided with water valves (6).

7. The high geothermal tunnel lateral chamber heat extraction device according to claim 1, characterized in that: It also includes a steel template (4) for closing the opening of the lateral cavern (3).

8. The high geothermal tunnel lateral chamber heat extraction device according to claim 7, characterized in that: The steel template (4) is provided with casting holes and drilling holes for the inlet and outlet of the heat exchange pipe (2) to pass through.

9. The high geothermal tunnel lateral chamber heat extraction device according to claim 7, characterized in that: It also includes a reaction frame (5) arranged outside the steel template (4).

10. The high geothermal tunnel lateral chamber heat extraction device according to claim 1, characterized in that: It also comprises a plurality of temperature sensors, which are respectively installed on the support frame (1), the opening of the lateral cavern (3) and in the surrounding rock of the tunnel.

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