A tunnel portal pavement geothermal ice melting pipeline laying method

Abstract

The application belongs to the technical field of tunnel ice melting, and particularly relates to a laying method of a tunnel portal pavement geothermal ice melting pipeline, which comprises a heat extraction unit, a heat supply unit and a control device; the heat extraction unit comprises a heat extraction pipe, a first pressure monitor and a first circulating water pump; the heat supply unit comprises a heat exchange unit, a heat collection water tank, a second circulating water pump, a second pressure monitor, a temperature monitor, a total water inlet pipe, a total water outlet pipe and a road heat exchange pipe; the road heat exchange pipe is installed in a cement concrete surface layer of a cement concrete asphalt road; the cement concrete asphalt road comprises, from bottom to top, a road soil base layer, a road cushion layer, a cement concrete base layer, a heat insulation layer, a cement concrete surface layer, an asphalt lower surface layer and an asphalt upper surface layer. The application realizes the purpose of ice and snow melting by extracting geothermal energy and transmitting it to the ice and snow layer on the road surface; and the whole tunnel portal pavement geothermal ice melting pipeline is controlled according to pressure change and temperature change.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tunnel ice melting, and particularly relates to a tunnel portal pavement geothermal ice melting pipeline laying method. BACKGROUND

[0002] In some northern regions of China, the climate is cold in winter, and the road surface at the tunnel portal often appears to be icy, which can easily lead to traffic accidents such as vehicle loss of control, skidding, rear-end collision, and the like, and poses a serious threat to driving safety. Therefore, in order to reduce the impact of icing on traffic safety, it is crucial to take measures to melt ice on the road surface at the tunnel portal.

[0003] At present, road snow-melting and de-icing technologies are mainly divided into passive snow-melting and de-icing technologies and active snow-melting technologies. The passive snow-melting and de-icing technologies have some problems, such as environmental pollution, high cost, and limited use conditions. The active snow-melting technologies include carbon fiber electric heating snow-melting and de-icing and geothermal buried pipe snow-melting and de-icing. However, the carbon fiber heating cable is high in cost and consumes a large amount of electric energy during work, and a large amount of energy is wasted. The existing geothermal buried pipe snow-melting and de-icing technology lays the geothermal ice melting pipeline on the entire road surface layer, and the laying method is unreasonable, resulting in resource waste. At the same time, for cement concrete asphalt road structures, since the road heat exchange pipe is laid 2-4 cm below the upper surface of the cement concrete surface layer, the problem of cutting the contraction joint and the longitudinal joint to the heat exchange pipe during actual construction is not considered. In summary, when designing and constructing the tunnel portal pavement geothermal pipeline, it is necessary to design a specific geothermal ice melting pipeline laying method to avoid some problems encountered during construction and actual use. SUMMARY

[0004] In view of the deficiencies and shortcomings in the prior art, the present application aims to provide a tunnel portal pavement geothermal ice melting pipeline laying method. The tunnel portal pavement geothermal ice melting pipeline laid by the method is provided with a heat exchange pipe standard module at the center of the vehicle wheel track, and the snow-melting and de-icing range can enable the vehicle to drive normally, which not only reduces the consumption of materials, but also makes the laying method more convenient and reduces a lot of manpower and resources.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A tunnel portal pavement geothermal ice melting pipeline comprises a heat extraction unit, a heat supply unit, and a control device.

[0007] The heat extraction unit comprises a heat extraction pipe, a first pressure monitor and a first circulating water pump. The heat extraction pipe is embedded to extract geothermal heat, and is composed of parallel U-shaped PE pipes. The first circulating water pump is installed on the output end of the heat extraction pipe to ensure the normal circulation of water in the heat extraction section. The first pressure monitor is installed on the input end of the heat extraction pipe to monitor the water pressure. The water extracting geothermal heat flows into the heat exchange unit after the first circulating water pump, exchanges heat in the heat exchange unit, and then flows out and returns to the heat extraction pipe through the first pressure monitor to extract geothermal heat.

[0008] The heat supply unit comprises a heat exchange unit, a heat collection tank, a second circulating water pump, a second pressure monitor, a temperature monitor, a total water inlet pipe, a total water outlet pipe and a road heat exchange pipe. The water exchanged in the heat exchange unit flows out of the heat exchange unit, and then sequentially passes through the heat collection tank, the second circulating water pump, the total water inlet pipe, the road heat exchange pipe, the total water outlet pipe and the second pressure monitor, and then flows into the heat exchange unit to exchange heat, forming a heat mass circulation system. The heat collection tank stores the water exchanged by the heat exchange unit, the second circulating water pump provides power to ensure the normal circulation of water in the heat supply unit, and the second pressure monitor monitors the water pressure in the pipeline of the heat supply unit.

[0009] The road heat exchange pipe is installed in the cement concrete surface layer of the cement concrete asphalt road. The cement concrete asphalt road comprises, from bottom to top, a road subbase layer, a road cushion layer, a cement concrete base layer, a heat insulation layer, a cement concrete surface layer, an asphalt lower surface layer and an asphalt upper surface layer.

[0010] The road heat exchange pipe is laid under the upper surface of the cement concrete surface layer. The heat in the road heat exchange pipe is transferred to the asphalt lower surface layer and the asphalt upper surface layer through the cement concrete surface layer, and finally to the ice and snow layer on the surface of the cement concrete asphalt road, so as to achieve the purpose of snow melting and ice melting.

[0011] The road heat exchange pipe is composed of a heat exchange pipe standard module and a connecting pipe I, a connecting pipe II, a connecting pipe III and a connecting pipe IV, as shown in Figure 4 The heat exchange pipe standard module is composed of two U-shaped 304 threaded pipes connected in series, and the heat exchange pipe standard module is arranged at the center line of the vehicle tire track of the driving lane, as shown in Figure 4 As shown in Figures 4-6 ,

[0012] The above-mentioned tunnel portal pavement geothermal ice melting pipe laying method comprises the following steps:

[0013] Step 1: According to the specification requirements, the road cushion layer and the cement concrete base layer are laid on the road subbase layer in sequence. After the cement concrete base layer is laid, a heat insulation material is laid thereon to form a heat insulation layer.

[0014] Step 2: After the laying of the heat insulation layer is completed, the steel reinforcement support is placed on the heat insulation layer; after the laying of the steel reinforcement support is completed, the heat exchange pipe standard module is bound on the upper surface of the steel reinforcement support, and the heat exchange pipe standard module is connected into a whole through the connecting pipe I, the connecting pipe II, the connecting pipe III and the connecting pipe IV, that is, the road heat exchange pipe is formed, wherein the connecting pipe III is bound below the upper surface of the steel reinforcement support, such as Figures 5-6 .

[0015] Step 3: The water pressure test is performed on the connected road heat exchange pipe to check whether the water leakage and the water pressure are normal, so as to ensure the safety.

[0016] Step 4: The cement concrete surface layer is poured to reach the design elevation; when the cement concrete reaches 25%-30% of the design strength, the road transverse joint and the road longitudinal joint are cut by using a cutting machine, and then the road transverse joint and the road longitudinal joint are filled with a filling material after the cutting is completed. Then, the asphalt lower surface layer and the asphalt upper surface layer are sequentially laid on the cement concrete surface layer, and the laying is completed and compacted, that is, the laying of the cement concrete asphalt road is completed.

[0017] Step 5:

[0018] The hole is drilled outside the cement concrete asphalt road, the U-shaped PE pipe is buried to form the heat extraction pipe, the first circulating water pump is installed at the water outlet end of the heat extraction pipe, the first pressure monitor is installed at the water inlet end, the heat exchange unit is installed and connected with the heat extraction pipe through the pipeline, the layout of the heat extraction unit is completed. The heat collecting water tank, the total water inlet pipe and the total water outlet pipe are installed, the total water inlet pipe is connected with the connecting pipe I, the total water outlet pipe is connected with another connecting pipe I, then the pipeline is used to sequentially connect the heat exchange unit, the heat collecting water tank, the temperature sensor, the second circulating water pump, the total water inlet pipe, and then the pipeline is used to sequentially connect the total water outlet pipe, the temperature sensor, the second pressure monitor, the heat exchange unit, to form a heat mass circulation system, and the layout of the heat supply unit is completed. Finally, the ground heat ice melting system control device is installed to complete the installation of the entire tunnel portal pavement ground heat ice melting pipeline.

[0019] Step 6: The commissioning and acceptance of the tunnel portal pavement ground heat ice melting pipeline are completed.

[0020] Preferably, the heat collecting water tank can also perform secondary heating on the water.

[0021] Preferably, the temperature sensor is installed on the pipeline between the heat collecting water tank and the second circulating water pump, and another temperature sensor is also installed on the input end pipeline of the second pressure monitor, and the temperature sensor transmits data to the temperature monitor to monitor the temperature of the water in the total water inlet pipe and the total water outlet pipe.

[0022] Preferably, the temperature sensor is installed in the asphalt upper surface layer of the cement concrete asphalt road to transmit data to the temperature monitor to monitor the temperature of the surface of the cement concrete asphalt road.

[0023] Preferably, the total water inlet pipe and the total water outlet pipe are arranged on one side of the cement concrete asphalt road close to the heat taking unit, and a layer of thermal insulation cotton is wrapped on the outer surface of the total water inlet pipe and the total water outlet pipe to prevent heat loss due to ambient temperature.

[0024] Preferably, a plurality of rows of heat exchange pipe standard modules are arranged on each lane, each row of heat exchange pipe standard modules is connected in series by two heat exchange pipe standard modules through the connecting pipe II, and the heat exchange pipe standard modules adjacent to different lanes are connected in series through the connecting pipe III, so that each two rows of heat exchange pipe standard modules form a heat mass circulation pipeline, the water inlet end of the heat mass circulation pipeline is connected with the total water inlet pipe through the connecting pipe I, the water outlet end is connected with the total water outlet pipe through another connecting pipe I, and the two rows of heat pipe standard modules are connected in series through the connecting pipe IV.

[0025] Preferably, the control device is a geothermal ice melting system control device, and the working process is as follows: when the temperature sensor detects that the surface temperature of the cement concrete asphalt road is reduced to 2 DEG C, the temperature monitor transmits a signal to the geothermal ice melting system control device, the geothermal ice melting system control device starts the first circulating water pump, the second circulating water pump and the heat exchange unit, and ensures the normal operation of the heat taking unit and the heat supply unit; when extremely cold weather is encountered, the heat provided by the heat taking unit cannot meet the ice melting demand, and the temperature monitor monitors that the surface temperature of the cement concrete asphalt road is below 0 DEG C for more than 10 hours, the geothermal ice melting system control device opens the heating switch of the heat collecting water tank, and the water of the heat supply unit is secondarily heated to improve the temperature and achieve the purpose of snow melting and ice melting; during the operation of the tunnel entrance pavement geothermal ice melting pipeline, the first pressure monitor of the heat taking unit and the second pressure monitor of the heat supply unit monitor the pressure, and when the water pressure is monitored to be abnormal, a signal is transmitted to the geothermal ice melting system control device, the geothermal ice melting system control device immediately closes the whole tunnel entrance pavement geothermal ice melting pipeline to prevent safety accidents, and subsequent workers can repair and maintain according to the place where the pressure monitoring is abnormal.

[0026] Compared with the prior art, the advantages and beneficial effects of the present application are as follows:

[0027] 1. The heat collecting water tank of the present application can start the heating function of the heat collecting water tank to secondarily heat the water in the heat collecting water tank when the road ice melting cannot meet the requirements, and then deliver the water to the road heat exchange pipe for snow melting and ice melting.

[0028] 2. The heat taking unit and the heat supply unit of the present application are both provided with pressure monitors, once the pressure monitors monitor that the water pressure in the pipeline is abnormal, a signal is transmitted to the control device, the control device immediately closes the operation of the whole tunnel entrance pavement geothermal ice melting pipeline to ensure the safety of operation and facilitate subsequent repair work.

[0029] 3. The laying mode of the road heat exchange pipe is optimized, the heat exchange pipe standard module is arranged at the center of the vehicle wheel trace band, and the snow melting and ice melting range can make the vehicle normally run, which not only reduces the consumption of materials, but also makes the laying mode more convenient, and a lot of manpower and material resources are reduced.

[0030] 4. The problem of cutting the heat exchange pipe when cutting the road transverse joint (shrink joint) and the road longitudinal joint in the actual construction process is considered, for the road transverse joint and the road longitudinal joint, the laying path is designed to avoid cutting the heat exchange pipe when cutting.

[0031] 5. The road heat exchange pipe adopts a 304 threaded pipe, which has the advantages of good adhesion with cement concrete and good heat transfer efficiency.

[0032] 6. Each group of 304 threaded pipe standard modules is processed in the factory, can be directly transported to the construction site for assembly, and after assembly, is fixed on the steel support, and then cement concrete is poured. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a three-dimensional schematic view of the tunnel portal pavement geothermal ice melting pipe.

[0034] Figure 2 It is a top view of the tunnel portal pavement geothermal ice melting pipe.

[0035] Figure 3 It is a sectional view of the cement concrete asphalt road.

[0036] Figure 4 It is a pipe plan schematic view of the heat supply unit between two road transverse joints in the cement concrete asphalt road.

[0037] Figure 5 It is a pipe three-dimensional schematic view of the heat supply unit between two road transverse joints in the cement concrete asphalt road.

[0038] Figure 6 It is a pipe top view of the heat supply unit between two road transverse joints in the cement concrete asphalt road.

[0039] Figure 7 It is a plane schematic view of the heat exchange pipe standard module.

[0040] The reference numerals in the figure: 1 - road subbase, 2 - road cushion, 3 - cement concrete base, 4 - thermal insulation layer, 5 - cement concrete surface layer, 6 - asphalt lower surface layer, 7 - asphalt upper surface layer, 8 - maintenance road, 9 - road heat exchange pipe, 10 - heat extraction pipe, 11 - first pressure monitor, 12 - first circulating water pump, 13 - heat exchange unit, 14 - heat collection tank, 15 - second circulating water pump, 16 - second pressure monitor, 17 - temperature monitor, 18 - total water inlet pipe, 19 - total water outlet pipe, 20 - control device, 21 - road transverse joint, 22 - road longitudinal joint, 23 - lateral formwork, 24 - vehicle wheel track center line, 25 - connecting pipe I, 26 - connecting pipe II, 27 - connecting pipe III, 28 - connecting pipe IV, 29 - driving direction, 30 - heat exchange pipe standard module. DETAILED DESCRIPTION

[0041] The laying method of the heat exchange pipe of the present application will be described in detail below in combination with the tunnel pavement example and the accompanying drawings.

[0042] As shown in the figure, a tunnel portal pavement geothermal ice melting pipe includes a heat extraction unit, a heat supply unit and a control device. Figure 1

[0043] The heat extraction unit includes a heat extraction pipe 10, a first pressure monitor 11 and a first circulating water pump 12. The heat extraction pipe 10 is buried to extract geothermal heat, and is composed of parallel U-shaped PE pipes. The first circulating water pump 12 is installed on the output end of the heat extraction pipe 10 to ensure the normal circulation of water in the heat extraction section. The first pressure monitor 11 is installed on the input end of the heat extraction pipe 10 to monitor the water pressure. The water extracting geothermal heat passes through the first circulating water pump 12, flows into the heat exchange unit 13, exchanges heat in the heat exchange unit 13, flows out, passes through the first pressure monitor 11 and returns to the heat extraction pipe 10 to extract geothermal heat.

[0044] ​The heat supply unit comprises a heat exchange unit 13, a heat collection tank 14, a second circulating water pump 15, a second pressure monitor 16, a temperature monitor 17, a total water inlet pipe 18, a total water outlet pipe 19 and a road heat exchange pipe 9. The water that has been heat exchanged in the heat exchange unit 13 flows out of the heat exchange unit 13, sequentially passes through the heat collection tank 14, the second circulating water pump 15, the total water inlet pipe 18, the road heat exchange pipe 9, the total water outlet pipe 19 and the second pressure monitor 16, and then flows into the heat exchange unit 13 for heat exchange, thereby forming a heat mass circulation system. The heat collection tank 14 stores the water that has been heat exchanged and flows out of the heat exchange unit 13, and the heat collection tank 14 can heat the water again. The second circulating water pump 15 provides power to ensure the normal circulation of water in the heat supply unit. The second pressure monitor 16 monitors the pressure of the water in the pipeline of the heat supply unit. A temperature sensor is installed on the pipeline between the heat collection tank 14 and the second circulating water pump 15, and another temperature sensor is installed on the input pipeline of the second pressure monitor 16. The temperature sensors transmit data to the temperature monitor 17 to monitor the temperature of the water in the total water inlet pipe 18 and the total water outlet pipe 19.

[0045] The road heat exchange pipe 9 is installed in the cement concrete surface layer 5 of the cement concrete asphalt road. The cement concrete asphalt road comprises, from bottom to top, a road subbase layer 1, a road cushion layer 2, a cement concrete base layer 3, a heat insulation layer 4, the cement concrete surface layer 5, an asphalt lower surface layer 6 and an asphalt upper surface layer 7. The road heat exchange pipe 9 is laid at a depth of 2 cm below the upper surface of the cement concrete surface layer 5. The heat in the road heat exchange pipe 9 is transferred to the asphalt lower surface layer 6 and the asphalt upper surface layer 7 through the cement concrete surface layer 5, and finally to the ice and snow layer on the surface of the cement concrete asphalt road, so as to achieve the purpose of melting snow and ice. A temperature sensor is installed in the asphalt upper surface layer 7 of the cement concrete asphalt road to transmit data to the temperature monitor 17 to monitor the temperature of the surface of the cement concrete asphalt road. The total water inlet pipe 18 and the total water outlet pipe 19 are arranged on the side of the cement concrete asphalt road close to the heat extraction unit. Due to the influence of ambient temperature, a layer of thermal insulation cotton is wrapped around the outer surfaces of the total water inlet pipe 18 and the total water outlet pipe 19 to prevent heat loss.

[0046] The road heat exchange pipe 9 is composed of a heat exchange pipe standard module 30 and connecting pipes I 25, 1.35 m connecting pipe II 26, 1.25 m connecting pipe III 27 and 10 cm connecting pipe IV 28, as shown in Figure 4 The heat exchange pipe standard module 30 is composed of two U-shaped 304 threaded pipes connected in series. The size of the heat exchange pipe standard module 30 is 2.4 m in length and 47 cm in width. The center lines of the two pipes in the U-shaped 304 threaded pipe are 15 cm apart, and the pipe diameter is 20 mm, as shown in Figure 7As shown. The heat exchanger tube standard module 30 is arranged at the center line 24 of the vehicle wheel track, close to the edges of the cement concrete asphalt road on both sides. The center line 24 of the vehicle wheel track is 230.85m away from the lateral formwork 230.85m on both sides of the cement concrete asphalt road. The distance between the center lines 24 of adjacent vehicle wheel tracks in one lane is 1.8m. Figure 4 As shown. Figures 4-6 The heat exchanger tube standard module 30 and connecting pipes 25 / 26 / 27 / 28 are all made of 304 threaded steel pipe with an outer diameter of 20mm and an inner diameter of 18mm. The advantages of 304 threaded steel pipe are that it has a high heat transfer coefficient and the thread shape can be combined with cement concrete. Multiple rows of heat exchanger tube standard modules 30 are laid in each lane. Each row of heat exchanger tube standard modules 30 consists of two heat exchanger tube standard modules 30 connected in series by connecting pipe II 26 and fixed to the upper surface of the steel reinforcement support. Adjacent heat exchanger tube standard modules 30 in different lanes are connected in series by connecting pipe III 27. Thus, every two rows of heat exchanger tube standard modules 30 form a heat and mass circulation pipeline. The water inlet of this heat and mass circulation pipeline is connected to the main water inlet pipe 18 through connecting pipe I 25, and the water outlet is connected to the main water outlet pipe 19 through another connecting pipe I 25. The two rows of heat exchanger tube standard modules 30 are connected in series by connecting pipe IV 28. The road heat exchange pipe 9 forms an integral part of the cement concrete surface layer 5 with the concrete surface layer 5. The standard heat exchange pipe module 30 is 21.5 cm away from the road transverse joint. The longitudinal distance between two adjacent rows of standard heat exchange pipe modules 30 in a carriageway is 10 cm, and the lateral distance is 1.35 m. The longitudinal distance is along the driving direction, and the lateral distance is perpendicular to the driving direction. Figures 4-6 The image shows a 5m section of the road heat exchange pipe 9 laid out in plan view, a 3D view of the road heat exchange pipe 9 tied to the steel reinforcement support, and a top view of the road heat exchange pipe 9 tied to the steel reinforcement support.

[0047] Figure 1 This is a layout diagram of the geothermal de-icing pipeline at the tunnel entrance. The road heat exchange pipe 9 is laid from 10m outside the tunnel entrance to 10m inside the tunnel entrance, with a total length of 20m and a single lane width of 3.5m. Figures 4-6 This is a plan view and a three-dimensional view of the road heat exchange pipe 9 laid between adjacent transverse joints with a 5m interval. 5m out of 20m is used for explanation, and the remaining 15m is explained in the same way.

[0048] The control device 20 is a geothermal ice melting system control device, which automatically opens and closes the entire tunnel portal pavement geothermal ice melting pipeline according to pressure changes and temperature changes. The working process is as follows: when the temperature sensor detects that the temperature of the cement concrete asphalt road surface is reduced to 2℃, the temperature monitor 17 transmits a signal to the geothermal ice melting system control device, and the geothermal ice melting system control device opens the first circulating water pump 12, the second circulating water pump 15 and the heat exchange unit 13 to ensure the normal operation of the heat extraction unit and the heat supply unit; when extremely cold weather is encountered, the heat extraction unit cannot meet the ice melting demand, and the temperature monitor 17 monitors that the temperature of the cement concrete asphalt road surface is below 0℃ for more than 10 hours, the geothermal ice melting system control device opens the heating switch of the heat collection water tank 14 to perform secondary heating on the water of the heat supply unit, so that the temperature is increased to achieve the purpose of snow melting and ice melting; during the operation of the tunnel portal pavement geothermal ice melting pipeline, the first pressure monitor 11 of the heat extraction unit and the second pressure monitor 16 of the heat supply unit monitor the pressure, and when the water pressure is abnormal, a signal is transmitted to the geothermal ice melting system control device, and the geothermal ice melting system control device immediately closes the entire tunnel portal pavement geothermal ice melting pipeline to prevent safety accidents, and subsequent maintenance personnel can repair and maintain according to the place where the pressure monitoring is abnormal.

[0049] The above-mentioned tunnel portal pavement geothermal ice melting pipeline laying method comprises the following steps:

[0050] Step 1:

[0051] According to the specification requirements, 20cm-thick road cushion 2 and 20cm-thick cement concrete base 3 are laid on the road soil base 1 in turn, and after the cement concrete base 3 is laid, heat insulation material is laid thereon to form a 2cm-thick heat insulation layer 4.

[0052] Step 2:

[0053] After the heat insulation layer 4 is laid, a steel reinforcement support is placed every 5m thereon, the steel reinforcement support has a size of 4.9m in length, 2.27m in width and 0.22m in height, and the distance between the steel reinforcement support and the lateral formwork 23 on both sides of the cement concrete surface layer 5 is 0.615m; after the steel reinforcement support is laid, the heat exchange pipe standard module 30 is bound on the upper surface of the steel reinforcement support, and the heat exchange pipe standard module 30 is connected into a whole, i.e. the road heat exchange pipe 9, through the connection pipe I 25, the 1.35m connection pipe II 26, the 1.25m connection pipe III 27 and the 10cm connection pipe IV 28, wherein the connection pipe III 27 is bound at a position 0.11m deep below the upper surface of the steel reinforcement support to prevent the connection pipe III 27 from being cut when the road longitudinal joint 22 is cut, as shown in Figures 5-6At this time, marks are made on the lateral template 23 every 5 m for cutting joint treatment after the cement concrete is poured. For the expansion joint at the tunnel entrance, according to the requirements of the cement concrete pavement design specification, the construction is carried out according to the support fixing method, and the force transmission rod can be bound on the steel support.

[0054] Step 3:

[0055] The connected road heat exchange pipe 9 is subjected to a water pressure test to check whether it leaks and whether the water pressure is normal, so as to ensure safety.

[0056] Step 4:

[0057] A 26 cm thick cement concrete surface layer 5 is poured to reach the design elevation, and when the cement concrete reaches 25%-30% of the design strength, the road transverse joint 21 and the road longitudinal joint 22 are cut by a cutting machine, and after the cutting is completed, the road transverse joint 21 and the road longitudinal joint 22 are filled with joint filling material. Then, a 6 cm thick asphalt lower layer 6 and a 4 cm thick asphalt upper layer 7 are laid on the cement concrete surface layer 5 in turn, and after the laying is completed, compaction is carried out, that is, the paving of the cement concrete asphalt road is completed.

[0058] Step 5:

[0059] A 100 m deep hole is drilled outside the cement concrete asphalt road to bury a U-shaped PE pipe to form a heat extraction pipe 10, and a first circulating water pump 12 is installed at the water outlet end of the heat extraction pipe 10, a first pressure monitor 11 is installed at the water inlet end, a heat exchange unit 13 is installed and connected to the heat extraction pipe 10 through a pipeline, and the layout of the heat extraction unit is completed. A heat collection water tank 14, a total water inlet pipe 18 and a total water outlet pipe 19 are installed, the total water inlet pipe 18 is connected to a connecting pipe I 25, the total water outlet pipe 19 is connected to another connecting pipe I 25, then a pipeline is used to connect the heat exchange unit 13, the heat collection water tank 14, a temperature sensor, a second circulating water pump 15, the total water inlet pipe 18 in turn, and then a pipeline is used to connect the total water outlet pipe 19, a temperature sensor, a second pressure monitor 16, the heat exchange unit 13 in turn, to form a heat mass circulation system, and the layout of the heat supply unit is completed. Finally, a ground heat ice melting system control device is installed to complete the installation of the tunnel entrance pavement ground heat ice melting pipeline.

[0060] Step 6:

[0061] The commissioning and acceptance of the tunnel entrance pavement ground heat ice melting pipeline are completed.

[0062] The above is a detailed description of specific examples of the present application, and does not limit the scope of the present application in any way. Any modification or modification made by a person skilled in the art based on the above disclosed technical content should be considered as an equivalent effective implementation example, and should be considered as falling within the scope of the technical solution of the present application.

Claims

1. A method for laying a geothermal de-icing pipeline at a tunnel entrance, the geothermal de-icing pipeline at the tunnel entrance comprising a heat extraction unit, a heat supply unit, and a control device; the heat extraction unit comprising a heat extraction pipe, a first pressure monitor, and a first circulating water pump; the heat extraction pipe is composed of parallel U-shaped PE pipes, the first circulating water pump is installed at the output end of the heat extraction pipe, and the first pressure monitor is installed at the input end of the heat extraction pipe; water for extracting geothermal heat flows into a heat exchange unit after passing through the first circulating water pump, undergoes heat exchange in the heat exchange unit, flows out, and then returns to the heat extraction pipe via the first pressure monitor to extract geothermal heat; The heating unit includes a heat exchanger, a hot water tank, a second circulating water pump, a second pressure monitor, a temperature monitor, a main inlet pipe, a main outlet pipe, and a road heat exchange pipe. Water that has undergone heat exchange in the heat exchanger flows out of the heat exchanger, passes sequentially through the hot water tank, the second circulating water pump, the main inlet pipe, the road heat exchange pipe, the main outlet pipe, and the second pressure monitor, and then flows back into the heat exchanger for heat exchange, forming a heat and mass circulation system. The hot water tank stores the water that has undergone heat exchange in the heat exchanger, the second circulating water pump provides power, and the second pressure monitor monitors the water pressure in the heating unit's pipelines. The road heat exchange pipe is installed in the cement concrete surface layer of the cement concrete asphalt road; the cement concrete asphalt road includes, from bottom to top, the road subbase, the cement concrete base, the heat insulation layer, the cement concrete surface layer, the asphalt lower layer, and the asphalt upper layer; Road heat exchange pipes are laid beneath the surface of the cement concrete pavement. The heat in the road heat exchange pipes is transferred through the cement concrete pavement to the lower and upper asphalt layers, and finally to the ice and snow layer on the cement concrete asphalt road surface. The road heat exchange pipe consists of standard heat exchange pipe modules and connecting pipes I, II, III, and IV. Each standard heat exchange pipe module is composed of two U-shaped 304 threaded pipes connected in series and is arranged at the center line of the vehicle wheel tracks of the driving lane. Multiple rows of standard heat exchange pipe modules are laid in each driving lane. Each row of standard heat exchange pipe modules consists of two standard heat exchange pipe modules connected in series through connecting pipe II. Adjacent standard heat exchange pipe modules in different driving lanes are connected in series through connecting pipe III. Thus, every two rows of standard heat exchange pipe modules form a heat and mass circulation pipeline. The water inlet of this heat and mass circulation pipeline is connected to the main water inlet pipe through connecting pipe I, and the water outlet is connected to the main water outlet pipe through another connecting pipe I. The two rows of standard heat exchange pipe modules are connected in series through connecting pipe IV. Its features are, Includes the following steps: Step 1: According to the specifications, lay the road subbase and cement concrete base layer in sequence on the road subbase. After the cement concrete base layer is laid, lay the heat insulation material on it to form a heat insulation layer. Step 2: After the insulation layer is laid, place the steel reinforcement support on it; after the steel reinforcement support is laid, tie the heat exchange pipe standard module to the upper surface of the steel reinforcement support, and connect the heat exchange pipe standard module into a whole through connecting pipe I, connecting pipe II, connecting pipe III, and connecting pipe IV to form a road heat exchange pipe, wherein connecting pipe III is tied to the lower part of the upper surface of the steel reinforcement support. Step 3: Conduct a water pressure test on the connected road heat exchange pipes to check for leaks and whether the water pressure is normal; Step 4: Pour the cement concrete surface layer to reach the design elevation. When the cement concrete reaches 25%-30% of the design strength, use a cutting machine to cut the road transverse and longitudinal joints. After cutting, fill the road transverse and longitudinal joints with joint filler. Then, lay the asphalt lower layer and asphalt upper layer on the cement concrete surface layer in sequence. After laying, compact it to complete the laying of the cement concrete asphalt road. Step 5: Drill holes outside the cement concrete asphalt road and bury U-shaped PE pipes to form heat extraction pipes. Install the first circulating water pump at the outlet end and the first pressure monitor at the inlet end of the heat extraction pipes. Install the heat exchange unit and connect it to the heat extraction pipes through pipelines to complete the layout of the heat extraction unit. Install the hot water tank, the main inlet pipe, and the main outlet pipe. Connect the main inlet pipe to connecting pipe I and the main outlet pipe to another connecting pipe I. Then, connect the heat exchange unit, the hot water tank, the temperature sensor, the second circulating water pump, and the main inlet pipe in sequence through pipelines. Then, connect the main outlet pipe, the temperature sensor, the second pressure monitor, and the heat exchange unit in sequence through pipelines to form a heat and mass circulation system, completing the layout of the heating unit. Finally, install the geothermal de-icing system control device to complete the installation of the geothermal de-icing pipelines on the road surface at the tunnel entrance. Step 6: Complete the commissioning and acceptance of the geothermal de-icing pipeline at the tunnel entrance.

2. The laying method according to claim 1, characterized in that, The water is heated a second time using a hot water tank.

3. The laying method according to claim 1, characterized in that, A temperature sensor is installed on the pipeline between the hot water tank and the second circulating water pump. Similarly, another temperature sensor is installed on the pipeline at the input end of the second pressure monitor. The temperature sensor transmits data to the temperature monitor to monitor the temperature of the water in the main inlet pipe and the main outlet pipe.

4. The laying method according to claim 1, characterized in that, Temperature sensors are installed in the asphalt surface layer of cement concrete asphalt roads to transmit data to a temperature monitor in order to monitor the surface temperature of the cement concrete asphalt roads.

5. The laying method according to claim 1, characterized in that, The main inlet and outlet water pipes are located on the side of the cement concrete asphalt road near the heating unit, and a layer of insulation cotton is wrapped around the outer surface of the main inlet and outlet water pipes.

6. The laying method according to claim 1, characterized in that, The control device is a geothermal de-icing system control device, and its working process is as follows: When the temperature sensor detects that the surface temperature of the cement concrete asphalt road has dropped to 2°C, the temperature monitor transmits a signal to the geothermal de-icing system control device, which then starts the first circulating water pump, the second circulating water pump, and the heat exchange unit to ensure the normal operation of the heat extraction unit and the heating unit; when encountering extremely cold weather, if the temperature monitor detects that the surface temperature of the cement concrete asphalt road has been below 0°C for more than 10 hours, the geothermal de-icing system control device turns on the heating switch of the hot water collection tank to reheat the water in the heating unit; during the operation of the geothermal de-icing pipeline on the road surface at the tunnel entrance, the first pressure monitor of the heat extraction unit and the second pressure monitor of the heating unit monitor the pressure. When an abnormal water pressure is detected, a signal is transmitted to the geothermal de-icing system control device, which immediately shuts down the entire geothermal de-icing pipeline on the road surface at the tunnel entrance.

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