Thermal insulation structure for reducing piston wind in tunnel in cold region

Abstract

The invention relates to a heat preservation structure for reducing piston wind in a tunnel in a cold region. The heat preservation structure comprises an unpowered ventilation system, a heating system, a drainage system and a temperature control system. The unpowered ventilation system comprises a plurality of ventilation pipes which are obliquely crossed with the tunnel ballast bed; one end of the ventilation pipe penetrates through the heating system, and the other end penetrates through the tunnel ballast bed; the heating systems are arranged at equal intervals in the longitudinal direction of the tunnel and comprise rectangular concrete cavities arranged under a tunnel ballast bed, heat preservation plates laid on the inner surfaces of the rectangular concrete cavities and electric heating wires fixed to the inner surfaces of the heat preservation plates. The drainage system comprises transverse water-permeable blind pipes, longitudinal water-permeable blind pipes and a central ditch; one end of the transverse water-permeable blind pipe is connected with a longitudinal water-permeable blind pipe of a tunnel wall foot, the other end of the transverse water-permeable blind pipe is connected with a central ditch, and the transverse water-permeable blind pipe is longitudinally arranged along the tunnel; the central ditch penetrates through the heating system along the longitudinal direction of the tunnel; the temperature control system comprises a power distribution control box and a temperature sensor. The aim of cold protection and heat preservation of the tunnel in the cold region can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel thermal insulation and anti-freezing damage, and in particular to a thermal insulation structure for reducing piston wind in a cold region tunnel. Background Art

[0002] my country's cold regions are very vast, accounting for about 43.5% of the land area, mainly distributed in the high latitudes of the northeast and the high altitude areas of the west. In recent years, with the rapid development of my country's transportation infrastructure construction, the mileage of highway and railway tunnels has continued to grow, and more and more cold region tunnels have entered the engineering construction sequence. Affected by the harsh operating environment, most cold region tunnels often face frost damage problems such as ice hanging, lining cracking, and block falling after completion, which poses many challenges to the design and construction of tunnels, and also brings many difficulties to the maintenance and management of tunnels. In the cold season, the piston wind generated by vehicles driving in the tunnel has a great impact on the thermal environment inside the tunnel. It is one of the main reasons for the drop in temperature in the tunnel, freezing of the drainage system, frost heaving of the surrounding rock, and ultimately the formation of frost damage. Therefore, how to reduce the impact of piston wind on the tunnel temperature field has become a key issue that needs to be urgently solved in the field of cold region tunnel engineering.

[0003] At present, the insulation measures for tunnels in cold regions are mainly divided into active insulation measures and passive insulation measures. Active insulation measures mainly use methods such as electric heating and ground source heat pumps to increase the temperature of tunnel surrounding rocks, linings and other structures. Passive insulation measures mainly improve the cold resistance of tunnels by laying insulation materials and installing snow sheds. The above measures have a certain effect of cold protection and heat preservation in theory, but it is difficult to cope with the impact of piston wind generated by high-speed vehicles on the temperature field of the tunnel. In the cold season, high-speed vehicles entering the tunnel will inevitably cause cold air outside the tunnel to invade the tunnel, and promote strong thermal convection and heat conduction between the air and structural layers in the tunnel, providing basic temperature conditions for the formation of tunnel frost damage.

[0004] Considering the influence of piston wind on the temperature field of tunnels in cold regions, according to the principle of cold protection and heat preservation, the insulation structure that reduces the influence of piston wind on the temperature field of tunnels mainly involves three aspects: ① Raising the wind temperature of piston wind entering the tunnel to reduce the influence of piston wind on the temperature field of the tunnel; ② Optimizing the drainage measures of the tunnel to prevent the drainage system from freezing and blocking due to the influence of piston wind; ③ Optimizing the active insulation measures of the tunnel to prevent the surrounding rock from frost heaving due to the cooling effect of piston wind. However, there is currently no suitable insulation structure that can achieve the purpose of cold protection and heat preservation for tunnels in cold regions. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a heat-insulating structure for reducing piston wind in cold-region tunnels, which can realize cold-proof and heat-insulating effects on cold-region tunnels.

[0006] In order to solve the above problems, the present invention discloses a heat preservation structure for reducing piston wind in cold-region tunnels, which is characterized in that: the structure includes an unpowered ventilation system, a heating system, a drainage system and a temperature control system; the unpowered ventilation system includes a plurality of ventilation pipes obliquely intersecting the tunnel roadbed; one end of the ventilation pipe passes through the heating system, and the other end passes through the tunnel roadbed; the heating system is arranged at equal intervals along the longitudinal direction of the tunnel, including a rectangular concrete cavity directly below the tunnel roadbed, an insulation board laid on the inner surface of the rectangular concrete cavity and an electric heating wire fixed on the inner surface of the insulation board; the drainage system includes a transverse permeable blind pipe, a longitudinal permeable blind pipe, and a heat preservation board. blind pipe and central ditch; one end of the transverse permeable blind pipe is connected to the longitudinal permeable blind pipe at the foot of the tunnel wall, and the other end is connected to the central ditch, and the transverse permeable blind pipe is arranged along the longitudinal direction of the tunnel; the central ditch runs through the heating system along the longitudinal direction of the tunnel; the temperature control system includes a power distribution control box installed on the side wall of the tunnel and temperature sensors evenly distributed on the top of the central ditch, the transverse permeable blind pipe and the longitudinal permeable blind pipe; the output end of the power distribution control box is respectively connected to the input end of the heating wire and the temperature sensor, and the input end of the power distribution control box is connected to the output end of the temperature sensor.

[0007] The ventilation pipes are arranged at a spacing of 80 to 100 cm in the longitudinal direction of the heating system, 50 to 70 cm in the transverse direction, and 50 to 60 cm in the vertical direction.

[0008] The distance between adjacent heating systems is 25~35 m.

[0009] The top surface and left and right sides of the heating system are obliquely penetrated by one end of a plurality of ventilation pipes, the other end of the ventilation pipe penetrates the top surface of the tunnel roadbed, and the inclination direction of the ventilation pipe is consistent with the driving direction of the vehicle.

[0010] The angle between the ventilation pipe and the penetrated plane is 40~80°; the spacing between adjacent ventilation pipes along the transverse direction of the tunnel roadbed is 1~3 m.

[0011] The distance between the rectangular concrete cavity and the top surface of the tunnel roadbed is 2-3 m, and the rectangular concrete cavity is 4 m long, 2.5 m wide and 3.0 m high.

[0012] The heating wire is fixed to the inner surface of the insulation board through waterproof rivets, and the winding spacing of the heating wire is 15-25 cm.

[0013] The power of the heating wire is 25 W / m, and the limiting heating temperature is 70°C.

[0014] The cross-section of the central water ditch is circular and is made of a prefabricated reinforced concrete pipe with a diameter of 80-90 cm and a thickness of 10-20 cm; the central water ditch is arranged directly below the tunnel roadbed, passes through the rectangular concrete cavity, and the outer surface of the central water ditch is tangent to the inner surface of the heating system.

[0015] The transverse permeable blind pipes are arranged obliquely, and the arrangement spacing of the transverse permeable blind pipes along the longitudinal direction of the tunnel is 6 to 10 m.

[0016] A polyurethane insulation layer is arranged around the transverse water-permeable blind pipe, and the thickness is 5 to 10 cm.

[0017] A concrete base is provided below the transverse permeable blind pipe.

[0018] The power distribution control box automatically controls the power supply to the heating wire according to the temperature change of the temperature sensor to ensure that the temperature in the central water ditch, the transverse water-permeable blind pipe and the longitudinal water-permeable blind pipe is between 2 and 5°C; when the temperature in the central water ditch, the transverse water-permeable blind pipe and the longitudinal water-permeable blind pipe is lower than 2°C, the power supply to the heating wire is automatically turned on, and when the temperature is higher than 5°C, the power supply is automatically stopped.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The present invention provides a heating wire in the heating system. The heating wire can increase the temperature of the transverse water-permeable blind pipe, the longitudinal water-permeable blind pipe and the central water ditch through the heating effect, thereby preventing the drainage system from being blocked by ice due to the influence of piston wind.

[0020] 2. The present invention connects a ventilation pipe between the heating system and the top surface of the tunnel roadbed. The hot air heated by the electric heating wire in the rectangular concrete cavity enters the tunnel through the ventilation pipe under the action of the vehicle piston wind, and mixes with the cold air brought into the tunnel by the piston wind, thereby increasing the air temperature in the tunnel and preventing the tunnel from freezing. In the case where there is no vehicle passing and no piston wind is generated, the density of the hot air in the rectangular concrete cavity is lower than the density of the cold air in the tunnel. Under the action of the temperature difference, the hot air in the rectangular concrete cavity will also flow into the tunnel, heating the air in the tunnel, thereby preventing the tunnel from freezing.

[0021] 3. The present invention proposes preventive measures to weaken piston wind, while also taking into account the purpose of cold protection and heat preservation of drainage. The greater the piston wind, the more hot air will enter the tunnel from the rectangular concrete cavity, which can greatly weaken the influence of the piston wind on the temperature field of the tunnel. At the same time, it helps to maintain the normal operation of the tunnel drainage system and play a role in preventing and controlling frost damage in cold-region tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 It is a side view of the unpowered ventilation system of the present invention.

[0025] Figure 3 It is a top view of the unpowered ventilation system of the present invention.

[0026] Figure 4 It is a schematic diagram of the heating system of the present invention.

[0027] Figure 5 Schematic diagram of the drainage system of the present invention.

[0028] Figure 6 Schematic diagram of the temperature control system of the present invention.

[0029] Figure 7 It is a schematic diagram of fixing the heating wire in the present invention.

[0030] Figure 8 It is a schematic diagram of the heating wire winding method in the present invention.

[0031] Fig. 9 It is a cross-sectional view of the transverse water-permeable blind pipe in the present invention.

[0032] In the figure: 1—unpowered ventilation system; 2—heating system; 3—drainage system; 4—temperature control system; 5—ventilation pipe; 6—tunnel roadbed; 7—rectangular concrete cavity; 8—insulation board; 9—electric heating wire; 10—waterproof rivet; 11—transverse permeable blind pipe; 12—longitudinal permeable blind pipe; 13—central ditch; 14—power distribution control box; 15—temperature sensor; 16—tunnel; 17—polyurethane insulation layer; 18—concrete base. DETAILED DESCRIPTION

[0033] like Figures 1 to 9As shown, a heat preservation structure for reducing piston wind in cold-region tunnels includes a non-powered ventilation system 1, a heating system 2, a drainage system 3 and a temperature control system 4. The non-powered ventilation system 1 includes a plurality of ventilation pipes 5 obliquely intersecting with the tunnel roadbed 6; one end of the ventilation pipe 5 passes through the heating system 2, and the other end passes through the tunnel roadbed 6; the heating system 2 is arranged at equal intervals along the longitudinal direction of the tunnel 16, including a rectangular concrete cavity 7 located directly below the tunnel roadbed 6, an insulation board 8 laid on the inner surface of the rectangular concrete cavity 7, and an electric heating wire 9 fixed on the inner surface of the insulation board 8; the drainage system 3 includes a transverse permeable blind pipe 11, a longitudinal permeable blind pipe 12 and a central water ditch 13; one end of the transverse permeable blind pipe 11 is connected to the tunnel roadbed 6; the other end of the ventilation pipe 5 passes through the heating system 2 ...; the heating system 2 is arranged at equal intervals along the longitudinal direction of the tunnel 16; the heating system 2 is arranged at equal intervals along the longitudinal direction of the tunnel 16; the The longitudinal permeable blind pipe 12 at the foot of the tunnel 16 is connected, and the other end is connected to the central ditch 13, and the transverse permeable blind pipe 11 is arranged along the longitudinal direction of the tunnel 16; the central ditch 13 runs through the heating system 2 along the longitudinal direction of the tunnel 16; the temperature control system 4 includes a power distribution control box 14 installed on the side wall of the tunnel 16 and temperature sensors 15 evenly distributed on the top of the central ditch 13, the transverse permeable blind pipe 11 and the longitudinal permeable blind pipe 12; the output end of the power distribution control box 14 is respectively connected to the electric heating wire 9 and the input end of the temperature sensor 15 to achieve the purpose of power supply. The input end of the power distribution control box 14 is connected to the output end of the temperature sensor 15.

[0034] The ventilation pipe 5 has a circular cross section with a diameter of 8 to 15 cm, preferably 10 cm; and is made of polyvinyl chloride with a thickness of 1 to 3 cm, preferably 2 cm.

[0035] The ventilation pipes 5 are arranged at a longitudinal spacing of 80-100 cm, preferably 100 cm, along the heating system 2; the lateral spacing is 50-70 cm, preferably 60 cm; and the vertical spacing is 50-60 cm, preferably 60 cm.

[0036] The distance between adjacent heating systems 2 is 25-35 m, preferably 30 m.

[0037] The top surface and left and right sides of the heating system 2 are obliquely penetrated by one end of a plurality of ventilation pipes 5, the other end of the ventilation pipe 5 penetrates the top surface of the tunnel roadbed 6, and the inclination direction of the ventilation pipe 5 is consistent with the driving direction of the vehicle.

[0038] The angle between the ventilation pipe 5 and the penetrated plane is 40-80°, preferably 60°; the spacing between adjacent ventilation pipes 5 along the transverse direction of the tunnel roadbed 6 is 1-3 m, preferably 3 m.

[0039] The distance between the rectangular concrete cavity 7 and the top surface of the tunnel roadbed 6 is 2-3 m, preferably 3 m, and the rectangular concrete cavity 7 is 4 m long, 2.5 m wide and 3.0 m high.

[0040] The insulation board 8 is made of polyphenolic material, with a thermal conductivity of no more than 0.03 W / (m·K) and a thickness of 3 to 5 cm. Preferably, the thermal conductivity is 0.025 W / (m·K) and the thickness is 5 cm.

[0041] The heating wire 9 is fixed to the inner surface of the insulation board 8 by waterproof rivets 10, and the winding spacing of the heating wire 9 is 15-25 cm, preferably 20 cm.

[0042] The power of the heating wire 9 is 25 W / m, and the limiting heating temperature is 70°C.

[0043] The cross section of the central water ditch 13 is circular, and is made of a reinforced concrete prefabricated pipe with a diameter of 80-90 cm and a thickness of 10-20 cm, preferably a reinforced concrete prefabricated pipe with a diameter of 90 cm and a thickness of 20 cm. The central water ditch 13 is arranged directly below the tunnel roadbed 6, passes through the rectangular concrete cavity 7, and the outer surface of the central water ditch 13 is tangent to the inner surface of the heating system 2.

[0044] The cross-section of the transverse water-permeable blind pipe 11 and the longitudinal water-permeable blind pipe 12 is circular, made of polypropylene, and has a diameter of 8 to 10 cm, preferably 10 cm.

[0045] The transverse permeable blind pipe 11 is arranged at an angle so that the water in the longitudinal drainage blind pipe 12 can automatically flow into the central ditch 13 through the transverse permeable blind pipe 11. The arrangement spacing of the transverse permeable blind pipe 11 along the longitudinal direction of the tunnel 16 is 6 to 10 m, preferably 10 m.

[0046] A polyurethane insulation layer 17 is arranged around the transverse water-permeable blind pipe 11, with a thickness of 5 to 10 cm, preferably 5 cm.

[0047] A concrete base 18 is provided below the transverse water-permeable blind pipe 11 to support the transverse water-permeable blind pipe 11 .

[0048] The power distribution control box 14 automatically controls the power supply to the heating wire 9 according to the temperature change of the temperature sensor 15 to ensure that the temperature in the central water ditch 13, the horizontal water-permeable blind pipe 11 and the longitudinal water-permeable blind pipe 12 is between 2 and 5°C; when the temperature in the central water ditch 13, the horizontal water-permeable blind pipe 11 and the longitudinal water-permeable blind pipe 12 is lower than 2°C, the power supply to the heating wire 9 is automatically turned on, and when the temperature is higher than 5°C, the power supply is automatically stopped.

[0049] How it works In the cold season, high-speed vehicles entering Tunnel 16 will inevitably cause cold air outside Tunnel 16 to invade Tunnel 16, which can easily lead to a drop in temperature inside Tunnel 16, freezing of the drainage system, frost heaving of the surrounding rocks, and ultimately frost damage.

[0050] The heating wire 9 on the inner surface of the insulation board 8 in the heating system 2 of the present invention can increase the air temperature in the rectangular concrete cavity 7 through the heating effect of the heating wire 9. The hot air in the rectangular concrete cavity 7 can enter the tunnel 16 through the ventilation pipe 5, mix with the cold air brought into the tunnel 16 by the piston effect of the vehicle, and produce convection heat exchange, thereby increasing the air temperature in the tunnel 16 and reducing the influence of the piston wind on the frost heave of the surrounding rock of the tunnel 16. Through heat conduction and convection heat exchange, the heating system 2 can heat the drainage system 3 of the tunnel 16, thereby achieving the purpose of cold-proofing and heat-insulating the tunnel drainage measures.

[0051] The temperature control system 4 of the present invention can automatically control the power supply to the heating system 2 according to the temperature in the central ditch 13, the transverse permeable blind pipe 11 and the longitudinal permeable blind pipe 12. When the heating system 2 heats the air temperature in the tunnel 16, no additional power is required. When a vehicle enters the tunnel 16, the negative pressure area formed at the rear of the vehicle sucks out the hot air in the heating system 2 through the ventilation pipe 5. In addition, the density of the hot air in the heating system 2 is lower than the density of the cold air in the tunnel 16, and convection heat exchange can occur autonomously to heat the air in the tunnel 16.

[0052] Therefore, the present invention achieves the purpose of preventing and controlling frost damage by heating the piston wind entering the tunnel and optimizing the tunnel drainage measures.

Claims

1. A heat preservation structure for reducing piston wind in cold region tunnels, characterized by: The structure comprises an unpowered ventilation system (1), a heating system (2), a drainage system (3) and a temperature control system (4); the unpowered ventilation system (1) comprises a plurality of ventilation pipes (5) obliquely intersecting with the tunnel ballast (6); one end of the ventilation pipe (5) passes through the heating system (2) and the other end passes through the tunnel ballast (6); the heating system (2) is arranged at equal intervals along the longitudinal direction of the tunnel (16), and comprises a rectangular concrete cavity (7) arranged directly below the tunnel ballast (6), an insulation board (8) laid on the inner surface of the rectangular concrete cavity (7), and an electric heating wire (9) fixed on the inner surface of the insulation board (8); the drainage system (3) comprises a transverse permeable blind pipe (11), a longitudinal permeable blind pipe (12) and a central water ditch (13); one end of the transverse permeable blind pipe (11) is connected to the tunnel ballast (6); the heating system (2) is arranged at equal intervals along the longitudinal direction of the tunnel (16), and comprises a rectangular concrete cavity (7) arranged directly below the tunnel ballast (6), an insulation board (8) laid on the inner surface of the rectangular concrete cavity (7), and an electric heating wire (9) fixed on the inner surface of the insulation board (8); the drainage system (3) comprises a transverse permeable blind pipe (11), a longitudinal permeable blind pipe (12) and a central water ditch (13); one end of the transverse permeable blind pipe (11) is connected to the tunnel ballast (6); The longitudinal water-permeable blind pipe (12) is connected to the foot of the tunnel (16), and the other end is connected to the central water ditch (13), and the transverse water-permeable blind pipe (11) is arranged along the longitudinal direction of the tunnel (16); the central water ditch (13) penetrates the heating system (2) along the longitudinal direction of the tunnel (16); the temperature control system (4) comprises a power distribution control box (14) installed on the side wall of the tunnel (16) and temperature sensors (15) evenly distributed on the top of the central water ditch (13), the transverse water-permeable blind pipe (11) and the longitudinal water-permeable blind pipe (12); the output end of the power distribution control box (14) is respectively connected to the heating wire (9) and the input end of the temperature sensor (15), and the input end of the power distribution control box (14) is connected to the output end of the temperature sensor (15).

2. The heat preservation structure for reducing piston wind in cold region tunnels according to claim 1, characterized in that: The ventilation pipes (5) are arranged at a longitudinal spacing of 80 to 100 cm along the heating system (2), a transverse spacing of 50 to 70 cm, and a vertical spacing of 50 to 60 cm.

3. The heat preservation structure for reducing piston wind in cold region tunnels as claimed in claim 1, characterized in that: The distance between adjacent heating systems (2) is 25-35 m.

4. The heat preservation structure for reducing piston wind in a cold region tunnel as claimed in claim 1, characterized in that: The top surface and left and right sides of the heating system (2) are obliquely penetrated by one end of a plurality of ventilation pipes (5), the other end of the ventilation pipe (5) penetrates the top surface of the tunnel ballast (6), and the inclination direction of the ventilation pipe (5) is consistent with the driving direction of the vehicle.

5. The heat preservation structure for reducing piston wind in cold region tunnels as claimed in claim 4, characterized in that: The angle between the ventilation pipe (5) and the penetrated plane is 40 to 80 degrees; the spacing between adjacent ventilation pipes (5) along the lateral direction of the tunnel ballast (6) is 1 to 3 meters.

6. The heat preservation structure for reducing piston wind in a cold region tunnel as claimed in claim 1, characterized in that: The distance between the rectangular concrete cavity (7) and the top surface of the tunnel ballast (6) is 2-3 m, and the rectangular concrete cavity (7) is 4 m long, 2.5 m wide and 3.0 m high.

7. The heat preservation structure for reducing piston wind in a cold region tunnel as claimed in claim 1, characterized in that: The heating wire (9) is fixed to the inner surface of the insulation board (8) via waterproof rivets (10), and the winding spacing of the heating wire (9) is 15 to 25 cm.

8. The heat preservation structure for reducing piston wind in a cold region tunnel as claimed in claim 7, characterized in that: The power of the electric heating wire (9) is 25 W / m, and the maximum heating temperature is 70°C.

9. The heat preservation structure for reducing piston wind in a cold region tunnel as claimed in claim 1, characterized in that: The cross section of the central water ditch (13) is circular and is made of a reinforced concrete prefabricated pipe with a diameter of 80 to 90 cm and a thickness of 10 to 20 cm. The central water ditch (13) is arranged directly below the tunnel ballast (6) and penetrates the rectangular concrete cavity (7), and the outer surface of the central water ditch (13) is tangent to the inner surface of the heating system (2).

10. The heat preservation structure for reducing piston wind in a cold region tunnel according to claim 1, characterized in that: The transverse water-permeable blind pipes (11) are arranged at an angle, and the arrangement spacing of the transverse water-permeable blind pipes (11) along the longitudinal direction of the tunnel (16) is 6 to 10 m.

11. The heat preservation structure for reducing piston wind in a cold region tunnel according to claim 10, characterized in that: A polyurethane insulation layer (17) is provided around the transverse water-permeable blind pipe (11) and has a thickness of 5 to 10 cm.

12. The heat preservation structure for reducing piston wind in a cold region tunnel according to claim 11, characterized in that: A concrete base (18) is provided below the transverse water-permeable blind pipe (11).

13. The heat preservation structure for reducing piston wind in a cold region tunnel according to claim 1, characterized in that: The power distribution control box (14) automatically controls the power supply to the heating wire (9) according to the temperature change of the temperature sensor (15), so as to ensure that the temperature in the central water ditch (13), the transverse water-permeable blind pipe (11) and the longitudinal water-permeable blind pipe (12) is between 2°C and 5°C; when the temperature in the central water ditch (13), the transverse water-permeable blind pipe (11) and the longitudinal water-permeable blind pipe (12) is lower than 2°C, the power supply to the heating wire (9) is automatically turned on, and when the temperature is higher than 5°C, the power supply is automatically stopped.

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