Cold region tunnel drainage pipe water flow freezing model comprehensive test system and use method thereof

Abstract

The present application relates to a kind of cold region tunnel drainage pipe water flow freezing model comprehensive test system, the system includes environmental test chamber and the top water tank, bottom water tank, refrigerator and data acquisition instrument placed in environmental test chamber.Top water tank is erected on lifting support, top water tank is connected with hose;The outlet end I of hose is connected with drainage pipe, the outlet end II of drainage pipe is inserted into bottom water tank;Water pump is arranged in bottom water tank, and water pump is connected with top water tank;The outer surface of drainage pipe is laid with refrigerant delivery pipe, and the outer surface of refrigerant delivery pipe is wrapped with a layer of thermal insulation cotton;The both ends of refrigerant delivery pipe are connected with the refrigerant outlet and inlet of refrigerator;Temperature sensor, water flow velocity sensor and high-definition camera are respectively arranged in drainage pipe;Data acquisition instrument is electrically connected with temperature sensor, water flow velocity sensor and high-definition camera by data acquisition line.Meanwhile, the application also discloses the use method of the system.The present application is simple in manufacture, strong in practicality, and low in test cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel engineering, and particularly relates to a cold region tunnel drainage pipe water flow freezing model comprehensive test system and a use method thereof. BACKGROUND

[0002] In recent years, with the increasingly perfect road network, railway and highway infrastructure is extending to cold regions with poor climatic conditions such as high latitude and high altitude. Due to design or construction reasons, many high-altitude and high-latitude tunnels in cold regions have varying degrees of frost damage. For example, the water in the back of the lining structure of Qidaoliang Tunnel freezes and expands, causing the drainage ditch to freeze; the lining and drainage ditch of Tiziliang Tunnel freeze and expand due to water accumulation, causing obvious cracking; and the improper insulation of the drainage pipe in the Kuiqian Tunnel causes the tunnel to freeze for 2870 m. Analysis of the above tunnel frost damage phenomena shows that the freezing of the drainage system is one of the root causes of the freezing of the tunnel in the cold region. Solving the problem of tunnel drainage anti-freezing is of great significance to ensure the safe operation of the tunnel in the cold region, and the basis for preventing and treating the freezing of the drainage system is to clarify the water flow freezing law of the drainage pipe in the cold region tunnel.

[0003] At present, there is less theoretical support for the study of the water flow freezing law of the drainage pipe in the cold region tunnel, and most of the research is from the experimental point of view. For example, under the condition of a single environmental temperature, the freezing test of static water in the drainage pipe is carried out, and the temperature change of the static water is measured to analyze the freezing law of the drainage pipe. However, the current research has the following problems: (1) The freezing test of the drainage pipe under the condition of a single environmental temperature cannot reflect the actual water flow freezing law of the drainage pipe in the cold region tunnel. Because in the actual cold region tunnel, the water in the drainage pipe is flowing rather than static, and the water flow velocity in the drainage pipe is different due to the different water pressures of the tunnel site, the water flow in the drainage pipe is different due to the different degrees of groundwater abundance of the tunnel site, and the temperature in the drainage pipe is different due to the different positions of the drainage in the tunnel. (2) The freezing test of the drainage pipe under the condition of a single environmental temperature only monitors the temperature of the water flow in the drainage pipe, and cannot accurately obtain the water flow freezing law of the drainage pipe in the cold region tunnel. The macroscopic manifestation of water freezing is that the temperature is lower than 0℃. However, the freezing of the water flow in the drainage pipe is a dynamic process, including the temperature and water flow velocity changes at each position of the drainage pipe in the freezing process, the ice layer initiation position in the drainage pipe, and the ice layer expansion.

[0004] Therefore, it is necessary to propose a cold region tunnel drainage pipe water flow freezing model comprehensive test system, which can accurately obtain the temperature, water flow velocity, ice layer initiation position and ice layer expansion process at each position in the drainage system under the comprehensive consideration of the water flow velocity in the drainage pipe, the temperature of the drainage pipe, and the water flow in the drainage pipe, thereby providing guidance for preventing and treating the freezing of the drainage system. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a cold region tunnel drainage pipe water flow freezing model comprehensive test system which is simple to make, highly practical and low in test cost.

[0006] Another technical problem to be solved by the present application is to provide a use method of the cold region tunnel drainage pipe water flow freezing model comprehensive test system.

[0007] To solve the above problems, the cold region tunnel drainage pipe water flow freezing model comprehensive test system provided by the present application has the following characteristics: the system comprises an environmental test box, a top-end water tank, a bottom-end water tank, a refrigerating machine and a data acquisition instrument arranged in the environmental test box; the top-end water tank is arranged on a lifting support, and one side of the top-end water tank is connected with a hose; an outlet end I of the hose is connected with a drainage pipe, and an outlet end II of the drainage pipe extends into the bottom-end water tank; a water pump is arranged in the bottom-end water tank, and the water pump is connected with the top-end water tank through a return pipe; a refrigerant conveying pipe is spirally arranged on the outer surface of the drainage pipe, and the outer surface of the refrigerant conveying pipe is wrapped with a layer of thermal insulation cotton; the two ends of the refrigerant conveying pipe are connected with the refrigerant outlet and the refrigerant inlet of the refrigerating machine respectively; the drainage pipe is respectively provided with a temperature sensor, a water flow velocity sensor and a high-definition camera; and the data acquisition instrument is electrically connected with the temperature sensor, the water flow velocity sensor and the high-definition camera through data acquisition lines.

[0008] The lifting support comprises a bottom steel plate, a top steel plate and a jack; the bottom of the jack is connected with the bottom steel plate through bottom bolts, and the top of the jack is connected with the top steel plate through top bolts; and the top steel plate is arranged with the top-end water tank.

[0009] The top-end water tank is in the shape of a cuboid, a cube or a cylinder, the bottom surface of the top-end water tank is not larger than the top steel plate, and the volume of the top-end water tank is not less than 1 m 3 .

[0010] One side edge of the top-end water tank is provided with a water outlet I, and the water outlet I is connected with the hose through a stop valve; and the stop valve and the hose are connected through a clamp I.

[0011] The hose and the drainage pipe are connected through a clamp II.

[0012] The water outlet II of the return pipe extends into the top-end water tank, and the water inlet is connected with the water outlet III of the water pump through a clamp III; and the water suction inlet of the water pump is lower than the liquid level of the bottom-end water tank.

[0013] The temperature environment of the environmental test box is -30-40 DEG C.

[0014] The length of the thermal insulation cotton is the same as the length of the drainage pipe.

[0015] The bottom end water tank is cuboid, cubic or cylindrical, and has a volume of not less than 1 m 3 .

[0016] The temperature regulation range of the refrigerating machine is -20-0℃.

[0017] A plurality of temperature monitoring sections are arranged in the drainage pipe every 20 cm, and 37 temperature sensors are arranged in a meshed manner at each temperature monitoring section; a high-definition camera is arranged at the top of each temperature monitoring section.

[0018] A plurality of water flow velocity monitoring sections are arranged in the drainage pipe every 20 cm, and 37 water flow velocity sensors are arranged in a meshed manner at each water flow velocity monitoring section, and the temperature monitoring section and the water flow velocity monitoring section are separated by 10 cm.

[0019] The use method of the cold region tunnel drainage pipe water flow freezing model comprehensive test system as described above comprises the following steps:

[0020] (1) Assembling the model test system:

[0021] ①In the environmental test box, a bottom steel plate with a size of 2 m*2 m is laid; the bottom of the jack is fixed on the bottom steel plate through bottom bolts; the top steel plate is fixed on the top of the jack through top bolts; finally, the lifting support is formed;

[0022] ②37 temperature sensors are arranged in a meshed manner in the drainage pipe every 20 cm; 37 water flow velocity sensors are arranged in a meshed manner at intervals of 10 cm from the temperature sensors; a high-definition camera is arranged at the vertex position of the temperature sensor; all the temperature sensors, water flow velocity sensors and high-definition cameras are electrically connected with the data acquisition instrument through data acquisition lines; finally, the monitoring and monitoring system is formed; the refrigerant conveying pipe is laid on the outer surface of the drainage pipe, and the drainage pipe with the refrigerant conveying pipe is wrapped with thermal insulation cotton;

[0023] ③The top end water tank is placed and fixed on the top steel plate, a stop valve is installed at the water outlet I of the top end water tank, a hose is sleeved at the outlet of the stop valve, and is fixed by a clamp I; the other end of the hose is sleeved with the drainage pipe provided with the temperature sensor, the water flow velocity sensor and the high-definition camera, and is fixed by a clamp II; the water outlet IV of the drainage pipe is connected with the bottom end water tank; the water pump is placed in the bottom end water tank; the water outlet III of the water pump is connected with the return pipe through the clamp III, and the water outlet II of the return pipe is placed in the top end water tank; finally, the water flow circulation system is formed;

[0024] (2) Drainage pipe freezing test:

[0025] i. Set the environmental temperature in the environmental test chamber; adjust the lifting height of the jack to make the lifting support reach a predetermined height; open the water stop valve and control the opening and closing degree of the water stop valve to make the water flow in the drain pipe flow to the bottom water tank according to the preset flow rate and flow; open the water pump to transport the water in the bottom water tank to the top water tank;

[0026] ii. After the environmental temperature in the environmental test chamber reaches uniformity, open the refrigeration machine; set the temperature of the refrigeration machine output refrigerant to make the refrigerant flow in the refrigerant conveying pipe and form a loop to cool the drain pipe;

[0027] iii. Open the monitoring and monitoring system, and use the data acquisition line to collect the temperature, water flow rate, icing position and ice layer development data of each position in the drain pipe in real time;

[0028] iv. When all the data are monitored to have no obvious change with time, close the water stop valve and the water pump to stop the water flow circulation system; at the same time, close the temperature control system of the environmental test chamber and the refrigeration machine to stop the temperature control system; finally, close the data acquisition instrument to stop the monitoring and monitoring system;

[0029] 6. Continue the drain pipe freezing test according to other settings:

[0030] Resets the environmental temperature in the environmental test chamber, the height of the lifting support, the opening and closing degree of the water stop valve, and the temperature of the refrigeration machine output refrigerant to meet the water flow freezing test in the drain pipe under different environmental temperatures, different water flow rates and water flow in the drain pipe, and different negative temperature conditions; then restart the test according to the step 5.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] 1. Compared with the conventional freezing test of static water in the drain pipe under a single environmental temperature condition, the water in the drain pipe in the present application is flowing, and the effects of water flow rate in the drain pipe, drain pipe water flow and environmental temperature and other factors on the freezing of the drain pipe are also considered, which is more close to the actual freezing condition of the drain pipe in the tunnel in cold regions.

[0033] 2. Compared with the conventional drain pipe freezing test which only obtains the temperature of the water flow, the present application arranges mesh temperature sensors and water flow rate sensors at different positions in the drain pipe, and also arranges high-definition cameras to monitor the temperature, water flow rate, and icing position and icing process of each position in the drain pipe in real time, which more comprehensively obtains the freezing law of the drain pipe.

[0034] 3. Compared with the traditional drainage pipe freezing test, the application controls the speed of water flow in the drainage pipe by changing the height of the lifting support, controls the water flow in the drainage pipe by changing the opening degree of the water stop valve, controls the temperature of the drainage pipe by adjusting the refrigerant temperature of the refrigeration machine, and is simple to operate.

[0035] 4. The system can accurately obtain the temperature, water flow speed, freezing position and ice layer expansion process of each position in the drainage system.

[0036] 5. The application is simple to manufacture, has strong practicability, has low test cost, can be used for analyzing the water flow freezing law of the drainage pipe of the tunnel in the cold region, and further provides guidance for preventing and treating the freezing of the drainage system of the tunnel in the cold region. BRIEF DESCRIPTION OF DRAWINGS

[0037] The specific embodiments of the application will be further described in detail below with reference to the accompanying drawings.

[0038] Figure 1 It is a structural schematic diagram of the application.

[0039] Figure 2 It is a half structural schematic diagram of the drainage pipe of the application.

[0040] Figure 3 It is a lifting support schematic diagram of the application.

[0041] Figure 4 It is a front view of the drainage pipe of the application.

[0042] Figure 5 It is a temperature monitoring section schematic diagram of the application.

[0043] Figure 6 It is a water flow speed monitoring section schematic diagram of the application.

[0044] Figure 7 It is a refrigerant conveying pipe of the application.

[0045] In the figure: 1-environmental test box; 2-top water tank; 3-bottom water tank; 4-lifting support; 5-clamp I; 6-water stop valve; 7-hose; 8-drainage pipe; 9-clamp II; 10-pumping pump; 11-backflow pipe; 12-clamp III; 13-refrigerant conveying pipe; 14-thermal insulation cotton; 15-refrigeration machine; 16-temperature sensor; 17-water flow speed sensor; 18-high-definition camera; 19-data acquisition instrument; 20-bottom steel plate; 21-top steel plate; 22-jack; 23-bottom bolt; 24-top bolt; 25-data acquisition line. DETAILED DESCRIPTION

[0046] As Figures 1-7As shown, the cold region tunnel drainage pipe water flow freezing model comprehensive test system, the system includes an environmental test chamber 1 and placed in the environmental test chamber 1 top tank 2, bottom tank 3, refrigerator 15 and data acquisition instrument 19.

[0047] The top tank 2 is erected on the lifting support 4, one side of the top tank 2 is connected with the hose 7; the outlet end I of the hose 7 is connected with the drainage pipe 8, the outlet end II of the drainage pipe 8 extends into the bottom tank 3; the bottom tank 3 is provided with a water pump 10, the water pump 10 is connected with the top tank 2 through the return pipe 11; the outer surface of the drainage pipe 8 is spirally laid with the refrigerant conveying pipe 13, the outer surface of the refrigerant conveying pipe 13 is wrapped with a layer of thermal insulation cotton 14 to prevent the cold energy in the refrigerant conveying pipe 13 from being lost. The two ends of the refrigerant conveying pipe 13 are connected with the refrigerant outlet and the refrigerant inlet of the refrigerator 15 respectively, so that the refrigerant circulates in the loop formed by the refrigerant conveying pipe 13 and the refrigerator 15. The drainage pipe 8 is respectively provided with a temperature sensor 16, a water flow velocity sensor 17 and a high-definition camera 18; the data acquisition instrument 19 is electrically connected with the temperature sensor 16, the water flow velocity sensor 17 and the high-definition camera 18 through the data acquisition line 25.

[0048] The lifting support 4 includes a bottom steel plate 20, a top steel plate 21 and a jack 22. The bottom of the jack 22 is connected with the bottom steel plate 20 through the bottom bolt 23, and the top is connected with the top steel plate 21 through the top bolt 24; the top steel plate 21 is erected with the top tank 2.

[0049] The top tank 2 is a cuboid, a cube or a cylinder, the bottom surface is not greater than the top steel plate 21, and the volume is not less than 1 m 3 .

[0050] One side edge of the top tank 2 is provided with a water outlet I, the water outlet I is connected with the hose 7 through the stop valve 6. The stop valve 6 can control the amount of water flowing out by controlling the opening degree of the valve. The stop valve 6 and the hose 7 are connected through the clamp I 5 to prevent water leakage.

[0051] The hose 7 and the drainage pipe 8 are connected through the clamp II 9 to prevent water leakage. The drainage pipe 8 is a polyethylene pipe, the pipe diameter is 10-50 cm, and the length is 2-4 m.

[0052] The water outlet II of the return pipe 11 extends into the top tank 2, and the water inlet is connected with the water outlet III of the water pump 10 through the clamp III 12; the water suction port of the water pump 10 is lower than the liquid level of the bottom tank 3. The material of the return pipe 11 is ordinary PVC pipe, and the diameter is 10-15 cm.

[0053] The environmental test chamber 1 provides a temperature environment for the water flow freezing test of the drainage pipe 8, and the temperature environment is-30-40℃, and the temperature can be adjusted.

[0054] The length of the heat preservation cotton 14 is the same as the length of the drain pipe 8. The heat preservation cotton 14 is made of polyethylene foam and has a thickness of 6-10 cm.

[0055] The refrigerant conveying pipe 13 is made of low-temperature-resistant silica gel pipe and has a diameter of 1-2 cm.

[0056] The bottom-end water tank 3 is in the shape of a cuboid, a cube or a cylinder and has a volume of no less than 1 m 3 .

[0057] The temperature adjustment range of the refrigeration machine 15 is-20-0℃.

[0058] A plurality of temperature monitoring sections are arranged in the drain pipe 8 at intervals of 20 cm, and 37 temperature sensors 16 are arranged in a mesh shape at each temperature monitoring section for monitoring the water flow and air temperature in the drain pipe 8. A high-definition camera 18 is arranged at the top of each temperature monitoring section for monitoring the ice formation position and ice layer development in the drain pipe 8.

[0059] A plurality of water flow velocity monitoring sections are arranged in the drain pipe 8 at intervals of 20 cm, and 37 water flow velocity sensors 17 are arranged in a mesh shape at each water flow velocity monitoring section for monitoring the water flow velocity in the drain pipe 8. The temperature monitoring sections and the water flow velocity monitoring sections are spaced apart by 10 cm.

[0060] The use method of the cold region tunnel drain pipe water flow freezing model comprehensive test system comprises the following steps:

[0061] (1) Assemble the model test system:

[0062] ①In the environmental test chamber 1, lay a bottom steel plate 20 with a size of 2 m x 2 m; fix the bottom of the jack 22 to the bottom steel plate 20 through the bottom bolts 23 on the bottom steel plate 20; fix the top steel plate 21 to the top of the jack 22 through the top bolts 24 on the top of the jack 22; and finally, assemble the lifting support 4.

[0063] ②In the drain pipe 8, arrange 37 temperature sensors 16 in a mesh shape at intervals of 20 cm; arrange 37 water flow velocity sensors 17 in a mesh shape at intervals of 10 cm from the temperature sensors 16; arrange a high-definition camera 18 at the top position where the temperature sensors 16 are arranged; electrically connect all the temperature sensors 16, water flow velocity sensors 17 and high-definition cameras 18 to the data acquisition instrument 19 through the data acquisition lines 25; finally, assemble the monitoring and monitoring system; lay the refrigerant conveying pipe 13 on the outer surface of the drain pipe 8, and then wrap the drain pipe 8 with the refrigerant conveying pipe 13 with the heat preservation cotton 14.

[0064] ③Put the top tank 2 on the top steel plate 21 and fix it, install the water stop valve 6 at the water outlet I of the top tank 2, and put the hose 7 into the outlet of the water stop valve 6, and fix it with the clamp I 5; put the drain pipe 8 with temperature sensor 16, water flow rate sensor 17 and high-definition camera 18 installed into the other end of the hose 7, and fix it with the clamp II 9; connect the bottom tank 3 to the water outlet IV of the drain pipe 8; put the water pump 10 into the bottom tank 3, and make the water suction port of the water pump 10 as close to the bottom surface of the bottom tank 9 as possible; connect the return pipe 11 to the water outlet III of the water pump 10 through the clamp III 12, and put the water outlet II of the return pipe 11 into the top tank 2; finally, form the water flow circulation system.

[0065] In the water flow circulation system, the water flowing from the top tank 2 into the bottom tank 3 through the drain pipe 8 finally returns to the top tank 2 through the water pump 10 and the return pipe 11, achieving the purpose of water flow recycling.

[0066] ⑵Freezing test of the drain pipe 8:

[0067] i. Adjust the environmental temperature in the environmental test chamber 1; adjust the lifting height of the jack 22 to make the lifting support 4 reach the predetermined height; open the water stop valve 6 and control the opening and closing degree of the water stop valve 6 to make the water flow in the drain pipe 8 flow into the bottom tank 3 according to the preset flow rate and flow volume; open the water pump 10 to transport the water in the bottom tank 3 to the top tank 2.

[0068] ii. After the environmental temperature in the environmental test chamber 1 reaches uniformity, start the refrigeration machine 15; set the temperature of the refrigerant output by the refrigeration machine 15 to make the refrigerant flow in the refrigerant conveying pipe 13 and form a loop to cool the drain pipe 8.

[0069] iii. Start the monitoring and monitoring system, and use the data acquisition line 25 to collect the temperature, water flow rate, ice formation position and ice layer development data of each position in the drain pipe 8 in real time.

[0070] iv. When all the data are monitored to have no obvious change with time, stop the water flow circulation system by closing the water stop valve 6 and the water pump 10; at the same time, stop the temperature control system by closing the temperature control system and the refrigeration machine 15 of the environmental test chamber 1; finally, stop the monitoring and monitoring system by closing the data acquisition instrument 19.

[0071] ⑶ Continue the freezing test of the drain pipe 8 according to other settings:

[0072] The environmental temperature in the environmental test chamber 1, the height of the lifting support 4, the opening degree of the stop valve 6, and the temperature of the refrigerant output by the refrigerating machine 15 are reset to meet the water flow freezing test in the drain pipe under different environmental temperatures, different water flow velocities and water flow in the drain pipe, and different negative temperature conditions; and then the test is restarted according to step 2.

Claims

1. A comprehensive test system for a water flow freezing model of a drainage pipe of a tunnel in a cold region, characterized in that: The system comprises an environmental test chamber (1), a top water tank (2), a bottom water tank (3), a refrigerating machine (15) and a data acquisition instrument (19) arranged in the environmental test chamber (1); the top water tank (2) is arranged on a lifting support (4), and one side of the top water tank (2) is connected with a hose (7); an outlet end I of the hose (7) is connected with a drain pipe (8), and an outlet end II of the drain pipe (8) extends into the bottom water tank (3); a water pump (10) is arranged in the bottom water tank (3), and the water pump (10) is connected with the top water tank (2) through a return pipe (11); a refrigerant conveying pipe (13) is spirally arranged on the outer surface of the drain pipe (8), and the outer surface of the refrigerant conveying pipe (13) is wrapped with a layer of thermal insulation cotton (14); the two ends of the refrigerant conveying pipe (13) are connected with the refrigerant outlet and the refrigerant inlet of the refrigerating machine (15) respectively; the drain pipe (8) is respectively provided with a temperature sensor (16), a water flow rate sensor (17) and a high-definition camera (18); the data acquisition instrument (19) is electrically connected with the temperature sensor (16), the water flow rate sensor (17) and the high-definition camera (18) through data acquisition lines (25); a plurality of temperature monitoring sections are arranged in the drain pipe (8) every 20 cm, and 37 temperature sensors (16) are arranged in a meshed manner at each temperature monitoring section; and the high-definition camera (18) is arranged at the top end of each temperature monitoring section.

2. The cold region tunnel drainage pipe water flow freezing model comprehensive test system according to claim 1, characterized in that: The lifting support (4) comprises a bottom steel plate (20), a top steel plate (21) and a jack (22); the bottom of the jack (22) is connected with the bottom steel plate (20) through bottom bolts (23), and the top of the jack (22) is connected with the top steel plate (21) through top bolts (24); and the top steel plate (21) is arranged with the top water tank (2).

3. The cold region tunnel drainage pipe water flow freezing model comprehensive test system according to claim 2, characterized in that: The top water tank (2) is cuboid, cubic or cylindrical in shape, with the bottom surface no larger than the top surface steel plate (21) and a volume no less than 1 m 3 .

4. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: One side edge of the top water tank (2) is provided with a water outlet I, and the water outlet I is connected with the hose (7) through a stop valve (6); the stop valve (6) and the hose (7) are connected through a clamp I (5).

5. The cold region tunnel drainage pipe water flow freezing model comprehensive test system according to claim 1, characterized in that: The hose (7) and the drain pipe (8) are connected through a clamp II (9).

6. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: The water outlet II of the return pipe (11) extends into the top water tank (2), and the water inlet is connected with the water outlet III of the water pump (10) through a clamp III (12); and the water suction port of the water pump (10) is lower than the liquid level of the bottom water tank (3).

7. The cold region tunnel drainage pipe water flow freezing model comprehensive test system according to claim 1, characterized in that: The temperature environment of the environmental test chamber (1) is -30-40℃.

8. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: The length of the thermal insulation cotton (14) is the same as the length of the drain pipe (8).

9. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: The bottom end water tank (3) is in the shape of a cuboid, a cube or a cylinder, with a volume not less than 1 m 3 .

10. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: The temperature regulation range of the refrigerating machine (15) is -20-0℃.

11. The cold region tunnel drainage pipe water flow freezing model comprehensive test system of claim 1, wherein: A plurality of water flow velocity monitoring sections are arranged in the drain pipe (8) every 20 cm, and 37 water flow rate sensors (17) are arranged in a meshed manner at each water flow velocity monitoring section, and the temperature monitoring section and the water flow velocity monitoring section are separated by 10 cm.

12. The use method of the cold region tunnel drain pipe water flow freezing model comprehensive test system according to claim 1, comprising the following steps:

1. Assembling the model test system: ①In the environmental test chamber (1), lay a bottom steel plate (20) with a size of 2 m x 2 m; fix the bottom of the jack (22) to the bottom steel plate (20) through the bottom bolts (23); fix the top steel plate (21) to the top of the jack (22) through the top bolts (24); finally, assemble the lifting support (4); ②In the drain pipe (8), arrange 37 temperature sensors (16) in a mesh shape every 20 cm; arrange 37 water flow velocity sensors (17) in a mesh shape at intervals of 10 cm from the temperature sensors (16); install a high-definition camera (18) at the vertex position where the temperature sensors (16) are installed; electrically connect all the temperature sensors (16), water flow velocity sensors (17), and high-definition cameras (18) to the data acquisition instrument (19) through the data acquisition line (25); finally, assemble the monitoring and monitoring system; lay the refrigerant delivery pipe (13) on the outer surface of the drain pipe (8), and then wrap the drain pipe (8) with the refrigerant delivery pipe (13) with thermal insulation cotton (14); ③Place and fix the top water tank (2) on the top steel plate (21), install the stop valve (6) at the water outlet I of the top water tank (2), and sleeve the hose (7) at the outlet of the stop valve (6), and fix it with the clamp I (5); sleeve the drain pipe (8) with the temperature sensor (16), water flow velocity sensor (17), and high-definition camera (18) installed at the other end of the hose (7), and fix it with the clamp II (9); connect the bottom water tank (3) to the water outlet IV of the drain pipe (8); put the water pump (10) into the bottom water tank (3); connect the return pipe (11) to the water outlet III of the water pump (10) through the clamp III (12), and place the water outlet II of the return pipe (11) in the top water tank (2); finally, assemble the water flow circulation system; 2. Freezing test of the drain pipe (8): ⅰAdjust the environmental temperature in the environmental test chamber (1); adjust the lifting height of the jack (22) to make the lifting support (4) reach the predetermined height; open the stop valve (6) and control the opening degree of the stop valve (6) to make the water flow in the drain pipe (8) flow to the bottom water tank (3) according to the preset flow rate and flow; open the water pump (10) to deliver the water in the bottom water tank (3) to the top water tank (2); ⅱAfter the environmental temperature in the environmental test chamber (1) reaches uniformity, start the refrigeration machine (15); set the temperature of the refrigerant output by the refrigeration machine (15) to make the refrigerant flow in the refrigerant delivery pipe (13) and form a loop to cool the drain pipe (8); ⅲStart the monitoring and monitoring system, and use the data acquisition line (25) to collect the temperature, water flow velocity, ice formation position, and ice layer development data of each position in the drain pipe (8) in real time; When all the data are monitored to have no obvious change over time, the water stop valve (6) and the water pump (10) are closed, so that the water flow circulation system stops working; meanwhile, the temperature control system of the environmental test chamber (1) and the refrigerator (15) are closed, so that the temperature control system stops working; finally, the data acquisition instrument (19) is closed, so that the monitoring and monitoring system stops working; (3) continue the drain pipe (8) freezing test according to other settings: The environmental temperature in the environmental test chamber (1), the height of the lifting support (4), the opening degree of the water stop valve (6), and the temperature of the refrigerant output by the refrigerator (15) are reset to meet the water flow freezing test in the drain pipe under different environmental temperatures, different water flow velocities and water flow rates in the drain pipe, and different negative temperature conditions; then the test is restarted according to the step (2).

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