A ventilated cold region tunnel longitudinal temperature distribution experimental device

Abstract

The invention discloses a ventilation type cold region tunnel longitudinal temperature distribution experimental device, comprising a constant temperature storehouse, a wind speed control device, a tunnel model, a constant temperature tank, a wind speed sensor, a temperature sensor, and a data acquisition system. The constant temperature storehouse is used to provide a cold source, the wind speed control device is used to provide wind energy, the tunnel model is composed of tunnel model units, the constant temperature tank is composed of constant temperature tank units, and the constant temperature tank units are independently arranged, the constant temperature tank units are wrapped on the outer surface of the tunnel model units, and the wind speed sensor and the temperature sensor are arranged in the tunnel model and are electrically connected to the data acquisition system. The experimental device for testing the longitudinal temperature distribution law of cold region tunnels under unidirectional or bidirectional ventilation conditions provided by the invention can simulate the distribution law of the longitudinal temperature of long tunnels under conditions of different tunnel lengths, different tunnel entrance temperatures, different tunnel entrance wind speeds, different surrounding rock initial temperatures, etc., and can provide accurate parameters for the laying length of the insulation layer of long tunnels in cold regions.

Description

Technical Field

[0001] The invention relates to a cold region tunnel experimental device, in particular to a ventilation type cold region tunnel longitudinal temperature distribution experimental device. Background Art

[0002] In high-latitude areas such as the northwest and northeast of my country, as well as high-altitude areas in western my country, more and more tunnels are being built, and the length of tunnels is getting longer and longer. Taking the highway tunnels in the western Sichuan plateau as an example, there are more than 152 kilometers / 88 tunnels built and under construction. In the foreseeable future, the number of tunnels in the western Sichuan plateau will reach 304 kilometers / 162; and for the Ya'an-Linzhi section of the Sichuan-Tibet Railway, the proportion of tunnels even exceeds 90%. It is preliminarily estimated that there are more than 7 tunnels with a length of more than 30km, and some tunnels are above 4200m above sea level. At present, for medium and short tunnels in cold regions, the same anti-freeze and thaw measures are usually adopted in the whole tunnel, and the thickness of the insulation layer is the same. Although with the increasing number of long tunnels, the method of laying insulation layers at both ends of long tunnels is also considered, but the laying length is basically based on foreign empirical formulas or engineering analogies, which does not conform to the actual situation in my country. There are no reference technical specifications and materials for the design parameters of anti-freeze and thaw in cold region tunnels. The method of conducting field tests on on-site tunnels can obtain the most realistic and practical results, and can provide accurate parameters for the length of the insulation layer. However, there are two problems. First, the test results can only represent the longitudinal temperature distribution law of a specific tunnel. There are many factors that affect the longitudinal temperature distribution law of the tunnel, such as the average temperature of the coldest month at the tunnel entrance, natural wind speed, wind direction, tunnel length, etc., and the promotion and application have certain limitations. In addition, field tests in cold areas require a lot of manpower, material and financial resources, and the project volume is large, and the economic practicality is general. Second, only the data test results after the completion and opening of the tunnel can represent the actual longitudinal temperature distribution law of the tunnel. The field test has serious post-satisfaction and is difficult to meet the actual needs of the design. Theoretical analysis is too idealistic, with too many assumptions, and it is difficult to meet the needs of the project. Even if it can meet the needs, it needs to be verified. Therefore, in general, there is still a lack of an effective means to study the longitudinal temperature distribution law of tunnels in cold areas. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a ventilated cold-region tunnel longitudinal temperature distribution experimental device, through which the distribution law of the longitudinal temperature of a long tunnel under conditions of different tunnel lengths, different tunnel entrance temperatures, different tunnel entrance wind speeds, different surrounding rock initial temperatures, etc. can be simulated, thereby providing a basis for the design of the laying length of the insulation layer of a long tunnel in cold regions.

[0004] The objective of the present invention is achieved through the following technical solutions: a ventilated cold zone tunnel longitudinal temperature distribution experimental device, comprising a constant temperature storehouse, a wind speed control device, a tunnel model, a constant temperature tank, a wind speed sensor, a temperature sensor, and a data acquisition system, wherein the constant temperature storehouse is used to provide a cold source, the wind speed control device is arranged in the constant temperature storehouse and is used to provide wind energy, the tunnel model is formed by splicing tunnel model units and is connected to the constant temperature storehouse, the constant temperature tank is composed of constant temperature tank units and the constant temperature tank units are independently arranged, the constant temperature tank unit is wrapped on the outer surface of the tunnel model unit, the wind speed sensor and the temperature sensor are arranged in the tunnel model and are both electrically connected to the data acquisition system.

[0005] Preferably, the constant temperature warehouse includes a warehouse and a device for controlling the temperature in the warehouse, and a circular hole consistent with the inner diameter of the tunnel model is provided on one side of the warehouse; the wind speed control device includes an axial flow fan, the central axis of the axial flow fan coincides with the central axis of the tunnel model, and the outer dimensions of the axial flow fan are larger than the circular hole size.

[0006] Preferably, the constant temperature storehouse is provided with one and is connected to one end of the tunnel model, or is provided with two and is respectively connected to the two ends of the tunnel model.

[0007] Preferably, the tunnel model adopts PVC pipes, the tunnel model units are connected by male and female joints, and the connections are sealed by sealants.

[0008] Preferably, the thermostatic tank unit is cylindrical, and the inner wall of the thermostatic tank unit is made of 0.2-0.5 mm thick aluminum material. The thermostatic tank unit includes a water storage tank, and the water storage tank is provided with inlet and outlet water pipes. The inlet and outlet water pipes are composed of a horizontal pipe and two vertical pipes, and the two ends of the horizontal pipe are respectively connected to the two vertical pipes.

[0009] Preferably, a plurality of connecting rods are provided at one end of the thermostatic bath unit, and connecting holes corresponding to the connecting rods are provided at the other end thereof, and the length of the connecting rods is not less than half the length of the thermostatic bath unit.

[0010] Preferably, the male and female joints between the tunnel model units are arranged in a constant temperature bath unit.

[0011] Preferably, there are several wind speed sensors and temperature sensors, which are evenly arranged. The temperature sensors are arranged on the upper and lower sides of the tunnel model. One of the wind speed sensors is arranged at one end of the tunnel model and is used to detect the wind speed of the wind speed control device.

[0012] Preferably, a wind speed sensor and a temperature sensor are installed at one end of each tunnel model unit.

[0013] Preferably, the cross-sectional size of the tunnel model is 1:50, and the length of each tunnel model unit is 3m.

[0014] The beneficial effects of the present invention are as follows: by using the experimental device for testing the longitudinal temperature distribution law of cold-region tunnels under one-way or two-way ventilation conditions provided by the present invention, the longitudinal temperature distribution law of long tunnels under conditions of different tunnel lengths, different tunnel entrance temperatures, different tunnel entrance wind speeds, different surrounding rock initial temperatures, etc. can be simulated, and accurate parameters can be provided for the laying length of the insulation layer of long tunnels in cold regions. On the one hand, it can effectively prevent the occurrence of freezing damage to the tunnel lining and ensure driving safety; on the other hand, it can effectively reduce construction costs, improve economic efficiency, and provide a basis for the construction and design of long tunnels in cold regions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a one-way ventilation experimental device;

[0016] Figure 2 for Figure 1 Longitudinal section in

[0017] Figure 3 It is a two-way ventilation experimental device;

[0018] Figure 4 for Figure 3 Longitudinal section in

[0019] Figure 5 A longitudinal cross-sectional view of the experimental device in the present invention;

[0020] Figure 6 It is a thermostatic bath model;

[0021] Figure 7 It is a schematic diagram of the structure of the thermostatic bath model unit;

[0022] Figure 8 The tunnel model. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0024] Example 1

[0025] like Figure 1-6As shown, a ventilation type cold zone tunnel longitudinal temperature distribution experimental device includes a constant temperature storehouse 1 and a wind speed control device; the constant temperature storehouse 1 is provided with a refrigeration system and a storehouse, and the temperature in the storehouse can be accurately controlled by the refrigeration system. A circular hole 11 is opened on one side of the storehouse (a hole in the shape of a tunnel can also be opened to make the experiment more realistic), and the size of the circular hole 11 is consistent with the inner diameter of the tunnel model. The wind speed control device is installed in the storehouse at a distance of 10-20cm from the circular hole 11. The central axis of the axial flow fan 12 coincides with the central axis of the tunnel. The external dimensions of the axial flow fan 12 are larger than the circular hole 11 on the storehouse wall, so as to ensure that a uniform parallel wind beam can be input into the tunnel model, and the axial flow fan 12 simulates natural ventilation. The axial flow fan 12 has different gears, and can form winds of different intensities by adjusting. The axial flow fan 12 is used to transport the cold air in the warehouse forward at a certain speed, thereby forming winds of different wind speeds. The cold air blows toward the tunnel through the circular hole 11 on the wall of the warehouse. A wind speed sensor 3 and a temperature sensor 4 are installed at the entrance of the tunnel. The wind speed value entering the tunnel can be tested by the wind speed sensor 3, and the temperature value of the cold air entering the tunnel can be known by the temperature sensor 4. The wind speed at the tunnel entrance can be adjusted by the axial flow fan 12, and the temperature at the tunnel entrance can be adjusted by adjusting the refrigeration system. The temperature range of the refrigeration system is 0~-35℃, which can cover the average temperature value of the coldest month in any high-latitude and high-altitude area in my country.

[0026] The tunnel model is simulated by a round thick-walled PVC pipe, and the cross-sectional size is considered to be 1:50. The tunnel model is composed of multiple tunnel model units 2. Each model unit is 3m long. Male and female interfaces are set at both ends of the model. It can be assembled into a tunnel model of any length. The joints are sealed with sealant. Temperature sensors 4 are arranged on the upper and lower sides of the inner wall of the tunnel. The longitudinal distance of the temperature sensor 4 is considered to be 3m. Wind speed sensors 3 are arranged at the same position, and the leads of all temperature sensors 4 and wind speed sensors 3 are connected to the data acquisition box. The tunnel model is placed on a bracket, and the height of the model should be consistent with the height of the tunnel axis and the center of the warehouse opening.

[0027] The thermostatic bath is composed of thermostatic bath units 5, which are controlled by a constant temperature cold bath. Each thermostatic bath is 3m long. The tunnel model is installed in the thermostatic bath. The thermostatic bath unit 5 is cylindrical, and the inner wall of the thermostatic bath unit 5 is made of 0.3mm thick aluminum. The thermostatic bath unit 5 includes a water storage tank, which is provided with an inlet and outlet water pipe. The inlet and outlet water pipe consists of a horizontal pipe and two vertical pipes. The two ends of the horizontal pipe are connected to the two vertical pipes respectively. This allows the thermostatic bath to be close to the tunnel model to ensure the simulation of the thermostatic bath.

[0028] Furthermore, a plurality of connecting rods are provided at one end of the thermostatic bath unit 5, and a connecting hole corresponding to the connecting rod is provided at the other end thereof, and the length of the connecting rod is not less than half the length of the thermostatic bath unit 5. The connecting parts between the thermostatic bath units 5 are made of a material with good thermal conductivity, so that heat is transferred between the thermostatic bath units 5 in contact, so that the measured data is more in line with reality.

[0029] The temperature of the surrounding rock outside the tunnel can be simulated by the thermostatic bath, and the actual initial temperature of the surrounding rock of the tunnel can be simulated by controlling the temperature of the thermostatic bath. Each thermostatic bath can be independently temperature-controlled, and thus the initial ground temperature of the surrounding rock in the longitudinal direction of the tunnel can be simulated to simulate different tunnel burial depths.

[0030] The data acquisition system is connected to the wind speed sensor 3 and the temperature sensor 4 in the model. It mainly collects the temperature data along the longitudinal direction of the tunnel and the wind speed data at different depths during the experiment. The data can be collected automatically throughout the experiment. The collection frequency can be determined according to actual needs.

[0031] The whole experimental process is:

[0032] 1. Equip a constant temperature warehouse 1, open a hole on the cold side wall as required, install the wind speed control device in place in the warehouse, and debug it to ensure that the negative temperature required by the experiment can be achieved.

[0033] 2. Process and manufacture assembled tunnel models as required. The length of the tunnel model is mainly 3m per section to facilitate transportation and installation.

[0034] 3. Install a constant temperature cold bath and set it aside.

[0035] 4. Assemble the tunnel model in a constant temperature bath and install temperature and wind speed measuring points as required during the assembly process.

[0036] 5. Turn on the constant temperature bath system and data acquisition test system. After the temperature around the tunnel model reaches the experimental requirements and stabilizes, prepare the constant temperature warehouse 1.

[0037] 6. Open the constant temperature warehouse 1. After the temperature in the warehouse drops to the experimental requirement, turn on the wind speed control device, remove the partitions on the side wall holes of the warehouse, and allow cold air to enter the model tunnel for the experiment. The wind speed is adjusted step by step from small to large.

[0038] 7. When the temperature in the tunnel model is basically stable, the experiment under this condition ends. Then adjust the wind force and conduct the next level of wind speed experiment. When all the required levels of wind speed have been completed, stop this experiment.

[0039] 8. Adjust the temperature of the constant temperature bath and constant temperature warehouse 1 according to the experimental requirements and conduct the next experiment.

[0040] 9. Conduct corresponding experiments by assembling devices with different tunnel lengths.

[0041] Example 2

[0042] like Figure 3-7 As shown, a ventilation type cold region tunnel longitudinal temperature distribution experimental device includes a constant temperature warehouse 1, which is composed of a refrigeration system and a warehouse. There are two rooms in total, one main and one auxiliary. The main constant temperature warehouse 1 is fixed, and the auxiliary constant temperature warehouse 1 is mobile and can be moved freely. The temperature in the warehouse can be accurately controlled by the refrigeration system. A circular hole 11 is opened on one side of the warehouse (in order to make the experiment more realistic, it can also be opened in the shape of a tunnel). The size of the circular hole 11 is consistent with the inner diameter of the tunnel model. Pulleys are installed at the four corners of the lower part of the auxiliary constant temperature warehouse 1, which can be moved freely, thereby providing a more convenient cold source for the experiment.

[0043] Wind speed control device, in the warehouse, an axial flow fan 12 is installed at a distance of 10-20cm from the circular hole 11. The central axis of the axial flow fan 12 coincides with the central axis of the tunnel. The external dimensions of the axial flow fan 12 are larger than the circular hole 11 on the warehouse wall, ensuring that a uniform parallel wind beam can be input into the tunnel model, and natural ventilation is simulated by the axial flow fan 12. The axial flow fan 12 has different gears, and winds of different intensities can be formed by adjustment. The axial flow fan 12 is used to transport the cold air in the warehouse forward at a certain speed, thereby forming winds of different wind speeds. The cold air blows toward the tunnel through the circular hole 11 on the warehouse wall. A wind speed sensor 3 and a temperature sensor 4 are installed at the entrance of the tunnel. The wind speed value entering the tunnel can be tested by the anemometer, and the temperature value of the cold air entering the tunnel can be known by the temperature sensor 4. The wind speed at the tunnel entrance can be adjusted by the axial flow fan 12, and the air temperature at the tunnel entrance can be adjusted by adjusting the refrigeration system. The temperature range of the refrigeration system is 0~-35℃, which can cover the average temperature of the coldest month in any high latitude and high altitude area in my country.

[0044] The tunnel model is simulated by a round thick-walled PVC pipe, and the cross-sectional size is considered to be 1:50. The tunnel model is composed of multiple tunnel model units 2, each model unit is 3m long, and male and female interfaces are set at both ends of the model. It can be assembled into a tunnel model of any length. The joints are sealed with sealant. Temperature sensors 4 are arranged on the upper and lower sides of the inner wall of the tunnel. The longitudinal distance of the temperature sensor 4 is considered to be 3m. Wind speed sensors 3 are arranged at the same position, and the leads of all temperature sensors 4 and anemometers are connected to the data acquisition box. The tunnel model is placed on a bracket, and the height of the model should be consistent with the height of the tunnel axis and the center of the warehouse opening.

[0045] The thermostatic bath adopts a constant temperature cold bath for temperature control, and each thermostatic bath is 3m long. The thermostatic bath unit 5 is cylindrical, and the inner wall of the thermostatic bath unit 5 is made of 0.3mm thick aluminum. The thermostatic bath unit 5 includes a water storage tank, and the water storage tank is provided with an inlet and outlet water pipe, and the inlet and outlet water pipe is composed of a horizontal pipe and two vertical pipes, and the two ends of the horizontal pipe are respectively connected to the two vertical pipes. The inlet and outlet water pipe is composed of a horizontal pipe and two vertical pipes, which can increase the water pressure inside the thermostatic bath, so that the thermostatic bath can be close to the tunnel model to ensure the simulation of the thermostatic bath.

[0046] Furthermore, a plurality of connecting rods 51 are provided at one end of the thermostatic bath unit 5, and a connecting hole 52 corresponding to the connecting rod 51 is provided at the other end thereof, and the length of the connecting rod 51 is not less than half the length of the thermostatic bath unit 5. The connecting parts between the thermostatic bath units 5 are made of a material with good thermal conductivity, so that heat is transferred between the thermostatic bath units 5 in contact, so that the measured data is more in line with reality.

[0047] The temperature of the surrounding rock outside the tunnel can be simulated by the thermostatic bath, and the actual initial temperature of the surrounding rock of the tunnel can be simulated by controlling the temperature of the thermostatic bath. Each thermostatic bath can be independently temperature-controlled, and thus the initial ground temperature of the surrounding rock in the longitudinal direction of the tunnel can be simulated to simulate different tunnel burial depths.

[0048] The data acquisition system is connected to the wind speed sensor 3 and the temperature sensor 4 in the model. It mainly collects the temperature data along the longitudinal direction of the tunnel and the wind speed data at different depths during the experiment. The data can be collected automatically throughout the experiment. The collection frequency can be determined according to actual needs.

[0049] The whole experimental process is:

[0050] 1. Equip a constant temperature warehouse 1, open a hole on the cold side wall as required, install the wind speed control device in place in the warehouse, and debug it to ensure that the negative temperature required by the experiment can be achieved.

[0051] 2. Process and manufacture assembled tunnel models as required. The length of the tunnel model is mainly 3m per section to facilitate transportation and installation.

[0052] 3. Install a constant temperature cold tank and set it aside.

[0053] 4. Assemble the tunnel model in a constant temperature bath and install temperature and wind speed sensors as required during the assembly process.

[0054] 5. Turn on the constant temperature bath system and data acquisition test system. After the temperature around the tunnel model reaches the experimental requirements and stabilizes, prepare the constant temperature warehouse 1.

[0055] 6. According to the temperature simulation values ​​at both ends of the tunnel, open the constant temperature warehouse 1 and set the corresponding temperature value. After the temperature in the warehouse drops to the experimental requirement, open the wind speed control devices according to the experimental requirements, remove the partitions of the warehouse side wall holes, and allow cold air to enter the model tunnel for experiments. The wind speed is adjusted step by step from small to large.

[0056] 7. When the temperature in the tunnel model is basically stable, the experiment under this condition ends. Then adjust the wind force and conduct the next level of wind speed experiment. When all the required wind speed levels are completed, stop this experiment.

[0057] 8. Adjust the temperature of the constant temperature bath and constant temperature warehouse 1 according to the experimental requirements and conduct the next experiment.

[0058] 9. Conduct corresponding experiments by assembling devices with different tunnel lengths.

[0059] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A ventilation type cold region tunnel longitudinal temperature distribution experimental device, characterized in that: It includes a constant temperature warehouse, a wind speed control device, a tunnel model, a constant temperature tank, a wind speed sensor, a temperature sensor, and a data acquisition system. The constant temperature warehouse is used to provide a cold source. The wind speed control device is arranged in the constant temperature warehouse and is used to provide wind energy. The tunnel model is composed of tunnel model units and is connected to the constant temperature warehouse. The constant temperature tank is composed of constant temperature tank units and the constant temperature tank units are independently arranged. The constant temperature tank unit is wrapped on the outer surface of the tunnel model unit. The wind speed sensor and the temperature sensor are arranged in the tunnel model and are electrically connected to the data acquisition system. The thermostatic tank unit is cylindrical, and the inner wall of the thermostatic tank unit is made of 0.2-0.5 mm thick aluminum material. The thermostatic tank unit includes a water storage tank, and the water storage tank is provided with an inlet and outlet water pipe, and the inlet and outlet water pipe is composed of a horizontal pipe and two vertical pipes, and the two ends of the horizontal pipe are respectively connected to the two vertical pipes; A plurality of connecting rods are provided at one end of the thermostatic bath unit, and connecting holes corresponding to the connecting rods are provided at the other end thereof, and the length of the connecting rods is not less than half the length of the thermostatic bath unit; The male and female joints between the tunnel model units are arranged in the constant temperature bath unit; The constant temperature warehouse is provided with one and connected to one end of the tunnel model, or is provided with two and connected to both ends of the tunnel model respectively; The constant temperature warehouse comprises a warehouse and a wind speed control device for controlling the temperature in the warehouse, a circular hole having the same inner diameter as the tunnel model is provided on one side of the warehouse; the wind speed control device comprises an axial flow fan, the central axis of the axial flow fan coincides with the central axis of the tunnel model, and the outer dimensions of the axial flow fan are larger than the circular hole dimensions; The wind speed sensors and temperature sensors are provided in multiple numbers and are evenly arranged. The temperature sensors are arranged on the upper and lower sides of the tunnel model. One of the wind speed sensors is arranged at one end of the tunnel model and is used to detect the wind speed of the wind speed control device. A wind speed sensor and a temperature sensor are installed at one end of each tunnel model unit; In the warehouse, an axial flow fan is installed 10-20cm away from the circular hole. The central axis of the axial flow fan coincides with the central axis of the tunnel. The external dimensions of the axial flow fan are larger than the circular hole on the warehouse wall, ensuring that a uniform parallel wind beam can be input into the tunnel model, simulating natural ventilation through the axial flow fan. The axial flow fan has different gear levels, and can form winds of different intensities by adjusting them. The axial flow fan is used to transport the cold air in the warehouse forward at a certain speed, thereby forming winds of different wind speeds. The cold air blows toward the tunnel through the circular holes on the warehouse wall. Wind speed sensors and temperature sensors are installed at the entrance of the tunnel. The wind speed sensor can be used to test the wind speed value entering the tunnel, and the temperature sensor can be used to know the temperature value of the cold air entering the tunnel. The wind speed at the tunnel entrance can be adjusted by an axial flow fan, and the air temperature at the tunnel entrance can be adjusted by adjusting the refrigeration system. The temperature range of the refrigeration system is 0~-35℃.

2. According to claim 1, a ventilation type cold region tunnel longitudinal temperature distribution experimental device is characterized by: The tunnel model adopts PVC pipes, and the units of the tunnel model are connected by male and female joints, and the connections are sealed by sealants.

3. The longitudinal temperature distribution experimental device for a ventilated cold region tunnel according to claim 1 is characterized by: The cross-sectional size of the tunnel model is 1:50, and the length of each tunnel model unit is 3m.

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