A ground temperature monitoring device and construction method

Abstract

This application relates to the field of geothermal energy, and particularly to a ground temperature monitoring device and a construction method. It includes signal cables located in a monitoring well, which are composed of multiple sections connected end to end. Each section of the signal cable is provided with a temperature sensor, and the temperature sensor is connected to the signal cable. At least one first baffle component for reducing air convection is provided on the outer surface of each temperature sensor. The first baffle component of this application can reduce the air convection in the monitoring well, making the air convection at the temperature sensor the weakest, reducing the influence of air convection on the temperature, improving the accuracy of data monitoring of each temperature sensor, making the positions of different underground depths represented by different temperatures more accurate, so as to obtain more accurate calculation results to evaluate the sustainability of ground source heat pump exploitation and guide the parameter design effect of ground source heat pump exploitation.

Description

Technical Field

[0001] This application relates to the field of geothermal energy, and particularly to a ground temperature monitoring device and a construction method thereof. Background Art

[0002] The ground temperature field is the manifestation of the earth's internal heat energy on the earth's crust through rocks with different thermal conductivities. Geothermal energy resources are renewable energy sources, and it is of great significance to develop shallow geothermal energy resources. In recent years, geothermal energy resources have mainly been developed using ground-source heat pumps.

[0003] Dig a plurality of monitoring well groups in the shallow ground temperature field, and install a plurality of temperature sensors in the monitoring well groups to monitor the ground temperature at different depths underground. Monitor the ground temperature field and calculate the impact on the ground temperature field after the ground-source heat pump extracts shallow geothermal energy.

[0004] In the related art, a cable is used to connect a plurality of temperature sensors together and the cable is placed in the monitoring well. However, due to the different ground temperatures of different depths underground, and the convection of air and water media in the monitoring well, the temperature of different depths underground will also be driven to form convection, resulting in inaccurate data monitored by the temperature sensors at each layer underground, and thus the formation depth corresponding to each temperature cannot be accurately monitored.

[0005] Regarding the above-mentioned related art, the inventor believes that due to the different temperatures at different depths underground, and the convection of air and water media in the monitoring well, the temperature at different depths will also be driven to form convection, resulting in inaccurate data monitored by the temperature sensors at different formations, and the underground depth corresponding to each temperature cannot be accurately monitored. Summary of the Invention

[0006] In order to solve the problem that the temperature between different formations will form convection with the convection of air and water media in the monitoring well, resulting in inaccurate data monitored by the temperature sensors at each layer and the underground depth corresponding to each temperature cannot be accurately monitored, this application provides a ground temperature monitoring device and a construction method thereof.

[0007] In a first aspect, a ground temperature monitoring device provided by this application adopts the following technical solution:

[0008] A ground temperature monitoring device is located in a monitoring well and includes a plurality of signal cables connected end to end. Each of the signal cables is provided with a temperature sensor, the temperature sensor is connected to the signal cable, and at least one first baffle component for reducing air convection is provided on the outer surface of each temperature sensor.

[0009] By adopting the above technical solution, the temperature sensor transmits signals through signal cables. In the monitoring well, air convection can cause temperature convection between different depths underground. A first baffle assembly is provided at each end of the temperature sensor. The first baffle assembly can reduce the air convection in the monitoring well, making the air convection at the temperature sensor the weakest, reducing the influence of air convection on temperature, improving the accuracy of data monitoring of each temperature sensor, making the positions of the formation depths represented by different temperatures more accurate, and thus obtaining a more accurate calculation result to evaluate the sustainability of the ground source heat pump exploitation and guiding the parameter design of the ground source heat pump exploitation.

[0010] Optionally, a ground temperature monitoring device further includes a first protective tube with a sealed bottom. The plurality of temperature sensors are located inside the first protective tube, and the first baffle assembly is located between the temperature sensors and the first protective tube.

[0011] By adopting the above technical solution, the bottom of the first protective tube is a sealed structure, which can prevent groundwater from entering the first protective tube and affecting the accuracy of temperature sensor data monitoring. The first baffle assembly can reduce the air convection inside the first protective tube, thereby ensuring that the temperatures between different depths of the underground formation do not form convection with the flowing air, and improving the accuracy of temperature sensor data monitoring.

[0012] Optionally, a ground temperature monitoring device further includes a second protective tube with an open-bottom structure and a plurality of second baffle assemblies. The first protective tube is located inside the second protective tube, and the second baffle assemblies are located inside the second protective tube and arranged on the outer surface of the first protective tube.

[0013] By adopting the above technical solution, the bottom of the second protective tube is an open-bottom structure, enabling groundwater to enter the second protective tube, which can ensure the pressure balance in the monitoring well and prevent the monitoring well from collapsing due to pressure imbalance. The second baffle assembly can reduce the air convection inside the second protective tube and reduce the influence of air on temperature during the process of the formation temperature being transmitted into the second protective tube, thereby ensuring the accuracy of temperature sensor data monitoring.

[0014] Optionally, the first baffle assembly includes an annular first installation body and a first baffle member for reducing air convection. The first installation body and the first baffle member are connected, and the first installation body is sleeved on the temperature sensor.

[0015] By adopting the above technical solution, the first baffle member is sleeved on the temperature sensor through the first installation body, thereby reducing the air convection inside the first protective tube and enabling the temperature sensor to accurately monitor the formation temperature.

[0016] Optionally, the second baffle assembly includes at least two baffle sheets circumferentially arranged on the outer surface of the first protective tube, and there is a gap between adjacent two baffle sheets.

[0017] By adopting the above technical solution, at least two baffle plates are of a split structure. When installing the second partition assembly in the second protection tube, there is a gap between two adjacent baffle plates, and the baffle plates will move up and down to release the pressure in the second protection tube during installation, facilitating the installation of the second partition assembly.

[0018] Optionally, the baffle plate is made of a flexible material.

[0019] By adopting the above technical solution, when the baffle plate made of a flexible material is installed in the second protection tube, it forms a moving state to release the pressure in the second protection tube.

[0020] Optionally, a ground temperature monitoring device further includes a load-bearing rope, and the load-bearing rope is connected to the signal cable.

[0021] By adopting the above technical solution, multiple temperature sensors are connected in sequence to form a longer length, resulting in an increase in the overall weight. The load-bearing rope can support multiple sections of signal cables and multiple sequentially connected temperature sensors to prevent the multiple sections of signal cables and multiple temperature sensors from breaking.

[0022] In a second aspect, a construction method of a ground temperature monitoring device provided in this application adopts the following technical solution:

[0023] A construction method of a ground temperature monitoring device includes the following steps:

[0024] S100. Drill multiple monitoring wells on the ground;

[0025] S200. Place a protection tube and a partition assembly in each monitoring well, and sleeve the partition assembly outside the protection tube;

[0026] S300. Place multiple sections of signal cables and multiple temperature sensors in the protection tube to monitor the temperature of the formation.

[0027] By adopting the above technical solution, multiple sections of signal cables and multiple temperature sensors are placed in the protection tube of the monitoring well to monitor the temperature of the formation at different depths. The partition assembly can reduce the air convection inside the monitoring well and outside the protection tube, making the monitoring data of each temperature sensor more accurate.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. The temperature sensor of the present application transmits signals through a signal cable. In the monitoring well, air convection can cause temperature convection between different depths underground. The first baffle assembly can reduce the air convection in the monitoring well, reduce the influence of air convection on temperature, improve the accuracy of data monitoring of each temperature sensor, make the position of the formation depth represented by different temperatures more accurate, and thus obtain a more accurate calculation result to evaluate the sustainability of ground source heat pump exploitation and guide the parameter design of ground source heat pump exploitation.

[0030] 2. The bottom of the first protective tube of the present application is a sealed structure, which can prevent groundwater from entering the first protective tube and affecting the accuracy of temperature sensor data monitoring. The first baffle assembly can reduce the air convection in the first protective tube, thereby ensuring that the temperature between different depths of the underground formation does not form convection with the flowing air, and improving the accuracy of temperature sensor data monitoring.

[0031] 3. The bottom of the second protective tube of the present application is an open structure, which enables groundwater to enter the second protective tube, can ensure the pressure balance in the monitoring well, and prevent the monitoring well from collapsing due to pressure imbalance. The second baffle assembly can reduce the air convection in the second protective tube, reduce the influence of air on temperature during the process of formation temperature transferring into the second protective tube, and thus ensure the accuracy of temperature sensor data monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of the present application.

[0033] Figure 2 is a schematic structural diagram of the present application showing the first baffle assembly and the signal cable.

[0034] Figure 3 is a schematic structural diagram of the present application showing the first protective tube and the second baffle assembly.

[0035] Figure 4 is a schematic structural diagram of the present application showing the first baffle assembly and the temperature sensor.

[0036] Figure 5 is another embodiment of the second baffle assembly 5 of the present application.

[0037] Figure 6 is a schematic structural diagram of the present application showing that the first baffle assembly is a regularly arranged fluff.

[0038] DESCRIPTION OF THE REFERENCE NUMERALS: 1. Temperature sensor, 2. First baffle assembly, 21. First installation body, 22. First baffle, 3. First protective tube, 4. Second protective tube, 5. Second baffle assembly, 51. Dividing piece, 52. Body, 521. Through hole, 6. Load-bearing rope, 7. Signal cable. Detailed implementation mode

[0039] The following further elaborates on this application in conjunction with the attached Figures 1-6 drawings.

[0040] An embodiment of this application discloses a ground temperature monitoring device.

[0041] Referring to Figure 1 and Figure 2 , a ground temperature monitoring device is located in a monitoring well and includes a second protective pipe 4, a first protective pipe 3, multiple sections of signal cables 7 and multiple temperature sensors 1. The first protective pipe 3 is located inside the second protective pipe 4. One section of signal cable 7 is electrically connected to one temperature sensor 1. An insulating material is wrapped around the outside of the signal cable 7 and the temperature sensor 1 to form a distributed sensor cable. A waterproof joint is provided at one end of the signal cable 7 closest to the bottom of the monitoring well to prevent water from entering the signal cable. One end of the signal cable 7 closest to the wellhead of the monitoring well at the top is connected to the monitoring data forwarding module. The signal cable 7 and multiple temperature sensors 1 are located inside the first protective pipe 3. The end of the first protective pipe 3 close to the bottom of the well is a sealed structure. A first partition assembly 2 is sleeved on each end of each temperature sensor 1. The first partition assembly 2 is located between the temperature sensor 1 and the first protective pipe 3.

[0042] According to the actual depth of the monitoring well, the number of sections of the multiple sections of signal cables 7 can be increased or decreased arbitrarily. The signal cable 7 has four cores. The communication protocol uses RS485. Each section of signal cable 7 defines a device address before use, and the addresses of each temperature sensor 1 cannot be the same.

[0043] Referring to Figure 3 , the end of the second protective pipe 4 close to the bottom of the well is an open structure. Multiple second partition assemblies 5 are provided inside the second protective pipe 4. The multiple second partition assemblies 5 are arranged vertically and sleeved on the first protective pipe 3. The multiple second partition assemblies 5 are spaced apart.

[0044] Referring to Figure 4 , a first partition assembly 2 is provided at each end of the temperature sensor 1. The two first partition assemblies 2 reduce the air convection in the upper and lower directions of the temperature sensor 1, making the air convection at the temperature sensor 1 the weakest.

[0045] The spacing between adjacent temperature sensors 1 can be 1m, 3m or 10m. The spacing is selected according to the actual ground temperature gradient to better monitor the temperature of different depths of underground strata.

[0046] The first partition assembly 2 includes an annular first mounting body 21 and a first partition member 22 for reducing air convection. The first mounting body 21 and the first partition member 22 are connected. The first mounting body 21 is sleeved on the temperature sensor 1. The first mounting body 21 is a heat-shrinkable tube, which is fixedly connected to the signal cable 7, or glue is coated on the side wall of the inner ring of the first mounting body 21 to glue it to the signal cable 7. The first partition member 22 contacts the inner wall of the first protection tube 3, further reducing air convection in the first protection tube 3.

[0047] Referring to Figure 4 , the first partition member 22 is a plurality of orderly arranged columnar or rod-shaped structures. There are gaps between the plurality of columnar structures or the plurality of rod-shaped structures, which allows air to flow through the gaps, reduces air convection in the first protection tube 3, and reduces the speed and flow rate of air convection.

[0048] Referring to Figure 2 and Figure 4 , a load-bearing rope 6 is arranged in the first protection tube 3. One end of the load-bearing rope 6 is connected to an external suspension mechanism. The load-bearing rope 6 is fixedly connected to the signal cable 7 through a buckle or a strap. The load-bearing rope 6 supports multiple sections of signal cables 7 and multiple temperature sensors 1 connected in sequence.

[0049] A cover plate is clamped at the end of the second protection tube 4 far from the bottom of the well. The cover plate is rotatably connected to the second protection tube 4. A hole is opened at the central part of the cover plate. The end of the first protection tube 3 far from the bottom of the well extends into the hole of the cover plate. The cover plate limits the first protection tube 3, facilitating the insertion of the first protection tube 3 into the second protection tube 4, and at the same time preventing the first protection tube 3 from shaking or displacing after installation.

[0050] An implementation manner of the second partition assembly 5:

[0051] The second partition assembly 5 includes five sector-shaped partition pieces 51. There are gaps between adjacent two partition pieces 51. The five partition pieces 51 are circumferentially and evenly distributed on the outer surface of the first protection tube 3. Glue is coated on the side of the partition piece 51 close to the first protection tube 3 to glue it to the first protection tube 3. The other side of the partition piece 51 contacts the inner wall of the second protection tube 4, reducing air convection in the second protection tube 4.

[0052] The material of the partition piece 51 is a rubber thin sheet. During the process of installing it into the second protection tube 4, the rubber thin sheet will move up and down. The movement of the rubber thin sheet facilitates the release of the pressure in the second protection tube 4 during installation and is convenient for installation.

[0053] The wall thickness of the first protection tube 3 and the second protection tube 4 is 0.3 cm. The inner diameter of the first protection tube 3 is 2.5 cm, and the inner diameter of the second protection tube 4 is 170 cm.

[0054] A construction method of a ground temperature monitoring device, the steps of which are as follows:

[0055] S100. Drill a plurality of monitoring wells on the ground;

[0056] S200. Place a protective pipe in each monitoring well, and sleeved a partition assembly outside the protective pipe:

[0057] S210. Sleeve a second partition assembly outside the first protective pipe, and place a second protective pipe in each monitoring well;

[0058] S220. Place the first protective pipe and the second partition assembly into the second protective pipe.

[0059] S300. Place multiple sections of signal cables and multiple temperature sensors in the protective pipe to monitor the temperature of the formation at different depths:

[0060] S310. Electrically connect a section of signal cable to a temperature sensor, sleeved a first partition assembly at both ends of each temperature sensor, and connect the multiple sections of signal cables end to end to form a distributed sensor cable;

[0061] S320. Connect a load-bearing rope to the distributed sensor cable, and place the multiple sections of cables and the load-bearing rope into the first protective pipe;

[0062] S330. Seal the cover plate at the wellhead of the monitoring well, and insert the end of the first protective pipe away from the bottom of the well into the hole of the cover plate to complete the construction.

[0063] The implementation principle of a ground temperature monitoring device and a construction method in an embodiment of the present application is as follows: During the installation of the ground temperature monitoring device in the monitoring well, when the first protective pipe 3 and the second partition assembly 5 are installed in the second protective pipe 4, during the downward movement of the partition piece 51, there will be up and down movements, which is convenient for the installation of the first protective pipe 3 and the second partition assembly 5.

[0064] The temperatures at different depths underground will be transmitted to the temperature sensor 1 through the second protective pipe 4 and the first protective pipe 3. The temperature sensor 1 collects the temperature at the corresponding depth position. The second partition assembly 5 reduces the air convection in the second protective pipe 4, ensuring that the temperature transmission will not form mutual disturbances. The first partition assembly 2 at both ends of the sensor chip also reduces the air convection in the first protective pipe 3, improving the accuracy of the temperature data of the corresponding depth position collected by the temperature sensor 1. The collected data is transmitted to the control center through the sensor chip and the signal cable, facilitating the staff to calculate accurate results to evaluate the sustainability of the ground source heat pump exploitation and guiding the parameter design of the ground source heat pump exploitation.

[0065] Refer to Figure 5 , Another implementation manner of the second partition assembly 5:

[0066] The second partition assembly 5 includes a body 52. An installation round hole is formed at the central position of the body 52, facilitating the sleeving of the second partition assembly 5 on the first protection tube 3. A plurality of through holes 521 are also formed on the body 52. The plurality of through holes 521 can enable the air in the second protection tube 4 to form convection, which is convenient for installation. At the same time, it also reduces the air convection in the second protection tube 4, reducing the speed and flow rate of the air convection.

[0067] Referring to Figure 6 , the first partition member 22 can be a plurality of orderly arranged villi. The villi are distributed in one layer, and there are gaps between the villi.

[0068] The plurality of orderly arranged villi can also be distributed in multiple layers; the density and size of the villi can be adjusted according to actual needs.

[0069] The first partition member 22 can also be a plurality of disordered or disorderly arranged columnar or rod-shaped structures, villi or columnar or rod-shaped structures.

[0070] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A ground temperature monitoring device is located in a monitoring well, characterized in that: It includes multiple sections of signal cables (7) connected end to end. Each section of the signal cable (7) is provided with a temperature sensor (1). The temperature sensor (1) is connected to the signal cable (7). At least one first baffle component (2) for reducing air convection is arranged on the outer surface of each temperature sensor (1). It further includes a first protective tube (3) with a sealed bottom. The multiple temperature sensors (1) are located inside the first protective tube (3), and the first baffle component (2) is located between the temperature sensor (1) and the first protective tube (3). It further includes a second protective tube (4) with an open-bottom structure and multiple second baffle components (5). The first protective tube (3) is located inside the second protective tube (4), and the second baffle component (5) is located inside the second protective tube (4) and arranged on the outer surface of the first protective tube (3). The second baffle component (5) includes at least two dividing sheets (51) circumferentially arranged on the outer surface of the first protective tube (3), and there is a gap between adjacent dividing sheets (51). The dividing sheet (51) is made of a flexible material. The first baffle component (2) includes an annular first mounting body (21) and a first baffle member (22) for reducing air convection. The first mounting body (21) and the first baffle member (22) are connected, and the first mounting body (21) is sleeved on the temperature sensor (1).

2. The ground temperature monitoring device according to claim 1, characterized in that: It further includes a load-bearing rope (6), and the load-bearing rope (6) is connected to the signal cable (7).

3. A construction method of a ground temperature monitoring device according to any one of claims 1-2, the steps of which are as follows: S100. Drill multiple monitoring wells on the ground; S200. Place a protective tube in each monitoring well and sleeve a baffle component outside the protective tube; S300. Place multiple sections of signal cables and multiple temperature sensors in the protective tube to monitor the temperature of the formation.

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