Buried pipeline corrosion detection device

Abstract

The invention provides a buried pipeline corrosion detection device. The buried pipeline corrosion detection device comprises an underground detection device and a control cabinet, the underground detection device comprises a soil fixation sleeve; the counterweight pipe is mounted in the soil fixing sleeve; the test steel pipe is fixed in the counterweight pipe and is used as a test cathode; under the action of the counterweight tube, the test steel tube, the T-shaped reference electrode and the T-shaped auxiliary anode electrode are in contact with soil; the control cabinet comprises a control cabinet body; the heating device is arranged on the control cabinet body and used for heating liquid; the temperature controller is connected with the heating device and used for controlling parameters of the heating device; and the current controller is connected with the test steel tube, the T-shaped reference electrode, the T-shaped auxiliary anode cable and the cathode cable, and is used for controlling the potential of the T-shaped auxiliary anode cable and receiving potential information of the test steel tube and the cathode cable.

Description

Technical Field

[0001] The invention relates to the field of metal corrosion monitoring, and in particular to a buried pipeline corrosion detection device. Background Art

[0002] In the prior art, the buried metal pipeline corrosion monitoring device and method collect the maximum instantaneous current density through the induction charge device buried in the soil above the detection pipeline, and then analyze the corrosion condition of the buried steel pipe or adopt a multi-metal sleeve layer device. On the one hand, it maintains the characteristic of the hanging piece to accurately reflect the metal corrosion, and on the other hand, it can grasp the corrosion time of each layer. It is mainly used for corrosion detection in pipelines or by distributing acoustic wave sensors on the surface of the pipeline to sense the local quality changes of the pipeline surface, thereby realizing the corrosion monitoring function.

[0003] However, it is not possible to define and judge the corrosion state; nor is it possible to detect and evaluate the corrosion degree through specific devices by collecting and comparing the protection potential of the production pipeline as described in this patent, or it is not possible to determine the corrosion state by analyzing the current protection state and combining it with the environment in which the pipeline is located. It is mainly used for internal corrosion detection or it is not possible to determine the corrosion state by analyzing the current protection state and combining it with the environment in which the pipeline is located.

[0004] Therefore, how to provide a buried pipeline corrosion detection device that can detect and evaluate the degree of corrosion and analyze and judge the corrosion state in combination with the environment in which the pipeline is located has become the main research direction. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] Therefore, a first object of the present invention is to provide a buried pipeline corrosion detection device.

[0007] To achieve the above-mentioned purpose, the technical solution of the first aspect of the present invention provides a buried pipeline corrosion detection device for a production pipeline under cathodic protection, the detection device comprising: an underground detection device and a control cabinet; the underground detection device comprising: a soil-solidifying casing; a counterweight pipe installed in the soil-solidifying casing; a test steel pipe fixed in the counterweight pipe as a test cathode; a first liquid supply pipe and a first liquid return pipe are respectively connected at both ends of the test steel pipe; a pipe surface temperature sensor is arranged on the surface of the test steel pipe for detecting the temperature of the surface of the test steel pipe; a T-type reference electrode is fixed on the counterweight pipe; a T-type auxiliary anode electrode is fixed on the counterweight pipe; under the action of the counterweight pipe, the test steel pipe, the T-type reference electrode and the T-type auxiliary anode electrode are in contact with the soil; a negative cable, connected to the production pipeline; the control cabinet includes: a control cabinet body; a heating device, which is arranged on the control cabinet body and is used to heat the liquid; a second liquid supply pipe, one end of the second liquid supply pipe is connected to the first liquid supply pipe, and the other end of the second liquid supply pipe is connected to the heating device, and is used to supply liquid to the first liquid supply pipe; a second liquid return pipe, one end of the second liquid return pipe is connected to the first liquid return pipe, and the other end of the second liquid return pipe is connected to the heating device, and is used to recover the liquid flowing out of the first liquid return pipe; a temperature controller, which is connected to the heating device and is used to control the parameters of the heating device; a current controller, which is connected to the test steel pipe, the T-type reference electrode, the T-type auxiliary anode cable and the negative cable, and is used to control the potential of the T-type auxiliary anode cable and receive the potential information of the test steel pipe and the negative cable.

[0008] Furthermore, the heating device includes: an electric heating outer tube, which is arranged on the control cabinet body; an electric heating rod, which is fixed in the electric heating outer tube and is used to heat the liquid; a first temperature transmitter, which is connected to the electric heating outer tube and is used to detect the temperature of the liquid flowing out of the electric heating outer tube; a circulating pump, one end of the circulating pump is connected to the electric heating outer tube, and the other end of the circulating pump is connected to the second liquid return pipe, which is used to provide power for the circulation of the liquid.

[0009] Furthermore, the heating device also includes: a first temperature transmitter housing, a first temperature transmitter is arranged in the first temperature transmitter housing; one end of the first temperature transmitter housing is connected to the electric heating outer tube, and the other end of the first temperature transmitter housing is connected to the circulation pump; a safety pressure relief valve, the safety pressure relief valve is arranged on the first temperature transmitter housing, and is used to ensure that the pressure in the first temperature transmitter housing is in an installed state; a pressure relief drain pipe, which is connected to the safety pressure relief valve and is used to discharge the liquid or gas discharged by the safety pressure relief valve.

[0010] Furthermore, the buried pipeline corrosion detection device also includes: a T-shaped auxiliary anode nut, used to fix the T-shaped auxiliary anode on the configuration tube; a T-shaped reference electrode nut, used to fix the T-shaped reference electrode on the configuration tube; a T-shaped auxiliary anode cable, one end of the T-shaped auxiliary anode cable is connected to the T-shaped auxiliary anode, and the other end of the T-shaped auxiliary anode cable is connected to the current controller; a T-shaped reference electrode cable, one end of the T-shaped reference electrode cable is connected to the T-shaped reference electrode, and the other end of the T-shaped reference electrode cable is connected to the current controller.

[0011] Furthermore, the buried pipeline corrosion detection device also includes: a second temperature transmitter, which is arranged on the production pipeline and is connected to the temperature controller, and is used to send the temperature of the production pipeline to the temperature controller.

[0012] Furthermore, the buried pipeline corrosion detection device also includes: a third temperature transmitter, which is arranged on the test steel pipe, one end of the third temperature transmitter is connected to the pipe surface temperature sensor, and the other end of the third temperature transmitter is connected to the temperature controller, and the third temperature transmitter is used to send the temperature of the test steel pipe to the temperature controller.

[0013] Furthermore, the buried pipeline corrosion detection device also includes: a first relay, one end of the first relay is connected to the temperature controller, the other end of the first relay is connected to the electric heating rod, and the first relay is used to control the operation of the electric heating rod; a second relay, one end of the second relay is connected to the temperature controller, the other end of the second relay is connected to the circulation pump, and the second relay is used to control the operation of the circulation pump.

[0014] Furthermore, the buried pipeline corrosion detection device also includes: a controllable rectifier, which is arranged in the control cabinet, one end of the controllable rectifier is connected to the T-type auxiliary anode cable, and the other end of the controllable rectifier is connected to the negative cable, thereby forming a closed loop, and the controllable rectifier is connected to the second controller, and the second controller controls the voltage output by the controllable rectifier.

[0015] Furthermore, the buried pipeline corrosion detection device also includes: a first voltmeter, connected to the positive pole of the controllable rectifier, for detecting the output voltage of the controlled rectifier; an ammeter, connected to the positive pole of the controlled rectifier, for detecting the output current of the controlled rectifier; a second voltmeter, one end of the second voltmeter is connected to the T-type reference cable, and the other end of the second voltmeter is connected to the test steel pipe, for detecting the voltage at both ends of the test steel pipe.

[0016] Furthermore, the buried pipeline corrosion detection device also includes: a casing head, which is arranged at one end of the soil-fixing casing and is used to fix the soil-fixing casing; and a floor bracket, which is arranged on the control cabinet body and is used to support the control cabinet body.

[0017] The buried pipeline radiation detection device of the present invention can simulate the temperature operating conditions of the production pipeline, realize on-site measurement of key corrosion parameters, compare the on-site protection potential of the production pipeline, and judge the corrosion status of the pipeline; in addition, after interlocking control with the power supply of the production pipeline cathodic protection system, it can realize real-time command and control adjustment of the cathodic protection output status to ensure that the cathodic protection effect is in the best state. The buried pipeline radiation detection device of the present invention can accurately monitor the corrosion status of the pipeline under the condition of cathodic protection, and in particular, it proposes a buried pipeline corrosion monitoring device that can be applied on site, which can analyze and judge the corrosion status in combination with the environment in which the pipeline is located, and improve the corrosion protection effect by comparing the current protection status and adjusting the protection index through information interaction with the power supply equipment.

[0018] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 is a schematic structural diagram of an underground detection device according to an embodiment of the present invention;

[0021] Figure 2 is one of the structural schematic diagrams of a control cabinet according to an embodiment of the present invention;

[0022] Figure 3 is one of the structural schematic diagrams of a control cabinet according to an embodiment of the present invention;

[0023] Figure 4 is a schematic structural diagram of a buried pipeline corrosion detection device according to an embodiment of the present invention;

[0024] Figure 5 1 is a coordinate schematic diagram of a buried pipeline corrosion detection device according to an embodiment of the present invention.

[0025] in, Figures 1 to 4 The correspondence between the reference numerals and nouns in the figure is as follows:

[0026] 1Soil-fixing casing, 2Casing head, 3Counterweight tube, 4T-shaped auxiliary anode, 5T-shaped auxiliary anode cable, 6T-shaped auxiliary anode nut, 7T-shaped reference electrode, 8T-shaped reference electrode cable, 9T-shaped reference electrode nut, 10Test steel pipe, 11First liquid supply pipe, 12First liquid return pipe, 13Tube surface temperature sensor, 14Temperature sensor cable, 15Cathode cable, 16Test steel pipe potential collection cable, 17Control cabinet, 18Floor bracket, 19Threading pipe, 20Second liquid supply pipe, 21Second liquid return pipe, 22Temperature controller, 23First Temperature transmitter, 24 second temperature transmitter, 25 third temperature transmitter, 26 first relay, 27 second relay, 28 electric heating rod, 29 circulating pump, 30 first temperature transmitter housing, 31 safety pressure relief valve, 32 pressure relief drain pipe, 33 electric heating outer pipe, 34 current controller, 35 controllable rectifier, 36 first voltmeter, 37 ammeter, 40 second voltmeter, 41 potential collection cable for testing steel pipe, 44 power switch, 45 incoming cable, 46 leakage protector, 47 production pipeline, 49 cable connecting the production pipeline. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0029] Refer to the following Figures 1 to 4 The buried pipeline corrosion detection device in some embodiments of the present invention is described.

[0030] like Figures 1 to 4 As shown, the embodiment of the first aspect of the present invention provides an invention content including a buried pipeline corrosion monitoring device, including a detection device buried below the ground and a control cabinet installed on the ground. Figure 1 The below-ground detection device includes a soil-fixing casing 1, a casing head 2; a counterweight tube 3 installed in the soil-fixing casing, a T-shaped auxiliary anode 4 and a T-shaped auxiliary anode cable 5 connected to the counterweight tube 3 from bottom to top, a T-shaped auxiliary anode nut 6, a T-shaped reference electrode 7, a T-shaped reference electrode cable 8, a T-shaped reference electrode nut 9, a test steel pipe 10, a first return water pipe 12 connected to the test steel pipe, a pipe surface temperature sensor 13 probe installed on the surface of the test steel pipe, a temperature sensor cable 14, a negative cable 15 connected to the surface of the test pipe, and a test steel pipe potential collection cable 16.

[0031] The ground mounted control cabinet includes a control cabinet body 17, a floor bracket 18, a threading tube 19, and a second liquid supply pipe 20 and a second liquid return pipe 21 connected to the underground detection device. Figure 2 . For devices in the control cabinet, see Figure 3 , including a temperature controller 22, a second temperature transmitter 24 connected to the temperature controller 22, a temperature sensor probe connected to the monitored production pipeline 47, and a cable 49 connected to the production pipeline, a third temperature transmitter 25, and an underground device pipe surface temperature sensor probe 13 and a temperature sensor cable 14 connected thereto; a first relay 26 and a second relay 27 connected to the temperature controller 22; an electric heating rod 28 connected to the first relay 26, and a circulating pump 29 connected to the second relay 27; a first temperature transmitter housing 30, a safety pressure relief valve 31 installed on the upper side of the first temperature transmitter housing 30, and a pressure relief drain pipe 32 connected to the outlet of the safety pressure relief valve 31; the first temperature transmitter 23 is installed in the center of the first temperature transmitter housing 30, and the electric heating rod 28 is installed in the center of the electric heating outer tube 33; the electric heating outer tube 33, the first temperature transmitter housing 30, and the circulating pump 29 are connected by PPR pipes. A current controller 34, a controlled rectifier 35 connected to the current controller 34, a first voltmeter 36 and an ammeter 37 connected to the outlet of the controlled rectifier 35; a T-shaped auxiliary anode cable 5 output by the controlled rectifier, a negative electrode cable 15 output by the controlled rectifier; a second voltmeter 40 connected to the current controller 34, a potential collection cable 41 for a test steel pipe of an underground device connected to the second voltmeter 40, and a T-shaped reference electrode cable 8; the T-shaped auxiliary anode cable 5 output by the controlled rectifier 35 is connected to the T-shaped auxiliary anode cable 5 of the underground buried device; a cable 49 connected to the production pipeline connected to the current controller 34. A power switch 44, an incoming cable 45 connected to the power switch, and a leakage protector 46 connected to the power switch through a cable; a temperature controller 22, a current controller 34, a controlled rectifier 35, a first voltmeter 36, an ammeter 37, a second voltmeter 40, a first relay 26, a second relay 27, an electric heating rod 28, a circulation pump 29, a first temperature transmitter 23, a second temperature transmitter 24, a third temperature transmitter 25 and a leakage protector 46 are connected through cables. A first water supply pipe 11 connected to the circulation pump 29, and a first water return pipe 12 connected to the electric heating outer pipe 33. The negative cable 15 on the surface of the test pipeline is connected to the negative cable 15 output by the controlled rectifier; and the T-shaped auxiliary anode cable 5 is connected to the T-shaped auxiliary anode cable 5 output by the controlled rectifier.

[0032] (1) According to Figure 1 Assemble the underground part of the invention device (the material of the test pipe used is the same as that of the monitored production pipeline 47); the specific installation sequence is: First, installation of the soil-fixing casing 1: Select the installation point of the underground device. The recommended installation point is as follows: Figure 4 A hole is drilled at a selected location at a vertical distance of 50 cm from the pipeline on one side of the production pipeline 47 using a soil drilling drill with the same outer diameter as the soil-fixing casing 1. The depth is slightly deeper than the pipeline burial depth by 10 cm to 20 cm. The soil-fixing casing 1 is installed into the drill hole. The bottom of the soil-fixing casing 1 is as deep as Figure 4 The bottom burial depth of the production pipeline 47 is consistent, and the soil-fixing casing 1 is left 30cm to 50cm above the ground. Second, the connection and installation of the internal components of the soil-fixing casing 1: the two ends of the test steel pipe 10 are connected to hot-melt insulating elbows, and the insulating elbows are connected to the first water supply pipe 11 and the first return pipe 12; after the surface of the test steel pipe 10 is cleaned, install 13-chip temperature sensor probe on the surface of the pipe near the insulating elbow; the surface of the test steel pipe 10 is anti-corrosive with adhesive tape; keep the first water supply pipe 11 and the first return pipe 12 facing upwards, and open the lower surface of the test steel pipe 10, with an opening size of 1cm 2 Up to 100cm 2 (The breach area is calculated based on the level of the pipeline anti-corrosion layer obtained from the test); install the first water supply pipe 11 and the first water return pipe 12 of the connected test steel pipe 10 into the pre-opened position of the counterweight pipe 3 from bottom to top, and pass the temperature sensor cable through the opening of the counterweight pipe 3 where the nearest insulating elbow is located; install the T-shaped reference electrode 7 into the pre-opened position of the counterweight pipe 3 from bottom to top, and tighten the T-shaped reference electrode nut 9 of the T-shaped reference electrode 7; install the T-shaped auxiliary anode 4 and the T-shaped auxiliary anode cable 5 into the pre-opened position of the counterweight pipe 3 from bottom to top, and tighten the T-shaped auxiliary The T-shaped auxiliary anode nut 6 of the auxiliary anode 4; the T-shaped auxiliary anode cable 5, the temperature sensor cable 14, the negative cable 15 connected to the surface of the test pipe, and the test steel pipe potential collection cable 16 are bound with the first water supply pipe 11 from bottom to top with nylon tie; the components in the installed and connected soil-fixing casing 1 are placed from top to bottom into the soil-fixing casing 1 that has been buried in the soil; the downward opening surface of the key components of the internal components of the soil-fixing casing 1, the T-shaped auxiliary anode 4, and the downward part of the T-shaped reference electrode 7 are in close contact with the soil under the action of the deadweight of the counterweight tube 3. Finally, the casing head 2 is installed at the upper end of the soil-fixing casing 1, and the first water supply pipe 11 and the first return water pipe 12 pass through the reserved holes on the casing head 2; the T-shaped auxiliary anode cable 5, the temperature sensor cable 14, the negative cable 15 connected to the surface of the test pipe, and the test steel pipe potential collection cable 16 pass through the cable reserved holes on the casing head 2.

[0033] (2) According to Figure 2Arrange the ground part of the device of the invention; the installation relationship is: install the floor bracket 18 above the installation position of the soil-fixing casing 1 of the underground device; install the control cabinet body 17 on the floor bracket 18; the cable from the underground device passes through the threading tube 19, the cable reserved hole on the butt casing head 2 and the reserved hole on the bottom of the ground control cabinet body 17; the first water supply pipe 11 installed in the control cabinet body 17 is connected to the upper end of the second liquid supply pipe 20 passing through the reserved opening at the bottom of the control cabinet body 17, and the lower end of the second liquid supply pipe 20 is connected to the first water supply pipe 11 from the underground device; the first return water pipe 12 installed in the control cabinet body 17 is connected to the upper end of the second return water pipe 21 passing through the reserved opening at the bottom of the control cabinet body 17, and the lower end of the 21-water supply pipe is connected to the first return water pipe 12 from the underground device.

[0034] (3) According to Figure 3 Install and check the connections of each device in the cabinet.

[0035] (4) Remove the safety relief valve 31 on the upper part of the first temperature transmitter housing 30 in the control cabinet 17, and slowly and intermittently inject insulating oil (transformer oil can be used) into the first temperature transmitter housing 30 from the installation port of the safety relief valve 31. After filling, draw out 20 ml with a syringe and reinstall the safety relief valve 31.

[0036] (5) Start the control cabinet power supply 44, the temperature controller 22 collects the temperature of the surface of the monitored production pipeline 47 through the second temperature transmitter 24 and the second temperature transmitter 24 buried on the surface of the production pipeline 47; the temperature controller 22 collects the temperature of the surface of the test steel pipe 10 through the third temperature transmitter 25 and the 13-temperature sensor probe installed on the surface of the underground test steel pipe of the device of the present invention. The temperature controller 22 collects the temperature of the medium in the process through the first temperature transmitter 23.

[0037] (6) When the surface temperature of the test steel pipe tested by the temperature controller 22 is 3°C lower than the surface temperature of the production pipeline 47 (this temperature difference can be set), the temperature controller 22 connects the power supply of the electric heating rod 28 through the first relay 26 to heat the insulating oil in the process connected to the underground device; at the same time, the temperature controller 22 connects the power supply of the circulation pump 29 through the second relay 27, and the medium flows through the inside of the buried test steel pipe 10 under the action of the circulation pump 29, thereby heating the buried test steel pipe 10.

[0038] (7) When the temperature controller 22 detects that the surface temperature of the test steel pipe is equal to the surface temperature of the production pipeline 47, the controller 1 cuts off the power supply of the electric heating rod 28 through the first relay 26 to stop heating. Through steps 5-7, the surface temperature of the underground test steel pipe 10 of the invention device is consistent with the surface temperature of the production pipeline 47.

[0039] (8) At the same time as step 5, the power switch 44 is started, and at the same time, the current controller 34 connects the cable 49 connected to the production pipeline and the negative cable 15 on the test steel pipe 10 buried underground by the invention patent through the internal circuit, so as to realize the cathodic protection of the test steel pipe 10, which is maintained for at least 15 minutes (this time 34 can be set by the controller 2); the current controller 34 collects the cathodic protection power-on potential VTBH1 of the currently monitored production pipeline 47 through the cable 49 connected to the production pipeline (set a separate storage location).

[0040] (9) The current controller 34 disconnects the cable 49 connected to the production pipeline and the negative cable 15 on the test steel pipe 10, and at the same time, the current controller 34 controls the controlled rectifier 35 to start working.

[0041] (10) Under the control of the current controller 34, the controlled rectifier 35 starts from 0V output and increases the output voltage at a certain voltage amplitude (such as 0.2V). At the same time, the first voltmeter 36 and the ammeter 37 measure the output voltage VT0.2, VT0.4, VT0.6, etc. and the output current IT0.2, IT0.4, IT0.6, etc. of the controlled rectifier, and feed back the values ​​to the current controller 34 for storage in a fixed position; each amplitude voltage value is output stably for 200 seconds, disconnected for 20 seconds and then increased to the next voltage.

[0042] (11) At the beginning of each amplitude voltage value stabilization, the current controller 34 transmits the operating status information of the controlled rectifier 35 to the second voltmeter 40. The second voltmeter 40 automatically adjusts the data acquisition cycle to 30 seconds, and reads a group of power-on protection potential data of the test steel pipe when each group of voltage is output stably:

[0043] VT0230, VT0260, VT0290, VT02120, VT02150, VT02180;

[0044] VT0430, VT0460, VT0490, VT04120, VT04150, VT04180;

[0045] VT0630, VT0660, VT0690, VT06120, VT06150, VT06180.

[0046] The second voltmeter 40 transmits each set of power-on protection potential data to the current controller 34 for fixed position storage, and reads the potential of each power-on voltage at 150 seconds as the power-on protection potential corresponding to each output voltage, such as VT02150, VT04150, VT06150, etc., and stores it in a fixed position.

[0047] (12) When each amplitude voltage value ends, the current controller 34 controls the controlled rectifier 35 to disconnect the output, and transmits the disconnection status information of the controlled rectifier 35 to the second voltmeter 40. The second voltmeter 40 automatically adjusts the data collection cycle to 50 milliseconds. When the current controller 34 controls the controlled rectifier 35 to disconnect the output, the second voltmeter 40 reads a set of instantaneous power-off protection potentials at 50 millisecond intervals:

[0048] VD0250, VD02100, VD02150, VD02200, VD02250, VD02300;

[0049] VD0450, VD04100, VD04150, VD04200, VD04250, VD04300;

[0050] VD0650, VD06100, VD062150, VD06200, VD06250, VD06300.

[0051] The voltmeter 2 transmits each set of power-off protection potential data to the current controller 34 for fixed position storage, and reads the potential at an interval of 150 milliseconds when each output voltage is disconnected as the power-off protection potential corresponding to each output voltage, such as VD02150, VD04150, VD06150, etc., and stores it in a fixed position.

[0052] (13) The current controller 34 automatically calculates the rate of change of the on-off protection potential difference and the rate of increase of the off-power protection potential data. The calculation formula is:

[0053] On-off potential difference change rate VTDCBHVn=(VTn150-VDn150) / VDn150;

[0054] The power-off potential increase rate VDZJVn=(VDn+1150-VDn150) / VDn150.

[0055] (14) For ease of understanding, refer to Figure 5 , the current controller 34 starts to calculate from the minimum data. When the on-off potential difference change rate VTDCBHVn≥5%, the corresponding Figure 5 The 1# inflection point data is the first cathode protection potential, which is the most positive protection potential under the current production conditions. The current controller 34 records the corresponding power-on protection potential VTbh1 and the power-off protection potential VTbh1. When the power-off potential increase rate VDZJVn≤5%, the corresponding Figure 5 The 2# inflection point data is the second cathode protection potential, which is the most negative protection potential under the current production conditions. The current controller 34 records the corresponding power-on protection potential VTbh2 and the power-off protection potential VTbh2.

[0056] (15) The current controller 34 turns off the controlled rectifier output.

[0057] (16) The current controller 34 reconnects the cable 49 connected to the production pipeline and the negative electrode cable 15 on the buried test steel pipe 10 through the internal circuit to monitor the cathodic protection potential.

[0058] (17) Determination of corrosion status: The current controller 34 compares and monitors the cathodic protection potential VTBH1 and VTbh1, VTbh2; when VTBH1<VTbh1, it is determined that the current detection pipeline (current detection position) is in an under-protected state and the pipeline is corroded; when VTbh1<VTBH1≤VTbh2, it is determined that the current detection pipeline (current detection position) is in a well-protected state and the pipeline is not corroded; when VTBH1>VTbh2, it is determined that the current detection pipeline (current detection position) is in an over-protected state and the pipeline has a high risk of hydrogen evolution corrosion.

[0059] (18) The current controller 34 can communicate with the constant potential instrument communicator of the protection station to adjust the output state of the constant potential instrument, thereby keeping the output of the cathodic protection system in a good state at all times.

[0060] In this specification, the term "plurality" means two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0061] In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A buried pipeline corrosion detection device, characterized in that: include: Underground detection devices and control cabinets; The underground detection device comprises: Soil-fixing casing; A counterweight pipe installed in the soil-fixing casing; A test steel pipe, fixed in the weight pipe, serving as a test cathode; The two ends of the test steel pipe are respectively connected to a first liquid supply pipe and a first liquid return pipe; A pipe surface temperature sensor is arranged on the surface of the test steel pipe and is used to detect the temperature of the surface of the test steel pipe; A T-type reference electrode fixed on the weight tube; A T-shaped auxiliary anode electrode fixed on the counterweight tube; Under the action of the weight tube, the test steel pipe, the T-shaped reference electrode and the T-shaped auxiliary anode electrode are in contact with the soil; A negative cable connected to the production pipeline; The control cabinet comprises: Control cabinet body; A heating device, arranged on the control cabinet body, for heating the liquid; a second liquid supply pipe, one end of which is connected to the first liquid supply pipe, and the other end of which is connected to the heating device, for supplying liquid to the first liquid supply pipe; a second liquid return pipe, one end of which is connected to the first liquid return pipe, and the other end of which is connected to the heating device, for recovering liquid flowing out of the first liquid return pipe; A temperature controller, connected to the heating device, for controlling parameters of the heating device; A current controller is connected to the test steel pipe, the T-type reference electrode, the T-type auxiliary anode cable and the negative cable, and is used to control the potential of the T-type auxiliary anode cable and receive potential information of the test steel pipe and the negative cable.

2. The buried pipeline corrosion detection device according to claim 1 is characterized in that: The heating device comprises: An electric heating outer tube is arranged on the control cabinet body; An electric heating rod, fixed in the electric heating outer tube, for heating the liquid; A first temperature transmitter is connected to the electrically heated outer tube and is used to detect the temperature of the liquid flowing out of the electrically heated outer tube; A circulation pump, one end of which is connected to the electric heating exterior, and the other end of which is connected to the second liquid return pipe, is used to provide power for the circulation of the liquid.

3. The buried pipeline corrosion detection device according to claim 2, characterized in that: The heating device also includes: A first temperature transmitter housing, wherein the first temperature transmitter is arranged in the first temperature transmitter housing; one end of the first temperature transmitter housing is connected to the electric heating outer tube, and the other end of the first temperature transmitter housing is connected to the circulation pump; A safety pressure relief valve, which is arranged on the housing of the first temperature transmitter and is used to ensure that the pressure in the housing of the first temperature transmitter is in an installed state; The pressure relief liquid discharge pipe is connected to the safety pressure relief valve and is used to discharge the liquid or gas discharged by the safety pressure relief valve.

4. The buried pipeline corrosion detection device according to claim 1, characterized in that: Also includes: A T-shaped auxiliary anode nut, used for fixing the T-shaped auxiliary anode on the configuration tube; A T-shaped reference electrode nut, used for fixing the T-shaped reference electrode on the configuration tube; A T-shaped auxiliary anode cable, one end of which is connected to the T-shaped auxiliary anode, and the other end of which is connected to the current controller; A T-shaped reference electrode cable, one end of which is connected to the T-shaped reference electrode, and the other end of which is connected to the current controller.

5. The buried pipeline corrosion detection device according to claim 1, characterized in that: Also includes: The second temperature transmitter is arranged on the production pipeline and is connected to the temperature controller, and is used for sending the temperature of the production pipeline to the temperature controller.

6. The buried pipeline corrosion detection device according to any one of claims 1 to 5, characterized in that: Also includes The third temperature transmitter is arranged on the test steel pipe, one end of the third temperature transmitter is connected to the pipe surface temperature sensor, and the other end of the third temperature transmitter is connected to the temperature controller. The third temperature transmitter is used to send the temperature of the test steel pipe to the temperature controller.

7. The buried pipeline corrosion detection device according to claim 2, characterized in that: Also includes: A first relay, one end of which is connected to the temperature controller, and the other end of which is connected to the electric heating rod, and the first relay is used to control the operation of the electric heating rod; A second relay, one end of the second relay is connected to the temperature controller, the other end of the second relay is connected to the circulation pump, and the second relay is used to control the operation of the circulation pump.

8. The buried pipeline corrosion detection device according to any one of claims 1 to 7, characterized in that: Also includes: A controlled rectifier is arranged in the control cabinet, one end of the controlled rectifier is connected to the T-type auxiliary anode cable, and the other end of the controlled rectifier is connected to the negative cable, thereby forming a closed loop. The controlled rectifier is connected to the second controller, and the second controller controls the voltage output by the controlled rectifier.

9. The buried pipeline corrosion detection device according to claim 8, characterized in that: Also includes: a first voltmeter, connected to the positive electrode of the controlled rectifier, and used to detect the output voltage of the controlled rectifier; an ammeter connected to the positive electrode of the controlled rectifier and used to detect the output current of the controlled rectifier; A second voltmeter, one end of which is connected to the T-type reference cable, and the other end of which is connected to the test steel pipe, is used to detect the voltage at both ends of the test steel pipe.

10. The buried pipeline corrosion detection device according to any one of claims 1 to 7, characterized in that: Also includes: A casing head, arranged at one end of the soil-fixing casing, and used for fixing the soil-fixing casing; A floor stand is arranged on the control cabinet body and is used to support the control cabinet body.

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