Multifunctional experimental device and method for simulating corrosion state in submarine pipeline

Abstract

The invention provides a multifunctional experimental device and method for simulating a corrosion state in a submarine pipeline, and belongs to the field of pipeline corrosion internal detection. The experimental device comprises an experimental device body, a heating device and a circulating pump, a medium in the experimental device body can be externally heated through the circulating pump, and in other words, the circulating pump can continuously convey the medium heated by the heating device to the experimental device body. The test method comprises a corrosion coupon experiment, a corrosion probe experiment and a double-layer pipe annulus corrosion simulation experiment. When a corrosion coupon experiment and a corrosion probe experiment are carried out, a corrosion probe and a corrosion coupon are respectively inserted into the experiment device main body, and corrosion rate data are continuously monitored and detected for 7 days; when a double-layer pipe annulus corrosion simulation experiment is carried out, wireless wall thickness detectors are sequentially attached to the three clamping grooves, and the average corrosion rate of the wireless wall thickness detectors is based on thickness measurement data of the wireless wall thickness detectors. According to the invention, a plurality of corrosion rate simulation parallel experiments can be simultaneously carried out, the operation is simple, the safety is high, and the controllability is high.

Description

Technical Field

[0001] The invention relates to the field of pipeline corrosion internal detection, and in particular to a multifunctional experimental device and method for simulating the internal corrosion state of a submarine pipeline. Background Art

[0002] Long-distance pipelines, that is, pipelines for long-distance transportation, can transport oil hundreds or thousands of kilometers, and the annual oil transportation capacity of a single pipeline is between millions and tens of millions of tons. Internal corrosion of long-distance pipelines is a potential and huge risk faced by offshore oil platform facilities and oil and gas gathering, transportation, storage and transportation systems during operation. Long-term monitoring of the internal corrosion status is an important prerequisite and necessary measure to ensure the safe production and stable operation of offshore oil and gas storage and transportation facilities. Therefore, a detailed understanding of the internal corrosion status of long-distance pipelines can effectively achieve early warning, early prevention, timely treatment and precise maintenance of their leaks.

[0003] With the increasing use of long-distance pipelines, the wall thickness of pipelines often decreases due to water dew point erosion, gravel scouring, crude oil scouring, bacterial corrosion and other reasons, which in turn causes stress changes in the structure and ultimately leads to crude oil leakage accidents.

[0004] More than 60 patents, including CN115078234A, CN219036316U, CN116500061A, CN220912938U, CN221405321U, and CN221301032U, have conducted practical and effective explorations in the field of internal corrosion detection of pipelines. However, the patents currently published for protection only involve corrosion rate prediction methods, internal corrosion detection equipment and devices, etc. There are no relevant experimental methods or devices for corrosion rates and insulation test blocks. At the same time, the existing patented technology has only been verified and tested for a single detection technology, which will cause large experimental data errors and reduce the rigor and authenticity of the corrosion experiment. Summary of the invention

[0005] In view of this, the present invention aims to provide a multifunctional experimental device and method for simulating the corrosion state in a submarine pipeline, which has a simple process flow and is easy to operate. The main material of the experimental device is consistent with that of a real submarine pipeline, which can not only carry out corrosion rate simulation experiments more targeted, but also be more in line with the actual corrosion conditions on site, thereby obtaining more scientific and accurate corrosion rate data; multiple corrosion rate simulation parallel experiments can be carried out simultaneously, greatly eliminating experimental errors; the experimental device described in the present invention can also perform accurate quantitative analysis on water quality, dissolved oxygen content, microbial content, etc., to assist in exploring various indirect factors affecting the corrosion rate.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is implemented as follows: it includes an experimental device main body, a heating device and a circulating pump, the water inlet of the circulating pump is connected to the second water outlet of the heating device, the water outlet of the circulating pump is connected to the first water inlet of the experimental device main body, the first water outlet of the experimental device main body is connected to the second water inlet of the heating device through a pipeline, the circulating pump can be used to evenly circulate and heat the medium in the experimental device main body, that is, the circulating pump can continuously transport the medium heated by the heating device to the experimental device main body, and the experimental device can simultaneously carry out the following three types of corrosion rate simulation experiments: corrosion hanging plate experiment, corrosion probe experiment and double-layer pipe annulus corrosion simulation experiment.

[0007] Furthermore, the material of the main body of the experimental device is the same as that of the submarine pipeline, and the outside of the main body of the experimental device is provided with a first exhaust port, a corrosion hanger insertion port, a plug-in corrosion probe insertion port, a first water inlet, a first water outlet and a first bottom row, and at the same time, the inner cavities of the first exhaust port, the corrosion hanger insertion port, the plug-in corrosion probe insertion port, the first water inlet, the first water outlet and the first bottom row are respectively connected to the inner cavity of the main body of the experimental device;

[0008] The outside of the experimental device body is also equipped with a joint for installing a temperature sensor and a pressure gauge, and the two joints are respectively connected to the inner cavity of the experimental device body. The temperature sensor is used to measure the temperature inside the experimental device body, and the pressure gauge is used to measure the pressure inside the experimental device body.

[0009] The outside of the main body of the experimental device is also provided with a first card slot, a second card slot and a third card slot, and the first card slot, the second card slot and the third card slot are respectively used to install a wireless wall thickness detector.

[0010] Furthermore, a first detachable flange, a second detachable flange and a third detachable flange are installed on the outside of the main body of the experimental device, and a corrosion hanger, a corrosion probe and three insulation test blocks are installed on the inside of the main body of the experimental device. At the same time, the upper end of the corrosion hanger is connected to the corrosion hanger insertion port, and the upper end of the corrosion probe is connected to the plug-in corrosion probe insertion port. The detachable flange blind plates of the first detachable flange, the second detachable flange and the third detachable flange are respectively fixedly welded to a conduit, and at the same time, the three insulation test blocks are respectively detachably installed at the lower end of the conduit, and the insulation test blocks are in conflict with the inner wall of the main body of the experimental device.

[0011] Furthermore, the material of the heating device is 316L stainless steel, and a temperature control element, a second water inlet, a second exhaust port, a second water outlet, and a second bottom row are arranged on the outside of the heating device, and at the same time, the inner cavities of the second water inlet, the second exhaust port, the second water outlet, and the second bottom row are respectively connected to the inner cavity of the heating device;

[0012] An MCH ceramic heating rod is installed inside the heating device. One end of the MCH ceramic heating rod is electrically connected to the temperature control element in a plug-in manner. The temperature control element and the temperature variable sensor arranged on the main body of the experimental device are connected by a 485 three-core signal line. At the same time, the temperature control element is externally connected to a PLC. The PLC controls the opening, closing or temperature adjustment of the temperature control element by receiving the temperature feedback signal of the temperature variable sensor, thereby realizing the control of the MCH ceramic heating rod.

[0013] Furthermore, the temperature sensor is equipped with automatic / manual switching function, as well as low warning / high warning function. The maximum allowable temperature difference range is ±2°C, and the interlocking MCH ceramic heating rod starts at low and stops at high.

[0014] The temperature sensor is equipped with low-low alarm and high-high alarm. The minimum allowable range of the alarm threshold is ±5℃, and the interlocking MCH ceramic heating rod is shut down.

[0015] Furthermore, the overall inner and outer materials of the circulation pump are 316L stainless steel, all connecting pipelines are quick-plug type, the quick-plug plugs are made of 316L stainless steel, and the connecting pipes are PU hoses; the first bottom row, the first exhaust port, the second bottom row and the second exhaust port are all made of 316L stainless steel.

[0016] Furthermore, the experimental device can simulate the effect of the insulation layer on the corrosion of the outer tube after the inner tube of the double-layer tube leaks, and its average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the three card slots on the outer wall of the main body of the experimental device;

[0017] When the average corrosion rate is greater than or equal to 0.03 mm / a, the experimental results of the corrosion coupon shall be used as the benchmark; when the average corrosion rate is less than 0.03 mm / a, the experimental results of the corrosion probe shall be used as the benchmark;

[0018] The experimental device can simulate the effect of the insulation layer on the corrosion of the outer pipe after the inner pipe of a double-layer pipe leaks. The staff will replace different insulation test blocks according to actual simulation needs.

[0019] An experimental method for simulating the corrosion state in a submarine pipeline is carried out by the above-mentioned experimental device, and the experimental method includes a corrosion coupon experiment, a corrosion probe experiment and a double-layer pipe annulus corrosion simulation experiment; the corrosion coupon experiment and the corrosion probe experiment are respectively used to simulate the corrosion rate of the medium on the pipe wall, wherein the corrosion probe experiment can accurately analyze the water quality, dissolved oxygen content, and microbial content; when performing the corrosion coupon experiment and the corrosion probe experiment, the corrosion probe and the corrosion coupon are respectively inserted into the main body of the experimental device to continuously monitor and detect the corrosion rate data for 7 days;

[0020] The double-layer pipe annulus corrosion simulation experiment is used to simulate the influence of different insulation material layers on the outer pipe corrosion after the inner pipe of the double-layer pipe leaks. When conducting the double-layer pipe annulus corrosion simulation experiment, the wireless wall thickness detector is attached to the first card slot, the second card slot and the third card slot in turn, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector.

[0021] Furthermore, the corrosion coupon test / corrosion probe test includes the following steps:

[0022] Step 11, injecting configured seawater or real seawater into the heating device, the configured seawater or real seawater is also called medium;

[0023] Step 12, when the medium in the heating device is about to overflow, turn on the circulation pump and the temperature control element of the heating device, so that the medium flows into the main body of the experimental device, and the medium circulates from the main body of the experimental device back to the heating device along with the circulation pump until the main body of the experimental device and the heating device are slowly filled;

[0024] Step 13, when the main body of the experimental device is close to overflowing, stop the water intake;

[0025] Step 14, when the temperature reaches a preset temperature as observed by the temperature sensor provided on the main body of the experimental device, the temperature control element is switched from a manual state to an automatic state;

[0026] Step 15, observing the pressure change in the main body of the experimental device from a pressure gauge provided on the main body of the experimental device;

[0027] Step 16, insert the corrosion probe into the plug-in corrosion probe insertion port, and insert the corrosion hanger into the corrosion hanger insertion port to simulate the corrosion rate of the medium on the pipe wall; when the average corrosion rate is greater than 0.03mm / a, the corrosion hanger test results are used as the benchmark; when the average corrosion rate is less than 0.03mm / a, the corrosion probe test results are used as the benchmark.

[0028] Furthermore, the double-layer pipe annulus corrosion simulation experiment includes the following steps:

[0029] Step 21, injecting configured seawater or real seawater into the heating device, the configured seawater or real seawater is also called medium;

[0030] Step 22, when the medium in the heating device is about to overflow, turn on the circulation pump and the temperature control element of the heating device, so that the medium flows into the main body of the experimental device, and the medium circulates from the main body of the experimental device back to the heating device along with the circulation pump until the main body of the experimental device and the heating device are slowly filled;

[0031] Step 23, when the main body of the experimental device is close to overflowing, stop the water intake;

[0032] Step 24, when the temperature reaches a preset temperature as observed by the temperature sensor provided on the main body of the experimental device, the temperature control element is switched from a manual state to an automatic state;

[0033] Step 25, observing the pressure change in the main body of the experimental device from a pressure gauge provided on the main body of the experimental device;

[0034] Step 26, attaching the wireless wall thickness detector to the first card slot, the second card slot and the third card slot in sequence, with one card slot corresponding to an insulation test block of different materials, to simulate the influence of different insulation material layers on the corrosion of the outer pipe after the inner pipe of the double-layer pipe leaks, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the card slot on the outer wall of the main body of the experimental device;

[0035] Step 27, when other insulation test blocks need to be replaced, the medium in the experimental device body and the heating device is emptied, and then the first removable flange, the second removable flange, and the third removable flange are disassembled, and the conduit is pulled out at the same time, and then the insulation test block at the bottom of the conduit is replaced;

[0036] Step 28, repeating steps 21 to 26, simulating the effect of different insulation material layers on the corrosion of the outer tube after the inner tube of the double-layer tube leaks, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the outer wall slot of the main body of the experimental device.

[0037] Compared with the prior art, the multifunctional experimental device and method for simulating the corrosion state in a submarine pipeline described in the present invention have the following advantages: the entire set of experimental device and process method has the advantages of simple operation, convenient installation, low energy consumption, small footprint, safety and high controllability.

[0038] (1) The present invention can simultaneously carry out multiple corrosion rate simulation parallel experiments, greatly eliminating experimental errors;

[0039] (2) The main material of the experimental device is consistent with the real submarine pipeline, which not only allows for more targeted corrosion rate simulation experiments, but also better conforms to the actual corrosion conditions on site, thereby obtaining more scientific and accurate corrosion rate data;

[0040] (3) The device of the present invention can also perform accurate quantitative analysis on water quality, dissolved oxygen content, microbial content, etc., and assist in exploring various indirect factors that affect the corrosion rate;

[0041] (4) The present invention can simulate the effect of the insulation layer on the outer tube corrosion after the inner tube of the double-layer tube leaks;

[0042] (5) Through the PLC control of temperature sensors and temperature control elements, the temperature is controlled autonomously, the temperature control is more accurate, and the temperature safety hazards caused by damage to the MCH ceramic heating rod are avoided;

[0043] (6) When the medium needs to be replaced, the first exhaust port, the second exhaust port, the first bottom row and the second bottom row are opened at the same time to empty the medium in the experimental device body and the heating device, making it convenient and quick to replace the internal medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 A schematic diagram of a multifunctional experimental device for simulating corrosion conditions in a submarine pipeline according to the present invention;

[0046] Figure 2 It is a front view of the main body of the experimental device of the present invention;

[0047] Figure 3 A top view of the main body of the experimental device.

[0048] Figure 4 It is a side view of the main body of the experimental device.

[0049] Figure 5 is a front view of the heating device;

[0050] Figure 6 A top view of the heating device.

[0051] Figure 7 A side view of the heating device.

[0052] Figure 8 It is a schematic diagram of the main body of the experimental device (showing the internal structure);

[0053] Fig. 9 A schematic diagram of a heating device (showing its internal structure).

[0054] Description of reference numerals:

[0055] 1. Experimental device body; 2. Circulation pump; 3. Heating device;

[0056] 11. First exhaust port; 12. Corrosion hanger insertion port; 13. Temperature sensor; 14. Pressure gauge; 15. Plug-in corrosion probe insertion port; 16. First water inlet; 17. First water outlet; 18. First card slot; 19. Second card slot; 20. Third card slot; 21. First bottom row; 22. First detachable flange; 23. Second detachable flange; 24. Third detachable flange; 25. Corrosion hanger; 26. Corrosion probe; 27. Wood block; 28. Polyurethane foam; 29. ​​Asbestos insulation cloth;

[0057] 31. Temperature control element; 32. Second water inlet; 33. Second exhaust port; 34. Second water outlet; 35. Second bottom row; 36. MCH ceramic heating rod. DETAILED DESCRIPTION

[0058] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0059] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0060] like Figure 1-Figure 9 As shown, the present invention is a multifunctional experimental device for simulating the corrosion state in a submarine pipeline, comprising an experimental device body 1, a heating device 3 and a circulating pump 2, wherein the water inlet of the circulating pump 2 is connected to the second water outlet 34 of the heating device 3, the water outlet of the circulating pump 2 is connected to the first water inlet 16 of the experimental device body 1, and the first water outlet 17 of the experimental device body 1 is connected to the second water inlet 32 ​​of the heating device 3 through a pipeline. The experimental device is subjected to overall circulation heating in the form of external heating, in order to make the temperature distribution more uniform. Specifically, the medium in the experimental device body 1 can be uniformly circulated and heated by the circulating pump 2, that is, the circulating pump 2 can continuously transport the medium heated by the heating device 3 to the experimental device body 1, the temperature sensor 13 of the experimental device body 1 and the temperature control element 31 of the heating device 3 are connected by a 485 three-core signal line, supplying a 24V voltage, and the temperature control element 31 is externally connected to a PLC control, thereby realizing overall circulation heating of the experimental device, and the following three types of corrosion rate simulation experiments can be carried out simultaneously through the experimental device: corrosion hanging plate experiment, corrosion probe experiment and double-layer pipe annulus corrosion simulation experiment.

[0061] The material of the main body 1 of the experimental device is the same as that of the submarine pipeline, which is X65 steel. The outside of the main body 1 of the experimental device is provided with a first exhaust port 11, a corrosion hanger insertion port 12, a plug-in corrosion probe insertion port 15, a first water inlet 16, a first water outlet 17 and a first bottom row 21. At the same time, the inner cavities of the first exhaust port 11, the corrosion hanger insertion port 12, the plug-in corrosion probe insertion port 15, the first water inlet 16, the first water outlet 17 and the first bottom row 21 are respectively connected to the inner cavity of the main body 1 of the experimental device;

[0062] The outside of the experimental device body 1 is also equipped with a joint for installing a pressure gauge 14 and a temperature sensor 13. The two joints are respectively connected to the inner cavity of the experimental device body 1. The temperature sensor 13 is used to measure the temperature inside the experimental device body 1, and the pressure gauge 14 is used to measure the pressure inside the experimental device body 1.

[0063] The outside of the experimental device body 1 is also provided with a first card slot 18, a second card slot 19 and a third card slot 20, and the first card slot 18, the second card slot 19 and the third card slot 20 are respectively used to install a wireless wall thickness detector.

[0064] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0065] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0066] The outside of the experimental device body 1 is installed with a first detachable flange 22, a second detachable flange 23 and a third detachable flange 24, and the inside of the experimental device body 1 is installed with a corrosion hanger 25, a corrosion probe 26 and three insulation test blocks. At the same time, the upper end of the corrosion hanger 25 is connected to the corrosion hanger insertion port 12, and the upper end of the corrosion probe 26 is connected to the plug-in corrosion probe insertion port 15. The detachable flange blind plates of the first detachable flange 22, the second detachable flange 23 and the third detachable flange 24 are respectively fixedly welded to a conduit, and at the same time, the three insulation test blocks are respectively detachably installed at the lower end of the conduit, and the insulation test blocks just conflict with the inner wall of the experimental device body 1.

[0067] The three insulation blocks are wood block 27, polyurethane foam 28, and asbestos insulation cloth 29. It should be noted that in actual application, the staff can select insulation test blocks of other materials according to actual experimental needs. The three insulation test blocks of wood block 27, polyurethane foam 28, and asbestos insulation cloth 29 are preferably selected, but they are not limited to the three insulation test blocks of wood block 27, polyurethane foam 28, and asbestos insulation cloth 29. The installation positions of the three insulation test blocks can also be replaced as needed. For example, the wood block 27 can be installed on the conduit at the lower end of the first detachable flange 22, or on the conduit at the lower end of the second detachable flange 23, or on the conduit at the lower end of the third detachable flange 24. Similarly, the polyurethane foam 28 and asbestos insulation cloth 29 can also be installed on the conduit at the lower end of the first detachable flange 22, or on the conduit at the lower end of the second detachable flange 23, or on the conduit at the lower end of the third detachable flange 24.

[0068] The three slots are respectively arranged corresponding to the three detachable flanges, that is, the first slot 18 is arranged corresponding to the first detachable flange 22, the second slot 19 is arranged corresponding to the second detachable flange 23, and the third slot 20 is arranged corresponding to the third detachable flange 24. When the three insulation test blocks are respectively installed in place, the position of the first insulation test block just corresponds to the position of the first slot 18, the position of the second insulation test block just corresponds to the position of the second slot 19, and the position of the third insulation test block just corresponds to the position of the third slot 20, thereby ensuring that the wireless wall thickness detector can obtain accurate and effective thickness measurement data.

[0069] The material of the heating device 3 is 316L stainless steel. The outside of the heating device 3 is provided with a temperature control element 31, a second water inlet 32, a second exhaust port 33, a second water outlet 34 and a second bottom row 35. At the same time, the inner cavities of the second water inlet 32, the second exhaust port 33, the second water outlet 34 and the second bottom row 35 are respectively connected to the inner cavity of the heating device 3;

[0070] The heating device 3 is internally installed with an MCH ceramic heating rod 36, one end of which is electrically connected to the temperature control element 31, preferably in a plug-in electrical connection mode, and the temperature control element 31 is connected to the temperature sensor 13 provided on the experimental device body 1 by a 485 three-core signal line connection, and the temperature control element 31 is externally connected to a PLC, which controls the opening, closing or temperature adjustment of the temperature control element 31 by receiving the temperature feedback signal of the temperature sensor 13, thereby realizing the control of the MCH ceramic heating rod 36. The MCH ceramic heating rod 36 has multiple advantages such as corrosion resistance, high efficiency and energy saving, safety and environmental protection.

[0071] The temperature sensor 13 is provided with an automatic / manual switching function, the purpose of which is to improve the overall controllability. The temperature sensor 13 is provided with a low warning / high warning function, the maximum allowable range of the temperature difference is ±2°C, and the interlocking MCH ceramic heating rod 36 starts at a low level and stops at a high level, the purpose of which is to improve the accuracy of the experiment;

[0072] During the actual experiment, the temperature setting values ​​of the low warning and the high warning are set according to the actual experimental needs. For example, when the medium temperature in the main body 1 of the experimental device exceeds the preset temperature of +2°C, the temperature variable sensor 13 triggers a high warning, and the temperature control element 31 controls the MCH ceramic heating rod 36 to stop heating; when the medium temperature in the main body 1 of the experimental device is lower than the preset temperature of -2°C, the temperature variable sensor 13 triggers a low warning, and the temperature control element 31 controls the MCH ceramic heating rod 36 to start heating, thereby realizing the temperature variable sensor 13 interlocking the MCH ceramic heating rod 36 to start low and stop high.

[0073] The temperature variable sensor 13 is provided with a low-low alarm and a high-high alarm. The minimum allowable range of the alarm threshold is ±5°C, and the MCH ceramic heating rod 36 is interlocked to be shut down. The purpose of this setting is to improve the overall safety. In the actual experimental process, the temperature setting values ​​of the low-low alarm and the high-high alarm are set according to the actual experimental needs. For example, when the medium temperature in the main body 1 of the experimental device is greater than or equal to or less than ±5°C than the preset temperature, the temperature variable sensor 13 triggers the temperature control element 31 to control the MCH ceramic heating rod 36 to shut down, and then check whether the MCH ceramic heating rod 36 is damaged.

[0074] The circulation pump 2 is made of 316L stainless steel inside and outside. All connecting pipelines are quick-plug type. The quick-plug plugs are made of 316L stainless steel. The connecting pipes are PU hoses. The first bottom row 21, the first exhaust port 11, the second bottom row 35 and the second exhaust port 33 are all made of 316L stainless steel.

[0075] Combining the three types of corrosion rate simulation experiments, the average corrosion rate can be obtained, with the unit of "millimeter per year", i.e. mm / a.

[0076] The experimental device can simulate the effect of the insulation layer on the corrosion of the outer pipe after the inner pipe of the double-layer pipe (pipe in pipe) leaks. The average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the three card slots on the outer wall of the main body 1 of the experimental device;

[0077] When the average corrosion rate is greater than or equal to 0.03 mm / a, the experimental result of the corrosion coupon 25 is used as the benchmark; when the average corrosion rate is less than 0.03 mm / a, the experimental result of the corrosion probe 26 is used as the benchmark;

[0078] The experimental device can simulate the effect of the insulation layer on the corrosion of the outer pipe after the inner pipe of a double-layer pipe (pipe in pipe) leaks. The staff will replace different insulation test blocks according to the actual simulation needs.

[0079] The present invention also discloses an experimental method for simulating the corrosion state in a submarine pipeline, which is carried out by the experimental device as described above. The experimental method includes a corrosion coupon experiment, a corrosion probe experiment and a double-layer pipe annulus corrosion simulation experiment; the corrosion coupon experiment and the corrosion probe experiment are respectively used to simulate the corrosion rate of the medium on the pipe wall, wherein the corrosion probe experiment can accurately analyze the water quality, dissolved oxygen content, and microbial content; when performing the corrosion coupon experiment and the corrosion probe experiment, the corrosion probe 26 and the corrosion coupon 25 are respectively inserted into the main body 1 of the experimental device to continuously monitor and detect the corrosion rate data for 7 days;

[0080] The double-layer pipe annulus corrosion simulation experiment is used to simulate the influence of different insulation material layers on the outer pipe corrosion after the inner pipe of the double-layer pipe leaks. When conducting the double-layer pipe annulus corrosion simulation experiment, the wireless wall thickness detector is sequentially attached to the first card slot 18, the second card slot 19 and the third card slot 20, and its average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector.

[0081] The corrosion coupon test / corrosion probe test includes the following steps:

[0082] Step 11, injecting configured seawater or real seawater into the heating device 3, the configured seawater or real seawater is also called medium;

[0083] Step 12, when the medium in the heating device 3 is about to overflow, the circulation pump 2 and the temperature control element 31 of the heating device 3 are turned on, so that the medium flows into the experimental device body 1, and the medium circulates from the experimental device body 1 back to the heating device 3 along with the circulation pump 2 until the experimental device body 1 and the heating device 3 are slowly filled;

[0084] Step 13, when the experimental device body 1 is close to overflowing, stop the water intake;

[0085] Step 14, when the temperature reaches a preset temperature as observed by the temperature sensor 13 provided on the main body 1 of the experimental device, the temperature control element 31 is switched from the manual state to the automatic state;

[0086] Step 15, observing the pressure change in the experimental device body 1 from the pressure gauge 14 provided on the experimental device body 1;

[0087] Step 16, insert the corrosion probe 26 into the plug-in corrosion probe insertion port 15, and insert the corrosion hanger 25 into the corrosion hanger insertion port 12, to simulate the corrosion rate of the medium on the pipe wall; when the average corrosion rate is greater than 0.03mm / a, the corrosion hanger test results are used as the benchmark; when the average corrosion rate is less than 0.03mm / a, the corrosion probe test results are used as the benchmark.

[0088] The double-layer pipe annulus corrosion simulation experiment includes the following steps:

[0089] Step 21, injecting configured seawater or real seawater into the heating device 3, the configured seawater or real seawater is also called medium;

[0090] Step 22, when the medium in the heating device 3 is about to overflow, the circulation pump 2 and the temperature control element 31 of the heating device 3 are turned on, so that the medium flows into the experimental device body 1, and the medium circulates from the experimental device body 1 back to the heating device 3 along with the circulation pump 2 until the experimental device body 1 and the heating device 3 are slowly filled;

[0091] Step 23, when the experimental device body 1 is close to overflowing, stop the water intake;

[0092] Step 24, when the temperature reaches a preset temperature as observed by the temperature sensor 13 provided on the main body 1 of the experimental device, the temperature control element 31 is switched from the manual state to the automatic state;

[0093] Step 25, observing the pressure change in the experimental device body 1 from the pressure gauge 14 provided on the experimental device body 1;

[0094] Step 26, attach the wireless wall thickness detector to the first card slot 18, the second card slot 19 and the third card slot 20 in sequence, and one card slot corresponds to an insulation test block of different materials, so as to simulate the influence of different insulation material layers on the corrosion of the outer pipe after the inner pipe of the double-layer pipe leaks, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the card slot of the outer wall of the experimental device body 1;

[0095] Step 27, when other insulation test blocks need to be replaced, the medium in the experimental device main body 1 and the heating device 3 is emptied, and then the first removable flange 22, the second removable flange 23, and the third removable flange 24 are removed, and the catheter is pulled out at the same time, and then the insulation test block at the bottom of the catheter is replaced; it should be noted here that the purpose of emptying is to replace the test block, and whether it is necessary to empty when the test block is not replaced depends on the experimental requirements.

[0096] Step 28, repeating steps 21 to 26, simulating the effect of different insulation material layers on the corrosion of the outer tube after the inner tube of the double-layer tube leaks, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the outer wall slot of the experimental device body 1.

[0097] Embodiment 1:

[0098] First, open the first exhaust port 11 and the second exhaust port 33, and then let the configured seawater or real seawater (medium) enter the heating device 3 from the second water inlet 32. When it is observed through the second exhaust port 33 that the medium in the heating device 3 is about to overflow, turn on the circulation pump 2 and the temperature control element 31 at the same time. At this time, the temperature control element 31 is set to manual state, and the medium flows from the second water outlet 34 through the first water inlet 16 along with the circulation pump 2, and then enters the inside of the experimental device body 1. Then the medium circulates from the first water outlet 17 to the second water inlet 32 ​​until the medium slowly fills the experimental device body 1 and the heating device 3. When it is observed from the first exhaust port 11 that the experimental device body 1 is close to overflowing, stop the water intake, and close the first exhaust port 11 and the second exhaust port 33 at the same time.

[0099] When the temperature observed from the temperature sensor 13 reaches the preset temperature, the temperature control element 31 is switched to the automatic state.

[0100] The pressure change in the experimental device body 1 can be observed from the pressure gauge 14 .

[0101] When the medium needs to be replaced, the first exhaust port 11 , the second exhaust port 33 , the first bottom row 21 and the second bottom row 35 are opened simultaneously to drain the medium in the experimental device body 1 and the heating device 3 .

[0102] After the experiment is completed, the media in the experimental device body 1 and the heating device 3 are emptied in sequence.

[0103] Embodiment 2:

[0104] First, open the first exhaust port 11 and the second exhaust port 33, and then let the configured seawater or real seawater (medium) enter the heating device 3 from the second water inlet 32. When it is observed through the second exhaust port 33 that the medium in the heating device 3 is about to overflow, turn on the circulation pump 2 and the temperature control element 31 at the same time. At this time, the temperature control element 31 is set to manual state, and the medium flows from the second water outlet 34 through the first water inlet 16 along with the circulation pump 2, and then enters the inside of the experimental device body 1. Then the medium circulates from the first water outlet 17 to the second water inlet 32 ​​until the medium slowly fills the experimental device body 1 and the heating device 3. When it is observed from the first exhaust port 11 that the experimental device body 1 is close to overflowing, stop the water intake, and close the first exhaust port 11 and the second exhaust port 33 at the same time.

[0105] When the temperature observed from the temperature change sensor 13 reaches the preset temperature, it is switched to the automatic state.

[0106] The corrosion probe 26 is inserted into the plug-in corrosion probe insertion port 15, and the corrosion coupon 25 is inserted into the corrosion coupon insertion port 12, so as to simulate the corrosion rate of the medium on the pipe wall.

[0107] The corrosion rate data was continuously monitored for 7 days. After calculation, when the average corrosion rate was greater than or equal to 0.03 mm / a, the corrosion coupon test results were used as the benchmark; when the average corrosion rate was less than 0.03 mm / a, the corrosion probe test results were used as the benchmark.

[0108] After the experiment is completed, the media in the experimental device body 1 and the heating device 3 are emptied in sequence.

[0109] Embodiment 3:

[0110] First, open the first exhaust port 11 and the second exhaust port 33, and then let the configured seawater or real seawater (medium) enter the heating device 3 from the second water inlet 32. When it is observed through the second exhaust port 33 that the medium in the heating device 3 is about to overflow, turn on the circulation pump 2 and the temperature control element 31 at the same time. At this time, the temperature control element 31 is set to manual state, and the medium flows from the second water outlet 34 through the first water inlet 16 along with the circulation pump 2, and then enters the inside of the experimental device body 1. Then the medium circulates from the first water outlet 17 to the second water inlet 32 ​​until the medium slowly fills the experimental device body 1 and the heating device 3. When it is observed from the first exhaust port 11 that the experimental device body 1 is close to overflowing, stop the water intake, and close the first exhaust port 11 and the second exhaust port 33 at the same time.

[0111] When the temperature observed from the temperature change sensor 13 reaches the preset temperature, it is switched to the automatic state.

[0112] The wireless wall thickness detector is sequentially attached to the first card slot 18, the second card slot 19 and the third card slot 20 to simulate the influence of different insulation material layers on the corrosion of the outer pipe after the inner pipe of a double-layer pipe (pipe in pipe) leaks. The average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the outer wall card slot of the experimental device body 1.

[0113] After the experiment is completed, the media in the experimental device body 1 and the heating device 3 are emptied in sequence.

[0114] Embodiment 4:

[0115] The first detachable flange 22, the second detachable flange 23, and the third detachable flange 24 are disassembled in sequence, and the catheter is pulled out at the same time, and the insulation test block at the bottom of the catheter is replaced.

[0116] First, open the first exhaust port 11 and the second exhaust port 33, and then let the configured seawater or real seawater (medium) enter the heating device 3 from the second water inlet 32. When it is observed through the second exhaust port 33 that the medium in the heating device 3 is about to overflow, turn on the circulation pump 2 and the temperature control element 31 at the same time. At this time, the temperature control element 31 is set to manual state, and the medium flows from the second water outlet 34 through the first water inlet 16 along with the circulation pump 2, and then enters the inside of the experimental device body 1. Then the medium circulates from the first water outlet 17 to the second water inlet 32 ​​until the medium slowly fills the experimental device body 1 and the heating device 3. When it is observed from the first exhaust port 11 that the experimental device body 1 is close to overflowing, stop the water intake, and close the first exhaust port 11 and the second exhaust port 33 at the same time.

[0117] When the temperature observed from the temperature change sensor 13 reaches the preset temperature, it is switched to the automatic state.

[0118] The wireless wall thickness detector is sequentially attached to the first card slot 18, the second card slot 19 and the third card slot 20 to simulate the influence of different insulation material layers on the corrosion of the outer pipe after the inner pipe of a double-layer pipe (pipe in pipe) leaks. The average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the outer wall card slot of the experimental device body 1.

[0119] After the experiment is completed, the media in the experimental device body 1 and the heating device 3 are emptied in sequence.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multifunctional experimental device for simulating corrosion conditions in submarine pipelines, characterized in that: The experimental device comprises an experimental device body (1), a heating device (3) and a circulating pump (2); the water inlet of the circulating pump (2) is connected to the second water outlet (34) of the heating device (3); the water outlet of the circulating pump (2) is connected to the first water inlet (16) of the experimental device body (1); the first water outlet (17) of the experimental device body (1) is connected to the second water inlet (32) of the heating device (3) through a pipeline; the circulating pump (2) can uniformly circulate and heat the medium in the experimental device body (1), that is, the circulating pump (2) can continuously transport the medium heated by the heating device (3) to the experimental device body (1); and the experimental device can simultaneously carry out the following three types of corrosion rate simulation experiments: a corrosion hanging plate experiment, a corrosion probe experiment and a double-layer pipe annulus corrosion simulation experiment.

2. A multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 1, characterized in that: The material of the experimental device body (1) is the same as that of the submarine pipeline. The outside of the experimental device body (1) is provided with a first exhaust port (11), a corrosion hanger insertion port (12), a plug-in corrosion probe insertion port (15), a first water inlet (16), a first water outlet (17) and a first bottom row (21). At the same time, the inner cavities of the first exhaust port (11), the corrosion hanger insertion port (12), the plug-in corrosion probe insertion port (15), the first water inlet (16), the first water outlet (17) and the first bottom row (21) are respectively connected to the inner cavity of the experimental device body (1); A connector for installing a temperature sensor (13) and a pressure gauge (14) is also installed on the outside of the experimental device body (1), and the two connectors are respectively connected to the inner cavity of the experimental device body (1), the temperature sensor (13) is used to measure the temperature inside the experimental device body (1), and the pressure gauge (14) is used to measure the pressure inside the experimental device body (1); A first card slot (18), a second card slot (19) and a third card slot (20) are also provided on the outside of the experimental device body (1), and the first card slot (18), the second card slot (19) and the third card slot (20) are respectively used to install a wireless wall thickness detector.

3. A multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 2, characterized in that: A first detachable flange (22), a second detachable flange (23) and a third detachable flange (24) are installed on the outside of the experimental device body (1), and a corrosion hanger (25), a corrosion probe (26) and three insulation test blocks are installed on the inside of the experimental device body (1). At the same time, the upper end of the corrosion hanger (25) is connected to the corrosion hanger insertion port (12), and the upper end of the corrosion probe (26) is connected to the plug-in corrosion probe insertion port (15). The detachable flange blind plates of the first detachable flange (22), the second detachable flange (23) and the third detachable flange (24) are respectively fixedly welded to a conduit. At the same time, the three insulation test blocks are respectively detachably installed at the lower end of the conduit, and the insulation test blocks are in conflict with the inner wall of the experimental device body (1).

4. The multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 2 is characterized in that: The material of the heating device (3) is 316L stainless steel. The outside of the heating device (3) is provided with a temperature control element (31), a second water inlet (32), a second air outlet (33), a second water outlet (34) and a second bottom row (35). Meanwhile, the inner cavities of the second water inlet (32), the second air outlet (33), the second water outlet (34) and the second bottom row (35) are respectively connected to the inner cavity of the heating device (3); An MCH ceramic heating rod (36) is installed inside the heating device (3). One end of the MCH ceramic heating rod (36) is electrically connected to a temperature control element (31) in a plug-in manner. The temperature control element (31) is connected to a temperature sensor (13) provided on the main body (1) of the experimental device by a 485 three-core signal line. At the same time, the temperature control element (31) is externally connected to a PLC. The PLC controls the opening, closing or temperature adjustment of the temperature control element (31) by receiving a temperature feedback signal from the temperature sensor (13), thereby realizing control of the MCH ceramic heating rod (36).

5. A multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 4, characterized in that: The temperature sensor (13) is provided with an automatic / manual switching function and a low warning / high warning function, the maximum allowable range of the temperature difference is ±2°C, and the interlocking MCH ceramic heating rod (36) starts at a low level and stops at a high level; The temperature change sensor (13) is provided with a low-low alarm and a high-high alarm, the minimum allowable range of the alarm threshold is ±5°C, and the interlocking MCH ceramic heating rod (36) is turned off.

6. The multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 1 is characterized in that: The circulation pump (2) is made of 316L stainless steel inside and outside. All connecting pipelines are quick-plug type. The quick-plug plug is made of 316L stainless steel. The connecting pipe is a PU hose. The first bottom row (21), the first exhaust port (11), the second bottom row (35) and the second exhaust port (33) are all made of 316L stainless steel.

7. The multifunctional experimental device for simulating corrosion state in submarine pipelines according to claim 1 is characterized by: The experimental device can simulate the effect of the insulation layer on the corrosion of the outer pipe after the inner pipe of the double-layer pipe leaks. The average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the three slots on the outer wall of the main body (1) of the experimental device. When the average corrosion rate is greater than or equal to 0.03 mm / a, the experimental result of the corrosion coupon (25) is used as the benchmark; when the average corrosion rate is less than 0.03 mm / a, the experimental result of the corrosion probe (26) is used as the benchmark; The experimental device can simulate the effect of the insulation layer on the corrosion of the outer pipe after the inner pipe of a double-layer pipe leaks. The staff will replace different insulation test blocks according to actual simulation needs.

8. An experimental method for simulating corrosion conditions in a submarine pipeline, characterized in that: The experiment is carried out by the experimental device according to any one of claims 1 to 7, wherein the experimental method includes a corrosion coupon experiment, a corrosion probe experiment and a double-layer pipe annulus corrosion simulation experiment; the corrosion coupon experiment and the corrosion probe experiment are respectively used to simulate the corrosion rate of the medium on the pipe wall, wherein the corrosion probe experiment can accurately analyze the water quality, dissolved oxygen content and microbial content; when the corrosion coupon experiment and the corrosion probe experiment are carried out, the corrosion probe (26) and the corrosion coupon (25) are respectively inserted into the main body (1) of the experimental device to continuously monitor the corrosion rate data for 7 days; The double-layer pipe annulus corrosion simulation experiment is used to simulate the influence of different insulation material layers on the outer pipe corrosion after the inner pipe of the double-layer pipe leaks. When the double-layer pipe annulus corrosion simulation experiment is carried out, the wireless wall thickness detector is sequentially attached to the first card slot (18), the second card slot (19) and the third card slot (20), and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector.

9. The experimental method for simulating corrosion conditions in submarine pipelines according to claim 8, characterized in that: The corrosion coupon test / corrosion probe test includes the following steps: Step 11, injecting configured seawater or real seawater into the heating device (3), the configured seawater or real seawater is also called medium; Step 12, when the medium in the heating device (3) is about to overflow, the circulation pump (2) and the temperature control element (31) of the heating device (3) are turned on to allow the medium to flow into the experimental device body (1), and the medium is then circulated from the experimental device body (1) back to the heating device (3) along with the circulation pump (2) until the experimental device body (1) and the heating device (3) are slowly filled; Step 13, when the experimental device body (1) is close to overflowing, stop the water intake; Step 14, when the temperature reaches a preset temperature as observed by the temperature sensor (13) provided on the main body (1) of the experimental device, the temperature control element (31) is switched from a manual state to an automatic state; Step 15, observing the pressure change in the experimental device body (1) from the pressure gauge (14) provided on the experimental device body (1); Step 16, inserting the corrosion probe (26) into the plug-in corrosion probe insertion port (15), and inserting the corrosion hanger (25) into the corrosion hanger insertion port (12), to simulate the corrosion rate of the medium on the pipe wall; when the average corrosion rate is greater than 0.03 mm / a, the corrosion hanger test results are used as a reference; when the average corrosion rate is less than 0.03 mm / a, the corrosion probe test results are used as a reference.

10. The experimental method for simulating corrosion conditions in a submarine pipeline according to claim 8, characterized in that: The double-layer pipe annulus corrosion simulation experiment includes the following steps: Step 21, injecting the configured seawater or real seawater into the heating device (3), the configured seawater or real seawater is also called medium; Step 22, when the medium in the heating device (3) is about to overflow, the circulation pump (2) and the temperature control element (31) of the heating device (3) are turned on to allow the medium to flow into the experimental device body (1), and the medium is then circulated from the experimental device body (1) back to the heating device (3) along with the circulation pump (2) until the experimental device body (1) and the heating device (3) are slowly filled; Step 23, when the experimental device body (1) is close to overflowing, stop the water intake; Step 24, when the temperature reaches a preset temperature as observed by the temperature sensor (13) provided on the main body (1) of the experimental device, the temperature control element (31) is switched from a manual state to an automatic state; Step 25, observing the pressure change in the experimental device body (1) from the pressure gauge (14) provided on the experimental device body (1); Step 26, attaching the wireless wall thickness detector to the first card slot (18), the second card slot (19) and the third card slot (20) in sequence, with each card slot corresponding to an insulation test block of a different material, so as to simulate the influence of different insulation material layers on the corrosion of the outer tube after the inner tube of the double-layer tube leaks, and the average corrosion rate thereof is based on the thickness measurement data of the wireless wall thickness detector attached to the card slot of the outer wall of the experimental device body (1); Step 27, drain the medium in the experimental device body (1) and the heating device (3), then remove the first detachable flange (22), the second detachable flange (23), and the third detachable flange (24), and at the same time, pull out the catheter, and then replace the insulation test block at the bottom of the catheter; Step 28, repeating steps 21 to 26, simulating the effect of different insulation material layers on the corrosion of the outer tube after the inner tube of the double-layer tube leaks, and the average corrosion rate is based on the thickness measurement data of the wireless wall thickness detector attached to the outer wall slot of the experimental device body (1).

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