Pipeline corrosion monitoring system under the insulation layer

Abstract

The present application relates to the technical field of pipeline corrosion and condensation, in particular to a pipeline corrosion monitoring and detecting system under the pipeline thermal insulation layer, which is applied to the pipeline and its thermal insulation structure, the thermal insulation structure of the pipeline comprises a thermal insulation layer and a plurality of protective layers arranged outside the thermal insulation layer, and the monitoring and detecting system comprises a plurality of detecting circuits; for any one of the detecting circuits, two ends thereof are connected with two protective layers which are spaced apart by a preset number of protective layers, and the detecting circuit is used for detecting the capacitance value of the capacitor with the two connected protective layers as two poles. In this way, the two protective layers connected with the detecting circuit can be regarded as two poles of a capacitor, and the capacitance value thereof is detected, so that whether the pipeline between the two protective layers has the possibility of corrosion is determined based on the capacitance value, and a basis is provided for preventive maintenance of the pipeline.

Description

Technical Field

[0001] This invention relates to the field of pipeline corrosion and condensation technology, specifically to a corrosion monitoring and detection system under pipeline insulation layers. Background Technology

[0002] In the field of pipeline corrosion and condensation technology, such as in the petrochemical industry, thermal insulation of pipelines using insulation structures is essential. Figure 1 As shown, in the prior art, the insulation structure of a pipeline typically includes an insulation layer 1 and a protective layer 4 set on the outside of the insulation layer, as well as parts on it or parts used for connection and fixing, such as insulation layer joints 2, binding steel strips or binding wires 3, protective layer interfaces 5, and self-tapping screws or rivets 6, etc.

[0003] The insulation layer is generally made of asbestos-like material. When the asbestos-like material in the insulation layer absorbs water (which may be condensation or water seeping from the environment), it creates a particularly corrosive environment that can damage the pipeline. Therefore, it is especially important to monitor and detect corrosion under the pipeline insulation layer. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a corrosion monitoring and detection system under the pipeline insulation layer for monitoring and detecting corrosion under the pipeline insulation layer.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This application provides a corrosion monitoring and detection system for pipelines under insulation layers, which is applied to pipelines and their insulation structures. The insulation structure of the pipeline includes an insulation layer and multiple protective layers disposed on the outside of the insulation layer. The monitoring and detection system includes multiple detection circuits.

[0007] For any one of the detection circuits, its two ends are respectively connected to two protective layers spaced a preset number of protective layers, which are used to detect the capacitance value of the capacitor with the two protective layers connected as its two poles.

[0008] Furthermore, in some embodiments of this application, the preset quantity is 0.

[0009] Furthermore, in some embodiments of this application, the preset quantity is 1.

[0010] Furthermore, in some embodiments of this application, the lengths along the pipe axis of the two protective layers connected to the same detection circuit are greater than the lengths along the pipe axis of the protective layer located between the two protective layers.

[0011] Furthermore, in some embodiments of this application, each of the detection circuits includes: a main control module, a first switch, a second switch, a third switch, and a fourth switch;

[0012] The first terminal of the main control module is grounded and connected to the first terminal of the first switch; the second terminal of the main control module is connected to the first terminal of the second switch and to the second terminal of the third switch.

[0013] The second terminal of the first switch is grounded and connected to the first terminal of the third switch and the first protective layer under test, respectively.

[0014] The second terminal of the second switch is connected to the first terminal of the fourth switch and is also connected to the second protective layer to be tested.

[0015] The second terminal of the fourth switch is grounded;

[0016] The main control module is used to send, receive, and analyze calculation signals to detect the capacitance value of the capacitor with the first protective layer under test and the second protective layer under test as the two poles.

[0017] Furthermore, in some embodiments of this application, the detection circuit further includes a communication module;

[0018] The communication module is used to transmit the analysis and calculation results of the main control module to a preset terminal.

[0019] Furthermore, in some embodiments of this application, the communication module includes at least one of a wired communication module, a WiFi module, a Bluetooth module, and a 4G / 5G network module.

[0020] Furthermore, in some embodiments of this application, the main control module includes any one of a 555 monostable measurement circuit, a bridge measurement circuit, and a capacitance measurement chip.

[0021] This invention relates to the field of pipeline corrosion and condensation technology, specifically to a corrosion monitoring and detection system for pipelines under insulation layers. This system is applied to pipelines and their insulation structures. The insulation structure includes an insulation layer and multiple protective layers disposed outside the insulation layer. The monitoring and detection system includes multiple detection circuits. For any given detection circuit, its two ends are respectively connected to two protective layers spaced a predetermined number of times apart, used to detect the capacitance value of a capacitor formed by the two connected protective layers as its two poles. Thus, the two protective layers connected to the detection circuit can be treated as the two poles of a capacitor, and their capacitance value can be detected. Based on the capacitance value, it can be determined whether corrosion is possible between the two protective layers, providing a basis for the protection and maintenance of pipeline insulation structures. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the insulation structure of pipelines in the prior art;

[0024] Figure 2 This is a cross-sectional schematic diagram of the insulation structure of a pipeline in the prior art;

[0025] Figure 3 This is a schematic diagram of the distribution of the detection circuit in the corrosion monitoring system under the pipe insulation layer provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the distribution of the detection circuit in a corrosion monitoring system under the pipe insulation layer provided in another embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the detection circuit in the corrosion monitoring system under the pipe insulation layer provided in the embodiments of this application;

[0028] Figure 6 This is a circuit diagram of the detection circuit in the corrosion monitoring system under the pipe insulation layer provided in the embodiments of this application;

[0029] Figure 7 This is a schematic diagram of a 555 monostable measurement circuit in the prior art. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] Figure 2 This is a cross-sectional schematic diagram of the insulation structure of a pipeline in the prior art, such as... Figure 2As shown, an insulation layer 20 is provided on the outside of the pipe 10, and multiple protective layers (41-49) are provided on the outside of the insulation layer 20. The protective layers can be made of metal. They are arranged around the outside of the protective layers, and insulating materials such as insulating tape are provided at the joints of adjacent protective layers. This part is the prior art in this field. Only the part closely related to this application is introduced here. Other parts can be understood by referring to the insulation structure of pipelines in the petrochemical field in the prior art. They will not be described in detail here.

[0032] Based on this, the corrosion monitoring and detection system under the insulation layer of the pipeline provided in this application is applied to the insulation structure of the above-mentioned pipeline. As mentioned above, the insulation structure of the pipeline includes an insulation layer and multiple protective layers disposed on the outside of the insulation layer. The monitoring and detection system includes multiple detection circuits. For any detection circuit, its two ends are respectively connected to two protective layers spaced apart by a preset number of protective layers, which are used to detect the capacitance value of the capacitance between the two protective layers connected to it as two poles.

[0033] It should be noted that, with protective layer 41 as one electrode, 42 as the other electrode, and insulation layer 20 as the dielectric, this local structure can be considered as a capacitor, and the capacitance value of this capacitor is expressed as follows:

[0034] Q=f(d1,l1,d2,l2,gap,pip,med)

[0035] Wherein, d1 is the radius of protective layer 41; l1 is the length of protective layer 41 along the pipe axis; d2 is the radius of protective layer 42; l2 is the length of protective layer 42 along the pipe axis; gap is the gap state, that is, the gap state between protective layer 41 and protective layer 42; pip is the pipe specification; med is the material of insulation layer 20.

[0036] As shown in the above formula, when the pipe specifications are fixed (i.e., d1, l1, d2, l2, gap, and pip parameters remain constant), the capacitance value is only related to med. The dielectric constant of asbestos, a common insulation material, is between 3 and 4.8, while that of water is 78.3. Therefore, if water is present in the insulation layer 20 at a certain location, med will increase, leading to an increase in capacitance. Thus, by detecting the capacitance value, it is possible to detect the presence of water under the insulation layer, thereby enabling pre-corrosion detection.

[0037] In some embodiments of this application, the preset quantity mentioned above can be 0. In this case, the protective layers connected to the same detection circuit are two adjacent protective layers (such as 41 and 42). Figure 3 As shown ( Figures 3-6In the diagram, number 100 represents the detection circuit. It's understandable that, considering the actual length of the protective layer during installation, the joints (circumferential joints) between each insulation layer are electrically isolated (i.e., non-conductive) using insulating materials such as butyl rubber. Therefore, by adding a monitoring circuit between adjacent protective layers, the capacitance value can indicate whether there is water beneath each protective layer, thus enabling the detection of pipeline corrosion before it occurs.

[0038] In other embodiments of this application, the preset quantity mentioned above can be 1. In this case, the protective layers connected to the same detection circuit are separated by a protective layer (such as 41 and 43). Figure 4 As shown. It should be noted that in practical applications, when detecting the capacitance between adjacent protective layers, the insulating material between adjacent protective layers, such as butyl rubber, as described in the above embodiments, has a significant impact on the specific capacitance value. Therefore, detecting the capacitance value of a capacitor composed of two protective layers separated by one protective layer can reduce the influence of the insulating material between them on the detected capacitance value, thereby improving the detection effect.

[0039] Furthermore, in some embodiments of this application, when the preset quantity is 1, the lengths along the pipe axis of the two protective layers connected by the same detection circuit can be set to be greater than the length along the pipe axis of the protective layer located between the two protective layers. For example, when a monitoring circuit connects 41 and 43, the lengths along the pipe axis of 41 and 43 can be set to be greater than the length along the pipe axis of 42. For instance, the lengths along the pipe axis of 41 and 42 can be set to 5-10m, while the length along the pipe axis of 42 can be set to 0.5m, further avoiding the influence of objects between the two connected protective layers on the detection effect and further improving the detection effect.

[0040] Figure 5 This is a schematic diagram of the detection circuit in the corrosion monitoring system under the pipe insulation layer provided in this application embodiment. Figure 5 As shown, when measuring the capacitance of the pipe's protective layer, each detection circuit can use a shielded cable to connect the two plates of the capacitor (i.e., the two protective layers in the pipe's insulation structure) to the measurement circuit. The shielding layer (metal layer) of the shielded cable is connected to ground. Similarly, the use of shielded cables ensures signal transmission and thus improves the detection effect.

[0041] In practical applications, the cables are very long during on-site implementation, and the resulting external capacitance has a certain impact on the detection results. Therefore, in this embodiment, by setting multiple switches in the detection circuit to detect multiple capacitance values ​​and then calculating the multiple capacitance values, the external capacitance generated by the cable is removed, and a more accurate capacitance value of the capacitor composed of the two protective layers is obtained, thereby improving the detection effect.

[0042] Figure 6This is a circuit diagram of the detection circuit in the corrosion monitoring system under the pipe insulation layer provided in this application embodiment, as shown below. Figure 6 As shown, in order to avoid external capacitance generated by the cable, the detection circuit in this embodiment of the application specifically includes: a main control module, a first switch A1, a second switch B1, a third switch A2 and a fourth switch B2;

[0043] The main control module has a first terminal grounded and connected to the first terminal of the first switch A1; a second terminal of the main control module is connected to the first terminal of the second switch B2 and to the second terminal of the third switch A2; the second terminal of the first switch A1 is grounded and connected to the first terminal of the third switch A2 and the first protective layer under test; the second terminal of the second switch is connected to the first terminal of the fourth switch B2 and to the second protective layer under test; the second terminal of the fourth switch B2 is grounded; the main control module is used to send, receive, and analyze calculation signals to detect the capacitance value of the capacitor with the first and second protective layers under test as its two poles.

[0044] The external capacitance generated by the cable is equivalently represented by Cpex1 and Cpex2, and the actual capacitance to be measured is represented by Cx. The specific application and calculation are as follows:

[0045] State 1: A1 and B1 are closed, A2 and B2 are open, and the measured value X1 = Cx + Cpex2 is obtained;

[0046] State 2: A2 and B1 are closed, A1 and B2 are open, and the measured value X2 = Cpex1 + Cpex2 is obtained;

[0047] State 3: A2 and B2 are closed, A1 and B1 are open, and the measured value X3 = Cx + Cpex1 is obtained;

[0048] The final capacitance value to be measured is Cx = (X1 + X3 - X2) / 2.

[0049] In this application, the main control module can be used to measure capacitance. Its measurement part includes, but is not limited to, a 555 monostable measurement circuit that converts the capacitance value into pulse time for measurement; a bridge measurement circuit, such as a four-wire bridge circuit; and direct measurement using a capacitance value measurement chip PCAP01 (or PCAP04 series, etc.).

[0050] Among them, the circuit that uses the 555 monostable measurement circuit for measurement is as follows: Figure 7 As shown, it should be noted that, Figure 7 This is just a schematic diagram of the 555 monostable measurement circuit. The specific circuit parameters are not intended to be limiting. In practical applications, they can be adjusted and selected according to the actual situation.

[0051] In addition, the main control module of the detection circuit in the pipeline insulation layer corrosion monitoring system provided in this application may also include a communication module for transmitting the analysis and calculation results of the main control module to a preset terminal such as a mobile phone or tablet. The communication module may include at least one of a wired communication module, a WiFi module, a Bluetooth module, and a 4G / 5G network module.

[0052] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0053] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0054] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0055] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0056] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0057] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0058] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0059] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A corrosion monitoring and detection system for pipelines under insulation layers, applied to pipelines and their insulation structures, wherein the insulation structure of the pipeline includes an insulation layer and multiple protective layers disposed on the outside of the insulation layer, and the monitoring and detection system includes multiple detection circuits; For any of the detection circuits, two protective layers with a preset number of protective layers are respectively connected to its two ends, which are used to detect the capacitance value of the two protective layers connected to it as two poles. in, Each of the detection circuits includes: a main control module, a first switch (A1), a second switch (B1), a third switch (A2), and a fourth switch (B2); The first terminal of the main control module is grounded and connected to the first terminal of the first switch (A1); the second terminal of the main control module is connected to the first terminal of the second switch (B1) and to the second terminal of the third switch (A2); The second terminal of the first switch (A1) is grounded and connected to the first terminal of the third switch (A2) and the first protective layer under test, respectively. The second terminal of the second switch (B1) is connected to the first terminal of the fourth switch (B2) and is also connected to the second protective layer to be tested; The second terminal of the fourth switch (B2) is grounded; The main control module is used to send, receive, and analyze calculation signals. It performs multiple measurements by controlling the combined states of the first switch (A1), the second switch (B1), the third switch (A2), and the fourth switch (B2), and calculates based on the results of the multiple measurements to detect the capacitance values ​​of the first and second protective layers under test as two poles, and to eliminate the interference of parasitic capacitance generated by the connecting cable on the measurement results. The preset quantity is 0 or 1; When the preset quantity is 1, the capacitance value of the capacitor formed by two protective layers with a protective layer between them is detected. This can reduce the influence of the insulating material between them on the detected capacitance value, thereby improving the detection effect. The process of detecting the capacitance values ​​of the first and second protective layers as electrodes includes: The external capacitance generated by the cable is equivalently represented by Cpex1 and Cpex2, and the actual capacitance to be measured is represented by Cx. The specific application and calculation are as follows: State 1: A1 and B1 are closed, A2 and B2 are open, and the measured value X1 = Cx + Cpex2 is obtained; State 2: A2 and B1 are closed, A1 and B2 are open, and the measured value X2 = Cpex1 + Cpex2 is obtained; State 3: A2 and B2 are closed, A1 and B1 are open, and the measured value X3 = Cx + Cpex1 is obtained; The final capacitance value to be measured is Cx = (X1 + X3 - X2) / 2; The main control module includes any one of a 555 monostable measurement circuit, a bridge measurement circuit, and a capacitance measurement chip. The length of the two protective layers connected to the same detection circuit along the pipe axis is greater than the length of the protective layer located between the two protective layers along the pipe axis, which can further avoid the influence of objects between the two connected protective layers on the detection effect and further improve the detection effect.

2. The corrosion monitoring and detection system under the pipeline insulation layer according to claim 1, characterized in that, The detection circuit also includes a communication module; The communication module is used to transmit the analysis and calculation results of the main control module to a preset terminal.

3. The corrosion monitoring and detection system under the pipeline insulation layer according to claim 2, characterized in that, The communication module includes at least one of a wired communication module, a WiFi module, a Bluetooth module, and a 4G / 5G network module.

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