TWM500771U - Cathodic corrosion protection multifunctional device - Google Patents

Description

Cathodic corrosion protection multifunctional device

This creation is about a cathodic corrosion protection system, especially a cathodic corrosion protection system that improves the accuracy of potential detection.

According to Cathodic Protection (CP), a metal structure that uses an electrochemical principle to provide an anti-corrosion current to a metal structure to be protected, so that the metal structure can achieve an anti-corrosion effect, for a metal structure buried in the underground or under the sea. Cathodic corrosion protection has been regarded as the only effective anti-corrosion method by oil and gas pipelines or dock foundations. However, many pipelines equipped with cathodic corrosion protection still cause corrosion. The reason is that in addition to poor construction. In addition, it is mainly due to the failure to implement a continuous and effective anti-corrosion effect detection. At present, the industry generally evaluates whether a cathodic anti-corrosion system has an effect through various potential detection methods, such as detecting the polarization potential by means of a power-off method. Referring to the first figure, a mechanical switch 13 is used to control and switch a rectifier 12 to apply an anti-corrosion current to a structure 20 to be protected, such as a hydrocarbon line, and a sacrificial anode 21 such as a titanium mesh. For polarization), a potential detector 11 and a potential logger 14 are used to measure and record the structure 20 at the rectifier 12 The polarization potential and the depolarization potential for a period of time (usually 24 hours or longer) after power-off, when the two potentials reach a certain value or more (such as 100mv), the structure 20 is considered to be effective. Protection, wherein the potential detector 11 may specifically include a reference electrode such as a copper sulfate electrode or The silver chloride electrode, and the foregoing detailed software and hardware operation procedures for polarization potential detection are all well-known techniques, and can be specifically referred to the reference specification established by the American Society of Corrosion Engineers (NACE), and will not be described in detail herein.

Referring to the first figure, although the conventional cathodic corrosion protection system can verify the anti-corrosion effect by detecting the polarization potential, the mechanical switch 13 is used to control the activation or deactivation of the polarization, so the voltage will continue to be input during the polarization process. On the structure 20, after long-term use, the reference electrode of the potential detector 11 easily generates or adheres oxides and impurities, affecting the accuracy of potential detection; in addition, the contact of the mechanical switch 13 is easy to switch between opening and closing operations. Spark is generated, so it is not suitable for petrochemical oil and gas applications where fireworks are strictly prohibited. The practicality and applicability of conventional cathodic corrosion protection systems are limited. Therefore, how to improve the above-mentioned defects, that is, the creators of this case The technical difficulties to be solved are located.

In view of the potential detecting device of the existing cathodic corrosion protection system, the use of a mechanical switch to control the polarization action causes the reference electrode to be easily oxidized and affects the detection accuracy, and the mechanical switch is also prone to sparks, which limits its application field and reduces product reliability and Practicality, the purpose of this creation is to develop a potential detection device for a cathodic corrosion protection system that improves the accuracy of potential detection.

In order to achieve the above objective, the present invention provides a cathode anti-corrosion multifunctional device comprising: a rectifier having a positive terminal and a negative terminal, the rectifier being provided with a control signal input terminal; and a high power semiconductor switch. The high-power semiconductor open relationship is connected to the rectifier; a control module is respectively connected to the control signal input end of the rectifier and the high-power semiconductor switch.

By using a high-power semiconductor switch instead of a conventional mechanical switch, the voltage during the polarization process can be displayed as a high-speed switching pulse signal, and the pulse signal can also impact the impurities such as oxides on the reference electrode. The falling off, the potential detection is better and more accurate, and the high-power semiconductor switch is a contactless electronic switch, so it can be applied to petrochemical oil and gas fields that need to prohibit pyrotechnics, so that the creation can greatly improve the accuracy of potential detection. Degree and product suitability.

[Use]

11‧‧‧potentiometric detector

12‧‧‧Rectifier

13‧‧‧Mechanical switch

14‧‧‧ Potential Recorder

20‧‧‧structures

21‧‧‧ Sacrificial anode

[this creation]

3‧‧‧Rectifier

31‧‧‧ Positive

32‧‧‧ negative end

33‧‧‧Control signal input

4‧‧‧potentiometric detector

5‧‧‧Media environment

6‧‧‧High power semiconductor switch

7‧‧‧Control Module

71‧‧‧Isolation amplification comparison circuit

72‧‧‧Storage output module

8‧‧‧structures

9‧‧‧ Sacrificial anode

The first figure is a schematic diagram of the structure used.

The second picture is a schematic diagram of the structure of the creation.

The third picture is a schematic diagram of the action of this creation.

Referring to the second figure, the present invention provides a cathode anti-corrosion multifunctional device comprising: a rectifier 3, the rectifier 3 is actually a power supply, and the rectifier 3 is provided with a positive end 31 and a negative end 32. The rectifier 3 is further provided with a control signal input terminal 33. The positive terminal 31 and the negative terminal 32 of the rectifier 3 are generally respectively connected to a structure 8 to be protected and a sacrificial anode 9 for the structure 8 and the sacrificial anode. 9 is generally buried in a medium environment 5 (such as seawater, soil or concrete), in the cathodic corrosion protection system, the medium environment 5 can provide the equivalent of an electrolyte (electrolyte); a high-power semiconductor switch 6, the high power The semiconductor switch 6 is connected to the rectifier 3 for switching the operating state of the rectifier 3 as a control rectifier 3 for the structure 8 In the present embodiment, the high-power semiconductor switch 6 is connected between the positive terminal 31 of the rectifier 3 and the sacrificial anode 9. In addition, the high-power semiconductor switch 6 is preferably Insulated Gate Bipolar Transistor (IGBT) can be used to maintain high-speed switching in high-power applications. A control module 7, the control module 7 and the rectifier 3 are respectively controlled. The signal input terminal 33 is connected to the high-power semiconductor switch 6 for controlling the operation of the rectifier 3 and the high-power semiconductor switch 6; a potential detector 4, the potential detector 4 and the control module 7 communication connection for measuring the potential of the structure 8 and transmitting the result (measurement signal or value) back to the control module 7 for feedback control, the potential detector 4 is generally disposed on the structure 8 In the vicinity, the potential detector 4 is usually provided with a reference electrode. According to the difference of the medium environment 5 in which the structure 8 is located, a reference electrode of different materials, such as a copper sulfate electrode, a silver electrode, a silver chloride electrode or Aluminum magnesium In addition, the present invention may further include an isolation amplification comparison circuit 71 connected between the control module 7 and the potential detector 4, and more specifically, the isolation amplification comparison. The circuit 71 generally includes an isolation amplifier and a comparator, and the isolation amplifier can be used to electrically isolate the measurement signal of the potential detector 4 and then amplify the signal to improve the anti-noise interference capability of the measurement signal; The device is configured to compare the isolated amplified measurement signal with a preset value, and output a corresponding feedback control signal to the control module 7 according to the comparison result, so that the control module 7 can The feedback control signal is used to compensate the voltage and current of the anti-corrosion operation, so that the creation can simultaneously have the function of automatic compensation of the anti-corrosion operation, and it is worth mentioning that the isolation amplification comparison circuit 71 and the control module 7 Can also be integrated The storage output module 72 is electrically connected to the isolation and amplification comparison circuit 71. The storage output module 72 is usually provided with a storage output module 72. The storage device, such as a memory or a hard disk, is used for recording and storing the measurement signal or value of the potential detector 4. The storage output module 72 can also be provided with an output communication interface such as USB, RS-232 or RS-485. To enable an external device such as a computer to be connected to and access the measurement signal or value, thereby enhancing the practicality of the creation; please refer to the third figure, and use the cathode corrosion protection system of the present invention. When the polarization potential detection is performed to verify the anti-corrosion effect, the control module 7 can control and turn on the rectifier 3 and the high-power semiconductor switch 6, apply an anti-corrosion current to the structure 8 (ie, perform a polarization operation), and then transmit the power. The semiconductor switch 6 operates to turn off the anti-corrosion current, and at the same time, the potential detector 4 is used to measure the polarization potential and the depolarization potential of the structure 8, and the corrosion resistance of the system can be evaluated according to the difference between the two potentials. The detection action flow here is the same as the conventional one; please refer to the second figure and the third figure. It is worth mentioning that by using the high-power semiconductor switch 6 instead of the conventional mechanical switch 13, the creation is Control techniques such as pulse width modulation (PWM) can be used to control the operation of the high-power semiconductor switch 6 during polarization, so that the voltage during the polarization process appears as a high-speed switching pulse signal instead of continuing as usual. In addition to the same performance as the continuous input power supply, the signal can also be adjusted according to the requirements of the polarization time and frequency. At the same time, the pulse signal can also impact the impurities such as oxide on the reference electrode to cause it to fall off. The potential detection is better and more accurate, and the high-power semiconductor switch 6 is a contactless electronic switch, so it can be applied to petrochemical oil and gas fields where fireworks are prohibited, so that the creation can greatly improve the accuracy of potential detection and products. The function of the applicability; in addition, the control module 7 is provided by the present invention, and the control module 7 communicates with the rectifier 3 and the potential detector 4 respectively. The connection can be configured as a feedback configuration. Thus, the control module 7 can control the anti-corrosion current of the rectifier 3 according to the result of the potential detection to adjust the anti-corrosion effect, so as to realize the automatic compensation function of the anti-corrosion current. At the same time, the creation of the polarization time allows the control module 7 to perform automatic potential detection operations in a regular timing manner, so that the creation can improve various functions such as detection accuracy, automatic detection, automatic feedback compensation, and the like. This creation can save both monitoring manpower and ease of use.

3‧‧‧Rectifier

31‧‧‧ Positive

32‧‧‧ negative end

33‧‧‧Control signal input

4‧‧‧potentiometric detector

5‧‧‧Media environment

6‧‧‧High power semiconductor switch

7‧‧‧Control Module

71‧‧‧Isolation amplification comparison circuit

72‧‧‧Storage output module

8‧‧‧structures

9‧‧‧ Sacrificial anode

Claims (5)

A cathode anti-corrosion multifunctional device comprises: a rectifier, the rectifier is provided with a positive terminal and a negative terminal, the rectifier is provided with a control signal input terminal; and a high-power semiconductor switch is connected to the rectifier; A control module is respectively connected to the control signal input end of the rectifier and the high power semiconductor switch. The cathodic corrosion protection multifunction device of claim 1, wherein the high power semiconductor switch is an insulated double gate transistor (IGBT). The cathode anti-corrosion multi-function device of claim 1, further comprising a potential detector, wherein the potential detector is in communication with the control module. The cathodic corrosion protection multi-function device of claim 3, further comprising an isolation amplification comparison circuit connected between the control module and the potential detector. The cathode anti-corrosion multi-function device of claim 4, further comprising a storage output module electrically connected to the isolation amplification comparison circuit.