Device for monitoring electric leakage discharge of electrolytic cell and monitoring method

Abstract

The invention relates to a device for monitoring electric leakage discharge of an electrolytic bath and a monitoring method. The device comprises a power grid power supply unit, a contactor, a hydrogen production power supply, a proton exchange membrane electrolytic bath body, at least one sound pickup, a controller, an alarm unit, a valve control unit and a signal conditioner, the power grid power supply unit is connected with the hydrogen production power source through the contactor, the proton exchange membrane electrolytic bath body is connected with the hydrogen production power source and the valve control unit, and the sound pick-up is arranged on the periphery of the proton exchange membrane electrolytic bath body and used for collecting sound signals in the operation process of the proton exchange membrane electrolytic bath body. The sound pickup is connected with the signal conditioner, and the controller is connected with the signal conditioner, the alarm unit, the valve control unit and the contactor, so that timely monitoring can be realized, the omission ratio is low, and the operation safety can be improved.

Description

Technical Field

[0001] This invention relates to the field of electrolytic cell technology, and in particular to a device and method for monitoring leakage discharge in electrolytic cells. Background Technology

[0002] In water electrolysis for hydrogen production, proton exchange membrane (PEM) electrolyzers have become one of the mainstream technologies for green hydrogen production due to their advantages such as high current density, fast response speed, and high hydrogen purity. However, under long-term operation or abnormal conditions (such as membrane electrode damage, impurity blockage, gas permeation, or pressure fluctuations), micro-gap discharges (commonly known as "pop-pop" discharges) are prone to occur at the pores of the membrane electrodes in PEM electrolyzers. This is a typical manifestation of leakage in the electrolyzer and a precursor to an explosion or serious malfunction.

[0003] Currently, the industry commonly uses the following technologies to monitor the safety status of electrolyzers: 1. Single-cell voltage monitoring: By detecting the voltage value of each electrolysis cell, a significant drop in voltage (e.g., 10%~20% below normal) indicates potential membrane electrode damage or leakage. The limitation of this method is that in the initial stage of discharge, it may only affect a small local area, and the overall voltage of the single cell may not have changed significantly, making early warning impossible. 2. Temperature monitoring: This uses temperature sensors to detect localized overheating in the electrolyzer (discharge generates additional heat). The limitation of this method is that temperature changes require heat accumulation, and the response lags behind the occurrence of discharge. 3. Pressure monitoring: This monitors sudden changes in hydrogen / oxygen outlet pressure (e.g., pressure fluctuations caused by leakage). This method also suffers from lag and cannot directly correlate with discharge phenomena.

[0004] Therefore, we want to see if we can develop a device and monitoring method for monitoring leakage discharge in electrolytic cells to solve the technical problems of slow monitoring response and high false negative rate in the existing technology. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a device and monitoring method for detecting leakage discharge in electrolytic cells that offers timely monitoring response and a low rate of missed detection.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a device for monitoring leakage discharge in an electrolyzer, comprising: a power grid supply unit, a contactor, a hydrogen production power supply, a proton exchange membrane electrolyzer body, at least one microphone, a controller, an alarm unit, a valve control unit, and a signal conditioner. The power grid supply unit is connected to the hydrogen production power supply via the contactor. The proton exchange membrane electrolyzer body is connected to both the hydrogen production power supply and the valve control unit. The microphone is positioned around the proton exchange membrane electrolyzer body to collect sound signals during the operation of the proton exchange membrane electrolyzer body. The microphone is connected to the signal conditioner. The controller is connected to the signal conditioner, the alarm unit, the valve control unit, and the contactor.

[0007] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the controller is a PLC controller.

[0008] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the PLC controller has a built-in sound feature analysis algorithm.

[0009] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the power grid supply unit provides 380V AC power.

[0010] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the valve control unit includes a hydrogen outlet solenoid valve, an oxygen outlet solenoid valve, and a water supply pipeline electric valve.

[0011] Preferably, the device for monitoring leakage discharge in an electrolyzer according to the present invention is further configured such that: there are two microphones, one of which is installed on the upper side of the proton exchange membrane electrolyzer body, and the other is installed on the lower side of the proton exchange membrane electrolyzer body.

[0012] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the microphone is an explosion-proof microphone.

[0013] Preferably, the device for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured such that the signal conditioner includes an amplifier and a filter.

[0014] To achieve the above objectives, another technical solution adopted by the present invention is: a monitoring method for monitoring leakage discharge in an electrolyzer, comprising the following steps: A. Sound signal acquisition: sound signals during the operation of the proton exchange membrane electrolyzer are acquired by a microphone placed around the proton exchange membrane electrolyzer body, and the sound signals are converted into analog electrical signals; B. Signal conditioning: the microphone then transmits the analog electrical signals to a signal conditioner, which amplifies the weak sound signals and uses a filter to retain the high-frequency band of 1kHz~15kHz while filtering out low-frequency pumping noise interference; C. Analog input to the controller: the analog signal is input to the controller after being conditioned by the signal conditioner. The analog electrical signal is connected to the analog input unit of the controller; D. The controller extracts parameters, namely the sound pressure level RMS value, the high-frequency energy ratio, and the sound pulse rise edge slope; E. It determines whether there is leakage discharge. When any one of the three parameters, namely the sound pressure level RMS value, the high-frequency energy ratio, and the sound pulse rise edge slope, exceeds the preset threshold and continues for more than the set time, the controller can determine that an early leakage discharge fault has occurred. It then simultaneously triggers the alarm unit and the emergency stop command, disconnects the contactor to cut off the power supply, and drives the valve control unit to quickly close to block the material flow. If none of the three parameters exceed the preset threshold, then monitoring continues.

[0015] Preferably, the monitoring method for monitoring leakage discharge in an electrolytic cell according to the present invention is further configured as follows: in step E, the preset threshold of the sound pressure level RMS value is 85dB, the preset threshold of the high-frequency energy ratio is 30%, and the preset threshold of the rise edge slope is 50dB / ms.

[0016] Compared with the prior art, the present invention has the following advantages: The device for monitoring leakage discharge in an electrolyzer is simple in structure and easy to install. It uses a microphone to collect the sound during the operation of the proton exchange membrane electrolyzer in real time, converts the sound wave signal into an electrical signal, and transmits it to a signal conditioner. The signal conditioner amplifies weak sound signals and retains the high-frequency band of 1kHz to 15kHz, filtering out interference such as low-frequency pumping noise. The signal conditioner then transmits the signal to a PLC controller, where a built-in algorithm calculates the sound pressure level RMS value, the high-frequency energy ratio, and the rise slope of the sound pulse in real time. When any one of these three core characteristic parameters exceeds a preset threshold and remains so for a set time, the PLC controller can determine that an early leakage discharge fault has occurred. It will then simultaneously trigger the alarm unit and emergency stop command within a few hundred milliseconds, directly disconnecting the contactor to cut off the power supply and driving the valve control unit to quickly close to block the flow of materials. This allows for rapid identification and proactive safety interception of early signs of explosions or serious faults in the electrolytic cell before significant abnormalities occur in voltage, temperature, or gas concentration. By adopting the monitoring method in this invention, timely monitoring, low missed detection rate, and improved operational safety can be achieved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the device used to monitor leakage discharge in an electrolytic cell in this invention.

[0018] Figure 2 This is a flowchart of the monitoring method in this invention.

[0019] Figure 1 The components are as follows: 1. Power grid supply unit; 2. Contactor; 3. Hydrogen production power supply; 4. Proton exchange membrane electrolyzer body; 5. Microphone; 6. Controller; 7. Alarm unit; 8. Valve control unit; 80. Hydrogen outlet solenoid valve; 81. Oxygen outlet solenoid valve; 82. Water supply pipeline electric valve; 9. Signal conditioner. Detailed Implementation

[0020] The following detailed description of the device and method for monitoring leakage discharge in an electrolytic cell according to the present invention is provided through specific embodiments.

[0021] Please see Figure 1A device for monitoring leakage discharge in an electrolyzer includes: a mains power supply unit 1, a contactor 2, a hydrogen production power supply 3, a proton exchange membrane electrolyzer body 4, at least one microphone 5, a controller 6, an alarm unit 7, a valve control unit 8, and a signal conditioner 9. The valve control unit 8 includes a hydrogen outlet solenoid valve 80, an oxygen outlet solenoid valve 81, and a water supply pipeline electric valve 82. The microphone 5 is positioned around the proton exchange membrane electrolyzer body 4 to collect sound signals during the operation of the proton exchange membrane electrolyzer body 4 and convert the sound signals into analog electrical signals (such as 0~10V or 4~20mA). In this embodiment, the mains power supply unit 1 provides 380V AC power. The microphone 5 is an explosion-proof microphone. There are two microphones 5; one is installed on the upper side of the proton exchange membrane electrolyzer body 4, and the other is installed on the lower side. The mains power supply unit 1 is connected to the hydrogen production power supply 3 via a contactor 2. The hydrogen production power supply 3 converts 380V AC power to DC power, minimizing voltage fluctuations to reduce the impact on the electrolyzer's operation. The proton exchange membrane electrolyzer body 4 is connected to both the hydrogen production power supply 3 and the valve control unit 8. The microphone 5 is connected to the signal conditioner 9.

[0022] The controller 6 is connected to the signal conditioner 9, the alarm unit 7, the valve control unit 8, and the contactor 2, respectively. The controller 6 may include a microprocessor (MCU), which may include a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), a timing module, an analog-to-digital converter (A / D converter), and complex input / output ports. Alternatively, the controller 6 may employ other types of integrated circuits, such as application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs). In this embodiment, the controller 6 is a PLC controller. The PLC controller has a built-in sound feature analysis algorithm and calculates the following three parameters of the sound signal in real time: first, the sound pressure level RMS value (the root mean square value within a 100ms time window, reflecting the overall sound intensity); second, the high-frequency energy ratio (the proportion of sound pressure energy in the 1kHz~15kHz frequency band to the total energy, identifying the high-frequency characteristics of the discharge); and third, the sound pulse rise slope (the rate of change of sound pressure level per unit time, capturing the short and explosive characteristics of the discharge sound). Specifically, in this embodiment, the preset threshold for the sound pressure level RMS value is 85dB, and the preset threshold for the high-frequency energy ratio is 30dB. The preset threshold for the rising edge slope is 50dB / ms. When any of the above three parameters exceeds the preset threshold and continues for more than a set time (50ms in this embodiment), the PLC controller can determine that a leakage discharge abnormality has occurred. It then simultaneously triggers the alarm unit 7 and the emergency stop command, directly disconnects the contactor 2 to cut off the power supply (response time ≤0.1s), and drives the valve control unit 8 to close quickly to block the flow of materials. In this embodiment, the PLC controller outputs a signal through a relay or IO module to drive the hydrogen outlet solenoid valve 80, the oxygen outlet solenoid valve 81, and the water supply pipeline electric valve 82 to close completely within 0.5s, blocking hydrogen / oxygen leakage and the reaction water source.

[0023] The working principle of the device for monitoring leakage discharge in an electrolytic cell in this invention is as follows: the microphone 5 collects the sound during the operation of the proton exchange membrane electrolytic cell 4 in real time, and converts the sound wave signal into an electrical signal and transmits it to the signal conditioner 9. The signal conditioner 9 amplifies the weak sound signal and retains the high frequency band of 1kHz~15kHz, while filtering out interference such as low frequency pumping noise. Then, the signal conditioner 9 transmits the signal to the PLC controller. The PLC controller's built-in algorithm calculates three core characteristic parameters in real time: the sound pressure level RMS value, the high frequency energy ratio, and the sound pulse rise slope. When any of these three core characteristic parameters exceeds a preset threshold and continues for more than a set time, the PLC controller can determine that an early leakage discharge fault has occurred. Then, within a few hundred milliseconds, it simultaneously triggers the alarm unit 7 and the emergency stop command, directly disconnects the contactor 2 to cut off the power supply, and drives the valve control unit 8 to quickly close to block the flow of materials. Thus, before the voltage, temperature, and gas concentration become obviously abnormal, it can quickly identify and actively intercept the precursors of an electrolytic cell explosion or serious fault.

[0024] Please see Figure 1 and Figure 2 A monitoring method for monitoring leakage discharge in an electrolyzer includes the following steps: A) Sound signal acquisition: Sound signals during the operation of the proton exchange membrane electrolyzer 4 are acquired by a microphone 5 placed around the proton exchange membrane electrolyzer 4 and converted into analog electrical signals; B) Signal conditioning: The microphone 5 then transmits the analog electrical signals to a signal conditioner 9, which amplifies the weak sound signals and uses a filter to retain the high-frequency band of 1kHz to 15kHz while filtering out low-frequency pumping noise interference; C) Analog input to the controller: The analog electrical signals conditioned by the signal conditioner 9 are connected to the analog input unit of the controller; D) Parameter extraction by the controller: The controller extracts the sound pressure level RMS value, high... The controller monitors three parameters: frequency band energy ratio, sound pulse rise edge slope, and frequency band energy ratio. E. It determines whether leakage discharge exists. If any one of these three parameters exceeds a preset threshold and persists for more than a set time, the controller can determine that an early leakage discharge fault has occurred. It then simultaneously triggers the alarm unit 7 and an emergency stop command, disconnects contactor 2 to cut off power, and drives the valve control unit 8 to quickly close to block material flow. In this embodiment, the preset threshold for the sound pressure level RMS value is 85dB, the preset threshold for the frequency band energy ratio is 30%, the preset threshold for the rise edge slope is 50dB / ms, and the set time is 50ms. If none of the three parameters exceed the preset threshold, monitoring continues.

[0025] In summary, the monitoring device and method of this invention can achieve timely monitoring, low false negative rate, and improved operational safety by monitoring leakage discharge in electrolytic cells.

[0026] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some examples of its application, and are not intended to limit the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention.

Claims

1. A device for monitoring leakage discharge in an electrolytic cell, characterized in that: include: The system comprises a power grid supply unit, a contactor, a hydrogen production power supply, a proton exchange membrane electrolyzer body, at least one microphone, a controller, an alarm unit, a valve control unit, and a signal conditioner. The power grid supply unit is connected to the hydrogen production power supply via the contactor. The proton exchange membrane electrolyzer body is connected to both the hydrogen production power supply and the valve control unit. The microphone is positioned around the proton exchange membrane electrolyzer body to collect sound signals during its operation. The microphone is connected to the signal conditioner. The controller is connected to the signal conditioner, the alarm unit, the valve control unit, and the contactor.

2. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The controller is a PLC controller.

3. The device for monitoring leakage discharge in an electrolytic cell as described in claim 2, characterized in that: The PLC controller has a built-in sound feature analysis algorithm.

4. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The power grid supply unit provides 380V AC power.

5. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The valve control unit includes a hydrogen outlet solenoid valve, an oxygen outlet solenoid valve, and a water supply pipeline electric valve.

6. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The number of microphones is two, one of which is installed on the upper side of the proton exchange membrane electrolyzer body, and the other is installed on the lower side of the proton exchange membrane electrolyzer body.

7. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The microphone is an explosion-proof microphone.

8. The device for monitoring leakage discharge in an electrolytic cell as described in claim 1, characterized in that: The signal conditioner includes an amplifier and a filter.

9. A monitoring method for monitoring leakage discharge in an electrolytic cell using the apparatus described in any one of claims 1 to 8, characterized in that, Includes the following steps: A. Sound signal acquisition: Sound signals during the operation of the proton exchange membrane electrolyzer are acquired by microphones placed around the proton exchange membrane electrolyzer body and converted into analog electrical signals. B. Signal Conditioning: Next, the microphone transmits the analog electrical signal to the signal conditioner. The weak sound signal is amplified by the amplifier of the signal conditioner, and the high frequency band of 1kHz~15kHz is retained by the filter of the signal conditioner, while low frequency pumping noise interference is filtered out. C. The analog input of the controller connects the analog electrical signal conditioned by the signal conditioner to the analog input unit of the controller. D. The controller extracts three parameters: sound pressure level RMS value, high frequency energy ratio, and sound pulse rise slope. E. To determine if leakage discharge exists, if any one of the three parameters—sound pressure level RMS value, high-frequency energy ratio, and sound pulse rise edge slope—exceeds the preset threshold and continues for more than the set time, the controller can determine that an early leakage discharge fault has occurred. It will then simultaneously trigger the alarm unit and emergency stop command, disconnect the contactor to cut off the power supply, and drive the valve control unit to quickly close to block the flow of materials. If none of the three parameters exceed the preset threshold, then monitoring will continue.

10. A monitoring method for monitoring leakage discharge in an electrolytic cell as described in claim 9, characterized in that: In step E, the preset threshold for the sound pressure level RMS value is 85dB, the preset threshold for the high-frequency energy ratio is 30%, and the preset threshold for the rise edge slope is 50dB / ms.

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