Electrolytic tank system monitoring control method and electrolytic tank system

Abstract

The invention relates to the field of water electrolysis equipment, in particular to an electrolytic bath system monitoring control method and an electrolytic bath system. On the basis that the cost and the size are not increased too much, a plurality of sensors and control units are arranged to monitor and control the pressurization risk and working conditions of hydrogen and oxygen pipelines of the electrolytic cell in real time, and two control methods are arranged for improving the reliability of the system. The hydrogen pipeline is controlled through a pressure monitoring sensor and a mechanical pressure release valve in combination with a program; the oxygen pipeline is controlled through a flow sensor, an electromagnetic valve and a temperature sensor in combination with a program. According to the pressure monitoring and control method for the electrolytic cell, the working condition adaptability of the electrolytic cell is greatly improved, and meanwhile, the parameter controllability and the use safety in the use process of the electrolytic cell are greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of water electrolysis equipment, and in particular to an electrolytic cell system monitoring and control method and an electrolytic cell system. Background Art

[0002] In the industry where existing electrolytic hydrogen production products are located, the PEM electrolyzer that uses pure water electrolysis is the current mainstream technical direction. The PEM electrolyzer is the core component of electrolytic hydrogen production products. It uses electrical energy to decompose water into hydrogen and oxygen, providing sufficient hydrogen supply for hydrogen products such as hydrogen-rich water machines and hydrogen-oxygen machines. In the hydrogen-rich water machine, the PEM electrolyzer is connected to the circulating liquid circuit such as the water tank and the water pump. The hydrogen produced by electrolysis is passed into the drinking water prepared by the water machine, and the hydrogen is dissolved in the water through a special mixing device for users to drink; in the hydrogen-oxygen machine, the PEM electrolyzer quickly decomposes water into high-purity hydrogen and oxygen. The generated gases are mixed in specific channels inside or outside the machine to form a hydrogen-oxygen mixed gas for users to inhale.

[0003] The PEM electrolyzer is mainly composed of end plates, insulating layers, bipolar plates, porous diffusion layers, catalyst layers, and proton exchange membranes. Among them, the end plates are used to fix the electrolyzer components; the bipolar plates are used to guide the transfer and distribution of current, heat, etc.; the porous diffusion layer is used to provide certain mechanical support and protection for the proton membrane, and to achieve uniform distribution and transmission of gas and liquid; the catalyst layer is the core place of the electrochemical reaction, which is used to promote the electrolysis reaction; the proton exchange membrane is a key core component of the PEM electrolyzer, which is used as a solid electrolyte to conduct protons and at the same time prevent the gas on both sides of the electrode from mixing, thereby improving the electrolysis efficiency. When the PEM electrolyzer is working, the electrolyzed water is transported to the anode, and an oxidation reaction occurs after the anode loses electrons to generate oxygen and hydrogen ions (H+); the generated hydrogen ions (H+) pass through the proton exchange membrane to the cathode under the promotion of the electric field force and concentration gradient, and obtain electrons on the catalyst layer of the cathode to undergo a reduction reaction to generate hydrogen. Compared with other forms of electrolyzers, the PEM electrolyzer has the advantages of good dynamic response, high hydrogen purity, and compact structure.

[0004] In practical applications, PEM electrolyzers usually need to face a variety of different working conditions, such as different input and output conditions, different operating times, different users, etc., including some working conditions with safety risks. For example, when the output pipeline of the electrolyzer is blocked, the pressure of the anode and cathode of the electrolyzer will continue to increase and the reactants will stagnate, which will lead to a series of problems such as overheating and dry burning of the electrolyzer, posing a greater safety risk.

[0005] Whether the hydrogen produced by the electrolyzer is sufficient, stable, and safe enough determines the actual output of hydrogen from the hydrogen product, or whether the prepared hydrogen-rich water has sufficient flow and hydrogen concentration, and also determines whether the instrument poses a safety threat to the user. Therefore, ensuring the performance and safety of the core component electrolyzer is a key factor in the performance and safety of the entire hydrogen product. Summary of the invention

[0006] In view of the above problems, the present invention provides the following technical solutions:

[0007] A monitoring and control method for an electrolyzer system, the electrolyzer system comprising a PEM electrolyzer, a pure water tank, a water pump, and a solenoid valve, wherein the PEM electrolyzer is provided with an electrolyzed water input port, an oxygen output port, and a hydrogen output port; the pure water tank outlet is sequentially connected to the water pump, a flow rate sensor, and a solenoid valve; the solenoid valve outlet has two switchable paths, one of which is connected to the electrolyzed water input port, and the other is connected to the pure water tank inlet; the water separated from the pipe of the oxygen output port is returned to the pure water tank through the pipe, and the oxygen separated from the pipe of the oxygen output port is discharged through the pipe;

[0008] When the electrolyzer system is working, the PEM electrolyzer is in operation, the water in the pure water tank is pumped to the solenoid valve, and the outlet of the solenoid valve is switched to the electrolytic water input port; when the flow rate detected by the flow rate sensor is less than the flow rate threshold, the emergency protection step is executed. If the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed, the emergency protection step is executed again;

[0009] The contents of the emergency protection steps are:

[0010] Stop the operation of the PEM electrolyzer, and switch the solenoid valve outlet to the pure water tank inlet. After waiting for a preset time and the flow rate detected by the flow rate sensor is greater than the flow rate threshold, the solenoid valve outlet is switched to the electrolyzed water input port, and start the operation of the PEM electrolyzer.

[0011] Furthermore, if the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed n times in succession, the operation of the electrolytic cell system is stopped; wherein n is the threshold of the number of consecutive executions.

[0012] Furthermore, the PEM electrolyzer is also provided with a temperature sensor. When the temperature sensor detects that the temperature of the PEM electrolyzer exceeds a temperature threshold, the operation of the electrolyzer system is stopped.

[0013] Furthermore, a pressure sensor is provided on the pipeline of the hydrogen output port. When the pressure sensor detects that the pressure exceeds the alarm threshold, an alarm is issued. When the pressure detected by the pressure sensor exceeds the safety threshold, the operation of the electrolyzer system is directly stopped.

[0014] Furthermore, a mechanical pressure relief valve is provided on the pipeline of the hydrogen outlet. When the pressure on the pipeline of the hydrogen outlet exceeds the safety threshold, the mechanical pressure relief valve automatically opens to force pressure relief. The safety threshold of the pressure relief valve is less than the maximum withstand pressure of the electrolytic cell, for example, less than 0.3Mpa.

[0015] The present invention also provides an electrolytic cell system, which uses the above method to perform system monitoring and control.

[0016] Beneficial effects: On the basis of not increasing the cost too much and the volume too much, by setting up multiple sensors and control units, the pressurization risk conditions of the hydrogen and oxygen pipelines of the electrolyzer are respectively monitored and controlled in real time, and in order to improve the reliability of the system, two control methods are set up. The hydrogen pipeline is controlled by a pressure monitoring sensor and a mechanical pressure relief valve in combination with a program; the oxygen pipeline is controlled by a flow sensor, a solenoid valve and a temperature sensor in combination with a program. Through this electrolyzer pressure monitoring and control method, the adaptability of the electrolyzer to the working conditions has been greatly improved, and at the same time, the controllability of parameters and the safety of use of the electrolyzer during use have been greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a system structure diagram of the present invention;

[0018] Figure 2 This is a control flow chart of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] When the PEM electrolyzer is in operation, electrolyzed water is transported from the pure water tank to the anode of the electrolyzer through a pump. The electrolyzed water undergoes an oxidation reaction at the anode to generate oxygen. The unconsumed electrolyzed water flows out from the anode oxygen outlet together with the oxygen. After water and gas separation, the electrolyzed water is circulated to the pure water tank, and the oxygen is output to the oxygen output port through a pipeline; the generated hydrogen ions gather at the cathode and are reduced to hydrogen, which flows out from the hydrogen outlet of the electrolyzer and is output to the hydrogen outlet through a pipeline.

[0021] During the operation of the electrolyzer, the current and voltage are continuously loaded under software control. When the pipeline at the hydrogen output port is blocked, the hydrogen continuously produced by the electrolyzer continuously pressurizes the internal structure of the electrolyzer, the proton membrane, the transmission pipeline and the joints, creating a greater explosion safety risk; when the oxygen pipeline is blocked, due to the continuous increase of product gas, the volume of the pipeline continues to decrease, and the electrolyzed water output at the anode and oxygen at the same time will stagnate. In severe cases, backflow will occur, and the water circulation inside the electrolyzer will be broken, which will cause dry burning in severe cases, resulting in a greater temperature overload and fire risk.

[0022] like Figures 1 to 2 As shown, a monitoring and control method for an electrolyzer system is provided, wherein the electrolyzer system comprises a PEM electrolyzer, a pure water tank, a water pump, and a solenoid valve, wherein the PEM electrolyzer is provided with an electrolyzed water input port, an oxygen output port, and a hydrogen output port; the pure water tank outlet is connected to the water pump, a flow rate sensor, and a solenoid valve in sequence; the solenoid valve outlet has two switchable paths, one of which is connected to the electrolyzed water input port, and the other is connected to the pure water tank inlet; the water separated from the pipe of the oxygen output port is returned to the pure water tank through the pipe, and the oxygen separated from the pipe of the oxygen output port is discharged through the pipe;

[0023] When the electrolyzer system is working, the PEM electrolyzer is in operation, the water in the pure water tank is pumped to the solenoid valve, and the outlet of the solenoid valve is switched to the electrolytic water input port; when the flow rate detected by the flow rate sensor is less than the flow rate threshold, the emergency protection step is executed. If the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed, the emergency protection step is executed again. If the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed n times in succession, the operation of the electrolyzer system is stopped; wherein n is the threshold of the number of consecutive executions;

[0024] The contents of the emergency protection steps are:

[0025] Stop the operation of the PEM electrolyzer, and switch the solenoid valve outlet to the pure water tank inlet. After waiting for a preset time and the flow rate detected by the flow rate sensor is greater than the flow rate threshold, the solenoid valve outlet is switched to the electrolyzed water input port, and start the operation of the PEM electrolyzer.

[0026] When the oxygen output pipeline is blocked, the anode pressure of the PEM electrolyzer increases, and the pressure of the electrolytic water input pipeline increases accordingly, which reduces the flow rate detected by the flow sensor. As the anode pressure increases and fluctuates, backflow may even occur in severe cases, so oxygen may flow back to the water pump, causing the water pump to fail to work or even be damaged. However, since there is water and oxygen in the pipeline at the same time, the use of conventional check valves and other structures is not effective. Therefore, in the present invention, the blockage of the oxygen output pipeline is determined by flow rate detection, and at the same time, the outlet of the solenoid valve is switched to the inlet of the pure water tank in the emergency protection step, and the flow rate in the water pump is quickly increased for a preset time. Even if some oxygen has entered the water pump, the oxygen can be quickly taken out to prevent damage to the water pump.

[0027] In a further embodiment, the PEM electrolyzer is further provided with a temperature sensor, and when the temperature sensor detects that the temperature of the PEM electrolyzer exceeds a temperature threshold, the operation of the electrolyzer system is stopped.

[0028] In this embodiment, considering that when the oxygen outlet is blocked, the flow rate sensor and other equipment fail, and the emergency protection steps are not performed, the PEM electrolyzer will dry burn and cause the temperature to rise. At this time, after the temperature sensor detects that the temperature is abnormal, the electrolyzer system is directly stopped, which can further improve safety redundancy and ensure the safety of the entire system.

[0029] In a further embodiment, a pressure sensor is provided on the pipeline of the hydrogen output port. When the pressure sensor detects that the pressure exceeds the alarm threshold, an alarm is issued. When the pressure detected by the pressure sensor exceeds the safety threshold, the operation of the electrolyzer system is directly stopped. At the same time, a mechanical pressure relief valve is also provided on the pipeline of the hydrogen output port. When the pressure on the pipeline of the hydrogen output port exceeds the safety threshold, the mechanical pressure relief valve automatically opens to force pressure relief.

[0030] The dual protection of sensors and mechanical pressure relief valves can greatly improve the safety when the hydrogen outlet pipeline is blocked.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for monitoring and controlling an electrolytic cell system, characterized in that: The electrolyzer system comprises a PEM electrolyzer, a pure water tank, a water pump, and a solenoid valve, wherein the PEM electrolyzer is provided with an electrolyzed water input port, an oxygen output port, and a hydrogen output port; the pure water tank outlet is connected to the water pump, a flow rate sensor, and a solenoid valve in sequence; the solenoid valve outlet has two switchable paths, one of which is connected to the electrolyzed water input port, and the other is connected to the pure water tank inlet; the water separated from the pipe of the oxygen output port is returned to the pure water tank through the pipe, and the oxygen separated from the pipe of the oxygen output port is discharged through the pipe; When the electrolyzer system is working, the PEM electrolyzer is in operation, the water in the pure water tank is pumped to the solenoid valve, and the outlet of the solenoid valve is switched to the electrolytic water input port; when the flow rate detected by the flow rate sensor is less than the flow rate threshold, the emergency protection step is executed. If the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed, the emergency protection step is executed again; The contents of the emergency protection steps are: Stop the operation of the PEM electrolyzer, and switch the solenoid valve outlet to the pure water tank inlet. After waiting for a preset time and the flow rate detected by the flow rate sensor is greater than the flow rate threshold, the solenoid valve outlet is switched to the electrolyzed water input port, and start the operation of the PEM electrolyzer.

2. The electrolytic cell system monitoring and control method according to claim 1, characterized in that: If the flow rate detected by the flow rate sensor is still less than the flow rate threshold after the emergency protection step is executed n times in succession, the operation of the electrolytic cell system is stopped; wherein n is the threshold of the number of consecutive executions.

3. The electrolytic cell system monitoring and control method according to claim 1, characterized in that: The PEM electrolyzer is also provided with a temperature sensor. When the temperature sensor detects that the temperature of the PEM electrolyzer exceeds a temperature threshold, the operation of the electrolyzer system is stopped.

4. The electrolytic cell system monitoring and control method according to claim 1, characterized in that: A pressure sensor is provided on the pipeline of the hydrogen output port. When the pressure sensor detects that the pressure exceeds the alarm threshold, an alarm is issued. When the pressure detected by the pressure sensor exceeds the safety threshold, the operation of the electrolyzer system is directly stopped.

5. The electrolytic cell system monitoring and control method according to claim 1, characterized in that: A mechanical pressure relief valve is also provided on the pipeline of the hydrogen output port. When the pressure on the pipeline of the hydrogen output port exceeds the safety threshold, the mechanical pressure relief valve automatically opens to force pressure relief.

6. An electrolytic cell system, characterized in that Use the methods described in claims 1 to 5 to carry out system monitoring and control.

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