Electrolytic cell system monitoring and control method, electrolytic cell system

Abstract

The present invention relates to the field of electrolytic water equipment, and specifically to an electrolyzer system monitoring and control method, and an electrolyzer system. On the basis of not increasing the cost and volume too much, by setting up multiple sensors and control units, the pressurization risk and working 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 working conditions is greatly improved, and at the same time, the controllability of parameters and the safety of use of the electrolyzer during use 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 use of PEM electrolyzers for pure water electrolysis is the current mainstream technical direction. The PEM electrolyzer is the core component of electrolytic hydrogen production products. It uses electricity to decompose water into hydrogen and oxygen, providing an adequate supply of hydrogen for hydrogen products such as hydrogen-rich water machines and hydrogen-oxygen machines. In hydrogen-rich water machines, the PEM electrolyzer is connected to circulating liquid circuits such as water tanks and water pumps. The hydrogen produced by electrolysis is introduced into the drinking water prepared by the water machine. A special mixing device dissolves the hydrogen in the water for users to drink. In hydrogen-oxygen machines, the PEM electrolyzer quickly decomposes water into higher-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] A PEM electrolyzer primarily consists of end plates, an insulating layer, bipolar plates, a porous diffusion layer, a catalyst layer, and a proton exchange membrane. The end plates secure the cell components; the bipolar plates direct the transfer and distribution of current and heat; the porous diffusion layer provides mechanical support and protection for the proton exchange membrane, and ensures uniform distribution and transport of gases and liquids; the catalyst layer is the core site of the electrochemical reaction, promoting the electrolysis reaction; and the proton exchange membrane is a key component of the PEM electrolyzer, serving as a solid electrolyte to conduct protons while preventing mixing of gases on either side of the electrodes, thereby improving electrolysis efficiency. During operation, the electrolyzed water is transported to the anode, where it loses electrons and undergoes an oxidation reaction to produce oxygen and hydrogen ions (H+). Driven by the electric field and concentration gradient, the generated hydrogen ions (H+) cross the proton exchange membrane to the cathode, where they gain electrons on the catalyst layer and undergo a reduction reaction to produce hydrogen. Compared to other electrolyzers, PEM electrolyzers offer advantages such as excellent dynamic response, high hydrogen purity, and a compact structure.

[0004] In practical applications, PEM electrolyzers typically face a variety of operating conditions, such as varying input and output conditions, operating times, and users. These conditions include some that pose safety risks. For example, when the electrolyzer output pipeline is clogged, the pressure at the anode and cathode of the electrolyzer will continue to increase, causing stagnation of reactants. This can lead to a series of problems, such as overheating and dry burning of the electrolyzer, posing a significant safety risk.

[0005] Whether the electrolyzer produces sufficient, stable, and safe hydrogen determines the actual hydrogen output of the hydrogen product, or whether the hydrogen-rich water produced has sufficient flow rate and hydrogen concentration, and further determines whether the instrument poses a safety threat to the user. Therefore, ensuring the performance and safety of the core component, the 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 method for monitoring and controlling an electrolyzer system includes a PEM electrolyzer, a pure water tank, a water pump, and a solenoid valve. 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. Water separated from the oxygen output port pipe is returned to the pure water tank via the pipe, while oxygen separated from the oxygen output port pipe is discharged via 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 electrolyzed 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 at the same time, switch the solenoid valve outlet to the pure water tank inlet. After waiting for the preset time and the flow rate detected by the flow 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 at the same time.

[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 consecutively, the operation of the electrolytic cell system is stopped; wherein n is the consecutive execution number threshold.

[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 installed on the hydrogen outlet pipeline. When the pressure on the hydrogen outlet pipeline exceeds a 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 pressure of the electrolyzer, for example, less than 0.3 MPa.

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

[0016] Beneficial effects: Without increasing the cost or volume too much, multiple sensors and control units are provided to monitor and control the pressurization risk conditions of the electrolyzer's hydrogen and oxygen pipelines in real time. In order to improve the reliability of the system, two control methods are provided. 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. This electrolyzer pressure monitoring and control method greatly improves the adaptability of the electrolyzer to its working conditions, and at the same time, greatly improves the controllability of parameters and the safety of use of the electrolyzer during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It 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 purposes, 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 making 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 and oxygen flow out from the anode oxygen outlet together. 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 the 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 the pipeline.

[0021] During the operation of the electrolyzer, the current and voltage are continuously loaded under software control. When the hydrogen output pipe is blocked, the hydrogen continuously produced by the electrolyzer continuously pressurizes the internal structure of the electrolyzer, the proton membrane, the transmission pipe and the joints, creating a greater explosion safety risk; when the oxygen pipe is blocked, due to the continuous increase of product gas, the volume of the pipe 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. In severe cases, dry burning will occur, 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 shown, wherein the electrolyzer system includes 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 routes, 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 oxygen output port pipe is returned to the pure water tank through the pipe, and the oxygen separated from the oxygen output port pipe 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 electrolyzed 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 continuously, the operation of the electrolyzer system is stopped; wherein n is the threshold value of the number of consecutive executions;

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

[0025] Stop the operation of the PEM electrolyzer, and at the same time, switch the solenoid valve outlet to the pure water tank inlet. After waiting for the preset time and the flow rate detected by the flow 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 at the same time.

[0026] When the oxygen output pipeline becomes clogged, the anode pressure of the PEM electrolyzer increases, and the pressure in the electrolyzed water inlet pipeline increases accordingly, causing the flow rate detected by the flow sensor to decrease. As the anode pressure increases and fluctuates, backflow may even occur in severe cases, causing oxygen to flow back into the water pump, causing the water pump to stop working or even damage. However, due to the coexistence of water and oxygen in the pipeline, using conventional structures such as check valves is ineffective. Therefore, in the present invention, the blockage of the oxygen output pipeline is determined by flow rate detection. At the same time, in an emergency protection step, the solenoid valve outlet is switched to the pure water tank inlet for a preset time, rapidly increasing the flow rate in the water pump. Even if some oxygen has already entered the water pump, it can be quickly removed 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 executed, the PEM electrolyzer will dry burn and cause the temperature to rise. At this time, after the temperature abnormality is detected by the temperature sensor, 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 of the hydrogen output pipeline when it 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 principles of the present invention. These improvements and modifications should also be regarded as within 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 includes 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 oxygen output port pipe is returned to the pure water tank through the pipe, and the oxygen separated from the oxygen output port pipe 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 electrolyzed 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 at the same time, switch the solenoid valve outlet to the pure water tank inlet. After waiting for the preset time and the flow rate detected by the flow 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 at the same time.

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 continuously, 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 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 method according to any one of claims 1 to 5 to perform system monitoring and control.

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