PEM water electrolysis hydrogen production system and load regulation control method

Abstract

The PEM water electrolysis hydrogen production system comprises a hydrogen storage tank, a PEM electrolytic bath, a water supply system and a power conversion device, the pure water input end of the PEM electrolytic bath is connected with the water supply system, the power input end of the PEM electrolytic bath is connected with the power conversion device, and the hydrogen output end of the PEM electrolytic bath is connected with the hydrogen storage tank; and the power conversion device is configured to adjust the output current based on the real-time pressure of the hydrogen storage tank, so that the hydrogen production load of the PEM electrolytic bath is controlled, and the pressure of the hydrogen storage tank is stable. The PEM water electrolysis hydrogen production technology is applied to the hydrogen production, storage and adding integrated hydrogen energy supply station, the real-time pressure of the hydrogen storage tank is collected, the output current of the power conversion device is adjusted through the PID algorithm, the hydrogen production load of the PEM electrolytic cell is controlled, the pressure of the hydrogen storage tank is stable, and meanwhile frequent starting and stopping of the electrolytic cell are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by water electrolysis, and particularly to a PEM water electrolysis hydrogen production system and a load regulation control method. Background Art

[0002] With the gradual maturity of the water electrolysis hydrogen production technology, the technology of integrated hydrogen production, storage and supply stations has been widely promoted. Proton Exchange Membrane (PEM) water electrolysis hydrogen production is an electrolytic water technology that uses a proton exchange membrane as a solid electrolyte to replace the diaphragm and liquid electrolyte used in alkaline electrolytic cells, and has the advantages of high current density, high hydrogen purity, fast response speed, etc.

[0003] However, in the current integrated hydrogen production, storage and supply stations based on PEM water electrolysis hydrogen production, the start-stop control of the hydrogen production equipment is usually determined by the hydrogen storage volume at the back end. As the hydrogen consumption at the hydrogen-using end continues, when the hydrogen storage volume drops to a certain level, the hydrogen production equipment is started to fill hydrogen into the buffer tank; when the hydrogen storage volume reaches the designed value, the hydrogen production equipment automatically shuts down. This process of frequent start and stop will not only affect the performance of the electrolytic cell, but also lead to the attenuation of the electrolytic cell life. Summary of the Invention

[0004] To solve the above problems, the present invention proposes a PEM water electrolysis hydrogen production system and a load regulation control method, which apply the PEM water electrolysis hydrogen production technology to the integrated hydrogen production, storage and supply stations. By collecting the real-time pressure of the hydrogen storage tank and adjusting the output current of the power conversion device through the PID algorithm, the hydrogen production load of the PEM electrolytic cell is controlled to achieve the pressure stability of the hydrogen storage tank and avoid the frequent start and stop of the electrolytic cell.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A PEM water electrolysis hydrogen production system includes a hydrogen storage tank, a PEM electrolytic cell, a water supply system and a power conversion device. The pure water input end of the PEM electrolytic cell is connected to the water supply system, the power input end is connected to the power conversion device, and the hydrogen output end is connected to the hydrogen storage tank; the power conversion device is configured to adjust the output current based on the real-time pressure of the hydrogen storage tank, so as to control the hydrogen production load of the PEM electrolytic cell and make the pressure of the hydrogen storage tank stable.

[0007] Further, the water supply system is configured to reduce the water supply flow rate when the load of the PEM electrolytic cell decreases, and increase the water supply flow rate when the load of the PEM electrolytic cell increases, so as to maintain the temperature of the PEM electrolytic cell within the set range.

[0008] Further, the power conversion device includes an IGBT converter, and the IGBT converter can adjust the output current based on the real-time pressure of the hydrogen storage tank.

[0009] Furthermore, a pressure sensor is provided on the hydrogen storage tank, and the pressure sensor can monitor the hydrogen pressure in the hydrogen storage tank in real time.

[0010] Furthermore, it also includes a hydrogen purification device, which is arranged between the PEM electrolyzer and the hydrogen storage tank and is used to purify the hydrogen output by the PEM electrolyzer.

[0011] A load regulation control method for a PEM water electrolysis hydrogen production system, comprising:

[0012] Calculate the difference a between the rated pressure value and the current pressure value of the hydrogen storage tank;

[0013] Set the load adjustment pressure range value b;

[0014] If a>b, the PEM water electrolysis hydrogen production system is controlled to operate at rated conditions;

[0015] If a≤b, the PEM water electrolysis hydrogen production system is controlled to enter the load regulation pressure operating condition.

[0016] Furthermore, when the PEM water electrolysis hydrogen production system operates at rated conditions, the output current of the power conversion device is increased to the rated value, and the water supply flow of the water supply system is increased to the rated value.

[0017] Furthermore, when the PEM water electrolysis hydrogen production system enters the load regulation pressure operating condition, the PEM electrolyzer load regulation PID algorithm control is executed to reduce the output current of the power conversion device and simultaneously reduce the water supply flow of the water supply system.

[0018] Furthermore, when executing the PEM electrolyzer load regulation PID algorithm control, the hydrogen storage tank pressure change time c is monitored simultaneously.

[0019] Furthermore, if it is monitored that the hydrogen storage tank pressure change time c is greater than or equal to the set time, the PEM electrolyzer load adjustment PID algorithm coefficient is changed to meet the hydrogen storage tank pressure fast response process.

[0020] The beneficial effects of the present invention are:

[0021] This invention can solve the problem of frequent startup and shutdown of the water electrolysis device due to pressure changes in the back-end storage tank in the integrated hydrogen production, storage and fueling station, while also enabling the electrolyzer to quickly reach optimal working conditions. Compared with the traditional integrated hydrogen production, storage and fueling station system control, which requires frequent startup and shutdown of the PEM water electrolysis device, this invention has the following advantages:

[0022] 1. Improve system operating efficiency. The present invention allows the electrolyzer to shut down without power outage and operate at low load when the demand for hydrogen production is low, while keeping the electrolyzer temperature down slowly. When the demand for hydrogen production is high, the electrolyzer can quickly operate at a high-efficiency stage.

[0023] 2. Reduce the performance degradation of the electrolyzer. Due to frequent startup and shutdown as well as frequent decreases and increases in temperature, the activity and service life of the electrolyzer membrane and catalyst will be affected. Operating with the load adjustment method and control method of the present invention can effectively reduce the number of startup and shutdown times of the electrolyzer and reduce the performance degradation of the electrolyzer.

[0024] 3. Reduce the volume of the hydrogen storage tank and lower the cost. In the present invention, the electrolyzer can quickly reach the rated load and quickly operate at the best efficiency to meet the hydrogen usage requirements, which can effectively reduce the volume of the hydrogen storage tank and lower the cost. Description of the Drawings

[0025] Figure 1 is a block diagram of a PEM water electrolysis hydrogen production system according to Embodiment 1 of the present invention.

[0026] Figure 2 is one of the flowcharts of the load adjustment control method for a PEM water electrolysis hydrogen production system according to Embodiment 2 of the present invention.

[0027] Figure 3 is the second flowchart of the load adjustment control method for a PEM water electrolysis hydrogen production system according to Embodiment 2 of the present invention.

[0028] Figure 4 is the curve of the hydrogen storage tank pressure changing with time in Embodiment 2 of the present invention.

[0029] Figure 5 is the curve of the electrolyzer current changing with time in Embodiment 2 of the present invention.

[0030] Figure 6 is the curve of the electrolyzer water flow rate changing with time in Embodiment 2 of the present invention. Detailed Embodiments

[0031] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed embodiments of the present invention are now described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] Embodiment 1

[0033] As Figure 1As shown in the figure, this embodiment provides a PEM water electrolysis hydrogen production system, including a hydrogen storage tank, a PEM electrolyzer, a water supply system, and a power conversion device. The pure water input end of the PEM electrolyzer is connected to the water supply system, the power input end is connected to the power conversion device, and the hydrogen output end is connected to the hydrogen storage tank. The power conversion device is configured to adjust the output current based on the real-time pressure of the hydrogen storage tank, thereby controlling the hydrogen production load of the PEM electrolyzer and stabilizing the pressure of the hydrogen storage tank.

[0034] In this embodiment, the water supply system is configured to reduce the water supply flow rate when the load of the PEM electrolyzer decreases, and increase the water supply flow rate when the load of the PEM electrolyzer increases, so as to maintain the temperature of the PEM electrolyzer within the set range.

[0035] Preferably, the power conversion device can adopt an IGBT converter, which can adjust the output current based on the real-time pressure of the hydrogen storage tank.

[0036] Preferably, a pressure sensor is provided on the hydrogen storage tank, which can monitor the hydrogen pressure in the hydrogen storage tank in real time.

[0037] Preferably, the PEM water electrolysis hydrogen production system of this embodiment further includes a hydrogen purification device, which is arranged between the PEM electrolyzer and the hydrogen storage tank and is used to purify the hydrogen output by the PEM electrolyzer.

[0038] Embodiment 2

[0039] This embodiment is based on Embodiment 1:

[0040] As Figure 2 shown, this embodiment provides a method for controlling the load regulation of a PEM water electrolysis hydrogen production system, including: calculating the difference between the rated pressure and the current pressure of the hydrogen storage tank (K110), setting the load regulation pressure range (K111), applying the load regulation PID algorithm (K112), controlling the output of the power conversion device (K113), controlling the flow rate of the water supply system (K114), and controlling the pressure change time (K115).

[0041] As Figure 3 shown, the method for controlling the load regulation of the PEM water electrolysis hydrogen production system of this embodiment can be implemented by the following steps:

[0042] Calculate the difference a between the rated pressure value and the current pressure value of the hydrogen storage tank, and set the load regulation pressure range value b;

[0043] If a > b, then control the PEM water electrolysis hydrogen production system to operate under rated conditions, increase the output current of the power conversion device to the rated value, and increase the water supply flow rate of the water supply system to the rated value;

[0044] If a ≤ b, then control the PEM water electrolysis hydrogen production system to enter the load regulation pressure operating condition, execute the PEM electrolyzer load regulation PID algorithm control, reduce the output current of the power conversion device, and at the same time reduce the water supply flow rate of the water supply system.

[0045] Preferably, when executing the PEM electrolyzer load regulation PID algorithm control, simultaneously monitor the change time c of the hydrogen storage tank pressure; if it is monitored that the change time c of the hydrogen storage tank pressure is greater than or equal to the set time, then change the PEM electrolyzer load regulation PID algorithm coefficient to meet the rapid response process of the hydrogen storage tank pressure.

[0046] Table 1 - Operating data of the PEM water electrolysis hydrogen production system

[0047]

[0048] Specifically, as Figures 4 to 6 shown, and as shown in Table 1, the operating data of the PEM water electrolysis hydrogen production system of this embodiment at a certain operating condition and time period can be seen. When the pressure of the hydrogen storage tank approaches the rated pressure of the hydrogen storage tank (3.0 Mpa), the electrolyzer current drops to the lowest load operation of the electrolyzer, and at the same time the water flow rate of the electrolyzer drops to the lowest water volume operation of the electrolyzer; when the pressure of the hydrogen storage tank decreases, the electrolyzer quickly increases the load and increases the water flow rate to meet the hydrogen demand of the hydrogen storage tank. At the same time, during the load regulation process, monitor the pressure change time (1 min). If the change time exceeds the set time (30 s), change the load regulation PID algorithm parameters to play a flexible regulation role.

[0049] In summary, compared with the prior art, the PEM water electrolysis hydrogen production system and the load regulation control method of the present invention have the following advantages:

[0050] 1. Solve the problem of frequent start and stop of the water electrolysis hydrogen production device. For the problem of the change in the pressure of the hydrogen storage tank at the back end of the water electrolysis hydrogen production system, such as when the pressure drops from the rated pressure (~3.0 Mpa) to the start pressure of the water electrolysis hydrogen production system (~2.6 Mpa), it is necessary to start the water electrolysis hydrogen production system. When the pressure of the hydrogen storage tank increases to the rated pressure (~3.0 Mpa), the water electrolysis hydrogen production system needs to be shut down or the hydrogen is emptied. This method causes the water electrolysis hydrogen production system to start and stop frequently, or wastes hydrogen. The present invention optimizes the load regulation method and control method through the load regulation advantage of the PEM electrolyzer. When the pressure of the storage tank is (~2.95 Mpa), reduce the electrolyzer load to the lowest load (~10%) and the raw water flow rate (~2.0 m 3 / h); when the pressure of the storage tank decreases (~2.6 Mpa), increase the electrolyzer load (~100%) and the raw water flow rate (~3.5 m 3(h), according to the storage tank pressure change range (2.6 - 3 Mpa) and the electrolyzer load adjustment range (10% - 100%), linearize the electrolyzer load adjustment to reduce the start-stop times of the water electrolysis hydrogen production system.

[0051] 2. Improve the system operation efficiency and quickly respond to the change of the hydrogen storage tank pressure. When the hydrogen production demand is low, the electrolyzer does not shut down and operates at a low load, while keeping the electrolyzer temperature decreasing slowly; when the hydrogen production demand is high, the electrolyzer can quickly operate at a high efficiency stage. Within a certain period of time, the system operation efficiency can be increased by more than 30%, thus improving the overall system operation efficiency.

[0052] 3. Reduce the performance degradation of the electrolyzer. Frequent start-stop and frequent temperature changes will affect the electrolyzer membrane (decrease by 10% - 15% after 1000 times) and the catalyst activity (decrease by 20% - 30% after 500 times) and service life. The load adjustment method and control method of the present invention effectively reduce the start-stop times of the electrolyzer. When using hydrogen frequently, the system can almost operate without shutdown. When using hydrogen infrequently, the shutdown times can be reduced by more than 50%, thereby reducing the performance degradation of the electrolyzer caused by frequent start-stop.

[0053] Example 3

[0054] This example is based on Example 1:

[0055] This example provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the PEM water electrolysis hydrogen production system load adjustment control method of Example 1. Among them, the computer program can be in the form of source code, object code, executable file or some intermediate form, etc.

[0056] Example 4

[0057] This example is based on Example 1:

[0058] This example provides a computer-readable storage medium, storing a computer program, and when the computer program is executed by a processor, it implements the PEM water electrolysis hydrogen production system load adjustment control method of Example 1. Among them, the computer program can be in the form of source code, object code, executable file or some intermediate form, etc. The storage medium includes: any entity or device capable of carrying the computer program code, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the storage medium does not include electrical carrier signals and telecommunication signals.

[0059] It should be noted that, for the foregoing method embodiments, for the sake of simplicity of description, they are expressed as a series of action combinations. However, those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

Claims

1. A PEM water electrolysis hydrogen production system, characterized in that, It includes a hydrogen storage tank, a PEM electrolyzer, a water supply system and a power conversion device. The pure water input end of the PEM electrolyzer is connected to the water supply system, the power input end is connected to the power conversion device, and the hydrogen output end is connected to the hydrogen storage tank; the power conversion device is configured to adjust the output current based on the real-time pressure of the hydrogen storage tank, so as to control the hydrogen production load of the PEM electrolyzer and stabilize the pressure of the hydrogen storage tank.

2. A PEM water electrolysis hydrogen production system according to claim 1, characterized in that, The water supply system is configured to reduce the water supply flow rate when the load of the PEM electrolyzer decreases, and increase the water supply flow rate when the load of the PEM electrolyzer increases, so as to maintain the temperature of the PEM electrolyzer within the set range.

3. A PEM water electrolysis hydrogen production system according to claim 1, characterized in that, The power conversion device includes an IGBT inverter, and the IGBT inverter can adjust the output current based on the real-time pressure of the hydrogen storage tank.

4. A PEM water electrolysis hydrogen production system according to claim 1, characterized in that, A pressure sensor is provided on the hydrogen storage tank, and the pressure sensor can monitor the hydrogen pressure in the hydrogen storage tank in real time.

5. A PEM water electrolysis hydrogen production system according to claim 1, characterized in that, It further includes a hydrogen purification device, and the hydrogen purification device is arranged between the PEM electrolyzer and the hydrogen storage tank for purifying the hydrogen output by the PEM electrolyzer.

6. A load regulation control method for a PEM water electrolysis hydrogen production system, applied to the PEM water electrolysis hydrogen production system according to claim 1, characterized in that, The load adjustment control method includes: Calculating the difference a between the rated pressure value and the current pressure value of the hydrogen storage tank; Setting the load adjustment pressure range value b; If a > b, then control the PEM water electrolysis hydrogen production system to operate under rated conditions; If a ≤ b, then control the PEM water electrolysis hydrogen production system to enter the load adjustment pressure condition for operation.

7. A load regulation control method for a PEM water electrolysis hydrogen production system according to claim 6, characterized in that When the PEM water electrolysis hydrogen production system operates under rated conditions, raise the output current of the power conversion device to the rated value and raise the water supply flow rate of the water supply system to the rated value.

8. A load regulation control method for a PEM water electrolysis hydrogen production system according to claim 6, characterized in that, When the PEM water electrolysis hydrogen production system enters the load adjustment pressure condition for operation, execute the PEM electrolyzer load adjustment PID algorithm control, reduce the output current of the power conversion device, and at the same time reduce the water supply flow rate of the water supply system.

9. A load regulation control method for a PEM water electrolysis hydrogen production system according to claim 8, characterized in that, When executing the PEM electrolyzer load adjustment PID algorithm control, monitor the hydrogen storage tank pressure change time c at the same time.

10. A load regulation control method for a PEM water electrolysis hydrogen production system according to claim 9, characterized in that, If it is monitored that the hydrogen storage tank pressure change time c is greater than or equal to the set time, then change the PEM electrolyzer load adjustment PID algorithm coefficient to meet the rapid response process of the hydrogen storage tank pressure.

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