Method and system for controlling pressure difference between hydrogen and oxygen on two sides in balanced water electrolysis hydrogen production

Abstract

The invention discloses a method and a system for controlling the pressure difference between hydrogen and oxygen in balanced water electrolysis hydrogen production. The pressure difference control on the two sides of hydrogen and oxygen is realized through the multi-stage progressive pressure regulating module, and the pressure on the hydrogen side is always higher than a preset first threshold value of the pressure on the oxygen side through the back pressure regulating module; under the basic pressure environment provided by the back pressure adjusting module, the pressure difference of the two sides of hydrogen and oxygen is monitored in real time, and when the pressure difference exceeds the target fluctuation range, the hydrogen and oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module; if the hydrogen-oxygen pressure difference is not recovered to the target fluctuation range after being corrected by the basic function differential pressure correction module, or the hydrogen-oxygen pressure difference directly exceeds a safety set value, the hydrogen-oxygen pressure difference is further corrected through the safety function differential pressure correction module; and if the safety function differential pressure correction module is ineffective in correction and the pressure on any side of hydrogen and oxygen reaches a physical protection set value, the physical protection module is started to execute physical pressure relief operation, so that the problem of differential pressure control caused by pressure fluctuation of the balanced electrolytic cell is solved.

Description

Technical Field

[0001] This invention specifically relates to a method and system for controlling the pressure difference between hydrogen and oxygen in a balanced electrolysis water hydrogen production process. Background Technology

[0002] In scenarios involving highly volatile renewable energy sources (such as photovoltaic and wind power) power supply, PEM hydrogen production can achieve start-up and load regulation speeds in the millisecond to second range, precisely matching the drastic fluctuations in new energy power generation, which in turn leads to drastic fluctuations in system pressure.

[0003] PEM (Polymer Electrolysis Membrane) water electrolysis processes are generally divided into two technical routes: balanced and differential pressure. In a balanced electrolysis process, the pressures on both sides of the membrane are close, with the hydrogen side pressure slightly higher than the oxygen side, typically not exceeding 5 bar. In a differential pressure electrolysis process, the hydrogen side is at the system pressure (1.6 MPa or 3.0 MPa), while the oxygen side is at a slightly positive pressure. For balanced electrolyzers, it is necessary to control the pressure difference between the hydrogen and oxygen sides, primarily to increase system reliability from a mechanical strength and safety perspective. During the operation of a PEM electrolyzer, the following pressure fluctuations may occur: ① Pressure fluctuations due to the highly volatile nature of renewable energy sources; ② Pressure fluctuations due to system start-up and shutdown; ③ Thermal expansion and contraction of gases caused by temperature differences. Water electrolysis is the process of separating water into hydrogen and oxygen. Once the hydrogen production load (i.e., the electrolysis current) fluctuates, the pressures on both the hydrogen and oxygen sides will also fluctuate with the load. Since the volume ratio of H2 to O2 generated by water electrolysis is 2:1, if the current changes instantaneously, the rate of increase or decrease in hydrogen is twice that of oxygen, thus causing an imbalance in the pressures on both sides. Therefore, specific process design is needed to adapt to such changes. If adjustment is only made by regulating the valve, the differential pressure on both sides will exceed the reasonable range if the adjustment fails.

[0004] In addition, as a small-scale chemical plant, the water electrolysis system must consider the implementation of the basic process and the implementation of the safe process in case of failure. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the issue that pressure fluctuations on both sides of hydrogen and oxygen in existing water electrolysis hydrogen production scenarios lead to low system safety and reliability and reduced lifespan of the fuel cell membrane. This invention provides a method and system for controlling the pressure difference between hydrogen and oxygen in balanced water electrolysis hydrogen production.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] This invention provides a method for controlling the pressure difference between hydrogen and oxygen in a balanced electrolysis water hydrogen production process. The method is characterized by controlling the pressure difference between hydrogen and oxygen through a multi-stage progressive pressure regulating module, and includes the following steps:

[0008] S1 uses a back pressure regulation module to change the hydrogen side pressure based on the oxygen side pressure, and the hydrogen side pressure is always higher than a predetermined first threshold of the oxygen side pressure.

[0009] S2 monitors the pressure difference between hydrogen and oxygen in real time under the basic pressure provided by the back pressure regulation module. When the pressure difference exceeds the target fluctuation range, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module.

[0010] S3 If, after correction by the basic function differential pressure correction module, the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference will be further corrected by the safety function differential pressure correction module.

[0011] S4 If the differential pressure correction module of the safety function is ineffective and the pressure on either side of hydrogen or oxygen reaches the physical protection setting value, the physical protection module is activated to perform a physical pressure relief operation.

[0012] This solution effectively addresses the differential pressure control challenge caused by pressure fluctuations in balanced electrolyzers, achieving precise, safe, and stable pressure control on both the hydrogen and oxygen sides. Furthermore, the use of a multi-stage pressure regulating module significantly improves the system's response speed to pressure fluctuations, effectively extends the service life of the fuel cell membrane, and comprehensively enhances the system's operational reliability.

[0013] Preferably, the back pressure adjustment module changes the hydrogen-side pressure based on the oxygen-side pressure, including:

[0014] By adjusting the hydrogen back pressure valve and the oxygen back pressure valve in a coordinated manner, the hydrogen side pressure changes based on the oxygen side pressure, and the hydrogen side pressure is always maintained above the predetermined first threshold of the oxygen side pressure.

[0015] Preferably, the hydrogen back pressure valve and the oxygen back pressure valve are adjusted in a coordinated manner to change the hydrogen-side pressure based on the oxygen-side pressure, including:

[0016] The opening pressure of the hydrogen back pressure valve is directly mechanically set by the oxygen side pressure. This method uses a physical connection (such as a pressure-sensing pipe) to bring the oxygen side pressure to the valve core control chamber of the hydrogen back pressure valve, so that the oxygen side pressure directly participates in the closing force of the hydrogen valve, thereby achieving passive, real-time tracking of the hydrogen valve opening pressure to the oxygen side pressure.

[0017] In this scheme, the hydrogen-side pressure is changed based on the oxygen-side pressure through a purely mechanical linkage. This purely mechanical linkage method does not rely on an external power source or complex control logic, resulting in a simple structure, strong anti-interference capability, and the ability to provide basic differential pressure protection under extreme conditions, thus offering high safety performance.

[0018] Preferably, the opening pressure of the hydrogen back pressure valve is set based on the feedback of the electrical signal of the oxygen side pressure. This method utilizes an oxygen pressure sensor to detect the oxygen side pressure and generate an electrical signal. The control system calculates the required hydrogen valve opening pressure based on this electrical signal and directly sends the corresponding setting command to the hydrogen back pressure valve (usually an electrically controlled regulating valve).

[0019] In this scheme, the hydrogen-side pressure is adjusted based on the oxygen-side pressure using an electrical signal feedback method. This method retains the simplicity of a mechanical valve while introducing the flexibility of electronic control, allowing for easy adjustment of the target pressure differential, fast response, and higher control accuracy than a purely mechanical method.

[0020] Preferably, while independently controlling the oxygen back pressure valve based on the electrical signal feedback of the oxygen side pressure, the hydrogen back pressure valve is also maintained at the predetermined first threshold based on the electrical signal of the oxygen side pressure. The oxygen side maintains its own pressure stability through an independent closed-loop control loop; the hydrogen side, based on the same oxygen side pressure signal, actively maintains a fixed pressure difference value higher than the oxygen side pressure through another control loop, achieving precise control through dual-loop coordination.

[0021] In this scheme, the hydrogen-side pressure is adjusted based on the oxygen-side pressure through a fully electronically controlled independent tracking method. This method achieves autonomous stabilization of the oxygen-side pressure and high-precision tracking of the hydrogen-side pressure, resulting in excellent system dynamic performance. It better adapts to complex operating conditions such as rapid load changes, providing optimal system control performance and safety assurance.

[0022] Preferably, the predetermined first threshold is 0.1~0.3 MPa.

[0023] Preferably, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range using a basic functional differential pressure correction module, including:

[0024] When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the first set value, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen correction switch valve, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is less than the second set value, the hydrogen correction switch valve is closed.

[0025] When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the third set value, the oxygen side pressure is adjusted by adjusting the opening of the oxygen correction switch valve, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is greater than the fourth set value, the oxygen correction switch valve is closed.

[0026] The hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side.

[0027] Preferably, the first set value is greater than or equal to the second set value, and the third set value is less than or equal to the fourth set value.

[0028] Preferably, the hydrogen-oxygen pressure difference is further corrected by a safety function differential pressure correction module, including:

[0029] When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the fifth set value, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen safety correction switch valve, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is less than the sixth set value, the hydrogen safety correction switch valve is closed.

[0030] When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the seventh set value, the oxygen side pressure is adjusted by adjusting the opening of the oxygen safety correction switch valve, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is greater than the eighth set value, the oxygen safety correction switch valve is closed.

[0031] The hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side.

[0032] Preferably, the fifth setting value is greater than or equal to the sixth setting value, and the seventh setting value is less than or equal to the eighth setting value.

[0033] Preferably, the fifth setting value is greater than the first setting value, and the seventh setting value is less than the third setting value.

[0034] This invention also provides a pressure difference control system for hydrogen and oxygen in a balanced electrolysis water hydrogen production process. The system includes a hydrogen separator and an oxygen separator, as well as a pressure difference sensor and a pressure regulating module electrically connected to the hydrogen and oxygen separators. The pressure difference sensor is used to acquire the pressure difference between the hydrogen and oxygen sides; the pressure regulating module is used to adjust the pressure difference between the hydrogen and oxygen sides.

[0035] The pressure regulating module includes a back pressure regulating module, a basic function differential pressure correction module, a safety function differential pressure correction module, and a physical component module;

[0036] The back pressure adjustment module makes the hydrogen side pressure and oxygen side pressure change synchronously, and the hydrogen side pressure is always higher than the oxygen side pressure by a predetermined first threshold.

[0037] Under the basic pressure environment provided by the back pressure regulation module, the pressure difference between hydrogen and oxygen is monitored in real time. When the pressure difference exceeds the target fluctuation range, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module.

[0038] If the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range after correction by the basic function differential pressure correction module, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference will be further corrected by the safety function differential pressure correction module.

[0039] If the differential pressure correction module fails to correct the pressure, and the pressure on either the hydrogen or oxygen side reaches the physical protection setting value, the physical protection module will be activated to perform a physical pressure relief operation.

[0040] The positive and progressive effects of this invention are as follows:

[0041] The present invention provides a method for controlling the pressure difference between hydrogen and oxygen in a balanced electrolysis water production process. This method utilizes a multi-stage progressive pressure regulating module to achieve pressure difference control on both sides, effectively solving the differential pressure control problem caused by pressure fluctuations in balanced electrolyzers. This results in precise, safe, and stable pressure control on both sides of the hydrogen and oxygen. Simultaneously, the use of a multi-stage pressure regulating module significantly improves the system's response speed to pressure fluctuations, effectively extends the service life of the fuel cell membrane, and comprehensively enhances the system's operational reliability.

[0042] The pressure difference control system on both sides of hydrogen and oxygen in the balanced electrolysis of water hydrogen production of the present invention has a simple structure and high reliability. Attached Figure Description

[0043] Figure 1 This is a flowchart of the pressure difference control method on both sides of hydrogen and oxygen in Example 1.

[0044] Figure 2 This is a schematic diagram of the back pressure adjustment module in Embodiment 1.

[0045] Figure 3 This is a schematic diagram of the back pressure adjustment module in another embodiment.

[0046] Figure 4 This is a schematic diagram of the back pressure adjustment module in another embodiment.

[0047] Figure 5 This is a flowchart of the basic function differential pressure correction module adjusting the pressure on both sides of hydrogen and oxygen in Embodiment 1.

[0048] Figure 6 This is a flowchart illustrating the adjustment of the pressure on both sides of the hydrogen and oxygen sides by the safety function differential pressure correction module in Embodiment 1.

[0049] Figure 7 This is a schematic diagram of the pressure difference control system on both sides of hydrogen and oxygen in Example 1.

[0050] Explanation of reference numerals in the attached figures:

[0051] Hydrogen separator 100

[0052] Oxygen separator 200

[0053] Differential pressure sensor 300

[0054] Voltage regulating module 400

[0055] Hydrogen back pressure valve 411

[0056] Oxygen back pressure valve 412

[0057] Hydrogen pressure sensor 413

[0058] Oxygen pressure sensor 414

[0059] Hydrogen correction switch valve 421

[0060] Oxygen Correction Switch Valve 422

[0061] Hydrogen safety correction switch valve 431

[0062] Oxygen Safety Correction Switch Valve 432

[0063] Hydrogen safety valve 441

[0064] Oxygen safety valve 442 Detailed Implementation

[0065] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0066] Example 1

[0067] This invention provides a method for controlling the pressure difference between hydrogen and oxygen in a balanced electrolysis water hydrogen production process. The method utilizes a multi-stage progressive pressure regulating module to achieve pressure difference control between the hydrogen and oxygen sides, and includes the following steps:

[0068] S1 uses a back pressure regulation module to change the hydrogen side pressure based on the oxygen side pressure, and the hydrogen side pressure is always higher than a predetermined first threshold of the oxygen side pressure.

[0069] In this embodiment, the predetermined first threshold is 0.2 MPa.

[0070] Under the basic pressure environment provided by the back pressure regulation module, S2 monitors the pressure difference between hydrogen and oxygen in real time. When the pressure difference exceeds the target fluctuation range, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module.

[0071] If the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range after correction by the basic function differential pressure correction module, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference will be further corrected by the safety function differential pressure correction module.

[0072] If the differential pressure correction module fails to correct the pressure, and the pressure on either the hydrogen or oxygen side reaches the physical protection setting value, the physical protection module will be activated to perform a physical pressure relief operation.

[0073] In this embodiment, the opening pressure of the hydrogen back pressure valve 411 is directly mechanically set by the oxygen side pressure. This method uses a physical connection (such as a pressure-sensing pipe) to guide the oxygen side pressure to the valve core control chamber of the hydrogen back pressure valve 411, allowing the oxygen side pressure to directly participate in constituting the closing force of the hydrogen back pressure valve 411, thereby achieving passive, real-time tracking of the opening pressure of the hydrogen back pressure valve 411 to the oxygen side pressure. Specifically, as shown... Figure 2 As shown, step S1 includes:

[0074] Step S101 (Pressure Reference Setting and Coupling): Configure a mechanical oxygen back pressure valve 412 and a mechanical hydrogen back pressure valve 411. Through a physical pressure-sensing pipeline, the pressure of the oxygen back pressure valve 412 (i.e., the real-time oxygen side pressure P_O) is led to the valve core control chamber of the hydrogen back pressure valve 411, so that the real-time oxygen side pressure P_O directly acts on the valve core of the hydrogen back pressure valve 411.

[0075] Step S102 (Formation of Linkage Opening Condition): The valve core of the hydrogen back pressure valve 411 is simultaneously subjected to the force of a preset spring. Therefore, its actual opening pressure P_H_open is jointly determined by the real-time oxygen side pressure P_O and the elastic force of the preset spring, satisfying the relationship: P_H_open = P_O + δ, where δ is the fixed pressure offset corresponding to the spring force, and this offset δ is the predetermined first threshold.

[0076] Step S103 (Automatic Pressure Following): During system operation, the hydrogen back pressure valve 411 opens only when the hydrogen-side pressure P_H is greater than the real-time changing opening pressure P_H_open. This mechanism forces the hydrogen-side pressure P_H to always be at least higher than the oxygen-side pressure P_O by an offset δ, thereby automatically and passively realizing the hydrogen-side pressure following the changes in the oxygen-side pressure, thus completing step S1.

[0077] In some other embodiments, the opening pressure of the hydrogen back pressure valve 411 is set based on an electrical signal feedback from the oxygen side pressure. This method utilizes an oxygen pressure sensor 414 to detect the oxygen side pressure and generate an electrical signal. The control system calculates the required opening pressure of the hydrogen back pressure valve 411 based on this signal and directly sends a corresponding setting command to the hydrogen back pressure valve 411 (typically an electrically controlled regulating valve). Specifically, for example... Figure 3 As shown, step S1 includes:

[0078] Step S111 (Signal Detection and Target Calculation): The oxygen-side pressure P_O is detected in real time by the oxygen pressure sensor 414, and a first electrical signal is generated. The control system receives the first electrical signal and calculates the target set value P_H_set of the opening pressure of the hydrogen back pressure valve 411 in real time according to the formula P_H_set=P_O+ΔP1, where ΔP1 is a predetermined first threshold.

[0079] Step 112 (Valve status command setting): The control system converts the target setting value of the opening pressure P_H_set into a corresponding control command and outputs it to an electrically controlled hydrogen back pressure valve 411 (e.g., a regulating valve with an electric positioner).

[0080] Step S113 (Execution and Feedback Loop): The electrically controlled hydrogen back pressure valve 411 responds to the control command and adjusts its internal state (such as the positioner zero point or spring preload) to dynamically set its equivalent opening pressure to P_H_set. This process is repeated periodically, so that the opening pressure of the hydrogen back pressure valve 411 is continuously fed back and reset according to the real-time oxygen side pressure P_O, thereby forcing the hydrogen side pressure P_H to follow the change of P_O and always keep P_H>P_O+ΔP1, thus realizing step S1.

[0081] In other embodiments, while independently controlling the oxygen back pressure valve 412 based on the electrical signal feedback of the oxygen side pressure, the hydrogen back pressure valve 411 is maintained at a predetermined first threshold based on the oxygen side pressure electrical signal. The oxygen side maintains its own pressure stability through an independent closed-loop control loop; the hydrogen side, based on the same oxygen side pressure signal, actively maintains a fixed pressure difference value higher than the oxygen side pressure through another control loop, achieving precise control through dual-loop coordination. Specifically, as shown... Figure 4 As shown, step S1 includes:

[0082] Step S121 (Independent and Stable Control of Oxygen-Side Pressure): The oxygen-side pressure P_O is detected in real time by the oxygen pressure sensor 414. The control system compares the detected P_O with an independent oxygen-side pressure target value P_O_target, and dynamically adjusts the opening of an electronically controlled oxygen back pressure valve 412 through a first closed-loop control algorithm (such as PID) to stabilize the actual oxygen-side pressure P_O within the allowable fluctuation range of P_O_target.

[0083] Step S122 (Precise Follow-up Control of Hydrogen Side Pressure): While step S121 is being performed, the control system synchronously performs the following operations:

[0084] Step S1221 (Target Generation): Using the same oxygen-side pressure P_O detected in real time in step S121 as a feedforward signal, the instantaneous target value P_H_target of the hydrogen-side pressure is generated in real time according to the formula P_H_target=P_O+ΔP2, where ΔP2 is the preset first threshold.

[0085] Step S1222 (Closed-loop correction): The actual hydrogen pressure P_H is detected in real time by the hydrogen pressure sensor 413. P_H is compared with the instantaneous target value P_H_target. The opening adjustment amount of an electrically controlled hydrogen back pressure valve 411 is calculated by the second closed-loop control algorithm.

[0086] Step S1223 (joint execution): The control system adjusts the opening degree of the electrically controlled oxygen back pressure valve 412 and the electrically controlled hydrogen back pressure valve 411 in parallel according to the calculation results of steps S121 and S1222.

[0087] Step S123 (Cooperative achievement of the goal): Through the parallel and coordinated control of steps S121 and S122, while achieving the stability of the oxygen side pressure itself, the hydrogen side pressure P_H is precisely made to track the instantaneous target value P_H_target in real time, that is, to always satisfy P_H=P_O+ΔP2, thereby completing step S1 with high precision and high dynamic response.

[0088] like Figure 5 Specifically, step S2 includes:

[0089] Obtain the pressure difference DP (Differential Pressure) between the hydrogen side pressure and the oxygen side pressure: H2-O2;

[0090] When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the first set value Set_1, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen correction switch valve 421, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is less than the second set value Set_2, the hydrogen correction switch valve 421 is closed.

[0091] When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the third set value Set_3, the oxygen side pressure is adjusted by adjusting the opening of the oxygen correction switch valve 422, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is greater than the fourth set value Set_4, the oxygen correction switch valve 422 is closed.

[0092] Among them, the hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side; the first setting value Set_1 is greater than or equal to the second setting value Set_2, and the third setting value Set_3 is less than or equal to the fourth setting value Set_4.

[0093] like Figure 6 Specifically, step S3 includes:

[0094] When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the fifth set value Set_5, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen safety correction switch valve 431, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is less than the sixth set value Set_6, the hydrogen safety correction switch valve 431 is closed.

[0095] When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the seventh set value Set_7, the oxygen side pressure is adjusted by adjusting the opening of the oxygen safety correction switch valve 432, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is greater than the eighth set value Set_8, the oxygen safety correction switch valve 432 is closed.

[0096] Among them, the hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side; the fifth setting value Set_5 is greater than or equal to the sixth setting value Set_6, and the seventh setting value Set_7 is less than or equal to the eighth setting value Set_8.

[0097] In this embodiment, the fifth setting value Set_5 is greater than the first setting value Set_1, and the seventh setting value Set_7 is less than the third setting value Set_3.

[0098] This invention also provides a pressure difference control system for hydrogen and oxygen sides in a balanced water electrolysis hydrogen production process, such as... Figure 7 As shown, the system includes a hydrogen separator 100 and an oxygen separator 200, as well as a differential pressure sensor 300 and a pressure regulating module 400 electrically connected to the hydrogen separator 100 and the oxygen separator 200; the differential pressure sensor 300 is used to acquire the pressure difference between the hydrogen and oxygen sides; the pressure regulating module 400 is used to regulate the pressure difference between the hydrogen and oxygen sides.

[0099] The pressure regulating module includes a back pressure regulating module, a basic function differential pressure correction module, a safety function differential pressure correction module, and a physical component module;

[0100] The back pressure regulation module includes a hydrogen back pressure valve 411, an oxygen back pressure valve 412, a hydrogen pressure sensor 413, and an oxygen pressure sensor 414. The back pressure regulation module synchronizes the changes in hydrogen-side pressure with those in the oxygen-side pressure, ensuring that the hydrogen-side pressure is always higher than a predetermined first threshold value for the oxygen-side pressure.

[0101] The basic differential pressure correction module includes a hydrogen correction switch valve 421 and an oxygen correction switch valve 422. Under the base pressure provided by the back pressure regulation module, the pressure difference between the hydrogen and oxygen sides is monitored in real time. When the pressure difference exceeds the target fluctuation range, the basic differential pressure correction module corrects the hydrogen-oxygen pressure difference to the target fluctuation range.

[0102] The safety function differential pressure correction module includes a hydrogen safety correction switch valve 431 and an oxygen safety correction switch valve 432. If the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range after correction by the basic function differential pressure correction module, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference is further corrected by the safety function differential pressure correction module.

[0103] The physical protection module includes a hydrogen safety valve 441 and an oxygen safety valve 442. If the differential pressure correction module fails to correct the pressure, and the pressure on either the hydrogen or oxygen side reaches the physical protection setting value, the physical protection module is activated to perform a physical pressure relief operation.

[0104] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for controlling the pressure difference between hydrogen and oxygen sides in a balanced water electrolysis hydrogen production process, characterized in that, The pressure difference between hydrogen and oxygen is controlled through a multi-stage progressive pressure regulating module, including the following steps: S1 uses a back pressure regulation module to change the hydrogen side pressure based on the oxygen side pressure, and the hydrogen side pressure is always higher than a predetermined first threshold of the oxygen side pressure. S2 monitors the pressure difference between hydrogen and oxygen in real time under the basic pressure provided by the back pressure regulation module. When the pressure difference exceeds the target fluctuation range, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module. S3 If, after correction by the basic function differential pressure correction module, the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference will be further corrected by the safety function differential pressure correction module. S4 If the differential pressure correction module of the safety function is ineffective and the pressure on either side of hydrogen or oxygen reaches the physical protection setting value, the physical protection module is activated to perform a physical pressure relief operation.

2. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 1, characterized in that, The back pressure regulation module adjusts the hydrogen-side pressure based on the oxygen-side pressure, including: By adjusting the hydrogen back pressure valve and the oxygen back pressure valve in a coordinated manner, the hydrogen side pressure changes based on the oxygen side pressure, and the hydrogen side pressure is always maintained above the predetermined first threshold of the oxygen side pressure.

3. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 2, characterized in that, By interlocking the hydrogen back pressure valve and the oxygen back pressure valve, the hydrogen-side pressure changes based on the oxygen-side pressure, including: The opening pressure of the hydrogen back pressure valve is directly mechanically set by the oxygen side pressure. Alternatively, the opening pressure of the hydrogen back pressure valve can be set based on the electrical signal feedback of the oxygen side pressure. Alternatively, while independently controlling the oxygen back pressure valve based on the electrical signal feedback of the oxygen side pressure, the hydrogen back pressure valve is maintained at the predetermined first threshold based on the electrical signal of the oxygen side pressure.

4. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 1, characterized in that, The predetermined first threshold is 0.1~0.3 MPa.

5. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 1, characterized in that, The hydrogen-oxygen pressure difference is corrected to the target fluctuation range using the basic differential pressure correction module, including: When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the first set value, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen correction switch valve, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is less than the second set value, the hydrogen correction switch valve is closed. When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the third set value, the oxygen side pressure is adjusted by adjusting the opening of the oxygen correction switch valve, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is greater than the fourth set value, the oxygen correction switch valve is closed. The hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side.

6. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 5, characterized in that, The first setting value is greater than or equal to the second setting value, and the third setting value is less than or equal to the fourth setting value.

7. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 5, characterized in that, The hydrogen-oxygen pressure difference is further corrected through the safety function differential pressure correction module, including: When the hydrogen side pressure is greater than the oxygen side pressure and the pressure difference is greater than or equal to the fifth set value, the hydrogen side pressure is adjusted by adjusting the opening of the hydrogen safety correction switch valve, and the hydrogen-oxygen pressure difference is monitored in real time. When the hydrogen-oxygen pressure difference is less than the sixth set value, the hydrogen safety correction switch valve is closed. When the hydrogen side pressure is less than the oxygen side pressure and the pressure difference is less than or equal to the seventh set value, the oxygen side pressure is adjusted by adjusting the opening of the oxygen safety correction switch valve, and the hydrogen-oxygen pressure difference is detected in real time. When the hydrogen-oxygen pressure difference is greater than the eighth set value, the oxygen safety correction switch valve is closed. The hydrogen-oxygen pressure difference refers to the difference between the pressure value on the hydrogen side and the pressure value on the oxygen side.

8. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 7, characterized in that, The fifth setting value is greater than or equal to the sixth setting value, and the seventh setting value is less than or equal to the eighth setting value.

9. The method for controlling the pressure difference between hydrogen and oxygen sides in balanced water electrolysis hydrogen production as described in claim 7, characterized in that, The fifth setting value is greater than the first setting value, and the seventh setting value is less than the third setting value.

10. A pressure difference control system for hydrogen and oxygen sides in a balanced electrolysis water hydrogen production process, characterized in that, The system includes a hydrogen separator and an oxygen separator, as well as a differential pressure sensor and a pressure regulating module electrically connected to the hydrogen separator and the oxygen separator; the differential pressure sensor is used to acquire the pressure difference between the hydrogen and oxygen sides; the pressure regulating module is used to adjust the pressure difference between the hydrogen and oxygen sides. The pressure regulating module includes a back pressure regulating module, a basic function differential pressure correction module, a safety function differential pressure correction module, and a physical component module; The back pressure adjustment module makes the hydrogen side pressure and oxygen side pressure change synchronously, and the hydrogen side pressure is always higher than the oxygen side pressure by a predetermined first threshold. Under the basic pressure environment provided by the back pressure regulation module, the pressure difference between hydrogen and oxygen is monitored in real time. When the pressure difference exceeds the target fluctuation range, the hydrogen-oxygen pressure difference is corrected to the target fluctuation range through the basic function differential pressure correction module. If the hydrogen-oxygen pressure difference still fails to return to the target fluctuation range after correction by the basic function differential pressure correction module, or if the hydrogen-oxygen pressure difference directly exceeds the safety setting value, the hydrogen-oxygen pressure difference will be further corrected by the safety function differential pressure correction module. If the differential pressure correction module fails to correct the pressure, and the pressure on either the hydrogen or oxygen side reaches the physical protection setting value, the physical protection module will be activated to perform a physical pressure relief operation.

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