A constant pressure hydrogen production device for pure water and a control method

Abstract

The present application relates to the technical field of PEM hydrogen production, and particularly relates to a constant-pressure hydrogen production device for pure water and a control method, the hydrogen production device comprising a water storage device, a resin filter and a PEM electrolysis device, the water inlet end of the resin filter is in communication with the water outlet end of the water storage device, and the water inlet end of the PEM electrolysis device is in communication with the water outlet end of the resin filter; the device further comprises an oxygen outlet end in communication with the positive electrode of the PEM electrolysis device and a hydrogen outlet end in communication with the negative electrode of the PEM electrolysis device. The present application aims to provide a constant-pressure hydrogen production device for pure water and a control method, by adaptively controlling the gas pressure of the negative electrode and the positive electrode of the hydrogen production device, so as to solve the problem of insufficient negative electrode pressure, and meanwhile, the problem of reverse anode permeation caused by excessive negative electrode pressure can be avoided.

Description

Technical Field

[0001] This invention relates to the field of PEM hydrogen production technology, specifically to a constant pressure hydrogen production device for pure water and a control method thereof. Background Technology

[0002] As the utilization of clean energy gradually increases, its intermittent nature makes the demand for energy storage extremely urgent. Hydrogen energy is a good bridge, with the following main advantages: first, hydrogen-to-electricity conversion can be achieved efficiently through PEM; second, hydrogen has a relatively high energy density and is relatively easy to store; and third, hydrogen-to-electricity conversion has the potential for large-scale application.

[0003] Currently, among water electrolysis hydrogen production technologies, proton exchange membrane electrolysis (PEMWE) has been gradually industrialized. However, in the civilian sector, it is limited by factors such as the small amount of hydrogen produced, resulting in insufficient negative electrode pressure. Additional pressure needs to be provided for compression, leading to high energy consumption. At the same time, due to the lack of suitable gas pressure regulation, simply increasing the pressure at the hydrogen production end can easily lead to reverse anode permeation, causing dangerous hydrogen-oxygen mixing. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a constant pressure hydrogen production device and control method for pure water. By adaptively controlling the gas pressure of the negative electrode and the positive electrode of the hydrogen production device, the problem of insufficient negative electrode pressure can be solved, while avoiding the problem of reverse anode permeation caused by excessive negative electrode pressure.

[0005] This invention is achieved through the following technical solution:

[0006] A constant pressure hydrogen production device for pure water includes a water storage device, a resin filter, and a PEM electrolysis device. The inlet of the resin filter is connected to the outlet of the water storage device, and the inlet of the PEM electrolysis device is connected to the outlet of the resin filter. The device also includes an oxygen outlet connected to the positive electrode of the PEM electrolysis device and a hydrogen outlet connected to the negative electrode of the PEM electrolysis device. The hydrogen production device further includes a processing module, a first electronic expansion valve connected between the oxygen outlet and the positive electrode of the PEM electrolysis device, a second electronic expansion valve connected between the hydrogen outlet and the negative electrode of the PEM electrolysis device, a first pressure sensor connected between the first electronic expansion valve and the positive electrode of the PEM electrolysis device, and a second pressure sensor connected between the second electronic expansion valve and the negative electrode of the PEM electrolysis device. The first pressure sensor, the first electronic expansion valve, the second pressure sensor, and the second electronic expansion valve are all signal-connected to the processing module.

[0007] The hydrogen production device also includes a gasbag, which is disposed inside a water storage device.

[0008] The hydrogen production device also includes a one-way valve and a safety valve. The one-way valve is connected to the inlet of the water storage device, and the safety valve is connected to the top of the water storage device.

[0009] The water storage device is also equipped with a water level sensor, and both the water level sensor and the one-way valve are connected to the processing module via signal connection.

[0010] The hydrogen production device further includes a first gas-liquid separation device and a second gas-liquid separation device. The feed end of the first gas-liquid separation device is connected to the positive electrode of the PEM electrolysis device, the water outlet end of the first gas-liquid separation device is connected to the water inlet end of the water storage device, and the gas outlet end of the first gas-liquid separation device is connected to the oxygen outlet end. The first electronic expansion valve is located between the gas outlet end and the oxygen outlet end of the first gas-liquid separation device. The feed end of the second gas-liquid separation device is connected to the negative electrode of the PEM electrolysis device, the water outlet end of the second gas-liquid separation device is connected to the water inlet end of the water storage device, and the gas outlet end of the second gas-liquid separation device is connected to the hydrogen outlet end. The second electronic expansion valve is located between the gas outlet end and the hydrogen outlet end of the second gas-liquid separation device.

[0011] This invention also discloses a constant pressure control method for a PEM hydrogen production unit, comprising the following steps:

[0012] A. The first pressure sensor detects the gas pressure value at the negative electrode of the PEM electrolysis device, and the control module adjusts the opening of the first electronic expansion valve according to the gas pressure value at the positive electrode to maintain the gas pressure value at the positive electrode at 8-10MPa. The minimum opening of the first electronic expansion valve is 10%.

[0013] B. The second pressure sensor detects the gas pressure at the positive electrode of the PEM electrolysis device, and the control module adjusts the opening of the second electronic expansion valve according to the gas pressure at the negative electrode to maintain the gas pressure at the negative electrode at 9-11 MPa. The minimum opening of the second electronic expansion valve is 30%.

[0014] Specifically, when the pressure at the positive electrode is less than 1 MPa, the first electronic expansion valve closes; when the pressure at the negative electrode is less than 1 MPa, the second electronic expansion valve closes.

[0015] Among them, the gas pressure value of the positive electrode is inversely proportional to the opening degree of the first electronic expansion valve, and the gas pressure value of the negative electrode is inversely proportional to the opening degree of the second electronic expansion valve.

[0016] The pressure at the positive electrode is maintained at 9 MPa.

[0017] The negative electrode pressure is maintained at 10 MPa.

[0018] The beneficial effects of this invention are:

[0019] This invention discloses a constant pressure hydrogenation device and control method for pure water. The device includes a processing module, a first electronic expansion valve, a second electronic expansion valve, a first pressure sensor, and a second pressure sensor. The first and second pressure sensors detect the gas pressure at the negative and positive electrodes in the electrolysis device, respectively. Since a smaller opening of the electronic expansion valve results in a larger gas pressure at either the negative or positive electrode, the processing module dynamically adjusts the opening and closing degrees of the first and second electronic expansion valves to achieve dynamic pressure balance at the negative electrode. This solves the problem of insufficient negative electrode pressure and also prevents excessive negative electrode pressure from causing reverse anode permeation. Attached Figure Description

[0020] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0021] Figure 1 This is a block diagram of the present invention.

[0022] Figure Labels

[0023] Water storage device--100, one-way valve--101, airbag--102, safety valve--103, water level sensor--104,

[0024] Resin filter -- 200, PEM electrolysis unit -- 300, Oxygen outlet -- 401, Hydrogen outlet -- 402.

[0025] First electronic expansion valve -- 501, Second electronic expansion valve -- 502, First pressure sensor -- 503, Second pressure sensor -- 504, First gas-liquid separator -- 505, Second gas-liquid separator -- 506

[0026] Processing module -- 600. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] As the utilization of clean energy gradually increases, its intermittent nature makes the demand for energy storage extremely urgent. Hydrogen energy is a good bridge, with the following main advantages: first, hydrogen-to-electricity conversion can be achieved efficiently through PEM; second, hydrogen has a relatively high energy density and is relatively easy to store; and third, hydrogen-to-electricity conversion has the potential for large-scale application.

[0031] Currently, among water electrolysis hydrogen production technologies, proton exchange membrane electrolysis (PEMWE) has been gradually industrialized. However, in the civilian sector, it is limited by factors such as the small amount of hydrogen produced, resulting in insufficient negative electrode pressure. Additional pressure needs to be provided for compression, leading to high energy consumption. At the same time, due to the lack of suitable gas pressure regulation, simply increasing the pressure at the hydrogen production end can easily lead to reverse anode permeation, causing dangerous hydrogen-oxygen mixing.

[0032] To address the aforementioned problems, this embodiment discloses a constant pressure hydrogen device for pure water, the structure of which is as follows: Figure 1As shown, the hydrogen production device includes a water storage device 100, a resin filter 200, a PEM electrolysis device 300, an oxygen outlet 401 connected to the positive electrode of the PEM electrolysis device 300, and a hydrogen outlet 402 connected to the negative electrode of the PEM electrolysis device 300. The inlet of the resin filter 200 is connected to the outlet of the water storage device 100, and the inlet of the PEM electrolysis device 300 is connected to the outlet of the resin filter 200. The hydrogen production device also includes a processing module 600 connected between the oxygen outlet 401 and the positive electrode of the PEM electrolysis device 300. The first electronic expansion valve 501, the second electronic expansion valve 502 connected between the hydrogen outlet 402 and the negative electrode of the PEM electrolysis device 300, the first pressure sensor 503 connected between the first electronic expansion valve 501 and the positive electrode of the PEM electrolysis device 300, and the second pressure sensor 504 connected between the second electronic expansion valve 502 and the negative electrode of the PEM electrolysis device 300 are all connected to the processing module 600 for signal transmission.

[0033] This embodiment also discloses a constant pressure control method for a PEM hydrogen production unit, including the following steps:

[0034] A. The first pressure sensor 503 detects the gas pressure value of the negative electrode of the PEM electrolysis device 300, and adjusts the opening of the first electronic expansion valve 501 according to the gas pressure value of the positive electrode so that the gas pressure value of the positive electrode is maintained at 8-10MPa. The minimum opening of the first electronic expansion valve 501 is 10%.

[0035] B. The second pressure sensor 504 detects the gas pressure value at the positive electrode of the PEM electrolysis device 300, and adjusts the opening of the second electronic expansion valve 502 according to the gas pressure value at the negative electrode so that the gas pressure value at the negative electrode is maintained at 9-11 MPa. The minimum opening of the second electronic expansion valve 502 is 30%.

[0036] In practical use, the opening and closing degree of the first electronic expansion valve 501 is inversely proportional to the gas pressure at the positive electrode; that is, the higher the gas pressure at the positive electrode, the smaller the opening degree of the first electronic expansion valve 501. Similarly, the opening and closing degree of the second electronic expansion valve 502 is inversely proportional to the gas pressure at the negative electrode, so as to achieve a balance between the current gas pressure at the positive and negative electrodes. Preferably, the gas pressure at the positive electrode is maintained at 9 MPa, and the gas pressure at the negative electrode is maintained at 10 MPa.

[0037] Specifically, the present invention provides a constant pressure hydrogenation device and control method for pure water, which includes a processing module 600, a first electronic expansion valve 501, a second electronic expansion valve 502, a first pressure sensor 503, and a second pressure sensor 504. The first pressure sensor 503 and the second pressure sensor 504 detect the gas pressure at the negative and positive electrodes in the electrolysis device, respectively. Since the smaller the opening of the electronic expansion valve, the greater the gas pressure at the negative or positive electrode, the processing module 600 dynamically adjusts the opening degree of the first electronic expansion valve 501 and the second electronic expansion valve 502 to achieve dynamic balance of gas pressure at the negative electrode, thereby solving the problem of insufficient negative electrode pressure and avoiding the problem of reverse anode permeation caused by excessive negative electrode pressure.

[0038] Furthermore, the hydrogen production device also includes a one-way valve 101 and a safety valve 103. The one-way valve 101 is connected to the inlet of the water storage device 100, and the safety valve 103 is connected to the top of the water storage device 100. In this embodiment, the one-way valve 101 is connected to an external water source, allowing for the replenishment of water to the water storage device 100 at any time. The water storage device 100 is a sealed, barrel-shaped structure, and an air bladder 102 is installed inside. Normally, the air bladder 102 is compressed. When the liquid level in the water storage device 100 decreases, the air bladder 102 expands, balancing the pressure within the water storage device 100 and reducing the frequency of water replenishment. Furthermore, a water level sensor 104 is installed inside the water storage device 100. Both the water level sensor 104 and the one-way valve 101 are connected to the processing module 600. When the water level sensor 104 detects that the liquid level in the water storage device 100 is below a certain value, it sends a signal to the processing module 600 to control the opening and closing of the one-way valve 101, achieving automatic water replenishment.

[0039] Furthermore, the hydrogen production device also includes a first gas-liquid separation device 505 and a second gas-liquid separation device 506. The feed end of the first gas-liquid separation device 505 is connected to the positive electrode of the PEM electrolysis device 300, the water outlet end of the first gas-liquid separation device 505 is connected to the water inlet end of the water storage device 100, the gas outlet end of the first gas-liquid separation device 505 is connected to the oxygen outlet end 401, and the first electronic expansion valve 501 is located between the gas outlet end and the oxygen outlet end 401 of the first gas-liquid separation device 505. The feed end of the second gas-liquid separation device 506 is connected to the negative electrode of the PEM electrolysis device 300, the water outlet end of the second gas-liquid separation device 506 is connected to the water inlet end of the water storage device 100, the gas outlet end of the second gas-liquid separation device 506 is connected to the hydrogen outlet end 402, and the second electronic expansion valve 502 is located between the gas outlet end and the hydrogen outlet end 402 of the second gas-liquid separation device 506. Since the oxygen and hydrogen produced at the positive or negative electrode of the PEM electrolysis device 300 inevitably contain a certain amount of gaseous water, the hydrogen and gaseous water, as well as the oxygen and gaseous water, are separated by the first gas-liquid separation device 505 and the second gas-liquid separation device 506. The separated gaseous water is then transported back to the water storage device 100 for recycling.

[0040] It should be noted that the processing module 600 in this embodiment is preferably a PLC processor. The structures and working principles of other components such as resin filter 200, PEM electrolysis device 300, one-way valve 101, safety valve 103, water level sensor 104, first electronic expansion valve 501, second electronic expansion valve 502, first pressure sensor 503, second pressure sensor 504, first gas-liquid separation device 505, and second gas-liquid separation device 506 are all existing technologies and will not be described in detail here.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A constant pressure control method for a PEM hydrogen production unit, characterized in that: The hydrogen production device includes a water storage device, a resin filter, a PEM electrolysis device, an oxygen outlet connected to the positive electrode of the PEM electrolysis device, and a hydrogen outlet connected to the negative electrode of the PEM electrolysis device. The water inlet of the resin filter is connected to the water outlet of the water storage device, and the water inlet of the PEM electrolysis device is connected to the water outlet of the resin filter. The hydrogen production device further includes a processing module, a first electronic expansion valve connected between the oxygen outlet and the positive electrode of the PEM electrolysis device, a second electronic expansion valve connected between the hydrogen outlet and the negative electrode of the PEM electrolysis device, a first pressure sensor connected between the first electronic expansion valve and the positive electrode of the PEM electrolysis device, and a second pressure sensor connected between the second electronic expansion valve and the negative electrode of the PEM electrolysis device. The first pressure sensor, the first electronic expansion valve, the second pressure sensor, and the second electronic expansion valve are all signal-connected to the processing module. The control method includes the following steps: A. The first pressure sensor detects the gas pressure at the positive electrode of the PEM electrolysis unit, and the control module adjusts the opening of the first electronic expansion valve according to the gas pressure at the positive electrode to maintain the gas pressure at the positive electrode at 8-10 MPa. The minimum opening of the first electronic expansion valve is 10%. B. The second pressure sensor detects the gas pressure value at the negative electrode of the PEM electrolysis device, and the control module adjusts the opening of the second electronic expansion valve according to the gas pressure value at the negative electrode to maintain the gas pressure value at the negative electrode at 9-11 MPa. The minimum opening of the second electronic expansion valve is 30%.

2. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The hydrogen production device also includes a gasbag, which is disposed inside a water storage device.

3. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The hydrogen production device also includes a one-way valve and a safety valve. The one-way valve is connected to the inlet of the water storage device, and the safety valve is connected to the top of the water storage device.

4. The constant pressure control method for a PEM hydrogen production unit according to claim 3, characterized in that: The water storage device is also equipped with a water level sensor, and both the water level sensor and the one-way valve are connected to the processing module via signal connection.

5. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The hydrogen production device further includes a first gas-liquid separation device and a second gas-liquid separation device. The feed end of the first gas-liquid separation device is connected to the positive electrode of the PEM electrolysis device. The water outlet of the first gas-liquid separation device is connected to the water inlet of the water storage device. The gas outlet of the first gas-liquid separation device is connected to the oxygen outlet. The first electronic expansion valve is located between the gas outlet and the oxygen outlet of the first gas-liquid separation device. The feed end of the second gas-liquid separator is connected to the negative electrode of the PEM electrolysis device, the water outlet end of the second gas-liquid separator is connected to the water inlet end of the water storage device, the gas outlet end of the second gas-liquid separator is connected to the hydrogen outlet end, and the second electronic expansion valve is located between the gas outlet end and the hydrogen outlet end of the second gas-liquid separator.

6. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: When the pressure at the positive electrode is less than 1 MPa, the first electronic expansion valve closes; when the pressure at the negative electrode is less than 1 MPa, the second electronic expansion valve closes.

7. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The gas pressure at the positive electrode is inversely proportional to the opening degree of the first electronic expansion valve, and the gas pressure at the negative electrode is inversely proportional to the opening degree of the second electronic expansion valve.

8. The constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The pressure at the positive electrode is maintained at 9 MPa.

9. A constant pressure control method for a PEM hydrogen production unit according to claim 1, characterized in that: The negative electrode pressure is maintained at 10 MPa.

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