System for accurately controlling pressure on oxygen side and hydrogen side of alkaline electrolytic cell

Abstract

The utility model relates to a system for accurately controlling pressure on oxygen and hydrogen sides of an alkaline electrolytic bath, which is characterized in that the input end of an oxygen separator is connected with an oxygen side outlet of the electrolytic bath, the oxygen output end of the oxygen separator is connected with an oxygen exhaust pipe, and the input end of a hydrogen separator is connected with a hydrogen side outlet of the electrolytic bath; the hydrogen output end of the hydrogen separator is connected with a hydrogen exhaust pipe; two pressure regulating valves are respectively arranged on the oxygen exhaust pipe and the hydrogen exhaust pipe, one regulating valve is used for controlling the pressure balance on the oxygen and hydrogen sides of the electrolytic bath, and the other regulating valve is used for controlling the pressure balance between the two valves. And under the precise control of the double regulating valves, the electrolytic cell can be ensured to operate under a safer and more stable pressure working condition.

Description

Technical Field

[0001] The utility model relates to a system for accurately controlling the pressures on both sides of oxygen and hydrogen in an alkaline electrolytic cell, belonging to the technical field of producing hydrogen by electrolyzing water. Background Art

[0002] In the process of producing hydrogen by alkaline electrolysis, if the pressure of the hydrogen and oxygen pipelines at the outlet of the electrolyzer changes, it will cause the mutual penetration of hydrogen and oxygen, directly affecting the purity of the gas and the safety of system operation. Therefore, the pressure balance on both sides of the oxygen and hydrogen in the alkaline electrolyzer must be dynamically adjusted during the hydrogen production process.

[0003] A single regulating valve is usually used in existing equipment to adjust the pressure of the hydrogen production system. For example, the application with publication number CN117987881A discloses an alkaline electrolyzer hydrogen production system and a pressure control method, including an alkaline electrolyzer, a test power supply, an anode separation tank, a cathode separation tank, an anode treatment system, a cathode treatment system, a first back pressure valve, a second back pressure valve, a first differential pressure level gauge and a second differential pressure level gauge. It uses the liquid level difference and the back pressure valve for regulation, which can prevent the liquid level in the tank from suddenly changing and overflowing, thereby preventing corrosion damage to other parts of the hydrogen production system, avoiding oxygen and hydrogen mixing, and ensuring the safety of the alkaline electrolyzer hydrogen production system. However, the outlet pressure of the oxygen and hydrogen discharge pipe changes greatly with the change in the amount of hydrogen and oxygen used. At this time, the pressure regulation of the hydrogen production system cannot be met by using a single regulating valve, and it is very easy to increase the oxygen value in hydrogen, resulting in unqualified product hydrogen purity or increased hydrogen in oxygen, affecting the safety of system operation.

[0004] Based on this, it is necessary to develop a method that can ensure that the alkaline electrolyzer hydrogen production system can achieve precise control of the system pressure on both sides of oxygen and hydrogen when the client usage changes, so as to ensure the safe and stable operation of the system. Summary of the invention

[0005] The utility model provides a system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolytic cell, which can maintain the pressure balance on both sides of oxygen and hydrogen in the system to ensure the safe operation of the hydrogen production system.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer, comprising an electrolyzer, an oxygen separator and a hydrogen separator, wherein the input end of the oxygen separator is connected to the oxygen side outlet of the electrolyzer, the oxygen output end of the oxygen separator is connected to the oxygen exhaust pipe, the input end of the hydrogen separator is connected to the hydrogen side outlet of the electrolyzer, and the hydrogen output end of the hydrogen separator is connected to the hydrogen exhaust pipe;

[0008] A first regulating valve of the oxygen exhaust pipe and a second regulating valve of the oxygen exhaust pipe are sequentially installed on the oxygen exhaust pipe, wherein the first regulating valve of the oxygen exhaust pipe is arranged close to the oxygen separator, and an oxygen exhaust pipe pressure detection remote transmission device is installed between the first regulating valve of the oxygen exhaust pipe and the second regulating valve of the oxygen exhaust pipe;

[0009] A first regulating valve of the hydrogen exhaust pipe and a second regulating valve of the hydrogen exhaust pipe are sequentially installed on the hydrogen exhaust pipe, wherein the first regulating valve of the hydrogen exhaust pipe is arranged close to the hydrogen separator, and a remote transmission device for detecting pressure of the hydrogen exhaust pipe is installed between the first regulating valve of the hydrogen exhaust pipe and the second regulating valve of the hydrogen exhaust pipe;

[0010] As a further design of the utility model, the oxygen exhaust pipe pressure detection remote transmission device and the hydrogen exhaust pipe pressure detection remote transmission device can be set to the same or different pressure values;

[0011] As a further design of the utility model, the second regulating valve of the oxygen exhaust pipe, the remote transmission device for detecting the pressure of the oxygen exhaust pipe, the second regulating valve of the hydrogen exhaust pipe and the remote transmission device for detecting the pressure of the hydrogen exhaust pipe are simultaneously connected to the PLC, and the pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe are controlled in real time by the PLC;

[0012] As a further design of the utility model, the second regulating valve of the oxygen exhaust pipe, the oxygen exhaust pipe pressure detection remote transmission device, the second regulating valve of the hydrogen exhaust pipe and the hydrogen exhaust pipe pressure detection remote transmission device are connected to the DCS at the same time, and the pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe is controlled in real time by the DCS.

[0013] Through the above technical solution, compared with the prior art, the utility model has the following beneficial effects:

[0014] The utility model provides a system for accurately controlling the pressures on both sides of oxygen and hydrogen in an alkaline electrolyzer. Two pressure regulating valves are respectively arranged on the oxygen exhaust pipe and the hydrogen exhaust pipe. One pressure regulating valve is used to control the pressure balance on both sides of the oxygen and hydrogen in the electrolyzer, thereby ensuring the stability and safety of the production and separation processes of hydrogen and oxygen. The other pressure regulating valve is used to control the pressure balance between the two regulating valves, thereby helping to optimize the pressure distribution of the entire exhaust pipeline, reducing the influence of pressure fluctuations on the system, and improving the reliability and efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 It is a schematic diagram of a preferred embodiment provided by the utility model.

[0017] In the figure: 1-the second regulating valve of the oxygen exhaust pipe, 2-the first regulating valve of the oxygen exhaust pipe, 3-the first regulating valve of the hydrogen exhaust pipe, 4-the second regulating valve of the hydrogen exhaust pipe, 5-the pressure detection and remote transmission device of the oxygen separator, 6-the pressure detection and remote transmission device of the hydrogen separator, 7-the pressure detection and remote transmission device of the oxygen exhaust pipe, 8-the pressure detection and remote transmission device of the hydrogen exhaust pipe, 9-the oxygen separator, 10-the hydrogen separator, 11-the oxygen separator liquid level gauge, 12-the hydrogen separator liquid level gauge, 13-the electrolytic cell, 14-the alkali solution circulation pump. DETAILED DESCRIPTION

[0018] The utility model is now further described in detail in conjunction with the accompanying drawings. In the description of this application, it should be understood that the terms "left side", "right side", "upper part", "lower part", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second", etc. do not indicate the importance of the components, and therefore cannot be understood as a limitation on the utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution by example, and do not limit the scope of protection of the utility model.

[0019] As described in the background technology, regarding the pressure on both sides of the oxygen and hydrogen in the electrolyzer, if no pressure control measures are taken, as the reaction proceeds, it is easy to cause the liquid level difference between the hydrogen separator and the oxygen separator in the gas-liquid separation system to become larger and larger, resulting in abnormal operation of the system with oxygen and hydrogen mixing, which is dangerous. Existing equipment usually uses a single regulating valve to adjust the pressure of the hydrogen production system. However, when the pressure changes frequently or requires minor adjustments, the single regulating valve may not be able to stabilize the pressure within the ideal range in a timely and accurate manner. At the same time, when the system pressure fluctuates rapidly, the response speed of the single regulating valve may be insufficient, resulting in a lag in pressure adjustment, affecting the stability and safety of the hydrogen production system.

[0020] In order to solve the above problems, the present application provides a system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer, which is used to ensure that when the pressure at the oxygen and hydrogen exhaust port of the alkaline electrolyzer changes, the pressure on both sides of oxygen and hydrogen in the hydrogen production system is accurately controlled, thereby reducing the cross-talk between oxygen and hydrogen, maintaining the stability of the system, and ensuring the safe operation of the system.

[0021] Specific as Figure 1As shown, the whole system first includes an oxygen separator 9, a hydrogen separator 10, an electrolyzer 13 and an alkali liquid circulation pump 14. The input end of the oxygen separator 9 is connected to the oxygen side outlet of the electrolyzer 13, and the input end of the hydrogen separator 10 is connected to the hydrogen side outlet of the electrolyzer 13. The electrolyte output by the electrolyzer 13 is divided into two paths, one path is rich in oxygen and enters the oxygen separator 9, and the other path is rich in hydrogen and enters the hydrogen separator 10. In the oxygen separator 9 and the hydrogen separator 10, the oxygen and hydrogen in the electrolyte are separated from the electrolyte by gravity. The oxygen output end of the oxygen separator 9 is connected to the oxygen exhaust pipe, and the oxygen separated in the oxygen separator 9 is directly discharged to the outside through the oxygen exhaust pipe. The hydrogen output end of the hydrogen separator 10 is connected to the hydrogen exhaust pipe, and the hydrogen separated by the hydrogen separator 10 enters the hydrogen purification system through the hydrogen exhaust pipe. The alkaline electrolyte in the separator is combined after separating oxygen and hydrogen, and then is pressurized by the alkaline solution circulation pump 14 and then returned to the electrolytic cell 13, thereby forming an alkaline solution circulation in the hydrogen production system.

[0022] The biggest innovation of the present application is described below, namely, a first regulating valve 2 for oxygen exhaust pipe and a second regulating valve 1 for oxygen exhaust pipe are sequentially installed on the oxygen exhaust pipe, wherein the first regulating valve 2 for oxygen exhaust pipe is arranged close to the oxygen separator 9, and an oxygen exhaust pipe pressure detection and remote transmission device 7 is installed between the first regulating valve 2 for oxygen exhaust pipe and the second regulating valve 1 for oxygen exhaust pipe; a first regulating valve 3 for hydrogen exhaust pipe and a second regulating valve 4 for hydrogen exhaust pipe are sequentially installed on the hydrogen exhaust pipe, wherein the first regulating valve 3 for hydrogen exhaust pipe is arranged close to the hydrogen separator 10, and a hydrogen exhaust pipe pressure detection and remote transmission device 8 is installed between the first regulating valve 3 for hydrogen exhaust pipe and the second regulating valve 4 for hydrogen exhaust pipe.

[0023] Obviously, this system adopts a dual valve configuration. On the oxygen exhaust pipe, the first regulating valve 2 of the oxygen exhaust pipe is used to control the pressure balance on both sides of the oxygen and hydrogen of the electrolyzer, and the second regulating valve 1 of the oxygen exhaust pipe is used to adjust the pressure from the outlet of the first regulating valve 2 of the oxygen exhaust pipe to the discharge into the air. Similarly, on the hydrogen exhaust pipe, the first regulating valve 3 of the hydrogen exhaust pipe is used to control the liquid level balance on both sides of the oxygen and hydrogen of the electrolyzer, and the second regulating valve 4 of the hydrogen exhaust pipe is used to adjust the pressure balance at the outlet of the first regulating valve 3 of the hydrogen exhaust pipe. If the second regulating valve 1 of the oxygen exhaust pipe and the second regulating valve 4 of the hydrogen exhaust pipe are not set in the system, the pressure at the outlet of the first regulating valve 2 of the oxygen exhaust pipe and the first regulating valve 3 of the hydrogen exhaust pipe will fluctuate continuously with the change of the actual use conditions, resulting in the stability and safety of the system operation being threatened. On the other hand, the setting of the second regulating valve 1 of the oxygen exhaust pipe and the second regulating valve 4 of the hydrogen exhaust pipe can control the pressure fluctuation at the outlet of the first regulating valve 2 of the oxygen exhaust pipe and the first regulating valve 3 of the hydrogen exhaust pipe, avoiding the influence on the pressure on both sides of the electrolyzer.

[0024] Of course, in order to monitor the pressure between the two regulating valves in real time, an oxygen exhaust pipe pressure detection remote transmission device 7 is installed between the first regulating valve 2 of the oxygen exhaust pipe and the second regulating valve 1 of the oxygen exhaust pipe, and a hydrogen exhaust pipe pressure detection remote transmission device 8 is installed between the first regulating valve 3 of the hydrogen exhaust pipe and the second regulating valve 4 of the hydrogen exhaust pipe. The setting of the intermediate position can also accurately transmit the pressure data to the control system, so that the operator can understand the pressure situation in time and make corresponding adjustments and decisions. When the oxygen exhaust pipe has a large pressure change, the second regulating valve 1 of the oxygen exhaust pipe is used to control the pressure of the oxygen exhaust pipe pressure detection remote transmission device 7 to achieve the balance of the oxygen side system pressure. When the hydrogen exhaust pipe has a large pressure change, the second regulating valve 4 of the hydrogen exhaust pipe is used to control the pressure of the hydrogen exhaust pipe pressure detection remote transmission device 8 to achieve the balance of the hydrogen side system pressure.

[0025] It should be noted that although the oxygen exhaust pipe pressure detection remote transmission device 7 and the hydrogen exhaust pipe pressure detection remote transmission device 8 are consistent in component model selection, the two can be set to the same or different pressure values ​​to meet actual working conditions.

[0026] The control system in this application provides two preferred designs. The first one is that the second regulating valve 1 of the oxygen exhaust pipe, the oxygen exhaust pipe pressure detection remote transmission device 7, the second regulating valve 4 of the hydrogen exhaust pipe and the hydrogen exhaust pipe pressure detection remote transmission device 8 are electrically connected to the PLC at the same time, and the pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe are controlled in real time by the PLC.

[0027] The second is that the second regulating valve of the oxygen exhaust pipe, the oxygen exhaust pipe pressure detection remote transmission device, the second regulating valve of the hydrogen exhaust pipe and the hydrogen exhaust pipe pressure detection remote transmission device are connected to the DCS at the same time, and the discharge pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe is controlled in real time by the DCS.

[0028] The above-mentioned regulating operations of the first regulating valve 2 of the oxygen exhaust pipe, the second regulating valve 1 of the oxygen exhaust pipe, the first regulating valve 3 of the hydrogen exhaust pipe and the second regulating valve 4 of the hydrogen exhaust pipe also need to be used in conjunction with the fluctuations in the hydraulic pressure in the oxygen separator 9 and the hydrogen separator 10. Therefore, in order to further ensure the stability and safety of the system operating pressure, the present application installs an oxygen separator liquid level gauge 11 and an oxygen separator pressure detection remote transmission device 5 on the oxygen separator 9, and installs a hydrogen separator liquid level gauge 12 and a hydrogen separator pressure detection remote transmission device 6 on the hydrogen separator 10, which helps to monitor the liquid level and pressure conditions in the oxygen separator 9 or the hydrogen separator 10 in real time, and provide key data for the stable operation and control of the system.

[0029] It should be noted that the various types of regulating valves and pressure detection remote transmission devices mentioned in this application are conventionally selected by technical personnel in this field and are used according to actual working conditions, so there is no need to elaborate here.

[0030] In summary, under the precise control of the dual regulating valves, the alkaline electrolyzer hydrogen production system of the present application operates safely and reliably, preventing the occurrence of cross-gas between the oxygen and hydrogen sides during changes in the exhaust pipe pressure of hydrogen or oxygen.

[0031] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0032] The meaning of "and / or" described in this application means that the situations where each exists alone or both exist at the same time are included.

[0033] The term “connection” as used in this application may mean a direct connection between components or an indirect connection between components via other components.

[0034] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer, comprising an electrolyzer, an oxygen separator and a hydrogen separator, wherein the input end of the oxygen separator is connected to the oxygen side outlet of the electrolyzer, the oxygen output end of the oxygen separator is connected to the oxygen exhaust pipe, the input end of the hydrogen separator is connected to the hydrogen side outlet of the electrolyzer, and the hydrogen output end of the hydrogen separator is connected to the hydrogen exhaust pipe; characterized in that: A first regulating valve of the oxygen exhaust pipe and a second regulating valve of the oxygen exhaust pipe are sequentially installed on the oxygen exhaust pipe, wherein the first regulating valve of the oxygen exhaust pipe is arranged close to the oxygen separator, and an oxygen exhaust pipe pressure detection remote transmission device is installed between the first regulating valve of the oxygen exhaust pipe and the second regulating valve of the oxygen exhaust pipe; A first regulating valve and a second regulating valve of the hydrogen exhaust pipe are installed in sequence on the hydrogen exhaust pipe, wherein the first regulating valve of the hydrogen exhaust pipe is arranged close to the hydrogen separator, and a hydrogen exhaust pipe pressure detection remote transmission device is installed between the first regulating valve and the second regulating valve of the hydrogen exhaust pipe.

2. The system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer according to claim 1, characterized in that: The oxygen exhaust pipe pressure detection remote transmission device and the hydrogen exhaust pipe pressure detection remote transmission device can be set to the same or different pressure values.

3. The system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer according to claim 1, characterized in that: The second regulating valve of the oxygen exhaust pipe, the oxygen exhaust pipe pressure detection remote transmission device, the second regulating valve of the hydrogen exhaust pipe and the hydrogen exhaust pipe pressure detection remote transmission device are connected to the PLC at the same time, and the pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe is controlled in real time by the PLC.

4. The system for accurately controlling the pressure on both sides of oxygen and hydrogen in an alkaline electrolyzer according to claim 1, characterized in that: The second regulating valve of the oxygen exhaust pipe, the oxygen exhaust pipe pressure detection remote transmission device, the second regulating valve of the hydrogen exhaust pipe and the hydrogen exhaust pipe pressure detection remote transmission device are connected to the DCS at the same time, and the pressure of the oxygen exhaust pipe and the hydrogen exhaust pipe is controlled in real time by the DCS.

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