An electrolytic hydrogen production system adapted to high pressure and low load and frequent start-stop
By introducing an oxygen and hydrogen separator circulation system into the alkaline electrolysis hydrogen production system, combined with a dehydrogenator and a deoxygenator, the problem of unstable operation of the alkaline electrolysis hydrogen production system under high pressure, low load and frequent start-stop conditions was solved, realizing rapid start-stop and stable operation of the system and reducing energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGZHENG ENG
- Filing Date
- 2025-08-07
- Publication Date
- 2026-07-14
AI Technical Summary
Under high pressure, low load, and frequent start-stop conditions, the alkaline electrolysis hydrogen production system suffers from hydrogen and oxygen infiltration, leading to system instability, excessive oxygen in hydrogen and excessive hydrogen in oxygen, resulting in long system interlock shutdown and start-up times.
An oxygen and hydrogen separator circulation system is adopted, combined with a dehydrogenator and a deoxygenator. The impurity content in oxygen and hydrogen is reduced through catalytic reaction, and the gas circulation volume is controlled by a circulation compressor and a regulating valve to achieve rapid start-up and stable operation.
It effectively reduces the hydrogen-to-oxygen ratio in the oxygen output of the oxygen separator and the oxygen-to-hydrogen ratio in the hydrogen output of the hydrogen separator, avoiding system interlock shutdowns, achieving rapid start-up and shutdown, and reducing energy consumption.
Smart Images
Figure CN224494363U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electrolytic hydrogen production technology, and in particular to an electrolytic hydrogen production system adapted to high pressure, low load and frequent start-stop. Background Technology
[0002] Currently, there are several industrial methods for hydrogen production, including hydrogen production through natural gas steam reforming, hydrogen production through methanol reforming, hydrogen production through water gas, and hydrogen production through water electrolysis. Among these, water electrolysis provides an inexhaustible source of raw material water, and the reaction product after energy use is also water. Furthermore, the electricity generated from water electrolysis can utilize environmentally friendly energy sources such as wind, solar, and nuclear power. Therefore, hydrogen production through water electrolysis has good social and economic benefits.
[0003] As is well known, new energy power, represented by photovoltaic and wind power generation, is characterized by strong volatility, large fluctuation range, and frequent start-stop. Meanwhile, downstream hydrogen-consuming industries, represented by chemical synthesis, are characterized by high hydrogen pressure (>5.5MPa). Alkaline electrolysis hydrogen production systems have advantages such as low price and large processing scale.
[0004] However, current alkaline electrolysis hydrogen production systems suffer from drawbacks such as limited operational flexibility, long cold start-up times, and low operating pressure (≤1.6 MPa). A key reason for these shortcomings is the poor resistance of the diaphragm in the alkaline electrolyzer to hydrogen and oxygen permeation. During operation and shutdown cycles, a small amount of hydrogen and oxygen permeates, leading to excessive levels of oxygen in hydrogen and hydrogen in oxygen under low load or high pressure, resulting in interlocking shutdowns. Simultaneously, shutdown processes also cause excessive levels of oxygen in hydrogen and hydrogen in oxygen, necessitating nitrogen purging, resulting in prolonged start-up times and significant hydrogen waste. Therefore, to fully adapt to the operational characteristics of new energy power generation, alkaline electrolysis hydrogen production systems must be optimized to meet the requirements of high pressure, low load, and rapid start-up and shutdown. Utility Model Content
[0005] The purpose of this invention is to provide an electrolytic hydrogen production system that is adaptable to high pressure, low load, and frequent start-stop, so as to at least partially solve the above-mentioned problems of the prior art.
[0006] To achieve the above objectives, this utility model provides an electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop operations, comprising:
[0007] Electrolytic cell 1 is connected to oxygen separator 2 and hydrogen separator 3 respectively;
[0008] Oxygen separator 2, oxygen cooler 4, oxygen droplet trap 6, dehydrogenator 8, oxygen circulating compressor 10 and oxygen separator 2 are connected in sequence to form a cycle. Among them, oxygen droplet trap 6 is also connected to an oxygen discharge pipe. Oxygen circulating compressor 10 returns the oxygen processed by dehydrogenator 8 to oxygen separator 2 and mixes it with the oxygen input into oxygen separator 2 from electrolysis cell 1.
[0009] Hydrogen separator 3, hydrogen cooler 5, hydrogen droplet trap 7, deoxygenator 9, hydrogen recirculation compressor 11 and hydrogen separator 3 are connected in sequence to form a cycle. The hydrogen droplet trap 7 is also connected to a hydrogen discharge pipe. The hydrogen recirculation compressor 11 returns the hydrogen processed by the deoxygenator 9 to the hydrogen separator 3 and mixes it with the hydrogen input into the hydrogen separator 3 from the electrolyzer 1.
[0010] The system also includes an alkaline solution treatment device, which is connected to the oxygen separator 2 and the hydrogen separator 3 respectively, for receiving and processing the alkaline solution obtained after separation by the oxygen separator 2 and the hydrogen separator 3.
[0011] Preferably, the alkali treatment equipment includes an alkali circulation pump 13 and an alkali cooler 12. The alkali circulation pump 13 receives alkali obtained after separation by the oxygen separator 2 and the hydrogen separator 3. The alkali is then cooled by the alkali cooler 12 and returned to the electrolytic cell 1.
[0012] Preferably, the system also includes an oxygen hydrogen content detector for detecting the hydrogen content in the oxygen after treatment by the oxygen droplet trap 6, and adjusting the ratio of oxygen supplied to the oxygen discharge pipe to oxygen supplied to the dehydrogenator 8 based on the detection result.
[0013] Preferably, the system further includes a circulating oxygen regulating valve V3 disposed between the oxygen circulating compressor 10 and the oxygen separator 2, and / or an oxygen outlet regulating valve V1 disposed on the oxygen discharge pipeline, wherein the circulating oxygen regulating valve V3 and / or the oxygen outlet regulating valve V1 are used to regulate the ratio of discharged oxygen to oxygen returned to the oxygen separator 2.
[0014] Preferably, the input end of the oxygen hydrogen content detector is connected to the oxygen droplet trap 6, the first output end of the oxygen hydrogen content detector is provided with a first valve and connected to the oxygen discharge pipeline, the second output end of the oxygen hydrogen content detector is provided with a second valve and connected to the dehydrogenator 8, and the oxygen hydrogen content detector is used to adjust the opening and closing of the first valve and / or the second valve according to the oxygen hydrogen content detection result.
[0015] Preferably, the system also includes a hydrogen oxygen content detector for detecting the oxygen content in the hydrogen after treatment by the hydrogen droplet trap 7, and adjusting the ratio of hydrogen transmitted to the hydrogen discharge pipeline to hydrogen transmitted to the deoxygenator 9 based on the detection result.
[0016] Preferably, the system further includes a hydrogen outlet regulating valve V2 installed on the hydrogen discharge pipeline, and / or a circulating hydrogen regulating valve V4 installed between the hydrogen circulation compressor 11 and the hydrogen separator 3. The hydrogen outlet regulating valve V2 and / or the circulating hydrogen regulating valve V4 are used to regulate the ratio of discharged hydrogen to hydrogen returned to the hydrogen separator 3.
[0017] Preferably, the input end of the hydrogen oxygen content detector is connected to the hydrogen droplet trap 7, the first output end of the hydrogen oxygen content detector is provided with a third valve and connected to the hydrogen discharge pipeline, the second output end of the hydrogen oxygen content detector is provided with a fourth valve and connected to the deoxygenator 9, and the hydrogen oxygen content detector is used to adjust the opening and closing of the third valve and / or the fourth valve according to the hydrogen oxygen content detection result.
[0018] Compared with the prior art, the present invention has at least the following advantages:
[0019] By adopting the solution provided in this utility model embodiment, the oxygen produced by the electrolyzer can be returned to the oxygen separator after dehydrogenation treatment, and the hydrogen produced by the electrolyzer can be returned to the hydrogen separator after deoxygenation treatment. This reduces the proportion of oxygen and hydrogen in the oxygen output from the oxygen separator and the proportion of hydrogen and oxygen in the hydrogen output from the hydrogen separator. This avoids the system from exceeding the standard in the proportion of hydrogen in oxygen or oxygen in hydrogen when the system is running at high pressure and low load, which would cause the system to shut down due to interlocking and become unable to operate. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of an example structure of an electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop, as provided in Embodiment 1 of this utility model. Detailed Implementation
[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate to understand the embodiments of the utility model described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a product or device comprising a series of units is not necessarily limited to those explicitly listed, but may include other units not explicitly listed or inherent to such product or device.
[0023] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0024] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.
[0025] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.
[0026] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.
[0027] Example 1
[0028] Embodiment 1 of this utility model provides an electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop operations. Figure 1 A schematic diagram of an example structure of the system is shown below. Figure 1 As shown, the system includes:
[0029] Electrolytic cell 1 is connected to oxygen separator 2 and hydrogen separator 3 respectively;
[0030] Oxygen separator 2, oxygen cooler 4, oxygen droplet trap 6, dehydrogenator 8, oxygen circulating compressor 10 and oxygen separator 2 are connected in sequence to form a cycle. Among them, oxygen droplet trap 6 is also connected to an oxygen discharge pipe. Oxygen circulating compressor 10 returns the oxygen processed by dehydrogenator 8 to oxygen separator 2 and mixes it with the oxygen input into oxygen separator 2 from electrolysis cell 1.
[0031] Hydrogen separator 3, hydrogen cooler 5, hydrogen droplet trap 7, deoxygenator 9, hydrogen recirculation compressor 11 and hydrogen separator 3 are connected in sequence to form a cycle. The hydrogen droplet trap 7 is also connected to a hydrogen discharge pipe. The hydrogen recirculation compressor 11 returns the hydrogen processed by the deoxygenator 9 to the hydrogen separator 3 and mixes it with the hydrogen input into the hydrogen separator 3 from the electrolyzer 1.
[0032] The system also includes an alkaline solution treatment device, which is connected to the oxygen separator 2 and the hydrogen separator 3 respectively, for receiving and processing the alkaline solution obtained after separation by the oxygen separator 2 and the hydrogen separator 3.
[0033] Among them, oxygen separator 2, oxygen cooler 4, oxygen droplet trap 6, hydrogen separator 3, hydrogen cooler 5, and hydrogen droplet trap 7 are all conventional equipment. Dehydrogenator 8 is a catalytic dehydrogenation device; its principle is to use a catalyst to react hydrogen and oxygen at room temperature to produce water, thereby removing hydrogen from the oxygen. Oxygen circulation compressor 10 is a reciprocating or centrifugal compressor; its main function is to pressurize the oxygen circulation system, thus providing power to the oxygen circulation pipeline. Deoxygenator 9 is a catalytic deoxygenation device; its principle is similar to that of the dehydrogenator, also using a catalyst to react hydrogen and oxygen at room temperature, thereby removing oxygen from the hydrogen. Hydrogen circulation compressor 11 is a reciprocating compressor; its main function is to pressurize the hydrogen circulation system, thereby providing power to the hydrogen circulation pipeline.
[0034] Among them, such as Figure 1 As shown, in a preferred embodiment, the alkali treatment equipment may include an alkali circulation pump 13 and an alkali cooler 12. The alkali circulation pump 13 receives alkali obtained after separation by the oxygen separator 2 and the hydrogen separator 3. The alkali is then cooled by the alkali cooler 12 and returned to the electrolytic cell 1. It is readily understood that other types of alkali treatment equipment can also be used. For example, the alkali may not be recycled, or it may be returned directly to the electrolytic cell 1 without cooling, or the alkali may undergo other treatments before being returned to the electrolytic cell 1.
[0035] In a preferred embodiment, the system further includes an oxygen hydrogen content detector for detecting the hydrogen content in the oxygen after treatment by the oxygen droplet trap 6, and adjusting the ratio of oxygen supplied to the oxygen discharge pipe to oxygen supplied to the dehydrogenator 8 based on the detection result.
[0036] refer to Figure 1 As shown, the system may also include a circulating oxygen regulating valve V3 disposed between the oxygen circulating compressor 10 and the oxygen separator 2, and / or an oxygen outlet regulating valve V1 disposed on the oxygen discharge pipeline. The circulating oxygen regulating valve V3 and / or the oxygen outlet regulating valve V1 are used to regulate the ratio of discharged oxygen to oxygen returned to the oxygen separator 2.
[0037] In another implementation (non- Figure 1 As shown), the input end of the oxygen hydrogen content detector is connected to the oxygen droplet trap 6, the first output end of the oxygen hydrogen content detector is provided with a first valve and connected to the oxygen discharge pipeline, the second output end of the oxygen hydrogen content detector is provided with a second valve and connected to the dehydrogenator 8, and the oxygen hydrogen content detector is used to adjust the opening and closing of the first valve and / or the second valve according to the oxygen hydrogen content detection result.
[0038] In a preferred embodiment, the system further includes a hydrogen oxygen content detector for detecting the oxygen content in the hydrogen after treatment by the hydrogen droplet trap 7, and adjusting the ratio of hydrogen supplied to the hydrogen discharge pipeline to hydrogen supplied to the deoxygenator 9 based on the detection result.
[0039] refer to Figure 1 As shown, the system may also include a hydrogen outlet regulating valve V2 installed on the hydrogen discharge pipeline, and / or a circulating hydrogen regulating valve V4 installed between the hydrogen circulation compressor 11 and the hydrogen separator 3. The hydrogen outlet regulating valve V2 and / or the circulating hydrogen regulating valve V4 are used to regulate the ratio of discharged hydrogen to hydrogen returned to the hydrogen separator 3.
[0040] In another implementation (non- Figure 1 As shown, the input end of the hydrogen oxygen content detector is connected to the hydrogen droplet trap 7, the first output end of the hydrogen oxygen content detector is provided with a third valve and connected to the hydrogen discharge pipeline, the second output end of the hydrogen oxygen content detector is provided with a fourth valve and connected to the deoxygenator 9, and the hydrogen oxygen content detector is used to adjust the opening and closing of the third valve and / or the fourth valve according to the hydrogen oxygen content detection result.
[0041] refer to Figure 1 As shown, an example of the system operation process provided in this embodiment of the present invention is as follows:
[0042] When operating in high-pressure and low-load mode, the oxygen produced by electrolyzer 1 passes through oxygen separator 2 to separate the alkali solution and oxygen. The oxygen is then cooled by oxygen cooler 4 and then passes through oxygen droplet precipitator 6. Part of the gas is sent out or vented via regulating valve V1, while the other part undergoes catalytic dehydrogenation in dehydrogenator 8 to remove hydrogen from the oxygen. After passing through oxygen compressor 10 and circulating oxygen regulating valve V3, the gas returns to the oxygen separator, thus reducing the hydrogen content in the oxygen and preventing system interlock shutdown. Similarly, the hydrogen produced by the electrolyzer passes through hydrogen separator 3 to separate the alkali solution and hydrogen. After being cooled by hydrogen cooler 5 and then passing through hydrogen droplet precipitator 7, part of the gas is sent out via regulating valve V2, while the other part undergoes catalytic deoxygenation in deoxygenator 9 to remove oxygen from the hydrogen. After passing through hydrogen circulating compressor 11, the hydrogen returns to the oxygen separator, thus reducing the oxygen content in the hydrogen, preventing hydrogen venting, and preventing system interlock shutdown.
[0043] When the system is operating under high load or low pressure, and the oxygen-hydrogen and hydrogen-oxygen ratios in the system do not exceed the standards, the circulating compressor and circulating gas regulating valve can be shut off, and all gases can be vented or enter downstream units, thereby reducing energy consumption and extending the life of the compressor and catalytic converter.
[0044] When the system is shut down, the gas pressure can be reduced to a safe pressure (e.g., 0.5 MPa) through the oxygen and hydrogen outlet regulating valves V1 and V2. Then, the electrolyzer is gradually shut down, and the oxygen and hydrogen outlet regulating valves V1 and V2 are completely closed. At the same time, the hydrogen and oxygen circulation compressors 10 and 11 are turned on, and the circulation gas regulating valves V3 and V4 are turned on to eliminate the hydrogen and oxygen that have seeped in during the shutdown process. This ensures that the hydrogen-oxygen ratio and oxygen-hydrogen ratio in the system meet the standards during the shutdown process. This continues until the alkali circulation pump has circulated for the preset time and / or the alkali temperature is below the threshold. Then, the circulation compressor and the circulation gas regulating valve are turned off to maintain pressure, thereby ensuring that the hydrogen and oxygen in the system meet the safety requirements and achieve the purpose of rapid startup.
[0045] When the system is started, the oxygen-side regulating valve V1 can be closed, while the oxygen-side circulating compressor and oxygen-side circulating gas regulating valve can be opened to quickly increase the pressure. The hydrogen-side regulating valve V2 is set to automatic to ensure the system liquid level balance. At the same time, the hydrogen-side circulating compressor and hydrogen-side circulating gas regulating valve are opened to ensure that the oxygen in the hydrogen is quickly qualified and enters the downstream process.
[0046] Pressure gauges can be installed on the oxygen separator 2 side and the hydrogen separator 3 side respectively. These pressure gauges can be flexibly installed in the circulation system on the oxygen separator 2 side and the circulation system on the hydrogen separator 3 side.
[0047] When the electrolytic hydrogen production system is started, the pressure on the oxygen separator 2 side and the pressure on the hydrogen separator 3 side are obtained through a pressure gauge. If the pressure on the hydrogen separator 3 side is lower than the pressure on the oxygen separator 2 side and the difference is greater than the pressure difference threshold, the hydrogen outlet regulating valve V2 is adjusted to a smaller value. If the pressure on the hydrogen separator 3 side is higher than the pressure on the oxygen separator 2 side and the difference is greater than the pressure difference threshold, the hydrogen outlet regulating valve V2 is adjusted to a larger value.
[0048] By adopting the solution provided in this utility model embodiment, the oxygen produced by the electrolyzer can be returned to the oxygen separator after dehydrogenation treatment, and the hydrogen produced by the electrolyzer can be returned to the hydrogen separator after deoxygenation treatment. This reduces the proportion of oxygen and hydrogen in the oxygen output from the oxygen separator and the proportion of hydrogen and oxygen in the hydrogen output from the hydrogen separator. This avoids the system from exceeding the standard in the proportion of hydrogen in oxygen or oxygen in hydrogen when the system is running at high pressure and low load, which would cause the system to shut down due to interlocking and become unable to operate.
[0049] By setting regulating valves, the circulation volume of hydrogen and oxygen in the system can be flexibly controlled and adjusted. The circulation volume can be intelligently controlled according to different loads, thereby reducing energy consumption and catalyst consumption while ensuring that the concentration does not exceed the standard.
[0050] During system shutdown and startup, hydrogen and oxygen are circulated through a hydrogen and oxygen loop to eliminate hydrogen and oxygen that seep in during shutdown, preventing excessive levels of oxygen in hydrogen and hydrogen in oxygen. This eliminates the need for the nitrogen purging and replacement process required in traditional methods, enabling rapid system startup and shutdown and quick attainment of oxygen levels in hydrogen, thus meeting the needs of hydrogen production from wind power and photovoltaics.
[0051] Example 2
[0052] Embodiment 2 of this utility model provides an application example of the electrolytic hydrogen production system provided in Embodiment 1. (See reference...) Figure 1 The system shown incorporates oxygen dehydrogenation and hydrogen deoxygenation cycles into the alkaline electrolysis hydrogen production system. This allows for the targeted removal of hydrogen and oxygen that permeate the system during high-pressure, low-load operation and system start-up and shutdown. Consequently, the entire system can operate stably under high-pressure, low-load conditions, and the alkaline system can be quickly started and stopped, enabling the hydrogen to rapidly reach the required standard for downstream purification.
[0053] Taking a 2000 cubic meter alkaline hydrogen production system as an example, the process is as follows:
[0054] When the system starts up, close the oxygen-side regulating valve V1, and simultaneously open the oxygen-side circulating compressor 10 and the oxygen-side circulating gas regulating valve V3 to quickly increase the load (e.g., requiring a load greater than 800 Nm). 3 / hH2), while the hydrogen-side regulating valve V2 is set to automatic to ensure the alkali liquid level is balanced. At the same time, the hydrogen-side circulating compressor 11 and the hydrogen-side circulating gas regulating valve V4 are turned on to ensure that the oxygen in the hydrogen is quickly qualified (e.g., <0.5%) and enters the downstream process.
[0055] When operating under a high pressure of 5.5MPa and a low load of less than 30%, with V1 and V2 open, two 1000 cubic meter electrolytic cells or one 2000 cubic meter electrolytic cell operating simultaneously will generate less than 300 Nm of electricity. 3 / h oxygen contains 3% hydrogen.
[0056] Oxygen separator 2 receives oxygen generated by electrolyzer 1 at a concentration of less than 300 Nm. 3 / h oxygen with a hydrogen content of 3%, and 1200Nm of oxygen transferred with oxygen-side circulating compressor 10. 3 / h oxygen with 0% hydrogen content, after merging, the alkaline solution and oxygen are separated, 1500Nm 3 Oxygen with a hydrogen content of 0.6% per hour is cooled by oxygen cooler 4 and then passes through oxygen droplet trap 6, resulting in a final concentration of 300 Nm³. 3 Oxygen with a hydrogen content of 0.6% is supplied or vented via regulating valve V1 at a rate of 1200 Nm. 3 Oxygen with a hydrogen content of 0.6% per hour undergoes catalytic dehydrogenation in dehydrogenator 8, resulting in 200 Nm³ of oxygen. 3 Oxygen with a hydrogen content of 0% per hour flows into oxygen separator 2 after passing through oxygen compressor 10 and circulating oxygen regulating valve V3.
[0057] Similar to the oxygen cycle, the electrolyzer produces 600 Nm³. 3 / h of hydrogen gas with an oxygen content of 1.2% and 1200Nm 3 / h Hydrogen gas with 0% oxygen content is collected and then passes through hydrogen separator 3 to separate the alkaline solution from the hydrogen gas. 1800Nm 3 The hydrogen gas, containing 0.4% oxygen per hour, is cooled by hydrogen cooler 5 and then passes through hydrogen droplet trap 7, reaching a flow rate of 600 Nm. 3 Hydrogen gas with an oxygen content of 0.4% is discharged through regulating valve V2 at a speed of 1200 Nm³. 3 Hydrogen gas with an oxygen content of 0.4% per hour undergoes catalytic deoxygenation in deoxidizer 9, at a speed of 1200 Nm³. 3 Hydrogen gas with an oxygen content of 0% per hour is returned to the oxygen separator after passing through the hydrogen recirculation compressor 11, thereby reducing the oxygen content in the hydrogen and preventing system interlock shutdown and subsequent venting of hydrogen.
[0058] When the system pressure is below 1.6 MPa or the operating load is greater than 800 Nm 3 When the oxygen content in the system is less than 1.5% and the oxygen content in the hydrogen content is less than 0.5%, the circulating compressor and circulating gas regulating valve can be shut off, and all gases can be vented or enter downstream units, thereby reducing energy consumption and extending the life of the compressor and catalytic converter.
[0059] When the system is shut down, the gas pressure can be reduced to a safe pressure (e.g., 0.5 MPa), then the electrolyzer can be gradually shut off, and the hydrogen and oxygen outlet regulating valves V1 and V2 can be completely closed. Simultaneously, the hydrogen and oxygen circulating compressors 10 and 11 can be started, and the circulating gas regulating valves V3 and V4 can be opened, ensuring the oxygen circulating flow rate is greater than 400 Nm³. 3 / h, hydrogen circulation volume is approximately 800 Nm³. 3 / h is used to eliminate the hydrogen and oxygen that permeate during the shutdown process, ensuring that the hydrogen-oxygen ratio and oxygen-hydrogen ratio in the system meet the standards during the shutdown process. After the alkaline solution circulation pump circulates for more than half an hour and the alkaline solution temperature is lower than 50°C, the circulation compressor and circulation gas adjustment valve are shut down to maintain pressure, thereby ensuring that the hydrogen and oxygen in the system meet the safety requirements and achieve the purpose of rapid start-up.
[0060] When the system starts up, the oxygen-side regulating valve V1 can be closed, while the oxygen-side circulating compressor and the oxygen-side circulating gas regulating valve can be opened simultaneously to quickly increase the load (e.g., greater than 800 Nm). 3 The hydrogen side regulating valve V2 is set to automatic to ensure system liquid level balance. At the same time, the hydrogen side circulating compressor and the hydrogen side circulating gas regulating valve are turned on to ensure that the oxygen in the hydrogen is quickly qualified (<0.5%) and enters the downstream process.
[0061] It is easy to understand that the parameters in the system implementation method provided in Embodiment 2 of this utility model are all examples and are not intended to limit the application scenarios of the system provided by this utility model. Electrolysis hydrogen production systems with various parameters are possible without departing from the technical concept and principles of this utility model.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. An electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop operations, characterized in that, include: An electrolytic cell (1) is connected to an oxygen separator (2) and a hydrogen separator (3), respectively. The oxygen separator (2), oxygen cooler (4), oxygen droplet trap (6), dehydrogenator (8), oxygen circulating compressor (10) and oxygen separator (2) are connected in sequence to form a cycle. The oxygen droplet trap (6) is also connected to an oxygen discharge pipe. The oxygen circulating compressor (10) returns the oxygen processed by the dehydrogenator (8) to the oxygen separator (2) and mixes it with the oxygen input into the oxygen separator (2) from the electrolyzer (1). The hydrogen separator (3), hydrogen cooler (5), hydrogen droplet trap (7), deoxygenator (9), hydrogen circulation compressor (11) and hydrogen separator (3) are connected in sequence to form a cycle. The hydrogen droplet trap (7) is also connected to the hydrogen discharge pipe. The hydrogen circulation compressor (11) returns the hydrogen processed by the deoxygenator (9) to the hydrogen separator (3) and mixes it with the hydrogen input into the hydrogen separator (3) from the electrolyzer (1). The system also includes an alkaline solution treatment device, which is connected to the oxygen separator (2) and the hydrogen separator (3) respectively, for receiving the alkaline solution obtained after separation by the oxygen separator (2) and the hydrogen separator (3) and processing it.
2. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 1, characterized in that, The alkaline solution treatment equipment includes an alkaline solution circulation pump (13) and an alkaline solution cooler (12). The alkaline solution circulation pump (13) receives alkaline solution after separation by an oxygen separator (2) and a hydrogen separator (3). The alkaline solution is cooled by the alkaline solution cooler (12) and then returned to the electrolytic cell (1).
3. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 1, characterized in that, It also includes an oxygen hydrogen content detector, used to detect the hydrogen content in the oxygen after it has been processed by the oxygen droplet trap (6), and to adjust the ratio of oxygen supplied to the oxygen discharge pipe to oxygen supplied to the dehydrogenator (8) based on the detection results.
4. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 1 or 3, characterized in that, It also includes a circulating oxygen regulating valve (V3) provided between the oxygen circulating compressor (10) and the oxygen separator (2), and / or an oxygen outlet regulating valve (V1) provided on the oxygen discharge pipeline, the circulating oxygen regulating valve (V3) and / or the oxygen outlet regulating valve (V1) being used to regulate the ratio of discharged oxygen to oxygen returned to the oxygen separator (2).
5. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 3, characterized in that, The input end of the oxygen hydrogen content detector is connected to the oxygen droplet trap (6). The first output end of the oxygen hydrogen content detector is equipped with a first valve and connected to the oxygen discharge pipeline. The second output end of the oxygen hydrogen content detector is equipped with a second valve and connected to the dehydrogenator (8). The oxygen hydrogen content detector is used to adjust the opening and closing of the first valve and / or the second valve according to the oxygen hydrogen content detection result.
6. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 1, characterized in that, It also includes a hydrogen oxygen content detector, used to detect the oxygen content in the hydrogen after it has been treated by the hydrogen droplet trap (7), and to adjust the ratio of hydrogen transmitted to the hydrogen discharge pipe to hydrogen transmitted to the deoxygenator (9) based on the detection results.
7. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 1 or 6, characterized in that, It also includes a hydrogen outlet regulating valve (V2) installed on the hydrogen discharge pipeline, and / or a circulating hydrogen regulating valve (V4) installed between the hydrogen circulating compressor (11) and the hydrogen separator (3). The hydrogen outlet regulating valve (V2) and / or the circulating hydrogen regulating valve (V4) are used to regulate the ratio of discharged hydrogen to hydrogen returned to the hydrogen separator (3).
8. The electrolytic hydrogen production system adapted to high pressure, low load, and frequent start-stop according to claim 6, characterized in that, The input end of the hydrogen oxygen content detector is connected to the hydrogen droplet trap (7), the first output end of the hydrogen oxygen content detector is equipped with a third valve and connected to the hydrogen discharge pipeline, the second output end of the hydrogen oxygen content detector is equipped with a fourth valve and connected to the deoxygenator (9), and the hydrogen oxygen content detector is used to adjust the opening and closing of the third valve and / or the fourth valve according to the hydrogen oxygen content detection result.