A hydrogen production system and pressure maintaining method thereof

Abstract

The present invention discloses a hydrogen production system and a pressure maintenance method thereof. The hydrogen production system includes an electrolyzer, a gas separator, a gas processing output component and a switching component. The switching component is used to switch the gas processing output component to a first state in which it is connected to the corresponding gas separator for gas supply and is isolated from subsequent equipment, or a second state in which it is connected to the corresponding gas separator and subsequent equipment. When the hydrogen production system produces hydrogen, the switching component switches the gas processing output component to be connected to the corresponding gas separator and subsequent equipment to achieve normal hydrogen production. When the hydrogen production system is shut down, the switching component switches the gas processing output component to be isolated from the subsequent equipment and connected to the corresponding gas separator for gas supply, so as to achieve shutdown and pressure maintenance of the hydrogen production system, thereby avoiding the risk of explosive flammable gas mixture precipitated from the alkali solution due to pressure relief during shutdown of the hydrogen production system, thereby improving the operational stability of the hydrogen production system.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to a hydrogen production system and a pressure maintaining method thereof. Background Art

[0002] At present, in the hydrogen production process of water electrolysis, when the electrolyzer stops producing hydrogen, the pressure will be automatically released to 0.2MPa. At this time, the alkali liquid circulation pump of the hydrogen production system continues to run until the alkali liquid temperature drops to around 50℃, then the pump is stopped and the hydrogen production system is stopped.

[0003] However, during the pressure relief process, the gas in the alkaline solution will gradually precipitate, resulting in excessive hydrogen in oxygen and oxygen in hydrogen, which will have an adverse impact on the long-term safe and stable operation of the hydrogen production system. Summary of the Invention

[0004] In view of this, the first object of the present invention is to provide a hydrogen production system that reduces the risk of explosive flammable gas mixture precipitating from the alkaline solution during the shutdown and pressure relief process of the hydrogen production system by maintaining pressure, thereby improving the operating stability of the hydrogen production system.

[0005] A second object of the present invention is to provide a pressure maintaining method.

[0006] In order to achieve the above first object, the present invention provides the following solution:

[0007] A hydrogen production system comprising:

[0008] electrolytic cell;

[0009] Gas separators, the number of the gas separators is two, and the crude gas inlet of one of the gas separators is connected to the hydrogen outlet of the electrolyzer, and the crude gas inlet of the other gas separator is connected to the oxygen outlet of the electrolyzer;

[0010] A gas processing output assembly is provided in one-to-one correspondence with the gas separator, wherein the gas inlet of the gas processing output assembly is connected to the gas outlet of the corresponding gas separator;

[0011] A switching component is used to switch the gas processing output component to a first state in which it is connected to the corresponding gas separator for gas supply and isolated from subsequent equipment, or a second state in which it is isolated from the corresponding gas separator and connected to subsequent equipment.

[0012] When the hydrogen production system is shut down, the switching component switches the gas processing output component to the first state.

[0013] When the hydrogen production system produces hydrogen, the switching component switches the gas processing output component to the second state.

[0014] In a specific embodiment, the hydrogen production system further comprises a controller;

[0015] The controller is connected to the switching component by signal and is used to control the switching state of the switching component.

[0016] In another specific embodiment, the gas processing output assembly includes a scrubber and a gas-liquid separator;

[0017] The first gas inlet of the scrubber is the gas inlet of the gas processing output component. The gas outlet of the scrubber is connected to the gas inlet of the gas-liquid separator. The gas outlet of the gas-liquid separator outputs the gas to be purified.

[0018] In another specific embodiment, the gas processing output assembly further comprises a gas cooler;

[0019] The gas inlet of the gas cooler is communicated with the gas outlet of the scrubber, and the gas outlet of the gas cooler is communicated with the gas inlet of the gas-liquid separator.

[0020] In another specific embodiment, the gas processing output assembly further comprises a pressure maintaining tank;

[0021] The gas inlet of the pressure-maintaining tank is communicated with the gas outlet of the gas-liquid separator, and the gas outlet of the pressure-maintaining tank is communicated with the gas inlet of the corresponding gas separator.

[0022] In another specific embodiment, the switching component comprises:

[0023] a first switch valve, wherein the inlet of the first switch valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the first switch valve is connected to a subsequent device;

[0024] a second on-off valve, wherein the inlet of the second on-off valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the second on-off valve is connected to the gas inlet of the pressure-maintaining tank;

[0025] a third on-off valve, wherein the inlet of the third on-off valve is connected to the gas outlet of the pressure-maintaining tank, and the outlet of the third on-off valve is connected to the gas inlet of the gas separator or the second gas inlet of the scrubber;

[0026] When the hydrogen production system is shut down, the first switch valve and the second switch valve are closed, and the third switch valve is opened;

[0027] When the hydrogen production system produces hydrogen, the third switch valve is closed, the first switch valve and the second switch valve are opened, and when the pressure value in the pressure maintaining tank is greater than or equal to a preset value, the second switch valve is closed.

[0028] In another specific embodiment, the switching assembly further includes a pressure transmitter, which is mounted on the pressure-maintaining tank and is used to detect the gas pressure in the pressure-maintaining tank. The pressure transmitter is signal-connected to the controller. When the pressure value detected by the pressure transmitter is greater than or equal to the preset value, the controller controls the second switch valve to close.

[0029] and / or

[0030] The pressure-maintaining tank is also equipped with a liquid level detection component connected to the controller signal. The bottom end of the pressure-maintaining tank is provided with a drain outlet, and a drain valve connected to the controller signal is installed at the drain outlet. When the liquid level detection component detects that the liquid level in the pressure-maintaining tank is greater than or equal to a preset height, the controller controls the drain valve to open and drain the liquid.

[0031] In another specific embodiment, the outlet of the third switching valve is connected to the gas inlet of the gas separator;

[0032] The liquid phase overflow port of the scrubber is connected to the liquid inlet of the gas separator via a fourth switch valve, and the first gas inlet of the scrubber is connected to the gas outlet of the gas separator via a fifth switch valve;

[0033] When the hydrogen production system produces hydrogen, the fourth switch valve and the fifth switch valve are opened;

[0034] When the hydrogen production system is shut down, the fourth switch valve and the fifth switch valve are closed.

[0035] In another specific embodiment, the outlet of the third on-off valve is connected to the second gas inlet of the scrubber;

[0036] The gas inlet of the gas cooler is connected to the gas outlet of the scrubber via a sixth switch valve;

[0037] When the hydrogen production system produces hydrogen, the sixth switch valve is opened;

[0038] When the hydrogen production system is shut down, the sixth switch valve is closed.

[0039] In another specific embodiment, the switching component comprises:

[0040] a first switch valve, wherein the inlet of the first switch valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the first switch valve is connected to the subsequent equipment;

[0041] a second on-off valve, wherein the inlet of the second on-off valve is communicated with the gas outlet of the gas-liquid separator, and the outlet of the second on-off valve is communicated with the gas inlet of the gas separator or the second gas inlet of the scrubber;

[0042] a third on-off valve, wherein the inlet of the third on-off valve is connected to the gas outlet of the scrubber, and the outlet of the third on-off valve is connected to the gas inlet of the gas-liquid separator;

[0043] When the hydrogen production system is shut down, the first switch valve and the third switch valve are closed, and the second switch valve is opened;

[0044] When the hydrogen production system produces hydrogen, the second switch valve is closed, and the first switch valve and the third switch valve are opened.

[0045] In another specific embodiment, the outlet of the second switching valve is connected to the gas inlet of the gas separator;

[0046] The liquid phase overflow port of the scrubber is connected to the liquid inlet of the gas separator via a fourth switch valve, and the first gas inlet of the scrubber is connected to the gas outlet of the gas separator via a fifth switch valve;

[0047] When the hydrogen production system produces hydrogen, the fourth switch valve and the fifth switch valve are opened;

[0048] When the hydrogen production system is shut down, the fourth switch valve and the fifth switch valve are closed.

[0049] In another specific embodiment, the outlet of the second on-off valve is in communication with the second gas inlet of the scrubber;

[0050] The gas inlet of the gas cooler is connected to the gas outlet of the scrubber via a sixth switch valve;

[0051] When the hydrogen production system produces hydrogen, the sixth switch valve is opened;

[0052] When the hydrogen production system is shut down, the sixth switch valve is closed.

[0053] In another specific embodiment, the hydrogen production system further comprises an analyzer;

[0054] The analyzer is provided in a one-to-one correspondence with the gas processing output component, and the analyzer is used to detect the content of oxygen in hydrogen or hydrogen in oxygen.

[0055] The various embodiments according to the present invention can be arbitrarily combined as needed. The embodiments obtained after these combinations are also within the scope of the present invention and are part of the specific implementation methods of the present invention.

[0056] The hydrogen production system provided by the present invention, when producing hydrogen, switches the gas processing output assembly through a switching assembly to connect with the corresponding gas separator and subsequent equipment. When the hydrogen production system is shut down, the switching assembly switches the gas processing output assembly to be isolated from the subsequent equipment and connects the gas supply to the corresponding gas separator, thereby maintaining pressure during the shutdown of the hydrogen production system. This avoids the risk of explosive and flammable gas mixtures being precipitated from the alkali solution due to pressure relief during the shutdown of the hydrogen production system, thereby improving the operational stability of the hydrogen production system.

[0057] In addition, during the pressure maintenance process, the gas in the hydrogen production system is used to maintain the pressure without the need to connect to an external gas source, which improves safety and saves energy.

[0058] In order to achieve the above second object, the present invention provides the following solution:

[0059] A pressure maintaining method, using any one of the above described hydrogen production systems, comprising:

[0060] Determining the state of the hydrogen production system;

[0061] If the hydrogen production system is in a shutdown state, controlling the switching component to switch to a first state in which the gas processing output component is connected to the corresponding gas separator for gas supply and isolated from subsequent equipment;

[0062] If the hydrogen production system is in a hydrogen production state, the switching component is controlled to switch to a second state in which the gas processing output component is in communication with the corresponding gas separator and subsequent equipment.

[0063] The pressure maintaining method provided by the present invention realizes pressure maintaining when the hydrogen production system is shut down, avoids the risk of explosive flammable gas mixture being precipitated in the alkali solution due to pressure relief when the hydrogen production system is shut down, and thus improves the operational stability of the hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0065] Figure 1 A schematic structural diagram of a hydrogen production system provided in Example 1 of the present invention;

[0066] Figure 2 A schematic structural diagram of a hydrogen production system provided in Example 2 of the present invention;

[0067] Figure 3 A schematic structural diagram of a hydrogen production system provided in Example 3 of the present invention;

[0068] Figure 4 A schematic structural diagram of a hydrogen production system provided in Example 4 of the present invention;

[0069] Figure 5 This is a flow chart of the pressure maintaining method provided by the present invention. DETAILED DESCRIPTION

[0070] The following is a combination of the embodiments of the present invention Figure 1-5 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0071] In the description of the present invention, it should be understood that the terms "upper," "lower," "top," and "bottom" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the positions or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0072] Combine Figure 1 As shown, the first aspect of the present invention provides a hydrogen production system 1000, which reduces the risk of explosive flammable gas mixture precipitated from the alkaline solution during the pressure relief process of the hydrogen production system 1000 by maintaining pressure, thereby improving the operating stability of the hydrogen production system 1000.

[0073] The hydrogen production system 1000 includes an electrolyzer 100, a gas separator 200, a gas processing and output assembly 300, and a switching assembly. The electrolyzer 100 has a hydrogen outlet and an oxygen outlet. The hydrogen outlet is located on the hydrogen side of the electrolyzer 100, where hydrogen is output, and the oxygen outlet is located on the oxygen side of the electrolyzer 100. Alkaline solution enters the electrolyzer 100 and produces hydrogen and oxygen through electrolysis.

[0074] There are two gas separators 200, one connected to the hydrogen outlet and the other to the oxygen outlet of the electrolyzer 100. Specifically, the crude gas inlet of one gas separator 200 is connected to the hydrogen outlet of the electrolyzer 100, functioning as a hydrogen separator. The crude gas inlet of the other gas separator 200 is connected to the oxygen outlet of the electrolyzer 100, functioning as an oxygen separator. A mixture of hydrogen and alkali liquor enters the hydrogen separator, while a mixture of oxygen and alkali liquor enters the oxygen separator.

[0075] Specifically, the hydrogen production system 1000 further includes an alkali liquid pump 700 and an alkali liquid heat exchanger 800. The inlet of the alkali liquid pump 700 is respectively connected to the liquid outlets of the two gas separators 200, the alkali liquid inlet of the alkali liquid heat exchanger 800 is connected to the outlet of the alkali liquid pump 700, and the alkali liquid outlet of the alkali liquid heat exchanger 800 is connected to the inlet of the electrolyzer 100. In other words, the present invention outputs the alkali liquid from the hydrogen separator and the oxygen separator through the alkali liquid pump 700, cools it through the alkali liquid heat exchanger 800, and then delivers it to the electrolyzer 100.

[0076] The gas processing output assemblies 300 are arranged in a one-to-one correspondence with the gas separators 200, and the gas inlet of each gas processing output assembly 300 is connected to the gas outlet of the corresponding gas separator 200. That is, the gas inlet of one gas processing output assembly 300 is connected to the gas outlet of the hydrogen separator, and the gas inlet of the other gas processing output assembly 300 is connected to the gas outlet of the oxygen separator.

[0077] The switching assembly is used to switch the gas processing output assembly 300 between a first state, in which it is connected to the corresponding gas separator 200 for gas supply and isolated from subsequent equipment, or a second state, in which it is connected to both the corresponding gas separator 200 and subsequent equipment. It should be noted that the subsequent equipment herein refers to equipment used to purify (or store) oxygen or hydrogen.

[0078] When the hydrogen production system 1000 is shut down, the switching component switches the gas processing output component 300 to the first state. At this time, the gas processing output component 300 is isolated from the subsequent equipment and connected to the corresponding gas separator 200 for gas supply, so as to realize the shutdown and pressure maintenance of the hydrogen production system 1000, avoiding the risk of precipitation of explosive flammable gas mixture in the alkaline solution due to the pressure relief of the hydrogen production system 1000, thereby improving the operating stability of the hydrogen production system 1000.

[0079] When the hydrogen production system 1000 produces hydrogen, the switching component switches the gas processing output component 300 to the second state. At this time, the gas processing output component 300 is connected to the corresponding gas separator 200 and subsequent equipment to supply gas to the subsequent equipment.

[0080] In order to facilitate the switching component to switch the state of the gas processing output component 300, the hydrogen production system 1000 also includes a controller 500, which is connected to the switching component signal and is used to control the switching component to switch the state of the gas processing output component 300.

[0081] It should be noted that controlling the switching component to switch the state of the gas processing output component 300 through the controller 500 is only a specific embodiment of the present invention. In actual applications, the switching component can also be manually controlled to switch the state of the gas processing output component 300.

[0082] Specifically, the present invention discloses a gas processing output assembly 300 including a scrubber 301 and a gas-liquid separator 302. The first gas inlet of the scrubber 301 serves as the gas inlet of the gas processing output assembly 300. The gas outlet of the scrubber 301 is connected to the gas inlet of the gas-liquid separator 302, and the gas outlet of the gas-liquid separator 302 outputs the gas to be purified. Specifically, in the gas processing output assembly 300 connected to the hydrogen separator, the hydrogen separated by the hydrogen separator enters the scrubber 301, is cleaned by the pure water in the scrubber 301, and the cleaned hydrogen enters the gas-liquid separator 302. In the gas processing output assembly 300 connected to the oxygen separator, the oxygen separated by the oxygen separator enters the scrubber 301, is cleaned by the pure water in the scrubber 301, and the cleaned oxygen enters the gas-liquid separator 302.

[0083] Furthermore, the present invention discloses that an alkali liquid outlet is provided at the bottom of the gas-liquid separator 302 , and an alkali liquid switch valve 307 is installed at the alkali liquid outlet. The alkali liquid separated in the gas-liquid separator 302 is discharged by controlling the alkali liquid switch valve 307 to open.

[0084] Furthermore, the present invention discloses that the gas processing output component 300 also includes a gas cooler 303, the gas inlet of the gas cooler 303 is connected to the gas outlet of the scrubber 301, and the gas outlet of the gas cooler 303 is connected to the inlet of the gas-liquid separator 302. The gas cooler 303 is used to cool the gas after being washed by the scrubber 301.

[0085] Furthermore, the present invention discloses that the hydrogen production system 1000 also includes an analyzer 600, which is arranged in a one-to-one correspondence with the gas processing output component 300. The analyzer 600 located on the hydrogen side is used to detect the oxygen content in hydrogen, and the analyzer 600 located on the oxygen side is used to detect the hydrogen content in oxygen.

[0086] Specifically, an analyzer switch valve 601 is provided between the inlet of the analyzer 600 and the gas outlet of the gas-liquid separator 302. When the hydrogen production system 1000 is started to stably produce gas, a small amount of gas is introduced into the analyzer 600 by opening the analyzer switch valve 601 to measure the content of hydrogen in oxygen or oxygen in hydrogen.

[0087] Example 1

[0088] like Figure 1As shown, the gas processing output assembly 300 further includes a pressure-maintaining tank 304. The gas inlet of the pressure-maintaining tank 304 is connected to the gas outlet of the gas-liquid separator 302, and the gas outlet of the pressure-maintaining tank 304 is connected to the gas inlet of the corresponding gas separator 200. Hydrogen is buffered in the pressure-maintaining tank 304 connected to the hydrogen separator, and oxygen is buffered in the pressure-maintaining tank 304 connected to the oxygen separator.

[0089] Furthermore, the switching assembly includes a first on-off valve 401, a second on-off valve 402, and a third on-off valve 403. The inlet of the first on-off valve 401 is connected to the gas outlet of the gas-liquid separator 302, and the outlet of the first on-off valve 401 is connected to subsequent equipment. The inlet of the second on-off valve 402 is connected to the gas outlet of the gas-liquid separator 302, and the outlet of the second on-off valve 402 is connected to the gas inlet of the pressure-maintaining tank 304. The inlet of the third on-off valve 403 is connected to the gas outlet of the pressure-maintaining tank 304, and the outlet of the third on-off valve 403 is connected to the gas inlet of the gas separator 200.

[0090] When the hydrogen production system 1000 is shut down, the first switch valve 401 and the second switch valve 402 are closed, and the third switch valve 403 is opened, so that the gas in the pressure maintaining tank 304 can enter the gas separator 200 to maintain the pressure of the hydrogen production system 1000; when the hydrogen production system 1000 is producing hydrogen, the third switch valve 403 is closed, and the first switch valve 401 and the second switch valve 402 are opened, so that part of the hydrogen or oxygen output by the gas-liquid separator 302 enters the subsequent equipment through the first switch valve 401, and the other part enters the pressure maintaining tank 304 through the second switch valve 402. When the pressure value in the pressure maintaining tank 304 is greater than or equal to the preset value, the second switch valve 402 is closed.

[0091] During the initial stage of hydrogen production by the hydrogen production system 1000, the content of hydrogen in oxygen or oxygen in hydrogen may exceed the standard. At this time, the second switch valve 402 is closed, the analyzer switch valve 601 is opened, and the gas separated by the gas-liquid separator 302 is introduced into the corresponding analyzer 600 to measure the content of hydrogen in oxygen or oxygen in hydrogen. When the standard is met, the second switch valve 402 is opened, and pressure is injected into the pressure maintaining tank 304. After the required working pressure is reached, the second switch valve 402 is closed.

[0092] In order to facilitate the acquisition of the working pressure in the pressure-maintaining tank 304 to control the opening and closing of the second switch valve 402, the present invention discloses that the switching component also includes a pressure transmitter 404. The pressure transmitter 404 is installed on the pressure-maintaining tank 304 and is used to detect the gas pressure in the pressure-maintaining tank 304. The pressure transmitter 404 is connected to the controller 500 by signal. When the pressure value detected by the pressure transmitter 404 is greater than or equal to the preset value, the controller 500 controls the second switch valve 402 to close.

[0093] It should be noted that the preset value is set according to actual needs and is not limited to one or certain specific values.

[0094] Furthermore, the present invention discloses that a liquid level detection component 305 is also installed on the pressure-maintaining tank 304 . The liquid level detection component 305 is connected to the controller 500 for signal detection and is used to detect the liquid level value in the pressure-maintaining tank 304 .

[0095] Specifically, the liquid level detecting component 305 is a liquid level gauge.

[0096] The bottom of the pressure-maintaining tank 304 is provided with a drain port for easy drainage. A drain valve 306, connected to the controller 500, is installed at the drain port. When the liquid level detector 305 detects that the liquid level in the pressure-maintaining tank 304 is greater than or equal to a preset height, the controller 500 controls the drain valve 306 to open and drain the liquid.

[0097] It should be noted that the preset height is set according to actual needs and is not limited to one or certain specific values.

[0098] It should also be noted that the control of the opening and closing of the drain valve 306 by the controller 500 in cooperation with the liquid level detection component 305 disclosed in the present invention is only a specific embodiment of the present invention. In actual applications, a transparent observation window can also be provided on the side wall of the pressure-maintaining tank 304 to observe the liquid level in the pressure-maintaining tank 304 through the observation window and manually control the opening and closing of the drain valve 306.

[0099] Furthermore, the present invention discloses a fourth on-off valve 405 disposed between the liquid overflow port of the scrubber 301 and the liquid inlet of the gas separator 200. Specifically, the liquid overflow port of the scrubber 301 and the liquid inlet of the gas separator 200 are connected via the fourth on-off valve 405. A fifth on-off valve 406 is disposed between the first gas inlet of the scrubber 301 and the gas outlet of the gas separator 200. Specifically, the first gas inlet of the scrubber 301 and the gas outlet of the gas separator 200 are connected via the fifth on-off valve 406. The fourth on-off valve 405 and the fifth on-off valve 406 are each signal-connected to a controller 500, which controls the opening and closing of the fourth on-off valve 405 and the fifth on-off valve 406.

[0100] When the hydrogen production system 1000 produces hydrogen, the fourth switch valve 405 and the fifth switch valve 406 are opened, so that the gas separated by the gas separator 200 can smoothly enter the corresponding scrubber 301 through the fifth switch valve 406, and the liquid in the scrubber 301 can enter the gas separator 200 through the fourth switch valve 405.

[0101] When the hydrogen production system 1000 is shut down, the fourth switch valve 405 and the fifth switch valve 406 are closed, so that the gas in the pressure-maintaining tank 304 can smoothly enter the corresponding gas separator 200 to ensure the pressure in the gas separator 200.

[0102] The operation process of the hydrogen production process of the hydrogen production system 1000 in this embodiment is as follows: the alkali liquid coming out of the alkali liquid heat exchanger 800 enters the electrolytic cell 100, and hydrogen and oxygen are generated through electrolysis reaction, wherein the hydrogen and alkali liquid mixture enters the hydrogen separator, and the gas phase obtained after separation enters the scrubber 301 on the hydrogen side. During the process, pure water will be added to the scrubber 301 on the hydrogen side, and finally the gas phase is fully washed. The liquid in the scrubber 301 on the hydrogen side flows into the hydrogen separator along the fourth switch valve 405, and the gas coming out of the scrubber 301 on the hydrogen side enters the cooler on the hydrogen side. After the gas is cooled, it enters the gas-liquid separator 302 on the hydrogen side, and is further removed by separation. The alkaline liquid component in the gas eventually obtains crude hydrogen and leaves through the first switch valve to enter the subsequent equipment (purification process equipment); similarly, the oxygen and alkaline liquid coming out of the oxygen side of the electrolyzer 100 enter the oxygen separator, and the separated gas phase enters the scrubber 301 on the oxygen side. The liquid in the scrubber 301 on the oxygen side enters the oxygen separator through the fourth switch valve 405 on the corresponding side. The washed gas enters the cooler on the oxygen side, and after cooling, enters the gas-liquid separator 302 on the oxygen side to remove the liquid alkaline liquid in the feed. The alkaline liquid separated by the hydrogen separator and the oxygen separator comes out from the bottom of the two separators and merges into the alkaline liquid pump 700. After being pressurized, it flows back into the alkaline liquid heat exchanger 800.

[0103] When hydrogen production system 1000 is started and producing gas stably, the analyzer on-off valve 601 on the hydrogen side is opened to introduce a small amount of gas into the analyzer 600 on the corresponding side to detect the oxygen content in the hydrogen. The analyzer on-off valve 601 on the oxygen side is also opened to introduce a small amount of gas into the analyzer 600 on the corresponding side to measure the hydrogen content in the oxygen. When both levels meet the standards, the controller 500 opens the second on-off valves 402 on the oxygen and hydrogen sides, respectively, to pressurize the corresponding pressure-maintaining tanks 304. When the pressure on the pressure transmitter 404 reaches the operating pressure, the corresponding second on-off valves 402 are closed.

[0104] When the hydrogen production system 1000 is shut down, the first switch valve 401 and the second switch valve 402 on the hydrogen side and the oxygen side are closed respectively, the fourth switch valve 405 and the fifth switch valve 406 are closed, and the third switch valve 403 is opened, so that the gas inside the pressure maintaining tank 304 on the hydrogen side and the oxygen side gradually flows into the gas separator 200 on the corresponding side, ultimately realizing the pressure maintaining function of the entire process.

[0105] Example 2

[0106] like Figure 2 As shown, the hydrogen production system 1000 in this embodiment is similar in structure to the hydrogen production system 1000 in Example 1, except that the switching component includes a first switch valve 401, a second switch valve 402, a third switch valve 403 and a sixth switch valve 407, but does not include a fourth switch valve 405 and a fifth switch valve 406, the outlet of the third switch valve 403 is connected to the second gas inlet of the scrubber 301, and the gas inlet of the gas cooler 303 is connected to the gas outlet of the scrubber 301 through the sixth switch valve 407, that is, the scrubber 301, the gas separator 200 and the electrolyzer 100 are pressurized at the same time.

[0107] When the hydrogen production system 1000 is producing hydrogen, the sixth switch valve 407 is opened to allow the gas scrubbed by the scrubber 301 to enter the gas cooler 303; when the hydrogen production system 1000 is shut down, the sixth switch valve 407 is closed to prevent the gas in the scrubber 301 from entering the gas cooler 303.

[0108] Example 3

[0109] like Figure 3 As shown, the structure of this embodiment is similar to that of the first embodiment, except that the pressure-maintaining tank 304 is not provided in this embodiment, and the setting positions of the switch valves in the switching assembly are different.

[0110] Specifically, the switching component includes a first switch valve 401, a second switch valve 402, a third switch valve 403, a fourth switch valve 404 and a fifth switch valve 405. The inlet of the first switch valve 401 is connected to the gas outlet of the gas-liquid separator 302, and the outlet of the first switch valve 401 is connected to the subsequent equipment. The opening and closing of the first switch valve 401 realizes the connection and disconnection between the gas outlet of the gas-liquid separator 302 and the subsequent equipment.

[0111] The inlet of the second switch valve 402 is connected to the gas outlet of the gas-liquid separator 302, and the outlet of the second switch valve 402 is connected to the gas inlet of the gas separator 200. The gas outlet of the gas-liquid separator 302 and the gas inlet of the gas separator 200 are connected and disconnected by opening and closing the second switch valve 402.

[0112] The inlet of the third switch valve 403 is connected to the gas outlet of the gas cooler 303, and the outlet of the third switch valve 403 is connected to the gas inlet of the gas-liquid separator 302. The gas outlet of the gas cooler 303 and the gas inlet of the gas-liquid separator 302 are connected and disconnected by opening and closing the third switch valve 403.

[0113] The liquid phase overflow port of the scrubber 301 is connected to the liquid inlet of the gas separator 200 via a fourth switch valve 404 , and the first gas inlet of the scrubber 301 is connected to the gas outlet of the gas separator 200 via a fifth switch valve 405 .

[0114] When the hydrogen production system 1000 is shut down, the first switch valve 401, the third switch valve 403, the fourth switch valve 404 and the fifth switch valve 405 are closed, and the second switch valve 402 is opened to maintain the pressure of the gas-liquid separator 302, the gas separator 200 and the electrolyzer 100.

[0115] It should be noted that, when the ambient temperature is low and there is a risk of the alkaline solution in the scrubber 301 overflowing, the fourth switch valve 404 and / or the fifth switch valve 405 may be opened to maintain the pressure of the scrubber 301 .

[0116] When the hydrogen production system 1000 produces hydrogen, the second switch valve 402 is closed, and the first switch valve 401 , the third switch valve 403 , the fourth switch valve 404 and the fifth switch valve 405 are opened.

[0117] In this embodiment, after the hydrogen production system 1000 is shut down, the gas-liquid separator 302 in the hydrogen production system 1000 is used instead of the pressure-maintaining tank 304 to supply gas to the gas separator 200, thereby maintaining the pressure of the electrolyzer 100. In other words, this embodiment utilizes existing components in the hydrogen production system 1000 to maintain pressure, eliminating the need for additional components, reducing the number of components, and lowering costs.

[0118] Example 4

[0119] like Figure 4 As shown, the structure of this embodiment is similar to that of embodiment three, except that, in this embodiment, the switching component includes a first switch valve 401, a second switch valve 402, a third switch valve 403 and a sixth switch valve 406, the outlet of the second switch valve 402 is connected to the second gas inlet of the scrubber 301, and the gas inlet of the gas cooler 303 is connected to the gas outlet of the scrubber 301 through the sixth switch valve 406.

[0120] When the hydrogen production system 1000 is producing hydrogen, the sixth switch valve 406 is opened and the second switch valve 402 is closed; when the hydrogen production system 1000 is shut down, the sixth switch valve 406 is closed and the second switch valve 402 is opened.

[0121] That is, in this embodiment, the scrubber 301 , the gas separator 200 and the electrolytic cell 100 are all kept at pressure.

[0122] like Figure 5 As shown, the second aspect of the present invention provides a pressure maintaining method, using the hydrogen production system 1000 in any one of the above embodiments, comprising:

[0123] Step S1: Determine whether the hydrogen production system 1000 is in a shutdown state. If so, go to step S2; if not, go to step S3;

[0124] Step S2: Control the switching component to switch to the first state where the gas processing output component 300 is connected to the corresponding gas separator 200 for gas supply and isolated from subsequent equipment;

[0125] Step S3: Control the switching component to switch to the second state where the gas processing output component 300 is in communication with the corresponding gas separator 200 and subsequent equipment.

[0126] The pressure maintaining method provided by the present invention realizes pressure maintaining of the hydrogen production system 1000 during shutdown, avoiding the risk of explosive flammable gas mixture precipitated from the alkali solution due to pressure relief during shutdown of the hydrogen production system 1000, thereby improving the operational stability of the hydrogen production system 1000.

[0127] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0128] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and inventive features disclosed herein.

[0129] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0130] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A hydrogen production system, characterized in that: include: electrolytic cell; Gas separators, the number of the gas separators is two, and the crude gas inlet of one of the gas separators is connected to the hydrogen outlet of the electrolyzer, and the crude gas inlet of the other gas separator is connected to the oxygen outlet of the electrolyzer; A gas processing output assembly is provided in one-to-one correspondence with the gas separator, wherein the gas inlet of the gas processing output assembly is connected to the gas outlet of the corresponding gas separator; A switching component is used to switch the gas processing output component to a first state in which it is connected to the corresponding gas separator for gas supply and isolated from subsequent equipment, or a second state in which it is connected to the corresponding gas separator and subsequent equipment. When the hydrogen production system is shut down, the switching component switches the gas processing output component to the first state. When the hydrogen production system produces hydrogen, the switching component switches the gas processing output component to the second state.

2. The hydrogen production system according to claim 1, characterized in that: Also includes a controller; The controller is connected to the switching component by signal and is used to control the switching state of the switching component.

3. The hydrogen production system according to claim 2, characterized in that: The gas processing output component includes a scrubber and a gas-liquid separator; The first gas inlet of the scrubber is the gas inlet of the gas processing output component. The gas outlet of the scrubber is connected to the gas inlet of the gas-liquid separator. The gas outlet of the gas-liquid separator outputs the gas to be purified.

4. The hydrogen production system according to claim 3, characterized in that: The gas processing output assembly further includes a gas cooler; The gas inlet of the gas cooler is communicated with the gas outlet of the scrubber, and the gas outlet of the gas cooler is communicated with the gas inlet of the gas-liquid separator.

5. The hydrogen production system according to claim 4, characterized in that: The gas processing output assembly also includes a pressure-maintaining tank; The gas inlet of the pressure-maintaining tank is communicated with the gas outlet of the gas-liquid separator, and the gas outlet of the pressure-maintaining tank is communicated with the gas inlet of the corresponding gas separator.

6. The hydrogen production system according to claim 5, characterized in that: The switching component includes: a first switch valve, wherein the inlet of the first switch valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the first switch valve is connected to a subsequent device; a second on-off valve, wherein the inlet of the second on-off valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the second on-off valve is connected to the gas inlet of the pressure-maintaining tank; a third on-off valve, wherein the inlet of the third on-off valve is connected to the gas outlet of the pressure-maintaining tank, and the outlet of the third on-off valve is connected to the gas inlet of the gas separator or the second gas inlet of the scrubber; When the hydrogen production system is shut down, the first switch valve and the second switch valve are closed, and the third switch valve is opened; When the hydrogen production system produces hydrogen, the third switch valve is closed, the first switch valve and the second switch valve are opened, and when the pressure value in the pressure maintaining tank is greater than or equal to a preset value, the second switch valve is closed.

7. The hydrogen production system according to claim 6, characterized in that: The switching assembly further includes a pressure transmitter, which is mounted on the pressure-maintaining tank and is used to detect the gas pressure in the pressure-maintaining tank. The pressure transmitter is connected to the controller by signal. When the pressure value detected by the pressure transmitter is greater than or equal to the preset value, the controller controls the second switch valve to close. and / or The pressure-maintaining tank is also equipped with a liquid level detection component connected to the controller signal. The bottom end of the pressure-maintaining tank is provided with a drain outlet, and a drain valve connected to the controller signal is installed at the drain outlet. When the liquid level detection component detects that the liquid level in the pressure-maintaining tank is greater than or equal to a preset height, the controller controls the drain valve to open and drain the liquid.

8. The hydrogen production system according to claim 6, characterized in that: The outlet of the third switch valve is connected to the gas inlet of the gas separator; The liquid phase overflow port of the scrubber is connected to the liquid inlet of the gas separator via a fourth switch valve, and the first gas inlet of the scrubber is connected to the gas outlet of the gas separator via a fifth switch valve; When the hydrogen production system produces hydrogen, the fourth switch valve and the fifth switch valve are opened; When the hydrogen production system is shut down, the fourth switch valve and the fifth switch valve are closed.

9. The hydrogen production system according to claim 6, characterized in that: The outlet of the third switch valve is connected to the second gas inlet of the scrubber; The gas inlet of the gas cooler is connected to the gas outlet of the scrubber via a sixth switch valve; When the hydrogen production system produces hydrogen, the sixth switch valve is opened; When the hydrogen production system is shut down, the sixth switch valve is closed.

10. The hydrogen production system according to claim 4, characterized in that: The switching component includes: a first switch valve, wherein the inlet of the first switch valve is connected to the gas outlet of the gas-liquid separator, and the outlet of the first switch valve is connected to the subsequent equipment; a second on-off valve, wherein the inlet of the second on-off valve is communicated with the gas outlet of the gas-liquid separator, and the outlet of the second on-off valve is communicated with the gas inlet of the gas separator or the second gas inlet of the scrubber; a third on-off valve, wherein the inlet of the third on-off valve is connected to the gas outlet of the scrubber, and the outlet of the third on-off valve is connected to the gas inlet of the gas-liquid separator; When the hydrogen production system is shut down, the first switch valve and the third switch valve are closed, and the second switch valve is opened; When the hydrogen production system produces hydrogen, the second switch valve is closed, and the first switch valve and the third switch valve are opened.

11. The hydrogen production system according to claim 10, characterized in that: The outlet of the second switch valve is connected to the gas inlet of the gas separator; The liquid phase overflow port of the scrubber is connected to the liquid inlet of the gas separator via a fourth switch valve, and the first gas inlet of the scrubber is connected to the gas outlet of the gas separator via a fifth switch valve; When the hydrogen production system produces hydrogen, the fourth switch valve and the fifth switch valve are opened; When the hydrogen production system is shut down, the fourth switch valve and the fifth switch valve are closed.

12. The hydrogen production system according to claim 10, characterized in that: The outlet of the second on-off valve is in communication with the second gas inlet of the scrubber; The gas inlet of the gas cooler is connected to the gas outlet of the scrubber via a sixth switch valve; When the hydrogen production system produces hydrogen, the sixth switch valve is opened; When the hydrogen production system is shut down, the sixth switch valve is closed.

13. The hydrogen production system according to any one of claims 1 to 12, characterized in that: Also included are analyzers; The analyzer is provided in a one-to-one correspondence with the gas processing output component, and the analyzer is used to detect the content of oxygen in hydrogen or hydrogen in oxygen.

14. A pressure maintaining method, characterized in that: The hydrogen production system according to any one of claims 1 to 13 comprises: Determining the state of the hydrogen production system; If the hydrogen production system is in a shutdown state, controlling the switching component to switch to a first state in which the gas processing output component is connected to the corresponding gas separator for gas supply and isolated from subsequent equipment; If the hydrogen production system is in a hydrogen production state, the switching component is controlled to switch to a second state in which the gas processing output component is in communication with the corresponding gas separator and subsequent equipment.

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