Oxygen recovery device and oxygen recovery system

Abstract

The utility model discloses an oxygen recovery device and an oxygen recovery system, and relates to the technical field of water electrolysis hydrogen production, the oxygen recovery device comprises an air separation device, a purification part and a heat exchanger, and the air separation device is used for outputting a liquid nitrogen cold source; the purification part is used for introducing to-be-recovered oxygen, purifying the to-be-recovered oxygen and then outputting purified oxygen; the heat exchanger is provided with an oxygen inlet pipeline, a cold source inlet pipeline and a liquid oxygen outlet pipeline, and the oxygen inlet pipeline is connected with the purification part and used for introducing the purified oxygen; the cold source inlet pipeline is used for being connected with the liquid nitrogen cold source conveyed by the air separation device and conducting heat exchange and cooling on the purified oxygen to generate liquid oxygen, and the liquid oxygen outlet pipeline outputs the liquid oxygen. The method is used for utilizing to-be-recycled oxygen and solving the economic loss caused by the fact that the to-be-recycled oxygen cannot be utilized.

Description

Technical Field

[0001] This application relates to the field of hydrogen production technology through water electrolysis, and in particular to an oxygen recovery device and an oxygen recovery system. Background Technology

[0002] Currently, oxygen recovery generally involves compressing and storing the crude oxygen to be recovered. However, due to the high cost of oxygen compression and storage, transportation costs, short sales distance, and narrow sales market, the oxygen produced by electrolysis of water to produce hydrogen is usually directly vented. However, when the gas production volume is large, direct venting results in significant economic losses. Utility Model Content

[0003] The main purpose of this application is to provide an oxygen recovery device and system for utilizing oxygen to be recovered, aiming to solve the economic losses caused by the inability to utilize oxygen to be recovered.

[0004] To achieve the above objectives, this application proposes an oxygen recovery device, comprising:

[0005] Air separation unit, used to output liquid nitrogen cold source;

[0006] The purification section is used to receive the oxygen to be recovered, and to output purified oxygen after purification treatment.

[0007] The heat exchanger has an oxygen inlet pipeline, a cold source inlet pipeline, and a liquid oxygen outlet pipeline. The oxygen inlet pipeline is connected to the purification unit for receiving the purified oxygen.

[0008] The inlet cold source pipeline is used to connect to the liquid nitrogen cold source delivered by the air separation unit, to exchange heat and cool the purified oxygen to generate liquid oxygen, and the outlet liquid oxygen pipeline outputs the liquid oxygen.

[0009] In one embodiment, the purification unit includes a first separator having an inlet pipe and an outlet pipe. The first separator is used to receive the oxygen to be recovered through the inlet pipe and to output the separated liquid through the outlet pipe.

[0010] In one embodiment, the purification unit further includes a purification device connected to the first separator. The purification device is used to receive the oxygen to be recovered delivered by the first separator, and after purification, output it to the oxygen inlet pipeline.

[0011] In one embodiment, the heat exchanger further includes a nitrogen outlet pipeline, through which nitrogen gas generated after the liquid nitrogen cold source undergoes heat exchange in the heat exchanger is output.

[0012] The purification unit also includes a cooler connected to the nitrogen outlet pipeline. The cooler is used to receive nitrogen gas delivered by the nitrogen outlet pipeline. After cooling the oxygen to be recovered by the received nitrogen gas, the cooled oxygen is output to the first separator.

[0013] In one embodiment, the oxygen recovery device further includes a heating device, the cooler is used to output cooled nitrogen gas, at least a portion of the nitrogen gas output by the cooler is transferred to the purification device, and the heating device is provided on the connecting pipeline between the cooler and the purification device;

[0014] The nitrogen gas, used as a purging gas, is heated by the heating device and then introduced into the purification device.

[0015] In one embodiment, the oxygen recovery device is provided with a nitrogen output pipe, and other portions of the nitrogen output from the cooler are discharged through the nitrogen output pipe according to a preset nitrogen flow rate range.

[0016] In one embodiment, a first temperature detection component is provided on the intake pipe of the first separator, and the first temperature detection component is used to detect the temperature inside the intake pipe;

[0017] The purification unit also includes a cooler, and the cooler has an exhaust pipe on the pipeline for receiving nitrogen. The exhaust pipe is equipped with a first valve assembly, which is used to operate within a preset operating temperature range so that the temperature inside the intake pipe does not exceed the preset operating temperature range.

[0018] In one embodiment, a first flow detection component is provided on the outlet pipe of the first separator, and the first flow detection component is used to detect the flow rate inside the outlet pipe;

[0019] The intake pipe is equipped with a second valve assembly, which is used to operate according to a preset oxygen flow range so that the flow rate in the outlet pipe does not exceed the preset oxygen flow range.

[0020] In one embodiment, the oxygen recovery device further includes a second separator connected to the liquid oxygen outlet pipeline, which is used to receive the liquid oxygen transmitted by the liquid oxygen outlet pipeline and to transmit the liquid oxygen after gas separation to an external liquid oxygen storage device.

[0021] In one embodiment, a third valve assembly is provided on the connecting pipeline between the second separator and the external liquid oxygen storage device. The third valve assembly is configured to operate according to a preset separator liquid level to ensure that the liquid level of the second separator does not exceed the preset separator liquid level range; and / or,

[0022] The third valve assembly is used to operate according to a preset liquid oxygen level range so that the liquid level of the external liquid oxygen storage device does not exceed the preset liquid oxygen storage level range.

[0023] In one embodiment, the second separator is provided with a venting pipe, and the gas separated by the second separator is discharged through the venting pipe according to a preset venting pressure range.

[0024] In one embodiment, a switching valve is provided between the second separator and the external liquid oxygen storage device. The switching valve is used to control the connection of the pipeline between the second separator and the external liquid oxygen storage device when a running signal is received.

[0025] In one embodiment, the heat exchanger further includes a nitrogen outlet pipeline through which nitrogen gas generated after heat exchange is output.

[0026] The nitrogen outlet pipeline is equipped with a second temperature detection component, which is used to detect the temperature inside the nitrogen outlet pipeline. The cold source inlet pipeline is equipped with a fourth valve component, which is used to operate according to a preset first temperature range so that the temperature inside the nitrogen outlet pipeline does not exceed the preset first temperature range.

[0027] The fourth valve assembly is also used to control the cold source inlet pipeline to shut off when the temperature inside the nitrogen outlet pipeline is not greater than a preset second temperature.

[0028] Wherein, the second temperature is not greater than the minimum value of the first temperature range.

[0029] In one embodiment, a third temperature detection component is provided on the liquid oxygen outlet pipeline, the third temperature detection component being used to detect the temperature inside the liquid oxygen outlet pipeline;

[0030] The inlet cold source pipeline is equipped with a fifth valve assembly, which is used to operate within a preset third temperature range so that the temperature inside the outlet liquid oxygen pipeline does not exceed the preset third temperature range.

[0031] This application also proposes an oxygen recovery system, including a hydrogen production device and an oxygen recovery device as described above. The hydrogen production device includes an electrolyzer, an oxygen-side gas-liquid separator, and the purification unit. The oxygen-evolution side gas of the electrolyzer is first separated by the oxygen-side gas-liquid separator and then enters the purification unit.

[0032] The technical solution of this application is that the heat exchanger uses liquid nitrogen from the air separation unit as a cold source to perform heat exchange treatment on the oxygen to be recovered. This can effectively utilize the cold energy of liquid nitrogen and avoid the waste caused by directly releasing the liquid nitrogen from the air separation unit, thereby improving energy utilization and reducing waste. The oxygen after heat exchange becomes liquid oxygen, which is used to effectively treat and utilize the oxygen to be recovered, reducing energy waste and environmental impact caused by direct emissions.

[0033] Before heat exchange to prepare liquid oxygen, the oxygen to be recovered is purified by the purification unit and then purified oxygen is output. The purification unit can improve the purity of oxygen. Liquid oxygen can also be prepared by heat exchange with liquid nitrogen, which can reduce the content of other gases in the oxygen to be recovered, further improve the purity of oxygen, and expand the applicable scenarios of the oxygen to be recovered. The recovered liquid oxygen can also be used as a liquid oxygen product, which can effectively improve economic benefits.

[0034] By adjusting the heat exchange process to prepare liquid oxygen according to different requirements for liquid oxygen and liquid nitrogen, the system can meet the needs of different production processes and improve its flexibility. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 A schematic diagram of an embodiment of the oxygen recovery device provided in this application;

[0037] Figure 2 A simplified structural diagram of an embodiment of the purification section provided in this application;

[0038] Figure 3 A simplified structural diagram of an embodiment of the oxygen recovery device provided in this application;

[0039] Figure 4 A simplified structural diagram of an embodiment of the oxygen recovery system provided in this application.

[0040] Explanation of icon numbers:

[0041] 100. Purification section; 110. First separator; 120. Purification apparatus; 130. Cooler;

[0042] 200. Heat exchanger;

[0043] 300. Air separation unit;

[0044] 410. Second separator; 420. Liquid oxygen storage device;

[0045] 500. Heating device;

[0046] 610. Electrolytic cell; 620. Oxygen-side gas-liquid separation device.

[0047] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0049] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0050] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0051] Hydrogen production by water electrolysis involves electrolyzing water into hydrogen and oxygen in an electrolyzer. In terms of oxygen recovery, the crude oxygen to be recovered is usually compressed and stored. However, due to the high cost of compressing and storing gaseous oxygen, the high transportation cost, the short sales distance, and the narrow sales market, the oxygen to be recovered, as a byproduct of hydrogen production by water electrolysis, is usually directly vented.

[0052] With the development of hydrogen production through water electrolysis, the scale of industrial hydrogen production using water electrolysis is increasing. Generally, the scale of industrial hydrogen production through water electrolysis in the market is around 1000-8000 standard cubic meters per hour. With the expansion of scale, a single hydrogen production unit can even produce oxygen as a byproduct of up to 4000 standard cubic meters per hour, reaching the oxygen production of a small air separation unit, which has high recovery value and significance. In the field of hydrogen production through water electrolysis, the crude oxygen has high purity, and the preparation of liquid oxygen does not require compressor pressurization or large amounts of nitrogen energy consumption, resulting in higher overall energy consumption but lower cost. When liquid oxygen is sold as pharmaceutical oxygen, its selling price can be 3-4 times that of liquid nitrogen, giving it higher economic value. However, when the gas production volume is large, directly venting the oxygen results in significant economic losses.

[0053] Air separation units are also used for oxygen production. An air separation unit is a production facility that uses cryogenic technology to pressurize and cool air for distillation, producing liquid nitrogen, liquid oxygen, and liquid argon. Air contains approximately 78% nitrogen and 21% oxygen, with nitrogen being far more abundant than oxygen. For air separation units with a fixed processing capacity, although the output of liquid nitrogen is greater than that of liquid oxygen, the demand for liquid oxygen is greater in applications such as pharmaceuticals. Existing air separation units typically adjust the production of liquid nitrogen and liquid oxygen based on sales demand, and generally handle excess nitrogen by direct venting. For companies building air separation units for their own liquid nitrogen use, due to the limited number of processes that can utilize cold energy, they generally use ambient temperature vaporizers to directly vaporize the liquid nitrogen before use. However, this approach cannot effectively utilize the cold energy of the liquid nitrogen.

[0054] Therefore, if liquid nitrogen can be used to produce liquid oxygen, it will not only reduce nitrogen venting and energy consumption, but also combine sales volume with equipment output, which has great economic significance.

[0055] Based on this, this application proposes an oxygen recovery device and system. It is used to utilize the oxygen to be recovered and to produce liquid oxygen by using liquid nitrogen from an air separation unit as a cold source, thereby improving economic value.

[0056] Reference Figures 1 to 4 The oxygen recovery device includes a purification unit 100 and a heat exchanger 200. The purification unit 100 is used to receive the oxygen to be recovered, and outputs purified oxygen after purification treatment. The heat exchanger 200 has an oxygen inlet pipeline, a cold source inlet pipeline, and a liquid oxygen outlet pipeline.

[0057] The oxygen recovery device also includes an air separation unit 300, which is used to output a liquid nitrogen cold source. The oxygen inlet pipeline is connected to the purification unit 100 to receive purified oxygen after purification by the purification unit 100; the cold source inlet pipeline is used to connect to the liquid nitrogen cold source delivered by the air separation unit 300 to exchange heat and cool the purified oxygen to generate liquid oxygen, which is then output through the liquid oxygen outlet pipeline.

[0058] Understandably, heat exchanger 200 uses liquid nitrogen supplied from air separation unit 300 as a cold source to perform heat exchange on the incoming oxygen to be recovered. The heat exchange medium is liquid nitrogen and oxygen. Generally, liquid nitrogen with a temperature of -196℃ has extremely strong cooling capacity. Using liquid nitrogen as a cold source, heat exchanger 200 allows the liquid nitrogen to absorb the heat from the oxygen to be recovered, cooling the oxygen to below -183℃, thus turning the oxygen from a gas into a liquid.

[0059] In this way, the cold energy of liquid nitrogen can be effectively utilized, avoiding waste caused by directly releasing liquid nitrogen, thereby improving energy efficiency and reducing waste. The oxygen after heat exchange becomes liquid oxygen, which can be used to effectively treat and utilize the oxygen to be recovered, reducing energy waste and environmental impact caused by direct emissions. Preparing liquid oxygen through liquid nitrogen heat exchange can also reduce the content of other gases in the oxygen to be recovered, improve oxygen purity, and expand the applicable scenarios for the recovered oxygen. The recovered liquid oxygen can be used as a liquid oxygen product in applications such as pharmaceutical oxygen, which can effectively improve economic benefits.

[0060] Compared to traditional air separation units 300 primarily used for generating liquid nitrogen, this system has a simpler overall structure, requires fewer pieces of equipment, and incurs lower costs. Furthermore, the generated liquid oxygen has higher application and economic value, effectively improving energy utilization and industrial economic efficiency. In addition, because existing air separation units 300 adjust the production of liquid nitrogen and liquid oxygen based on sales demand, the embodiments of this application regulate the heat exchange process for liquid oxygen production according to different needs for liquid oxygen and liquid nitrogen, thus meeting the requirements of different production processes and improving system flexibility.

[0061] In the embodiments of this application, before preparing liquid oxygen through heat exchange, the oxygen to be recovered is first purified by the purification unit 100. The purification unit 100 is designed to remove at least hydrogen, moisture, and other substances from the oxygen, thereby improving the oxygen purity. This prevents impurities from entering the heat exchanger 200 and causing contamination and blockage, leading to equipment corrosion, reduced heat exchange efficiency, and shorter service life of the heat exchanger 200. Furthermore, it can further improve the purity of the prepared liquid oxygen, increase economic efficiency, and enhance the safety and reliability of subsequent liquid oxygen utilization.

[0062] Reference Figure 2Optionally, the purification unit 100 includes, but is not limited to, a separator, a purification device 120, and a cooler 130. The separator can be a gas-water separator used to separate electrolytes and other liquid media to ensure gas purity. The purification device 120 can be a device with drying and adsorption functions, used to remove moisture from the gas using adsorbents such as molecular sieves. The cooler 130 is used to lower the gas temperature to facilitate subsequent gas purification and recycling. In the embodiments of this application, the purification unit 100 is mainly used to receive oxygen to be recycled, especially crude oxygen produced by water electrolysis for hydrogen production that may contain impurities, to purify the crude oxygen and obtain purified oxygen.

[0063] In some specific embodiments of this application, the system can also be interlocked and adjusted by designing detection components (such as temperature detection components, pressure detection components, flow detection components, etc.) and valve components in each connecting pipeline to ensure stable system operation.

[0064] Optionally, the oxygen recovery device also includes a control component, which is used to connect with the aforementioned valve components and detection components. Specifically, control components can be set separately for each valve component and each interlocking relationship to achieve separate control of different valve components and interlocking relationships; or, control components can be set for at least some or all interlocking relationships to achieve integrated control.

[0065] In one embodiment, the purification unit 100 includes a first separator 110, which has an inlet pipe and an outlet pipe. The first separator 110 is used to receive oxygen to be recovered through the inlet pipe and to output the gas after separation of liquid through the outlet pipe.

[0066] Optionally, the first separator 110 is connected to the oxygen to be recovered via an inlet pipe, and is mainly used to receive crude oxygen generated by water electrolysis. This crude oxygen, which may contain impurities, is used to purify the oxygen to be recovered. After separating the liquid from the crude oxygen, it is output through an outlet pipe. Additionally, it should be noted that in some embodiments of this application, before the oxygen to be recovered is connected to the first separator 110, the hot crude hydrogen or other crude oxygen that may contain impurities after gas-liquid separation can be cooled in advance by a cooler 130 or similar device to further improve the purity of the oxygen. The specific configuration can be adjusted according to actual conditions and is not limited here.

[0067] In one embodiment, the purification unit 100 further includes a purification device 120, which is connected to the first separator 110. The purification device 120 is used to receive the oxygen to be recovered from the first separator 110, and after purification, output it to the oxygen inlet pipeline.

[0068] After the oxygen to be recovered, conveyed by the first separator 110, is purified by the purification device 120, the purified oxygen is then fed into the heat exchanger 200 through the oxygen inlet pipeline for further heat exchange and to generate liquid oxygen. Pre-purification of the oxygen before it enters the purification device 120 prevents impurities in the oxygen from damaging the purification device 120 and affecting purification efficiency and quality.

[0069] Optionally, the purification device 120 can be, but is not limited to, a purifier that performs purification treatment through physical filtration (using filter materials such as sieves and filter paper to filter particulate matter in the gas), chemical adsorption (using activated carbon molecular sieves to adsorb organic matter and other pollutants in the gas), catalytic conversion, membrane separation, etc., to purify the oxygen to be recovered and improve the oxygen purity.

[0070] Furthermore, when the heat exchanger 200 also has a nitrogen outlet pipeline, the nitrogen generated after the liquid nitrogen cold source exchanges heat through the heat exchanger 200 is output through the nitrogen outlet pipeline.

[0071] In one embodiment, the nitrogen generated after heat exchange in the liquid nitrogen cold source through the heat exchanger 200 is output through the nitrogen outlet pipeline. The purification unit 100 also includes a cooler 130, which is connected to the nitrogen outlet pipeline. The cooler 130 is used to receive the nitrogen transmitted by the nitrogen outlet pipeline. After the nitrogen to be recovered is cooled by the received nitrogen, the cooled oxygen is output to the first separator 110.

[0072] Understandably, in the embodiments of this application, the cooler 130 is used to connect the oxygen to be recovered, especially the crude oxygen produced by water electrolysis for hydrogen production, which may contain impurities and is intended for recycling. The cooler is also used to connect the nitrogen gas delivered by the nitrogen outlet pipeline. Liquid nitrogen, as a cold source, will vaporize into low-temperature nitrogen gas after heat exchange. The oxygen to be recovered enters the cooler 130 before entering the first separator 110, and the low-temperature nitrogen gas is delivered to the cooler 130. The low-temperature nitrogen gas is designed as a cooling medium for the crude oxygen, which can cool the temperature of the oxygen to be recovered and effectively reduce its temperature. By cooling the oxygen to be recovered with low-temperature nitrogen gas, on the one hand, the temperature of the oxygen to be recovered can be reduced, which is convenient for subsequent purification and heat exchange; on the other hand, the cooling capacity of the low-temperature nitrogen gas can be further utilized to reduce energy waste.

[0073] Reference Figure 1 In one embodiment, the oxygen recovery device further includes a heating device 500, a cooler 130 for outputting cooled nitrogen, at least a portion of the nitrogen output from the cooler 130 being transferred to a purification device 120, and a heating device 500 being provided on the connecting pipeline between the cooler 130 and the purification device 120. Nitrogen, used as a purging gas, is heated by the heating device 500 and then input into the purification device 120.

[0074] Furthermore, the oxygen recovery device is equipped with a nitrogen output pipe, and other parts of the nitrogen output from the cooler 130 are discharged through the nitrogen output pipe according to the preset nitrogen flow range.

[0075] After the oxygen to be recovered is cooled, at least a portion of the cooled nitrogen is transferred to the purification unit 120 via cooler 130, while the remaining nitrogen is discharged through a nitrogen output line for use as a purging gas. The nitrogen is heated by heating device 500 before being introduced into the purification unit. Nitrogen is an inert gas. Using at least a portion of the nitrogen output from cooler 130 as a purging gas, heated by heating device 500, and then introduced into the purification unit 120 requiring regeneration, effectively displaces moisture and other impurities within the purification unit 120. Using nitrogen for purging not only achieves industrial cleaning and protects equipment from corrosion and contamination, but also extends the service life of the purification unit 120.

[0076] In some alternative embodiments of this application, nitrogen gas is used as a purging gas. After being heated by the heating device 500, it is input into the purification device 120 and output according to a preset nitrogen pressure range. The pipeline of the purification device 120 for outputting nitrogen gas is equipped with a pressure detection component P11 and a valve component Q11. The pressure detection component P11 is used to detect the pressure inside the pipeline of the purification device 120 for outputting nitrogen gas. The pressure detection component P11 is used to operate according to the preset nitrogen pressure range so that the pressure inside the pipeline of the purification device 120 for outputting nitrogen gas does not exceed the preset nitrogen pressure range, thereby ensuring the stability of the nitrogen system pressure.

[0077] Optionally, the pressure detection component P11 can be, but is not limited to, a pressure transmitter, pressure sensor, or other device used to detect the pressure inside the pipe. The pressure detection component P11 is interlocked with the valve assembly Q11 to adjust the nitrogen pressure. When the pressure inside the pipeline outputting nitrogen from the purification device 120 exceeds a preset nitrogen pressure range, a deviation signal is output. The control component, etc., sends a corresponding control command to the valve assembly Q11 based on the received deviation signal. Upon receiving the control command, the valve assembly Q11 automatically adjusts its opening to increase or decrease the nitrogen flow rate inside the pipe, thereby adjusting the pressure inside the pipe to the preset nitrogen pressure range. Interlocking the pressure detection component P11 and the valve assembly Q11, through this automatic adjustment mechanism, allows for rapid response and adjustment of the opening when the amount of nitrogen output from the purification device 120 changes, improving the convenience, accuracy, stability, and safety of operation and control, and ensuring stable nitrogen pressure in the system during operation. Specific embodiments of interlocking the pressure detection component and valve assembly in other embodiments of this application can be referred to in this section for further details, and will not be repeated here.

[0078] The remaining portion of the nitrogen output from the cooler 130 is discharged through the nitrogen output pipe within a preset nitrogen flow range. Optionally, a valve assembly Q12 is provided on the nitrogen output pipe, and a flow detection assembly P12 is provided on the nitrogen output pipe of the purification device 120. The flow detection assembly P12 is used to detect the nitrogen flow rate input to the purification device 120, and the valve assembly Q12 is used to operate within a preset nitrogen flow range so that the nitrogen flow rate input to the purification device 120 does not exceed the preset nitrogen flow range.

[0079] The flow detection component P12 can be, but is not limited to, any device suitable for detecting gas flow, such as a turbine flow meter, vortex flow meter, or target flow meter. Interlocking the flow detection component P12 with the valve assembly Q12 enables nitrogen flow control, ensuring the nitrogen flow rate meets process requirements and preventing excessive or insufficient flow from affecting subsequent processes or wasting resources. When the flow detected by the flow detection component P12 deviates from the preset nitrogen flow range, it outputs a deviation signal. The control component, etc., sends a corresponding control command to the valve assembly Q12 based on the received deviation signal. Upon receiving the control command, the valve assembly Q12 automatically adjusts its opening to increase or decrease the nitrogen flow rate in the pipe. Interlocking the flow detection component P12 with the valve assembly Q12, through this automatic adjustment mechanism, allows for rapid response and adjustment when the nitrogen flow rate changes, controlling the nitrogen flow within the set range and achieving stable nitrogen flow control. Specific embodiments of interlocking the flow detection component and valve assembly in other embodiments of this application can be referred to in this section for further details, and will not be repeated here.

[0080] It should be noted that, in the embodiments of this application, on the one hand, the purification device 120 is used to receive the oxygen to be recovered from the first separator 110, and after purification, outputs the purified oxygen to the oxygen inlet pipeline of the heat exchanger 200; on the other hand, nitrogen is used as a purging gas, heated by the heating device 500 and then input into the purification device 120. Purification is performed through the purification device 120, and by reducing the number of purification devices 120, the space occupied by the equipment can be reduced. In some alternative embodiments of this application, the purification device 120 specifically adopts a purifier, and the number of purifiers can be one or more, used to process the oxygen to be recovered through the same purifier, or to process the oxygen to be recovered through different purifiers; the specific configuration can be determined according to actual conditions and is not limited here.

[0081] In one embodiment, the first separator 110 has a first temperature detection component T1 on its inlet pipe, which is used to detect the temperature inside the inlet pipe. The cooler 130 has an exhaust pipe on its nitrogen inlet pipe, and a first valve component Q21 is provided on the exhaust pipe. The first valve component Q21 is used to operate within a preset operating temperature range so that the temperature inside the inlet pipe does not exceed the preset operating temperature range.

[0082] The first temperature detection component T1 is interlocked with the first valve component Q21 to adjust the temperature inside the intake pipe. By regulating the nitrogen discharged from the exhaust pipe of the cooler 130, the intake of the first separator 110 is indirectly controlled to ensure that the intake temperature remains within a safe preset operating temperature range. When the first temperature detection component detects that the temperature inside the intake pipe exceeds the preset operating temperature range, these valve components can increase or decrease the flow rate of the pipe by opening, closing, or adjusting the opening degree. This controls the exhaust flow rate of the pipe used to connect nitrogen to the cooler 130, ensuring that the temperature of the oxygen to be recovered entering the first separator 110 is within the preset operating temperature range. It also ensures that the first separator 110 and the cooler 130 can operate within a safe preset operating temperature range, avoiding equipment damage and performance impact caused by excessive temperature. This also ensures stable and safe system operation, and also ensures that the cooler 130 effectively processes the oxygen to be recovered, improves the quality of the oxygen to be recovered, and reduces energy consumption.

[0083] In one embodiment, a first flow detection component P2 is provided on the outlet pipe of the first separator 110, which is used to detect the flow rate inside the outlet pipe. A second valve component Q22 is provided on the inlet pipe, which is used to operate according to a preset oxygen flow rate range so that the flow rate inside the outlet pipe does not exceed the preset oxygen flow rate range.

[0084] The first separator 110 is used to separate the incoming oxygen into gas and liquid, and then output the oxygen after liquid separation through the outlet pipeline. A first flow detection component P2 is installed on the outlet pipeline of the first separator 110 for outputting the oxygen to be recovered. The first flow detection component P2 is used to detect the flow rate in the outlet pipeline in real time. The first flow detection component P2 is interlocked with the second valve component Q22 to adjust the flow rate in the outlet pipeline, ensuring that the gas flow rate is maintained within a safe preset range, so as to avoid system overload and ensure gas processing efficiency.

[0085] In one embodiment, the oxygen recovery device further includes a second separator 410, which is connected to the liquid oxygen outlet pipeline and is used to receive the liquid oxygen transmitted by the liquid oxygen outlet pipeline and to transmit the liquid oxygen after gas separation to the external liquid oxygen storage device 420.

[0086] The second separator 410 has a first inlet and a first outlet. The first inlet is connected to the liquid oxygen outlet pipeline and is used to receive liquid nitrogen from the liquid oxygen outlet pipeline of the heat exchanger 200. The first outlet is connected to an external liquid oxygen storage device 420. The second separator 410 is used to separate the liquid oxygen, removing the gas from it, and then transmits the liquid oxygen to the external liquid oxygen storage device 420 through the first outlet. Optionally, a throttling valve Q6 or other valve assembly is provided between the second separator 410 and the liquid oxygen outlet pipeline. The second separator 410 performs gas-liquid separation on the throttled liquid oxygen, allowing the separated liquid oxygen to be directly stored as a product in the liquid oxygen outlet device. Because different gases have different boiling points, the second separator 410 also has the function of removing gaseous impurities. Before the liquid oxygen is recycled, it is first separated by the second separator 410. This process can remove nitrogen or other gaseous impurities from the liquid oxygen, resulting in higher purity liquid oxygen, improving oxygen utilization and reducing energy waste. It can also be used to further apply liquid oxygen in fields such as medical treatment, chemical industry, and metal processing. Because liquid oxygen has high economic value, this process can further improve economic efficiency.

[0087] In one embodiment, the second separator 410 is provided with a venting pipe, and the gas separated by the second separator 410 is discharged through the venting pipe according to a preset venting pressure range.

[0088] The venting pipeline allows gaseous impurities in the second separator 410 to be released. The venting pipeline is designed with pressure regulation to maintain stable pressure within the second separator 410. Optionally, the venting pipeline is equipped with a pressure detection component P3 and a valve component Q3. Valve component Q3 operates within a preset venting pressure range. Interlocking pressure detection component P3 and valve component Q3 allows for adjustment of the venting pressure. Specifically, based on the pressure detection results of the venting pipeline by pressure detection component P3, the opening of valve component Q3 is adjusted to automatically regulate and control the venting pressure. This improves system response speed and control accuracy, ensuring the detected venting pressure remains within the preset venting pressure range, preventing equipment damage and safety accidents caused by excessive pressure, thus providing equipment safety protection and further ensuring pressure stability within the oxygen system.

[0089] A third valve assembly Q41 is provided on the connecting pipeline between the second separator 410 and the external liquid oxygen storage device 420, and is implemented in at least one of the following embodiments:

[0090] As an example, the third valve assembly Q41 is used to operate according to a preset separator level so that the level of the second separator 410 does not exceed the preset separator level range.

[0091] As another example, the third valve assembly Q41 is used to operate according to a preset liquid oxygen level range so that the liquid level of the external liquid oxygen storage device 420 does not exceed the preset liquid oxygen level range.

[0092] Optionally, the second separator 410 is provided with a liquid level detection component L1, which is used to detect the liquid level of the second separator 410. In some other alternative embodiments of this application, a liquid level detection component can also be provided corresponding to the external liquid oxygen storage device 420. The liquid level detection component L1 and the third valve component Q41 are interlocked to achieve liquid level control. The third valve component is used to control the opening degree of the third valve component based at least on the liquid level of the second separator 410 (and the liquid level of the liquid oxygen storage device 420), so that the liquid level of the second separator 410 does not exceed a preset separator liquid level range, and the liquid level of the external liquid oxygen storage device 420 does not exceed a preset liquid oxygen storage liquid level range. When the liquid level of the second separator 410 detected by the liquid level detection component L1 deviates from the preset separator liquid level range, a deviation signal is output. The control component, etc., sends a corresponding control command to the third valve component Q41 based on the received deviation signal, so that the third valve component Q41 automatically adjusts its opening degree after receiving the control command to increase or decrease the liquid oxygen flow rate in the pipe. Interlocking the liquid level detection component L1 with the third valve component Q41 enables an automatic adjustment mechanism that allows for rapid response and adjustment when the liquid levels of the second separator 410 and / or the liquid oxygen storage device 420 are abnormal. This controls the liquid level of the second separator 410 within a preset separator level range and the liquid level of the external liquid oxygen storage device 420 within a preset liquid oxygen storage level range, achieving stable control of the liquid oxygen level. Specific embodiments of interlocking the flow detection component with the valve component in other embodiments of this application can be found in this section, and will not be described in detail here.

[0093] Reference Figure 1 In one embodiment, a switching valve Q42 is provided between the second separator 410 and the external liquid oxygen storage device 420. The switching valve Q42 is used to control the connection of the pipeline between the second separator 410 and the external liquid oxygen storage device 420 when a running signal is received.

[0094] In another embodiment, the second separator 410 is provided with a liquid level detection component L1, which is used to detect the liquid level of the second separator 410 and output a liquid level detection signal (or a liquid level detection component provided in the liquid oxygen storage device 420 is used to detect the liquid level of the liquid oxygen storage device 420 and output a liquid level detection signal). A switching valve Q42 is provided between the second separator 410 and the external liquid oxygen storage device 420, which is used to control the connection or disconnection of the pipeline between the second separator 410 and the external liquid oxygen storage device 420 according to the liquid level detection signal.

[0095] Understandably, before startup, all valve components, flow detection components, pressure detection components, and temperature detection components of the oxygen recovery device are in the closed state. After startup, the liquid level detection component L1 first determines that the liquid level of the second separator 410 has reached the normal level (and / or the liquid level detection component located in the liquid oxygen storage device 420 determines that the liquid level of the liquid oxygen storage device 420 has reached the normal level), and / or after receiving the operation signal, the switch valve Q42 is then controlled to open to start operation. The switch valve Q42 is used to control the opening of the switch valve only after determining that the liquid level has reached the normal level and that operation is required. The switch valve Q42 can be used as a startup switch valve to prevent gas from entering the liquid oxygen storage device 420, improving system safety and stability; it can also be used as an emergency switch valve to connect or disconnect the pipeline between the second separator 410 and the liquid oxygen storage device 420, preventing liquid level imbalance between the second separator 410 and the liquid oxygen storage device 420.

[0096] In one embodiment, the heat exchanger 200 further includes a nitrogen outlet line for discharging nitrogen generated after heat exchange.

[0097] A second temperature detection component T2 is provided on the nitrogen outlet pipeline. The second temperature detection component T2 is used to detect the temperature inside the nitrogen outlet pipeline. A fourth valve assembly is provided on the cold source inlet pipeline. The fourth valve assembly is used to operate according to a preset first temperature range so that the temperature inside the nitrogen outlet pipeline does not exceed the preset first temperature range.

[0098] The fourth valve assembly is also used to control the shut-off of the cold source pipeline when the temperature inside the nitrogen outlet pipeline is not greater than a preset second temperature.

[0099] The second temperature is not greater than the minimum value of the first temperature range.

[0100] The fourth valve assembly can be controlled by one or more valve assemblies. When there is one valve assembly, it can be controlled by a regulating valve (electrically, pneumatically, or hydraulically driven, used to adjust the opening degree according to the control signal, thereby controlling the fluid flow), a proportional-integral-derivative (PID) controller (used to automatically adjust the valve opening degree according to the deviation of the detected pipe temperature from the preset operating temperature range), an intelligent controller, or a control system integration, etc. When there are multiple valve assemblies, they can be on / off valves (containing only two states: fully open or fully closed), regulating valves (electrically, pneumatically, or hydraulically driven, used to adjust the opening degree according to the control signal, thereby controlling the fluid flow), proportional-integral-derivative (PID) controllers (used to automatically adjust the valve opening degree according to the deviation of the detected pipe temperature from the preset operating temperature range), intelligent controllers, or control system integration, etc. Taking the fourth valve assembly, which uses a combination of regulating valve Q51 and on / off valve Q52, as an example, the nitrogen outlet pipeline is used to discharge nitrogen after heat exchange. A second temperature detection component T2 is installed on the nitrogen outlet pipeline of the heat exchanger 200. The second temperature detection component T2 is used to detect the temperature inside the nitrogen outlet pipeline. The second temperature detection component T2 and the fourth valve assembly are interlocked to control the temperature inside the nitrogen outlet pipeline and further ensure the stability of the prepared liquid oxygen temperature. The opening of the cold source inlet pipeline is controlled by regulating valve Q51 to maintain the temperature inside the nitrogen outlet pipeline within a preset first temperature range. This configuration allows for control of the nitrogen outlet pipe temperature, ensuring that the temperature of the nitrogen discharged from the heat exchanger 200 does not exceed a preset first temperature range. It also ensures that the heat exchanger 200 and cooler 130 operate within a safe temperature range that allows for efficient recovery, preventing excessively high temperatures from affecting recovery efficiency or even damaging the equipment and impacting performance. Furthermore, it ensures that the cooler 130 effectively processes the oxygen to be recovered, maintains a stable temperature for the prepared liquid oxygen, improves the quality of the oxygen to be recovered, and reduces energy consumption.

[0101] Understandably, when the outlet nitrogen temperature is below the second temperature, it means that there is already sufficient cooling capacity in the system. Continuing to add liquid nitrogen will not only fail to improve efficiency but will also waste resources. Because the temperature of liquid nitrogen is extremely low, if the outlet nitrogen temperature is already below 0°C, continuing to add liquid nitrogen may cause overcooling of the pipes or equipment in contact with the liquid nitrogen, or even damage such as material brittleness, affecting the safety and reliability of system operation and increasing maintenance costs. Therefore, the opening degree of the cold source inlet pipe is determined by the first temperature range, and the second temperature is used to determine whether to shut off the cold source inlet pipe and stop the cold source from entering. The second temperature is set to be no greater than the minimum value of the first temperature range. Specifically, the first temperature range is set to any temperature range including the range of 0℃ to 5℃, and the second temperature is set to 0℃ or any other temperature suitable for actual use. The second temperature detection component T2 and the switching valve Q52 are interlocked. When the second temperature detection component T2 detects that the temperature of the nitrogen outlet reaches 0℃ or other preset second temperature, the switching valve Q52 is controlled to close, so as to further control the shut-off of the cold source inlet pipe and control the stop of liquid nitrogen entering, thereby realizing the control of the nitrogen outlet temperature and ensuring the safe and stable operation of the system.

[0102] In one embodiment, a third temperature detection component T3 is provided on the liquid oxygen outlet pipeline, which is used to detect the temperature inside the liquid oxygen outlet pipeline. A fifth valve component Q51 is provided on the cold source inlet pipeline, which is used to operate according to a preset third temperature range so that the temperature inside the liquid oxygen outlet pipeline does not exceed the preset third temperature range.

[0103] Optionally, the third temperature range can be any temperature range not exceeding -183℃ or any other temperature range suitable for practical use. The third temperature detection component T3 and the fifth valve component Q51 are interlocked to control the temperature inside the liquid oxygen outlet pipeline. The liquid oxygen outlet pipeline is used to discharge the liquid oxygen generated after heat exchange. The heat exchanger 200 has a third temperature detection component T3 on its liquid oxygen outlet pipeline. The third temperature detection component T3 is used to detect the temperature inside the liquid oxygen outlet pipeline to keep it within the preset third temperature range, thereby controlling the liquid oxygen outlet temperature. This configuration allows for the control of the internal temperature of the liquid oxygen outlet pipeline to ensure that the temperature of the liquid oxygen discharged from the heat exchanger 200 does not exceed the preset third temperature. By controlling the amount of liquid nitrogen entering through the fifth valve assembly Q51, the temperature of the liquid oxygen outlet is maintained within a suitable third temperature range. This ensures the production and purity of liquid oxygen. It also prevents premature vaporization of liquid oxygen in the pipeline, thereby reducing energy consumption, improving energy efficiency, and preventing pipeline blockage caused by excessively low liquid oxygen temperatures, such as condensation and ice crystal formation. This effectively improves the efficiency of liquid oxygen production and ensures the safe and stable operation of the system.

[0104] In addition, a pressure detection component P4 and a throttle valve Q6 can be installed on the liquid oxygen outlet pipeline. The pressure detection component P4 is used to detect the pressure inside the liquid oxygen outlet pipeline, and the throttle valve Q6 is used to operate within a preset first pressure range. The pressure detection component P4 and the throttle valve Q6 are interlocked to ensure that the pressure inside the liquid oxygen outlet pipeline does not exceed the preset first pressure range. The throttle valve Q6 is used to throttle, cool, and depressurize the produced liquid oxygen. When the liquid oxygen passes through the throttle valve Q6, the flow rate increases and the pressure decreases, thereby achieving a cooling effect. During the throttling process, due to the pressure reduction, some components in the liquid oxygen will flash into gas, thereby achieving separation from the liquid oxygen and achieving the effect of flashing impurity gases. In addition, the throttle valve Q6 can also precisely control the flow rate of liquid oxygen, which is used to further optimize the safety and stability of the system by controlling the flow rate of liquid oxygen and the pressure inside the pipeline.

[0105] It should be noted that, in this application, the fifth valve assembly located on the cold source pipeline can be the same valve assembly or a different valve assembly than the aforementioned fourth valve assembly; this is not limited here.

[0106] In some other optional embodiments of this application, the oxygen recovery device further includes a control component. This control component is connected to the aforementioned valve assembly and detection component. Specifically, a control component can be set separately for each valve assembly and each interlocking relationship to achieve separate control of different valve assemblies and interlocking relationships; or, a control component can be set for at least some or all interlocking relationships to achieve integrated control. The control component includes a PLC or DCS controller, a programmable logic controller, etc., for processing valve and instrument signals. Optionally, the control component specifically includes a control circuit, a voltage and current detection circuit (or a power analysis circuit), a comparison circuit, a calculation circuit, etc., to control the valve assembly and other control devices in the pipeline based on the detection results of the detection component, for controlling the opening or closing of corresponding interfaces and pipelines, and for controlling the flow rate, pressure, temperature, etc. in the pipeline.

[0107] In the foregoing embodiments of this application, the valve assembly can be, but is not limited to, a switching valve (containing only two states: fully open or fully closed), a regulating valve (electrically, pneumatically, or hydraulically driven, used to adjust the opening degree according to a control signal, thereby controlling the flow rate of the fluid), a proportional-integral-derivative (PID) controller (used to automatically adjust the valve opening degree according to the deviation between the detected parameters and the preset operating parameter range), an intelligent controller, and a control system integration (including a control system integrating control components, at least one valve, etc., used to realize automatic control of the flow rate of fluid in the pipe). The pressure detection assembly can be, but is not limited to, a pressure transmitter, a pressure sensor, etc.; the temperature detection assembly can be, but is not limited to, a temperature transmitter, a temperature sensor, a metal thermometer, a pressure-temperature detector, etc.; the flow detection assembly can be, but is not limited to, a turbine flow meter, a vortex flow meter, a target flow meter, etc.; the level detection assembly can be, but is not limited to, a level gauge (such as a magnetic float level gauge, a glass tube level gauge, a radar level gauge, etc.), a level sensor, a differential pressure transmitter, etc. Specific configurations can be made according to actual conditions and are not limited here.

[0108] Reference Figures 1 to 4 This application also proposes an oxygen recovery system, which includes a hydrogen production device and an oxygen recovery device as described in the above embodiments. The hydrogen production device includes an electrolyzer 610, an oxygen-side gas-liquid separator 620, and a purification unit 100. The oxygen-evolving gas in the electrolyzer 610 is first separated by the oxygen-side gas-liquid separator 620 before entering the purification unit 100. Water is electrolyzed into gases (hydrogen and oxygen) in the electrolyzer. The evolved oxygen passes through the oxygen-side gas-liquid separator 620 to remove entrained liquid impurities before entering the purification unit 100 for further impurity removal and purity enhancement. The specific structure of the oxygen recovery device and the purification unit 100 is as described in the above embodiments. Since the oxygen recovery system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0109] The specific implementation process of the oxygen recovery system in this application is as follows:

[0110] Before starting the machine, all valve components, flow detection components, pressure detection components, and temperature detection components of the oxygen recovery unit are in the closed state.

[0111] After powering on, first confirm that the oxygen system is functioning normally, then open the control valve Q42 to initiate operation. Specifically, keep the control valve Q42 closed to shut off the pipeline between the second separator 410 and the external liquid oxygen storage device 420; and simultaneously or sequentially execute steps one through five below:

[0112] Step 1: Interlock the first flow detection component P2 with the second valve component Q22 to adjust the flow rate in the outlet pipeline, ensuring that the flow rate in the outlet pipeline does not exceed the preset oxygen flow rate range, and ensuring that the oxygen flow rate is maintained within the safe preset range.

[0113] Step 2: Interlock the pressure detection component P3 with the valve component Q3 to adjust the venting pressure of the venting pipeline so that the detected venting pressure is within the preset venting pressure range.

[0114] Step 3: Interlock the second temperature detection component T2 and the fourth valve component to control the temperature inside the nitrogen outlet pipeline. Control the opening of the cold source pipeline by adjusting valve Q51 to keep the temperature inside the nitrogen outlet pipeline from exceeding the preset first temperature range, and further ensure the temperature stability of liquid oxygen.

[0115] Step 4: Interlock the third temperature detection component T3 and the fifth valve component Q51 to control the temperature inside the liquid oxygen pipeline. By controlling the temperature inside the liquid oxygen pipeline to not exceed the preset third temperature range, the temperature of the liquid oxygen is maintained within a suitable third temperature range to control the liquid oxygen temperature.

[0116] Step 5: Interlock the liquid level detection component L1 with the third valve component Q41 to control the liquid level of the second separator 410 within the preset separator liquid level range (and / or control the liquid level of the external liquid oxygen storage device 420 within the preset liquid oxygen storage level range), thereby achieving stable control of the liquid oxygen level.

[0117] After startup, the oxygen in heat exchanger 200 begins to cool down. When the temperature inside the liquid oxygen pipeline detected by the third temperature detection component T3 drops to -183℃, after completing steps one to five above, i.e., after confirming that the flow rate inside the outlet pipeline does not exceed the preset oxygen flow rate range, the venting pressure does not exceed the preset venting pressure range, the temperature inside the nitrogen outlet pipeline does not exceed the preset first temperature range, the temperature inside the liquid oxygen outlet pipeline does not exceed the preset third temperature range, and the liquid level in the second separator 410 does not exceed the preset separator liquid level range (and / or, the liquid level in the external liquid oxygen storage device 420 does not exceed the preset liquid oxygen storage liquid level range), it is further determined whether to run the system.

[0118] During system operation, the primary function is to determine that the nitrogen system is operating normally and, at least, that the liquid level in the hydrogen production unit has reached the normal level. Specifically, this can be achieved by first confirming, via the liquid level detection component L1, that the liquid level in the second separator 410 has reached the normal level (and / or by confirming, via the liquid level detection component located in the liquid oxygen storage device 420, that the liquid level in the liquid oxygen storage device 420 has reached the normal level), and / or by controlling the opening of the switching valve Q42 after receiving an operation signal, to initiate operation. Furthermore, the normal operation of the system is ensured through the implementation of at least one of the following schemes one through seven, or other alternative control schemes:

[0119] Option 1: Interlock the second temperature detection component T2 and the fourth valve component to control the temperature inside the nitrogen outlet pipeline. Control the opening of the cold source pipeline by adjusting valve Q51 to keep the temperature inside the nitrogen outlet pipeline from exceeding the preset first temperature range, and further ensure the temperature stability of liquid oxygen.

[0120] Option 2: Interlock the liquid level detection component L1 with the third valve component Q41 to control the liquid level of the second separator 410 within the preset separator liquid level range (and / or, control the liquid level of the external liquid oxygen storage device 420 within the preset liquid oxygen storage level range), thereby achieving stable control of the liquid oxygen level.

[0121] Option 3: Interlock the second temperature detection component T2 and the switching valve Q52. When the second temperature detection component T2 detects that the temperature of the nitrogen outlet reaches 0℃ or other preset second temperature, it controls the switching valve Q52 to close, so as to further control the shut-off of the cold source pipeline and achieve the control of the nitrogen outlet temperature.

[0122] Option 4: Interlock the first temperature detection component T1 with the first valve component Q21 to adjust the temperature inside the intake pipe. By controlling the exhaust flow of the pipeline used to access nitrogen in the cooler 130, ensure that the temperature of the oxygen to be recovered entering the first separator 110 is within the preset operating temperature range, and ensure that the first separator 110 and the cooler 130 can operate within a safe preset operating temperature range.

[0123] Option 5: Interlock the flow detection component P12 with the valve component Q12 to achieve nitrogen flow control, thereby ensuring that the nitrogen flow rate meets the process requirements and achieving stable control of the nitrogen flow rate.

[0124] Option 6: Interlock the pressure detection component P11 with the valve component Q11 to adjust the nitrogen pressure so that the pressure inside the pipeline of the purification device 120 used to output nitrogen does not exceed the preset nitrogen pressure range, thus ensuring the stability of the nitrogen system pressure.

[0125] Option 7: Interlock the pressure detection component P4 and the throttle valve Q6 to ensure that the pressure inside the liquid oxygen pipeline does not exceed the preset first pressure range, which is used to throttle, cool and depressurize the produced liquid oxygen.

[0126] When the system is operating normally, all valve components, flow detection components, pressure detection components, and temperature detection components of the oxygen recovery device are in the open state.

[0127] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. An oxygen recovery device, characterized in that, include: Air separation unit, used to output liquid nitrogen cold source; The purification section is used to receive the oxygen to be recovered, and to output purified oxygen after purification treatment. The heat exchanger has an oxygen inlet pipeline, a cold source inlet pipeline, and a liquid oxygen outlet pipeline. The oxygen inlet pipeline is connected to the purification unit for receiving the purified oxygen. The inlet cold source pipeline is used to connect to the liquid nitrogen cold source delivered by the air separation unit, to exchange heat and cool the purified oxygen to generate liquid oxygen, and the outlet liquid oxygen pipeline outputs the liquid oxygen.

2. The oxygen recovery device as described in claim 1, characterized in that, The purification unit includes a first separator, which has an inlet pipe and an outlet pipe. The first separator is used to receive the oxygen to be recovered through the inlet pipe and to output the separated liquid through the outlet pipe.

3. The oxygen recovery device as described in claim 2, characterized in that, The purification section further includes a purification device connected to the first separator. The purification device is used to receive the oxygen to be recovered from the first separator, and after purification, output it to the oxygen inlet pipeline.

4. The oxygen recovery device as described in claim 3, characterized in that, The heat exchanger also has a nitrogen outlet pipeline, through which the nitrogen generated after the liquid nitrogen cold source exchanges heat through the heat exchanger is output. The purification unit also includes a cooler connected to the nitrogen outlet pipeline. The cooler is used to receive nitrogen gas delivered by the nitrogen outlet pipeline. After cooling the oxygen to be recovered by the received nitrogen gas, the cooled oxygen is output to the first separator.

5. The oxygen recovery device as described in claim 4, characterized in that, The oxygen recovery device also includes a heating device, the cooler is used to output cooled nitrogen, at least a portion of the nitrogen output by the cooler is transferred to the purification device, and the heating device is provided on the connecting pipeline between the cooler and the purification device; The nitrogen gas, used as a purging gas, is heated by the heating device and then introduced into the purification device.

6. The oxygen recovery device as described in claim 4, characterized in that, The oxygen recovery device is equipped with a nitrogen output pipe, and other parts of the nitrogen output from the cooler are discharged through the nitrogen output pipe according to a preset nitrogen flow range.

7. The oxygen recovery device as described in claim 2, characterized in that, The first separator is equipped with a first temperature detection component on its air intake pipe, which is used to detect the temperature inside the air intake pipe. The purification unit also includes a cooler, and the cooler has an exhaust pipe on the pipeline for receiving nitrogen. The exhaust pipe is equipped with a first valve assembly, which is used to operate within a preset operating temperature range so that the temperature inside the intake pipe does not exceed the preset operating temperature range.

8. The oxygen recovery device as described in claim 2, characterized in that, The first separator is equipped with a first flow detection component on its outlet pipe, which is used to detect the flow rate inside the outlet pipe. The intake pipe is equipped with a second valve assembly, which is used to operate according to a preset oxygen flow range so that the flow rate in the outlet pipe does not exceed the preset oxygen flow range.

9. The oxygen recovery device as described in claim 1, characterized in that, The oxygen recovery device further includes a second separator, which is connected to the liquid oxygen outlet pipeline and is used to receive the liquid oxygen transmitted by the liquid oxygen outlet pipeline and to transmit the liquid oxygen after gas separation to an external liquid oxygen storage device.

10. The oxygen recovery device as described in claim 9, characterized in that, A third valve assembly is provided on the connection pipeline between the second separator and the external liquid oxygen storage device. This third valve assembly operates according to a preset separator liquid level to ensure that the liquid level in the second separator does not exceed the preset separator liquid level range; and / or, The third valve assembly is used to operate according to a preset liquid oxygen level range so that the liquid level of the external liquid oxygen storage device does not exceed the preset liquid oxygen storage level range.

11. The oxygen recovery device as described in claim 9, characterized in that, The second separator is equipped with a venting pipe, and the gas separated by the second separator is discharged through the venting pipe according to a preset venting pressure range.

12. The oxygen recovery device as described in claim 9, characterized in that, A switching valve is provided between the second separator and the external liquid oxygen storage device. The switching valve is used to control the connection of the pipeline between the second separator and the external liquid oxygen storage device when a running signal is received.

13. The oxygen recovery device according to any one of claims 1-12, characterized in that, The heat exchanger also has a nitrogen outlet pipeline, through which the nitrogen gas generated after heat exchange is output. The nitrogen outlet pipeline is equipped with a second temperature detection component, which is used to detect the temperature inside the nitrogen outlet pipeline. The cold source inlet pipeline is equipped with a fourth valve component, which is used to operate according to a preset first temperature range so that the temperature inside the nitrogen outlet pipeline does not exceed the preset first temperature range. The fourth valve assembly is also used to control the cold source inlet pipeline to shut off when the temperature inside the nitrogen outlet pipeline is not greater than a preset second temperature. Wherein, the second temperature is not greater than the minimum value of the first temperature range.

14. The oxygen recovery device according to any one of claims 1-12, characterized in that, A third temperature detection component is provided on the liquid oxygen outlet pipeline, which is used to detect the temperature inside the liquid oxygen outlet pipeline. The inlet cold source pipeline is equipped with a fifth valve assembly, which is used to operate within a preset third temperature range so that the temperature inside the outlet liquid oxygen pipeline does not exceed the preset third temperature range.

15. An oxygen recovery system, comprising a hydrogen production device and an oxygen recovery device as described in any one of claims 1-14, wherein the hydrogen production device comprises an electrolyzer, an oxygen-side gas-liquid separator, and the purification unit, wherein the oxygen-evolution side gas of the electrolyzer is first separated by the oxygen-side gas-liquid separator before entering the purification unit.

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