Oxygen recovery and recycling system and fuel cell
By designing an oxygen recovery and circulation system, the problem of low oxygen utilization in traditional PEM fuel cell systems for underwater unmanned surface vessels was solved, achieving efficient oxygen recovery and reuse, and extending the endurance of the unmanned surface vessels.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO CYCOL POWER TECH CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-06-26
AI Technical Summary
Traditional PEM fuel cell systems have low oxygen utilization rates in underwater unmanned surface vessels (USVs), which necessitates carrying more oxygen and cannot meet the requirements for long-term underwater operations.
Design an oxygen recovery and circulation system, including a first pipeline, a second pipeline, a water separator and storage tank, a hydrogen remover, and a circulation component, to achieve oxygen reuse by separating and recovering oxygen discharged from the fuel cell stack.
It improves oxygen utilization, reduces the amount of oxygen carried, and extends the endurance of unmanned surface vessels.
Smart Images
Figure CN224417767U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of fuel cells, and in particular to an oxygen recovery and circulation system and a fuel cell. Background Technology
[0002] Traditional PEM fuel cell systems use air as the source of cathode reactant gas, and the air is pressurized by a compressor to provide a high metering ratio to the PEM fuel cell system. The reacted cathode gas, along with water, is directly discharged into the atmosphere.
[0003] In underwater unmanned surface vessels (USVs), traditional air-supplying PEM fuel cell systems cannot meet the demands of prolonged underwater oxygen-free operations. Therefore, using a pure hydrogen-pure oxygen fuel cell system is an effective solution. However, pure hydrogen-pure oxygen fuel cell systems used in enclosed underwater environments cannot directly exhaust the cathode gas after the reaction, unlike traditional fuel cell systems; because the gas after the reaction contains a large amount of oxygen, oxygen utilization is low, requiring the transport of more oxygen. Utility Model Content
[0004] The purpose of this invention is to provide an oxygen recovery and circulation system and a fuel cell, so as to alleviate the technical problem of low oxygen utilization rate and the need to carry more oxygen in pure hydrogen and pure oxygen fuel cell systems.
[0005] This utility model provides an oxygen recovery and circulation system, including a first pipeline for connecting to a fuel cell stack, a second pipeline for connecting to a fuel cell stack, and a water distribution and storage device;
[0006] The second pipeline is connected to the water distribution and storage device, and a return pipeline connected to the first pipeline is provided on the water distribution and storage device;
[0007] A hydrogen remover and a circulation assembly are provided on the return pipeline. The circulation assembly is used to supply oxygen that has passed through the hydrogen remover into the first pipeline.
[0008] In an optional embodiment, an oxygen supply pipeline is also included, one end of which is used to connect to the oxygen supply system and the other end is used to connect to the first pipeline.
[0009] A first pressure reducing valve, a first proportional valve, and a first pressure sensor are sequentially installed along the oxygen flow direction on the oxygen supply pipeline.
[0010] In an optional embodiment, both the first pipeline and the second pipeline are connected to a humidifier; the oxygen in the first pipeline enters the fuel cell stack after passing through the humidifier, and the water and water vapor in the second pipeline pass through the humidifier and humidify the oxygen in the humidifier.
[0011] In an optional embodiment, a hydrogen sensor is provided on the water distribution and storage device.
[0012] In an optional embodiment, a first drainage pipe is also included, one end of which is connected to the water distribution reservoir and the other end is connected to the tail drain water tank, and a first drainage valve is provided on the first drainage pipe.
[0013] In an optional embodiment, a second drainage pipe is also included, one end of which is connected to the tailwater storage tank, and a second drainage valve is provided on the second drainage pipe.
[0014] In an optional embodiment, a drain pump is provided on the second drain pipe.
[0015] In an optional embodiment, a liquid level sensor is installed on the tailwater storage tank.
[0016] In an optional embodiment, the fuel cell stack is further included, the fuel cell stack having a first inlet and a first outlet, the first pipeline being connected to the first inlet and the first outlet being connected to the second pipeline.
[0017] The first and second pipelines of the oxygen recovery and circulation system provided by this utility model are used to connect to the fuel cell stack. When the mixed gas and water discharged from the fuel cell stack enter the water separator, the water separator can separate the gas and water. The separated gas can enter the first pipeline, thus realizing the recovery of oxygen and its return to the first pipeline, improving the oxygen utilization rate and reducing the amount of oxygen that needs to be carried.
[0018] The oxygen recovery and circulation system is a highly efficient oxygen recovery and circulation technology that separates oxygen and water vapor at the first outlet of the fuel cell stack, recovers the oxygen, and resupplyes it to the fuel cell stack, ensuring maximum oxygen utilization, reducing oxygen consumption, and optimizing system operating efficiency.
[0019] This invention provides a fuel cell, including the oxygen recovery and circulation system described in any of the foregoing embodiments.
[0020] Compared with the prior art, the fuel cell provided by this utility model has the oxygen recovery and circulation system provided by this utility model, and thus has all the beneficial effects of the oxygen recovery and circulation system provided by this utility model. Attached Figure Description
[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0022] Figure 1 A schematic diagram of the structure of the oxygen recovery and circulation system provided in an embodiment of this utility model.
[0023] Icons: 100-First pipeline; 200-Second pipeline; 300-Humidifier; 400-Water separator / storage unit; 500-Hydrogen sensor; 600-Hydrogen remover; 700-Return pipeline; 800-Circulation assembly; 900-Fuel cell stack; 110-Oxygen supply pipeline; 120-First pressure sensor; 130-First proportional valve; 140-First pressure reducing valve; 150-First drain pipeline; 160-Edge exhaust water tank; 170-Second drain pipeline; 180-First drain valve; 190-Drain pump; 210-Second drain valve. Detailed Implementation
[0024] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate a sequence number, nor should they be interpreted as indicating or implying relative importance.
[0025] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0026] In the description of this application, it should be noted that the terms "inner", "outer", "left", "right", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0027] In the description of this application, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.
[0028] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings.
[0029] Reference Figure 1 The present invention provides an oxygen recovery and circulation system, including a first pipeline 100 for connecting to a fuel cell stack 900, a second pipeline 200 for connecting to a fuel cell stack 900, and a water distribution and storage device 400.
[0030] The second pipeline 200 is connected to the water distribution and storage device 400, and a return pipeline 700 connected to the first pipeline 100 is provided on the water distribution and storage device 400.
[0031] A hydrogen remover 600 and a circulation assembly 800 are provided on the return pipeline 700. The circulation assembly 800 is used to supply oxygen that has passed through the hydrogen remover into the first pipeline 100.
[0032] In some embodiments, the first pipeline 100 and the second pipeline 200 of the oxygen recovery and circulation system are both connected to the fuel cell stack 900. Oxygen enters the fuel cell stack 900 from the first pipeline 100. After the reaction, the oxygen and the generated water enter the second pipeline 200 and then enter the water separator 400.
[0033] Water and oxygen are separated in the water separator 400. The oxygen in the water separator 400 enters the return pipe 700 and then enters the first pipe 100, thus realizing the recovery and reuse of oxygen. This can make efficient use of oxygen, reduce the weight of the unmanned surface vessel, and thus extend the endurance of the unmanned surface vessel.
[0034] In an optional embodiment, an oxygen supply pipeline 110 is also included, one end of which is used to connect to the oxygen supply system and the other end is used to connect to the first pipeline 100.
[0035] A first pressure reducing valve 140, a first proportional valve 130, and a first pressure sensor 120 are sequentially arranged on the oxygen supply pipeline 110 along the direction of oxygen flow.
[0036] The first pipeline 100 is connected to the oxygen supply pipeline 110, which is used to connect to a high-pressure oxygen cylinder. Oxygen is stored in the high-pressure oxygen cylinder by compression. The pressure of the oxygen inside the cylinder is generally above 350 bar. Under high pressure conditions, the volume of oxygen can be significantly reduced, facilitating storage. This is particularly suitable for space-constrained equipment such as underwater unmanned surface vessels, providing a large oxygen storage capacity in a small volume. The oxygen stored in the high-pressure cylinder is pressured to 1-2 MPa through the first pressure reducing valve 140 at the cylinder opening before being delivered to the fuel cell stack 900.
[0037] Oxygen passing through the first pressure reducing valve 140 passes through the first proportional valve 130. The first pressure sensor 120 collects the pressure of the oxygen passing through the first proportional valve 130, thereby realizing the pressure control of pure oxygen in the fuel cell system. When the fuel cell system is running, the fuel cell control system can adjust the oxygen flow of the fuel cell stack 900 in real time according to the different oxygen requirements of the system. This can ensure the precise supply of oxygen, keep the electrochemical reaction efficient and stable, and reduce oxygen waste.
[0038] In an optional embodiment, both the first pipeline 100 and the second pipeline 200 are connected to the humidifier 300; the oxygen in the first pipeline 100 enters the fuel cell stack 900 after passing through the humidifier 300, and the water and water vapor in the second pipeline 200 humidify the oxygen in the humidifier 300 after passing through the humidifier 300.
[0039] The proton exchange membrane (PEM) in a fuel cell stack 900 is a core component of the stack, typically using proton conductor materials such as Nafion. To ensure the conductivity and reaction efficiency of the electrolyte membrane, oxygen and hydrogen must maintain a certain level of humidity. If the oxygen is too dry, the proton exchange membrane will dry out, leading to a decrease in the stack's conductivity, which in turn affects the battery's output power and stability.
[0040] Humidifiers 300 are installed on both the first pipeline 100 and the second pipeline 200. The humidified oxygen enters the fuel cell stack 900. The wastewater and exhaust gas discharged from the fuel cell stack 900 enter the humidifiers 300. The water and water vapor humidify the oxygen, so that the humidification is completed before the oxygen enters the fuel cell stack 900.
[0041] The humidifier is a membrane tube humidifier, its core feature being its unique hollow hydrophilic membrane tube design. When dry oxygen flows through the inside of these membrane tubes, the oxygen is humidified. Simultaneously, the dry oxygen absorbs the heat from the excess oxygen released after the fuel cell stack reaction. On the outside of the membrane tubes, the moisture and heat from the reacted oxygen are transferred to the oxygen inside the membrane tubes. By bundling multiple such hollow membrane tubes together and fitting them with an outer shell, a membrane tube humidifier is constructed.
[0042] In an optional embodiment, a hydrogen sensor 500 is provided on the water distribution and storage device 400.
[0043] After the hydrogen-oxygen electrochemical reaction, the gas emitted from the cathode of the PEM fuel cell mainly consists of: oxygen (unreacted), water and water vapor, and a small amount of hydrogen. A water separator 400 separates the gas and water. The water separator 400 uses physical methods, such as cyclone separators, baffle separators, or a combination of various water separation methods, to separate liquid water from oxygen. The separated oxygen enters the oxygen supply line 110. A circulation assembly 800 is installed on the oxygen supply line 110. The circulation assembly 800 can be a circulation pump or an ejector, etc. The circulation assembly 800 supplies the oxygen from the oxygen supply line 110 into the first line 100, thereby improving the oxygen utilization efficiency.
[0044] Because the oxygen separated in the water separator 400 contains a small amount of hydrogen, if it is not removed in time, its accumulation will lead to an increase in the hydrogen concentration in the oxygen, which may cause safety problems once it reaches the explosion limit. Therefore, a hydrogen sensor 500 is installed at the outlet of the water separator 400 to detect the hydrogen concentration in the oxygen, and a hydrogen remover 600 is installed before the inlet of the circulation component. If catalytic combustion is used, the low concentration of hydrogen in the oxygen can be removed to ensure the safety of the system.
[0045] In an optional embodiment, a first drain pipe 150 is also included, one end of which is connected to the water distribution reservoir 400 and the other end is connected to the tail drain water tank 160. A first drain valve 180 is provided on the first drain pipe 150.
[0046] In some embodiments, one end of the first drain pipe 150 is connected to the water separator 400, and the other end is connected to the tail drain water tank 160. When water and gas discharged from the fuel cell stack 900 enter the water separator 400, the gas in the water separator 400 enters the return pipe 700. The water separated by the water separator 400 enters the tail drain water tank 160 from the first drain pipe 150. Water can enter the first drain pipe 150 and then enter the tail drain water tank 160.
[0047] Once the liquid water stored in the water distributor 400 reaches a certain height, the first drain valve 180 opens, and the liquid flows into the tail drain tank 160. The fuel cell controller can identify the water level in the water distributor 400 through the sensor installed on the water distributor 400, and control the opening and closing of the first drain valve 180 to ensure that only liquid water can enter the tail drain tank 160, preventing oxygen loss.
[0048] In an optional embodiment, a second drainage pipe 170 is also included, one end of which is connected to the tailwater storage tank 160, and a drainage pump 190 and a second drainage valve 210 are provided on the second drainage pipe 170.
[0049] In an optional embodiment, a drain pump 190 is provided on the second drain pipe 170.
[0050] In an optional embodiment, a liquid level sensor is provided on the tailwater storage tank 160.
[0051] In some embodiments, a second drain pipe 170 is provided on the tailrace water tank 160, and a second drain valve 210 is provided on the second drain pipe 170. A liquid level sensor is provided on the tailrace water tank 160. The fuel cell controller can identify the water level in the tailrace water tank 160 through the liquid level sensor and control the opening and closing of the second drain valve 210 and the drain pump 190. When the second drain valve 210 is opened, the drain pump 190 discharges the water in the tailrace water tank 160. The function of the drain pump 190 is to increase the pressure during drainage to overcome the water pressure underwater on the unmanned surface vessel. The second drain valve 210 is only opened during drainage to prevent seawater backflow.
[0052] In an optional embodiment, a fuel cell stack 900 is also included, the fuel cell stack 900 having a first inlet and a first outlet, the first pipeline 100 being connected to the first inlet and the first outlet being connected to the second pipeline 200.
[0053] In an optional implementation, an oxygen sensor is also included, which is used to detect the oxygen concentration in the environment in which the oxygen recovery and circulation system is located.
[0054] The first inlet of the fuel cell stack 900 is used for the entry of oxygen, and the first outlet is used for the discharge of water vapor and oxygen. After the water vapor enters the water separator 400, the water vapor liquefies and flows downward under the action of gravity. The water vapor separates from the oxygen, and the oxygen enters the return pipe 700.
[0055] To ensure that the oxygen concentration is within a safe range, the oxygen concentration sensor monitors the oxygen concentration in the system in real time to prevent the oxygen concentration from exceeding the limit.
[0056] The first pipeline 100 and the second pipeline 200 of the oxygen recovery and circulation system provided by this utility model are used to connect to the fuel cell stack 900. When the mixed gas and water discharged from the fuel cell stack 900 enter the water separator 400, the water separator 400 can separate the gas and water. The separated gas can enter the first pipeline 100, thus realizing the recovery of oxygen and its return to the first pipeline 100, improving the oxygen utilization rate and reducing the amount of oxygen that needs to be carried.
[0057] This invention provides a fuel cell, including the oxygen recovery and circulation system described in any of the foregoing embodiments.
[0058] Compared with the prior art, the fuel cell provided by this utility model has the oxygen recovery and circulation system provided by this utility model, and thus has all the beneficial effects of the oxygen recovery and circulation system provided by this utility model.
[0059] Pure oxygen fuel cell systems utilize pure oxygen, rather than oxygen from the air, for electrochemical reactions. In underwater environments, oxygen can be pre-stored and directly supplied via oxygen cylinders or tanks, thus solving the problem of unmanned surface vessels (UUVs) operating in oxygen-free environments. This is a significant advantage for UUVs because the oxygen carried within the UUV's cabin during underwater operations is limited and insufficient to meet the continuous power generation needs of the fuel cell system.
[0060] In a pure oxygen fuel cell system (POFC), oxygen is pre-stored in a high-pressure form, reducing the need for complex components related to air input in the fuel cell system (such as air filters and air compressors), thereby effectively reducing the system's size and weight. For unmanned underwater vehicles (UUVs), this reduction in size and weight directly improves the UUV's endurance.
[0061] In pure oxygen fuel cell systems (POFCs), the electrochemical reaction using pure oxygen and pure hydrogen results in significantly higher reaction efficiency than traditional PEM systems. For underwater unmanned surface vessels (USVs), this means POFCs can provide stable power for longer periods. Combined with efficient hydrothermal and energy management subsystems, this effectively enhances the endurance of USVs, making them particularly suitable for long-duration deep-sea exploration missions.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. An oxygen recovery and circulation system, characterized in that, It includes a first conduit (100) for connecting to the fuel cell stack (900), a second conduit (200) for connecting to the fuel cell stack (900), and a water distribution and storage device (400). The second pipeline (200) is connected to the water distribution reservoir (400), and a return pipeline (700) connected to the first pipeline (100) is provided on the water distribution reservoir (400). A hydrogen remover (600) and a circulation assembly (800) are provided on the return line (700), the circulation assembly (800) being used to supply oxygen that has passed through the hydrogen remover into the first line (100).
2. The oxygen recovery and circulation system according to claim 1, characterized in that, It also includes an oxygen supply pipeline (110), one end of which is used to connect to the oxygen supply system and the other end is used to connect to the first pipeline (100); A first pressure reducing valve (140), a first proportional valve (130), and a first pressure sensor (120) are sequentially arranged on the oxygen supply pipeline (110) along the direction of oxygen flow.
3. The oxygen recovery and circulation system according to claim 1, characterized in that, Both the first pipeline (100) and the second pipeline (200) are connected to the humidifier (300); the oxygen in the first pipeline (100) enters the fuel cell stack (900) after passing through the humidifier (300), and the water and water vapor in the second pipeline (200) pass through the humidifier (300) and humidify the oxygen in the humidifier (300).
4. The oxygen recovery and circulation system according to claim 1, characterized in that, A hydrogen sensor (500) is installed on the water distribution and storage device (400).
5. The oxygen recovery and circulation system according to claim 1, characterized in that, It also includes a first drainage pipe (150), one end of which is connected to the water distribution reservoir (400), and the other end is connected to the tail drain water tank (160). A first drainage valve (180) is provided on the first drainage pipe (150).
6. The oxygen recovery and circulation system according to claim 5, characterized in that, It also includes a second drainage pipe (170), one end of which is connected to the tail drain water tank (160), and a second drainage valve (210) is provided on the second drainage pipe (170).
7. The oxygen recovery and circulation system according to claim 6, characterized in that, A drainage pump (190) is installed on the second drainage pipe (170).
8. The oxygen recovery and circulation system according to claim 6, characterized in that, A liquid level sensor is installed on the tailwater storage tank (160).
9. The oxygen recovery and circulation system according to claim 8, characterized in that, It also includes a fuel cell stack (900) having a first inlet and a first outlet, the first pipeline (100) being connected to the first inlet and the first outlet being connected to the second pipeline (200).
10. A fuel cell, characterized in that, Includes the oxygen recovery and circulation system according to any one of claims 1-9.