A humidification system for a fuel cell

Abstract

The present application relates to fuel cell technology field, disclose a kind of humidification system of fuel cell, including electric pile, booster, air inlet pipe, air exhaust pipe, first water separator, first water storage tank, second water storage tank and humidifier, first water separator is connected to air exhaust pipe, first water separator is communicated with first water storage tank, humidifier is connected to air inlet pipe, first water storage tank is connected with first humidification pipeline between humidifier, second water storage tank is connected with second humidification pipeline between humidifier, select valve is provided on second humidification pipeline;It further includes controller, humidity meter is provided on air inlet pipe, first flowmeter is provided on first humidification pipeline, second flowmeter is provided on second humidification pipeline.When air is dry and the moisture of first humidification pipeline is insufficient to humidify air, controller controls select valve to open, by controlling the opening of select valve, it can be guaranteed that the moisture of first humidification pipeline, second humidification pipeline meets the humidification demand to air.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a humidification system for a fuel cell. Background Technology

[0002] Hydrogen fuel cells are power generation devices that use hydrogen as fuel and convert the chemical energy in the fuel directly into electrical energy through an electrochemical reaction. Among them, proton exchange membrane fuel cells (PEMFCs) have attracted much attention due to their characteristics such as fast start-up, high energy conversion rate, strong environmental adaptability, high power density, and relatively low operating temperature. They have a very broad application prospect in transportation, stationary power stations, portable power, and aerospace and defense fields.

[0003] When a PEMFC uses a solid polymer proton exchange membrane as the electrolyte, the current that the PEMFC can provide is directly related to the number of protons passing through the proton exchange membrane. Ohmic polarization will cause resistance to electromigration. To reduce this ohmic polarization, it is necessary to improve the proton conductivity of the proton exchange membrane. However, the conductivity of the proton exchange membrane based on the PFSA structure is almost linearly related to the water content. Therefore, if the proton exchange membrane cannot maintain sufficient humidity under gas purging during PEMFC operation, its proton conductivity will decrease, the internal resistance of the cell will increase, and the efficiency of the fuel cell will decrease. This makes it easier to generate heat and worsen the dry membrane phenomenon. In severe cases, it can lead to damage to the membrane electrode assembly and prevent the fuel cell from working properly.

[0004] To maintain the humidity of the proton exchange membrane and thus preserve battery performance, PEMFC water-cooled fuel cell stacks typically undergo external pre-humidification of the gas supplied to the stack to ensure sufficient water content in the proton exchange membrane. For example, patent application CN116864738A discloses a fuel cell spray humidification device, comprising: a water distributor, a water storage tank, a pre-humidification chamber, and a water pump; the inlet of the water distributor is connected to the turbine outlet of the expander, and the water outlet of the water distributor is connected to the water storage tank; water from the water storage tank enters the pre-humidification chamber under the action of the water pump; the pre-humidification chamber is connected to the air path of the fuel cell stack, and a one-way valve is installed on the pipeline connecting the pre-humidification chamber and the air path of the fuel cell stack; the humidified air discharged from the turbine of the expander passes through the water distributor to separate liquid water, which enters the water storage tank; the water from the water storage tank, under the action of the water pump, enters the pre-humidification chamber to humidify the incoming air; the humidified air then enters the air path of the fuel cell stack via the pre-humidified gas circuit.

[0005] The aforementioned fuel cell humidification device recovers moisture from the exhaust gas of the turbine through a water distributor, stores it in an outlet tank, and then uses it to humidify the incoming air, achieving a pre-humidification effect. The amount of water obtained after processing the exhaust gas by the water distributor is variable. Normally, air humidification involves providing a near-saturated humid gas. However, the moisture content of the air entering the fuel cell stack is variable due to factors such as air humidity, air pressure, velocity, and temperature. Therefore, the amount of moisture that needs to be replenished is also variable. When the air is dry and moisture levels are low, more moisture needs to be replenished, and the water from the exhaust gas distributor alone cannot meet the humidification requirements. Summary of the Invention

[0006] The purpose of this invention is to provide a humidification system for a fuel cell to solve the problem in the prior art where the moisture content in the air is variable, and when the air is dry and the moisture content is reduced, the water from the exhaust gas distributor alone cannot meet the humidification requirements of the air.

[0007] To achieve the above objectives, the present invention provides a humidification system for a fuel cell, including a fuel cell stack, a booster, an air intake pipe, and an air exhaust pipe, wherein the pressure wheel of the booster is connected to the air intake pipe, and the turbine of the booster is connected to the air exhaust pipe;

[0008] It also includes a first water distributor, a first water storage tank, a second water storage tank, and a humidifier. The first water distributor is connected to the air exhaust pipe, and the drain outlet of the first water distributor is connected to the first water storage tank. The exhaust outlet of the first water distributor is connected to a tailpipe. The humidifier is connected to the air intake pipe and is located between the pressure roller and the fuel cell stack. A first humidification pipeline is connected between the outlet of the first water storage tank and the humidifier. A second humidification pipeline is connected between the outlet of the second water storage tank and the humidifier. A selector valve is provided on the second humidification pipeline.

[0009] It also includes a controller, a hygrometer is provided on the air intake pipe between the pressure roller and the humidifier, a first flow meter is provided on the first humidification pipe, a second flow meter is provided on the second humidification pipe, the hygrometer, the first flow meter, the second flow meter, and the selector valve are all connected to the controller, and the controller is used to control the opening degree of the selector valve to adjust the working state of the second humidification pipe.

[0010] Preferably, the humidifier is connected to a first return water pipe, which is connected to the first water storage tank.

[0011] Preferably, the humidifier is further provided with an atomizing nozzle, and the first humidification pipe and the second humidification pipe are both connected to the atomizing nozzle.

[0012] Preferably, a water supply pipeline is connected between the outlet of the first water storage tank and the inlet of the second water storage tank, and an on / off valve is arranged on the water supply pipeline.

[0013] Preferably, an intercooler and a second water distributor are arranged sequentially along the air intake direction between the humidifier and the fuel cell stack on the air intake pipe, and a second return water pipe is connected between the drain outlet of the second water distributor and the first water storage tank.

[0014] Preferably, the device further includes a hydrogen tank and a third water distributor. The hydrogen tank is connected to the fuel cell stack via a hydrogen inlet pipe, the fuel cell stack is connected to the third water distributor via a hydrogen exhaust pipe, the drain outlet of the third water distributor is connected to the first water storage tank via a third return water pipeline, and the exhaust outlet of the third water distributor is connected to the hydrogen inlet pipe.

[0015] Preferably, it also includes an ultrafine filter, which is connected between the first water distributor and the first water storage tank.

[0016] Preferably, the system further includes an energy storage device connected to the first humidification pipeline, and the first flow meter is arranged between the energy storage device and the humidifier.

[0017] Preferably, an air filter is also connected to the air intake pipe, and the air filter is connected to the air intake side of the pressure roller.

[0018] Compared with existing technologies, the humidification system for a fuel cell according to an embodiment of the present invention has the following advantages: After the air discharged from the turbine side of the turbocharger undergoes gas-liquid separation in the first water separator, the moisture can be stored in the first water tank. Since the first water tank is connected to the humidifier via a first humidification pipeline, moisture can enter the humidifier to humidify the air entering the fuel cell stack via the pressure wheel. Additionally, the humidification system also includes a second water tank, which is connected to the humidifier via a second humidification pipeline. The controller obtains data from the first flow meter, the second flow meter, and the hygrometer, and uses this data to make judgments. The controller determines whether the water supplied by the first humidification pipeline meets the air humidification requirements. Based on the judgment structure, the selector valve can be controlled to open or close. Controlling the opening or closing of the selector valve allows water from the second water tank to selectively enter the humidifier. When there is enough water in the first humidification pipeline to humidify the air, the controller controls the selector valve to close, and the second humidification pipeline does not participate in the humidification operation. When the air is dry and there is insufficient water in the first humidification pipeline to humidify the air, the controller controls the selector valve to open. By controlling the opening degree of the selector valve, it can be ensured that the water entering the first and second humidification pipelines meets the air humidification requirements. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the humidification system of the fuel cell of the present invention.

[0020] In the diagram, 1. Fuel cell stack, 2. Supercharger, 3. Pressure roller, 4. Turbine, 5. Motor, 6. Air intake pipe, 7. Air exhaust pipe, 8. First water distributor, 9. First water tank, 10. Second water tank, 11. Humidifier, 12. Tail exhaust pipe, 13. First humidification pipe, 14. Second humidification pipe, 15. Selector valve, 16. Hygrometer, 17. First flow meter, 18. Second flow meter, 19. First return water pipe, 20. Atomizing nozzle, 21. Water supply pipe, 22. On / off valve, 23. Intercooler, 24. Second water distributor, 25. Second return water pipe, 26. Hydrogen tank, 27. Third water distributor, 28. Hydrogen intake pipe, 29. Hydrogen exhaust pipe, 30. Third return water pipe, 31. Ultrafine filter, 32. Accumulator, 33. Air filter. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0022] A preferred embodiment of the humidification system for a fuel cell according to the present invention, such as... Figure 1As shown, the humidification system of the fuel cell includes a stack 1, a booster 2, an air intake pipe 6, an air exhaust pipe 7, a first water distributor 8, a first water storage tank 9, a second water storage tank 10, and a humidifier 11. The stack 1 is the main structure of the fuel cell. The anode of the stack 1 is used to enter and exit hydrogen gas, and the cathode of the stack 1 is used to enter and exit air. The stack 1 is cooled by air cooling. The air intake pipe 6 and the air exhaust pipe 7 are both connected to the anode side of the stack 1.

[0023] The turbocharger 2 is a turbocharger structure. The turbocharger 2 includes a pressure roller 3, a turbine 4 and a motor 5. The motor 5 is connected between the pressure roller 3 and the turbine 4. The pressure roller 3 is connected to the air intake pipe 6 and the turbine 4 is connected to the air exhaust pipe 7. The air discharged from the air exhaust pipe 7 drives the turbine 4 to rotate. The turbine 4 drives the pressure roller 3 to work through the motor 5, which can compress the air in the air intake pipe 6.

[0024] The first water separator 8 is connected to the air exhaust pipe 7, and its drain outlet is connected to the first water storage tank 9. The exhaust outlet of the first water separator 8 is connected to the tailpipe 12. The first water separator 8 is used to separate liquid and gas in the exhaust air. The tailpipe 12 can discharge the gas from the separation point to the atmosphere, while the first water storage tank 9 can store the liquid discharged from the first water separator 8 and use the liquid to humidify the air entering the fuel cell stack 1.

[0025] The humidifier 11 is located between the pressure roller 3 and the fuel cell stack 1. A first humidification pipe 13 is connected between the outlet of the first water tank 9 and the humidifier 11, and a second humidification pipe 14 is connected between the outlet of the second water tank 10 and the humidifier 11. A selector valve 15 is installed on the second humidification pipe 14. Both the first humidification pipe 13 and the second humidification pipe 14 are used to deliver water into the humidifier 11 to humidify the air. The selector valve 15 is used to adjust the working state of the second humidification pipe 14. At the same time, by adjusting the opening of the selector valve 15, the amount of water entering the humidifier 11 through the second humidification pipe 14 can be adjusted.

[0026] The first water tank 9 and the second water tank 10 are both used to store water for humidifying the air. The humidifier 11 is connected between the pressure roller 3 and the fuel cell stack 1. The air compressed by the pressure roller 3 enters the humidifier 11 before entering the fuel cell stack 1, and is fully mixed with the water transported through the first humidification pipe 13 and the second humidification pipe 14 to humidify the air.

[0027] The humidification system of the fuel cell also includes a controller (not shown in the figure), a hygrometer 16, a first flow meter 17, and a second flow meter 18. The hygrometer 16, the first flow meter 17, the second flow meter 18, and the selector valve 15 are all connected to the controller. The hygrometer 16 is connected to the air intake pipe 6 and is located between the pressure roller 3 and the humidifier 11. The hygrometer 16 is used to detect the humidity of the gas after it has been compressed by the pressure roller 3, so that the controller can determine the amount of water required to reach saturation humidity under the given humidity, pressure, and temperature conditions.

[0028] The first flow meter 17 is installed in the first humidification pipeline 13, and the second flow meter 18 is installed in the second humidification pipeline 14. The first flow meter 17 is used to detect the water flow rate in the first humidification pipeline 13, and the second flow meter 18 is used to detect the water flow rate in the second humidification pipeline 14. The detected flow rate information is transmitted to the controller. The controller can determine whether the water delivered to the humidifier 11 meets the water volume requirement for air humidification based on the water flow rate. Based on the determination result, the controller transmits action information to the selector valve 15 to adjust the on / off state and the opening degree of the selector valve 15 during operation, thereby adjusting the working state of the second humidification pipeline 14.

[0029] The air discharged from the turbine 4 side of the turbocharger 2 of the fuel cell's humidification system enters the first water separator 8 for gas-liquid separation. The moisture can then be stored in the first water tank 9. Since the first water tank 9 is connected to the humidifier 11 via the first humidification pipeline 13, moisture can enter the humidifier 11 to humidify the air entering the fuel cell stack 1 via the pressure roller 3. Additionally, the humidification system also includes a second water tank 10, which is connected to the humidifier 11 via the second humidification pipeline 14. The controller receives data from the first flow meter 17, the second flow meter 18, and the hygrometer 16, and uses this data to determine whether the first humidification pipeline 13 needs replenishment. Whether the water content meets the air humidification requirements can be determined by controlling the opening and closing of the selective valve 15. Controlling the opening and closing of the selective valve 15 allows water in the second water tank 10 to selectively enter the humidifier 11. When the water in the first humidification pipeline 13 is sufficient to humidify the air, the controller controls the selective valve 15 to close, and the second humidification pipeline 14 does not participate in the humidification operation. When the air is dry and the water in the first humidification pipeline 13 is insufficient to humidify the air, the controller controls the selective valve 15 to open. By controlling the opening degree of the selective valve 15, it can be ensured that the water entering the first humidification pipeline 13 and the second humidification pipeline 14 meets the air humidification requirements.

[0030] Preferably, the humidifier 11 is connected to a first return water pipe 19, which is connected to the first water storage tank 9.

[0031] The water entering the humidifier 11 through the first humidification pipe 13 and the second humidification pipe 14 mixes with the air, but some of the water will condense into liquid and be stored in the humidifier 11. The first return water pipe 19 can transport the condensed liquid to the first water storage tank 9 to increase the water content of the first water storage tank 9 for air humidification.

[0032] Preferably, the humidifier 11 is also provided with an atomizing nozzle 20, and the first humidification pipe 13 and the second humidification pipe 14 are both connected to the atomizing nozzle 20.

[0033] The humidifier 11 is equipped with atomizing nozzles 20, which can atomize the water delivered by the first humidification pipe 13 and the second humidification pipe 14 into tiny droplets, making it easier to mix with the air.

[0034] Preferably, a water supply pipe 21 is connected between the outlet of the first water storage tank 9 and the inlet of the second water storage tank 10, and an on / off valve 22 is arranged on the water supply pipe 21.

[0035] A water supply pipe 21 connects the first water tank 9 and the second water tank 10. When there is too much water in the first water tank 9, the on / off valve 22 can be opened to transfer the excess water to the second water tank 10 for storage, thus preventing too much water from being transferred to the humidifier 11.

[0036] Excessive moisture in the air cannot be carried away in gaseous form, which can damage the battery. Furthermore, the oxygen concentration decreases, leading to a slower reaction rate in the fuel cell stack 1. In addition, excessive moisture increases the chance of contamination of the membrane electrode assembly (MEA). Harmful components such as metal ions, CO, and S from the environment, as well as metal ions generated within the battery, can diffuse to the electrode surface and membrane along with the excess moisture, causing metal ion poisoning of the membrane and catalyst. Therefore, the water replenishment pipe 21 effectively prevents excessive moisture from being delivered by the first humidification pipe 13.

[0037] Preferably, an intercooler 23 and a second water distributor 24 are arranged sequentially on the air intake pipe 6 between the humidifier 11 and the fuel cell stack 1 along the air intake direction. A second return water pipe 25 is connected between the drain outlet of the second water distributor 24 and the first water storage tank 9.

[0038] Intercooler 23 cools the air to ensure the oxygen temperature meets the operating requirements of fuel cell stack 1. After cooling the air, moisture in the air condenses into droplets. A second water distributor 24 is arranged between intercooler 23 and fuel cell stack 1 to collect the droplets. The collected droplets are then transported to the first water storage tank 9 via the second return water pipeline 25 to humidify the air and improve water utilization.

[0039] Preferably, it also includes a hydrogen tank 26 and a third water distributor 27. The hydrogen tank 26 is connected to the fuel cell stack 1 by a hydrogen inlet pipe 28. The fuel cell stack 1 is connected to the third water distributor 27 by a hydrogen exhaust pipe 29. The drain outlet of the third water distributor 27 is connected to the first water storage tank 9 by a third return water pipe 30. The exhaust outlet of the third water distributor 27 is connected to the hydrogen inlet pipe 28.

[0040] Some of the hydrogen entering fuel cell stack 1 will not react. This unreacted gas is discharged through hydrogen exhaust pipe 29. The hydrogen carries away moisture from fuel cell stack 1. The gas then enters the third water separator 27, which separates the liquid water from the hydrogen. The liquid water is then transported to the first water storage tank 9 through the third return water pipe 30 for storage, increasing the water source and improving water utilization. Furthermore, the exhaust port of the third water separator 27 is connected to the hydrogen inlet pipe 28, allowing the discharged hydrogen to re-enter fuel cell stack 1 for further reaction, thus improving hydrogen utilization.

[0041] Preferably, it also includes an ultrafine filter 31, which is connected between the first water distributor 8 and the first water storage tank 9.

[0042] During the reaction, the membrane electrode of the fuel cell stack 1 will degrade, and some metal ions will dissolve in the droplets and be discharged with the air. After the droplets undergo gas-liquid separation in the first water separator 8, the metal ions dissolve in the water. When the water enters the first water storage tank 9, the ultrafine filter 31 can filter the metal ions.

[0043] Preferably, it also includes an accumulator 32, which is connected to the first humidification pipeline 13, and a first flow meter 17 is arranged between the accumulator 32 and the humidifier 11.

[0044] An accumulator 32 is installed on the first humidification pipeline 13. The accumulator 32 can stabilize the pressure of water transported by the first humidification pipeline 13, ensuring that water is delivered to the humidifier 11 at a constant pressure. A first flow meter 17 is arranged between the accumulator 32 and the humidifier 11, which can accurately measure the amount of water transported by the first humidification pipeline 13.

[0045] Preferably, an air filter 33 is also connected to the air intake pipe 6, and the air filter 33 is connected to the air intake side of the pressure roller 3.

[0046] An air filter 33 is connected to the air intake pipe 6. The air filter 33 can filter out harmful components in the air to avoid damaging the fuel cell stack 1.

[0047] In summary, this invention provides a humidification system for a fuel cell. Air discharged from the turbine side of the turbocharger undergoes gas-liquid separation in a first water separator, allowing moisture to be stored in a first water tank. Since the first water tank is connected to a first humidification pipeline, moisture can enter the humidifier to humidify the air entering the fuel cell stack via the pressure wheel. Additionally, the humidification system also includes a second water tank, which is connected to the humidifier via a second humidification pipeline. The controller receives data from the first flow meter, the second flow meter, and the hygrometer, and uses this data to determine the first humidification... Whether the water replenished by the humidification pipeline meets the air humidification requirements can be determined by controlling the opening and closing of the selective valve based on the judgment structure. Controlling the opening and closing of the selective valve allows water in the second water tank to selectively enter the humidifier. When there is enough water in the first humidification pipeline to humidify the air, the controller controls the selective valve to close, and the second humidification pipeline does not participate in the humidification operation. When the air is dry and the water in the first humidification pipeline is insufficient to humidify the air, the controller controls the selective valve to open. By controlling the opening degree of the selective valve, it can be ensured that the water entering the first and second humidification pipelines meets the air humidification requirements.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A humidification system for a fuel cell, characterized in that, It includes a fuel cell stack (1), a turbocharger (2), an air intake pipe (6) and an air exhaust pipe (7), wherein the pressure wheel (3) of the turbocharger (2) is connected to the air intake pipe (6) and the turbine (4) of the turbocharger (2) is connected to the air exhaust pipe (7); It also includes a first water distributor (8), a first water storage tank (9), a second water storage tank (10), and a humidifier (11). The first water distributor (8) is connected to the air exhaust pipe (7). The drain outlet of the first water distributor (8) is connected to the first water storage tank (9). The exhaust outlet of the first water distributor (8) is connected to a tailpipe (12). The humidifier (11) is connected to the air intake pipe (6). The humidifier (11) is located between the pressure roller (3) and the fuel cell stack (1). The outlet of the first water storage tank (9) is connected to the humidifier (11) via a first humidification pipe (13). The outlet of the second water storage tank (10) is connected to the humidifier (11) via a second humidification pipe (14). A selector valve (15) is provided on the second humidification pipe (14). It also includes a controller. A hygrometer (16) is provided on the air intake pipe (6) between the pressure roller (3) and the humidifier (11). A first flow meter (17) is provided on the first humidification pipeline (13), and a second flow meter (18) is provided on the second humidification pipeline (14). The hygrometer (16), the first flow meter (17), the second flow meter (18), and the selector valve (15) are all connected to the controller. The controller is used to control the opening degree of the selector valve (15) to adjust the working state of the second humidification pipeline (14).

2. The humidification system for a fuel cell according to claim 1, characterized in that, The humidifier (11) is connected to a first return water pipe (19), which is connected to the first water storage tank (9).

3. The humidification system for a fuel cell according to claim 2, characterized in that, The humidifier (11) is also equipped with an atomizing nozzle (20), and the first humidification pipe (13) and the second humidification pipe (14) are both connected to the atomizing nozzle (20).

4. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, A water supply pipeline (21) is connected between the outlet of the first water storage tank (9) and the inlet of the second water storage tank (10), and an on / off valve (22) is arranged on the water supply pipeline (21).

5. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, An intercooler (23) and a second water distributor (24) are arranged sequentially on the air intake pipe (6) between the humidifier (11) and the fuel cell stack (1) along the air intake direction. The drain outlet of the second water distributor (24) is connected to the first water storage tank (9) by a second return water pipe (25).

6. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, It also includes a hydrogen tank (26) and a third water distributor (27). The hydrogen tank (26) is connected to the fuel cell stack (1) by a hydrogen inlet pipe (28). The fuel cell stack (1) is connected to the third water distributor (27) by a hydrogen exhaust pipe (29). The drain outlet of the third water distributor (27) is connected to the first water storage tank (9) by a third return water pipeline (30). The exhaust outlet of the third water distributor (27) is connected to the hydrogen inlet pipe (28).

7. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, It also includes an ultrafine filter (31), which is connected between the first water distributor (8) and the first water storage tank (9).

8. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, It also includes an energy storage device (32) connected to the first humidification pipeline (13), and the first flow meter (17) is arranged between the energy storage device (32) and the humidifier (11).

9. The humidification system for a fuel cell according to any one of claims 1-3, characterized in that, An air filter (33) is also connected to the air intake pipe (6), and the air filter (33) is connected to the air intake side of the pressure roller (3).

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