Closed-loop control method for anode of hydrogen fuel cell
By constructing a closed-loop circuit and using a water-gas separator and a hydrogen-water separator to separate unreacted hydrogen and water, and combining this with a steam generator to regulate humidity, the problem of hydrogen and water being discharged from the vehicle after the anode reaction of the fuel cell was solved, achieving efficient resource utilization and stable system operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WISDOM FUJIAN AUTOMOBILE CO LTD
- Filing Date
- 2026-01-14
- Publication Date
- 2026-04-10
AI Technical Summary
Existing fuel cells discharge unreacted hydrogen and water from the vehicle after the anode reaction, resulting in resource waste.
A closed-loop circuit is formed by a water-gas separator, a hydrogen-water separator, and a hydrogen circulation pump. Unreacted hydrogen and water are separated by the water-gas separator and the hydrogen-water separator. The hydrogen circulation pump recovers the dried hydrogen to the anode inlet of the fuel cell stack. Combined with the steam generator to adjust the wettability of the proton exchange membrane, a closed-loop circulation of hydrogen is achieved.
It improves energy efficiency, reduces resource waste, and ensures the stable operation and efficient energy conversion of fuel cell systems.
Smart Images
Figure CN121839773A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cells, and more specifically to a closed-loop control method for the anode of a hydrogen fuel cell. Background Technology
[0002] A fuel cell is a device that directly converts the chemical energy of fuel and oxidant into electrical energy through an electrochemical reaction. Its core principle breaks through the traditional energy conversion mode of combustion power generation. It continuously supplies fuel (such as hydrogen, methanol, natural gas, etc.) and oxidant (usually oxygen or air), and an oxidation-reduction reaction occurs under the action of an electrode catalyst, so that chemical energy is efficiently converted into electrical energy. Only water, carbon dioxide or a small amount of other byproducts are produced in the process. The energy conversion efficiency can reach 40%-60%, which is much higher than the efficiency of about 30% of internal combustion engines. Moreover, there is no combustion process, which significantly reduces heat loss and pollutant emissions.
[0003] A fuel cell typically consists of three parts: an anode, a cathode, and an electrolyte membrane. At the anode, fuel is catalytically decomposed into protons and electrons. Protons migrate through the electrolyte membrane to the cathode, while electrons form an electric current through an external circuit. Finally, at the cathode, they combine with the oxidant to produce water or other products. This design eliminates the need for mechanical transmission components, operates almost silently, and reacts rapidly, making it particularly suitable for applications requiring quick response. However, existing fuel cells produce unreacted hydrogen after the anode reaction. This unreacted hydrogen, along with the water produced, is typically discharged outside the vehicle, resulting in resource waste. Summary of the Invention
[0004] The purpose of this invention is to provide a closed-loop control method for the anode of a hydrogen fuel cell, which aims to improve the problem of unreacted hydrogen gas remaining after the anode reaction in the fuel cell. Unreacted hydrogen gas is usually discharged outside the vehicle along with the water produced by the reaction, causing resource waste.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: A closed-loop control method for the anode of a hydrogen fuel cell includes a fuel cell stack, a gas-liquid separator, a hydrogen-liquid separator, and a hydrogen circulation pump. The gas-liquid separator is connected to the anode outlet of the fuel cell stack, and the top outlet of the gas-liquid separator is connected to the inlet of the hydrogen-liquid separator. A hydrogen discharge valve is provided at the exhaust port of the gas-liquid separator. The exhaust port of the hydrogen-liquid separator is connected to the hydrogen circulation pump, which is connected to the first anode inlet of the fuel cell stack. A drain valve is provided at the bottom drain port of the hydrogen-liquid separator. Specifically, it includes the following steps: S01. The compressor drives the hydrogen in the hydrogen storage tank to enter the second anode inlet of the fuel cell stack after the pressure is reduced by the pressure reducing valve; S02. The hydrogen gas after reaction at the anode of the fuel cell stack enters the gas-liquid separator; S03. The gas-water separator separates hydrogen and nitrogen. Hydrogen enters the hydrogen-water separator through the top outlet, and nitrogen enters the exhaust pipe through the exhaust port. The timer periodically controls the exhaust valve to open the exhaust pipe and discharge nitrogen. S04. The hydrogen-water separator separates hydrogen gas and liquid water. The hydrogen gas is discharged through the top exhaust port of the hydrogen-water separator, and the liquid water is collected at the bottom drain port of the hydrogen-water separator. The liquid level sensor controls the drain valve to open the bottom drain port to drain the water. S05. The hydrogen circulation pump delivers hydrogen to the first inlet of the fuel cell stack; S06. Adjust the compressor speed and the power of the hydrogen circulation pump according to the load requirements of the fuel cell stack.
[0006] Furthermore, the drain outlet is connected to the return water tank, the outlet of the return water tank is connected to the water supply pipe, the water supply pipe is connected to the hydrogen circulation pump and the first inlet, and a steam generator is installed thereon.
[0007] Furthermore, it also includes the following steps, A01. Set the lower and upper threshold values for proton exchange membrane wettability; A02. The humidity sensor detects the wettability of the proton exchange membrane and determines whether it is between the lower threshold and the upper threshold. If it is less than the lower threshold, proceed to step A03; if it is greater than the upper threshold, proceed to step A04. A03. Reduce the opening of the drain valve, turn on the steam generator for 5 seconds, and determine whether the wettability of the proton exchange membrane is greater than the lower threshold. If yes, proceed to step A05; otherwise, proceed to step A06. A04. Increase the opening of the drain valve, shut down the steam generator, and return to step A2; A05. After maintaining the drain valve opening and the steam generator power for 10 seconds, turn off the steam generator, return the drain valve opening control to the liquid level sensor, and return to step A02. A06. Close the drain valve, increase the power of the steam generator, and after a 10-second delay, turn off the steam generator when the wettability of the proton exchange membrane exceeds the lower threshold. Return the control of the drain valve opening to the liquid level sensor and return to step A02.
[0008] Furthermore, the inlet and outlet of the return water tank are connected, and the horizontal height of the inlet of the return water tank is higher than the horizontal height of the outlet of the return water tank.
[0009] Furthermore, a hydrogen recovery tank is provided between the hydrogen-water separator and the hydrogen circulation pump.
[0010] Furthermore, step S05 also includes the following steps: S051. Is there hydrogen gas being input at the first inlet? If so, proceed to step S052. S052. Identify the hydrogen flow rate a at the first inlet and reduce the hydrogen output b from the hydrogen storage tank, where a equals b.
[0011] Furthermore, step S06 also includes the following steps: S061. Has the load requirement of the fuel cell stack changed? If so, proceed to step S062. Otherwise, maintain the power of the hydrogen circulation pump and the hydrogen output of the hydrogen storage tank. S062. Has the load demand of the fuel cell stack decreased? If so, maintain the power of the hydrogen circulation pump and reduce the hydrogen output of the hydrogen storage tank; otherwise, proceed to step S063. S063. The hydrogen circulation pump is operating at full power, increasing the opening of the drain valve to fill the hydrogen supply gap in the hydrogen storage tank.
[0012] Furthermore, both the drain valve and the hydrogen discharge valve are electromagnetically controlled valves.
[0013] Furthermore, the anode plate of the fuel cell stack has multiple parallel serpentine flow channels.
[0014] Furthermore, a sealing groove is provided on the side of the serpentine flow channel.
[0015] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: A water-gas separator, a hydrogen-water separator, and a hydrogen circulation pump form a recovery loop. The hydrogen after the reaction is absorbed, purified, and then output back to the anode inlet of the fuel cell stack. The hydrogen after the reaction contains unreacted hydrogen, water vapor, and trace amounts of nitrogen. The water-gas separator blocks the hydrogen, allowing nitrogen and trace amounts of hydrogen to pass through. The hydrogen enters the exhaust pipe to separate and remove impurities from the nitrogen and hydrogen. The hydrogen enters the hydrogen-water separator through the top outlet of the water-gas separator. The hydrogen-water separator uses the gravity of the water vapor to separate the hydrogen and liquid water. The dry hydrogen is discharged through the top exhaust port of the hydrogen-water separator. The hydrogen circulation pump drives the hydrogen into the anode inlet of the fuel cell stack, realizing a closed-loop circulation and improving energy utilization. Attached Figure Description
[0016] Figure 1 This is a system block diagram of the hydrogen fuel cell anode closed-loop control method described in this invention; Figure 2 This is a flowchart of the hydrogen fuel cell anode closed-loop control method described in this invention; Figure 3 This is a block diagram of the proton exchange membrane wettability adjustment in the hydrogen fuel cell anode closed-loop control method of the present invention; Figure 4 This is a flowchart illustrating step S05 of the hydrogen fuel cell anode closed-loop control method of the present invention. Figure 5This is a flowchart illustrating step S06 of the hydrogen fuel cell anode closed-loop control method of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0018] Additionally, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are all based on the orientation or positional relationship shown in the accompanying drawings. They are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element of the present invention must have a specific orientation. Therefore, they should not be construed as limitations on the present invention.
[0019] When an element is referred to as being "fixed to," "set on," or "contained on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to," it can be directly connected to or indirectly connected to that other element.
[0020] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Example
[0021] Please refer to Figure 1-5 As shown, this embodiment provides a closed-loop control method for the anode of a hydrogen fuel cell. Please refer to [the documentation / reference]. Figure 1 As shown, the system includes a fuel cell stack, a gas-liquid separator, a hydrogen-liquid separator, and a hydrogen circulation pump. The gas-liquid separator is connected to the anode outlet of the fuel cell stack. The top outlet of the gas-liquid separator is connected to the inlet of the hydrogen-liquid separator, and a hydrogen discharge valve is installed at the exhaust port of the gas-liquid separator. The exhaust port of the hydrogen-liquid separator is connected to the hydrogen circulation pump, which is connected to the first anode inlet of the fuel cell stack. A drain valve is installed at the bottom drain port of the hydrogen-liquid separator. In this embodiment, both the drain valve and the hydrogen discharge valve are electromagnetically controlled valves, facilitating intelligent opening control of the drain valve and the hydrogen discharge valve.
[0022] Please refer to Figure 2 As shown, the closed-loop control method for the anode of a hydrogen fuel cell specifically includes the following steps: S01. The compressor drives the hydrogen in the hydrogen storage tank to enter the second anode inlet of the fuel cell stack after the pressure is reduced by the pressure reducing valve; S02. The hydrogen gas after reaction at the anode of the fuel cell stack enters the gas-liquid separator; S03. The gas-water separator separates hydrogen and nitrogen. Hydrogen enters the hydrogen-water separator through the top outlet, and nitrogen enters the exhaust pipe through the exhaust port. The timer periodically controls the exhaust valve to open the exhaust pipe and discharge nitrogen. S04. The hydrogen-water separator separates hydrogen gas and liquid water. The hydrogen gas is discharged through the top exhaust port of the hydrogen-water separator, and the liquid water is collected at the bottom drain port of the hydrogen-water separator. The liquid level sensor controls the drain valve to open the bottom drain port to drain the water. S05. The hydrogen circulation pump delivers hydrogen to the first inlet of the fuel cell stack; S06. Adjust the compressor speed and the power of the hydrogen circulation pump according to the load requirements of the fuel cell stack.
[0023] A water-gas separator, a hydrogen-water separator, and a hydrogen circulation pump form a recovery loop. The hydrogen after the reaction is absorbed, purified, and then output back to the anode inlet of the fuel cell stack. The hydrogen after the reaction contains unreacted hydrogen, water vapor, and trace amounts of nitrogen. The water-gas separator blocks the hydrogen, allowing nitrogen and trace amounts of hydrogen to pass through. The hydrogen enters the exhaust pipe to separate and remove impurities from the nitrogen and hydrogen. The hydrogen enters the hydrogen-water separator through the top outlet of the water-gas separator. The hydrogen-water separator uses the gravity of the water vapor to separate the hydrogen and liquid water. The dry hydrogen is discharged through the top exhaust port of the hydrogen-water separator. The hydrogen circulation pump drives the hydrogen into the anode inlet of the fuel cell stack, realizing a closed-loop circulation and improving energy utilization.
[0024] The drain outlet connects to the return water tank, and the outlet of the return water tank connects to the water supply pipe. The water supply pipe is connected to the hydrogen circulation pump and the first inlet, and is equipped with a steam generator. The return water tank recovers liquid water, and the steam generator converts the liquid water into water vapor, which enters the output pipe of the hydrogen circulation pump, increasing the humidity of the hydrogen and thus regulating the wettability of the proton exchange membrane. The inlet of the return water tank is connected to the drain outlet, and the horizontal level of the inlet is higher than that of the outlet. By controlling the inlet of the return water tank to be at a higher position and the outlet at a lower position, it is ensured that the recovered water in the return water tank can supply water to the steam generator even when the water level is low.
[0025] Please refer to Figure 3 As shown, the hydrogen fuel cell anode closed-loop control method further includes the following steps: A01. Set the lower and upper threshold values for proton exchange membrane wettability; A02. The humidity sensor detects the wettability of the proton exchange membrane and determines whether it is between the lower threshold and the upper threshold. If it is less than the lower threshold, proceed to step A03; if it is greater than the upper threshold, proceed to step A04. A03. Reduce the opening of the drain valve, turn on the steam generator for 5 seconds, and determine whether the wettability of the proton exchange membrane is greater than the lower threshold. If yes, proceed to step A05; otherwise, proceed to step A06. Drive the steam generator with the initial power to humidify the hydrogen and increase the wettability of the proton exchange membrane.
[0026] A04. Increase the opening of the drain valve, shut down the steam generator, and return to step A2; A05. After maintaining the drain valve opening and the steam generator power for 10 seconds, turn off the steam generator, return the drain valve opening control to the liquid level sensor, and return to step A02. A06. Close the drain valve, increase the power of the steam generator, and after a 10-second delay, shut off the steam generator. The drain valve opening control is returned to the level sensor, and the process returns to step A02. If the initial power is insufficient to increase the proton exchange membrane wettability, close the drain valve, control the liquid water in the recovery loop to connect, increase the humidity of hydrogen at the front end of the hydrogen circulation pump, increase the power of the steam generator, and further increase the humidity of hydrogen at the rear end of the hydrogen circulation pump, thereby maximizing the proton exchange membrane wettability. Continue this process until the proton exchange membrane wettability exceeds the lower threshold, maintaining this level for 10 seconds to further increase the wettability.
[0027] A value below the lower threshold indicates that the proton exchange membrane's wettability is too low, while a value above the upper threshold indicates that the proton exchange membrane's wettability is too high. When low wettability is detected, the steam generator is turned on to use recovered hydrogen to increase the wettability of the proton exchange membrane. When wettability is too high, the opening of the drain valve is increased to reduce the accumulation of liquid water in the recovery loop, increase the dryness of the recovered hydrogen, and ensure that the proton exchange membrane is maintained in its high-efficiency operating range.
[0028] Furthermore, a hydrogen recovery tank is installed between the hydrogen-water separator and the hydrogen circulation pump. The hydrogen recovery tank recovers the dried hydrogen, providing power adjustment space for the hydrogen circulation pump and preventing the recovered hydrogen from accumulating in the recovery circuit when the hydrogen circulation pump is operating at low power, which would increase the pressure at the anode outlet of the fuel cell stack and damage the hydrogen exchange membrane.
[0029] Please refer to Figure 4 As shown, specifically, step S05 also includes the following steps: S051. Is there hydrogen gas being input at the first inlet? If so, proceed to step S052. S052. Identify the hydrogen flow rate 'a' at the first inlet and reduce the hydrogen output 'b' from the hydrogen storage tank, where 'a' equals 'b'. While ensuring the hydrogen supply to the fuel cell stack is met, utilize hydrogen recovery to reduce the hydrogen output from the storage tank, thereby extending the storage tank's lifespan and reducing costs.
[0030] Please refer to Figure 5As shown, specifically, step S06 further includes the following steps: S061. Has the load requirement of the fuel cell stack changed? If so, proceed to step S062. Otherwise, maintain the power of the hydrogen circulation pump and the hydrogen output of the hydrogen storage tank. S062. Has the load demand of the fuel cell stack decreased? If so, maintain the power of the hydrogen circulation pump and reduce the hydrogen output of the hydrogen storage tank. Otherwise, proceed to step S063. Under the condition of reduced load demand, prioritize the use of recycled hydrogen to further reduce the hydrogen consumption of the hydrogen storage tank, increase the service life of the hydrogen storage tank, and reduce costs.
[0031] S063. With the hydrogen circulation pump operating at full power, the opening of the drain valve is increased to address the hydrogen supply shortfall from the hydrogen storage tank. Under increased load demand, all recovered hydrogen is fed into the fuel cell stack, and the drain valve opening is increased to prevent excessive water accumulation in the recovery circuit, which could affect the performance of the hydrogen circulation pump. This maximizes the utilization of recovered hydrogen, minimizing hydrogen consumption in the storage tank, thereby extending its service life and reducing costs.
[0032] Furthermore, multiple parallel serpentine flow channels are formed on the anode plate of the fuel cell stack. These serpentine flow channels effectively reduce the flow resistance of the coolant and ensure uniform hydrogen distribution. Sealing grooves are formed on the sides of the serpentine flow channels. In this embodiment, the sealing grooves are 2.4 mm wide and 0.5 mm deep, used to seal the serpentine flow channels and prevent gas leakage.
[0033] Actual measurements show that the hydrogen fuel cell anode closed-loop control method disclosed in this embodiment, when started at -30℃, completes anode drainage within 30 seconds, and the stack output power stabilizes at over 95% of the rated value, achieving efficient hydrogen utilization, dynamic moisture removal, and stable system operation. In this embodiment, the lower threshold, upper threshold, hydrogen flow rate a, and hydrogen output b are all actual values set according to different systems, and are not specifically limited here.
[0034] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A closed-loop control method for the anode of a hydrogen fuel cell, characterized in that, The device includes a fuel cell stack, a gas-liquid separator, a hydrogen-liquid separator, and a hydrogen circulation pump. The gas-liquid separator is connected to the anode outlet of the fuel cell stack. The top outlet of the gas-liquid separator is connected to the inlet of the hydrogen-liquid separator. The exhaust port of the gas-liquid separator is equipped with a hydrogen discharge valve. The exhaust port of the hydrogen-liquid separator is connected to the hydrogen circulation pump. The hydrogen circulation pump is connected to the first anode inlet of the fuel cell stack. The bottom drain port of the hydrogen-liquid separator is equipped with a drain valve. Specifically, it includes the following steps: S01. The compressor drives the hydrogen in the hydrogen storage tank to enter the second anode inlet of the fuel cell stack after the pressure is reduced by the pressure reducing valve; S02. The hydrogen gas after reaction at the anode of the fuel cell stack enters the gas-liquid separator; S03. The gas-water separator separates hydrogen and nitrogen. Hydrogen enters the hydrogen-water separator through the top outlet, and nitrogen enters the exhaust pipe through the exhaust port. The timer periodically controls the exhaust valve to open the exhaust pipe and discharge nitrogen. S04. The hydrogen-water separator separates hydrogen gas and liquid water. The hydrogen gas is discharged through the top exhaust port of the hydrogen-water separator, and the liquid water is collected at the bottom drain port of the hydrogen-water separator. The liquid level sensor controls the drain valve to open the bottom drain port to drain the water. S05. The hydrogen circulation pump delivers hydrogen to the first inlet of the fuel cell stack; S06. Adjust the compressor speed and the power of the hydrogen circulation pump according to the load requirements of the fuel cell stack.
2. The hydrogen fuel cell anode closed-loop control method according to claim 1, characterized in that: The drain outlet is connected to the return water tank, the outlet of the return water tank is connected to the water supply pipe, the water supply pipe is connected to the hydrogen circulation pump and the first inlet, and is equipped with a steam generator.
3. The hydrogen fuel cell anode closed-loop control method according to claim 2, characterized in that: It also includes the following steps, A01. Set the lower and upper threshold values for proton exchange membrane wettability; A02. The humidity sensor detects the wettability of the proton exchange membrane and determines whether it is between the lower threshold and the upper threshold. If it is less than the lower threshold, proceed to step A03; if it is greater than the upper threshold, proceed to step A04. A03. Reduce the opening of the drain valve, turn on the steam generator for 5 seconds, and determine whether the wettability of the proton exchange membrane is greater than the lower threshold. If yes, proceed to step A05; otherwise, proceed to step A06. A04. Increase the opening of the drain valve, shut down the steam generator, and return to step A2; A05. After maintaining the drain valve opening and the steam generator power for 10 seconds, turn off the steam generator, return the drain valve opening control to the liquid level sensor, and return to step A02. A06. Close the drain valve, increase the power of the steam generator, and after a 10-second delay, turn off the steam generator when the wettability of the proton exchange membrane exceeds the lower threshold. Return the control of the drain valve opening to the liquid level sensor and return to step A02.
4. The hydrogen fuel cell anode closed-loop control method according to claim 2, characterized in that: The inlet and outlet of the return water tank are connected, and the horizontal height of the inlet of the return water tank is higher than the horizontal height of the outlet of the return water tank.
5. The hydrogen fuel cell anode closed-loop control method according to claim 1, characterized in that: A hydrogen recovery tank is installed between the hydrogen-water separator and the hydrogen circulation pump.
6. The hydrogen fuel cell anode closed-loop control method according to claim 5, characterized in that: Step S05 further includes the following steps: S051. Is there hydrogen gas being input at the first inlet? If so, proceed to step S052. S052. Identify the hydrogen flow rate a at the first inlet and reduce the hydrogen output b from the hydrogen storage tank, where a equals b.
7. The hydrogen fuel cell anode closed-loop control method according to claim 6, characterized in that: Step S06 further includes the following steps: S061. Has the load requirement of the fuel cell stack changed? If so, proceed to step S062. Otherwise, maintain the power of the hydrogen circulation pump and the hydrogen output of the hydrogen storage tank. S062. Has the load demand of the fuel cell stack decreased? If so, maintain the power of the hydrogen circulation pump and reduce the hydrogen output of the hydrogen storage tank; otherwise, proceed to step S063. S063. The hydrogen circulation pump is operating at full power, increasing the opening of the drain valve to fill the hydrogen supply gap in the hydrogen storage tank.
8. The hydrogen fuel cell anode closed-loop control method according to claim 1, characterized in that: Both the drain valve and the hydrogen discharge valve are electromagnetically controlled valves.
9. The closed-loop control method for the anode of a hydrogen fuel cell according to claim 1, characterized in that: The anode plate of the fuel cell stack has multiple parallel serpentine flow channels.
10. The hydrogen fuel cell anode closed-loop control method according to claim 9, characterized in that: The serpentine flow channel has a sealing groove on its side.