Fuel cell condensation recovery system and method of operation control

Abstract

The application relates to the technical field of fuel cells, in particular to a fuel cell condensation recovery system and an operation control method. The fuel cell condensation recovery system is used for a fuel cell stack, the fuel cell stack comprises a stack body, a stack air inlet end plate and a stack air outlet end plate; the fuel cell condensation recovery system comprises a gas-water separation assembly, a refrigeration assembly and a hydrogen recovery assembly; the gas-water separation assembly is communicated with a gas-water discharge pipeline; the refrigeration assembly is used for cooling the gas-water separation assembly, so that water vapor of a gas-water mixture discharged into the gas-water separation assembly is condensed to realize hydrogen separation; the hydrogen recovery assembly is connected to a gas outlet of the gas-water separation assembly and is used for recovering hydrogen in the gas-water separation assembly. The fuel cell condensation recovery system improves hydrogen utilization and improves the economy of fuel cell stack operation.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a fuel cell condensation recovery system and operation control method. Background Technology

[0002] A fuel cell is an electrochemical power generation device that directly converts the chemical energy of fuels such as hydrogen and various hydrogen-rich gases and oxidants into electrical energy through electrode reactions.

[0003] During operation at room temperature, the water inside a PEMFC (Proton Exchange Membrane Fuel Cell) stack primarily originates from the humidification water produced by the gas at the cathode / anode and the water generated by the electrochemical reaction on the cathode side. Water is discharged from the stack mainly through three methods: residual gas exhaust on the cathode side, pulsed exhaust on the cathode side, and pulsed exhaust on the anode side. Water transport within the stack includes "electro-dragging" and "reverse osmosis." During the reaction, the proton exchange membrane needs to be sufficiently wetted because protons generated in the anode catalyst layer are transported as hydrated protons (H3O+). Therefore, protons carry some water from the anode side to the cathode side; this process is called "electro-dragging." Since hydrogen protons and electrons react with oxygen in the cathode catalyst layer to produce water, while no water is generated on the anode side, a concentration difference exists between the two sides of the membrane. Water from the cathode side diffuses through the membrane to the anode side; this process is called "reverse osmosis." A large amount of liquid water accumulates in the GDL (Gas Diffusion Layer), hindering the supply of reactant gases and leading to a decrease in the stack voltage.

[0004] In sub-zero environments, if the heat generated by the chemical reaction during fuel cell startup is sufficient to support the discharge of water in gaseous or liquid form, the temperature will gradually rise to the normal operating temperature (70-80°C) as the reaction proceeds. If it is insufficient to support the discharge of water in gaseous or liquid form, ice will form, obstructing the passage of reactant gases, freezing the membrane electrode assembly, and causing the electrochemical reaction to stop. In severe cases of freezing, it can also cause irreversible damage to the membrane electrode assembly.

[0005] More importantly, during fuel cell operation, the supply of hydrogen fuel far exceeds the amount consumed in the reaction. Furthermore, in order to effectively remove the wastewater generated inside, the fuel cell periodically vents the gas to remove the wastewater, which leads to hydrogen waste and reduces hydrogen utilization efficiency. Summary of the Invention

[0006] This application provides a fuel cell condensation recovery system and operation control method, which improves hydrogen utilization and enhances the economic efficiency of fuel cell stack operation.

[0007] In a first aspect, this application provides a fuel cell condensation recovery system applied to a fuel cell stack, wherein the fuel cell stack includes a stack body, a stack inlet end plate, and a stack exhaust end plate, and the stack exhaust end plate is provided with gas and water discharge pipes; the fuel cell condensation recovery system includes:

[0008] Gas-water separation component, connected to the gas-water discharge pipe;

[0009] A refrigeration component is fitted to the gas-water separation component and is used to cool down and condense the water vapor in the gas-water separation component.

[0010] A hydrogen recovery component is connected to the outlet of the gas-water separation component and is used to recover hydrogen.

[0011] In some embodiments, the refrigeration assembly includes a semiconductor refrigeration integrated plate having a cold surface and a hot surface that are opposite to each other, and the gas-water separation assembly includes a semiconductor cold end exhaust plate and a negative pressure gas-water separation chamber disposed in the semiconductor cold end exhaust plate.

[0012] The hot side of the semiconductor cooling integrated plate is attached to the fuel cell stack exhaust end plate, and the cold side of the semiconductor cooling integrated plate is attached to the semiconductor cold end exhaust end plate.

[0013] In some embodiments, the fuel cell stack inlet end plate is provided with a hydrogen inlet pipe, characterized in that the hydrogen recovery assembly includes:

[0014] A hydrogen recovery pipeline, the first end of which is connected to the gas outlet of the gas-water separation chamber;

[0015] A gas extraction device is connected to the second end of the hydrogen recovery pipeline and is used to extract hydrogen from the gas-water separation chamber.

[0016] A hydrogen circulation pipeline, connecting the pumping device and the hydrogen inlet pipeline, is used to return the recovered hydrogen to the hydrogen inlet pipeline.

[0017] In some embodiments, the hydrogen circulation pipeline is provided with a hydrogen circulation valve, which is a one-way mechanical constant pressure valve. When the hydrogen pressure in the hydrogen circulation pipeline is greater than a preset pressure, the one-way mechanical constant pressure valve causes the hydrogen circulation pipeline to unidirectionally flow to the hydrogen inlet pipeline.

[0018] In some embodiments, it also includes:

[0019] A temperature detection component is used to detect the internal temperature of the gas-liquid separation component;

[0020] A control component, connected to the temperature detection component and the cooling component, is used to adjust the operation of the cooling component according to the temperature detected by the temperature detection component.

[0021] In some embodiments, the gas-water discharge pipeline is equipped with a hydrogen exhaust valve, the gas-water separation component is equipped with a drainage control valve, and the hydrogen recovery component is equipped with a recovery control valve. The hydrogen exhaust valve, the drainage control valve, and the recovery control valve are all connected to the control component and are opened and closed under the control of the control component.

[0022] In some embodiments, the gas-liquid separation assembly includes a liquid level detection assembly, which is connected to the control assembly. The control assembly is used to control the opening and closing of the drainage control valve based on the liquid level detected by the liquid level detection assembly.

[0023] Secondly, this application provides an operation control method applicable to the fuel cell condensation recovery system as described in any of the preceding claims, the operation control method comprising:

[0024] The gas-water mixture discharged from the fuel cell stack is condensed to separate the gas and water.

[0025] Collect the hydrogen gas after gas-water separation.

[0026] In some embodiments, the step of condensing the gas-water mixture discharged from the fuel cell stack to achieve gas-water separation includes the following prior to:

[0027] The operating status of the fuel cell stack is detected, and the gas-water discharge pipe is opened to discharge the gas-water mixture based on the operating status.

[0028] The operating status includes the output voltage of the fuel cell stack. When the output voltage is lower than a preset value, the gas-water discharge pipe is opened.

[0029] In some embodiments, the step of condensing the gas-water mixture discharged from the fuel cell stack body to achieve gas-water separation includes:

[0030] The temperature of the gas-water separation component is detected and the operation of the refrigeration component is adjusted.

[0031] In some embodiments, the step of collecting the hydrogen gas after gas-water separation includes:

[0032] Detect the liquid level in the gas-liquid separation component, and drain the water after the liquid level in the gas-liquid separation component is higher than the preset liquid level;

[0033] Hydrogen is discharged from the gas-water separation component after drainage is completed or after a preset time has elapsed since the gas-water mixture was introduced into the gas-water separation component through the gas-water discharge pipe.

[0034] Compared with the prior art, the technical solution provided in this application has the following advantages: Excess hydrogen is fed into the fuel cell body through the fuel cell inlet end plate for reaction. As the reaction proceeds, the generation and permeation of liquid water cause liquid water accumulation in the gas diffusion layer, affecting the supply of reactant gas, and the liquid water needs to be discharged. While discharging the accumulated water, excess hydrogen is also discharged. The high temperature generated by the battery reaction also causes some liquid water to evaporate into water vapor, that is, what is discharged from the gas-water discharge pipe is a mixture of hydrogen, water vapor, and liquid water. In order to separate and recover hydrogen, this application sets up a gas-water separation component connected to the gas-water discharge pipe, so that the gas-water mixture enters the gas-water separation component. Then, a cooling component is used to cool the gas-water separation component, so that the water vapor in the gas-water separation component condenses into liquid water, realizing the separation of hydrogen and water vapor. Finally, a hydrogen recovery component is used to extract and recover the hydrogen in the gas-water separation component, so as to recover and reuse the hydrogen discharged from the gas-water discharge pipe, improve the hydrogen utilization rate and the operating economy of the fuel cell.

[0035] The hydrogen recovery assembly preferably includes a pumping device, which draws hydrogen from the gas-water separation assembly to create a negative pressure, thereby accelerating the entry of the gas-water mixture from the fuel cell stack into the gas-water separation assembly and rapidly improving the operating efficiency of the fuel cell stack. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0039] Figure 1 This is a schematic diagram of a fuel cell condensation recovery system provided in one embodiment of this application;

[0040] Figure 2 A simplified control logic diagram of a fuel cell condensation recovery system;

[0041] Figure 3 This is a flowchart of an operation control method provided in one embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1-Inlet plate of fuel cell stack; 2-Fuel cell stack body; 3-Exhaust plate of fuel cell stack; 4-Semiconductor cooling integrated board; 5-Semiconductor cold end exhaust plate; 6-Gas-water separation chamber; 7-Water collector; 8-Ejector device; 9-Hydrogen inlet pipe; 10-Hydrogen circulation pipe; 11-Hydrogen recovery pipe; 12-Condensate collection pipe; 13-Gas-water discharge pipe; 14-Membrane electrode; 15-Bipolar plate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0046] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0047] To address the technical problem of low hydrogen utilization rate in existing fuel cell stacks, this application provides a fuel cell condensation recovery system and operation control method, which can realize hydrogen recovery and utilization, improve hydrogen utilization rate, and enhance the economic efficiency of fuel cell operation.

[0048] A fuel cell is essentially a power generation system that converts chemical energy into electrical energy. For proton exchange membrane fuel cells, a fuel supply system, oxidant system, power generation system, water management system, thermal management system, electrical system, and control system are required.

[0049] Proton exchange membrane fuel cells (PEMFCs) use a polymer membrane capable of conducting ions as the electrolyte, hence they are also called polymer electrolyte fuel cells (PEFCs), solid polymer fuel cells (SPFCs), or solid polymer electrolyte fuel cells (SPEFCs). Figure 1 As shown, a fuel cell stack typically includes a stack body 2, a stack inlet end plate 1, a stack outlet end plate 3, bipolar plates 15, and a membrane electrode assembly (MEA) 14. The MEA 14 consists of a proton exchange membrane and catalyst layers on both sides. The bipolar plates 15 (also called separators) provide gas flow channels, prevent hydrogen and oxygen from mixing in the cell chamber, and establish a current path between the series-connected anode and cathode. The MEA 14 consists of three parts: the proton exchange membrane, the catalyst layer, and the gas diffusion layer. In a fuel cell, the MEA 14 enables the chemical reaction between hydrogen and oxygen to produce water and generate electricity. The proton exchange membrane, as the core component of the MEA 14, isolates hydrogen and oxygen, conducts protons, and prevents electron transfer. The catalyst layer promotes the chemical reaction and improves reaction efficiency. The gas diffusion layer provides the reactant gases and collects the generated current.

[0050] The bipolar plate 15 serves to separate reactant gases, collect current, and conduct heat in the fuel cell. Combined with the membrane electrode 14, the bipolar plate 15 and the membrane electrode 14 together constitute the electrochemical reaction cell of the fuel cell. This application primarily uses an air-cooled fuel cell stack as an example. While cooling the fuel cell stack, the cooling air also provides the oxygen required for the reaction. Therefore, the main function of the stack inlet end plate 1 is to transport hydrogen. The gas-water discharge pipe 13 extends through the exhaust end plate to discharge excess hydrogen, liquid water, and water vapor generated by evaporation, preventing any impact on the cell's reaction efficiency.

[0051] like Figure 1As shown in the figure, this application provides a fuel cell condensation recovery system, which mainly includes a gas-water separation component, a refrigeration component, and a hydrogen recovery component. The gas-water separation component is located at one end of the fuel cell stack exhaust end plate 3 and is connected to the gas-water discharge pipe 13. The refrigeration component is used to cool the gas-water separation component, so that the water vapor in the gas-water mixture discharged into the gas-water separation component condenses and is separated from the hydrogen. The hydrogen recovery component is connected to the gas outlet of the gas-water separation component and is used to draw hydrogen from the gas-water separation component.

[0052] During the operation of the fuel cell stack, excess hydrogen is fed into the membrane electrode 14 inside the stack body 2 through the stack inlet plate 1 for reaction. As the reaction proceeds, the generation and permeation of liquid water cause liquid water accumulation in the gas diffusion layer, affecting the supply of reaction gas. It is necessary to discharge the liquid water. At the same time as discharging the accumulated water, excess hydrogen is also discharged. The high temperature generated by the battery reaction will also cause some of the liquid water to evaporate into water vapor. That is, what is discharged from the gas-water discharge pipe 13 is a mixture of hydrogen, water vapor and liquid water.

[0053] To separate and recover hydrogen, this application connects a gas-water separation component to a gas-water discharge pipe 13, allowing the gas-water mixture to enter the gas-water separation component after discharge. A refrigeration component is then used to cool the gas-water separation component, causing water vapor in the component to condense into liquid water, thus separating hydrogen and water vapor. Finally, a hydrogen recovery component is used to recover the hydrogen in the gas-water separation component, enabling the reuse of the hydrogen discharged from the gas-water discharge pipe 13. The recovered hydrogen can be reintroduced into the fuel cell stack body 2 through the fuel cell stack inlet end plate 1 for circulation, thereby improving hydrogen utilization and the economic efficiency of fuel cell operation.

[0054] Furthermore, the hydrogen recovery component preferably includes a suction device 8, which draws hydrogen from the gas-water separation component to generate negative pressure, thereby accelerating the entry of the gas-water mixture of the fuel cell stack into the gas-water separation component and rapidly improving the operating efficiency of the fuel cell stack.

[0055] In a preferred embodiment of this application, the cooling component employs a semiconductor cooling integration plate 4. The semiconductor cooling integration plate 4 has a hot side and a cold side. The cold side is attached to the gas-water separation component to cool it, causing water vapor to condense and separate from hydrogen. The hot side is attached to the fuel cell stack exhaust end plate 3 to heat the fuel cell stack. This prevents the problem that, in sub-zero temperatures, the heat generated by the chemical reaction during fuel cell stack startup is insufficient to support the discharge of water in a gaseous or liquid state, leading to damage to the membrane electrode 14 and reduced or even stopped reaction efficiency. This application utilizes the cold side of the semiconductor cooling integration plate 4 as the cooling component, fully leveraging the characteristics of semiconductor cooling. While cooling the gas-water separation component to promote water vapor condensation, the hot side of the semiconductor cooling integration plate 4 heats the fuel cell stack exhaust end plate 3, ensuring stable fuel cell stack reaction under low-temperature conditions.

[0056] In some embodiments, the hot side of the semiconductor support integrated plate and the stack exhaust end plate 3 are detachably connected so that after the fuel cell stack is operating stably, the stack exhaust end plate 3 and the semiconductor cooling integrated plate 4 can be separated to reduce the temperature rise of the fuel cell stack and ensure the stability of the battery reaction.

[0057] The gas-water separation assembly mainly includes a semiconductor cold-end exhaust plate 5 and a negative pressure gas-water separation chamber. The semiconductor cold-end exhaust plate 5 is a hollow shell structure, and the negative pressure gas-water separation chamber 6 is located inside the semiconductor cold-end exhaust plate 5. The gas-water discharge pipe 13 passes through the stack exhaust plate 3 and the semiconductor cold-end exhaust plate 5 in sequence and connects to the gas-water separation chamber 6, used to discharge the gas-water mixture composed of hydrogen, water vapor and liquid water accumulated in the stack body 2 to the gas-water separation chamber 6. The cold side of the semiconductor cooling integrated plate 4 is attached to the semiconductor cooling integrated plate 4, and the gas-water separation chamber 6 is cooled by cooling the semiconductor cold-end exhaust plate 5, promoting the condensation of water vapor in the gas-water separation chamber 6 and separating it from hydrogen. The hot side of the semiconductor cooling integrated plate 4 is attached to the stack exhaust plate 3, and the temperature inside the stack body 2 is increased by heating the stack exhaust plate 3, avoiding the fuel cell stack start-up temperature being too low in sub-zero low temperature environments, which would cause the reaction to stop and damage the membrane electrode 14.

[0058] In other words, in the above embodiments, a composite end plate consisting of a semiconductor cold-end exhaust end plate 5, a semiconductor refrigeration integrated plate 4, and a fuel cell stack exhaust end plate 3 is used to replace the traditional ordinary exhaust end plate structure. At the same time, a gas-water separation chamber 6 is set inside the semiconductor cold-end exhaust end plate 5. While the cold surface of the semiconductor refrigeration integrated plate 4 is used to cool the semiconductor cold-end exhaust end plate 5 and the gas-water separation chamber 6, the hot surface of the semiconductor refrigeration integrated plate 4 is used to heat the fuel cell stack, so as to ensure that the fuel cell stack can reach a stable operating temperature even when starting in a low-temperature environment, thereby improving the operational stability.

[0059] In some embodiments, the fuel cell stack is air-cooled. The cooling air cools the stack body 2 while also providing the oxygen required for the reaction. Therefore, the stack inlet end plate 1 only has a hydrogen inlet pipe 9, which supplies excess hydrogen required for the reaction to the stack body 2. The hydrogen reaches the membrane electrode 14 through the anode channel. Of course, the stack inlet end plate 1 can be equipped with an oxygen inlet pipe as needed, ensuring that oxygen can reach the reaction position through the cathode channel.

[0060] The hydrogen recovery assembly includes a hydrogen recovery pipe 11, an extraction device 8, and a hydrogen circulation pipe 10. The first end of the hydrogen recovery pipe 11 is connected to the outlet of the gas-water separation chamber 6, and the second end is connected to the extraction device 8. The extraction device 8 can be a vacuum pump or an ejector, etc., which generates negative pressure within the gas-water separation chamber 6 by suction, sealing and isolating the gas-water separation chamber 6 and the hydrogen recovery pipe 11, maintaining a negative pressure within the gas-water separation chamber 6 so that the gas-water mixture discharged from the gas-water discharge pipe 13 can enter the gas-water separation chamber 6 for condensation and separation. When hydrogen recovery is needed, the extraction device 8 is connected to the gas-water separation chamber 6 through the hydrogen recovery pipe 11, simultaneously extracting and recovering hydrogen while restoring the gas-water separation chamber 6 to a certain negative pressure. The hydrogen circulation pipe 10 delivers the recovered hydrogen to the hydrogen inlet pipe 9, realizing the recycling and reuse of hydrogen and improving its utilization rate.

[0061] Furthermore, the hydrogen circulation pipeline 10 is equipped with a hydrogen circulation valve, which is a one-way mechanical constant pressure valve. Only when the pressure output from the extraction device 8 to the hydrogen circulation pipeline 10 is greater than the preset pressure, such as the pressure of the hydrogen inlet pipeline 9, will the hydrogen circulation pipeline 10 and the hydrogen inlet pipeline 9 be connected in one direction. This ensures that the hydrogen output from the extraction device 8 can only be output from the hydrogen circulation pipeline 10 to the hydrogen inlet pipeline 9 in one direction, effectively preventing the hydrogen from the hydrogen inlet pipeline 9 from flowing back into the hydrogen circulation pipeline 10 and affecting the hydrogen recovery and utilization. At the same time, it also ensures the inlet pressure of the hydrogen inlet pipeline 9.

[0062] In some embodiments, the fuel cell condensation recovery system provided in this application further includes a temperature detection component and a control component. The temperature detection component can be disposed within the gas-liquid separation component and used to detect the temperature of the gas-liquid separation component. Exemplarily, the temperature detection component can be disposed inside the gas-liquid separation chamber 6 or between the outside of the gas-liquid separation chamber 6 and the inside of the semiconductor cold-end exhaust plate 5. Both the temperature detection component and the refrigeration component are connected to the control component so that the control component can adjust the operation of the refrigeration component according to the temperature detected by the temperature detection component, thereby maintaining a suitable low temperature within the gas-liquid separation component and promoting water vapor condensation and hydrogen and water vapor separation.

[0063] like Figure 2As shown, the control component can be a combination of a condensate recovery controller and a fuel cell stack controller. The condensate recovery controller and the fuel cell stack controller are connected and can exchange information. The gas-water discharge pipe 13 is equipped with a hydrogen exhaust valve; the gas-water separation component, i.e., the gas-water separation chamber 6, is connected to the condensate collection pipe 12 and the water collector 7. The condensate collection pipe 12 is equipped with a drain control valve; the hydrogen recovery pipe 11 of the hydrogen recovery component can be equipped with a recovery control valve. When the recovery control valve is open, it connects the extraction device 8 and the gas-water separation chamber 6 to facilitate the extraction and recovery of hydrogen. When the recovery control valve is closed, it seals the gas-water separation chamber 6, maintaining a negative pressure state in the gas-water separation chamber 6 so that the gas-water mixture discharged from the gas-water discharge pipe 13 can enter the gas-water separation chamber 6 for condensation and separation from hydrogen. The hydrogen inlet pipe 9 is also equipped with a hydrogen inlet valve. The hydrogen inlet valve, hydrogen exhaust valve, drain control valve and recovery control valve are all connected to the control component so that the control component can control the corresponding valves to open or close, discharge the gas-water mixture inside the fuel cell stack 2 to the gas-water separation component for condensation and separation, then discharge the separated liquid water to the water collector 7, and recover and transport the separated dry hydrogen to the hydrogen inlet pipe 9.

[0064] Continue reading Figure 2 The hydrogen inlet valve and hydrogen outlet valve can be connected to the fuel cell stack controller of the control component, so that the fuel cell stack controller can control the supply of hydrogen and the discharge of the gas-water mixture according to the operating status. For example, when the output voltage of the fuel cell stack drops below a preset value, the fuel cell stack controller controls the hydrogen outlet valve to open, discharging the gas-water mixture accumulated inside the stack body 2 to the gas-water separation component, thus preventing the gas-water mixture from affecting the reaction rate of the fuel cell stack. The drain control valve, recovery control valve, air extraction device 8, temperature detection component, refrigeration component, and negative pressure chamber environmental parameter detection of the gas-water separation component are all connected to the condensation recovery controller, so that the condensation recovery controller can control the operating parameters of the refrigeration component, discharge the wastewater after gas-water separation to the water collector 7, and pump and transport the hydrogen after gas-water separation to the hydrogen inlet pipe 9.

[0065] Furthermore, a liquid level detection component is provided inside the gas-liquid separation chamber 6. The liquid level detection component is connected to the condensation recovery controller of the control component and is used to feed back the detected liquid level information of the gas-liquid separation chamber 6 to the condensation recovery controller so that the condensation recovery controller can promptly control the drainage control valve to open and drain the water, thereby preventing the liquid level in the gas-liquid separation chamber 6 from being too high and affecting the entry of the gas-liquid mixture and the condensation efficiency of water vapor, thus improving the separation efficiency of hydrogen and water vapor.

[0066] See also Figure 1 and Figure 2 The operation process of the above-mentioned fuel cell condensation recovery system is as follows:

[0067] The fuel cell stack controller opens the hydrogen inlet valve, allowing hydrogen to flow through the anode channel to the anode inlet. It then diffuses through the diffusion layer to the catalyst layer, where it undergoes oxidation under the action of the Pt / C catalyst, generating hydrogen ions and releasing free electrons. The hydrogen ions are transported from the anode to the cathode by combining with acid radicals in the proton exchange membrane electrolyte, while the free electrons move from the anode to the cathode via the external circuit. Oxygen flows through the cathode channel to the cathode inlet, then diffuses through the diffusion layer to the catalyst layer. There, it undergoes reduction under the action of the catalyst, combining with free electrons from the external circuit and hydrogen ions from the anode to form water, releasing a large amount of heat.

[0068] During the reaction, the proton exchange membrane needs to be fully wetted because the protons generated in the anode catalyst layer are transported in the form of hydrated protons (H3O+). Therefore, the protons will carry some water from the anode side to the cathode side; this process is called "electro-dragging." Since hydrogen protons and electrons react with oxygen in the cathode catalyst layer to produce water, while no water is produced on the anode side, there is a concentration difference of water on both sides of the membrane. Water from the cathode side diffuses through the membrane to the anode side; this process is called "reverse osmosis."

[0069] Hydrogen flows from the fuel cell stack inlet end plate 1 into the fuel cell stack body 2. After undergoing the aforementioned reaction within the fuel cell stack, the hydrogen generates a large amount of gas-water mixture (50-60°C), which contains hydrogen, water vapor, and liquid accumulating water. The gas-water mixture passes through the gas-water discharge pipe 13, via the fuel cell stack exhaust end plate 3, the semiconductor cooling integrated plate 4, and the semiconductor cold end exhaust end plate 5, into the negative pressure gas-water separation chamber 6. After the water vapor condenses, it separates from the hydrogen to form dry hydrogen and condensate. The condensate enters the water collector 7 through the condensate collection pipe 12. The dry hydrogen then enters the extraction device 8 through the hydrogen recovery pipe 11, and is then sent back to the fuel cell stack's hydrogen inlet pipe 9 via the hydrogen circulation pipe 10, thus achieving hydrogen recovery and recycling.

[0070] After the condensation recovery controller powers on the semiconductor refrigeration integrated board 4, it lowers the temperature of the semiconductor cold-end exhaust plate 5 to (5-10°C), creating a temperature difference (45-50°C) with the gas-water mixture discharged from the fuel cell body 2. This causes rapid condensation, resulting in the separation of dry air and condensate. The negative pressure environment in the negative pressure gas-water separation chamber 6 is generated by the suction device 8, further accelerating the condensation of the gas-water mixture discharged from the fuel cell body 2 into dry hydrogen and condensate. Alternatively, the negative pressure gas-water separation chamber 6 can utilize various flow path environments. Simultaneously with the temperature reduction of the semiconductor cold-end exhaust plate 5, the temperature of the fuel cell exhaust plate 3 rises, causing the internal temperature of the fuel cell body 2 to quickly reach its normal operating temperature (70-80°C), further improving the fuel cell's adaptability and performance to ambient temperatures.

[0071] After the fuel cell stack is started, the fuel cell stack controller opens the hydrogen inlet valve, and the stack enters the operating state. The condensation recovery controller is activated at the same time and interacts with the fuel cell stack controller. The condensation recovery controller uses the electrical parameter information of the stack body 2 and the temperature detected by the temperature detection component to regulate the semiconductor refrigeration integrated plate 4, so that the temperature of the stack exhaust end plate 3 and the semiconductor cold end exhaust end plate 5 in the system is adjusted to the normal operating range.

[0072] Then, the extraction device 8 and the recovery control valve on the hydrogen recovery pipeline 11 are opened to create a negative pressure environment in the gas-water separation chamber 6. After 1-2 seconds, once the negative pressure environment is established and the design pressure is met, the recovery control valve is closed. At this time, the system waits for the exhaust action signal from the fuel cell stack controller. Upon receiving the exhaust action signal from the fuel cell stack controller, the system enters a condensation delay state of 2 seconds to ensure that the water vapor discharged into the gas-water separation chamber 6 is fully condensed. The liquid level detection component detects the liquid level in the gas-water separation chamber 6. If the upper limit signal detection condition of the liquid level in the gas-water separation chamber 6 is met at this state, that is, the liquid level is higher than the preset liquid level, the drain control valve is triggered to open for 1 second to discharge wastewater into the water collector 7.

[0073] If the above-mentioned condensation delay or liquid level limit is not met, the condensation recovery controller will keep the drain control valve closed. After drainage is completed or the condensation delay ends, the recovery control valve will be opened to recover hydrogen. While the pumping device 8 is pumping and recovering hydrogen, it will create a certain negative pressure in the gas-liquid separation chamber 6. When a negative pressure environment is formed again in the gas-liquid separation chamber 6, the recovery control valve will be closed.

[0074] The aforementioned fuel cell condensation recovery system can recover hydrogen through gas-water separation, effectively reducing hydrogen waste during fuel cell stack operation and improving hydrogen utilization. A negative pressure environment is created within the gas-water separation chamber 6 by the extraction device 8, increasing the wastewater discharge rate during fuel cell operation and effectively improving fuel cell efficiency. The refrigeration component uses a semiconductor refrigeration integrated board 4, with its hot side attached to the exhaust end plate. While the cold side of the semiconductor refrigeration integrated board 4 cools the gas-water separation chamber, its hot side heats the fuel cell stack exhaust end plate 3, ensuring that the fuel cell stack can quickly heat up to a stable operating temperature at low temperatures. This effectively improves the fuel cell's adaptability to ambient temperatures during operation, broadening its application scenarios.

[0075] This application also provides an operation control method applicable to the fuel cell condensation recovery system provided in the above embodiments; such as Figure 3 As shown, the operation control method includes:

[0076] Step S10: Condense the gas-water mixture discharged from the fuel cell stack to separate the gas and water;

[0077] Step S20: Collect the hydrogen gas after gas-water separation.

[0078] Furthermore, step S10 may also include:

[0079] Step S01: Detect the operating status of the fuel cell stack, and control the gas-water discharge pipe 13 to open and discharge the gas-water mixture according to the operating status;

[0080] The operating status includes the output voltage of the fuel cell stack. When the output voltage is lower than a preset value, the gas-water discharge pipe 13 is opened.

[0081] The operating status of the fuel cell stack mainly includes output electrical parameters, specifically the output voltage. When the output voltage is lower than a preset value, it indicates that a large amount of gas-water mixture has accumulated inside the stack body 2, affecting the reaction efficiency of the stack body 2. After detecting this information, the fuel cell stack controller controls the hydrogen exhaust valve of the gas-water discharge pipe 13 to open, discharging the gas-water mixture of hydrogen, water vapor, and liquid water to the gas-water separation component, reducing the impact on the reaction efficiency of the stack body 2 and ensuring the output voltage.

[0082] After the gas-water mixture is discharged into the gas-water separation component, the condensation recovery controller interacts with the fuel cell stack controller to obtain information that the gas-water mixture has entered the gas-water separation component. The condensation recovery controller detects the temperature of the gas-water separation component through the temperature detection component, and then controls the cooling component to cool down the gas-water separation component according to the detected temperature, so that the water vapor in the gas-water mixture sent into the gas-water separation component is quickly condensed and separated from the hydrogen.

[0083] Finally, the condensate from the gas-liquid separation is discharged to the water collector 7. Then, the dried hydrogen is drawn back by the extraction device 8 and transported to the hydrogen inlet pipe 9, realizing hydrogen recovery and recycling, and improving hydrogen utilization efficiency. The process of discharging condensate and recovering hydrogen is as follows: The liquid level in the gas-liquid separation component is detected to determine whether it is higher than the preset level. If it is higher than the preset level, the drain control valve is opened to drain the water, preventing the liquid level in the gas-liquid separation component from affecting the entry of the gas-liquid mixture into the gas-liquid separation component and the condensation and gas-liquid separation. After the drainage is completed, the recovery control valve is opened and the extraction device 8 is started to draw back the hydrogen in the gas-liquid separation component and transport it to the hydrogen inlet pipe.

[0084] If the liquid level in the gas-liquid separator does not meet the drainage requirements, hydrogen will be drawn out of the gas-liquid separator after a preset time of introducing the gas-liquid mixture, maintaining a negative pressure environment within the gas-liquid separator. This preset time is a condensation delay to ensure that the gas-liquid mixture entering the gas-liquid separator can be fully condensed, achieving the separation of water vapor and hydrogen. This preset time can be 2 seconds or can be set according to actual needs.

[0085] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0086] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0087] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A fuel cell condensation recovery system, applied to a fuel cell stack, the fuel cell stack comprising a stack body, a stack inlet end plate, and a stack exhaust end plate, the stack exhaust end plate being provided with gas and water discharge pipes; characterized in that, The fuel cell condensation recovery system includes: A gas-water separation component is connected to the gas-water discharge pipe. The gas-water separation component includes a semiconductor cold end exhaust plate and a negative pressure gas-water separation chamber disposed in the semiconductor cold end exhaust plate. A refrigeration component, fitted to the gas-water separation component, is used to cool and condense water vapor in the gas-water separation component. The refrigeration component includes a semiconductor refrigeration integrated plate, which has a cold side and a hot side facing away from each other. The hot side of the semiconductor refrigeration integrated plate is fitted to the fuel cell stack exhaust end plate, and the cold side of the semiconductor refrigeration integrated plate is fitted to the semiconductor cold end exhaust end plate. A hydrogen recovery component is connected to the outlet of the gas-water separation component and is used to recover hydrogen.

2. The fuel cell condensation recovery system according to claim 1, wherein the fuel cell stack inlet end plate is provided with a hydrogen inlet pipe, characterized in that, The hydrogen recovery assembly includes: A hydrogen recovery pipeline, the first end of which is connected to the gas outlet of the gas-water separation chamber; A gas extraction device is connected to the second end of the hydrogen recovery pipeline and is used to extract hydrogen from the gas-water separation chamber. A hydrogen circulation pipeline, connecting the pumping device and the hydrogen inlet pipeline, is used to return the recovered hydrogen to the hydrogen inlet pipeline.

3. The fuel cell condensation recovery system according to claim 2, characterized in that, The hydrogen circulation pipeline is equipped with a hydrogen circulation valve, which is a one-way mechanical constant pressure valve. When the hydrogen pressure in the hydrogen circulation pipeline is greater than a preset pressure, the one-way mechanical constant pressure valve causes the hydrogen circulation pipeline to flow unidirectionally to the hydrogen inlet pipeline.

4. The fuel cell condensation recovery system according to any one of claims 1-3, characterized in that, Also includes: A temperature detection component is used to detect the internal temperature of the gas-liquid separation component; A control component, connected to the temperature detection component and the cooling component, is used to adjust the operation of the cooling component according to the temperature detected by the temperature detection component.

5. The fuel cell condensation recovery system according to claim 4, characterized in that, The gas-water discharge pipeline is equipped with a hydrogen exhaust valve, the gas-water separation component is equipped with a drainage control valve, and the hydrogen recovery component is equipped with a recovery control valve. The hydrogen exhaust valve, the drainage control valve, and the recovery control valve are all connected to the control component and are opened and closed under the control of the control component.

6. The fuel cell condensation recovery system according to claim 5, characterized in that, The gas-liquid separation component is equipped with a liquid level detection component, which is connected to the control component. The control component is used to control the opening and closing of the drainage control valve according to the liquid level detected by the liquid level detection component.

7. An operation control method applicable to the fuel cell condensation recovery system according to any one of claims 1-6, characterized in that, The operation control method includes: The gas-water mixture discharged from the fuel cell stack is condensed to separate the gas and water. Collect the hydrogen gas after gas-water separation.

8. The operation control method according to claim 7, characterized in that, The step of condensing the gas-water mixture discharged from the fuel cell stack to separate the gas and water includes the following prior to the step of: The operating status of the fuel cell stack is detected, and the gas-water discharge pipe is opened to discharge the gas-water mixture based on the operating status. The operating status includes the output voltage of the fuel cell stack. When the output voltage is lower than a preset value, the gas-water discharge pipe is opened.

9. The operation control method according to claim 7, characterized in that, The step of condensing the gas-water mixture discharged from the fuel cell stack to separate the gas and water includes: The temperature of the gas-water separation component is detected and the operation of the refrigeration component is adjusted.

10. The operation control method according to claim 7, characterized in that, The step of collecting the hydrogen gas after gas-water separation includes: Detect the liquid level in the gas-liquid separation component, and drain the water after the liquid level in the gas-liquid separation component is higher than the preset liquid level; Hydrogen is discharged from the gas-water separation component after drainage is completed or after a preset time has elapsed since the gas-water mixture was introduced into the gas-water separation component through the gas-water discharge pipe.

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