Hydrogen fuel cell stack humidity control device and control method thereof

Abstract

This invention discloses a humidity control device for a hydrogen fuel cell stack, relating to the field of fuel cell technology. It includes an air compressor, an intercooler, and an atomizer, connected sequentially. A gas-water separator is also provided at the stack outlet. The intercooler and atomizer are connected via a pipeline. A mixing chamber is provided between the intercooler outlet and the gas-water separator. A first switching valve is provided between the intercooler outlet and the mixing chamber inlet. A proportional valve and a first check valve are provided between the mixing chamber outlet and the atomizer inlet. A second check valve is provided between the gas-water separator and the mixing chamber. A humidity sensor is provided at the atomizer outlet. The mixing chamber has an outlet pipeline with a second switching valve on the outlet pipeline. This invention features a simple structure, convenient operation, rapid air humidification, and free humidity adjustment.

Description

Technical Field

[0001] This invention relates to the field of fuel cell stack humidification technology, specifically to a humidity control device and control method for a hydrogen fuel cell stack. Background Technology

[0002] Proton exchange membrane fuel cells are complex nonlinear systems coupled with multiple physics fields. The proton exchange membrane has certain requirements for the humidity of the reactant gas. Excessive humidity will cause flooding, while insufficient humidity will cause membrane drying. Frequent flooding and membrane drying in proton exchange membrane fuel cells will reduce the durability of the system, affect its performance, and even shorten its service life.

[0003] Flooding can reduce the activity of the catalyst layer, accelerate material corrosion and catalyst loss, reduce the active surface area, and even cause liquid water to accumulate in the gas flow channels, leading to poor gas flow and severely affecting the operation and performance of proton exchange membrane fuel cells. Since proton conduction in proton exchange membrane fuel cells requires water molecules as a carrier, membrane dryness significantly reduces proton conductivity, impacting normal cell operation.

[0004] Existing fuel cell humidification methods include bubbling the gas with water, exchanging water through a water-permeable medium, and exchanging water on the surface of the adsorbent (enthalpy wheel). Although these humidification schemes have improved the humidification performance of fuel cell test platforms, they have the disadvantage of uncontrollable humidity. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a hydrogen fuel cell stack humidity control device and control method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A humidity control device for a hydrogen fuel cell stack includes an air compressor, an intercooler, an atomizer, and a gas-water separator. The air compressor, intercooler, atomizer, fuel cell stack, and gas-water separator are connected in sequence. The intercooler and atomizer are connected through a pipe 1. The atomizer is connected to the fuel cell stack through a pipe 2. The fuel cell stack and gas-water separator are connected through a pipe 3. A mixing chamber is provided between the outlet end of the intercooler and the gas-water separator. The outlet end of the intercooler and the inlet end of the mixing chamber are connected through a pipe 6 and equipped with a first switching valve. The outlet end of the mixing chamber and the inlet end of the atomizer are connected through a pipe 7 and equipped with a proportional valve and a first check valve. The gas-water separator and the mixing chamber are connected through a pipe 4 and equipped with a second check valve. A humidity sensor is provided at the outlet end of the atomizer. The mixing chamber is provided through a pipe 5 and equipped with a second switching valve.

[0008] Based on the above technical solution, the first switching valve controls the six-way disconnection of the pipeline.

[0009] Based on the above technical solution, the proportional valve is a hydraulic proportional valve, which controls the flow rate of the water circuit.

[0010] Based on the above technical solutions, pipeline one is a water-gas mixing pipeline.

[0011] Based on the above technical solution, a filter is connected to the inlet end of the air compressor.

[0012] Based on the above technical solution, the first check valve and the second check valve are hydraulic check valves, used to prevent backflow of water medium in the pipeline.

[0013] Based on the above technical solution, the atomizer is an air compression atomizer, which is used to atomize the liquid water in the mixing chamber into mist particles to humidify the air.

[0014] Based on the above technical solution, the mixing chamber is used to collect the liquid water separated by the gas-water separator and introduce it into the atomizer.

[0015] Based on the above technical solutions, pipelines six and seven shall be selected from one or any combination of two of the following: gas pipelines, liquid pipelines, or water-gas mixed pipelines.

[0016] Based on the above technical solution, a control method for a humidity control device of a hydrogen fuel cell stack is provided, the method comprising the following steps:

[0017] Step 1: Collect water generated during fuel cell stack operation: After the fuel cell stack is started, the pressure of the gas-water separator is increased to the level of the mixing chamber by opening the second switch valve, closing the first switch valve, and closing the proportional valve. The water filtered by the gas-water separator enters the mixing chamber through the second check valve due to the pressure difference.

[0018] Step 2: Humidify the fuel cell stack: Close the second switch valve, open the first switch valve, and open the proportional valve to make the pressure in the mixing chamber higher than the pressure at the front end of the atomizer. The water in the mixing chamber flows into the atomizer through the proportional valve and the first one-way valve.

[0019] Step 3: Adjust humidity: Determine whether the data W collected by the humidity sensor is within the required humidity range. If so, maintain the current frequency and opening of the second switching valve, the first switching valve, and the proportional valve. If not, determine whether the data W collected by the humidity sensor is greater than the required humidity range. If so, decrease the opening of the proportional valve. If not, increase the opening of the proportional valve and repeat the above steps to adjust the humidity until the data W collected by the humidity sensor is within the required humidity range.

[0020] Compared with the prior art, the advantages of the present invention are as follows:

[0021] (1) Compared with the prior art, the humidity control device for hydrogen fuel cell stack in this invention has a simple structure and is easy to operate. It can quickly humidify the air and freely and frequently adjust the humidity. The control system responds quickly and accurately, and the humidification effect is obvious.

[0022] (2) The hydrogen fuel cell stack humidity control device of the present invention adds a mixing chamber, which can be used as a reaction water collector and a water vapor mixing chamber. It is small in size and compact in structure, making it very suitable for the system integration design of hydrogen fuel cell stacks. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a hydrogen fuel cell stack humidity control device in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of a control method for a hydrogen fuel cell stack humidity regulation device in an embodiment of the present invention. Detailed Implementation

[0025] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0027] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0028] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0029] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0030] See Figure 1 The schematic diagram shown in this embodiment of the invention illustrates a humidity control device for a hydrogen fuel cell stack, comprising an air compressor, an intercooler, an atomizer, and a gas-water separator. The air compressor, intercooler, atomizer, fuel cell stack, and gas-water separator are sequentially connected. The intercooler and atomizer are connected via pipe one, the atomizer is connected to the fuel cell stack via pipe two, and the fuel cell stack and gas-water separator are connected via pipe three. A mixing chamber is provided between the outlet of the intercooler and the gas-water separator. The outlet of the intercooler and the inlet of the mixing chamber are connected via pipe six and equipped with a first switching valve. The outlet of the mixing chamber and the inlet of the atomizer are connected via pipe seven and equipped with a proportional valve and a first check valve. The gas-water separator and the mixing chamber are connected via pipe four and equipped with a second check valve. A humidity sensor is provided at the outlet of the atomizer, and the mixing chamber has pipe five with a second switching valve.

[0031] The intercooler outlet and the mixing chamber inlet are connected by a water pipe, and the first switch valve controls the opening and closing of the pipe. The intercooler outlet has a branch pipe, namely pipe six, which connects to the mixing chamber to connect the intercooler and the mixing chamber. When this branch pipe is opened, the pressure in the intercooler and the mixing chamber is equalized. Compressed air enters the mixing chamber and then enters the atomizer through a proportional valve, which increases the air humidity and achieves the purpose of regulation and control.

[0032] The mixing chamber outlet and the atomizer inlet are connected by pipe seven, which is a water pipe. The proportional valve is a hydraulic proportional valve that controls the flow rate of the water. The water pipe at the mixing chamber outlet allows reactor reaction water to enter the atomizer. After the flow rate is regulated by the proportional valve, the water enters the atomizer for air humidification.

[0033] Pipeline 1 is a water-air pipeline. Pipeline 1 is mainly a compressed air pipeline. When humidification is adjusted, the water in the mixing chamber flows into Pipeline 1 through the proportional valve and the one-way valve, and enters the atomizer together with the air for humidification and atomization.

[0034] Pipeline 6 and Pipeline 7 can be one of the following: gas pipeline, liquid pipeline, or water-gas mixture pipeline, or a combination of both.

[0035] A filter is connected to the inlet of the air compressor. The air enters the air compressor after being filtered by the filter, ensuring that the air meets the requirements of the fuel cell stack for the content of air impurities.

[0036] The first and second check valves are hydraulic check valves used to prevent backflow of water in the pipeline. The humidity control method of a hydrogen fuel cell stack humidity regulation device in this invention involves multiple, high-frequency adjustments of the switching valve and proportional valve. To prevent backflow of fluid caused by left-right changes in gas pressure, the check valves effectively prevent this situation from occurring.

[0037] The atomizer is an air compression atomizer, used to atomize liquid water in the mixing chamber into mist particles to humidify the air. Air compression atomizers, also called jet atomizers, are based on the Venturi principle. They utilize compressed air passing through a narrow nozzle to create a high-speed airflow. The resulting negative pressure propels liquid or other fluids onto an obstruction. The high-speed impact causes the liquid to splash outwards, turning droplets into mist particles that are then ejected from the outlet pipe. This embodiment utilizes this characteristic for air atomization and humidification.

[0038] The mixing chamber is used to collect the liquid water separated by the gas-water separator and introduce it into the atomizer. The main functions of the mixing chamber are, on the one hand, to act as a reaction water collector, and on the other hand, to act as a pre-mixing device for gas-water mixing. This configuration allows for both humidity regulation and control, and utilizes the characteristics of the fuel cell stack's gas path to achieve humidity control without adding power-consuming equipment.

[0039] See Figure 2 The diagram shown is a principle block diagram of a humidity control method for a hydrogen fuel cell stack according to an embodiment of the present invention. The control method for a humidity control device for a hydrogen fuel cell stack includes the following steps:

[0040] Step 1: Collect water generated during fuel cell stack operation: After the fuel cell stack is started, the pressure of the gas-water separator is increased to the level of the mixing chamber by opening the second switch valve, closing the first switch valve, and closing the proportional valve. The water filtered by the gas-water separator enters the mixing chamber through the second check valve due to the pressure difference.

[0041] Step 2: Humidify the fuel cell stack: Close the second switch valve, open the first switch valve, and open the proportional valve to make the pressure in the mixing chamber higher than the pressure at the front end of the atomizer. The water in the mixing chamber flows into the atomizer through the proportional valve and the first one-way valve.

[0042] Step 3: Adjust humidity: Determine whether the data W collected by the humidity sensor is within the required humidity range. If so, maintain the current frequency and opening of the second switching valve, the first switching valve, and the proportional valve. If not, determine whether the data W collected by the humidity sensor is greater than the required humidity range. If so, decrease the opening of the proportional valve. If not, increase the opening of the proportional valve and repeat the above steps to adjust the humidity until the data W collected by the humidity sensor is within the required humidity range.

[0043] The gas-water separator filters out the water discharged from the fuel cell stack. The proportional valve and the first switching valve are closed, and the second switching valve is opened, causing the pressure in the gas-water separator to be higher than that in the mixing chamber. The water filtered by the gas-water separator flows into the mixing chamber through the second check valve due to the pressure difference.

[0044] The first check valve prevents gas from flowing from pipe one into the mixing chamber when the pressure in the mixing chamber is low.

[0045] Open the first switching valve and the proportional valve, and close the second switching valve to make the pressure in the mixing chamber higher than the pressure at the front end of the atomizer. Water in the mixing chamber flows into the atomizer through the proportional valve and the first one-way valve due to the pressure difference.

[0046] The humidity of the fuel cell stack is adjusted by regulating the opening of the proportional valve.

[0047] The second check valve prevents gas in the mixing chamber from flowing to the gas-water separator when the pressure in the mixing chamber is high.

[0048] The atomizer atomizes the liquid water discharged from the mixing chamber and then it enters the fuel cell stack. The humidity sensor collects the humidity at the inlet of the fuel cell stack.

[0049] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0050] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0051] This invention is not limited to the embodiments described above. Those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A humidity control device for a hydrogen fuel cell stack, comprising an air compressor, an intercooler, an atomizer, and a gas-water separator, wherein the air compressor, intercooler, atomizer, fuel cell stack, and gas-water separator are connected in sequence, characterized in that: The intercooler and atomizer are connected by pipe one, the atomizer is connected to the fuel cell stack by pipe two, the fuel cell stack and the gas-water separator are connected by pipe three, a mixing chamber is provided between the outlet end of the intercooler and the gas-water separator, the outlet end of the intercooler and the inlet end of the mixing chamber are connected by pipe six and a first switching valve is provided, the outlet end of the mixing chamber and the inlet end of the atomizer are connected by pipe seven and a proportional valve and a first check valve are provided, the gas-water separator and the mixing chamber are connected by pipe four and a second check valve is provided. The outlet end of the atomizer is provided with a humidity sensor, the mixing chamber is provided with pipe five and pipe five is provided with a second switching valve.

2. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: The first switching valve controls the six-way disconnection of the pipeline.

3. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: The proportional valve is a hydraulic proportional valve, which controls the flow rate of the water circuit.

4. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: The first pipeline is a water-air mixing pipeline.

5. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: A filter is connected to the inlet end of the air compressor.

6. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: The first and second check valves are hydraulic check valves used to prevent backflow of water in the pipeline.

7. The humidity control device for a hydrogen fuel cell stack as described in claim 1, characterized in that: The atomizer is an air compression atomizer, used to atomize liquid water in the mixing chamber into mist particles to humidify the air.

8. A humidity control device for a hydrogen fuel cell stack as claimed in claim 1, characterized in that: The mixing chamber is used to collect the liquid water separated by the gas-water separator and introduce it into the atomizer.

9. A humidity control device for a hydrogen fuel cell stack as claimed in claim 1, characterized in that: Pipeline 6 and Pipeline 7 are selected from one or any combination of two of the following: gas pipeline, liquid pipeline, or water-gas mixture pipeline.

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