Simulation system for generation and discharge of liquid water in fuel cell

Abstract

The invention discloses a simulation system for generation and discharge of liquid water in a fuel cell, and relates to the technical field of fuel cells, the simulation system comprises a simulation fuel cell, a water injection pump, an air compressor and a controller, the controller controls the water injection pump to inject water into a water inlet of a simulation anode flow field end plate in the simulation fuel cell, the injected water firstly fills the simulated anode flow channel and then uniformly permeates through the ultrafiltration membrane and the carbon paper to reach the simulated cathode flow channel, so that the actual process of generating liquid water in the fuel cell and permeating the liquid water into the cathode flow channel is equivalently represented; meanwhile, an air compressor is controlled by a controller to inject air into an air inlet of a simulated cathode flow field end plate in the simulated fuel cell, and the process that air is injected into the cathode end of the actual fuel cell and residual air outside the reaction of the cathode end purges and discharges liquid water in a cathode flow channel is equivalently characterized; therefore, the simulation system can be used for observing the generation and transportation characteristics of liquid water in the fuel cell, and guidance is provided for the design of a bipolar plate runner of the fuel cell.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a simulation system for generating and discharging liquid water inside a fuel cell. Background Art

[0002] Fuel cells are an efficient and clean energy conversion technology that directly converts the chemical energy of fuel into electrical energy. They offer advantages such as high energy density, high efficiency, and environmental friendliness, and have garnered widespread attention in recent years. During fuel cell operation, hydrogen fuel is supplied to the anode. A catalyst activates the hydrogen into hydrogen ions and electrons. The hydrogen ions travel through a proton exchange membrane into the electrolyte, then through the membrane to the cathode catalyst layer. The electrons are then removed from the anode catalyst layer by an external circuit. Air (oxygen) is supplied to the cathode, where the catalyst activates the oxygen into oxygen ions. In the cathode catalyst layer, the oxygen ions combine with hydrogen ions from the anode to form water, which is then discharged. Flow channels are located on both the anode and cathode plates of a fuel cell. The channels on the anode plate distribute hydrogen evenly to the corresponding reaction layers, while those on the cathode plate distribute oxygen evenly to the corresponding reaction layers. Furthermore, the channels on the cathode plate discharge generated water and unreacted gases.

[0003] The performance and durability of fuel cells are highly dependent on internal water management. Improper water management may lead to reduced fuel cell output power, reduced durability, and accelerated aging of battery components. By observing the water dynamics inside the fuel cell, researchers can more accurately evaluate and optimize the bipolar plate flow channel structure and develop more efficient water management strategies. However, fuel cells are usually made of metal or other opaque materials, and their internal water dynamic processes cannot be directly observed. Therefore, developing a simulation system for the generation and discharge of liquid water inside the fuel cell to facilitate the observation of the generation and transport characteristics of liquid water inside the fuel cell is of great significance to the design of the bipolar plate flow channels of the fuel cell. Summary of the Invention

[0004] To solve the above technical problems, an embodiment of the present application provides a simulation system for the generation and discharge of liquid water inside a fuel cell, so as to observe the generation and transport characteristics of liquid water inside the fuel cell and provide guidance for the design of the bipolar plate flow channel of the fuel cell.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A simulation system for generating and discharging liquid water inside a fuel cell, comprising:

[0007] A simulated fuel cell, the simulated fuel cell comprising a simulated anode flow field end plate and a simulated cathode flow field end plate, the simulated anode flow field end plate being provided with a water inlet and a simulated anode flow channel connected to the water inlet, the simulated cathode flow field end plate being provided with an air inlet, a first outlet and a simulated cathode flow channel connected to the air inlet and the first outlet, the simulated anode flow channel and the simulated cathode flow channel being provided correspondingly, an ultrafiltration membrane being provided on the side of the simulated anode flow channel facing the simulated cathode flow channel, and carbon paper being provided on the side of the simulated cathode flow channel facing the simulated anode flow channel;

[0008] a water injection pump, the water injection pump being connected to the water inlet of the simulated anode flow field end plate, and the water injection pump being used to inject water into the water inlet of the simulated anode flow field end plate;

[0009] an air compressor, the air compressor being connected to the air inlet on the simulated cathode flow field end plate, and the air compressor being used to inject air into the air inlet on the simulated cathode flow field end plate;

[0010] A controller is used to control the flow rate of water injected by the water injection pump into the water inlet of the simulated anode flow field end plate, and to control the flow rate of air injected by the air compressor into the air inlet of the simulated cathode flow field end plate.

[0011] Optionally, the process of the controller controlling the water injection pump to inject water flow into the water inlet of the simulated anode flow field end plate includes:

[0012] Based on the current of the actual fuel cell, the water production per unit time inside the actual fuel cell is calculated, and the water injection pump is controlled to inject water into the water inlet of the simulated anode flow field end plate at a flow rate equal to the calculated water production per unit time inside the actual fuel cell.

[0013] Optionally, the process of the controller controlling the air compressor to inject air flow into the air inlet of the simulated cathode flow field end plate includes:

[0014] Based on the current and stoichiometric ratio of the actual fuel cell, the volume flow rate of excess air outside the cathode end reaction of the actual fuel cell is calculated, and the air compressor is controlled to inject air into the air inlet of the simulated cathode flow field end plate at a flow rate that is the calculated volume flow rate of excess air outside the cathode end reaction of the actual fuel cell.

[0015] Optionally, the simulated anode flow field end plate is further provided with a second outlet, and the simulated anode flow channel is connected to the water inlet and the second outlet.

[0016] Optionally, the material of the simulated anode flow field end plate is acrylic transparent glass, and the material of the simulated cathode flow field end plate is acrylic transparent glass.

[0017] Optionally, the simulation system further includes a high-speed camera, which is used to photograph and record the flow of water in the simulated cathode flow channel.

[0018] Optionally, the simulation system further includes a water storage container and a weighing device;

[0019] The water storage container is used to receive the water flowing out of the first outlet of the simulated cathode flow field end plate;

[0020] The weighing device is used to measure the weight of the water received by the water storage container from the first outlet of the simulated cathode flow field end plate.

[0021] Optionally, the simulation system further includes a first valve and a liquid flow meter;

[0022] The first valve is located on the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate, and is used to control the opening and closing of the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate;

[0023] The liquid flow meter is located on the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate, and is used to monitor the flow rate of water injected into the water inlet of the simulated anode flow field end plate.

[0024] Optionally, the simulation system further includes a second valve and a gas flow meter;

[0025] The second valve is located on the connecting passage between the air compressor and the air inlet of the simulated cathode flow field end plate, and is used to control the opening and closing of the connecting passage between the air compressor and the air inlet of the simulated cathode flow field end plate;

[0026] The gas flow meter is located on the connecting channel between the air compressor and the air inlet of the simulated cathode flow field end plate, and is used to monitor the flow rate of air injected into the air inlet of the simulated cathode flow field end plate.

[0027] Optionally, the simulated anode flow channel and the simulated cathode flow channel are parallel flow channels, serpentine flow channels, staggered flow channels, matrix flow channels, wavy flow channels or indented flow channels.

[0028] Compared with the existing technology, the above technical solution has the following advantages:

[0029] The simulation system for the generation and discharge of liquid water inside a fuel cell provided in an embodiment of the present application includes a simulated fuel cell, a water injection pump, an air compressor and a controller. The controller controls the water injection pump to inject water into the water inlet of the simulated anode flow field end plate in the simulated fuel cell. The injected water first fills the simulated anode flow channel, and then evenly penetrates through the ultrafiltration membrane over the entire surface, and then penetrates through the carbon paper to reach the simulated cathode flow channel. After stable operation, the flow rate of water injected by the water injection pump into the water inlet of the simulated anode flow field end plate is equal to the permeation flow rate of water from the simulated anode flow channel through the ultrafiltration membrane and carbon paper to the simulated cathode flow channel, thereby equivalently representing the process of liquid water generation and penetration into the cathode flow channel in an actual fuel cell. At the same time, the controller controls the air compressor to Air is injected into the air inlet of the simulated cathode flow field end plate in the simulated fuel cell, and the flow rate of the injected air is equivalent to the flow rate of excess air outside the cathode end reaction of the fuel cell, thereby equivalently representing the process of injecting air into the cathode end of the actual fuel cell and the excess air outside the cathode end reaction to blow out the liquid water in the cathode flow channel; it can be seen that the simulation system provided in the embodiment of the present application simulates the process of liquid water generation and discharge inside the fuel cell by injecting water into the simulated anode flow channel, pressurizing water to infiltrate water into the simulated cathode flow channel, and injecting air into the simulated cathode flow channel, which is close to the process of liquid water generation and discharge inside the actual fuel cell, and can be used to observe the generation and transport characteristics of liquid water inside the fuel cell, and provide guidance for the design of fuel cell bipolar plate flow channels. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0031] Figure 1 A schematic diagram of a framework of a simulation system for generating and discharging liquid water inside a fuel cell provided in an embodiment of the present application;

[0032] Figure 2 A schematic top view of a simulated anode flow field end plate of a simulated fuel cell in a simulation system for generating and discharging liquid water inside a fuel cell provided by an embodiment of the present application;

[0033] Figure 3 A schematic top view of a simulated cathode flow field end plate of a simulated fuel cell in a simulation system for generating and discharging liquid water inside a fuel cell provided by an embodiment of the present application;

[0034] Figure 4A schematic diagram of the relationship between the weight of water flowing out of the first outlet of the simulated cathode flow field end plate and the time of the weight of water received by the water storage container in a simulation system for the production and discharge of liquid water inside a fuel cell provided in an embodiment of the present application.

[0035] Reference numerals:

[0036] 10-Simulated fuel cell; 20-Water injection pump; 30-Air compressor; 40-Controller; 11-Simulated anode flow field end plate; 12-Simulated cathode flow field end plate; K1-Water inlet; K2-Air inlet; K3-First outlet; K4-Second outlet; L1-Simulated anode flow channel; L2-Simulated cathode flow channel; 13-Ultrafiltration membrane; 14-Carbon paper; 50-High-speed camera; 60-Water storage container; 70-Weighing machine; 21-First valve; 22-Liquid flow meter; 31-Second valve; 32-Gas flow meter. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] As described in the background technology section, developing a simulation system for the generation and discharge of liquid water inside a fuel cell to facilitate observation of the generation and transport characteristics of liquid water inside the fuel cell is of great significance for the design of the bipolar plate flow channel of the fuel cell.

[0039] In view of this, an embodiment of the present application provides a simulation system for the generation and discharge of liquid water inside a fuel cell. Figure 1 A schematic diagram of a simulation system for generating and discharging liquid water inside a fuel cell provided in an embodiment of the present application is shown. Figure 1As shown, the simulation system includes a simulated fuel cell 10, a water injection pump 20, an air compressor 30 and a controller 40; wherein, the simulated fuel cell 10 includes a simulated anode flow field end plate 11 and a simulated cathode flow field end plate 12, the simulated anode flow field end plate 11 is provided with a water inlet K1, and the simulated cathode flow field end plate 12 is provided with an air inlet K2 and a first outlet K3; the water injection pump 20 is connected to the water inlet K1 of the simulated anode flow field end plate 11, and the water injection pump 20 is used to inject water into the water inlet K1 of the simulated anode flow field end plate 11; the air compressor 30 is connected to the air inlet K2 on the simulated cathode flow field end plate 12, and the air compressor 30 is used to inject air into the air inlet K2 on the simulated cathode flow field end plate 12; the controller 40 is used to control the flow rate of water injected by the water injection pump 20 into the water inlet K1 of the simulated anode flow field end plate 11, and to control the flow rate of air injected by the air compressor 30 into the air inlet K2 of the simulated cathode flow field end plate 12.

[0040] In order to better understand this application, Figure 2 The schematic diagram of the top view of the simulated anode flow field end plate 11 of the simulated fuel cell 10 in the simulation system for generating and discharging liquid water inside the fuel cell provided by the embodiment of the present application is shown. Figure 1 and Figure 2 As shown, the simulated anode flow field end plate 11 is provided with a simulated anode flow channel L1 connected to the water inlet K1. It is understood that the simulated anode flow channel L1 of the simulated anode flow field end plate 11 is the same as the anode flow channel of the anode flow field end plate in an actual fuel cell, and can be a parallel flow channel, a serpentine flow channel, a staggered flow channel, a matrix flow channel, a wavy flow channel, or an indented flow channel, etc. Figure 2 The simulated anode flow channel L1 is demonstrated using a parallel flow channel as an example.

[0041] Figure 3 The schematic diagram of the top view of the simulated cathode flow field end plate 12 of the simulated fuel cell 10 in the simulation system for generating and discharging liquid water inside the fuel cell provided by the embodiment of the present application is shown. Figure 1 and Figure 3 As shown, the simulated cathode flow field end plate 12 is provided with a simulated cathode flow channel L2 communicating with the air inlet K2 and the first outlet K3. It is understood that the simulated cathode flow channel L2 of the simulated cathode flow field end plate 12 is the same as the cathode flow channel of the cathode flow field end plate in an actual fuel cell, and can be parallel flow channels, serpentine flow channels, staggered flow channels, matrix flow channels, wavy flow channels, or indented flow channels, etc. Figure 2 The simulated cathode flow channel L2 is demonstrated using a parallel flow channel as an example.

[0042] In the embodiment of the present application, the groove width of the simulated anode flow channel L1 and the simulated cathode flow channel L2 can be 0.1mm-5mm, the groove depth can be 0.1mm-5mm, and the ridge width can be 0.1mm-5mm.

[0043] It should be noted that, similar to an actual fuel cell, in the simulated fuel cell 10, the simulated anode flow channel L1 and the simulated cathode flow channel L2 are correspondingly arranged, that is, the shapes and positions of the simulated anode flow channel L1 and the simulated cathode flow channel L2 are correspondingly arranged. Figure 1-Figure 3 As shown, an ultrafiltration membrane 13 is provided on the side of the simulated anode flow channel L1 facing the simulated cathode flow channel L2, and a carbon paper 14 is provided on the side of the simulated cathode flow channel L2 facing the simulated anode flow channel L1.

[0044] When the simulation system provided by the embodiment of the present application is running, the water injection pump 20 injects water into the water inlet K1 of the simulated anode flow field end plate 11. The injected water first flows along the simulated anode flow channel L1. Since the ultrafiltration membrane 13 needs to be under a certain pressure to penetrate water, the water injected into the water inlet K1 of the simulated anode flow field end plate 11 will first fill the simulated anode flow channel L1, and then penetrate through the ultrafiltration membrane 13, and then penetrate through the carbon paper 14 to reach the simulated cathode flow channel L2. It can be understood that when the simulation system provided by the embodiment of the present application is running stably, the flow rate of water injected by the water injection pump 20 into the water inlet K1 of the simulated anode flow field end plate 11 is equal to the permeation flow rate of water from the simulated anode flow channel L1 through the ultrafiltration membrane 13 and the carbon paper 14 to the simulated cathode flow channel L2, thereby equivalently representing the process of liquid water generation and penetration into the cathode flow channel inside the actual fuel cell. It can also be understood that the flow rate of water injected by the water injection pump 20 into the water inlet K1 of the simulated anode flow field end plate 11 is the weight of water injected by the water injection pump 20 into the water inlet K1 of the simulated anode flow field end plate 11 per unit time, and can be set according to the actual water production per unit time inside the fuel cell.

[0045] It should be noted that the liquid water generated inside the actual fuel cell also penetrates into the cathode flow channel through carbon paper, which is also called a membrane electrode. In the simulation system provided in the embodiment of the present application, an ultrafiltration membrane 13 is provided on the side of the simulated anode flow channel L1 toward the simulated cathode flow channel L2, so that the water injected from the water inlet K1 of the simulated anode flow field end plate 11 first fills the simulated anode flow channel L1, and then evenly penetrates through the ultrafiltration membrane 13 on the entire surface. This is because, if the ultrafiltration membrane 13 is not provided on the side of the simulated anode flow channel L1 toward the simulated cathode flow channel L2, the water injected from the water inlet K1 of the simulated anode flow field end plate 11 is likely to partially penetrate from the carbon paper 14 to the simulated cathode flow channel L2 before filling the simulated anode flow channel L1. In an actual fuel cell, fuel hydrogen is supplied to the anode end, and the fuel hydrogen is evenly distributed through the anode flow channel, so that an electrochemical reaction occurs on the entire surface of the fuel cell to generate water. Therefore, in the simulation system provided in the embodiment of the present application, an ultrafiltration membrane 13 is arranged on the side of the simulated anode flow channel L1 facing the simulated cathode flow channel L2, so as to ensure that the water injected from the water inlet K1 of the simulated anode flow field end plate 11 first fills the simulated anode flow channel L1, and then evenly penetrates through the ultrafiltration membrane 13 on the entire surface, approaching the process of liquid water generation and penetration into the cathode flow channel in an actual fuel cell.

[0046] At the same time, when the simulation system provided in the embodiment of the present application is in operation, air is injected into the air inlet K2 of the simulated cathode flow field end plate 12 through the air compressor 30, and the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12 by the air compressor 30 is controlled by the controller 40, thereby equivalently representing the process of injecting air into the cathode end of an actual fuel cell and blowing out the liquid water in the cathode flow channel with excess air outside the cathode end reaction.

[0047] It can be understood that the flow rate of air injected by the air compressor 30 into the air inlet K2 of the simulated cathode flow field end plate 12 is the volume of air injected by the air compressor 30 into the air inlet K2 of the simulated cathode flow field end plate 12 per unit time. Since no actual electrochemical reaction occurs in the simulation system provided in the embodiment of the present application, the flow rate of air injected by the air compressor 30 into the air inlet K2 of the simulated cathode flow field end plate 12 should be equivalent to the flow rate of excess air outside the reaction at the cathode end of the actual fuel cell, that is, the volume of excess air generated at the cathode end of the actual fuel cell per unit time).

[0048] As we know, in the field of fuel cells, the molar ratio between fuel (such as hydrogen) and oxygen is the stoichiometric ratio. The stoichiometric ratio represents the number of moles of oxygen required to consume one mole of fuel for a complete reaction. This proportional relationship ensures the completeness of the reaction. Excess air outside the reaction is used to purge liquid water out of the cathode flow channel. Therefore, the flow rate of excess air outside the cathode end reaction of the actual fuel cell can be obtained based on the cathode air volume flow rate (the volume of air introduced per unit time) of the actual fuel cell and the stoichiometric ratio. This is used to set the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12 in the simulation system provided in the embodiment of the present application. Different intake air flow rates represent the flow rate of excess air outside the cathode end reaction of the actual fuel cell under different operating conditions.

[0049] From the above analysis, it can be seen that the simulation system provided in the embodiment of the present application simulates the process of liquid water generation and discharge inside the fuel cell by injecting water into the simulated anode flow channel and pressurizing water to penetrate the simulated cathode flow channel and injecting air into the simulated cathode flow channel. This simulates the process of liquid water generation and discharge inside the actual fuel cell, and can be used to observe the generation and transport characteristics of liquid water inside the fuel cell, and provide guidance for the design of fuel cell bipolar plate flow channels. Compared with the existing technology that sets up a complex structure to observe the generation and discharge process of liquid water inside the actual fuel cell, or the simulated generation and discharge process of liquid water inside the fuel cell does not match the actual process, the simulation system provided in the embodiment of the present application not only approximates the process of liquid water generation and discharge inside the actual fuel cell, but also has a simple structure and is easy to implement.

[0050] Optionally, in some embodiments of the present application, the process of the controller 40 controlling the water injection pump 20 to inject water flow into the water inlet K1 of the simulated anode flow field end plate 11 includes:

[0051] Based on the current of the actual fuel cell, the water production per unit time inside the actual fuel cell is calculated, and the water injection pump 20 is controlled to inject water into the water inlet K1 of the simulated anode flow field end plate 11 at a flow rate equal to the calculated water production per unit time inside the actual fuel cell.

[0052] According to Faraday's law of electrolysis, the amount of water produced per unit time inside the fuel cell (i.e., the water flow rate) is closely related to the current of the fuel cell. Specifically, the amount of water produced per unit time inside the fuel cell is It can be expressed as:

[0053] (1)

[0054] Where I is the fuel cell current (in A), which includes the fuel cell current density and the fuel cell active area; is the molar mass of water (18 g / mol), n is the number of electrons involved in the reaction in the fuel cell. For hydrogen fuel cells, n=2; F is the Faraday constant (about 96485 C / mol).

[0055] As can be seen from formula (1), the controller 40 can calculate the water production per unit time inside the actual fuel cell based on the current of the actual fuel cell, and control the water injection pump 20 to inject water into the water inlet K1 of the simulated anode flow field end plate 11 at a flow rate equal to the calculated water production per unit time inside the actual fuel cell, thereby approximating the liquid water production process in the actual fuel cell.

[0056] For example, the flow area of ​​the anode flow channel is 234 cm 2 When the flow rate of water injected into the simulated anode flow channel L1 is 0.39 g / min, the corresponding actual current density is 0.3 A / cm 2 When the flow rate of water injected into the simulated anode flow channel L1 is 2.61g / min, the corresponding actual current density is 2A / cm 2 The water production flow rate.

[0057] Optionally, in some embodiments of the present application, the process in which the controller 40 controls the air compressor 30 to inject air flow into the air inlet K2 of the simulated cathode flow field end plate 12 includes:

[0058] Based on the current and stoichiometric ratio of the actual fuel cell, the volume flow rate of excess air outside the cathode end reaction of the actual fuel cell is calculated, and the air compressor 30 is controlled to inject air into the air inlet K2 of the simulated cathode flow field end plate 12 at a flow rate that is the calculated volume flow rate of excess air outside the cathode end reaction of the actual fuel cell.

[0059] Fuel cell cathode air volume flow rate per unit time V air (Unit is m 3 / s) represents the volume of air injected into the cathode end of the fuel cell per unit time, which can be specifically expressed as:

[0060] (2)

[0061] Where I is the fuel cell current (in A), which includes the fuel cell current density and the fuel cell active area; λ is the stoichiometric ratio, which indicates the number of moles of oxygen required to consume 1 mole of fuel (such as hydrogen) in the case of complete reaction; R is the ideal gas constant (8.3143 J / mol); T is the gas temperature; and F is the Faraday constant (approximately 96485 C / mol). is the volume fraction of oxygen in the air; P is the gas pressure (unit: Pa).

[0062] It can be understood that the volume flow rate V' of the excess air outside the cathode end reaction of the fuel cell air (Unit is m 3 / s) can be expressed as:

[0063] (3)

[0064] For example, the cathode channel has a flow area of ​​234 cm 2 , the current density of the cathode flow channel is 0.3A / cm 2 When the stoichiometric ratio λ is 1.3, the volume flow rate of excess air outside the cathode end reaction of the corresponding fuel cell is 0.15 LPM; the flow channel area of ​​the cathode flow channel is 234 cm 2 , the current density of the cathode flow channel is 2A / cm 2 When the stoichiometric ratio λ is 1.8, the volume flow rate of excess air outside the cathode end reaction of the corresponding fuel cell is 2.77LPM.

[0065] It should be noted that in an actual fuel cell, after air is introduced into the air inlet of the cathode flow field end plate, the air circulates within the cathode flow channel. During the air's circulation within the cathode flow channel, it continuously undergoes electrochemical reactions with fuel ions (such as hydrogen ions), causing the air flow rate to gradually decrease, ultimately becoming excess air outside the reaction. In the simulation system provided in the embodiment of the present application, the volume flow rate of excess air outside the cathode end reaction of the actual fuel cell is directly set to the flow rate of air injected by the air compressor 30 into the air inlet K2 of the simulated cathode flow field end plate 12. In this way, the flow rate of air in the simulated cathode flow channel L2 is less than the flow rate of air in the cathode flow channel in the actual fuel cell. In other words, the air flowing in the simulated cathode flow channel L2 has a weaker ability to purge and discharge liquid water, but this precisely reflects the cathode flow channel's ability to transport liquid water. In other words, in this simulation, if a type of cathode flow channel has a stronger ability to transport liquid water, then in an actual fuel cell, that type of cathode flow channel will have a stronger ability to transport liquid water.

[0066] Based on any of the above embodiments, optionally, in some embodiments of the present application, such as Figure 2As shown, in addition to being provided with a water inlet K1 and a simulated anode flow channel L1 connected to the water inlet K1, the simulated anode flow field end plate 11 is also provided with a second outlet K4, and the simulated anode flow channel L1 is connected to the water inlet K1 and the second outlet K4. This is because, as previously known, the water injected from the water inlet K1 of the simulated anode flow field end plate 11 must first fill the simulated anode flow channel L1 and then evenly permeate through the ultrafiltration membrane 13. In the process of the injected water filling the simulated anode flow channel L1, the gas in the simulated anode flow channel L1 needs to be discharged. Although the gas in the simulated anode flow channel L1 can pass through the ultrafiltration membrane 13 and the carbon paper 14 to reach the simulated cathode flow channel L2 and then be discharged from the first outlet K3, in this embodiment, the simulated anode flow field end plate 11 is further provided with a second outlet K4 so that the gas in the simulated anode flow channel L1 can be quickly discharged through the second outlet K4, which is conducive to the injected water quickly filling the simulated anode flow channel L1 and allowing the simulation system to quickly enter a stable operating state.

[0067] As is known from the foregoing, the simulation system provided in the embodiments of the present application is mainly for facilitating the observation of the generation and transport characteristics of liquid water inside the fuel cell and for guiding the design of the bipolar plate flow channels of the fuel cell. Based on this, optionally, in some embodiments of the present application, the material of the simulated anode flow field end plate 11 can be acrylic transparent glass, and the material of the simulated cathode flow field end plate 12 can be acrylic transparent glass. In this way, the simulated anode flow channel L1 in the simulated anode flow field end plate 11 is clearly visible, and the simulated cathode flow channel L2 in the simulated cathode flow field end plate 12 is also clearly visible, so that the flow of water in the simulated anode flow channel L1 and the simulated cathode flow channel L2 can be clearly seen, so as to facilitate the optimization of the anode flow channel and the cathode flow channel. The acrylic transparent glass can be sapphire glass.

[0068] Further optionally, in some embodiments of the present application, such as Figure 1 As shown, the simulation system may further include a high-speed camera 50, which may be used to capture and record the flow of water in the simulated cathode flow channel L2, so as to optimize the cathode flow channel and the anode flow channel according to the flow of water in the simulated cathode flow channel L2.

[0069] In addition to using the above-mentioned visualization method to study the generation and discharge process of liquid water inside the fuel cell, a quantitative method can also be used to study the generation and discharge process of liquid water inside the fuel cell. Optionally, in some embodiments of the present application, such as Figure 1 As shown, the simulation system can also include a water storage container 60 and a weighing device 70, wherein the water storage container 60 is used to receive water flowing out from the first outlet K3 of the simulated cathode flow field end plate 12; the weighing device 70 is used to measure the weight of the water received by the water storage container 60 from the first outlet K3 of the simulated cathode flow field end plate 12.

[0070] Optionally, the water storage container 60 may be a beaker, and the weighing device 70 may be a balance scale.

[0071] For ease of understanding, Figure 4 FIG. 1 shows a schematic diagram showing the relationship between the weight of water flowing out of the first outlet K3 of the simulated cathode flow field end plate 12 and the time taken up by the water storage container 60, as shown in FIG. Figure 4 As shown, the water injection pump 20 starts to inject water into the water inlet K1 of the simulated anode flow field end plate 11. The injected water first fills the simulated anode flow channel L1, and then penetrates into the simulated cathode flow channel L2 through the ultrafiltration membrane 13 and the carbon paper 14, and finally passes through the simulated cathode flow channel L2 and flows out from the first outlet K3. Therefore, after a period of time from the start of water injection, the water flowing out of the first outlet K3 will gradually increase. The shorter the intermediate period t (i.e., the intercept on the horizontal axis of time), the better the drainage performance of the simulated cathode flow channel L2. Under different operating conditions of the fuel cell, the intercept t is different, which can represent different drainage capabilities.

[0072] Based on any of the above embodiments, optionally, in some embodiments of the present application, such as Figure 1 As shown, the simulation system may further include a first valve 21 and a liquid flow meter 22;

[0073] The first valve 21 is located on the connecting channel between the water injection pump 20 and the water inlet K1 of the simulated anode flow field end plate 11, and is used to control the opening and closing of the connecting channel between the water injection pump 20 and the water inlet K1 of the simulated anode flow field end plate 11;

[0074] The liquid flow meter 22 is located on the connecting channel between the water injection pump 20 and the water inlet K1 of the simulated anode flow field end plate 11 , and is used to monitor the flow rate of water injected into the water inlet K1 of the simulated anode flow field end plate 11 .

[0075] Optionally, the water injection pump 20 can be a peristaltic pump, an injection pump, a centrifugal pump or a gear pump, etc., and the controller 40 can control the valve size of the water injection pump 20 to adjust the flow rate of water injected by the water injection pump 20 into the water inlet K1 of the simulated anode flow field end plate 11; and in this embodiment, the first valve 21 is used to control the opening and closing of the connecting channel between the water injection pump 20 and the water inlet K1 of the simulated anode flow field end plate 11, and the liquid flow meter 22 is used to monitor the flow rate of water injected into the water inlet K1 of the simulated anode flow field end plate 11, so that the flow rate of water injected into the water inlet K1 of the simulated anode flow field end plate 11 can be more accurately controlled.

[0076] In addition, the controller 40 may also control the valve size of the water injection pump 20 according to the flow rate of water injected into the water inlet K1 of the simulated anode flow field end plate 11 monitored by the liquid flow meter 22 .

[0077] Similarly, in some embodiments of the present application, Figure 1 As shown, the simulation system may further include a second valve 31 and a gas flow meter 32;

[0078] The second valve 31 is located on the connecting channel between the air compressor 30 and the air inlet K2 of the simulated cathode flow field end plate 12, and is used to control the opening and closing of the connecting channel between the air compressor 30 and the air inlet K2 of the simulated cathode flow field end plate 12;

[0079] The gas flow meter 32 is located on the connecting channel between the air compressor 30 and the air inlet K2 of the simulated cathode flow field end plate 12 , and is used to monitor the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12 .

[0080] Optionally, the air compressor 30 can be a high-pressure air tank, etc., and the controller 40 can control the valve size of the air compressor 30 to adjust the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12; and in this embodiment, the second valve 31 is used to control the opening and closing of the connecting channel between the air compressor 30 and the air inlet K2 of the simulated cathode flow field end plate 12, and the gas flow meter 32 is used to monitor the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12, so that the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12 can be more accurately controlled.

[0081] In addition, the controller 40 may also control the valve size of the air compressor 30 according to the flow rate of air injected into the air inlet K2 of the simulated cathode flow field end plate 12 monitored by the gas flow meter 32 .

[0082] The various parts in this manual are described in a combination of parallel and progressive manners. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0083] With respect to the above description of the disclosed embodiments, the features described in the various embodiments in this specification may be interchanged or combined with one another to enable those skilled in the art to implement or use the present 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 the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simulation system for the generation and discharge of liquid water inside a fuel cell, characterized in that: include: A simulated fuel cell, the simulated fuel cell comprising a simulated anode flow field end plate and a simulated cathode flow field end plate, the simulated anode flow field end plate being provided with a water inlet and a simulated anode flow channel connected to the water inlet, the simulated cathode flow field end plate being provided with an air inlet, a first outlet and a simulated cathode flow channel connected to the air inlet and the first outlet, the simulated anode flow channel and the simulated cathode flow channel being provided correspondingly, an ultrafiltration membrane being provided on the side of the simulated anode flow channel facing the simulated cathode flow channel, and carbon paper being provided on the side of the simulated cathode flow channel facing the simulated anode flow channel; a water injection pump, the water injection pump being connected to the water inlet of the simulated anode flow field end plate, and the water injection pump being used to inject water into the water inlet of the simulated anode flow field end plate; an air compressor, the air compressor being connected to the air inlet on the simulated cathode flow field end plate, and the air compressor being used to inject air into the air inlet on the simulated cathode flow field end plate; A controller is used to control the flow rate of water injected by the water injection pump into the water inlet of the simulated anode flow field end plate, and to control the flow rate of air injected by the air compressor into the air inlet of the simulated cathode flow field end plate.

2. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, characterized in that: The process of the controller controlling the water injection pump to inject water into the water inlet of the simulated anode flow field end plate includes: Based on the current of the actual fuel cell, the water production per unit time inside the actual fuel cell is calculated, and the water injection pump is controlled to inject water into the water inlet of the simulated anode flow field end plate at a flow rate equal to the calculated water production per unit time inside the actual fuel cell.

3. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The process of the controller controlling the air compressor to inject air flow into the air inlet of the simulated cathode flow field end plate includes: Based on the current and stoichiometric ratio of the actual fuel cell, the volume flow rate of excess air outside the cathode end reaction of the actual fuel cell is calculated, and the air compressor is controlled to inject air into the air inlet of the simulated cathode flow field end plate at a flow rate that is the calculated volume flow rate of excess air outside the cathode end reaction of the actual fuel cell.

4. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The simulated anode flow field end plate is further provided with a second outlet, and the simulated anode flow channel is connected to the water inlet and the second outlet.

5. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The material of the simulated anode flow field end plate is acrylic transparent glass, and the material of the simulated cathode flow field end plate is acrylic transparent glass.

6. The simulation system for generating and discharging liquid water in a fuel cell according to claim 5, characterized in that: The simulation system further includes a high-speed camera, which is used to photograph and record the flow of water in the simulated cathode flow channel.

7. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The simulation system also includes a water storage container and a weighing device; The water storage container is used to receive the water flowing out of the first outlet of the simulated cathode flow field end plate; The weighing device is used to measure the weight of the water received by the water storage container from the first outlet of the simulated cathode flow field end plate.

8. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The simulation system further includes a first valve and a liquid flow meter; The first valve is located on the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate, and is used to control the opening and closing of the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate; The liquid flow meter is located on the connecting channel between the water injection pump and the water inlet of the simulated anode flow field end plate, and is used to monitor the flow rate of water injected into the water inlet of the simulated anode flow field end plate.

9. The simulation system for generating and discharging liquid water in a fuel cell according to claim 1, wherein: The simulation system also includes a second valve and a gas flow meter; The second valve is located on the connecting passage between the air compressor and the air inlet of the simulated cathode flow field end plate, and is used to control the opening and closing of the connecting passage between the air compressor and the air inlet of the simulated cathode flow field end plate; The gas flow meter is located on the connecting channel between the air compressor and the air inlet of the simulated cathode flow field end plate, and is used to monitor the flow rate of air injected into the air inlet of the simulated cathode flow field end plate.

10. The simulation system for generating and discharging liquid water in a fuel cell according to any one of claims 1 to 9, characterized in that: The simulated anode flow channel and the simulated cathode flow channel are parallel flow channels, serpentine flow channels, staggered flow channels, matrix flow channels, wavy flow channels or indented flow channels.

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