Flow frame assembly and stack composed thereof

Abstract

This invention provides a fluid flow frame assembly and a fuel cell stack composed of it. The fluid flow frame assembly includes an integrally formed fluid flow frame, which comprises a frame body and a primary flow channel disposed on the frame body. The depth of the primary flow channel varies uniformly along the electrolyte flow direction and includes a deep buried region, a transition region, and a shallow buried region. The ratio of the depth of the shallow buried region to the depth of the deep buried region is less than 1, and the depth of the deep buried region accounts for more than 20% of the overall thickness of the fluid flow frame. The length of the shallow buried region is defined as L1, and the total length of the primary flow channel is L0. Then, L1 / L0 is not greater than 90%. This invention creatively designs the positive and negative electrode fluid flow frames as a whole and sets the primary flow channel as a variable-speed flow channel including a deep buried region, a transition region, and a shallow buried region. By optimizing the control of the depth ratio of the deep buried region and the length ratio of the shallow buried region, a significant reduction in the flow resistance of the fuel cell stack can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flow batteries, and particularly to a flow frame assembly and a stack composed thereof. Background Art

[0002] Flow batteries, especially all-vanadium redox flow batteries (abbreviated as vanadium batteries, VRB), are a new type of high-efficiency and large-capacity energy storage battery with a long lifespan and high safety. Currently, they have been successfully demonstrated and applied to the smooth power output of wind farms. In the future, in the broad new energy field, such as wind power generation, photovoltaic power generation, smart grids, etc., they have broad application prospects.

[0003] Currently, the flow battery stacks in the prior art are mainly composed of an outer end plate, an insulating plate, an end frame, a current collector plate, and multiple single cells stacked together. A single cell is composed of a flow frame assembly, an electrode, a separator, etc. As Figure 1 shown, the flow frame assembly consists of three components: a positive flow frame 100, a bipolar plate 200, and a negative flow frame 300. The bipolar plate is sandwiched between two flow frames, playing a role in separating the electrolyte and conducting current. As Figure 2 and Figure 3 ]>shown, the positive flow frame 100 and the negative flow frame 300 have the same structure, both consisting of a frame body 101, a primary flow channel 102, a secondary flow channel 103, and a bipolar plate mating surface 104. The thickness of the positive flow frame 100 is set as a1, the depth of the primary flow channel 102 is set as b1, and the depth of the secondary flow channel 103 is set as c1. The relationship is b1 = c1 < a1, and the depth b1 of the primary flow channel 102 generally does not exceed 50% of the total thickness of the flow frame.

[0004] However, the current problem with the stack is that the flow resistance is relatively large, resulting in: 1) a relatively large pump loss in the system; 2) an increased risk of stack leakage. To address the aforementioned problems, the prior art usually adopts the following solutions: 1) Optimize the flow channels of the flow frame. Since the positive and negative flow frames are two components and are limited in thickness, the proportion of the reduction in flow resistance is limited while ensuring a uniform flow field; 2) Thin the electrode and attach a flow channel plate on the bipolar plate. Adopting this form can significantly reduce the flow resistance, but it increases the material cost and the assembly of the flow channel plate is complex, increasing the assembly cost of the stack. Summary of the Invention

[0005] The main object of the present invention is to provide a flow frame assembly and a stack composed thereof to solve the problem in the prior art that the vanadium battery stack has a large flow resistance, resulting in a large pump loss in the system and a leakage risk.

[0006] Existing technologies typically reduce fuel cell stack flow resistance by optimizing the fluid flow frame channel or attaching flow channel plates to the bipolar plates. However, since the positive and negative electrode fluid flow frames are made of two separate materials, their thickness is limited, and even with optimized fluid flow frame channels, the reduction in flow resistance is very limited. While thinning the electrodes and attaching flow channel plates to the bipolar plates can significantly reduce flow resistance, it also increases material costs and complicates flow channel plate assembly, thus increasing fuel cell stack assembly costs. To address these issues, this invention creatively designs the positive and negative electrode fluid flow frames as a single unit, and sets the primary flow channel as a variable-speed flow channel including a deep-buried region, a transition region, and a shallow-buried region. By optimizing and controlling the depth and length of the deep-buried and shallow-buried regions, a significant reduction in fuel cell stack flow resistance can be achieved. Based on this approach, the solution of this invention is provided.

[0007] To achieve the above objectives, a first aspect of the present invention provides a fluid flow frame assembly, comprising an integrally formed fluid flow frame, the fluid flow frame including a frame body and a primary flow channel disposed on the frame body; the depth of the primary flow channel varies uniformly along the electrolyte flow direction, and the primary flow channel includes a deep buried region, a transition region and a shallow buried region, the ratio of the depth of the shallow buried region to the depth of the deep buried region is less than 1, and the depth of the deep buried region accounts for more than 20% of the overall thickness of the fluid flow frame; the length of the shallow buried region is defined as L1, and the total length of the primary flow channel is L0, then L1 / L0 is not greater than 90%.

[0008] In some embodiments, the depth of the deep burial zone accounts for 20-90% of the overall thickness of the fluid flow frame; And / or, the depth of the buried zone accounts for 30-85% of the overall thickness of the fluid flow frame; And / or, the L1 / L0 ratio is not greater than 50%.

[0009] In some embodiments, the depth of the primary flow channel gradually decreases along the flow direction of the electrolyte inlet and gradually increases along the flow direction of the electrolyte outlet.

[0010] In some embodiments, the depth of the primary flow channel gradually increases along the flow direction of the electrolyte inlet and gradually decreases along the flow direction of the electrolyte outlet.

[0011] In some embodiments, the primary flow channel includes a primary flow channel A and a primary flow channel B. The primary flow channel A is disposed on a first side of the frame, and the primary flow channel B is disposed on a second side opposite to the first side. The primary flow channel A and the primary flow channel B are axially symmetrical.

[0012] In some embodiments, the frame is further provided with a secondary flow channel that communicates with the primary flow channel.

[0013] In some embodiments, the depth of the secondary flow channel is 0.8-3.7 mm, and the depth of the secondary flow channel accounts for less than 40% of the overall thickness of the fluid flow frame; And / or, the depth of the secondary flow channel accounts for 20-40% of the overall thickness of the fluid flow frame.

[0014] In some embodiments, the secondary flow channel includes a secondary flow channel A disposed on the frame and a secondary flow channel plate that is installed in conjunction with the frame, wherein the secondary flow channel A is disposed on a first side of the frame.

[0015] In some embodiments, the secondary flow channel plate includes a flow channel plate body and a secondary flow channel B disposed on the flow channel plate body. The secondary flow channel A and the secondary flow channel B have the same structure and are arranged in a mirror-symmetric manner after the flow frame assembly is assembled into a whole.

[0016] In some embodiments, the frame is further provided with a recessed platform for placing the bipolar plate, the recessed platform being sealed to one side of the bipolar plate, and the secondary flow channel plate being sealed to the other side of the bipolar plate.

[0017] A second aspect of the present invention provides a flow battery stack in which the flow frame assembly described in the first aspect is employed.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The fluid flow frame assembly provided by this invention designs the positive and negative electrode fluid flow frames as a whole, and sets the primary flow channel as a variable speed flow channel including a deep buried region, a transition region and a shallow buried region. The ratio of the depth of the shallow buried region to the depth of the deep buried region is less than 1, and the depth of the deep buried region accounts for more than 20% of the overall thickness of the fluid flow frame. This combination ensures that the length of the shallow buried region accounts for no more than 90% of the total length of the primary flow channel, thereby achieving a significant reduction in the flow resistance of the fuel cell stack.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a fluid flow frame assembly in the prior art.

[0022] Figure 2 This is a schematic diagram of the structure of the fluid flow frame in the prior art.

[0023] Figure 3 This is a cross-sectional view of the fluid flow frame in the prior art.

[0024] Figure 4 This is a schematic diagram of the fluid flow frame assembly provided in Embodiment 1 of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure of the fluid flow frame in the fluid flow frame assembly provided in Embodiment 1 of the present invention.

[0026] Figure 6 This is a cross-sectional view of the primary flow channel in the fluid flow frame assembly provided in Embodiment 1 of the present invention.

[0027] Figure 7 This is a cross-sectional view of the primary flow channel in the fluid flow frame assembly provided in Embodiment 1 of the present invention.

[0028] Explanation of reference numerals in the attached figures 10. Fluid flow frame; 100. Positive electrode fluid flow frame; 101. Frame body; 1011. First side surface; 1012. Second side surface; 102. Primary flow channel; 1021. Primary flow channel A; 1022. Primary flow channel B; 1023. Deep burial area; 1024. Transition area; 1025. Shallow burial area; 103. Secondary flow channel; 1031. Secondary flow channel A; 104. Bipolar plate mating surface; 105. Settlement platform; 200. Bipolar plate; 300. Negative electrode fluid flow frame; 400. Secondary flow channel plate; 401. Flow channel plate body; 402. Secondary flow channel B; 500. Electrolyte inlet.

[0029] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0032] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0033] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0034] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0035] In this invention, unless otherwise stated, the deep burial area refers to the region with the greatest depth in the primary flow channel.

[0036] In this invention, unless otherwise stated, the shallow buried area refers to the region with the lowest depth in the primary flow channel.

[0037] In this invention, unless otherwise stated, the transition zone refers to the area between the deep burial zone and the shallow burial zone in the primary flow channel. The depth of this area gradually changes and decreases with the flow direction of the electrolyte, so that the line connecting the end of the deep burial zone and the beginning of the shallow burial zone is sloped.

[0038] It should be noted that the slope angle θ of the transition zone refers to the angle between the line connecting the end (or initial end) of the deep buried zone and the initial end (or end) of the shallow buried zone and the plane where the liquid flow frame is located.

[0039] As mentioned earlier, the positive and negative electrode flow frames of existing vanadium redox flow battery stacks are made of two materials. Due to the limitations in their thickness, even with optimization and adjustment of the flow frame channels, the reduction in flow resistance is very limited while ensuring a uniform flow field.

[0040] To solve the above problems, such as Figure 4 , Figure 5 , Figure 6 , Figure 7As shown, an embodiment of the present invention provides a fluid flow frame assembly, including an integrally formed fluid flow frame 10. The fluid flow frame 10 includes a frame body 101 and a primary flow channel 102 disposed on the frame body 101. The depth of the primary flow channel 102 varies uniformly along the electrolyte flow direction, and the primary flow channel 102 includes a deep buried region 1023, a transition region 1024, and a shallow buried region 1025. The ratio of the depth of the shallow buried region 1025 to the depth of the deep buried region 1023 is less than 1, and the depth of the deep buried region 1023 accounts for more than 20% of the overall thickness of the fluid flow frame 10. The length of the shallow buried region 1025 is defined as L1, and the total length of the primary flow channel 102 is defined as L0. Then, L1 / L0 is not greater than 90%.

[0041] The fluid flow frame assembly provided by this invention designs the positive and negative electrode fluid flow frames as a whole, and sets the primary flow channel as a variable speed flow channel including a deep buried region, a transition region and a shallow buried region. The ratio of the depth of the shallow buried region to the depth of the deep buried region is less than 1, and the depth of the deep buried region accounts for more than 20% of the overall thickness of the fluid flow frame. This combination ensures that the length of the shallow buried region accounts for no more than 90% of the total length of the primary flow channel, thereby achieving a significant reduction in the flow resistance of the fuel cell stack.

[0042] It is worth noting that this invention innovatively integrates the positive and negative electrode flow frames into a single material. Compared with existing technologies, the overall thickness of the flow frame is increased, allowing for a significant increase in the depth of the primary flow channels on the flow frame. Furthermore, it should be noted that this invention does not impose any particular requirements on the thickness of the flow frame; the appropriate thickness can be designed according to the specific application scenario.

[0043] In some embodiments, the depth of the deep burial zone 1023 accounts for 20-90% of the overall thickness of the fluid flow frame 10. The percentage of the depth of the deep burial zone in the overall thickness of the fluid flow frame can be, for example, any value between 20% and 90% of 20%, 24%, 25%, 28%, 30%, 33%, 35%, 36%, 38%, 40%, 42%, 45%, 48%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 20-90%. Preferably, the depth of the deep burial zone 1023 accounts for 30-85% of the overall thickness of the fluid flow frame. During research, it was found that the ratio of the depth of the shallow burial zone to the depth of the deep burial zone is less than 1. By ensuring that the depth of the deep burial zone accounts for 30-85% of the overall thickness of the fluid flow frame, flow resistance can be significantly reduced while maintaining a uniform flow field.

[0044] It should be noted that the present invention does not have any special requirements for the depth of the shallow buried area and the depth of the deep buried area. It is only necessary to ensure that the ratio between the two is less than 1 and the depth of the deep buried area 1023 accounts for 30-85% of the overall thickness of the liquid flow frame. Under the condition of satisfying the aforementioned ratio range, the depth values ​​of the deep buried area and the shallow buried area can be designed independently according to the actual application scenario.

[0045] In some embodiments, the L1 / L0 ratio is no greater than 50%. The L1 / L0 ratio can be, for example, any value of 0, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or no greater than 50%. During the research, it was found that by making the ratio of the shallow burial zone depth to the deep burial zone depth less than 1, and the depth of the deep burial zone accounting for more than 20% of the overall thickness of the fluid flow frame, combined with an L1 / L0 ratio no greater than 50%, the flow resistance of the fuel cell stack can be significantly reduced compared to existing technologies.

[0046] like Figure 6 As shown, in some embodiments, the depth of the primary flow channel 102 gradually decreases along the flow direction of the electrolyte inlet 500, and the depth of the primary flow channel 102 gradually increases along the flow direction of the electrolyte outlet. In some embodiments, the transition zone has a slope angle θ, and 0° < θ ≤ 90°. Preferably, θ is 30°-90°.

[0047] like Figure 7 As shown, in some embodiments, the depth of the primary flow channel 102 gradually increases along the flow direction of the electrolyte inlet 500, and the depth of the primary flow channel 102 gradually decreases along the flow direction of the electrolyte outlet. In some embodiments, the transition zone has a slope angle θ, and 90°≤θ<180°. Preferably, θ is 90°-120°.

[0048] In some embodiments, the primary flow channel 102 includes a primary flow channel A 1021 and a primary flow channel B 1022. The primary flow channel A 1021 is disposed on a first side 1011 of the frame 101, and the primary flow channel B 1022 is disposed on a second side 1012 opposite to the first side 1011. The primary flow channel A 1021 and the primary flow channel B 1022 are axially symmetrical.

[0049] It should be noted that, as Figure 5As shown, primary flow channels A and B are respectively located on two opposite sides of the flow frame, and the mirror image of primary flow channel B is symmetrical to primary flow channel A along the vertical central axis of the frame. There is no particular requirement for the number of primary flow channels in this invention; the number can be optimized and adjusted according to actual needs. Specifically, the number of primary flow channels A and B is the same, and both primary flow channels A and B are configured as variable-speed flow channels.

[0050] like Figure 4 and Figure 5 As shown, in this embodiment of the invention, there are two primary flow channels A, and the two primary flow channels A are symmetrically distributed along the horizontal central axis of the frame. One primary flow channel A is connected to the electrolyte inlet, and the other primary flow channel A is connected to the electrolyte outlet. The primary flow channel B is arranged in a similar manner to the primary flow channel A, and will not be described in detail here.

[0051] In some embodiments, the frame 101 is further provided with a secondary flow channel 103 that communicates with the primary flow channel 102. It should be noted that the present invention provides interconnected primary and secondary flow channels on the frame. The flow rate is first dispersed by the primary flow channel guide groove, and then the flow velocity is balanced by the secondary flow channel, resulting in a more uniform distribution of the electrolyte within the electrode, eliminating flow dead zones, and ensuring full utilization of the active material.

[0052] In some embodiments, the depth of the secondary flow channel 103 is 0.8-3.7 mm, and the depth of the secondary flow channel 103 accounts for less than 40% of the overall thickness of the liquid flow frame. The depth of the secondary flow channel can be, for example, any value between 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.1 mm, 2.4 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.3 mm, 3.5 mm, 3.7 mm, or 0.8-3.7 mm. The percentage of the depth of the secondary flow channel to the overall thickness of the liquid flow frame can be, for example, any value below 10%, 15%, 16%, 18%, 20%, 23%, 25%, 28%, 30%, 32%, 35%, 36%, 37%, 38%, 39%, 40%. Preferably, the depth of the secondary flow channel accounts for 20-40% of the overall thickness of the liquid flow frame. During the research, it was found that controlling the depth of the secondary flow channel to be 20-40% of the overall thickness of the liquid flow frame can better play the role of diverting electrolyte and is conducive to balancing the flow field.

[0053] In some embodiments, the secondary flow channel 103 includes a secondary flow channel A 1031 disposed on the frame 101 and a secondary flow channel plate 400 that is installed in cooperation with the frame 101, wherein the secondary flow channel A 1031 is disposed on the first side 1011 of the frame 101.

[0054] like Figure 5 As shown, in this embodiment of the invention, the secondary flow channel A is connected to the primary flow channel A. On the first side of the frame, the electrolyte first passes through the guide groove of the primary flow channel A to disperse the flow rate, and then passes through the secondary flow channel A to balance the flow rate, so that the electrolyte is more evenly distributed in the electrode. On the second side of the frame, the electrolyte first passes through the primary flow channel B on the frame to disperse the flow rate, and then passes through the secondary flow channel plate that is installed in conjunction with the frame.

[0055] In some embodiments, the secondary flow channel plate 400 includes a flow channel plate body 401 and a secondary flow channel B 402 disposed on the flow channel plate body 401. The secondary flow channel A 1031 and the secondary flow channel B 402 have the same structure and are mirror-symmetrical after the liquid flow frame assembly is assembled into a whole. It is worth noting that the secondary flow channel plate is provided with a secondary flow channel B that is mirror-symmetrical to the secondary flow channel A. The electrolyte after being guided and dispersed passes through the secondary flow channel B on the secondary flow channel plate. The function of the secondary flow channel B is the same as that of the secondary flow channel A, both of which can play the role of diverting electrolyte and balancing the flow field.

[0056] In some embodiments, the frame 101 is further provided with a recessed platform 105 for placing the bipolar plate 200. The recessed platform 105 is sealed to one side of the bipolar plate 200, and the secondary flow channel plate 400 is sealed to the other side of the bipolar plate 200. This invention places the bipolar plate between the liquid flow frame and the secondary flow channel plate, effectively separating the electrolyte from the conductive current. Simultaneously, the sealed area between the bipolar plate and the liquid flow frame is located within the recessed platform of the liquid flow frame, eliminating external leakage in the bipolar plate's sealed area and significantly reducing the risk of overall leakage.

[0057] It should be noted that the present invention does not impose any particular requirements on the specific method of the sealing connection; methods well-known in the art can be used for sealing. These methods will not be elaborated upon here, and those skilled in the art should not interpret them as limitations on the present invention. Exemplarily, the present invention can achieve sealing through welding, rubber gaskets, hot melting, or adhesives.

[0058] In some embodiments, the depth of the recess 105 is 2.8-4.8 mm, and the depth of the assembly groove accounts for 30-55% of the overall thickness of the fluid flow frame. It should be noted that the other dimensions of the recess are matched with the bipolar plate. By setting the recess, the bipolar plate is embedded into the fluid flow frame, which greatly reduces the size of the bipolar plate and lowers the cost of the fuel cell stack.

[0059] like Figure 4 As shown, in some embodiments, the secondary flow channel plate 400 is integrally formed and also includes a bipolar plate mating surface disposed on the flow channel plate body 401. The bipolar plate 200 is sealed to the secondary flow channel plate 400 through the bipolar plate mating surface, and the secondary flow channel B 402 is disposed on the opposite side of the bipolar plate mating surface.

[0060] The assembly method of the fluid flow frame assembly described in this invention is as follows: First, the bipolar plate is placed into the settling platform and matched with it (not shown in the attached figure). The bipolar plate and the settling platform can be sealed by welding, rubber gaskets, hot melt, or glue. Next, the side of the secondary flow channel plate with the bipolar plate mating surface is placed into the flow frame settling platform and matched with it (not shown in the attached figure). The secondary flow channel plate and the bipolar plate can be sealed by welding, rubber gaskets, hot melt, or glue. After sealing, the secondary flow channel plate is completely matched with the primary flow channel. In this way, the flow frame, bipolar plate, and secondary flow channel plate form the flow frame assembly.

[0061] In the embodiments provided by this invention, the bipolar plate is located between the liquid flow frame and the secondary flow channel plate, serving to separate the electrolyte from the conduction current. The secondary flow channel B below the secondary flow channel plate has the same function as the secondary flow channel A, serving to divert the electrolyte and balance the flow field. By designing the positive and negative electrode liquid flow frames as a whole, the depth of the primary flow channel is significantly increased, resulting in a substantial reduction in the flow resistance of the fuel cell stack.

[0062] As previously described, a second aspect of the present invention provides a flow battery stack in which the flow frame assembly described in the first aspect is employed.

[0063] The following will use examples, combined with Figures 4 to 7 The present invention will be described in detail below. Unless otherwise specified, all raw materials used in the following examples are commercially available.

[0064] In the following examples, the sealed connection between the bipolar plate and the settling platform, and the sealed connection between the secondary flow channel plate and the bipolar plate are achieved by welding.

[0065] In the following examples, the total length of the primary flow channel is 175 mm, the thickness of the flow frame is 6.8 mm, the thickness of the bipolar plate is 0.8 mm, and the depth of the settling platform is 3.8 mm. Figure 6The slope angle θ of the intermediate transition zone is 80°. Figure 7 The slope angle θ of the intermediate transition zone is 100°.

[0066] In the following embodiments, unless otherwise stated, when the length of the shallow buried zone accounts for 0% of the total length of the primary flow channel (i.e., L1 / L0), the depth of the shallow buried zone refers to the minimum depth value of the transition zone.

[0067] In the following examples, unless otherwise stated, the mainstream numerical simulation software currently used for simulating fuel cell stack flow resistance is COMSOL. By establishing numerical models of objects such as flow channels and porous electrodes in the software and setting the corresponding parameters in the embodiments, the flow resistance of the fuel cell stack under operating conditions can be simulated and calculated.

[0068] Example 1

[0069] like Figure 4 , Figure 5 , Figure 6 As shown, the fluid flow frame assembly A1 includes an integrally formed fluid flow frame 10. The fluid flow frame 10 includes a frame body 101 and a primary flow channel 102 disposed on the frame body 101. The depth of the primary flow channel 102 gradually decreases along the flow direction of the electrolyte inlet 500, and the primary flow channel 102 sequentially includes a deep buried region 1023, a transition region 1024, and a shallow buried region 1025 along the flow direction of the electrolyte inlet 500. The ratio of the depth of the shallow buried region 1025 to the depth of the deep buried region 1023 is 0.4:1. The depth of the deep buried region is 3.4 mm, accounting for approximately 50% of the overall thickness of the fluid flow frame. The proportion of the length of the shallow buried region 1025 in the total length of the primary flow channel 102 (i.e., L1 / L0) is 0. The frame 101 is also provided with a secondary flow channel 103 that communicates with the primary flow channel 102. The primary flow channel 102 and the secondary flow channel 103 are interconnected. The secondary flow channel 103 includes a secondary flow channel A 1031 disposed on the frame 101 and a secondary flow channel plate 400 that is installed in cooperation with the frame 101. The secondary flow channel A 1031 is disposed on the first side 1011 of the frame 101, and the secondary flow channel plate 400 is disposed on the second side 1012 of the first side 1011. The secondary flow channel plate 400 includes a flow channel plate body 401 and a secondary flow channel B 402 disposed on the flow channel plate body 401. The secondary flow channel A 1031 and the secondary flow channel B 402 have the same structure and are mirror-symmetrical after the liquid flow frame assembly is assembled into a whole. The depths of secondary flow channel A 1031 and secondary flow channel B 402 are both 1.4 mm, meaning that the depth of secondary flow channel 103 accounts for approximately 20% of the overall thickness of the fluid flow frame. The frame 101 is also provided with a recessed platform 105 for placing the bipolar plate 200. One side of the bipolar plate 200 is sealed to the recessed platform 105, and the other side is sealed to the secondary flow channel plate 400.

[0070] Simulation results show that the stack current resistance of the fluid flow frame assembly A1 in this embodiment is 40.2 kPa; Figure 1 The existing fluid flow frame assembly in the technology is used as a control group (the thickness a1 of the fluid flow frame in the control group is 3 mm, the depth b1 of the primary flow channel is 1.4 mm, and the depth c1 of the secondary flow channel is 1.4 mm). The current resistance of the fuel cell stack in the control group is 80 kPa.

[0071] Example 2

[0072] The flow frame assembly A2 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1, the depth of the deep buried area is 3.4 mm, accounting for about 50% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 25% of the total length of the primary flow channel 102; other parameters and structures are the same as those of the flow frame assembly A1.

[0073] Simulation results show that the stack resistance of the fluid flow frame assembly A2 in this embodiment is 55.1 kPa.

[0074] Example 3

[0075] The flow frame assembly A3 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1, the depth of the deep buried area is 3.4 mm, which accounts for about 50% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 50% of the total length of the primary flow channel 102; other parameters and construction are the same as those of the flow frame assembly A1.

[0076] Simulation results show that the stack resistance of the fluid flow frame assembly A3 in this embodiment is 67.2 kPa.

[0077] Example 4 The flow frame assembly A4 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1, the depth of the deep buried area is 3.4 mm, which accounts for about 50% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 90% of the total length of the primary flow channel 102; other parameters and construction are the same as those of the flow frame assembly A1.

[0078] Simulation results show that the stack resistance of the fluid flow frame assembly A4 in this embodiment is 78 kPa.

[0079] Example 5

[0080] The flow frame assembly A5 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.7:1, the depth of the deep buried area is 2.0 mm, accounting for approximately 29.4% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 0% of the total length of the primary flow channel 102. Other parameters and structures are the same as those of the flow frame assembly A1.

[0081] Simulation results show that the stack current resistance of the fluid flow frame assembly A5 in this embodiment is 54.2 kPa.

[0082] Example 6

[0083] The flow frame assembly A6 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.52:1, the depth of the deep buried area is 2.7 mm, which accounts for approximately 39.7% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 0% of the total length of the primary flow channel 102. Other parameters and structures are the same as those of the flow frame assembly A1.

[0084] Simulation results show that the stack current resistance of the fluid flow frame assembly A6 in this embodiment is 43.5 kPa.

[0085] Example 7

[0086] like Figure 4 , Figure 5 and Figure 7 As shown, the flow frame assembly A7 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the depth of the primary flow channel 102 gradually increases along the flow direction of the electrolyte inlet 500, and the primary flow channel 102 includes a shallow buried area 1025, a transition area 1024, and a deep buried area 1023 in sequence along the flow direction of the electrolyte inlet 500. The ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1. The depth of the deep buried area is 3.4 mm, which accounts for about 50% of the overall thickness of the flow frame. The length of the shallow buried area 1025 accounts for 25% of the total length of the primary flow channel 102. Other parameters and structures are the same as those of the flow frame assembly A1.

[0087] Simulation results show that the stack current resistance of the fluid flow frame assembly A7 in this embodiment is 50.6 kPa.

[0088] Example 8

[0089] The flow frame assembly A8 has a similar structure to the flow frame assembly A1 provided in Embodiment 7. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1, the depth of the deep buried area is 3.4 mm, which accounts for about 50% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 50% of the total length of the primary flow channel 102; other parameters and construction are the same as those of the flow frame assembly A1.

[0090] Simulation results show that the stack current resistance of the fluid flow frame assembly A8 in this embodiment is 67.6 kPa.

[0091] Comparative Example 1 The flow frame assembly DA1 has a similar structure to the flow frame assembly A1 provided in Embodiment 1. The difference is that in this embodiment, the ratio of the depth of the shallow buried area 1025 to the depth of the deep buried area 1023 is 0.4:1, the depth of the deep buried area is 0.8mm, which accounts for about 11.7% of the overall thickness of the flow frame, and the length of the shallow buried area 1025 accounts for 0% of the total length of the primary flow channel 102. Other parameters and structures are the same as those of the flow frame assembly A1.

[0092] Simulation results show that the stack current resistance of the fluid flow frame assembly DA1 in this comparative example is 228 kPa.

[0093] By comparing Examples 1-4 and Comparative Example 1, it can be seen that, when the ratio of shallow burial zone depth to deep burial zone depth and the slope angle of the transition zone are fixed, the flow resistance of the fuel cell stack increases as the proportion of the shallow burial zone length in the total length of the primary flow channel increases. When the proportion of the shallow burial zone length in the total length of the primary flow channel is less than 50%, the flow resistance is reduced even more.

[0094] By comparing Examples 1, 5-6 and Comparative Example 1, it can be seen that, with the fluid flow frame assembly provided by the present invention having a fixed fluid flow frame thickness, shallow burial zone depth, deep burial zone depth ratio and transition zone slope angle, as the proportion of the deep burial zone depth in the overall thickness of the fluid flow frame increases, the reduction in fuel cell stack flow resistance increases accordingly. When the proportion of the deep burial zone depth in the overall thickness of the fluid flow frame is more than 20%, the fuel cell stack flow resistance is significantly reduced.

[0095] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0096] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A fluid flow frame assembly, characterized in that, The device includes an integrally formed fluid flow frame, comprising a frame body and a primary flow channel disposed on the frame body; the depth of the primary flow channel varies uniformly along the electrolyte flow direction, and the primary flow channel includes a deep buried zone, a transition zone, and a shallow buried zone, wherein the ratio of the depth of the shallow buried zone to the depth of the deep buried zone is less than 1, and the depth of the deep buried zone accounts for more than 20% of the overall thickness of the fluid flow frame; the length of the shallow buried zone is defined as L1, and the total length of the primary flow channel is defined as L0, then L1 / L0 is not greater than 90%.

2. The fluid flow frame assembly according to claim 1, characterized in that, The depth of the buried zone accounts for 20-90% of the overall thickness of the fluid flow frame; and / or The L1 / L0 ratio is no greater than 50%.

3. The fluid flow frame assembly according to claim 1, characterized in that, The depth of the primary flow channel gradually decreases along the flow direction of the electrolyte inlet and gradually increases along the flow direction of the electrolyte outlet.

4. The fluid flow frame assembly according to claim 1, characterized in that, The depth of the primary flow channel gradually increases along the flow direction of the electrolyte inlet and gradually decreases along the flow direction of the electrolyte outlet.

5. The fluid flow frame assembly according to claim 3 or 4, characterized in that, The primary flow channel includes primary flow channel A and primary flow channel B. Primary flow channel A is disposed on the first side of the frame, and primary flow channel B is disposed on the second side opposite to the first side. The primary flow channel A and primary flow channel B are axially symmetrical.

6. The fluid flow frame assembly according to claim 5, characterized in that, The frame is also provided with a secondary flow channel communicating with the primary flow channel; and / or The depth of the secondary flow channel is 0.8-3.7 mm, and the depth of the secondary flow channel accounts for less than 40% of the overall thickness of the liquid flow frame.

7. The fluid flow frame assembly according to claim 6, characterized in that, The secondary flow channel includes a secondary flow channel A disposed on the frame and a secondary flow channel plate that is installed in conjunction with the frame. The secondary flow channel A is disposed on the first side of the frame.

8. The fluid flow frame assembly according to claim 7, characterized in that, The secondary flow channel plate includes a flow channel plate body and a secondary flow channel B disposed on the flow channel plate body. The secondary flow channel A and the secondary flow channel B have the same structure and are arranged in a mirror symmetrical manner after the liquid flow frame assembly is assembled into a whole.

9. The fluid flow frame assembly according to claim 8, characterized in that, The frame is also provided with a recessed platform for placing the bipolar plate. The recessed platform is sealed to one side of the bipolar plate, and the secondary flow channel plate is sealed to the other side of the bipolar plate.

10. A flow battery stack, characterized in that, The flow battery stack uses the flow frame assembly as described in any one of claims 1-9.

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