Flow battery distribution area design method

Abstract

The invention discloses a flow battery distribution area design method, which comprises the following steps of: formulating a corresponding flow channel distribution area hierarchical structure according to a flow channel distribution type; determining the number of transfer stations of the electrolyte distribution area of each level in the hierarchical structure of the flow channel distribution area, and designing that the total through-flow sectional area of each branch between the transfer stations of two adjacent levels is consistent; according to the total through-flow sectional area of each branch of any transfer station in the electrolyte distribution area and the number and confluence condition of all branches connected with the liquid outlet end of the transfer station, the through-flow amount of each branch is calculated, and then the through-flow sectional area and the through-flow length of the corresponding branch are designed according to the through-flow amount of the branch. Through-flow speeds, through-flow time and through-flow flows of all branches in the electrolyte distribution area are designed to be consistent. When the number of the branch structures is expanded, the size of the branches can be directly calculated, the calculation result is accurate, the distribution is more uniform, the reaction efficiency of the flow battery is greatly improved, and the design efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of liquid flow batteries, and in particular to a method for designing a liquid flow battery distribution area. Background Art

[0002] The design of the pole frame distribution area of ​​the flow battery has a great impact on the electrode reaction area. Generally, in the design process of the flow battery, when the electrolyte flows from the inlet through the distribution area into the reaction area, the performance of the designed product is often insufficient due to uneven electrolyte distribution, which specifically includes uneven flow, uneven speed and uneven time. 1) Compared with uneven speed and time, when the flow distribution is uneven, it will have a greater impact on the performance of the product; for example, in the area where the flow distribution is too little, this part of the area does not participate in the reaction or rarely participates in the reaction. At the same time, in the area where the flow distribution is excessive, the polarization loss is too large. 2) The uneven speed is mainly manifested in the uneven electrolyte reaction efficiency, resulting in performance differences between the flow channels. 3) The uneven time is mainly manifested in the time response speed. The electrolyte that first enters the reaction zone flow channel participates in the reaction first, which results in the equipment only being able to exert part of its performance at the beginning of operation.

[0003] For example, the Chinese invention patent with the existing publication number CN109841873B discloses a liquid flow frame suitable for a liquid flow battery stack or a liquid flow battery, which is provided with free flow areas at the liquid inlet and liquid outlet ends of the electrode reaction zone, and more than two grooves as secondary flow guide channels are opened in each free flow area to improve the uniformity of electrolyte distribution. However, the flow area of ​​each secondary flow guide channel in this technical means is consistent, which greatly limits the design size of the secondary flow guide channel. For example, each expansion of the secondary flow guide channel needs to be verified by a large amount of experimental data to modify the flow length, and the design efficiency is low. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method for designing a distribution area of ​​a flow battery to solve the technical problems mentioned in the prior art.

[0005] A method for designing a distribution area of ​​a flow battery, the method comprising the following steps:

[0006] A corresponding hierarchical structure of flow channel distribution areas is formulated according to the flow channel distribution type, wherein the hierarchical structure of the flow channel distribution areas has at least one level of electrolyte distribution areas, and the electrolyte distribution area includes at least one transfer station and a plurality of branches, wherein the liquid inlet of the branch is connected to the liquid inlet of the flow channel or the liquid outlet of the electrolyte distribution area of ​​the upper level through the transfer station, and the liquid outlet of the branch is connected to the transfer station of the electrolyte distribution area of ​​the lower level or connected to the liquid outlet of the flow channel after passing through the reaction area of ​​the flow battery;

[0007] Determine the number of transfer stations of the electrolyte distribution area at each level in the hierarchical structure of the flow channel distribution area, and design the total flow cross-sectional area of ​​each branch between the transfer stations in the electrolyte distribution areas of two adjacent levels to be consistent;

[0008] Calculate the flow rate of each branch according to the total flow cross-sectional area of ​​each branch of any transfer station in the electrolyte distribution area and the number and confluence of all branches connected to the liquid outlet, and design the flow cross-sectional area and flow length of the branch according to the flow rate of the branch according to the set design conditions;

[0009] The design condition is: design the flow velocity, flow time and flow rate of all the branches in the electrolyte distribution area of ​​each level to be consistent with each other.

[0010] Optionally, the design condition further includes: the depth of each of the branches in the flow channel distribution area hierarchical structure is the same.

[0011] Optionally, the flow cross-sectional area of ​​the liquid inlet and the liquid outlet of each branch in the hierarchical structure of the flow channel distribution area is the same.

[0012] Optionally, when the liquid outlets of all the branches connected to the liquid outlet end of the transfer station have no confluence area, the flow cross-sectional areas of the liquid inlets of all the branches connected to the liquid outlet end of the transfer station are the same.

[0013] Optionally, when at least one of the liquid outlets of all the branches connected to the liquid outlet end of the transfer station has a confluence area, the sum of the flow cross-sectional areas of the liquid outlets of all the branches connected to the liquid inlet end of the transfer station after confluence is equal to the flow cross-sectional area of ​​the liquid outlets of the branches where no confluence area exists.

[0014] Optionally, the hierarchical structures of the flow channel distribution areas at the liquid inlet end and the liquid outlet end of the reaction zone of the liquid flow battery are symmetrically arranged.

[0015] Optionally, the structure of the reaction zone of the liquid flow battery is any one of parallel flow channels, interdigitated flow channels and winding flow channels.

[0016] Optionally, the liquid inlets of the parallel flow channels and the winding flow channels are respectively arranged in one-to-one correspondence with the liquid outlet ends of the hierarchical structure of the flow channel distribution area located on the liquid inlet end side of the reaction zone of the liquid flow battery, and the liquid outlets of the parallel flow channels and the winding flow channels are respectively arranged in one-to-one correspondence with the liquid inlet ends of the hierarchical structure of the flow channel distribution area located on the liquid outlet end side of the reaction zone of the liquid flow battery.

[0017] Optionally, the liquid inlets of the interdigitated flow channels are alternately arranged with the liquid outlet ends of the hierarchical structure of the flow channel distribution area located on the liquid inlet end side of the reaction zone of the liquid flow battery, and the liquid outlets of the interdigitated flow channels are alternately arranged with the liquid inlet ends of the hierarchical structure of the flow channel distribution area located on the liquid inlet end side of the reaction zone of the liquid flow battery, and the liquid inlets and liquid outlets of the interdigitated flow channels are interconnected.

[0018] The beneficial effects that the present invention can produce include:

[0019] The present invention provides a method for designing a liquid flow battery distribution area. By designing a transfer station, the electrolyte input from the liquid inlet end of the flow channel is evenly distributed to multiple branches, so that the corresponding number of branch structures can be arbitrarily configured according to the flow channel structure of the reaction zone of the liquid flow battery, thereby reducing the design limitations of the flow channel size. At the same time, when designing the branch flow channel structure, the total flow cross-sectional area of ​​the transfer station in the electrolyte distribution area is decomposed step by step, so that the flow flow of all branches connected to the liquid outlet end of the transfer station is designed to be consistent, and then the flow cross-sectional area and flow length of the corresponding branch are calculated according to the flow flow of the branch, the flow calculation formula and the distance time formula, so as to ensure that the flow velocity, flow time and flow flow of all branches in the electrolyte distribution area of ​​each level are designed to be consistent. Compared with the existing flow channel design method, when the number of branch structures is expanded, the size of the branch can be directly calculated without a large amount of experimental data for verification. The calculation result is accurate and the distribution is more uniform, which greatly improves the reaction efficiency of the liquid flow battery and improves the design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a flow chart of a method for designing a distribution area of ​​a flow battery according to the present invention;

[0021] Figure 2 It is a schematic diagram of the hierarchical structure of the flow channel distribution area in Example 1 of the present invention;

[0022] Figure 3 It is a cross-sectional schematic diagram of a branch of the hierarchical structure of the flow channel distribution area in the present invention;

[0023] Figure 4 It is a schematic diagram of the hierarchical structure of the flow channel distribution area of ​​Example 2 of the present invention;

[0024] Figure 5 Schematic diagram of the hierarchical structure of the flow channel distribution area in Example 3 of the present invention Figure 1 ;

[0025] Figure 6 Schematic diagram of the hierarchical structure of the flow channel distribution area in Example 3 of the present invention Figure 2 ;

[0026] Figure 7It is a schematic diagram of the hierarchical structure of the flow channel distribution area of ​​Example 4 of the present invention;

[0027] Figure 8 It is a schematic diagram of the structure that the reaction area of ​​the liquid flow battery in the present invention is a parallel flow channel;

[0028] Fig. 9 It is a schematic diagram of the structure that the reaction area of ​​the liquid flow battery in the present invention is an interdigital flow channel;

[0029] Fig.10 It is a schematic diagram of the structure that the reaction area of ​​the liquid flow battery in the present invention is a winding flow channel;

[0030] In the figure: 1. Hierarchical structure of flow channel distribution area, 2. Transfer station, 3. Branch, 4. Reaction area. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-Figure 10 As shown, the present invention provides a method for designing a liquid flow battery distribution area, the method comprising the following steps: first, according to the flow channel distribution type, a corresponding flow channel distribution area hierarchical structure 1 is formulated, the flow channel distribution area hierarchical structure 1 has at least one level of electrolyte distribution area, the electrolyte distribution area includes at least one transfer station 2 and a plurality of branches 3, the liquid inlet of the branch 3 is connected to the liquid inlet of the flow channel or the liquid outlet of the electrolyte distribution area of ​​the previous level through the transfer station 2, the liquid outlet of the branch 3 is connected to the transfer station 2 of the electrolyte distribution area of ​​the next level or is connected to the liquid outlet of the flow channel after passing through the reaction area 4 of the liquid flow battery; and determining each level in the flow channel distribution area hierarchical structure 1 The number of transfer stations 2 in the electrolyte distribution area of ​​each level is designed to make the total flow cross-sectional area of ​​each branch between the transfer stations 2 in the electrolyte distribution areas of two adjacent levels consistent; then, according to the total flow cross-sectional area of ​​each branch of any transfer station 2 in the electrolyte distribution area and the number and confluence of all branches 3 connected to its outlet, the flow rate of each branch 3 is calculated respectively, and the flow cross-sectional area and flow length of the corresponding branch 3 are designed according to the set design conditions and the flow rate of the branch 3; the design conditions are: the flow velocity, flow time and flow rate of all branches 3 in the electrolyte distribution area of ​​each level are designed to be consistent, wherein;

[0033] L = V × t;

[0034] Q = A × V;

[0035] A = a × b;

[0036] Among them, L is the total length of the flow cross-sectional area of ​​branch 3, t is the total time flowing through the flow cross-sectional area of ​​branch 3, V is the flow velocity flowing through the flow cross-sectional area of ​​branch 3, Q is the flow rate at the flow cross-sectional area of ​​branch 3, A is the flow cross-sectional area of ​​branch 3, a is the depth of branch 3, and b is the width of branch 3.

[0037] In the above, the electrolyte input from the liquid inlet end of the flow channel is evenly distributed to multiple branches 3 by designing the transfer station 2, so that the corresponding number of branch 3 structures can be arbitrarily configured according to the flow channel structure of the reaction zone 4 of the flow battery, reducing the design limitations of the flow channel size; at the same time, when designing the flow channel structure of the branch 3, the total flow cross-sectional area of ​​the transfer station 2 in the electrolyte distribution area is decomposed step by step, so that the flow flow of all branches 3 connected to the liquid outlet end of the transfer station 2 is designed to be consistent, and then the flow cross-sectional area and flow length of the corresponding branch 3 are calculated according to the flow flow of the branch 3, the flow calculation formula and the distance time formula, so as to ensure that the flow velocity, flow time and flow flow of all branches 3 in each level of the electrolyte distribution area are designed to be consistent. It is worth noting that compared with the existing flow channel design method, the flow battery distribution area design method can directly calculate the size of the branch 3 when expanding the number of branch 3 structures, without the need for a large amount of experimental data to verify, and its calculation results are accurate, and the distribution is more uniform, which greatly improves the reaction efficiency of the flow battery and improves the design efficiency.

[0038] In the above, the design conditions also include: the depth of each branch 3 in the hierarchical structure 1 of the flow channel distribution area is the same, so as to ensure that the thickness of the hierarchical structure 1 of the flow channel distribution area is consistent with the thickness design of the reaction area 4 of the liquid flow battery, which is convenient for the sealing installation of the cover plate and the pole frame; at the same time, the design variables of the flow cross-sectional area of ​​the branch 3 are reduced, and the flow cross-sectional area of ​​the branch 3 is adjusted only by changing the width of the branch 3, thereby reducing the amount of calculation and further improving the design efficiency.

[0039] In the above, the flow cross-sectional area of ​​the liquid inlet and the liquid outlet of each branch 3 in the hierarchical structure 1 of the flow channel distribution area is the same, so as to ensure that the flow rate of the branches 3 in each level of the electrolyte distribution area is consistent. Specifically, when the liquid outlets of all branches 3 connected to the liquid outlet end of the transfer station 2 do not have a confluence area, the flow cross-sectional area of ​​the liquid inlets of all branches 3 connected to the liquid outlet end of the transfer station 2 is the same; when at least one of the liquid outlets of all branches 3 connected to the liquid outlet end of the transfer station 2 has a confluence area, the sum of the flow cross-sectional areas of the liquid outlets of all branches 3 connected to the liquid inlet end of the transfer station 2 after confluence is equal to the flow cross-sectional area of ​​the liquid outlet of the branch 3 without a confluence area.

[0040] In the above, the hierarchical structure 1 of the flow channel distribution area at the liquid inlet end and the liquid outlet end of the reaction area 4 of the flow battery is symmetrically arranged to ensure uniform and consistent electrolyte distribution at the liquid inlet end and the liquid outlet end of the reaction area 4 of the flow battery, avoid areas with过少 flow distribution or excessive flow distribution in the reaction area 4, and reduce polarization loss. Specifically, the structure of the reaction area 4 of the flow battery is any one of a parallel flow channel, an interdigitated flow channel, and a serpentine flow channel. Among them, the liquid inlet of the parallel flow channel and the serpentine flow channel are respectively arranged in one-to-one correspondence with the liquid outlet end of the hierarchical structure 1 of the flow channel distribution area on one side of the liquid inlet end of the reaction area 4 of the flow battery, and the liquid outlets of the parallel flow channel and the serpentine flow channel are respectively arranged in one-to-one correspondence with the liquid inlet end of the hierarchical structure 1 of the flow channel distribution area on one side of the liquid outlet end of the reaction area 4 of the flow battery; the liquid inlets of the interdigitated flow channels are alternately arranged with the liquid outlet ends of the hierarchical structure 1 of the flow channel distribution area on one side of the liquid inlet end of the reaction area 4 of the flow battery, the liquid outlets of the interdigitated flow channels are alternately arranged with the liquid inlet ends of the hierarchical structure 1 of the flow channel distribution area on one side of the liquid inlet end of the reaction area 4 of the flow battery, and the liquid inlets and liquid outlets of the interdigitated flow channels are interconnected.

[0041] Example 1: As Figure 2 shown, a hierarchical structure 1 of the flow channel distribution area is established, and a transfer station 2 and two branches 3 are configured to form a hierarchical electrolyte distribution area; among them, the total through-flow cross-sectional area of the transfer station 2 is designed to be the same as the total through-flow cross-sectional area of the liquid inlet end of the flow channel, and the structural sizes of the two branches 3 are designed to be the same to evenly distribute the through-flow of the transfer station 2 and ensure the same through-flow time and through-flow speed of the two branches 3.

[0042] Example 2: As Figure 4 shown, the difference between this example and Example 1 is that the structural sizes of the two branches 3 are designed to be different; among them, the through-flow of the first branch and the second branch is the same, and the through-flow speed is the same, but the through-flow length of the first branch is greater than that of the second branch; therefore, from L = V×t, it can be known that when L1>L2 and V1 = V2, t1<t2, that is, the short-distance flow channel preferentially supplies electrolyte to the reaction area 4 of the flow battery, resulting in different through-flow times of the two branches 3. In the above examples, since the through-flow length L of the branch is certain, if the through-flow speed V is adjusted to ensure t1 = t2, the through-flow speeds of the two branches 3 will be different, that is, V1<V2, which cannot meet the design requirements. For this reason, in the case of ensuring that the total volume of the through-flow of the first branch and the second branch remains unchanged, the present invention adjusts the through-flow time of the two branches 3 to be the same to meet the design requirements by reducing the cross-sectional area of the middle flow channel of the first branch to increase the local through-flow speed of the electrolyte; among them, let the lengths of both sides of the middle flow channel of the first branch be L0, and the following relationship formula 1 can be obtained:

[0043]

[0044] Among them, A1=a1×b1, A2=a2×b2, b1=b2, so we get the second relationship:

[0045]

[0046] Then, the lengths of both sides of the middle flow channel of the first branch are calculated according to the second relational expression, so as to design the length of the middle flow channel of the first branch.

[0047] Example 3: Figure 5 As shown, a hierarchical structure 1 of the flow channel distribution area is established, and two levels of electrolyte distribution areas are configured, wherein the electrolyte distribution area of ​​the first level is configured with a transfer station 2 and two branches 3, and the electrolyte distribution area of ​​the second level is configured with two transfer stations 2 and four branches 3. It should be noted that the flow lengths of the branches 3 of the electrolyte distribution areas of the same level are the same; then, each branch 3 and the transfer station 2 are connected, and first, the two transfer stations 2 of the electrolyte distribution area of ​​the second level are respectively connected to the electrolyte distribution area of ​​the first level. The two outlets of the distribution area are connected to the two branches 3, and then the inlets of the four branches 3 of the second-level electrolyte distribution area are symmetrically connected to the two transfer stations 2 of the second-level electrolyte distribution area. At the same time, the outlet end of one of the branches 3 of the two transfer stations 2 of the second-level electrolyte distribution area forms a confluence area, so that the second-level electrolyte distribution area has three outlets, but the flow rate of the three outlets is different, among which the flow rate of the outlet of the confluence area is greater than the flow rate of other outlets. Therefore, Figure 6 As shown, in order to solve the problem of flow uniformity, the cross-sectional area of ​​the two branches 3 in the confluence area is adjusted to half of the original, so that the flow rate is halved synchronously, thereby ensuring that the flow rate, flow velocity and flow time of the three outlets are consistent.

[0048] Example 4: Figure 7 As shown, the difference from Example 3 is that the flow length of the branch 3 of the second-level electrolyte distribution area located in the confluence area is shorter than the flow length of other branches 3; wherein the flow rate and flow velocity of the four branches 3 are consistent, but the flow time is inconsistent. Therefore, the middle flow channel of the branch 3 of the short flow channel is widened according to the relationship three, wherein the relationship three is:

[0049]

[0050] By designL 2-2 The segmented flow channel has a decelerating effect on the electrolyte passing through the short flow channel branch 3, thereby ensuring that the flow time of the four branches 3 is consistent.

Claims

1. A method for designing a flow battery distribution area, characterized in that: The method comprises the following steps: A corresponding hierarchical structure of flow channel distribution areas is formulated according to the flow channel distribution type, wherein the hierarchical structure of the flow channel distribution areas has at least one level of electrolyte distribution areas, and the electrolyte distribution area includes at least one transfer station and a plurality of branches, wherein the liquid inlet of the branch is connected to the liquid inlet of the flow channel or the liquid outlet of the electrolyte distribution area of ​​the upper level through the transfer station, and the liquid outlet of the branch is connected to the transfer station of the electrolyte distribution area of ​​the lower level or connected to the liquid outlet of the flow channel after passing through the reaction area of ​​the flow battery; Determine the number of transfer stations of the electrolyte distribution area at each level in the hierarchical structure of the flow channel distribution area, and design the total flow cross-sectional area of ​​each branch between the transfer stations in the electrolyte distribution areas of two adjacent levels to be consistent; Calculate the flow rate of each branch according to the total flow cross-sectional area of ​​each branch of any transfer station in the electrolyte distribution area and the number and confluence of all branches connected to the liquid outlet, and design the flow cross-sectional area and flow length of the branch according to the flow rate of the branch according to the set design conditions; The design condition is: design the flow velocity, flow time and flow rate of all the branches in the electrolyte distribution area of ​​each level to be consistent with each other.

2. A method for designing a flow battery distribution area according to claim 1, characterized in that: The design condition also includes: the depth of each of the branches in the flow channel distribution area hierarchical structure is the same.

3. A method for designing a flow battery distribution area according to claim 1, characterized in that: The flow cross-sectional area of ​​the liquid inlet and the liquid outlet of each branch in the hierarchical structure of the flow channel distribution area is the same.

4. A method for designing a flow battery distribution area according to claim 3, characterized in that: When the liquid outlets of all the branches connected to the liquid outlet end of the transfer station have no confluence area, the flow cross-sectional areas of the liquid inlets of all the branches connected to the liquid outlet end of the transfer station are the same.

5. A method for designing a flow battery distribution area according to claim 3, characterized in that: When at least one of the liquid outlets of all the branches connected to the liquid outlet end of the transfer station has a confluence area, the sum of the flow cross-sectional areas of the liquid outlets of all the branches connected to the liquid inlet end of the transfer station after confluence is equal to the flow cross-sectional area of ​​the liquid outlets of the branches without the confluence area.

6. A method for designing a flow battery distribution area according to claim 1, characterized in that: The hierarchical structures of the flow channel distribution areas at the liquid inlet end and the liquid outlet end of the reaction area of ​​the liquid flow battery are symmetrically arranged.

7. A method for designing a flow battery distribution area according to claim 6, characterized in that: The structure of the reaction zone of the liquid flow battery is any one of parallel flow channels, interdigitated flow channels and serpentine flow channels.

8. A method for designing a flow battery distribution area according to claim 7, characterized in that: The liquid inlets of the parallel flow channels and the winding flow channels are respectively arranged in one-to-one correspondence with the liquid outlet ends of the hierarchical structure of the flow channel distribution area located on the side of the liquid inlet end of the reaction zone of the liquid flow battery, and the liquid outlets of the parallel flow channels and the winding flow channels are respectively arranged in one-to-one correspondence with the liquid inlet ends of the hierarchical structure of the flow channel distribution area located on the side of the liquid outlet end of the reaction zone of the liquid flow battery.

9. A method for designing a flow battery distribution area according to claim 7, characterized in that: The liquid inlets of the interdigital flow channels are alternately arranged with the liquid outlet ends of the hierarchical structure of the flow channel distribution area located on the liquid inlet end side of the reaction zone of the liquid flow battery, and the liquid outlets of the interdigital flow channels are alternately arranged with the liquid inlet ends of the hierarchical structure of the flow channel distribution area located on the liquid inlet end side of the reaction zone of the liquid flow battery, and the liquid inlet and liquid outlet of the interdigital flow channels are interconnected.

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