Non-uniform-section alkaline electrolytic cell header pipe structure and alkaline electrolytic cell comprising same

Abstract

The utility model relates to an electrolytic bath fluid distribution system, in particular to a non-uniform-section alkaline electrolytic bath header pipe structure and an alkaline electrolytic bath comprising the same, which can enable the flow velocity distribution of electrolyte in each flow channel to be more uniform, reduce the energy loss in the electrolysis process and obviously improve the working efficiency of the electrolytic bath. The alkali liquor inlet header pipe comprises an alkali liquor inlet header pipe with a variable section, the alkali liquor inlet header pipe is provided with a flow channel communicated with an electrolytic bath in the length direction, and the size of the flow channel is gradually increased or decreased so as to adjust the flow speed and flow of alkali liquor.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrolytic cell fluid distribution system especially a kind of structure of non-equal-section alkaline electrolytic cell manifold and the alkaline electrolytic cell comprising the structure. BACKGROUND

[0002] As the core equipment of hydrogen production, the working principle of alkaline electrolytic cell is to generate hydrogen and oxygen by electrolysis of water in alkaline solution. However, as the volume of electrolytic cell increases, the flow and heat transfer problems of internal alkaline solution become more and more obvious, and the traditional equal-section design is easy to cause uneven distribution of fluid in the electrolytic cell, which further affects the electrolysis efficiency. In large-scale industrial applications, this phenomenon is particularly prominent, especially the uneven distribution of temperature and concentration in the tank will lead to incomplete local reaction, reducing the overall performance. Uneven flow of alkaline solution in electrolytic cell not only affects fluid heat transfer and mass transfer, but also causes the generation of parasitic current (bypass current). Parasitic current usually occurs in the case of uneven current distribution, which will cause local energy loss and reduce the electrolysis efficiency. The traditional equal-section design is difficult to control these problems, and it is urgent to optimize the flow channel design to improve the uniformity of alkaline solution flow and reduce the influence of parasitic current on the performance of electrolytic cell. SUMMARY

[0003] To solve the above technical problems, the utility model provides a kind of structure of non-equal-section alkaline electrolytic cell manifold and the alkaline electrolytic cell comprising the structure, it can make the flow rate distribution of electrolyte in each flow channel more uniform, reduce the energy loss in electrolysis process, significantly improve the working efficiency of electrolytic cell.

[0004] The technical scheme is as follows: a kind of structure of non-equal-section alkaline electrolytic cell manifold, characterized in that it comprises an alkaline solution inlet manifold with varying cross section, the alkaline solution inlet manifold is provided with flow channels communicating with the electrolytic cell along the length direction, and the size of the flow channels gradually increases or decreases to adjust the flow rate and flow of alkaline solution.

[0005] Further characterized in that the cross section of the flow channel near the inlet of the electrolytic cell is the largest.

[0006] A kind of alkaline electrolytic cell using the manifold structure, characterized in that it comprises a complete cathode chamber, a cathode electrode, a separator, an anode electrode and an anode chamber.

[0007] After using the utility model, the cross section of the flow channel gradually changes, which can effectively control the flow rate and pressure distribution of alkaline solution, ensure the uniformity of fluid in each electrolysis unit, and further reduce the influence of parasitic current. This design can reduce the vortex and dead zone problems in the fluid, enhance the flow stability, and reduce the local overheating or subcooling phenomenon in the tank. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 This is a schematic diagram of the overall structure of the electrolytic cell of this utility model;

[0009] Figure 2 This is a schematic diagram of the manifold structure of this utility model;

[0010] Figure 3 This is a flow distribution chart for the central manifold in this embodiment of the present invention. Detailed Implementation

[0011] See Figure 1 , Figure 2 As shown, a non-uniform cross-section alkaline electrolytic cell manifold structure includes an alkaline inlet manifold 1 with varying cross-section. The alkaline inlet manifold 1 has flow channels connecting to the electrolytic cell along its length, with the channel dimensions gradually increasing or decreasing to adjust the flow velocity and flow rate of the alkaline solution. The flow channel near the electrolytic cell inlet has the largest cross-section, and the cross-section of the alkaline inlet manifold 1 is also the largest, gradually decreasing towards the other end, typically using a taper angle of 0.8° to 5°. In the figure, 2 represents the electrolytic cell stack, 3 represents the alkaline outlet manifold, and 4 represents the branch pipe (corresponding to the flow channel) entering the electrolytic cell stack.

[0012] An alkaline electrolytic cell using a lumped tube structure is characterized by comprising a fully operational cathode chamber, cathode electrode, diaphragm, anode electrode, and anode chamber.

[0013] The following section focuses on optimizing the structural parameters of the alkali inlet manifold to ensure uniform flow velocity distribution of the electrolyte in each channel, while controlling the pressure drop within a reasonable range, reducing local overflow or dead zones in the channels, thereby improving electrolysis efficiency.

[0014] The objective function for optimization is to minimize the velocity uniformity parameter σ%, which is specifically expressed as:

[0015]

[0016] Where N is the number of flow channels, Ui is the velocity of the i-th flow channel, and Um is the average velocity of all flow channels. Minimizing this parameter ensures the uniformity of the velocity distribution. The optimization parameters of the duct mainly include the cross-sectional areas S1 and S2 at the front and rear ends, the height H and width W, the number of flow channels N (i.e., the number of branch pipes on a single duct), and the aspect ratio r of the branch pipes. The cross-sectional shapes of the flow channels include rectangles, waist shapes, funnel shapes, etc.

[0017] By adjusting the above parameters, the optimal combination of structural parameters that maximizes fluid flow uniformity and minimizes pressure drop is found. Each parameter has its corresponding physical constraints to ensure structural feasibility and stability in practical applications.

[0018] The specific optimization method for manifold design includes the following steps:

[0019] 1. Initialize parameters: Set the initial values and their variation ranges of the inlet position X_in, Y_in, manifold height H, width W, and the number of flow channels N. Initialize the flow rate U_in of the electrolyte and set the pressure drop limit. The cross-sectional area is related to the height H, width W, X_in, and Y_in to give the initial coordinate points for subsequent calculations.

[0020] 2. Calculate the velocity distribution: Based on each set of parameters, calculate the velocity distribution in each flow channel through numerical simulation or theoretical modeling.

[0021] 3. Calculate the flow rate uniformity parameter rU%: Use the formula to calculate the uniformity parameter σ% of the flow rate distribution, which serves as the objective function.

[0022] 4. Adjust the structural parameters: Use optimization algorithms such as gradient descent, genetic algorithms, or other applicable optimization algorithms to gradually adjust the structural parameters X_in, Y_in, H, W, and N to minimize the σ% parameter.

[0023] 5. Verify the constraint conditions: After each adjustment, verify whether the parameters meet the structural constraint conditions such as pressure loss, geometric size limitations, etc. If not, adjust the parameters again until a suitable solution is found.

[0024] 6. Output the optimal parameter combination: When the objective function σ% reaches the optimal value and the constraint conditions meet the requirements, output the optimized structural parameter combination.

[0025] The above design method is verified in practice.

[0026] The optimization process is simulated using MATLAB. The initialization parameters are X_in = -2, Y_in = 7, H = 0.05, W = 0.1, and N = 300. The optimal parameter combination calculated by the optimization algorithm is X_in = 1.5, Y_in = 7.5, H = 0.052, and W = 0.12. The flow rate uniformity parameter after optimization is only 2.5%, indicating that the velocity distribution in the flow channel is highly uniform, as shown in Figure 3 .

[0027] The optimized non-uniform cross-section design ensures uniform distribution of the flow rate and flow of the caustic solution, avoiding the problem of parasitic current caused by local flow rate non-uniformity. The uniformity of current density distribution improves the efficiency of electrolysis, significantly reducing the generation of local overcurrent density and ineffective current, thereby reducing the impact of parasitic current and ensuring the long-term efficient operation of the electrolytic cell.

[0028] By using a non-uniform cross-section design, the fluid flow within the electrolytic cell can be made more uniform, reducing the problem of low local electrolysis efficiency caused by uneven fluid distribution. This design is suitable for large-scale industrial production, reduces energy consumption, and improves the overall stability and lifespan of the electrolytic cell.

[0029] By using a simplified resistance network model, the computational cost in the design and optimization process is significantly reduced, the design cycle is accelerated, and it is applicable to a variety of fluid systems, demonstrating strong versatility.

Claims

1. A manifold structure for an alkaline electrolytic cell with a non-uniform cross-section, characterized in that, It includes an alkaline inlet manifold with varying cross-section, wherein the alkaline inlet manifold has a flow channel connected to the electrolytic cell along its length, and the size of the flow channel gradually increases or decreases to adjust the flow rate and volume of the alkaline solution.

2. The non-uniform cross-section alkaline electrolytic cell manifold structure according to claim 1, characterized in that, The cross-section of the flow channel is largest near the inlet of the electrolytic cell.

3. An alkaline electrolytic cell using the lumped tube structure of claim 1, characterized in that, It includes a fully operational cathode chamber, cathode electrode, diaphragm, anode electrode, and anode chamber.

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