Gas exhaust system and method for single-flow zinc-nickel flow battery

Abstract

The invention provides a gas exhaust system and method for a single-flow zinc-nickel flow battery. The gas exhaust system comprises a liquid storage tank, a pressurizing device, a gas exhaust device and a pipeline, the bottom of the liquid storage tank is connected with an inlet of the pressurizing device through a pipeline, an outlet of the pressurizing device is connected with a positive electrode of the single-flow zinc-nickel flow battery through a pipeline and used for pressurizing a positive electrode cavity of the single-flow zinc-nickel flow battery, and a negative electrode of the single-flow zinc-nickel flow battery is connected with an inlet of the exhaust device through a pipeline. The exhaust device is used for releasing the pressure of the positive cavity to exhaust; an outlet of the exhaust device is connected with the top of the liquid storage tank. By means of actively-controlled pressure fluctuation (firstly boosting and then suddenly dropping), detained gas is physically pushed and pumped out, the exhaust efficiency is high, and flow channel dead corners and bubbles on the surface of an electrode can be effectively removed.

Description

Technical Field

[0001] This invention relates to the field of flow battery technology, and in particular to a gas exhaust system and method for a single-flow zinc-nickel flow battery. Background Technology

[0002] Single-flow zinc-nickel flow batteries, as a promising energy storage technology, have attracted attention due to their high energy density and relatively low cost. However, during battery operation, especially at the positive electrode (nickel electrode), side reactions such as oxygen evolution occur, producing gases (such as oxygen). Due to the structural characteristics of single-flow batteries, the positive electrode electrolyte is permeated into the positive electrode cavity by pressure from the negative electrode electrolyte, and an electrochemical reaction occurs by wetting the nickel electrode. Side reactions often occur at the nickel electrode, preventing the generated gases from being smoothly discharged with the electrolyte flow, thus gradually accumulating in the positive electrode cavity.

[0003] The accumulation of gas can lead to a series of problems: 1) It occupies the effective reaction area, resulting in increased internal resistance, enhanced polarization, and performance degradation of the battery; 2) It forms gas resistance, which hinders the full contact between the electrolyte and the active material of the electrode, affecting the battery's capacity and efficiency; 3) Long-term accumulation may lead to excessively high local pressure on the electrode, and may even pose a risk to the battery's sealing structure.

[0004] Currently, a common solution is to use a dual-channel design, allowing the positive electrode to also pass through the liquid. This method increases pump consumption, and long-term flushing of the nickel electrode can also damage the active material, reducing the system's energy efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a gas discharge system and method for a single-flow zinc-nickel flow battery, in order to solve the problems of increased pump consumption and loss of active material due to long-term flushing of the nickel electrode, which reduces the energy efficiency of the system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a gas venting system for a single-flow zinc-nickel flow battery, comprising a storage tank, a pressurizing device, an venting device, and a pipeline; the bottom of the storage tank is connected to the inlet of the pressurizing device via a pipeline, the outlet of the pressurizing device is connected to the positive electrode of the single-flow zinc-nickel flow battery via a pipeline, for pressurizing the positive electrode cavity of the single-flow zinc-nickel flow battery, the negative electrode of the single-flow zinc-nickel flow battery is connected to the inlet of the venting device via a pipeline, the venting device is used to release the pressure in the positive electrode cavity to achieve venting, and the outlet of the venting device is connected to the top of the storage tank.

[0007] Furthermore, the storage tank is filled with electrolyte, and the top of the storage tank is a cavity with an exhaust port on the storage tank at the cavity.

[0008] Furthermore, the outlet of the venting device is connected to the cavity at the top of the storage tank.

[0009] Furthermore, the pressurizing device is a pump that delivers the electrolyte to the positive electrode of the single-flow zinc-nickel flow battery.

[0010] Furthermore, the exhaust device is a solenoid valve. When the solenoid valve is closed, it blocks the negative outlet pipe of the single-flow zinc-nickel flow battery, causing the pressurizing device to pressurize the positive electrode cavity of the single-flow zinc-nickel flow battery. When the solenoid valve is open, it generates an instantaneous pulse fluid to flush the compressed or accumulated gas.

[0011] Furthermore, the solenoid valve is connected to an external controller, which is used to trigger the venting operation of the solenoid valve to close and open at preset fixed time intervals.

[0012] Furthermore, the solenoid valve is connected to an external controller, which is used to trigger the venting operation of the solenoid valve to close and open based on the battery's running time, charging status, and voltage / current fluctuations.

[0013] Furthermore, the solenoid valve is a two-position, two-way solenoid valve.

[0014] Furthermore, a pressure sensor is installed on the pipeline between the negative electrode outlet of the single-flow zinc-nickel flow battery and the exhaust device to monitor changes in the pressure inside the chamber and feed the signal back to the controller.

[0015] Secondly, the present invention provides a gas discharge method, comprising the following steps: S1: During normal battery operation, the controller sends a closing command to the solenoid valve according to predetermined logic or a received trigger signal; S2: The solenoid valve is closed, and the pressure inside the positive electrode chamber of the single-flow zinc-nickel flow battery increases; S3: Maintain the closed state for a predetermined period of time. The increased pressure will compress and drive the trapped gas from the positive electrode cavity to the negative electrode cavity, while at the same time causing some gas to dissolve in the electrolyte. S4: The controller sends an opening command to the solenoid valve. The solenoid valve opens, and the gas that has permeated from the positive electrode chamber into the negative electrode chamber is discharged in a pulse, forming a rapid flow of fluid. The pressure drop and fluid pulse can flush out the compressed and accumulated gas, as well as the gas that has been re-precipitated due to the pressure drop, from the negative electrode chamber, into the subsequent pipeline, and finally to the storage tank for gas-liquid separation. S5: The solenoid valve remains open, and the battery returns to normal operating mode until the next venting trigger.

[0016] Compared with the prior art, the present invention has the following technical effects: This invention utilizes actively controlled pressure fluctuations (first increasing pressure and then suddenly decreasing it) to physically "push" and "extract" stagnant gas, resulting in high exhaust efficiency and effectively removing dead zones in the flow channel and bubbles on the electrode surface.

[0017] It does not require continuous high flow rate operation or constant opening of the vent valve. It only needs to be operated briefly when necessary, which has minimal impact on the normal operation of the system, hardly increases the additional pumping energy consumption, and there is no continuous loss of electrolyte.

[0018] It can be achieved simply by adding a solenoid valve and a controller to the existing system outlet, with low retrofit costs, high reliability, and easy integration into existing battery systems.

[0019] It can be linked with the battery management system (BMS) to intelligently start and stop the battery according to its actual operating conditions, achieving precise control. Attached Figure Description

[0020] Figure 1 This is a system structure diagram of the present invention.

[0021] Figure 2 This is a logic block diagram of the present invention.

[0022] Figure 3 This is the curve showing the relationship between the energy efficiency and cycle life of the fuel cell stack of this invention.

[0023] in: 1. Storage tank; 2. Pressurization device; 3. Exhaust device. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings: Example 1, please refer to Figure 1 This invention provides a gas exhaust system for a single-flow zinc-nickel flow battery, comprising a storage tank 1, a pressurizing device 2, an exhaust device 3, and pipelines; the bottom of the storage tank 1 is connected to the inlet of the pressurizing device 2 via a pipeline, and the outlet of the pressurizing device 2 is connected to the positive electrode of the single-flow zinc-nickel flow battery via a pipeline, for pressurizing the positive electrode cavity of the single-flow zinc-nickel flow battery; the negative electrode of the single-flow zinc-nickel flow battery is connected to the inlet of the exhaust device 3 via a pipeline, and the exhaust device 3 is used to release the pressure in the positive electrode cavity to achieve exhaust; the outlet of the exhaust device 3 is connected to the top of the storage tank 1.

[0025] This invention addresses the problem of gas retention in the positive electrode cavity of single-flow zinc-nickel batteries in the prior art, which is difficult to effectively expel. By actively controlling the opening and closing of the outlet solenoid valve, the pressure fluctuation generated is used to expel the retained gas.

[0026] Example 2: This invention provides a gas exhaust system for a single-flow zinc-nickel flow battery, comprising: Battery body: includes positive electrode, negative electrode and separator; Electrolyte storage tank and circulation pipeline: used to contain and circulate alkaline zinc-nickel electrolyte; Pump: Used to drive the electrolyte to circulate between the battery body and the storage tank; Also includes: Solenoid valve: installed on the fuel cell stack outlet pipe or outlet manifold; Controller: Electrically connected to the solenoid valve, configured to periodically or according to triggering conditions send control signals to the solenoid valve to cause it to execute a rapid "close-open" action sequence.

[0027] The specific working process of the "close-open" action sequence is as follows: Shutdown Phase: The controller commands the solenoid valve to close, blocking the fuel cell outlet pipeline. At this time, the pump continues to run, causing the pressure inside the positive electrode chamber to gradually increase. The increased pressure compresses and drives the trapped gas from the positive electrode chamber to the negative electrode chamber, while simultaneously dissolving some of the gas in the electrolyte.

[0028] Opening Phase: After maintaining the closed state for a brief period (e.g., 0.1-5 seconds), the controller commands the solenoid valve to open rapidly. The negative electrode chamber outlet suddenly opens, and the internal pressure is released instantaneously, forming a rapid surge of fluid. This pressure drop and fluid pulse effectively flush out the compressed and accumulated gas, as well as the gas that has been re-precipitated due to the pressure drop, from the negative electrode chamber, into subsequent pipelines, and finally to the storage tank for gas-liquid separation.

[0029] Furthermore, the controller can also trigger the venting operation based on the battery's operating parameters (such as operating time, charging status, voltage / current fluctuations) or a preset fixed time interval.

[0030] Furthermore, the solenoid valve is preferably a two-position, two-way solenoid valve with a diameter matching the pipeline and a fast response speed (millisecond level).

[0031] Furthermore, a pressure sensor can be installed on the pipeline between the negative electrode cavity outlet and the solenoid valve to monitor changes in the cavity pressure and feed the signal back to the controller to achieve more precise intelligent control (for example, triggering exhaust when the pressure reaches a set threshold).

[0032] Example 3: The present invention provides a gas discharge method, comprising the following steps: S1: During normal battery operation, the controller sends a closing command to the solenoid valve according to predetermined logic or a received trigger signal; S2: The solenoid valve is closed, and the pressure inside the positive electrode chamber of the single-flow zinc-nickel flow battery increases; S3: Maintain the closed state for a predetermined period of time. The increased pressure will compress and drive the trapped gas from the positive electrode cavity to the negative electrode cavity, while at the same time causing some gas to dissolve in the electrolyte. S4: The controller sends an opening command to the solenoid valve. The solenoid valve opens, and the gas that has permeated from the positive electrode chamber into the negative electrode chamber is discharged in a pulse, forming a rapid flow of fluid. The pressure drop and fluid pulse can flush out the compressed and accumulated gas, as well as the gas that has been re-precipitated due to the pressure drop, from the negative electrode chamber, into the subsequent pipeline, and finally to the storage tank for gas-liquid separation. S5: The solenoid valve remains open, and the battery returns to normal operating mode until the next venting trigger.

[0033] Example 4, as Figure 1 As shown, a single-flow zinc-nickel battery gas venting system includes a battery body, a liquid storage tank 1, and a pressurizing device 2. A venting device is installed on the battery outlet pipeline. This venting device is connected to a controller via a signal line.

[0034] The controller can be a simple timer or part of a battery management system (BMS). In this example, the controller is set to trigger a venting procedure every 30 minutes of operation.

[0035] Exhaust procedure begins: The controller sends a signal, and the exhaust device 3 is quickly shut off (action time <100ms).

[0036] After the exhaust device is closed, the pressurizing device 2 continues to work, and the pressure in the positive electrode chamber starts to rise from atmospheric pressure P0.

[0037] The pressure rises to P1 when the device remains in the off state for t1 = 1 second.

[0038] The controller sends a signal, and the exhaust device 3 opens rapidly (action time < 100ms).

[0039] The outlet suddenly opens, and the high-pressure fluid inside the cavity carries the gas out in a pulse, causing the pressure to drop rapidly to P0 or even momentarily slightly below P0 (forming a negative pressure impact).

[0040] The pulsed flow successfully expelled the accumulated gas.

[0041] With the venting device kept open, the system resumes normal operation. Performing this operation periodically effectively prevents long-term gas accumulation in the positive electrode cavity, ensuring stable and efficient battery operation.

[0042] The core protection of this invention lies in the innovative method of actively controlling pressure fluctuations to efficiently remove trapped gas in the positive electrode cavity of a single-flow zinc-nickel flow battery. Specifically, this is manifested in: 1) System Structure Basic components of a gas exhaust system. A gas exhaust system for a single-flow zinc-nickel flow battery includes a storage tank 1, a pressurizing device 2, an exhaust device 3, and connecting pipes; the bottom of the storage tank 1 is connected to the inlet of the pressurizing device 2 via a pipe, and the outlet of the pressurizing device 2 is connected to the positive electrode of the single-flow zinc-nickel flow battery via a pipe, for pressurizing the positive electrode cavity of the battery; the negative electrode of the battery is connected to the inlet of the exhaust device 3 via a pipe, and the outlet of the exhaust device 3 is connected to the top of the storage tank 1.

[0043] The storage tank 1 is filled with electrolyte, and its top has a cavity structure with an exhaust port.

[0044] The outlet of the exhaust device 3 is connected to the cavity at the top of the liquid storage tank 1 to facilitate gas-liquid separation.

[0045] The pressurizing device 2 is a pump used to deliver electrolyte to the positive electrode of the battery; the venting device 3 is a solenoid valve, which can block the negative electrode outlet pipe of the battery to pressurize the positive electrode cavity when closed, and can generate instantaneous pulse fluid to flush the gas when opened; preferably, the solenoid valve is a two-position two-way solenoid valve with fast response speed.

[0046] An intelligent solution for controlling the aforementioned gas discharge system includes an external controller for the solenoid valve, which is configured to periodically trigger the closing and opening operations of the solenoid valve at preset fixed time intervals.

[0047] The controller is configured to intelligently trigger the venting operation based on the actual operating parameters of the battery.

[0048] A pressure sensor is installed on the pipeline between the negative electrode outlet of the single-flow zinc-nickel flow battery and the exhaust device 3 to monitor the pressure change inside the chamber and feed the signal back to the controller to achieve precise trigger control based on the pressure threshold.

[0049] A gas venting method for a single-flow zinc-nickel flow battery, based on the aforementioned gas venting system, includes the following steps: S1: During normal battery operation, the controller sends a closing command to the solenoid valve according to predetermined logic or a received trigger signal; S2: The solenoid valve is closed, and the pressure inside the positive electrode chamber of the single-flow zinc-nickel flow battery increases; S3: Maintain the closed state for a predetermined period of time. The increased pressure will compress and drive the trapped gas from the positive electrode cavity to the negative electrode cavity, while at the same time causing some gas to dissolve in the electrolyte. S4: The controller sends an opening command to the solenoid valve. The solenoid valve opens, and the gas that has permeated from the positive electrode chamber into the negative electrode chamber is discharged in a pulse, forming a rapid flow of fluid. The pressure drop and fluid pulse can flush out the compressed and accumulated gas, as well as the gas that has been re-precipitated due to the pressure drop, from the negative electrode chamber, into the subsequent pipeline, and finally to the storage tank for gas-liquid separation. S5: The solenoid valve remains open, and the battery returns to normal operating mode until the next venting trigger.

[0050] Through the physical process of "first pressurizing (pushing) and then rapidly depressurizing (extracting)," the stagnant gas in the dead corners of the flow channel and on the electrode surface is effectively removed.

[0051] The exhaust operation is triggered in conjunction with the battery management system (BMS), which intelligently starts and stops the exhaust operation based on the actual operating conditions of the battery, thereby achieving precise and energy-efficient exhaust management.

[0052] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0053] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0054] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0055] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0056] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A gas exhaust system for a single-flow zinc-nickel flow battery, characterized in that, It includes a storage tank (1), a pressurizing device (2), an exhaust device (3), and pipelines; the bottom of the storage tank (1) is connected to the inlet of the pressurizing device (2) through a pipeline, the outlet of the pressurizing device (2) is connected to the positive electrode of the single-flow zinc-nickel flow battery through a pipeline, which is used to pressurize the positive electrode cavity of the single-flow zinc-nickel flow battery, the negative electrode of the single-flow zinc-nickel flow battery is connected to the inlet of the exhaust device (3) through a pipeline, the exhaust device (3) is used to release the pressure of the positive electrode cavity to achieve exhaust, and the outlet of the exhaust device (3) is connected to the top of the storage tank (1).

2. The gas exhaust system for a single-flow zinc-nickel flow battery according to claim 1, characterized in that, Electrolyte is filled into the storage tank (1). The top of the storage tank (1) is a cavity, and an exhaust port is provided on the storage tank (1) in the cavity.

3. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 2, characterized in that, The outlet of the exhaust device (3) is connected to the cavity at the top of the liquid storage tank (1).

4. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 1, characterized in that, The pressurizing device (2) is a pump that delivers the electrolyte to the positive electrode of the single-flow zinc-nickel flow battery.

5. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 1, characterized in that, The exhaust device (3) is a solenoid valve. When the solenoid valve is closed, it blocks the negative outlet pipe of the single-flow zinc-nickel flow battery, so that the pressurizing device (2) pressurizes the positive electrode cavity of the single-flow zinc-nickel flow battery. When the solenoid valve is open, it generates instantaneous pulse fluid to flush the compressed or accumulated gas.

6. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 5, characterized in that, An external controller is connected to the solenoid valve. The controller is used to trigger the venting operation of the solenoid valve to close and open at preset fixed time intervals.

7. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 5, characterized in that, An external controller is connected to the solenoid valve. The controller is used to trigger the venting operation of the solenoid valve to close and open based on the battery's running time, charging status, and voltage / current fluctuations.

8. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 5, characterized in that, The solenoid valve is a two-position, two-way solenoid valve.

9. A gas exhaust system for a single-flow zinc-nickel flow battery according to claim 7, characterized in that, A pressure sensor is installed on the pipeline between the negative electrode outlet of the single-flow zinc-nickel flow battery and the exhaust device (3) to monitor the pressure change in the cavity and feed the signal back to the controller.

10. A method for venting gas, characterized in that, A gas exhaust system for a single-flow zinc-nickel flow battery according to any one of claims 1 to 9 includes the following steps: S1: During normal battery operation, the controller sends a closing command to the solenoid valve according to predetermined logic or a received trigger signal; S2: The solenoid valve is closed, and the pressure inside the positive electrode chamber of the single-flow zinc-nickel flow battery increases; S3: Maintain the closed state for a predetermined period of time. The increased pressure will compress and drive the trapped gas from the positive electrode cavity to the negative electrode cavity, while causing some of the gas to dissolve in the electrolyte. S4: The controller sends an opening command to the solenoid valve. The solenoid valve opens, and the gas that has permeated from the positive electrode chamber into the negative electrode chamber is discharged in a pulse, forming a rapid flow of fluid. The pressure drop and fluid pulse can flush out the compressed and accumulated gas, as well as the gas that has been re-precipitated due to the pressure drop, from the negative electrode chamber, into the subsequent pipeline, and finally to the storage tank for gas-liquid separation. S5: The solenoid valve remains open, and the battery returns to normal operating mode until the next venting trigger.

Images