Flow battery system structure

Abstract

The invention relates to the field of flow batteries, and discloses a flow battery system structure, which is characterized in that a first end of a first storage tank is connected with a galvanic pile positive electrode input end through a positive electrode electrolyte output pipeline, and a second end of the first storage tank is connected with a galvanic pile positive electrode output end through a positive electrode electrolyte return pipeline; the first end of the second storage tank is connected with the galvanic pile negative electrode input end through a negative electrode electrolyte output pipeline, and the second end of the second storage tank is connected with the galvanic pile negative electrode output end through a negative electrode electrolyte return pipeline; the first end and the second end of the multi-cavity OCV battery module are correspondingly connected with the positive electrode electrolyte output pipeline and the positive electrode electrolyte return pipeline respectively, and the third end and the fourth end of the multi-cavity OCV battery module are correspondingly connected with the negative electrode electrolyte output pipeline and the negative electrode electrolyte return pipeline respectively; according to the multi-cavity OCV battery module, the positive electrode electrolyte flow pumped out of the first storage tank and the negative electrode electrolyte flow pumped out of the second storage tank are depressurized and then conveyed to a multi-cavity OCV battery in the multi-cavity OCV battery module, so that the power consumption of a circulating pump is reduced, and the overall efficiency of a battery system is improved.

Description

Technical Field

[0001] The present invention relates to the field of flow batteries, and particularly to a flow battery system structure. Background Art

[0002] Flow batteries (FB) have the characteristics and advantages that the system capacity and power are decoupled from each other, the response speed is fast, it is safe and reliable, the cycle life is long, and the electrolyte can be recycled. As a representative energy storage technology, the all-vanadium flow battery has more application prospects in the field of large-scale long-term electrochemical energy storage, and can play an important supporting role in ensuring new energy consumption, power grid peak shaving and power consumption safety.

[0003] The open circuit voltage (OCV) of the FB can directly reflect the potential difference between the positive and negative electrode electrolytes of the FB, and is closely related to the ionic valence states and concentrations of the active substances in the positive and negative electrode electrolytes. It is the most commonly used method in actual engineering to estimate the state of charge (SOC) of the battery system, and is also the key basis for managing and controlling the charge and discharge of the battery system. Currently, in actual engineering, a single-section (two-electrode cavity) OCV battery is configured on the FB electrolyte pipeline to monitor the state of the battery electrolyte in real time, so as to characterize and estimate the SOC value of the FB system. However, taking the most mature all-vanadium flow battery as an example, the measured value of the OCV battery with a two-cavity design structure cannot accurately reflect the imbalance state of the electrolyte caused by vanadium ion migration or side reactions. Even if the electrolyte imbalance is very serious, the value displayed by the OCV may still be normal. Therefore, the OCV battery with this structure cannot accurately evaluate whether the specific states of the positive and negative electrode electrolytes are normal, affecting the accuracy of evaluating the SOC, performance and stability of the long-term operation of the FB system, and is not conducive to the dispatching and operation and maintenance to accurately judge the state of the energy storage system. Summary of the Invention

[0004] In view of this, the present invention provides a flow battery system structure to solve the problem of how to monitor a flow battery using a multi-cavity OCV battery.

[0005] The present invention provides a liquid flow battery system structure, comprising: a multi-chamber OCV battery module, a first storage tank, a second storage tank, a stack, a positive electrolyte output pipeline, a positive electrolyte return pipeline, a negative electrolyte output pipeline, and a negative electrolyte return pipeline. Among them, the first end of the first storage tank is connected to the positive electrolyte input end of the stack through the positive electrolyte output pipeline, and the second end of the first storage tank is connected to the positive electrolyte output end of the stack through the positive electrolyte return pipeline; the first end of the second storage tank is connected to the negative electrolyte input end of the stack through the negative electrolyte output pipeline, and the second end of the second storage tank is connected to the negative electrolyte output end of the stack through the negative electrolyte return pipeline; the first end and the second end of the multi-chamber OCV battery module are respectively connected to the positive electrolyte output pipeline and the positive electrolyte return pipeline, and the third end and the fourth end of the multi-chamber OCV battery module are respectively connected to the negative electrolyte output pipeline and the negative electrolyte return pipeline; the multi-chamber OCV battery module pumps the positive electrolyte liquid flow pumped out from the first storage tank and the negative electrolyte liquid flow pumped out from the second storage tank to the multi-chamber OCV battery inside after pressure reduction.

[0006] The present invention realizes the reduction of the power consumption of the circulation pump, improves the overall efficiency of the battery system, and reduces the investment and operation costs through effective pressure reduction. It can realize the reliable application of the multi-chamber OCV battery. At the same time, adding a pressure reduction device is also beneficial to extending the service life of the multi-chamber OCV battery. The process is simple and easy to operate, can ensure the long-term efficient and stable operation of the battery, and is easy for later operation and maintenance.

[0007] In an optional embodiment, the multi-chamber OCV battery module comprises: a multi-chamber OCV battery, a first pressure reduction device, a second pressure reduction device, a third storage tank, and a first magnetic pump. Among them, the first end of the multi-chamber OCV battery is connected to the first end of the first pressure reduction device, the second end of the multi-chamber OCV battery is connected to the positive electrolyte return pipeline, the third end of the multi-chamber OCV battery is connected to the first end of the second pressure reduction device, and the fourth end of the multi-chamber OCV battery is connected to the negative electrolyte return pipeline; the second end of the first pressure reduction device is connected to the positive electrolyte output pipeline; the second end of the second pressure reduction device is connected to the negative electrolyte output pipeline.

[0008] In an optional embodiment, the first pressure reduction device comprises a first pressure reducing valve.

[0009] In an optional embodiment, the second pressure reduction device comprises a second pressure reducing valve.

[0010] In an alternative embodiment, the positive electrolyte output pipeline includes a first positive electrolyte output pipeline and a second positive electrolyte output pipeline, and a first pressurizing device is arranged on the positive electrolyte output pipeline. Among them, the first storage tank is connected to the first end of the first pressurizing device through the first positive electrolyte output pipeline; the second end of the first pressurizing device is respectively connected to the positive electrolyte input end of the stack and the second end of the first pressure-reducing device through the second positive electrolyte output pipeline.

[0011] In an alternative embodiment, the first pressurizing device includes: a second magnetic pump.

[0012] In an alternative embodiment, the negative electrolyte output pipeline includes a first negative electrolyte output pipeline and a second negative electrolyte output pipeline, and a second pressurizing device is arranged on the negative electrolyte output pipeline. Among them, the second storage tank is connected to the first end of the second pressurizing device through the first negative electrolyte output pipeline; the second end of the second pressurizing device is respectively connected to the negative electrolyte input end of the stack and the second end of the second pressure-reducing device through the second negative electrolyte output pipeline.

[0013] In an alternative embodiment, the second pressurizing device includes: a third magnetic pump.

[0014] In an alternative embodiment, the stack includes: a plurality of battery stacks connected in series. Among them, the positive electrolyte input end of each battery stack is connected to the output end of the positive electrolyte output pipeline, and the positive electrolyte output end of each battery stack is connected to the input end of the positive electrolyte return pipeline; the negative electrolyte input end of each battery stack is connected to the output end of the negative electrolyte output pipeline, and the negative electrolyte output end of each battery stack is connected to the input end of the negative electrolyte return pipeline. Description of the Drawings

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is a structural diagram of a flow battery system according to an embodiment of the present invention;

[0017] Figure 2 is a specific structural diagram of a flow battery system according to an embodiment of the present invention. Detailed Embodiments

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the internal communication of two components. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In related technologies, multi-chamber OCV batteries are installed on independent branches in a flow battery system. The selected circulation pump needs to have the same power as the circulation pump used in the main circuit to avoid the diaphragm in the OCV battery from rupturing due to excessive pressure difference during battery operation, resulting in a large auxiliary power consumption of the system, thereby affecting the overall efficiency of the battery system and increasing the system investment cost and operating cost, which is not conducive to large-scale popularization and application.

[0023] Based on the above problems, in this embodiment, a flow battery system structure is provided, as Figure 1 shown, including: a multi-chamber OCV battery module, a first storage tank, a second storage tank, an electrolyzer stack, a positive electrolyte output pipeline, a positive electrolyte return pipeline, a negative electrolyte output pipeline, and a negative electrolyte return pipeline.

[0024] As Figure 1As shown, the first end of the first storage tank is connected to the positive electrolyte input end of the stack through the positive electrolyte output pipeline, and the second end of the first storage tank is connected to the positive electrolyte output end of the stack through the positive electrolyte return pipeline; the first end of the second storage tank is connected to the negative electrolyte input end of the stack through the negative electrolyte output pipeline, and the second end of the second storage tank is connected to the negative electrolyte output end of the stack through the negative electrolyte return pipeline; the first end and the second end of the multi-chamber OCV battery module are respectively connected to the positive electrolyte output pipeline and the positive electrolyte return pipeline, and the third end and the fourth end of the multi-chamber OCV battery module are respectively connected to the negative electrolyte output pipeline and the negative electrolyte return pipeline.

[0025] Specifically, the multi-chamber OCV battery module reduces the pressure of the positive electrolyte liquid flow pumped out from the first storage tank and the negative electrolyte liquid flow pumped out from the second storage tank and then transports them to the multi-chamber OCV battery inside.

[0026] Specifically, a pressure reduction module is provided, which reduces the liquid path pressure and then transports it to the multi-chamber OCV battery, thereby reducing the power consumption of the magnetic pump for supplying liquid to the multi-chamber OCV battery itself, so as to achieve the purpose of improving the overall efficiency of the battery system and reducing costs. The multi-chamber OCV battery measures the state of charge of the battery system to monitor the internal electrolyte state during the actual operation of the FB, evaluate the battery performance, and predict the battery life.

[0027] Specifically, the first storage tank is used to store the positive electrolyte, and the second storage tank is used to store the negative electrolyte. The stack is the main component for charging and discharging. Optionally, the stack includes: a plurality of battery stacks connected in series, wherein the positive electrolyte input end of each battery stack is connected to the output end of the positive electrolyte output pipeline, and the positive electrolyte output end of each battery stack is connected to the input end of the positive electrolyte return pipeline; the negative electrolyte input end of each battery stack is connected to the output end of the negative electrolyte output pipeline, and the negative electrolyte output end of each battery stack is connected to the input end of the negative electrolyte return pipeline.

[0028] Optionally, the flow battery includes: dual-flow battery systems such as all-vanadium flow batteries, polysulfide sodium bromide flow batteries, iron-chromium flow batteries, and vanadium-bromine flow batteries.

[0029] In some alternative embodiments, as Figure 2 shown, the multi-chamber OCV battery module includes: a multi-chamber OCV battery, a first pressure reduction device, a second pressure reduction device, a third storage tank, and a first magnetic pump. Among them, the first pressure reduction device includes a first pressure reducing valve. The second pressure reduction device includes a second pressure reducing valve. The multi-chamber OCV battery has more than two chambers. Taking the four-chamber OCV battery as an example

[0030] As Figure 2As shown, the first end of the multi-chamber OCV battery is connected to the first end of the first step-down device, the second end of the multi-chamber OCV battery is connected to the positive electrolyte return pipeline, the third end of the multi-chamber OCV battery is connected to the first end of the second step-down device, and the fourth end of the multi-chamber OCV battery is connected to the negative electrolyte return pipeline; the second end of the first step-down device is connected to the positive electrolyte output pipeline; the second end of the second step-down device is connected to the negative electrolyte output pipeline.

[0031] Specifically, the first pressure reducing valve is used to reduce the liquid flow pressure of the positive electrolyte output pipeline, the second pressure reducing valve is used to reduce the liquid flow pressure of the negative electrolyte output pipeline, the first magnetic pump is used to provide the power for the liquid circuit circulation of the multi-chamber OCV battery, and the third storage tank is used to store the independent circulation electrolyte of the multi-chamber OCV battery.

[0032] In some alternative embodiments, as Figure 2 shown, the positive electrolyte output pipeline includes a first positive electrolyte output pipeline and a second positive electrolyte output pipeline, and a first pressurizing device is provided on the positive electrolyte output pipeline. The first pressurizing device includes: a second magnetic pump. Among them, the first storage tank is connected to the first end of the first pressurizing device through the first positive electrolyte output pipeline; the second end of the first pressurizing device is respectively connected to the positive electrolyte input end of the stack and the second end of the first step-down device through the second positive electrolyte output pipeline.

[0033] In some alternative embodiments, as Figure 2 shown, the negative electrolyte output pipeline includes a first negative electrolyte output pipeline and a second negative electrolyte output pipeline, and a second pressurizing device is provided on the negative electrolyte output pipeline. The second pressurizing device includes: a third magnetic pump. Among them, the second storage tank is connected to the first end of the second pressurizing device through the first negative electrolyte output pipeline; the second end of the second pressurizing device is respectively connected to the negative electrolyte input end of the stack and the second end of the second step-down device through the second negative electrolyte output pipeline.

[0034] Figure 2 In, the second magnetic pump is used to provide the power for the liquid circuit circulation of the positive electrode of the stack, and the third magnetic pump is used to provide the power for the liquid circuit circulation of the negative electrode of the stack.

[0035] Specifically, referring to Figure 2, the functions of the second magnetic pump and the third magnetic pump are to pump the positive electrolyte and the negative electrolyte into the stack respectively. Before the electrolyte enters the stack, a branch is separated and enters the multi-chamber OCV battery. The liquid pressure of the liquid path entering the multi-chamber OCV battery is the same as that of the liquid path entering the stack; before entering the multi-chamber OCV battery, a first pressure reducing valve and a second pressure reducing valve are installed to reduce the pressure. The first magnetic pump simultaneously pumps the electrolyte in the third storage tank into the multi-chamber OCV battery. The electrolyte that has reacted through the stack and the multi-chamber OCV battery returns to the first storage tank, the second storage tank, and the third storage tank respectively through the pipeline, forming a complete liquid path closure. The specific reaction process is as follows:

[0036] (1) The positive electrolyte is stored in the first storage tank, enters the stack through the pipeline by the second magnetic pump, and returns to the first storage tank after reacting in the stack.

[0037] (2) The negative electrolyte is stored in the second storage tank, enters the stack through the pipeline by the third magnetic pump, and returns to the second storage tank after reacting in the stack.

[0038] (3) The electrolyte in the first storage tank passes through the pipeline branch by the first magnetic pump, and after passing through the first pressure reducing valve, the electrolyte is pumped into the four-chamber OCV battery. After reacting in the four-chamber OCV battery, it returns to the first storage tank through the pipeline.

[0039] (4) The electrolyte in the second storage tank passes through the pipeline branch by the third magnetic pump, and after passing through the second pressure reducing valve, the electrolyte is pumped into the four-chamber OCV battery. After reacting in the four-chamber OCV battery, it returns to the second storage tank through the pipeline.

[0040] (5) The electrolyte in the third storage tank is pumped into the four-chamber OCV battery through the pipeline by the first magnetic pump. After reacting in the four-chamber OCV battery, it returns to the third storage tank through the pipeline.

[0041] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A liquid flow battery system structure, characterized in that: include: A multi-chamber OCV battery module, a first storage tank, a second storage tank, a battery stack, a positive electrode electrolyte output pipeline, a positive electrode electrolyte return pipeline, a negative electrode electrolyte output pipeline and a negative electrode electrolyte return pipeline, wherein: The first end of the first storage tank is connected to the positive electrode input end of the stack through the positive electrode electrolyte output pipeline, and the second end of the first storage tank is connected to the positive electrode output end of the stack through the positive electrode electrolyte reflux pipeline; The first end of the second storage tank is connected to the negative electrode input end of the stack through the negative electrode electrolyte output pipeline, and the second end of the second storage tank is connected to the negative electrode output end of the stack through the negative electrode electrolyte reflux pipeline; The first end and the second end of the multi-cavity OCV battery module are respectively connected to the positive electrode electrolyte output pipeline and the positive electrode electrolyte return pipeline, and the third end and the fourth end of the multi-cavity OCV battery module are respectively connected to the negative electrode electrolyte output pipeline and the negative electrode electrolyte return pipeline; The multi-chamber OCV battery module reduces the pressure of the positive electrode electrolyte flow pumped out of the first storage tank and the negative electrode electrolyte flow pumped out of the second storage tank and then transports them to the multi-chamber OCV battery inside the module.

2. The liquid flow battery system structure according to claim 1, characterized in that: The multi-chamber OCV battery module includes: a multi-chamber OCV battery, a first pressure reducing device, a second pressure reducing device, a third storage tank and a first magnetic pump, wherein: The first end of the multi-cavity OCV battery is connected to the first end of the first pressure reducing device, the second end of the multi-cavity OCV battery is connected to the positive electrode electrolyte return pipeline, the third end of the multi-cavity OCV battery is connected to the first end of the second pressure reducing device, and the fourth end of the multi-cavity OCV battery is connected to the negative electrode electrolyte return pipeline; The second end of the first pressure reducing device is connected to the positive electrode electrolyte output pipeline; The second end of the second pressure reducing device is connected to the negative electrode electrolyte output pipeline.

3. The liquid flow battery system structure according to claim 2, characterized in that: The first pressure reducing device includes a first pressure reducing valve.

4. The liquid flow battery system structure according to claim 2, characterized in that: The second pressure reducing device includes a second pressure reducing valve.

5. The liquid flow battery system structure according to claim 2, characterized in that: The positive electrode electrolyte output pipeline includes a first positive electrode electrolyte output pipeline and a second positive electrode electrolyte output pipeline, and a first pressurizing device is arranged on the positive electrode electrolyte output pipeline, wherein: The first storage tank is connected to the first end of the first pressurizing device through the first positive electrolyte output pipeline; The second end of the first pressurizing device is connected to the positive electrode input end of the battery stack and the second end of the first pressure reducing device respectively through the second positive electrode electrolyte output pipeline.

6. The liquid flow battery system structure according to claim 5, characterized in that: The first pressurizing device includes: a second magnetic pump.

7. The liquid flow battery system structure according to claim 2, characterized in that: The negative electrode electrolyte output pipeline includes a first negative electrode electrolyte output pipeline and a second negative electrode electrolyte output pipeline, and a second pressurizing device is arranged on the negative electrode electrolyte output pipeline, wherein: The second storage tank is connected to the first end of the second pressurizing device through the first negative electrode electrolyte output pipeline; The second end of the second pressurizing device is connected to the negative electrode input end of the battery stack and the second end of the second pressure reducing device respectively through the second negative electrode electrolyte output pipeline.

8. The liquid flow battery system structure according to claim 7, characterized in that: The second pressurizing device includes: a third magnetic pump.

9. The liquid flow battery system structure according to any one of claims 1 to 8, characterized in that: The battery stack comprises: a plurality of battery stacks connected in series, wherein: The positive electrode input end of each battery stack is connected to the output end of the positive electrode electrolyte output pipeline, and the positive electrode output end of each battery stack is connected to the input end of the positive electrode electrolyte reflux pipeline; The negative electrode input end of each battery stack is connected to the output end of the negative electrode electrolyte output pipeline, and the negative electrode output end of each battery stack is connected to the input end of the negative electrode electrolyte reflux pipeline.

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