Sampling device for testing valence state of flow battery

Abstract

The utility model belongs to the technical field of flow battery testing, and particularly relates to a sampling device for testing the valence state of a flow battery, which comprises a positive electrode sampling assembly, a conduit and a negative electrode sampling assembly connected to the positive electrode sampling assembly, the positive electrode sampling assembly comprises a positive electrode bottle and a liquid discharge valve, and the negative electrode sampling assembly comprises a negative electrode bottle. The one-way inflation valve and the liquid inlet valve are connected with the negative electrode bottle, and the positive electrode bottle is connected with the negative electrode bottle through the liquid discharge valve; and the conduit is communicated with the outlet of the liquid discharge valve and then extends into the anode bottle. According to the sampling device for testing the valence state of the flow battery, the one-way inflation valve is connected with the inert gas source, and the conduit extends to the bottom of the positive electrode bottle, so that the electrolyte can be effectively prevented from being oxidized, and the testing accuracy is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to liquid flow battery test technical field, concretely relates to a sampling device for liquid flow battery valence state test. BACKGROUND

[0002] In the operation process of all-vanadium redox flow battery, the valence state imbalance of electrolyte is mainly caused by side reactions, such as hydrogen evolution, oxidation reaction, etc. Accurate testing of the valence state of electrolyte is crucial for evaluating the health status of the battery and conducting valence state leveling.

[0003] However, the existing test method is to take out the positive and negative electrolyte and then conduct offline titration. In this process, the divalent vanadium ion V 2+ is chemically active and easily reacts with oxygen in the air to be oxidized; once the divalent vanadium ion V 2+ is oxidized, it will change the real valence state distribution of vanadium ions in the electrolyte, resulting in a significant deviation between the test results and the actual working conditions, and cannot accurately reflect the real running state of the battery. The sampling device in the prior art lacks effective anti-oxidation measures in design, and it is difficult to avoid the contact of divalent vanadium ion V 2+ with air, which cannot guarantee the test accuracy.

[0004] Therefore, it is necessary to provide a new sampling device for liquid flow battery valence state test. UTILITY MODEL CONTENTS

[0005] Therefore, the utility model provides a sampling device for liquid flow battery valence state test, which is connected with an inert gas source through a one-way inflation valve and has a conduit extending to the bottom of the positive electrode bottle, can effectively prevent the oxidation of electrolyte and ensure the test accuracy.

[0006] The utility model solves the technical scheme adopted by its technical problems: provide a sampling device for liquid flow battery valence state test, include: positive electrode sampling component, conduit, connect negative electrode sampling component on positive electrode sampling component, positive electrode sampling component includes positive electrode bottle and liquid drain valve, negative electrode sampling component includes negative electrode bottle, with the one-way inflation valve and liquid inlet valve who links to each other with negative electrode bottle, the conduit is communicated after with the outlet of liquid drain valve and extends into the positive electrode bottle.

[0007] Further, the positive electrode sampling assembly further comprises an adapter provided at the opening of the positive electrode bottle, the adapter is provided with a through hole in communication with the internal cavity of the positive electrode bottle, the adapter is threadedly connected with the top opening of the positive electrode bottle, the adapter is connected with the liquid drain valve, and the conduit extends into the positive electrode bottle through the through hole.

[0008] Further, the adapter is provided with a gas pressure balance hole in communication with the internal cavity of the positive electrode bottle.

[0009] Further, the lower part of the liquid discharge valve is connected with the adapter through screw thread.

[0010] Further, the negative sampling assembly further comprises a mounting seat arranged at the top end of the negative bottle and a one-way air exhaust valve arranged on the mounting seat; the one-way air filling valve, the liquid inlet valve and the mounting seat are connected.

[0011] Further, the negative bottle is a transparent or translucent cylindrical bottle body, and volume graduation lines are further arranged on the outer side of the negative bottle.

[0012] Further, a flange is sealingly connected to the bottom of the negative bottle, and the lower part of the flange is connected with the liquid discharge valve.

[0013] Further, a sealing gasket is further arranged between the flange and the liquid discharge valve, and the sealing gasket is made of elastic acid-resistant material.

[0014] Further, one end of the one-way air filling valve is in communication with the internal cavity of the negative bottle, and the other end of the one-way air filling valve is connected with an inert gas source; the liquid inlet valve is connected with a sampling valve on the negative electrolyte storage tank.

[0015] Further, the conduit extends into the bottom of the internal cavity of the positive bottle, and the conduit is connected with the liquid discharge valve through hot melt welding or screw thread.

[0016] The sampling device for flow battery valence state test of the utility model has the advantages that the sampling device for flow battery valence state test of the utility model adopts a one-way air filling valve to connect an inert gas source, and the negative electrolyte is protected by inert gas before sampling, and the negative electrolyte directly flows into the positive bottle through the liquid discharge valve and the conduit after sampling, and reacts with the positive electrolyte, so that the negative electrolyte is effectively prevented from being oxidized, and the testing accuracy is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further described in connection with the drawings and examples.

[0018] Fig. 1 It is the structure schematic diagram of the sampling device for flow battery valence state test of the utility model;

[0019] Fig. 2 It is the explosion drawing of the sampling device for flow battery valence state test of the utility model;

[0020] Fig. 3 is a sectional view of the sampling device for flow battery valence state test.

[0021] The names of the components in the figure and their numbers are as follows:

[0022] The sampling device 100;

[0023] The positive sampling assembly 1, the positive bottle 11, the adapter 12, the air pressure balance hole 121, the liquid discharge valve 13;

[0024] The negative sampling assembly 2, the negative bottle 21, the flange 211, the mounting seat 22, the one-way air inlet valve 23, the one-way air outlet valve 24, the liquid inlet valve 25;

[0025] The conduit 3. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the utility model will be described in detail in conjunction with the drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the utility model in a schematic manner, so it only shows the components related to the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model protection.

[0027] As Figs. 1-3 shown, the embodiment provides a sampling device 100 for flow battery valence state test, which comprises a positive sampling assembly 1, a conduit 3 and a negative sampling assembly 2 connected to the positive sampling assembly 1.

[0028] In some embodiments, the positive sampling assembly 1 comprises a positive bottle 11, an adapter 12 and a liquid discharge valve 13 arranged at the opening of the positive bottle 11. The positive bottle 11 is a cylindrical bottle body, and the internal cavity of the positive bottle 11 is suitable for placing the electrolyte of the flow battery. The adapter 12 is arranged at the opening of the positive bottle 11, and a through hole is arranged in the middle of the adapter 12 and communicates with the internal cavity of the positive bottle. The top opening of the positive bottle 11 is circular, the adapter 12 cooperates with the top opening of the positive bottle 11, and the adapter 12 and the top opening of the positive bottle 11 are connected by threads. An air pressure balance hole 121 is formed in the adapter 12, which communicates with the internal cavity of the positive bottle 11 and is suitable for balancing the air pressure in the internal cavity of the positive bottle 11 with the outside. The lower part of the liquid discharge valve 13 is connected with the adapter 12 by threads, and the liquid discharge valve 13 is used to control the opening and closing of the electrolyte flowing into the positive bottle 11.

[0029] In some embodiments, the negative sampling assembly 2 comprises a negative bottle 21, a mounting seat 22 provided on the negative bottle 21 by screwing or gluing, a one-way air charging valve 23, a one-way air exhausting valve 24 and a liquid inlet valve 25 provided on the mounting seat 22. The mounting seat 22 and the one-way air charging valve 23 and the one-way air exhausting valve 24 can be connected by means of a socket. The mounting seat 22 and the liquid inlet valve 25 can be connected by screwing or gluing. The negative bottle 21 is a cylindrical bottle body, and the internal cavity of the negative bottle 21 is suitable for placing the electrolyte of the flow battery. The negative bottle 21 is a transparent or translucent cylindrical bottle body, and volume graduation lines are further provided on the outer side of the negative bottle 21. A flange 211 is sealingly connected to the bottom of the negative bottle 21 by screwing or gluing, and the flange 211 is connected to the liquid discharge valve 13 by bolts. A sealing gasket is further provided between the flange 211 and the liquid discharge valve 13, and the sealing gasket is made of elastic acid-resistant material. The mounting seat 22 is sealingly mounted on the top of the negative bottle 21, and the one-way air charging valve 23 is fixedly connected to the mounting seat 22. One end of the one-way air charging valve 23 communicates with the internal cavity of the negative bottle 21, and the other end of the one-way air charging valve 23 is connected to an inert gas source, such as a nitrogen cylinder. The one-way air exhausting valve 24 communicates with the negative bottle 21 and can only exhaust air to the outside of the negative bottle 21. One end of the liquid inlet valve 25 communicates with the internal cavity of the negative bottle 21, and the other end of the liquid inlet valve 25 is connected to a sampling valve on the negative electrolyte storage tank through a pipeline (not shown in the figure), for directly obtaining the electrolyte in the internal cavity of the negative electrolyte storage tank.

[0030] In some other embodiments, a transparent window is provided on the bottle body of the negative bottle 21. The liquid level in the negative bottle 21 is read through the transparent window.

[0031] In some embodiments, the liquid discharge valve 13 is a ball valve, one end of the cathode sampling assembly 2 is connected to the internal ball valve outlet of the liquid discharge valve 13, the cathode sampling assembly 2 passes through the through hole of the adapter 12, and the other end of the cathode sampling assembly 2 communicates with the bottom of the internal cavity of the positive bottle 11. The cathode sampling assembly 2 is connected to the liquid discharge valve 13 by hot melting welding or screwing. In some other embodiments, the cathode sampling assembly 2 is connected to the liquid discharge valve 13 by screwing. The cathode sampling assembly 2 is elongated as a whole, and the lower end is a tapered port, which can reduce the contact with air as much as possible and can also control the flow rate of the electrolyte.

[0032] In some embodiments, the sampling device 100 is made of acid-resistant material, such as glass, PP, PVC, etc., which further ensures the structural stability and durability of the sampling device 100.

[0033] The utility model discloses a sampling device 100 for liquid flow battery valence state test includes positive electrode sampling subassembly 1, fixed on the positive electrode sampling subassembly 1 negative electrode sampling subassembly 2 and pipe 3, and positive electrode sampling subassembly 1 includes positive electrode bottle 11, sets up the adapter 12 and liquid discharge valve 13 at the positive electrode bottle 11 opening, and negative electrode sampling subassembly 2 includes negative electrode bottle 21, sets up the mounting seat 22 on negative electrode bottle 21, sets up the one-way inflation valve 23, one-way exhaust valve 24 and liquid inlet valve 25 on the mounting seat 22. Adopt one-way inflation valve connection inert gas source, by adopting inert gas protection, effectively prevent electrolyte oxidation, ensure the testing accuracy, and the pipe 3 extends to the positive electrode bottle bottom, makes negative electrode electrolyte directly injects under positive electrode high valence vanadium ion solution, further ensures the testing accuracy, and the positive electrode bottle 11 and adapter 12 pass through the screw connection, can quick dismount, is convenient for sampling and mixing operation respectively, and the adapter 12 is set up the air pressure balance hole 121, can make the positive electrode bottle 11 internal cavity and external air pressure keep balance, avoids the electrolyte flow not to be smooth because of the air pressure difference, improves the environmental adaptability of sampling device 100.

[0034] Specific examples are:

[0035] Embodiment 1

[0036] A sampling device 100 for liquid flow battery valence state test is used for valence state leveling, and the average valence state of positive and negative electrolyte is obtained.

[0037] First, the positive electrolyte volume V pos and the negative electrolyte volume V neg are directly read from the battery management system BMS, and the unit is L.

[0038] Then, the positive electrode bottle 11 of the lower half of the sampling device 100 is taken out from the sampling device 100, and the volume V p is taken out from the positive electrode liquid tank sampling valve and put into the positive electrode bottle 11, wherein V p = V pos / k. (k is any positive number, ensuring that V p + V n is less than the volume of the positive electrode bottle 11, and V n is less than the maximum value of the negative electrode bottle scale). Wherein V n = V neg / k.

[0039] Subsequently, connect the one-way charging valve 23 on the negative electrode bottle 21 to the nitrogen pipeline, connect the liquid inlet valve 25 to the pipeline, open the liquid inlet valve 25 and the liquid outlet valve 13, open the one-way charging valve 23, and purge nitrogen for 2-10 minutes (preferably 3 minutes). Connect the liquid inlet valve 25 to the sampling valve on the negative electrode electrolyte storage tank through the pipeline. Since the pipeline connected to the liquid inlet valve 25 is connected to the sampling valve of the negative electrode storage tank, the sampling valve of the negative electrode storage tank is closed at this time. Then close the liquid outlet valve 13 and reduce the nitrogen flow rate by partially closing the one-way charging valve 23.

[0040] Then, open the sampling valve on the negative electrode storage tank, and the negative electrode electrolyte flows into the negative electrode bottle 21 until the level of the negative electrode electrolyte slightly exceeds the highest mark on the negative electrode bottle 21. Then, close the sampling valve and the inlet valve 25 of the negative electrode storage tank. Liquid exceeding the highest mark is discharged directly through the drain valve 13, and then the drain valve 13 is closed.

[0041] Finally, reconnect the positive electrode bottle 11 to the adapter 12. Open the drain valve 13 to release V. n The volume of negative electrode electrolyte is filled, the drain valve 13 is closed, and the one-way gas charging valve 23 and nitrogen gas are closed. At this time, V n The volume of negative electrode electrolyte flows directly into the bottom of positive electrode bottle 11 through conduit 3, allowing divalent vanadium ions to react promptly and fully with high-valent vanadium ions in the positive electrode electrolyte, thus effectively avoiding oxidation during the sampling process.

[0042] The mixture at this stage requires no special preservation; subsequent titration can proceed as normal. After titration, the concentrations of vanadium ions with valences of 3, 4, and 5 are cV, respectively. 3+ cVO 2+ , The average valence state Val_aver can be calculated using the following formula. Then, based on the deviation of this average valence state from the value 3.5, the required amount of reducing agent or the amount of electrons to be introduced can be determined.

[0043] The formula for calculating the average price state is:

[0044]

[0045] Where Val_aver is the average valence state, cV 3+ The concentration of trivalent vanadium ions, cVO 2+ This represents the concentration of tetravalent vanadium ions. This represents the concentration of pentavalent vanadium ions.

[0046] Example 2

[0047] A sampling device 100 for testing the valence state of a flow battery is used for testing the valence state of the negative electrode electrolyte. The operation process is the same as in Example 1.

[0048] V is added to positive electrode bottle 11. pThe known concentration of the volume is The electrolyte of the vanadium ion of 4 valences.

[0049] Put V n The volume of the measured vanadium ion of 3 valences 2+ , V 3+ The negative electrolyte.

[0050] The concentration of the vanadium ion of 4 valences Must be greater than the concentration of the vanadium ion of 2 valences, generally 1.6-2 mol / L. The following reactions occur:

[0051] VO 2+ + V 2+ + 2H + → 2V 3+ + H2O

[0052] Titrate the mixed solution to obtain the concentration of the vanadium ion of 4 valences The concentration of the vanadium ion of 3 valences The initial concentration of the vanadium ion of 2 valences cV 2+ , the concentration of the vanadium ion of 3 valences cV 3+ , and the valence state Val_n of the negative electrolyte are calculated by the following formula:

[0053]

[0054]

[0055]

[0056] Wherein, cV 2+ is the concentration of the vanadium ion of 2 valences, cV 3+ is the concentration of the vanadium ion of 3 valences, Val_n is the valence state of the negative electrolyte, is the concentration of the vanadium ion of 4 valences.

[0057] In the description of the embodiments of the utility model, unless there are explicit provisions and limitations, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0058] Based on the above ideal embodiments according to the utility model, through the above description, relevant staff can make various changes and modifications without deviating from the scope of the utility model. The technical scope of the utility model is not limited to the contents in the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. A sampling device for testing the valence state of flow batteries, characterized in that, include: A positive electrode sampling assembly, a conduit, and a negative electrode sampling assembly connected to the positive electrode sampling assembly. The positive electrode sampling assembly includes a positive electrode bottle and a drain valve. The negative electrode sampling assembly includes a negative electrode bottle, a one-way gas filling valve, and a liquid inlet valve connected to the negative electrode bottle. The positive electrode bottle is connected to the negative electrode bottle through the drain valve. The conduit extends into the positive electrode bottle after communicating with the outlet of the drain valve.

2. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, The positive electrode sampling assembly also includes an adapter disposed at the opening of the positive electrode bottle. The adapter has a through hole communicating with the internal cavity of the positive electrode bottle. The adapter is threaded to the top opening of the positive electrode bottle. The adapter is connected to the drain valve. The conduit passes through the through hole and extends into the positive electrode bottle.

3. The sampling device for testing the valence state of a flow battery according to claim 2, characterized in that, The adapter is provided with a pressure balance hole, which is connected to the internal cavity of the positive electrode bottle.

4. The sampling device for testing the valence state of a flow battery according to claim 2, characterized in that, The lower part of the drain valve is connected to the adapter via a thread.

5. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, The negative electrode sampling assembly also includes a mounting base disposed at the top of the negative electrode bottle and a one-way vent valve disposed on the mounting base; the one-way vent valve and the liquid inlet valve are connected to the mounting base.

6. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, The negative electrode bottle is a transparent or semi-transparent cylindrical bottle, and volume scale lines are provided on the side of the negative electrode bottle.

7. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, A flange is sealed to the bottom of the negative electrode bottle, and the lower part of the flange is connected to the drain valve.

8. The sampling device for testing the valence state of a flow battery according to claim 7, characterized in that, A sealing gasket is also provided between the flange and the drain valve. The sealing gasket is made of an elastic acid-resistant material.

9. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, One end of the one-way inflation valve is connected to the internal cavity of the negative electrode bottle, and the other end of the one-way inflation valve is connected to an inert gas source; the liquid inlet valve is connected to the sampling valve on the negative electrode electrolyte storage tank.

10. The sampling device for testing the valence state of a flow battery according to claim 1, characterized in that, The conduit extends to the bottom of the cavity inside the positive electrode bottle, and the conduit is connected to the drain valve by hot-melt welding or thread.

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