A connecting structure of an all-vanadium redox flow battery stack liquid inlet and outlet joint

Abstract

The utility model discloses a kind of connection structure of all-vanadium redox flow battery stack liquid inlet and outlet joint, including liquid inlet and outlet plate, backing plate, guide plate and joint, backing plate is set between liquid inlet and outlet plate and guide plate, and inner thread structure adapted with joint is equipped on backing plate, outer thread structure is equipped on the outer periphery of joint, and sealing groove for installing sealing ring is set in the outer periphery of joint front section, inlet and outlet are set on guide plate, and the outer periphery of guide plate is equipped with the sealing groove for installing sealing ring. Its structure is reliable, and use performance is good, on the one hand, the sealing groove of joint front section outer periphery is assembled sealing ring, and local sealing is formed at joint place in cooperation with backing plate inner thread hole;On the other hand, the sealing groove of guide plate outer periphery along edge circumferential encircles assembly sealing ring, and coverage range completely surrounds inlet and outlet, and forms the global sealing of guide plate and backing plate bonding surface.

Description

Technical Field

[0001] This utility model relates to the field of vanadium redox flow battery stack technology, specifically to a connection structure for the inlet and outlet connectors of a vanadium redox flow battery stack. Background Technology

[0002] A typical vanadium redox flow battery consists of a power unit (stack), an energy storage unit (vanadium electrolyte and storage tank), and a vanadium electrolyte delivery unit (pipelines, valves, circulation pumps, heat exchangers, etc.). The vanadium redox flow battery stack is typically secured by end plates that fasten the inlet / outlet plates, current collectors, and multiple individual cells. Each individual cell typically consists of positive and negative electrode frames, positive and negative electrodes, a proton exchange membrane, bipolar plates, and seals. The positive and negative electrodes of a single cell are housed within their respective frames, separated by the proton exchange membrane for hydrogen ion conduction; the positive and negative electrodes of a single cell are separated from the negative electrode of the preceding cell and the positive electrode of the following cell, respectively, by bipolar plates for electron conduction.

[0003] Traditional vanadium redox flow battery stack inlet / outlet plate connections can be achieved by directly bonding the connector to the flow guide plate and then connecting it to external piping. However, if the bonding is weak or needs to be removed, the connector may be damaged, and the entire flow guide plate may become unusable, resulting in material waste. Alternatively, a connecting plate can be added between the inlet / outlet plate and the flow guide plate. However, this makes stack assembly inconvenient, and during stack removal, residual electrolyte can seep between the flow guide plate and the inlet / outlet plate, leading to corrosion of the inlet / outlet plate and even potential leakage. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a connection structure for the liquid inlet and outlet connector of a vanadium redox flow battery stack.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: a connection structure for the liquid inlet and outlet connector of a vanadium redox flow battery stack, including a liquid inlet and outlet plate, a pad, a guide plate and a connector;

[0006] The gasket is placed between the inlet / outlet liquid plate and the guide plate, and the gasket has an internal thread structure that is compatible with the connector.

[0007] The connector has an external thread structure on its outer periphery, and a sealing groove for installing a sealing ring is opened on the outer periphery of the front section of the connector.

[0008] The guide plate has an inlet and an outlet, and the outer circumference of the guide plate has a sealing groove for installing a sealing ring.

[0009] Furthermore, the inner circumferential wall of the connector is provided with an internal thread structure, which is used to achieve a threaded connection with the external thread structure of the external pipeline to complete the connection between the connector and the external pipeline.

[0010] Furthermore, the guide plate has two liquid inlets and two liquid outlets, which are symmetrically distributed on the guide plate.

[0011] Furthermore, the number of sealing grooves opened on the outer periphery of the front section of the joint is at least one, and each sealing groove is spaced apart along the axial direction of the joint.

[0012] Furthermore, the sealing groove on the outer periphery of the guide plate is arranged circumferentially around the edge of the guide plate, and the coverage of the sealing groove can completely surround the liquid inlet and liquid outlet on the guide plate to prevent electrolyte from leaking from the connection between the guide plate and the pad.

[0013] Furthermore, the length of the external thread structure on the outer periphery of the connector matches the thickness of the gasket. When the connector and the gasket are threadedly connected in place, the front end of the connector can tightly abut against the side wall of the inlet and outlet liquid plates.

[0014] The present invention has the following beneficial effects: The connection structure of the inlet and outlet connector of the vanadium redox flow battery stack provided by the present invention is as follows:

[0015] (1) Its structure is reliable and its performance is good. On the one hand, a sealing ring is installed in the sealing groove on the outer periphery of the front section of the connector, which cooperates with the threaded hole in the pad to form a local seal at the connector. On the other hand, a sealing ring is installed in the sealing groove around the edge of the guide plate, and the coverage area completely surrounds the inlet and outlet, forming a global seal on the contact surface of the guide plate and the pad. The double sealing structure can effectively block the path of electrolyte leakage from the thread gap between the connector and the pad, and the contact gap between the guide plate and the pad, avoiding electrolyte leakage caused by unreliable sealing in the traditional connection method, thereby preventing the inlet and outlet plates from being corroded, reducing the risk of leakage, and ensuring the long-term stable operation of the fuel cell stack.

[0016] (2) This solution abandons the traditional method of directly bonding the joint. Instead, it achieves a detachable connection between the joint and the fuel cell stack body by matching the external thread on the outer circumference of the joint with the internal thread on the gasket. When it is necessary to replace the joint or maintain the fuel cell stack, it can be disassembled simply by loosening the joint. There is no need to damage the gasket, guide plate or inlet / outlet liquid plate, avoiding the problems of the traditional bonding method and reducing material waste. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 1 The reference numerals in the attached drawings are respectively: 1-inlet / outlet plate, 2-pad, 3-guide plate, 4-connector, 5-sealing ring. Detailed Implementation

[0019] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0020] like Figure 1 As shown, a connection structure for the electrolyte inlet / outlet connector of a vanadium redox flow battery stack is characterized by comprising an inlet / outlet plate 1, a pad 2, a guide plate 3, and a connector 4. The pad 2 is disposed between the inlet / outlet plate 1 and the guide plate 3, and the pad 2 has an internal thread structure adapted to the connector 4. The internal thread structure is a "bridge" connecting the connector 4 to the stack body (inlet / outlet plate 1 and guide plate 3). The threaded fit enables the detachable installation of the connector 4, solving the problem that damage to the connector 4 in traditional adhesive bonding methods requires the scrapping of the guide plate 3, thus reducing material waste. The pad 2 is sandwiched between the inlet / outlet plate 1 and the guide plate 3, filling the assembly gap between them. At the same time, it forms a synergistic seal with the sealing ring 5 on the outer periphery of the guide plate 3 and the sealing ring 5 of the connector 4, further blocking the path of electrolyte leakage from the mating surface of the inlet / outlet plate 1 and the guide plate 3. In addition, the pad 2 can reduce the direct contact between the guide plate 3 and the inlet / outlet plate 1, avoid wear on the contact surface caused by the difference in materials or assembly stress between the two, and reduce the risk of corrosion of the inlet / outlet plate 1 after the electrolyte seeps into the gap between the two, thus indirectly ensuring the safety of the fuel cell stack (such as preventing leakage caused by corrosion).

[0021] The connector 4 has an external thread structure on its outer periphery, and a sealing groove for installing the sealing ring 5 is opened on the front outer periphery of the connector 4. The inner peripheral wall of the connector 4 has an internal thread structure, which is used to achieve a threaded connection with the external thread structure of the external pipeline to complete the docking of the connector 4 with the external pipeline. The external thread structure on the outer periphery is adapted to the internal thread of the gasket 2 to achieve a detachable connection between itself and the fuel cell stack body; at the same time, as an "interface component" between the fuel cell stack and the external pipeline, it connects to the external pipeline through its own structure (such as the internal thread) to ensure the stable transmission of electrolyte between the fuel cell stack and the external delivery unit. The sealing groove on the front outer periphery is used to install the sealing ring 5. When the connector 4 and the gasket 2 are threadedly connected in place, the sealing ring 5 is squeezed between the mating surfaces of the connector 4 and the gasket 2, preventing electrolyte leakage from the threaded fit gap between the connector 4 and the gasket 2. This is a key sealing element to prevent fuel cell stack leakage. The length of the external thread structure on the outer periphery of the connector 4 matches the thickness of the pad 2. When the connector 4 and the pad 2 are threadedly connected in place, the front end of the connector 4 can tightly abut against the side wall of the inlet / outlet liquid plate 1.

[0022] The guide plate 3 has an inlet and an outlet, and the outer periphery of the guide plate 3 has a sealing groove for installing the sealing ring 5. When the guide plate 3 is in contact with the pad 2, the sealing ring 5 is compressed, which can effectively block the electrolyte from leaking from the gap between the outer periphery of the guide plate 3 and the pad 2, forming a "double seal" with the sealing ring 5 at the joint 4, improving the overall sealing reliability.

[0023] During assembly, the pad 2 is clamped between the inlet / outlet plate 1 and the guide plate 3. The sealing ring 5 is installed in the sealing groove on the outer periphery of the guide plate 3. When the guide plate 3 and the pad 2 are in contact, the sealing ring 5 is compressed, forming an outer periphery seal between the guide plate 3 and the pad 2. The sealing ring 5 is installed in the sealing groove at the front of the connector 4. The external thread on the outer periphery of the connector 4 is screwed into the internal thread of the pad 2, so that the connector 4 and the pad 2 are threadedly connected. At this time, the sealing ring 5 of the connector 4 is squeezed, forming a partial seal between the connector 4 and the pad 2. Finally, the double-layer sealing structure of the connector 4 sealing ring 5 + the guide plate 3 sealing ring 5 blocks the electrolyte leakage path.

[0024] In this embodiment, the guide plate 3 has two inlets and two outlets, which are symmetrically distributed on the guide plate 3. The symmetrical distribution of the two inlets allows the electrolyte to enter simultaneously from both sides of the guide plate 3, dispersing fluid impact and resulting in a more uniform overall pressure distribution within the guide plate 3. The symmetrical distribution of the two outlets allows the collected electrolyte to exit simultaneously from both sides, avoiding localized pressure buildup. This uniform pressure distribution reduces excessive localized compression of the sealing ring 5 within the sealing groove on the outer periphery of the guide plate 3 (preventing the sealing ring 5 from deforming and failing due to excessive localized pressure), and also reduces the force required for electrolyte to seep into the gap between the guide plate 3 and the pad 2, further reducing the risk of leakage.

[0025] In this embodiment, at least one sealing groove is formed on the outer periphery of the front section of the connector 4, and the sealing grooves are spaced apart along the axial direction of the connector 4. When the number of sealing grooves is "at least one", the sealing ring 5 in a single sealing groove can form a first sealing barrier on the mating surface of the connector 4 and the pad 2, directly blocking the leakage of electrolyte from the mating gap between the outer periphery of the connector 4 and the inner threaded hole of the pad 2. When multiple sealing grooves are set along the axial direction, the sealing ring 5 in each groove can form a "series-type multiple seal". Even if a certain sealing ring 5 is slightly worn or aged due to long-term use, the subsequent axially spaced sealing rings 5 ​​can still continue to play a sealing role, preventing the electrolyte from directly leaking to the outside after breaking through a single sealing layer, significantly improving the sealing redundancy of the connector 4 and adapting to the sealing reliability requirements of the fuel cell stack during long-term operation.

[0026] In this embodiment, the sealing groove on the outer periphery of the guide plate 3 is arranged circumferentially around the edge of the guide plate 3, and the coverage of the sealing groove can completely surround the liquid inlet and liquid outlet on the guide plate 3, preventing electrolyte leakage from the connection between the guide plate 3 and the pad 2. When the guide plate 3 and the pad 2 are in contact, the sealing ring 5 in the sealing groove is compressed and tightly fills the gap between them, which can directly block the path of electrolyte leakage from the internal channel of the guide plate 3 and the periphery of the liquid inlet / outlet to the outside (the contact gap between the guide plate 3 and the pad 2), avoiding electrolyte corrosion of the inlet / outlet plates 1 after breaking through the gap, or causing the risk of leakage of the fuel cell stack.

[0027] Additionally, it should be noted that components not described in detail in this article are existing technologies.

[0028] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A connection structure for the inlet and outlet connectors of a vanadium redox flow battery stack, characterized in that, It includes inlet and outlet plates (1), pads (2), guide plates (3) and connectors (4); The pad (2) is disposed between the inlet / outlet liquid plate (1) and the guide plate (3), and the pad (2) is provided with an internal thread structure that is compatible with the connector (4); The connector (4) has an external thread structure on its outer periphery, and the front section of the connector (4) has a sealing groove for installing the sealing ring (5). The guide plate (3) is provided with an inlet and an outlet, and the outer periphery of the guide plate (3) is provided with a sealing groove for installing the sealing ring (5).

2. The connection structure of the inlet and outlet connectors of the vanadium redox flow battery stack according to claim 1, characterized in that, The inner circumferential wall of the connector (4) is provided with an internal thread structure, which is used to achieve a threaded connection with the external thread structure of the external pipeline to complete the docking of the connector (4) with the external pipeline.

3. The connection structure of the inlet and outlet connectors of the vanadium redox flow battery stack according to claim 1, characterized in that, The guide plate (3) has two liquid inlets and two liquid outlets, and the two liquid inlets and two liquid outlets are symmetrically distributed on the guide plate (3).

4. The connection structure of the inlet and outlet connectors of the vanadium redox flow battery stack according to any one of claims 1 to 3, characterized in that, The number of sealing grooves opened on the outer periphery of the front section of the connector (4) is at least one, and each sealing groove is spaced apart along the axial direction of the connector (4).

5. The connection structure of the inlet / outlet connector of the vanadium redox flow battery stack according to claim 4, characterized in that, The sealing groove opened on the outer periphery of the guide plate (3) is arranged around the edge of the guide plate (3) in a circumferential manner, and the coverage of the sealing groove can completely surround the liquid inlet and liquid outlet on the guide plate (3) to prevent electrolyte from leaking from the connection between the guide plate (3) and the pad (2).

6. The connection structure of the inlet / outlet connector of the vanadium redox flow battery stack according to claim 5, characterized in that, The length of the outer thread structure of the connector (4) matches the thickness of the pad (2). When the connector (4) and the pad (2) are threadedly connected in place, the front end of the connector (4) can tightly abut against the side wall of the inlet / outlet liquid plate (1).

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