All-vanadium redox flow energy storage device

Abstract

This utility model relates to the field of vanadium redox flow battery technology, and more particularly to a vanadium redox flow energy storage device, including a positive electrolyte tank and a negative electrolyte tank. The positive and negative electrolyte tanks are connected to a power unit via an electrolyte delivery unit. The power unit includes a fuel cell stack, with heat dissipation fins on both sides of the stack. Spiral cooling pipes are threaded through the heat dissipation fins and connected between the electrolyte delivery unit and the fuel cell stack. The electrolyte first passes through the cooling pipes and heat dissipation fins, which cools both the electrolyte and the fuel cell stack, ensuring efficient electrochemical reactions within the stack.

Description

Technical Field

[0001] This utility model relates to the field of vanadium redox flow battery technology, and in particular to a vanadium redox flow energy storage device. Background Technology

[0002] Vanadium redox flow storage (VRF) systems mainly consist of power units, energy storage units, electrolyte delivery units, and battery management systems. The optimal operating temperature range for the stack (power unit) is typically 25-40°C. This range ensures efficient electrochemical reactions while avoiding electrolyte decomposition and material aging, making it the optimal choice for balancing system performance, efficiency, and lifespan. However, in outdoor energy storage systems operating in high-temperature environments during summer (e.g., ambient temperatures above 35°C), insufficient heat dissipation design can lead to heat transfer from the environment to the stack. Furthermore, during grid peak shaving or emergency power supply, the stack operates at 1.2-1.5 times its rated power. During charging and discharging, electrochemical polarization, ohmic polarization, and concentration polarization generate Joule heating, all of which cause temperature rise and lead to the degradation of high-valence vanadium ions (such as VO2+). + At high temperatures, disproportionation reactions easily occur, generating V2O5 precipitates that clog electrode pores, flow channels, and filters, leading to the loss of active materials in the electrolyte and rapid capacity decay. Simultaneously, the proton exchange membrane undergoes accelerated chemical degradation at high temperatures, resulting in decreased proton conductivity, increased gas permeability, reduced mechanical strength, and increased susceptibility to damage. Furthermore, it accelerates the aging of electrode materials and system seals, severely impacting system lifespan. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a full vanadium redox flow energy storage device in response to the above-mentioned technical deficiencies, thereby solving the problem of high temperature affecting the system life of the full vanadium redox flow energy storage device.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a full vanadium redox flow energy storage device, including a positive electrode electrolyte storage tank and a negative electrode electrolyte storage tank. The positive electrode electrolyte storage tank and the negative electrode electrolyte storage tank are connected to a power unit through an electrolyte delivery unit. The power unit includes a fuel cell stack. Heat dissipation fins are provided on the left and right sides of the fuel cell stack. Spiral cooling pipes are installed inside the heat dissipation fins. The cooling pipes are connected between the electrolyte delivery unit and the fuel cell stack.

[0005] To further optimize this technical solution, the main material of the cooling pipeline is an insulating material with good thermal conductivity.

[0006] To further optimize this technical solution, one end of the fuel cell stack is provided with a positive electrode liquid inlet, a positive electrode liquid outlet, a negative electrode liquid inlet, and a negative electrode liquid outlet. Each set of heat dissipation fins contains two sets of cooling pipes. The heat dissipation fins include a first heat dissipation fin and a second heat dissipation fin. One end of the two sets of cooling pipes of the first heat dissipation fin is connected to the positive electrode liquid inlet and the negative electrode liquid outlet, respectively. One end of the two sets of cooling pipes of the second heat dissipation fin is connected to the negative electrode liquid inlet and the positive electrode liquid outlet, respectively. The ends of the four sets of cooling pipes away from the fuel cell stack are connected to the positive electrode electrolyte tank and the negative electrode electrolyte tank, respectively, through the electrolyte delivery unit.

[0007] To further optimize this technical solution, the positive electrode electrolyte storage tank and the negative electrode electrolyte storage tank are arranged vertically side by side at the bottom of the box. At least two sets of power units are installed inside the box. The two sets of power units share one set of positive electrode electrolyte storage tank and one set of negative electrode electrolyte storage tank. The two sets of power units are respectively located at the top of the positive electrode electrolyte storage tank and the negative electrode electrolyte storage tank. The top of the box is equipped with a box cover.

[0008] To further optimize this technical solution, an exhaust fan is provided in the middle of the length direction of the cover, and air inlets are provided at both ends of the enclosure and the power unit respectively.

[0009] Compared with the prior art, this utility model has the following advantages: 1. The electrolyte first passes through the cooling pipes and heat dissipation fins, which can cool the electrolyte and the fuel cell stack, ensuring that the electrochemical reaction in the fuel cell stack proceeds efficiently; 2. Fresh low-temperature gas enters the tank through the air inlet, flows through the heat dissipation fins and cooling pipes first, and is then discharged by the exhaust fan, further improving the heat dissipation efficiency; 3. The existence of the cooling pipes extends the flow length of the electrolyte at the fuel cell stack inlet and outlet, increases the resistance of the electrolyte pipes, reduces the overall bypass current of the system, and further reduces the heat generation of the system. Attached Figure Description

[0010] Figure 1 A schematic diagram of the external structure of a vanadium redox flow energy storage device;

[0011] Figure 2 This is a schematic diagram of a vanadium redox flow storage device with the tank cover opened.

[0012] Figure 3 This is a schematic diagram of the power unit in a vanadium redox flow energy storage device.

[0013] Figure 4 A schematic diagram of a vanadium redox flow storage device after removing the casing;

[0014] Figure 5 A top view of the interior of a vanadium redox flow storage device;

[0015] Figure 6This is a schematic diagram of the inner structure of the tank cover in a vanadium redox flow energy storage device.

[0016] In the diagram: 1. Positive electrolyte storage tank; 2. Negative electrolyte storage tank; 3. Electrolyte stack; 31. Positive electrolyte inlet; 32. Positive electrolyte outlet; 33. Negative electrolyte inlet; 34. Negative electrolyte outlet; 4. First heat dissipation fin; 5. Second heat dissipation fin; 6. Housing; 60. Air inlet; 7. Cooling pipes; 8. Housing cover; 9. Exhaust fan. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0018] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" used in this application to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are used solely for the convenience of describing this disclosure and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] Combination Figures 1 to 6 As shown, a vanadium redox flow storage device includes a positive electrolyte tank 1 and a negative electrolyte tank 2. The positive electrolyte tank 1 and negative electrolyte tank 2 are arranged longitudinally side-by-side at the bottom of a housing 6. The positive electrolyte tank 1 and negative electrolyte tank 2 are connected to power units via an electrolyte delivery unit. At least two sets of power units are installed inside the housing 6; in this embodiment, two sets are provided. The two sets of power units share one set of positive electrolyte tank 1 and negative electrolyte tank 2. The two sets of power units are respectively located on the upper part of the positive electrolyte tank 1 and negative electrolyte tank 2 and are arranged axially symmetrically. A housing cover 8 is provided on the top of the housing 6, and an exhaust fan 9 is located in the middle of the length direction of the housing cover 8. The exhaust fan 9 is located at the top between the positive electrolyte tank 1 and negative electrolyte tank 2. Air inlets 60 are provided at both ends of the housing 6 corresponding to the power units.

[0020] Combination Figures 3 to 4As shown, the power unit includes a fuel cell stack 3. Heat dissipation fins are provided on both the left and right sides of the fuel cell stack 3. A spirally ascending cooling pipe 7 is threaded through the heat dissipation fins, connecting the electrolyte delivery unit and the fuel cell stack 3. The main body of the cooling pipe 7 is made of a thermally conductive insulating material; in this embodiment, its main body can be made of a thermally conductive ceramic material. One end of the fuel cell stack 3 is provided with a positive electrode liquid inlet 31, a positive electrode liquid outlet 32, a negative electrode liquid inlet 33, and a negative electrode liquid outlet 34. Two sets of cooling pipes 7 are installed in each set of heat dissipation fins. The heat dissipation fins include a first heat dissipation fin 4 and a second heat dissipation fin 5. One end of the two sets of cooling pipes 7 of the first heat dissipation fin 4 is connected to the positive electrode liquid inlet 31 and the negative electrode liquid outlet 34, respectively. One end of the two sets of cooling pipes 7 of the second heat dissipation fin 5 is connected to the negative electrode liquid inlet 33 and the positive electrode liquid outlet 32, respectively. The ends of the four sets of cooling pipes 7 away from the fuel cell stack 3 are connected to the positive electrode electrolyte storage tank 1 and the negative electrode electrolyte storage tank 2 through the electrolyte delivery unit, respectively.

[0021] When using, combine Figures 1 to 6 As shown, the electrolyte entering and exiting the fuel cell stack 3 must first pass through the cooling pipe 7, which cools the electrolyte and the fuel cell stack 3, ensuring efficient electrochemical reactions within the fuel cell stack 3. The exhaust fan 9 can expel the hot air accumulated inside the housing 6 from the top, while fresh, low-temperature gas enters the housing 6 through the air inlet 60, flows through the heat dissipation fins and cooling pipe 7, and is then discharged by the exhaust fan 9, further improving heat dissipation efficiency. At the same time, the presence of the cooling pipe 7 extends the flow length of the electrolyte at the inlet and outlet of the fuel cell stack 3, increasing the resistance of the electrolyte pipe, which helps reduce the overall bypass current of the system and further reduces the generation of system heat.

[0022] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A vanadium redox flow battery energy storage device, comprising a positive electrolyte storage tank (1) and a negative electrolyte storage tank (2), wherein the positive electrolyte storage tank (1) and the negative electrolyte storage tank (2) are connected to a power unit via an electrolyte delivery unit, characterized in that: The power unit includes a fuel cell stack (3), and heat dissipation fins are provided on the left and right sides of the fuel cell stack (3). A spiral cooling pipe (7) is inserted inside the heat dissipation fins, and the cooling pipe (7) is connected between the electrolyte delivery unit and the fuel cell stack (3).

2. The all-vanadium redox flow storage device according to claim 1, characterized in that: The main material of the cooling pipeline (7) is an insulating material with good thermal conductivity.

3. The all-vanadium redox flow storage device according to claim 1, characterized in that: One end of the fuel cell stack (3) is provided with a positive electrode liquid inlet (31), a positive electrode liquid outlet (32), a negative electrode liquid inlet (33), and a negative electrode liquid outlet (34). Two sets of cooling pipes (7) are respectively installed in each set of heat dissipation fins. The heat dissipation fins include a first heat dissipation fin (4) and a second heat dissipation fin (5). One end of the two sets of cooling pipes (7) of the first heat dissipation fin (4) is connected to the positive electrode liquid inlet (31) and the negative electrode liquid outlet (34) respectively. One end of the two sets of cooling pipes (7) of the second heat dissipation fin (5) is connected to the negative electrode liquid inlet (33) and the positive electrode liquid outlet (32) respectively. The ends of the four sets of cooling pipes (7) away from the fuel cell stack (3) are connected to the positive electrode electrolyte storage tank (1) and the negative electrode electrolyte storage tank (2) respectively through the electrolyte delivery unit.

4. The all-vanadium redox flow storage device according to claim 1, characterized in that: The positive electrolyte storage tank (1) and the negative electrolyte storage tank (2) are arranged longitudinally side by side at the bottom of the box (6). At least two sets of power units are arranged inside the box (6). The two sets of power units share one set of positive electrolyte storage tank (1) and negative electrolyte storage tank (2). The two sets of power units are respectively arranged at the top of the positive electrolyte storage tank (1) and the negative electrolyte storage tank (2). The top of the box (6) is provided with a box cover (8).

5. The all-vanadium redox flow storage device according to claim 4, characterized in that: An exhaust fan (9) is provided in the middle of the length direction of the cover (8), and air inlets (60) are provided at the two ends of the box body (6) corresponding to the power unit.

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