Vanadium-lithium combined energy storage power station system

Abstract

The utility model discloses a vanadium-lithium combined energy storage power station system which comprises a frame body, a vanadium liquid flow unit, a lithium battery unit and a control unit, the vanadium liquid flow unit is arranged on the bottom layer of the frame body and comprises a negative electrolyte storage tank and a positive electrolyte storage tank, an electric pile and a circulating pipeline system are connected between the negative electrolyte storage tank and the positive electrolyte storage tank, and an electrolyte cooling system is arranged on the outer side of the electric pile; the lithium battery unit is arranged on the middle layer of the frame body and comprises a plurality of connected lithium battery modules, and air ducts are arranged among the plurality of lithium battery modules; the control unit is arranged on the top layer of the frame body and comprises a plurality of collecting modules, and the collecting modules are connected with the electrolyte cooling system and the air channel. According to the utility model, the rack body is arranged in a layered manner, and all units are integrated on the rack body, so that the purposes of compact structure and function integration are achieved. And the electrolyte cooling system and the air duct of the lithium battery module are connected with the acquisition module of the control unit, so that synergism of thermal management is realized.

Description

Technical Field

[0001] This utility model relates to the field of energy storage power station technology, and in particular to a vanadium-lithium combined energy storage power station system. Background Technology

[0002] With the rapid development of new energy sources, the importance of energy storage power stations is becoming increasingly prominent. Vanadium-lithium hybrid energy storage power stations combine the advantages of vanadium redox flow storage and lithium battery energy storage, featuring long lifespan, high safety, high energy density, and rapid response.

[0003] However, hybrid energy storage power stations have the following problems: the mechanical layout of traditional hybrid energy storage power stations is loose, and the space between various components is not fully utilized, resulting in a large footprint and low space utilization of the entire system; vanadium redox flow batteries usually use electrolyte circulation for heat dissipation, while lithium batteries may use air cooling or liquid cooling. These two heat dissipation methods have significant differences in design and operation, making it difficult to achieve compatibility. This can easily lead to uneven heat dissipation, causing some batteries to overheat, affecting battery performance and lifespan, and may even cause safety accidents. Utility Model Content

[0004] To address the aforementioned problems, this invention provides a vanadium-lithium combined energy storage power station system to solve the issues of low space utilization and uneven heat dissipation in existing hybrid energy storage power stations.

[0005] This utility model is implemented as follows:

[0006] A vanadium-lithium combined energy storage power station system includes:

[0007] Frame;

[0008] A vanadium liquid flow unit is located at the bottom of the frame. The vanadium liquid flow unit includes a negative electrode electrolyte storage tank and a positive electrode electrolyte storage tank. A fuel cell stack and a circulation pump are connected between the negative electrode electrolyte storage tank and the positive electrode electrolyte storage tank. An electrolyte cooling system is provided on the outside of the fuel cell stack.

[0009] A lithium battery unit is disposed in the middle layer of the frame. The lithium battery unit includes multiple interconnected lithium battery modules, and air ducts are provided between the multiple lithium battery modules.

[0010] The control unit is located on the top layer of the frame. The control unit includes several acquisition modules, which are respectively connected to the electrolyte cooling system and the air duct.

[0011] Furthermore, the control unit also includes a bidirectional DC-DC converter, which is connected to the lithium battery cell and the battery stack, respectively.

[0012] Furthermore, the circulation pump includes a negative electrode circulation pump and a positive electrode circulation pump. The inlet end of the negative electrode circulation pump is connected to the outlet of the negative electrode electrolyte storage tank, and the outlet end of the negative electrode circulation pump is connected to the negative electrode chamber of the fuel cell stack. The inlet end of the positive electrode circulation pump is connected to the outlet of the positive electrode electrolyte storage tank, and the outlet end of the positive electrode circulation pump is connected to the positive electrode chamber of the fuel cell stack.

[0013] Furthermore, the outlet of the negative electrode chamber is connected to the inlet of the negative electrode electrolyte storage tank through a negative electrode manifold, and the outlet of the positive electrode chamber is connected to the inlet of the positive electrode electrolyte storage tank through a positive electrode manifold.

[0014] Furthermore, the bidirectional DC-DC converter is connected to the main power grid bus via a copper-aluminum composite busbar.

[0015] Furthermore, multiple lithium battery modules are connected via series or parallel circuits.

[0016] Furthermore, multiple lithium battery modules are embedded in the middle layer of the frame in a honeycomb arrangement, with each lithium battery module being evenly distributed.

[0017] Furthermore, a graphene phase change plate is provided between the fuel cell stack and the lithium battery module.

[0018] The beneficial effects of this utility model are:

[0019] This utility model discloses a vanadium-lithium combined energy storage power station system. By arranging the frame in layers, it integrates each unit onto the frame, achieving a compact structure, integrated functions, and improved space utilization. The electrolyte cooling system and the air ducts of the lithium battery modules are both connected to the data acquisition module of the control unit, enabling coordinated thermal management. When the electrolyte or lithium battery module temperature is too high, the data acquisition module can simultaneously accelerate the heat dissipation of both, improving the overall thermal management performance of the system. By combining the energy storage characteristics of vanadium redox flow batteries and lithium batteries, it achieves efficient and reliable energy storage and dispatch. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Frame;

[0023] 2. Vanadium liquid flow unit; 21. Negative electrode electrolyte storage tank; 22. Positive electrode electrolyte storage tank; 23. Fuel cell stack; 231. Negative electrode chamber; 232. Positive electrode chamber; 24. Negative electrode circulation pump; 25. Positive electrode circulation pump; 26. Negative electrode manifold; 27. Positive electrode manifold;

[0024] 3. Lithium battery unit; 31. Lithium battery module; 32. Air duct;

[0025] 4. Control unit; 41. Acquisition module; 42. Bidirectional DC-DC converter; 43. Copper-aluminum composite busbar. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Many specific details are set forth in the following description to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] like Figure 1 The diagram shows the vanadium-lithium combined energy storage power station system of this utility model, including a frame 1, a vanadium redox flow unit 2, a lithium battery unit 3, and a control unit 4. The vanadium redox flow unit 2 is located at the bottom of the frame 1 and includes a negative electrolyte storage tank 21 and a positive electrolyte storage tank 22. A fuel cell stack 23 and a circulation pump are connected between the negative electrolyte storage tank 21 and the positive electrolyte storage tank 22. An electrolyte cooling system (not shown in the figure) is provided on the outside of the fuel cell stack 23. The lithium battery unit 3 is located in the middle layer of the frame 1 and includes multiple interconnected lithium battery modules 31. A duct 32 is provided between the multiple lithium battery modules 31. The control unit 4 is located at the top layer of the frame 1 and includes several acquisition modules 41. The acquisition modules 41 adopt axial flow fans and are respectively connected to the electrolyte cooling system and the duct 32.

[0028] The frame 1 adopts a frame structure, welded together from multiple channel steels, rectangular tubes, or square tubes, capable of withstanding sufficient strength and rigidity. The frame 1 employs a layered structure, divided into a top layer, a middle layer, and a bottom layer. The vanadium redox flow unit 2 is located at the bottom layer of the frame 1. The vanadium redox flow unit 2 includes a negative electrode electrolyte storage tank 21 and a positive electrode electrolyte storage tank 22. A battery stack 23 and a circulation pump connect the negative electrode electrolyte storage tank 21 and the positive electrode electrolyte storage tank 22, forming a circulation loop for the electrolyte. Each vanadium redox flow battery stack 23 is simultaneously connected to both positive and negative electrode electrolytes, and the stacks are connected in series and parallel to form a battery unit. The negative electrode electrolyte storage tank 21 stores the negative electrode electrolyte, and the positive electrode electrolyte storage tank 22 stores the positive electrode electrolyte. The circulation pumps include a negative electrode circulation pump 24 and a positive electrode circulation pump 25. The inlet of the negative electrode circulation pump 24 is connected to the outlet of the negative electrode electrolyte storage tank 21 via a pipeline, and the outlet of the negative electrode circulation pump 24 is connected to the negative electrode chamber 231 of the fuel cell stack 23 via a pipeline. The inlet of the positive electrode circulation pump 25 is connected to the outlet of the positive electrode electrolyte storage tank 22 via a pipeline, and the outlet of the positive electrode circulation pump 25 is connected to the positive electrode chamber 232 of the fuel cell stack 23 via a pipeline. The outlet of the negative electrode chamber 231 is connected to the inlet of the negative electrode electrolyte storage tank 21 via the negative electrode manifold 26, and the outlet of the positive electrode chamber 232 is connected to the inlet of the positive electrode electrolyte storage tank 22 via the positive electrode manifold 27, thus forming a complete electrolyte circulation system.

[0029] The negative electrode circulation pump 24 draws the negative electrode electrolyte from the negative electrode electrolyte storage tank 21 and delivers it to the negative electrode chamber 231 of the fuel cell stack 23; the positive electrode circulation pump 25 draws the positive electrode electrolyte from the positive electrode electrolyte storage tank 22 and delivers it to the positive electrode chamber 232 of the fuel cell stack 23. Inside the fuel cell stack 23, the electrolyte undergoes a redox reaction through an ion exchange membrane, realizing the mutual conversion of electrical energy and chemical energy. The electrolyte in the negative electrode chamber 231 flows back to the negative electrode electrolyte storage tank 21 through the negative electrode current collector 26; the electrolyte in the positive electrode chamber 232 flows back to the positive electrode electrolyte storage tank 22 through the positive electrode current collector 27, forming a circulation.

[0030] An electrolyte cooling system is installed on the outside of the fuel cell stack 23 to control the electrolyte temperature and ensure the normal operation of the fuel cell stack 23. The electrolyte cooling system is connected to the acquisition module 41 through a pipe. In this embodiment, the electrolyte cooling system uses electrolyte heat dissipation pipes, which are attached parallel to the outer frame on the back of the fuel cell stack 23 and arranged in a serpentine pattern along the height of the fuel cell stack 23. The inner side of the heat dissipation pipes is in close contact with the outer surface of the current collector plate of the fuel cell stack 23, maintaining a gap of 5-8 mm to allow for thermal expansion. When the electrolyte temperature exceeds a set threshold, the acquisition module 41 accelerates its operation and forces convection to cool the electrolyte cooling system, thereby reducing the electrolyte temperature.

[0031] The lithium battery unit 3 is located in the middle layer of the frame 1, and includes multiple interconnected lithium battery modules 31. Air ducts 32 are provided between the multiple lithium battery modules 31 for ventilation and heat dissipation, and these ducts 32 are connected to the data acquisition module 41 via pipes. When the temperature of the lithium battery module 31 exceeds a set threshold, the data acquisition module 41 accelerates its operation, forcibly cooling the lithium battery module 31 through the air ducts 32 via convection. The multiple lithium battery modules 31 are connected in series or parallel circuits, allowing for flexible configuration of the battery pack's voltage and capacity according to actual needs.

[0032] To further improve the heat dissipation performance of the lithium battery unit 3, multiple lithium battery modules 31 are embedded in the middle layer of the frame 1 in a honeycomb arrangement. Each lithium battery module 31 is evenly distributed, so that air can flow evenly through each module to achieve efficient heat dissipation.

[0033] The control unit 4 is located on the top layer of the frame 1 and includes several data acquisition modules 41 and a bidirectional DC-DC converter 42. The data acquisition modules 41 are connected to the electrolyte cooling system and the air duct 32 via pipes, respectively, to control the temperature of the electrolyte and the lithium battery module 31. The bidirectional DC-DC converter 42 is connected to the lithium battery unit 3 and the battery stack 23, respectively, to realize energy conversion and scheduling between the lithium battery and the vanadium redox flow battery. The bidirectional DC-DC converter 42 is connected to the main power grid bus via a copper-aluminum composite busbar 43 to ensure efficient power transmission and stable operation.

[0034] Based on grid demand or the status of the energy storage system, the control unit 4 sends charging and discharging commands to the lithium battery module 31 via the bidirectional DC-DC converter 42. During charging, the lithium battery module 31 absorbs electrical energy from the main grid bus through the copper-aluminum composite busbar 43; during discharging, the lithium battery module 31 releases electrical energy back to the main grid bus.

[0035] To further improve the system's thermal management performance, a graphene phase change plate (not shown in the figure) is installed between the fuel cell stack 23 and the lithium battery module 31. Its matrix is ​​a paraffin / expanded graphite composite material. The bottom of the graphene phase change plate contacts the top cover of the fuel cell stack 23, and its top abuts against the bottom of the lithium battery module 31. The graphene phase change plate possesses excellent thermal conductivity and phase change energy storage characteristics, enabling efficient heat transfer and storage between the fuel cell stack 23 and the lithium battery module 31. This effectively reduces system temperature fluctuations and improves system stability and reliability. When the temperature of the fuel cell stack 23 or the lithium battery module 31 rises, the graphene phase change plate absorbs and stores heat; when the temperature decreases, the graphene phase change plate releases heat, achieving bidirectional heat regulation and reducing system temperature fluctuations.

[0036] In operation, the vanadium-lithium combined energy storage power station system of this invention prioritizes the discharge of lithium battery modules 31 during peak grid demand periods and schedules the charging of vanadium redox flow batteries during off-peak periods. A bidirectional DC-DC converter 42 regulates the energy flow between the lithium battery and the vanadium redox flow battery in real time to ensure system power balance. The control unit 4 monitors the temperature of the electrolyte and lithium battery modules 31 in real time and achieves precise temperature control by adjusting the rotation speed of the acquisition module 41.

[0037] While this utility model discloses preferred embodiments to achieve the above objectives, it is not intended to limit the structural features of this utility model. Anyone skilled in the art should know that any easily conceivable variations or modifications are possible under the technical spirit of this utility model and are covered by the patent claims of this utility model.

Claims

1. A vanadium-lithium combined energy storage power station system, characterized in that, include: Frame; A vanadium liquid flow unit is located at the bottom of the frame. The vanadium liquid flow unit includes a negative electrode electrolyte storage tank and a positive electrode electrolyte storage tank. A fuel cell stack and a circulation pump are connected between the negative electrode electrolyte storage tank and the positive electrode electrolyte storage tank. An electrolyte cooling system is provided on the outside of the fuel cell stack. A lithium battery unit is disposed in the middle layer of the frame. The lithium battery unit includes multiple interconnected lithium battery modules, and air ducts are provided between the multiple lithium battery modules. The control unit is located on the top layer of the frame. The control unit includes several acquisition modules, which are respectively connected to the electrolyte cooling system and the air duct.

2. The vanadium-lithium combined energy storage power station system according to claim 1, characterized in that, The control unit also includes a bidirectional DC-DC converter, which is connected to the lithium battery cell and the battery stack, respectively.

3. The vanadium-lithium combined energy storage power station system according to claim 2, characterized in that, The circulation pump includes a negative electrode circulation pump and a positive electrode circulation pump. The inlet end of the negative electrode circulation pump is connected to the outlet of the negative electrode electrolyte storage tank, and the outlet end of the negative electrode circulation pump is connected to the negative electrode chamber of the fuel cell stack. The inlet end of the positive electrode circulation pump is connected to the outlet of the positive electrode electrolyte storage tank, and the outlet end of the positive electrode circulation pump is connected to the positive electrode chamber of the fuel cell stack.

4. The vanadium-lithium combined energy storage power station system according to claim 3, characterized in that, The outlet of the negative electrode chamber is connected to the inlet of the negative electrode electrolyte storage tank through the negative electrode manifold, and the outlet of the positive electrode chamber is connected to the inlet of the positive electrode electrolyte storage tank through the positive electrode manifold.

5. The vanadium-lithium combined energy storage power station system according to claim 2, characterized in that, The bidirectional DC-DC converter is connected to the main power grid bus via a copper-aluminum composite busbar.

6. The vanadium-lithium combined energy storage power station system according to claim 1 or 2, characterized in that, Multiple lithium battery modules are connected in series or parallel circuits.

7. The vanadium-lithium combined energy storage power station system according to claim 6, characterized in that, Multiple lithium battery modules are embedded in the middle layer of the frame in a honeycomb arrangement, with each lithium battery module being evenly distributed.

8. The vanadium-lithium combined energy storage power station system according to claim 1, characterized in that, A graphene phase change plate is provided between the fuel cell stack and the lithium battery module.

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