Pressure self-balancing electrolyte storage device and liquid flow energy storage system

Abstract

The utility model provides a pressure self-balancing electrolyte storage device and a liquid flow energy storage system, the pressure self-balancing electrolyte storage device comprises a liquid storage tank used for storing electrolyte, the top of the liquid storage tank is provided with an elastic air bag, and the elastic air bag is communicated with the liquid storage tank through a pressure regulating pipe. The elastic air bag is installed at the top of the liquid storage tank, the elastic air bag is communicated with the air space in the liquid storage tank through the pressure adjusting pipe, and when positive pressure is generated in the liquid storage tank, the positive pressure in the liquid storage tank can be relieved through expansion of the elastic air bag; when negative pressure is generated in the liquid storage tank, the negative pressure in the liquid storage tank can be compensated through contraction of the elastic air bag, and therefore the phenomenon that the tank body is damaged due to the fact that the negative pressure or positive pressure in the liquid storage tank is too large is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid flow energy storage batteries, in particular to an electrolyte storage device with pressure self - balance and a liquid flow energy storage system. Background Art

[0002] The vanadium battery, also known as the all - vanadium redox flow battery, is a redox battery in which multi - valent vanadium ions are in a circulating liquid state. The all - vanadium redox flow battery system mainly consists of a power unit, an electrolyte, an electrolyte storage unit, a pipeline transportation system, a BMS (Battery Management System), a thermal management system, etc. The all - vanadium redox flow battery has prominent features such as high capacity, flexible capacity configuration, long service life, safety and environmental protection, etc., and is now widely used in fields such as wind - solar complementary power generation, power grid peak shaving and valley filling, uninterruptible power supply, emergency power supply, etc. Wind power generation and photovoltaic power generation are random, volatile, and greatly affected by natural factors. After being connected to the power grid, they will cause fluctuations in the grid voltage and frequency, affecting the safe and stable operation of the power grid. The power grid also faces increasingly severe challenges in the problem of absorbing large - scale new energy. By introducing the all - vanadium redox flow battery, the operation stability of the power system can be effectively improved, the frequency can be adjusted, the load fluctuation can be compensated, the utilization rate of power equipment can be increased, etc., promoting the grid connection and use of renewable energy.

[0003] During the charge - discharge process of the all - vanadium redox flow battery system, the air pressure in the positive and negative electrode storage tanks will fluctuate, resulting in positive or negative pressure in the positive and negative electrode storage tanks. If not compensated, it is easy to cause damage to the storage tanks.

[0004] Chinese Patent with publication number CN107579267B discloses an automatic pressure - relief device for an electrolyte storage tank. This patent uses a water - seal device, which can effectively isolate the electrolyte in the electrolyte storage tank from the outside atmosphere. Only by ensuring the liquid level height in the water storage chamber, when the pressure in the electrolyte storage tank exceeds the set pressure, the gas in the electrolyte storage tank can automatically be discharged through the exhaust port of the electrolyte storage tank, the intake port, the water in the water storage chamber, and the exhaust port of the water - seal device, avoiding over - pressure in the electrolyte storage tank and ensuring the safety and reliability of the electrolyte storage tank. However, the disadvantages of this patent are as follows: when the electrolyte storage tank generates negative pressure, the water is sucked into the pipeline to form a water column of corresponding height to compensate for the pressure change. If the water - seal pipe is too low, the water is easily sucked into the electrolyte storage tank; if the water - seal pipe is too high, when the negative pressure in the electrolyte storage tank reaches the critical value of the negative pressure that the electrolyte storage tank can withstand, the electrolyte storage tank will be sucked flat, causing significant losses to the system. Content of the Utility Model

[0005] The utility model provides a pressure-self-balancing electrolyte storage device and a liquid flow energy storage system, which solve the problems in the prior art of using a water seal device to balance the gas pressure in an electrolyte storage tank. When a large negative pressure is generated in the electrolyte storage tank, water is easily sucked into the electrolyte storage tank when the water seal tube is too low, or the electrolyte storage tank is sucked flat when the water seal tube is too high, causing significant losses to the system.

[0006] The technical solution of the utility model is achieved in this way:

[0007] The utility model first aspect provides a pressure self-balancing electrolyte storage device, comprising a liquid storage tank for storing electrolyte, an elastic air bag is installed on the top of the liquid storage tank, and the elastic air bag is connected to the liquid storage tank through a pressure regulating pipe.

[0008] The utility model installs an elastic airbag on the top of the liquid storage tank, and connects the elastic airbag with the gas space inside the liquid storage tank by using a pressure regulating pipe. When positive pressure is generated inside the liquid storage tank, the expansion of the elastic airbag can be used to relieve the positive pressure inside the liquid storage tank; when negative pressure is generated inside the liquid storage tank, the contraction of the elastic airbag can be used to compensate for the negative pressure inside the liquid storage tank, thereby avoiding damage to the tank body caused by excessive negative pressure or positive pressure inside the liquid storage tank.

[0009] Specifically, a valve is installed on the pressure regulating tube to prevent external air from entering the liquid storage tank and reacting with the electrolyte when installing / disassembling the elastic airbag.

[0010] Preferably, a pressure transmitter and an exhaust valve are installed on the top of the liquid storage tank, and the pressure transmitter is used to monitor the air pressure inside the liquid storage tank. The pressure transmitter and the exhaust valve are respectively connected to the controller; when the pressure transmitter monitors that the air pressure inside the liquid storage tank is higher than the set upper limit value, the controller automatically controls the exhaust valve to open to relieve the pressure of the liquid storage tank.

[0011] Preferably, the top of the liquid storage tank is connected to a gas cylinder, inert gas is stored in the gas cylinder, a solenoid valve is provided on the pipeline connecting the gas cylinder and the liquid storage tank, and the solenoid valve is connected to the controller; when the pressure transmitter monitors that the air pressure inside the liquid storage tank is lower than the set lower limit value, the solenoid valve can be controlled to open by the controller, and the pressure of the liquid storage tank is compensated through the gas cylinder.

[0012] Further, the solenoid valve is an electromagnetic three-way valve, which is installed on the pressure regulating pipe, and the valve is located between the electromagnetic three-way valve and the elastic airbag; the three interfaces of the electromagnetic three-way valve are respectively connected to the liquid storage tank, the elastic airbag and the gas cylinder, and the electromagnetic three-way valve is connected to the controller; when the pressure transmitter monitors that the internal air pressure of the liquid storage tank is between the set lower limit value and the set upper limit value, the controller controls the electromagnetic three-way valve to connect the elastic airbag and the liquid storage tank, and balances the air pressure fluctuation in the liquid storage tank through the expansion or contraction of the elastic airbag; when the pressure transmitter monitors that the internal air pressure of the liquid storage tank is lower than the set lower limit value, the controller controls the electromagnetic three-way valve to connect the gas cylinder and the liquid storage tank, and fills the liquid storage tank with gas from the gas cylinder to balance the air pressure.

[0013] Preferably, a liquid level monitoring assembly is provided on one side of the liquid storage tank for monitoring the electrolyte liquid level in the liquid storage tank.

[0014] In a second aspect of the present invention, a liquid flow energy storage system is provided, which includes an electric stack, a positive electrode storage tank, a negative electrode storage tank, a positive electrode electrolyte circulation pump, and a negative electrode electrolyte circulation pump, and both the positive electrode storage tank and the negative electrode storage tank adopt the electrolyte storage device described above.

[0015] Preferably, an SOC monitoring assembly is connected in parallel at both ends of the electric stack through pipelines for monitoring the voltage of the liquid flow energy storage system. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of a pressure self-balancing electrolyte storage device of the present invention;

[0018] Figure 2 It is a schematic structural diagram of a liquid flow energy storage system of the present invention;

[0019] In the figure: 1. Liquid storage tank; 2. Elastic airbag; 3. Pressure regulating pipe; 4. Valve; 5. Pressure transmitter; 6. Exhaust valve; 7. Gas cylinder; 8. Electromagnetic three-way valve; 9. Liquid level monitoring assembly; 10. Electric stack; 11. Positive electrode storage tank; 12. Negative electrode storage tank; 13. Positive electrode electrolyte circulation pump; 14. Negative electrode electrolyte circulation pump; 15. SOC monitoring assembly. Detailed Embodiments

[0020] The technical solution of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present utility model.

[0021] Referring to Figure 1 , in the first aspect of the embodiment of the present utility model, a pressure self-balancing electrolyte storage device is provided, including a liquid storage tank 1 for storing electrolyte. An elastic airbag 2 is installed at the top of the liquid storage tank 1, and the elastic airbag 2 is communicated with the liquid storage tank 1 through a pressure regulating pipe 3.

[0022] In the present utility model, by installing the elastic airbag 2 at the top of the liquid storage tank 1 and connecting the elastic airbag 2 with the gas space inside the liquid storage tank 1 through the pressure regulating pipe 3, when positive pressure is generated inside the liquid storage tank 1, the expansion of the elastic airbag 2 can be used to relieve the positive pressure inside the liquid storage tank 1; when negative pressure is generated inside the liquid storage tank 1, the contraction of the elastic airbag 2 can be used to compensate for the negative pressure inside the liquid storage tank 1, thereby avoiding damage to the tank body caused by excessive negative or positive pressure inside the liquid storage tank 1.

[0023] During the specific implementation process, a certain amount of inert gas is pre-filled in the elastic airbag 2 to make the elastic airbag 2 in a slightly positive pressure state, which is convenient for balancing the air pressure through the contraction of the elastic airbag 2 when negative pressure appears in the liquid storage tank 1.

[0024] Specifically, a valve 4 is installed on the pressure regulating pipe 3, which is convenient for avoiding external air from entering the liquid storage tank 1 and reacting with the electrolyte when installing / removing the elastic airbag 2.

[0025] Preferably, a pressure transmitter 5 and an exhaust valve 6 are installed at the top of the liquid storage tank 1. The pressure transmitter 5 is used to monitor the air pressure inside the liquid storage tank 1, and the pressure transmitter 5 and the exhaust valve 6 are respectively connected to the controller; when the pressure transmitter 5 monitors that the air pressure inside the liquid storage tank 1 is higher than the set upper limit value, the controller automatically controls the exhaust valve 6 to open to relieve the pressure of the liquid storage tank 1.

[0026] In this embodiment, by setting the exhaust valve 6, double protection can be realized for the liquid storage tank 1 in cooperation with the elastic airbag 2. When the expansion of the elastic airbag 2 is not enough to balance the positive pressure inside the liquid storage tank 1, the exhaust valve 6 can be opened to perform emergency pressure relief on the liquid storage tank 1 to avoid bursting of the tank body due to excessive positive pressure inside the liquid storage tank 1, thereby fully ensuring the safe operation of the liquid storage tank 1.

[0027] During the specific implementation process, two exhaust valves 6 are provided, one for use and one for standby, with stronger reliability.

[0028] Preferably, the top of the liquid storage tank 1 is connected to a high-pressure gas cylinder 7, inert gas is stored in the gas cylinder 7, and a solenoid valve is provided on the pipeline connecting the gas cylinder 7 and the liquid storage tank 1, and the solenoid valve is connected to the controller; when the pressure transmitter 5 detects that the air pressure inside the liquid storage tank 1 is lower than the set lower limit value, the solenoid valve can be controlled to open by the controller, and the pressure of the liquid storage tank 1 is compensated through the gas cylinder 7.

[0029] In this embodiment, the gas cylinder 7 can be provided to cooperate with the elastic airbag 2 to achieve double protection for the liquid storage tank 1. When the contraction of the elastic airbag 2 is not sufficient to balance the negative pressure inside the liquid storage tank 1, the liquid storage tank 1 can be urgently pressurized by the gas cylinder 7 to avoid excessive negative pressure inside the liquid storage tank 1 from sucking the tank body, thereby fully ensuring the safe operation of the liquid storage tank 1.

[0030] Furthermore, the solenoid valve is an electromagnetic three-way valve 8, which is installed on the pressure regulating pipe 3, and the valve 4 is located between the electromagnetic three-way valve 8 and the elastic airbag 2; the three interfaces of the electromagnetic three-way valve 8 are respectively connected to the liquid storage tank 1, the elastic airbag 2, and the gas cylinder 7, and the electromagnetic three-way valve 8 is connected to the controller; when the pressure transmitter 5 monitors that the internal air pressure of the liquid storage tank 1 is between the set lower limit value and the set upper limit value, the controller controls the electromagnetic three-way valve 8 to connect the elastic airbag 2 and the liquid storage tank 1, and balances the air pressure fluctuation in the liquid storage tank 1 by the expansion or contraction of the elastic airbag 2; when the pressure transmitter 5 monitors that the internal air pressure of the liquid storage tank 1 is lower than the set lower limit value, the controller controls the electromagnetic three-way valve 8 to connect the gas cylinder 7 and the liquid storage tank 1, and inflates the liquid storage tank 1 through the gas cylinder 7 to balance the air pressure.

[0031] Preferably, a liquid level monitoring component 9 is provided on one side of the liquid storage tank 1 for monitoring the electrolyte level in the liquid storage tank 1 .

[0032] During the specific implementation process, the liquid level monitoring component 9 can use a liquid level sensor or a transparent connecting tube. In this embodiment, a transparent connecting tube is used. The top end of the connecting tube is connected to the gas part inside the liquid storage tank 1, and the bottom end of the connecting tube is connected to the liquid part inside the liquid storage tank 1. The connecting vessel principle is used to monitor the internal liquid level of the liquid storage tank 1.

[0033] Reference Figure 2 The second aspect of the embodiment of the utility model provides a liquid flow energy storage system, including a battery stack 10, a positive electrode storage tank 11, a negative electrode storage tank 12, a positive electrode electrolyte circulation pump 13, and a negative electrode electrolyte circulation pump 14. The positive electrode storage tank 11 and the negative electrode storage tank 12 both use the electrolyte storage device described above; the positive electrode of the battery stack 10 is connected to the positive electrode storage tank 11 through the positive electrode electrolyte circulation pump 13 and the pipeline, and the negative electrode of the battery stack 10 is connected to the negative electrode storage tank 12 through the negative electrode electrolyte circulation pump 14 and the pipeline.

[0034] Preferably, both ends of the stack 10 are connected in parallel through pipelines with an SOC monitoring component 15 for monitoring the voltage of the liquid flow energy storage system.

[0035] The pressure self-balancing process of the electrolyte storage device in this embodiment is as follows:

[0036] When a positive pressure is generated in the liquid storage tank 1 and the air pressure is lower than the set upper limit value, the elastic airbag 2 expands under the action of the positive pressure to automatically balance the positive pressure inside the liquid storage tank 1; when the pressure transmitter 5 monitors that the air pressure inside the liquid storage tank 1 is higher than the set upper limit value, it indicates that the elastic airbag 2 is about to expand to the limit. At this time, the exhaust valve 6 is controlled by the controller to open, and the liquid storage tank 1 is urgently depressurized to quickly balance the positive pressure inside the liquid storage tank 1.

[0037] When a negative pressure is generated inside the liquid storage tank 1 and the air pressure is higher than the set lower limit value, the electromagnetic three-way valve 8 is controlled by the controller to switch to the airbag position to connect the elastic airbag 2 and the liquid storage tank 1. The elastic airbag 2 contracts under the action of the negative pressure to automatically balance the negative pressure inside the liquid storage tank 1; when the pressure transmitter 5 monitors that the air pressure inside the liquid storage tank 1 is lower than the set lower limit value, it indicates that the contraction of the elastic airbag 2 can no longer balance the negative pressure inside the liquid storage tank 1. At this time, the electromagnetic three-way valve 8 is controlled by the controller to switch to the gas cylinder 7 position to connect the gas cylinder 7 and the liquid storage tank 1, and the liquid storage tank 1 is pressurized by the gas cylinder 7 to quickly balance the negative pressure inside the liquid storage tank 1.

[0038] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pressure-self-balancing electrolyte storage device, comprising a liquid storage tank (1) for storing electrolyte, characterized in that: An elastic airbag (2) is installed on the top of the liquid storage tank (1), and the elastic airbag (2) is connected to the liquid storage tank (1) via a pressure regulating pipe (3).

2. A pressure self-balancing electrolyte storage device as claimed in claim 1, characterized in that: A valve (4) is installed on the pressure regulating pipe (3).

3. A pressure self-balancing electrolyte storage device as claimed in claim 2, characterized in that: A pressure transmitter (5) and an exhaust valve (6) are installed on the top of the liquid storage tank (1). The pressure transmitter (5) is used to monitor the air pressure inside the liquid storage tank (1). The pressure transmitter (5) and the exhaust valve (6) are respectively connected to a controller.

4. A pressure self-balancing electrolyte storage device as claimed in claim 3, characterized in that: The top of the liquid storage tank (1) is connected to a gas cylinder (7), inert gas is stored in the gas cylinder (7), and a solenoid valve is provided on the pipeline connecting the gas cylinder (7) and the liquid storage tank (1), and the solenoid valve is connected to a controller.

5. A pressure self-balancing electrolyte storage device as claimed in claim 4, characterized in that: The solenoid valve is a solenoid three-way valve (8), which is installed on a pressure regulating pipe (3), and the valve (4) is located between the solenoid three-way valve (8) and the elastic airbag (2); three interfaces of the solenoid three-way valve (8) are respectively connected to a liquid storage tank (1), an elastic airbag (2), and a gas cylinder (7), and the solenoid three-way valve (8) is connected to a controller.

6. A pressure self-balancing electrolyte storage device as claimed in claim 1, characterized in that: A liquid level monitoring component (9) is provided on one side of the liquid storage tank (1).

7. A liquid flow energy storage system, comprising a battery stack (10), a positive electrode storage tank (11), a negative electrode storage tank (12), a positive electrode electrolyte circulation pump (13), and a negative electrode electrolyte circulation pump (14), characterized in that: The positive electrode storage tank (11) and the negative electrode storage tank (12) both adopt the electrolyte storage device as described in any one of claims 1 to 6.

8. A liquid flow energy storage system according to claim 7, characterized in that: Both ends of the battery stack (10) are connected in parallel with an SOC monitoring component (15) via a pipeline.

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