CN216793755U

CN216793755U - Flow battery system based on underground space

Info

Publication number: CN216793755U
Application number: CN202123195620.XU
Authority: CN
Inventors: 赵天寿; 韦东波; 魏磊
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2022-06-21
Anticipated expiration: 2031-12-17

Abstract

The application relates to the technical field of flow batteries, and provides a flow battery system based on underground space, which comprises: the first liquid storage tank is arranged underground and is used for storing a first electrolyte solution; the second liquid storage tank is used for storing a second electrolyte solution, and the second electrolyte solution and the first electrolyte solution are respectively used for generating electrochemical reactions with opposite polarities; and the galvanic pile is respectively communicated with the first liquid storage tank and the second liquid storage tank. The utility model provides a redox flow battery system's based on underground space first liquid storage pot locates the underground, so first liquid storage pot can not occupy subaerial space, and this just makes redox flow battery system's the stock solution container that is used for storing electrolyte solution can not occupy the ground space to save redox flow battery system's occupation of land space, saved occupation of land cost.

Description

Flow battery system based on underground space

Technical Field

The application relates to the technical field of flow batteries, in particular to a flow battery system based on an underground space.

Background

The flow battery system is a novel electric energy storage and high-efficiency conversion device, and has the characteristics of large storage capacity, long service life, high efficiency, no toxicity, no harm and environmental friendliness. The flow battery system comprises two electrolyte reservoirs, a galvanic pile, electrolyte inlet and outlet pipelines and other parts for conveying electrolyte. Wherein, two electrolyte reservoirs are used for splendid attire anodal electrolyte and negative pole electrolyte respectively.

The energy of the electrolyte of the flow battery determines the electric quantity of the flow battery, so that the volume of a liquid storage device of the flow battery is usually large to contain more electrolyte, so that the energy of the electrolyte is more, and therefore the volume of a flow battery system is usually large, which results in a large occupied space and a high occupied cost of the flow battery system.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a redox flow battery system based on underground space, can reduce the occupation of land space of redox flow battery system to the occupation of land cost has been reduced. The specific scheme is as follows:

the embodiment of the application provides a flow battery system, includes:

the first liquid storage tank is arranged underground and is used for storing a first electrolyte solution;

the second liquid storage tank is used for storing a second electrolyte solution, and the second electrolyte solution and the first electrolyte solution are respectively used for generating electrochemical reactions with opposite polarities;

and the galvanic pile is respectively communicated with the first liquid storage tank and the second liquid storage tank.

The utility model provides a redox flow battery system's based on underground space first liquid storage pot locates the underground, so first liquid storage pot can not occupy subaerial space, and this just makes redox flow battery system's the stock solution container that is used for storing electrolyte solution can not occupy the ground space to save redox flow battery system's occupation of land space, saved occupation of land cost.

Optionally, the flow battery system further comprises:

the first liquid storage chamber is a space arranged underground, and the first liquid storage tank is arranged in the first liquid storage chamber.

This embodiment is through setting up first stock solution room, and the underground is located to the first liquid storage pot of being more convenient for, and the setting of first stock solution room also can provide better space for overhauing, and the flow battery system other parts of being more convenient for also set up in first stock solution room.

Optionally, an artificial detection space is arranged between the first liquid storage tank and the inner side wall of the first liquid storage chamber, and a first artificial detection channel is arranged between the artificial detection space and the ground.

After this embodiment sets up artifical measuring channel, in the measurement personnel can enter into artifical measuring space from artifical measuring channel to can maintain, detect first liquid storage pot from the outside of first liquid storage pot in artifical measuring space.

Optionally, the flow battery system further comprises a control system, a leakage detection device is arranged at the bottom of the first liquid storage chamber, and the leakage detection device is located outside the first liquid storage tank and is in communication connection with the control system.

This embodiment sets up weeping detection device in the bottom of first stock solution room, can take place to reveal at first stock solution pot and detect out fast to operating personnel in time maintain, reduce the bad consequence because of revealing and cause.

Optionally, an anti-corrosion layer is arranged on the inner wall of the first liquid storage chamber.

The embodiment sets up the anti-corrosion coating on the inner wall of first stock solution room, can be so that can not corrode, the infringement to the locular wall of first stock solution room when the seepage takes place for first liquid storage pot, can not soak underground through the locular wall of first stock solution room to can avoid the weeping to soak underground and destroy ecological environment better.

Optionally, a liquid conveying channel is arranged between the first liquid storage tank and the ground.

The embodiment is provided with the liquid conveying channel, so that the electrolyte solution can be conveniently input into the first liquid storage tank or pumped out of the first liquid storage tank, and the convenience of storing and taking the electrolyte solution is improved.

Optionally, the electric pile is arranged in an underground space, and an electrified cable leading to the ground is electrically connected to the electric pile.

This embodiment sets up the pile in the space underground for the distance between pile and the first liquid storage pot can set up than nearer, thereby makes more be convenient for between pile and the first liquid storage pot through the pipeline intercommunication. In addition, with the pile setting in the space of underground, benefit from the better heat conductivity of underground soil and cliff, the heat that produces among the pile operation process can in time be released for the temperature of pile is difficult to too high and influences the working property, and in addition, the temperature difference change in underground space is very little, and the temperature is comparatively stable, makes the operational environment of pile be difficult for crossing excessively, thereby makes the pile can move more reliably, is favorable to the thermal management of pile.

In addition, because the height difference between the underground electric pile and the first liquid storage tank is small, the work required to be done by the circulating pump can be effectively reduced, and the energy storage efficiency of the flow battery system is improved. The galvanic pile is arranged in the underground space, so that the occupied space of the flow battery can be further reduced, and the occupied cost is reduced.

Optionally, a second manual detection channel is arranged between the underground space where the electric pile is located and the ground, and the electrified cable is located in the second manual detection channel.

This embodiment leads to the circular telegram cable to ground through the artifical test channel of second, can be so that operating personnel detects the circular telegram cable through the artifical test channel of second, and in addition, operating personnel also can arrive the underground space that the pile belongs to from the artifical test channel of second to carry out inspection maintenance etc. to the pile.

Optionally, an air flow channel is arranged between the underground space where the electric pile is located and the ground, and the air flow channel and the second manual detection channel are arranged in a separated mode.

The gas flow channel can discharge gases such as hydrogen generated in the redox reaction process of the galvanic pile so as to prevent explosion, improve the safety and ensure the normal work of the galvanic pile.

Optionally, the galvanic pile is arranged on the ground, a liquid outlet is arranged on the first liquid storage tank, a liquid inlet communicated with the liquid outlet is arranged on the galvanic pile, and the height difference between the liquid outlet and the liquid inlet is not more than 10 meters.

This embodiment sets up the pile subaerial, is more convenient for detect and maintain the pile, and the installation of pile is also simpler. The difference in height between the liquid inlet on the liquid outlet on the first liquid storage pot and the inlet on the pile is not more than the meter, and the difference in height ratio is less, and like this, the electrolyte solution in the first liquid storage pot also can be taken into the pile more easily.

Optionally, the side wall of the first reservoir contacts with the side wall of the first reservoir to support the side wall of the first reservoir.

Because the first liquid storage chamber plays a supporting role on the side wall of the first liquid storage tank, the side wall of the first liquid storage tank can be thinner, so that the material consumption, the production cost and the like of the first liquid storage tank can be reduced, and meanwhile, the structural stability of the first liquid storage tank can be better ensured.

Optionally, the first liquid storage tank is a plastic tank, and the material of the plastic tank includes at least one of polyvinyl chloride, polypropylene, and polytetrafluoroethylene.

When the first liquid storage tank is a plastic tank, the first liquid storage tank has better chemical stability, lighter weight, lower cost and more convenient production and manufacture.

Optionally, the anti-corrosion layer is any one of an epoxy anti-corrosion layer, a phenolic resin anti-corrosion layer, a silicon-titanium oxide composite anti-corrosion layer and a polyvinyl chloride free foaming plate.

Drawings

Fig. 1 is a schematic structural diagram of an example of a flow battery system based on an underground space according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another example of a flow battery system based on an underground space according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of another example of a flow battery system based on a subterranean space according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of another example of a flow battery system based on an underground space according to an embodiment of the present application.

The numbers in the figures are respectively:

110. a first reservoir; 111. a liquid delivery channel; 113. manually detecting a space; 114. a first manual detection channel; 120. a first liquid storage tank; 130. a galvanic pile; 131. an electrified cable; 132. a second manual detection channel; 134. a bipolar plate; 135. a collector plate; 136. an end plate; 137a, a positive electrode; 137b, a negative electrode; 137c, ion exchange membranes; 138. a liquid inlet pipeline; 138a, a circulation pump; 139. a liquid outlet pipeline; 140. a second reservoir; 150. a second liquid storage tank; 160. a power conversion system; 161. a power conversion system for charging; 162. a power conversion system for discharge; 170. a control system; 180. an electric quantity detection sensor;

10. a ground surface; 20. a wind power generation system; 30. a solar power generation system; 40. an external power grid.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. In the description of the embodiments herein, "/" means "or" unless otherwise specified, for example, a/B may mean a or B; "and/or" herein is merely an association describing an associated object, and means that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality" means two or more than two.

In the following, the terms "first", "second" and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", "third" may explicitly or implicitly include one or more of the features.

With the aggravation of energy crisis and environmental pollution, the power generation of renewable energy sources such as wind power generation and photovoltaic power generation is rapidly developed. Wind power generation and photovoltaic power generation are connected to the network in a large proportion, but the wind power generation amount changes along with the change of wind speed and wind direction, seasonal characteristics exist, and the power generation amounts in different seasons in different regions are different; photovoltaic output is influenced by weather, obvious change also exists in the day, and the fluctuation of temperature also has an influence to photovoltaic power generation simultaneously, and the distribution of electricity is the biggest in daytime in spring and winter generally. Therefore, the power generation fluctuation of new energy resources such as wind power, photoelectricity and the like is strong, the unpredictability is strong, and the uncontrollable performance is large, so that the power grid is difficult to schedule, and the development of the wind power and the photoelectricity is greatly limited.

When a large amount of new energy is incorporated into the power grid, the fluctuation of the power grid is increased, and the safety of the power grid is or will be impacted. Therefore, the large-scale energy storage technology and the wind power generation technology can be combined to improve the controllability of the output power of the wind power generation, and the dispatching of peak shaving, frequency modulation and the like of a power grid is facilitated.

The existing large-scale energy storage technology mainly takes electrochemical energy storage and water pumping energy storage. The water pumping energy storage technology is mature, the safety is high, but the defects of large limitation of geographical environment, inflexible electricity storage form and the like exist, so that the water pumping energy storage technology cannot be popularized and applied on a large scale.

Electrochemical energy storage is generally classified into lithium batteries, lead-acid batteries, and flow batteries. The safety of the lithium battery is low; the lead-acid battery has small power, consumes metal electrodes in the charging and discharging process to cause power reduction and has short service life. According to research, the electrolyte solution of the all-vanadium redox flow battery and the iron-chromium redox flow battery can be repeatedly recycled, and the all-vanadium redox flow battery and the iron-chromium redox flow battery have high safety, long service life and good charge and discharge characteristics, so that the all-vanadium redox flow battery is increasingly used in the new energy fields such as wind power and the like and in peak regulation and frequency modulation of a power grid.

The principle of the flow battery is briefly described below with reference to the accompanying drawings.

As shown in fig. 1 and 4, the flow battery mainly includes a liquid storage tank, a stack 130, a piping system, a circulating pump 138a, and other components.

The reservoirs include a first reservoir 120 and a second reservoir 150 for holding the positive electrolyte solution and the negative electrolyte solution, respectively. The piping system is used to communicate the reservoir with the stack 130 and the circulation pump 138a is used to flow the electrolyte solution between the reservoir and the stack 130.

As shown in fig. 1, the flow battery may include one stack 130, and as shown in fig. 4, the flow battery may also include a plurality of stacks 130.

As shown in fig. 1, the stack 130 may include one or more stack units, adjacent stack units are separated by bipolar plates 134, current collecting plates 135 are respectively disposed at two sides of the stack 130, the current collecting plates 135 are used for connecting with an external circuit to introduce or discharge current, end plates 136 are disposed at outer sides of the current collecting plates 135, and the end plates 136 are used for fixing the plurality of stack units. The stack unit includes a positive electrode 137a and a negative electrode 137b with an ion exchange membrane 137c disposed between the positive electrode 137a and the negative electrode 137 b.

The stack 130 is the main site of electrode reaction, and the electrode area and the number of stack units of the stack 130 determine the output power of the flow battery. The electrolyte solution is a storage medium for energy, and the concentration and volume of the electrolyte solution determine the energy storage capacity of the flow battery, so that the design of the flow battery is more flexible.

The electrodes of the flow battery only provide a reaction interface for the active material, do not undergo electrochemical reaction per se, and the positive and negative active materials are usually stored in an electrolyte in an ionic state and placed in positive and negative storage tanks, respectively. During the charging and discharging process, the electrolyte enters the electric pile 130 through the circulating pump 138a, and the redox reaction occurs on the electrode surface to realize the interconversion between chemical energy and electric energy.

In the following, the energy storage principle of the redox flow battery is briefly described by taking the all-vanadium redox flow battery as an example.

As shown in figures 1 and 4, electric energy in the all-vanadium redox flow battery is stored in acid electrolytes of vanadium ions with different valence states in a chemical energy mode, and positive electrolyte comprises VO²⁺Ion (vanadium ion of valence 4) and

ions (5-valent vanadium ions), the negative electrode electrolyte comprising V²⁺Ions (vanadium ions of valence 2) and V³⁺Ions (vanadium ions with valence of 3), the vanadium ions are stored in the liquid storage tank in the mode of electrolyte solution, and the electrolyte solution enters the electric pile 130 to carry out oxidation-reduction reaction through a circulating pump 138 a.

As shown in fig. 1 and 4, under the action of the circulation pump 138a, the positive electrolyte solution flows into the region of the stack 130 where the positive electrode is located, flows out of the stack 130 after the reduction reaction of the positive electrode, and flows into the first storage tank 120; the negative electrolyte solution flows into the region of the stack 130 where the negative electrode is located, flows out of the stack 130 after the oxidation reaction of the negative electrode, and flows into the second liquid storage tank 150, thereby circulating. The ion exchange membrane 137c allows ions to pass through under the action of concentration difference and potential difference, and the electrolyte of the positive electrode 137b and the electrolyte of the negative electrode 137b can be blocked by the ion exchange membrane 137c, so that self-discharge is avoided.

The positive electrode 137a and the negative electrode 137b may be porous electrodes, and active materials (i.e., ions included in the electrolyte) undergo a redox reaction at the surface of the porous electrodes, and collect and conduct current through the bipolar plate 134, so that chemical energy stored in the electrolyte solution is converted into electrical energy. The principle of the iron-chromium flow battery is similar to that of the all-vanadium flow battery, and the details are not repeated here.

Compared with other energy storage mechanisms, the all-vanadium flow battery and the iron-chromium flow battery have many technical advantages, especially the advantages of manufacturing cost, whole cycle life, energy efficiency, safety and the like. However, the energy density of these two flow batteries is low, and is about 20Wh/L to 30 Wh/L. In actual use, the energy density of the flow battery is lower than the theoretical value, and is less than 20Wh/L, so that more electrolyte solution is needed to store more electricity, so that the volume of the liquid storage tank of the flow battery system is large, and the occupied space is large.

Therefore, this application provides a redox flow battery system, this redox flow battery system adopt underground space to place the redox flow battery system, can reduce the occupation of land space of redox flow battery system to reduce the occupation of land cost, can reduce the reliance of redox flow battery to ground space by a wide margin.

As shown in fig. 2 to 4, a flow battery system based on a subterranean space provided by an embodiment of the present application includes: a first reservoir 120, a second reservoir 150, and a stack 130.

The first liquid storage tank 120 is arranged underground and used for storing a first electrolyte solution, the second liquid storage tank 150 is used for storing a second electrolyte solution, the second electrolyte solution and the first electrolyte solution are respectively used for generating electrochemical reactions with opposite polarities, and the electric pile 130 is respectively communicated with the first liquid storage tank 120 and the second liquid storage tank 150.

In the present embodiment, the first liquid storage tank 120 is disposed underground, which means that the first liquid storage tank 120 is entirely located below the ground. The first reservoir tank 120 may be buried underground, or the first reservoir tank 120 may be placed in a space provided underground.

In the embodiment of the present application, the second electrolyte solution may be a positive electrolyte solution, and the first electrolyte solution may be a negative electrolyte solution, or the second electrolyte solution may be a negative electrolyte solution, and the first electrolyte solution may be a positive electrolyte solution.

The second liquid storage tank 150 may be installed above the ground or under the ground. To further reduce the footprint of the flow battery system, the second reservoir 150 may be located underground.

The first liquid storage tank 120 may be a metal tank, a plastic tank, or a tank body made of other materials. When the first liquid storage tank 120 is a plastic tank, the first liquid storage tank 120 has better chemical stability, lighter weight, lower cost and more convenient production and manufacture.

Specifically, the material of the first liquid storage tank 120 may be at least one of polyvinyl chloride, polypropylene and polytetrafluoroethylene, and the plastic tank may also be a material with stable chemical properties, which is not particularly limited in this application.

The first reservoir 120 may be cylindrical, truncated cone, cube, or the like, or may be other regular or irregular shapes.

The depth of the first liquid storage tank 120 in the ground can be selected according to the local geothermal temperature rise curve, specifically, when the redox flow battery is an all-vanadium redox flow battery, the temperature of the environment where the first liquid storage tank 120 is located is selected to be between 15 ℃ and 35 ℃, and when the redox flow battery is an iron-chromium redox flow battery, the temperature of the environment where the first liquid storage tank 120 is located is selected to be between 45 ℃ and 70 ℃.

The material, shape, and arrangement of the second liquid storage tank 150 can refer to the first liquid storage tank, and will not be described herein.

The first liquid storage tank 120 of the redox flow battery system provided by the embodiment of the application is arranged underground, so that the first liquid storage tank 120 does not occupy the space on the ground, and the liquid storage container for storing the electrolyte solution of the redox flow battery system does not occupy the space on the ground, so that the occupied space of the redox flow battery system is saved, and the occupied cost is saved.

This application sets up first liquid storage pot 120 underground, benefits from the better heat conductivity of underground soil and cliff, and the heat that produces can in time be released in the redox flow battery system operation process for the temperature of the electrolyte solution in first liquid storage pot 120 is difficult to too high. In addition, the heat exchange between the first liquid storage tank 120 located underground and the atmosphere is very small, so the temperature difference of the environment where the first liquid storage tank 120 is located is not easy to change greatly along with the change of the atmospheric temperature, that is, the temperature difference of the environment where the first liquid storage tank 120 is located is very small, the temperature is relatively stable, and when the ground temperature is relatively low, the temperature of the electrolyte solution in the first liquid storage tank 120 located underground is not easy to be too low. Therefore, the electrolyte solution can be better ensured to work at a stable environment temperature, the chemical performance of the electrolyte solution is more stable, the flow battery system is more stable and reliable, and the energy consumption for controlling the temperature of the electrolyte solution can be reduced.

In one embodiment, as shown in fig. 2 to 4, the flow battery system may further include: the first reservoir 110, the first reservoir 110 is a space disposed underground, and the first reservoir 120 is disposed in the first reservoir 110.

The first reservoir 110 may be a cavity located underground, which may be a rock cavern or an earth cavern.

When the first reservoir 110 is a soil cave provided in the ground, the first reservoir 110 may be formed by drilling with a pile driver, and the inner wall of the soil cave may be formed by tamping, so that the first reservoir 110 has better structural stability.

The size of the first reservoir 110 can be determined according to the capacity (energy storage capacity) of the flow battery, and the larger the space of the first reservoir 110 is, the larger the volume of the first reservoir 120 can be accommodated, so that the larger the volume of the electrolyte solution that can be stored in the first reservoir 120 is, the larger the capacity of the flow battery is.

The shape of the first reservoir 110 may be cylindrical, cubic, truncated cone, etc., or may be any other regular or irregular shape. Those skilled in the art can design the shape and size of first reservoir 110 according to practical circumstances, and the present application is not particularly limited.

The shape of the first reservoir 110 may correspond to the shape of the first reservoir 120, for example, when the first reservoir 120 is cylindrical, the first reservoir 110 may also be cylindrical, and when the first reservoir 120 is cubic, the first reservoir 110 may also be cubic, so that the space of the first reservoir 110 may be more fully utilized, the first reservoir 120 may store more electrolyte solution, and the energy storage capability of the flow battery system is improved.

Alternatively, as shown in fig. 2, a liquid delivery channel 111 may be provided between the first storage tank 120 and the ground, and the liquid delivery channel 111 may be a pipe, through which the electrolyte solution can be added to the first storage tank 120 or withdrawn from the first storage tank 120.

The end of the liquid delivery channel 111 that leads to the ground 10 may be provided with a cover that is opened when the electrolyte solution is to be pumped or added, and closed after the pumping or adding is finished.

As shown in fig. 2 and 4, a liquid inlet pipe 138 and a liquid outlet pipe 139 may be disposed between the electric pile 130 and the first liquid storage tank 120, the liquid inlet pipe 138 is used for allowing the electrolyte solution in the first liquid storage tank 120 to flow into the electric pile 130, the liquid outlet pipe 139 is used for allowing the reacted electrolyte solution in the electric pile 130 to flow into the first liquid storage tank 120, and the liquid inlet pipe 138 and the liquid storage pipe are two different pipes separately disposed.

A circulation pump 138a may be disposed on the liquid inlet pipe 138 and/or the liquid outlet pipe 139, and the electrolyte solution in the first storage tank 120 can flow into the pile 130 through the circulation pump 138a, and flow out of the pile 130 into the first storage tank 120. An electrifying cable leading to the ground 10 can be electrically connected to the circulating pump 138a, the circulating pump 138a is connected with a power supply on the ground 10 through the electrifying cable, and the circulating pump 138a can also be in communication connection with the control system 170, so that the control system 170 can control the starting, stopping and rotating speed of the circulating pump 138 a.

The control System 170 may also be referred to as a Battery Management System (BMS).

The liquid inlet pipe 138 and the liquid storage pipe may be provided with valves, each valve is connected to the control system 170 through a cable, and the control system 170 controls the open/close state of each pipe through the valve.

The communication mode between the second liquid storage tank 150 and the electric pile 130 can refer to the first liquid storage tank 120, and the details are not repeated here.

Optionally, a temperature sensor and a flow rate sensor may be disposed in the stack 130, and the control system 170 may obtain flow rate data of the flow rate sensor in the stack 130, and control the operating state of the circulation pump 138a according to the flow rate data to adjust the flow rate. The stack 130 may include a temperature control device, and the control system 170 may acquire temperature data of a temperature sensor in the stack 130 and control the operation of the temperature control device of the stack 130 according to the temperature data, so as to maintain the normal operating temperature of the stack 130.

Taking the first electrolyte solution stored in the first storage tank 120 as the positive electrolyte solution as an example, the circulation process of the positive electrolyte solution is as follows: the positive electrolyte solution in the first liquid storage tank 120 flows into the region where the positive electrode in the electric pile 130 is located from the liquid inlet pipeline 138 under the action of the circulating pump 138a to perform a reduction reaction, the reacted positive electrolyte solution flows out from the liquid outlet pipeline 139 and flows into the first liquid storage tank 120 under the action of the circulating pump 138a, and the positive electrolyte solution flowing into the first liquid storage tank 120 has chemical energy and can discharge.

To increase the power of the flow battery system, as shown in fig. 4, the flow battery system may include a plurality of stacks 130, and the plurality of stacks 130 are respectively in communication with the first reservoir tank 120. The output power of the stack 130 can range from 1KW to 250KW, and a person skilled in the art can select the required output power of the stack 130 according to actual needs.

In this embodiment, the first liquid storage chamber 110 is provided to facilitate the first liquid storage tank 120 to be arranged underground.

For all-vanadium flow battery, when the working temperature is lower than 10 ℃, the V of the negative electrode side²⁺Ions and V³⁺Ions can be precipitated, and when the temperature is higher than 40 ℃, VO on the positive electrode side²⁺The ions are thermally evolved. Therefore, the flow battery system has certain requirements on the environmental temperature, and therefore the requirement on the temperature control in the liquid storage tank is high.

In addition, because the electrolyte solution is rich in acid, alkali or heavy metal ions, when a liquid storage tank for storing the electrolyte solution leaks, the electrolyte solution easily and quickly flows to the surrounding to cause great pollution to the environment. In this application embodiment, the first liquid storage tank 120 is disposed in the first liquid storage chamber 110, even if the first liquid storage tank 120 leaks, the leaked electrolyte solution is mostly located in the first liquid storage chamber 110 and is not easy to leak, so that the environment is not easily polluted.

In one embodiment, as shown in fig. 2 and 3, the flow battery system may further include a power conversion system 160, the power conversion system 160 is disposed on the ground 10, the power conversion system 160 is electrically connected to the stack 130, and the power conversion system 160 is configured to be electrically connected to the external power grid 40 for electric energy transmission.

The power conversion system 160 may include: transformers, converters, rectifiers, etc., but are not limited thereto.

In one embodiment, an inner wall of the first reservoir 110 may be provided with an anti-corrosion layer.

It is understood that the material of the anti-corrosion layer should be a material that does not easily react with acid, alkali, heavy metal ions, etc., for example, the anti-corrosion layer may be any one of an epoxy anti-corrosion layer, a phenolic resin anti-corrosion layer, a silicon titanium oxide composite anti-corrosion layer, and a polyvinyl chloride free foaming plate, but is not limited thereto.

In the embodiment, the anti-corrosion layer is disposed on the inner wall of the first reservoir 110, so that the wall of the first reservoir 110 is not corroded or damaged when the first reservoir 120 leaks, and the wall of the first reservoir 110 is not immersed underground, thereby better preventing the leaked liquid from immersing underground and damaging the ecological environment.

In one embodiment, the bottom of the first reservoir 110 may be provided with a leak detection device, which is located outside the first reservoir 120 and is in communication with the control system 170 of the flow battery system.

The control system 170 may be installed in a place such as an operation room where an operator can check the control system in time. The control system 170 can monitor the working state of the flow battery in real time, which is beneficial to maintenance.

The liquid leakage detection device is in communication connection with the control system 170, when the liquid leakage detection device detects liquid leakage, a liquid leakage signal is sent to the control system 170, and the control system 170 can send out prompt information after receiving the liquid leakage signal to prompt an operator to check and maintain.

The liquid leakage detection device may be a point type liquid leakage sensor, a belt type (also called a line type or a rope type) liquid leakage sensor, or other devices capable of detecting liquid leakage, and the present application is not particularly limited.

In the embodiment, the leakage detection device is arranged at the bottom of the first liquid storage chamber 110, so that the leakage of the first liquid storage tank 120 can be quickly detected, the operation personnel can maintain the leakage in time, and the adverse consequences caused by the leakage can be reduced.

In one embodiment, the side walls of the first reservoir 110 and the first reservoir 120 may contact to support the side walls of the first reservoir 120.

That is, in this embodiment, the inner sidewall of the first reservoir 110 contacts the outer sidewall of the first reservoir 120, and the inner sidewall of the first reservoir 110 supports the outer sidewall of the first reservoir 120.

In this embodiment, the entire outer sidewall of the first reservoir 120 may be in contact with the first reservoir 110, such that the entire outer sidewall of the first reservoir 120 is supported by the sidewall of the first reservoir 110. The shape of the first reservoir 110 may match the shape of the first reservoir 120, for example, the first reservoir 110 may be a cylindrical space, and the first reservoir 120 may also be a cylindrical tank, such that the sidewall of the first reservoir 120 may be better supported by the first reservoir 110.

Alternatively, a portion of the outer sidewall of the first reservoir 120 may contact the first reservoir 110 to provide a partial support for the first reservoir 120, which may also provide increased strength to the first reservoir 120. For example, the first fluid reservoir 120 may be a cylindrical container, the first fluid reservoir 110 may be a cubic container, the first fluid reservoir 120 may be internally cut into the first fluid reservoir 110, and a sidewall of the first fluid reservoir 110 may support a contacted sidewall of the first fluid reservoir 120.

In this embodiment, since the first liquid storage chamber 110 supports the sidewall of the first liquid storage tank 120, the sidewall of the first liquid storage tank 120 can be thinner, so that the material consumption and production cost of the first liquid storage tank 120 can be reduced, and the structural stability of the first liquid storage tank 120 can be better ensured.

In one embodiment, as shown in FIG. 2, a manual detection space 113 may be formed between the first reservoir 120 and the inner sidewall of the first reservoir 110, and a first manual detection channel 114 may be formed between the manual detection space 113 and the floor 10.

After the manual detection channel is arranged, a detector can enter the manual detection space 113 from the manual detection channel, so that the first liquid storage tank 120 can be maintained and detected from the outer side of the first liquid storage tank 120 in the manual detection space 113.

In the embodiment of the present application, when the entire outer sidewall of the first liquid storage tank 120 is aligned with the sidewall of the first liquid storage chamber 110, there is no space between the first liquid storage tank 120 and the first liquid storage chamber 110 for the manual detection space 113, in this case, the top of the first liquid storage chamber 110 can be opened to the ground 10, the top of the first liquid storage chamber 110 has an opening, the opening at the top of the first liquid storage chamber 110 is covered by a cover, when the first liquid storage tank 120 needs to be overhauled, the cover can be opened, and the first liquid storage tank 120 can be lifted out from the opening at the top of the first liquid storage chamber 110.

In one embodiment, as shown in fig. 2-4, the stack 130 may be located in an underground space, with the stack 130 having electrically connected thereto an electrical cable 131 leading to the surface 10.

An anti-corrosion layer may also be disposed on an inner wall of the space where the stack 130 is located, and the specific material of the anti-corrosion layer may refer to the material of the anti-corrosion layer on the inner wall of the first liquid storage chamber 110, which is not described herein again.

In this embodiment, the underground depth of the stack 130 may be substantially the same as the underground depth of the first reservoir 110, so that the stack 130 and the first reservoir 110 are in communication through a pipe.

Specifically, the underground space for placing the pile 130 may be formed by drilling the pile driver.

The power cable 131 connected to the stack 130 may be electrically connected to the power conversion system 160.

As shown in fig. 4, the power conversion system 160 may include a charging power conversion system 161 and a discharging power conversion system 162, and the power-on cable 131 connected to the cell stack 130 may include a charging cable electrically connected to the charging power conversion system 161 and a discharging cable electrically connected to the discharging power conversion system 162.

In the embodiment, the electric pile 130 is arranged in the underground space, so that the distance between the electric pile 130 and the first liquid storage tank 120 can be relatively short, and the electric pile 130 and the first liquid storage tank 120 are more convenient to communicate through a pipeline. In addition, with pile 130 setting in the space of underground, benefit from the better heat conductivity of underground soil and cliff, the heat that pile 130 operation in-process produced can in time be released for pile 130's temperature is difficult to too high and influences the working property, and in addition, the temperature difference in underground space changes for a short time, and the temperature is comparatively stable, makes pile 130's operational environment be difficult for crossing excessively, thereby makes pile 130 can move more reliably, is favorable to pile 130's thermal management.

In addition, because the height difference between the underground electric pile 130 and the first liquid storage tank 120 is small, the work required by the circulating pump 138a can be effectively reduced, and the energy storage efficiency of the flow battery system is improved. The stack 130 is arranged in the underground space, so that the occupied space of the flow battery can be further reduced, and the occupied cost is reduced.

In an alternative embodiment, when the stack 130 is disposed in an underground space, the height of the first reservoir 110 from the ground 10 may be set to be relatively high, for example, the height of the first reservoir 110 from the ground 10 may be no less than 10 meters, so that the electrolyte solution is less susceptible to the external environment temperature change, and the performance of the flow battery system is more reliable.

In one embodiment, as shown in fig. 2, a second manual detection channel 132 may be provided between the underground space where the electric pile 130 is located and the ground 10, and the power cable 131 is located in the second manual detection channel 132.

In the present embodiment, the electrified cable 131 is led to the ground 10 through the second manual detection channel 132, so that the operator can detect the electrified cable 131 through the second manual detection channel 132, and in addition, the operator can also reach the underground space where the electric pile 130 is located from the second manual detection channel 132 to inspect and maintain the electric pile 130.

In one embodiment, an air flow channel may be provided between the underground space where the electric pile 130 is located and the ground 10, and the air flow channel is separated from the second manual detection channel 132.

The gas flow channel can discharge gases such as hydrogen generated in the redox reaction process of the galvanic pile 130, so as to prevent explosion, improve safety and ensure the normal work of the galvanic pile 130.

In one embodiment, the electric pile 130 may also be disposed on the ground 10, the first liquid storage tank 120 is provided with a liquid outlet, the electric pile 130 is provided with a liquid inlet communicated with the liquid outlet, and a height difference between the liquid outlet and the liquid inlet is not greater than 10 meters.

Specifically, the liquid outlet of the first liquid storage tank 120 may be communicated with the liquid inlet of the electric pile 130 through a pipeline, and the electrolyte solution in the first liquid storage tank 120 flows into the electric pile 130 through the pipeline for oxidation/reduction reaction after flowing out from the liquid outlet.

The height difference between the liquid outlet of the first liquid storage tank 120 and the liquid inlet of the electric pile 130 may be, but is not limited to, 1 meter, 3 meters, 5 meters, 8 meters, or 10 meters.

In the present embodiment, the stack 130 is disposed on the ground 10, so that the stack 130 is more conveniently detected and maintained, and the stack 130 is simpler to install. The difference in height between the liquid outlet of the first liquid storage tank 120 and the liquid inlet of the electric pile 130 is not greater than 10 m, and the difference in height is relatively small, so that the electrolyte solution in the first liquid storage tank 120 can be easily pumped into the electric pile 130.

In one embodiment, as shown in fig. 2, the flow battery system may further include a second reservoir 140 located underground and separated from the first reservoir 110, the second reservoir 150 being located within the second reservoir 140.

The specific arrangement of the second liquid storage chamber 140 and the second liquid storage tank 150 can refer to the first liquid storage chamber 110 and the first liquid storage tank 120, which are not described herein again.

In another embodiment, the first reservoir 120 and the second reservoir 150 may both be placed within the first reservoir 110, in which case the first reservoir 110 may be provided larger to accommodate both reservoirs simultaneously, making the flow battery system simpler.

In one embodiment, first reservoir 110 and second reservoir 140 may both be holes defined by soil, with first reservoir 110 and second reservoir 140 being two different holes. The physical volume is 5-100 cubic meters, and the depth range of the hole opening of the obtained hole from the ground 10 is 10-50 meters after measurement is carried out according to a local heat temperature rise curve, so that the temperature of the soil hole can be between 15 and 35 ℃. The diameter of each hole is 1.5 meters, the volume range of each hole which can be filled with electrolyte solution is 17000L-88000L, and the energy density of the electrolyte solution is 30Wh/L, so that each hole can store 510KWh-2550KWh electric energy. In this example, the energy storage capacity of the flow battery can be improved by increasing the number of the liquid storage chambers to store more electrolyte solution.

The arrangement of the first reservoir 110 and the second reservoir 140 may refer to a cavern, and the detailed description is omitted here.

In another embodiment, first reservoir 110 and second reservoir 140 may also be caverns, the cavern cavity may be irregular, and the depth of the cavern from ground 10 is measured according to a local thermal temperature rise curve to be 180-220 m, which may satisfy the temperature of the cavern at about 50 ℃. The physical volume of the cavern can be 5-10 cubic meters, the height is 80 meters, and the maximum width is 60 meters. The inner layer of the cave is coated with an anti-corrosion layer which is formed by coating epoxy anti-corrosion paint so as to prevent electrolyte solution in the first liquid storage tank 120 and the second liquid storage tank 150 from leaking to corrode the rock wall.

The first reservoir 120 and the second reservoir 150 are made of a molded PTFE or PP or PVC material. The first reservoir 120 and the second reservoir 150 may be formed by splicing sheets of plastic to facilitate the creation of large reservoirs.

The electric pile 130 is arranged in the underground space, and the electric pile 130 is positioned between the first liquid storage tank 120 and the second liquid storage tank 150, so that the pumping work can be effectively reduced, and the energy storage efficiency of the system is improved.

The charging and discharging process of the flow battery system will be briefly described below.

As shown in fig. 2 and 3, when the flow battery system is charged, the high-voltage ac power of the external power grid 40 or the electricity generated by the new energy power plant (wind power plant or solar power plant) is converted into the dc power with a stable voltage through the power conversion system 160, for example, the electricity generated by the wind power generation system 20 or the solar power generation system 30 is converted into the dc power with a stable voltage through the power conversion system 160, and then is transmitted to the positive and negative terminals of the stack 130 through the energizing cable 131. Specifically, after the control system 170 receives the charging command signal, the control system 160 controls the power conversion system 160 to supply the converted direct current to the stack 130, and the control system 170 controls the rotor of the circulation pump 138a to rotate and acquire the rotation speed of the rotor of the circulation pump 138a to perform speed feedback control, so that the positive and negative electrolyte solutions enter the stack 130 through the pipeline at a stable and controllable flow rate to participate in the charging chemical reaction of the flow battery.

For clarity of illustration, the power cables between the various devices are omitted from FIG. 3.

Taking an all-vanadium flow battery as an example, during charging, the galvanic pile 130 oxidizes the vanadium ions with valence 4 in the positive electrolyte solution into vanadium ions with valence 5, and reduces the vanadium ions with valence 3 in the negative electrolyte solution into vanadium ions with valence 2. The specific chemical equation of the charging process is as follows:

and (3) positive electrode:

negative electrode: v³⁺+e^-→V²⁺

And (3) total reaction:

the State of Charge (SOC) of a battery refers to the percentage of the current remaining capacity of the battery to the rated capacity of the battery when the battery is fully charged, and can be expressed as:

the value range of the SOC is 0-1, and the larger the SOC is, the more the electric quantity stored by the battery is.

The first liquid storage tank 120 and the second liquid storage tank 150 can be internally provided with an electric quantity detection sensor 180, a temperature sensor, a concentration detector, a pressure sensor and the like, and all detection components in the first liquid storage tank 120 and the second liquid storage tank 150 can be in communication connection with the control system 170 through communication cables.

The electric quantity detection sensor 180 may be a hall current sensor or other components capable of monitoring electric quantity.

The control system 170 of the flow battery system obtains data of the electric quantity monitoring element, estimates the SOC of the flow battery, determines whether the flow battery is fully charged, and controls the circulating pump 138a to stop working when the flow battery is determined to be fully charged, thereby preventing overcharge.

When the control system 170 obtains the discharge command, it generates a control signal and controls the operation rate of the circulation pump 138a, so as to control the flow rate of the electrolyte solution flowing into the stack 130, the electrolyte solution flowing into the stack 130 generates an oxidation-reduction reaction in the bipolar plate 134 of the stack 130, electrons are conducted by the bipolar plate 134 and flow from the negative electrode to the positive electrode after passing through the current collecting plate 135, and H of the positive electrode⁺Ions flow to the negative electrode through the ion exchange membrane 137c, and the formed current is transmitted to the power conversion system 160 through the electrified cable 131, and is converted into high-voltage alternating current with the same frequency adapted to the external power grid 40, so that the alternating current is provided for a user end, and finally peak load elimination and new energy storage of the power grid are realized. The specific chemical equation of the discharge process is as follows:

and (3) positive electrode:

negative electrode: v₂-→V₃ ⁺+e^-

And (3) total reaction:

when the SOC is 0, the control system 170 controls the circulation pump 138a to stop operating and issues a message indicating that the discharge is completed.

Taking the iron-chromium flow battery as an example, during charging, the electric pile 130 makes the 2-valent Fe ions in the positive electrolyte solution lose electrons and oxidize into 3-valent Fe ions, so that the 3-valent chromium ions in the negative electrolyte solution obtain electrons and reduce into 2-valent chromium ions. The specific chemical equation of the charging process is as follows:

and (3) positive electrode: fe²⁺→Fe³⁺+e

Negative electrode: cr (chromium) component³⁺+e→Cr²⁺

And (3) total reaction: fe²⁺+Cr³⁺→Fe³⁺+Cr²⁺

The specific chemical equation of the discharge process is as follows:

and (3) positive electrode: fe³⁺+e→Fe²⁺

Negative electrode: cr (chromium) component²⁺→Cr³⁺+e

And (3) total reaction: fe³⁺+Cr²⁺→Fe²⁺+Cr³⁺

It should be understood that the above description is only for the purpose of helping those skilled in the art to better understand the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application. Various equivalent modifications or changes, or combinations of any two or more of the above, may be apparent to those skilled in the art in light of the above examples given. Such modifications, variations, or combinations are also within the scope of the embodiments of the present application.

It should also be understood that the foregoing descriptions of the embodiments of the present application focus on highlighting differences between the various embodiments, and that the same or similar elements that are not mentioned may be referred to one another and, for brevity, are not repeated herein.

It should also be understood that the manner, the case, the category, and the division of the embodiments in the present application are only for convenience of description, and should not constitute a particular limitation, and features in various manners, categories, cases, and embodiments may be combined without contradiction.

It is also to be understood that the terminology and/or the description of the various embodiments herein is consistent and mutually inconsistent if no specific statement or logic conflicts exists, and that the technical features of the various embodiments may be combined to form new embodiments based on their inherent logical relationships.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and all the changes or substitutions should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A flow battery system based on a subterranean space, comprising:

the first liquid storage tank (120), the said first liquid storage tank (120) locates underground, is used for storing the first electrolyte solution;

a second liquid storage tank (150) for storing a second electrolyte solution, wherein the second electrolyte solution and the first electrolyte solution are respectively used for generating electrochemical reactions with opposite polarities;

and the galvanic pile (130) is respectively communicated with the first liquid storage tank (120) and the second liquid storage tank (150).

2. The flow battery system of claim 1, further comprising:

the first liquid storage chamber (110), the first liquid storage chamber (110) is the space of locating underground, first liquid storage pot (120) are located in first liquid storage chamber (110).

3. The flow battery system of claim 2, wherein a manual detection space (113) is provided between the first reservoir (120) and an inner sidewall of the first reservoir (110), and a first manual detection channel (114) is provided between the manual detection space (113) and the ground.

4. The flow battery system according to claim 2, further comprising a control system, wherein a leakage detection device is disposed at a bottom of the first reservoir (110), and the leakage detection device is located outside the first reservoir (120) and is in communication connection with the control system (170).

5. The flow battery system according to claim 2, wherein an inner wall of the first reservoir (110) is provided with an anti-corrosion layer.

6. The flow battery system of claim 1, wherein a fluid delivery channel (111) is provided between the first reservoir (120) and ground.

7. The flow battery system according to any one of claims 1-6, wherein the stack (130) is disposed in an underground space, and an energizing cable (131) leading to the ground is electrically connected to the stack (130).

8. The flow battery system according to claim 7, wherein a second manual detection channel (132) is provided between the underground space where the electric stack (130) is located and the ground, and the electrified cable (131) is located in the second manual detection channel (132).

9. The flow battery system according to claim 8, wherein an air flow channel is arranged between an underground space where the galvanic pile (130) is located and the ground, and the air flow channel is separated from the second manual detection channel (132).

10. The flow battery system according to any one of claims 1-6, wherein the stack (130) is disposed on the ground, a liquid outlet is disposed on the first liquid storage tank (120), a liquid inlet communicated with the liquid outlet is disposed on the stack (130), and a height difference between the liquid outlet and the liquid inlet is not greater than 10 meters.