Iron-chromium flow battery system

Abstract

An iron-chromium flow battery energy storage system disclosed by the present invention comprises a battery power module and a battery capacity module, the battery power module comprises a container, an electrical control unit, an electrolyte circulation and pipeline unit, an electric pile unit and a tail gas absorption unit are arranged in the container body, and the electric pile unit comprises a plurality of electric piles. The electrolyte circulating and pipeline unit comprises a positive and negative electrode electrolyte circulating pump, a positive and negative electrode liquid inlet pipeline, a positive and negative electrode liquid outlet pipeline and a positive and negative electrode input pipeline, and the outlet end of the positive and negative electrode electrolyte circulating pump is connected with the inlet of each electric pile through the positive and negative electrode liquid inlet pipeline; each galvanic pile outlet is respectively connected with a battery capacity module outside the container through positive and negative electrode liquid outlet pipelines; the battery capacity module is used for storing electrolyte, penetrates through the container through a positive and negative input pipeline and is connected with the positive and negative electrolyte circulating pump; the electrical control unit is used for collecting data of the battery power module and sending instructions. The tail gas absorption unit is used for absorbing tail gas of the battery capacity module.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery energy storage, and in particular to an iron-chromium liquid flow battery system. Background Art

[0002] A general liquid flow battery system is composed of a power module unit, an electrolyte storage tank module unit, a pipeline system unit, etc. It has the characteristics of high capacity, long life, wide application fields and high safety. It has been widely used in scenarios such as long-term energy storage, new energy consumption, and power-assisted market transactions.

[0003] However, due to the complexity of the flow battery process system, the on-site construction procedures are cumbersome, and the flow battery system is a non-standard customized product. The workload in the early design stage is large, making it difficult to respond to demand quickly and do land planning.

[0004] Therefore, there is an urgent need for an iron-chromium flow battery system that has standardized product characteristics, flexibility and strong scalability, can reduce initial design costs and on-site construction costs, and greatly shorten the construction period of the flow battery system. Summary of the invention

[0005] The present invention aims to provide an iron-chromium liquid flow battery system, which can reduce the initial design cost and on-site construction cost, and greatly shorten the construction period of the liquid flow battery system.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides an iron-chromium liquid flow battery system, comprising: the battery system comprises a battery power module and a battery capacity module,

[0008] The battery power module includes a container, and an electrical control unit, an electrolyte circulation and pipeline unit, a battery stack unit and an exhaust gas absorption unit are sequentially arranged inside the container.

[0009] The battery stack unit is equipped with a plurality of battery stacks, and the battery stack is an iron-chromium liquid flow battery stack;

[0010] The electrolyte circulation and pipeline unit includes positive and negative electrolyte circulation pumps, positive and negative electrode inlet pipelines, positive and negative electrode outlet pipelines and positive and negative electrode input pipelines. The outlet ends of the positive and negative electrolyte circulation pumps are respectively connected to the inlet of each battery stack through the positive and negative electrode inlet pipelines, and each battery stack outlet is respectively connected to the battery capacity module outside the container through the positive and negative electrode outlet pipelines.

[0011] The battery capacity module is used to store electrolyte, and the battery capacity module is connected to the positive and negative electrolyte circulation pumps through the positive and negative electrode input pipes penetrating the side wall of the container;

[0012] The electrical control unit and the exhaust gas absorption unit are respectively arranged at two ends of the container. The electrical control unit is used for collecting data and sending instructions for the battery power module, and the exhaust gas absorption unit is used for absorbing the exhaust gas generated by the battery system.

[0013] The technical effects and advantages of the present invention are as follows: the present invention connects the battery capacity module with the positive and negative electrolyte circulation pumps in the battery power module through a pipeline to realize the transportation and circulation of the electrolyte; the battery capacity module is connected with the alkali absorption storage tank in the tail gas absorption area in the battery power module through a pipeline to realize the absorption of the tail gas in the battery capacity module;

[0014] The battery power module provided by the present invention has a highly integrated module structure system, battery process system, instrument control system, electrical system, temperature control system, emergency ventilation system, fire alarm system, lighting and video monitoring system, acid recovery and leakage alarm system, etc., realizing the integrated coupling of multi-professional comprehensive systems.

[0015] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic structural diagram of an iron-chromium liquid flow battery system according to an embodiment of the present invention;

[0018] Figure 2 This is a front view of a battery power module in an embodiment of the present invention;

[0019] Figure 3 It is a schematic diagram of the structure of the battery stack and the battery stack coil of the battery power module in an embodiment of the present invention;

[0020] Figure 4 A side view of the interior of a battery power module in an embodiment of the present invention;

[0021] Figure 5 A side view of a battery power module without a battery stack in an embodiment of the present invention;

[0022] Figure 6This is a front view of the electrolyte circulation and pipeline unit in an embodiment of the present invention;

[0023] Figure 7 It is a partial front view of the electrolyte circulation and pipeline unit in the embodiment of the present invention;

[0024] Figure 8 A side view of an electrolyte circulation and pipeline unit according to an embodiment of the present invention;

[0025] Fig. 9 It is a partial side view of the electrolyte circulation and pipeline unit in an embodiment of the present invention;

[0026] Fig.10 This is a schematic diagram of the electrical room structure in an embodiment of the present invention;

[0027] In the figure, 0, container; 1, battery stack area; 11, battery stack; 111, root valve; 112, flange; 113, battery stack coil; 114, coil bracket; 12, battery stack bracket; 13, pipe bracket; 14, OCV battery 14; 141, OCV battery 14 pipeline; 15, positive electrode liquid inlet branch pipe; 16, negative electrode liquid inlet branch pipe; 17, positive electrode liquid outlet branch pipe; 18, negative electrode liquid outlet branch pipe; 2, pump area; 21, positive electrode electrolyte circulation pump; 22, negative electrode electrolyte circulation pump; 23, positive electrode liquid inlet main pipe; 231, Positive electrode pressure gauge; 232, positive electrode liquid inlet valve; 24, negative electrode liquid inlet main pipe; 241, negative electrode pressure gauge; 242, negative electrode liquid inlet valve; 25, positive electrode liquid outlet main pipe; 26, negative electrode liquid outlet main pipe; 27, positive electrode input pipeline; 28, negative electrode input pipeline; 29, negative electrode to positive electrode mixing pipeline; 291, negative electrode to positive electrode mixing valve; 210, positive electrode to negative electrode mixing pipeline; 2101, positive electrode to negative electrode mixing valve; 3, tail gas absorption area; 4, electrical room; 5, high point exhaust valve; 6, drain pipe; 61, drain valve. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] To address the deficiencies of the prior art, the present invention discloses an iron-chromium flow battery system. Figure 1 As shown, the battery system includes a battery power module and a battery capacity module. The battery capacity module includes a positive electrode storage tank and a negative electrode storage tank. The battery capacity module is used to provide and store electrolyte for the battery power module. The battery power module is an iron-chromium liquid flow battery power module with an external storage tank.

[0030] The battery power module has a rated power of 180kW and is integrated in a container 0, which has a size of 7300mm×2438mm×2591mm. Figure 2 As shown, the internal space of container 0 is divided into four areas according to function, namely, battery stack area 1, pump area 2, exhaust gas absorption area 3 and electrical room 4; corresponding functional units are arranged in the corresponding functional areas, namely, battery stack unit, electrolyte circulation and pipeline unit, exhaust gas absorption unit and electrical control unit.

[0031] Each unit of the battery power module is described in turn:

[0032] The stack area 1 is the area where the iron-chromium liquid flow battery stack is placed. The stack area 1 is the key area for electrochemical reactions (i.e., charging and discharging reactions), where the conversion of chemical energy and electrical energy is completed; the stack unit mainly includes four 45kW stacks 11, and the stack area 1 is equipped with a stack bracket 12, and each stack 11 is fixed to the stack bracket 12 by bolts.

[0033] The stack support 12 is divided into two layers, with two stacks 11 arranged on each layer, numbered 1, 2, 3 and 4 from the upper left, upper right, lower left and lower right respectively; the stack support 12 adopts a steel structure support connected to the internal support beam of the container 0, which can play a role in supporting the stack 11 and the DC line.

[0034] The battery stacks 11 are connected in series in pairs and then in parallel, and every two battery stacks 11 are connected in series to form a battery cluster; for example, battery stacks 11 No. 1 and battery stacks 11 No. 4 are connected in series to form one battery cluster, and battery stacks 11 No. 2 and battery stacks 11 No. 3 are connected in series to form the second battery cluster.

[0035] like Figure 3 As shown, the inlet and outlet of the stack 11 are connected to the stack coil 113 through the root valve 111 respectively, and a coil bracket 114 is provided on the outer wall of the stack 11, and the stack coil 113 is fixedly installed on the coil bracket 114; the coil can be prefabricated, and the coil can be installed and connected after the stack 11 is installed; at the same time, the stack coil 113 can be disassembled through the flange 112, which does not affect the installation, maintenance and disassembly of the stack 11. The stack coil 113 is used in the embodiment of the present invention to increase the length of the pipeline and reduce the leakage current of the pipeline.

[0036] The battery stacks 11 are connected by DC cables, and the series DC circuit inlet of each battery cluster is provided with a protection device in the form of a metal switch box with the same protection level as the distribution box; in the embodiment of the present invention, there are two sets of protection devices inside each container 0, and the protection devices include multiple key electrical protection elements and key connection elements (specifically relays, fuses, busbars, etc.).

[0037] The protection device selection of the series DC circuit of each battery cluster is adapted to the voltage and current of each series DC circuit. The protection device provided in the present invention can effectively improve the safety of the DC side of the battery stack 11 under the battery stack electrical series architecture, and reduce the large leakage current loss caused by the excessively high series voltage during the standby process.

[0038] The battery stack unit also includes an OCV battery 14, a voltage transmitter, a current transmitter, and a liquid flow battery management system, etc. The OCV battery 14 is used to monitor the open circuit voltage of the battery system and calculate the capacity of the battery system. Among them, the OCV battery 14 is connected to the positive and negative electrode liquid inlet pipes and the positive and negative electrode liquid outlet pipes through four OCV battery pipes 141 respectively; that is, the positive electrode liquid inlet of the OCV battery 14 is connected to the positive electrode liquid inlet pipe 23 through the first OCV battery pipe, the negative electrode liquid inlet of the OCV battery 14 is connected to the negative electrode liquid inlet pipe 24 through the second OCV battery pipe, the positive electrode liquid outlet of the OCV battery 14 is connected to the positive electrode liquid outlet pipe 25 through the third OCV battery pipe, and the negative electrode liquid outlet of the OCV battery 14 is connected to the negative electrode liquid outlet pipe 26 through the fourth OCV battery pipe.

[0039] A voltage transmitter is installed on each battery stack 11 and OCV battery 14, and a current transmitter is installed in the series DC circuit of each battery cluster. Both the voltage transmitter and the current transmitter can filter PCS DC harmonics; in the embodiment of the present invention, there are 5 voltage transmitters and 2 current transmitters.

[0040] Each voltage transmitter and each voltage transmitter are connected to the liquid flow battery management system, and each voltage transmitter and each voltage transmitter are used to send the monitored voltage value and current value to the liquid flow battery management system (FBMS); the liquid flow battery management system is used to monitor the battery system status and the cut-off protection of the battery stack 11 during charging and discharging.

[0041] The liquid flow battery management system uses the voltage value of a single battery stack 11 as a cutoff condition to perform cutoff protection on the charging and discharging of each battery stack 11, including:

[0042] When the battery power module is in a charging state, when the voltage value of any battery stack 11 is higher than a first set value, the liquid flow battery management system cuts off the charging of the corresponding battery stack 11;

[0043] When the battery power module is in a discharging state, when the voltage value of any battery stack 11 is lower than a first set value, the liquid flow battery management system cuts off the discharge of the corresponding battery stack 11;

[0044] When the battery power module is in standby mode, the liquid flow battery management system uses the voltage value of a single battery stack 11 as a protection condition. When the voltage value of any battery stack 11 is lower than a second set value, the liquid flow battery management system performs low-current charging on the corresponding battery stack 11 to maintain the voltage.

[0045] The battery stack unit also includes a combustible gas alarm and a harmful gas alarm, which are respectively installed on the inner wall of the top of the container 0 above the battery stack 11 (that is, installed on the top of the battery stack area 1);

[0046] The combustible gas alarm and the harmful gas alarm are respectively connected to the liquid flow battery management system. After detecting the target gas, the combustible gas alarm and the harmful gas alarm transmit signals to the liquid flow battery management system. After receiving the information, the liquid flow battery management system performs safety interlock protection on the battery stack 11.

[0047] like Figure 4 and Figure 5 As shown, the electrolyte circulation and pipeline unit includes positive and negative electrolyte circulation pumps (i.e., positive electrolyte circulation pump 21 and negative electrolyte circulation pump 22), positive and negative electrode liquid inlet pipelines (i.e., positive electrode liquid inlet pipeline and negative electrode liquid inlet pipeline), positive and negative electrode liquid outlet pipelines (i.e., positive electrode liquid outlet pipeline and negative electrode liquid outlet pipeline), positive and negative electrode input pipelines (i.e., positive electrode input pipeline 27 and negative electrode input pipeline 28) and pipeline support 13;

[0048] Among them, the positive and negative electrolyte circulation pumps and the positive and negative input pipelines are mainly located in the pump area 2 inside the container 0, and the positive and negative liquid inlet pipelines, positive and negative liquid outlet pipelines and pipeline supports 13 are mainly located in the electric propulsion area; each liquid inlet pipeline and liquid outlet pipeline contains a specially designed coil to reduce the leakage current of the battery system.

[0049] The positive and negative electrolyte circulation pumps use fluorine-lined magnetic pumps, which have the advantages of leak-free design, corrosion resistance, compact structure, high efficiency and energy saving, low noise and vibration, easy maintenance, multi-functional applicability and precise control. The power of the positive and negative electrolyte pumps is selected according to the power and number of the battery stack 11 in the battery power module, the pipeline design and the capacity module size, and is generally between 5.5-12.5kW.

[0050] The positive and negative electrolyte circulation pumps are used to transmit positive and negative electrolytes to the battery stack 11 respectively. The inlet ends of the positive and negative electrolyte circulation pumps are connected to one end of the positive and negative input pipes. The other ends of the positive and negative input pipes pass through the side wall of the container 0 and are connected to the external positive and negative electrode storage tanks. The positive and negative electrode input pipes input the electrolyte in the positive and negative electrode storage tanks into the positive and negative electrolyte circulation pumps; wherein, a manual butterfly valve is provided at one end of the positive and negative electrode input pipes located outside the container 0. The valve is opened after being installed on site and is normally open during subsequent normal operation.

[0051] The outlet ends of the positive and negative electrolyte circulation pumps are connected to the inlet of each battery stack 11 through the positive and negative electrode liquid inlet pipes, and the outlet of each battery stack 11 is connected to the positive and negative electrode liquid storage tanks in the external battery capacity module through the positive and negative electrode liquid outlet pipes that penetrate the side wall of the container 0. Among them, the pipe bracket 13 is installed in the battery stack area 1 inside the container 0, and the positive and negative electrode liquid inlet pipes and the positive and negative electrode liquid outlet pipes are both installed and fixed on the pipe bracket 13.

[0052] Therefore, the embodiment of the present invention sets the 45kW battery stack 11 as a two-inlet and two-outlet design; the positive and negative electrode liquid inlet pipes include positive and negative electrode liquid inlet main pipes and positive and negative electrode liquid inlet branches, and the positive and negative electrode liquid outlet pipes include positive and negative electrode liquid outlet main pipes and positive and negative electrode liquid outlet branches; the outlet ends of the positive and negative electrode electrolyte circulation pumps are respectively connected to one end of the positive and negative electrode liquid inlet main pipes, and the other ends of the positive and negative electrode liquid inlet main pipes are respectively connected to the inlet of each battery stack 11 through a plurality of positive and negative electrode liquid inlet branches.

[0053] like Figure 6 As shown, in the embodiment of the present invention, the pipes near the top inner wall of the container 0 are the positive and negative electrode liquid inlet main pipes (including the positive electrode liquid inlet main pipe 23 and the negative electrode liquid inlet main pipe 24). The present invention divides the positive and negative electrode liquid inlet main pipes into four vertical positive and negative electrode liquid inlet branches (including the positive electrode liquid inlet branch pipe 15 and the negative electrode liquid inlet branch pipe 16). For example, Figure 6 As shown, one end of the positive electrode liquid inlet main pipe 23 away from the positive electrode electrolyte circulation pump 21 is connected to a vertical positive electrode liquid inlet branch pipe 15, and three vertical positive electrode liquid inlet branch pipes 15 are also connected to the main body of the positive electrode liquid inlet main pipe 23; similarly, one end of the negative electrode liquid inlet main pipe 24 away from the negative electrode electrolyte circulation pump 22 is connected to a vertical negative electrode liquid inlet branch pipe 16, and three vertical negative electrode liquid inlet branch pipes 16 are also connected to the main body of the negative electrode liquid inlet main pipe 24;

[0054] Therefore, stack No. 1 and stack No. 3 share two positive electrode liquid inlet branch pipes 15 and two negative electrode liquid inlet branch pipes 16; stack No. 2 and stack No. 4 share another two positive electrode liquid inlet branch pipes 15 and two negative electrode liquid inlet branch pipes 16.

[0055] The outlets of the four battery stacks 11 are respectively connected to one end of a plurality of positive and negative electrode liquid outlet branch pipes (including a positive electrode liquid outlet branch pipe 17 and a negative electrode liquid outlet branch pipe 18), and the other ends of the plurality of positive and negative electrode liquid outlet branch pipes are connected to one end of the positive and negative electrode liquid outlet main pipes, and the other ends of the positive and negative electrode liquid outlet main pipes penetrate the inner wall of the container 0 and extend to the outside of the container 0 to be connected to the positive and negative electrode liquid storage tanks in the battery capacity module;

[0056] Among them, a first valve is set at one end of the positive and negative electrode liquid outlet main pipes located outside the container 0. The first valve is a manual butterfly valve. The valve is opened after being installed on site and is in a normally open state during subsequent normal operation.

[0057] like Figure 7 As shown, intermixing pipes are alternately installed between the positive and negative electrode liquid inlet main pipes and the positive and negative electrode liquid outlet main pipes, and the intermixing pipes include a negative electrode to positive electrode intermixing pipe 29 and a positive electrode to negative electrode intermixing pipe 210, that is, a positive electrode to negative electrode intermixing pipe 210 connecting the positive electrode liquid inlet main pipe 23 with the negative electrode liquid outlet pipe, and a negative electrode to positive electrode intermixing pipe 29 connecting the negative electrode liquid inlet main pipe 24 with the positive electrode liquid outlet main pipe 25; wherein, intermixing valves are installed on the intermixing pipes, so the intermixing valves include a positive electrode to negative electrode intermixing pipe 210 valve and a negative electrode to positive electrode intermixing pipe 29 valve; the intermixing pipe valves are generally in a normally closed state, and are only manually opened for intermixing operations under special circumstances.

[0058] like Figure 8 and Fig. 9 As shown, in the present invention, liquid inlet valves (including positive liquid inlet valve 232 and negative liquid inlet valve 242) are installed on the positive and negative electrode liquid inlet main pipes, and the liquid inlet valves are arranged on one side of the pipe close to the positive and negative electrode electrolyte circulation pumps; the liquid inlet valves are used to control whether the electrolyte of the positive and negative electrode electrolyte circulation pumps flows to the battery stack 11, and are generally in a normally open state. There are some special working conditions that require closing the liquid inlet valves. For example: when the positive and negative electrode electrolytes need to be prevented from mixing in the battery stack 11, it is necessary to close the liquid inlet valve and open the mixing valve to achieve the goal of preventing the electrolytes from mixing in the battery stack 11.

[0059] Since the present invention is provided with a mixing pipeline, the positive and negative electrolyte circulation pumps in the battery power module not only serve as electrolyte conveyor belts during normal charging and discharging, but also when the positive and negative electrolytes need to be mixed, the present invention can achieve this through the positive and negative electrolyte circulation pumps and the mixing pipeline, without the need to add a mixing pump.

[0060] like Fig. 9As shown, the positive electrode liquid inlet main pipe 23 and the negative electrode liquid inlet main pipe 24 are both installed with pressure gauges (i.e., the positive electrode pressure gauge 231 and the negative electrode pressure gauge 241), and the pressure gauges are used to monitor the inlet pressure and the inlet pressure difference of the positive and negative electrode electrolytes; the pressure gauges are connected to the liquid flow battery management system, and the pressure gauges send the inlet pressure and the inlet pressure difference to the liquid flow battery management system, and the liquid flow battery management system is used to perform pressure interlocking protection on the battery stack 11;

[0061] When the stack pressure or the stack pressure difference is too high, the liquid flow battery management system triggers the pressure interlock protection to make the battery system stop urgently to protect the battery stack 11 .

[0062] A high-point exhaust valve 5 is installed at the highest point of the positive and negative main pipes; when filling or other working conditions requiring exhaust are performed, the high-point exhaust valve 5 can be opened to lead out a hose to exhaust the system;

[0063] like Figure 6 As shown, the bottoms of the positive and negative electrode liquid inlet branches and the positive and negative electrode liquid outlet branches are connected with drain pipes 6 (the drain pipes 6 include positive electrode drain pipes and negative electrode drain pipes) and drain valves. The drain pipes 6 and the drain valves 61 are used to drain each battery stack 11, flange 112 and valve before maintenance, and facilitate the disassembly of a single battery stack 11 without affecting the use of other battery stacks 11.

[0064] A leakage cofferdam is provided at the bottom of the container 0, and the leakage cofferdam is located below the electrolyte circulation and pipeline unit and the battery stack unit (that is, located in the pump area 2 and the battery stack area 1); an anti-corrosion mat is laid inside the leakage cofferdam, and a leakage sensor connected to the liquid flow battery management system is laid on the anti-corrosion mat;

[0065] When leakage occurs in the battery system, the leakage cofferdam will block the leakage in the pump area 2 and the battery stack area 1 inside the container 0, preventing waste liquid from overflowing and avoiding pollution of other areas; at the same time, the leakage sensor will trigger an alarm when it detects leakage, causing the liquid flow battery management system to display an alarm message; the liquid flow battery management system triggers the relevant protection mechanism to stop the operation of the battery system and reminds the operation and maintenance personnel to perform maintenance inspections.

[0066] The electrical control unit and the tail gas absorption unit (i.e., the electrical room 4 and the tail gas absorption area 3) are respectively arranged at the two ends inside the container 0, and the tail gas absorption unit includes an alkali absorption tank, on which an air intake pipe is installed, and the alkali absorption tank is filled with a sodium hydroxide solution of a predetermined concentration; one end of the air intake pipe is connected to the gas phase space of the alkali absorption tank, and the other end of the air intake pipe is located below the liquid level inside the alkali absorption tank to absorb the exhaust gas of the alkali absorption tank; and a first check valve is installed on the air intake pipe;

[0067] The positive and negative electrode liquid storage tanks in the battery capacity module are respectively connected to the positive and negative electrode liquid outlet main pipes in the positive and negative electrode liquid outlet pipelines. An exhaust pipe is arranged on the top of the positive and negative electrode liquid storage tanks. A second check valve and a flame arrester are installed on the exhaust pipe.

[0068] Among them, the function of setting a check valve on the air inlet pipe of the alkali absorption tank in the embodiment of the present invention is: when the temperature of the battery system decreases or other reasons cause the pressure of the positive and negative electrode storage tanks in the battery capacity module to decrease, it can prevent the alkaline solution in the alkali absorption tank from being sucked back into the positive and negative electrode storage tanks and polluting the battery system.

[0069] The flame arrester provided on the exhaust pipes of the positive and negative electrode liquid storage tanks in the embodiment of the present invention has the following function: when a battery system fails, a small amount of flammable gas will be generated, and the flame arrester can prevent the generated flammable gas from exploding when encountering sparks.

[0070] The operating principle of the tail gas absorption unit is:

[0071] The exhaust gas of the battery power module flows back to the battery capacity module through the positive and negative electrode liquid outlet pipes. The exhaust gas gathers on the top of the positive and negative electrode storage tanks in the battery capacity module, and flows into the sodium hydroxide solution in the alkali absorption tank through the exhaust pipes and check valves on the top of the positive and negative electrode storage tanks. The acid gas reacts with the alkali absorption liquid, and the acid gas is absorbed and neutralized to generate sodium chloride and water. The purified gas is discharged outside the container 0 through the exhaust pipe of the alkali absorption tank, thereby achieving the effect of absorbing the exhaust gas of the iron-chromium liquid flow battery system.

[0072] Since the air inlet pipe of the alkali absorption tank is located below the liquid level, there is a certain liquid sealing pressure, and the check valve on the air inlet pipe also requires a certain pressure to open; therefore, the exhaust gas pressure inside the battery capacity module of the iron-chromium liquid flow battery system can only be exhausted to the alkali absorption tank when it reaches a certain value.

[0073] One end of the interior of the container 0 is an electrical room 4 (i.e., an electrical control unit is provided at one end of the interior of the container 0). Fig.10 As shown, the electrical control unit includes a power module sub-FBMS, a positive and negative pump inverter, a power distribution cabinet, an uninterruptible power supply UPS, an air conditioner and a combustible gas alarm;

[0074] The power module sub-FBMS is installed on the inner wall of container 0, and the power module sub-FBMS is respectively connected to the positive and negative pump inverters, the power distribution cabinet, the uninterruptible power supply UPS, the air conditioner and the combustible gas alarm; the power module sub-FBMS mainly performs functions such as data collection, data identification and issuing instructions.

[0075] The positive and negative electrode pump frequency converters are mainly installed below the power module sub-FBMS, and the power module sub-FBMS is used to adjust the frequency of the positive and negative electrode electrolyte circulation pumps by controlling the positive and negative electrode pump frequency converters.

[0076] The power distribution cabinet is installed on the inner wall of the container 0 and is located on the right side of the power module sub-FBMS. Various switches and equipment instrument wiring are installed inside the power distribution cabinet.

[0077] The uninterruptible power supply UPS is mainly located in the lower part of the electrical room 4. The uninterruptible power supply UPS is used to provide basic power supply for the battery system (such as battery power module, air conditioner, instrument and power module sub-FBMS, etc.) when the external power supply is cut off.

[0078] The air conditioner is installed on the door of the electrical room 4 of the container 0, and the power module sub-FBMS is used to control the air conditioner switch, air conditioner mode and air conditioner temperature.

[0079] The combustible gas alarm is installed on the top of the container 0. The combustible gas alarm is used to detect combustible gas and send a signal to the power module sub-FBMS.

[0080] It can be seen that the electrical control unit is the data collection and control instruction sending end of the battery power module. It mainly collects the current, voltage, pressure, leakage, toxic and harmful gases and combustible gas data in the battery power module, and controls the operation of the entire battery system through the liquid flow battery management system FBMS.

[0081] Among them, the power module sub-FBMS is placed in a convenient location in the electrical room 4, which is conducive to personnel observing parameters and operations during inspection and debugging; the external interface of the electrical control unit is the communication connection between the power module sub-FBMS and the station main FBMS and EMS;

[0082] Electrical room 4 is adjacent to pump area 2. The power distribution cabinet, UPS and positive / negative pump inverter are reasonably distributed in electrical room 4, with reasonable wiring and compact layout. The air conditioner is hung on the container 0 door of electrical room 4, and the air outlet design is reasonable and saves space.

[0083] The present invention has the characteristics of high standardization and high integration. The main components can be pre-stocked and assembled quickly on site. The electrical cabinets and all equipment in the electrical room 4, the positive and negative electrolyte circulation pumps, and more than 60% of the pipelines, the battery stack 11 and the alkali absorption storage tank can be pre-fabricated in advance. The above components can be produced synchronously with the container 0 body, which can save production time and the workload of on-site assembly.

[0084] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An iron-chromium liquid flow battery system, characterized in that: The battery system includes a battery power module and a battery capacity module. The battery power module comprises a container (0), wherein an electrical control unit, an electrolyte circulation and pipeline unit, a battery stack unit and an exhaust gas absorption unit are sequentially arranged inside the container (0); The battery stack unit is equipped with a plurality of battery stacks (11), and the battery stack (11) is an iron-chromium liquid flow battery stack; The electrolyte circulation and pipeline unit comprises positive and negative electrolyte circulation pumps, positive and negative electrode liquid inlet pipelines, positive and negative electrode liquid outlet pipelines and positive and negative electrode input pipelines (28), the outlet ends of the positive and negative electrode electrolyte circulation pumps are respectively connected to the inlet of each battery stack (11) through the positive and negative electrode liquid inlet pipelines, and the outlet of each battery stack (11) is respectively connected to the battery capacity module outside the container (0) through the positive and negative electrode liquid outlet pipelines; The battery capacity module is used to store electrolyte, and the battery capacity module is connected to the positive and negative electrolyte circulation pumps through the positive and negative electrode input pipes (28) penetrating the side wall of the container (0); The electrical control unit and the exhaust gas absorption unit are respectively arranged at two ends inside the container (0); the electrical control unit is used for collecting data and sending instructions for the battery power module; and the exhaust gas absorption unit is used for absorbing the exhaust gas generated by the battery system.

2. An iron-chromium flow battery system according to claim 1, characterized in that: A battery stack support (12) is installed inside the container (0), the battery stack support (12) is connected to a support beam inside the container (0), and the battery stack (11) is installed on the battery stack support (12); The battery stacks (11) are connected in series in pairs and then in parallel, and each two battery stacks (11) are connected in series to form a battery cluster, and the battery stacks (11) are connected by direct current cables; The series DC circuit of each battery cluster is provided with a protection device, which includes a plurality of key electrical protection elements and key connection elements.

3. An iron-chromium liquid flow battery system according to claim 1 or 2, characterized in that: The battery stack unit comprises an OCV battery (14), a voltage transmitter, a current transmitter and a liquid flow battery management system. The OCV battery 14 is used to monitor the open circuit voltage of the battery system and calculate the battery capacity of the battery system; each battery stack (11) and the OCV battery (14) are equipped with a voltage transmitter, and each battery cluster series DC circuit is equipped with a current transmitter, and the voltage transmitter and the current transmitter can filter PCS DC harmonics; Each voltage transmitter and each voltage transmitter are connected to a liquid flow battery management system, and each voltage transmitter and each voltage transmitter are used to send monitored voltage values ​​and current values ​​to the liquid flow battery management system; the liquid flow battery management system is used to monitor the battery system state and the cut-off protection of the battery stack (11) during charging and discharging; When the battery power module is charged or discharged, the liquid flow battery management system uses the voltage value of a single battery stack (11) as a cutoff condition to perform cutoff protection on the charging and discharging of each battery stack (11).

4. The iron-chromium flow battery system according to claim 3, characterized in that: The battery stack unit further comprises a combustible gas alarm and a harmful gas alarm, wherein the combustible gas alarm and the harmful gas alarm are respectively installed on the top inner wall of the container (0) above the battery stack (11); The flammable gas alarm and the harmful gas alarm are respectively connected to a liquid flow battery management system. After detecting the target gas, the flammable gas alarm and the harmful gas alarm transmit signals to the liquid flow battery management system. The liquid flow battery management system is used to perform safety interlock protection on the battery stack (11) after receiving the information.

5. The iron-chromium flow battery system according to claim 3, characterized in that: The positive and negative electrode liquid inlet pipelines include positive and negative electrode liquid inlet main pipes and positive and negative electrode liquid inlet branch pipes, and the positive and negative electrode liquid outlet pipelines include positive and negative electrode liquid outlet main pipes and positive and negative electrode liquid outlet branch pipes; The outlet ends of the positive and negative electrode electrolyte circulation pumps are respectively connected to one end of the positive and negative electrode liquid inlet main pipes, and the other ends of the positive and negative electrode liquid inlet main pipes are respectively connected to the inlet of each battery stack (11) through a plurality of positive and negative electrode liquid inlet branch pipes; The outlets of each battery stack (11) are respectively connected to one end of a plurality of positive and negative electrode liquid outlet branch pipes, the other ends of the plurality of positive and negative electrode liquid outlet branch pipes are connected to one end of the positive and negative electrode liquid outlet main pipes, and the other ends of the positive and negative electrode liquid outlet main pipes penetrate the inner wall of the container (0) and extend to the outside of the container (0) to be connected to the battery capacity module; Mixing pipes are installed alternately between the positive and negative electrode liquid inlet pipes and the positive and negative electrode liquid outlet pipes, and mixing valves are installed on the mixing pipes; a first valve is provided at one end of the positive and negative electrode liquid outlet pipes located outside the container (0).

6. The iron-chromium flow battery system according to claim 5, characterized in that: Pressure gauges are installed on the positive and negative electrode liquid inlet pipes and the positive and negative electrode liquid outlet pipes, and the pressure gauges are used to monitor the inlet pressure and inlet pressure difference of the positive and negative electrode electrolytes; the pressure gauges are connected to the liquid flow battery management system, and the liquid flow battery management system is used to perform pressure interlocking protection on the battery stack (11); A high-point exhaust valve (5) is installed at the highest point of the positive and negative electrode liquid inlet main pipes and the positive and negative electrode liquid outlet main pipes, and a drain pipe (6) and a drain valve (61) are provided at the bottom of the positive and negative electrode liquid inlet branch pipes and the positive and negative electrode liquid outlet branch pipes; When the stack pressure or stack pressure difference is too high, the liquid flow battery management system triggers pressure interlock protection, causing the battery system to stop suddenly to protect the battery stack (11).

7. An iron-chromium liquid flow battery system according to claim 5 or 6, characterized in that: A leakage cofferdam is arranged at the bottom of the container (0), and the leakage cofferdam is located below the electrolyte circulation and pipeline unit and the battery stack (11) unit; an anti-corrosion mat is laid inside the leakage cofferdam, and a leakage sensor connected to the liquid flow battery management system is laid on the anti-corrosion mat.

8. The iron-chromium flow battery system according to claim 1, characterized in that: The tail gas absorption unit comprises an alkali absorption tank, an air intake pipe is installed on the alkali absorption tank, a sodium hydroxide solution of a predetermined concentration is filled inside the alkali absorption tank, the air intake pipe is located below the liquid level inside the alkali absorption tank, and a first check valve is installed on the air intake pipe; The battery capacity module includes positive and negative electrode liquid storage tanks, which are respectively connected to the positive and negative electrode liquid outlet main pipes in the positive and negative electrode liquid outlet pipelines. Exhaust pipes are arranged on the tops of the positive and negative electrode liquid storage tanks, and a second check valve and a flame arrester are installed on the exhaust pipes.

9. The iron-chromium flow battery system according to claim 1, characterized in that: The inlet and outlet of the cell stack (11) are respectively connected to the cell stack coil (113) through a root valve (111), and the cell stack coil (113) is installed and fixed on the outer wall of the cell stack (11) through a coil bracket (114).

10. The iron-chromium flow battery system according to claim 1, characterized in that: The electrical control unit includes a power module sub-FBMS, a positive and negative pump frequency converter, a power distribution cabinet, an uninterruptible power supply UPS, an air conditioner and a combustible gas alarm; The power module sub-FBMS is installed on the inner wall of the container (0), and the power module sub-FBMS is respectively connected to the positive and negative pump inverters, the power distribution cabinet, the uninterruptible power supply UPS, the air conditioner and the combustible gas alarm; The positive and negative electrode pump frequency converter is installed below the power module sub-FBMS, and the power module sub-FBMS is used to adjust the frequency of the positive and negative electrode electrolyte circulation pumps by controlling the positive and negative electrode pump frequency converter; The power distribution cabinet is installed on the inner wall of the container (0), and various switches and equipment instrument wiring are installed inside the power distribution cabinet; The uninterruptible power supply UPS is used to provide basic power supply for the battery system when the external power supply is cut off; The air conditioner is installed on the door of the container (0), and the power module sub-FBMS is used to control the air conditioner switch, air conditioner mode and air conditioner temperature; The combustible gas alarm is installed on the top of the container (0), and is used to detect combustible gas and send a signal to the power module sub-FBMS.

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