Flow battery system

Abstract

The utility model provides a flow battery system. The flow battery system comprises an electric pile, a positive electrode liquid storage device, a negative electrode liquid storage device, a positive electrode liquid inlet channel, a positive electrode liquid outlet channel, a negative electrode liquid inlet channel and a negative electrode liquid outlet channel, a positive electrode liquid storage device and the positive electrode short circulation channel are connected in parallel between the positive electrode liquid inlet channel and the positive electrode liquid outlet channel, and the positive electrode short circulation channel is closer to the positive electrode of the electric pile than the positive electrode liquid storage device; and / or the system further comprises a negative electrode short circulation channel, a negative electrode liquid storage device and the negative electrode short circulation channel are connected between the negative electrode liquid inlet channel and the negative electrode liquid outlet channel in parallel, and the negative electrode short circulation channel is closer to the negative electrode of the electric pile than the negative electrode liquid storage device. The flow battery system disclosed by the utility model can greatly shorten a circulation loop of the electrolyte, requires less energy for electrolyte circulation, and has the characteristics of high battery system efficiency, high electrolyte utilization rate, stable battery operation and the like.

Description

Technical Field

[0001] The utility model relates to the field of liquid flow batteries, in particular to a liquid flow battery system. Background Art

[0002] Liquid flow batteries are characterized by good safety and long service life, and are ideal batteries for long-term energy storage applications. Liquid flow batteries charge and discharge electrolytes when the electrolyte liquid circulates in the battery stack to achieve the conversion of electrical energy and chemical energy. The liquid flow battery system mainly includes the battery stack, circulation pump, circulation pipeline, liquid storage device, electrolyte, energy storage converter (PCS), etc. Usually, the positive and negative electrolytes are stored in the positive and negative liquid storage devices. When the battery is working, the electrolyte needs to flow between the liquid storage device and the battery stack to achieve a continuous charging and discharging process. During the operation of the battery, a circulation pump is required to provide liquid flow power, which consumes the power of the battery or the external power grid, reducing the efficiency of the charge and discharge energy conversion of the liquid flow battery, which is not conducive to the promotion and use of liquid flow batteries.

[0003] Therefore, how to minimize the energy consumption of the circulation pump while ensuring the normal operation of the battery is a technical problem that needs to be solved urgently in this field. Utility Model Content

[0004] In order to solve the above technical problems, the purpose of the utility model is to provide a liquid flow battery system, which can reduce energy consumption by involving a short circulation channel.

[0005] To achieve the above-mentioned purpose, the utility model provides a liquid flow battery system, including a battery stack, a positive electrode liquid storage device, a negative electrode liquid storage device, a positive electrode liquid inlet channel, a positive electrode liquid outlet channel, a negative electrode liquid inlet channel, and a negative electrode liquid outlet channel; the inlet and outlet of the positive electrode of the battery stack are respectively connected to the positive electrode liquid inlet channel and the positive electrode liquid outlet channel; the inlet and outlet of the negative electrode of the battery stack are respectively connected to the negative electrode liquid inlet channel and the negative electrode liquid outlet channel;

[0006] in:

[0007] The liquid flow battery system also includes a positive electrode short circulation channel, the positive electrode storage device and the positive electrode short circulation channel are connected in parallel between the positive electrode liquid inlet channel and the positive electrode liquid outlet channel, and the positive electrode short circulation channel is closer to the positive electrode of the battery stack than the positive electrode storage device; and / or, the liquid flow battery system also includes a negative electrode short circulation channel, the negative electrode storage device and the negative electrode short circulation channel are connected in parallel between the negative electrode liquid inlet channel and the negative electrode liquid outlet channel, and the negative electrode short circulation channel is closer to the negative electrode of the battery stack than the negative electrode storage device.

[0008] In the above flow battery system, the positive electrode liquid storage device is used to store the positive electrode electrolyte, convey the positive electrode electrolyte to the positive electrode liquid inlet channel, recycle the positive electrode electrolyte from the positive electrode liquid outlet channel, etc. A liquid storage device commonly used in the art can be adopted, such as a liquid storage tank.

[0009] In the above flow battery system, the negative electrode liquid storage device is used to store the negative electrode electrolyte, convey the negative electrode electrolyte to the negative electrode liquid inlet channel, recycle the negative electrode electrolyte from the negative electrode liquid outlet channel, etc. A liquid storage device commonly used in the art can be adopted, such as a liquid storage tank.

[0010] In the above flow battery system, the positive electrode liquid inlet channel is used to convey the positive electrode electrolyte from the positive electrode storage tank and the positive electrode short - circuit circulation channel to the positive electrode inlet of the stack, and the positive electrode liquid outlet channel is used to convey the positive electrode electrolyte from the positive electrode outlet of the stack to the positive electrode storage tank and the positive electrode short - circuit circulation channel. The positive electrode storage tank and the positive electrode short - circuit circulation channel can adopt the electrolyte conveying channels commonly used in the art, such as electrolyte conveying pipes.

[0011] In the above flow battery system, the negative electrode liquid inlet channel is used to convey the negative electrode electrolyte from the negative electrode storage tank and the negative electrode short - circuit circulation channel to the negative electrode inlet of the stack, and the negative electrode liquid outlet channel is used to convey the negative electrode electrolyte from the negative electrode outlet of the stack to the negative electrode storage tank and the negative electrode short - circuit circulation channel. The negative electrode storage tank and the negative electrode short - circuit circulation channel can adopt the electrolyte conveying channels commonly used in the art, such as electrolyte conveying pipes.

[0012] In the above flow battery system, the positive electrode short - circuit circulation channel is used to directly return the positive electrode electrolyte from the positive electrode outlet of the stack to the positive electrode inlet of the stack without returning to the positive electrode liquid storage device, and continue the charge - discharge reaction. The positive electrode short - circuit circulation channel can be any channel through which the positive electrode electrolyte can flow, such as a pipe identical to the positive electrode liquid inlet channel and the positive electrode liquid outlet channel.

[0013] In the above flow battery system, the negative electrode short - circuit circulation channel is used to directly return the negative electrode electrolyte from the negative electrode outlet of the stack to the negative electrode inlet of the stack without returning to the negative electrode liquid storage device, and continue the charge - discharge reaction. The negative electrode short - circuit circulation channel can be any channel through which the negative electrode electrolyte can flow, such as a pipe identical to the negative electrode liquid inlet channel and the negative electrode liquid outlet channel.

[0014] In the above flow battery system, the connection relationships between the positive and negative electrodes of the stack, the positive electrode liquid storage device and the negative electrode liquid outlet tank, the positive electrode short - circuit circulation channel, the negative electrode short - circuit circulation channel, etc. can also be:

[0015] The inlet of the positive electrode of the stack is communicated with the outlet of the positive electrode liquid storage device through the positive electrode liquid inlet channel, and the outlet of the positive electrode of the stack is communicated with the inlet of the positive electrode liquid storage device through the positive electrode liquid outlet channel;

[0016] The inlet of the negative electrode of the stack is communicated with the outlet of the negative electrode liquid storage device through the positive electrode liquid inlet channel, and the outlet of the negative electrode of the stack is communicated with the inlet of the negative electrode liquid storage device through the negative electrode liquid outlet channel;

[0017] The outlet of the positive electrode of the stack and the inlet of the positive electrode of the stack are communicated through the positive electrode short circulation channel;

[0018] The outlet of the negative electrode of the stack and the inlet of the negative electrode of the stack are communicated through the negative electrode short circulation channel.

[0019] In the above flow battery system, preferably, the distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the stack through the positive electrode short circulation channel to the inlet of the positive electrode of the stack < the distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the stack through the positive electrode liquid storage device to the inlet of the positive electrode of the stack;

[0020] The distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the stack through the negative electrode short circulation channel to the inlet of the negative electrode of the stack < the distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the stack through the negative electrode liquid storage device to the inlet of the negative electrode of the stack.

[0021] In the above flow battery system, preferably, the flow battery system further includes a positive electrode short circulation channel and a negative electrode short circulation channel; wherein:

[0022] The positive electrode liquid storage device and the positive electrode short circulation channel are connected in parallel between the positive electrode liquid inlet channel and the positive electrode liquid outlet channel, and the positive electrode short circulation channel is closer to the positive electrode of the stack than the positive electrode liquid storage device;

[0023] The negative electrode liquid storage device and the negative electrode short circulation channel are connected in parallel between the negative electrode liquid inlet channel and the negative electrode liquid outlet channel, and the negative electrode short circulation channel is closer to the negative electrode of the stack than the negative electrode liquid storage device.

[0024] In the above flow battery system, preferably, the flow battery system further includes a positive electrode long circulation pump and a negative electrode long circulation pump;

[0025] The positive electrode long circulation pump is arranged at the outlet of the positive electrode liquid storage device;

[0026] The negative electrode long circulation pump is arranged at the outlet of the negative electrode liquid storage device.

[0027] In the above flow battery system, preferably, the positive electrode long circulation pump is arranged between the outlet of the positive electrode liquid storage device and the connection point of the positive electrode short circulation channel and the positive electrode liquid inlet channel;

[0028] The negative long-cycle pump is arranged between the outlet of the negative liquid storage device and the connection of the negative short-cycle channel and the negative liquid inlet channel.

[0029] In the above flow battery system, preferably, the flow battery system further includes a positive short-cycle pump and a negative short-cycle pump; the positive short-cycle pump is arranged above the positive short-cycle channel; the negative short-cycle pump is arranged above the negative short-cycle channel. By arranging a booster pump above the positive short-cycle channel and the negative short-cycle channel, it can ensure that the electrolyte return liquid in the short-cycle channel enters the stack of the flow battery system after flowing into the liquid inlet channel.

[0030] In the above flow battery system, preferably, the stack includes a plurality of sub-stacks with their circuits connected in series and their liquid paths connected in parallel.

[0031] In the above flow battery system, preferably, the stack includes a plurality of groups of sub-stack groups connected in parallel with each other;

[0032] Wherein, each sub-stack group includes a plurality of sub-stacks with their circuits connected in series and their liquid paths connected in parallel, as well as a positive liquid inlet sub-channel, a positive liquid outlet sub-channel, a negative liquid inlet sub-channel, a negative liquid outlet sub-channel, a positive short-cycle sub-channel, and a negative short-cycle sub-channel. The positive short-cycle sub-channel is connected between the positive liquid inlet sub-channel and the positive liquid outlet sub-channel, and the negative short-cycle sub-channel is connected between the negative liquid inlet sub-channel and the negative liquid outlet sub-channel.

[0033] In the above flow battery system, preferably, the flow battery system is one of an iron-chromium flow battery, a vanadium redox flow battery, a zinc-bromine flow battery, a zinc-iron flow battery, an all-iron flow battery, a zinc-nickel flow battery, and an organic flow battery.

[0034] In the above flow battery system, preferably, the positive long-cycle pump and the negative long-cycle pump are respectively booster pumps with a pressure regulation function. For example: a magnetic pump with a power of 15 kw and a frequency of 50 Hz, a head of 28 m, and the frequency can be adjusted between 5 - 50 Hz. The booster pump with a pressure regulation function can adjust the pressure as needed, so that the return liquid and the new liquid in the flow battery system have different ratios during operation. The ratio range can be controlled to 0 - 99%, and the mixing ratio relationship can be adjusted at any time according to requirements.

[0035] In the above flow battery system, preferably, the positive short-circuit pump and the negative short-circuit pump are respectively booster pumps with pressure regulating functions. For example, a magnetic pump with a power of 2.2 kw and a frequency of 50 Hz, with a head of 19 m, and the frequency can be adjusted between 5 - 50 Hz. The booster pump with pressure regulating function can adjust the pressure as needed, so that the return liquid and the new liquid of the flow battery system have different proportions during operation. This proportion range can be controlled from 0 - 99%, and the mixing ratio relationship can be adjusted at any time according to requirements.

[0036] In the flow battery system of the present utility model, through the positive short-circuit channel and the negative short-circuit channel, part of the return liquid of the positive electrolyte and the return liquid of the negative electrolyte can directly return to the stack of the flow battery system to continue the charge and discharge reaction without returning to the positive electrolyte tank and the negative electrolyte tank, thereby reducing the length of the electrolyte return path and the energy consumption of the return flow. In particular, the energy consumption of the flow battery system with a circulation pump can be reduced.

[0037] The flow battery system of the present utility model can greatly shorten the circulation loop of the electrolyte, requires less energy for electrolyte circulation, and has the characteristics of high battery system efficiency, high electrolyte utilization rate, and stable battery operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic structural diagram of the flow battery system with a group of short-circuit pipes provided for Example 1.

[0039] Figure 2 Schematic structural diagram of the flow battery system with several sub-stacks provided for Example 2.

[0040] Figure 3 Schematic structural diagram of the flow battery system with two groups of short-circuit pipes provided for Example 3.

[0041] Among them, 1. Negative short-circuit pump, 2. Positive short-circuit pump, 3. Positive liquid storage tank, 4. Positive long-circuit pump, 5. Stack, 6. Negative long-circuit pump, 7. Negative liquid storage tank;

[0042] 8. Positive liquid outlet pipe, 9. Positive liquid inlet pipe, 10. Negative liquid outlet pipe, 11. Negative liquid inlet pipe, 12. Positive short-circuit pipe, 13. Negative short-circuit pipe;

[0043] 14. First branch point, 15. Second branch point, 16. First confluence point, 17. Second confluence point;

[0044] 51. Sub-stack, 501. First stack group, 502. Second stack group;

[0045] 101. First negative short-circuit pump, 102. Second negative short-circuit pump;

[0046] 201. First positive short - cycle pump, 202. Second positive short - cycle pump;

[0047] 80. Positive liquid outlet main pipe, 801. First positive liquid outlet pipe, 802. Second positive liquid outlet pipe;

[0048] 90. Positive liquid inlet main pipe, 901. First positive liquid inlet pipe, 902. Second positive liquid inlet pipe;

[0049] 100. Negative liquid outlet main pipe, 1001. First negative liquid outlet pipe, 1002. Second negative liquid outlet pipe;

[0050] 110. Negative liquid inlet main pipe, 1101. First negative liquid inlet pipe, 1102. Second negative liquid inlet pipe;

[0051] 1201. First positive short - cycle pipe, 1202. Second positive short - cycle pipe, 1301. First negative short - cycle pipe, 1302. Second negative short - cycle pipe. Detailed implementation mode

[0052] For a clearer understanding of the technical features, objectives, and beneficial effects of the present utility model, the technical solution of the present utility model is described in detail below, but it should not be construed as a limitation on the implementable scope of the present utility model.

[0053] Embodiment 1

[0054] This embodiment provides a flow battery system with a set of short - cycle pipes, and its structure is as Figure 1 shown.

[0055] The flow battery system includes a negative short - cycle pump 1, a positive short - cycle pump 2, a positive liquid storage tank 3, a positive long - cycle pump 4, an electrolytic stack 5, a negative long - cycle pump 6, a negative liquid storage tank 7, a positive liquid outlet pipe 8, a positive liquid inlet pipe 9, a negative liquid outlet pipe 10, a negative liquid inlet pipe 11, a positive short - cycle pipe 12, and a negative short - cycle pipe 13; where:

[0056] The inlet of the positive electrode of the electrolytic stack 5 is connected to the outlet of the positive liquid storage tank 3 through the positive liquid inlet pipe 9, and the outlet of the positive electrode of the electrolytic stack 5 is connected to the inlet of the positive liquid storage tank 3 through the positive liquid outlet pipe 8;

[0057] The inlet of the negative electrode of the electrolytic stack 5 is connected to the outlet of the negative liquid storage tank 7 through the negative liquid inlet pipe 11, and the outlet of the negative electrode of the electrolytic stack 5 is connected to the inlet of the negative liquid storage tank 7 through the negative liquid outlet pipe 10;

[0058] The outlet of the positive electrode of the electrolytic stack 5 and the inlet of the positive electrode of the electrolytic stack 5 are connected through the positive short - cycle pipe 12;

[0059] The outlet of the negative electrode of the stack 5 and the inlet of the negative electrode of the stack 5 are connected through the negative electrode short circulation pipe 13;

[0060] The positive electrode liquid storage tank 3 and the positive electrode short circulation pipe 12 form a parallel positional relationship between the positive electrode liquid inlet pipe 9 and the positive electrode liquid outlet pipe 8. Moreover, the positive electrode short circulation pipe 12 is closer to the positive electrode of the stack 5 than the positive electrode liquid storage tank 3. That is, compared with the connection point of the positive electrode liquid storage tank 3 and the positive electrode liquid outlet pipe 8 (i.e., the inlet of the positive electrode liquid storage tank 3), the connection point of the positive electrode short circulation pipe 12 and the positive electrode liquid outlet pipe 8 is closer to the outlet of the positive electrode of the stack 5. Compared with the connection point of the positive electrode liquid storage tank 3 and the positive electrode liquid inlet pipe 9 (i.e., the outlet of the positive electrode liquid storage tank 3), the connection point of the positive electrode short circulation pipe 12 and the positive electrode liquid inlet pipe 9 is closer to the inlet of the positive electrode of the stack 5;

[0061] The negative electrode liquid storage tank 7 and the negative electrode short circulation pipe 13 form a parallel positional relationship between the negative electrode liquid inlet pipe 11 and the negative electrode liquid outlet pipe 10. Moreover, the negative electrode short circulation pipe 13 is closer to the negative electrode of the stack 5 than the negative electrode liquid storage tank 7. That is, compared with the connection point of the negative electrode liquid storage tank 7 and the negative electrode liquid outlet pipe 10 (i.e., the inlet of the negative electrode liquid storage tank 7), the connection point of the negative electrode short circulation pipe 13 and the negative electrode liquid outlet pipe 10 is closer to the outlet of the negative electrode of the stack 5. Compared with the connection point of the negative electrode liquid storage tank 7 and the negative electrode liquid inlet pipe 11 (i.e., the outlet of the negative electrode liquid storage tank 7), the connection point of the negative electrode short circulation pipe 13 and the negative electrode liquid inlet pipe 11 is closer to the inlet of the negative electrode of the stack 5;

[0062] The distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the stack 5 through the positive electrode short circulation pipe 12 to the inlet of the positive electrode of the stack 5 < the distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the stack 5 through the positive electrode liquid storage tank 3 to the inlet of the positive electrode of the stack 5;

[0063] The distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the stack 5 through the negative electrode short circulation pipe 13 to the inlet of the negative electrode of the stack 5 < the distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the stack 5 through the negative electrode liquid storage tank 7 to the inlet of the negative electrode of the stack 5;

[0064] A positive electrode long circulation pump 4 is provided on the positive electrode liquid inlet pipe 9 between the outlet of the positive electrode liquid storage tank 3 and the connection point of the positive electrode short circulation pipe 12 and the positive electrode liquid inlet pipe 9; a positive electrode short circulation pump 2 is provided on the positive electrode short circulation pipe 12; both the positive electrode long circulation pump 4 and the positive electrode short circulation pump 2 are booster pumps with pressure regulating functions. By controlling their pressures, the proportion of the positive electrode electrolyte entering the positive electrode short circulation pipe 12 and the electrode liquid entering the positive electrode liquid storage tank 3 can be controlled. Thus, the proportion of the positive electrode electrolyte (new liquid) entering the positive electrode liquid inlet pipe 9 from the positive electrode liquid storage tank 3 and the positive electrode electrode liquid (return liquid) entering the positive electrode liquid inlet pipe 9 from the positive electrode short circulation pipe 12 can be controlled; moreover, during the working process, the pressure of the booster pump can be adjusted as needed to real-time control the proportion of the above-mentioned new liquid and return liquid;

[0065] A negative long - cycle pump 6 is provided on the negative - electrode liquid inlet pipe between the outlet of the negative - electrode liquid storage tank 7 and the connection point of the negative - electrode short - cycle pipe 13 and the negative - electrode liquid inlet pipe 11; a negative - electrode short - cycle pump 1 is provided on the negative - electrode short - cycle pipe 13; both the negative - long - cycle pump 6 and the negative - electrode short - cycle pump 1 are booster pumps with pressure - regulating functions. By controlling the pressures of the two, the ratio of the negative - electrode electrolyte entering the negative - electrode short - cycle pipe 13 and the electrode liquid entering the negative - electrode liquid storage tank 7 can be controlled. Thus, the ratio of the negative - electrode electrolyte (new liquid) entering the negative - electrode liquid inlet pipe 11 from the negative - electrode liquid storage tank 7 and the negative - electrode electrode liquid (return liquid) entering the negative - electrode liquid inlet pipe 11 from the negative - electrode short - cycle pipe 13 can be controlled; moreover, during the working process, the pressure of the booster pump can be adjusted as needed to real - time regulate the ratio of the above - mentioned new liquid and return liquid.

[0066] Example 2

[0067] This example provides a flow - battery system with several sub - stacks. The flow battery is an iron - chromium flow - battery energy - storage system, and its structure is as Figure 2 shown.

[0068] The stack of this flow - battery system is composed of 10 sub - stacks 51. The voltage of a single sub - stack 51 is 50V and the power is 10kW. The circuits of the 10 sub - stacks 51 are connected in series and the liquid paths are connected in parallel. That is, the positive electrodes of the 10 sub - stacks 51 form a parallel relationship with the positive - electrode liquid inlet pipe and the positive - electrode liquid outlet pipe, and the negative electrodes of the 10 sub - stacks 51 form a parallel relationship with the negative - electrode liquid inlet pipe and the negative - electrode liquid outlet pipe. Thus, a stack with a voltage of 500V and a power of 100kW is formed. The other structures of this flow - battery system are the same as those in Example 1.

[0069] When this flow - battery system is charged from 0SOC, it is adjusted by four pumps together. The positive - and negative - electrode return - liquid ratio rapidly decreases from a maximum of 99% and finally stabilizes at around 30%. When approaching 100SOC, the return - liquid ratio drops to 0.

[0070] When this flow - battery system is discharged from 100SOC, the positive - and negative - electrode return - liquid ratio rapidly decreases from a maximum of 99% and finally stabilizes at around 30%. When approaching 10% SOC, the return - liquid ratio drops to 0.

[0071] When this flow - battery system is charged and discharged, its voltage and current are relatively stable without sudden changes. Moreover, the liquid - circulation power of this flow - battery system decreases by 20% - 40% compared with the power without a short - cycle channel, thus being able to save the electric energy required for electrolyte circulation.

[0072] Example 3

[0073] This embodiment provides a flow battery system with several sub-stacks and two sets of short-circuit pipes. The flow battery is an iron-chromium flow battery energy storage system, and its structure is as shown in Figure 3 shown.

[0074] The stack of this flow battery system is composed of 20 sub-stacks. The voltage of a single sub-stack is 50V and the power is 10kw. Among them, the 20 sub-stacks are divided into the first stack group 501 and the second stack group 502. And there are provided a first positive electrode inlet pipe 901, a first positive electrode outlet pipe 801, a first negative electrode inlet pipe 1101, a first negative electrode outlet pipe 1001, a second positive electrode inlet pipe 902, a second positive electrode outlet pipe 802, a second negative electrode inlet pipe 1102, a second negative electrode outlet pipe 1002, a first positive electrode short-circuit pipe 1201, a first negative electrode short-circuit pipe 1301, a second positive electrode short-circuit pipe 1202, a second negative electrode short-circuit pipe 1302, a first positive electrode short-circuit pump 201, a first negative electrode short-circuit pump 101, a second positive electrode short-circuit pump 202, a second negative electrode short-circuit pump 102, a positive electrode long-circuit pump 4, and a negative electrode long-circuit pump 6;

[0075] The positive electrodes of the sub-stacks in the first stack group 501 are connected to the first positive electrode inlet pipe 901 and the first positive electrode outlet pipe 801, and the negative electrodes of the sub-stacks in the first stack group 501 are connected to the first negative electrode inlet pipe 1101 and the first negative electrode outlet pipe 1001. The circuits of the 10 sub-stacks in the first stack group 501 are connected in series and the liquid paths are connected in parallel. That is, the positive electrodes of the 10 sub-stacks form a parallel relationship between the first positive electrode inlet pipe 901 and the first positive electrode outlet pipe 801, and the negative electrodes of the 10 sub-stacks form a parallel relationship between the first negative electrode inlet pipe 1101 and the first negative electrode outlet pipe 1001. Thus, a combined stack with a voltage of 500V and a power of 100kw is formed;

[0076] The inlet of the positive electrode of the first stack group 501 is communicated with the outlet of the positive electrode storage tank 3 through the first positive electrode inlet pipe 901, and the outlet of the positive electrode of the first stack group 501 is communicated with the inlet of the positive electrode storage tank 3 through the first positive electrode outlet pipe 801;

[0077] The inlet of the negative electrode of the first stack group 501 is communicated with the outlet of the negative electrode storage tank 7 through the first positive electrode inlet pipe 901, and the outlet of the negative electrode of the first stack group 501 is communicated with the inlet of the negative electrode storage tank 7 through the first negative electrode outlet pipe 1001;

[0078] The outlet of the positive electrode of the first stack group 501 and the inlet of the positive electrode of the first stack group 501 are communicated through the first positive electrode short-circuit pipe 1201;

[0079] The outlet of the negative electrode of the first stack group 501 and the inlet of the negative electrode of the first stack group 501 are communicated through the first negative electrode short-circuit pipe 1301;

[0080] The positive electrode liquid storage tank 3 and the first positive electrode short - circulation pipe 1201 form a parallel positional relationship between the first positive electrode liquid inlet pipe 901 and the first positive electrode liquid outlet pipe 801. Moreover, the first positive electrode short - circulation pipe 1201 is closer to the positive electrode of the first stack group 501 than the positive electrode liquid storage tank 3. That is, compared with the connection point of the positive electrode liquid storage tank 3 and the first positive electrode liquid outlet pipe 801 (i.e., the inlet of the positive electrode liquid storage tank 3), the connection point of the first positive electrode short - circulation pipe 1201 and the first positive electrode liquid outlet pipe 801 is closer to the outlet of the positive electrode of the first stack group 501. Compared with the connection point of the positive electrode liquid storage tank 3 and the first positive electrode liquid inlet pipe 901 (i.e., the outlet of the positive electrode liquid storage tank 3), the connection point of the first positive electrode short - circulation pipe 1201 and the first positive electrode liquid inlet pipe 901 is closer to the inlet of the positive electrode of the first stack group 501;

[0081] The negative electrode liquid storage tank 7 and the first negative electrode short - circulation pipe 1301 form a parallel positional relationship between the negative electrode liquid inlet pipe and the first negative electrode liquid outlet pipe 1001. Moreover, the first negative electrode short - circulation pipe 1301 is closer to the negative electrode of the first stack group 501 than the negative electrode liquid storage tank 7. That is, compared with the connection point of the negative electrode liquid storage tank 7 and the first negative electrode liquid outlet pipe 1001 (i.e., the inlet of the negative electrode liquid storage tank 7), the connection point of the first negative electrode short - circulation pipe 1301 and the first negative electrode liquid outlet pipe 1001 is closer to the outlet of the negative electrode of the first stack group 501. Compared with the connection point of the negative electrode liquid storage tank 7 and the first negative electrode liquid inlet pipe 1101 (i.e., the outlet of the negative electrode liquid storage tank 7), the connection point of the first negative electrode short - circulation pipe 1301 and the first negative electrode liquid inlet pipe 1101 is closer to the inlet of the negative electrode of the first stack group 501;

[0082] The distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the first stack group 501 through the first positive electrode short - circulation pipe 1201 to the inlet of the positive electrode of the first stack group 501 < the distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the first stack group 501 through the positive electrode liquid storage tank 3 to the inlet of the positive electrode of the first stack group 501;

[0083] The distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the first stack group 501 through the first negative electrode short - circulation pipe 1301 to the inlet of the negative electrode of the first stack group 501 < the distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the first stack group 501 through the negative electrode liquid storage tank 7 to the inlet of the negative electrode of the first stack group 501;

[0084] The positive electrodes of the individual sub-stacks in the second stack group 502 are connected to the second positive inlet pipe 902 and the second positive outlet pipe 802, and the negative electrodes of the individual sub-stacks in the second stack group 502 are connected to the second negative inlet pipe 1102 and the second negative outlet pipe 1002; the circuits of the 10 sub-stacks in the second stack group 502 are connected in series and the liquid paths are connected in parallel, that is, the positive electrodes of the 10 sub-stacks form a parallel relationship between the second positive inlet pipe 902 and the second positive outlet pipe 802, and the negative electrodes of the 10 sub-stacks form a parallel relationship between the second negative inlet pipe 1102 and the second negative outlet pipe 1002, thereby forming a combined stack with a voltage of 500V and a power of 100kw;

[0085] The inlet of the positive electrode of the second stack group 502 is communicated with the outlet of the positive electrode liquid storage tank 3 through the second positive inlet pipe 902, and the outlet of the positive electrode of the second stack group 502 is communicated with the inlet of the positive electrode liquid storage tank 3 through the second positive outlet pipe 802;

[0086] The inlet of the negative electrode of the second stack group 502 is communicated with the outlet of the negative electrode liquid storage tank 7 through the second positive inlet pipe 902, and the outlet of the negative electrode of the second stack group 502 is communicated with the inlet of the negative electrode liquid storage tank 7 through the second negative outlet pipe 1002;

[0087] The outlet of the positive electrode of the second stack group 502 and the inlet of the positive electrode of the second stack group 502 are communicated through the second positive short-circuit pipe 1202;

[0088] The outlet of the negative electrode of the second stack group 502 and the inlet of the negative electrode of the second stack group 502 are communicated through the second negative short-circuit pipe 1302;

[0089] The positive electrode liquid storage tank 3 and the second positive short-circuit pipe 1202 form a parallel positional relationship between the second positive inlet pipe 902 and the second positive outlet pipe 802, and the second positive short-circuit pipe 1202 is closer to the positive electrode of the second stack group 502 than the positive electrode liquid storage tank 3, that is, compared with the connection point of the positive electrode liquid storage tank 3 and the second positive outlet pipe 802 (i.e., the inlet of the positive electrode liquid storage tank 3), the connection point of the second positive short-circuit pipe 1202 and the second positive outlet pipe 802 is closer to the outlet of the positive electrode of the second stack group 502, and compared with the connection point of the positive electrode liquid storage tank 3 and the second positive inlet pipe 902 (i.e., the outlet of the positive electrode liquid storage tank 3), the connection point of the second positive short-circuit pipe 1202 and the second positive inlet pipe 902 is closer to the inlet of the positive electrode of the second stack group 502;

[0090] The negative electrode liquid storage tank 7 and the second negative electrode short circulation pipe 1302 form a parallel positional relationship between the negative electrode liquid inlet pipe and the second negative electrode liquid outlet pipe 1002. Moreover, the second negative electrode short circulation pipe 1302 is closer to the negative electrode of the second fuel cell stack group 502 than the negative electrode liquid storage tank 7. That is, compared with the connection point of the negative electrode liquid storage tank 7 and the second negative electrode liquid outlet pipe 1002 (i.e., the inlet of the negative electrode liquid storage tank 7), the connection point of the second negative electrode short circulation pipe 1302 and the second negative electrode liquid outlet pipe 1002 is closer to the outlet of the negative electrode of the second fuel cell stack group 502. Compared with the connection point of the negative electrode liquid storage tank 7 and the second negative electrode liquid inlet pipe 1102 (i.e., the outlet of the negative electrode liquid storage tank 7), the connection point of the second negative electrode short circulation pipe 1302 and the second negative electrode liquid inlet pipe 1102 is closer to the inlet of the negative electrode of the second fuel cell stack group 502;

[0091] The distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the second fuel cell stack group 502 through the second positive electrode short circulation pipe 1202 to the inlet of the positive electrode of the second fuel cell stack group 502 < the distance that the positive electrode electrolyte passes from the outlet of the positive electrode of the second fuel cell stack group 502 through the positive electrode liquid storage tank 3 to the inlet of the positive electrode of the second fuel cell stack group 502;

[0092] The distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the second fuel cell stack group 502 through the second negative electrode short circulation pipe 1302 to the inlet of the negative electrode of the second fuel cell stack group 502 < the distance that the negative electrode electrolyte passes from the outlet of the negative electrode of the second fuel cell stack group 502 through the negative electrode liquid storage tank 7 to the inlet of the negative electrode of the second fuel cell stack group 502;

[0093] The main positive electrode liquid inlet pipe 90 connected to the outlet of the positive electrode liquid storage tank is divided into a first positive electrode liquid inlet pipe 901 and a second positive electrode liquid inlet pipe 902 at the first branch point 14, and then are respectively connected to the positive electrode inlets of each sub - fuel cell stack; the positive electrode outlets of each sub - fuel cell stack are respectively connected to the first positive electrode liquid outlet pipe 801 and the second positive electrode liquid outlet pipe 802, and then the first positive electrode liquid outlet pipe 801 and the second positive electrode liquid outlet pipe 802 converge at the first convergence point 16 into the main positive electrode liquid outlet pipe 80, and then enter the positive electrode liquid storage tank;

[0094] The main negative electrode liquid inlet pipe 110 connected to the outlet of the negative electrode liquid storage tank is divided into a first negative electrode liquid inlet pipe 1101 and a second negative electrode liquid inlet pipe 1102 at the second branch point 15, and then are respectively connected to the negative electrode inlets of each sub - fuel cell stack; the negative electrode outlets of each sub - fuel cell stack are respectively connected to the first negative electrode liquid outlet pipe 1001 and the second negative electrode liquid outlet pipe 1002, and then the first negative electrode liquid outlet pipe 1001 and the second negative electrode liquid outlet pipe 1002 converge at the second convergence point 17 into the main negative electrode liquid outlet pipe 100, and then enter the negative electrode liquid storage tank;

[0095] A positive long - circulation pump 4 is provided on the positive - liquid inlet main pipe 90 between the outlet of the positive - liquid storage tank 3 and the connection point (i.e., the first branch point 14) of the first positive - liquid inlet pipe 901 and the second positive - liquid inlet pipe 902; a negative long - circulation pump 6 is provided on the negative - liquid inlet main pipe 110 between the outlet of the negative - liquid storage tank 7 and the connection point (i.e., the second branch point 15) of the first negative - liquid inlet pipe 1101 and the second negative - liquid inlet pipe 1102; a first positive - short - circulation pump 201 is provided on the first positive - short - circulation pipe 1201, and a second positive - short - circulation pump 202 is provided on the second positive - short - circulation pipe 1202; a first negative - short - circulation pump 101 is provided on the first negative - short - circulation pipe 1301, and a second negative - short - circulation pump 102 is provided on the second negative - short - circulation pipe 1302;

[0096] The positive long - circulation pump 4, the first positive - short - circulation pump 201, and the second positive - short - circulation pump 202 are all booster pumps with pressure - regulating functions. By controlling their pressures, the proportion of the positive - electrode electrolyte entering the first positive - short - circulation pipe 1201 and the second positive - short - circulation pipe 1202 and the electrode liquid entering the positive - liquid storage tank 3 can be controlled. Thus, the proportion of the positive - electrode electrolyte (new liquid) entering the first positive - liquid inlet pipe 901 and the second positive - liquid inlet pipe 902 from the positive - liquid storage tank 3 and the positive - electrode liquid (return liquid) entering the positive - liquid inlet main pipe 90 from the first positive - short - circulation pipe 1201 and the second positive - short - circulation pipe 1202 can be controlled; moreover, during the working process, the pressure of the booster pump can be adjusted as needed to real - time control the proportion of the above - mentioned new liquid and return liquid;

[0097] The negative long - circulation pump 6, the first negative - short - circulation pump 101, and the second negative - short - circulation pump 102 are all booster pumps with pressure - regulating functions. By controlling their pressures, the proportion of the negative - electrode electrolyte entering the first negative - short - circulation pipe 1301 and the second negative - short - circulation pipe 1302 and the electrode liquid entering the negative - liquid storage tank 7 can be controlled. Thus, the proportion of the negative - electrode electrolyte (new liquid) entering the first negative - liquid inlet pipe 1101 and the second negative - liquid inlet pipe 1102 from the negative - liquid storage tank 7 and the negative - electrode liquid (return liquid) entering the negative - liquid inlet main pipe 110 from the first negative - short - circulation pipe 1301 and the second negative - short - circulation pipe 1302 can be controlled; moreover, during the working process, the pressure of the booster pump can be adjusted as needed to real - time control the proportion of the above - mentioned new liquid and return liquid.

[0098] When the flow - battery system is charged from 0 SOC, the proportion of the positive and negative return liquids rapidly decreases from a maximum of 99% and finally stabilizes at around 20%. When approaching 100 SOC, the return - liquid proportion drops to 0.

[0099] When the flow - battery system is discharged from 100 SOC, the proportion of the positive and negative return liquids rapidly decreases from a maximum of 99% and finally stabilizes at around 20%. When approaching 10 SOC, the return - liquid proportion drops to 0.

[0100] When the flow battery system is charging and discharging, the voltage and current are both relatively stable without sudden changes, and the liquid circulation power of the battery system decreases by 15%-30% compared with the power without the short-circuiting device. Others are the same as in Embodiment 1 and will not be described herein again.

[0101] Based on the disclosure and teachings of the above specification, those skilled in the art of the present utility model can also make changes and modifications to the above embodiments. Therefore, the present utility model is not limited to the above specific embodiments, and any obvious improvements, substitutions or variations made by those skilled in the art on the basis of the present utility model fall within the protection scope of the present utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present utility model.

Claims

1. A liquid flow battery system, comprising a battery stack, a positive electrode liquid storage device, a negative electrode liquid storage device, a positive electrode liquid inlet channel, a positive electrode liquid outlet channel, a negative electrode liquid inlet channel, and a negative electrode liquid outlet channel; the inlet and outlet of the positive electrode of the battery stack are respectively connected to the positive electrode liquid inlet channel and the positive electrode liquid outlet channel; the inlet and outlet of the negative electrode of the battery stack are respectively connected to the negative electrode liquid inlet channel and the negative electrode liquid outlet channel; Features: The liquid flow battery system also includes a positive electrode short circulation channel, the positive electrode storage device and the positive electrode short circulation channel are connected in parallel between the positive electrode liquid inlet channel and the positive electrode liquid outlet channel, and the positive electrode short circulation channel is closer to the positive electrode of the battery stack than the positive electrode storage device; and / or, the liquid flow battery system also includes a negative electrode short circulation channel, the negative electrode storage device and the negative electrode short circulation channel are connected in parallel between the negative electrode liquid inlet channel and the negative electrode liquid outlet channel, and the negative electrode short circulation channel is closer to the negative electrode of the battery stack than the negative electrode storage device.

2. The liquid flow battery system according to claim 1, characterized in that: The distance traveled by the positive electrode electrolyte from the outlet of the positive electrode of the stack through the positive electrode short circulation channel to the inlet of the positive electrode of the stack is less than the distance traveled by the positive electrode electrolyte from the outlet of the positive electrode of the stack through the positive electrode storage device to the inlet of the positive electrode of the stack; The distance traveled by the negative electrode electrolyte from the outlet of the negative electrode of the battery stack through the negative electrode short circulation channel to the inlet of the negative electrode of the battery stack is less than the distance traveled by the negative electrode electrolyte from the outlet of the negative electrode of the battery stack through the negative electrode storage device to the inlet of the negative electrode of the battery stack.

3. The liquid flow battery system according to claim 1 or 2, characterized in that: The flow battery system also includes a positive electrode long circulation pump and a negative electrode long circulation pump; The positive electrode long circulation pump is arranged at the outlet of the positive electrode liquid storage device; The negative electrode long circulation pump is arranged at the outlet of the negative electrode liquid storage device.

4. The liquid flow battery system according to claim 3, characterized in that: The positive electrode long circulation pump is arranged between the outlet of the positive electrode liquid storage device and the connection between the positive electrode short circulation channel and the positive electrode liquid inlet channel; The negative electrode long circulation pump is arranged between the outlet of the negative electrode liquid storage device and the connection between the negative electrode short circulation channel and the negative electrode liquid inlet channel.

5. The liquid flow battery system according to claim 1 or 2, characterized in that: The liquid flow battery system also includes a positive electrode short circulation pump and a negative electrode short circulation pump; The positive electrode short circulation pump is arranged on the positive electrode short circulation channel; The negative electrode short circulation pump is arranged on the negative electrode short circulation channel.

6. The liquid flow battery system according to claim 1 or 2, characterized in that: The battery stack includes a plurality of sub-battery stacks whose circuits are connected in series and whose liquid circuits are connected in parallel.

7. The liquid flow battery system according to claim 1 or 2, characterized in that: The battery stack includes a plurality of sub-battery stack groups connected in parallel with each other; Among them, each of the sub-stack groups includes a number of sub-stacks with circuits connected in series and liquid circuits connected in parallel, as well as a positive electrode liquid inlet sub-channel, a positive electrode liquid outlet sub-channel, a negative electrode liquid inlet sub-channel, a negative electrode liquid outlet sub-channel, a positive electrode short cycle sub-channel, and a negative electrode short cycle sub-channel. The positive electrode short cycle sub-channel is connected between the positive electrode liquid inlet sub-channel and the positive electrode liquid outlet sub-channel, and the negative electrode short cycle sub-channel is connected between the negative electrode liquid inlet sub-channel and the negative electrode liquid outlet sub-channel.

8. The liquid flow battery system according to claim 1 or 2, characterized in that: The liquid flow battery system is one of an iron-chromium liquid flow battery, an all-vanadium liquid flow battery, a zinc-bromine liquid flow battery, a zinc-iron liquid flow battery, an all-iron liquid flow battery, a zinc-nickel liquid flow battery, and an organic liquid flow battery.

9. The liquid flow battery system according to claim 3, characterized in that: The positive electrode long circulation pump and the negative electrode long circulation pump are respectively booster pumps with a pressure regulating function.

10. The liquid flow battery system according to claim 5, characterized in that: The positive short-circuit pump and the negative short-circuit pump are respectively booster pumps with a pressure regulating function.

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