Coupling system of flow battery and compressed air energy storage and peak regulation method

Abstract

The invention relates to a flow battery and compressed air energy storage coupling system and a peak regulation method. The flow battery and compressed air energy storage coupling system comprises a flow battery subsystem, a compressed air energy storage subsystem and a heat management and control subsystem. The flow battery subsystem comprises a capacity unit, a power unit and a power unit. The compressed air energy storage subsystem comprises an air storage and release unit and a heat storage and cold storage unit. The heat management and control subsystem comprises a heat storage and cold storage unit and a heat exchange network, a power unit in the flow battery subsystem drives electrolyte to circulate between a capacity unit and the power unit through the heat exchange network, and the heat exchange network exchanges heat with the heat storage and cold storage unit through an inter-system heat exchanger; the flow battery subsystem and the compressed air energy storage subsystem are used for coordinating heat complementation between the flow battery subsystem and the compressed air energy storage subsystem, so that electrolyte circulating between the electrolyte storage device and the electric pile device can be at a relatively proper temperature, the flow battery can maintain relatively high operation performance, a heater and a refrigerator do not need to be additionally arranged, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of energy utilization, in particular, to a coupling system of a flow battery and compressed air energy storage and a peak shaving method. BACKGROUND

[0002] The flow battery is a high-performance electrochemical energy storage technology that uses positive and negative electrolyte to be separated and circulated. The flow battery can be used not only as an energy storage device for solar and wind power generation processes, but also for grid peak shaving. The flow battery system mainly consists of an electric pile, a liquid storage tank, a circulating pump, a heat exchanger and a control device. The flow battery system has the characteristics of intrinsic safety, high capacity, fast response speed, long cycle service life and the like. The temperature of the electrolyte in the flow battery directly affects the chemical reaction speed in the electric pile and the ion mobility therein. Generally speaking, increasing the temperature can accelerate the chemical reaction of the battery, thereby improving the output performance of the battery. However, too high temperature can cause the electrolyte to evaporate and the internal pressure of the battery to increase, thereby affecting the performance of the battery. SUMMARY

[0003] The purpose of the present disclosure is to provide a coupling system of a flow battery and compressed air energy storage and a peak shaving method, which can heat exchange the electrolyte entering the electric pile to keep the electrolyte at a more suitable temperature, and use the compressed air energy storage system for heat exchange, so that the heat of the flow battery and the compressed air energy storage is complementary, so that the energy can be reasonably utilized, to at least partially solve the above technical problems.

[0004] To achieve the above purpose, the first aspect of the present disclosure provides a coupling system of a flow battery and compressed air energy storage, comprising: a flow battery subsystem, comprising a capacity unit for storing electrolyte, a power unit for mutual conversion of chemical energy and electrical energy, and a power unit for circulating electrolyte between the capacity unit and the power unit; a compressed air energy storage subsystem, comprising a gas storage unit and a heat storage and cold storage unit, the gas storage unit is used for compressed storage and expansion release of air, and the heat storage and cold storage unit is used for heat exchange with the gas storage unit; and a heat control subsystem, comprising the heat storage and cold storage unit and a heat exchange network, the electrolyte in the flow battery subsystem circulates between the capacity unit and the power unit through the heat exchange network, the heat exchange network comprises an inter-system heat exchanger, the heat exchange network exchanges heat with the heat storage and cold storage unit through the inter-system heat exchanger, and is used for coordinating the heat complementarity between the flow battery subsystem and the compressed air energy storage subsystem.

[0005] Optionally, the inter-system heat exchanger comprises a first inter-system heat exchanger and a second inter-system heat exchanger, each of the first inter-system heat exchanger and the second inter-system heat exchanger comprises a battery side heat exchange flow path and an air energy storage side heat exchange flow path, the capacity unit comprises an electrolyte storage device, the power unit comprises a stack device, an outlet of the electrolyte storage device is in communication with an inlet of the stack device through the battery side heat exchange flow path of the first inter-system heat exchanger, an outlet of the stack device is in communication with an inlet of the electrolyte storage device through the battery side heat exchange flow path of the second inter-system heat exchanger, and the air energy storage side heat exchange flow paths of the first inter-system heat exchanger and the second inter-system heat exchanger are in communication with the heat storage and heat release unit.

[0006] Optionally, the electrolyte storage device comprises a positive electrolyte storage tank and a negative electrolyte storage tank, the battery side heat exchange flow path of the first inter-system heat exchanger comprises a first heat exchange flow path and a second heat exchange flow path, an outlet of the positive electrolyte storage tank is in communication with a positive electrolyte inlet of the stack device through the first heat exchange flow path, and an outlet of the negative electrolyte storage tank is in communication with a negative electrolyte inlet of the stack device through the second heat exchange flow path.

[0007] Optionally, the heat exchange network comprises a positive electrolyte first liquid supply path and a positive electrolyte second liquid supply path, the positive electrolyte first liquid supply path is used for connecting an outlet of the positive electrolyte storage tank and a positive electrolyte inlet of the stack device, so that the positive electrolyte in the positive electrolyte storage tank can be transported to the stack device through the positive electrolyte first liquid supply path, a first circulating pump and a first control valve are arranged on the positive electrolyte first liquid supply path in sequence along a liquid flow direction, the first control valve can control on-off of the positive electrolyte first liquid supply path, the first heat exchange flow path is connected in parallel with the first control valve through the positive electrolyte second liquid supply path, and the positive electrolyte second liquid supply path on both sides of the first heat exchange flow path is respectively provided with a second control valve and a third control valve capable of controlling on-off of the positive electrolyte second liquid supply path.

[0008] Optionally, the heat exchange network comprises a first negative electrolyte supply path and a second negative electrolyte supply path, the first negative electrolyte supply path is used to connect the liquid outlet of the negative electrolyte storage tank and the negative electrolyte inlet of the stack device, so that the negative electrolyte in the negative electrolyte storage tank can be transported into the stack device through the first negative electrolyte supply path, the second circulating pump and the fourth control valve are arranged on the first negative electrolyte supply path in sequence along the flow direction, the fourth control valve can control the on-off of the first negative electrolyte supply path, the second heat exchange flow path is connected in parallel with the fourth control valve through the second negative electrolyte supply path, and the fifth control valve and the sixth control valve capable of controlling the on-off of the second negative electrolyte supply path are arranged on the second negative electrolyte supply path on both sides of the second heat exchange flow path.

[0009] Optionally, the battery side heat exchange flow path of the second inter-system heat exchanger comprises a third heat exchange flow path and a fourth heat exchange flow path, the positive electrolyte outlet of the stack device is connected with the return port of the positive electrolyte storage tank through the third heat exchange flow path, and the negative electrolyte outlet of the stack device is connected with the return port of the negative electrolyte storage tank through the fourth heat exchange flow path.

[0010] Optionally, the heat exchange network comprises a first negative electrolyte supply path and a second negative electrolyte supply path, the first negative electrolyte supply path is used to connect the liquid outlet of the negative electrolyte storage tank and the negative electrolyte inlet of the stack device, so that the negative electrolyte in the negative electrolyte storage tank can be transported into the stack device through the first negative electrolyte supply path, the second circulating pump and the fourth control valve are arranged on the first negative electrolyte supply path in sequence along the flow direction, the fourth control valve can control the on-off of the first negative electrolyte supply path, the second heat exchange flow path is connected in parallel with the fourth control valve through the second negative electrolyte supply path, and the fifth control valve and the sixth control valve capable of controlling the on-off of the second negative electrolyte supply path are arranged on the second negative electrolyte supply path on both sides of the second heat exchange flow path.

[0011] Optionally, the heat exchange network comprises a first negative electrolyte supply path and a second negative electrolyte supply path, the first negative electrolyte supply path is used to connect the liquid outlet of the negative electrolyte storage tank and the negative electrolyte inlet of the stack device, so that the negative electrolyte in the negative electrolyte storage tank can be transported into the stack device through the first negative electrolyte supply path, the second circulating pump and the fourth control valve are arranged on the first negative electrolyte supply path in sequence along the flow direction, the fourth control valve can control the on-off of the first negative electrolyte supply path, the second heat exchange flow path is connected in parallel with the fourth control valve through the second negative electrolyte supply path, and the fifth control valve and the sixth control valve capable of controlling the on-off of the second negative electrolyte supply path are arranged on the second negative electrolyte supply path on both sides of the second heat exchange flow path.

[0012] Optionally, the heat storage and cold storage unit comprises a cooler group for radiating heat from the gas in the compressor group, a reheater group for heating the gas in the expander group, a first heat storage tank, and a second heat storage tank, the first heat storage tank being in communication with the inlet of the reheater group to provide heat transfer medium to the reheater group, and the second heat storage tank being in communication with the inlet of the cooler group to provide heat transfer medium to the cooler group; the outlet of the reheater group is in communication with the second heat storage tank, and the outlet of the cooler group is in communication with the first heat storage tank. The two ends of the air energy storage side heat exchange flow path of the first inter-system heat exchanger are in communication with the first heat storage tank and the second heat storage tank, respectively, and the two ends of the air energy storage side heat exchange flow path of the second inter-system heat exchanger are in communication with the first heat storage tank and the second heat storage tank, respectively.

[0013] The second aspect of the present disclosure provides a peak shaving method for peak shaving of a power grid by the coupling system of the hydraulic battery and the compressed air energy storage according to the first aspect of the present disclosure, and the method comprises: obtaining a peak shaving signal; in response to the peak shaving signal, simultaneously starting the flow battery subsystem and the compressed air energy storage subsystem, so that the flow battery subsystem first stores / releases energy, and after the compressed air energy storage subsystem operates to full load, the flow battery subsystem and the compressed air energy storage subsystem simultaneously store / release energy.

[0014] Through the above technical solution, the electrolyte in the flow battery subsystem circulates between the capacity unit and the power unit through the heat exchange network, the heat exchange network comprises an inter-system heat exchanger, and the heat exchange network exchanges heat with the heat storage and cold storage unit through the inter-system heat exchanger, so as to coordinate the heat complementation between the flow battery subsystem and the compressed air energy storage subsystem, so that the electrolyte entering the power unit from the capacity unit or the electrolyte entering the capacity unit from the power unit is at a relatively appropriate temperature. For example, the electrolyte entering the power unit from the capacity unit can be heated through the inter-system heat exchanger of the heat exchange network before entering the power unit, so that the electrolyte entering the power unit is at an appropriate temperature, thereby enabling the battery to maintain high operating performance. And the electrolyte entering the power unit is heated by the air energy storage subsystem, without the need for additional heaters and coolers, saving costs, and enabling the heat complementation between the two, thereby more effectively utilizing the heat between the flow battery subsystem and the compressed air energy storage subsystem.

[0015] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram illustrating the working principle of a coupling system of a flow battery and compressed air energy storage provided in an exemplary embodiment of this disclosure; Figure 2 This is a diagram showing the flow path of the medium in each flow path when heating the positive and negative electrolytes delivered from the positive and negative electrolyte storage tanks to the fuel cell stack device, provided in an exemplary embodiment of this disclosure; wherein, the flow path of the medium from the fuel cell stack device to the positive and negative electrolyte storage tanks is not shown. Figure 3 This is a diagram showing the flow path of the medium in each flow path during the cooling of the positive and negative electrolytes transported from the positive and negative electrolyte storage tanks to the fuel cell stack device, provided in an exemplary embodiment of this disclosure; wherein, the flow path of the medium transported by the fuel cell stack device to the positive and negative electrolyte storage tanks is not shown. Figure 4 This is a diagram showing the flow path of the medium in each flow path when the positive electrolyte storage tank and the negative electrolyte storage tank directly supply the positive electrolyte and the negative electrolyte to the fuel cell stack without heat exchange, according to an exemplary embodiment of this disclosure; wherein, the flow path of the medium from the fuel cell stack to the positive electrolyte storage tank and the negative electrolyte storage tank is not shown. Figure 5 This is a diagram showing the flow path of the medium in each flow path during the cooling of the positive and negative electrolytes transported from the fuel cell stack to the positive and negative electrolyte storage tanks, provided in an exemplary embodiment of this disclosure; wherein, the flow path of the medium when the positive and negative electrolytes are transported from the positive and negative electrolyte storage tanks to the fuel cell stack is not shown; Figure 6 This is a diagram showing the flow path of the medium in each flow path when the positive electrode electrolyte and negative electrode electrolyte are directly transported to the positive electrode electrolyte storage tank and the negative electrode electrolyte storage tank by the fuel cell stack device, provided in an exemplary embodiment of this disclosure; wherein, the flow path of the medium when the positive electrode electrolyte and negative electrode electrolyte storage tank are transported to the fuel cell stack device is not shown; Figure 7 This is a flowchart of the peak-shaving method provided in an exemplary embodiment of this disclosure.

[0017] Explanation of reference numerals in the attached figures 1-Electric motor; 2-Compressor unit; 201-First compressor; 202-Second compressor; 203-Third compressor; 204-Fourth compressor; 3-Gas storage chamber; 4-Expander unit; 401-First expander; 402-Second expander; 403-Third expander; 404-Fourth expander; 5-Generator; 6-Cooler unit; 601-First cooler; 602-Second cooler; 603-Third cooler; 604-Fourth cooler; 7-Reheater unit; 701-First reheater; 702-Second reheater; 703-Third reheater; 704-Fourth reheater; 8-Inter-system heat exchanger; 81-First inter-system heat exchanger; 82-Second inter-system heat exchanger; 8a-Air energy storage side heat exchange flow path; 8 b - Battery-side heat exchange flow path; 81b - First heat exchange flow path; 82b - Second heat exchange flow path; 83b - Third heat exchange flow path; 84b - Fourth heat exchange flow path; 10 - First heat storage tank; 11 - Second heat storage tank; 12 - Capacity unit; 120 - Electrolyte storage device; 121 - Positive electrode electrolyte storage tank; 122 - Negative electrode electrolyte storage tank; 13 - Power unit; 131 - First circulation pump; 132 - Second circulation pump; 14 - Power unit; 140 - Stack device; 15 - First control valve; 16 - Second control valve; 17 - Third control valve; 18 - Fourth control valve; 19 - Fifth control valve; 20 - Sixth control valve; 21 - Seventh control valve; 22 - Eighth control valve; 23 - Ninth control valve; 24 - Tenth control valve; 1a - First supply circuit for positive electrode electrolyte; 1b - Second supply circuit for positive electrode electrolyte; 1c - First return circuit for positive electrode electrolyte; 1d - Second return circuit for positive electrode electrolyte; 2a - First supply circuit for negative electrode electrolyte; 2b - Second supply circuit for negative electrode electrolyte; 2c - First return circuit for negative electrode electrolyte; 2d - Second return circuit for negative electrode electrolyte. Detailed Implementation

[0018] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0019] In this disclosure, unless otherwise stated, the terms "first," "second," etc., are used to distinguish one element from another and do not have sequential or material significance. Furthermore, in the description with reference to the accompanying drawings, the same reference numerals in different drawings denote the same elements.

[0020] The first aspect of this disclosure provides a coupling system for a flow battery and compressed air energy storage, such as... Figures 1 to 6As shown, the system includes a flow battery subsystem, a compressed air energy storage subsystem, and a thermal management subsystem. The flow battery subsystem includes a capacity unit 12 for storing electrolyte, a power unit 14 for converting chemical energy into electrical energy, and a power unit 13 for driving the electrolyte to circulate between the capacity unit 12 and the power unit 14. The compressed air energy storage subsystem includes a gas storage / release unit and a heat / cold storage unit. The gas storage / release unit is used for the compression storage and expansion release of air, while the heat / cold storage unit exchanges heat with the gas storage / release unit to cool the air during compressed air energy storage or to heat the air during expansion release. The thermal management subsystem includes a heat / cold storage unit and a heat exchange network. The electrolyte in the flow battery subsystem circulates between the capacity unit 12 and the power unit 14 through the heat exchange network and is driven by the power unit 13. The heat exchange network includes an inter-system heat exchanger 8, which exchanges heat with the thermal and cold storage units to coordinate the heat complementarity between the flow battery subsystem and the compressed air energy storage subsystem. This ensures that the electrolyte flowing from the capacity unit 12 to the power unit 14, or vice versa, is at a suitable temperature. For example, the electrolyte flowing from the capacity unit 12 to the power unit 14 can be heat-exchanged through the inter-system heat exchanger 8 before entering the power unit 14, ensuring that the electrolyte entering the power unit 14 is at a suitable temperature, thereby allowing the battery to maintain high operating performance. Furthermore, heat exchange between the electrolyte flowing into the power unit 14 and the air energy storage subsystem eliminates the need for separate heaters and coolers, saving costs and making more efficient use of the heat between the two systems.

[0021] In the above embodiments, the thermal management subsystem coordinates the electrolyte in the flow battery subsystem and the thermal and cold storage units in the compressed air energy storage subsystem to achieve thermal complementarity. It can also regulate the operation of the two subsystems. For example, the start-up and shutdown of the flow battery subsystem and the compressed air energy storage subsystem, as well as the dynamic response process of the two subsystems when used for peak shaving of the power system, can all be indirectly regulated by the thermal management subsystem coordinating the thermal complementarity of the thermal and cold storage units in the flow battery subsystem and the compressed air energy storage subsystem.

[0022] In other possible implementations, the heat from the flow battery subsystem can be used to assist in the startup of the compressed air energy storage subsystem, for example, to heat the control cabinet in the compressed air energy storage subsystem, which will not be elaborated here.

[0023] Furthermore, the thermal management subsystem includes thermal and cold storage units that are the same as those in the compressed air energy storage subsystem. It utilizes the existing devices in the compressed air energy storage subsystem. The heat exchange network in the thermal management subsystem can exchange heat with the thermal and cold storage units in the compressed air energy storage subsystem through the inter-system heat exchanger 8, and can also be used to supply electrolyte in the flow battery subsystem for circulation between the capacity unit 12 and the power unit 14. One heat exchange network has multiple uses, which can reduce the use of various devices in the coupled system, save costs, and make the structure of the coupled system more streamlined.

[0024] In some embodiments, the inter-system heat exchanger 8 includes a first inter-system heat exchanger 81 and a second inter-system heat exchanger 82. Both the first inter-system heat exchanger 81 and the second inter-system heat exchanger 82 include a battery-side heat exchange flow path 8b and an air energy storage-side heat exchange flow path 8a. The capacity unit 12 includes an electrolyte storage device 120, and the power unit 14 includes a fuel cell stack 140. The outlet of the electrolyte storage device 120 can be connected to the inlet of the fuel cell stack 140 through the battery-side heat exchange flow path of the first inter-system heat exchanger 81, so that the electrolyte can be heat exchanged through the inter-system heat exchanger 8 before being introduced into the fuel cell stack 140, so that the electrolyte is at a suitable reaction temperature before being introduced into the fuel cell stack 140, thereby accelerating the chemical reaction of the electrolyte. The outlet of the fuel cell stack 140 is connected to the inlet of the electrolyte storage device 120 via the battery-side heat exchange path 8b of the second inter-system heat exchanger 82. This allows the electrolyte in the fuel cell stack 140 to undergo heat exchange in the second inter-system heat exchanger 82 before being introduced into the electrolyte storage device 120, ensuring that the electrolyte is at a suitable temperature before being introduced into the electrolyte storage device 120. The air storage-side heat exchange path 8a of both the first inter-system heat exchanger 81 and the second inter-system heat exchanger 82 is connected to the thermal and cold storage unit, enabling both the first and second inter-system heat exchangers 81 and 82 to exchange heat with the electrolyte flowing through the thermal and cold storage unit and the heat exchange network.

[0025] The compressed air energy storage subsystem is a physical energy storage technology that utilizes off-peak electricity or curtailed wind and solar power to compress air, releasing the compressed air during peak grid periods to drive an expander to generate electricity. The subsystem includes a motor 1, a compressor unit 2, an air storage chamber 3, an expander unit 4, and a generator 5. When the subsystem stores compressed air energy, the motor 1 consumes off-peak electricity or curtailed wind and solar power to drive the compressor unit 2, compressing the air from ambient pressure and low temperature to high temperature and high pressure. The high-temperature, high-pressure gas is then cooled by a thermal and cold storage unit and stored in the air storage chamber 3. When the compressed air expands and releases energy, the low-temperature, high-pressure gas in the air storage chamber 3 is heated by the thermal and cold storage unit before being introduced into the expander unit 4. The expander unit 4 rotates and drives the generator 5 to generate electricity, thus releasing the stored compressed air energy.

[0026] Compressed air energy storage systems have advantages such as large capacity, long service life, and good economic performance. However, compressed air energy storage systems have slow response speeds, with a normal response time of 3 to 9 minutes from 0 to 100% load, while electrochemical responses are in the order of seconds or milliseconds. By coupling the compressed air energy storage subsystem with the flow battery subsystem, both subsystems can be started simultaneously when energy storage / release is required. The flow battery subsystem prioritizes energy storage / release due to its fast response speed. Once the compressed air energy storage subsystem is running, both subsystems can simultaneously perform energy storage / release to meet the needs of applications with high transient response requirements.

[0027] In addition, the thermal and cold storage units in the compressed air energy storage subsystem exchange heat with the electrolyte in the flow battery subsystem through the inter-system heat exchanger 8 of the heat exchange network to maintain the optimal operating temperature of the electrolyte and ensure the high-performance operation of the flow battery subsystem.

[0028] In some embodiments, the thermal and cold storage unit includes a cooler assembly 6 for dissipating heat from the gas in the compressor unit 2, a reheater assembly 7 for exchanging heat with the gas in the expander unit 4, a first thermal storage tank 10, and a second thermal storage tank 11, wherein the first thermal storage tank 10 is a high-temperature thermal storage tank, and the second thermal storage tank 11 is a low-temperature thermal storage tank. The first thermal storage tank 10 is connected to the inlet of the reheater assembly 7 to provide a heat transfer medium to the reheater assembly 7 for heating the gas introduced into the expander unit 4. The outlet of the reheater assembly 7 is connected to the second thermal storage tank 11 so that the heat transfer medium in the reheater assembly 7 is discharged into the second thermal storage tank 11 after heat exchange. The second thermal storage tank 11 is connected to the inlet of the cooler assembly 6 to provide a heat transfer medium to the cooler assembly 6 for cooling the gas compressed by the compressor unit 2. The outlet of the cooler assembly 6 is connected to the first thermal storage tank 10 so that the heat transfer medium in the cooler assembly 6 after heat exchange is discharged into the first thermal storage tank 10.

[0029] In the above embodiment, compressor unit 2 includes multiple compressors, expander unit 4 includes multiple expanders, cooler unit 6 includes multiple coolers, and reheater unit 7 includes multiple reheaters. The motor 1 drives multiple compressors to rotate, forming a multi-stage compression of air. Air is sequentially fed into multiple compressors for compression. Coolers are installed between adjacent compressors to cool the compressed air before it enters the next stage compressor. The compressed gas is then cooled by the coolers before entering the air storage chamber 3. The inlet of each cooler is connected to a second heat storage tank 11, which provides a lower-temperature heat transfer medium to the cooler to cool the compressed air. The outlet of each cooler is connected to a first heat storage tank 10, allowing the heat transfer medium, which has heated up after passing through the cooler, to be discharged into the first heat storage tank 10. Figure 1 As shown, compressor unit 2 includes four compressors: compressor 201, compressor 202, compressor 203, and compressor 204. Cooler unit 6 includes four coolers: cooler 601, cooler 602, cooler 603, and cooler 604. Air is compressed sequentially by compressors 201, 202, 203, and 204 and then stored in air storage chamber 3. Coolers 601, 602, and 603 are positioned between adjacent compressors to cool the air after compression before it enters the next stage compressor. After compression by compressor 204, the compressed air is cooled by cooler 604 before entering air storage chamber 3. The second heat storage tank 11, which is a low-temperature heat storage tank connected to the cooler inlet, supplies heat transfer medium to each cooler. After being heated by the cooler, the heat transfer medium can be discharged into the first heat storage tank 10, which is a high-temperature heat storage tank. The heat transfer medium can be any suitable medium, for example, water.

[0030] Furthermore, during energy release, the compressed gas in the gas storage chamber 3 passes sequentially through multiple expanders, which drive the generator 5 to generate electricity. Before entering the expanders, the compressed air in the gas storage chamber 3 can be heated by a reheater. A reheater can be installed between adjacent expanders. The gas after passing through the previous expander can be reheated before entering the next expander. The first heat storage tank 10, constructed as a high-temperature heat storage tank, can introduce a higher-temperature heat transfer medium into the reheater. The cooled heat transfer medium after passing through the reheater can be stored in the second heat storage tank 11, constructed as a low-temperature liquid storage tank. Figure 1As shown, expander unit 4 includes four expanders: first expander 401, second expander 402, third expander 403, and fourth expander 404. Reheater unit 7 includes first reheater 701, second reheater 702, third reheater 703, and fourth reheater 704. Compressed gas exiting gas storage chamber 3 is first heated by first reheater 701, then enters first expander 401. After expansion in first expander 401, the compressed gas sequentially enters second expander 402, third expander 403, and fourth expander 404, and is then discharged from fourth expander 404. A reheater is installed between each of the two expanders, namely second reheater 702, third reheater 703, and fourth reheater 704. Compressed gas, after expansion in the previous expander, passes through the reheater before entering the next expander. The first heat storage tank 10, which is constructed as a high-temperature heat storage tank, is connected to the inlet of each reheater to provide a high-temperature heat transfer medium to the reheater; after the heat transfer medium is cooled down by the reheater, it can be discharged into the second heat storage tank 11, which is constructed as a low-temperature heat storage tank.

[0031] It should be understood that both coolers and reheaters are heat exchangers.

[0032] In some embodiments, the two ends of the air energy storage side heat exchange flow path 8a of the first inter-system heat exchanger 81 are respectively connected to the first heat storage tank 10 and the second heat storage tank 11. Depending on the actual operating conditions, the heat transfer medium can be introduced from the first heat storage tank 10 through the air energy storage side heat exchange flow path 8a of the first inter-system heat exchanger 81 into the second heat storage tank 11; or the heat transfer medium can be introduced from the second heat storage tank 11 through the air energy storage side heat exchange flow path 8a of the first inter-system heat exchanger 81 into the first heat storage tank 10.

[0033] The two ends of the air energy storage side heat exchange flow path 8a of the second system inter-heat exchanger 82 are respectively connected to the first heat storage tank 10 and the second heat storage tank 11. According to the actual operating conditions, the heat transfer medium can be introduced from the first heat storage tank 10 through the air energy storage side heat exchange flow path 8a of the second system inter-heat exchanger 82 into the second heat storage tank 11; or the heat transfer medium can be introduced from the second heat storage tank 11 through the air energy storage side heat exchange flow path 8a of the second system inter-heat exchanger 82 into the first heat storage tank 10. Among them, the first heat storage tank 10 is a high-temperature heat storage tank, and the second heat storage tank 11 is a low-temperature heat storage tank, which has been described above and will not be repeated here.

[0034] In some embodiments, the battery-side heat exchange path 8b of the first inter-system heat exchanger 81 includes a first heat exchange path 81b and a second heat exchange path 82b. The electrolyte storage device 120 includes a positive electrolyte storage tank 121 and a negative electrolyte storage tank 122. The outlet of the positive electrolyte storage tank 121 can be connected to the positive electrolyte inlet of the fuel cell stack 140 through the first heat exchange path 81b, and the outlet of the negative electrolyte storage tank 122 can be connected to the negative electrolyte inlet of the fuel cell stack 140 through the second heat exchange path 82b. The first inter-system heat exchanger 81 can simultaneously exchange heat between the positive electrolyte input from the positive electrolyte storage tank 121 to the fuel cell stack 140 and the negative electrolyte input from the negative electrolyte storage tank 122 to the fuel cell stack 140. This facilitates centralized heat exchange between the positive and negative electrolytes input to the fuel cell stack 140, resulting in a higher degree of integration and reducing the number of inter-system heat exchangers 8, thus saving costs.

[0035] In the above embodiments, the first inter-system heat exchanger 81 can be constructed as a three-pass heat exchanger. Of course, the first inter-system heat exchanger 81 is not limited to a three-pass heat exchanger, and can also be a heat exchanger with a higher tube pass, as long as it meets the function of the first inter-system heat exchanger 81.

[0036] In some embodiments, the heat exchange network includes a first positive electrolyte supply path 1a and a second positive electrolyte supply path 1b. The power unit 13 includes a first circulation pump 131. The first positive electrolyte supply path 1a connects the outlet of the positive electrolyte storage tank 121 and the inlet of the positive electrolyte in the fuel cell stack 140, so that the positive electrolyte in the positive electrolyte storage tank 121 can be transported to the fuel cell stack 140 through the first positive electrolyte supply path 1a. A first circulating pump 131 and a first control valve 15 are sequentially arranged along the liquid flow direction on the first liquid supply path 1a. The first control valve 15 can control the opening and closing of the first liquid supply path 1a for the positive electrode electrolyte. The first heat exchange flow path 81b is connected in parallel with the first control valve 15 through the second liquid supply path 1b for the positive electrode electrolyte. A second control valve 16 and a third control valve 17 that can control the opening and closing of the second liquid supply path 1b for the positive electrode electrolyte are respectively arranged on the second liquid supply path 1b on both sides of the first heat exchange flow path 81b.

[0037] In the above embodiment, the first circulating pump 131 can transport the positive electrolyte in the positive electrolyte storage tank 121 to the fuel cell stack 140 through a pipeline. The first heat exchange flow path 81b of the first inter-system heat exchanger 81 is connected in parallel with the first control valve 15 provided on the first positive electrolyte supply path 1a through the second positive electrolyte supply path 1b. A second control valve 16 and a third control valve 17 that can control the opening and closing of the second positive electrolyte supply path 1b are respectively provided on the second positive electrolyte supply path 1b on both sides of the first heat exchange flow path 81b. When the positive electrolyte is introduced into the fuel cell stack 140 through the positive electrolyte storage tank 121, the positive electrolyte can be selectively heat-exchanged before being introduced into the fuel cell stack 140 or directly introduced into the fuel cell stack 140.

[0038] When heat exchange is required for the positive electrolyte input to the fuel cell stack 140 via the first inter-system heat exchanger 81, the first control valve 15 can be closed, and the second control valve 16 and the third control valve 17 can be opened, so that the positive electrolyte input from the positive electrolyte storage tank 121 to the fuel cell stack 140 can enter the positive electrolyte inlet of the fuel cell stack 140 after passing through the first heat exchange flow path 81b. Figure 2 and Figure 3 As shown, the positive electrolyte flows from the outlet of the positive electrolyte storage tank 121 through the first circulation pump 131, the second control valve 16, the first heat exchange flow path 81b, and the third control valve 17, and then through the positive electrolyte inlet of the fuel cell stack 140 to the fuel cell stack 140. This ensures that the positive electrolyte introduced from the positive electrolyte storage tank 121 into the fuel cell stack 140 is heated through the first heat exchange flow path 81b before being introduced into the fuel cell stack 140, so that the positive electrolyte introduced into the fuel cell stack 140 is at a suitable temperature, thereby accelerating the reaction rate of the positive electrolyte.

[0039] Depending on the required positive electrolyte temperature, the flow direction of the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 can be controlled. When heating the positive electrolyte is required, the heat transfer medium can be introduced from the first heat storage tank 10 into the air storage side heat exchange path 8a of the first inter-system heat exchanger 81, and the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 is cooled by heat exchange before being introduced into the second heat storage tank 11. When cooling the positive electrolyte is required, the heat transfer medium can be introduced from the second heat storage tank 11 into the air storage side heat exchange path 8a of the first inter-system heat exchanger 81, and the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 is heated by heat exchange before being introduced into the first heat storage tank 10.

[0040] When it is not necessary to exchange heat with the positive electrolyte input to the fuel cell stack 140 through the first inter-system heat exchanger 81, the first control valve 15 can be opened and the second control valve 16 and the third control valve 17 can be closed, so that the positive electrolyte in the positive electrolyte storage tank 121 can directly enter the fuel cell stack 140 through the positive electrolyte inlet after passing through the first circulation pump 131 and the first control valve 15.

[0041] In some embodiments, the heat exchange network system includes a first negative electrolyte supply path 2a and a second negative electrolyte supply path 2b. The power unit 13 also includes a second circulation pump 132. The first negative electrolyte supply path 2a is used to connect the outlet of the negative electrolyte storage tank 122 and the inlet of the negative electrolyte in the fuel cell stack 140, so that the negative electrolyte in the negative electrolyte storage tank 122 can be transported to the fuel cell stack 140 through the first negative electrolyte supply path 2a. A second circulating pump 132 and a fourth control valve 18 are sequentially arranged along the liquid flow direction on the first liquid supply path 2a. The fourth control valve 18 can control the opening and closing of the first liquid supply path 2a of the negative electrode electrolyte. The second heat exchange flow path 82b is connected in parallel with the fourth control valve 18 through the second liquid supply path 2b of the negative electrode electrolyte. A fifth control valve 19 and a sixth control valve 20 that can control the opening and closing of the second liquid supply path 2b of the negative electrode electrolyte are respectively arranged on the second liquid supply path 2b on both sides of the second liquid supply path 82b of the negative electrode electrolyte.

[0042] In the above embodiment, the second circulating pump 132 can transport the negative electrolyte in the negative electrolyte storage tank 122 to the fuel cell stack 140 through a pipeline. The second heat exchange flow path 82b of the first system heat exchanger 81 is connected in parallel with the fourth control valve 18 provided on the first negative electrolyte supply path 2a through the second negative electrolyte supply path 2b. A fifth control valve 19 and a sixth control valve 20 are respectively provided on the second negative electrolyte supply path 2b on both sides of the second heat exchange flow path 82b, which can control the opening and closing of the second negative electrolyte supply path 2b. When the positive electrolyte is introduced into the fuel cell stack 140 through the positive electrolyte storage tank 121, the negative electrolyte can be selectively heat-exchanged and then introduced into the fuel cell stack 140 or directly introduced into the fuel cell stack 140.

[0043] When heat exchange is required for the negative electrolyte entering the fuel cell stack 140 via the first inter-system heat exchanger 81, the fourth control valve 18 can be closed, while the fifth control valve 19 and the sixth control valve 20 are opened. This allows the negative electrolyte, supplied from the negative electrolyte storage tank 122 to the fuel cell stack 140, to undergo heat exchange in the second heat exchange path 82b before being introduced into the fuel cell stack 140. Figure 2 and Figure 3As shown, the negative electrode electrolyte is introduced into the fuel cell stack 140 through the negative electrode electrolyte inlet after passing through the second circulation pump 132, the fifth control valve 19, the second heat exchange flow path 82b, and the sixth control valve 20. The negative electrode electrolyte undergoes heat exchange in the second heat exchange flow path 82b before being introduced into the fuel cell stack 140, ensuring that the negative electrode electrolyte entering the fuel cell stack 140 is at a suitable temperature, thereby accelerating the reaction rate of the electrolyte chemical reaction.

[0044] Depending on the required temperature of the negative electrode electrolyte, the flow direction of the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 can be controlled. When heating of the negative electrode electrolyte is required, the heat transfer medium can be introduced from the first heat storage tank 10 into the air storage side heat exchange path 8a of the first inter-system heat exchanger 81, and the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 is cooled by heat exchange before being introduced into the second heat storage tank 11. When cooling of the negative electrode electrolyte is required, the heat transfer medium can be introduced from the second heat storage tank 11 into the air storage side heat exchange path 8a of the first inter-system heat exchanger 81, and the heat transfer medium in the air storage side heat exchange path 8a of the first inter-system heat exchanger 81 is heated by heat exchange before being introduced into the first heat storage tank 10.

[0045] When heat exchange with the negative electrode electrolyte of the input fuel cell stack 140 is not required through the first inter-system heat exchanger 81, the fourth control valve 18 can be opened, while the fifth control valve 19 and the sixth control valve 20 are closed. Figure 4 As shown, the negative electrode electrolyte is output from the negative electrode electrolyte storage tank 122, passes through the second circulation pump 132 and the fourth control valve 18, and then enters the fuel cell stack 140 through the negative electrode electrolyte inlet.

[0046] In some embodiments, the battery-side heat exchange path of the second intersystem heat exchanger 82 includes a third heat exchange path 83b and a fourth heat exchange path 84b. The positive electrolyte outlet of the fuel cell stack 140 is connected to the return port of the positive electrolyte storage tank 121 through the third heat exchange path 83b, and the negative electrolyte outlet of the fuel cell stack 140 is connected to the return port of the negative electrolyte storage tank 122 through the fourth heat exchange path 84b.

[0047] In the above embodiments, the positive electrolyte outlet of the fuel cell stack 140 is connected to the return port of the positive electrolyte storage tank 121 via a third heat exchange flow path 83b. This allows the positive electrolyte flowing from the fuel cell stack 140 to the positive electrolyte storage tank 121 to reach a suitable temperature through heat exchange before being introduced into the positive electrolyte storage tank 121. The negative electrolyte outlet of the fuel cell stack 140 is connected to the return port of the negative electrolyte storage tank 122 via a fourth heat exchange flow path 84b. This allows the negative electrolyte flowing from the fuel cell stack 140 to the negative electrolyte storage tank 122 to reach a suitable temperature through heat exchange before being introduced into the negative electrolyte storage tank 122.

[0048] Furthermore, the second inter-system heat exchanger 82 can simultaneously exchange heat between the positive electrolyte flowing from the fuel cell stack 140 to the positive electrolyte storage tank 121 and the negative electrolyte flowing from the fuel cell stack 140 to the negative electrolyte storage tank 122. This facilitates centralized heat exchange between the positive electrolyte input from the fuel cell stack 140 to the positive electrolyte storage tank 121 and the negative electrolyte input from the fuel cell stack 140 to the negative electrolyte storage tank 122, resulting in a higher degree of integration and reducing the number of inter-system heat exchangers 8, thus saving costs.

[0049] In the above embodiments, the second inter-system heat exchanger 82 can be constructed as a three-pass heat exchanger. Of course, the second inter-system heat exchanger 82 is not limited to a three-pass heat exchanger, and can also be a heat exchanger with a higher tube pass, as long as it meets the function of the second inter-system heat exchanger 82.

[0050] In some embodiments, the heat exchange network includes a first return path 1c for the positive electrolyte and a second return path 1d for the positive electrolyte. The first return path 1c connects the positive electrolyte outlet of the fuel cell stack 140 and the return port of the positive electrolyte storage tank 121, so that the positive electrolyte in the fuel cell stack 140 can flow into the positive electrolyte storage tank 121 through the first return path 1c. A seventh control valve 21 is provided on the first return path 1c to control the opening and closing of the first return path 1c. The third heat exchange flow path 83b is connected in parallel with the seventh control valve 21 through the second return path 1d for the positive electrolyte. An eighth control valve 22 is provided on at least one side of the second return path 1d for the positive electrolyte of the third heat exchange flow path 83b to control the opening and closing of the second return path 1d for the positive electrolyte.

[0051] In the above embodiments, it is possible to select whether to allow heat exchange by introducing the electrolyte in the positive electrode electrolyte storage tank 121 into the fuel cell stack 140. For example... Figure 1 , Figure 5 and Figure 6As shown, the eighth control valve 22 is located between the positive electrolyte outlet of the fuel cell stack 140 and the third heat exchange flow path 83b. When heat exchange is required, the seventh control valve 21 can be closed and the eighth control valve 22 can be opened. The positive electrolyte flowing out of the fuel cell stack 140 flows out of the positive electrolyte outlet of the fuel cell stack 140 and flows through the second return path 1d of the positive electrolyte into the third heat exchange flow path 83b of the second inter-system heat exchanger 82 for heat exchange. After heat exchange, the positive electrolyte flows into the positive electrolyte storage tank 121.

[0052] When heat exchange is not required, the seventh control valve 21 can be opened and the eighth control valve 22 can be closed, so that the positive electrolyte flowing out of the positive electrolyte outlet of the stack device 140 can be directly introduced into the positive electrolyte storage tank 121 through the first return liquid path 1c of the positive electrolyte.

[0053] In some embodiments, the heat exchange network includes a first return path 2c for the negative electrolyte and a second return path 2d for the negative electrolyte. The first return path 2c is used to connect the negative electrolyte outlet of the fuel cell stack 140 and the return port of the negative electrolyte storage tank 122, so that the negative electrolyte in the fuel cell stack 140 flows back to the negative electrolyte storage tank 122 through the first return path 2c. A ninth control valve 23 is provided on the first return path 2c to control the on / off state of the first return path 2c. The fourth heat exchange flow path 84b is connected in parallel with the ninth control valve 23 through the second return path 2d for the negative electrolyte. A tenth control valve 24 is provided on at least one side of the second return path 2d for the negative electrolyte to control the on / off state of the second return path 2d for the negative electrolyte.

[0054] In the above embodiments, it is possible to select whether to allow heat exchange by introducing the electrolyte into the negative electrode electrolyte storage tank 122 into the fuel cell stack 140. For example... Figure 1 , Figure 5 and Figure 6 As shown, the tenth control valve 24 is located between the outlet of the negative electrolyte in the fuel cell stack 140 and the fourth heat exchange flow path 84b. When heat exchange is required, the ninth control valve 23 can be closed and the tenth control valve 24 can be opened. The negative electrolyte discharged from the outlet of the negative electrolyte in the fuel cell stack 140 can enter the fourth heat exchange flow path 84b of the second system inter-heat exchanger 82 through the second return liquid path 2d of the negative electrolyte for heat exchange. After heat exchange, the negative electrolyte is then fed into the negative electrolyte storage tank 122.

[0055] When heat exchange is not required, the ninth control valve 23 can be opened and the tenth control valve 24 can be closed. The negative electrolyte discharged from the negative electrolyte outlet of the fuel cell stack 140 can be directly introduced into the negative electrolyte storage tank 122 through the first negative electrolyte return path 2c.

[0056] To better understand the operation of the coupled system of flow battery and compressed air energy storage, the following is a brief description of its operation with reference to the accompanying drawings. The operation of the compressed air energy storage subsystem has already been described above and will not be repeated here. This section focuses on describing the operation of the flow battery subsystem and the inter-system heat exchanger 8 connected to it. It should be noted that the first heat storage tank 10 can be a high-temperature heat storage tank, and the second heat storage tank 11 can be a low-temperature heat storage tank.

[0057] When it is necessary to heat the positive and negative electrolytes supplied to the fuel cell stack 140 from the positive electrolyte storage tank 121 and the negative electrolyte storage tank 122, such as Figure 2 As shown, a heat transfer medium is introduced from the first heat storage tank 10 into the air energy storage side heat exchange flow path 8a in the first inter-system heat exchanger 81, and the heat transfer medium in the air energy storage side heat exchange flow path 8a in the first inter-system heat exchanger 81 flows out into the second heat storage tank 11. In the flow battery subsystem, for the positive electrode electrolyte supply path, the first control valve 15 can be closed, and the second control valve 16 and the third control valve 17 can be opened. The positive electrode electrolyte in the positive electrode electrolyte storage tank 121 is driven by the first circulation pump 131 and enters the first heat exchange flow path 81b of the first inter-system heat exchanger 81 through the second positive electrode electrolyte supply path 1b for heating. The heated positive electrode electrolyte flows to the positive electrode electrolyte inlet of the stack device 140, and then enters the stack device 140 through the positive electrode electrolyte inlet. For the negative electrolyte supply circuit, the fourth control valve 18 can be closed, and the fifth control valve 19 and the sixth control valve 20 can be opened. The negative electrolyte in the negative electrolyte storage tank 122 is driven by the second circulation pump 132 through the second negative electrolyte supply circuit 2b into the second heat exchange circuit 82b. After being heated in the first heat exchange circuit 81b, the negative electrolyte flows to the negative electrolyte inlet of the fuel cell stack 140, and then enters the fuel cell stack 140 through the negative electrolyte inlet. After the reaction, the positive electrolyte in the fuel cell stack 140 flows back to the positive electrolyte storage tank 121 through the first positive electrolyte return circuit 1c and / or the second positive electrolyte return circuit 1d, thus forming a supply and return loop for the positive electrolyte between the positive electrolyte storage tank 121 and the fuel cell stack 140. After the reaction, the negative electrode electrolyte in the fuel cell stack 140 will flow back to the negative electrode electrolyte storage tank 122 through the first return liquid path 2c and / or the second return liquid path 2d of the negative electrode electrolyte, which will not be described in detail here.

[0058] Furthermore, when it is necessary to cool down the positive and negative electrolytes supplied to the fuel cell stack 140 from the positive electrolyte storage tank 121 and the negative electrolyte storage tank 122, such as... Figure 3As shown, it is only necessary to change the flow direction of the heat transfer medium in the air energy storage side heat exchange flow path 8a of the first system inter-heat exchanger 81. That is, the heat transfer medium is introduced from the second heat storage tank 11 into the air energy storage side heat exchange flow path 8a of the first system inter-heat exchanger 81 and then flows out to the first heat storage tank. The operation in the flow battery subsystem is the same as the operation of heating the positive and negative electrolytes, and will not be described again here.

[0059] When it is not necessary to heat or cool the positive and negative electrolytes supplied to the fuel cell stack 140 from the positive electrolyte storage tank 121 and the negative electrolyte storage tank 122, such as Figure 4 As shown, for the positive electrolyte supply circuit, the second control valve 16 and the third control valve 17 can be closed, and the first control valve 15 can be opened, allowing the positive electrolyte in the positive electrolyte storage tank 121 to directly enter the fuel cell stack 140 through the first positive electrolyte supply circuit 1a under the drive of the first circulation pump 131. For the negative electrolyte supply circuit, the fifth control valve 19 and the sixth control valve 20 can be closed, and the fourth control valve 18 can be opened, allowing the negative electrolyte in the negative electrolyte storage tank 122 to directly enter the fuel cell stack 140 through the first negative electrolyte supply circuit 2a under the drive of the second circulation pump 132.

[0060] When it is necessary to cool the positive electrolyte flowing back from the fuel cell stack 140 to the positive electrolyte storage tank 121 and the negative electrolyte flowing back from the fuel cell stack 140 to the negative electrolyte storage tank 122, a heat transfer medium is introduced from the second heat storage tank 11 into the air energy storage side heat exchange flow path 8a of the second inter-system heat exchanger 82, and then flows out from the air energy storage side heat exchange flow path 8a of the second inter-system heat exchanger 82 into the first heat storage tank 10. For example... Figure 5 As shown, in the flow battery subsystem, for the positive electrolyte return path, the seventh control valve 21 needs to be closed and the eighth control valve 22 needs to be opened. The positive electrolyte discharged from the positive electrolyte outlet of the stack 140 passes through the eighth control valve 22 on the second positive electrolyte return path 1d and enters the third heat exchange path 83b in the second system inter-heat exchanger 82 for cooling before being introduced into the positive electrolyte storage tank 121. For the negative electrolyte return path, the ninth control valve 23 needs to be closed and the tenth control valve 24 needs to be opened. The negative electrolyte discharged from the negative electrolyte outlet of the stack 140 passes through the tenth control valve 24 on the second negative electrolyte return path 2d and enters the third heat exchange path 83b in the second system inter-heat exchanger 82 for cooling before being introduced into the negative electrolyte storage tank 122.

[0061] When it is not necessary to cool the positive electrolyte flowing back from the fuel cell stack 140 to the positive electrolyte storage tank 121 and the negative electrolyte flowing back from the fuel cell stack 140 to the negative electrolyte storage tank 122, such as Figure 6 As shown, in the flow battery subsystem, for the positive electrolyte return path, the seventh control valve 21 can be opened and the eighth control valve 22 can be closed, allowing the positive electrolyte discharged from the stack device 140 to flow directly into the positive electrolyte storage tank 121 through the first positive electrolyte return path 1c. For the negative electrolyte return path, the ninth control valve 23 can be opened and the tenth control valve 24 can be closed, allowing the negative electrolyte discharged from the stack device 140 to flow directly into the negative electrolyte storage tank 122 through the first negative electrolyte return path 2c.

[0062] It should be noted that the above-described working process is only one of the common working modes of the flow battery and compressed air energy storage coupling system. Working processes that can be achieved through this coupling system but are not listed above are also within the scope of protection of this disclosure.

[0063] Furthermore, it should be understood that the fuel cell stack 140 in the flow battery subsystem can be connected to external devices or circuits. When the flow battery subsystem is used to supply power to external devices or circuits, it acts as a power source; when external devices or circuits supply power to the flow battery subsystem, it is in an energy storage state and acts as a load. For example, if the flow battery subsystem can be connected to the power grid, then when it is used to provide electrical energy to the grid, it acts as a power source; when the grid supplies power to the flow battery subsystem, it is in an energy storage state and acts as a load.

[0064] The second aspect of this disclosure provides a peak-shaving method that uses a coupling system of a hydraulic battery and compressed air energy storage provided in the first aspect of this disclosure to perform peak shaving on the power grid, such as... Figure 7 As shown, the method includes: S100, acquire peak-shaving signal; S200, in response to the peak shaving signal, simultaneously starts the flow battery subsystem and the compressed air energy storage subsystem, so that the flow battery subsystem stores / releases energy first, and after the compressed air energy storage subsystem runs to full load, the flow battery subsystem and the compressed air energy storage subsystem store / release energy simultaneously.

[0065] In the above embodiments, the peak-shaving signal in step S100 includes an energy storage signal and an energy release signal. When the peak-shaving signal is an energy storage signal, in response to the peak-shaving signal, the flow battery subsystem and the compressed air energy storage subsystem are started simultaneously, so that the flow battery subsystem stores energy first, and after the compressed air energy storage subsystem reaches full load, the flow battery subsystem and the compressed air energy storage subsystem simultaneously store energy. When the peak-shaving signal is an energy release signal, in response to the peak-shaving signal, the flow battery subsystem and the compressed air energy storage subsystem are started simultaneously, so that the flow battery subsystem releases energy first, and after the compressed air energy storage subsystem reaches full load, the flow battery subsystem and the compressed air energy storage subsystem simultaneously release energy.

[0066] In some implementations, it should be understood that, due to uneven electricity load, the power grid is often overloaded during peak electricity demand. At this time, it is necessary to activate generators that are not operating normally. During off-peak periods, electrical energy can be stored.

[0067] The coupling system of flow battery and compressed air energy storage disclosed herein can be used for peak shaving in the power grid. During peak electricity consumption periods, a control system (not shown in the figure) that controls the coupling system of flow battery and compressed air energy storage receives a peak shaving signal, which is an energy release signal. The control system then controls the simultaneous startup of the flow battery subsystem and the compressed air energy storage subsystem. At this time, the flow battery electronic system acts as the power source, supplying electrical energy to the power grid. The gas in the gas storage chamber 3 of the compressed air energy storage subsystem is heated by a thermal and cold storage unit before being introduced into the expander unit 4. The expander unit 4 rotates and drives the generator 5 to generate electricity, which is then used to supply electrical energy to the power grid. As mentioned above, electrochemical energy storage operates on the order of seconds to milliseconds. The flow battery subsystem has a fast response speed, and it prioritizes energy release based on its fast response speed. Once the compressed air energy storage subsystem is operational, both the flow battery subsystem and the compressed air energy storage subsystem release energy simultaneously to meet the needs of rapid response such as peak shaving and frequency regulation.

[0068] During periods of low electricity demand, a control device (not shown in the figure) that controls the coupled system of the flow battery and compressed air energy storage receives a peak-shaving signal. This peak-shaving signal is also an energy storage signal. The control system then simultaneously activates both the flow battery subsystem and the compressed air energy storage subsystem. At this time, the flow battery subsystem acts as a load, and electrical energy is used to charge it, allowing the flow battery to store energy. Simultaneously, the motor 1 in the compressed air energy storage subsystem uses electrical energy to drive the compressor unit 2 to compress and store air for energy storage. As mentioned above, electrochemical energy storage operates on the order of seconds to milliseconds. The flow battery subsystem has a fast response speed, and it prioritizes energy storage due to this advantage. Once the compressed air energy storage subsystem is operational, both systems simultaneously store energy to meet the demands of rapid response, such as peak shaving and frequency regulation.

[0069] In some other possible implementations, the compressed air energy storage subsystem can be in a shutdown state, and the first circulation pump 131 and the second circulation pump 132 in the flow battery subsystem can be in a low-frequency circulation standby state. It should be understood that when the compressed air energy storage subsystem is in a shutdown state, the first heat storage tank 10 and the second heat storage tank 11 of the thermal and cold storage unit can meet the requirements for heat exchange between the inter-system heat exchanger 8 and the electrolyte in the flow battery subsystem.

[0070] When the control system, which controls the coupled system of the flow battery and compressed air energy storage, receives a peak-shaving signal, it simultaneously starts both the flow battery subsystem and the compressed air energy storage subsystem. At this time, the peak-shaving signal can be an energy release signal. The first circulation pump 131 and the second circulation pump 132 in the flow battery subsystem switch from a low-frequency standby state to a high-frequency operating state, with a response time of approximately 0.05s to 1s. The electrolyte in the flow battery subsystem exchanges heat with the thermal and cold storage unit through the inter-system heat exchanger 8 before entering the fuel cell stack 140 for discharge. Once the compressed air energy storage subsystem is operational, both the flow battery subsystem and the compressed air energy storage subsystem release energy simultaneously to provide power to the grid.

[0071] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0073] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A coupling system for a flow battery and compressed air energy storage, characterized in that, include: The flow battery subsystem includes a capacity unit for storing electrolyte, a power unit for the interconversion of chemical energy and electrical energy, and a power unit for driving the electrolyte to circulate between the capacity unit and the power unit. A compressed air energy storage subsystem includes a gas storage and release unit and a heat storage and cold storage unit. The gas storage and release unit is used for the compression storage and expansion release of air, and the heat storage and cold storage unit is used for heat exchange with the gas storage and release unit. as well as The thermal management subsystem includes the thermal and cold storage unit and a heat exchange network. The electrolyte in the flow battery subsystem circulates between the capacity unit and the power unit through the heat exchange network. The heat exchange network includes an inter-system heat exchanger, which exchanges heat with the thermal and cold storage unit to coordinate the thermal complementarity between the flow battery subsystem and the compressed air energy storage subsystem.

2. The coupling system according to claim 1, characterized in that, The inter-system heat exchanger includes a first inter-system heat exchanger and a second inter-system heat exchanger. Both the first and second inter-system heat exchangers include a battery-side heat exchange path and an air energy storage-side heat exchange path. The capacity unit includes an electrolyte storage device, and the power unit includes a fuel cell stack. The outlet of the electrolyte storage device is connected to the inlet of the fuel cell stack via the battery-side heat exchange path of the first inter-system heat exchanger. The outlet of the fuel cell stack is connected to the inlet of the electrolyte storage device via the battery-side heat exchange path of the second inter-system heat exchanger. The air energy storage-side heat exchange paths of both the first and second inter-system heat exchangers are connected to the thermal and cold storage unit.

3. The coupling system according to claim 2, characterized in that, The electrolyte storage device includes a positive electrolyte storage tank and a negative electrolyte storage tank. The battery-side heat exchange flow path of the first inter-system heat exchanger includes a first heat exchange flow path and a second heat exchange flow path. The outlet of the positive electrolyte storage tank can be connected to the positive electrolyte inlet of the fuel cell stack through the first heat exchange flow path, and the outlet of the negative electrolyte storage tank can be connected to the negative electrolyte inlet of the fuel cell stack through the second heat exchange flow path.

4. The coupling system according to claim 3, characterized in that, The heat exchange network includes a first positive electrolyte supply path and a second positive electrolyte supply path. The power unit includes a first circulating pump. The first positive electrolyte supply path connects the outlet of the positive electrolyte storage tank and the inlet of the positive electrolyte in the fuel cell stack, so that the positive electrolyte in the positive electrolyte storage tank can be transported to the fuel cell stack through the first positive electrolyte supply path. The first circulating pump and a first control valve are sequentially arranged along the liquid flow direction on the first positive electrolyte supply path. The first control valve can control the opening and closing of the first positive electrolyte supply path. The first heat exchange flow path is connected in parallel with the first control valve through the second positive electrolyte supply path. A second control valve and a third control valve that can control the opening and closing of the second positive electrolyte supply path are respectively arranged on the second positive electrolyte supply path on both sides of the first heat exchange flow path.

5. The coupling system according to claim 4, characterized in that, The heat exchange network includes a first negative electrolyte supply path and a second negative electrolyte supply path. The power unit also includes a second circulation pump. The first negative electrolyte supply path connects the outlet of the negative electrolyte storage tank and the inlet of the negative electrolyte in the fuel cell stack, so that the negative electrolyte in the negative electrolyte storage tank can be transported to the fuel cell stack through the first negative electrolyte supply path. The second circulation pump and a fourth control valve are sequentially arranged along the liquid flow direction on the first negative electrolyte supply path. The fourth control valve can control the on / off state of the first negative electrolyte supply path. The second heat exchange flow path is connected in parallel with the fourth control valve through the second negative electrolyte supply path. A fifth control valve and a sixth control valve, which can control the on / off state of the second negative electrolyte supply path, are respectively arranged on the second negative electrolyte supply path on both sides of the second heat exchange flow path.

6. The coupling system according to any one of claims 3-5, characterized in that, The battery-side heat exchange path of the second system inter-heat exchanger includes a third heat exchange path and a fourth heat exchange path. The positive electrolyte outlet of the fuel cell stack is connected to the return port of the positive electrolyte storage tank through the third heat exchange path, and the negative electrolyte outlet of the fuel cell stack is connected to the return port of the negative electrolyte storage tank through the fourth heat exchange path.

7. The coupling system according to claim 6, characterized in that, The heat exchange network includes a first return path and a second return path for the positive electrolyte. The first return path connects the positive electrolyte outlet of the fuel cell stack to the return port of the positive electrolyte storage tank, allowing the positive electrolyte in the fuel cell stack to flow into the positive electrolyte storage tank through the first return path. A seventh control valve is installed on the first return path to control its on / off state. The third heat exchange path is connected in parallel with the seventh control valve through the second return path. An eighth control valve is installed on at least one side of the second return path of the third heat exchange path to control its on / off state.

8. The coupling system according to claim 7, characterized in that, The heat exchange network includes a first return path and a second return path for the negative electrode electrolyte. The first return path connects the negative electrode electrolyte outlet of the fuel cell stack to the return outlet of the negative electrode electrolyte storage tank, so that the negative electrode electrolyte in the fuel cell stack can flow back to the negative electrode electrolyte storage tank through the first return path. A ninth control valve is provided on the first return path to control the on / off state of the first return path. The fourth heat exchange flow path is connected in parallel with the ninth control valve through the second return path. A tenth control valve is provided on at least one side of the second return path of the fourth heat exchange flow path to control the on / off state of the second return path.

9. The coupling system according to any one of claims 1-2, characterized in that, The thermal and cold storage unit includes a cooler assembly for dissipating heat from the gas in the compressor unit, a reheater assembly for heating the gas in the expander unit, a first thermal storage tank, and a second thermal storage tank. The first thermal storage tank is connected to the inlet of the reheater assembly to provide a heat transfer medium to the reheater assembly. The second thermal storage tank is connected to the inlet of the cooler assembly to provide a heat transfer medium to the cooler assembly. The outlet of the reheater assembly is connected to the second thermal storage tank, and the outlet of the cooler assembly is connected to the first thermal storage tank. The two ends of the air energy storage side heat exchange flow path of the first inter-system heat exchanger are respectively connected to the first heat storage tank and the second heat storage tank, and the two ends of the air energy storage side heat exchange flow path of the second inter-system heat exchanger are respectively connected to the first heat storage tank and the second heat storage tank.

10. A peak-shaving method, characterized in that, Peak shaving of the power grid using a coupling system of flow battery and compressed air energy storage as described in any one of claims 1-9, the method comprising: Obtain peak-shaving signals; In response to the peak-shaving signal, the flow battery subsystem and the compressed air energy storage subsystem are started simultaneously, so that the flow battery subsystem stores / releases energy first, and after the compressed air energy storage subsystem reaches full load, the flow battery subsystem and the compressed air energy storage subsystem store / release energy simultaneously.

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