Multi-mode integrated energy storage system

Abstract

The present application provides a multi-mode integrated energy storage system, which includes an electric motor, a generator, a compressed gas energy storage unit, a mechanical energy storage unit, and a thermal energy storage unit; the compressed gas energy storage unit includes a compressor, a gas storage tank, a first heating chamber, and a turbine connected in sequence; the input end of the mechanical energy storage unit is connected to the compressor, and the output end of the mechanical energy storage unit is connected to the generator; the thermal energy storage unit includes a thermal energy storage module and a steam turbine, the input end of the thermal energy storage module is connected to the power generation system, the output end of the thermal energy storage module is connected to the steam turbine, and the steam turbine is connected to the generator. Through the three energy storage units, the conversion, storage, and reverse transmission of electric energy can be jointly realized. The three energy storage units can cooperate and complement each other, and have a reasonable energy storage duration and response speed. In addition, the multi-mode integrated energy storage system stores electric energy through three different energy storage units, improves the electric energy storage efficiency, effectively reduces the fluctuations of the power grid, and improves the stability of the power grid.

Description

Technical Field

[0001] This application relates to the technical field of energy storage and utilization, and particularly to a multi-mode integrated energy storage system. Background Art

[0002] With the large-scale grid-connected power generation of renewable energy, higher requirements are put forward for the safety and stability of the power system. Establishing an energy storage system, using the energy storage system to achieve a higher level of power consumption, and realizing functions such as power grid frequency modulation and peak shaving can effectively improve the stability of the power grid.

[0003] Currently, the common energy storage mode of the energy storage system is compressed gas energy storage. This energy storage system includes a compressor, a gas storage tank, a heating chamber, a turbine, and a generator. During the low electricity consumption period, the surplus electricity in the power generation system drives the compressor to compress the gas and stores the compressed gas in the gas storage tank, realizing the conversion and storage of electricity. During the high electricity consumption period, the compressed gas stored in the gas storage tank is heated and expanded through the heating chamber, and then drives the turbine to do work to drive the generator to generate electricity. The electricity generated by the generator is transmitted to the power grid through the line, realizing the frequency modulation and peak shaving of the power grid. However, with the continuous development of new energy technologies, a single-mode energy storage system can no longer meet the needs of the power grid. Summary of the Invention

[0004] Based on this, this application provides a multi-mode integrated energy storage system to solve the deficiencies of the related technologies.

[0005] The multi-mode integrated energy storage system provided by this application includes a motor, a generator, a compressed gas energy storage unit, a mechanical energy storage unit, and a thermal energy storage unit;

[0006] The motor is connected to the power generation system, and the generator is connected to the power grid;

[0007] The compressed gas energy storage unit includes a compressor, a gas storage tank, a first heating chamber, and a turbine connected in sequence. The compressor is connected to the motor, and the turbine is connected to the generator;

[0008] The input end of the mechanical energy storage unit is connected to the compressor, and the output end of the mechanical energy storage unit is connected to the generator;

[0009] The thermal energy storage unit includes a thermal energy storage module and a steam turbine. The input end of the thermal energy storage module is connected to the power generation system, the output end of the thermal energy storage module is connected to the steam turbine, and the steam turbine is connected to the generator.

[0010] In one possible implementation, the mechanical energy storage unit includes an energy storage tank, a piston rod and an elastic member. The energy storage tank is connected to the compressor. The first end of the piston rod extends into the energy storage tank and is slidingly connected to the energy storage tank. The second end of the piston rod extends out of the energy storage tank and is transmission-connected to the generator. The elastic member is arranged in the energy storage tank and connected to the piston rod. When the mechanical energy storage unit stores energy, the piston rod drives the elastic member to undergo elastic deformation.

[0011] In a possible implementation, the energy storage tank is also connected to the steam turbine.

[0012] In one possible implementation, a plurality of containers are provided in the accommodating chamber of the energy storage tank, with a spacing area between the plurality of containers. There are a plurality of piston rods, and the first ends of the plurality of piston rods extend into the plurality of containers in a one-to-one correspondence. A piston is provided at the first end of each piston rod, and the piston separates the container into a first chamber and a second chamber. The first chamber is in communication with the spacing area, and an elastic member connected to the corresponding piston rod is provided in each container.

[0013] When the mechanical energy storage unit is storing energy, the compressor introduces compressed gas into the interval area.

[0014] In one possible implementation, the mechanical energy storage unit also includes a connecting member, a screw, a driving wheel and a bracket, the connecting member is respectively connected to the second end of each piston rod, the end of the screw is connected to the side of the connecting member away from the piston rod, the bracket is fixedly installed on one side of the energy storage tank, the driving wheel is rotatably installed on the bracket, and the driving wheel is respectively connected to the screw and the generator.

[0015] In a possible implementation, the mechanical energy storage unit further includes a driven wheel, the diameter of the driven wheel is larger than the diameter of the driving wheel, and the driven wheel is transmission-connected to the driving wheel and the generator respectively.

[0016] In one possible implementation, the thermal energy storage module includes a second heating chamber, a first cold salt storage tank, a hot salt storage tank, and a steam generator;

[0017] The second heating chamber is connected to the power generation system, the feed end of the second heating chamber is connected to the discharge end of the first cold salt storage tank, the discharge end of the second heating chamber is connected to the feed end of the hot salt storage tank, the discharge end of the hot salt storage tank is connected to the feed end of the steam generator, the air outlet of the steam generator is connected to the steam turbine, and the discharge end of the steam generator is connected to the feed end of the first cold salt storage tank.

[0018] In one possible implementation, the thermal energy storage module also includes a second cold salt storage tank, the discharge end of the hot salt storage tank is also connected to the feed end of the first heating chamber, the discharge end of the first heating chamber is connected to the feed end of the second cold salt storage tank, and the feed end of the second heating chamber is respectively connected to the discharge end of the first cold salt storage tank and the discharge end of the second cold salt storage tank.

[0019] In a possible implementation, the multi-mode integrated energy storage system further includes a condenser, which is connected between the outlet of the steam turbine and the inlet of the steam generator.

[0020] In a possible implementation, the compressor is connected to the gas storage tank through a first pipeline, a first valve is provided on the first pipeline, the gas storage tank is connected to the first heating chamber through a second pipeline, a second valve is provided on the second pipeline, the compressor is connected to the energy storage tank through a third pipeline, a third valve is provided on the third pipeline, the energy storage tank is connected to the steam turbine through a fourth pipeline, and a fourth valve is provided on the fourth pipeline.

[0021] The multi-mode integrated energy storage system provided by the present application is provided with a compressed gas energy storage unit, a mechanical energy storage unit and a thermal energy storage unit. Through the three energy storage units, the conversion, storage and reverse transmission of electric energy can be jointly realized. Moreover, the compressed gas energy storage unit, the mechanical energy storage unit and the thermal energy storage unit can cooperate and complement each other. Compared with the energy storage system with a single energy storage mode, the multi-mode integrated energy storage system has a reasonable energy storage duration and response speed. In addition, the multi-mode integrated energy storage system stores electric energy through three different energy storage units, stores the electric energy that the power grid fails to consume, improves the electric energy storage efficiency, effectively reduces the fluctuation of the power grid, improves the stability of the power grid, and realizes the frequency modulation and peak shaving of the power grid. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of the multi-mode integrated energy storage system provided by the embodiment of the present application;

[0024] Figure 2 It is a schematic structural diagram of a mechanical energy storage unit provided by the embodiment of the present application;

[0025] Figure 3 It is a schematic structural diagram of another mechanical energy storage unit provided by the embodiment of the present application.

[0026] Description of the Reference Numerals:

[0027] 100 - Electric motor;

[0028] 200 - Generator;

[0029] 300 - Compressed gas energy storage unit; 310 - Compressor; 320 - Gas storage tank; 330 - First heating chamber; 340 - Turbine; 350 - First pipeline; 351 - First valve; 360 - Second pipeline; 361 - Second valve;

[0030] 400 - Mechanical energy storage unit; 410 - Energy storage tank; 411 - Container; 4111 - First chamber; 412 - Spacer region; 420 - Piston rod; 430 - Elastic member; 440 - Connecting member; 450 - Screw; 460 - Driving wheel; 470 - Driven wheel;

[0031] 500 - Thermal energy storage unit; 510 - Thermal energy storage module; 511 - Second heating chamber; 512 - First cold salt storage tank; 513 - Hot salt storage tank; 514 - Steam generator; 515 - Second cold salt storage tank; 520 - Steam turbine;

[0032] 610 - Positive conveying line; 620 - Reverse conveying line;

[0033] 700 - Condenser;

[0034] 800 - Third pipeline; 810 - Third valve;

[0035] 900 - Fourth pipeline; 910 - Fourth valve. Detailed implementation manners

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings in the preferred embodiments of this application. In the drawings, the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this application. The embodiments described below by referring to the drawings are exemplary and are intended to explain this application and should not be construed as limiting this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the drawings.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" shall be understood in a broad sense. For example, it may be a fixed connection or an indirect connection through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0039] In the description and claims of the present application, and in the above-mentioned drawings, the terms "first", "second", "third" (if any) are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0040] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or display that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or displays.

[0041] Currently, energy storage systems usually have a single energy storage mode, such as a compressed gas energy storage system or a mechanical energy storage system, etc. Taking the compressed gas energy storage system as an example, during the low electricity consumption period, the surplus electricity in the power generation system drives a compressor to compress gas, and the conversion and storage of electricity are achieved by storing the gas compressed by the compressor. During the high electricity consumption period, the compressed gas drives a generator to generate electricity, and the electricity generated by the generator is transmitted to the power grid through a line. However, the compressed gas energy storage system has a long energy storage duration but a slow response when converting and storing electricity. The energy storage system using mechanical energy storage has a fast response but a short energy storage duration. Moreover, the single-mode energy storage system has a low storage efficiency for electricity. With the continuous development of new energy technologies, the single-mode energy storage system cannot meet the requirements of the power grid.

[0042] After repeated thinking and verification, the inventors of the present application found that if an energy storage system with multiple energy storage modes is provided, the multiple energy storage modes have different response speeds and energy storage durations. During the process of converting and storing electricity, the multiple energy storage modes can cooperate and complement each other. Compared with the energy storage system with a single energy storage mode, this energy storage system has a reasonable energy storage duration and response speed. In addition, the multi-mode integrated energy storage system stores electricity through three different energy storage units and stores the electricity that the power grid fails to absorb, which can effectively improve the storage efficiency of electricity.

[0043] In view of this, the inventors of the present application have designed a multi-mode integrated energy storage system, which is provided with a compressed gas energy storage unit, a mechanical energy storage unit, and a thermal energy storage unit. The input end of the compressed gas energy storage unit is connected to the motor, and the output end is connected to the engine. The input end of the mechanical energy storage unit is connected to the compressor of the compressed gas energy storage unit, and the output end is connected to the generator. The thermal energy storage unit includes a thermal energy storage module and a steam turbine. The input end of the thermal energy storage module is connected to the power generation system, the output end of the thermal energy storage module is connected to the steam turbine, and the steam turbine is connected to the generator. The multi-mode integrated energy storage system can realize the conversion, storage, and reverse transmission of the surplus electric energy in the power generation system through the coordinated complementarity of the compressed gas energy storage unit, the mechanical energy storage unit, and the thermal energy storage unit, has a reasonable energy storage duration and response speed, and a high storage efficiency of electric energy.

[0044] The technical solution of the multi-mode integrated energy storage system provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0045] Figure 1 The following is a schematic structural diagram of the multi-mode integrated energy storage system provided by the embodiments of the present application. Refer to Figure 1 As shown in the figure, the multi-mode integrated energy storage system provided by the embodiments of the present application includes a motor 100, a generator 200, a compressed gas energy storage unit 300, a mechanical energy storage unit 400, and a thermal energy storage unit 500. The motor 100 is connected to the power generation system, and the generator 200 is connected to the power grid. The compressed gas energy storage unit 300 includes a compressor 310, a gas storage tank 320, a first heating chamber 330, and a turbine 340 connected in sequence. The compressor 310 is connected to the motor 100, and the turbine 340 is connected to the generator 200. The input end of the mechanical energy storage unit 400 is connected to the compressor 310, and the output end of the mechanical energy storage unit 400 is connected to the generator 200. The thermal energy storage unit 500 includes a thermal energy storage module 510 and a steam turbine 520. The input end of the thermal energy storage module 510 is connected to the power generation system, the output end of the thermal energy storage module 510 is connected to the steam turbine 520, and the steam turbine 520 is connected to the generator 200.

[0046] Schematically, as Figure 1 shown, the power generation system can be respectively connected to the input ends of the motor 100 and the thermal energy storage unit 500 through a positive transmission line 610. The positive transmission line 610 can be provided with two branches, one branch is connected to the motor 100, and the other branch is connected to the input end of the thermal energy storage unit 500. Among them, the power generation system can be a photovoltaic power generation system or a wind power generation system, etc., which is not uniquely limited here. The generator 200 can be connected to the power grid through a reverse transmission line 620. During the peak electricity consumption period, the electric energy generated by the generator 200 can be transmitted to the power grid through the reverse transmission line 620 to realize the frequency modulation and peak shaving of the power grid. Among them, the turbine 340 can be radial flow, axial flow, or radial-axial flow, etc., which is not uniquely limited here.

[0047] During the low electricity consumption period, the surplus electricity in the power generation system can be transmitted to the motor 100 through the positive transmission line 610. The motor 100 converts the electrical energy into mechanical energy, and then drives the compressor 310 to compress the gas. A part of the gas compressed by the compressor 310 is transported and stored in the gas storage tank 320 to realize the conversion and storage of electrical energy by the compressed gas energy storage unit 300. The number of gas storage tanks 320 can be multiple, and those skilled in the art can set the specific number of gas storage tanks 320 according to actual needs, which is not uniquely limited here. Another part of the gas compressed by the compressor 310 is transported to the mechanical energy storage unit 400. In the mechanical energy storage unit 400, the compression potential energy of the gas can be converted into mechanical energy for storage. The electricity not stored by the compressed gas energy storage unit 300 and the mechanical energy storage unit 400 can be transmitted to the thermal energy storage module 510 of the thermal energy storage unit 500 through the positive transmission line 610, and this part of the electricity is converted into thermal energy for storage in the thermal energy storage module 510.

[0048] During the high electricity consumption period, in the compressed gas energy storage unit 300, the compressed gas stored in the gas storage tank 320 can be transported to the first heating chamber 330 for heating to expand the volume of the compressed gas. The expanded gas does work through the turbine 340 to convert the compression potential energy of the gas into mechanical energy and drive the generator 200 to generate electricity. The mechanical energy stored in the mechanical energy storage unit 400 drives the generator 200 to generate electricity; the thermal energy stored in the thermal energy storage module 510 can be converted into mechanical energy through the steam turbine 520 and drive the generator 200 to generate electricity. The electricity generated by the generator 200 under the combined drive of the compressed gas energy storage unit 300, the mechanical energy storage unit 400, and the thermal energy storage unit 500 is reversely transmitted to the power grid through the reverse transmission line 620.

[0049] The multi-mode integrated energy storage system provided by this application is provided with a compressed gas energy storage unit 300, a mechanical energy storage unit 400, and a thermal energy storage unit 500, and the conversion, storage, and reverse transmission of electrical energy can be jointly realized through the three energy storage units. Moreover, the compressed gas energy storage unit 300, the mechanical energy storage unit 400, and the thermal energy storage unit 500 can cooperate and complement each other. Compared with the energy storage system with a single energy storage mode, the multi-mode integrated energy storage system has a reasonable energy storage duration and response speed. In addition, the multi-mode integrated energy storage system stores electrical energy through three different energy storage units, stores the electrical energy that the power grid fails to consume, improves the electrical energy storage efficiency, effectively reduces the fluctuations of the power grid, enhances the stability of the power grid, and realizes the frequency modulation and peak shaving of the power grid.

[0050] Figure 2 It is a schematic structural diagram of a mechanical energy storage unit provided by an embodiment of this application; Figure 3This is a schematic structural diagram of another mechanical energy storage unit provided by an embodiment of the present application. In one embodiment, as Figures 2 - 3 shown, the mechanical energy storage unit 400 includes an energy storage tank 410, a piston rod 420, and an elastic member 430. The energy storage tank 410 is connected to the compressor 310. The first end of the piston rod 420 extends into the energy storage tank 410 and is slidably connected to the energy storage tank 410. The second end of the piston rod 420 extends out of the energy storage tank 410 and is drivingly connected to the generator 200. The elastic member 430 is disposed in the energy storage tank 410 and is connected to the piston rod 420. When the mechanical energy storage unit 400 stores energy, the piston rod 420 drives the elastic member 430 to undergo elastic deformation.

[0051] During the low electricity consumption period, a part of the gas compressed by the compressor 310 can be transported to the energy storage tank 410. After this part of the gas enters the energy storage tank 410, it can push the piston rod 420 to move and the compressed gas is stored in the energy storage tank 410. During the movement of the piston rod 420, the elastic member 430 is driven to undergo elastic deformation. Among them, the elastic member 430 can be a spring or a cylindrical structure made of an elastic material such as rubber, and is not uniquely limited herein.

[0052] During the high electricity consumption period, the compressed gas stored in the energy storage tank 410 can be released. As the compressed gas in the energy storage tank 410 is released, the elastic member 430 undergoes elastic recovery and then pushes the piston rod 420 to reset. During the reset process of the piston rod 420, the generator 200 is directly driven to generate electricity.

[0053] In this structure, during the low electricity consumption period, as the compressed gas enters the energy storage tank 410, the compressed gas pushes the piston rod 420 to move, causing the elastic member 430 to undergo elastic deformation, and the mechanical energy is stored through the elastic deformation of the elastic member 430. During the high electricity consumption period, as the compressed gas in the energy storage tank 410 is released, the elastic recovery of the elastic member 430 drives the piston rod 420 to reset, and the piston rod 420 drives the generator 200 to generate electricity during the reset process to achieve the conversion of mechanical energy into electrical energy.

[0054] In a possible implementation manner, the reverse conveying line 620 is further provided with a branch connected to the compressor 310. During the low electricity consumption period, the electric quantity generated by the generator 200 driven by the piston rod 420 during movement can be transmitted to the compressor 310 through this branch and drive the compressor 310 to compress the gas. The above setting can effectively improve the energy utilization efficiency of the energy storage system, and further improve the electricity storage efficiency.

[0055] In a specific embodiment, as Figure 1 shown, the energy storage tank 410 is further connected to the steam turbine 520.

[0056] During the low electricity consumption period, as compressed gas is introduced into the energy storage tank 410, not only mechanical energy but also the compressed potential energy of the gas can be stored in the energy storage tank 410. During the high electricity consumption period, in addition to realizing the conversion of mechanical energy into electrical energy, the compressed gas released from the energy storage tank 410 can be led to the steam turbine 520, driving the steam turbine 520 to do work and then driving the generator 200 to generate electricity.

[0057] With this structure, the mechanical energy storage unit 400 can achieve secondary storage of the compressed potential energy of the gas, effectively improving the energy storage efficiency of the energy storage system. During the high electricity consumption period, especially when the electricity consumption of the power grid surges, the mechanical energy stored in the energy storage tank 410 and the compressed potential energy of the gas are used to drive the generator 200 to generate electricity, realizing effective power increase and grid connection to meet the requirements of balancing the power grid.

[0058] In a specific embodiment, as Figure 2 and Figure 3 shown, a plurality of containers 411 are arranged in the accommodating cavity of the energy storage tank 410, and there is an interval region 412 between the plurality of containers 411. The number of piston rods 420 is multiple, and the first ends of the multiple piston rods 420 extend into the multiple containers 411 one by one, and pistons are arranged at the first ends of the respective piston rods 420. The piston divides the container 411 into a first chamber 4111 and a second chamber, and the first chamber 4111 communicates with the interval region 412. Elastic members 430 connecting the corresponding piston rods 420 are respectively arranged in the respective containers 411. When the mechanical energy storage unit 400 stores energy, the compressor 310 introduces compressed gas into the interval region 412.

[0059] Schematically, each container 411 can be a cylindrical structure, and through holes can be provided on the side wall of the cylindrical structure to communicate the first chamber 4111 and the interval region 412 in the energy storage tank 410. Those skilled in the art can set the specific number of containers 411 in the energy storage tank 410 according to actual needs, and there is no unique limitation here. It can be understood that the number of piston rods 420 is the same as the number of containers 411, the second ends of the respective piston rods 420 extend out of the second chambers of the corresponding containers 411 and the energy storage tank 410, and elastic members 430 are arranged in the respective containers 411. In a possible implementation manner, the compressor 310 can be connected to the energy storage tank 410 through a pipeline, so that the gas compressed by the compressor 310 can be introduced into the interval region 412 in the energy storage tank 410. Part of the compressed gas located in the interval region 412 can enter the first chamber 4111 of each container 411 and push the piston rod 420 to move while driving the elastic member 430 to undergo elastic deformation.

[0060] In this structure, a plurality of containers 411 are arranged in the accommodating cavity of the energy storage tank 410. The interval region 412 between the plurality of containers 411 in the energy storage tank 410 can be used to store compressed gas, which can improve the power storage efficiency of the mechanical energy storage unit 400. In addition, when the elastic member 430 is a cylindrical structure made of an elastic material and is arranged in the second chamber of each container 411, the above arrangement can improve the energy conversion rate of the mechanical energy storage unit 400. Specifically, when the mechanical energy storage unit 400 stores energy, under the same pressure, the deformation amount of the elastic member 430 is larger. Correspondingly, when the mechanical energy storage unit 400 releases energy, the recovery amount of the elastic member 430 is also relatively high. When the mechanical energy storage unit 400 releases energy, the mechanical energy stored in the elastic member 430 that cannot be released can be reduced, and the energy conversion rate of the mechanical energy storage unit 400 can be improved.

[0061] In a more specific embodiment, as Figure 2 and Figure 3 shown, the mechanical energy storage unit 400 further includes a connecting member 440, a screw rod 450, a driving wheel 460, and a bracket (not shown in the figure). The connecting member 440 is respectively connected to the second ends of the piston rods 420. The end of the screw rod 450 is connected to the side of the connecting member 440 facing away from the piston rod 420. The bracket is fixedly installed on one side of the energy storage tank 410. The driving wheel 460 is rotatably installed on the bracket, and the driving wheel 460 is respectively in transmission connection with the screw rod 450 and the generator 200.

[0062] Exemplarily, the connecting member 440 can be a sheet-like structure, and the surface of the connecting member 440 facing away from the piston rod 420 is fixedly connected to the end of the screw rod 450.

[0063] In a possible implementation manner, as Figure 2 shown, an internal threaded hole coaxial with the driving wheel 460 is provided on the driving wheel 460, and the screw rod 450 penetrates through the internal threaded hole and is threadedly connected to the internal threaded hole. Exemplarily, the driving wheel 460 includes a first wheel disc and a second wheel disc located on the first wheel disc. The first wheel disc and the second wheel disc are coaxially arranged, and the internal threaded hole respectively penetrates through the first wheel disc and the second wheel disc. The bracket is fixed relative to the energy storage tank 410. The first wheel disc of the driving wheel 460 can be rotatably installed on the bracket through a sliding bearing. When the piston rods 420 move relative to the bracket, the screw rod 450 can be driven to move synchronously. When the screw rod 450 moves, it drives the driving wheel 460 to rotate through the thread. When the driving wheel 460 rotates, its second wheel disc drives the generator 200 to generate electricity.

[0064] In another possible implementation manner, as Figure 3As shown, a gear can be used as the driving wheel 460, which can be rotatably mounted on the bracket via a rotating shaft, and the gear is engaged with the screw 450. When the screw 450 moves relative to the bracket, the driving wheel 460 can be driven to rotate, thereby driving the generator 200 to generate electricity.

[0065] In this structure, when the piston rod 420 moves relative to the energy storage tank 410, it can drive the driving wheel 460 to rotate, and the rotation of the driving wheel 460 can drive the generator 200 to generate electricity.

[0066] Further, such as Figure 2 and Figure 3 As shown, the mechanical energy storage unit 400 further includes a driven wheel 470 . The diameter of the driven wheel 470 is larger than that of the driving wheel 460 . The driven wheel 470 is transmission-connected to the driving wheel 460 and the generator 200 , respectively.

[0067] For example, the driven wheel 470 can be rotatably mounted on the bracket, and the connection between the driven wheel 470 and the bracket can be the same as the connection between the driving wheel 460 and the bracket. The driven wheel 470 and the driving wheel 460 can be driven by a synchronous belt, a chain, or the driven wheel 470 and the driving wheel 460 are meshed with each other, which is not limited here.

[0068] This structure, when the driving wheel 460 rotates, can drive the driven wheel 470 to rotate, thereby driving the generator 200 to generate electricity. The driven wheel 470 can increase the torque output by the driving wheel 460, ensuring that the driving wheel 460 can stably drive the generator 200 to generate electricity when rotating.

[0069] In one embodiment, Figure 1 As shown, the thermal energy storage module 510 includes a second heating chamber 511, a first cold salt storage tank 512, a hot salt storage tank 513, and a steam generator 514. The second heating chamber 511 is connected to the power generation system, with the feed end of the second heating chamber 511 connected to the discharge end of the first cold salt storage tank 512, and the discharge end of the second heating chamber 511 connected to the feed end of the hot salt storage tank 513. The discharge end of the hot salt storage tank 513 is connected to the feed end of the steam generator 514, the outlet of the steam generator 514 is connected to the steam turbine 520, and the discharge end of the steam generator 514 is connected to the feed end of the first cold salt storage tank 512.

[0070] Among them, during the low electricity consumption period, the electricity generated by the power generation system that is surplus and not stored by the compressed gas energy storage unit 300 and the mechanical energy storage unit 400 can be transmitted to the second heating chamber 511 through the positive transmission line 610. This electricity drives the second heating chamber 511 to heat the cold salt inside it, realizing the conversion of electrical energy into thermal energy. The thermal energy generated by the second heating chamber 511 is absorbed by the cold salt transported by the first cold salt storage tank 512 and stored in the hot salt storage tank 513, thus completing the storage of thermal energy. During the high electricity consumption period, the hot salt stored in the hot salt storage tank 513 is transported to the steam generator 514 to achieve heat transfer. The steam generator 514 generates a large amount of steam by the heat transported by the hot salt storage tank 513 and drives the steam turbine 520 to do work, thereby driving the generator 200 to generate electricity, realizing the conversion of thermal energy into electrical energy. During this process, the electricity generated by the generator 200 is transmitted to the power grid through the reverse transmission line 620.

[0071] Schematically, a cold salt pump can be provided on the pipeline connecting the first cold salt storage tank 512 and the second heating chamber 511 to achieve the transportation of cold salt; a hot salt pump can be provided on the pipeline connecting the hot salt storage tank 513 and the steam generator 514 to achieve the transportation of hot salt.

[0072] Through the above settings, the thermal energy storage unit 500 can achieve the mutual conversion between electrical energy and thermal energy and improve the energy storage efficiency. During the low electricity consumption period, the thermal energy storage module 510 of the thermal energy storage unit 500 can convert the surplus electricity in the power generation system into heat for storage; during the high electricity consumption period, the thermal energy storage module 510 and the steam turbine 520 convert the heat stored in the thermal energy storage module 510 into electricity and transmit it to the power grid.

[0073] As Figure 1 shown, in one embodiment, the thermal energy storage module 510 further includes a second cold salt storage tank 515. The discharge end of the hot salt storage tank 513 is also connected to the feed end of the first heating chamber 330. The discharge end of the first heating chamber 330 is connected to the feed end of the second cold salt storage tank 515. The feed end of the second heating chamber 511 is respectively connected to the discharge end of the first cold salt storage tank 512 and the discharge end of the second cold salt storage tank 515.

[0074] Exemplarily, the pipeline connected to the discharge end of the hot salt storage tank 513 is provided with two branches, one of which is connected to the feed end of the steam generator 514, and the other branch is connected to the feed end of the first heating chamber 330. The hot salt transported from the hot salt storage tank 513 to the first heating chamber 330 is heat-exchanged with the compressed gas transported from the gas tank 320 to the first heating chamber 330 to heat the compressed gas in the first heating chamber 330. The second cold salt storage tank 515 can store the cold salt delivered from the discharge end of the first heating chamber 330. When the thermal energy storage unit 500 is storing energy, the second heating chamber 511 can heat the cold salt transported from the first cold salt storage tank 512 and the cold salt transported from the second cold salt storage tank 515, respectively. In particular, a cold salt pump can be provided on the pipeline connecting the second cold salt storage tank 515 and the second heating chamber 511 to achieve the transport of cold salt.

[0075] In this embodiment, when the compressed gas energy storage unit 300 releases energy, it can provide heat to the first heating chamber 330 through the hot salt stored in the hot salt storage tank 513, thereby reducing the input of external energy, realizing multiple utilization of energy, improving energy utilization efficiency, and reducing energy storage costs.

[0076] In one embodiment, Figure 1 As shown, the multi-mode integrated energy storage system further includes a condenser 700 , which is connected between the gas outlet of the steam turbine 520 and the liquid inlet of the steam generator 514 .

[0077] Illustratively, the steam generated by the steam generator 514 can be recovered by the condenser 700 after driving the steam turbine 520 to perform work. The steam is condensed into liquid water in the condenser 700 and transported back to the steam generator 514. Illustratively, the liquid inlet of the steam generator 514 can also be connected to a water supply device via a pipeline, so that water can be replenished into the steam generator 514 through the water supply device.

[0078] By providing the condenser 700 , water recycling can be achieved, thereby reducing the energy storage cost of the multi-mode integrated energy storage system.

[0079] Figure 1 It is shown that the compressor 310 is connected to the gas storage tank 320 through a first pipeline 350, and a first valve 351 is provided on the first pipeline 350; the gas storage tank 320 is connected to the gas turbine 340 through a second pipeline 360, and a second valve 361 is provided on the second pipeline 360; the compressor 310 is connected to the energy storage tank 410 through a third pipeline 800, and a third valve 810 is provided on the third pipeline 800; the energy storage tank 410 is connected to the steam turbine 520 through a fourth pipeline 900, and a fourth valve 910 is provided on the fourth pipeline 900.

[0080] Among them, the working state of the compressed gas energy storage unit 300 can be controlled by controlling the first valve 351 and the second valve 361. Specifically, when the first valve 351 is opened and the second valve 361 is closed, the compressed gas energy storage unit 300 can convert the surplus power in the power generation system into the compression potential energy of the gas and store it during the low electricity consumption period. During the high electricity consumption period, the first valve 351 can be closed and the second valve 361 can be opened, and the compressed gas energy storage unit 300 converts the compression potential energy of the gas into electric energy and transmits it to the power grid.

[0081] The working state of the mechanical energy storage unit 400 can be controlled by controlling the third valve 810 and the fourth valve 910. When the third valve 810 is opened and the fourth valve 910 is closed, the mechanical energy storage unit 400 can convert the surplus power in the power generation system into mechanical energy and store it during the low electricity consumption period. During the high electricity consumption period, the third valve 810 can be closed and the fourth valve 910 can be opened, and the mechanical energy storage unit 400 converts the mechanical energy into electric energy and transmits it to the power grid.

[0082] In addition, by controlling the first valve 351, the second valve 361, the third valve 810, and the fourth valve 910, one of the mechanical energy storage unit 400 and the compressed gas energy storage unit 300 can be controlled to work, or the mechanical energy storage unit 400 and the compressed gas energy storage unit 300 can be controlled to work simultaneously.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-mode integrated energy storage system, characterized in that, including electric motors, generators, compressed gas energy storage units, mechanical energy storage units, and thermal energy storage units; The electric motor is connected to the power generation system, and the generator is connected to the power grid; The compressed gas energy storage unit includes a compressor, a gas storage tank, a first heating chamber, and a turbine connected in sequence, the compressor is connected to the motor, and the turbine is connected to the generator; The input end of the mechanical energy storage unit is connected to the compressor, and the output end of the mechanical energy storage unit is connected to the generator; The thermal energy storage unit includes a thermal energy storage module and a steam turbine, the input end of the thermal energy storage module is connected to the power generation system, the output end of the thermal energy storage module is connected to the steam turbine, and the steam turbine is connected to the generator; The mechanical energy storage unit includes an energy storage tank, a piston rod, and an elastic member. The energy storage tank is connected to the compressor. The first end of the piston rod extends into the energy storage tank and is slidably connected to the energy storage tank. The second end of the piston rod extends out of the energy storage tank and is transmission-connected to the generator. The elastic member is disposed in the energy storage tank and connected to the piston rod. When the mechanical energy storage unit stores energy, the piston rod drives the elastic member to undergo elastic deformation. The energy storage tank is also connected to the steam turbine; The energy storage tank has a plurality of containers disposed in the accommodating cavity, each container being a cylindrical structure, with a spacing area between the containers. The number of piston rods is multiple, and the first ends of the plurality of piston rods extend into the plurality of containers in a one-to-one correspondence. A piston is disposed at the first end of each piston rod, and the piston separates the container into a first chamber and a second chamber, the first chamber being in communication with the spacing area, and each container is provided with the elastic member connected to the corresponding piston rod. When the mechanical energy storage unit is storing energy, the compressor introduces compressed gas into the spaced area; The thermal energy storage module includes a second heating chamber, a first cold salt storage tank, a hot salt storage tank and a steam generator.

2. The multi-mode integrated energy storage system according to claim 1, wherein The mechanical energy storage unit also includes a connecting piece, a screw, a driving wheel and a bracket. The connecting piece is respectively connected to the second end of each piston rod, the end of the screw is connected to the side of the connecting piece away from the piston rod, the bracket is fixedly installed on one side of the energy storage tank, the driving wheel is rotatably installed on the bracket, and the driving wheel is respectively connected to the screw and the generator.

3. The multi-mode integrated energy storage system according to claim 2, characterized in that, The mechanical energy storage unit further includes a driven wheel, the diameter of which is larger than the diameter of the driving wheel, and the driven wheel is transmission-connected to the driving wheel and the generator respectively.

4. The multimode integrated energy storage system according to claim 1, characterized in that, The second heating chamber is connected to the power generation system, the feed end of the second heating chamber is connected to the discharge end of the first cold salt storage tank, the discharge end of the second heating chamber is connected to the feed end of the hot salt storage tank, the discharge end of the hot salt storage tank is connected to the feed end of the steam generator, the air outlet of the steam generator is connected to the steam turbine, and the discharge end of the steam generator is connected to the feed end of the first cold salt storage tank.

5. The multi-mode integrated energy storage system according to claim 4, wherein The thermal energy storage module further includes a second cold salt storage tank. The discharge end of the hot salt storage tank is also connected to the feed end of the first heating chamber. The discharge end of the first heating chamber is connected to the feed end of the second cold salt storage tank. The feed end of the second heating chamber is respectively connected to the discharge end of the first cold salt storage tank and the discharge end of the second cold salt storage tank.

6. The multi-mode integrated energy storage system according to claim 4, wherein The multi-mode integrated energy storage system further includes a condenser, which is connected between the outlet of the steam turbine and the inlet of the steam generator.

7. The multimode integrated energy storage system according to any one of claims 1-6, characterized in that, The compressor is connected to the gas storage tank through a first pipeline, and a first valve is provided on the first pipeline. The gas storage tank is connected to the first heating chamber through a second pipeline, and a second valve is provided on the second pipeline. The compressor is connected to the energy storage tank through a third pipeline, and a third valve is provided on the third pipeline. The energy storage tank is connected to the steam turbine through a fourth pipeline, and a fourth valve is provided on the fourth pipeline.

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