Working condition self-adaptive water pumping compressed air energy storage device

Abstract

The utility model relates to the technical field of energy storage, in particular to a working condition self-adaptive water pumping and compressed air energy storage device which comprises a water storage pond, a reversible pump turbine, a water-gas co-containing cabin and a compressor. The water storage tank is connected with one end of the reversible pump turbine through a first pipeline, and the other end of the reversible pump turbine is connected with the water-gas co-containing cabin through a second pipeline; an alternating-current excitation motor is arranged on the reversible water pump water wheel, and a double-fed converter is arranged on the alternating-current excitation motor; the AC excitation motor and the double-fed converter are electrically connected with the power grid, can generate and supply power to the power grid, and can absorb the power of the power grid to drive a mechanical load. Compared with a fixed-rotating-speed synchronous motor in a traditional energy storage device, the alternating-current excitation doubly-fed motor is variable in rotating speed, by continuously changing the rotating speed, the alternating-current excitation doubly-fed motor can adapt to continuously-changing working conditions, pressure pulsation is reduced, it is ensured that a water pump and a water turbine always run in the optimal working condition, and high efficiency of energy conversion is ensured.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a working condition-adaptive water-pumped compressed air energy storage device. Background Art

[0002] In recent years, the use of renewable energy such as wind power and photovoltaic power generation has gradually developed. However, due to their intermittent and volatile nature that are not controlled by humans, their further development has become a certain obstacle.

[0003] Based on the above situation, a method of storing energy by pumping water and compressing air has emerged. Water is injected into the water-gas co-containment chamber through a water pump, which is equivalent to building a virtual dam between the downstream water storage tank and the pressure vessel connected to the water pump. By controlling the air pressure in the water-gas co-containment chamber, the drop between the upstream and downstream of the virtual dam can be changed, thereby storing excess electricity. When discharging, the water in the water-gas co-containment chamber drives the turbine to rotate to generate electricity, and then the stored energy is released for use. This method has certain positive significance, but it also has certain disadvantages. For example, the pressure change range in the water-gas co-containment chamber is large, which makes the pressure at the inlet of the turbine or water pump continue to change, but the electric power of the device driving the water pump is usually not adjustable. Therefore, when the energy storage power of the power grid changes continuously, the existing energy storage system cannot follow this change in real time, thereby affecting the energy efficiency and power generation quality of the energy storage system. Utility Model Content

[0004] In order to solve the above technical problems or partially solve the above technical problems, the present application provides a working condition adaptive water pumping compressed air energy storage device.

[0005] The present application provides a working condition adaptive water-pumping compressed air energy storage device, comprising a water storage tank, a reversible pump-turbine, a water-gas co-containment chamber and a compressor; the water storage tank is connected to one end of the reversible pump-turbine through a first pipeline, and the other end of the reversible pump-turbine is connected to the water-gas co-containment chamber through a second pipeline; the reversible pump-turbine is provided with an AC excitation motor, and the AC excitation motor is provided with a doubly-fed converter; the AC excitation motor and the doubly-fed converter are both electrically connected to a power grid.

[0006] Optionally, the rotor of the AC excitation motor is electrically connected to the doubly-fed converter.

[0007] Optionally, the stator of the AC excitation motor is connected to the power grid.

[0008] Optionally, the compressor is provided with an electric motor for driving the compressor to operate, and the electric motor is connected to the power grid.

[0009] Optionally, a first throttle valve is provided on the second pipeline.

[0010] Optionally, a branch pipe is provided on the second pipeline, one end of the branch pipe is connected to a section of the second pipeline where the first throttle valve is connected to the liquid volume chamber of the water-vapor co-containment chamber, and the other end of the branch pipe is connected to the gas volume chamber of the water-vapor co-containment chamber.

[0011] Optionally, a second throttle valve is provided on the branch pipeline.

[0012] Optionally, a sprinkler head is provided at one end of the branch pipe communicating with the gas volume chamber.

[0013] Optionally, the exhaust port of the compressor is connected to the gas volume chamber of the water-gas co-containing chamber through a third pipeline, and a third throttle valve is provided on the third pipeline.

[0014] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following advantages:

[0015] The working condition adaptive pumping compressed air energy storage device provided in the present application can both generate electricity and send electricity to the power grid, and absorb electricity from the power grid to drive mechanical loads; compared with the fixed-speed synchronous motor in the traditional energy storage device, the AC-excited doubly-fed motor in the present application is a variable-speed motor. By constantly changing the speed, it can adapt to the changing working conditions, reduce pressure pulsation, ensure that the water pump and turbine are always in the optimal working condition, and ensure high efficiency of energy conversion; in addition, when storing energy, by constantly changing the speed, the input power of the reversible water pump turbine is steplessly adjustable, and is no longer a fixed value, but the water pump input power is changed in real time according to the actual demand of the power grid for energy storage, so as to constantly adapt to and match the energy storage demand of the power grid; in addition, the reversible water pump turbine in the present application adopts an integrated setting, and when the actual layout construction is carried out, the equipment volume is small, and at the same time, the amount of engineering excavation can be reduced, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 This is a schematic structural diagram of the working condition adaptive water-pumping compressed air energy storage device described in an embodiment of the present application.

[0019] in,

[0020] 1. Water storage tank; 10. First pipeline; 2. Reversible pump turbine; 20. Second pipeline; 21. First throttle valve; 22. Second throttle valve; 23. Branch pipeline; 24. Sprinkler head; 3. Water-gas co-containment chamber; 4. Doubly-fed converter; 5. Third pipeline; 50. Third throttle valve; 6. AC excitation motor; 60. Rotor; 61. Stator; 7. Compressor; 70. Electric motor; 8. Power grid. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0024] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0027] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0028] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0029] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] Reference Figure 1 As shown, the present embodiment provides a working condition adaptive water-pumping compressed air energy storage device comprising a water storage tank 1, a reversible pump-turbine 2, a water-gas co-containment chamber 3, and a compressor 7; the water storage tank 1 is connected to one end of the reversible pump-turbine 2 via a first pipe 10, and the other end of the reversible pump-turbine 2 is connected to the water-gas co-containment chamber 3 via a second pipe 20; the reversible pump-turbine 2 is provided with an AC excitation motor 6, and the AC excitation motor 6 is provided with a doubly-fed converter 4; the AC excitation motor 6 and the doubly-fed converter 4 are both electrically connected to the power grid 8.

[0031] Exemplarily, the water storage tank 1 can be open, and can be dug on site and rebuilt in the actual process; the water-gas co-containment chamber 3 is a high-pressure sealing structure to ensure that the specified pressure change can be achieved.

[0032] In addition, when the reversible pump-turbine 2 acts as a water pump, that is, when it pumps water into the water-gas co-containment chamber 3, its power source is the surplus electric energy in the power grid 8; and when the reversible pump-turbine 2 acts as a water turbine, that is, when water flows from the water-gas co-containment chamber 3 through the reversible pump-turbine 2 into the water storage tank 1, the electric energy it generates will be transmitted to the power grid 8.

[0033] In the present application, the AC excitation motor 6 and the doubly fed converter 4 are combined to replace the traditional turbine-generator and water pump-motor combination, so that they can realize the role of both the motor and the generator; the AC excitation motor 6 and the doubly fed converter 4 are combined to decouple the mechanical angular velocity from the electrical angular velocity, that is, while maintaining the 50 Hz operating frequency on the stator 61 side unchanged, the mechanical speed can be continuously changed within a certain range, so that they can adapt to each other when dealing with changing water flow conditions to ensure the high efficiency of energy conversion; the energy storage and release process is realized by filling and draining the water-gas co-containment tank 3.

[0034] Compared with the fixed-speed synchronous motor in the traditional energy storage device, the AC-excited doubly-fed motor in the present application is of variable speed. By constantly changing the speed, it can adapt to the changing working conditions, reduce pressure pulsation, ensure that the water pump and the turbine are always in the optimal working condition, and ensure high efficiency of energy conversion; in addition, when storing energy, by constantly changing the speed, the input power of the reversible pump-turbine 2 is steplessly adjustable. It is no longer a fixed value, but the water pump input power is changed in real time according to the actual demand of the energy storage power of the power grid 8, constantly adapting to and matching the energy storage demand of the power grid 8; in addition, the reversible pump-turbine 2 in the present application adopts an integrated setting. During the actual layout construction, the equipment occupies a small volume, and at the same time, it can also reduce the amount of engineering excavation and reduce costs.

[0035] In some further embodiments, the rotor 60 of the AC excitation motor 6 is electrically connected to the doubly-fed converter 4, and the stator 61 of the AC excitation motor 6 is connected to the power grid 8; so that during normal operation, current exists on both the stator 61 side and the rotor 60 side, and finally connected to the power grid 8 to transmit electric power.

[0036] In some further embodiments, the compressor 7 is provided with an electric motor 70 for driving the compressor 7 to operate, and the electric motor 70 is connected to the power grid 8; specifically, the electric motor 70 is used to drive the compressor 7 to pressurize the water-gas co-containment chamber 3.

[0037] In some further embodiments, a first throttle valve 21 is provided on the second pipeline 20 , and the first throttle valve 21 is provided on the second pipeline 20 to control the opening and closing of the second pipeline 20 .

[0038] In some further embodiments, a branch pipe 23 is provided on the second pipe 20, one end of the branch pipe 23 is connected to a section of the second pipe 20 where the first throttle valve 21 is connected to the liquid volume chamber of the water-vapor co-containment chamber 3, and the other end of the branch pipe 23 is connected to the gas volume chamber of the water-vapor co-containment chamber 3.

[0039] The liquid in the water-gas co-containment chamber 3 is relatively located at the bottom, and the area at the bottom is recorded as the liquid volume chamber, while the gas is relatively located at the top, and the area at the top is recorded as the gas volume chamber.

[0040] When compression is being carried out in the water-vapor co-containment chamber 3, the temperature inside it will change, and the temperature change will in turn affect the pressure. In order to more accurately control the temperature change in the water-vapor co-containment chamber 3, a branch pipe 23 connected to the gas volume chamber is provided to allow the water entering the water-vapor co-containment chamber 3 to fully exchange heat with the compressed gas, thereby avoiding the influence of the material temperature on the pressure.

[0041] In some further embodiments, a second throttle valve 22 is provided on the branch pipeline 23 ; the second throttle valve 22 on the branch pipeline 23 is used to control the opening and closing of the branch pipeline 23 .

[0042] In some further embodiments, a spray head 24 is provided at one end of the branch pipe 23 that is connected to the gas volume chamber; the spray head 24 is used to spray water entering the water-gas co-containment chamber 3 over a larger area, thereby more fully exchanging heat with the compressed gas.

[0043] In some further embodiments, the exhaust port of the compressor 7 is connected to the gas volume chamber of the water-vapor co-containment chamber 3 through a third pipe 5, and a third throttle valve 50 is provided on the third pipe 5; specifically, the compressor 7 is connected to the water-vapor co-containment chamber 3 through the third pipe 5, and when the gas volume chamber needs to be pressurized, the compressor 7 works, thereby compressing the gas into the water-vapor co-containment chamber 3 to achieve pressurization.

[0044] The whole device consists of the following three stages.

[0045] Preset stage: Before the whole system starts working, a certain amount of gas is first charged into the water-gas co-containment chamber 3 by the compressor 7 to make the internal pressure reach the preset pressure, that is, to create a high-pressure environment at the water-gas interface. After that, the compressor 7 is only used to supplement the internal air leakage of the system and no longer participates in the energy storage and release of the system.

[0046] Energy storage stage: water is filled into the water-gas co-containment chamber 3 by using the reversible pump turbine 2, the AC excitation motor 6 and the doubly-fed converter 4. Since the gas part is compressed, the temperature will slowly rise, so the second throttle valve 22 is adjusted to allow part of the water to enter the interior by spraying, accelerate the heat exchange between the water and the gas part, and adjust the temperature inside the water-gas co-containment chamber 3, so as to keep the internal pressure constant.

[0047] Energy release stage: the water inside the water-gas co-containment chamber 3 is released, and power is generated by the reversible pump-turbine 2, the AC excitation motor 6, and the doubly-fed converter 4. In the process of compressed air pushing water outward to do work, the expansion of the gas will cause the gas temperature and pressure to decrease. At this time, high-pressure steam is introduced into the water-gas co-containment chamber 3 to compensate for the decrease in gas pressure.

[0048] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

Claims

1. A working condition adaptive pumped compressed air energy storage device, characterized in that: The invention comprises a water storage tank (1), a reversible pump turbine (2), a water-gas co-containment tank (3) and a compressor (7); the water storage tank (1) is connected to one end of the reversible pump turbine (2) via a first pipeline (10), and the other end of the reversible pump turbine (2) is connected to the water-gas co-containment tank (3) via a second pipeline (20); an AC excitation motor (6) is provided on the reversible pump turbine (2), and a doubly-fed converter (4) is provided on the AC excitation motor (6); the AC excitation motor (6) and the doubly-fed converter (4) are both electrically connected to a power grid (8).

2. The working condition adaptive pumped compressed air energy storage device according to claim 1, characterized in that: The rotor (60) of the AC excitation motor (6) is electrically connected to the double-fed converter (4).

3. The working condition adaptive pumped compressed air energy storage device according to claim 1, characterized in that: The stator (61) of the AC excitation motor (6) is connected to the power grid (8).

4. The working condition adaptive pumped compressed air energy storage device according to claim 1, characterized in that: The compressor (7) is provided with an electric motor (70) for driving the compressor (7) to operate, and the electric motor (70) is connected to the power grid (8).

5. The working condition adaptive pumped compressed air energy storage device according to claim 1, characterized in that: The second pipeline (20) is provided with a first throttle valve (21).

6. The working condition adaptive pumped compressed air energy storage device according to claim 5, characterized in that: The second pipeline (20) is provided with a branch pipeline (23), one end of the branch pipeline (23) is connected to a section of the second pipeline (20) where the first throttle valve (21) is in communication with the liquid volume chamber of the water-gas co-accommodation chamber (3), and the other end of the branch pipeline (23) is in communication with the gas volume chamber of the water-gas co-accommodation chamber (3).

7. The working condition adaptive pumped compressed air energy storage device according to claim 6, characterized in that: The branch pipeline (23) is provided with a second throttle valve (22).

8. The working condition adaptive pumped compressed air energy storage device according to claim 6, characterized in that: A spray head (24) is provided at one end of the branch pipe (23) that is in communication with the gas volume chamber.

9. The working condition adaptive pumped compressed air energy storage device according to claim 1, characterized in that: The exhaust port of the compressor (7) is in communication with the gas volume chamber of the water-gas co-accommodation chamber (3) via a third pipeline (5), and a third throttle valve (50) is provided on the third pipeline (5).

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