High-stability vacuum flywheel energy storage and collaborative heat dissipation system

Abstract

The invention discloses a high-stability vacuum flywheel energy storage and collaborative heat dissipation system, which comprises a flywheel rotor, a thermoelectric-radiation collaborative heat dissipation system and an intelligent radiation coating system.The high-stability vacuum flywheel energy storage and collaborative heat dissipation system solves the technical problems of low thermoelectric conversion efficiency, short service life of thermoelectric materials and the like in the prior art through innovative design; while the stability of the vacuum environment is maintained, collaborative breakthrough of thermoelectric conversion efficiency and system reliability is realized, and an innovative solution is provided for a high-power-density energy storage system. The method is especially suitable for application scenes with strict requirements on power density and reliability, such as power grid frequency modulation and spacecrafts.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of flywheel energy storage, in particular to a high-stability vacuum flywheel energy storage and collaborative heat dissipation system. BACKGROUND

[0002] The flywheel energy storage system has broad application prospects in the fields of power grid frequency modulation, rail transit and aerospace due to its high power density, fast response and long cycle life. However, when the flywheel system operates in a vacuum environment, its heat dissipation problem becomes a key bottleneck restricting performance improvement.

[0003] The related technology mainly relies on a single temperature difference path in the axial direction of the flywheel for thermoelectric conversion, which fails to fully utilize the three-dimensional temperature gradient distribution of the rotor, resulting in that the Seebeck effect of the thermoelectric material cannot be fully utilized, and the actual measured energy conversion efficiency is generally low. At the same time, due to the lack of active regulation of the temperature field, the heat accumulation phenomenon in the high-temperature area is serious, which further reduces the conversion efficiency and service life of the thermoelectric material. In order to adapt to high-power scenarios, the existing technology has to use a combination scheme of multiple heat pipes and composite coatings. This design not only increases the moment of inertia of the rotor, but also significantly increases the weight of the system. More importantly, the complex internal structure makes the dynamic balance adjustment of the flywheel more difficult, and harmonic vibration problems are likely to occur when the speed exceeds 20000 rpm. Under high-temperature environment, the difference in thermal expansion coefficient between the thermoelectric material and the metal matrix will cause interface stress accumulation. Accelerated aging tests show that the heat dissipation performance is severely weakened. SUMMARY

[0004] Therefore, the embodiment of the present application provides a high-stability vacuum flywheel energy storage and collaborative heat dissipation system to solve the technical problems of low thermoelectric conversion efficiency, complex system structure and reliability contradiction in the prior art.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application provides the following technical scheme: According to the first aspect of the embodiment of the present application, the embodiment of the present application provides a high-stability vacuum flywheel energy storage and collaborative heat dissipation system, which comprises a flywheel rotor and a thermoelectric-radiation collaborative heat dissipation system. The axial center of the flywheel rotor is provided with a stepped cavity, and the inner wall of the cavity is plated with a heat conduction layer. The thermoelectric-radiation collaborative heat dissipation system comprises a three-layer composite thermoelectric module and an intelligent radiation coating system; the three-layer composite thermoelectric module is arranged in the cavity and closely adheres to the heat conduction layer, and the three-layer composite thermoelectric module comprises a high-temperature layer, a medium-temperature layer and a low-temperature layer arranged at equal intervals according to a preset interval; the intelligent radiation coating system comprises radiation coatings with different emissivities arranged on the high-temperature layer, the medium-temperature layer and the low-temperature layer, respectively.

[0006] Further, the high-temperature layer adopts SiGe alloy material; the medium-temperature layer adopts material; and the low-temperature layer adopts a nanowire structure to enhance the interface heat conduction.

[0007] Further, the intelligent radiation coating system comprises a high-temperature layer coating coating, a medium-temperature layer coating natural oxidation coating, and a low-temperature layer coating Au coating.

[0008] Further, the high-temperature layer is connected with a loop heat pipe coated on the coating, and the loop heat pipe is used for transferring heat to the coating.

[0009] Further, the loop heat pipe is made of copper-graphene composite material and filled with gallium-based liquid metal working medium.

[0010] Further, the heat conduction layer is a copper heat conduction layer.

[0011] Further, the adjacent layers of the high-temperature layer, the medium-temperature layer and the low-temperature layer are all spaced by 50 mm.

[0012] Further, the three-layer composite thermoelectric module is tightly attached to the heat conduction layer through silver paste conductive adhesive, and the high-temperature layer is close to the side of the heat conduction layer.

[0013] Further, the outer edge of the flywheel rotor is embedded with a motor rotor, and the motor rotor and a motor stator form a brushless motor system.

[0014] Further, the flywheel rotor is made of carbon fiber composite material, and the motor rotor is made of rare earth permanent magnet.

[0015] Compared with the prior art, the high-stability vacuum flywheel energy storage and collaborative heat dissipation system has the following beneficial effects: 1) Multi-stage gradient thermoelectric conversion: a plurality of layers of thermoelectric materials are arranged along the flywheel axial direction to form a three-dimensional temperature difference network, so that the thermoelectric conversion efficiency is improved; in the related art, the thermoelectric conversion is mainly dependent on a single temperature difference path along the flywheel axial direction, and the three-dimensional temperature gradient distribution of the rotor is fully utilized, so that the Seebeck effect of the thermoelectric material is fully utilized, and the actual energy conversion efficiency is increased.

[0016] 2) Intelligent radiation coating system: a segmented high / medium / low emissivity coating combination is adopted to realize directional radiation heat dissipation; a graphene-enhanced loop heat pipe is adopted, and a liquid metal working medium is embedded in the loop heat pipe, so that the heat conduction coefficient is increased to 3 times of that of a traditional heat pipe; the temperature main control field is actively regulated and controlled, the heat accumulation phenomenon in the high-temperature region is reduced, and the conversion efficiency and service life of the thermoelectric material are further improved.

[0017] 3) The device of the present application solves the technical problems of low thermoelectric conversion efficiency and short service life of thermoelectric materials in the prior art through innovative design, while maintaining the stability of the vacuum environment, realizing the synergistic breakthrough of thermoelectric conversion efficiency and system reliability, and providing an innovative solution for high-power-density energy storage systems. It is especially suitable for power grid frequency modulation, spacecraft and other application scenarios with strict requirements on power density and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the present application serve to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 A high-stability vacuum flywheel energy storage and collaborative heat dissipation system flywheel rotor overall structure diagram is provided for the embodiments of the present application; Figure 2 A high-stability vacuum flywheel energy storage and collaborative heat dissipation system flywheel rotor cavity cross-section structure diagram is provided for the embodiments of the present application; Figure 3 A high-stability vacuum flywheel energy storage and collaborative heat dissipation system thermoelectric-radiation collaborative heat dissipation system structure diagram is provided for the embodiments of the present application; Figure 4 A high-stability vacuum flywheel energy storage and collaborative heat dissipation system annular heat pipe structure diagram is provided for the embodiments of the present application.

[0019] In the figure: 1-copper heat conduction layer; 2-high temperature layer coating; 3-high temperature layer; 4-medium temperature layer; 5-low temperature layer; 6-annular heat pipe; 7-medium temperature layer coating; 8-low temperature layer coating. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0021] The following detailed description is exemplary and is intended to provide further detailed description of the present application. Unless otherwise specified, all technical terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs. The terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the exemplary embodiments according to the present application.

[0022] The present application aims at the following technical problems existing in the prior art of vacuum flywheel energy storage system: 1) The problem of low thermoelectric conversion efficiency: the prior art uses a single-stage thermoelectric module, which only utilizes a single axial temperature difference path, resulting in: insufficient utilization of the Seebeck effect, with actual conversion efficiency generally below 10%; serious heat accumulation at the hot end, with material operating temperature exceeding the optimal range; low thermoelectric output power density, which cannot meet high power requirements.

[0023] 2) The problem of contradiction between complex system structure and reliability: the prior art often uses multiple-stage liquid cooling pipelines to increase rotational inertia; the layout of the heat pipe and the coating lacks coordination, resulting in an increase of more than 40% in thermal resistance; harmonic vibration is easily generated at speeds above 20,000 rpm.

[0024] To solve the above technical problems, the high-stability vacuum flywheel energy storage and collaborative cooling system of the present application embodiment significantly improves the cooling efficiency and operating stability of the flywheel energy storage in a vacuum environment through an innovative thermoelectric-radiation collaborative cooling architecture and an optimized vacuum maintenance scheme.

[0025] The high-stability vacuum flywheel energy storage and collaborative cooling system of the present application embodiment includes a flywheel rotor and a thermoelectric-radiation collaborative cooling system, which realizes the transfer and export of heat generated by the flywheel system through the setting of the thermoelectric-radiation collaborative cooling system.

[0026] In this embodiment, as shown in Figure 1 , the axial center of the flywheel rotor is provided with a stepped cavity, and the inner wall of the cavity is plated with a 0.1mm thick copper heat conduction layer 1. The outer edge of the flywheel rotor is embedded with a motor rotor, and the motor rotor and the motor stator form a brushless motor system. The flywheel rotor is made of carbon fiber composite material, and the motor rotor is made of rare earth permanent magnet.

[0027] In this embodiment, as shown in Figure 2 , the thermoelectric-radiation collaborative cooling system includes a three-layer composite thermoelectric module and an intelligent radiation coating system; the three-layer composite thermoelectric module is arranged in the cavity and closely adheres to the copper heat conduction layer 1, and the three-layer composite thermoelectric module includes a high-temperature layer 3, a medium-temperature layer 4 and a low-temperature layer 5 arranged at equal intervals according to a predetermined interval. In this embodiment, the three-layer composite thermoelectric module is closely adhered to the copper heat conduction layer 1 by silver paste conductive adhesive, and the high-temperature layer 3 is close to one side of the copper heat conduction layer 1. The intelligent radiation coating system includes radiation coatings with different emissivities arranged on the high-temperature layer 3, the medium-temperature layer 4 and the low-temperature layer 5, i.e. the high-temperature layer coating 2, the medium-temperature layer coating 7 and the low-temperature layer coating 8.

[0028] In this embodiment, the high-temperature layer 3 is made of SiGe alloy material with a temperature resistance of 350℃; the medium-temperature layer 4 is made of material; and the low-temperature layer 5 is made of nanowire structure to enhance interface heat conduction. The adjacent layers of the high-temperature layer 3, the medium-temperature layer 4 and the low-temperature layer 5 are all spaced apart by 50mm. The intelligent radiation coating system includes the high-temperature layer coating 2 coated on the high-temperature layer 3, the medium-temperature layer coating 7 coated on the medium-temperature layer 4, and the low-temperature layer coating 8 coated on the low-temperature layer 5. Coating (high temperature layer coating 2), middle temperature layer 4 coated Natural oxidation coating (middle temperature layer coating 7), low temperature layer 5 coated Au coating (emissivity 0.08) (low temperature layer coating 8). In this embodiment, high temperature zone: > 150℃; middle temperature zone: 80-150℃; low temperature zone: < 80℃.

[0029] High temperature layer 3 and high temperature layer 3 coated Coating is connected with annular heat pipe 6, annular heat pipe 6 is used for transmitting heat to Coating, avoid its overheating. In this embodiment, annular heat pipe 6 is made of copper-graphene composite material, and is filled with gallium-based liquid metal working medium, and the outer diameter of heat pipe is 30mm, and the wall thickness is 2mm.

[0030] From the technical common sense, the application can be realized by other embodiments without departing from the spirit or essential characteristics thereof. Therefore, the above disclosed embodiments are only examples, and are not the only ones. All changes within the scope of the application or within the scope equivalent to the application are included in the application.

[0031] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system or a computer program product. Therefore, the application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, optical storage, etc.) containing computer usable program code.

[0032] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks

[0033] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction devices, which implement the functions specified in the flowcharts and / or block diagrams. Figure 1one or more processes and / or blocks Figure 1 the function specified in the one or more blocks.

[0034] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, so that the instructions executed on the computer or other programmable data processing devices provide processes for implementing the flow Figure 1 one or more processes and / or blocks Figure 1 the steps of the function specified in the one or more blocks.

[0035] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand: the specific embodiments of the present application can still be modified or replaced by the equivalent, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered within the protection scope of the claims of the present application.

Claims

1. A high-stability vacuum flywheel energy storage and collaborative heat dissipation system, characterized in that, The system comprises a flywheel rotor and a thermoelectric-radiation synergistic heat dissipation system. The axial center of the flywheel rotor is provided with a stepped cavity, and the inner wall of the cavity is plated with a heat conduction layer. The thermoelectric-radiation synergistic heat dissipation system comprises a three-layer composite thermoelectric module and an intelligent radiation coating system; the three-layer composite thermoelectric module is arranged in the cavity and closely adheres to the heat conduction layer, and the three-layer composite thermoelectric module comprises a high-temperature layer, a medium-temperature layer and a low-temperature layer arranged at equal intervals according to a preset interval. The intelligent radiation coating system comprises radiation coatings with different emissivities arranged on the high-temperature layer, the medium-temperature layer and the low-temperature layer respectively.

2. A high-stability vacuum flywheel energy storage and synergistic heat dissipation system according to claim 1, characterized in that, The high-temperature layer adopts SiGe alloy material; the medium-temperature layer adopts material; and the low-temperature layer adopts a nanowire structure to enhance interface heat conduction.

3. The high-stability vacuum flywheel energy storage and synergistic heat dissipation system according to claim 1, characterized in that, The smart radiant coating system includes a high temperature layer coated with a coating, a medium temperature layer coated with a natural oxide coating, a low temperature layer coated with Au coating.

4. The high-stability vacuum flywheel energy storage and synergistic heat dissipation system according to claim 3, characterized in that, The high temperature layer is coated with a high temperature layer The coating is connected with a loop heat pipe for transferring heat to The coating.

5. A high-stability vacuum flywheel energy storage and synergic heat dissipation system according to claim 4, characterized in that, The annular heat pipe is made of copper-graphene composite material and filled with gallium-based liquid metal working medium.

6. The high-stability vacuum flywheel energy storage and synergic heat dissipation system according to claim 1, characterized in that, The heat conduction layer is a copper heat conduction layer.

7. The high-stability vacuum flywheel energy storage and synergic heat dissipation system according to claim 1, characterized in that, The interval between adjacent layers of the high-temperature layer, the medium-temperature layer and the low-temperature layer is 50 mm.

8. The high-stability vacuum flywheel energy storage and synergic heat dissipation system according to claim 1, characterized in that, The three-layer composite thermoelectric module closely adheres to the heat conduction layer through silver paste conductive adhesive, and the high-temperature layer is close to one side of the heat conduction layer.

9. The high-stability vacuum flywheel energy storage and synergistic heat dissipation system of claim 1, wherein, The outer edge of the flywheel rotor is embedded with a motor rotor, and the motor rotor and a motor stator constitute a brushless motor system.

10. The high-stability vacuum flywheel energy storage and synergic heat dissipation system according to claim 9, characterized in that, The flywheel rotor is made of carbon fiber composite material, and the motor rotor is made of rare earth permanent magnet.

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