Flywheel coupling fused salt energy storage thermal power peak regulation power generation system and operation method

Abstract

The invention provides a flywheel coupling fused salt energy storage thermal power peak regulation power generation system and an operation method. The method comprises the steps that the operation state of the power generation system is obtained; and according to the operation state, determining a power grid power supply main body and a supplementary power supply main body from the thermal power generating unit, the fused salt energy storage module and the flywheel energy storage module so as to perform peak regulation of the power generation system. According to the method, through multi-dimensional complementation of high frequency-low frequency, short time-long time and power type-energy type of a flywheel energy storage module and a fused salt energy storage module, the seesaw trapping of single energy storage in response speed and duration is broken, the peak regulation rate, depth and safety of a thermal power generating unit are remarkably improved, and meanwhile peak regulation coal consumption and carbon emission are greatly reduced; the collaborative architecture of flywheel stabilization fluctuation, fused salt energy translation and thermal power stable support provides an innovative paradigm for constructing a thermal power peak regulation system with high elasticity, low cost and long service life, and powerfully supports a power grid to consume fluctuating renewable energy sources and realizes dynamic balance of source grid load storage.

Description

Technical Field

[0001] This invention belongs to the field of thermal power peak shaving technology, specifically relating to a thermal power peak shaving power generation system and operation method of flywheel coupled molten salt energy storage. Background Technology

[0002] Against the backdrop of building a new power system and accelerating the green energy transition, thermal power units face severe challenges in peak-shaving flexibility: on the one hand, the high proportion of renewable energy grid connection leads to increased grid load fluctuations, requiring thermal power to undertake deep, rapid, and frequent peak-shaving tasks; on the other hand, traditional coal-fired units are limited by large thermal inertia, slow ramp-up rate (usually <2% of rated load / minute), and high minimum stable combustion load (40%-50% of rated load), which can easily cause problems such as a sharp drop in boiler efficiency, hydrodynamic instability, excessive pollutant emissions, and accelerated equipment lifespan loss during deep peak-shaving, putting pressure on both economic efficiency and safety.

[0003] Existing peak-shaving technologies each have their own shortcomings when considering individual energy storage solutions: electrochemical energy storage offers fast response but is limited in capacity, has a short lifespan, and is costly; molten salt thermal energy storage (such as binary nitrate) offers advantages such as large capacity (hundreds of megawatt-hours), long lifespan (>25 years), and low cost, but its thermal inertia causes response delays (minutes), making it difficult to track rapid power fluctuations ranging from seconds to minutes; flywheel energy storage, with its millisecond-level response, million-cycle lifespan, and instantaneous high-power throughput capability (megawatt-level), can accurately smooth high-frequency fluctuations, but its self-discharge characteristics (hours) and energy density (typically <50Wh / kg) limit its ability to support continuous peak-shaving needs on an hourly scale. Therefore, there is an urgent need to develop multi-timescale collaborative composite energy storage systems to overcome the bottleneck of thermal power peak-shaving.

[0004] To address the aforementioned issues, it is necessary to propose a flywheel-coupled molten salt energy storage thermal power peak-shaving generation system and its operation method that are reasonably designed and effectively solve these problems. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art, and to provide a thermal power peak-shaving power generation system and operation method with flywheel coupled molten salt energy storage.

[0006] One aspect of the present invention provides an operation method for a thermal power peak-shaving generation system with flywheel coupled molten salt energy storage, the power generation system comprising a thermal power unit, a molten salt energy storage module, and a flywheel energy storage module; the operation method comprising:

[0007] Step 1: Obtain the operating status of the power generation system;

[0008] Step 2: Based on the operating status of the power generation system, determine the main power supply entity and the supplementary power supply entity from the thermal power unit, the molten salt energy storage module and the flywheel energy storage module, so as to carry out peak regulation of the power generation system.

[0009] Optionally, step two specifically includes:

[0010] When the power generation system is in normal operation, the molten salt energy storage module and the flywheel energy storage module are in a silent state, and the thermal power unit directly supplies power to the grid.

[0011] Optionally, step two may also include:

[0012] When the power generation system is in a peak-shaving fluctuation state, the thermal power unit supplies power to the grid, and at the same time uses the electricity stored in the molten salt energy storage module and the flywheel energy storage module as supplementary power supply; wherein, the electricity stored in the flywheel energy storage module is used first for supplementary power supply.

[0013] Optionally, step two may also include:

[0014] When the power generation system is in a deep energy storage state, electrical energy is preferentially stored in the flywheel energy storage module, while the remaining electrical energy is stored in the molten salt energy storage module.

[0015] Optionally, step two may also include:

[0016] When the power generation system is in a low-frequency operating state, the thermal power unit is adjusted to operate at the minimum load, and supplementary power is provided by the molten salt energy storage module and the flywheel energy storage module respectively.

[0017] Optionally, step two may also include:

[0018] When the power generation system is in a state of rapid load increase, the flywheel energy storage module shall give priority to grid power supply, while the molten salt energy storage module shall provide supplementary power supply.

[0019] Optionally, step two may also include:

[0020] When the power generation system is in a rapid load reduction state, the redundant power generation during the load reduction process of the thermal power unit is respectively sent to the flywheel energy storage module and the molten salt energy storage module for storage.

[0021] Optionally, step two may also include:

[0022] When the generator set is in a stable operating state, the energy stored in the molten salt energy storage module is used to heat the boiler feedwater of the thermal power unit, and the excess energy is used for power generation and peak shaving.

[0023] Another aspect of the present invention provides a thermal power peak-shaving power generation system with flywheel coupled molten salt energy storage, including a thermal power unit, a molten salt energy storage module and a flywheel energy storage module;

[0024] The flywheel energy storage module includes a flywheel motor, a flywheel body, a flywheel drive shaft, and a flywheel housing; wherein, the flywheel motor is connected to the flywheel body via the flywheel drive shaft, and the flywheel body is disposed within the flywheel housing;

[0025] The molten salt energy storage module includes a high-temperature molten salt storage tank, a molten salt heat exchanger, a molten salt generator set, and a low-temperature molten salt storage tank;

[0026] The thermal power unit includes a feedwater heater;

[0027] The outlet of the high-temperature molten salt storage tank is connected to the high-temperature side inlet of the molten salt heat exchanger, and the high-temperature side outlet of the molten salt heat exchanger is connected to the inlet of the low-temperature molten salt storage tank.

[0028] The low-temperature side outlet of the molten salt heat exchanger is connected to the molten salt generator set;

[0029] The heat source side of the feedwater heater is connected to the high-temperature molten salt storage tank, and the cold source side of the feedwater heater is connected to the feedwater circuit of the thermal power unit.

[0030] The flywheel energy storage module and the molten salt energy storage module are electrically connected to the power grid and operate in coordination with the thermal power unit to achieve the peak-shaving function of the power grid.

[0031] Optionally, renewable energy generation modules may also be included;

[0032] The renewable energy power generation module is connected to the flywheel motor and the cryogenic molten salt storage tank, respectively.

[0033] This invention discloses a flywheel-coupled molten salt energy storage thermal power peak-shaving generation system and its operation method. The operation method includes: acquiring the operating status of the power generation system; and, based on the operating status of the power generation system, determining the main power supply entity and supplementary power supply entity from the thermal power unit, molten salt energy storage module, and flywheel energy storage module to perform peak shaving of the power generation system. This method, through the multi-dimensional complementarity of the flywheel energy storage module and molten salt energy storage module in terms of "high frequency-low frequency, short time-long time, power type-energy type," not only breaks the "seesaw" dilemma of single energy storage in response speed and duration, but also significantly improves the peak shaving rate (climb rate increased to 5%-8% / minute), depth (minimum load reduced to 20%-30%), and safety (avoiding frequent boiler start-ups and shutdowns) of the thermal power unit, while greatly reducing peak shaving coal consumption and carbon emissions. Its synergistic architecture of "flywheel smoothing fluctuations + molten salt energy shifting + thermal power stability support" provides an innovative paradigm for building a highly resilient, low-cost, and long-life thermal power peak-shaving system, effectively supporting the grid's absorption of fluctuating renewable energy and achieving dynamic balance between power generation, grid, load, and storage. Attached Figure Description

[0034] Figure 1This is a schematic diagram of a flywheel coupled molten salt energy storage thermal power peak-shaving power generation system according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic flowchart illustrating the operation method of a flywheel coupled molten salt energy storage thermal power peak-shaving power generation system according to another embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1 As shown, one aspect of the present invention provides a thermal power generation system with flywheel coupled molten salt energy storage, including a thermal power unit, a molten salt energy storage module and a flywheel energy storage module.

[0038] The flywheel energy storage module includes a flywheel motor 1, a flywheel body 2, a flywheel drive shaft 3, and a flywheel housing 4; wherein, the flywheel motor 1 is connected to the flywheel body 2 through the flywheel drive shaft 3, and the flywheel body 2 is disposed in the flywheel housing 4.

[0039] The molten salt energy storage module includes a high-temperature molten salt storage tank 5, a molten salt heat exchanger 6, a molten salt generator set 7, and a low-temperature molten salt storage tank 8. The thermal power unit includes a feedwater heater 9.

[0040] The outlet of the high-temperature molten salt storage tank 5 is connected to the high-temperature inlet of the molten salt heat exchanger 6, and the high-temperature outlet of the molten salt heat exchanger 6 is connected to the inlet of the low-temperature molten salt storage tank 8. The low-temperature outlet of the molten salt heat exchanger 6 is connected to the molten salt generator set 7.

[0041] The heat source side of the feedwater heater 9 is connected to the high-temperature molten salt storage tank 5, and the cold source side of the feedwater heater 9 is connected to the feedwater circuit of the thermal power unit.

[0042] The flywheel energy storage module and the molten salt energy storage module are electrically connected to the power grid and operate in coordination with the thermal power unit to realize the peak-shaving function of the power grid.

[0043] For example, such as Figure 1 As shown, it also includes renewable energy generation modules, which can include wind and solar power generation or photovoltaic power generation, etc. The renewable energy generation modules are connected to a flywheel motor and a cryogenic molten salt storage tank, respectively. The redundant power generated by wind and solar renewable energy sources that cannot be connected to the grid during peak periods can be stored in the flywheel energy storage module and the molten salt energy storage module.

[0044] Specifically, the redundant power generation from the thermal power generation and renewable energy generation modules can be used to heat the low-temperature molten salt into high-temperature molten salt in the low-temperature molten salt storage tank 8, and then store it in the high-temperature molten salt storage tank 5. The heat stored in the high-temperature molten salt can not only heat the boiler feedwater of the thermal power unit, but also generate electricity. When power generation is needed, the high-temperature molten salt is used to heat part of the steam extracted from the steam turbine in the molten salt heat exchanger 6, and the electricity is generated and fed into the grid through the molten salt generator set 7.

[0045] The flywheel coupled molten salt energy storage thermal power peak-shaving power generation system of the present invention couples thermal power units, molten salt energy storage modules and flywheel energy storage modules into a new type of power system, which can not only achieve a significant reduction in carbon emissions from thermal power generation groups, but also achieve flexible peak-shaving of the power system.

[0046] like Figure 2 As shown, another aspect of the present invention provides an operation method for a thermal power peak-shaving power generation system with flywheel coupled molten salt energy storage, wherein the power generation system includes a thermal power unit, a molten salt energy storage module, and a flywheel energy storage module; the operation method includes:

[0047] Step 1: Obtain the operating status of the power generation system.

[0048] Step 2: Based on the operating status of the power generation system, determine the main power supply entity and the supplementary power supply entity from the thermal power unit, the molten salt energy storage module and the flywheel energy storage module, so as to carry out peak regulation of the power generation system.

[0049] Specifically, the process of grid peak shaving based on the operating status of the power generation system can be as follows:

[0050] 1) When the power generation system is in normal operation, the molten salt energy storage module and the flywheel energy storage module are in a silent state, and the thermal power unit directly supplies power to the grid.

[0051] 2) When the power generation system is in a peak-shaving fluctuation state, the thermal power unit supplies power to the grid, and at the same time uses the electricity stored in the molten salt energy storage module and the flywheel energy storage module as supplementary power supply to smooth power fluctuations; wherein, the electricity stored in the flywheel energy storage module is used first for supplementary power supply, which can realize a rapid response to peak-shaving fluctuations.

[0052] 3) When the power generation system is in a deep energy storage state, i.e., during periods of high renewable energy generation, electrical energy is preferentially stored in the flywheel energy storage module, while the remaining electrical energy is stored in the molten salt energy storage module. In other words, the redundant power generated by the renewable energy power generation module is stored in both the flywheel energy storage module and the molten salt energy storage module.

[0053] 4) When the power generation system is in a low-frequency operating state, the thermal power unit is adjusted to operate at the minimum load, and supplementary power is provided by the molten salt energy storage module and the flywheel energy storage module respectively.

[0054] 5) When the power generation system is in a state of rapid load increase, the flywheel energy storage module shall give priority to grid power supply, while the molten salt energy storage module shall provide supplementary power supply, and the load output of the energy storage system shall be reduced while waiting for the thermal power unit load to increase.

[0055] In this step, when the entire power generation system needs to rapidly increase its load, power is supplied first through the flywheel energy storage module and then through the molten salt energy storage module. This not only provides a buffer for the load increase of the thermal power unit, but also enables the power generation system to flexibly increase its load.

[0056] 6) When the power generation system is in a rapid load reduction state, the thermal power unit does not need to reduce the load rapidly, which would shorten the equipment life. Instead, the redundant power generation during the load reduction process of the thermal power unit is sent to the flywheel energy storage module and the molten salt energy storage module for storage.

[0057] In this step, when the entire power generation system needs to reduce load quickly, in order to avoid the impact of rapid load reduction on the lifespan of thermal power units, the redundant power generation during the load reduction process can be stored, and the storage should be prioritized in the flywheel energy storage module, which can better adapt to the multiple peak adjustments of the power system within a day.

[0058] It should be noted that, in this embodiment, the energy stored in the flywheel energy storage module and the molten salt energy storage module comes from two sources: one is the redundant power generation when the thermal power unit rapidly reduces its load, and the other is the redundant power generation that cannot be connected to the grid during peak periods of renewable energy generation such as wind and solar power.

[0059] 7) When the generator set is in a stable operating state, the energy stored in the molten salt energy storage module is used to heat the boiler feedwater of the thermal power unit, and the excess energy is used for power generation and peak shaving.

[0060] The operating method of the flywheel-coupled molten salt energy storage thermal power peak-shaving generation system of the present invention includes: acquiring the operating status of the power generation system; and determining the main power supply entity and supplementary power supply entity from the thermal power unit, molten salt energy storage module, and flywheel energy storage module according to the operating status of the power generation system, so as to perform peak shaving of the power generation system. This method, through the multi-dimensional complementarity of the flywheel energy storage module and the molten salt energy storage module in terms of "high frequency-low frequency, short time-long time, power type-energy type", not only breaks the "seesaw" dilemma of single energy storage in response speed and duration, but also significantly improves the peak shaving rate (climbing rate increased to 5%-8% / minute), depth (minimum load reduced to 20%-30%), and safety (avoiding frequent boiler start-ups and shutdowns) of the thermal power unit, while greatly reducing peak shaving coal consumption and carbon emissions. Its synergistic architecture of "flywheel smoothing fluctuations + molten salt energy shifting + thermal power stability support" provides an innovative paradigm for building a highly resilient, low-cost, and long-life thermal power peak-shaving system, effectively supporting the grid's absorption of fluctuating renewable energy and achieving dynamic balance between power generation, grid, load, and storage.

[0061] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An operation method for a flywheel coupled molten salt energy storage thermal power peak-shaving generation system, characterized in that, The power generation system includes a thermal power unit, a molten salt energy storage module, and a flywheel energy storage module; the operation method includes: Step 1: Obtain the operating status of the power generation system; Step 2: Based on the operating status of the power generation system, determine the main power supply entity and the supplementary power supply entity from the thermal power unit, the molten salt energy storage module and the flywheel energy storage module, so as to carry out peak shaving of the power generation system.

2. The operating method according to claim 1, characterized in that, Step two specifically includes: When the power generation system is in normal operation, the molten salt energy storage module and the flywheel energy storage module are in a silent state, and the thermal power unit directly supplies power to the grid.

3. The operating method according to claim 1, characterized in that, Step two also specifically includes: When the power generation system is in a peak-shaving fluctuation state, the thermal power unit supplies power to the grid, and at the same time uses the electricity stored in the molten salt energy storage module and the flywheel energy storage module as supplementary power supply; wherein, the electricity stored in the flywheel energy storage module is used first for supplementary power supply.

4. The operating method according to claim 1, characterized in that, Step two also specifically includes: When the power generation system is in a deep energy storage state, electrical energy is preferentially stored in the flywheel energy storage module, while the remaining electrical energy is stored in the molten salt energy storage module.

5. The operating method according to claim 1, characterized in that, Step two also specifically includes: When the power generation system is in a low-frequency operating state, the thermal power unit is adjusted to operate at the minimum load, and supplementary power is provided by the molten salt energy storage module and the flywheel energy storage module respectively.

6. The operating method according to claim 1, characterized in that, Step two may also include: When the power generation system is in a state of rapid load increase, the flywheel energy storage module shall give priority to grid power supply, while the molten salt energy storage module shall provide supplementary power supply.

7. The operating method according to claim 1, characterized in that, Step two may also include: When the power generation system is in a rapid load reduction state, the redundant power generation during the load reduction process of the thermal power unit is respectively sent to the flywheel energy storage module and the molten salt energy storage module for storage.

8. The operating method according to claim 1, characterized in that, Step two also specifically includes: When the generator set is in a stable operating state, the energy stored in the molten salt energy storage module is used to heat the boiler feedwater of the thermal power unit, and the excess energy is used for power generation and peak shaving.

9. A thermal power peak-shaving generation system with flywheel coupled molten salt energy storage, characterized in that, This includes thermal power units, molten salt energy storage modules, and flywheel energy storage modules; The flywheel energy storage module includes a flywheel motor, a flywheel body, a flywheel drive shaft, and a flywheel housing; wherein, the flywheel motor is connected to the flywheel body via the flywheel drive shaft, and the flywheel body is disposed within the flywheel housing; The molten salt energy storage module includes a high-temperature molten salt storage tank, a molten salt heat exchanger, a molten salt generator set, and a low-temperature molten salt storage tank; The thermal power unit includes a feedwater heater; The outlet of the high-temperature molten salt storage tank is connected to the high-temperature side inlet of the molten salt heat exchanger, and the high-temperature side outlet of the molten salt heat exchanger is connected to the inlet of the low-temperature molten salt storage tank. The low-temperature side outlet of the molten salt heat exchanger is connected to the molten salt generator set; The heat source side of the feedwater heater is connected to the high-temperature molten salt storage tank, and the cold source side of the feedwater heater is connected to the feedwater circuit of the thermal power unit. The flywheel energy storage module and the molten salt energy storage module are electrically connected to the power grid and operate in coordination with the thermal power unit to achieve the peak-shaving function of the power grid.

10. The power generation system according to claim 9, characterized in that, It also includes renewable energy generation modules; The renewable energy power generation module is connected to the flywheel motor and the cryogenic molten salt storage tank, respectively.

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