Solid phase heat storage chimney power generation peak shaving system and method

Abstract

The application discloses a solid-phase heat storage chimney power generation peak regulation system and method, and the system comprises a normal-temperature air intake adjusting air door, a heat release heat exchanger, a solid heat storage medium, an air heat exchanger, a hot air collecting chamber, an air adjusting air door, a chimney, a fan impeller and a power generation device. In the heat storage stage, high-temperature flue gas and / or high-temperature working medium are introduced into the heat release heat exchanger by an external heat source, and heat exchange is carried out with the solid heat storage medium during the flow process, so that heat is transferred into the solid heat storage medium, and heat energy is stored. In the heat release and power generation stage, the normal-temperature air intake adjusting air door and the hot air adjusting air door are opened, normal-temperature air from the outside enters from the bottom of the solid heat storage system, flows from bottom to top in the air heat exchanger, and fully exchanges heat with the high-temperature solid heat storage medium, so that the heat stored in the solid heat storage medium is absorbed, hot air is formed, the hot air drives the fan impeller to rotate during the rising process, and then the power generation device is driven to run, and the power generation process is completed.

Description

Technical Field

[0001] This invention belongs to the field of flexible peak shaving and solid thermal storage technology for thermal power plants, and particularly relates to a solid-phase thermal storage chimney power generation peak shaving system and method. Background Technology

[0002] With the continuous growth in installed capacity and power generation of renewable energy sources such as wind power and photovoltaics, their proportion in the power system is constantly increasing. Due to the fluctuating and intermittent nature of renewable energy power generation, thermal power units, especially coal-fired units, need to frequently participate in peak-shaving operations to maintain grid stability. Configuring energy storage systems in thermal power units to store and release energy is of great significance for improving the peak-shaving capacity and operational flexibility of the units.

[0003] Sensible heat storage technology stores and releases thermal energy by raising or lowering the temperature of the storage medium. It features simple structure, large storage capacity, and suitability for large-scale energy storage. Currently, sensible heat storage media mainly include molten salt and solid particles. Molten salt storage systems suffer from limitations such as operating temperature range restricted by melting point and corrosiveness to equipment. In contrast, solid particles, such as quartz sand and ceramic particles, offer advantages such as good chemical stability, low cost, wide availability, and long-term stable operation under high-temperature conditions. They are suitable for high-temperature heat storage scenarios and show promising application prospects in the field of thermal power unit heat storage and peak shaving.

[0004] Among existing patents, Chinese invention patent application CN114576118A entitled "A Solar Chimney Power Generation System Combined with Solar Photovoltaic and Photothermal Technology". The essence of this invention patent is that solar energy heats the air, and the thermal lift is generated based on the different air densities at different temperatures, which drives the fan in the chimney to rotate. It is a technology for utilizing solar energy.

[0005] Among existing patents, Chinese invention patent application CN113390075A, entitled "A Solid Thermal Storage Power Generation Peak-Shaving and Frequency-Regulating System and Working Method for Thermal Power Plants," describes a system where, during off-peak electricity hours (the thermal storage process), a peak-shaving and frequency-regulating electric heater supplies power to heat solid thermal storage bricks. During non-off-peak electricity hours (the heat release process), a high-temperature fan draws air into the solid thermal storage boiler, where it exchanges heat with the solid thermal storage bricks to become hot air. This hot air then heats water in the water supply pipeline into superheated steam via a wind-water heat exchanger. The superheated steam is then sent into the turbine to drive a generator to produce electricity. However, during the heat release process, as the solid thermal storage medium releases heat, its temperature gradually decreases, causing the temperature of the heated steam or air to drop accordingly. The lower-temperature steam cannot enter the turbine to perform work. This system utilizes off-peak electricity to heat the thermal storage bricks for energy storage, and the stored heat energy is used to indirectly generate electricity through the heat exchanger, thus limiting the overall utilization efficiency of the thermal storage system.

[0006] In summary, there is an urgent need to design a peak-shaving system and method for solid thermal energy storage power generation in thermal power plants to overcome the aforementioned technical deficiencies. Summary of the Invention

[0007] To address the aforementioned technical problems in existing technologies, this invention provides a solid-phase thermal energy storage chimney power generation peak-shaving system and method. During the peak-shaving and thermal energy storage process, high-temperature flue gas and / or high-temperature working fluid (steam, water) from the power plant unit heat the thermal energy storage solid, raising its temperature and storing heat. During the peak-shaving and heat release process, air is heated by the high-temperature thermal energy storage solid, forming high-temperature air. Based on the density difference between air at different temperatures, a thermal lift is generated, creating an airflow that drives the fan impeller in the flow channel / chimney to rotate, driving the generator to generate electricity. The generated electricity is used to support peak-shaving operation. The high-temperature flue gas / working fluid (steam / water) of the power plant boiler heats the solid thermal energy storage medium, utilizing the solid thermal energy storage to heat the air. The hot air generates lift in the chimney, driving the generator to generate electricity, thus achieving the peak-shaving purpose of the thermal power plant power generation system.

[0008] The technical solution adopted in this invention is:

[0009] The first aspect of this invention relates to a solid-phase thermal energy storage chimney power generation peak-shaving system, characterized in that it comprises at least a solid thermal energy storage system, a hot air collection system, and a chimney power generation system, wherein:

[0010] The solid thermal energy storage system includes a heat release heat exchanger (2) and a solid thermal energy storage medium (3). The heat release heat exchanger (2) is installed inside and through the solid thermal energy storage medium (3) and is used to introduce high-temperature flue gas and / or high-temperature working fluid generated by the thermal power generator set during the thermal energy storage stage, and transfer its heat to the solid thermal energy storage medium for storage, thereby realizing the storage of thermal energy.

[0011] The hot air collection system includes a normal temperature air inlet regulating damper (1), an air heat exchanger (4), and a hot air collection chamber (5). The hot air collection chamber (5) is located above the solid heat storage medium (3) and is used to collect heated air. The normal temperature air inlet regulating damper (1) is located between the bottom of the solid heat storage system and the foundation and is used to regulate the flow rate of outside air entering the solid heat storage system. The air heat exchanger (4) is located inside the solid heat storage medium (3), and the inlet and outlet of the air heat exchanger (4) are connected to the normal temperature air inlet regulating damper (1) and the hot air collection chamber (5) respectively, so that the incoming air can exchange heat with the solid heat storage medium to form hot air.

[0012] The chimney power generation system includes a hot air regulating damper (6), a chimney (7), a fan impeller (8), and a power generation device (9). The chimney (7) is located at the outlet of the top of the hot air collection chamber (5). The hot air regulating damper (6) is located at the outlet of the hot air collection chamber (5) and is used to adjust the opening to control the flow rate of hot air entering the chimney (7). The fan impeller (8) is located inside the chimney (7). The power generation device (9) is connected to the fan impeller (8). The flowing air entering the chimney (7) drives the fan impeller (8) to rotate, thereby driving the power generation device (9) connected to it to generate electricity.

[0013] Furthermore, the solid heat storage medium (3) is a material with high temperature resistance, high specific heat capacity and good thermal stability, and its temperature resistance is not lower than 880°C.

[0014] Furthermore, the solid heat storage medium (3) includes any one of quartz sand, ceramic particles, and magnesium bricks.

[0015] Furthermore, the solid heat storage medium (3) may be in the form of granular structure with a particle size of 0.5 mm to 25 mm and a shape factor of 0.7 to 0.85; or it may be a block structure with or without through holes.

[0016] Furthermore, the high-temperature working medium includes steam or water.

[0017] Furthermore, both the heat release heat exchanger (2) and the air heat exchanger (4) can be tubular heat exchangers, with the surface form selected as a bare tube or a finned structure.

[0018] Optionally, the air heat exchanger (4) may be a through hole opened from top to bottom on the solid heat storage medium (3). The upper and lower ends of the through hole are respectively connected to the ambient temperature air intake regulating damper (1) and the hot air collection chamber (5). Air flows from bottom to top through the through hole and absorbs the heat stored in the solid heat storage medium during the flow.

[0019] Furthermore, the chimney (7) has a preset height H. c and cross-sectional dimensions, the preset height H c The parameters are determined based on the system's maximum thermal storage capacity, air flow rate, air temperature rise in the thermal storage area, and environmental parameters.

[0020] Furthermore, the actual installation height of the chimney should be greater than H. c H c Determine based on the following formula:

[0021]

[0022] Where K is the frictional resistance correction coefficient, ranging from 1.2 to 1.5; P is the maximum thermal storage power, in W; Tout Q represents the ambient air temperature at the bottom of the chimney, in Kelvin (K); Q represents the airflow rate, in cubic meters per second (m³). 3 / s;ΔT tes The value represents the air temperature rise in the thermal storage area, expressed in Kelvin (K); g represents the acceleration due to gravity, expressed in m / s². 2 ;ρ out The density of the ambient air at the base of the chimney, in kg / m³. 3 .

[0023] A second aspect of the present invention relates to a peak-shaving method using the aforementioned solid-phase thermal energy storage chimney power generation peak-shaving system, characterized by comprising the following steps:

[0024] S1, Thermal Storage Stage

[0025] During the load reduction phase of the generator set, i.e. the heat storage phase, the high-temperature flue gas and / or high-temperature working fluid generated during the operation of the thermal power generator set are introduced into the solid heat storage system. Heat is released to the solid heat storage medium (3) through the heat release heat exchanger (2). The solid heat storage medium (3) absorbs the heat and rises in temperature to store thermal energy. The low-temperature flue gas and / or low-temperature working fluid after the heat is transferred to the solid heat storage system are returned to the thermal power generator set thermal system.

[0026] S2, Heat Release and Power Generation Stage

[0027] S21, Air heat exchange and temperature rise: The ambient temperature air intake regulating damper (1) is opened, and the ambient temperature air enters the solid heat storage medium (3). The air absorbs the heat stored in the solid heat storage medium (3) through the air heat exchanger (4), and the temperature rises.

[0028] S22, Hot air convergence: Adjust the opening of the ambient temperature air intake regulating damper (1) and the hot air regulating damper (6) to control the high temperature air from the solid heat storage system to converge in the hot air collection chamber (5);

[0029] S23, rising airflow enters the chimney: adjust the opening of the hot air regulating damper (6), and the hot air enters the chimney (7) and flows upward inside the chimney (7);

[0030] S24. Power generation: The rising airflow is driven by the thermal lift force generated by the density difference caused by the increase in air temperature. The rising airflow drives the fan impeller (8) installed inside the chimney (7) to rotate. The fan impeller (8) drives the power generation device (9) to generate electricity, realizing the conversion of stored thermal energy into electrical energy.

[0031] S25. Power generation regulation: By adjusting the opening of the ambient air intake regulating damper (1) and the hot air regulating damper (6), the power generation can be regulated to meet the peak-shaving operation requirements of the thermal power generating unit.

[0032] The technical concept of this invention is as follows: By setting up a solid thermal storage medium, the heat of high-temperature flue gas / working fluid (steam / water) is stored in the solid thermal storage system during the load reduction process of the generator set. During the load increase process of the generator set, the solid thermal storage system releases heat. The air entering the solid thermal storage system exchanges heat with the high-temperature solid thermal storage medium, resulting in an increase in temperature and a decrease in air density. This creates an upward airflow in the vertical channel / chimney located at the top of the solid thermal storage system, generating thermal lift and forming a natural convection phenomenon similar to the chimney effect. This invention utilizes this airflow with thermal lift to drive the fan impeller in the vertical channel / chimney to rotate, which in turn drives the generator to generate electricity. This achieves the direct conversion of the heat energy released from the solid thermal storage into electrical energy, improving the energy utilization efficiency of the solid thermal storage system and enhancing the peak-shaving capacity and operational flexibility of the thermal power unit.

[0033] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0034] (1) This invention utilizes the thermal lift generated by the air being heated during the heat release process of the solid thermal storage system to drive the fan impeller to rotate and drive the generator to generate electricity, thereby realizing the direct conversion of solid thermal storage thermal energy into electrical energy. The energy utilization efficiency of the thermal storage system is high.

[0035] (2) This invention utilizes the natural convection formed by the decrease in density of air after heating to achieve gas flow, resulting in low energy consumption and good economic efficiency of system operation.

[0036] (3) This invention realizes the organic combination of thermal power generator set heat storage function and chimney power generation function, so that the heat storage system has the ability to generate electricity directly during the heat release process, and the thermal power generator set has strong peak shaving ability and operation flexibility.

[0037] (5) In the heat release process of this invention, the heat does not return to the steam turbine to do work, which effectively avoids the problem of the heat release temperature of the solid heat storage system decreasing over time and the difficulty in matching the working fluid demand of the boiler.

[0038] (6) Compared with the existing patent "A Solid Thermal Storage Power Generation Peak Shaving and Frequency Regulation System and Working Method for Thermal Power Plants" (Publication No. CN113390075A), the energy released by the present invention is not directly returned to the thermal power unit with high temperature requirements. Instead, the rising airflow driven by thermal lift drives the fan impeller to generate electricity, which effectively avoids the problem of the heat release temperature dropping over time and the difficulty in matching the high working fluid requirements of the boiler.

[0039] (7) This invention utilizes the natural principle of air at different temperatures generating lift, with the aim of cooperating with the peak shaving of thermal power units. The heat comes from the high-temperature flue gas / working fluid of the thermal power generating unit, and the heat stored in the solid heat storage medium is used to heat the air. The operation includes heat storage and heat release processes. The flow of hot air drives the wind turbine impeller to generate electricity and the peak shaving process are coordinated with each other. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the solid thermal storage peak-shaving system for thermal power units according to the present invention.

[0041] Figure 2 This is a schematic diagram of the integrated solid thermal energy storage system of the air heat exchanger and solid thermal energy storage medium of the present invention.

[0042] In the diagram: 1-Ambient temperature air intake regulating damper; 2-Heat release heat exchanger; 3-Solid heat storage medium; 4-Air heat exchanger; 5-Hot air collection chamber; 6-Hot air regulating damper; 7-Chimney; 8-Fan impeller; 9-Power generation unit. Detailed Implementation

[0043] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0045] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0046] Example 1

[0047] refer to Figure 1 and Figure 2 The present invention provides a solid-phase thermal energy storage chimney power generation peak-shaving system, comprising at least a solid thermal energy storage system, a hot air collection system, and a chimney power generation system, wherein:

[0048] The solid thermal energy storage system includes a heat release heat exchanger 2 and a solid thermal energy storage medium 3. The heat release heat exchanger 2 is disposed in and penetrates the solid thermal energy storage medium 3. It is used to introduce high-temperature flue gas and / or high-temperature working fluid generated by the thermal power generator set during the thermal energy storage stage, and transfer its heat to the solid thermal energy storage medium for storage, thereby realizing the storage of thermal energy.

[0049] The hot air collection system includes a normal temperature air inlet regulating damper 1, an air heat exchanger 4, and a hot air collection chamber 5. The hot air collection chamber 5 is located above the solid heat storage medium 3 and is used to collect heated air. The normal temperature air inlet regulating damper 1 is located between the bottom of the solid heat storage system and the foundation and is used to regulate the flow rate of outside air entering the solid heat storage system. The air heat exchanger 4 is located inside the solid heat storage medium 3, and the inlet and outlet of the air heat exchanger 4 are respectively connected to the normal temperature air inlet regulating damper 1 and the hot air collection chamber 5, so that the incoming air exchanges heat with the solid heat storage medium to form hot air.

[0050] The chimney power generation system includes a hot air regulating damper 6, a chimney 7, a fan impeller 8, and a power generation device 9. The chimney 7 is located at the outlet of the top of the hot air collection chamber 5. The hot air regulating damper 6 is located at the outlet of the hot air collection chamber 5 and is used to adjust the opening to control the flow rate of hot air entering the chimney 7. The fan impeller 8 is located inside the chimney 7. The power generation device 9 is connected to the fan impeller 8. The flowing air entering the chimney 7 drives the fan impeller 8 to rotate, thereby driving the power generation device 9 connected to it to generate electricity.

[0051] In this embodiment, the solid heat storage medium 3 is a material with high temperature resistance, high specific heat capacity and good thermal stability, and its temperature resistance is not lower than 880°C.

[0052] In this embodiment, the solid heat storage medium 3 includes any one of quartz sand, ceramic particles, and magnesium bricks.

[0053] In this embodiment, the solid heat storage medium 3 may be in the form of granular structure with a particle size of 0.5 mm to 25 mm and a shape factor of 0.7 to 0.85; or it may be a block structure with or without through holes.

[0054] In this embodiment, the high-temperature working fluid includes steam or water.

[0055] In this embodiment, both the heat release heat exchanger 2 and the air heat exchanger 4 can be tubular heat exchangers, and the surface form can be a smooth tube or a finned structure.

[0056] In this embodiment, the air heat exchanger 4 may be a through hole opened from top to bottom on the solid heat storage medium 3. The upper and lower ends of the through hole are respectively connected to the ambient temperature air intake regulating damper 1 and the hot air collection chamber 5. Air flows from bottom to top through the through hole and absorbs the heat stored in the solid heat storage medium during the flow.

[0057] In this embodiment, the chimney 7 has a preset height H. c and cross-sectional dimensions, the preset height H c The parameters are determined based on the system's maximum thermal storage capacity, air flow rate, air temperature rise in the thermal storage area, and environmental parameters.

[0058] In this embodiment, the actual installation height of the chimney should be greater than H. c H c Determine based on the following formula:

[0059]

[0060] Where K is the frictional resistance correction coefficient, ranging from 1.2 to 1.5; P is the maximum thermal storage power, in W; T outQ represents the ambient air temperature at the bottom of the chimney, in Kelvin (K); Q represents the airflow rate, in cubic meters per second (m³). 3 / s;ΔT tes The value represents the air temperature rise in the thermal storage area, expressed in Kelvin (K); g represents the acceleration due to gravity, expressed in m / s². 2 ;ρ out The density of the ambient air at the base of the chimney, in kg / m³. 3 .

[0061] The operation of the system of this invention includes a heat storage stage and a heat release and power generation stage.

[0062] During the heat storage stage, high-temperature flue gas and / or high-temperature working fluid (steam or hot water) are introduced into the high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger 2 by an external heat source (such as a thermal power generator set). The high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger (2) is installed in the solid heat storage medium 3 of the solid heat storage system. During the flow process, the high-temperature flue gas or working fluid exchanges heat with the solid heat storage medium 3, transferring heat to the solid heat storage medium 3, thereby realizing the storage of thermal energy. By adjusting the flow rate of flue gas or working fluid entering the high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger 2, the heat storage power and heat storage rate can be controlled.

[0063] During this stage, the ambient air intake regulating damper 1 remains closed to prevent outside air from entering the system and carrying away heat. This allows the heat from the high-temperature flue gas and / or high-temperature working fluid (steam or hot water) to be stored in the solid heat storage medium 3, thereby improving heat storage efficiency.

[0064] During the heat release and power generation stage, the ambient air intake regulating damper 1 and the hot air regulating damper 6 are opened, allowing ambient air to enter from the bottom of the solid thermal storage system and flow upwards through the air heat exchanger 4. The air heat exchanger 4 penetrates the solid thermal storage medium 3, and during the air flow, it fully exchanges heat with the high-temperature solid thermal storage medium 3, causing the air to absorb the heat stored in the solid thermal storage medium 3 and rise in temperature, forming hot air.

[0065] The heated air is transported via air heat exchanger 4 to a hot air collection chamber 5 located above the solid thermal storage system for collection. The hot air regulating damper 6 is adjusted to allow the hot air in the hot air collection chamber 5 to enter the chimney 7. The chimney 7 is a vertical or nearly vertical channel. After the hot air enters the chimney 7, its increased temperature and decreased density create thermal lift, resulting in a continuous upward airflow within the chimney 7.

[0066] During the upward flow of air, the fan impeller 8, located at a certain height within the chimney 7, rotates under the drive of the airflow. This fan impeller 8 can be positioned at the lower or upper part of the chimney 7, with the specific location optimized according to the airflow velocity distribution. The rotation of the fan impeller 8 drives the connected power generation device 9, converting mechanical energy into electrical energy and completing the power generation process.

[0067] Example 2

[0068] A peak-shaving method for a solid-phase thermal energy storage chimney power generation system according to the present invention includes the following steps:

[0069] S1, Thermal Storage Stage

[0070] During the load reduction phase of the generator set, i.e. the heat storage phase, the high-temperature flue gas and / or high-temperature working fluid generated during the operation of the thermal power generator set are introduced into the solid heat storage system. Heat is released to the solid heat storage medium 3 through the heat release heat exchanger 2. The solid heat storage medium 3 absorbs the heat and rises in temperature to store thermal energy. The low-temperature flue gas and / or low-temperature working fluid after the heat is transferred to the solid heat storage system are returned to the thermal system of the thermal power generator set.

[0071] S2, Heat Release and Power Generation Stage

[0072] S21. Air heat exchange and temperature rise: When the ambient temperature air intake regulating damper 1 is opened, ambient temperature air enters the solid heat storage medium 3. The air absorbs the heat stored in the solid heat storage medium 3 through the air heat exchanger 4, and the temperature rises.

[0073] S22, Hot air convergence: Adjust the opening of the ambient temperature air intake regulating damper 1 and the hot air regulating damper 6 to control the high temperature air from the solid heat storage system to converge in the hot air collection chamber 5.

[0074] S23. Rising airflow enters the chimney: Adjust the opening of the hot air regulating damper 6, and the hot air enters the chimney 7 and flows upward inside the chimney 7;

[0075] S24. Power generation: The rising airflow is driven by the thermal lift force generated by the density difference caused by the increase in air temperature. The rising airflow drives the fan impeller 8 installed inside the chimney 7 to rotate. The fan impeller 8 drives the power generation device 9 to generate electricity, realizing the conversion of stored thermal energy into electrical energy.

[0076] S25. Power generation regulation: By adjusting the opening of the ambient air intake regulating damper 1 and the hot air regulating damper 6, the power generation can be regulated to meet the peak-shaving operation requirements of the thermal power generating unit.

[0077] Example 3

[0078] In this embodiment, the present invention is applied to a pulverized coal boiler-fired power generation unit. During solid thermal energy storage, a portion of the high-temperature flue gas from the tail flue of the pulverized coal boiler and / or the high-temperature working fluid from the superheater / reheater is introduced into the solid thermal energy storage system through a high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger 2. The high-temperature flue gas and / or working fluid flow within the high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger 2, transferring heat to the solid thermal energy storage medium 3, causing the solid thermal energy storage medium 3 to absorb heat and rise in temperature, thus achieving thermal energy storage. The low-temperature flue gas and / or low-temperature working fluid after heat exchange is returned to the tail flue of the boiler or enters the power plant's waste heat utilization system. After solid thermal energy storage is completed, the input of high-temperature flue gas and / or high-temperature working fluid is stopped.

[0079] When the pulverized coal boiler unit is operating at increased load or needs to release heat energy, the system enters the heat release and power generation stage. The ambient air inlet regulating damper 1 and the hot air regulating damper 6 are opened, allowing ambient air to enter the solid thermal storage system. This air flows upwards through the air heat exchanger 4, fully exchanging heat with the high-temperature solid thermal storage medium 3. After absorbing heat, the cold air's temperature rises and its density decreases, causing it to rise and enter the hot air collection chamber 5, forming continuously accumulating hot air. The hot air in the hot air collection chamber 5 enters the chimney 7 through the hot air regulating damper 6, forming an upward airflow under the action of thermal lift. This upward airflow drives the fan impeller 8 to rotate, which in turn drives the power generation device 9 to generate electricity, realizing the conversion of stored heat energy into electrical energy. This improves the energy utilization efficiency of the pulverized coal boiler unit during peak shaving and enhances the unit's peak shaving capacity and operational stability.

[0080] Example 4

[0081] In this embodiment, the present invention is applied to a circulating fluidized bed boiler thermal power generating unit. During the heat storage process, the unit's superheated / reheated steam is used as a high-temperature working fluid and introduced into the solid heat storage system through the high-temperature flue gas and / or high-temperature working fluid heat release heat exchanger 2. Heat is transferred to the solid heat storage medium 3 through convection, conduction and radiation, thereby allowing the solid heat storage medium 3 to absorb and store heat. The low-temperature working fluid after heat exchange is returned to the unit's feedwater.

[0082] When the circulating fluidized bed boiler unit needs to perform peak-shaving operation or release heat energy, the ambient air inlet regulating damper 1 and the hot air regulating damper 6 are opened. Ambient air enters the solid thermal storage system and flows upward through the through-holes of the solid thermal storage medium 3, absorbing heat stored in the medium during the flow. After absorbing heat, the cold air's temperature rises and its density decreases, rising into the hot air collecting chamber 5 and forming continuously collected hot air. The hot air in the hot air collecting chamber 5 enters the chimney 7 and forms a stable upward airflow. This upward airflow drives the fan impeller 8 to rotate, thereby driving the power generation unit 9 to generate electricity. The power generation is regulated by controlling the opening of the hot air regulating damper 6, meeting the peak-shaving requirements of the thermal power unit and improving the peak-shaving capacity and operational flexibility of the circulating fluidized bed boiler unit.

[0083] In this case, the hot air in the hot air collector 5 can also be returned to the circulating fluidized bed boiler as secondary air.

[0084] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0085] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0086] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0087] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0088] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0089] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A solid-phase thermal energy storage chimney power generation and peak-shaving system, characterized in that, It includes at least a solid thermal energy storage system, a hot air collection system, and a chimney power generation system, wherein: The solid thermal energy storage system includes a heat release heat exchanger (2) and a solid thermal energy storage medium (3). The heat release heat exchanger (2) is installed inside and through the solid thermal energy storage medium (3) and is used to introduce high-temperature flue gas and / or high-temperature working fluid generated by the thermal power generator set during the thermal energy storage stage, and transfer its heat to the solid thermal energy storage medium for storage, thereby realizing the storage of thermal energy. The hot air collection system includes a normal temperature air inlet regulating damper (1), an air heat exchanger (4), and a hot air collection chamber (5). The hot air collection chamber (5) is located above the solid heat storage medium (3) and is used to collect heated air. The normal temperature air inlet regulating damper (1) is located between the bottom of the solid heat storage system and the foundation and is used to regulate the flow rate of outside air entering the solid heat storage system. The air heat exchanger (4) is located inside the solid heat storage medium (3), and the inlet and outlet of the air heat exchanger (4) are connected to the normal temperature air inlet regulating damper (1) and the hot air collection chamber (5) respectively, so that the incoming air can exchange heat with the solid heat storage medium to form hot air. The chimney power generation system includes a hot air regulating damper (6), a chimney (7), a fan impeller (8), and a power generation device (9). The chimney (7) is located at the outlet of the top of the hot air collection chamber (5). The hot air regulating damper (6) is located at the outlet of the hot air collection chamber (5) and is used to adjust the opening to control the flow rate of hot air entering the chimney (7). The fan impeller (8) is located inside the chimney (7). The power generation device (9) is connected to the fan impeller (8). The flowing air entering the chimney (7) drives the fan impeller (8) to rotate, thereby driving the power generation device (9) connected to it to generate electricity.

2. The solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 1, characterized in that, The solid heat storage medium (3) is a material with high temperature resistance, high specific heat capacity and good thermal stability, and its temperature resistance is not lower than 880°C.

3. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 2, characterized in that, The solid thermal storage medium (3) includes any one of quartz sand, ceramic particles and magnesia bricks.

4. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 1, characterized in that, The solid heat storage medium (3) has a granular structure with a particle size of 0.5 mm to 25 mm and a shape factor of 0.7 to 0.85; or it has a block structure with or without through holes.

5. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 1, characterized in that, The high-temperature working medium includes steam or water.

6. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 1, characterized in that, Both the heat release heat exchanger (2) and the air heat exchanger (4) are tubular heat exchangers, and their surface forms are selected as bare tubes or finned structures.

7. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 4, characterized in that, The air heat exchanger (4) may be a through hole opened from top to bottom on the solid heat storage medium (3). The upper and lower ends of the through hole are respectively connected to the ambient temperature air intake regulating damper (1) and the hot air collection chamber (5). Air flows from bottom to top through the through hole and absorbs the heat stored in the solid heat storage medium during the flow.

8. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 1, characterized in that, The chimney (7) has a preset height H c and cross-sectional dimensions, the preset height H c The parameters are determined based on the system's maximum thermal storage capacity, air flow rate, air temperature rise in the thermal storage area, and environmental parameters.

9. A solid-phase thermal energy storage chimney power generation and peak-shaving system as described in claim 8, characterized in that, The actual height of the chimney should be greater than H. c H c Determine based on the following formula: Where K is the frictional resistance correction coefficient, ranging from 1.2 to 1.5; P is the maximum thermal storage power, in W; T out Q represents the ambient air temperature at the bottom of the chimney, in Kelvin (K); Q represents the airflow rate, in cubic meters per second (m³). 3 / s;ΔT tes The value represents the air temperature rise in the thermal storage area, expressed in Kelvin (K); g represents the acceleration due to gravity, expressed in m / s². 2 ;ρ out The density of the ambient air at the base of the chimney, in kg / m³. 3 .

10. A peak-shaving method using the solid-phase thermal storage chimney power generation peak-shaving system according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1, Thermal Storage Stage During the load reduction phase of the generator set, i.e. the heat storage phase, the high-temperature flue gas and / or high-temperature working fluid generated during the operation of the thermal power generator set are introduced into the solid heat storage system. Heat is released to the solid heat storage medium (3) through the heat release heat exchanger (2). The solid heat storage medium (3) absorbs the heat and rises in temperature to store thermal energy. The low-temperature flue gas and / or low-temperature working fluid after the heat is transferred to the solid heat storage system are returned to the thermal power generator set thermal system. S2, Heat Release and Power Generation Stage S21, Air heat exchange and temperature rise: The ambient temperature air intake regulating damper (1) is opened, and the ambient temperature air enters the solid heat storage medium (3). The air absorbs the heat stored in the solid heat storage medium (3) through the air heat exchanger (4), and the temperature rises. S22, Hot air convergence: Adjust the opening of the ambient temperature air intake regulating damper (1) and the hot air regulating damper (6) to control the high temperature air from the solid heat storage system to converge in the hot air collection chamber (5); S23, rising airflow enters the chimney: adjust the opening of the hot air regulating damper (6), and the hot air enters the chimney (7) and flows upward inside the chimney (7); S24. Power generation: The rising airflow is driven by the thermal lift force generated by the density difference caused by the increase in air temperature. The rising airflow drives the fan impeller (8) installed inside the chimney (7) to rotate. The fan impeller (8) drives the power generation device (9) to generate electricity, realizing the conversion of stored thermal energy into electrical energy. S25. Power generation regulation: By adjusting the opening of the ambient air intake regulating damper (1) and the hot air regulating damper (6), the power generation can be regulated to meet the peak-shaving operation requirements of the thermal power generating unit.

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