Flue gas heat storage system and method based on multi-distribution particle segregation

Abstract

This invention relates to a flue gas heat storage and release system and method based on multi-distribution particle segregation. It mainly consists of a first control valve (1), a second control valve (2), a boiler (3), an SCR denitrification reactor (4), an economizer (5), an air preheater (6), a third control valve (7), a fourth control valve (8), a first fan (9), a fifth control valve (10), a second fan (11), a vibrating particle bed (12), a multi-distribution particle system (13), and a flue gas mixer (14), all connected by pipelines. Corresponding control valves are installed on the pipelines to adjust the system's operating mode, thereby achieving different functions and fully utilizing the boiler flue gas energy across time and space. This system effectively improves the boiler's flexibility and reduces equipment costs and subsequent maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of flexible coal-fired power generation technology, specifically to a flue gas heat storage and release system and method based on multi-distribution particle segregation. Background Technology

[0002] Due to the intermittency, volatility, and priority access of renewable energy sources such as wind and solar power in the power system, traditional thermal power units need to improve their flexibility and frequently participate in peak shaving tasks.

[0003] To improve the load-change rate of power units, integrated thermal storage technology is an effective method that has gained significant attention in recent years. Common flexible thermal power units using integrated thermal storage technology add a heat exchanger, thermal storage medium, and steam generator to the original unit. During periods of low grid load, excess energy from the power unit is stored in the thermal storage medium; during peak grid load periods, the energy in the thermal storage medium is converted into steam to drive the turbine for power generation.

[0004] Currently, the main heat storage media used in peak shaving of thermal power units are molten salt and solid particles, typically heated by steam or electricity during the heat storage process. Compared to these two methods, flue gas heating overcomes the narrow-point heat transfer limitations of steam-water heat storage, significantly improving heat storage efficiency. Furthermore, the flue gas heat source temperature exceeds 700°C, achieving a larger heat transfer temperature difference and higher energy grade. However, because high-temperature flue gas contains dust and is corrosive, it is essential to add flue gas dust collectors and wear- and corrosion-resistant flue gas heat exchangers, which increases the cost of integrated heat storage systems. In addition, the high cost, corrosiveness, temperature limitations, and environmental safety concerns inherent in molten salt also restrict its widespread application.

[0005] While current integrated thermal storage technology can improve the load change rate of power units, the numerous new components in this integrated system result in high retrofit and ongoing operating costs. In reality, existing thermal power units consist of three main components: boiler, turbine, and generator. The boiler is the key factor limiting the load change rate, and delays in the pulverizing system are a major constraint on improving the boiler's load change rate. Therefore, utilizing integrated thermal storage technology to address boiler pulverizing system delays and enhance boiler flexibility is a novel approach to improving the unit's load change rate.

[0006] The most commonly used integrated thermal storage system is molten salt thermal storage. However, due to the dust and corrosiveness of high-temperature flue gas, it is necessary to add flue gas dust collectors and wear- and corrosion-resistant flue gas heat exchangers, which increases the cost of the integrated thermal storage system. In addition, the high cost, corrosiveness, temperature limitations, and environmental safety issues of molten salt itself also limit its widespread application. Other integrated thermal storage systems, such as the fluidized bed heat exchange system and heat exchanger for integrated thermal storage and power generation disclosed in CN 114963819 A, use electric heating to heat solid particles, converting high-grade electricity into low-grade heat storage, resulting in a decrease in energy grade. Additional supercritical carbon dioxide heat exchange equipment and turbine equipment are also required, leading to high investment costs. Another example is the device and method for improving the flexibility of a unit using flowing fly ash thermal storage for co-generation and heating disclosed in CN118462344 A. This system utilizes flowing fly ash to absorb steam heat when there is excess power generation, and converts the stored heat back into electricity and heat when power generation is insufficient. This device has high equipment investment costs, and the particle transportation of the hot and cold tanks requires a significant amount of energy. For example, CN 217402525 U discloses a thermal energy storage system for peak shaving in thermal power generation. This system utilizes particles entering the boiler to absorb heat. After dust removal from the particles, a particle heat exchanger is used to transfer the heat from the particles to the steam for peak shaving. This system requires the continuous transport of particles, resulting in high energy consumption. In addition, it requires particle dust collectors, particle heat exchangers, storage tanks, and other equipment, leading to a large investment.

[0007] It is evident that existing integrated heat storage technologies, whether by adding a steam generation system or adding turbine equipment, do not address the issue of improving the boiler's own flexibility and thus have significant limitations. Summary of the Invention

[0008] The purpose of this invention is to provide a flue gas heat storage and release system based on multi-distribution particle segregation to solve the above-mentioned technical problems.

[0009] Another objective of this invention is to provide a method for storing and releasing heat in flue gas based on multi-distributed particle segregation.

[0010] To achieve the above objectives, the present invention provides a flue gas heat storage and release system based on multi-distribution particle segregation, comprising:

[0011] The boiler is equipped with an SCR denitrification reactor, an economizer and an air preheater. The upper furnace of the boiler is provided with a flue gas outlet and the lower furnace of the boiler is provided with a flue gas return outlet.

[0012] The vibrating particle bed is divided into a particle layer and a ash removal layer from top to bottom. The particle layer is filled with mixed filter media particles of different sizes. Under the excitation of vibration, the mixed filter media particles can form a multi-distributed particle system to automatically complete the arrangement and thickness adjustment of the particle bed.

[0013] The vibrating particle bed is provided with a first flue gas inlet and a second flue gas inlet. In the heat storage state, the flue gas flows from the first flue gas inlet to the second flue gas inlet and exchanges heat with the low-temperature mixed filter media particles inside the particle layer. In the heat release state, the flue gas flows from the second flue gas inlet to the first flue gas inlet and exchanges heat with the high-temperature mixed filter media particles inside the particle layer.

[0014] The flue gas mixer is provided with a third flue gas inlet, a fourth flue gas inlet, and a mixed flue gas outlet. The first flue gas inlet of the vibrating particle bed is connected to the return flue gas outlet of the boiler through a third flue gas pipeline and is provided with a first control valve. The flue gas outlet of the boiler is connected to the third flue gas pipeline through a first flue gas pipeline and is provided with a second control valve. The flue gas outlet of the economizer is connected to the fourth flue gas inlet of the flue gas mixer through a second flue gas pipeline and is provided with a fourth control valve and a first fan. The second flue gas inlet of the vibrating particle bed is connected to the third flue gas inlet of the flue gas mixer. The mixed flue gas outlet of the flue gas mixer delivers the mixed flue gas to the front end of the SCR denitrification reactor through a fourth flue gas pipeline and is provided with a second fan and a fifth control valve.

[0015] The exhaust port of the air preheater is connected to the second flue gas pipeline via the fifth flue gas pipeline downstream of the first fan and is equipped with a third control valve.

[0016] Optionally, the vibrating particle bed is provided with multiple first flue gas inlets and multiple second flue gas inlets, and the flue gas mixer is provided with multiple third flue gas inlets; the third flue gas pipeline is connected to each of the first flue gas inlets through multiple branch pipelines, and each of the second flue gas inlets is connected to the corresponding third flue gas inlet.

[0017] Optionally, the first flue gas outlet is located at the top of the vibrating particle bed, and the second flue gas outlet is located on the side or bottom of the vibrating particle bed.

[0018] Optionally, the first flue gas outlet is located on a first side of the vibrating particle bed, and the second flue gas outlet is located on a second side or bottom of the vibrating particle bed.

[0019] Optionally, a porous partition baffle is provided between the particle layer and the ash removal layer of the vibrating particle bed.

[0020] Optionally, the aperture D of the partition baffle g Smaller than the minimum diameter D of the mixed filter media particles l Larger than the diameter D of the dust particles f .

[0021] Optionally, the ash removal layer is provided with heat exchange tubes for recovering residual heat from the dust during ash removal.

[0022] Optionally, the boiler's flue gas return port is located on the upper side of its burner and has a flue gas return path structure with four corner tangents or four wall tangents.

[0023] Optionally, the mixed filter media particles may include pebbles, quartz sand, alumina, silicon carbide, or basalt particles.

[0024] To achieve another objective mentioned above, the present invention provides a flue gas heat storage and release method based on multi-distribution particle segregation, which is used in any of the above-mentioned flue gas heat storage and release systems based on multi-distribution particle segregation, comprising:

[0025] Before thermal storage, a certain proportion of mixed filter media particles of different sizes are filled into the vibrating particle bed according to the incoming flow conditions; the vibrating particle bed is started, and the mixed filter media particles form a multi-distributed particle system under the excitation of vibration, automatically completing the arrangement and thickness adjustment of the particle bed.

[0026] During heat storage, the first and fourth control valves remain closed, while the second, third, and fifth control valves are open. The flue gas in the upper furnace of the boiler enters the vibrating particle bed under the traction of the second fan. Based on the inlet and outlet pressure drop of the vibrating particle bed, the vibrating particle bed is started and stopped at a certain vibration frequency and amplitude to achieve efficient heat exchange and dust removal between hot flue gas and cold particles under low pressure drop conditions. The flue gas at the outlet of the air preheater is mixed with the flue gas at the outlet of the vibrating particle bed in the flue gas mixer, and the mixed flue gas enters the front end of the SCR denitrification reactor.

[0027] During heat release, the first and fourth control valves are opened, while the second, third, and fifth control valves remain closed. The flue gas from the economizer outlet enters the vibrating particle bed under the traction of the first fan, completing the efficient heat exchange between the cold flue gas and the hot particles. After the heat exchange, the flue gas returns to the lower furnace of the boiler along the flue.

[0028] The flue gas heat storage and release system and method based on multi-distributed particle segregation provided by this invention differs from previous integrated heat storage systems. It eliminates the need for a separate steam generation system and directly utilizes the heat storage and release of the multi-distributed particle system to achieve cross-temporal and spatial utilization of boiler flue gas heat, forming a flexible thermal power unit based on the multi-distributed particle segregation flue gas heat storage and release system. When the grid load is low, the excess high-temperature flue gas in the boiler is introduced into a vibrating particle bed containing the multi-distributed particle system. When the grid load is high, the low-temperature flue gas displaces the energy stored in the multi-distributed particle system, transforming it into high-temperature flue gas which is then released back into the furnace. Steam is generated using the boiler's own steam generation system, effectively improving the boiler's flexibility. The multi-distributed particles can be directly sourced from natural resources, such as pebbles and quartz sand, which are inexpensive and easily obtained. The vibrating particle bed remains stationary most of the time, resulting in low energy consumption. The capture of dust particles in the flue gas enables the utilization of dust heat. Furthermore, throughout the process, the multi-distributed particle system serves as a heat storage medium, a heat exchanger, and a dust collector, reducing the equipment cost and subsequent maintenance costs of the integrated heat storage system. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a flue gas heat storage and release system based on multi-distribution particle segregation.

[0030] Figure 2 This is a structural diagram of a flue gas heat storage and release system based on multi-distribution particle segregation provided in the first embodiment of the present invention;

[0031] Figure 3 for Figure 2 The diagram shows the heat storage flue gas flow path of a flue gas heat storage and release system based on multi-distribution particle segregation.

[0032] Figure 4 for Figure 2 The diagram shows the heat release flue gas flow path of a flue gas heat storage and release system based on multi-distribution particle segregation.

[0033] Figure 5 A schematic diagram illustrating the formation of a multi-distributed particle system from mixed filter media particles in a vibrating particle bed;

[0034] Figure 6 This is a schematic diagram of dust movement from the front view perspective when a vibrating particle bed is vibrating violently.

[0035] Figure 7 This is a schematic diagram of dust movement from a side view when a vibrating particle bed is vibrating violently.

[0036] In the picture:

[0037] 1-First control valve; 2-Second control valve; 3-Boiler; 4-SCR reactor; 5-Economizer; 6-Air preheater; 7-Third control valve; 8-Fourth control valve; 9-First fan; 10-Fifth control valve; 11-Second fan; 12-Vibrating particle bed; 13-Multi-distribution particle system; 14-Flue gas mixer;

[0038] 15-Mixed filter media particles; 16-Separating baffle. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In this document, terms such as "upper," "lower," "inner," and "outer" are established based on the positional relationships shown in the accompanying drawings. Depending on the drawings, the corresponding positional relationships may also change. Therefore, they should not be interpreted as an absolute limitation on the scope of protection. Moreover, relational terms such as "first" and "second" are only used to distinguish one component from another that has the same name, and do not necessarily require or imply any such actual relationship or order between these components.

[0041] Please refer to Figure 1 , Figure 2 , Figure 1 This is a schematic diagram of a flue gas heat storage and release system based on multi-distribution particle segregation. Figure 2 This is a structural diagram of a flue gas heat storage and release system based on multi-distribution particle segregation, provided in the first embodiment of the present invention.

[0042] As shown in the figure, in one specific embodiment, the flue gas heat storage and release system based on multi-distribution particle segregation provided by the present invention mainly consists of a first control valve 1, a second control valve 2, a boiler 3, an SCR denitrification reactor 4, an economizer 5, an air preheater 6, a third control valve 7, a fourth control valve 8, a first fan 9, a fifth control valve 10, a second fan 11, a vibrating particle bed 12, a multi-distribution particle system 13, and a flue gas mixer 14, which are connected by pipelines. Corresponding control valves are provided on the pipelines. By adjusting the operating mode of the system through the control valves, different functions can be achieved, thereby realizing the full utilization of boiler flue gas energy.

[0043] In this embodiment, boiler 3 is a π-type boiler. SCR denitrification reactor 4, economizer 5 and air preheater 6 are located in the downflow flue of boiler 3. The upper furnace of boiler 3 is provided with a flue gas outlet to reduce the impact of flue gas extraction on the flue gas flow field inside the furnace. The lower furnace of boiler 3 is provided with a flue gas return outlet on the upper side of the burner, and the flue gas is returned in a tangential manner at the four corners or in a tangential manner on the four walls to reduce the impact of flue gas return on the flue gas flow field and combustion inside the furnace.

[0044] The vibrating particle bed 12 can vibrate up and down under the action of a vibrating motor. Its interior is divided into a particle layer and a ash removal layer from top to bottom. The particle layer is filled with mixed filter media particles 15 of different sizes. Under the excitation of vibration, the mixed filter media particles 15 can form a multi-distributed particle system 13 to automatically complete the arrangement and thickness adjustment of the particle bed.

[0045] To prevent the vibrating particle bed 12 from causing tension or damage to the connecting pipeline, the flue gas pipeline connected to the vibrating particle bed 12 can be made of a flexible or elastic pipe, for example, a corrugated pipe, to eliminate or block the transmission of vibration upstream and downstream along the flue gas pipeline.

[0046] The mixed filter media particles 15 are used to store heat in flue gas and filter dust particles in flue gas. The size and type of the mixed filter media particles 15 are not limited. They can be pebbles, quartz sand, alumina, silicon carbide or basalt particles, or a mixture of at least two types of particles.

[0047] A porous partition baffle 16 is provided between the granular layer and the ash removal layer, and the aperture D of the partition baffle 16 is... g The minimum diameter D of the mixed filter media particles is less than 15. l Larger than the diameter D of the dust particles f .

[0048] The vibrating particle bed 12 is provided with a first flue gas inlet A and a second flue gas inlet B. In the heat storage state, the flue gas flows from the first flue gas inlet A to the second flue gas inlet B and exchanges heat with the low-temperature mixed filter material particles 15 inside the particle layer. In the heat release state, the flue gas flows from the second flue gas inlet B to the first flue gas inlet A and exchanges heat with the high-temperature mixed filter material particles 15 inside the particle layer.

[0049] The flue gas mixer 14 can mix the flue gas filtered from the vibrating particle bed 12 and the flue gas from the air preheater 6, and output flue gas with a uniform temperature. The type of flue gas mixer 14 is not limited.

[0050] The flue gas mixer 14 is provided with a third flue gas port C, a fourth flue gas port D and a mixed flue gas outlet E; the first flue gas port A of the vibrating particle bed 12 is connected to the return flue gas port of the boiler 3 through the third flue gas pipeline and is provided with a first control valve 1. The first control valve 1 is opened when releasing heat. The amount of flue gas entering the lower furnace of the boiler 3 can be adjusted by controlling the valve opening to ensure the temperature of the flue gas entering the lower furnace of the boiler 3.

[0051] The flue gas outlet of boiler 3 is connected to the third flue gas pipeline through the first flue gas pipeline and is equipped with a second control valve 2. The second control valve 2 is opened during heat storage. By controlling the valve opening, a certain amount of flue gas from the upper furnace of boiler 3 is drawn into the vibrating particle bed 12. The type of the second control valve 2 is not limited.

[0052] The outlet of the economizer 5 is connected to the fourth flue gas outlet D of the flue gas mixer through the second flue gas pipeline and is equipped with a fourth control valve 8 and a first fan 9. The first fan 9 is located in the outlet pipeline of the economizer 5 to reduce the operating temperature and dust wear of the second fan 11.

[0053] The first fan 9 provides power for the flow of flue gas during the heat release process and conveys the flue gas from the economizer outlet to the vibrating particle bed 12 for heat exchange.

[0054] The second flue gas port B of the vibrating particle bed 12 is connected to the third flue gas port C of the flue gas mixer 14. The mixing outlet E of the flue gas mixer 14 transports the mixed flue gas to the front end of the SCR denitrification reactor 4 through the fourth flue gas pipeline. A second fan 11 and a fifth control valve 10 are provided. The second fan 11 is located at the mixing outlet E of the flue gas mixer 14 to reduce the operating temperature and dust wear of the second fan 11.

[0055] The second fan 11 provides power for the flow of flue gas in the heat storage process and transports the mixed flue gas to the front end of the SCR denitrification reactor 4.

[0056] The flue gas outlet of the air preheater 6 is connected to the second flue gas pipeline downstream of the first fan 9 via the fifth flue gas pipeline and is equipped with a third control valve 7. The third control valve 7 opens during heat storage, and by controlling the valve opening, a certain amount of flue gas from the air preheater 6 outlet is drawn into the flue gas mixer 14. Adjusting the opening of the third control valve 7 controls the outlet temperature of the flue gas mixer 4, ensuring the efficient operation of the SCR denitrification reactor 4.

[0057] In this embodiment, the vibrating particle bed 12 is provided with multiple first flue gas ports A and multiple second flue gas ports B, the flue gas mixer 14 is provided with multiple third flue gas ports C, the third flue gas pipeline is connected to each of the first flue gas ports A through multiple branch pipelines, and each of the second flue gas ports B is connected to the corresponding third flue gas port C.

[0058] The first flue gas inlet A of the vibrating particle bed 12 can be located at the top of the vibrating particle bed 12, and the second flue gas inlet B can be located on the side of the vibrating particle bed 12. If this structure is adopted, when the flue gas flows from the first flue gas inlet A to the second flue gas inlet B or from the second flue gas inlet B to the first flue gas inlet A, an "L"-shaped flue gas flow path is formed.

[0059] The first flue gas inlet A of the vibrating particle bed 12 can also be located on the first side of the vibrating particle bed 12, and the second flue gas inlet B can be located on the opposite second side of the vibrating particle bed 12. If this structure is adopted, when the flue gas flows from the first flue gas inlet A to the second flue gas inlet B or from the second flue gas inlet B to the first flue gas inlet A, a "I"-shaped flue gas flow path is formed.

[0060] Please continue to refer to this. Figure 3 , Figure 4 , Figure 3 for Figure 2 The diagram shows the heat storage flue gas flow path of a flue gas heat storage and release system based on multi-distribution particle segregation. Figure 4 for Figure 2 The diagram shows the heat release flue gas flow path of a flue gas heat storage and release system based on multi-distribution particle segregation.

[0061] As shown in the figure, under thermal storage conditions, the first control valve 1 and the fourth control valve 8 remain closed, while the second control valve 2, the third control valve 7, and the fifth control valve 10 are open. The flue gas in the furnace of the boiler 3 enters the vibrating particle bed 12 under the traction of the second fan 11. According to the inlet and outlet pressure drop of the vibrating particle bed 12, the vibrating particle bed 12 is started and stopped at a certain vibration frequency and amplitude to complete the efficient heat exchange and dust removal of hot flue gas and cold particles under low pressure drop conditions. The flue gas at the outlet of the air preheater 6 and the flue gas at the outlet of the vibrating particle bed 12 are mixed in the flue gas mixer 14, and the mixed flue gas enters the front end of the SCR denitrification reactor 4.

[0062] Under exothermic conditions, the first control valve 1 and the fourth control valve 8 are opened, while the second control valve 2, the third control valve 7 and the fifth control valve 10 remain closed. The flue gas from the economizer 5 outlet enters the vibrating particle bed 12 under the traction of the first fan 9, completing the efficient heat exchange between the cold flue gas and the hot particles. After the heat exchange, the flue gas returns to the lower furnace of the boiler 3 along the flue.

[0063] The above embodiments are merely preferred embodiments of the present invention and are not limited thereto. Targeted adjustments can be made according to actual needs to obtain different implementation methods. For example, heat exchange tubes can be added to the ash discharge layer to recover residual heat from the dust during ash discharge, etc. Since there are many possible implementation methods, they will not be listed here.

[0064] In addition to the flue gas heat storage and release system based on multi-distribution particle segregation described above, this invention also provides a flue gas heat storage and release method based on multi-distribution particle segregation, comprising the following steps:

[0065] Before thermal storage, according to the incoming flow conditions, a certain proportion of mixed filter media particles 15 of different sizes are filled into the vibrating particle bed 12; the vibrating particle bed 12 is started, and the mixed filter media particles 15 form a multi-distributed particle system 13 under the excitation of vibration, automatically completing the arrangement and thickness adjustment of the particle bed.

[0066] During heat storage, the first control valve 1 and the fourth control valve 8 remain closed, while the second control valve 2, the third control valve 7, and the fifth control valve 10 are open. The flue gas in the furnace of the boiler 3 enters the vibrating particle bed 12 under the traction of the second fan 11. According to the inlet and outlet pressure drop of the vibrating particle bed 12, the vibrating particle bed 12 is started and stopped at a certain vibration frequency and amplitude to complete the efficient heat exchange and dust removal of hot flue gas and cold particles under low pressure drop conditions. The flue gas at the outlet of the air preheater 6 and the flue gas at the outlet of the vibrating particle bed 12 are mixed in the flue gas mixer 14, and the mixed flue gas enters the front end of the SCR denitrification reactor 4.

[0067] During heat release, the first control valve 1 and the fourth control valve 8 are opened, while the second control valve 2, the third control valve 7 and the fifth control valve 10 remain closed. The flue gas from the economizer 5 outlet enters the vibrating particle bed 12 under the traction of the first fan 9, completing the efficient heat exchange between the cold flue gas and the hot particles. After heat exchange, the flue gas returns to the lower furnace of the boiler 3 along the flue.

[0068] The present invention has at least the following beneficial effects:

[0069] 1) This invention proposes a novel approach to improve boiler flexibility and increase unit load change rate by utilizing integrated thermal storage technology to address delays in boiler pulverizing systems. It directly utilizes a multi-distributed particulate system to achieve cross-temporal and spatial utilization of boiler flue gas heat, abandoning the traditional heat exchanger-storage tank-steam generator route. The multi-distributed particulate system functions as a heat exchanger, heat storage medium, and dust collector, effectively reducing the equipment cost and subsequent maintenance costs of the integrated thermal storage system. Dust collection reduces the impact of dust on the SCR reactor and the subsequent dust removal pressure, while the utilization of dust heat improves the thermal efficiency of the thermal storage system.

[0070] 2) This invention uses multi-distributed particulate matter as the energy storage material, utilizing the vibrational segregation characteristics of the particles to achieve automatic stratification during the arrangement stage and automatic dust removal during the regeneration stage. The multi-distributed particulate material can be directly obtained from the environment, is inexpensive, requires no sieving, has wide adaptability, and is not limited by geographical conditions.

[0071] 3) This invention stores excess flue gas heat in the boiler furnace in granules, and extracts it with low-temperature flue gas when rapid load change is required, and sends it back to the boiler furnace, effectively solving the delay problem of the pulverizing system and realizing rapid load change of the boiler.

[0072] 4) This invention features a simple structure, recyclable filter media particles, and tiered utilization of flue gas heat. It boasts advantages such as low investment cost, low operating energy consumption, wide operating temperature range, low operating pressure, and self-cleaning capability. Furthermore, the installation, commissioning, disassembly, maintenance, and automation upgrades of this invention do not affect the normal operation of the thermal power unit. It can be installed either during the initial equipment design phase or during equipment operation. It offers advantages such as ease of implementation, simple installation, and convenient modification.

[0073] The above provides a detailed description of the flue gas heat storage and release system and method based on multi-distribution particle segregation provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention, and the descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A flue gas heat storage system based on multi-distribution particle segregation, characterized in that, include: The boiler (3) is equipped with an SCR denitrification reactor (4), an economizer (5) and an air preheater (6). The upper furnace of the boiler (3) is provided with a flue gas outlet, and the lower furnace of the boiler (3) is provided with a flue gas return outlet. The vibrating particle bed (12) is provided with a first flue gas inlet and a second flue gas inlet. The interior of the vibrating particle bed (12) is divided into a particle layer and an ash removal layer from top to bottom. The particle layer is filled with mixed filter media particles of different sizes. Under the excitation of vibration, the mixed filter media particles can form a multi-distributed particle system (13) to automatically complete the arrangement and thickness adjustment of the particle bed. The flue gas mixer (14) is provided with a third flue gas port, a fourth flue gas port and a mixed flue gas outlet; the first flue gas port of the vibrating particle bed (12) is connected to the return flue gas port of the boiler (3) through the third flue gas pipeline and is provided with a first control valve (1); the flue gas outlet of the boiler (3) is connected to the third flue gas pipeline through the first flue gas pipeline and is provided with a second control valve (2) to connect to the first flue gas port of the vibrating particle bed (12); the flue gas outlet of the economizer (5) is connected to the fourth flue gas port of the flue gas mixer and is provided with a fourth control valve (8) and a first fan (9); the second flue gas port of the vibrating particle bed (12) is connected to the third flue gas port of the flue gas mixer (14); the mixed flue gas outlet of the flue gas mixer (14) is connected to the front end of the SCR denitrification reactor (4) and is provided with a second fan (11) and a fifth control valve (10). The exhaust port of the air preheater (6) is connected to the fourth exhaust port of the flue gas mixer (14) and is equipped with a third control valve (7).

2. The flue gas heat storage system based on multi-distribution particle segregation according to claim 1, characterized in that, The vibrating particle bed (12) is provided with multiple first flue gas ports and multiple second flue gas ports, and the flue gas mixer (14) is provided with multiple third flue gas ports; the third flue gas pipeline is connected to each of the first flue gas ports through multiple branch pipelines, and each of the second flue gas ports is connected to the corresponding third flue gas ports.

3. The flue gas heat storage system based on multi-distribution particle segregation according to claim 2, characterized in that, The first flue gas outlet is located at the top of the vibrating particle bed (12), and the second flue gas outlet is located on the side or bottom of the vibrating particle bed (12).

4. The flue gas heat storage system based on multi-distribution particle segregation according to claim 2, characterized in that, The first flue gas outlet is located on the first side of the vibrating particle bed (12), and the second flue gas outlet is located on the second side or bottom of the vibrating particle bed (12).

5. The multi-modal particle segregation based flue gas heat storage system of claim 1, wherein, The vibrating particle bed (12) has a porous partition between the particle layer and the ash removal layer.

6. The flue gas heat storage system based on multi-distribution particle segregation according to claim 5, characterized in that, The aperture of the partition baffle D g Smaller than the minimum diameter of the mixed filter media particles D l Larger than the diameter of dust particles D f .

7. The multi-modal particle segregation based flue gas heat storage system of claim 1, wherein, The ash unloading layer is equipped with heat exchange tubes for recovering residual heat from the dust during ash unloading.

8. The multi-modal particle segregation based flue gas heat storage system of claim 1, wherein, The flue gas return port of the boiler (3) is located on the upper side of its burner and has a flue gas return path structure with four corner tangents or four wall tangents.

9. The multi-modal particle segregation based flue gas heat storage system according to any one of claims 1 to 8, characterized in that, The mixed filter media particles include pebbles, quartz sand, alumina, silicon carbide, or basalt particles.

10. A flue gas heat storage and release method based on multi-distribution particle segregation, utilizing the flue gas heat storage and release system based on multi-distribution particle segregation as described in any one of claims 1 to 9, comprising: Before heat storage, according to the incoming flow conditions, a certain proportion of mixed filter media particles of different sizes are filled into the vibrating particle bed (12); the vibrating particle bed (12) is started, and the mixed filter media particles form a multi-distributed particle system (13) under the excitation of vibration, and the arrangement and thickness adjustment of the particle bed are automatically completed. During heat storage, the first control valve (1) and the fourth control valve (8) remain closed, while the second control valve (2), the third control valve (7), and the fifth control valve (10) are opened. The flue gas in the upper furnace of the boiler (3) enters the vibrating particle bed (12) under the traction of the second fan (11). According to the inlet and outlet pressure drop of the vibrating particle bed (12), the vibrating particle bed (12) is started and stopped at a certain vibration frequency and amplitude to complete the efficient heat exchange and dust removal of hot flue gas and cold particles under low pressure drop conditions. The flue gas at the outlet of the air preheater (6) is mixed with the flue gas at the outlet of the vibrating particle bed (12) in the flue gas mixer (14), and the mixed flue gas enters the front end of the SCR denitrification reactor (4). When releasing heat, the first control valve (1) and the fourth control valve (8) are opened, while the second control valve (2), the third control valve (7) and the fifth control valve (10) remain closed. The flue gas from the economizer (5) outlet enters the vibrating particle bed (12) under the traction of the first fan (9), completing the efficient heat exchange between the cold flue gas and the hot particles. After the heat exchange, the flue gas returns to the lower furnace of the boiler (3) along the flue.

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