Intermittent high-temperature flue gas waste heat recovery system with heat storage function

Abstract

The application discloses a kind of intermittent high-temperature flue gas waste heat recovery systems with heat storage function, including heat storage flue, water-cooled flue, boiler drum and steam heat accumulator;Heat storage flue is built-in heat storage body, its inlet is connected with the exhaust port of intermittent exhaust industrial kiln, one way is connected with the inlet of water-cooled flue, another way is connected with the inlet of two-phase flow passage of boiler drum, the outlet of water-cooled flue and the outlet of gas phase passage of boiler drum are connected with exhaust treatment device;The inlet of steam-liquid two-phase passage of boiler drum is connected with one way of boiler feed water, one way of boiler feed water exchanges heat with flue gas in boiler drum to generate steam, steam is discharged from the outlet of steam-liquid two-phase passage of boiler drum and is divided into two ways, one way is connected with the steam inlet of steam heat accumulator, another way is connected with the steam outlet of steam heat accumulator and is connected with user, another way of boiler feed water is connected with the water inlet of steam heat accumulator.The application is used to intermittent exhaust industrial kiln, can weaken temperature fluctuation of high-temperature flue gas, and strengthen boiler heat storage capacity.

Description

Technical Field

[0001] This invention belongs to the field of heat energy recovery and utilization technology, and relates to flue gas waste heat recovery, and particularly to an intermittent high-temperature flue gas waste heat recovery system with heat storage function. Background Technology

[0002] Industrial kilns in industries such as steel, building materials, and ceramics emit large amounts of intermittent high-temperature flue gas during production. Direct venting of this gas not only wastes energy but also causes serious environmental problems. Therefore, waste heat recovery from high-temperature flue gas has become a crucial aspect of energy conservation and emission reduction in the industrial sector. Currently, waste heat recovery technology is the mainstream solution in the industry, converting heat energy into steam through a "flue gas-water working medium" heat exchange, achieving cascaded energy utilization. This technology has been widely used due to its high equipment maturity and stable thermal efficiency. However, due to the inherent characteristics of industrial kiln flue gas, such as strong intermittency and drastic temperature fluctuations, existing waste heat recovery systems have revealed significant technical adaptability deficiencies in actual operation, restricting their application. The main problems are as follows: (1) The contradiction between intermittent flue gas emission and continuous steam demand is difficult to reconcile.

[0003] Industrial kilns often exhibit periodic flue gas emission characteristics due to their technological features, while downstream steam users require a continuous and stable steam supply. Existing waste heat boiler systems lack efficient heat storage capacity, leading to steam supply interruptions during kiln shutdowns, or necessitating reliance on backup boilers for supplemental steam, resulting in energy waste and equipment redundancy.

[0004] (2) Drastic fluctuations in flue gas temperature exacerbate equipment wear and tear.

[0005] The flue gas temperature in kilns fluctuates greatly due to the production process, directly impacting the metal materials of the boiler's heating surfaces. Although existing systems divert some flue gas through bypass flues, they lack a dynamic heat storage and buffering mechanism, failing to effectively mitigate the impact of temperature fluctuations on the boiler.

[0006] (3) The system's reliability and safety are insufficient under extreme operating conditions.

[0007] When the kiln load changes abruptly (such as emergency shutdown or rapid load increase), the existing waste heat boiler system often causes the following problems due to thermal inertia lag: instantaneous overheating of flue gas may damage the filter material of the bag filter; when the boiler is shut down in an emergency, insufficient heat storage capacity will prevent the waste heat from being discharged in time, and the kiln will be forced to limit production; the traditional cooling tower single temperature control method is inefficient at extreme high temperatures and requires the introduction of additional cold air for dilution, resulting in waste of heat energy. Summary of the Invention

[0008] In order to overcome the shortcomings of the prior art, the present invention aims to provide an intermittent high-temperature flue gas waste heat recovery system with heat storage function, which is applied to industrial kilns with intermittent flue gas discharge, thereby reducing the temperature fluctuation of high-temperature flue gas, enhancing the heat storage capacity of the boiler, solving at least one of the above three technical problems, and ultimately achieving the goal of improving energy utilization efficiency.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An intermittent high-temperature flue gas waste heat recovery system with heat storage function includes a heat storage flue, a water-cooled flue, a boiler drum, and a steam accumulator. The heat storage flue has a built-in heat storage body. Its inlet is connected to the exhaust port of an intermittently exhausting industrial kiln. Its outlet is divided into two paths: one path is connected to the inlet of the water-cooled flue, and the other path is connected to the inlet of the two-phase flow path of the boiler drum. The outlet of the water-cooled flue and the outlet of the gas phase passage of the boiler drum are connected to the tail gas treatment device. The inlet of the steam-liquid two-phase passage of the boiler drum is connected to one of the boiler feedwater paths. The boiler feedwater path exchanges heat with the flue gas in the boiler drum to generate steam. The steam is discharged from the outlet of the steam-liquid two-phase passage of the boiler drum and splits into two paths. One path is connected to the steam inlet of the steam accumulator, and the other path is connected to the user through the steam outlet of the steam accumulator. The other path of the boiler feedwater is connected to the water inlet of the steam accumulator.

[0010] In one embodiment, the heat storage material used in the heat storage body is selected according to the design flue gas inlet temperature, and different materials are selected in different projects. These materials include, but are not limited to, solid heat storage materials and phase change heat storage materials, such as inorganic hydrated salts, molten salts, oxides, and ceramic composite materials. After determining the flue gas inlet temperature and flow rate, the filling parameters are designed according to the flue gas inlet temperature and flow rate to maximize the heat storage capacity and minimize the equipment resistance, so that the entire heat storage body is the most economical.

[0011] In one embodiment, the heat storage body is arranged in multiple stages in the heat storage flue, with a gap between adjacent heat storage bodies; or, the heat storage flue with built-in heat storage body is arranged in multiple stages, with adjacent heat storage flues connected by pipes; along the flue gas flow direction, the heat storage capacity of the next stage heat storage body or the next stage heat storage flue is not higher than the heat storage capacity of the previous stage heat storage body or the previous stage heat storage flue.

[0012] In one embodiment, the intermittently venting industrial kiln is characterized by having a downward-facing water-cooled suction hood above the exhaust port, the outlet of which is connected to the inlet of the heat storage flue.

[0013] The outlet of the water-cooled flue is connected to flue valve one, and the outlet of the gas phase passage of the boiler drum is connected to flue valve two. The outlets of flue valve one and flue valve two converge at the tail gas treatment device. The tail gas treatment device includes a bag filter, an induced draft fan, and an exhaust flue connected in sequence.

[0014] In one embodiment, one path of the steam-liquid two-phase passage outlet of the boiler drum is connected to the steam inlet of the steam accumulator via the accumulator charging valve, and the other path is connected to the steam accumulator exhaust valve outlet via the boiler drum exhaust valve, and then both are connected to the water spray desuperheater via the pressure control valve, and finally supplied to the user; the other path of the boiler feedwater is connected to the steam accumulator inlet via the accumulator water supply valve.

[0015] In one embodiment, cooling water is introduced into the water-cooled jacket of the water-cooled flue, and the outlet pipe of the water-cooled jacket is divided into two paths. The main path is connected to the inlet of the cooling tower and then re-enters the water-cooled flue, while the branch path is connected to the hot water user via a hot water valve.

[0016] In one embodiment, a cooling air inlet valve for adjusting the air intake of the flue gas duct is provided between the outlet of the water-cooled flue gas duct and the outlet of the gas phase passage of the boiler drum and the exhaust gas treatment device.

[0017] The present invention also provides a method for intermittent high-temperature flue gas waste heat recovery based on the intermittent high-temperature flue gas waste heat recovery system with heat storage function, comprising: Intermittent exhaust gas from industrial kilns is fed into a heat storage flue, where the waste heat of the flue gas is stored by the heat storage body and the flue gas temperature fluctuations are reduced. After being stabilized in the heat storage flue, part or all of the flue gas enters the water working fluid in the boiler drum for heat exchange to generate steam for user use. When only part of the flue gas is used, the other part is discharged through the water-cooled flue. When the load changes drastically or the boiler is shut down for maintenance, all the flue gas stabilized in the heat storage flue will be discharged through the water-cooled flue for emergency discharge. When there is excess steam generated by the boiler drum, the excess steam is stored in the steam accumulator; when there is insufficient steam, the steam accumulator releases the stored steam to supplement it, ensuring continuous steam supply.

[0018] In one embodiment, the operating mode of the steam accumulator includes: when the boiler output is greater than the user demand, opening the accumulator charging valve and the accumulator water inlet valve to store excess steam and liquid water in the steam accumulator; when the boiler output is less than the user demand, opening the accumulator exhaust valve to release high-pressure steam to supplement the system gap.

[0019] In one embodiment, a pressure control valve is installed on the pipeline supplying steam to the user. When the input load decreases, the pressure control valve closes slightly to increase the system pressure, allowing excess steam to be stored under high pressure via the accumulator charging valve. When the input load increases, the pressure control valve opens wider to reduce the system pressure, while the steam accumulator releases high-pressure steam to replenish the system deficit, thus achieving sliding pressure operation.

[0020] Compared with existing technologies, this invention utilizes a designed regenerative flue to handle the intermittent exhaust gas from industrial kilns, employing a heat storage medium to store and release heat, thereby reducing fluctuations in exhaust gas temperature and minimizing thermal fatigue on boiler heating surfaces. Furthermore, by connecting a steam accumulator in parallel with the boiler drum, the heat storage and release of the steam accumulator are adjusted according to steam production, increasing heat storage density and preventing frequent boiler start-ups and shutdowns. The parallel connection of a water-cooled flue with the boiler drum ensures that excess exhaust gas can be discharged during boiler maintenance or when the flue gas load exceeds limits, without affecting the normal operation of the industrial kiln. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system structure of the present invention. Detailed Implementation

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] Because industrial kiln flue gas is characterized by large temperature fluctuations and difficulty in complete combustion, traditional waste heat boilers are prone to cracking of heating surfaces due to frequent thermal stress. Therefore, this invention provides an intermittent high-temperature flue gas waste heat recovery system with heat storage function to reduce flue gas temperature fluctuations, decrease thermal fatigue of boiler heating surfaces, improve heat storage efficiency and space utilization, and simultaneously ensure continuous operation and emergency safety of industrial kilns.

[0027] Please refer to Figure 1 The intermittent high-temperature flue gas waste heat recovery system of the present invention mainly includes a heat storage flue 3, a water-cooled flue 5, a boiler drum 10, and a steam accumulator 18. In this invention, high-temperature flue gas refers to flue gas discharged from the industrial kiln 1 at a temperature above several hundred degrees Celsius, which has high utilization value and is sufficient for steam production. Intermittent refers to the non-continuous nature of the flue gas exhaust from the industrial kiln 1. This can refer to the switching between emission and cessation, the switching between emission at a first temperature and emission at a second temperature, or the switching between emission at a first flow rate and emission at a second flow rate; obviously, it can also be a combination of the above emission methods. However, it is worth noting that this invention is obviously also applicable to structures with continuous emission. In fact, at the microscopic spatiotemporal level, there will inevitably be a period of time when the emission is "stable and continuous." Therefore, the intermittent nature of this invention should be interpreted broadly.

[0028] In this invention, the heat storage flue 3 is the core component for stabilizing boiler inlet temperature fluctuations, specifically achieved through an internally installed heat storage body 4. The heat storage flue 3 can be directly connected to the exhaust port of the industrial kiln 1 or via a flue gas collection device. The high-temperature flue gas generated by the industrial kiln 1 serves as a heat source, entering the heat storage flue 3 directly or after passing through the flue gas collection device. The heat storage body 4 stabilizes the drastic fluctuations in flue gas temperature through rapid heat absorption and release.

[0029] According to the above design, the present invention sets a high-temperature heat storage body 4 in the heat storage flue 3. The heat storage body 4 absorbs excess heat energy at high temperature and releases stored heat when the flue gas is interrupted, so that the boiler inlet temperature is always stable within a certain range, thereby greatly reducing the thermal fatigue of the heating surface and extending the boiler life compared with the prior art.

[0030] In this invention, the water-cooled flue 5 and the boiler drum 10 are the core components for ensuring continuous operation and emergency safety of industrial kilns. When the waste heat boiler is under maintenance or the flue gas load exceeds limits, the traditional system requires shutdown, severely impacting production continuity. Therefore, this invention incorporates a flue gas diversion structure at the outlet of the regenerable flue 3, dividing the flue gas into two paths: one connecting to the inlet of the water-cooled flue 5, and the other connecting to the inlet of the two-phase flow path of the boiler drum 10. The outlet of the water-cooled flue 5 and the outlet of the gas phase passage of the boiler drum 10 are connected to a tail gas treatment device. That is, by connecting the water-cooled flue 5 and the boiler drum 10 in parallel, the high-temperature flue gas, after being stabilized by the regenerable flue 3, can selectively enter either the water-cooled flue 5 or the boiler drum 10, or simultaneously enter both, with the flow rate adjusted as needed.

[0031] According to the above design, when the load changes drastically or the boiler is shut down for maintenance, the present invention can use the water-cooled flue 5 to discharge part of the flue gas in an emergency without affecting the normal operation of the kiln.

[0032] In this invention, the steam accumulator 18 and the boiler drum 10 are the core components for improving heat storage efficiency and space utilization. Traditional high-pressure steam accumulators are bulky and slow to respond, making them difficult to adapt to minute-level load fluctuations in industrial kilns. Therefore, this invention designs a parallel structure for the steam accumulator 18 and the boiler drum 10. The boiler feedwater 12 is divided into two paths: one connects to the inlet of the steam-liquid two-phase passage of the boiler drum 10, and the other connects to the inlet of the steam accumulator 18. A water inlet valve 17 is installed at the inlet of the steam accumulator 18. The high-temperature flue gas after stabilization in the heat storage flue 3 enters the boiler drum 10 and exchanges heat with the water medium to generate steam. The steam is discharged from the outlet of the steam-liquid two-phase passage of the boiler drum 10 and divided into two paths: one connects to the inlet of the steam accumulator 18, and the other connects to the user 31 along with the exhaust port of the steam accumulator 18.

[0033] According to the above design, the present invention uses a steam accumulator connected in parallel with the boiler steam drum. When there is excess steam, the excess steam is stored in the steam accumulator 18. When there is insufficient steam, the steam accumulator 18 releases the stored steam to supplement the pipeline network, ensuring continuous steam supply. This design increases the heat storage density while avoiding frequent boiler start-ups and shutdowns.

[0034] Depending on different processing capacities, space requirements, and actual temperature conditions, this invention can adopt a multi-stage heat storage design. The first design uses a heat storage flue 3 and multiple heat storage bodies 4. Each heat storage body 4 is arranged in multiple stages along the flue gas flow direction within the heat storage flue 3. Adjacent heat storage bodies 4 can have a certain distance between them, or the spaces between adjacent heat storage bodies 4 can be filled with a medium with a different heat storage capacity. The second design uses multiple heat storage flues 3 and multiple heat storage bodies 4. Each heat storage flue 3 contains one heat storage body 4, and the heat storage flues 3 are arranged in multiple stages along the flue gas flow direction. Adjacent heat storage flues 3 are connected by pipes. The two designs described above can also be used in combination.

[0035] The heat storage capacity of different stages can be the same or different. Preferably, along the flue gas flow direction, the heat storage capacity of the next stage heat storage body 4 or the next stage heat storage flue 3 is not higher than the heat storage capacity of the previous stage heat storage body 4 or the previous stage heat storage flue 3.

[0036] This structure provides more design options for different actual working conditions. By progressively decreasing the heat storage capacity, fluctuations can be smoothed out more effectively. The heat storage capacity can be achieved by selecting different materials, filling densities, and operating lengths for the heat storage body 4.

[0037] Furthermore, the flue gas collection device of the present invention is a water-cooled suction hood 2, which is arranged above the flue gas outlet of the industrial kiln 1 and connected to the flue gas outlet, with its outlet connected to the inlet of the heat storage flue 3. The opening of the water-cooled suction hood 2 faces downward or at an angle downward to collect flue gas and converge and transport it to the heat storage flue 3.

[0038] Furthermore, the present invention requires the flue gas to be purified before discharge. The exhaust gas treatment device used in the present invention includes a bag filter 7, an induced draft fan 8, and an exhaust flue 9 connected in sequence. The outlet of the water-cooled flue 5 is connected to a flue valve 6, and the outlet of the gas phase passage of the boiler drum 10 is connected to a flue valve 11. The outlets of flue valve 6 and flue valve 11 converge at the bag filter 7 for dust removal treatment, and then are discharged into the exhaust flue 9 by the induced draft fan 8.

[0039] Furthermore, under continuous high-temperature flue gas and high-load operation, the flue gas temperature of the industrial kiln 1 may continuously exceed the limit, leading to the burnout of the filter bags in the baghouse dust collector 7. Therefore, to enhance the safety and stability of the dust removal system, a cooling air inlet valve 30 is installed between the outlet of the water-cooled flue duct 5 and the outlet of the gas phase passage of the boiler drum 10 and the tail gas treatment device, located at the inlet of the baghouse dust collector 7. This valve is used to regulate the air intake of the exhaust flue duct 9, ensuring sufficient cooling of the flue gas and guaranteeing the safe operation of the baghouse dust collector 7. That is, when the flue gas temperature exceeds the limit, a certain amount of ambient cold air is mixed in to lower the flue gas temperature. This design ensures the safe operation of the baghouse dust collector 7 while preventing dust caking caused by sudden cooling of the flue gas, thus ensuring the long-term stable operation of the dust removal system.

[0040] Furthermore, in this invention, flue cooling water 27 is introduced into the water-cooled jacket of the water-cooled flue 5. The circulating water flows through the water-cooled flue 5 to absorb the waste heat of the flue gas. The flue cooling water 27 is connected to the water-cooled flue 5 via the flue cooling water pump 25. The outlet pipe of the water-cooled jacket of the water-cooled flue 5 is divided into two paths. The main path is connected to the inlet of the cooling tower 26. After being cooled by the cooling tower 26, the water is pumped back into the water-cooled flue 5 for reuse. The branch path is connected to the hot water user 29 via the hot water valve 28.

[0041] Furthermore, the present invention also performs certain pretreatment on the boiler feedwater 12. The initial boiler feedwater 12 first enters the water treatment equipment 13, then enters the low-pressure water pump 14 connected in series with the water treatment equipment 13, then enters the deaerator 15 connected to the low-pressure water pump 14, and then enters the boiler feedwater pump 16 connected to the deaerator 15. The boiler feedwater 12 is split into two paths from the outlet of the boiler feedwater pump 16. The first path is directly connected to the boiler drum 10, and the second path is connected to the inlet of the steam accumulator 18 via the accumulator water inlet valve 17. Furthermore, the present invention further designs the outlet pipeline of the steam-liquid two-phase passage of the boiler drum 10. The first branch of the outlet of the steam-liquid two-phase passage is connected to the steam inlet of the steam accumulator 18 via the accumulator charging valve 19. The second branch is connected to the outlet of the steam accumulator 18 via the boiler drum exhaust valve 21. They then pass together through the pressure control valve 22 to the spray desuperheater 24, and finally supply to the user 31. The spray desuperheater 24 is also connected to a spray desuperheating water pump 23 to further control the temperature and flow rate.

[0042] Furthermore, the water distribution ratio between the boiler drum 10 and the steam accumulator 18 can be dynamically adjusted through the aforementioned accumulator water inlet valve 17.

[0043] Based on the above structure, the main process of the intermittent high-temperature flue gas waste heat recovery method of the present invention is as follows: The intermittent exhaust gas from the industrial kiln 1 is sent into the heat storage flue 3, where the waste heat of the flue gas is stored through the heat storage body 4 and the flue gas temperature fluctuation is reduced. After being stabilized in the regenerable flue gas duct 3, some or all of the flue gas enters the water medium in the boiler drum 10 for heat exchange to generate steam for use by user 31. Obviously, when the boiler drum 10 only utilizes part of the flue gas, the other part is discharged through the water-cooled flue gas duct 5. In particular, when the load changes drastically or the boiler is shut down for maintenance, all the flue gas stabilized in the regenerable flue gas duct 3 will be discharged through the water-cooled flue gas duct 5 for emergency discharge. When the boiler drum 10 generates excess steam, the excess steam is stored in the steam accumulator 18; when the steam is insufficient, the steam accumulator 18 releases the stored steam to supplement it, ensuring continuous steam supply.

[0044] The operating modes of the steam accumulator 18 of the present invention include: when the boiler output is greater than the user demand, the accumulator charging valve 19 and the accumulator water inlet valve 17 are opened to store excess steam and liquid water in the steam accumulator 18; when the boiler output is less than the user demand, the accumulator exhaust valve 20 is opened to release high-pressure steam to supplement the system gap.

[0045] Furthermore, this invention introduces sliding pressure operation control: When there is excess steam, the accumulator charging valve 19 and the accumulator exhaust valve 20 are controlled to allow the steam accumulator 18 to store saturated water at high pressure. When there is insufficient steam, the accumulator charging valve 19 and the accumulator exhaust valve 20 are controlled to allow the steam accumulator 18 to quickly depressurize and release steam to make up for the shortfall.

[0046] When the input load decreases, the pressure control valve 22 is closed to increase the system pressure, and excess steam is stored under high pressure through the accumulator charging valve 19; when the input load increases, the pressure control valve 22 is opened to reduce the system pressure, and at the same time, the steam accumulator 18 releases high-pressure steam to replenish the system gap, thus achieving sliding pressure operation.

[0047] In summary, the intermittent high-temperature flue gas waste heat recovery system with heat storage function of the present invention can meet the needs of energy conservation, emission reduction and efficient energy utilization, and effectively realize the stable waste heat recovery of high-temperature flue gas emitted by intermittent industrial kilns.

[0048] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An intermittent high-temperature flue gas waste heat recovery system with heat storage function, characterized in that, It includes a heat storage flue (3), a water-cooled flue (5), a boiler drum (10), and a steam accumulator (18). The heat storage flue (3) has a built-in heat storage body (4). Its inlet is connected to the exhaust port of the intermittently exhausting industrial kiln (1). The outlet is divided into two paths: one path is connected to the inlet of the water-cooled flue (5), and the other path is connected to the two-phase flow path inlet of the boiler drum (10). The outlet of the water-cooled flue (5) and the gas phase passage outlet of the boiler drum (10) are connected to the tail gas treatment device. The inlet of the two-phase steam passage of the boiler drum (10) is connected to one of the boiler feedwater (12). One of the boiler feedwater (12) exchanges heat with the flue gas in the boiler drum (10) to generate steam. The steam is discharged from the outlet of the two-phase steam passage of the boiler drum (10) and divided into two paths. One path is connected to the steam inlet of the steam accumulator (18), and the other path is connected to the user (31) together with the exhaust port of the steam accumulator (18). The other path of the boiler feedwater (12) is connected to the water inlet of the steam accumulator (18).

2. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, The heat storage body (4) adopts solid heat storage material or phase change heat storage material. The filling parameters are designed according to the flue gas inlet temperature and flow rate to ensure maximum heat storage capacity and minimum equipment resistance.

3. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, The heat storage body (4) is arranged in multiple stages in the heat storage flue (3), and there is a gap between adjacent heat storage bodies (4); along the flue flow direction, the heat storage capacity of the next stage heat storage body (4) is not higher than the heat storage capacity of the previous stage heat storage body (4).

4. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, The heat storage flue (3) of the built-in heat storage body (4) is set in multiple stages, and adjacent heat storage flues (3) are connected by pipes; along the direction of flue gas flow, the heat storage capacity of the next stage heat storage flue (3) is not higher than that of the previous stage heat storage flue (3).

5. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, The industrial kiln (1) with intermittent smoke exhaust is provided with a water-cooled suction hood (2) with the hood opening facing downwards above the exhaust port, and the outlet of the water-cooled suction hood (2) is connected to the inlet of the heat storage flue (3).

6. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, The outlet of the water-cooled flue (5) is connected to flue valve one (6), and the outlet of the gas phase passage of the boiler drum (10) is connected to flue valve two (11). The outlets of flue valve one (6) and flue valve two (11) converge to the exhaust gas treatment device. The exhaust gas treatment device includes a bag filter (7), an induced draft fan (8), and an exhaust flue (9) connected in sequence.

7. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, One of the outlets of the steam-liquid two-phase passage of the boiler drum (10) is connected to the steam inlet of the steam accumulator (18) via the accumulator charging valve (19), and the other is connected to the outlet of the steam accumulator (18) via the boiler drum exhaust valve (21). They then pass through the pressure control valve (22) and are connected to the water spray desuperheater (24) before being supplied to the user (31).

8. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 7, characterized in that, The other path of the boiler feedwater (12) is connected to the inlet of the steam accumulator (18) through the accumulator water inlet valve (17).

9. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, Cooling water (27) is introduced into the water-cooled jacket of the water-cooled flue (5). The outlet pipe of the water-cooled jacket is divided into two paths. The main path is connected to the inlet of the cooling tower (26) and then re-enters the water-cooled flue (5). The branch path is connected to the hot water user (29) via the hot water valve (28).

10. The intermittent high-temperature flue gas waste heat recovery system with heat storage function according to claim 1, characterized in that, A cooling air inlet valve (30) for adjusting the air intake of the flue gas duct (9) is provided between the outlet of the water-cooled flue (5) and the outlet of the gas phase passage of the boiler drum (10) and the tail gas treatment device.

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