A denitrification device and control method for a cement kiln tail boiler

Abstract

The present invention discloses a denitrification device and control method for a cement kiln tail boiler, which relates to the field of flue gas treatment technology and is intended to address the problems of existing high-temperature, high-dust, and high-temperature, medium-dust denitrification systems, such as large footprint, high energy consumption, and reduced power generation from waste heat boilers. The device comprises a waste heat power generation boiler, a valve unit, a denitrification reactor, and a cleaning unit; the valve unit is disposed between the waste heat power generation boiler and the denitrification reactor and is used to switch the pipeline between the waste heat power generation boiler and the denitrification reactor according to the operating status of the waste heat power generation boiler; the cleaning unit is disposed within the denitrification reactor and is used to control the cleaning pressure and frequency of the cleaning unit according to the operating status of the waste heat power generation boiler; the operating status of the waste heat power generation boiler includes a normal state and a fault state.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and more particularly to a denitration device and a control method for a cement kiln tail boiler. Background Art

[0002] With the progress of ultra-low nitrogen oxide emissions in the cement industry, cement SCR denitrification transformation applications are increasing. For the denitrification of flue gas from the cement kiln tail, based on the characteristics of the cement kiln and the on-site conditions, there are currently four main SCR process solutions: high-temperature high-dust, high-temperature medium-dust, medium-temperature medium-dust, and low-temperature low-dust layout solutions. The current domestic cement industry engineering application technology route is the high-temperature high-dust and high-temperature medium-dust SCR denitrification systems. The high-temperature high-dust and high-temperature medium-dust SCR denitrification systems are generally arranged between the C1 outlet of the kiln tail preheater and the waste heat boiler. The flue gas temperature is generally 300-320°C. This process is greatly affected by dust, and a pre-dust removal system needs to be arranged in front of the SCR denitrification system. The layout method is greatly affected by the site, and the on-site layout and construction are relatively difficult. After the flue gas passes through the SCR system, it has a certain impact on the power generation of the waste heat boiler.

[0003] In summary, the existing high-temperature high-dust and high-temperature medium-dust denitrification systems have problems such as large footprint, high energy consumption, and reduced power generation of waste heat boilers. Summary of the Invention

[0004] The embodiment of the present invention provides a cement kiln tail boiler denitrification device and control method, which is used to solve the problems of existing high-temperature high-dust and high-temperature medium-dust denitrification systems, such as large footprint, high energy consumption, and reduced power generation of waste heat boilers.

[0005] The embodiment of the present invention provides a denitration device for a cement kiln tail boiler, comprising: a waste heat power generation boiler, a valve unit, a denitration reactor, and a ash cleaning unit;

[0006] The valve unit is provided between the waste heat power generation boiler and the denitration reactor, and is used to switch the pipeline between the waste heat power generation boiler and the denitration reactor according to the operating state of the waste heat power generation boiler;

[0007] The cleaning unit is arranged in the denitration reactor, and is used to control the cleaning pressure and cleaning frequency of the cleaning unit according to the operating state of the waste heat power generation boiler; the operating state of the waste heat power generation boiler includes a normal state and a fault state.

[0008] Preferably, the valve unit includes a cold air valve, a first switching valve, and a second switching valve;

[0009] A first pipeline connected to the denitration reactor is provided on the top of the waste heat power generation boiler, and the first switching valve is provided on the first pipeline;

[0010] A second pipeline connected to the denitration reactor is provided at the bottom of the waste heat power generation boiler, and the second switching valve is provided on the second pipeline.

[0011] Preferably, the valve unit further includes a cold air valve;

[0012] The cold air valve is provided on the first pipeline and is located between the waste heat power generation boiler and the first switching valve.

[0013] Preferably, the device further comprises a two-fluid spray gun;

[0014] The dual-fluid spray gun is arranged directly above the waste heat power generation boiler and is used to spray atomized ammonia water into the waste heat power generation boiler.

[0015] Preferably, the soot cleaning unit includes a rake soot blower and a sonic soot blower;

[0016] The rake soot blower and the sonic soot blower are respectively arranged on both sides of each catalyst layer;

[0017] A plurality of said rake-type sootblowers are sequentially arranged above each catalyst layer from top to bottom;

[0018] A plurality of the sonic soot blowers are sequentially arranged above each catalyst layer from top to bottom.

[0019] Preferably, the denitration reactor further includes a heat exchanger, which is disposed below the catalyst layer and is used to heat the compressed air in the denitration reactor.

[0020] Preferably, the denitration reactor further comprises a temperature detection device and a pressure detection device;

[0021] The temperature detection device is arranged at the inlet of the denitration reactor, and is used to detect the temperature of the flue gas entering the denitration reactor;

[0022] The pressure detection device is arranged in the denitration reactor and is used to detect the resistance change of each catalyst layer in the denitration reactor.

[0023] An embodiment of the present invention further provides a control method for a cement kiln tail boiler denitrification device, comprising:

[0024] When it is determined that the waste heat power generation boiler is operating normally, controlling to close the first switching valve provided on the first pipeline and to open the second switching valve provided on the second pipeline, so that the flue gas from the waste heat power generation boiler enters the denitration reactor through the second pipeline; or

[0025] When it is determined that the waste heat power generation boiler fails, the second switching valve set on the second pipeline is controlled to close and the first switching valve set on the first pipeline is opened, so that the flue gas passing through the waste heat power generation boiler enters the denitrification reactor through the first pipeline.

[0026] Preferably, the method further comprises: controlling the cleaning pressure and cleaning frequency of the cleaning unit according to the operating state of the waste heat power generation boiler;

[0027] When the waste heat power generation boiler operates normally, the cleaning pressure and cleaning frequency of the cleaning unit are relatively low; when the waste heat power generation boiler fails, the cleaning pressure and cleaning frequency of the cleaning unit are relatively high.

[0028] Preferably, when it is determined that the waste heat power generation boiler has failed, the method further includes:

[0029] Cold air is blown to the flue gas passing through the first pipeline through a cold air valve arranged on the first pipeline, so that the temperature of the flue gas entering the denitration reactor is reduced to a set temperature.

[0030] An embodiment of the present invention provides a denitrification device and control method for a cement kiln tail boiler, the device comprising: a waste heat power generation boiler, a valve unit, a denitrification reactor, and a cleaning unit; the valve unit is arranged between the waste heat power generation boiler and the denitrification reactor, and is used to switch the pipeline between the waste heat power generation boiler and the denitrification reactor according to the operating status of the waste heat power generation boiler; the cleaning unit is arranged in the denitrification reactor, and is used to control the cleaning pressure and cleaning frequency of the cleaning unit according to the operating status of the waste heat power generation boiler; the operating status of the waste heat power generation boiler includes a normal state and a fault state. This denitrification device is applied to the waste heat boiler at the tail end of the cement kiln. It switches the valve through the valve unit, so that the temperature of the flue gas entering the denitrification reactor can be continuously maintained at a medium temperature condition, avoiding the need to set up a pre-dust removal system, reducing the floor space, investment costs and system energy consumption, and making the system operation more stable; furthermore, the cleaning pressure and cleaning frequency of the cleaning unit are related to the operating status of the waste heat power generation boiler, which can ensure the stable operation of the system in high dust and medium dust environments. This device solves the problems of existing high-temperature and high-dust, high-temperature and medium dust denitrification systems, such as large floor space, high energy consumption, and reduced power generation of the waste heat boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A structural schematic diagram of a cement kiln tail boiler denitrification device provided by an embodiment of the present invention;

[0033] Figure 2 A schematic flow chart of a control method for a cement kiln tail boiler denitrification device provided by an embodiment of the present invention;

[0034] Among them, 1. Cold air valve; 2. First switching valve; 3. Second switching valve; 4. Temperature detection equipment; 5. Rake soot blower; 6. Sonic soot blower; 7. Heat exchanger; 8. Catalyst; 9. Ash hopper; 10. Pressure detection equipment; 11. Dual-fluid spray gun; 12. Waste heat power generation boiler. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Before introducing the device, it is necessary to first introduce the two operating states of the waste heat power generation boiler:

[0037] One operating state: When the waste heat power generation boiler is operating normally, the flue gas from the cement kiln tail passes through the waste heat power generation boiler and then enters the SCR denitrification reactor. In this operating state, the flue gas from the cement kiln tail passes through the waste heat power generation boiler and the temperature becomes about 200℃, and the dust concentration in the flue gas is about 50g / m 3 , the flue gas belongs to the medium temperature and medium dust conditions.

[0038] One operating state: When the waste heat power generation boiler fails, the flue gas from the cement kiln tail enters the SCR denitration reactor through the bypass of the waste heat power generation boiler to avoid affecting the flue gas from the cement kiln tail entering the SCR denitration reactor. Since the flue gas from the cement kiln tail has not been treated by the waste heat power generation boiler, the flue gas temperature at this time is about 300℃, and the dust concentration in the flue gas is about 80g / m 3 , the flue gas belongs to medium temperature and high dust conditions.

[0039] In practical applications, if flue gas desulfurization is performed for both operating states of a waste heat power generation boiler, a pre-dust removal system must be installed before the SCR denitrification system. Installing such a system increases construction difficulty and increases site size. To address these issues, an embodiment of the present invention provides a cement kiln tail boiler denitrification device that can desulfurize flue gas for both operating states of the waste heat power generation boiler without requiring a pre-dust removal system.

[0040] Figure 1 The schematic structural diagram of a cement kiln tail boiler denitrification device provided by an embodiment of the present invention is exemplarily shown. Figure 1 The following is a schematic diagram showing the structure of a denitration device for a cement kiln boiler according to an embodiment of the present invention. Figure 1 As shown, the device mainly includes: a waste heat power generation boiler 12, a valve unit, a denitrification reactor, and a dust cleaning unit.

[0041] In actual applications, the valve unit is provided between the waste heat power generation boiler 12 and the denitration reactor, and is used to switch the pipeline provided between the waste heat power generation boiler 12 and the denitration reactor according to the operating state of the waste heat power generation boiler 12. That is, at least two pipelines are provided between the waste heat power generation boiler 12 and the denitration reactor, and different valves are provided on different pipelines. By controlling the valves, the pipelines connecting the waste heat power generation boiler 12 and the denitration reactor are realized; further, in actual applications, since a large amount of dust is generated in the denitration reactor, in order not to affect the normal operation of the denitration reactor, preferably, a cleaning unit is provided in the denitration reactor. The cleaning unit is used to control the cleaning pressure and cleaning frequency of the cleaning unit according to the operating state of the waste heat power generation boiler 12. That is, when the concentration of the flue gas entering the denitration reactor is high, the cleaning pressure and cleaning frequency can be increased. Correspondingly, when the concentration of the flue gas entering the denitration reactor is low, the cleaning pressure and cleaning frequency can be reduced.

[0042] In this embodiment of the present invention, the waste heat power generation boiler 12 includes two operating states: normal operation and failure. Based on this, it can be determined that the cleaning unit also has two operating states: increasing the cleaning pressure and frequency, and decreasing the cleaning pressure and frequency. It should be noted that in this embodiment of the present invention, the specific values ​​of the cleaning pressure and frequency are not limited.

[0043] An embodiment of the present invention provides a denitrification device for a cement kiln tail boiler, which is applied to the waste heat boiler at the tail end of a cement kiln. The device switches the valve through a valve unit so that the temperature of the flue gas entering the denitrification reactor can be continuously maintained at a medium-temperature operating condition, avoiding the need to set up a pre-dust removal system, reducing the floor space, investment costs and system energy consumption, and making the system operation more stable; furthermore, the cleaning pressure and cleaning frequency of the cleaning unit are related to the operating state of the waste heat power generation boiler 12, which can ensure the stable operation of the system in high-dust and medium-dust environments. The device solves the problems of existing high-temperature and high-dust, high-temperature and medium-dust denitrification systems, such as large floor space, high energy consumption, and reduced power generation of the waste heat boiler.

[0044] In an embodiment of the present invention, the valve unit specifically includes a first switching valve 2 and a second switching valve 3. Specifically, a first pipeline connected to the denitrification reactor is provided at the top of the waste heat power generation boiler 12, and the first switching valve 2 is provided on the first pipeline; that is, the first pipeline is controlled by the first switching valve 2. When the first switching valve 2 is opened, the waste heat power generation boiler 12 and the denitrification reactor are connected through the first pipeline. Accordingly, when the first switching valve 2 is closed, the first pipeline between the waste heat power generation boiler 12 and the denitrification reactor is disconnected; further, a second pipeline connected to the denitrification reactor is provided at the bottom of the waste heat power generation boiler 12, and the second switching valve 3 is provided on the second pipeline; that is, the second pipeline is controlled by the second switching valve 3. When the second switching valve 3 is opened, the waste heat power generation boiler 12 and the denitrification reactor are connected through the second pipeline. Accordingly, when the second switching valve 3 is closed, the second pipeline between the waste heat power generation boiler 12 and the denitrification reactor is disconnected.

[0045] In practice, since waste heat power generation boiler 12 operates in two different states, the flue gas temperature passing through waste heat power generation boiler 12 varies in different states. To ensure that the flue gas temperature entering the denitration reactor remains consistent, a cold air valve 1 is preferably provided on the first pipeline. This cold air valve 1 is located between waste heat power generation boiler 12 and first switching valve 2. The temperature of the flue gas passing through the first pipeline can be adjusted to the desired temperature by adjusting the opening of cold air valve 1. In this embodiment of the present invention, the flue gas temperature entering the denitration reactor is controlled at 200°C.

[0046] In actual applications, the temperature of the flue gas from the tail of the cement kiln is about 300°. When the flue gas enters the waste heat power generation boiler 12, in order to reduce the temperature of the flue gas, preferably, a dual-fluid spray gun 11 is also provided on the top of the waste heat power generation boiler 12. The dual-fluid spray gun 11 can be used to atomize ammonia water and then spray it into the flue gas. When the atomized ammonia water evaporates into ammonia gas, it can absorb the temperature of the flue gas, thereby achieving the effect of reducing the flue gas temperature.

[0047] The cleaning unit provided in the embodiment of the present invention mainly includes a rake soot blower 5 and a sonic soot blower 6. In order to be able to evenly clean each catalyst layer 8, preferably, the rake soot blower 5 and the sonic soot blower 6 are respectively arranged on both sides of each catalyst layer 8, and multiple rake soot blowers 5 are sequentially arranged above each catalyst layer 8 from top to bottom; multiple sonic soot blowers 6 are sequentially arranged above each catalyst layer 8 from top to bottom. That is, a rake soot blower 5 and a sonic soot blower 6 are respectively arranged on both sides above each catalyst layer 8. In order to facilitate the control of the rake soot blower 5 and the sonic soot blower 6, the rake soot blower 5 can be arranged on one side and the sonic soot blower 6 can be arranged on the other side. In the embodiment of the present invention, it is sufficient to confirm that the rake soot blower 5 and the sonic soot blower 6 are respectively arranged on both sides of the catalyst layer 8 and located above the catalyst layer 8. There is no specific limitation on whether the rake soot blower 5 and the sonic soot blower 6 are arranged side by side or in a row.

[0048] In actual applications, since the catalyst layer 8 collects porous honeycomb catalysts 8, in order to prevent the presence of liquid water in the compressed air from causing the catalyst 8 to be deactivated, preferably, a heat exchanger 7 is also provided in the denitration reactor. The heat exchanger 7 is provided below the bottom catalyst layer 8. The compressed air in the denitration reactor can be heated by the heat exchanger 7, thereby avoiding the presence of liquid water in the compressed air.

[0049] Furthermore, the denitrification reactor is also provided with a temperature detection device 4 and a pressure detection device 10. Specifically, the temperature detection device 4 is provided at the inlet of the denitrification reactor to detect the temperature of the flue gas entering the denitrification reactor; the pressure detection device 10 is provided inside the denitrification reactor to detect the change in resistance of each catalyst layer 8 in the denitrification reactor.

[0050] Since a large amount of dust is generated in the denitration reactor, in order to recover the dust in the denitration reactor, preferably, an ash hopper 9 is provided at the bottom of the denitration reactor, through which the dust generated in the denitration reactor can be collected.

[0051] In order to more clearly introduce the denitration device for cement kiln tail boiler provided by the embodiment of the present invention, the following is combined with Figure 2 , the control method of the device is introduced in detail.

[0052] like Figure 2 As shown, the control method of the cement kiln tail boiler denitrification device includes the following steps:

[0053] Step 101: When it is determined that the waste heat power generation boiler 12 is operating normally, control the closing of the first switching valve 2 provided on the first pipeline and the opening of the second switching valve 3 provided on the second pipeline, so that the flue gas from the waste heat power generation boiler 12 enters the denitration reactor through the second pipeline; or

[0054] Step 102: When it is determined that the waste heat power generation boiler 12 fails, the second switching valve 3 provided on the second pipeline is controlled to be closed and the first switching valve 2 provided on the first pipeline is opened, so that the flue gas passing through the waste heat power generation boiler 12 enters the denitrification reactor through the first pipeline.

[0055] It should be noted that the control method can be executed by a processor located outside the device. Specifically, the processor is configured to map at least the two operating states of the waste heat power generation boiler 12 to the control unit and the dust removal unit. Furthermore, the mapping between the two operating states of the cold air valve 1, the dual-fluid spray gun 11, and the waste heat power generation boiler 12 can also be configured within the processor.

[0056] In step 101, when it is determined that the operating state of the waste heat power generation boiler 12 is normal, it can be determined that the flue gas from the cement kiln tail needs to pass through the waste heat power generation boiler 12 before entering the SCR denitrification reactor. In this operating state, the flue gas from the cement kiln tail reaches a temperature of about 200°C after passing through the waste heat power generation boiler 12, and the dust concentration in the flue gas is about 50g / m 3 , the flue gas belongs to the medium temperature and medium dust conditions.

[0057] In response to the current operating state of the waste heat power generation boiler 12, the processor controls the closing of the first switching valve 2 provided on the first pipeline, and then opens the second switching valve 3 provided on the second pipeline. Through the above control, the flue gas passing through the waste heat power generation boiler 12 can enter the denitrification reactor through the second pipeline. The temperature detection device 4 provided at the entrance of the denitrification reactor can detect the problem of the flue gas entering the denitrification reactor and send the detected real-time temperature to the processor. Since the flue gas at this time is operating under medium-temperature and medium-dust conditions, the processor can control the rake soot blower 5 and the sonic soot blower 6 to reduce the soot blowing pressure and reduce the soot blowing frequency at the same time. Furthermore, the pressure detection device 10 provided in the denitrification reactor is used to detect the resistance changes of each catalyst layer 8 in the denitrification reactor, and the above resistance changes are sent to the processor.

[0058] It should be noted that, in actual applications, since the temperature of the flue gas entering the waste heat power generation boiler 12 reaches about 300°, in order to cool the flue gas entering the waste heat power generation boiler 12, atomized ammonia water can be sprayed into the waste heat power generation boiler 12 through a dual-fluid spray gun 11 arranged above the waste heat power generation boiler 12. The sprayed atomized ammonia water absorbs the temperature in the flue gas and turns into ammonia gas.

[0059] A large amount of dust is generated in the denitrification reactor, which needs to be collected by the ash hopper 9 arranged at the bottom of the denitrification reactor. Further, the dust is discharged to the downstream ash conveying system through the ash hopper 9. At the same time, the flue gas entering the denitrification reactor passes through the catalyst 8 to efficiently remove nitrogen oxides and then enters the downstream equipment.

[0060] In step 102, when it is determined that the waste heat power generation boiler 12 has failed, it can be determined that the flue gas from the cement kiln tail enters the SCR denitrification reactor through the bypass of the waste heat power generation boiler 12. In this operating state, the flue gas from the cement kiln tail has not been processed by the waste heat power generation boiler 12, so the temperature of the flue gas is about 300°C and the dust concentration in the flue gas is about 80g / m 3 , the flue gas belongs to medium temperature and high dust conditions.

[0061] Based on the current operating state of the waste heat power generation boiler 12, the processor controls the closing of the second switching valve 3 provided on the second pipeline, and then opens the first switching valve 2 provided on the first pipeline. Through this control, the flue gas passing through the waste heat power generation boiler 12 can enter the denitration reactor through the first pipeline. The temperature detection device 4 provided at the inlet of the denitration reactor can detect the flue gas entering the denitration reactor and send the detected real-time temperature to the processor. It should be noted that in actual applications, because the flue gas from the cement kiln tail has not been processed by the waste heat power generation boiler 12, the temperature of the flue gas passing through the first pipeline is relatively high. In order to reduce the temperature of the flue gas passing through the first pipeline, a cold air valve 1 is preferably provided on the first pipeline, which is located between the first switching valve 2 and the waste heat power generation boiler 12. By adjusting the opening of the cold air valve 1, the flue gas in the first pipeline can be cooled, so that the temperature of the flue gas entering the denitration reactor can meet the set requirements. Furthermore, because the flue gas at this time is operating at medium temperature and high dust levels, the processor can control the rake soot blowers 5 and sonic soot blowers 6 to increase the soot blowing pressure and frequency. Furthermore, pressure detection equipment 10 installed within the denitrification reactor detects changes in the resistance of each catalyst layer 8 within the denitrification reactor and transmits these changes to the processor.

[0062] It should be noted that, in the embodiment of the present invention, when the waste heat power generation boiler 12 operates normally, the cleaning pressure and cleaning frequency of the cleaning unit are relatively low; when the waste heat power generation boiler 12 fails, the cleaning pressure and cleaning frequency of the cleaning unit are relatively high.

[0063] In summary, an embodiment of the present invention provides a denitrification device and control method for a cement kiln tail boiler, the device comprising: a waste heat power generation boiler, a valve unit, a denitrification reactor, and a cleaning unit; the valve unit is arranged between the waste heat power generation boiler and the denitrification reactor, and is used to switch the pipeline between the waste heat power generation boiler and the denitrification reactor according to the operating status of the waste heat power generation boiler; the cleaning unit is arranged in the denitrification reactor, and is used to control the cleaning pressure and cleaning frequency of the cleaning unit according to the operating status of the waste heat power generation boiler; the operating status of the waste heat power generation boiler includes a normal state and a fault state. This denitrification device is applied to the waste heat boiler at the tail end of the cement kiln. It switches the valve through the valve unit, so that the temperature of the flue gas entering the denitrification reactor can be continuously maintained at a medium temperature condition, avoiding the need to set up a pre-dust removal system, reducing the floor space, investment costs and system energy consumption, and making the system operation more stable; furthermore, the cleaning pressure and cleaning frequency of the cleaning unit are related to the operating status of the waste heat power generation boiler, which can ensure the stable operation of the system in high dust and medium dust environments. This device solves the problems of existing high-temperature and high-dust, high-temperature and medium dust denitrification systems, such as large floor space, high energy consumption, and reduced power generation of the waste heat boiler.

[0064] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0065] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A denitrification device for a cement kiln tail boiler, characterized in that: include: Waste heat power generation boiler, valve unit, denitrification reactor, ash cleaning unit; The valve unit is arranged between the waste heat power generation boiler and the denitration reactor, and is used to switch the pipeline between the waste heat power generation boiler and the denitration reactor according to the operating state of the waste heat power generation boiler; the valve unit includes a cold air valve, a first switching valve, and a second switching valve; a first pipeline connected to the denitration reactor is arranged at the top of the waste heat power generation boiler, and the first switching valve is arranged on the first pipeline; a second pipeline connected to the denitration reactor is arranged at the bottom of the waste heat power generation boiler, and the second switching valve is arranged on the second pipeline; the valve unit also includes a cold air valve; the cold air valve is arranged on the first pipeline and is located between the waste heat power generation boiler and the first switching valve; The soot cleaning unit is disposed in the denitration reactor and is used to control the soot cleaning pressure and frequency of the soot cleaning unit according to the operating state of the waste heat power generation boiler; the operating state of the waste heat power generation boiler includes a normal state and a fault state; the soot cleaning unit includes a rake soot blower and a sonic soot blower; the rake soot blower and the sonic soot blower are respectively disposed on both sides of each catalyst layer; a plurality of the rake soot blowers are sequentially disposed above each catalyst layer from top to bottom; A plurality of the sonic soot blowers are sequentially arranged above each catalyst layer from top to bottom.

2. The device according to claim 1, wherein The apparatus also includes a dual-fluid spray gun; The dual-fluid spray gun is arranged directly above the waste heat power generation boiler and is used to spray atomized ammonia water into the waste heat power generation boiler.

3. The device according to claim 1, wherein The denitration reactor further includes a heat exchanger, which is disposed below the catalyst layer and is used to heat the compressed air in the denitration reactor.

4. The device according to claim 1, wherein The denitration reactor also includes a temperature detection device and a pressure detection device; The temperature detection device is arranged at the inlet of the denitration reactor, and is used to detect the temperature of the flue gas entering the denitration reactor; The pressure detection device is arranged in the denitration reactor and is used to detect the resistance change of each catalyst layer in the denitration reactor.

5. A control method for a denitration device at the tail end of a cement kiln boiler, applied to the denitration device at the tail end of a cement kiln boiler according to any one of claims 1 to 4, characterized in that: include: When it is determined that the waste heat power generation boiler is operating normally, controlling to close a first switching valve provided on the first pipeline and to open a second switching valve provided on the second pipeline, so that the flue gas from the waste heat power generation boiler enters the denitration reactor through the second pipeline; When it is determined that the waste heat power generation boiler has failed, controlling to close the second switching valve provided on the second pipeline and to open the first switching valve provided on the first pipeline, so that the flue gas passing through the waste heat power generation boiler enters the denitration reactor through the first pipeline; Cold air is blown to the flue gas passing through the first pipeline through a cold air valve arranged on the first pipeline, so that the temperature of the flue gas entering the denitration reactor is reduced to a set temperature.

6. The method according to claim 5, wherein Also includes: Controlling the cleaning pressure and frequency of the cleaning unit according to the operating status of the waste heat power generation boiler; When the waste heat power generation boiler operates normally, the cleaning pressure and cleaning frequency of the cleaning unit are relatively low; when the waste heat power generation boiler fails, the cleaning pressure and cleaning frequency of the cleaning unit are relatively high.

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