A method and system for dust removal of a cement kiln temperature dust SCR denitration reactor

Abstract

The present application relates to the technical field of SCR denitration reactor, solves the technical problem that the catalyst surface is damaged by frequent dust removal in the current SCR system with medium temperature and dust, especially relates to S1, multiple pressure difference sensors are arranged on the inlet and outlet of the SCR denitration reactor and the upper and lower parts of the catalyst layer; S2, the total differential pressure of the inlet and outlet of the SCR denitration reactor and the differential pressure of the upper and lower regions of each catalyst layer are obtained through the arranged multiple pressure difference sensors; S3, the SCR dust removal system executes the conventional dust removal program. The present application can make corresponding dust removal treatment measures according to the dust accumulation and blockage of the catalyst, so as to reasonably select different dust removal modes according to the dust accumulation and blockage of the catalyst, and reasonably blow the dust frequency, which can achieve the ideal dust blowing effect, and better protect the catalyst from damage, thereby avoiding the blockage phenomenon of the catalyst channel.

Description

Technical Field

[0001] This invention relates to the field of SCR denitrification reactor technology, and in particular to a method and system for cleaning dust from a medium-temperature, medium-dust SCR denitrification reactor in a cement kiln. Background Technology

[0002] like Figure 1 The diagram shows the structure of an SCR denitrification reactor. The SCR denitrification reactor contains multiple layers of catalyst. Above the catalyst are the standard SCR denitrification system components: an acoustic soot blower, a rake soot blower (compressed air cleaning), and a powerful soot blower. The powerful soot blower uses a spiral vertical rod to unclog the catalyst channels and forcibly remove the dust clogging the catalyst channels. An ash conveying system is also provided at the bottom of the SCR denitrification reactor.

[0003] A 5000t / d cement kiln can generate 400,000 m³ / h of flue gas. However, the dust content in the flue gas entering a medium-temperature, medium-dust SCR system can reach 80 g / m³, resulting in 32 tons of dust passing through the SCR system per hour. Therefore, the operating frequency of the SCR sootblowing system acting on the catalyst has a significant impact on system operation. Excessive sootblowing increases compressed air consumption, and overly frequent purging by the rake sootblower can damage the catalyst surface. Insufficient sootblowing leads to thicker dust accumulation on the catalyst surface, affecting catalyst activity and potentially causing blockage of catalyst pores. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method and system for cleaning the catalyst in a medium-temperature, medium-dust SCR denitrification reactor in a cement kiln. This solves the technical problem that frequent cleaning of the catalyst in current medium-temperature, medium-dust SCR systems can easily damage its surface.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor of a cement kiln, the method comprising the following steps:

[0006] S1. Install multiple differential pressure sensors at the inlet and outlet of the SCR denitrification reactor and on the upper and lower parts of several catalyst layers.

[0007] S2. Obtain the total differential pressure at the inlet and outlet of the SCR denitrification reactor, as well as the partial differential pressure in the upper and lower regions of each catalyst layer, through multiple differential pressure sensors.

[0008] S3 and SCR dust removal systems perform routine dust removal procedures;

[0009] S4. Determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold.

[0010] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0011] If not, proceed to step S5;

[0012] S5. Determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold.

[0013] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0014] If not, then ash accumulation exists in other locations within the SCR denitrification reactor.

[0015] Furthermore, in step S1, the multiple differential pressure sensors are arranged as follows:

[0016] Total differential pressure sensors are installed at the inlet and outlet of the SCR denitrification reactor to monitor the total differential pressure of the SCR denitrification reactor.

[0017] Differential pressure sensors are installed in the upper and lower regions of each catalyst layer to monitor the differential pressure of each catalyst layer. Multiple differential pressure sensors are evenly distributed around the differential pressure transmitter. Differential pressure sensors are also added in the corners of the walls and at the maintenance doors around the SCR denitrification reactor. The locations of the differential pressure sensors are staggered from the catalyst beams.

[0018] Furthermore, in step S4, the first threshold value is 200 Pa, and the second threshold value is 100 Pa.

[0019] Furthermore, in step S5, the value of the third threshold is 150 Pa.

[0020] Furthermore, steps S4 and S5 also include:

[0021] S41. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0022] If so, return to step S2;

[0023] If not, the SCR cleaning system will continue to execute the enhanced cleaning procedure N times, where 1 < N ≤ 3;

[0024] S51. After the SCR cleaning system performs the enhanced cleaning procedure N times, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0025] If so, return to step S2;

[0026] If not, the SCR cleaning system will execute the powerful cleaning procedure N times, where 1 < N ≤ 3;

[0027] S52. Determine whether the differential pressure after executing the powerful dust removal program N times is less than or equal to the second threshold.

[0028] If so, return to step S2;

[0029] If not, locate the layer number of the catalyst where the blockage occurs and send a recommended maintenance alert.

[0030] Furthermore, step S1 or S2 also includes installing a current sensor in the ash conveying system at the bottom of the SCR denitrification reactor to measure the change in current during ash conveying.

[0031] In addition, a dust monitor is installed on the flue gas duct of the SCR denitrification reactor to monitor the dust content in the flue gas.

[0032] Furthermore, step S6 is included after step S5, specifically as follows:

[0033] S6. When the total differential pressure is greater than 200Pa, and the ash conveying current measured by the current sensor and the dust concentration in the flue gas measured by the dust monitor decrease, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than the second threshold.

[0034] If so, then the catalyst layer is free from ash accumulation and blockage.

[0035] If not, then the catalyst layer has ash accumulation or blockage.

[0036] The technical solution also provides a dust removal system, which includes:

[0037] The differential pressure acquisition module is used to acquire the total differential pressure at the inlet and outlet of the SCR denitrification reactor, as well as the partial differential pressure in the upper and lower regions of each catalyst layer, through multiple deployed differential pressure sensors.

[0038] The execution module is used by the SCR dust removal system to execute the regular dust removal procedure;

[0039] The first judgment module is used to determine whether the total differential pressure is greater than a first threshold when it is in the rising state, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than a second threshold.

[0040] The second judgment module is used to determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold.

[0041] Furthermore, the dust removal system also includes a third judgment module, which is used to determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than a second threshold when the total differential pressure is greater than 200 Pa and the dust conveying current measured by the current sensor and the dust concentration in the flue gas measured by the dust monitor decrease.

[0042] By means of the above technical solution, the present invention provides a method and system for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor of a cement kiln, which has at least the following beneficial effects:

[0043] 1. This invention monitors the total differential pressure of the SCR denitrification reactor and the corresponding partial differential pressure of the catalyst in real time, and sets corresponding threshold conditions as the basis for starting various cleaning procedures. It can take corresponding cleaning measures according to the ash accumulation and blockage of the catalyst, so as to reasonably select different cleaning methods according to the ash accumulation and blockage of the catalyst. The reasonable soot blowing frequency can achieve the ideal soot blowing effect and better protect the catalyst from damage, thereby avoiding the blockage of the catalyst pores.

[0044] 2. This invention monitors the differential pressure between the upper and lower regions of each catalyst layer. When the differential pressure is less than 100 Pa, the catalyst is free from ash accumulation and blockage. Therefore, it can quickly eliminate the possibility of catalyst blockage, thereby helping operators to quickly identify the cause of blockage and improve the reaction efficiency of the SCR denitrification reactor.

[0045] 3. After the enhanced cleaning process is executed, the differential pressure between the upper and lower regions of the catalyst is judged by a second threshold. If the differential pressure is greater than the second threshold, the enhanced cleaning process is performed N times to clear the catalyst channels that are blocked. In this way, corresponding treatment measures can be taken when the catalyst is severely blocked, thereby reducing the frequency of the enhanced cleaning process and reducing damage to the catalyst. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0047] Figure 1 This is a schematic diagram of the SCR denitrification reactor of the present invention;

[0048] Figure 2 This is a flowchart of the dust removal method in Embodiment 1 of the present invention;

[0049] Figure 3 This is a schematic diagram of the layout of the differential pressure sensor of the present invention;

[0050] Figure 4 This is a flowchart of the dust removal method in Embodiment 2 of the present invention;

[0051] Figure 5 This is a flowchart of the dust removal method in Embodiment 3 of the present invention;

[0052] Figure 6 This is a structural block diagram of the dust removal system of the present invention. Detailed Implementation

[0053] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This will allow for a full understanding of how the present application uses technical means to solve technical problems and achieve technical effects, and to facilitate its implementation.

[0054] Example 1

[0055] Please refer to Figures 1-3 This embodiment proposes a method for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor in a cement kiln, such as... Figure 2 As shown, the method includes the following steps:

[0056] S1. Multiple differential pressure sensors are installed at the inlet and outlet of the SCR denitrification reactor and on the upper and lower parts of several catalyst layers. A current sensor is installed in the ash conveying system at the bottom of the SCR denitrification reactor to measure the change in current during ash conveying. By installing a current sensor in the ash conveying system at the bottom of the SCR denitrification reactor and testing the change in current during ash conveying, the change in the current of the ash conveying system can be used to determine the change in the amount of ash conveyed. The change in the amount of ash in the ash conveying system can be used to determine the degree of catalyst dust blockage. A dust monitor is installed on the flue gas duct of the SCR denitrification reactor to monitor the dust content in the flue gas. By installing a dust monitor on the flue gas duct behind the reactor, the change in the dust content in the flue gas can reflect the degree of catalyst blockage and the ash removal effect.

[0057] In step S1, the multiple differential pressure sensors are arranged as follows: a total differential pressure sensor is installed at the inlet and outlet of the SCR denitrification reactor to monitor the total differential pressure of the SCR denitrification reactor; differential pressure sensors are installed in the upper and lower areas of each catalyst layer to monitor the partial differential pressure of each catalyst layer; the multiple differential pressure sensors are evenly distributed around the differential pressure transmitter; additional differential pressure sensors are installed at the corners of the walls around the SCR denitrification reactor and at the maintenance doors, and the placement of the differential pressure sensors is offset from the catalyst beam. Figure 3As shown, differential pressure sensors are installed above and below each catalyst layer in the SCR denitrification reactor to monitor the differential pressure of each catalyst layer. Changes in these differential pressures can indicate the degree of catalyst blockage. Differential pressure transmitters for each catalyst layer need to cover all areas. Due to the free edge effect of the fluid, the flue gas near the wall panels flows much slower than in other areas due to friction, causing pressure changes. The gas velocity slows down more significantly at the corners between the two wall panels and at access doors, making them more prone to dust accumulation. To accurately understand the differential pressure between the catalyst layers, differential pressure transmitters are evenly distributed in the central area, and differential pressure sensors are also specifically installed at the corners of the surrounding wall panels and at access doors to monitor changes in the total differential pressure. Simultaneously, to minimize the impact of the catalyst beams on the monitoring effect, the differential pressure transmitters should be placed away from the catalyst beams. Changes in both the total and partial differential pressures can accurately determine the location and degree of catalyst blockage.

[0058] S2. The total differential pressure at the inlet and outlet of the SCR denitrification reactor and the partial differential pressure in the upper and lower regions of each catalyst layer are obtained by deploying multiple differential pressure sensors. In this step, the total differential pressure at the inlet and outlet of the SCR denitrification reactor and the partial differential pressure in the upper and lower regions of the catalyst can be measured in real time by the multiple differential pressure sensors deployed in step S1, so as to ensure the accurate acquisition of the total differential pressure and partial differential pressure values ​​in the subsequent process.

[0059] The S3 and SCR cleaning systems execute a routine cleaning procedure, which is the normal operating procedure for the SCR cleaning system. This procedure primarily involves rake sootblowers and ultrasonic sootblowers. Specifically, during normal operation, both rake and ultrasonic sootblowers operate in a large-circulation cleaning mode. Each rake sootblower cleans for approximately 2-4 minutes with a 10-30 second interval, while each ultrasonic sootblower cleans for 5-15 seconds with a 10-30 second interval. Each SCR cleaning system has approximately 20 rake sootblowers and 24 ultrasonic sootblowers. The rake sootblowers offer strong cleaning effectiveness with a long cycle time, while the ultrasonic sootblowers offer weaker cleaning effectiveness with a shorter cycle time. The combination of both effectively removes dust from the catalyst surface, maintaining a pressure difference of less than 100 Pa between the upper and lower regions of the catalyst.

[0060] S4. Determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold.

[0061] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0062] If not, proceed to step S5;

[0063] In step S4, the first threshold is set to 200 Pa, and the second threshold is set to 100 Pa.

[0064] In this step, the enhanced dust removal procedure requires judgment based on comprehensive conditions. When an increase in the total differential pressure is detected, and the differential pressure in the upper and lower regions of the catalyst also increases, it indicates catalyst blockage in the area where the differential pressure is rising. If the partial differential pressure is greater than 100 Pa but less than 150 Pa, the rake sootblower will operate in conjunction with the sonic sootblower when it reaches a high-resistance area. When the rake sootblower reaches a high-resistance area, its speed will decrease, and the frequency converter frequency will drop from 50 Hz to 30 Hz. When it reaches a normal resistance area (less than 100 Pa), the frequency converter frequency of the rake sootblower will return to 50 Hz. While the sonic sootblower is operating in the large circulation area, it will also operate separately in the high-resistance area in conjunction with the rake sootblower, allowing the dust removal areas of the rake sootblower and the sonic sootblower to overlap, thereby enhancing the dust removal effect. When it is detected that the current to the ash conveying system increases after the rake sootblower reaches a high-resistance area, the dust detection device detects an increase in dust concentration, and the differential pressure in the high-resistance area decreases, it indicates that the dust removal is effective. Once the resistance returns to normal, the procedure will resume as normal.

[0065] S5. Determine whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the third threshold (150 Pa);

[0066] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0067] If not, then ash accumulation exists in other locations within the SCR denitrification reactor.

[0068] In step S5, the value of the third threshold is 150 Pa.

[0069] In this step, when an increase in total differential pressure is detected and there is a region with resistance exceeding 150 Pa, the rake blowing system simultaneously initiates a separate circulation of the rake sootblower in the high-resistance region during the main circulation. Upon reaching the high-resistance region, the moving speed is reduced, and the frequency converter frequency drops from 50 Hz to 30 Hz. When the system reaches the region with normal resistance (less than 70 Pa), the frequency converter frequency of the rake sootblower returns to 50 Hz. Simultaneously, the sonic sootblower continues its separate circulation in the high-resistance region in conjunction with the rake sootblower. When it is detected that the current to the ash conveying system increases after the rake sootblower reaches the high-resistance region, the dust detection device detects an increase in dust concentration, and the differential pressure in the high-resistance region decreases, it indicates that the cleaning is effective. Once the resistance returns to normal, the system resumes the regular cleaning procedure.

[0070] Example 2

[0071] Please refer to Figure 4 Based on Example 1, this example proposes a method for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor in a cement kiln. The method includes the following steps:

[0072] S1. Install multiple differential pressure sensors at the inlet and outlet of the SCR denitrification reactor and on the upper and lower parts of several catalyst layers.

[0073] S2. Obtain the total differential pressure at the inlet and outlet of the SCR denitrification reactor, as well as the partial differential pressure in the upper and lower regions of each catalyst layer, through multiple differential pressure sensors.

[0074] S3 and SCR dust removal systems perform routine dust removal procedures;

[0075] S4. Determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold.

[0076] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0077] If not, proceed to step S5;

[0078] S41. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0079] If so, return to step S2;

[0080] If not, the SCR cleaning system will continue to execute the enhanced cleaning procedure N (1 < N ≤ 3) times;

[0081] S5. Determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold.

[0082] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0083] If not, then ash accumulation exists in other locations within the SCR denitrification reactor;

[0084] S51. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0085] If so, return to step S2;

[0086] If not, the SCR cleaning system will continue to execute the powerful cleaning procedure N (1 < N ≤ 3) times;

[0087] S52. Determine whether the differential pressure after executing the enhanced dust removal procedure N times is less than or equal to the second threshold.

[0088] If so, return to step S2;

[0089] If not, locate the layer number of the catalyst where the blockage occurs and send a recommended maintenance alert.

[0090] In this step, if the rake sootblower runs three times in a high-resistance area and the resistance does not decrease, or the flue gas detection device does not detect a significant increase in dust content, and the current in the ash conveying system does not increase, it indicates that the catalyst in that area is severely clogged, and the rake sootblower and sonic sootblower are no longer able to clean the accumulated dust in that area. The SCR cleaning system then activates powerful cleaning. The rake sootblower avoids the area with increased resistance, while the sonic sootblower performs separate cleaning of that area during the large circulation. The powerful cleaning device is activated, using a spiral vertical rod to unclog the catalyst channels and forcibly remove the dust clogging them. When an increase in the ash conveying system current is detected, an increase in dust concentration is detected by the dust detection device, and the differential pressure in the high-resistance area decreases, along with a decrease in the total differential pressure of the SCR system, it indicates that the cleaning is effective. Normal cleaning is resumed after the resistance returns to normal. If three rounds of powerful cleaning still cannot reduce the catalyst resistance to less than 150 Pa, it indicates that the cleaning equipment is no longer able to solve the catalyst ash accumulation problem, and it is recommended to shut down the SCR system for maintenance.

[0091] In this embodiment, after the enhanced cleaning procedure is executed, the differential pressure between the upper and lower regions of the catalyst is judged using a second threshold. If the differential pressure is greater than the second threshold, N rounds of powerful cleaning procedure are performed to clear the catalyst channels that are blocked. This allows for appropriate treatment measures to be taken when the catalyst is severely blocked, thereby reducing the frequency of powerful cleaning procedure on the catalyst and reducing damage to the catalyst.

[0092] Example 3

[0093] Please refer to Figure 5 Based on Example 1, this example proposes a method for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor in a cement kiln. The method includes the following steps:

[0094] S1. Multiple differential pressure sensors are installed at the inlet and outlet of the SCR denitrification reactor and on the upper and lower parts of several catalyst layers. A current sensor is installed in the ash conveying system at the bottom of the SCR denitrification reactor to measure the change in current during ash conveying. By installing a current sensor in the ash conveying system at the bottom of the SCR denitrification reactor, the change in current during ash conveying can be tested. The change in current of the ash conveying system can determine the change in the amount of ash conveyed. The change in the amount of ash in the ash conveying system can determine the status of catalyst dust blockage.

[0095] In addition, a dust monitor is installed on the flue gas duct of the SCR denitrification reactor to monitor the dust content in the flue gas. By installing the dust monitor on the flue gas duct behind the reactor, the change in the dust content in the flue gas can reflect the catalyst blockage and the dust removal effect.

[0096] S2. Obtain the total differential pressure at the inlet and outlet of the SCR denitrification reactor, as well as the partial differential pressure in the upper and lower regions of each catalyst layer, through multiple differential pressure sensors.

[0097] S3 and SCR dust removal systems perform routine dust removal procedures;

[0098] S4. Determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold.

[0099] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0100] If not, proceed to step S5;

[0101] S41. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0102] If so, return to step S2;

[0103] If not, the SCR cleaning system will continue to execute the enhanced cleaning procedure N (1 < N ≤ 3) times;

[0104] S5. Determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold.

[0105] If so, the SCR cleaning system will execute an enhanced cleaning procedure;

[0106] If not, then ash accumulation exists in other locations within the SCR denitrification reactor;

[0107] S51. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold.

[0108] If so, return to step S2;

[0109] If not, the SCR cleaning system will continue to execute the powerful cleaning procedure N (1 < N ≤ 3) times;

[0110] S52. Determine whether the differential pressure after executing the enhanced dust removal procedure N times is less than or equal to the second threshold.

[0111] If so, return to step S2;

[0112] If not, locate the layer number of the catalyst where the blockage occurs and send a recommended maintenance alert;

[0113] S6. When the total differential pressure is greater than 200Pa, and the ash conveying current measured by the current sensor and the dust concentration in the flue gas measured by the dust monitor decrease, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than the second threshold.

[0114] If so, then the catalyst layer is free from ash accumulation and blockage.

[0115] If not, then the catalyst layer has ash accumulation or blockage.

[0116] In this embodiment, when the total differential pressure increases to more than 200 Pa, and the ash conveying current and flue gas dust concentration both decrease, this is not necessarily due to ash accumulation or blockage of the catalyst. It could also be caused by ash accumulation in other locations within the SCR denitrification reactor or sensor malfunction. Therefore, in this embodiment, by monitoring the differential pressure between the upper and lower regions of each catalyst layer, when the differential pressure is less than 100 Pa, there is no ash accumulation or blockage of the catalyst. This allows for the rapid detection of catalyst blockage, helping operators quickly identify the cause of blockage and improve the reaction efficiency of the SCR denitrification reactor.

[0117] Corresponding to the dust removal method provided in the above embodiments, this embodiment also provides a dust removal system. Since the dust removal system provided in this embodiment corresponds to the dust removal method provided in the above embodiments, the implementation methods of the aforementioned dust removal method are also applicable to the dust removal system provided in this embodiment, and will not be described in detail in this embodiment.

[0118] Please see Figure 6 The diagram shown is a structural block diagram of the dust removal system provided in this embodiment. The dust removal system includes a differential pressure acquisition module 10, an execution module 20, a first judgment module 30, a second judgment module 40, and a third judgment module 50.

[0119] The differential pressure acquisition module 10 is used to acquire the total differential pressure at the inlet and outlet of the SCR denitrification reactor and the partial differential pressure in the upper and lower regions of each catalyst layer through multiple differential pressure sensors. The execution module 20 is used to execute the conventional cleaning procedure of the SCR cleaning system. The first judgment module 30 is used to determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the partial differential pressure in the upper and lower regions of any catalyst layer is greater than the second threshold. The second judgment module 40 is used to determine whether the partial differential pressure in the upper and lower regions of each catalyst layer is greater than the third threshold. The third judgment module 50 is used to determine whether the partial differential pressure in the upper and lower regions of any catalyst layer is less than the second threshold when the total differential pressure is greater than 200 Pa and the ash conveying current measured by the current sensor and the flue gas dust concentration measured by the dust monitor decrease.

[0120] It should be noted that the system provided in the above embodiments is only illustrated by the division of the above functional modules when implementing its functions. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the system and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0121] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Since the above embodiments are substantially similar to the method embodiments, their descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0122] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0123] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for cleaning the dust in a medium-temperature, medium-dust SCR denitrification reactor of a cement kiln, characterized in that, The method includes the following steps: S1. Install multiple differential pressure sensors at the inlet and outlet of the SCR denitrification reactor and on the upper and lower parts of several catalyst layers. S2. Obtain the total differential pressure at the inlet and outlet of the SCR denitrification reactor, as well as the partial differential pressure in the upper and lower regions of each catalyst layer, through multiple differential pressure sensors. Step S1 or S2 also includes installing a current sensor in the ash conveying system at the bottom of the SCR denitrification reactor to measure the change in current during ash conveying. In addition, a dust monitor is installed on the flue gas duct of the SCR denitrification reactor to monitor the dust content in the flue gas; S3 and SCR dust removal systems perform routine dust removal procedures; S4. Determine whether the total differential pressure is greater than the first threshold when it is rising, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold. If so, the SCR cleaning system will execute an enhanced cleaning procedure; If not, proceed to step S5; S5. Determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold. If so, the SCR cleaning system will execute an enhanced cleaning procedure; If not, then ash accumulation exists in other locations within the SCR denitrification reactor; S6. When the total differential pressure is greater than 200Pa, and the ash conveying current measured by the current sensor and the dust concentration in the flue gas measured by the dust monitor decrease, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than the second threshold. If so, then the catalyst layer is free from ash accumulation and blockage. If not, then the catalyst layer has ash accumulation or blockage.

2. The dust removal method according to claim 1, characterized in that, In step S1, the multiple differential pressure sensors are arranged as follows: Total differential pressure sensors are installed at the inlet and outlet of the SCR denitrification reactor to monitor the total differential pressure of the SCR denitrification reactor. Differential pressure sensors are installed in the upper and lower regions of each catalyst layer to monitor the differential pressure of each catalyst layer. Multiple differential pressure sensors are evenly distributed around the differential pressure transmitter. Differential pressure sensors are also added in the corners of the walls and at the maintenance doors around the SCR denitrification reactor. The locations of the differential pressure sensors are staggered from the catalyst beams.

3. The dust removal method according to claim 1, characterized in that, In step S4, the first threshold is set to 200 Pa, and the second threshold is set to 100 Pa.

4. The dust removal method according to claim 1, characterized in that, In step S5, the value of the third threshold is 150 Pa.

5. The dust removal method according to claim 1, characterized in that, Steps S4 and S5 also include: S41. After the SCR cleaning system executes the enhanced cleaning procedure, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold. If so, return to step S2; If not, the SCR cleaning system will continue to execute the enhanced cleaning procedure N times, where 1 < N ≤ 3; S51. After the SCR cleaning system performs the enhanced cleaning procedure N times, determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than or equal to the second threshold. If so, return to step S2; If not, the SCR cleaning system will execute the powerful cleaning procedure N times, where 1 < N ≤ 3; S52. Determine whether the differential pressure after executing the powerful dust removal program N times is less than or equal to the second threshold. If so, return to step S2; If not, locate the layer number of the catalyst where the blockage occurs and send a recommended maintenance alert.

6. A system for implementing the dust removal method according to any one of claims 1-5, characterized in that, The system includes: Differential pressure acquisition module (10) is used to acquire the total differential pressure at the inlet and outlet of the SCR denitrification reactor and the partial differential pressure in the upper and lower regions of each catalyst layer through multiple differential pressure sensors. Execution module (20), the execution module (20) is used by the SCR dust removal system to execute the conventional dust removal procedure; The first judgment module (30) is used to determine whether the total differential pressure is greater than the first threshold when it is in the rising state, and whether the differential pressure between the upper and lower regions of any catalyst layer is greater than the second threshold. The second judgment module (40) is used to determine whether the differential pressure between the upper and lower regions of each catalyst layer is greater than the third threshold.

7. The dust removal system according to claim 6, characterized in that, It also includes a third judgment module (50), which is used to determine whether the differential pressure between the upper and lower regions of any catalyst layer is less than the second threshold when the total differential pressure is greater than 200 Pa and the ash conveying current measured by the current sensor and the flue gas dust concentration measured by the dust monitor decrease.

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