Intelligent SCR denitration air control system for cement kiln

Abstract

This application relates to an intelligent SCR denitrification air control system for cement kilns. Based on monitoring the uniformity of flue gas velocity and temperature distribution before and after the guide layer of the SCR reactor, the system automatically adjusts the flue gas flow rate and temperature distribution in each region of the catalyst entering the reactor, thereby improving the uniformity of flue gas distribution. The intelligent SCR denitrification air control system provided by this application can intelligently adjust according to actual working conditions, improve the uniformity of the flow field and temperature in the SCR reactor, and increase the denitrification efficiency.

Description

Technical Field

[0001] This application relates to the technical field of intelligent flue gas denitrification, and in particular to an intelligent SCR denitrification and air control system for cement kilns. Background Technology

[0002] Currently, in my country's cement industry, selective catalytic reduction (SCR) technology is mainly used for denitrification. The core of SCR denitrification efficiency lies in the performance of the catalyst and the uniformity of the flow field. When the catalyst has been selected, the uniformity of the flow field plays a crucial role in the denitrification efficiency.

[0003] First, as a consumable material, catalysts are not only expensive to manufacture, but also have specific temperature requirements for operation. The flue gas entering the catalyst bed needs to reach the catalyst's minimum design temperature. If fluctuations in the cement kiln's operating conditions or changes in the operating conditions of the associated waste heat boiler at the kiln tail cause the flue gas temperature entering the SCR reactor to fall below the catalyst's minimum allowable temperature, not only will the catalyst's catalytic efficiency be compromised, but it will also cause catalyst poisoning.

[0004] Secondly, previously, when the temperature of the flue gas entering the SCR reactor was lower than the minimum allowable temperature of the catalyst, the bypass duct would be opened to prevent the flue gas from entering the SCR reactor.

[0005] Finally, the flue gas distribution needs to be kept uniform. The relative deviation of the velocity of the flue gas entering the catalyst layer should be less than 15%, and the temperature deviation should be less than 10℃. Otherwise, uneven temperature distribution and flue gas deviation will seriously affect the catalytic efficiency and service life of the catalyst.

[0006] When flue gas enters the SCR reactor from the preheater or the waste heat boiler at the kiln tail, it not only faces complex operating conditions, but also is prone to problems such as flow deviation, temperature fluctuations, and uneven flow field distribution. Therefore, how to maximize the denitrification efficiency and service life of the catalyst under the existing catalyst configuration has become a major challenge in the industry. Summary of the Invention

[0007] Based on this, and in response to the shortcomings of existing technologies, this application provides an intelligent SCR denitrification air control system for cement kilns. This system is capable of intelligently and automatically adjusting the air volume, velocity, and temperature distribution of flue gas entering each area of ​​the SCR reactor according to the real-time flue gas velocity and temperature distribution of the catalyst layer inside the SCR reactor. This maintains the high-performance denitrification efficiency of the catalyst and improves its service life, further reducing the operating cost of the SCR device.

[0008] According to this application, an intelligent SCR denitrification air control system for cement kilns includes an SCR reactor guide layer, an SCR reactor catalyst layer, a flue gas pipeline, an SCR regulating air duct, a reactor intelligent monitoring system, and a remote intelligent control system. The SCR regulating air duct includes a main regulating pipe and several regulating branch pipes, each equipped with a valve. The reactor intelligent monitoring system includes a velocity monitoring device and a temperature monitoring device. The velocity monitoring device is installed at a distance H above the SCR reactor catalyst layer. The temperature monitoring device consists of three sets: a first temperature monitoring device, a second temperature monitoring device, and a third temperature monitoring device. The first temperature monitoring device includes multiple temperature sensors evenly distributed at a distance L above the SCR reactor guide layer. The second temperature monitoring device also includes multiple temperature sensors evenly distributed at a distance K above the SCR reactor catalyst layer. The third temperature monitoring device is installed on the high-temperature flue gas regulating branch pipe.

[0009] In one embodiment, the remote intelligent control system includes a first module, a second module, and a third module. The first module is a temperature uniformity control module, which transmits the data measured by the first and second temperature monitoring devices to the control center and calculates the temperature deviations Δt1 and Δt2. The second module is a velocity uniformity control module, which transmits the data from the velocity monitoring device to the control center and calculates the relative velocity deviation coefficient Cv. The third module is a working condition comparison module, which includes adjustment and memory functions. The adjustment function compares the calculation results of the first and second modules with the stored working condition cases and then quickly sends adjustment commands. The working condition comparison module compares the actual working conditions with the stored simulation calculation examples of various common working conditions. When the flue gas temperature and velocity distribution at the measured locations reported by the first, second, and velocity monitoring devices match the built-in examples, the matching case is selected and an adjustment command is sent to control the SCR regulating duct. The memory function records each adjustment operation command and adds it to the examples each time the reactor encounters a working condition other than the built-in examples.

[0010] In one embodiment, the SCR regulating duct is a bypass duct connected to the high-temperature tube of the preheater.

[0011] In one embodiment, the number of branches of the SCR regulating duct is nm, where m≥2. The valve on each branch controls the flue gas volume of that branch. The valve opening is controlled by the remote intelligent control system, and can also be manually controlled on-site.

[0012] In one embodiment, the speed monitoring device consists of v speed sensors evenly distributed at the cross-sectional location, where v ≥ 2, and the installation location is 200mm ≤ H ≤ 1000mm.

[0013] In one embodiment, the first temperature monitoring device and the second temperature monitoring device are respectively composed of p and q temperature sensors evenly distributed at their respective cross-sectional positions, where p and q ≥ 2, and the installation positions are 100mm ≤ L ≤ 1000mm and 100mm ≤ K ≤ 1000mm. The third temperature monitoring device has one or more temperature sensors arranged at the SCR regulating duct.

[0014] In one embodiment, the temperature deviation calculation formula for the first module is: △t1=Tpmax-Tpmin, where Tpmax is the maximum temperature among the p temperature sensors of the first temperature monitoring device, and Tpmin is the minimum temperature among the p temperature sensors of the first temperature monitoring device; △t2=Tqmax-Tqmin, where Tqmax is the maximum temperature among the q temperature sensors of the second temperature monitoring device, and Tqmin is the minimum temperature among the q temperature sensors of the second temperature monitoring device.

[0015] In one embodiment, Δt1≤10℃ or Δt2≤5℃, the average value Tp of p temperature sensors is higher than the minimum operating temperature of the catalyst, and Tqmin is higher than the minimum operating temperature of the catalyst.

[0016] In one embodiment, the relative speed deviation coefficient Cv of the second module is ≤15%.

[0017] In one embodiment, the third module adjusts the execution logic as follows:

[0018] When two or more of the following three conditions are met simultaneously, the actual operating conditions are considered to match the operating conditions of the built-in calculation example. The third module will directly adjust according to the instructions in the matching calculation example and control the SCR regulating duct. Specifically, the three conditions are: (1) The maximum and minimum values ​​of the flue gas temperature at the measured position fed back by the first temperature monitoring device are consistent with the corresponding position of the built-in calculation example; (2) The maximum and minimum values ​​of the flue gas temperature at the measured position fed back by the second temperature monitoring device are consistent with the corresponding position of the built-in calculation example; (3) The maximum and minimum values ​​of the flue gas velocity at the measured position fed back by the velocity monitoring device are consistent with the corresponding position of the built-in calculation example.

[0019] When the first or second temperature monitoring device reports that there is no matching built-in example for the flue gas temperature distribution at the measured location, manual intervention is possible. Adjustments are made based on the temperature of each branch pipe reported by the third temperature monitoring device, combined with the flue gas distribution within the reactor. After adjustment, the memory module records the operating conditions and adjustment instructions and adds them to the example.

[0020] Compared with the prior art, the beneficial effects of this application are as follows:

[0021] First, by setting up an SCR reactor flow guide layer, an SCR regulating duct, a reactor intelligent monitoring system, and a remote intelligent control system, the flow rate and temperature distribution of flue gas entering each region of the reactor catalyst can be automatically adjusted based on the monitoring of the uniformity of flue gas velocity and temperature distribution before and after the SCR reactor flow guide layer. This allows for real-time monitoring and adjustment of the uniformity of flue gas velocity and temperature distribution within the SCR reactor.

[0022] Secondly, by setting up speed monitoring devices, temperature monitoring devices, and data transmission devices, and combining them with the use of temperature uniformity control modules, speed uniformity control modules, and operating condition comparison modules, the temperature of the flue gas entering the SCR reactor is made higher than the minimum allowable temperature of the catalyst, thus avoiding catalyst poisoning and maximizing the high-performance denitrification efficiency of the catalyst.

[0023] Third, the remote intelligent control system calculates the temperature deviation and relative velocity deviation coefficients inside the SCR reactor through data, performs comprehensive analysis, and intelligently starts and adjusts the gas flow in each regulating duct, which can improve the catalytic efficiency and service life of the catalyst. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the execution logic in one embodiment of this application.

[0025] Figure 2 This is a schematic diagram of the SCR reactor and the upper duct in one embodiment of this application.

[0026] Figure 3 This is a diagram showing the arrangement of temperature sensors in a first temperature monitoring device according to an embodiment of this application.

[0027] Figure 4 This is a diagram showing the arrangement of temperature sensors in a second temperature monitoring device according to an embodiment of this application.

[0028] Figure 5 This is a diagram showing the arrangement of speed sensors in a speed monitoring device according to one embodiment of this application.

[0029] Figure 6 This is a schematic diagram of the external structure of an SCR reactor in one embodiment of this application.

[0030] Diagram description: 1. Main regulating pipe; 1-1. Main regulating pipe valve; 2. First regulating branch pipe; 2-1. First branch pipe valve; 3. Second regulating branch pipe; 3-1. Second branch pipe valve; 4. Third regulating branch pipe; 4-1. Third branch pipe valve; 5. Flue gas pipeline; 6. Third temperature monitoring device; 7. First temperature monitoring device; 8. SCR reactor flow guide layer; 9. Second temperature monitoring device; 10. Velocity monitoring device; 11. SCR reactor catalyst layer; 12. SCR reactor. Detailed Implementation

[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific implementation methods of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 this application.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical signal connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0035] See Figure 1 , Figure 1 This illustration shows an execution logic diagram in one embodiment of the present application, combined with... Figure 2 , Figure 2 This application shows a schematic diagram of the SCR reactor and upper duct in one embodiment. One embodiment of this application provides an intelligent SCR denitrification air control system for cement kilns, including a main regulating pipe 1, a main regulating pipe valve 1-1, a first regulating branch pipe 2, a first branch pipe valve 2-1, a second regulating branch pipe 3, a second branch pipe valve 3-1, a third regulating branch pipe 4, a third branch pipe valve 4-1, a flue gas pipeline 5, a third temperature monitoring device 6, a first temperature monitoring device 7, an SCR reactor guide layer 8, a second temperature monitoring device 9, and a velocity monitoring device. The system includes a measuring device 10, an SCR reactor catalyst layer 11, an SCR reactor 12, a reactor intelligent monitoring system, and a remote intelligent control system. Flue gas is drawn from the cyclone outlet at the top of the cement preheater through the regulating main pipe 1, and then the flue gas is divided into the first regulating branch pipe 2, the second regulating branch pipe 3, and the third regulating branch pipe 4. Control valves are individually installed on the regulating main pipe 1, the first regulating branch pipe 2, the second regulating branch pipe 3, and the third regulating branch pipe 4. In this embodiment, the flue gas pipeline 5 adopts a 180-degree large bend structure, so the flue gas in the pipe is deflected.

[0036] The reactor intelligent monitoring system includes a velocity monitoring device 10 and a temperature monitoring device. The velocity monitoring device 10 is installed at a distance H above the catalyst layer 11 of the SCR reactor. The temperature monitoring device consists of three sets: a first temperature monitoring device 7, a second temperature monitoring device 9, and a third temperature monitoring device 6. The first temperature monitoring device 7 includes multiple temperature sensors, which are evenly distributed and installed at a distance L above the flow guide layer 8 of the SCR reactor. The second temperature monitoring device 9 also includes multiple temperature sensors, which are evenly distributed at a distance K above the catalyst layer 11 of the SCR reactor. The third temperature monitoring device 6 is installed on the high-temperature flue gas regulating branch pipe.

[0037] In one embodiment, the remote intelligent control system includes a first module, a second module, and a third module. The first module is a temperature uniformity control module that transmits data measured by the first temperature monitoring device 7 and the second temperature monitoring device 9 to the control center, and calculates temperature deviations Δt1 and Δt2. The second module is a speed uniformity control module that transmits data from the speed monitoring device 10 to the control center, and calculates the relative speed deviation coefficient Cv. The third module is a working condition comparison module, including adjustment and memory functions. The adjustment function is based on the first and second modules. After comparing the calculation results of the block with the stored operating condition cases, the adjustment command is quickly sent. The operating condition comparison module compares the actual operating conditions with the stored simulation calculations of various common operating condition examples. When the first temperature monitoring device 7, the second temperature monitoring device 9, and the velocity monitoring device V10 report that the measured flue gas temperature and velocity distribution at the location matches the built-in examples, the matching case is selected and the adjustment command is sent to control the SCR regulating duct. The memory function records each adjustment operation command and adds it to the example each time the reactor encounters an operating condition other than the built-in examples.

[0038] In one embodiment, the SCR regulating duct is a bypass duct connected to the high-temperature tube of the preheater.

[0039] In one embodiment, the number of branches of the SCR regulating duct is m, where m≥2. The valve on each branch controls the flue gas volume of that branch. The valve opening is controlled by the remote intelligent control system, and can also be manually controlled on-site.

[0040] In one embodiment, the speed monitoring device 10 consists of v speed sensors evenly distributed at the cross-sectional location, where v ≥ 2, and the installation location is 200mm ≤ H ≤ 1000mm.

[0041] In one embodiment, the first temperature monitoring device 7 and the second temperature monitoring device 9 are respectively composed of p and q temperature sensors evenly distributed at their respective cross-sectional positions, where p and q ≥ 2, and the installation positions are 100mm ≤ L ≤ 1000mm and 100mm ≤ K ≤ 1000mm. The third temperature monitoring device 6 is provided with one or more temperature sensors at the SCR regulating duct.

[0042] In one embodiment, the formula for calculating the temperature deviation of the first module is:

[0043] △t1=Tpmax-Tpmin, where Tpmax is the maximum temperature among the p temperature sensors of the first temperature monitoring device, and Tpmin is the minimum temperature among the p temperature sensors of the first temperature monitoring device. △t2=Tqmax-Tqmin, where Tqmax is the maximum temperature among the q temperature sensors of the second temperature monitoring device, and Tqmin is the minimum temperature among the q temperature sensors of the second temperature monitoring device.

[0044] In one embodiment, Δt1≤10℃ or Δt2≤5℃, the average value Tp of p temperature sensors is higher than the minimum operating temperature of the catalyst, and Tqmin is higher than the minimum operating temperature of the catalyst.

[0045] In one embodiment, the relative speed deviation coefficient Cv of the second module is ≤15%.

[0046] In one embodiment, the third module adjusts the execution logic as follows:

[0047] When two or more of the following three conditions are met simultaneously, the actual operating conditions are considered to match the built-in calculation conditions. The third module will directly adjust according to the instructions in the matching calculation and control the SCR regulating duct. Specifically, the three conditions are: (1) The maximum and minimum values ​​of the flue gas temperature at the measured position fed back by the first temperature monitoring device 7 are consistent with the corresponding position of the built-in calculation; (2) The maximum and minimum values ​​of the flue gas temperature at the measured position fed back by the second temperature monitoring device 9 are consistent with the corresponding position of the built-in calculation; (3) The maximum and minimum values ​​of the flue gas velocity at the measured position fed back by the velocity monitoring device 10 are consistent with the corresponding position of the built-in calculation.

[0048] When the first temperature monitoring device 7 or the second temperature monitoring device 9 reports that there is no built-in example matching the flue gas temperature distribution at the measured location, manual intervention is possible. Adjustments are made based on the temperature of each branch pipe reported by the third temperature monitoring device, combined with the flue gas distribution in the reactor. After adjustment, the memory module records the operating conditions and adjustment operation instructions and adds them to the example.

[0049] Furthermore, the built-in calculations are based on the actual reactor structure, performing multi-condition three-dimensional simulation calculations, and recording each simulation calculation to form commonly used built-in calculations; the requirement that the maximum and minimum values ​​of the flue gas temperature (velocity) at the feedback measured location must be consistent with the corresponding positions of the built-in calculations means that: if the temperature sensors that feed back Tpmax and Tpmin (or Tqmax, Tqmin) in the temperature monitoring device T1 (or T2) are t1 and t2 respectively, then the temperature sensors that feed back Tpmax and Tpmin (or Tqmax, Tqmin) in the calculations that match the operating conditions must also be t1 and t2. Similarly, if the velocity sensors that feed back Vmax and Vmin in the velocity monitoring device V are v1 and v2, then the velocity sensors that feed back Vmax and Vmin in the calculations that match the operating conditions must also be v1 and v2.

[0050] Furthermore, the aforementioned in The standard deviation of the cross-sectional velocity. The average velocity of the cross section.

[0051] See also Figure 2 and Figure 6 The SCR reactor guide layer 8, the second temperature monitoring device 9, the velocity monitoring device 10, and the SCR reactor catalyst layer 11 are all installed inside the SCR reactor 12. Raw flue gas enters the SCR reactor 12 from the flue gas pipeline 5. The first module (temperature uniformity control module) and the second module (velocity uniformity control module) transmit the temperature and velocity distribution characteristics of the flue gas inside the reactor to the control center through the first temperature monitoring device 7, the second temperature monitoring device 9, and the velocity monitoring device 10, respectively. It is found that Δt1 > 10℃, Δt2 > 5℃, and Cv > 15%, indicating that there is a flow deviation in the flue gas temperature and flow field at this time.

[0052] At this time, the third module (operating condition comparison module) starts up, automatically opening the main regulating valve to the preset 100% and the branch valve to the preset 50% opening. A small amount of high-temperature flue gas enters the first regulating branch pipe 2, the second regulating branch pipe 3, and the third regulating branch pipe 4 after being distributed from the main regulating pipe 1, and then enters the SCR reactor 12. The temperature and velocity distribution characteristics of the flue gas in the reactor are collected for the second time by the first temperature monitoring device 7, the second temperature monitoring device 9, and the velocity monitoring device 10 and transmitted to the control center. It is found that there are still Δt1>10℃, Δt2>5℃ and Cv>15%. The control center compares the positions of the maximum and minimum values ​​in the first temperature monitoring device 7, the second temperature monitoring device 9, and the velocity monitoring device 10 with the built-in calculation examples.

[0053] Figure 3The diagram shows the arrangement of temperature sensors in the first temperature monitoring device 7 (in this embodiment, p equals 4, meaning T1 contains 4 temperature sensors): Tpmax = 200℃ appears at position t1, and Tpmin = 190℃ appears at position t3. Figure 4 The diagram shows the arrangement of temperature sensors in the second temperature monitoring device 9 (in this embodiment, q equals 4, meaning T2 contains 4 temperature sensors): Tqmax = 198℃ appears at position t1, and Tqmin = 191℃ appears at position t3. Figure 5 The speed sensor location diagram of the speed monitoring device is shown. In this embodiment, V equals 4, that is, V contains 4 speed sensors: Vmax appears at position v1 and Vmin appears at position v3. All of the above positions are consistent with the positions shown in the built-in calculation case 1. Therefore, the third module directly sends adjustment commands to adjust the branch valves at the corresponding positions.

[0054] After the automatic adjustment of the third module stops, the system will report that at this moment, △t1≤10℃ and Cv≤15% or △t2≤5℃ and Cv≤15% are simultaneously satisfied, and the adjustment is completed. (If the conditions are not met after the automatic adjustment of the third module stops, manual adjustment will be started, and after the adjustment is completed, the third module will record the operation and incorporate it into the calculation example.)

[0055] See also Figure 1 The main flue gas first passes through the first temperature monitoring device 7 to calculate Δt1, then through the velocity monitoring device 10 to calculate Cv, and finally through the second temperature monitoring device 9 to calculate Δt2. The remote intelligent control system compares whether Δt1≤10℃ and Cv≤15%, or Δt2≤5℃ and Cv≤15%, is satisfied. If the conditions are met, no adjustment is needed; if not, the maximum and minimum values ​​and their locations in the first temperature monitoring device 7, the second temperature monitoring device 9, and the velocity monitoring device 10 are transmitted to the third module (operating condition comparison module) for comparison with the built-in calculation examples. If the remote intelligent control system meets the operating condition comparison requirements... If a matching built-in example is found in the module, the third module sends an adjustment command to adjust the control valve at the corresponding position. At this time, the high-temperature flue gas enters through the control valve and enters the next round of data verification for Δt1, Cv, and Δt2. If the remote intelligent control system cannot find a matching built-in example in the operating condition comparison module, it opens the control valve according to the manually preset valve opening. The high-temperature flue gas enters through the control valve, and the temperature data of each branch pipe monitored and fed back by the third temperature monitoring device 6 is sent to the operating condition comparison module. The adjustment is carried out in combination with the flue gas distribution in the reactor. After the adjustment is completed, the memory module records the operating condition and adjustment operation command and adds it to the example.

[0056] This application's system monitors the uniformity of flue gas velocity and temperature distribution before and after the SCR reactor's guide layer, automatically adjusting the flue gas flow rate and temperature distribution in each zone of the reactor catalyst to improve the uniformity of flue gas distribution. The remote intelligent control system calculates the current temperature deviation and relative velocity deviation coefficient within the reactor based on data, performs comprehensive analysis, and intelligently starts and adjusts the gas flow rate in each regulating duct. The intelligent SCR denitrification air control system provided by this application can intelligently adjust according to actual operating conditions, improving the flow field and temperature uniformity within the SCR reactor and increasing denitrification efficiency.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An intelligent SCR denitrification and air control system for cement kilns, characterized in that, It includes an SCR reactor flow guide layer (8), an SCR reactor catalyst layer (11), a flue gas pipeline (5), an SCR regulating duct, a reactor intelligent monitoring system, and a remote intelligent control system. The SCR regulating duct includes a regulating main pipe (1) and several regulating branch pipes. Each regulating main pipe (1) and each regulating branch pipe is equipped with a valve. The reactor intelligent monitoring system includes a velocity monitoring device (10) and a temperature monitoring device. The velocity monitoring device (10) is installed at a distance H above the catalyst layer (11) of the SCR reactor. The temperature monitoring device consists of three sets, including a first temperature monitoring device (7), a second temperature monitoring device (9), and a third temperature monitoring device (6). The first temperature monitoring device (7) includes multiple temperature sensors, which are evenly distributed and installed at a distance L above the flow guide layer (8) of the SCR reactor. The second temperature monitoring device (9) also includes multiple temperature sensors, which are evenly distributed at a distance K above the catalyst layer (11) of the SCR reactor. The third temperature monitoring device (6) is installed on the high-temperature flue gas regulating branch pipe. The remote intelligent control system includes a first module, a second module and a third module. The first module is a temperature uniformity control module, which transmits the data measured by the first temperature monitoring device (7) and the second temperature monitoring device (9) to the control center. The first module calculates the temperature deviations Δt1 and Δt2. The second module is a speed uniformity control module, which transmits the data of the speed monitoring device (10) to the control center. The second module calculates the relative speed deviation coefficient Cv. The third module is the operating condition comparison module, which includes adjustment and memory functions. The adjustment function is to quickly send adjustment commands after comparing the calculation results of the first and second modules with the stored operating condition cases. The operating condition comparison module compares the actual operating conditions with the stored simulation calculations of various common operating condition examples. When the first temperature monitoring device (7), the second temperature monitoring device (9), and the velocity monitoring device (10) report that the measured flue gas temperature and velocity distribution at the measured location matches the built-in examples, the matching examples are selected and adjustment commands are sent to control the SCR regulating duct. The memory function is to record each adjustment operation command and add it to the examples each time the reactor encounters an operating condition other than the built-in examples.

2. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The SCR regulating duct is a bypass duct connected to the high-temperature pipe of the preheater.

3. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The SCR regulating duct has m branches, where m≥2. The valve on each branch controls the flue gas volume of that branch. The valve opening is controlled by the remote intelligent control system, and can also be manually controlled on-site.

4. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The speed monitoring device (10) consists of v speed sensors evenly distributed at the cross-sectional position, where v≥2, and the installation position is 200mm≤H≤1000mm.

5. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The first temperature monitoring device (7) and the second temperature monitoring device (9) are respectively composed of p and q temperature sensors evenly distributed at their respective cross-sectional positions, where p and q ≥ 2, and the installation positions are 100mm ≤ L ≤ 1000mm and 100mm ≤ K ≤ 1000mm. The third temperature monitoring device (6) is provided with one or more temperature sensors at the SCR regulating duct.

6. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The temperature deviation calculation formula for the first module is: △t1=Tpmax-Tpmin, where Tpmax is the maximum temperature among the p temperature sensors of the first temperature monitoring device, and Tpmin is the minimum temperature among the p temperature sensors of the first temperature monitoring device; △t2=Tqmax-Tqmin, where Tqmax is the maximum temperature among the q temperature sensors of the second temperature monitoring device, and Tqmin is the minimum temperature among the q temperature sensors of the second temperature monitoring device.

7. The intelligent SCR denitrification and air control system for cement kilns according to claim 6, characterized in that, If △t1≤10℃ or △t2≤5℃, the average value Tp of p temperature sensors is higher than the minimum operating temperature of the catalyst, and Tqmin is higher than the minimum operating temperature of the catalyst.

8. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The relative speed deviation coefficient Cv of the second module is ≤15%.

9. The intelligent SCR denitrification and air control system for cement kilns according to claim 1, characterized in that, The third module's adjustment execution logic is as follows: When two or more of the following three conditions are met simultaneously, the actual operating conditions are considered to match the operating conditions of the built-in calculation example. The third module will directly adjust according to the instructions in the matching calculation example and control the SCR regulating duct. Specifically, the three conditions are: (1) The maximum and minimum values ​​of the flue gas temperature at the measured location fed back by the first temperature monitoring device (7) are consistent with the corresponding location of the built-in calculation example; (2) The maximum and minimum values ​​of the flue gas temperature at the measured location fed back by the second temperature monitoring device (9) are consistent with the corresponding location of the built-in calculation example. (3) The speed monitoring device (10) feeds back the maximum and minimum values ​​of the flue gas velocity at the measured position, which are consistent with the corresponding positions of the built-in calculation examples; When the first temperature monitoring device (7) or the second temperature monitoring device (9) reports that there is no matching built-in example for the flue gas temperature distribution at the measured location, manual intervention is possible. Adjustments are made based on the temperature of each branch pipe reported by the third temperature monitoring device, combined with the flue gas distribution in the reactor. After the adjustment is completed, the memory module records the operating conditions and adjustment operation instructions and includes them in the example.

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