A urea solution high-efficiency atomization injection device suitable for SCR denitration

Abstract

The application discloses a urea solution high-efficiency atomization and injection device suitable for SCR denitration, which comprises a composite atomization unit, an intelligent control unit and a multi-dimensional sensing system; the composite atomization unit comprises a first-stage pre-membrane and flow stabilizing structure, a second-stage pneumatic ultrasonic standing wave generator and a third-stage gas-liquid shearing nozzle which are sequentially connected and in fluid communication; the intelligent control unit is electrically connected with the composite atomization unit; and the multi-dimensional sensing system is signal-connected with the intelligent control unit and is used for collecting atomization process parameters, equipment state parameters and system working condition parameters. The first-stage pre-membrane and flow stabilizing structure are used for converting a liquid column into a uniform liquid membrane, the second-stage pneumatic ultrasonic standing wave generator is used for realizing bulk breaking of the liquid membrane by using an ultrasonic standing wave field, and the third-stage gas-liquid shearing nozzle is used for finally performing pneumatic shearing and acceleration; the three-stage synergistic effect makes the liquid droplet size finer and the distribution more concentrated, and effectively improves the evaporation efficiency and reaction uniformity.

Description

Technical Field

[0001] This application belongs to the field of SCR denitrification technology, specifically relating to a high-efficiency atomizing spray device for urea solution suitable for SCR denitrification. Background Technology

[0002] Selective catalytic reduction (SCR) technology is currently widely used in industrial plants such as coal-fired boilers, gas turbines, and diesel engines to reduce nitrogen oxides (NOx). The mainstream method for emission reduction. In this technology, urea solution, as a reducing agent precursor, is atomized and injected into the flue gas, where it undergoes pyrolysis to generate ammonia, which then reacts with... A reduction reaction occurs on the catalyst surface. The atomization effect directly determines the evaporation rate of the urea solution, the uniformity of ammonia distribution, and the final denitrification efficiency.

[0003] In existing technologies, common urea solution atomization methods include pressure atomization, pneumatic atomization, and rotary atomization, but traditional atomization methods generally have the following problems:

[0004] Poor atomization uniformity makes it difficult for traditional single-mechanism atomization methods to maintain a stable droplet size distribution under wide load conditions. This can easily lead to excessively large local droplets or incomplete atomization, resulting in urea crystallization, increased ammonia escape, or decreased denitrification efficiency.

[0005] High energy consumption and poor adaptability mean that when the load fluctuates or the flue gas parameters change, there is a lack of effective closed-loop control methods. It often relies on fixed parameters to operate, and cannot achieve dynamic matching between the atomization process and the operating conditions, resulting in energy waste or deterioration of atomization quality.

[0006] The level of intelligence is low. Most existing systems lack the ability to perceive and make intelligent decisions in real time about key parameters of the atomization process (such as droplet size and nozzle status), making it difficult to achieve preventive maintenance and parameter self-tuning.

[0007] Therefore, developing a urea solution atomization and injection device that can achieve high efficiency, uniformity, reliability, and intelligent adaptation has become a key technical requirement for improving the overall performance and operational economy of SCR systems. Summary of the Invention

[0008] This application provides a high-efficiency atomizing spray device for urea solution suitable for SCR denitrification, aiming to solve the problems of poor atomization uniformity and low level of intelligence in the prior art.

[0009] In a first aspect, a high-efficiency atomizing spray device for urea solution suitable for SCR denitrification includes:

[0010] The composite atomization unit includes a first-stage pre-filming and flow stabilizing structure connected in sequence and in fluid communication, a second-stage pneumatic ultrasonic standing wave generator, and a third-stage gas-liquid shear nozzle.

[0011] An intelligent control unit, which is electrically connected to the composite atomizing unit;

[0012] A multi-dimensional sensing system, which is signal-connected to the intelligent control unit, is used to collect atomization process parameters, equipment status parameters, and system operating condition parameters.

[0013] The primary pre-filming and flow stabilizing structure includes a spiral guide groove formed on the inner wall of the gas channel, which transforms the input urea solution column into a uniform liquid film flowing along the wall.

[0014] The secondary pneumatic ultrasonic standing wave generator includes a Hartmann whistle structure, which uses high-speed airflow to generate an ultrasonic standing wave field, causing the liquid film generator to break up.

[0015] The three-stage gas-liquid shear nozzle is equipped with a primary air outlet and a secondary air outlet, which performs final pneumatic shearing and accelerated jetting on the ultrasonically broken droplets.

[0016] Optionally, the multi-dimensional sensing system includes:

[0017] A laser diffraction particle size analyzer is installed on the flue wall downstream of the spraying device to measure the Sottle mean diameter and particle size distribution span of the atomized droplets in real time.

[0018] A vibration sensor is installed at the nozzle head of the composite atomizing unit to monitor its vibration spectrum;

[0019] An infrared thermometer is aimed at the easily crystallizing area of ​​the spray gun head to monitor its wall temperature.

[0020] Optionally, the intelligent control unit is configured to perform the following closed-loop control:

[0021] Based on real-time collected flue gas flow rate and flue gas temperature, the target Sottle average diameter is dynamically calculated through a pre-stored empirical model or a two-dimensional lookup table.

[0022] Receive the SMD value measured by the laser diffraction particle size analyzer, and calculate the error and error rate between it and the Sottle mean diameter;

[0023] Based on the error and the rate of change of error, an adaptive fuzzy PID controller is used to collaboratively output adjustment commands for the atomized air pressure and the secondary air ratio.

[0024] Optionally, the intelligent control unit is further configured to perform feedforward compensation control, which, in response to a received signal of a sudden increase in external load, increases the urea solution supply and atomizing air pressure in advance, according to a preset feedforward model, before the measured SMD value changes.

[0025] Optionally, the intelligent control unit is also configured to perform state-based preventive control, which determines that there is a risk of crystallization when the high-frequency vibration energy value of the vibration sensor continuously exceeds a first threshold and the wall temperature monitored by the infrared thermometer continuously falls below a second threshold, and automatically executes a high-pressure purging procedure and / or increases the heat tracing temperature.

[0026] Continuously calculate and monitor the overall efficiency coefficient of the atomization system. When the overall efficiency coefficient When a continuous downward trend is observed, a preventative maintenance prompt will be generated.

[0027] Optionally, the overall efficiency coefficient The calculation formula is:

[0028]

[0029] in, The overall efficiency coefficient is given by K, which is a system characteristic constant determined by the equipment model and initial calibration. The target Sottle mean diameter under the current operating conditions. The real-time measured average diameter of Sottle. The working pressure for atomizing air, This is the volumetric flow rate of the atomized air.

[0030] Optionally, the intelligent control unit is also configured to perform parameter self-tuning:

[0031] A test signal is applied to the actuator according to a preset cycle or triggering condition;

[0032] Based on the SMD response characteristics of the atomized droplets, the internal parameters of the adaptive fuzzy PID controller are automatically adjusted. The internal parameters include the quantization factor, the scaling factor, and the PID gain.

[0033] Secondly, a method for controlling the atomization of urea solution in an SCR denitrification system, employing the aforementioned high-efficiency atomizing injection device for urea solution suitable for SCR denitrification, the method comprising the following steps:

[0034] The primary pre-filming and flow stabilizing structure forms a pre-shaped liquid film from the urea solution;

[0035] The ultrasonic standing wave field generated by the two-stage pneumatic ultrasonic standing wave generator breaks up the liquid film.

[0036] The three-stage gas-liquid shear nozzle performs pneumatic shearing and accelerated jetting of the broken droplets.

[0037] The multi-dimensional sensing system collects real-time data on the atomization process, equipment status, and system operating parameters.

[0038] Based on the parameters, the intelligent control unit performs closed-loop control, feedforward compensation, preventive control, or parameter self-tuning as described above.

[0039] Compared with the prior art, this application has at least the following beneficial effects:

[0040] This application transforms a liquid column into a uniform liquid film through a first-stage pre-filming and flow stabilization structure, a second-stage pneumatic ultrasonic standing wave generator uses the ultrasonic standing wave field to achieve bulk breaking of the liquid film, and a third-stage gas-liquid shearing nozzle performs final pneumatic shearing and acceleration. The synergistic effect of the three stages results in finer droplet size and more concentrated distribution, effectively improving evaporation efficiency and reaction uniformity.

[0041] The intelligent control unit of this application dynamically adjusts the atomizing air pressure and secondary air ratio through an adaptive fuzzy PID controller based on real-time collected flue gas parameters and droplet size data, thereby achieving closed-loop control of the atomizing particle size and ensuring that the ideal atomization effect can be maintained under different operating conditions. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the module connection of a high-efficiency atomizing spray device for urea solution suitable for SCR denitrification, provided in one embodiment of this application. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0044] This application provides a high-efficiency atomizing spray device for urea solution suitable for SCR denitrification, comprising:

[0045] The multi-stage pre-filming-shearing composite atomization unit achieves efficient urea solution fragmentation through the synergistic effect of multi-stage physical fields, organically combining the three mechanisms of pre-filming, ultrasonic standing wave action, and pneumatic shearing in a spatiotemporal sequence.

[0046] The multi-stage pre-filming-shearing composite atomization unit includes a first-stage pre-filming and flow stabilization structure, a second-stage pneumatic ultrasonic standing wave generating mechanism, and a third-stage gas-liquid shearing nozzle.

[0047] Specifically, the primary pre-filming and flow stabilization structure is at the initial stage of the atomization process. The urea solution first enters a specially designed spiral guiding structure, which consists of continuous spiral grooves precisely machined on the inner wall of the gas flow channel inlet section. Its function is to transform the axially flowing liquid into a thin liquid film that rotates and advances closely against the wall. This design achieves a fundamental transformation of the fluid morphology from a "liquid column" to a "liquid film," which not only significantly reduces the energy required for subsequent crushing processes but, more importantly, provides uniformly distributed material conditions for subsequent atomization stages, ensuring the uniformity of the final atomization effect from the source.

[0048] The secondary pneumatic ultrasonic standing wave generator incorporates an ultrasonic generation structure based on the Hartmann whistle principle in the downstream region after liquid film formation. When high-pressure atomized gas (or vapor) passes through this specifically shaped cavity, it generates high-intensity ultrasonic waves with frequencies ranging from 10kHz to 100kHz. These sound waves form a stable ultrasonic standing wave field through a precisely designed resonant chamber.

[0049] As the preformed liquid film continues to be conveyed forward and traverses the standing wave field, the liquid film as a whole is subjected to periodic high-intensity sound pressure. At the acoustic nodes, the alternating stress on the liquid film reaches its maximum, resulting in a uniform tearing effect at these specific locations. This atomization method is fundamentally different from traditional mechanical shearing: the ultrasonic standing wave generates a volumetric force acting on the entire volume of the liquid film, rather than a shearing force acting only on the surface. This allows the liquid film to break up synchronously and uniformly at its weakest nodes.

[0050] By precisely controlling the matching relationship between the standing wave frequency and the gas flow rate, the droplet breakup process can be dominated, ultimately generating a cluster of fine droplets with concentrated particle size distribution and excellent uniformity.

[0051] The three-stage gas-liquid shear nozzle is located in the final stage of the atomization process. It is responsible for the final shaping and spraying of the pre-crushed products from the previous stage. The liquid filaments and initial droplets formed after ultrasonic standing wave field pretreatment meet a high-speed secondary air (or air with a specific swirl angle) with a specially designed flow channel when they reach the nozzle outlet. This results in a final aerodynamic interaction, which performs final morphological regularization and particle size homogenization on the primary droplet group generated by ultrasonic atomization, corrects any possible local non-uniformity, and further improves the monodispersity of the droplet group. At the same time, the high-speed airflow provides the droplets with huge kinetic energy, enabling them to be sprayed into the SCR reactor at extremely high speed. This ensures that the urea droplets have sufficient penetration depth and ideal diffusion range in the high-speed flue gas, and finally forms a concentration and temperature distribution that meets the design requirements on the reactor cross section.

[0052] In one embodiment, an intelligent control system based on multi-sensor fusion is also provided, the system comprising: a multi-dimensional signal sensing unit and an intelligent control unit;

[0053] Among them, the multi-dimensional signal sensing unit is equipped with an in-situ particle size analysis subunit to monitor the core parameters of the atomization field. It integrates a laser particle size analyzer for high-temperature working conditions. The probe of the in-situ particle size analysis subunit is fixedly installed on the side wall of the flue about 1.2 meters downstream of the injector through a flange. This position has been verified by fluid simulation and experiments and can effectively capture representative urea droplet groups in the main flow field, avoiding interference from wall effects or local eddies.

[0054] The in-situ particle size analysis subunit measures and outputs two key atomization quality indicators in real time. The key atomization quality indicators include: Sottle mean diameter (SMD, D) 32 This directly reflects the evaporation characteristics and reactivity of the droplet group;

[0055] The particle size distribution span (Span) quantitatively characterizes the uniformity of atomization. The smaller the value, the more concentrated the particle size distribution and the more ideal the atomization effect.

[0056] Measurement data is uploaded to the central controller via isolated analog signals (4-20mA) or industrial real-time Ethernet (such as EtherCAT) to ensure signal anti-interference and real-time transmission.

[0057] Simultaneously, the multi-dimensional signal sensing unit establishes high-speed data communication with the upper-level SCR control system (DCS) or engine electronic control unit (ECU) to acquire and monitor key process parameters in real time, serving as the basis for control decisions. These key process parameters include:

[0058] The inlet flue gas volumetric flow rate of the SCR reactor is used to evaluate the reaction residence time and load.

[0059] The inlet flue gas temperature of the SCR reactor directly affects the evaporation and decomposition rate of the urea solution and the catalyst activity window.

[0060] The nitrogen oxide concentration at the inlet of the SCR reactor is the main basis for calculating the urea injection rate;

[0061] The supply flow rate and pressure of the urea solution itself are used to monitor the working status of the supply system and to perform material balance calculations.

[0062] Furthermore, the multi-dimensional signal sensing unit is also equipped with an online diagnostic subunit to achieve predictive maintenance and early warning of faults. The online diagnostic subunit deploys several status sensors at key locations on the injector body, including:

[0063] Vibration diagnostic sensor: An industrial-grade high-frequency piezoelectric accelerometer is installed on a rigid structure near the atomizing nozzle on the spray gun shaft. This sensor continuously monitors the vibration spectrum of the spray gun, focusing on analyzing the vibration energy changes in the high-frequency band above 5kHz. When crystals adhere to the nozzle or internal flow channel, they will change the dynamic characteristics of the structure, resulting in a significant increase in the vibration energy of the characteristic frequency band, thus providing an early warning of crystallization.

[0064] Wall temperature monitoring sensor: Employing a miniature, non-contact infrared temperature probe, precisely aimed at the easily crystallizing area on the outer side of the spray gun head, this sensor monitors the nozzle wall temperature in real time. The system compares the temperature with the flue gas dew point temperature and the system safety threshold. Once the wall temperature is detected to be abnormally low and continues to deviate from the set range, the system immediately triggers a crystallization risk warning, prompting that intervention or automatic purging program should be initiated.

[0065] The intelligent control unit adopts a control algorithm based on the adaptive fuzzy PID principle, which has high reliability and robustness in complex industrial processes;

[0066] The implementation of the control logic of the intelligent control unit mainly includes the following aspects:

[0067] The target SMD is dynamically calculated based on real-time operating conditions. The system pre-stores an empirical model fitted with a large amount of experimental data, the basic form of which is: ;

[0068] Where a, b, c, and d are constants determined through calibration. As a backup plan, the control unit also stores a two-dimensional lookup table indexed by flue gas temperature and flow rate. When the model calculation fails, it can automatically switch to the lookup table method to obtain the target value, ensuring the redundancy and reliability of the system.

[0069] The input variables of the controller include particle size deviation e(t) and its rate of change Δe(t), where e(t) is defined as the difference between the real-time measured SMD value and the target SMD; Δe(t) reflects the trend of the deviation over time. The output variables of the controller are the adjustment amount ΔP of the atomized air pressure and the adjustment coefficient K of the secondary air ratio.

[0070] The system's control strategy is embodied in a comprehensive fuzzy rule base, which contains approximately 25 to 49 control rules, fully covering various possible operating states. For example, when a large negative particle size deviation and a large negative rate of change are detected, it indicates that the current atomization effect is seriously deviating from the target and is continuously deteriorating. At this time, the controller will output a large positive pressure adjustment amount and a secondary air ratio coefficient to quickly correct the deviation by significantly increasing the atomization intensity. When the particle size deviation is small positive and the rate of change is close to zero, it indicates that the atomization effect is slightly deviating from the target but is stabilizing. At this time, the controller will output a small negative adjustment amount to optimize energy efficiency through fine-tuning.

[0071] In terms of multivariate coordinated control, the controller simultaneously outputs adjustment commands for atomized air pressure and secondary air ratio based on fuzzy inference results. The new atomized air pressure setpoint is the algebraic sum of the original setpoint and the adjustment amount; the new secondary air flow rate is determined by multiplying the adjustment coefficient by the urea flow rate. This multivariate coordinated control mechanism fully considers the coupling relationship between various actuators: in operating conditions requiring rapid response, a unidirectional coordination strategy is adopted to synchronously enhance or weaken the atomization intensity; in steady-state or fine-tuning operating conditions, a reverse fine-tuning strategy may be adopted to maximize energy efficiency through optimized proportioning.

[0072] The entire control process forms a closed-loop system with particle size as the direct control object. Through continuous monitoring, intelligent decision-making, and multi-variable collaboration, it ensures that the atomizing device can maintain the best atomization effect under various working conditions.

[0073] To improve the system's adaptability under complex working conditions and its long-term operational stability, the intelligent control unit also integrates anti-interference and self-learning functions.

[0074] Specifically, the anti-interference and self-learning functions are achieved through the following strategies:

[0075] A. Dynamic feedforward compensation mechanism: For transient conditions such as rapid engine acceleration and rapid boiler load increase, the system directly receives load change signals via CAN bus or hardwire. The control unit does not rely on relatively lagging particle size feedback, but immediately activates the feedforward control model. Based on the received signal strength and rate of change, the model predicts the trend of flue gas flow and temperature changes in advance, and accordingly quickly pre-adjusts the urea supply and atomizing air pressure to achieve advance compensation for sudden changes in operating conditions and effectively suppress atomization quality fluctuations during transient processes.

[0076] B. Based on condition monitoring, the preventive control strategy proactively prevents failures by evaluating the equipment status in real time, including real-time evaluation of crystallization and performance degradation.

[0077] Specifically, the anti-crystallization active control involves the control unit continuously analyzing the high-frequency energy components of the spray gun vibration signal and the wall temperature monitoring data of the nozzle area. When the high-frequency vibration energy continues to exceed the standard and the wall temperature is lower than the safety threshold, the system comprehensively determines the crystallization risk level. After the risk is confirmed, in addition to issuing a warning message, the system will automatically execute a high-pressure purging procedure after the next spraying cycle ends: that is, cut off the urea supply and use compressed air with the maximum flow rate to continuously purge the nozzle and related flow channels. At the same time, the electric heating power of the area is intelligently increased to eliminate the crystallization conditions from the root.

[0078] The control system has a built-in performance evaluation algorithm that continuously calculates and records the overall efficiency coefficient of the atomization system. The formula is:

[0079]

[0080] in, The overall efficiency coefficient is dimensionless, and K is a system characteristic constant determined by the equipment model and initial calibration. The target Sottle mean diameter under the current working conditions ( ), The real-time measured Sottle average diameter ( ), The working pressure (MPa) of the atomizing air. The volumetric flow rate of the atomized air (Nm³ / h);

[0081] This coefficient is a function of the target particle size and the current energy consumption and time. When the system finds that the efficiency coefficient is continuously decreasing through trend analysis, it can be determined that the core atomization components may be worn or the channel flow may be reduced. Then, a preventive maintenance prompt is generated to guide the operator to perform inspection and maintenance, avoid unplanned downtime, and thus realize performance degradation early warning and maintenance prompt.

[0082] C. Self-tuning and learning capabilities of control parameters: To adapt to the slow changes in equipment characteristics during long-term operation, the system has an online self-tuning function. The control unit will automatically start the tuning program according to the preset operating cycle or based on the operating stability index. This program applies a small test signal to the actuator and accurately records the response characteristics of the particle size. Based on the acquired system dynamic response data, the control algorithm automatically retunes its internal key parameters (such as fuzzy membership function, proportional factor, PID gain, etc.) to ensure that the dynamic characteristics of the controller always maintain the best match with the current actual state of the equipment, thereby ensuring that the control quality does not deteriorate throughout the entire equipment life cycle.

[0083] 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.

Claims

1. A high-efficiency atomizing spray device for urea solution suitable for SCR denitrification, characterized in that, include: The composite atomization unit includes a first-stage pre-filming and flow stabilizing structure connected in sequence and in fluid communication, a second-stage pneumatic ultrasonic standing wave generator, and a third-stage gas-liquid shear nozzle. An intelligent control unit, which is electrically connected to the composite atomizing unit; A multi-dimensional sensing system, which is signal-connected to the intelligent control unit, is used to collect atomization process parameters, equipment status parameters, and system operating condition parameters. The primary pre-filming and flow stabilizing structure includes a spiral guide groove formed on the inner wall of the gas channel, which transforms the input urea solution column into a uniform liquid film flowing along the wall. The secondary pneumatic ultrasonic standing wave generator includes a Hartmann whistle structure, which uses high-speed airflow to generate an ultrasonic standing wave field, causing the liquid film generator to break up. The three-stage gas-liquid shear nozzle is equipped with a primary air outlet and a secondary air outlet, which performs final pneumatic shearing and accelerated jetting on the ultrasonically broken droplets.

2. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 1, characterized in that, The multi-dimensional sensing system includes: A laser diffraction particle size analyzer is installed on the flue wall downstream of the spraying device to measure the Sottle mean diameter and particle size distribution span of the atomized droplets in real time. A vibration sensor is installed at the nozzle head of the composite atomizing unit to monitor its vibration spectrum; An infrared thermometer is aimed at the easily crystallizing area of ​​the spray gun head to monitor its wall temperature.

3. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 1 or 2, characterized in that, The intelligent control unit is configured to perform the following closed-loop control: Based on real-time collected flue gas flow rate and flue gas temperature, the target Sottle average diameter is dynamically calculated through a pre-stored empirical model or a two-dimensional lookup table. Receive the SMD value measured by the laser diffraction particle size analyzer, and calculate the error and error rate between it and the Sottle mean diameter; Based on the error and the rate of change of error, an adaptive fuzzy PID controller is used to collaboratively output adjustment commands for the atomized air pressure and the secondary air ratio.

4. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 3, characterized in that, The intelligent control unit is also configured to perform feedforward compensation control, which, in response to a received signal of a sudden increase in external load, increases the urea solution supply and atomizing air pressure in advance, according to a preset feedforward model, before the measured SMD value changes.

5. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 3, characterized in that, The intelligent control unit is also configured to perform state-based preventive control. When the high-frequency vibration energy value of the vibration sensor continues to exceed the first threshold and the wall temperature monitored by the infrared thermometer continues to be lower than the second threshold, it is determined that there is a risk of crystallization, and a high-pressure purging procedure is automatically executed and / or the heat tracing temperature is increased. Continuously calculate and monitor the overall efficiency coefficient of the atomization system. When the overall efficiency coefficient When a continuous downward trend is observed, a preventative maintenance prompt will be generated.

6. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 5, characterized in that, The overall efficiency coefficient The calculation formula is: in, The overall efficiency coefficient is given by K, which is a system characteristic constant determined by the equipment model and initial calibration. The target Sottle mean diameter under the current operating conditions. The real-time measured average diameter of Sottle. The working pressure for atomizing air, This is the volumetric flow rate of the atomized air.

7. The high-efficiency atomizing spray device for urea solution suitable for SCR denitrification according to claim 3, characterized in that, The intelligent control unit is also configured to perform parameter self-tuning: A test signal is applied to the actuator according to a preset cycle or triggering condition; Based on the SMD response characteristics of the atomized droplets, the internal parameters of the adaptive fuzzy PID controller are automatically adjusted. The internal parameters include the quantization factor, the scaling factor, and the PID gain.

8. A method for controlling the atomization of urea solution in an SCR denitrification system, characterized in that, The method, employing the spraying device as described in any one of claims 1-7, comprises the following steps: The primary pre-filming and flow stabilizing structure forms a pre-shaped liquid film from the urea solution; The ultrasonic standing wave field generated by the two-stage pneumatic ultrasonic standing wave generator breaks up the liquid film. The three-stage gas-liquid shear nozzle performs pneumatic shearing and accelerated jetting of the broken droplets. The multi-dimensional sensing system collects real-time data on the atomization process, equipment status, and system operating parameters. Based on the parameters, the intelligent control unit performs closed-loop control, feedforward compensation, preventive control, or parameter self-tuning as described in any one of claims 3-7.

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