Low-fly-ash synergistic deacidification system and operation control method thereof

Abstract

The invention relates to the technical field of waste incineration flue gas treatment, in particular to a low-fly-ash collaborative deacidification system and an operation control method thereof. The low-fly-ash collaborative deacidification system comprises a primary deacidification module, a secondary deacidification module, a third-stage deep purification module and a control module, and a control arithmetic unit of the control module receives monitoring data of a reaction tower inlet detection system, a reaction tower outlet detection system and a CEMS flue gas online monitoring system in real time. According to a preset algorithm, adjusting quantities of a deacidification agent flow control device of an in-furnace dry-process deacidification system in the primary deacidification module, a slurry preparation quantity control device of a semi-dry reaction tower in the secondary deacidification module and an alkali liquor flow control device of a wet-process tower in the tertiary deep purification module are dynamically calculated, and control signals are output to each control device; a closed-loop control loop including data acquisition, operation and execution is formed; efficient deacidification treatment is achieved, the fly ash generation amount and the treatment cost are remarkably reduced, operation of all levels of modules is optimized through a cooperative control mechanism, and consumables are saved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste incineration flue gas treatment, in particular to a flue gas deacidification process, in particular to a low fly ash collaborative deacidification system and an operation control method thereof. Background Art

[0002] Acidic gas pollutants in waste incineration flue gas primarily include sulfur dioxide (SO2), hydrogen chloride (HCl), and hydrogen fluoride (HF). Common methods for deacidification in waste incineration include wet, dry, and semi-dry methods. Wet deacidification is highly efficient, achieving removal efficiencies exceeding 99% for HCl and over 95% for SO2. However, it tends to produce large amounts of wastewater, requiring wastewater treatment equipment. Furthermore, the flue gas temperature after deacidification is relatively low, necessitating a flue gas reheating device to prevent chimney corrosion and white smoke. Dry activated carbon requires low investment, simple equipment, and easy maintenance, but the solid-liquid contact time is short, requiring more chemicals and resulting in relatively low purification efficiency. The semi-dry method combines the advantages of both dry and wet methods, offering high deacidification efficiency (90%-99%), simple equipment, stable operation, mature technology, and minimal wastewater discharge. However, it requires high operational skills, requiring strict control of the residence time and temperature difference between the reactor inlet and outlet.

[0003] With the continuous tightening of emission standards and the dual upgrade of fly ash disposal requirements, the waste incineration industry is facing multi-dimensional challenges: first, stricter pollutant limits directly push up the operating load of semi-dry reactors, resulting in a significant increase in fly ash generation; second, the improvement of fly ash resource utilization standards has increased the unit fly ash treatment cost; this dual pressure has made fly ash a core bottleneck restricting the economic feasibility of the project.

[0004] The current conventional deacidification process for waste incineration consists of a semi-dry process followed by dry activated carbon and a bag filter. This system can achieve a certain degree of pollutant control to meet emission standards, boasting a simple process chain and mature technology, but it cannot achieve ultra-low emissions. To achieve ultra-low emissions, a wet process must be added to this process. The process is: semi-dry process + dry activated carbon + bag filter + wet process. This process begins with a semi-dry process for initial deacidification, followed by dry activated carbon and a bag filter for supplementary deacidification. Finally, a wet scrubber provides deep purification to ensure that all emissions meet standards. When acidic pollutant concentrations increase and fluctuate frequently, the operating load of the semi-dry reactor increases significantly, resulting in reduced lime utilization, increased fly ash yield, and the occurrence of fouling within the reactor. To prevent subsequent SCR (selective catalytic reduction) poisoning, most dry activated carbon systems are deployed. However, pipeline dry processes have low material utilization and require the injection of large amounts of dry calcium hydroxide powder, which results in high fly ash production, increasing fly ash treatment costs and consumables. Although the wet method is at the end of the process chain and can ultimately control pollutant emissions to meet standards, it cannot coordinate with the semi-dry system for control and cannot effectively respond to increasing acid pollution concentrations and more frequent fluctuations. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in order to solve the shortcomings of the existing deacidification system in the above-mentioned background technology in fly ash treatment efficiency and coordinated control, the present invention provides a low fly ash coordinated deacidification system and operation control method. The system not only realizes efficient deacidification treatment, but also significantly reduces the fly ash generation and disposal cost, and through the coordinated control mechanism, optimizes the operation of modules at all levels of the deacidification system, further reducing the consumption of consumables.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a low fly ash collaborative deacidification system, comprising: The primary deacidification module includes an incinerator, a waste heat boiler, an in-furnace dry deacidification system and a boiler inertial dust collector connected in sequence, wherein the in-furnace dry deacidification system is provided with a deacidification agent flow control device; A secondary deacidification module comprises a semi-dry reaction tower, an activated carbon injection device and a bag dust collector connected in sequence, wherein the semi-dry reaction tower is provided with a slurry quantity control device, a reaction tower inlet detection system is provided between the outlet of the boiler inertial dust collector and the inlet of the semi-dry reaction tower, and a reaction tower outlet detection system is provided between the outlet of the semi-dry reaction tower and the inlet of the bag dust collector; A three-stage deep purification module includes a wet tower equipped with an alkali liquid flow control device and a CEMS flue gas online monitoring system at its outlet; The control module includes a control operator, which receives monitoring data from the reaction tower inlet detection system, the reaction tower outlet detection system and the CEMS flue gas online monitoring system in real time; dynamically calculates the adjustment amount of the deacidifying agent flow control device, the slurry quantity control device and the alkali solution flow control device according to a preset algorithm; and outputs control signals to each control device to form a closed-loop control circuit including data acquisition-calculation-execution.

[0007] By connecting the primary deacidification module, the secondary deacidification module and the tertiary deep purification module in series, the gradient removal of HCl / SO2 is achieved, reducing the pressure of end-of-pipe treatment; through the reaction tower inlet and outlet detection systems and the CEMS flue gas online monitoring system, real-time feedback adjustment is formed to ensure that emissions meet standards; the combination of boiler inertial dust collector and bag dust collector reduces the risk of fly ash clogging the subsequent SCR module.

[0008] According to one embodiment of the present invention, the system further includes a post-processing module comprising an SCR denitrification module and a GGH flue gas heat exchanger connected in sequence. The inlet of the SCR denitrification module is connected to the outlet of the bag filter, and the outlet of the GGH flue gas heat exchanger is connected to the inlet of the wet tower. The SCR denitrification module prevents high-dust flue gas from directly entering the catalyst, thereby extending its lifespan.

[0009] According to one embodiment of the present invention, the GGH flue gas heat exchanger is used to recover waste heat from the flue gas at the outlet of the wet process tower. The GGH flue gas heat exchanger recovers waste heat from the flue gas at the outlet of the wet process tower, thereby improving system energy efficiency.

[0010] According to one embodiment of the present invention, the operating temperature of the SCR denitrification module is triggered by the flue gas temperature at the outlet of the secondary deacidification module. This temperature is used to automatically start and stop the SCR denitrification module, preventing ABS poisoning (ammonium bisulfate blockage) caused by low-temperature operation.

[0011] According to one embodiment of the present invention, an induced draft fan is installed at the other outlet of the GGH flue gas heat exchanger. The outlet of the induced draft fan is connected to the inlet of the CEMS flue gas online monitoring system, and the outlet of the CEMS flue gas online monitoring system is connected to the chimney. The installation of the induced draft fan ensures compliance with final flue gas emission monitoring.

[0012] Also provided is an operation control method of the low fly ash collaborative deacidification system of the above solution, comprising the following steps: S1. Set the concentration control target value for each deacidification stage, including: HCl concentration setting value at the semi-dry reaction tower inlet and SO2 concentration set value , HCl concentration setting value at the outlet of semi-dry reactor , SO2 concentration setting value and temperature setting value ; HCl concentration set value at the final chimney outlet and SO2 concentration set value , S2. Real-time detection of the actual values ​​of pollutant concentrations at each stage of deacidification, including: Actual value of HCl concentration at the inlet of semi-dry reaction tower and actual SO2 concentration , Actual value of HCl concentration at the outlet of semi-dry reaction tower , actual value of SO2 concentration and actual temperature value ; Actual value of HCl concentration at the final chimney outlet and actual SO2 concentration ; S3. According to the deviation between the measured value and the set value, adjust the dosage of the deacidifying agent in stages: First determine whether the actual concentrations of HCl and SO2 at the inlet of the semi-dry reaction tower are less than the set values. If not, ≥ or ≥ , then adjust the injection amount of dry deacidification agent in the furnace; if so, then judge whether the actual value of the concentration of HCl and SO2 at the outlet of the semi-dry reaction tower is less than the set value, if not, that is ≥ or ≥ , then adjust the semi-dry lime slurry injection amount; if so, then determine whether the actual concentration of HCl and SO2 at the chimney outlet is less than the set value, if not, that is ≥ and ≥ , then adjust the amount of alkali solution injected into the wet tower; if so, calculate the load distribution weights of the deacidification units at all levels and dynamically optimize the coordinated operation of the low fly ash collaborative deacidification system.

[0013] Adjust the priority according to "in-furnace dry method → ​​semi-dry method → ​​wet method" to avoid over-reliance on terminal treatment and reduce operating costs; dynamic load distribution optimizes resource utilization.

[0014] According to one embodiment of the present invention, in step S3, the adjustment amount of the dry deacidification agent in the furnace is IN1 = K1× ( - )+K2×( - ); The adjustment amount of the semi-dry lime slurry IN2 = K3 × ( - )+K4×( - ); The adjustment amount of the wet tower alkali solution IN3 = K5 × ( - )+K6×( - ); where K1, K2, K3, K4, K5, and K6 are adjustment coefficients, ranging from 0.5 to 1.5.

[0015] According to one embodiment of the present invention, in step S3, the load distribution weights of the deacidification modules at each level include calculating the regulation requirements of the deacidification modules at each level, namely: ZN1=K7×( - )+K8×( - ); ZN2=K9×( - )+K10×( - ); ZN3=K11×( - )+K12×( - ); Among them, K7, K8, K9, K10, K11, and K12 are adjustment coefficients, ranging from 0.8 to 1.2; Normalizing the weights at all levels, we get: IN4=ZN1 / (ZN1+ZN2+ZN3); IN5=ZN2 / (ZN1+ZN2+ZN3); IN6=ZN3 / (ZN1+ZN2+ZN3).

[0016] Precise adjustment is achieved through adjustment coefficients K1~K6 (limited to 0.5-1.5) and adjustment coefficients K7~K12 (limited to 0.8-1.2) to avoid oscillation or response lag; normalized weight distribution (IN4~IN6) ensures the coordinated balance of the three-stage deacidification.

[0017] According to one embodiment of the present invention, in step S3, the coordinated operation of the low fly ash coordinated deacidification system is dynamically optimized, specifically: Select IN4 to control the deacidifying agent flow control device to spray the required deacidifying agent dry powder into the incinerator; select IN5 to control the slurry quantity control device to spray the required lime slurry into the semi-dry reaction tower; select IN6 to control the alkali solution flow control device to spray the required amount of alkali solution into the wet process tower.

[0018] According to one embodiment of the present invention, the further embodiment includes: S4. Train a neural network model based on historical operating data to predict pollutant concentration trends in real time; S5. When the predicted value exceeds the set value, adjust the amount of deacidification agent in advance, specifically: If the predicted chimney outlet HCl or SO2 concentration will exceed the set value in the next 5 minutes, deacidification agent will be added in increments of 1.2 times the weights IN4, IN5, and IN6; If the predicted concentration will be lower than the set value in the next 10 minutes, the dosage will be reduced by 0.8 times the weights IN4, IN5, and IN6.

[0019] The neural network predicts the pollutant concentration in the next 5 to 10 minutes, increases / decreases the dosage of the drug in advance, and reduces emission fluctuations; it is trained with historical data to adapt to different working conditions (changes in incineration load).

[0020] Beneficial effects of the present invention: (1) The acid gas is initially removed by the dry system in the furnace, and the amount of slurry input to the semi-dry reaction tower is reduced. At the same time, the setting of the boiler inertial dust collector effectively reduces the fly ash production of the flue gas system. Further, by reasonably setting the concentration setting values ​​of hydrogen chloride and sulfur dioxide at the inlet of the semi-dry reaction tower, setting the concentration setting values ​​of hydrogen chloride and sulfur dioxide at the outlet of the semi-dry reaction tower, and setting the concentration setting values ​​of hydrogen chloride and sulfur dioxide at the chimney outlet; reasonably reducing the load of the semi-dry reaction tower, low fly ash and high efficiency deacidification are achieved; (2) When the acid pollution concentration becomes higher and the fluctuation becomes more frequent, the injection amount of the dry process in the furnace can be adjusted to cope with it, reducing the load pressure and scaling risk of the semi-dry process; (3) Through the three-level collaborative control algorithm, tasks are reasonably allocated, with the dry method in the furnace as the rough decontamination, the semi-dry reaction tower as the main stabilization force, and the wet method as the final deep purification; the use of consumables is reduced while achieving accurate emission standards; (4) Improve deacidification efficiency through closed-loop control and dynamic weight distribution, achieve advanced control through neural network model prediction, and reduce environmental risks; (5) Reduce the energy consumption of the wet tower by recovering waste heat, give priority to the use of cheap dry deacidification agents in graded regulation, and reduce the amount of wet alkali solution used. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and examples.

[0022] Figure 1 It is a structural diagram of the system of the present invention.

[0023] Figure 2 It is a control flow chart of the operation control method of the present invention.

[0024] Figure 3 It is a logical framework diagram of the operation control method of the present invention.

[0025] In the figure: 1. Incinerator; 2. Waste heat boiler; 3. Dry deacidification system in the furnace; 4. Boiler inertial dust collector; 5. Deacidification agent flow control device; 6. Semi-dry reaction tower; 7. Activated carbon injection device; 8. Bag dust collector; 9. Slurry quantity control device; 10. Reaction tower inlet detection system; 11. Reaction tower outlet detection system; 12. Wet process tower; 13. Alkali solution flow control device; 14. CEMS flue gas online monitoring system; 15. Control operator; 16. SCR denitrification module; 17. GGH flue gas heat exchanger; 18. Induced draft fan; 19. Chimney. DETAILED DESCRIPTION

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0027] First, the professional terms used below are explained to facilitate a better understanding of the content of the embodiments.

[0028] Incinerator: It is a key equipment for harmless treatment of garbage or biomass. Its core mechanism is to promote the decomposition of organic matter in solid waste through a high-temperature environment (usually the temperature range is 850℃ to 1100℃), and convert it into harmless gas, water vapor and ash.

[0029] Flue gas: Flue gas here specifically refers to gases, particulate pollutants and their mixtures released during the incineration of garbage or biomass; waste incineration flue gas pollutants mainly include particulate matter (such as fly ash, smoke), acidic gases (such as sulfur dioxide, hydrogen chloride), nitrogen oxides, heavy metals (such as lead, mercury, cadmium), organic pollutants (such as dioxins, etc.) and greenhouse gases (such as carbon dioxide).

[0030] In-furnace dry method: This technology involves adding desulfurization agents such as limestone and gypsum into the incinerator. These additives react chemically with the SO2 or HCl generated by combustion under high temperature conditions, thereby effectively achieving the purpose of deacidification.

[0031] A boiler inertial dust collector is a device that separates dust by exploiting the difference in inertia between dust and gas during motion. Its operating principle is to place an obstacle in front of the dust-laden airflow, causing the airflow to change direction dramatically. Due to the greater inertia, the dust then breaks away from the airflow and strikes the obstacle or the wall of the dust collector. Gravity then causes it to fall into the hopper, thus purifying the gas.

[0032] Semi-dry reaction tower: uses atomized lime slurry (CaO content ≥ 90%) to contact the flue gas, uses the waste heat of the flue gas to evaporate water, and realizes gas-liquid-solid multiphase reaction, thereby achieving the purpose of deacidification; the rotary spray drying absorption tower (SDA) has become the mainstream configuration of waste incineration plants due to its high efficiency and economy.

[0033] Dry activated carbon system: Activated carbon is sprayed into the pipeline to adsorb and remove heavy metals, dioxins, etc. in the flue gas, and calcium hydroxide is sprayed into the pipeline to remove acidic pollutants in the flue gas.

[0034] Bag dust collector: It is a key equipment in the waste incineration flue gas treatment system used to remove dust, heavy metals, dioxins and other harmful substances generated during the incineration process. It has the advantages of high-efficiency filtration, high temperature resistance, and corrosion resistance. It filters the flue gas through the bag material to ensure that the flue gas emissions meet environmental protection standards.

[0035] Wet deacidification: This refers to a technology used to purify flue gas during waste incineration. It uses an alkaline solution (such as limestone solution) to react chemically with acidic gases (such as HCl and SO2) in the flue gas within a scrubber, producing salts and water. This removes the acidic components in the flue gas and achieves the purpose of deacidification. While wet deacidification is highly efficient, it requires high equipment requirements and can generate large amounts of wastewater, necessitating the use of wastewater treatment equipment.

[0036] Chimney: A garbage incineration chimney is a tall structure used to discharge waste gases from the incineration plant. It is an important component of the garbage incineration system, and its main function is to discharge the waste gases from the building.

[0037] Ultra-low emissions: Ultra-low emissions of waste incineration flue gas means that during the waste incineration process, the emission concentrations of pollutants such as smoke, sulfur dioxide, and nitrogen oxides are greatly reduced by adopting advanced flue gas treatment technology, reaching limits far below national emission standards, thereby achieving environmental friendliness and sustainable development.

[0038] Example 1 like Figure 1As shown, a low fly ash collaborative deacidification system includes a primary deacidification module, a secondary deacidification module, a tertiary deep purification module, a control module and a subsequent processing module, wherein the primary deacidification module includes an incinerator 1, a waste heat boiler 2, an in-furnace dry deacidification system 3 and a boiler inertial dust collector 4 connected in sequence, and the in-furnace dry deacidification system 3 is provided with a deacidifier flow control device 5; the secondary deacidification module includes a semi-dry reaction tower 6, an activated carbon injection device 7 and a bag dust collector 8 connected in sequence, the semi-dry reaction tower 6 is provided with a slurry quantity control device 9, a reaction tower inlet detection system 10 is provided between the outlet of the boiler inertial dust collector 4 and the inlet of the semi-dry reaction tower 6, and the outlet of the semi-dry reaction tower 6 is connected to the bag dust collector. 8, a reaction tower outlet detection system 11 is installed between the inlets. The three-stage deep purification module includes a wet tower 12, which is equipped with an alkali flow control device 13 and a CEMS flue gas online monitoring system 14 at its outlet. The control module includes a control operator 15, which receives real-time monitoring data from the reaction tower inlet detection system 10, the reaction tower outlet detection system 11, and the CEMS flue gas online monitoring system 14. It dynamically calculates the adjustment amount of the deacidifying agent flow control device 5, the slurry quantity control device 9, and the alkali flow control device 13 according to a preset algorithm, and outputs control signals to each control device, forming a closed-loop control circuit including data acquisition, calculation, and execution. The subsequent processing module includes an SCR denitrification module 16 and a GGH flue gas heat exchanger 17 connected in sequence. The inlet of the SCR denitrification module 16 is connected to the outlet of the bag filter 8, and the outlet of the GGH flue gas heat exchanger 17 is connected to the inlet of the wet tower 12.

[0039] The deacidification system utilizes a three-stage coordinated treatment process: primary deacidification is accomplished by the in-furnace dry system, which sprays deacidifier powder into the high-temperature zone of the incinerator to initially neutralize the acidic gases at their source. At the same time, the boiler inertial dust collector 4 effectively intercepts unreacted particles to prevent abnormal increases in dust concentration. Secondary deacidification is undertaken by the semi-dry reaction tower 6, which atomizes lime slurry through a dual-fluid nozzle to achieve efficient acid-base neutralization reaction in turbulent gas-liquid contact, stably fulfilling the main deacidification task. Tertiary deep purification is accomplished by the wet tower 12, which ultimately removes the acidic gases escaping from the first two stages through an alkaline solution spray system with closed-loop pH control.

[0040] A dry deacidification agent (such as Ca(OH)2) is sprayed into the high-temperature zone at the outlet of incinerator 1 to quickly neutralize HCl and SO2, removing approximately 60-80% of the acid gases. In the semi-dry reaction tower 6, lime slurry is atomized and reacts with the flue gas to further remove residual acid gases. Activated carbon adsorbs dioxins and heavy metals. Wet alkaline solution washing thoroughly removes trace pollutants (SO2 can be reduced to <10mg / Nm³). Gradual treatment avoids overloading of a single technology, and the overall deacidification efficiency is >99%.

[0041] Furthermore, the boiler's inertial dust collector 4 initially removes large fly ash particles (with an efficiency of approximately 50-70%), while the bag filter 8 efficiently captures fine particles (with an efficiency of >99.9%), reducing the amount of fly ash entering the SCR denitrification module 16. This significantly reduces the risk of SCR catalyst clogging and wear, extending its lifespan by over 30%. The SCR denitrification module 16 is placed after the bag filter 8 to prevent high-dust flue gas from directly contacting the catalyst. The flue gas heat exchanger 17 regulates the flue gas temperature to 280-400°C, preventing ammonium bisulfate (ABS) from clogging the catalyst at low temperatures and reducing the risk of SCR alkali metal poisoning and SO₃ poisoning. Denitrification efficiency remains stable at over 90%.

[0042] The reaction tower inlet detection system 10 and outlet detection system 11 (HCl / SO2 concentration, temperature) are combined with the online data of the CEMS flue gas online monitoring system 14 to dynamically track changes in pollutant concentrations.

[0043] The GGH flue gas heat exchanger 17 is used to recover waste heat from the flue gas at the outlet of the wet tower. This waste heat (approximately 50-70°C) is recovered from the flue gas at the outlet of wet tower 12, preheating the flue gas entering wet tower 12. This reduces the energy consumption for heating the alkali solution and reduces the system's total energy consumption by 10-15%. The operating temperature of the SCR denitrification module 16 is triggered by the flue gas temperature at the outlet of the secondary deacidification module. The temperature of the flue gas at the outlet of the secondary deacidification module is used to automatically start and stop the SCR denitrification module 16 to prevent ABS poisoning (ammonium bisulfate blockage) caused by low-temperature operation. An induced draft fan 18 is installed at the other outlet of the GGH flue gas heat exchanger 17. The outlet of the induced draft fan 18 is connected to the inlet of the CEMS flue gas online monitoring system 14, the outlet of which is connected to the chimney 19. The installation of the induced draft fan 18 ensures compliance with final flue gas emission monitoring regulations.

[0044] The reaction tower inlet detection system 10 and the reaction tower outlet detection system 11 can utilize a laser gas analyzer (TDLAS). The CEMS flue gas online monitoring system 14 includes a sampling probe, sampling pipeline, condenser, filter, dryer, gas analyzer, particulate matter monitor, data acquisition device, and data processing software. The deacidification agent flow control device 5 is a powder material flow control device, including a metering screw feeder, powder silo, powder pump, flow sensor, and controller. The slurry quantity control device 9 is a liquid flow control device, including a metering pump, lime slurry tank, flow meter, and controller. The alkali solution flow control device 13 is also a liquid flow control device, including a metering pump, alkali solution storage tank, flow meter, and controller.

[0045] Example 2 like Figure 2As shown, the operation control method of the low fly ash collaborative deacidification system realizes multi-system coordinated regulation through the control operator 15, and the dry deacidification injection amount in the furnace, the slurry amount control system of the semi-dry reaction tower 6 and the alkali liquid flow control system of the wet tower 12 respectively receive the adjustment signals output by the control operator 15, wherein the decision of the control operator 15 is based on the real-time parameter feedback from the reaction tower inlet detection system 10, the outlet detection system 11 and the CEMS flue gas online monitoring system 14, forming a closed-loop control structure of monitoring-operation-regulation, so that each deacidification unit can maintain independent operation and dynamically respond to changes in the overall working conditions.

[0046] The overall operation control method is: Step 1: Set the concentrations of hydrogen chloride and sulfur dioxide at the inlet of the semi-dry reaction tower 6 to 、 , set the outlet temperature of the semi-dry reaction tower 6 to , set the concentration setting values ​​of hydrogen chloride and sulfur dioxide at the outlet of semi-dry reaction tower 6 to be 、 , set the preset concentration values ​​of hydrogen chloride and sulfur dioxide at the outlet chimney 19 to 、 .

[0047] Step 2: Determine whether the concentrations of hydrogen chloride and sulfur dioxide at the inlet of the semi-dry reaction tower 6 are less than the preset values: If not, multiply the difference between the set value of hydrogen chloride at the inlet of the semi-dry reaction tower 6 and the actual value of hydrogen chloride by the value of coefficient K1 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide by the value of coefficient K2 to obtain IN1, that is, IN1=K1×( - )+K2×( - ), select IN1 to PID control the deacidification meter flow control device 5, and spray the required deacidification agent dry powder into the incinerator 1; if so, execute step 3.

[0048] Step 3: Determine whether the concentrations of hydrogen chloride and sulfur dioxide at the outlet of the semi-dry reaction tower 6 are less than the preset values: If not, multiply the difference between the set value of hydrogen chloride at the outlet of the semi-dry reaction tower 6 and the actual value of hydrogen chloride by the value of coefficient K3 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide by the value of coefficient K4 to obtain IN2, that is, IN2=K3×( - )+K4×( - ), select IN2 to PID control the slurry quantity control device 9 to spray the required lime slurry into the semi-dry reaction tower 6; if so, execute step 4.

[0049] Step 4: Determine whether the concentrations of hydrogen chloride and sulfur dioxide at the chimney 19 outlet are less than the preset values: If not, multiply the difference between the set value of hydrogen chloride and the actual value of hydrogen chloride at the chimney 19 by the value of coefficient K5 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide by the value of coefficient K6 to obtain IN3, that is, IN3=K5×( - )+K6×( - ), select IN3 to PID control the alkali solution flow control device 13 to spray the required amount of alkali solution into the wet process tower 12; if so, execute step 5.

[0050] Step 5: Add the difference between the set value of hydrogen chloride at the inlet of the semi-dry reaction tower 6 and the actual value of hydrogen chloride multiplied by the value of coefficient K7 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide multiplied by the value of coefficient K8 to obtain ZN1, that is, ZN1=K7×( - )+K8×( - ), the difference between the set value of hydrogen chloride at the outlet of the semi-dry reaction tower 6 and the actual value of hydrogen chloride multiplied by the value of coefficient K9 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide multiplied by the value of coefficient K10 are added to obtain ZN2, that is, ZN2=K9×( - )+K10×( - ), multiply the difference between the set value of hydrogen chloride at the chimney outlet 19 and the actual value of hydrogen chloride by the value of coefficient K11 and the difference between the set value of sulfur dioxide concentration and the actual value of sulfur dioxide by the value of coefficient K12 to obtain ZN3, that is, ZN3=K11×( - )+K12×( - ).

[0051] Step 6: Normalize the weights at all levels, that is, set IN4=ZN1 / (ZN1+ZN2+ZN3), IN5=ZN2 / (ZN1+ZN2+ZN3), IN6=ZN3 / (ZN1+ZN2+ZN3); Among them, K1, K2, K3, K4, K5, and K6 are adjustment coefficients ranging from 0.5 to 1.5; K7, K8, K9, K10, K11, and K12 are adjustment coefficients ranging from 0.8 to 1.2.

[0052] Step 7: Select IN4 to PID control the deacidifying agent flow control device 5, and spray the required deacidifying agent dry powder into the incinerator 1; select IN5 to PID control the slurry quantity control device 9, and spray the required lime slurry into the semi-dry reaction tower 6; select IN6 to PID control the alkali solution flow control device 13, and spray the required amount of alkali solution into the wet tower 12.

[0053] like Figure 3 As shown in the figure, SUB is used to calculate the deviation between the set value and the actual value of HCl and SO2 concentration; MUL is used to multiply the deviation by a coefficient (such as K1 to K12); ADD is used to sum the weighted deviations (such as IN1 to IN6); PID is used to dynamically adjust the deacidification agent dosage of each module according to IN1 to IN6 to achieve closed-loop control.

[0054] A progressive assessment based on three concentration thresholds—inlet, outlet, and chimney—prioritizes activation of the front-end deacidification unit (dry deacidification) to maximize its economic advantages. The more expensive back-end treatment unit (wet deacidification) is activated only when the front-end treatment is insufficient, reducing overall deacidification agent consumption by 20-30% and extending the wet system's service life (reducing unnecessary alkali addition). Through ZN1-ZN3, which quantifies the treatment intensity of each link, and IN4-IN6, dynamic load distribution is achieved to avoid overtreatment and achieve optimal synergistic matching among the three deacidification units, improving system response speed by over 40%. K1-K6 (limited to 0.5-1.5) are fast-response coefficients for immediate regulation, while K7-K12 (limited to 0.8-1.2) are balancing coefficients for load distribution, balancing regulation sensitivity with system stability. The coefficient ranges have been optimized through experiments to avoid oscillation or hysteresis. The system integrates detection and monitoring systems, control arithmetic units, actuators, operating condition changes, and feedback adjustments, achieving an upgrade from empirical control to predictive control. This reduces emission fluctuations by over 60%, enabling adaptive optimization of fuel composition changes and hardware systems. Combining feedforward-feedback composite control with multi-objective optimization ensures real-time control while achieving optimal system operation economics, representing a significant breakthrough in intelligent control for flue gas purification.

[0055] In addition, a neural network model is trained based on historical operating data to predict the trend of pollutant concentration changes in real time. When the predicted value exceeds the set value, the deacidification agent dosage is adjusted in advance, specifically: If the predicted HCl or SO2 concentration at the chimney 19 outlet will exceed the set value in the next 5 minutes, deacidification agent is added in increments of 1.2 times the weights IN4, IN5, and IN6; If the predicted concentration will be lower than the set value in the next 10 minutes, the dosage will be reduced by 0.8 times the weights IN4, IN5, and IN6.

[0056] Real-time predictions based on historical operating data using a neural network model can more accurately capture changing trends in pollutant concentrations. Compared to traditional adjustments based solely on current concentrations, predicting concentration changes within the next five or ten minutes allows for more precise control of pollutant concentrations, keeping them near set values ​​and avoiding overshoots or undershoots caused by delayed adjustments.

[0057] Pollutant generation and emissions can vary significantly under different operating conditions. A neural network-based predictive model can dynamically adjust deacidification agent dosage based on real-time operating data. This highly adaptable model can better cope with complex operating conditions and ensure effective control of pollutant concentrations in all situations.

[0058] If the concentration is predicted to fall below the set value in the next 10 minutes, the deacidification agent dosage is reduced by 0.8 times the weights IN4, IN5, and IN6. This strategy avoids adding the deacidification agent at the normal dosage even when the pollutant concentration is already sufficiently low, thereby reducing unnecessary deacidification agent use and lowering production costs.

[0059] Accurate prediction and dosage adjustment can make the use of deacidifier more reasonable, avoid the waste caused by excessive deacidifier addition due to inaccurate prediction, and maximize the conservation of deacidifier resources while ensuring the pollutant control effect.

[0060] Adjusting the deacidification agent dosage in advance based on forecast results can effectively reduce fluctuations in HCl or SO2 concentrations at the chimney outlet. Stable pollutant emission concentrations contribute to the stable operation of the entire environmental protection system, preventing the impact of large concentration fluctuations on subsequent treatment processes or equipment, and improving the reliability of the entire system.

[0061] This prediction-based adjustment strategy can provide a more reasonable parameter setting basis for the operation of the system. By analyzing the prediction results and adjusting the dosage, the deacidification agent dosage strategy and related operating parameters can be continuously optimized to keep the system in the best operating state and improve the overall performance and stability of the system.

[0062] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A low fly ash collaborative deacidification system, characterized in that: include: The primary deacidification module includes an incinerator, a waste heat boiler, an in-furnace dry deacidification system and a boiler inertial dust collector connected in sequence, wherein the in-furnace dry deacidification system is provided with a deacidification agent flow control device; A secondary deacidification module comprises a semi-dry reaction tower, an activated carbon injection device and a bag dust collector connected in sequence, wherein the semi-dry reaction tower is provided with a slurry quantity control device, a reaction tower inlet detection system is provided between the outlet of the boiler inertial dust collector and the inlet of the semi-dry reaction tower, and a reaction tower outlet detection system is provided between the outlet of the semi-dry reaction tower and the inlet of the bag dust collector; A three-stage deep purification module includes a wet tower equipped with an alkali liquid flow control device and a CEMS flue gas online monitoring system at its outlet; The control module includes a control operator, which receives monitoring data from the reaction tower inlet detection system, the reaction tower outlet detection system and the CEMS flue gas online monitoring system in real time; dynamically calculates the adjustment amount of the deacidifying agent flow control device, the slurry quantity control device and the alkali solution flow control device according to a preset algorithm; and outputs control signals to each control device to form a closed-loop control circuit including data acquisition-calculation-execution.

2. The low fly ash collaborative deacidification system according to claim 1, characterized in that: It also includes a subsequent processing module, which includes an SCR denitrification module and a GGH flue gas heat exchanger connected in sequence. The inlet of the SCR denitrification module is connected to the outlet of the bag filter, and the outlet of the GGH flue gas heat exchanger is connected to the inlet of the wet tower.

3. The low fly ash collaborative deacidification system according to claim 2, characterized in that: The GGH flue gas heat exchanger is used to recover the waste heat of the flue gas at the outlet of the wet tower.

4. The low fly ash collaborative deacidification system according to claim 2, characterized in that: The operating temperature of the SCR denitrification module is triggered by the outlet flue gas temperature of the secondary deacidification module.

5. The low fly ash collaborative deacidification system according to claim 2, characterized in that: An induced draft fan is provided on the other outlet of the GGH flue gas heat exchanger, the outlet of the induced draft fan is connected to the inlet of the CEMS flue gas online monitoring system, and the outlet of the CEMS flue gas online monitoring system is connected to the chimney.

6. An operation control method for the low fly ash collaborative deacidification system according to any one of claims 1 to 5, characterized in that: The steps include: S1. Set the concentration control target value for each deacidification stage, including: HCl concentration setting value at the semi-dry reaction tower inlet and SO2 concentration set value , HCl concentration setting value at the outlet of semi-dry reactor , SO2 concentration setting value and temperature setting value ; HCl concentration set value at the final chimney outlet and SO2 concentration set value , S2. Real-time detection of the actual values ​​of pollutant concentrations at each stage of deacidification, including: Actual value of HCl concentration at the inlet of semi-dry reaction tower and actual SO2 concentration , Actual value of HCl concentration at the outlet of semi-dry reaction tower , actual value of SO2 concentration and actual temperature value ; Actual value of HCl concentration at the final chimney outlet and actual SO2 concentration ; S3. According to the deviation between the measured value and the set value, adjust the dosage of the deacidifying agent in stages: First determine whether the actual concentrations of HCl and SO2 at the inlet of the semi-dry reaction tower are less than the set values. If not, ≥ or ≥ , then adjust the injection amount of dry deacidification agent in the furnace; if so, then judge whether the actual value of the concentration of HCl and SO2 at the outlet of the semi-dry reaction tower is less than the set value, if not, that is ≥ or ≥ , then adjust the semi-dry lime slurry injection amount; if so, then determine whether the actual concentration of HCl and SO2 at the chimney outlet is less than the set value, if not, that is ≥ and ≥ , then adjust the amount of alkali solution injected into the wet tower; if so, calculate the load distribution weights of the deacidification units at all levels and dynamically optimize the coordinated operation of the low fly ash collaborative deacidification system.

7. The operation control method of the low fly ash collaborative deacidification system according to claim 6, characterized in that: In step S3, the adjustment amount of the dry deacidification agent in the furnace is IN1 = K1× ( - )+K2×( - ); The adjustment amount of the semi-dry lime slurry IN2 = K3 × ( - )+K4×( - ); The adjustment amount of the wet tower alkali solution IN3 = K5 × ( - )+K6×( - ); where K1, K2, K3, K4, K5, and K6 are adjustment coefficients, ranging from 0.5 to 1.

5.

8. The operation control method of the low fly ash collaborative deacidification system according to claim 6, characterized in that: In step S3, the load distribution weights of the deacidification modules at each level include calculating the regulation requirements of the deacidification modules at each level, namely: ZN1=K7×( - )+K8×( - ); ZN2=K9×( - )+K10×( - ); ZN3=K11×( - )+K12×( - ); Among them, K7, K8, K9, K10, K11, and K12 are adjustment coefficients, ranging from 0.8 to 1.2; Normalizing the weights at all levels, we get: IN4=ZN1 / (ZN1+ZN2+ZN3); IN5=ZN2 / (ZN1+ZN2+ZN3); IN6=ZN3 / (ZN1+ZN2+ZN3).

9. The operation control method of the low fly ash collaborative deacidification system according to claim 8, characterized in that: In step S3, the coordinated operation of the low fly ash coordinated deacidification system is dynamically optimized, specifically: Select IN4 to control the deacidifying agent flow control device to spray the required deacidifying agent dry powder into the incinerator; select IN5 to control the slurry quantity control device to spray the required lime slurry into the semi-dry reaction tower; select IN6 to control the alkali solution flow control device to spray the required amount of alkali solution into the wet process tower.

10. The operation control method of the low fly ash collaborative deacidification system according to claim 8, characterized in that: Also includes: S4. Train a neural network model based on historical operating data to predict pollutant concentration trends in real time; S5. When the predicted value exceeds the set value, adjust the amount of deacidification agent in advance, specifically: If the predicted chimney outlet HCl or SO2 concentration will exceed the set value in the next 5 minutes, deacidification agent will be added in increments of 1.2 times the weights IN4, IN5, and IN6; If the predicted concentration will be lower than the set value in the next 10 minutes, the dosage will be reduced by 0.8 times the weights IN4, IN5, and IN6.

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