A waste incineration flue gas purification treatment system and a purification method thereof

Abstract

The application discloses a garbage incineration flue gas purification treatment system and a purification method thereof, and relates to the field of garbage incineration. The system comprises a plasma decomposition unit, a bag filter unit, an oxidation absorption unit and a membrane separation unit which are sequentially connected. The original flue gas is subjected to high-voltage discharge degradation of dioxin and oxidation modification of heavy metals by the plasma. The bag filter unit intercepts particulate matters through a filter cake layer. The oxidation absorption unit removes NOx and SOx by using a chlorine dioxide solution. The membrane separation unit performs filtration, sorting and in-situ electrolysis regeneration on the circulating liquid, so that the chlorine dioxide solution can be reused. The central control unit dynamically adjusts the discharge power and the amount of the chlorine dioxide solution based on multi-source sensor array data, a feedforward prediction model and a cost-optimal model, so that the operation cost of the system is significantly reduced. The application realizes reasonable use of resources in the purification treatment process of the flue gas.

Description

Technical Field

[0001] This invention relates to the field of waste incineration, specifically to a waste incineration flue gas purification system and purification method. Background Technology

[0002] Currently, the purification of flue gas from waste incineration generally adopts a semi-dry process using calcium hydroxide solution as the absorbent. In this process, lime slurry is transported to the top of the spray drying absorption tower and atomized and sprayed into the tower through nozzles. The water in the lime slurry evaporates under the high temperature of the flue gas, and the solid waste residue produced by the reaction is discharged from the bottom of the tower. The flue gas carrying a large amount of particulate matter is discharged from the absorption tower and then enters a bag filter for further treatment.

[0003] In existing technologies, the flue gas from waste incineration generates a large amount of solid waste residue during the purification process. This waste residue cannot be reused, resulting in serious resource waste. Summary of the Invention

[0004] This invention provides a waste incineration flue gas purification system and purification method to solve the problem that the solid waste residue generated during the purification process of flue gas in the prior art cannot be utilized as a resource.

[0005] This invention is achieved through the following technical solution:

[0006] A waste incineration flue gas purification and treatment system includes:

[0007] The plasma decomposition unit is used to receive the raw flue gas, use plasma generated by high-voltage discharge to degrade the dioxins in the raw flue gas, and oxidize and modify the gaseous heavy metals in the raw flue gas to obtain the first flue gas.

[0008] The bag filter unit is connected to the plasma decomposition unit; the bag filter unit is used to intercept solid particulate matter with a particle size larger than the filtration threshold in the first flue gas through the filter cake layer to obtain the second flue gas;

[0009] An oxidation absorption unit is connected to the bag filter unit; the oxidation absorption unit is used to inject chlorine dioxide solution into the second flue gas for oxidation absorption to remove NO from the second flue gas. X and SO X The oxidation absorption unit outputs circulating liquid at the bottom and target flue gas at the top.

[0010] A membrane separation unit is connected to the oxidation absorption unit; the membrane separation unit is used for filtering, membrane sorting and electrolytic regeneration of the circulating liquid to obtain a chlorine dioxide solution and transport it to the oxidation absorption unit;

[0011] Multi-source sensor array for collecting real-time operating condition data;

[0012] The central control unit is electrically connected to all the aforementioned units, and the multi-source sensor array is signal-connected to the central control unit. The central control unit has an embedded optimal dosing cost model, which adjusts the power of the plasma decomposition unit and the amount of chlorine dioxide solution sprayed by the oxidation absorption unit based on the real-time operating data.

[0013] Preferably, the multi-source sensor array includes:

[0014] A feedforward flue gas analyzer, installed at the flue outlet of a waste incinerator, is used to monitor NO in the raw flue gas in real time. X SO X and the concentration of HCl;

[0015] A redox potential sensor is installed on the circulation pipeline connecting the oxidation absorption unit and the membrane separation unit to detect the redox potential value of the circulating liquid.

[0016] Filter cake thickness sensor; the bag filter unit includes a filter bag, and the filter cake thickness sensor is disposed inside the bag filter unit and is used to detect the dust thickness on the surface of the filter bag;

[0017] The feedforward flue gas analyzer, the redox potential sensor, and the filter cake thickness sensor are all connected to the central control unit via signal transmission.

[0018] Preferably, it also includes a heat recovery unit, which is disposed between the waste incinerator and the plasma decomposition unit;

[0019] The heat recovery unit is equipped with a heat exchanger and a collection tank. The heat exchanger is used to recover the heat of the original flue gas through the heat exchange medium. The collection tank is used to collect the initial acid liquid generated by condensation during the cooling process of the original flue gas. The collection tank is connected to the membrane separation unit.

[0020] Preferably, it also includes a reheating unit; the reheating unit is connected to the outlet of the oxidation absorption unit, and the reheating unit is connected to the heat recovery unit through a heat medium circulation pipeline. The reheating unit uses the waste heat collected by the heat recovery unit to reheat the target flue gas discharged from the oxidation absorption unit, so that the target flue gas reaches the preset emission temperature.

[0021] Preferably, the oxidation absorption unit includes:

[0022] The absorption tower body includes an inner shell and an outer shell nested together. The bottom of the inner shell is connected to the bag filter unit through an air inlet channel passing through the outer shell. An accommodating chamber is provided between the upper end of the inner shell and the outer shell.

[0023] A flow guiding mechanism is disposed inside the inner shell and is used to guide the flue gas to form an upward vortex;

[0024] A reaction chamber is disposed on the outer shell and communicates with the upper end of the inner shell; the reaction chamber is provided with an injector for aiming at the rising flue gas, the injector being used to spray chlorine dioxide solution;

[0025] The discharge channel includes an exhaust channel and a liquid discharge channel. The exhaust channel is connected to the top of the reaction chamber. One end of the liquid discharge channel is connected to the bottom of the reaction chamber, and the other end of the liquid discharge channel is connected to the membrane separation unit.

[0026] Preferably, the membrane separation unit includes:

[0027] The pretreatment module is used to remove suspended solids and heavy metal flocculants from the circulating liquid to obtain a pretreated solution.

[0028] A membrane sorting module is used to separate the pretreatment solution into an enriched solution containing industrial salt and a regenerated solution containing chloride ions.

[0029] The electrolytic regeneration module is used to convert chloride ions in the liquid to be regenerated into chlorine dioxide solution through electrode reactions;

[0030] A circulation module is used to deliver chlorine dioxide solution to the oxidation absorption unit.

[0031] The present invention also provides a method for purifying flue gas from waste incineration, employing a waste incineration flue gas purification system as described in any of the above claims, comprising the following steps:

[0032] S710: Using a multi-source sensor array, real-time operating condition data is collected and transmitted to the central control unit; the real-time operating condition data includes the concentration of each component of the original flue gas, the oxidation-reduction potential of the circulating liquid, and the dust thickness on the surface of the filter bag.

[0033] S720. The central control unit uses a feedforward prediction model to predict the flue gas load change trend in the future period based on the real-time operating data, and adjusts the discharge power of the plasma decomposition unit based on the flue gas load change trend.

[0034] S730. The original flue gas is introduced into the plasma decomposition unit, and the plasma generated by the high-voltage discharge is used to degrade the dioxins in the original flue gas and oxidize and modify the gaseous heavy metals in the original flue gas into a captureable form to obtain the first flue gas.

[0035] S740. The central control unit dynamically adjusts the cleaning frequency and pulse intensity of the bag filter unit based on the real-time operating data and using adaptive cleaning logic.

[0036] S750. The first flue gas is introduced into the bag filter unit to intercept the dust particles therein and obtain the second flue gas.

[0037] S760. The central control unit calculates the optimal dosage of chlorine dioxide solution based on the real-time operating data and the optimal dosage cost model, and generates the corresponding dosage control command.

[0038] S770. The second flue gas is introduced into the oxidation absorption unit; the central control unit, according to the dosing control command, controls the oxidation absorption unit to inject chlorine dioxide solution into the second flue gas to remove NO. X and SO X The purified target flue gas is obtained, and a circulating liquid rich in reaction products is generated.

[0039] S780. The circulating liquid is transported to the membrane separation unit for filtration and membrane separation in sequence to produce industrial salt and chlorine-containing byproducts.

[0040] S790 and the central control unit synchronously adjust the electrolytic regeneration current of the membrane separation unit according to the optimal dosage, so as to regenerate the chlorine-containing byproducts in situ into chlorine dioxide solution and transport it to the oxidation absorption unit.

[0041] Preferably, in step S720, the step of using a feedforward prediction model to predict the trend of flue gas load changes in future periods includes:

[0042] S810. Using a feedforward flue gas analyzer, the component concentration change gradient of the flue gas and the flue gas velocity are obtained, and the load evolution curve within the prediction time window is calculated in combination with the real-time flue gas velocity.

[0043] S820. Based on the physical distance between the plasma decomposition unit and the feedforward flue gas analyzer and the flue gas velocity, the transmission delay t is calculated using the central control unit.

[0044] S830. Based on the load evolution curve, the discharge power of the plasma decomposition unit is adjusted in advance by the central control unit at time t, so that the plasma energy density generated by the high-voltage discharge is aligned with the peak value of the flue gas load in real time in spatial position.

[0045] Preferably, the adaptive dust removal logic is the following linear model:

[0046] P = C1 * ΔP + C2 * δ + C3

[0047] Where P represents the optimal pulse jet pressure; C1 represents the differential pressure contribution coefficient; ΔP represents the real-time differential pressure; C2 represents the filter cake thickness contribution coefficient; δ represents the real-time filter cake thickness; and C3 represents the basic jet pressure.

[0048] Preferably, the optimal model for the addition cost is:

[0049]

[0050] Where λ1 is the cost item weighting coefficient; C i λ represents the sum of ClO2 reagent dosage cost and system energy consumption cost at time i; λ2 is the weighting coefficient of the emission penalty term; L i Let L be the predicted emission concentration of pollutants at time i; X These are the preset emission standard limits.

[0051] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0052] 1. The plasma decomposition unit utilizes plasma generated by high-voltage discharge to break the dioxin structure at the molecular level, achieving efficient degradation of highly toxic substances; it can also oxidize gaseous heavy metals in the original flue gas in order to capture heavy metals.

[0053] 2. The membrane separation unit can filter, membrane sort, and electrolyze the reactants produced by the oxidation absorption unit to obtain a reusable chlorine dioxide solution, thus realizing the rational use of resources.

[0054] 3. The central control unit has an embedded optimal dosing cost model, which can dynamically adjust the discharge power and the amount of chlorine dioxide solution added based on real-time operating data fed back by sensors, significantly reducing the system's operating costs. Attached Figure Description

[0055] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0056] Figure 1 This is a schematic diagram of the structure of a waste incineration flue gas purification system according to a specific embodiment of the present invention;

[0057] Figure 2 This is a schematic diagram of the structure of the oxidation absorption unit in a specific embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of the structure of the heat recovery unit in a specific embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of the structure of the regenerative unit in a specific embodiment of the present invention;

[0060] Figure 5 This is a flowchart of a waste incineration flue gas purification method according to a specific embodiment of the present invention.

[0061] The attached diagram shows the markings and corresponding component names:

[0062] 10. Plasma decomposition unit; 20. Bag filter unit; 210. Filter bag; 30. Oxidation absorption unit; 310. Outer shell; 320. Inner shell; 330. Spiral blades; 340. Guide channel; 350. Reaction chamber; 360. Ejector; 370. Air inlet channel; 380. Exhaust channel; 390. Liquid discharge channel; 40. Membrane separation unit; 50. Heat recovery unit; 510. Heat recovery tank; 520. Mounting plate; 530. Flow pipe; 540. Baffle plate; 550. U-tube; 60. Regeneration unit; 610. Regeneration tank; 620. Flat plate finned heat exchanger. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for explaining the invention only and are not intended to limit the invention. In the description of this application, it should be understood that terms such as "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "high," "low," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They 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 limiting the scope of protection of this application.

[0064] Example 1:

[0065] refer to Figures 1-5 A waste incineration flue gas purification and treatment system, comprising:

[0066] The plasma decomposition unit 10 is used to receive the original flue gas, use the plasma generated by high voltage discharge to degrade the dioxins in the original flue gas, and oxidize and modify the gaseous heavy metals in the original flue gas to obtain the first flue gas.

[0067] The bag filter unit 20 is connected to the plasma decomposition unit 10; the bag filter unit 20 is used to intercept solid particles with a particle size larger than the filtration threshold in the first flue gas through the filter cake layer to obtain the second flue gas.

[0068] The oxidation absorption unit 30 is connected to the bag filter unit 20; the oxidation absorption unit 30 is used to inject chlorine dioxide solution into the second flue gas for oxidation absorption to remove NO from the second flue gas. Xand SO X The bottom of the oxidation absorption unit 30 outputs circulating liquid, and the top outputs the target flue gas.

[0069] The membrane separation unit 40 is connected to the oxidation absorption unit 30; the membrane separation unit 40 is used to filter, separate and electrolyze the circulating liquid to obtain chlorine dioxide solution and transport it to the oxidation absorption unit 30.

[0070] Multi-source sensor array for collecting real-time operating condition data;

[0071] The central control unit is electrically connected to all the above units, and the multi-source sensor array is signal connected to the central control unit. The central control unit has an embedded optimal dosing cost model, which adjusts the power of the plasma decomposition unit 10 and the amount of chlorine dioxide solution sprayed by the oxidation absorption unit 30 according to real-time operating data.

[0072] After the raw flue gas enters the plasma decomposition unit 10, the high-energy electrons generated by the plasma decomposition unit 10 undergo inelastic collisions with the flue gas molecules, impacting H2O and O2 molecules in the flue gas and generating a large number of free radicals, such as ·OH and O·. These free radicals can directly attack the carbon-oxygen bonds or carbon-chlorine bonds in the molecular chain of dioxins, oxidizing them into CO2, H2O, and HCl. At the same time, gaseous heavy metals that are difficult to capture in the flue gas, such as Hg, are also affected. 0 Under the influence of the plasma energy field, the gaseous heavy metals undergo charging or oxidation, transforming them into easily sedimentable oxides. At this point, the flue gas discharged from the plasma decomposition unit 10 is the first flue gas, in which dioxins are effectively removed. The first flue gas then enters the bag filter unit 20, which removes particles larger than the filtration threshold, thus producing the second flue gas, which contains NO. X and SO X When the second flue gas enters the oxidation absorption unit 30, the oxidation absorption unit 30 will spray a highly oxidizing chlorine dioxide solution directly onto the second flue gas. The chlorine dioxide will react with the NO. X and SO XOxidation occurs; for example, NO in the second flue gas reacts with chlorine dioxide solution to form HNO3, and SO2 reacts with chlorine dioxide solution to form H2SO4. These reactants, HNO3 and H2SO4, drip down to the bottom of the oxidation absorption unit 30, forming a circulating liquid. The purified target flue gas can then be discharged from the top of the oxidation unit. After entering the membrane separation unit 40, the circulating liquid undergoes several processes, including filtration, membrane sorting, and electrolytic regeneration. Finally, the membrane separation unit 40 produces chlorine dioxide solution, which is then transported to the oxidation absorption unit 30, thus achieving resource reuse. During the flue gas purification process, a multi-source sensor array can monitor the operating data of the waste incineration flue gas purification system in real time. The central control unit can use this operating data and an optimal addition cost model to adjust the power of the plasma decomposition unit 10 and the amount of chlorine dioxide solution injected by the oxidation absorption unit 30. This ensures that the target flue gas meets emission standards while maintaining a low operating cost for the waste incineration flue gas purification system, thereby achieving energy savings.

[0073] In the plasma decomposition unit 10, O· combines with O2 to generate O3, which can further oxidize organic matter and Hg in the flue gas. 0 .

[0074] In this embodiment, the plasma decomposition unit 10 can be a dielectric barrier discharge structure, which is a prior art, so its specific structure will not be described in detail here.

[0075] The multi-source sensor array includes:

[0076] A feedforward flue gas analyzer, installed at the flue outlet of a waste incinerator, is used to monitor NO in the raw flue gas in real time. X SO X and the concentration of HCl;

[0077] A redox potential sensor is installed on the circulation pipeline connecting the oxidation absorption unit 30 and the membrane separation unit 40 to detect the redox potential value of the circulating liquid.

[0078] Filter cake thickness sensor; The bag filter unit 20 includes a filter bag 210, and the filter cake thickness sensor is installed inside the bag filter unit 20 and is used to detect the dust thickness on the surface of the filter bag 210.

[0079] The feedforward flue gas analyzer, redox potential sensor, and filter cake thickness sensor are all connected to the central control unit.

[0080] The feedforward flue gas analyzer can be an integrated infrared analyzer, which can be used to monitor NO in raw flue gas. X SO X In addition to monitoring the concentration of HCl, it can also monitor the real-time flow rate of flue gas. The central control unit can adjust the flow rate based on pollutants (NOx, HCl, etc.).X SO X Calculate the pollutant load by taking the concentration and flow rate of HCl.

[0081] The oxidation-reduction potential sensor can be an ORP sensor, which can detect the oxidation-reduction potential of the circulating liquid in real time. The circulating liquid is rich in reactants such as H2SO4, HNO3, and H2SO4. The oxidizing power of the circulating liquid is low. When NO in the flue gas... X When the load increases, the content of reactants in the circulating liquid increases, which reduces the activity of the circulating liquid. At this time, the redox potential sensor can detect the decrease in the potential of the circulating liquid and transmit a signal to the central control unit. The central control unit increases the injection volume of chlorine dioxide solution based on the signal.

[0082] The filter cake thickness sensor can be a laser sensor. The filter cake thickness sensor uses the photoelectric reflection principle to detect the dust accumulation depth on the surface of the filter bag 210.

[0083] The multi-source sensor array also includes a differential pressure transmitter connected to the central control unit. In this embodiment, the inlet flue of the bag filter unit 20 is provided with a high-pressure end pressure tap, and the outlet flue of the bag filter unit 20 is provided with a low-pressure end pressure tap. The pressure from the high-pressure end pressure tap and the low-pressure end pressure tap are respectively guided to the differential pressure transmitter through pipelines, thereby detecting the differential pressure within the bag filter unit 20. The differential pressure transmitter can transmit the differential pressure signal to the central control unit. The central control unit implements adaptive cleaning logic based on the differential pressure and the filter cake thickness.

[0084] The waste incineration flue gas purification and treatment system also includes a heat recovery unit 50, which is located between the waste incinerator and the plasma decomposition unit 10.

[0085] The heat recovery unit 50 is equipped with a heat exchanger and a collection tank. The heat exchanger is used to recover the heat of the original flue gas through the heat exchange medium. The collection tank is used to collect the initial acid liquid generated by condensation during the cooling process of the original flue gas. The collection tank is connected to the membrane separation unit 40.

[0086] In this embodiment, the heat recovery unit 50 may include a heat recovery tank 510; the heat exchanger may include two mounting plates 520, multiple flow pipes 530, and multiple partitions 540; the two mounting plates 520 are fixed inside the heat recovery tank 510 and divide the inner cavity of the heat recovery tank 510 into a first chamber, a second chamber, and a third chamber from top to bottom; the two ends of the flow pipe 530 are respectively disposed on a mounting plate 520, the upper end of the flow pipe 530 is connected to the first chamber, and the lower end of the flow pipe 530 is connected to the third chamber.

[0087] The raw flue gas enters from the third chamber, passes through the flow pipe 530, and exits from the first chamber. The second chamber can be filled with a heat exchange medium, which can be heat transfer oil. The second chamber is connected to the regeneration unit 60 via a pipe, and a pump can be installed on the pipe to facilitate the flow of the heat transfer oil within it. A drain port can be installed above the second chamber, and an inlet port can be installed below it. Multiple baffles 540 can be installed within the second chamber, located on both sides of the axis of the heat recovery tank 510 and arranged alternately. This ensures that the heat transfer oil follows an S-shaped path from the inlet to the drain port, increasing the path length of the heat transfer oil and facilitating heat exchange between the flue gas and the heat transfer oil.

[0088] After the raw flue gas passes through the flow pipe 530, the temperature drops sharply. The water vapor and strong acidic substances in the flue gas will condense, and the resulting preliminary acid solution will be collected in the collection tank, which is the bottom of the third chamber. The preliminary acid solution is rich in chloride ions and can be directly transported to the membrane separation unit 40 through the pipeline as an electrolysis feedstock.

[0089] The lower end of the third chamber is connected to a U-shaped pipe 550 for water sealing, preventing the original flue gas from being discharged from the U-shaped pipe 550.

[0090] The waste incineration flue gas purification and treatment system also includes a reheat unit 60; the reheat unit 60 is connected to the outlet of the oxidation absorption unit 30, and the reheat unit 60 is connected to the heat recovery unit 50 through a heat medium circulation pipeline (not shown in the figure). The reheat unit 60 uses the waste heat collected by the heat recovery unit 50 to heat up and reheat the target flue gas discharged from the oxidation absorption unit 30, so that the target flue gas reaches the preset emission temperature.

[0091] The regenerative unit 60 may include a regenerative tank 610 and a flat-fin heat exchanger 620. The flat-fin heat exchanger 620 is located inside the regenerative tank 610 and is connected to the heat recovery unit 50 through a heat medium circulation pipeline. The air inlet of the regenerative tank 610 is connected to the outlet of the oxidation absorption unit 30. The temperature of the flue gas discharged from the oxidation absorption unit 30 drops to near the dew point, and the humidity is extremely high. Direct discharge would produce "white smoke" at the chimney outlet. However, after the flue gas is heated by the flat-fin heat exchanger 620 inside the regenerative tank 610, the humidity of the flue gas can be reduced, the "white smoke" phenomenon can be eliminated, the rise height of the flue gas after being discharged into the atmosphere can be increased, and the conditions for pollutant diffusion can be improved.

[0092] Oxidation absorption unit 30 includes:

[0093] The absorption tower body includes an inner shell 320 and an outer shell 310 nested inside and outside. The bottom of the inner shell 320 is connected to the bag filter unit 20 through an air inlet channel 370 passing through the outer shell 310. An accommodating chamber is provided between the upper end of the inner shell 320 and the outer shell 310.

[0094] A flow guiding mechanism is located inside the inner shell 320 and is used to guide the flue gas to form an upward vortex;

[0095] The reaction chamber 350 is disposed on the outer shell 310 and communicates with the upper end of the inner shell 320; the reaction chamber 350 is provided with an injector 360 for aiming at the rising flue gas, and the injector 360 is used to spray chlorine dioxide solution.

[0096] The discharge channel includes an exhaust channel 380 and a liquid discharge channel 390. The exhaust channel 380 is connected to the top of the reaction chamber 350. One end of the liquid discharge channel 390 is connected to the bottom of the reaction chamber 350, and the other end of the liquid discharge channel 390 is connected to the membrane separation unit 40.

[0097] In this embodiment, the second flue gas enters the lower part of the inner shell 320 through the inlet channel 370. Under the action of the guide mechanism, the second flue gas rises and forms a vortex, increasing its flow velocity. When the high-speed second flue gas flows into the lower part of the reaction chamber 350, the injector 360 sprays chlorine dioxide solution into the reaction chamber 350. The injector 360 can be located at the upper end of the reaction chamber 350, allowing the chlorine dioxide solution to flow counter-currently and collide with the second flue gas, ensuring full contact. The chlorine dioxide will react with the NO in the second flue gas. X and SO X Oxidation occurs; for example, NO in the second flue gas reacts with chlorine dioxide solution to form HNO3, and SO2 reacts with chlorine dioxide solution to form H2SO4. These reactants, HNO3 and H2SO4, are discharged from the drain channel 390 with droplets and transported to the membrane separation unit 40. The purified target flue gas enters the exhaust channel 380 from the upper end of the reaction chamber 350.

[0098] The flow guiding mechanism may include a spiral blade 330 and a flow guiding groove 340. The upper end of the inner shell 320 is a funnel shape with a gradually narrowing opening. The flow guiding groove 340 is located on the inner wall of the funnel of the inner shell 320. The second flue gas is first guided by the spiral blade 330 in the inner shell 320 to form a vortex. The flow guiding groove 340 further guides the vortex, so that the second flue gas has a larger flow velocity when it enters the reaction chamber 350.

[0099] Membrane separation unit 40 includes:

[0100] The pretreatment module is used to remove suspended solids and heavy metal flocculants from the circulating liquid to obtain a pretreated solution.

[0101] The membrane separation module is used to separate the pretreatment solution into an enriched solution containing industrial salt and a regenerated solution containing chloride ions.

[0102] The electrolytic regeneration module is used to convert chloride ions in the liquid to be regenerated into chlorine dioxide solution through electrode reactions;

[0103] The circulation module is used to transport the chlorine dioxide solution to the oxidation absorption unit 30.

[0104] In this embodiment, the circulating liquid generated by the oxidation absorption unit 30 first enters the pretreatment module. The pretreatment module may include a multi-media filter, such as a quartz sand and activated carbon layer, to remove suspended particles in the circulating liquid. The pretreatment module may also include a heavy metal trap, which is filled with sulfide functionalized resin to adsorb heavy metal flocculants in the circulating liquid, and finally obtain a pretreated solution.

[0105] The pretreatment solution then enters the membrane separation module, which may include an acid-resistant nanofiltration membrane and a reverse osmosis membrane. The membrane separation module uses the principles of charge selectivity and pore size sieving to separate the pretreatment solution into an enriched solution containing industrial salt and a regenerated solution containing chloride ions.

[0106] Then, the liquid to be regenerated enters the electrolytic regeneration module, which may include a membrane electrolyzer and a chlorine dioxide synthesizer; the central control unit controls the electrolytic regeneration module to electrolyze the liquid to be regenerated, so that the chloride ions in the liquid to be regenerated undergo an oxidation reaction and are converted back into chlorine dioxide, thereby forming a chlorine dioxide solution; the circulation module then sends the chlorine dioxide solution back to the oxidation absorption unit 30.

[0107] The present invention also provides a method for purifying flue gas from waste incineration, employing a waste incineration flue gas purification system as described above, comprising the following steps:

[0108] S710 uses a multi-source sensor array to collect real-time operating data and transmits the real-time operating data to the central control unit; the real-time operating data includes the concentration of each component of the original flue gas, the oxidation-reduction potential of the circulating liquid, and the dust thickness on the surface of the filter bag 210.

[0109] The concentrations of each component in the raw flue gas can be detected using a feedforward flue gas analyzer, specifically, the NO content in the raw flue gas can be detected. X SO X And the concentration of HCl.

[0110] The redox potential of the circulating fluid can be detected by a redox potential sensor.

[0111] The dust thickness on the surface of the filter bag 210 can be detected by a filter cake thickness sensor installed in the bag dust collection unit 20.

[0112] S720 and the central control unit use a feedforward prediction model to predict the flue gas load change trend in the future based on real-time operating data, and adjust the discharge power of the plasma decomposition unit 10 based on the flue gas load change trend.

[0113] Predicting future flue gas load trends using feedforward forecasting models includes:

[0114] S810: Using a feedforward flue gas analyzer, the component concentration change gradient of the flue gas and the flue gas velocity are obtained, and the load evolution curve within the prediction time window is calculated in combination with the real-time flue gas velocity.

[0115] Pollutant load = pollutant flow rate * pollutant concentration.

[0116] S820. Based on the physical distance d between the plasma decomposition unit 10 and the feedforward flue gas analyzer and the flue gas velocity v, the transmission delay t is calculated using the central control unit, t=d / v.

[0117] S830. Based on the load evolution curve, the discharge power of the plasma decomposition unit 10 is adjusted in advance by the central control unit at time t, so that the plasma energy density generated by the high-voltage discharge is aligned with the peak value of the flue gas load in real time in spatial position.

[0118] S730. The original flue gas is introduced into the plasma decomposition unit 10. The plasma generated by high-voltage discharge degrades the dioxins in the original flue gas and oxidizes and modifies the gaseous heavy metals in the original flue gas into a captureable form to obtain the first flue gas.

[0119] The high-energy electrons generated by the plasma decomposition unit 10 undergo inelastic collisions with flue gas molecules, impacting H2O and O2 molecules in the flue gas and generating a large number of free radicals, such as ·OH and O·. These free radicals can directly attack the carbon-oxygen bonds or carbon-chlorine bonds in the dioxin molecular chain, oxidizing it into CO2, H2O, and HCl. Simultaneously, gaseous heavy metals that are difficult to capture in the flue gas, such as Hg, are also affected. 0 Under the influence of the plasma energy field, it will become charged or oxidized, transforming gaseous heavy metals into oxide forms that are easy to settle.

[0120] Between steps S720 and S730, the original flue gas can be introduced into the heat recovery unit 50, and the heat exchanger inside the heat recovery unit 50 can be used to recover the heat of the original flue gas. During the cooling process, the initial acid liquid generated by condensation is discharged from the lower end of the heat recovery unit 50 and can be used to transport it to the membrane separation unit 40.

[0121] S740 and the central control unit dynamically adjust the cleaning frequency and pulse intensity of the bag filter unit 20 based on real-time operating data and adaptive cleaning logic.

[0122] The adaptive dust removal logic follows a linear model:

[0123] P = C1 * ΔP + C2 * δ + C3

[0124] Where P represents the optimal pulse jet pressure; C1 represents the differential pressure contribution coefficient; ΔP represents the real-time differential pressure; C2 represents the filter cake thickness contribution coefficient; δ represents the real-time filter cake thickness; and C3 represents the basic jet pressure.

[0125] △P can be obtained by detecting a differential pressure transmitter.

[0126] When the ΔP of a certain compartment in the bag filter unit 20 exceeds the preset threshold (e.g., 1200Pa) for 10 seconds or the δ exceeds the safe thickness (e.g., 15mm), the cleaning procedure for that compartment is triggered. At this time, the central control unit sends a command to the pulse valve control circuit of that compartment, sets the blowing pressure of this cleaning to the calculated value P, the pulse valve opens and compressed air is injected into the filter bag 210 at pressure P for a certain period of time in order to complete the cleaning.

[0127] In this embodiment, the bag dust collection unit 20 can be a bag dust collector, which belongs to the prior art, and its specific structure will not be described in detail here.

[0128] S750. The first flue gas is introduced into the bag filter unit 20 to intercept the dust particles and obtain the second flue gas.

[0129] Based on real-time operating data, the S760 and central control unit use the optimal dosage model to calculate the optimal dosage of chlorine dioxide solution and generate corresponding dosage control commands.

[0130] The optimal model for adding costs is:

[0131]

[0132] Where λ1 is the cost item weighting coefficient; C i λ represents the sum of ClO2 reagent dosage cost and system energy consumption cost at time i; λ2 is the weighting coefficient of the emission penalty term; L i Let L be the predicted emission concentration of pollutants at time i; X These are the preset emission standard limits.

[0133] S770, The second flue gas is introduced into the oxidation absorption unit 30; the central control unit, according to the dosing control command, controls the oxidation absorption unit 30 to inject chlorine dioxide solution into the second flue gas to remove NO. X and SO X The purified target flue gas is obtained, and a circulating liquid rich in reaction products is generated.

[0134] After step S770, the target flue gas can be introduced into the reheat unit 60, and the residual heat collected by the heat recovery unit 50 can be used to heat up and reheat the target flue gas discharged from the oxidation absorption unit 30, so that the target flue gas reaches the preset emission temperature.

[0135] S780: The circulating liquid is transported to the membrane separation unit 40, where it is filtered and separated by membrane to produce industrial salt and chlorine-containing byproducts.

[0136] S790 and the central control unit synchronously adjust the electrolytic regeneration current of the membrane separation unit 40 according to the optimal dosage, so as to regenerate the chlorine-containing byproducts in situ into chlorine dioxide solution and transport it to the oxidation absorption unit 30.

[0137] It should be noted that some steps in steps S710-S790 above have already been described in the embodiments of the waste incineration flue gas purification system, so some steps have not been repeated. For details, please refer to the embodiments of the waste incineration flue gas purification system above.

[0138] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0139] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Additionally, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

Claims

1. A waste incineration flue gas purification and treatment system, characterized in that, include: The plasma decomposition unit is used to receive the raw flue gas, use plasma generated by high-voltage discharge to degrade the dioxins in the raw flue gas, and oxidize and modify the gaseous heavy metals in the raw flue gas to obtain the first flue gas. The bag filter unit is connected to the plasma decomposition unit; the bag filter unit is used to intercept solid particulate matter with a particle size larger than the filtration threshold in the first flue gas through the filter cake layer to obtain the second flue gas; An oxidation absorption unit is connected to the bag filter unit; the oxidation absorption unit is used to inject chlorine dioxide solution into the second flue gas for oxidation absorption to remove NO from the second flue gas. X and SO X The oxidation absorption unit outputs circulating liquid at the bottom and target flue gas at the top. A membrane separation unit is connected to the oxidation absorption unit; the membrane separation unit is used for filtering, membrane sorting and electrolytic regeneration of the circulating liquid to obtain a chlorine dioxide solution and transport it to the oxidation absorption unit; Multi-source sensor array for collecting real-time operating condition data; The central control unit is electrically connected to all the above-mentioned units, and the multi-source sensor array is signal-connected to the central control unit. The central control unit has an embedded optimal dosing cost model, which adjusts the power of the plasma decomposition unit and the amount of chlorine dioxide solution sprayed by the oxidation absorption unit according to the real-time operating data. It also includes a heat recovery unit, which is located between the waste incinerator and the plasma decomposition unit; The heat recovery unit is equipped with a heat exchanger and a collection tank. The heat exchanger is used to recover the heat of the original flue gas through the heat exchange medium. The collection tank is used to collect the initial acid liquid generated by condensation during the cooling process of the original flue gas. The collection tank is connected to the membrane separation unit. The membrane separation unit includes: The pretreatment module is used to remove suspended solids and heavy metal flocculants from the circulating liquid to obtain a pretreated solution. A membrane sorting module is used to separate the pretreatment solution into an enriched solution containing industrial salt and a regenerated solution containing chloride ions. The electrolytic regeneration module is used to convert chloride ions in the liquid to be regenerated into chlorine dioxide solution through electrode reactions; A circulation module is used to deliver chlorine dioxide solution to the oxidation absorption unit.

2. The waste incineration flue gas purification system according to claim 1, characterized in that, The multi-source sensor array includes: A feedforward flue gas analyzer, installed at the flue outlet of a waste incinerator, is used to monitor NO in the raw flue gas in real time. X SO X and the concentration of HCl; A redox potential sensor is installed on the circulation pipeline connecting the oxidation absorption unit and the membrane separation unit to detect the redox potential value of the circulating liquid. Filter cake thickness sensor; the bag filter unit includes a filter bag, and the filter cake thickness sensor is disposed inside the bag filter unit and is used to detect the dust thickness on the surface of the filter bag; The feedforward flue gas analyzer, the redox potential sensor, and the filter cake thickness sensor are all connected to the central control unit via signal transmission.

3. The waste incineration flue gas purification system according to claim 2, characterized in that, It also includes a reheating unit; the reheating unit is connected to the outlet of the oxidation absorption unit, and the reheating unit is connected to the heat recovery unit through a heat medium circulation pipeline. The reheating unit uses the waste heat collected by the heat recovery unit to reheat the target flue gas discharged from the oxidation absorption unit, so that the target flue gas reaches the preset emission temperature.

4. The waste incineration flue gas purification system according to claim 1, characterized in that, The oxidation absorption unit includes: The absorption tower body includes an inner shell and an outer shell nested together. The bottom of the inner shell is connected to the bag filter unit through an air inlet channel passing through the outer shell. An accommodating chamber is provided between the upper end of the inner shell and the outer shell. A flow guiding mechanism is disposed inside the inner shell and is used to guide the flue gas to form an upward vortex; A reaction chamber is disposed on the outer shell and communicates with the upper end of the inner shell; the reaction chamber is provided with an injector for aiming at the rising flue gas, the injector being used to spray chlorine dioxide solution; The discharge channel includes an exhaust channel and a liquid discharge channel. The exhaust channel is connected to the top of the reaction chamber. One end of the liquid discharge channel is connected to the bottom of the reaction chamber, and the other end of the liquid discharge channel is connected to the membrane separation unit.

5. A method for purifying flue gas from waste incineration, employing the waste incineration flue gas purification system as described in any one of claims 1-4, characterized in that, Includes the following steps: S710: Using a multi-source sensor array, real-time operating condition data is collected and transmitted to the central control unit; the real-time operating condition data includes the concentration of each component of the original flue gas, the oxidation-reduction potential of the circulating liquid, and the dust thickness on the surface of the filter bag. S720. The central control unit uses a feedforward prediction model to predict the flue gas load change trend in the future period based on the real-time operating data, and adjusts the discharge power of the plasma decomposition unit based on the flue gas load change trend. S730. The original flue gas is introduced into the plasma decomposition unit, and the plasma generated by the high-voltage discharge is used to degrade the dioxins in the original flue gas and oxidize and modify the gaseous heavy metals in the original flue gas into a captureable form to obtain the first flue gas. S740. The central control unit dynamically adjusts the cleaning frequency and pulse intensity of the bag filter unit based on the real-time operating data and using adaptive cleaning logic. S750. The first flue gas is introduced into the bag filter unit to intercept the dust particles therein and obtain the second flue gas. S760. The central control unit calculates the optimal dosage of chlorine dioxide solution based on the real-time operating data and the optimal dosage cost model, and generates the corresponding dosage control command. S770, The second flue gas is introduced into the oxidation absorption unit; The central control unit, according to the dosing control command, controls the oxidation absorption unit to inject chlorine dioxide solution into the second flue gas to remove NO. X and SO X The purified target flue gas is obtained, and a circulating liquid rich in reaction products is generated. S780. The circulating liquid is transported to the membrane separation unit for filtration and membrane separation in sequence to produce industrial salt and chlorine-containing byproducts. S790. The central control unit synchronously adjusts the electrolytic regeneration current of the membrane separation unit according to the optimal dosage, regenerates the chlorine-containing byproduct in situ into a chlorine dioxide solution, and delivers it to the oxidation absorption unit.

6. The method for purifying flue gas from waste incineration according to claim 5, characterized in that, In step S720, the step of using a feedforward prediction model to predict the trend of flue gas load changes in future periods includes: S810. Using a feedforward flue gas analyzer, the component concentration change gradient of the flue gas and the flue gas velocity are obtained, and the load evolution curve within the prediction time window is calculated in combination with the real-time flue gas velocity. S820. Based on the physical distance between the plasma decomposition unit and the feedforward flue gas analyzer and the flue gas velocity, the transmission delay t is calculated using the central control unit. S830. Based on the load evolution curve, the discharge power of the plasma decomposition unit is adjusted in advance by the central control unit at time t, so that the plasma energy density generated by the high-voltage discharge is aligned with the peak value of the flue gas load in real time in spatial position.

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