1430 results about "Selective catalytic reduction" patented technology

The invention provides an intelligent optimization control method and platform under variable load operation of a coal-fired power plant, and relates to the technical field of intelligent optimization control, and the method comprises the steps: calling historical operation data, carrying out the load trend change analysis, and completing the construction of a control analysis module; analyzing and outputting instantaneous PID control parameters according to the real-time load data; after the instantaneous PID control parameters are switched to, a flue gas emission acquisition module is activated; real-time flue gas emission parameters are obtained; performing denitration control optimization to obtain a real-time PID control parameter, and switching to the real-time PID control parameter; presetting a flue gas emission window, dynamically updating real-time flue gas emission parameters, dynamically updating real-time PID (Proportion Integration Differentiation) control parameters and performing seamless switching control on an SCR (Selective Catalytic Reduction) system. The control method solves the technical problem that when a control method in the prior art is used for dealing with an SCR system, efficient control is difficult to achieve under the dynamically-changing load condition, and then the denitration effect and the system stability are affected.

The invention discloses an intelligent denitration control method and system based on PID (Proportion Integration Differentiation) and Transform. The method comprises the following steps: acquiring an operation parameter sequence of an SCR (Selective Catalytic Reduction) denitration system in real time; a time sequence input into the Transform model and the feature dimension are exchanged to form a reverse Transform model, the predicted outlet NOx concentration is obtained, an ammonia injection amount adjusting value is calculated according to the deviation between the predicted outlet NOx concentration and the target outlet NOx concentration, the opening degree of an ammonia injection valve is adjusted in real time, and the reverse Transform model is adjusted on line based on the deviation between the actual outlet NOx concentration and the predicted outlet NOx concentration. The method is applied to the field of denitration control, the change trend of the NOx concentration in a period of time in the future can be predicted more accurately, so that the injection amount of ammonia is adjusted in advance, and the lag defect of an original PID controller is effectively overcome.

The invention discloses a two-stage SCR urea injection amount control method, device and equipment, and relates to the technical field of engine exhaust aftertreatment. The method comprises the steps that the real-time working mode of an engine is obtained, and the control mode of a front-stage SCR and the control mode of a rear-stage SCR are determined according to the obtained working mode; on the basis of the determined control mode, the preceding-stage SCR and the post-stage SCR conduct corresponding urea injection amount calculation, and control mode switching is conducted according to the working state of the SCR; wherein the control mode of the front-stage SCR comprises an initial mode, a target efficiency mode and a high-efficiency mode, and the control mode of the rear-stage SCR comprises an initial mode and a high-efficiency mode. According to the method, the coordination control state of the two-stage SCR is determined according to the working mode of the engine, nitrogen oxide emission is more effectively reduced for different working modes, meanwhile, the influence of the DPF state on coordination control of the two-stage SCR is considered, and efficient coordination control over the urea injection amount of the two-stage SCR is achieved.

The invention relates to an SSZ-39 molecular sieve and preparation and application thereof.The preparation method comprises the following steps that 1, after water, an alkali source and a template agent are mixed, mesoporous Y zeolite and a silicon source are added, the mixture is stirred to be uniform, and the mixture is aged to be in a white gel shape; (2) transferring the obtained white gel into a reaction kettle, carrying out crystallization treatment, and filtering, washing, drying and calcining a crystallized product to obtain a Na-SSZ-39 molecular sieve; (3) carrying out ammonium ion exchange on the Na-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain an H-SSZ-39 molecular sieve; and (4) carrying out copper ion exchange on the H-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain the Cu-SSZ-39 catalyst. Aluminum used in the method is provided by mesoporous Y zeolite, the pure-phase SSZ-39 molecular sieve can be synthesized in a wide gel range, the crystallization time is shortened to 24 h, and after copper ion exchange, the pure-phase SSZ-39 molecular sieve shows high denitration activity in the selective catalytic reduction reaction of nitrogen oxide ammonia.

The invention discloses a modeling method for single channels of a selective catalytic reduction reactor, a plurality of SCR single channels are arranged in the reactor, a main channel is surrounded by a catalytic coating, a plurality of pore channels are formed in the catalytic coating, ammonia molecules are adsorbed on active sites of a catalyst, and a selective catalytic reduction reaction is carried out on the active sites of the catalyst. The modeling method comprises the steps that S1, an SCR single-channel mathematical model is established, wherein the SCR single-channel mathematical model comprises a component balance equation, a momentum balance equation and an enthalpy balance equation of a gas phase substance in a main channel, a gas phase component balance equation, an enthalpy balance equation, an NH3 coverage balance equation, a component balance equation of a gas phase-coating interface and a gas enthalpy balance equation; s2, giving an initial condition and a boundary condition, limiting part of unknown parameters, and substituting the parameters into each equation to obtain a closed equation set; the model established by the invention can obtain the nitrogen oxide conversion rate, so that the emission reduction performance of the reactor is evaluated. And the influence of mass transfer limitation and mild aging degree of the catalyst is considered, so that the evaluation is more accurate.

The invention relates to the technical field of environment-friendly emission of coal-fired power plants, and particularly discloses a nitrous oxide emission reduction control system and method for an SCR denitration device. The denitration inlet flue gas parameter monitoring module and the denitration outlet flue gas parameter monitoring module are arranged at an inlet and an outlet of the denitration device; the ammonia spraying flow adjusting device, the denitration ammonia nitrogen mixing device, the catalyst interlayer temperature collecting system and the denitration outlet flue gas parameter monitoring module are sequentially arranged in the denitration device according to the flue gas output direction. The control system further comprises a data analysis and decision module system. The system is used for monitoring and controlling the nitrous oxide emission concentration of a denitration device, optimal process parameters are calculated and set, a control system is input to adjust the chemical reaction component proportion and the reaction temperature, the denitration reaction is promoted to generate nitrogen, the yield of greenhouse gas nitrous oxide is reduced, and nitrous oxide emission reduction control is achieved.

The invention discloses a preparation method of a low-temperature SCR (Selective Catalytic Reduction) catalyst with coke loaded with transition metal oxide. The preparation method comprises the following steps: preparing superfine coal powder; removing mineral substances from the superfine coal powder to obtain ash-removed coal powder; chemically activating the deashed coal powder into an activated coal base; coking the activated coal base to form a coal coke carrier; and preparing a single Fe oxide catalyst and an Fe-Mn composite oxide catalyst which take the coal coke as a carrier. The catalyst is prepared from the coal, so that the utilization value of the coal can be improved, the conversion of the coal from fuel to raw materials can be accelerated, and the pollution of the coal to the environment is reduced. Meanwhile, compared with a noble metal catalyst and coke, the catalyst with the coke carrier prepared by the method disclosed by the invention is lower in price and wide in source, so that the preparation cost of the catalyst can be reduced, and compared with other matrix materials, the coke carrier prepared by the method disclosed by the invention takes superfine pulverized coal coke as a matrix, so that the cost of the catalyst is reduced. The preparation cost is lower, and the pore structure is richer.

The utility model provides a grate-fired furnace SCR denitration catalytic device which comprises a vertical flue, an inclined flue, a transverse flue, an ammonia spraying grid, a static mixer, a guide plate and a catalyst layer, the vertical flue, the inclined flue and the transverse flue are sequentially communicated end to end, a flue gas inlet is formed in the side wall of the vertical flue, and an outlet of the transverse flue is a flue gas outlet; the ammonia spraying grid is fixed on the inner wall of the vertical flue and is connected with an ammonia source, and an air spraying opening of the ammonia spraying grid is arranged upwards; an input port of the static mixer corresponds to the upper part of the air nozzle and is fixed on the inner wall of the vertical flue; the plurality of flow guide plates are arc-shaped plates, are arranged in parallel and are fixed at the joint of the vertical flue and the inclined flue; the SCR denitration catalytic device of the grate-fired furnace belongs to the technical field of SCR denitration, enables flue gas and ammonia gas to be fully mixed, enables a flow field to be uniform, and improves the effect of reducing nitric oxide gas.

The invention provides an ammonia-hydrogen engine aftertreatment device and a control method. The post-treatment device comprises an electric heater, an N2O decomposition catalyst, a selective catalytic reducer, an ammonia trapping catalyst, a sensor and a controller, the electric heater is arranged at the exhaust end of the ammonia-hydrogen engine, is powered and controlled by the controller and is used for heating exhaust of the ammonia-hydrogen engine. An N2O decomposition catalyst, a selective catalytic reducer and an ammonia trapping catalyst are sequentially arranged at the rear end of the electric heater; the sensors comprise three temperature sensors, one NOx sensor and one NH3 sensor; the controller receives a temperature signal of the temperature sensor and controls the working state of the electric heater according to the received temperature signal; and the controller receives the concentration signal of NOx and the concentration signal of NH3, and controls the working state of the electric heater according to the concentration signals. According to the invention, the decomposition efficiency of N2O can be improved, and the conversion efficiency of NOx can be improved.

The invention discloses an improved SCR (Selective Catalytic Reduction) denitration pretreatment device and an SCR denitration system, aiming at solving the technical problems that a pretreatment catalyst adopted at present is high in cost and is damaged. The system comprises a pretreatment reactor, a pretreatment catalyst in the pretreatment reactor forms a first pretreatment catalyst bed layer and a second pretreatment catalyst bed layer, the first pretreatment catalyst bed layer and the second pretreatment catalyst bed layer are sequentially arranged in the flue gas flowing direction, the first pretreatment catalyst bed layer is formed by stacking activated carbon particles, and the second pretreatment catalyst bed layer is formed by stacking activated carbon particles. The second pretreatment catalyst bed layer is formed by stacking porous ceramics. The adsorption performance of the activated carbon particles and the high-temperature-resistant and corrosion-resistant characteristics of the porous ceramic can be effectively utilized, the activated carbon particles and the porous ceramic have a synergistic effect to further remove sulfur dioxide in the flue gas, and dust in the to-be-denitrified flue gas is adsorbed and removed through the pretreatment catalyst. The interception capability on SO2 and dust is improved, and the problems of high use cost, easiness in damage and the like caused by independent use of an activated carbon-based desulfurization catalyst are solved.

The invention relates to a preparation method of a molecular sieve type SCR (Selective Catalytic Reduction) catalytic membrane, which comprises the following steps: taking an alpha-Al2O3 ceramic membrane tube as a carrier, carrying out alkali washing and acid washing on the ceramic membrane tube, and then drying to remove impurities in the ceramic membrane tube. Meanwhile, preparing a membrane preparation solution, firstly mixing a molecular sieve with a metal compound with an SCR effect, adding deionized water to prepare a mixed solution with the catalytic metal content of 0.1-0.3 mol / L, adjusting the pH value, heating and ultrasonically carrying out an ion exchange reaction, and adding a binder to prepare the membrane preparation solution; and loading the molecular sieve catalyst to the inner side of the alpha-Al2O3 ceramic membrane tube in a dip coating manner. And drying and roasting the membrane tube, and carrying out surface hydrophobic modification on the outer side of the ceramic membrane tube to obtain the molecular sieve SCR catalytic membrane. The efficient molecular sieve SCR catalytic membrane is obtained through one-time roasting, waste gas water and dust removal and SCR catalysis can be achieved at the same time, the conversion rate of NOx in the low-temperature environment is high, and the whole process is safe and environmentally friendly.

The invention discloses an improved SCR (Selective Catalytic Reduction) denitration device and an SCR denitration system. The technical problem that the denitration efficiency is reduced due to the influence of water vapor in flue gas to be denitrated on a denitration catalyst is solved. The SCR denitration device comprises an SCR denitration reactor, an activated carbon-based denitration catalyst is adopted as a denitration catalyst, and the working temperature of the activated carbon-based denitration catalyst is 120-200 DEG C; the flue gas dehumidification device is connected with the to-be-denitrated flue gas inlet and is used for reducing the content of water vapor in flue gas entering the to-be-denitrated flue gas inlet. The flue gas dehumidification device is arranged, so that the content of water vapor in flue gas entering the SCR denitration reactor is reduced, the influence of the water vapor on an activated carbon-based denitration catalyst can be avoided, the sufficient contact degree of nitrogen oxides and the denitration catalyst is ensured, and the relatively high denitration efficiency is maintained.

The invention discloses an SCR (Selective Catalytic Reduction) denitration system which comprises an SCR denitration tower, and a flue guide plate, a flue gas pre-mixer, a main ammonia spraying grid, an ammonia-smoke turbulator, a main catalyst layer, a supplementary ammonia spraying grid and a supplementary catalyst layer are sequentially arranged in the SCR denitration tower in the flue gas circulation direction; the main ammonia spraying grid comprises a plurality of first ammonia spraying branch pipes which are arranged in parallel at equal intervals in the direction perpendicular to the flue gas circulation direction, a row of first nozzles and a row of second nozzles are obliquely arranged on each first ammonia spraying branch pipe in the length direction, the number of the nozzles in each row is multiple, and the first nozzles and the second nozzles are arranged in a staggered mode and face different directions; each ammonia spraying branch pipe is communicated with the ammonia supply pipe, and an ammonia gas control valve is arranged on each first ammonia spraying branch pipe. Through cooperative use of the main ammonia injection grid and the supplementary ammonia injection grid, ammonia escape is reduced, uniform injection of ammonia gas in the whole reaction space is realized, and it is ensured that ammonia escape is maintained at a reasonable level.

A vehicle hybrid powertrain includes an internal combustion engine: an electrical drivetrain: a selective catalytic reduction (SCR) device coupled to receive exhaust from the internal combustion engine: a fuel burner; and a control system that controls heat applied to the SCR device including by controlling the fuel burner and the internal combustion engine.

A computer system comprising processing circuitry configured to obtain topographic data containing information about the topography of the road along which a heavy-duty vehicle is currently travelling, the topographic data including information about an upcoming downhill slope; acquire prediction data indicative of the braking requirements for the upcoming downhill slope, the braking requirements including how much brake power and / or brake energy that will be needed in the upcoming downhill slope to maintain the speed of the heavy-duty vehicle at or below a selected speed limit of the heavy-duty vehicle throughout the travel in the downhill slope; determine a brake blending combination which allows a Selective Catalytic Reduction System (SCR) of the heavy-duty vehicle to be kept as warm as possible while still fulfilling the braking requirements; and apply the determined brake blending combination to the heavy-duty vehicle while travelling along the downhill slope.

The invention discloses a bimetallic CO-SCR catalyst and a preparation method and application thereof, and belongs to the technical field of catalytic materials. The bimetallic CO-SCR catalyst comprises the following raw materials: an X metal precursor, a Y metal precursor, a ligand and a carrier, x metal in the X metal precursor is precious metal; y metal in the Y metal precursor is non-noble metal. According to the bimetal CO-SCR catalyst, coordination of bimetal X and Y is utilized, high oxygen resistance of the X-Y bimetal catalyst is achieved through the steric hindrance effect by means of the synergistic effect of ligands, the preparation method is simple, and an important reference basis is provided for preparation of the catalyst for CO selective catalytic reduction of NOx (CO-SCR) in the oxygen-containing environment.

The invention discloses an ammonia distillation method for a garbage incinerator SCR (Selective Catalytic Reduction) system. The problems that existing equipment is high in ammonia water steaming energy consumption and inconvenient to control are solved. The method comprises the following steps; the method comprises the following steps: S1, taking a 20-25% concentrated ammonia water solution as a raw material, and filling the concentrated ammonia water solution into a concentrated ammonia water storage tank for storage; s2, conveying 20-25% of concentrated ammonia water solution in a concentrated ammonia water storage tank into an ammonia distillation tower by using a first metering pump; ammonia gas in the concentrated ammonia water solution is separated out by using an ammonia distillation tower and is used for SCR (Selective Catalytic Reduction) denitration reaction; s3, dilute ammonia water generated at the bottom of the ammonia still is pumped out by a second metering pump and conveyed into a dilute ammonia water buffer tank for temporary storage, and the concentration of the dilute ammonia water is below 5%; s4, denitration is completed through a catalyst. The method has the beneficial effects that ammonia for SCR and SNCR in flue gas treatment equipment of the garbage incinerator is combined together, the ammonia still is used for separation and purification, ammonia gas is sprayed into the SCR, and raw materials of a reducing agent, the equipment cost and the operation cost are saved.

The invention discloses a steel tower type container for SCR denitration and an SCR denitration system. The technical problems that an existing SCR denitration pretreatment device / SCR denitration device is complex in structure, the engineering construction period control difficulty is large, and the construction period is long are solved. Comprising a steel outer cylinder and a steel inner supporting system arranged in the steel outer cylinder, and the bottom of the steel outer cylinder and the bottom of the steel inner supporting system are installed on a concrete base; the steel inner supporting system is provided with a center stand column and a plurality of layers of horizontal frames arranged in the axis direction of the center stand column at intervals, and the center stand column, the horizontal frames and the steel outer barrel are connected to form a steel tower. A part of the horizontal frames serve as partition plate supporting frames and are provided with sealing partition plates in a laid mode, the other part of the horizontal frames serve as catalyst supporting frames and are provided with catalyst breathable supporting layers in a laid mode, and the catalyst breathable supporting layers are used for being filled with denitration catalysts / pretreatment catalysts.

The invention discloses a denitration catalyst with a low sulfur dioxide oxidation rate, a preparation method of the denitration catalyst and application of the denitration catalyst in removal of nitrogen oxides through ammonia selective catalytic reduction. The denitration catalyst with the low sulfur dioxide oxidation rate is a titanium dioxide loaded vanadium pentoxide, molybdenum oxide and cerium oxide catalyst subjected to phosphorylation treatment. The preparation method comprises the following steps: (1) preparing a first solid-liquid mixture in which a vanadium pentoxide precursor, a molybdenum oxide precursor, a cerium oxide precursor and titanium dioxide are uniformly dispersed, drying the first solid-liquid mixture, grinding and roasting to obtain an intermediate product; and (2) preparing a second solid-liquid mixture in which the intermediate product and the precursor for phosphorylation are uniformly dispersed, drying the second solid-liquid mixture, grinding, and roasting to obtain the denitration catalyst with low sulfur dioxide oxidation rate. The low-cost control of NOx is realized, and the generation of sulfur trioxide is reduced at the same time.

The invention relates to the technical field of traction equipment, in particular to an SCR continuous casting copper billet traction clamping and conveying mechanism and traction method.The SCR continuous casting copper billet traction clamping and conveying mechanism comprises a plurality of pressing and conveying units distributed in the circumferential direction around the copper billet conveying axis, and each pressing and conveying unit comprises a conveying assembly and a pressing assembly; the conveying assembly comprises two conveying wheels and a soft belt arranged on the two conveying wheels in a transmission mode. By adopting a surface contact traction mode, the contact area between the mechanism and the surface of the copper billet can be effectively increased, so that the local stress on the surface of the copper billet is reduced, the copper billet is conveniently protected and prevented from being deformed and damaged, and meanwhile, the contact area increasing mode is also beneficial to improving the friction force, avoiding the slipping phenomenon and conveniently enabling the copper billet to be uniformly stressed, so that the service life of the copper billet is prolonged. Therefore, the traction stability of the copper billet is improved; by adopting a rotary traction mode, the traction work can be simpler and more convenient to operate, the structure mode is simplified, and the traction speed is more stable.

The invention relates to the technical field of flue gas denitrification, and discloses a flue gas baffle system for an SCR (Selective Catalytic Reduction) denitrification device and a use method.The flue gas baffle system is provided with a control system and a matrix flowmeter, a baffle assembly is composed of a plurality of baffle units, each flue is uniformly divided into a plurality of subareas, and each subarea corresponds to a group of adjusting units; and each baffle unit correspondingly controls one subarea of the cross section, so that the technical effects of automatically detecting the flow field at the inlet of the reactor and automatically adjusting the angle of the baffle under different loads or different flow field conditions are realized, the uniformity of the flue gas flow field under different loads is improved, the adaptability of the SCR denitration device to the loads is improved, and the service life of the SCR denitration device is prolonged. The ammonia escape amount when the load or the flow field changes is reduced, and the technical problem that in the prior art, an SCR denitration device cannot adjust the flue gas flow field according to the incoming flow characteristics of flue gas and cannot adjust the flue gas flow field when the performance of an existing flow equalizing device is damaged is solved.

The invention discloses a system of a belt type roasting machine for denitration by using return hot air, which comprises a return hot air blower, a first heat exchanger, a second heat exchanger, a second heat exchanger, a third heat exchanger, a third heat exchanger, a fourth heat exchanger, a fourth heat exchanger and a fourth heat exchanger, the first heat exchanger comprises a first heat exchange gas flow path and a second heat exchange gas flow path, the first heat exchanger comprises a first heat exchange gas flow path and a second heat exchange gas flow path, the first heat exchange gas flow path is communicated between an air box of the belt type roasting machine and a backheating fan, an air outlet of the backheating fan is opened towards an upper cover of the belt type roasting machine, the second heat exchanger comprises a third heat exchange gas flow path and a fourth heat exchange gas flow path which exchange heat with each other, and the third heat exchange gas flow path is communicated with the second heat exchange gas flow path; a flue gas outlet of the desulfurization system is communicated with the fourth heat exchange gas flow path, a gas inlet of the selective catalytic reduction reactor is communicated with the fourth heat exchange gas flow path, and a gas inlet of the denitration exhaust fan is communicated with a gas outlet of the selective catalytic reduction reactor. The system for denitration by using the return hot air of the belt type roasting machine can reduce the consumption of coal gas.

The invention provides an integral adsorbent based on a 3D printing technology. The halloysite nanotube and the hydroxypropyl methyl cellulose are selected as binders, and the halloysite nanotube has excellent high-temperature resistance, hardness, durability and chemical stability and can meet the application requirements of the catalyst under high-temperature complex working conditions, so that the catalyst structure keeps mechanical stability; the hydroxypropyl methyl cellulose has treatability and plasticity, can help to print complex shapes and structures, can effectively adhere printing materials due to super-strong adhesion force and interlayer adhesion, ensures firmness and stability of interlayer adhesion in the printing process, and is beneficial to reducing distortion and deformation in the printing process. The integral passive NOx adsorbent provided by the invention is simple and feasible in preparation method, is a non-noble metal adsorbent with economic benefits, and is connected in series with a downstream SCR (Selective Catalytic Reduction) treatment unit to realize ultralow emission in a NOx cold start stage.

The invention discloses a method for preserving heat of a urea NaOH and Mg (OH) 2 storage cabin, and aims at a ship which is provided with an SCR (Selective Catalytic Reduction) system, an EGR (Exhaust Gas Recirculation) system, an iCER (Initial Continuous Emission Reduction) system and a desulfurization system and needs to store urea, NaOH or Mg (OH) 2. Condensed water of the air conditioning unit is collected and then introduced into the storage cabin in a gravity mode, and the condensed water generation amount and the condensed water temperature of the air conditioning unit are analyzed and calculated. On the premise that the cabin capacity meets the condition, condensate water is used for cooling the urea cabin and then discharged into the clean cabin bottom water cabin, and the cooling capacity of the condensate water is utilized to the maximum extent. In winter or in a cold area, when the air conditioning unit does not need to operate, in order to avoid too low temperature of the solution cabin, the storage cabin can be heated by using the discharged water in the clean cabin bottom water cabin before discharging, so that the storage temperature of the urea, NaOH or Mg (OH) 2 solution is ensured to be 10-35 DEG C.

The invention discloses an integrated treatment method and system suitable for multi-component industrial waste gas, and relates to the technical field of industrial waste gas treatment, and the method comprises the steps of S1, waste gas pretreatment, S2, pre-oxidation and sulfur fixation, S3, thermal oxidation, S4, non-quenching temperature self-adaptive adjustment, S5, selective catalytic reduction denitration, S6, emission and monitoring, and S7, intelligent dynamic system control. The gradient temperature field of the heat storage ceramic body is used for providing accurate and stable air inlet temperature for the SCR reaction, an independent quenching device is omitted, and therefore the comprehensive energy consumption and the operation cost of the system are greatly reduced, and by additionally arranging the pre-oxidation layer and adopting the dual-function SCR catalyst, the heat storage effect of the system is greatly improved. The system effectively realizes advanced fixation of organic sulfur and efficient removal of nitrogen oxides, dynamically adjusts the ammonia injection amount and combustion intensity, ensures that the system can still maintain extremely high treatment efficiency and stability under flow fluctuation and complex working conditions, reduces ammonia escape to the greatest extent, and is convenient to use.

An exhaust aftertreatment system (10) in the exhaust stream of an internal combustion engine (12) that is at least partially powered by an alcohol fuel is permeable to an exhaust stream containing nitrogen oxides as well as an alcohol and / or formaldehyde. The exhaust aftertreatment system (10) comprises a metering device (14) for metering ammonia into the exhaust stream, a first SCR catalyst (16), and a second SCR catalyst (18), wherein the first SCR catalyst (16) is arranged in the exhaust stream downstream of the metering device (14) and is configured to generate a treated exhaust stream from the exhaust stream of the internal combustion engine (12) that contains nitrogen oxides and at least one nitrogen-containing hydrocarbon compound.The second SCR catalyst (18) is arranged in the exhaust stream downstream of the first SCR catalyst (16) and is designed to reduce the nitrogen oxides contained in the generated treated exhaust stream by consuming the nitrogen-containing hydrocarbon compound contained in the generated treated exhaust stream. Furthermore, a method for exhaust aftertreatment and the use of an exhaust aftertreatment system (10) are specified.

An exhaust aftertreatment system (10) in the exhaust stream of an internal combustion engine (12) that is at least partially powered by an alcohol fuel is permeable to an exhaust stream from the internal combustion engine (12) containing nitrogen oxides as well as an alcohol and / or formaldehyde. The exhaust aftertreatment system (10) comprises an oxidation catalyst (14) for removing methanol and formaldehyde from the exhaust stream, an SCR catalyst (18), and a metering device (16) for metering ammonia into the exhaust stream, wherein the oxidation catalyst (14) is arranged in the exhaust stream upstream of the SCR catalyst (18). The metering device (16) is arranged in the exhaust stream upstream of the SCR catalyst (18) and upstream or downstream of the oxidation catalyst (14). Furthermore, a method for exhaust aftertreatment and the use of the exhaust aftertreatment system (10) are specified.

The invention discloses a modeling method of an SCR (Selective Catalytic Reduction) denitration system mechanism hybrid prediction model based on Transform. Feature extraction is carried out on the collected data, a reaction kinetic equation is constructed, an Euler method is adopted for solving, and unknown model parameters are reserved; a section of working condition stable data is selected from the collected data and imported into a mechanism model, optimal model parameters are found, the mechanism model of the SCR denitration reaction is obtained, and the A side outlet flue concentration and the B side outlet flue concentration are calculated through the model; a Transform model is trained to compensate the SCR system mechanism model, and the compensated SCR system mechanism model serves as real-time soft measurement values output by the A side and the B side; input variable selection is carried out on all-condition data, A-side and B-side outlet flue concentrations obtained by the mechanism model in real time and outputs at the first two moments are included into an input variable set, and time delay processing is carried out on input variables; and the mechanism models of the A-side flue and the B-side flue are connected in series with a Transform model, the Transform model needs to be imported into the output of the mechanism models in real time, and finally the SCR denitration system hybrid prediction model is obtained.

A non-transitory computer-readable media having computer-readable instructions stored thereon that, when executed by at least one controller, cause the at least one controller to cause a first doser to cease dosing a first reductant portion of a reductant to a first exhaust portion of exhaust upstream of a first catalyst member disposed in a first leg of a selective catalytic reduction (SCR) system. The instructions can cause the at least one controller to cause a second doser to dose a second reductant portion of the reductant to a second exhaust portion of the exhaust upstream of a second catalyst member disposed in a second leg of the SCR system. The instructions can cause the at least one controller to determine a first conversion efficiency of the first leg while the first doser is not dosing the first reductant portion and the second doser is dosing the second reductant portion.

A system, method, and apparatus for detecting sensor tampering are provided. An aftertreatment system includes a first train having a first selective catalytic reduction (SCR) system, a first doser, and a first NOx sensor; a second train having a second SCR system, a second doser, and a second NOx sensor; and a controller. The controller determines satisfaction of activation conditions. The controller doses reductant to the first and second SCR systems. The controller determines the NOx levels of the first SCR system and the second SCR system. The controller adjusts the dosing of the first SCR system for a period of time. The controller measures the NOx levels of the first SCR system and the second SCR system. The controller determines a difference between the third and first NOx levels and a difference between the fourth and second NOx levels.The control generates an indication as to whether the first NOx sensor is displaced.