CN116696527A - Tail gas treatment method, device and system - Google Patents
Tail gas treatment method, device and system Download PDFInfo
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- CN116696527A CN116696527A CN202310960745.1A CN202310960745A CN116696527A CN 116696527 A CN116696527 A CN 116696527A CN 202310960745 A CN202310960745 A CN 202310960745A CN 116696527 A CN116696527 A CN 116696527A
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- 238000000034 method Methods 0.000 title claims abstract description 36
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 543
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 271
- 230000007423 decrease Effects 0.000 claims abstract description 17
- 238000010531 catalytic reduction reaction Methods 0.000 claims abstract description 11
- 238000010438 heat treatment Methods 0.000 claims abstract description 9
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 45
- 239000004202 carbamide Substances 0.000 claims description 45
- 238000002347 injection Methods 0.000 claims description 16
- 239000007924 injection Substances 0.000 claims description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 14
- 239000003054 catalyst Substances 0.000 claims description 10
- 230000003197 catalytic effect Effects 0.000 claims description 7
- 238000000746 purification Methods 0.000 claims description 7
- 238000001179 sorption measurement Methods 0.000 claims description 6
- 230000001590 oxidative effect Effects 0.000 claims description 4
- 230000008569 process Effects 0.000 abstract description 7
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 230000008878 coupling Effects 0.000 abstract description 5
- 238000010168 coupling process Methods 0.000 abstract description 5
- 238000005859 coupling reaction Methods 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 5
- 230000009467 reduction Effects 0.000 abstract description 5
- 238000006722 reduction reaction Methods 0.000 abstract description 5
- 230000006872 improvement Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 57
- 238000010586 diagram Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2250/00—Combinations of different methods of purification
- F01N2250/02—Combinations of different methods of purification filtering and catalytic conversion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2250/00—Combinations of different methods of purification
- F01N2250/12—Combinations of different methods of purification absorption or adsorption, and catalytic conversion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2250/00—Combinations of different methods of purification
- F01N2250/14—Combinations of different methods of purification absorption or adsorption, and filtering
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Exhaust Gas After Treatment (AREA)
Abstract
The embodiment of the application discloses a tail gas treatment method, a device and a system, wherein the method comprises the steps of determining the maximum heating rate and the maximum ammonia storage descending rate of a close-coupled SCR (selective catalytic reduction) based on a preset ammonia storage-temperature curve; acquiring a first ammonia storage value consumed by the close-coupled SCR in the process of treating NOx in the process of raising the temperature of the engine; determining a target ammonia storage capacity value of the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value; setting the ammonia storage capacity value of the close-coupled SCR as a target ammonia storage capacity value, and treating NOx in the tail gas by utilizing the close-coupled SCR. The application solves the problem that NH is easy to occur due to smaller volume of the tightly coupled SCR in the prior art 3 Leakage technical problem, realizing the improvement of NOx conversion capability of close coupling SCR and the reduction of NH 3 Leakage technical effect.
Description
Technical Field
The embodiment of the application relates to the technical field of tail gas treatment, in particular to a tail gas treatment method, device and system.
Background
Currently, the aftertreatment configuration of the national six doc+dpf+scr+asc (oxidation catalytic converter+diesel particulate filter+selective catalytic reduction system+activated carbon adsorption purification system) is small in the possibility of reducing NOx in a cold state due to a large heat capacity before SCR, and cannot face more severe emission regulations. With further upgrading of exhaust emission regulations, more stringent requirements are put on NOx emissions, so proposals have been made to increase close-coupled SCR components to reduce cold NOx emissions, but due to the smaller size of ccSCR (close-coupled SCR), NH can occur 3 (ammonia gas) leaks, NH that leaks 3 Generating N in an ingress DOC 2 O。
However, N 2 O is a typical strong greenhouse gas, the heating potential of which is CO 2 298 times, and N 2 O has extremely strong stability in the atmosphere and can generate strong damage to the ozone layer, thus N 2 O as an additional emission monitoring pollutant, how to reduce tail N in an aftertreatment device with coupled SCR components 2 The emission of O becomes a new problem.
Disclosure of Invention
The embodiment of the application provides a tail gas treatment method, device and system, which solve the problem that NH is easy to occur due to smaller volume of tightly coupled SCR in the prior art 3 Leakage technical problem.
The embodiment of the application provides a tail gas treatment method, which comprises the following steps:
determining a maximum heating rate and a maximum ammonia storage dropping rate of a close-coupled SCR based on a preset ammonia storage-temperature curve, wherein the preset ammonia storage-temperature curve is determined based on a catalyst type in an exhaust gas treatment system, and the close-coupled SCR is arranged at a position close to an engine turbine;
acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx during the temperature rise of the engine;
determining a target ammonia storage capacity value for the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value;
setting the ammonia storage capacity value of the close-coupled SCR as the target ammonia storage capacity value, and treating NOx in the tail gas by using the close-coupled SCR.
Further, after the treatment of NOx in the exhaust gas with the close-coupled SCR having the ammonia storage capacity value being the target ammonia storage capacity value, the exhaust gas treatment method further includes:
and sending the tail gas after the close-coupled SCR treatment into a close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from an engine turbine.
Further, obtaining a first ammonia storage value consumed by the close-coupled SCR in treating NOx during an engine temperature rise includes:
and inquiring a preset ammonia storage consumption table based on the temperature rise value, wherein the preset ammonia storage consumption table is used for representing the ammonia storage consumption value of the close-coupled SCR when treating NOx under different working conditions.
Further, determining a target ammonia storage capacity value for the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value comprises:
determining an ammonia storage actual value of the close-coupled SCR under a first temperature condition based on the maximum temperature rise rate and the maximum ammonia storage decline rate;
a target ammonia storage capacity value of the close-coupled SCR is determined based on the ammonia storage actual value and the first ammonia storage value.
Further, determining a target ammonia storage capacity value for the close-coupled SCR based on the ammonia storage actual value and the first ammonia storage value comprises:
judging whether the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value of the close-coupled SCR and the first ammonia storage value under a second temperature working condition, wherein the temperature of the second temperature working condition is higher than that of the first temperature working condition;
if the ammonia storage actual value is less than or equal to the sum of the maximum ammonia storage value and the first ammonia storage value, the target ammonia storage capacity value is the current ammonia storage actual value;
and if the ammonia storage actual value is larger than the sum of the maximum ammonia storage value and the first ammonia storage value, reducing the ammonia storage actual value by a preset value, and taking the reduced ammonia storage value as the target ammonia storage capacity value.
Further, after determining the target ammonia storage capacity value of the close-coupled SCR, the exhaust gas treatment method further includes:
determining a urea injection amount of a first urea nozzle based on the ammonia storage actual value and the target ammonia storage capacity value of the close-coupled SCR, wherein the first urea nozzle is arranged on one side of the close-coupled SCR close to an engine turbine;
and controlling the first urea nozzle to work by using the determined urea injection quantity.
The embodiment of the application also provides a tail gas treatment device, which comprises;
the system comprises a first data acquisition unit, a second data acquisition unit and a third data acquisition unit, wherein the first data acquisition unit is used for determining the maximum heating rate and the maximum ammonia storage descending rate of the close-coupled SCR based on a preset ammonia storage-temperature curve, the preset ammonia storage-temperature curve is determined and obtained based on the type of a catalyst in an exhaust gas treatment system, and the close-coupled SCR is arranged at a position close to a turbine of an engine;
a second data acquisition unit for acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx during an engine temperature rise;
and a target ammonia storage determination unit configured to determine a target ammonia storage capacity value of the close-coupled SCR based on the maximum temperature increase rate, the maximum ammonia storage decrease rate, and the first ammonia storage value.
Further, the exhaust gas treatment device further includes:
an ammonia storage capacity adjustment unit configured to set an ammonia storage capacity value of the close-coupled SCR to the target ammonia storage capacity value after the target ammonia storage capacity value is determined by the target ammonia storage determination unit;
and the tail gas treatment unit is used for treating NOx in the tail gas by utilizing the close-coupled SCR and sending the tail gas after the close-coupled SCR treatment into an close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is arranged close to the close-coupled SCR.
The embodiment of the application also provides an exhaust gas treatment system, which comprises the exhaust gas treatment device according to any embodiment, a first urea nozzle, a close-coupled SCR and a close-coupled ASC;
the close-coupled SCR is arranged at a position close to the turbine of the engine;
the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from the engine turbine;
the first urea nozzle is disposed on a side of the close-coupled SCR proximate to the engine turbine.
Further, the exhaust gas treatment system further comprises an oxidative catalytic converter, a diesel particulate filter, a selective catalytic reduction system and an activated carbon adsorption type purification system;
the oxidative catalytic converter, the diesel particulate filter, the selective catalytic reduction system, and the activated carbon adsorption-type purification system are sequentially disposed after the close-coupled ASC.
The embodiment of the application discloses a tail gas treatment method, a device and a system, wherein the method comprises the steps of determining the maximum heating rate and the maximum ammonia storage descending rate of a close-coupled SCR (selective catalytic reduction) based on a preset ammonia storage-temperature curve; acquiring a first ammonia storage value consumed by the close-coupled SCR in the process of treating NOx in the process of raising the temperature of the engine; determining a target ammonia storage capacity value of the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value; setting the ammonia storage capacity value of the close-coupled SCR as a target ammonia storage capacity value, and treating NOx in the tail gas by utilizing the close-coupled SCR. The present application determines a target ammonia storage capacity value for a close-coupled SCR by using a maximum ramp rate, a maximum ammonia storage decline rate, and a first ammonia storage value,and control close-coupled SCR to treat NOx by using target ammonia storage capacity value, solving the problem that NH is easy to occur in the prior art due to smaller volume of close-coupled SCR 3 Leakage technical problem, realizing the improvement of NOx conversion capability of close coupling SCR and the reduction of NH 3 Leakage technical effect.
Drawings
FIG. 1 is a flow chart of an exhaust gas treatment method according to an embodiment of the present application;
FIG. 2 is a block diagram of an exhaust gas treatment device according to an embodiment of the present application;
fig. 3 is a block diagram of an exhaust gas treatment system according to an embodiment of the present application.
Detailed Description
The application is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and in the drawings are used for distinguishing between different objects and not for limiting a particular order. The following embodiments of the present application may be implemented individually or in combination with each other, and the embodiments of the present application are not limited thereto.
Fig. 1 is a flowchart of a method for treating exhaust gas according to an embodiment of the present application.
As shown in fig. 1, the exhaust gas treatment method specifically includes the following steps:
s101, determining a maximum heating rate and a maximum ammonia storage descending rate of the close-coupled SCR based on a preset ammonia storage-temperature curve, wherein the preset ammonia storage-temperature curve is determined based on the type of a catalyst in an exhaust gas treatment system, and the close-coupled SCR is arranged at a position close to a turbine of an engine.
Wherein the catalyst used is different for the exhaust gas treatment system of the engine, the close-coupled SCR (Selective CatalyticReduction, selective catalytic Reduction system) and the ammonia storage decline rate are also different. For SCR, the ammonia storage capacity in SCR will decrease with increasing temperature, so different temperature conditions will correspond to different maximum ammonia storage values θ max 。
In transient conditions, close-coupled SCR (ccSCR) undergoes a rapid drop in ammonia storage capacity in the face of complex operating conditions, such as severe temperature changes, especially when ccSCR is subjected to rapid increases in temperature from low temperatures, and NOx entering the ccSCR cannot be NH to be released 3 At this time, NH is liable to occur after consumption 3 In case of slip, slip NH 3 Easy access to subsequent DOC for generating N 2 O does not meet the exhaust emission standard, so that the change of the ammonia storage capacity caused by the change of the working condition is considered when setting the ammonia storage set values of the temperatures.
Specifically, after determining the catalyst currently used in the exhaust system of the engine, a corresponding preset ammonia storage-temperature curve is present based on the catalyst, from which the maximum temperature increase rate Δt of ccSCR can be obtained max The method comprises the steps of carrying out a first treatment on the surface of the Maximum ammonia storage lowering rate Δθ max 。
S102, acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx in the process of raising the temperature of the engine.
Specifically, the temperature of the engine is lower during the starting process, and when the engine is started and gradually enters a high-speed running state, the temperature is gradually increased, during the temperature increase process, partial ammonia storage in the ccSCR is consumed by NOx entering the ccSCR, wherein the ammonia storage capacity refers to adsorption of gaseous NH on the ccSCR 3 Is provided).
Optionally, obtaining a first ammonia storage value that is consumed by the close-coupled SCR in treating NOx during an engine temperature rise includes: and inquiring a preset ammonia storage consumption table based on the temperature rise value, wherein the preset ammonia storage consumption table is used for representing the ammonia storage consumption value of the close-coupled SCR for treating NOx under different working conditions.
Specifically, for ccSCR under different catalysts, it is verified through experiments that a preset ammonia storage consumption table is configured in advance, and when a temperature rise preset value can be obtained by looking up the table based on a temperature rise value, the ccSCR needs to consume an ammonia storage value, that is, the first ammonia storage value Δθ, when NOx is treated.
S103, determining a target ammonia storage capacity value of the close-coupled SCR based on the maximum temperature rise rate, the maximum ammonia storage drop rate and the first ammonia storage value.
Specifically, when the maximum temperature increase rate DeltaT is obtained max Maximum ammonia storage rate of decrease Δθ max And further judging that the temperature is at the maximum temperature rising rate delta T after the first ammonia storage value delta theta max And a maximum ammonia storage decrease rate Δθ max The relationship between the actual ammonia storage value and the sum of the maximum ammonia storage value and the first ammonia storage value, and determining the target ammonia storage capacity value of ccSCR based on the relationship between the two.
S104, setting the ammonia storage capacity value of the close-coupled SCR as a target ammonia storage capacity value, and treating NOx in the tail gas by using the close-coupled SCR.
Specifically, after determining the target ammonia storage capacity value of the ccSCR, controlling the ammonia storage capacity of the ccSCR to be adjusted to the target ammonia storage capacity value so that the ccSCR can adsorb NOx in the exhaust gas in the maximum range and reduce NH 3 Is generated.
The method determines the target ammonia storage capacity value of the close-coupled SCR by using the maximum heating rate, the maximum ammonia storage descending rate and the first ammonia storage value, and controls the close-coupled SCR to treat NOx by using the target ammonia storage capacity value, thereby solving the problems that NH is easy to occur due to smaller volume of the close-coupled SCR in the prior art 3 Leakage technical problem, realizing the improvement of NOx conversion capability of close coupling SCR and the reduction of NH 3 Leakage technical effect.
Based on the above technical solutions, in S104, after the NOx in the exhaust gas is treated by the close-coupled SCR with the ammonia storage capacity as the target ammonia storage capacity value, the exhaust gas treatment method further includes: and sending the tail gas after the close-coupled SCR treatment into a close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from the turbine of the engine.
In particular, when ccSCR is faced with a rapid rise in temperature from low temperatures,the ammonia storage capacity of the ccSCR will drop rapidly and NOx entering the ccSCR will not be able to release NH 3 At this time, NH is liable to occur after consumption 3 Leakage, so in step S104, after ccSCR has adsorbed NOx in the exhaust gas to a maximum extent, in order to prevent the remaining NH from remaining 3 Leakage occurs, a tight coupling ASC (ccASC) is arranged behind the ccSCR, when the ccSCR is used for treating the tail gas, the treated tail gas immediately enters the ccASC, and the ccASC can adsorb NH generated by the ccSCR 3 So that ccSCR generates NH 3 Hardly enter DOC, i.e. greatly reduce N 2 And the generation of O increases double protection for the compliance of exhaust emission.
Based on the above technical solutions, S103, determining the target ammonia storage capacity value of the close-coupled SCR based on the maximum temperature rise rate, the maximum ammonia storage drop rate, and the first ammonia storage value specifically includes:
s1, determining an ammonia storage actual value of the close-coupled SCR under a first temperature working condition based on the maximum temperature rising rate and the maximum ammonia storage descending rate.
Specifically, the first temperature condition generally refers to a temperature condition at the time of engine start, that is, a condition at the time of low temperature of the engine, at which the ammonia storage actual value θ of ccSCR can be obtained by calculation.
S2, determining a target ammonia storage capacity value of the close-coupled SCR based on the ammonia storage actual value and the first ammonia storage value.
Specifically, after the ammonia storage actual value θ is obtained, the ammonia storage actual value θ is compared with the sum of the first ammonia storage value Δθ and the maximum ammonia storage value, and a target ammonia storage capacity value of ccSCR is determined based on the relationship between the two.
Optionally, S2, determining the target ammonia storage capacity value of the close-coupled SCR based on the ammonia storage actual value and the first ammonia storage value specifically includes: judging whether the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value of the close-coupled SCR and the first ammonia storage value under a second temperature working condition, wherein the temperature of the second temperature working condition is higher than that of the first temperature working condition; if the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value and the first ammonia storage value, the target ammonia storage capacity value is the current ammonia storage actual value; if the ammonia storage actual value is larger than the sum of the maximum ammonia storage value and the first ammonia storage value, the ammonia storage actual value is reduced by a preset value, and the reduced ammonia storage value is taken as a target ammonia storage capacity value.
Specifically, after obtaining the ammonia storage actual value θ and the first ammonia storage value Δθ under the first temperature condition, obtaining the maximum ammonia storage value θ of ccSCR under the second temperature condition (max, high temperature) The ccSCR is configured to operate at a higher temperature than the first temperature under different temperature conditions, where the second temperature condition is typically a temperature at which the engine is running at a high speed.
Calculating the maximum ammonia storage value theta (max, high temperature) And the sum of the first ammonia storage value delta theta, and then judging that the ammonia storage actual value theta is less than or equal to theta (max, high temperature) If the +delta theta is satisfied, controlling the ccSCR to maintain the current ammonia storage actual value theta to operate, namely the target ammonia storage capacity value theta Dmd θ; if not, the ammonia storage actual value θ needs to be reduced to be in accordance with θ (max, high temperature) Within the range of +Δθ, i.e., the ammonia storage actual value θ is reduced by a preset value, and the reduced ammonia storage value is taken as the target ammonia storage capacity value θ Dmd And controlling ccSCR to work.
Based on the above technical solutions, after determining the target ammonia storage capacity value of the close-coupled SCR in S103, the exhaust gas treatment method further includes: determining a urea injection amount of a first urea nozzle based on an ammonia storage actual value and a target ammonia storage capacity value of the close-coupled SCR, wherein the first urea nozzle is arranged on one side of the close-coupled SCR close to an engine turbine; and controlling the first urea nozzle to work by using the determined urea injection quantity.
Specifically, the first urea nozzle is disposed on a side of the ccSCR near the engine turbine such that an injection amount of the first urea nozzle does not cause NH after the ccSCR 3 Leakage, the injection amount of the first urea nozzle needs to be controlled, specifically, the ammonia storage actual value θ and the target ammonia storage capacity value θ based on ccSCR Dmd The corresponding urea injection amount required by the ccSCR can be calculated, and then the urea injection amount is used for controlling the first urea nozzle to inject urea, so that the ccSCR has higher NOx conversion capability. I.e. in steady stateUnder working conditions, P is reduced to N 2 The key factor of O is adjusted.
Wherein, the target ammonia storage capacity value theta of ccSCR Dmd Must be less than the maximum ammonia storage value θ of ccSCR max Preferably, the target ammonia storage capacity value θ of ccSCR Dmd Maximum ammonia storage value θ less than ccSCR max And the ammonia storage value consumed in ccSCR for NOx treatment (i.e., the first ammonia storage value Δθ described above).
In summary, in an embodiment of the present application, improved NOx conversion capability, NH reduction of a close-coupled SCR is achieved by using the following method 3 The technical effect of leakage: (1) Increasing hardware configuration ccASC to reduce NH of ccSCR 3 Risk of leakage; (2) Adjusting N reduction under steady state and transient conditions 2 The key factor of O, wherein, the steady state is to calculate the urea injection quantity of a first urea nozzle, and the transient state is to correct the target ammonia storage capacity value of ccSCR.
Fig. 2 is a block diagram of an exhaust gas treatment device according to an embodiment of the present application.
As shown in fig. 2, the exhaust gas treatment device includes;
a first data acquisition unit 21, configured to determine a maximum temperature rise rate and a maximum ammonia storage drop rate of the close-coupled SCR based on a preset ammonia storage-temperature curve, where the preset ammonia storage-temperature curve is determined based on a type of a catalyst in the exhaust gas treatment system, and the close-coupled SCR is disposed at a position close to a turbine of the engine;
a second data acquisition unit 22 for acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx during an engine temperature rise;
a target ammonia storage determining unit 23 for determining a target ammonia storage capacity value of the close-coupled SCR based on the maximum temperature increase rate, the maximum ammonia storage decrease rate, and the first ammonia storage value;
the close-coupled SCR control unit 24 is configured to set the ammonia storage capacity value of the close-coupled SCR to a target ammonia storage capacity value, and treat NOx in the exhaust gas with the close-coupled SCR.
Optionally, the close-coupled SCR control unit 24 is further configured to:
and sending the tail gas after the close-coupled SCR treatment into a close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from the turbine of the engine.
Optionally, the second data acquisition unit 22 is specifically configured to:
and inquiring a preset ammonia storage consumption table based on the temperature rise value, wherein the preset ammonia storage consumption table is used for representing the ammonia storage consumption value of the close-coupled SCR for treating NOx under different working conditions.
Alternatively, the target ammonia storage determining unit 23 includes:
an actual value determination subunit, configured to determine an ammonia storage actual value of the close-coupled SCR under the first temperature condition based on the maximum temperature rise rate and the maximum ammonia storage decrease rate;
a target value determination subunit for determining a target ammonia storage capacity value of the close-coupled SCR based on the ammonia storage actual value and the first ammonia storage value.
Optionally, the target value determining subunit is specifically configured to:
judging whether the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value of the close-coupled SCR and the first ammonia storage value under a second temperature working condition, wherein the temperature of the second temperature working condition is higher than that of the first temperature working condition;
if the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value and the first ammonia storage value, the target ammonia storage capacity value is the current ammonia storage actual value;
if the ammonia storage actual value is larger than the sum of the maximum ammonia storage value and the first ammonia storage value, the ammonia storage actual value is reduced by a preset value, and the reduced ammonia storage value is taken as a target ammonia storage capacity value.
Optionally, after the target value determining subunit determines the target ammonia storage capacity value of the close-coupled SCR, the exhaust gas treatment device further includes:
the urea injection amount determining unit is used for determining the urea injection amount of the first urea nozzle based on the ammonia storage actual value and the target ammonia storage capacity value of the close-coupled SCR, wherein the first urea nozzle is arranged on one side of the close-coupled SCR close to the turbine of the engine;
and the urea nozzle control unit is used for controlling the first urea nozzle to work by using the determined urea injection quantity.
The exhaust gas treatment device provided in the embodiment of the present application has the same implementation principle and technical effects as those of the foregoing exhaust gas treatment method embodiment, and for brevity, reference may be made to the corresponding content in the foregoing method embodiment where the device embodiment portion is not mentioned.
Fig. 3 is a block diagram of an exhaust gas treatment system according to an embodiment of the present application.
The exhaust gas treatment system comprises the exhaust gas treatment device (not shown in fig. 3) in any of the above embodiments, and as shown in fig. 3, the exhaust gas treatment system further comprises a first urea nozzle 31, a close-coupled SCR ccSCR and a close-coupled ASC ccASC;
the close-coupled SCR ccSCR is arranged at a position close to the turbine of the engine;
the close-coupled ASC ccASC is adjacent to the close-coupled SCR ccSCR and is arranged at one end of the close-coupled SCR ccSCR far away from the engine turbine;
the first urea nozzle 31 is arranged on the side of the close-coupled SCR ccSCR close to the engine turbine.
Specifically, the urea injection amount of the first urea nozzle 31 is based on the ammonia storage actual value θ of ccSCR and the target ammonia storage capacity value θ Dmd The calculated first urea nozzle 31 injects urea based on the calculated urea injection amount, so that ccSCR has a high NOx conversion capability. After ccSCR converts NOx, to prevent the presence of residual NH 3 Leakage occurs, ccASC is arranged after ccSCR, after the ccSCR is used for treating the tail gas, the treated tail gas immediately enters the ccASC, and the ccASC can adsorb NH generated by the ccSCR 3 So that ccSCR generates NH 3 Hardly enter DOC, i.e. greatly reduce N 2 And the generation of O increases double protection for the compliance of exhaust emission.
Optionally, as shown in fig. 3, the exhaust gas treatment system further includes an oxidation catalytic converter DOC, a diesel particulate filter DPF, a selective catalytic reduction system SCR, and an activated carbon adsorption purification system ASC;
the oxidation catalytic converter DOC, the diesel particulate filter DPF, the selective catalytic reduction system SCR and the activated carbon adsorption purification system ASC are arranged in sequence after the close coupling ASC ccASC.
Optionally, as shown in fig. 3, NOx monitoring sensors, i.e., nox_up, nox_m, nox_d, are also provided upstream, midstream, and downstream of the entire exhaust gas treatment system, respectively; a temperature sensor t_ccscr_us is also provided between ccSCR and the first urea nozzle 31; a temperature sensor T_DOC_us is arranged in front of the DOC; a temperature sensor T_DPF_us is arranged between the DOC and the DPF; a second urea nozzle 32 is provided between the DPF and the SCR; a temperature sensor t_scr_us is provided between the second urea nozzle 32 and the SCR; after ASC, a temperature sensor t_ds is also provided.
The exhaust gas treatment system provided by the embodiment of the present application includes the exhaust gas treatment device in the above embodiment, so the exhaust gas treatment system provided by the embodiment of the present application also has the beneficial effects described in the above embodiment, and will not be described herein.
In the description of embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
Finally, it should be noted that the foregoing description is only illustrative of the preferred embodiments of the present application and the technical principles employed. It will be understood by those skilled in the art that the present application is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the application. Therefore, while the application has been described in connection with the above embodiments, the application is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the application, which is set forth in the following claims.
Claims (10)
1. A method of treating exhaust gas, the method comprising:
determining a maximum heating rate and a maximum ammonia storage dropping rate of a close-coupled SCR based on a preset ammonia storage-temperature curve, wherein the preset ammonia storage-temperature curve is determined based on a catalyst type in an exhaust gas treatment system, and the close-coupled SCR is arranged at a position close to an engine turbine;
acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx during the temperature rise of the engine;
determining a target ammonia storage capacity value for the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value;
setting the ammonia storage capacity value of the close-coupled SCR as the target ammonia storage capacity value, and treating NOx in the tail gas by using the close-coupled SCR.
2. The exhaust gas treatment method according to claim 1, characterized in that after the treatment of NOx in the exhaust gas with the close-coupled SCR having an ammonia storage capacity value of the target ammonia storage capacity value, the exhaust gas treatment method further comprises:
and sending the tail gas after the close-coupled SCR treatment into a close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from an engine turbine.
3. The exhaust gas treatment method of claim 1, wherein obtaining a first ammonia storage value that the close-coupled SCR consumes in treating NOx during an engine temperature rise comprises:
and inquiring a preset ammonia storage consumption table based on the temperature rise value, wherein the preset ammonia storage consumption table is used for representing the ammonia storage consumption value of the close-coupled SCR when treating NOx under different working conditions.
4. The exhaust gas treatment method of claim 1, wherein determining the target ammonia storage capacity value of the close-coupled SCR based on the maximum ramp rate, the maximum ammonia storage decline rate, and the first ammonia storage value comprises:
determining an ammonia storage actual value of the close-coupled SCR under a first temperature condition based on the maximum temperature rise rate and the maximum ammonia storage decline rate;
a target ammonia storage capacity value of the close-coupled SCR is determined based on the ammonia storage actual value and the first ammonia storage value.
5. The exhaust gas treatment method of claim 4, wherein determining the target ammonia storage capacity value of the close-coupled SCR based on the ammonia storage actual value and the first ammonia storage value comprises:
judging whether the ammonia storage actual value is smaller than or equal to the sum of the maximum ammonia storage value of the close-coupled SCR and the first ammonia storage value under a second temperature working condition, wherein the temperature of the second temperature working condition is higher than that of the first temperature working condition;
if the ammonia storage actual value is less than or equal to the sum of the maximum ammonia storage value and the first ammonia storage value, the target ammonia storage capacity value is the current ammonia storage actual value;
and if the ammonia storage actual value is larger than the sum of the maximum ammonia storage value and the first ammonia storage value, reducing the ammonia storage actual value by a preset value, and taking the reduced ammonia storage value as the target ammonia storage capacity value.
6. The exhaust gas treatment method of claim 4, further comprising, after determining the target ammonia storage capacity value of the close-coupled SCR:
determining a urea injection amount of a first urea nozzle based on the ammonia storage actual value and the target ammonia storage capacity value of the close-coupled SCR, wherein the first urea nozzle is arranged on one side of the close-coupled SCR close to an engine turbine;
and controlling the first urea nozzle to work by using the determined urea injection quantity.
7. An exhaust gas treatment device, characterized in that the exhaust gas treatment device comprises;
the system comprises a first data acquisition unit, a second data acquisition unit and a third data acquisition unit, wherein the first data acquisition unit is used for determining the maximum heating rate and the maximum ammonia storage descending rate of the close-coupled SCR based on a preset ammonia storage-temperature curve, the preset ammonia storage-temperature curve is determined and obtained based on the type of a catalyst in an exhaust gas treatment system, and the close-coupled SCR is arranged at a position close to a turbine of an engine;
a second data acquisition unit for acquiring a first ammonia storage value consumed by the close-coupled SCR in treating NOx during an engine temperature rise;
a target ammonia storage determination unit configured to determine a target ammonia storage capacity value of the close-coupled SCR based on the maximum temperature increase rate, the maximum ammonia storage decrease rate, and the first ammonia storage value;
and the close-coupled SCR control unit is used for setting the ammonia storage capacity value of the close-coupled SCR to the target ammonia storage capacity value and treating NOx in the tail gas by utilizing the close-coupled SCR.
8. The exhaust gas treatment device of claim 7, wherein the close-coupled SCR control unit is further configured to:
and sending the tail gas after the close-coupled SCR treatment into a close-coupled ASC for ammonia treatment, wherein the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from an engine turbine.
9. An exhaust gas treatment system comprising the exhaust gas treatment device of any of the preceding claims 7-8, further comprising a first urea nozzle, a close-coupled SCR and a close-coupled ASC;
the close-coupled SCR is arranged at a position close to the turbine of the engine;
the close-coupled ASC is adjacent to the close-coupled SCR and is arranged at one end of the close-coupled SCR far away from the engine turbine;
the first urea nozzle is disposed on a side of the close-coupled SCR proximate to the engine turbine.
10. The exhaust gas treatment system of claim 9, further comprising an oxidative catalytic converter, a diesel particulate filter, a selective catalytic reduction system, and an activated carbon adsorption purification system;
the oxidative catalytic converter, the diesel particulate filter, the selective catalytic reduction system, and the activated carbon adsorption-type purification system are sequentially disposed after the close-coupled ASC.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050069476A1 (en) * | 2001-12-20 | 2005-03-31 | Blakeman Philip Gerald | Selective catalytic reduction |
| US20150240682A1 (en) * | 2014-01-20 | 2015-08-27 | Cummins Inc. | SYSTEMS AND METHODS TO MITIGATE NOx AND HC EMISSIONS |
| CN105102781A (en) * | 2013-03-27 | 2015-11-25 | 德尔福国际运营卢森堡有限公司 | Method of controlling ammonia levels in catalytic units |
| US20220025799A1 (en) * | 2020-07-21 | 2022-01-27 | Paccar Inc | Ammonia storage capacity of scr catalyst unit |
| US20220282653A1 (en) * | 2021-03-08 | 2022-09-08 | Jaguar Land Rover Limited | Apparatus and method for controlling reduction system |
| CN116446984A (en) * | 2023-03-22 | 2023-07-18 | 潍柴动力股份有限公司 | Modified SCR efficiency model, modification method and vehicle |
-
2023
- 2023-08-02 CN CN202310960745.1A patent/CN116696527B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050069476A1 (en) * | 2001-12-20 | 2005-03-31 | Blakeman Philip Gerald | Selective catalytic reduction |
| CN105102781A (en) * | 2013-03-27 | 2015-11-25 | 德尔福国际运营卢森堡有限公司 | Method of controlling ammonia levels in catalytic units |
| US20150240682A1 (en) * | 2014-01-20 | 2015-08-27 | Cummins Inc. | SYSTEMS AND METHODS TO MITIGATE NOx AND HC EMISSIONS |
| US20220025799A1 (en) * | 2020-07-21 | 2022-01-27 | Paccar Inc | Ammonia storage capacity of scr catalyst unit |
| US20220282653A1 (en) * | 2021-03-08 | 2022-09-08 | Jaguar Land Rover Limited | Apparatus and method for controlling reduction system |
| CN116446984A (en) * | 2023-03-22 | 2023-07-18 | 潍柴动力股份有限公司 | Modified SCR efficiency model, modification method and vehicle |
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