CN102330592B - Exhaust emission aftertreatment equipment and method for diesel engine - Google Patents

Abstract

The implementation mode of the invention relates to exhaust emission aftertreatment equipment and an exhaust emission aftertreatment method for a diesel engine, and particularly provides equipment used in a selective catalytic reduction (SCR) system of the diesel engine according to the implementation mode of the invention. The SCR system comprises a catalyst which is used for converting nitrogen oxide emitted by the diesel engine by using ammonia. The equipment comprises an acquisition device and a determination device, wherein the acquisition device is coupled to the catalyst and is used for acquiring a measurement value of at least one working condition of the catalyst; and the determination device is coupled to the acquisition device and is used for determining the ammonia storage capacity of the catalyst on the basis of the acquired measurement value so as to determine the ammonia surface coverage rate of the catalyst. The invention also discloses a method corresponding to the equipment. According to the scheme, the ammonia surface coverage rate and the ammonia storage capacity of the SCR catalyst can be more accurately estimated.

Description

The equipment and the method that are used for the toxic emission reprocessing of diesel engine

Technical field

Embodiments of the present invention relate generally to diesel engine, more specifically, relate to equipment and method for the toxic emission reprocessing of diesel engine.

Background technique

In present diesel engine field, selective catalytic reduction (SCR) is a kind of after-treatment system of important waste gas for the treatment of engine emission.The SCR after-treatment system generally includes: aqueous solution of urea storage tank, feedway, measuring apparatus, injection apparatus, catalyst converter and temperature and exhaust sensor etc.The basic functional principle of SCR after-treatment system is: waste gas enters the exhaust fixed tube after engine turbine is discharged from, at the exhaust fixed tube urea measuring and injecting device is installed, spray into aqueous solution of urea, urea at high temperature occurs to generate ammonia (NH after hydrolysis and the pyrolytic reaction ₃).Catalyst converter utilizes urea to convert the oxynitrides in the waste gas (NOx) to nitrogen (N as reducing agent ₂) and water.

In the SCR after-treatment system, the control urea injecting quantity is most important.Spray too much urea and can produce the ammonia leakage, and the urea that sprays very little will cause lower oxynitrides NOx conversion efficiency.In order to design SCR after-treatment system urea-spray control strategy, need to determine the status information of SCR reprocessing catalysis system.In the prior art, can utilize sensor Real-time Measuring amount temperature, air mass flow, NOx concentration, ammonia concentration.Yet, can't carry out directly and accurately measuring to catalytic carrier ammonia surface coverage in practice at present.

Be appreciated that catalytic carrier ammonia surface coverage will directly affect oxynitrides NOx in the waste gas and the concentration of ammonia, and the concentration of the oxynitrides NOx in the waste gas and ammonia is two most important states to SCR reprocessing urea injecting quantity controller's design.SCR reprocessing urea injecting quantity controller's design can reach oxynitrides NOx concentration in the waste gas and the target of ammonia leakage minimum by control catalytic carrier ammonia surface coverage.

Because catalytic carrier ammonia surface coverage can not be with conventional sensor measurement, so device that must design specialized is determined it or claimed estimation.This device is commonly called visualizer in the art.The state observer of existing catalytic carrier ammonia surface coverage mainly comprises the Systems with Linear Observation device and based on the visualizer of Kalman (Kalman) filtering.

On the other hand, the ammonia storage capacity of catalyst converter also is the factor that SCR reprocessing urea-spray amount controller must be considered.At present, in the SCR of Control-oriented after-treatment system, ammonia storage capacity is assumed to be constant usually.Yet, studies show that, SCR reprocessing catalyst converter ammonia storage capacity reduces along with the aging of SCR reprocessing catalyst converter.It has been generally acknowledged that, when time and temperature variation, SCR reprocessing catalyst converter ammonia storage capacity has very high uncertainty.Just because of this, just select SCR reprocessing catalytic carrier ammonia surface coverage to design the urea injecting quantity robust controller as controlled variable.

According to the definition of SCR reprocessing catalytic carrier ammonia surface coverage, there are inverse relation in ammonia storage capacity and ammonia surface coverage.Therefore, if select the ammonia surface coverage as controlled variable, then ammonia storage capacity must can be determined.And, the health status of present emission regulation demands online system failure diagnosis (OBD) monitoring SCR after-treatment system.Ammonia storage capacity is the key factor that reflects that directly SCR is aging.Estimate that SCR reprocessing catalyst converter ammonia storage capacity is that OBD confirms that SCR health status is essential.The state observer of existing ammonia storage capacity comprises the visualizer based on Kalamn filtering.

Existing based on Kalamn filtering the ammonia surface coverage and the state Observer Design of ammonia storage capacity be in supposition since the ammonia storage capacity dynamics that changes of the aging slow time that causes of SCR catalyst converter or synthermal relevant fast the time ammonia storage capacity dynamics of change design.The shortcoming of this design is: the kinetics mechanism of ammonia storage capacity is still uncertain, and actual ammonia storage capacity dynamics may be more complex.

Therefore, in the prior art, need a kind of more efficiently solution to determine adaptively SCR reprocessing carrier ammonia surface coverage and ammonia storage capacity.

Summary of the invention

In order to overcome the defects that exists in the prior art, embodiments of the present invention provide a kind of determine adaptively the carrier ammonia surface coverage of catalyst converter and equipment and the method for ammonia storage capacity in the SCR after-treatment system.

In a first aspect of the present invention, the equipment that uses in a kind of selective catalytic reduction in diesel engine (SCR) system is provided, this SCR system comprises that catalyst converter is to utilize ammonia to transform the nitrogen oxide of this diesel engine emissions.This equipment comprises: obtaining device, and it is coupled to described catalyst converter, and configuration is used for obtaining the measured value of this at least one operating mode of catalyst converter; And definite device, it is coupled to described obtaining device, and configuration is used for determining that based on this measured value that obtains the ammonia storage capacity of this catalyst converter is in order to determine the ammonia surface coverage of this catalyst converter.

According to some mode of execution of the present invention, determine that device comprises: unite definite device, configuration is used for based on this measured value that obtains, and determines together the ammonia surface coverage of this catalyst converter in company with the ammonia storage capacity of this catalyst converter.Alternatively, unite and determine that device comprises: based on definite device of model, configuration is used for described measured value by using the reaction model of the chemical reaction characteristic that characterizes described catalyst converter, determining the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter as independent variable.

According to some mode of execution of the present invention, further comprise based on definite device of model: computing device, configuration is used for calculating according to this measured value that obtains the Observed value of at least one operating mode; And first determine device, and configuration is used for based on described reaction model, determines the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter with described measured value and described Observed value.

According to some mode of execution of the present invention, obtaining device comprise following at least one: the first concentration acquisition device, configuration is used for obtaining the nitrous oxides concentration of this catalyst converter; The second concentration acquisition device, configuration is used for obtaining the ammonia concentration of this catalyst converter; And the temperature obtaining device, configuration is used for obtaining the temperature of this catalyst converter.

In a second aspect of the present invention, the method for using in a kind of selective catalytic reduction in diesel engine (SCR) system is provided, this SCR system comprises that catalyst converter is to utilize ammonia to transform the nitrogen oxide of this diesel engine emissions.The method comprises: the measured value that obtains this at least one operating mode of catalyst converter; And determine the ammonia storage capacity of this catalyst converter in order to determine the ammonia surface coverage of this catalyst converter based on this measured value that obtains.

According to some mode of execution of the present invention, determining the ammonia storage capacity of this catalyst converter based on this measured value that obtains comprises in order to determine the ammonia surface coverage of this catalyst converter: based on this measured value that obtains, determine together the ammonia surface coverage of this catalyst converter in company with the ammonia storage capacity of this catalyst converter.Alternatively, determine in company with the ammonia storage capacity of this catalyst converter that together the ammonia surface coverage of this catalyst converter comprises based on this measured value that obtains: with described measured value as independent variable, by using the reaction model of the chemical reaction characteristic that characterizes described catalyst converter, determine the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter.

According to some mode of execution of the present invention, determine that by the reaction model that uses the chemical reaction characteristic that characterizes described catalyst converter the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter comprise: the Observed value of calculating at least one operating mode according to this measured value that obtains as independent variable with described measured value; And based on described measured value and described Observed value, determine that with described reaction model the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.

According to some mode of execution of the present invention, the measured value that obtains this at least one operating mode of catalyst converter comprise obtain following at least one: the nitrous oxides concentration in this catalyst converter, the ammonia concentration in this catalyst converter; And the temperature in this catalyst converter.

It will be recognized by those skilled in the art by hereinafter describing, by adopting embodiments of the present invention, when determining based on the operating mode of the catalyst converter that measures or claiming to estimate the ammonia surface coverage of catalyst converter, the ammonia storage capacity of catalyst converter (or claiming storage ammonia ability) can not be assumed that constant in the prior art for another example like that all the time, or determines based on specific dynamics.On the contrary, embodiments of the present invention are not done any hypothesis to the dynamics of ammonia storage capacity, and it can be that constant also can be variable.Especially, can determine simultaneously based on the Chemical Reaction Model of catalyst converter ammonia storage volume and the ammonia surface coverage of catalyst converter.

The physical features that the ammonia storage volume of determining in this way and ammonia surface coverage can reflect the SCR catalyst converter more truly, exactly.In addition, the solution of the present invention's proposition is easy to realize and operation in practice.

Description of drawings

By reading with reference to the accompanying drawings detailed description hereinafter, above-mentioned and other purposes of embodiment of the present invention, the feature and advantage easy to understand that will become.In the accompanying drawings, show some mode of executions of the present invention in exemplary and nonrestrictive mode, wherein:

Fig. 1 shows the block diagram for the equipment 100 that uses in the SCR system according to exemplary embodiment of the invention;

Fig. 2 shows the block diagram for the equipment 200 that uses in the SCR system according to exemplary embodiment of the invention;

Fig. 3 shows the block diagram of determining device of uniting according to exemplary embodiment of the invention;

Fig. 4 shows the flow chart for the method 400 of using in the SCR system according to exemplary embodiment of the invention.

In the accompanying drawings, identical or corresponding label represents identical or corresponding part.

Embodiment

Below with reference to some illustrative embodiments principle of the present invention and spirit are described.Should be appreciated that providing these mode of executions only is for those skilled in the art can being understood better and then realize the present invention, and be not to limit the scope of the invention by any way.

Note, in the application's context, employed term " parameter " expression is any can indicate the value of the physical quantity of (target or the reality) physical state of diesel engine or operation conditions.And in this article, " parameter " physical quantity represented with it can Alternate.For example, " parameter of indication concentration " has the implication that is equal in this article with " concentration ".In addition, employed term " obtains " and comprises at present various means known or that develop in the future, and for example measure, read, estimate, estimate, etc.

Below with reference to some representative embodiments of the present invention, explain in detail principle of the present invention and spirit.At first with reference to figure 1, it shows the schematic diagram for the equipment 100 that uses in selective reduction reaction SCR system.

As mentioned above, the SCR system comprises catalyst converter.Catalyst converter utilizes urea to convert the oxynitrides in the waste gas of engine emission (NOx) to nitrogen (N as reducing agent usually ₂) and water.As shown in Figure 1, equipment 100 comprises obtaining device 102, and it can be coupled to the catalyst converter in the SCR system, and configuration is for the measured value of at least one operating mode of obtaining catalyst converter.In addition, equipment 100 also comprises determines device 104, and it is coupled to obtaining device 102, and configuration is used for determining that based on the described measured value that obtains the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.Specific operation and feature about obtaining device 102 and definite device 104 will be explained below.

Below with reference to Fig. 2, it shows the schematic diagram for the equipment 200 that uses in selective reduction reaction SCR system.Equipment 200 is that the concrete and refinement of above-described equipment 100 realizes.Equipment 200 comprises obtaining device 202 and the definite device 204 that is coupled with it, and it corresponds respectively to above-described device 102 and 104.Be described in detail below in conjunction with the feature of concrete example to equipment 200.

In some embodiments of the present invention, can determine based on following at least one working condition measuring value ammonia storage capacity and the ammonia surface coverage of catalyst converter: the nitrous oxides concentration in the catalyst converter, the ammonia concentration in the catalyst converter; And the temperature in the catalyst converter.Correspondingly, in these mode of executions, obtaining device 202 can comprise following at least one: the first concentration acquisition device 2022, configuration is used for obtaining the nitrous oxides concentration of catalyst converter; The second concentration acquisition device 2024, configuration is used for obtaining the ammonia concentration of catalyst converter; And temperature obtaining device 2026, configuration is used for obtaining the temperature of catalyst converter.

As example, the first concentration acquisition device 2022 and the second concentration acquisition device 2024 can configure respectively be used to utilizing suitable sensor to obtain the measured value of nitrous oxides concentration and the measured value of ammonia concentration.Equally, temperature obtaining device 2026 for example can configure for the measured temperature that obtains catalyst converter with suitable temperature transducer.Especially, according to some mode of execution, the entry end of catalyst converter and outlet end can be respectively arranged with upstream temperature sensor and downstream temperature sensor.At this moment, the temperature obtaining device 2026 in the obtaining device 202 of equipment 200 can be estimated based on the measured value of upstream temperature sensor and downstream temperature sensor the temperature of catalyst converter.For example, can be arithmetic mean value or the weighted mean value of upstream temperature and downstream temperature with the temperature computation of catalyst converter.

Note, above-described only is some possible example, and other any proper technology means of developing known or future at present all can be used for obtaining the working condition measuring value of catalyst converter.Scope of the present invention is unrestricted in this regard.

In an optional mode of execution of the present invention, can determine simultaneously according to a kind of mode of associating ammonia storage capacity and the ammonia surface coverage of catalyst converter.In other words, when determining the ammonia surface coverage of catalyst converter, ammonia storage capacity no longer must be constant, but is determined as dependent variable with the ammonia surface coverage alternatively.Correspondingly, in such mode of execution, definite device 204 of equipment 200 can comprise uniting determines device 2042, and its configuration is used for based on the described measured value that obtains, and determines together the ammonia surface coverage of catalyst converter in company with the ammonia storage capacity of catalyst converter.

Unite definite device 2042 and can determine simultaneously by any suitable mode ammonia storage capacity and the ammonia surface coverage of catalyst converter.For example, In some embodiments of the present invention, unite and determine that device can comprise the definite device (not shown) based on model, its configuration is used for described measured value as independent variable, by using the model of the chemical reaction characteristic that characterizes described catalyst converter, determine the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter.

In such mode of execution, can set up by any suitable means of developing known or future at present the reaction model (or abbreviation " reaction model ") of the chemical reaction characteristic that characterizes the SCR catalyst converter.Based on this reaction model, determine that device 204 will be used as independent variable by the catalyst converter working condition measuring value that obtaining device 202 obtains, in order to determine to estimate in other words simultaneously ammonia storage capacity and the ammonia surface coverage of catalyst converter.In other words, the ammonia storage capacity of catalyst converter and ammonia surface coverage are to serve as dependent variable in this reaction model.The below will describe the concrete example of a reaction model, and wherein, the independent variable of this reaction model comprises nitrous oxides concentration, ammonia concentration and the temperature in the catalyst converter.

In this mode of execution, as indicated above, temperature obtaining device 2026 for example can obtain the measured value of catalyst temperature in the following way:

$T=\frac{T_{\mathrm{Us}}+T_{\mathrm{Ds}}}{2}---\left(1\right)$

T wherein _UsAnd T _DsRespectively upstream temperature and the downstream temperature of catalyst converter.

The ammonia storage capacity of catalyst converter is expressed as Ω, and the ammonia surface coverage of catalyst converter is expressed as

Can set up in the following way the model that characterizes chemical reaction characteristic in the catalyst converter, that is, and reaction model:

${\stackrel{\·}{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}=c_{{\mathrm{NH}}_3}{a}_3\left(T\right)(1-{\mathrm{\Θ}}_{{\mathrm{NH}}_3})-[a_4\left(T\right)+a_5\left(T\right)c_{{\mathrm{NO}}_x}+a_6\left(T\right)]{\mathrm{\Θ}}_{{\mathrm{NH}}_3}---\left(2\right)$

${\stackrel{\·}{c}}_{{\mathrm{NO}}_x}=a_1{n}_{{\mathrm{NO}}_x,\mathrm{in}}^{*}-c_{N{O}_x}(a_0{a}_1{m}_{\mathrm{EG}}^{*}T+a_5\left(T\right)\mathrm{\Ω}{\mathrm{\Θ}}_{N{H}_3})---\left(3\right)$

${\stackrel{\·}{c}}_{N{H}_3}=a_1{n}_{{\mathrm{NH}}_3,\mathrm{in}}^{*}-c_{N{H}_3}[a_0{a}_1{m}_{\mathrm{EG}}^{*}T+a_3\left(T\right)\mathrm{\Ω}(1-{\mathrm{\Θ}}_{{\mathrm{NH}}_3})]+a_4\left(T\right)\mathrm{\Ω}{\mathrm{\Θ}}_{{\mathrm{NH}}_3}---\left(4\right)$

In formula (3)-(4), from temperature T, the nitrous oxides concentration measured value c of obtaining device 202 _NOxWith ammonia concentration measurement c _NH3Be independent variable.Other constants are defined as follows:

$a_0=\frac{R_{S,\mathrm{EG}}}{P_{\mathrm{amb}}};$

R _{S, EG}: engine exhaust constant (J/kgK);

P _Amb: external pressure (pa);

$a_1=\frac{n_{\mathrm{Cell}}}{\mathrm{\ϵ}{V}_C};$

n _Cell: catalyst converter infinitesimal number;

V _C: catalyst converter volume (m ³);

ε: void ratio;

$a_3\left(T\right)=S_C{\mathrm{\α}}_{\mathrm{Prob}}\sqrt{\frac{\mathrm{RT}}{2\mathrm{\πM}{r}_{N{H}_3}}};$

c _S: ammonia absorbing capacity, catalyst converter surface active atomic concentration (mol/m ³);

S _C: the area (m of surface activity atom ²/ mol);

α _Prob: sticking probability;

R: gas constant (J/molK)

The NH3 molecular weight

m ^* _EG: exhaust mass flow (kg/s)

$a_4\left(T\right)=k_{\mathrm{Des}}{e}^{\left(\frac{-E_{a,\mathrm{Des}}}{\mathrm{RT}}\right)}$

k _Des: NH3 desorption reactive rate (mol/m ³S);

E _ADes: NH3 desorption frequency factor;

$a_5\left(T\right)={\mathrm{RTk}}_{\mathrm{SCR}}{e}^{\left(\frac{-E_{a,\mathrm{SCR}}}{\mathrm{RT}}\right)}$

k _SCR: SCR chemical reaction frequency factor (m ²/ Ns)

E _ASCR: SCR chemical reaction activation energy (J/mol)

$a_6\left(T\right)=k_{\mathrm{Ox}}{e}^{\left(\frac{-E_{a,\mathrm{Ox}}}{\mathrm{RT}}\right)}$

k _OX: NH3 oxidation reaction frequency factor (m ²/ Ns)

E _AOX: NH3 oxidation reaction activation energy (J/mol)

Nitrous oxides concentration in the former machine discharging of diesel engine

The ammonia concentration that urea pump ejects

Note, above by the example of Chemical Reaction Model that is only used for characterizing catalyst converter of formula (2)-(4) foundation, be not intended to limit scope of the present invention.Can make in any suitable manner, take the working condition measuring value of SCR catalyst converter as independent variable, take the ammonia storage capacity of catalyst converter and ammonia surface coverage as dependent variable, set up the Chemical Reaction Model of SCR catalyst converter.

Based on the reaction model (for example, above-described exemplary reaction model) of the SCR catalyst converter of setting up, can determine by the set of equation of finding the solution the expression model ammonia storage capacity and the ammonia surface coverage of catalyst converter based on definite device of model.For example, still consider above to pass through the exemplary catalyst converter reaction model of formula (2)-(4) foundation as example.Based on formula (2)-(4), can derive following vector equation:

$\stackrel{\·}{x}=\mathrm{Ax}+\mathrm{\φ}(x,u)+\mathrm{\Ωf}\left(x\right)---\left(5\right)$

Wherein

Serve as controlled quentity controlled variable, and wherein:

$x=\left\{\begin{array}{c}{\mathrm{\Θ}}_{{\mathrm{NH}}_3}\\ c_{N{O}_X}\\ c_{N{H}_3}\end{array}\right\}$

$A=\left[\begin{array}{ccc}-(a_4\left(T\right)+a_1)& 0& 0\\ 0& -a_0{a}_1{m}_{\mathrm{EG}}^{*}T& 0\\ 0& 0& -a_0{a}_1{m}_{\mathrm{EG}}^{*}T\end{array}\right]$

$\mathrm{\φ}(x,u)=\left\{\begin{array}{c}{c}_{N{H}_3}{a}_3\left(T\right)(1-{\mathrm{\Θ}}_{{\mathrm{NH}}_3})-a_5\left(T\right){\mathrm{\Θ}}_{{\mathrm{NH}}_3}{c}_{N{O}_x}\\ a_1{n}_{{\mathrm{NO}}_x,\mathrm{in}}^{*}\\ a_{1}u\end{array}\right\}$

$f\left(x\right)=\left\{\begin{array}{c}0\\ -a_5\left(T\right){\mathrm{\Θ}}_{{\mathrm{NH}}_3}{c}_{{\mathrm{NO}}_x}\\ a_4\left(T\right){\mathrm{\Θ}}_{{\mathrm{NH}}_3}-a_3\left(T\right)c_{N{H}_3}(1-{\mathrm{\Θ}}_{{\mathrm{NH}}_3})\end{array}\right\}$

Here, in order to determine simultaneously more exactly ammonia storage capacity and the ammonia surface coverage of catalyst converter, according to some mode of execution of the present invention, the measured value of the catalyst converter operating mode that can obtain obtaining device 202 is further processed.For example, uniting the definite device based on model of determining in the device 2042 can comprise: the computing device (not shown), and its configuration is used for calculating according to the measured value that obtains the Observed value of corresponding operating mode; And first determine the device (not shown), and its configuration is used for based on reaction model, and the measured value of applying working condition and Observed value are determined the ammonia storage capacity of catalyst converter and the ammonia surface coverage of catalyst converter.

Particularly, as example, can operate based on definite device of model and to make nonlinear function φ (x, u) and f (x) satisfy local Li Puxisi (Lipchitz) condition, then have:

$\left|\right|\mathrm{\φ}(x,u)-\mathrm{\φ}(\hat{x},u)\left|\right|\≤{\mathrm{\α}}_1\left|\right|x-\hat{x}\left|\right|$

$\left|\right|f\left(x\right)-f\left(\hat{x}\right)\left|\right|\≤{\mathrm{\α}}_2\left|\right|x-\hat{x}\left|\right|$

α wherein ₁And α ₂It is constant.Consider simultaneously following Liapunov (Lyapunov) function:

$V=\frac{1}{2}{e}^{T}e+\frac{1}{2}\mathrm{\ρ}{\widetilde{\mathrm{\Ω}}}^2$

Wherein And

The State Viewpoint measured value of x,

The estimated value of Ω, and ρ＞0th, the weight factor constant.

Thus, can come in the following way to determine the Observed value of each working condition measuring value and correspondingly determine ammonia storage capacity and the ammonia surface coverage of catalyst converter based on definite device of model, so that:

${\stackrel{\·}{\hat{T}}}_{\mathrm{Ds}}=a_7{m}_{\mathrm{EG}}^{*}(T_{\mathrm{Us}}-{\hat{T}}_{\mathrm{Ds}})-a_9({\hat{T}}_{\mathrm{Ds}}^4-T_{\mathrm{amb}}^4)+L_1(T_{\mathrm{Us}}-{\hat{T}}_{\mathrm{Us}})---\left(6\right)$

$\hat{T}=\frac{T_{\mathrm{Us}}+T_{\mathrm{Ds}}}{2}---\left(7\right)$

${\stackrel{\·}{\widehat{\mathrm{\Θ}}}}_{{\mathrm{NH}}_3}=[a_4\left(\hat{T}\right)+a_6\left(\hat{T}\right)]{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}+{\hat{c}}_{{\mathrm{NH}}_3}{a}_3\left(\hat{T}\right)(1-{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3})-a_5\left(\hat{T}\right){\hat{c}}_{{\mathrm{NO}}_x}{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}---\left(8\right)$

${\stackrel{\·}{\hat{c}}}_{{\mathrm{NO}}_x}=-{\hat{c}}_{{\mathrm{NO}}_x}{a}_0{a}_1{m}_{\mathrm{EG}}^{*}\hat{T}+a_1{n}_{{\mathrm{NO}}_x,\mathrm{in}}^{*}-\widehat{\mathrm{\Ω}}{a}_5\left(\hat{T}\right){\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}{\hat{c}}_{{\mathrm{NO}}_x}+$ (9)

$L_1(c_{{\mathrm{NO}}_x}-{\hat{c}}_{{\mathrm{NO}}_x})-{\mathrm{\λ}}_1\mathrm{sign}(c_{{\mathrm{NO}}_x}-{\hat{c}}_{{\mathrm{NO}}_x})$

${\stackrel{\·}{\hat{c}}}_{{\mathrm{NH}}_3}=-{\hat{c}}_{{\mathrm{NH}}_3}{a}_0{a}_1{m}_{\mathrm{EG}}^{*}\hat{T}+a_{1}u+{\widehat{\mathrm{\Ω}}c}_{{\mathrm{NH}}_3}[a_4\left(\hat{T}\right){\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}-a_3\left(\hat{T}\right){\hat{c}}_{N{H}_3}(1-{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3})$ (10)

$+L_2(c_{N{H}_3}-{\hat{c}}_{{\mathrm{NH}}_3})-{\mathrm{\λ}}_2\mathrm{sign}(c_{{\mathrm{NH}}_3}-{\hat{c}}_{{\mathrm{NH}}_3})$

$\stackrel{\·}{\widehat{\mathrm{\Ω}}}=-\frac{1}{\mathrm{\ρ}}\{-a_5\left(\hat{T}\right){\hat{c}}_{{\mathrm{NO}}_x}{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}(c_{N{O}_x}-{\hat{c}}_{{\mathrm{NO}}_x})+$ (11)

$[a_4\left(\hat{T}\right){\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3}-a_3\left(\hat{T}\right){\hat{c}}_{{\mathrm{NH}}_3}(1-{\widehat{\mathrm{\Θ}}}_{{\mathrm{NH}}_3})](c_{N{H}_3}-{\hat{c}}_{{\mathrm{NH}}_3})\}$

Wherein with subscript " Λ " be the estimated value of respective measurement values or physical quantity, L ₁, L ₂, L ₃, λ ₁, λ ₂Be constant, they can be regulated and determine according to demand.In addition, sign is-symbol function is defined as follows:

$\mathrm{sign}\left(y\right)=\left\{\begin{array}{cc}-1:& y<0\\ 0:& y=0\\ 1& y>0\end{array}\right\}$

In this way, unite definite device (more specifically, definite device based on model) in fact can be regarded as the Adaptive Observer of a catalyst converter ammonia storage capacity and ammonia surface concentration, it is by the operation of "black box" pattern, thereby determine the ammonia storage capacity of catalyst converter and the estimated value of ammonia surface coverage (and other amounts, for example estimated value of working condition measuring value) based on the measured value of catalyst converter operating mode.Fig. 3 schematically shows the structured flowchart based on definite device of model.

Should be noted that the above-described measured value that only is based on the catalyst converter operating mode and determine the ammonia storage capacity of catalyst converter and the possible example of ammonia surface coverage.Based on instruction and the enlightenment that the present invention provides, those skilled in the art can easily expect the embodiment that any other is feasible.Therefore, anyly consider that when determining the estimated value of catalyst converter ammonia surface coverage ammonia storage capacity as the distortion of variable, all falls within the scope of the present invention.

Should be appreciated that shown in Fig. 1 and Fig. 2 and at above-described equipment 100 and 200 to utilize various ways to implement.For example, in some embodiments, equipment 100 and 200 can be implemented as intergrated circuit (IC), specific integrated circuit (ASIC), SOC(system on a chip) (SOC) or its combination in any.Alternatively or additionally, equipment 200 can also utilize software module to realize, namely is embodied as computer program.Scope of the present invention is unrestricted in this regard.

Below with reference to Fig. 4, it shows the flow chart for the method 400 of using in the SCR system according to exemplary embodiment of the invention.After method 400 beginnings, at step S402, obtain the measured value of at least one operating mode of the catalyst converter in the SCR system.In some embodiments, the measured value that obtains at least one operating mode of catalyst converter comprise obtain following at least one: the nitrous oxides concentration in the described catalyst converter, the ammonia concentration in the described catalyst converter; And the temperature in the described catalyst converter.

Next, method 400 proceeds to step S404, determines that based on the described measured value that obtains the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter at this.In some embodiments of the present invention, determining the ammonia storage capacity of described catalyst converter based on the described measured value that obtains comprises in order to determine the ammonia surface coverage of described catalyst converter: based on the described measured value that obtains, determine together the ammonia surface coverage of described catalyst converter in company with the ammonia storage capacity of described catalyst converter.Alternatively, determine in company with the ammonia storage capacity of described catalyst converter that together the ammonia surface coverage of described catalyst converter comprises based on the described measured value that obtains: with described measured value as independent variable, by using the reaction model of the chemical reaction characteristic that characterizes described catalyst converter, determine the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter.

In the mode of execution based on reaction model, determine that by the reaction model that uses the chemical reaction characteristic that characterizes described catalyst converter the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter comprise as independent variable with described measured value: the Observed value of calculating described at least one operating mode according to the described measured value that obtains; And based on described reaction model, determine that with described measured value and described Observed value the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.

Method 400 finishes after step S404.

The step that should be appreciated that in the method 400 record corresponds respectively to above operation and/or the function of each device in the equipment 100 and 200 of describing with reference to figure 1 and Fig. 2.Thus, above reference device 100 and each device of 200 and the feature described is equally applicable to each step of method 400.And each step of record can be carried out and/or executed in parallel according to different orders in the method 400.

In addition, should be appreciated that the method 400 of describing with reference to figure 4 can realize by computer program.For example, this computer program can comprise at least one computer-readable recording medium, and it has the computer readable program code part that is stored thereon.When computer-readable code part when for example processor is carried out, it is used for the step of manner of execution 400.

Above spirit of the present invention and principle have been explained in conjunction with some embodiments.According to the embodiment of the present invention, when determining based on the operating mode of the catalyst converter that measures or claiming to estimate the ammonia surface coverage of catalyst converter, the ammonia storage capacity of catalyst converter (or claiming storage ammonia ability) can not be assumed that constant in the prior art for another example like that all the time, or determines based on specific dynamics.On the contrary, embodiments of the present invention are not done any hypothesis to the dynamics of ammonia storage capacity, and it can be that constant also can be variable.Especially, can determine simultaneously based on the Chemical Reaction Model of catalyst converter ammonia storage volume and the ammonia surface coverage of catalyst converter.The physical features that the ammonia storage volume of determining in this way and ammonia surface coverage can reflect the SCR catalyst converter more truly, exactly.In addition, the solution of the present invention's proposition is easy to realize and operation in practice.

Should be noted that embodiments of the present invention can realize by the combination of hardware, software or software and hardware.Hardware components can utilize special logic to realize; Software section can be stored in the storage, and by suitable instruction execution system, for example microprocessor or special designs hardware are carried out.Those having ordinary skill in the art will appreciate that above-mentioned equipment and method can and/or be included in the processor control routine with computer executable instructions realizes, for example such as the mounting medium of disk, CD or DVD-ROM, provide such code such as the programmable memory of ROM (read-only memory) (firmware) or such as the data medium of optics or electronic signal carrier.Equipment of the present invention and module thereof can be by such as vlsi circuit or gate array, realize such as the semiconductor of logic chip, transistor etc. or such as the hardware circuit of the programmable hardware device of field programmable gate array, programmable logic device etc., also can use the software of being carried out by various types of processors to realize, also can by the combination of above-mentioned hardware circuit and software for example firmware realize.

Although should be noted that some devices or the sub-device of having mentioned equipment in above-detailed, this division only is not enforceable.In fact, according to the embodiment of the present invention, the feature of above-described two or more devices and function can be specialized in a device.Otherwise, the feature of an above-described device and function can Further Division for to be specialized by a plurality of devices.

In addition, although described in the accompanying drawings the operation of the inventive method with particular order,, this is not that requirement or hint must be carried out these operations according to this particular order, or the operation shown in must carrying out all could realize the result of expectation.On the contrary, the step of describing in the flow chart can change execution sequence.Additionally or alternatively, can omit some step, a plurality of steps be merged into a step carry out, and/or a step is decomposed into a plurality of steps carries out.

Although described the present invention with reference to some embodiments, should be appreciated that, the present invention is not limited to disclosed embodiment.The present invention is intended to contain interior included various modifications and the equivalent arrangements of spirit and scope of claims.The scope of claims meets the most wide in range explanation, thereby comprises all such modifications and equivalent structure and function.

Claims (10)

1. equipment that in the selective catalytic reduction SCR of diesel engine system, uses, described SCR system comprises catalyst converter to utilize ammonia to transform the nitrogen oxide of described diesel engine emissions, described equipment comprises:

Obtaining device, it is coupled to described catalyst converter, and configuration is for the measured value of at least one operating mode of obtaining described catalyst converter; And

Determine device, it is coupled to described obtaining device, and configuration determines that for the described measured value that obtains based on described obtaining device the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.

2. equipment according to claim 1, wherein said definite device comprises:

Unite definite device, configuration is determined the ammonia surface coverage of described catalyst converter together for the described measured value that obtains based on described obtaining device in company with the ammonia storage capacity of described catalyst converter.

3. equipment according to claim 2, the wherein said associating determines that device comprises:

Based on definite device of model, configuration is used for described measured value based on the reaction model of the chemical reaction characteristic that characterizes described catalyst converter, determining the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter as independent variable.

4. equipment according to claim 3, wherein said definite device based on model comprises:

Computing device, configuration calculate the Observed value of described at least one operating mode for the described measured value that obtains according to described obtaining device;

First determines device, and configuration is used for based on described reaction model, determines the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter with described measured value and described Observed value.

5. equipment according to claim 1, wherein said obtaining device comprise following at least one:

The first concentration acquisition device, configuration is used for obtaining the nitrous oxides concentration of described catalyst converter;

The second concentration acquisition device, configuration is used for obtaining the ammonia concentration of described catalyst converter; And

The temperature obtaining device, configuration is used for obtaining the temperature of described catalyst converter.

6. method of in the selective catalytic reduction SCR of diesel engine system, using, described SCR system comprises catalyst converter to utilize ammonia to transform the nitrogen oxide of described diesel engine emissions, described method comprises:

Obtain the measured value of at least one operating mode of described catalyst converter; And

Determine that based on the described measured value that obtains the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.

7. method according to claim 6, wherein determine the ammonia storage capacity of described catalyst converter based on the described measured value that obtains and comprise in order to determine the ammonia surface coverage of described catalyst converter:

Based on the described measured value that obtains, determine together the ammonia surface coverage of described catalyst converter in company with the ammonia storage capacity of described catalyst converter.

8. method according to claim 7, wherein determine in company with the ammonia storage capacity of described catalyst converter that together the ammonia surface coverage of described catalyst converter comprises based on the described measured value that obtains:

As independent variable, based on the reaction model of the chemical reaction characteristic that characterizes described catalyst converter, determine the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter with described measured value.

9. method according to claim 8, wherein determine that based on the reaction model of the chemical reaction characteristic that characterizes described catalyst converter the ammonia storage capacity of described catalyst converter and the ammonia surface coverage of described catalyst converter comprise as independent variable with described measured value:

Calculate the Observed value of described at least one operating mode according to the described measured value that obtains; And

Based on described reaction model, determine that with described measured value and described Observed value the ammonia storage capacity of described catalyst converter is in order to determine the ammonia surface coverage of described catalyst converter.

10. method according to claim 6, the measured value that wherein obtains at least one operating mode of described catalyst converter comprise obtain following at least one: the nitrous oxides concentration in the described catalyst converter, the ammonia concentration in the described catalyst converter; And the temperature in the described catalyst converter.

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