CN107614842B

CN107614842B - Emission-control equipment

Info

Publication number: CN107614842B
Application number: CN201680030092.5A
Authority: CN
Inventors: 中田辉男; 坂本隆行; 长冈大治
Original assignee: 50 Yen Self-Help Stop Stock Co
Current assignee: 50 Yen Self-Help Stop Stock Co
Priority date: 2015-05-27
Filing date: 2016-05-24
Publication date: 2019-11-08
Anticipated expiration: 2036-05-24
Also published as: JP6604034B2; WO2016190296A1; JP2016223292A; CN107614842A

Abstract

It include: SOx discharging amount calculation section (69),, based on value of the SOx uptake with the absorbed SOx of expression after the desulfurization degree of the interior ratio being desulfurized per unit time is multiplied by reduction catalyst absorption is absorbed by NOx, NOx when executing catalyst regeneration process successively to calculate absorbs the desulfurization amount per unit time in reduction catalyst for it；SOx uptake operational part (67), using the desulfurization amount successively calculated by SOx discharging amount calculation section (69), to estimate the newest SOx uptake that NOx absorbs reduction catalyst；And SOx purification executes control unit (68), and the execution of catalyst regeneration process is controlled based on the SOx uptake being deduced.

Description

Emission-control equipment

Technical field

The present invention relates to the row for making absorbed SOx be detached from the catalyst regeneration process removed is executed for NOx catalyst Air purifying apparatus.

Background technique

In the past, as to from the exhaust that internal combustion engine is discharged nitride (NOx) carry out reduction purification NOx catalyst, Such as known NOx absorbs reduction catalyst.NOx absorbs reduction catalyst and absorbs when exhaust is lean-burn environment to be contained in exhaust Some NOx, also, the NOx that will have been absorbed with the hydrocarbon contained in exhaust by reduction purification when exhaust is dense combustion environment without Evilization is simultaneously discharged.Therefore, in the case where the NOx uptake of catalyst has reached predetermined amount, in order to keep NOx absorbability extensive It is multiple, it is periodically required to the so-called NOx for make exhaust to become dense combustion state purification (for example, referring to patent document 1).

In addition, absorbing the oxysulfide (hereinafter referred to as SOx) for also absorbing in reduction catalyst and containing in exhaust in NOx. If SOx uptake increases, there are problems that the NOx detergent power for making NOx absorb reduction catalyst reduces.Therefore, in SOx In the case that uptake has reached predetermined amount, it is detached to make SOx absorb reduction catalyst from NOx with from sulfur poisoning (in S Poison) restore, the so-called SOx for being periodically required to that delivery temperature make to rise to SOx disengaging temperature is purified (for example, referring to patent Document 2).

Existing technical literature

Patent document

Patent document 1: Japanese Unexamined Patent Publication 2008-202425 bulletin

Patent document 2: Japanese Unexamined Patent Publication 2009-47086 bulletin

Summary of the invention

Subject to be solved by the invention

For example, for the SOx uptake that the absorbing material for being absorbed reduction catalyst by NOx adsorbs, by by source The result that SOx amount in fuel and the SOx amount phase adduction from machine oil subtract after being released to external SOx amount is accumulated Point, to estimate.

In the execution of SOx purification, such as think that being released to external SOx amount per unit time is constant basis.

SOx uptake for example in order to judge SOx purification (catalyst regeneration process) beginning or end and used.Cause This, if SOx uptake cannot be estimated accurately, it is likely that SOx purification can be executed all for naught, lead to fuel economy Deterioration.Thus, it is desirable that accurately estimate the SOx uptake adsorbed by NOx catalyst.

The purpose of the emission-control equipment of the disclosure is to make the precision of the presumption of the SOx uptake of NOx catalyst to improve, And suitably control the execution of catalyst regeneration process.

Means for solving the problems

The emission-control equipment of the disclosure makes the NOx catalyst that is arranged in the exhaust passage of internal combustion engine, execution Delivery temperature rises to desulfurization temperature so that the SOx absorbed by NOx catalyst is detached from the catalyst regeneration process removed, packet Include: desulfurization amount calculates component, based on by SOx uptake that NOx catalyst absorbs and indicating that absorbed SOx exist The desulfurization degree for the ratio being desulfurized per the scheduled time be multiplied after value, when execution successively to calculate catalyst regeneration process Desulfurization amount in NOx catalyst；Uptake estimates component, is pushed away using the desulfurization amount that component successively calculates is calculated by desulfurization amount Determine the newest SOx uptake of NOx catalyst；And control unit is executed, it is controlled based on the SOx uptake being deduced Catalyst regeneration process.

Invention effect

According to the emission-control equipment of the disclosure, the precision of the presumption of the SOx uptake of NOx catalyst, energy can be improved Enough it is appropriately performed catalyst regeneration process.

Detailed description of the invention

Fig. 1 is the monolithically fabricated figure for indicating the emission control system of present embodiment.

Fig. 2 is the timing diagram for illustrating the SOx purification control of present embodiment.

The block diagram of the setting processing of MAF target value when Fig. 3 is the SOx purification lean-burn control for indicating present embodiment.

Fig. 4 is the block diagram for indicating the setting processing of the target injection amount when SOx of present embodiment purifies dense combustion control.

Fig. 5 is the timing diagram for illustrating the catalyst temperature adjustment control of SOx purification control of present embodiment.

Fig. 6 is the block diagram ended processing for indicating the SOx purification control of present embodiment.

Fig. 7 is to illustrate that the SOx of present embodiment purifies the figure of the SOx uptake under control.

Fig. 8 is the block diagram for indicating the processing of the amount of injection learning correction of the In-cylinder injector of present embodiment.

Fig. 9 is the flow chart for illustrating the calculation process of the learning correction coefficient of In-cylinder injector of present embodiment.

Figure 10 is the block diagram for indicating the setting processing of MAF correction coefficient of present embodiment.

Specific embodiment

Hereinafter, uptake estimating device based on Detailed description of the invention one embodiment of the present invention and applying the uptake The emission control system of estimating device.

As shown in Figure 1, being respectively arranged with not to be schemed in each cylinder of diesel motor (hreinafter referred to as engine) 10 In-cylinder injector 11 of the high pressure fuel of the common rail pressure accumulation shown to each cylinder inner direct.The combustion of these each In-cylinder injectors 11 Material the amount of injection or fuel injection timing are controlled according to the indication signal inputted from electronic control unit (hereinafter referred to as ECU) 50 System.

It is connected with the inlet channel 12 for importing new gas on the inlet manifold 10A of engine 10, is connected on exhaust manifold 10B Having will be vented to exhaust passage 13 derived from outside.In inlet channel 12, air mistake is disposed with from inlet upstream Filter 14, inhaled air volume sensor (hereinafter referred to as MAF (Mass Air Flow) sensor) 40, variable capacity type booster 20 compressor 20A, intercooler 15, air inlet shutter 16 etc..In exhaust passage 13, it is disposed with from exhaust-gas upstream side The turbine 20B of variable capacity type booster 20, exhaust gas post-treatment device 30 etc..In addition, the expression of appended drawing reference 41 is drawn in Fig. 1 Speed probe is held up, appended drawing reference 42 indicates accelerator open degree sensor, and appended drawing reference 46 indicates boost-pressure sensor.

EGR (Exhaust Gas Recirculation: exhaust gas recirculatioon) device 21 includes: EGR channel 22, connection Exhaust manifold 10B and inlet manifold 10A；Cooler for recycled exhaust gas 23 cools down EGR gas；And EGR valve 24, adjust EGR amount.

Exhaust gas post-treatment device 30 be by configured in order from exhaust-gas upstream side in shell 30A oxidation catalyst 31, NOx absorb reduction catalyst (example of NOx catalyst) 32, particulate filter (hreinafter referred to as filter) 33 and It constitutes.In addition, being provided with exhaust steam injector 34, the exhaust in than the exhaust passage 13 on the upstream side of oxidation catalyst 31 Injector 34 according to from the indication signal that ECU50 is inputted come into exhaust passage 13 spray unburned fuel (mainly HC).

Oxidation catalyst 31 be, for example, by the ceramic systems supporting body surface such as honeycomb structure carry oxidation catalyst at Point and formed.If by exhaust steam injector 34 or In-cylinder injector 11 it is remote after spray to oxidation catalyst 31 and supply unburned combustion Material, then oxidation catalyst 31 is oxidized and increase delivery temperature.

It is, for example, by carrying alkali gold on the ceramic systems supporting body surface such as honeycomb structure that NOx, which absorbs reduction catalyst 32, Belong to etc. and formed.The NOx absorbs reduction catalyst 32 and absorbs the NOx in being vented when exhaust air-fuel ratio is lean burn, Also, absorbed NOx is gone back with the reducing agent (HC etc.) contained in exhaust when exhaust air-fuel ratio is dense combustion state Original purification.

Filter 33 is, for example, flowing side of the multiple units by will be divided by the partition wall of Porous along exhaust To configuration and by the upstream side of these units and downstream side alternately hole close and formed.Pore of the filter 33 in partition wall Or the PM (particulate material) in the trapping exhaust of surface, if also, PM accumulation estimated amount reach predetermined amount, execution is burnt The so-called filter forced regeneration removed.Pass through the oxidation catalyst 31 using exhaust pipe inspection or remote rear injection to the upstream side Unburned fuel is supplied, the delivery temperature flowed into filter 33 is warming up to PM ignition temperature, to be filtered device pressure Regeneration.

1st exhaust gas temperature sensor 43 is arranged on the position than oxidation catalyst 31 on the upstream side, aoxidizes to being flowed into Delivery temperature in catalyst 31 is detected.2nd exhaust gas temperature sensor 44 is configured in NOx and absorbs reduction catalyst 32 Between filter 33, the delivery temperature flowed into filter 33 is detected.NOx/ exhaust gas oxygensensor 45 is exhaust actual measurement portion of the invention One example of part, is arranged on the position than 33 downstream of filter, and detection has passed through NOx and absorbed reduction catalyst 32 Exhaust NOx value and λ value (hereinafter also referred to as excess air ratio).

ECU50 carries out the equal various controls of engine 10, and to be configured to include well known CPU, ROM, RAM, input interface, defeated Outgoing interface etc..In order to carry out these various controls, the sensor values of sensor class 40~46 is input into ECU50.In addition, There is in ECU50 as part thereof of functional imperative filter regeneration control unit 51, SOx purification control unit 60, NOx purification Control unit 70, MAF follow control unit 80, In-cylinder injector learning correction portion 90 and MAF correction coefficient operational part 98.These Each functional imperative illustrates as the element being comprised in the ECU50 as integrated hardware, still, additionally it is possible among these Any a part be set as individual hardware.

[control of filter forced regeneration]

Filter regeneration control unit 51 is detected according to the operating range of vehicle or not shown pressure difference transducer Pressure difference estimates the PM accumulating amount of filter 33 before and after filter, if also, PM accumulation estimated amount is more than the scheduled upper limit Threshold value then activates forced regeneration mark F_DPF(t at the time of referring to Fig. 2₁).If forced regeneration mark F_DPFIt is activated, then to exhaust After injector 34 sends the indication signal for making it execute exhaust pipe inspection or keeps its execution remote the transmission of each In-cylinder injector 11 The indication signal of injection makes delivery temperature be warming up to PM ignition temperature (for example, about 550 DEG C).If PM accumulation estimated amount is reduced to It indicates the scheduled lower threshold (decision threshold) being flared off, then closes forced regeneration mark F_DPF(at the time of referring to Fig. 2 t₂).In addition, closing forced regeneration mark F_DPFDecision threshold for example filter forced regeneration can also be started into (F_DPF=1) The upper limit afterwards adds up the amount of injection as benchmark by time or the upper limit.

[SOx purification control]

SOx purification control unit 60 executes control as follows: exhaust being made to become dense combustion state so that delivery temperature rises to desulfurization Temperature (for example, about 600 DEG C) makes NOx absorb reduction catalyst 32 and restores from SOx poisoning (hereinafter, the control is known as SOx Purify (catalyst regeneration process) control).

Fig. 2 indicates the timing diagram of the SOx purification control of present embodiment.As shown in Fig. 2, in forced regeneration mark F_DPFQuilt While closing, start the SOx purification mark F of SOx purification control_SPBe activated (t at the time of referring to Fig. 2₂).Thereby, it is possible to height Effect ground is transferred to SOx purification control, Neng Gouyou from the state that the forced regeneration by filter 33 rises delivery temperature Reduce fuel consumption in effect ground.

In the present embodiment, the lower dense burning of SOx purification control be by and with SOx purification lean-burn control and SOx it is net Change it is dense combustion control and realize, wherein the SOx purification lean-burn control in, using air system control make excess air ratio from (for example, about 1.5) it is superfluous to be reduced to 1st target gas of the value (about 1.0) more suitable than chemically correct fuel by lean-burn side when normal operation Rate (for example, about 1.3) purifies in dense combustion control in the SOx, makes excess air ratio from the 1st target gas using spraying system control Excess rate is reduced to the 2nd target gas excess rate (for example, about 0.9) of dense combustion side.Hereinafter, illustrate SOx purification lean-burn control and SOx purifies the details of dense combustion control.

[the air system control that SOx purifies lean-burn control]

Fig. 3 is MAF target value MAF when indicating SOx purification lean-burn control_{SPL_Trgt}Setting processing block diagram.1st mesh Mark excess air ratio setting chart 61 is referenced based on engine speed Ne and accelerator open degree Q (fuel injection amount of engine 10) Chart, be in advance based on experiment etc. and be set with SOx corresponding with these engine speeds Ne and accelerator open degree Q purification lean-burn control When excess air ratio target value λ_{SPL_Trgt}(the 1st target gas excess rate).

Firstly, setting chart from the 1st target gas excess rate using engine speed Ne and accelerator open degree Q as input signal 61 read excess air ratio target value λ when SOx purification lean-burn control_{SPL_Trgt}, and it is input to MAF target value operational part 62.Into One step, the MAF target value in MAF target value operational part 62, when based on formula below (1) operation SOx purification lean-burn control MAF_{SPL_Trgt}。

[numerical expression 1]

In numerical expression (1), Q_{Fnl_Corrd}Indicate the aftermentioned fuel injection amount by after learning correction (in addition to spraying it after remote Outside), Ro_FuelIndicate fuel specific gravity, AFR_stoRepresentation theory air-fuel ratio, Maf_{_ Corr}Indicate aftermentioned MAF correction coefficient.

If SOx purification mark F_SPBecome activation (t at the time of referring to Fig. 2₂), then it will be by 62 operation of MAF target value operational part MAF target value MAF_{SPL_Trgt}It is input to gradient (ramp) processing unit 63.Gradient processing unit 63 opens engine speed Ne and throttle Q is spent as input signal and reads gradient coefficient from each gradient coefficient chart 63A, 63B, also, will attached the gradient coefficient MAF target amount of taper MAF_{SPL_Trgt_Ramp}It is input to valve control unit 64.

Valve control unit 64 is in order to enable the practical MAF value MAF inputted from maf sensor 40_ActReach MAF target amount of taper MAF_{SPL_Trgt_Ramp}, and execute by air inlet shutter 16 to close side throttling and by EGR valve 24 to open side open feedback control System.

In this way, in the present embodiment, based on the excess air ratio read from the 1st target gas excess rate setting chart 61 Target value λ_{SPL_Trgt}And the fuel injection amount of each In-cylinder injector 11 sets MAF target value MAF_{SPL_Trgt}, it is based on the MAF mesh Scale value MAF_{SPL_Trgt}Air system is acted and carries out feedback control.Thus, it is not necessary to absorb the upper of reduction catalyst 32 in NOx It swims side and exhaust gas oxygensensor is set, alternatively, even if the case where the upstream side that NOx absorbs reduction catalyst 32 is provided with exhaust gas oxygensensor Under, it need not also use the sensor values of the exhaust gas oxygensensor, it will be able to be reduced to exhaust needed for SOx purification lean-burn control Desired excess air ratio.

In addition, by by the fuel injection amount Q after learning correction_{Fnl_Corrd}Fuel injection as each In-cylinder injector 11 Amount, so as to set MAF target value MAF with feedforward control_{SPL_Trgt}, can effectively exclude each In-cylinder injector 11 Deterioration year in year out or the influence of characteristic variations, individual difference etc..

In addition, by MAF target value MAF_{SPL_Trgt}The additional gradient coefficient set according to the operating condition of engine 10, So as to be effectively prevented the misfiring or due to torque changes of caused by the change dramatically of inhaled air volume engine 10 The deterioration etc. of caused driving.

[the fuel injection amount setting that SOx purifies dense combustion control]

Fig. 4 is to indicate that SOx purifies the exhaust pipe inspection in dense combustion control or the remote rear target injection amount Q sprayed_{SPR_Trgt} The block diagram of the setting processing of (the amount of injection per unit time).2nd target gas excess rate setting chart 65 is turned based on engine Fast Ne and accelerator open degree Q and referenced chart are in advance based on experiment etc. and are set with and these engine speeds Ne and accelerator open degree Q Corresponding SOx purifies excess air ratio target value λ when dense combustion control_{SPR_Trgt}(the 2nd target gas excess rate).

Firstly, setting chart from the 2nd target gas excess rate using engine speed Ne and accelerator open degree Q as input signal 65 reading SOx purify excess air ratio target value λ when dense combustion control_{SPR_Trgt}, and it is input to the amount of injection target value operational part 66.Further, in the amount of injection target value operational part 66, mesh when dense combustion control is purified based on formula below (2) operation SOx Mark the amount of injection Q_{SPR_Trgt}。

[numerical expression 2]

In numerical expression (2), MAF_{SPL_Trgt}MAF target value when being SOx purification lean-burn, is transported from above-mentioned MAF target value Calculation portion 62 inputs.In addition, Q_{Fnl_Corrd}Indicate that the aftermentioned MAF by after learning correction follows the fuel injection amount before control application (other than being sprayed after remote), Ro_FuelIndicate fuel specific gravity, AFR_stoRepresentation theory air-fuel ratio, Maf_{_ Corr}Indicate aftermentioned MAF Correction coefficient.

If aftermentioned SOx, which purifies dense combustion, indicates F_SPRBecome to activate, then it will be by the mesh of 66 operation of the amount of injection target value operational part Mark the amount of injection Q_{SPR_Trgt}Exhaust steam injector 34 or each In-cylinder injector 11 are sent to as injection indication signal.

In this way, in the present embodiment, based on the excess air ratio read from the 2nd target gas excess rate setting chart 65 Target value λ_{SPR_Trgt}And the fuel injection amount of each In-cylinder injector 11 sets target injection amount Q_{SPR_Trgt}.Thus, it is not necessary to Exhaust gas oxygensensor is arranged in the upstream side that NOx absorbs reduction catalyst 32, alternatively, even if absorbing the upper of reduction catalyst 32 in NOx In the case that trip side is provided with exhaust gas oxygensensor, the sensor values of the exhaust gas oxygensensor need not be also used, it will be able to effectively drop exhaust Desired excess air ratio needed for purifying dense combustion control as low as SOx.

In addition, by by the fuel injection amount Q after learning correction_{Fnl_Corrd}Fuel injection as each In-cylinder injector 11 Amount, so as to set target injection amount Q with feedforward control_{SPR_Trgt}, can effectively exclude the warp of each In-cylinder injector 11 Year deterioration or the influence of characteristic variations etc..

[catalyst temperature of SOx purification control adjusts control]

T at the time of such as Fig. 2₂~t₄It is shown, by alternately switching execution exhaust pipe inspection or the remote rear SOx purification sprayed Dense combustion indicates F_SPRActivation/closing (dense combustion/lean-burn), thus control SOx purification control in be flowed into NOx absorb reduced form Delivery temperature in catalyst 32 (hereinafter also referred to as catalyst temperature).If SOx, which purifies dense combustion, indicates F_SPRBe activated (F_SPR= 1), then catalyst temperature rises due to exhaust pipe inspection or remote rear injection (hereinafter, this period will be known as injection period T_{F_INJ}).On the other hand, if SOx purifies dense combustion and indicates F_SPRIt is closed, then catalyst temperature is due to exhaust pipe inspection or remote rear spray The stopping penetrated and reduce (hereinafter, interval T will be known as during this period_{F_INT})。

In the present embodiment, by setting from the injection period for first passing through the production such as experiment in advance, chart is (not shown) to be read Value corresponding with engine speed Ne and accelerator open degree Q, to set injection period T_{F_INJ}.In injecting time setting chart, With the operating condition of engine 10 be correspondingly set with it is pre- first pass through experiment etc. find out in order to make exhaust excess air ratio it is reliable Ground is reduced to the 2nd target gas excess rate and the injection period that needs.

Dense combustion, which is purified, in the highest SOx of catalyst temperature indicates F_SPRWhen being switched to closing from activation, pass through feedback control Setting interval T_{F_INT}.Specifically, being handled by PID control, which includes: to purify dense combustion mark F with SOx_SPRQuilt The ratio control that the deviation delta T of final catalyst temperatures and presumption catalyst temperature when closing proportionally changes input signal The integration control that the time integral value of system and deviation delta T proportionally change input signal and the time with deviation delta T The differential control that differential value proportionally changes input signal.With the temperature that can absorb the disengaging of reduction catalyst 32 SOx from NOx Degree is to set final catalyst temperatures, such as the entrance based on the oxidation catalyst 31 detected by the 1st exhaust gas temperature sensor 43 Temperature and exothermic reaction of inside of reduction catalyst 32 etc. is absorbed in oxidation catalyst 31 and NOx to estimate presumption catalysis Agent temperature.

T at the time of such as Fig. 5₁It is shown, if SOx purification mark F_SPDue to the end (F of filter forced regeneration_DPF=0) and by Activation, then SOx purifies dense combustion mark F_SPRAlso it is activated, also, is fed back calculated when previous SOx purifies control Every T_{F_INT}Also it is temporarily reset.That is, after the firm preparation, regeneration of filter for the first time, being set according to injection period setting chart Fixed injection period T_{F_INJ_1}Come execute exhaust pipe inspection or it is remote after injection (t at the time of referring to Fig. 5₁~t₂).In this way, due to not It carries out SOx purification lean-burn control and purifies SOx purification control dense combustion controls since SOx, so, it will not make to force in filter The delivery temperature risen in regeneration reduces, and can promptly be transferred to SOx purification control, can reduce fuel consumption.

Next, if SOx purifies dense combustion and indicates F_SPRDue to passing through injection period T_{F_INJ_1}And become to close, then SOx is purified Dense combustion indicates F_SPRIt is closed, until the interval T by being set by PID control_{F_INT_1}Until (t at the time of referring to Fig. 5₂~ t₃).Further, if SOx purifies dense combustion and indicates F_SPRDue to through super-interval T_{F_INT_1}And be activated, then again execute and injection period Between T_{F_INJ_2}Corresponding exhaust pipe inspection or it is remote after injection (t at the time of referring to Fig. 5₃~t₄).Then, these SOx are repeated Purify dense combustion mark F_SPRActivation/closing switching, until due to aftermentioned SOx purification control end determine and SOx purify Indicate F_SPIt is closed (t at the time of referring to Fig. 5_n) until.

In this way, in the present embodiment, according to based on the operating condition of engine 10 and the chart of reference makes to be catalyzed to set The injection period T that agent temperature rises and excess air ratio is made to be reduced to the 2nd target gas excess rate_{F_INJ}, also, utilize PID It controls to handle the interval T for declining catalyst temperature_{F_INT}.Thereby, it is possible to one side to purify the catalyst temperature in controlling for SOx Desired temperature range needed for degree effectively maintains purification, makes excess air ratio reliably be reduced to target excess on one side Rate.

[end of SOx purification control determines]

Fig. 6 is the block diagram ended processing for indicating SOx purification control.SOx uptake operational part 67 is based on numerical expression below (3), operation be assumed in exhaust there is a situation where and its full dose by NOx absorb reduction catalyst 32 absorbing material absorption Under SOx uptake SOx_{_ STR}(g).In the present embodiment, SOx uptake operational part 67 is in the starting of engine 10 based on number Formula (3) Lai Yici operation SOx uptake SOx_{_ STR}(g).SOx uptake operational part 67 is that uptake presumption component and additional quantity are calculated An example of component out.

[numerical expression 3]

SOx_{_STR}=∫ (SOx_{_Fuel}+SOx_{_oil}-SOx_{_out})

As shown in numerical expression (3), SOx uptake SOx_{_ STR}It is to the SOx amount SOx that will derive from fuel_{_ Fuel}(g/s) and come Derived from the SOx amount SOx of machine oil_{_ oil}(g/s) phase adduction subtracts SOx discharging amount SOx_{_ out}(g/s) result after is integrated and is obtained It arrives.Herein, from the SOx amount SOx of fuel_{_ Fuel}With the SOx amount SOx for deriving from machine oil_{_ oil}It is the operating based on internal combustion engine State and by operation.

SOx discharging amount SOx_{_ out}It is desulfurization amount per unit time.In SOx purification, SOx discharging amount calculation section 69 is used Following numerical expression (4) carries out operation, to calculate SOx discharging amount SOx_{_ out}.In addition, being put other than in SOx purification using SOx Output calculation section 69 absorbs catalyst temperature of reduction catalyst 32 etc. based on NOx and calculates SOx discharging amount SOx_{_ out}.In addition, Other than in SOx purification, the SOx amount SOx of fuel will be derived from_{_ Fuel}With the SOx amount SOx for deriving from machine oil_{_ oil}It is subtracted after addition SOx discharging amount SOx_{_ out}(g/s) result is equivalent to by SOx uptake SOx_{_ STR}The addition uptake (g/s) newly absorbed.

SOx discharging amount SOx_{_ out}=(SOx uptake SOx_{_ STR}* desulfurization degree per unit time) * desulfurization degree correction system Number ... (4)

Herein, the numerical expression (4) newly obtained based on inventor below opinion, it may be assumed that in SOx purification per unit time SOx discharging amount SOx_{_ out}According to SOx uptake SOx_{_ STR}And change, SOx uptake SOx_{_ STR}It is more, SOx discharging amount SOx_{_ out} More become more；And indicate the amount for being desulfurized (releasing) of every scheduled time (unit time) relative to SOx uptake SOx_{_ STR} The desulfurization degree of ratio be not dependent on SOx uptake SOx_{_ STR}Amount but it is same.

Desulfurization degree per unit time in the numerical expression (4) is according to the time from the beginning of SOx purification (when passing through Between) and change.In the present embodiment, the desulfurization degree chart 691 for indicating to pass through the corresponding relationship of time and desulfurization degree is stored In ECU60, SOx discharging amount calculation section 69 purifies the warp for executing the acquirement of control unit 68 from the beginning of SOx purification from SOx The time is spent, and is obtained from desulfurization degree chart 691 and passes through time corresponding desulfurization degree with this, is calculated using acquired desulfurization degree SOx discharging amount SOx_{_ out}。

In addition, desulfurization degree correction coefficient is for the temperature (catalyst temperature) for absorbing reduction catalyst 32 by NOx With the corrected correction coefficient of variation of desulfurization degree caused by the λ (excess air ratio) in exhaust.Desulfurization degree correction coefficient energy Enough first pass through in advance changes catalyst temperature and λ and measures SOx discharging amount and obtain.SOx discharging amount calculation section 69 is based on catalysis Agent temperature and λ determine corresponding desulfurization degree correction coefficient, and calculate SOx releasing using identified desulfurization degree correction coefficient Measure SOx_{_ out}.For catalyst temperature, the entrance temperature based on the oxidation catalyst 31 detected by the 1st exhaust gas temperature sensor 43 Degree and the HC/CO calorific value of the inside of reduction catalyst 32 is absorbed, to external heat dissipation capacity in oxidation catalyst 31 and NOx Etc. estimating.

If (1) purifying mark F from SOx_SPAccumulative exhaust pipe inspection or the remote rear the amount of injection sprayed and the accumulative spray are activated The amount of penetrating has reached the case where scheduled upper limit threshold amount, (2) timing from SOx purification control and has reached by the time The case where scheduled upper limit threshold time, (3) absorb reduction catalyst 32 by the NOx that SOx uptake operational part 67 calculates SOx uptake SOx_{_ STR}It is reduced to indicate among the case where SOx removes successfully scheduled threshold value (termination condition threshold value) Any one condition set up, then SOx purification executes control unit 68 and closes SOx purification mark F_SPAnd SOx purification is made to terminate (reference T at the time of Fig. 2₄, Fig. 5 at the time of t_n)。

In the present embodiment, as noted previously, as having used the numerical expression for meeting the opinion that inventor newly obtains, so energy SOx discharging amount SOx per unit time in enough accurately presumption SOx purifications_{_ out}.Therefore, can accurately estimate makes With SOx discharging amount SOx_{_ out}Obtained from SOx uptake SOx_{_ STR}.Thus, by using SOx uptake SOx_{_ STR}, so as to Enough suitably control the execution (being to terminate in the present embodiment) of SOx purification.

In addition, in the present embodiment, by the way that accumulative the amount of injection and process are arranged in the termination condition of SOx purification control The upper limit of time, so that fuel can be effectively prevented in the case where SOx purification is not in progress due to delivery temperature reduction etc. Consumption becomes superfluous.

Next, the SOx uptake SOx that explanation is estimated by present embodiment_{_ STR}。

For example, in the case where the SOx discharging amount for being assumed to release when SOx is purified and executed is constant basis per unit time Example (comparative example) in, estimate SOx as shown in phantom in fig. 7 and purify SOx uptake in execution.Herein, SOx discharging amount is Constant basis is such per unit time assumes that the opinion newly obtained with inventor misfits.Therefore, it can be said that the SOx deduced Uptake and actual state are significantly different.In the comparative example, it is than moment T1 that SOx uptake, which reaches termination condition threshold value, At the time of rearward.Although this indicates that actual SOx uptake reaches termination condition threshold value, still perform in a long time SOx purification.

In contrast, it is put using the numerical expression (4) for the present embodiment for meeting the opinion that inventor newly obtains to calculate SOx Output SOx_{_ out}Example (embodiment) in, it is shown in solid such as Fig. 7, SOx can be estimated and purify SOx uptake in execution SOx_{_ out}.It can be said that meeting the SOx discharging amount SOx for the opinion that inventor newly obtains compared with comparative example_{_ out}To meet reality State value.Therefore, compared with comparative example, the SOx uptake SOx being deduced also can accurately be estimated_{_ STR}.Thus, According to the present embodiment, the actual state of NOx absorption reduction catalyst 32 can be met holding for SOx purification is suitably controlled Row.According to the present embodiment, T1 suitably grasps SOx uptake SOx at the time of compared with comparative example earlier_{_ STR}Reach end The case where condition threshold, can suitably terminate SOx purification.Further, since can accurately estimate when SOx purification executes SOx uptake SOx_{_ STR}, so even if also can accurately estimate SOx uptake SOx after SOx purification_{_ STR}。

[NOx purification control]

NOx purification control unit 70 executes control as follows: being restored by making exhaust become dense combustion environment with that will be absorbed by NOx The NOx that type catalyst 32 absorbs come by reduction purification it is innoxious and release, to make NOx absorption reduction catalyst 32 NOx absorbability is restored and (control is known as NOx purification control).

[MAF follows control]

MAF follows control unit 80 and purifies under control or NOx purification control in (1) from the lean burn usually operated to SOx Dense combustion state switching during and (2) from SOx purify the dense combustion state under control or NOx purification control to usually operating During the switching of lean burn, the fuel injection timing that each In-cylinder injector 11 is corrected according to MAF variation and fuel spray are executed The control for the amount of penetrating (MAF follows control).

[the amount of injection learning correction of In-cylinder injector]

As shown in figure 8, In-cylinder injector learning correction portion 90 includes learning correction coefficient operational part 91, the amount of injection correction unit 92 and learning correction prohibition unit 93.

Learning correction coefficient operational part 91 is in the lean-burn operation of engine 10 based on the reality detected by NOx/ exhaust gas oxygensensor 45 λ value λ_ActWith presumption λ value λ_EstError delta λ, carry out the learning correction coefficient F of the amount of injection of each In-cylinder injector 11 of operation_Corr.In When exhaust is lean burn, since the HC concentration in exhaust is very low, so, the oxidation for carrying out HC by oxidation catalyst 31 is anti- The variation that λ value is vented caused by answering is small to the degree that can ignore.It is therefore contemplated that having passed through oxidation catalyst 31 and by downstream The practical λ value λ in exhaust that the NOx/ exhaust gas oxygensensor 45 of side detects_ActAnd the presumption λ value λ from the exhaust that engine 10 is discharged_Est Unanimously.That is, in these practical λ value λ_ActWith presumption λ value λ_EstIn the case where producing error delta λ, it can assume that be because to each Error caused by the instruction the amount of injection of In-cylinder injector 11 and the difference of actual ejection amount.

Learning correction coefficient operational part 91 by from presumption λ value λ_EstSubtract the practical λ detected by NOx/ exhaust gas oxygensensor 45 Value λ_ActError delta λ afterwards is multiplied by learning value gain K₁And corrected sensitivity coefficient K₂, thus operation learning value F_CorrAdpt (F_CorrAdpt=(λ_Est- λ_Act)×K₁×K₂).In the present embodiment, corrected sensitivity coefficient K₂Being will be by NOx/ exhaust gas oxygensensor The practical λ value λ of 45 detections_ActIt is read as input signal from corrected sensitivity coefficient chart 91A.In addition, for estimating λ Value λ_EstOperating condition according to engine 10 corresponding with engine speed Ne or accelerator open degree Q etc. is come constructive arithmetic.

The learning value F that will be calculated by learning correction coefficient operational part 91_CorrAdptIt is sent to learning value chart 91B, and Aftermentioned study prohibitory sign F_ProFor closing (F_Pro=0) update of Shi Zhihang learning value chart 91B.

Learning value chart 91B is referenced chart based on engine speed Ne and accelerator open degree Q, is set on the graph Multiple learning region of with good grounds engine speed Ne and accelerator open degree Q zoning.For these learning region, usage frequency is more Its range of region be set narrower, its range of the few region of usage frequency is set wider.Using frequency as a result, It spends study precision in more region to be enhanced, also, is effectively prevented in the less region of usage frequency and does not learn.

If the λ value for becoming exhaust continues the not converged λ unstable state within a predetermined range in certain period ground, learn school Positive prohibition unit 93 will forbid the study prohibitory sign F of renewal learning value chart 91B_ProActivate (F_Pro=1).

In the present embodiment, learn prohibitory sign F_ProIt is activated during any one following condition is set up: (1) SOx purification mark F_SPFor activation, (2) NOx purification mark F_NPFor activation, (3) filter regeneration mark F_DPFFor activation or (4) operating condition of engine 10 is transition operation.This is because in the state that these conditions are set up, practical λ value λ_ActChange Change causes error delta λ to become larger, and not can be carried out based on accurate learning value F_CorrAdptLearning value chart 91B update.About drawing 10 are held up whether in transient operating state, such as based on the practical λ value λ detected by NOx/ exhaust gas oxygensensor 45_ActTime variation amount, It is determined as transient operating state in the case where the time variation amount is greater than scheduled threshold value.

In addition, in the present embodiment, illustrating in study prohibitory sign F_ProActivation when forbid learning value chart 91B Update, but it is also possible to be configured to forbid learning value F_CorrAdptOperation.

Next, illustrating the control flow of the amount of injection learning correction of the In-cylinder injector 11 of present embodiment based on Fig. 9.

In step S300, it is based on engine speed Ne and accelerator open degree Q etc., to determine engine 10 whether in lean-burn operation State.If entering step S310 in lean-burn operation state in order to start the operation of learning correction coefficient.

In step s310, by from presumption λ value λ_EstSubtract the practical λ value λ detected by NOx/ exhaust gas oxygensensor 45_ActAfterwards Error delta λ, multiplied by learning value gain K₁And corrected sensitivity coefficient K₂, thus operation learning value F_CorrAdpt(F_CorrAdpt= (λ_Est- λ_Act)×K₁×K₂)。

In step s 320, determine learning value F_CorrAdptAbsolute value | F_CorrAdpt| whether it is in scheduled limitation In the range of value A.In absolute value | F_CorrAdpt| in the case where being more than limitation value A, this control is returned and stops this Study.

In step S330, determine whether to be closed study prohibitory sign F by learning correction prohibition unit 93_Pro.Prohibit in study Only indicate F_ProIn the case where closing (Yes), the update for executing learning value chart 91B is originally controlled to, and advances to step S340.On the other hand, in study prohibitory sign F_ProIn the case where activation (No), this control is without learning value chart 91B's It updates and is returned.

In step S340, based on engine speed Ne and accelerator open degree Q, referenced learning value chart 91B is (referring to figure 8) it is updated to the learning value F calculated in step s310_CorrAdpt.More specifically, it is set on learning value chart 91B Multiple learning region that with good grounds engine speed Ne and accelerator open degree Q is divided.Preferably usage frequency is more for these learning region Then its range is set narrower in region, then its range is set wider in usage frequency few region.Thereby, it is possible to Study precision is improved in the more region of usage frequency, can be effectively prevented in the less region of usage frequency and not learned It practises.

In step S350, from learning value chart and to using engine speed Ne and accelerator open degree Q as input signal The learning value that 91B is read adds " 1 ", thus operation learning correction coefficient F_Corr(F_Corr=1+F_CorrAdpt).The learning correction system Number F_CorrIt is input into the amount of injection correction unit 92 shown in Fig. 8.

The amount of injection correction unit 92 passes through to pilot injection Q_Pilot, pilot injection Q_Pre, main injection Q_Main, spray Q afterwards_After, it is remote after Spray Q_PostEach basic the amount of injection multiplied by learning correction coefficient F_Corr, thereby executing the correction of these fuel injection amounts.In this way, By with presumption λ value λ_EstWith practical λ value λ_ActThe corresponding learning value of error delta λ come to each 11 correction fuel of In-cylinder injector The amount of injection, so as to deviations such as the deterioration year in year out or characteristic variations, the individual differences that effectively exclude each injector 11.

[MAF correction coefficient]

98 operation of MAF correction coefficient operational part purifies MAF target value MAF when controlling in SOx_{SPL_Trgt}Or target injection Measure Q_{SPR_Trgt}Setting and NOx purification control when MAF target value MAF_{NPL_Trgt}Or target injection amount Q_{NPR_Trgt}Setting in Used MAF correction coefficient Maf_{_ Corr}。

In the present embodiment, the fuel injection amount of each In-cylinder injector 11 by NOx/ exhaust gas oxygensensor 45 by based on being detected Practical λ value λ_ActWith presumption λ value λ_EstError delta λ and correct.But since λ is air and fuel ratio, so, error delta λ The reason of be not necessarily limited to the influence of difference to the instruction the amount of injection and actual ejection amount of each In-cylinder injector 11.That is, for λ Error delta λ, not only the error of each In-cylinder injector 11 but also maf sensor 40 may also have an impact.

Figure 10 is the MAF correction coefficient Maf for indicating to be carried out by MAF correction coefficient operational part 98_{_ Corr}Setting processing frame Figure.It is referenced chart based on engine speed Ne and accelerator open degree Q that correction coefficient, which sets chart 99, is in advance based on experiment etc. It is set with the MAF correction system for indicating the sensor characteristics of maf sensor 40 corresponding with these engine speeds Ne and accelerator open degree Q Number Maf_{_ Corr}。

MAF correction coefficient operational part 98 is set using engine speed Ne and accelerator open degree Q as input signal from correction coefficient Determine chart 99 and reads MAF correction coefficient Maf_{_ Corr}, also, by MAF correction coefficient Maf_{_ Corr}It is sent to MAF target value operation Portion 62,72 and the amount of injection target value operational part 66,76.Thereby, it is possible to MAF target value MAF when controlling is purified in SOx_{SPL_Trgt} Or target injection amount Q_{SPR_Trgt}, NOx purification control when MAF target value MAF_{NPL_Trgt}Or target injection amount Q_{NPR_Trgt}Setting In effectively reflect the sensor characteristics of maf sensor 40.

[other]

In addition, can be fitted without departing from the spirit and scope of the invention the present invention is not limited to above-mentioned embodiment When deformation is implemented.

For example, in the above-described embodiment, closing forced regeneration mark F_DPFWhile activation SOx purification mark F_SP, It however, it can be, closing forced regeneration mark F_DPFAt the time of or earlier than this at the time of, SOx purification execute control unit 68 Determine SOx uptake SOx_{_ STR}It whether has been more than execution condition threshold (value bigger than termination condition threshold value), in SOx uptake SOx_{_ STR}In the case where being more than execution condition threshold, to activate SOx purification mark F_SPAnd the mode for executing SOx purification is controlled System, in the case where being less than, due to SOx uptake SOx_{_ STR}Indicate for execute SOx purification for still have it is more than needed, so with SOx purification mark F is not activated_SPMode without executing SOx purification is controlled.Thereby, it is possible to suitably inhibit SOx uptake SOx_{_ STR}SOx purification is executed in not more situation, the interval of the SOx execution purified can be lengthened, be can be improved combustion Expect economy.

In addition, in the above-described embodiment, for example, purified in the SOx that executes later for being just filtered device forced regeneration, Then the execution of filter forced regeneration and execute SOx purification, still, the invention is not limited thereto, is also possible to inhale by SOx The SOx uptake SOx that receipts amount operational part 67 calculates_{_ STR}In the case where being more than scheduled execution condition threshold, SOx purification is executed The execution of control unit 68 and filter forced regeneration independently starts the execution of SOx purification.

In addition, in the above-described embodiment, as NOx catalyst, for having enumerated NOx absorption reduction catalyst, But the invention is not limited thereto, NOx catalyst be also possible to using from urea water at ammonia as reducing agent come to containing in exhaust Some NOx carry out the selective reduction catalyst (SCR catalyst) of reduction purification.

The application, will be in it based on Japanese Patent Application (Patent 2015-107010) filed on May 27th, 2015 Hold and is incorporated herein as reference.

Industrial applicibility

Emission-control equipment of the invention, can be appropriate in the presumption precision for the SOx uptake that can be improved NOx catalyst It is useful that ground executes catalyst regeneration process this point.

The explanation of appended drawing reference

10 engines

11 In-cylinder injectors

12 inlet channels

13 exhaust passages

16 air inlet shutters

24 EGR valves

31 oxidation catalysts

32 NOx absorb reduction catalyst

33 filters

34 exhaust steam injectors

40 maf sensors

45 NOx/ exhaust gas oxygensensors

50 ECU

67 SOx uptake operational parts

68 SOx purification executes control unit

69 SOx discharging amount calculation sections

Claims

1. a kind of emission-control equipment, for the NOx catalyst being arranged in the exhaust passage of internal combustion engine, execution makes to be vented Temperature rises to desulfurization temperature so that the SOx absorbed by above-mentioned NOx catalyst is detached from the catalyst regeneration process removed；

Above-mentioned emission-control equipment includes:

Oxidation catalyst is arranged on the position that exhaust-gas upstream side is leaned on than above-mentioned NOx catalyst,

Temperature sensor is arranged on the position that exhaust-gas upstream side is leaned on than above-mentioned oxidation catalyst, to being flowed into above-mentioned oxidation Delivery temperature in catalyst is detected,

Desulfurization amount calculates component, based on the SOx uptake that will have been absorbed by NOx catalyst, indicates absorbed SOx every Value after desulfurization degree and desulfurization degree the correction coefficient multiplication for the ratio being desulfurized in the scheduled time, successively to calculate execution The desulfurization amount in above-mentioned NOx catalyst when above-mentioned catalyst regeneration process, wherein above-mentioned desulfurization degree correction coefficient is based on row Excess air ratio in gas and according to the presumption of the inlet temperature of the above-mentioned oxidation catalyst detected by above-mentioned temperature sensor The temperature of above-mentioned NOx catalyst and determination, for drawing to the excess air ratio in the temperature and exhaust by above-mentioned NOx catalyst The variation of the desulfurization degree risen is corrected,

Uptake estimates component, calculates the desulfurization amount that component successively calculates using by above-mentioned desulfurization amount, urges to estimate above-mentioned NOx The newest SOx uptake of agent, and

Control unit is executed, based on the above-mentioned SOx uptake being deduced out, to control holding for above-mentioned catalyst regeneration process Row.

2. emission-control equipment as described in claim 1, wherein

Above-mentioned desulfurization degree by the time according to changing from the execution of above-mentioned catalyst regeneration process.

3. the emission-control equipment as described in claim 1 or claim 2, wherein

Above-mentioned execution control unit proceeds as follows control: being termination condition threshold value feelings below in above-mentioned SOx uptake Under condition, terminate above-mentioned catalyst regeneration process.

4. emission-control equipment as claimed in claim 1 or 2, wherein

It further include that additional quantity calculates component, additional quantity calculating component successively calculates new by above-mentioned NOx catalyst due to exhaust The addition SOx uptake of absorption；

Above-mentioned uptake presumption component is newest to estimate using the addition SOx uptake that component calculates is calculated by above-mentioned additional quantity SOx uptake.

5. emission-control equipment as claimed in claim 4, wherein

Above-mentioned execution control unit proceeds as follows control: being more than scheduled execution condition threshold in above-mentioned SOx uptake In the case where value, above-mentioned catalyst regeneration process is executed.

6. emission-control equipment as claimed in claim 4, wherein

Above-mentioned execution control unit proceeds as follows control: above-mentioned SOx uptake be scheduled execution condition threshold with In the case where lower, above-mentioned catalyst regeneration process is limited.

7. emission-control equipment as claimed in claim 6, wherein

The exhaust passage of above-mentioned internal combustion engine also has the filter of arrested particles shape substance,

Above-mentioned execution control unit proceeds as follows control: being more than above-mentioned execution condition threshold in above-mentioned SOx uptake In the case where, then filter recovery process and execute above-mentioned catalyst regeneration process, above-mentioned SOx uptake be above-mentioned execution In condition threshold situation below, not then above-mentioned filter recovery process and execute above-mentioned catalyst regeneration process, above-mentioned mistake Filter regeneration processing is the processing for being flared off the particulate material of above-mentioned filter.