SE1650345A1 - A control system and a method for controlling the exhaust gas flow in an exhaust line of a combustion engine - Google Patents

Abstract

The present invention relates a control system and a method for controlling the exhaust flow in an exhaust line (3) of a combustion engine (2) comprising at least one exhaust treatment component (5) and an evaporator (7) of a WHR system. The control system comprises a valve arrangement (8, 9, 34-36) in the exhaust line control unit (10), a temperature sensor configured to sense a temperature related to the temperature of the exhaust treatment component (5) and a control unit (10) configured to position the valve arrangement (8, 9) in a first position when the exhaust treatment component has a lower temperature than a specific temperature in which position the exhaust gases are directed to the exhaust treatment component (5) before they are directed to the evaporator (7) and in a second position when the exhaust treatment component has a higher temperature than said specific temperature in which position the exhaust gases are directed to enter the evaporator (7) before they are directed to the exhaust treatment component (5),. (Fig. 1)

Description

”EG 2G St) A citntrei systeiri ariii a iriistheti inr' tfeiitreiiing the exiiaiist gas íitiw in an exhaiist Eine et' a cnnihnstieii engine ßACKcGRífiiíNß OF THF; iNVENTiON .ÅND RREÜR .ÅRT The present inyentien reiates to a controi system and a rnetheti for controiiiiig theexhanst gas iiew in an exhatist iine ofa eenihtistien eingine according to the preainhie et* ciztirn i , Exhatist iines of internal coinbustioii engines stich as diesei engines may' coinprise apiuraiity of exhaust treaitiiicnt tïeinpciiieiits stich ars, for exarnpifz., a SCR cattahfst(Seiectivte tffitaiyftitc Reduction). in erder te cieztri tiie extiaiist gases tfrein nitrege ioxides, a iirea sotutien is sprayerl into the exhaust Eine in a position iipstream etitheSCR cataiyst. The area sohitieri is Vaporized by the hot exhaitst se that arnnieniais iiirnnäti. Tiie annnerria, and initrogen exides in the exhatist gascs react With each etherin the SCR cattaiyfst sr) tonsatt riitrtigteii gris and ivattär' tfaper ienfneii. Tile eiïicififricyf efa SíÅÉR catatyest depends en its ternperatuie. The ahiiityf ef the SCÉR cataiyfst to reducenitregen exicies is eptiniai *within a temperature range tyhieii rnay tíie aheut ÉÛÛ-dštfíï.rät tower and iiigher exhanst gas ternperaturtäs the :sapaeityf ofethe SCR cataiyst te reduwaf riitrtigteri rixides is rerhiitfifci, *ii/HR syfstern (iiiiaste Heat Reeevery Syfstern) can be used fcr recoyeririg tifaste therniaieneirgy' and eenvert it te niechainitrai ernergyf er electric ernergytt A “ti/HR system inetutitfsa purnip Which pressurizes sind circuiattës a i/vtiiitirig rneiiiuni in a cieseii circuit. Tiiecirciiit cernprises an eyfapoiator vvhere the yiferttiiig medium is heated. arid evaptïratedby a heat setirce such as, fcr exarnpie, exhaust The presstirized and heatedgasenns Weirking niediuiii expands in an expandera The expancier generates niechanieaieiiergy' Vvnittii can be tiseri to stippert the täiigiiie aiiii/rtr :ttiriarzitttses in a vehicle,.Aiternativeiy the expander is connected to a generator generating eiectric energy. The*working nieciiuin ieaftfing tiie expander directed te a cenderiser. The vvorkingniediuin is :sciriicdt tioyvn in the :tendenser te a eternperature att ifviiich it eendenses. Tiie fiiei consrintptieri ef a coinbnstitöii engine can he rerhiced by ntearis etia *vifi-itšsysteni, C51 ”EG 2G 3G 'Ihe exhatist gases are eooted dottern in an evaptarattir otia Wii R systern. in view otthisfaet, the evaporator is arranged in a tiowifiistreain position of the exhanst treatmentcornporterits, in tttis position, the existenee otfttie exfaporattir tioes not iiittnertce on theoperation titthe exhanst treatment coinpoiierits, tioefevei; in case iavhen the eoinhiistionengine is high ioaded thiring a longer period oftime, there is a risk that the exhatistgases heat the täxhaust treatment components to a too higii ternperattire, in this eases,the exhatist tezttnieiit ttoiiipriiitfiits do riot providie an 'optiiriztt treatment ot the exhztiist gases and niight he permanent ty daniaged.

SUhih/ÉARY OF THE ÉNVENTIÛN The ohjeet tiftiie tiresent inventioii is to control the exhaust gas titan' in an exhatist iineeomprising at ieast one exhatist treatment component and an evaporator of a WHiåsystem in a manner sneh that the exhatisit treatment component pro vides a suhstaiitiaaitjy''optiirtztt treatnierit ritittie exhatist gztses zttso tturinig tiperatirig tttinttitioris Vwheii the exhaiist gases have a iiigii teinperatiire.

T he above rnentioned cihject is attiiiexfed hy the troiititrit sjystein acteortting to thectiarattterizirtg part otciairri t, išniirtg otierztting conditions wvheri an exhaiist treatnieiitcoinpoiieiit has a lower ternperattire than a specitic teinperatnre, the controi nnitiiiitiates a niovenient of a Vahfe arrangement to a first position in wvhich it direets theexhatisit gases to the exhaust treatment coinpciiient before the exhanst gas ftovv isttiitfectett to the evaporaittii: The stiecititt ttëiiiperzttiire iiizty he an tipper ternpiëitfatuite ot aternperatiire iange at Which the exhaust treatment component provides a suhstantiaityoptimai treatment of the exhatist gases. The specific teinperattire inay he a constanttemperature or a temperature varyiiig with other tiiaefitating pairainetrzirs, th' hen the valveztrrztrigerniäiit is in the iirst position, the ireiativety hot exhiaiist gases may increase orinaintain the teinperatiire the exhanst treatment component hetore they' are eooteddovvn in the evaporatoi". During operating conditions vtfhen the exhatist treatmentcomponent has a higher temperature tiiart the specific temperature, the rsoiitrcii unitinitiates a, irioverrienit titithie 'vztivtë ztrrarigerniëiit to a seeoritt ptësitiriii in tvhiehi theexhaiist gases are directed to the evaporattir hefore they are directed to the exhaiisttreatment eoinpoiieiit. in this ease, the exhanst gases are eooied down in the eitaporatorhetore they enter ithe exhaust treatment tfoinpriiieiit. in this case, the exhaiist enteriiig the exhanst treatment component iriostiy' have a tower temperature than the C51 ”EG 2G St) exhaust treatmeitt etirriptirient, a ttenseeliientetë, the 'exhtattist gatses iteet ttetvn theexhaust treatment eoinpoiterit. As seen as the exhaiist treatment eeinpeiieirt has heerieeeied to a teinperattire heievv the specific ternperature, the eontroi systems iiiitiates arnevernttënt ef the wait/tf arrangemeiit hattk te tite tirst tiesitieri. Tiie eeritrei synsteniinakes it possihie te aveid heating ef the exhaust treatment eeinpeiieirt te a tee hightemperature. As a eensequeriee, it is gtessihie te maintaiii a suhstaiitiaiiftf eptiinaitreatment ef the exhaiisit gases even When the exhaust gases iiave a very highterriperattttie, Furtherrnttire, the extiaiist gatses rntay' receive a iewer teiriperatiire ttfhtënthey iiave iiassed threugit the exhaiist treatment eernperieiit, As a eonsequehee, the*Working rnediuin in the evaperator niay the heated to a higher temperature When the vaive arraiigeiiient is in ithe second positien *which inereases the ettitfieney ef the XVHR Aeeerding te an einhetiiinerit ef the intfentien, the Vaive arrarigernent eernprises avaive inemher ti/hitfh aiternatitfeijy' direets exhattst gases frem an npsitream exiianst tim:seetiert te the tfxitatist treatrrient eerriperterit er te the 'exfatmrattiirx By iheans ef such avaive rneniiieií, it is easy te aiterriativeiy' direct the errhatist gas tiettf iiiitiatiy' te theexhaust treatment component er the evaporater. The exhanst iine inay eeinprise at ieastone interrnettiate exhatist iine tiireetiiig exhattst gases hettveen tiie exhaust treatmenteerriperierit and the evaperztttir and a tfaitve ihemhtër' ettrtfigured te centret tiie exhaustgas tioiw titreiigh the interrnediate erdiatist Eine. Wiren the ”tfaive arrangerneiit is in thefirst pesitieii, sneh an iritermediate exhattst Eine direets the exhaust gases tiern theexhatisit treatment, component te thie evaperatttirt When the *valve arrangeinent is in theseitenii ptisititiit, sueh an iriteirmediattä extiatist line rtireets tiie exhatist gases tiem theevaptirater te the exhaust treatment eeniperieiit, 'The exhatist gas fltaw tiireugh theinterniediate exhaust iine niay he eentreiiett hy a tfaive nieinber. Fttrtherrnere, thevahve arraiigeiiient may eernprise a vaive niemher tvhieh aiteinatixfeiy direets theexhaust trern the 'exhatist treatment tteirtpeiitfitt er tiie ewfatitirattrir' te adtwvitstirearn exhaust inte section. tššy niearis etetteir a valve inernher, it is easy toaiternativeiy ttireet the exhaust fiew frem the exhattst treatment eenipenent ei' thetinfaperator te a ttetvnstrrearn ieeateftt part ef the exhaiist iine, The tfahfe nieinher niay he 'efartaitrairy kind, Tite vatt/e rnenttitfi* rnay, ter täxarripiei he a hutteritiy vatt/tf. ifieeerdiiig to an ernhedinieiit ef the iiiveiitioir, the *vaive arrangement eeinprises avalve rneniher wviiieh., in said first pesitionf, is tttintigtireti te diretït exhaust gases frem an upstreanr exhaust Eine seetien te the errhaust treatment eernperierit and trein the C51 ”EG 2G St) evaporzttor to a, rlowrrstream exlrztrist line section, Such a valve irrenilififr irrayn, in saidseeonrl riositiori, he contigured to clireet exhaust gases front the upstreani exhairst Einesection to the evfariorator' and from the exhaust treatment component to the downstreaniexhaust line section, Srieh a valve rneriilie trams several tasks, Thus, a valve arrangernent including sueh a valve member may include few further valve niernhers. låetïtirtliiig to an enihodinifzrrt ofthe iiivtïiition, tlie valve arrangenient niay eomprise avfaltfe niemher vvhieh, in said first positions is ttoritigrirtëtl to riiceet exhttrrst gztses frornan uristreani exhaust line section to the ei furtlier *valve members .ftoctarcliiig to an eniliotlirtrent ofthe irrveiitirrn, the control systern oonrprises atemperature sensor eonfrgured to sense the temperature of the exhaust gases in anripstreani exhari st line section. ln this the control unit reeeisftfs information aboutthe ternsptërature til' the räxliaust gases vvhirth are lerl to tvarrls the exhaust treatmenteornporierit anti the evaporator: ln tifievif of this intiar'riiation, it is possible to adjust saidsriecitfie teniperattrre. Alternatively' or' in combination, the control system mayeornprise a sensor contigurrztl to sense the presstrre or the ternptfrætture til* the vvorltingnietlirrirr in the WHR system, ln rtrrler to provririe an 'etfticisenst tiperzttitiri of the WllRsystem, it is, for example, important to control the Cooling of the mforking rnerliuni in aeonderisei' of the lift/HR system. "flie Cooling demaiiti of the tiforking mediurn is related to the absorption of heat in the evraptirator. fkeeorrling to an einhotiiment of the invention, the exhaust treatment component is aSCR eatalftfst. The aliility of a SCR eatalyst to retluee nitrogeii oxides decreases aliovea temperature of ahont -f-l-SGWC. Tlius, it is suitable to use the control system foreontrolling the ternperatrire titlar StfÄRs Catalyst, Alternatively' or' in cornhirrzttitint, theexhairst treatment errniprrnent may iirchrde an rrxirlatiori eatalytic converter' ÜÜÜ, a tiartietrlate filter' DFF, or an amrnonia slip catalytie converter' ASC.

C51 ”EG 2G St) Attcoiiiliiig to an enihiiilinierit of the iiiveiitiori, the valve arifangenierit coinprifses avalve ineinher or valve pant contigured to change ilovt/ direction ofthe vvoiïlcitigniediuni in the evaporator. ln certain cases, the exhanst gas tlovv niay he directedthrough the evaporzttor in an iipposittë directions Whien. the *valve arifaiigfifirierit is in thefirst position or in the second position. ln this case, it is also favorahle to chaitge thedirection of the ttforliiiig inediuni flovv' through the evapoiator in order to favor the heattransfer in the evapoirator. This *valve rnenihiäi* inay he a part of a. *valve iiieinher eontiolling the täxhaust gas llowf. 'llhe aliove inentioned object is also achieved hy the inethotl defined in claini 14.

BRIEF DESCRlPTlON till: THE ßRAlWlNflS ln the following preferred enihodinieiits of the invention are clescrihed, as examples, With retereiitse to the attached clrawings, in vvhich: liig. l sliovtfs a cointrol system With a valve airaiigeitient according to a firsteinhodiinent of the inventioii vvhere the valve arrangeinent is in a. firstposition.

Pig. 2 sliovvs the valve arifangenierit in Fig. l in a settonil rpositioii. lïig. 3 shovvs an alternative enihodinieitt of the valve airaiigeiiterit in a firstposition, Pig. f-l shovvs the vfalve aiiaiigiiinent in Pig. 3 in a second position.

Fig. 5 sliovvs a fiirther alternative eirihtiiliirient of the 'valve arrztrigerrient in aiiirst position., Fig. 6 shows the valve arrangenient in Fig. 5 in a second position.

DlÉT/äjllglïl) DESCRlPTlON (FP PlšlÉFERREÜ Elvfllštflßllvllilhlfllß till: THElNV EEINÉllÛN Pig. l shotvs a stsheniatically' disclosed. vfehicle l powered hy a siipertvliargedtttiniliustiiiii erigirie 2. The ttoiiilinstitin erigine 2 iriay he a. diesel engirie. The veliittle lrnay he a lieavy vehicle. The vehicle lcoinprises an exhaust line 3 receiviitg exhaustgases front the coinhustion engine 2. "the exhaust line 3 coinprises a turhine 4 of atiirho aggregate. T he exhanst gases in the iixliaust liite 3 recfzixfe a retliiciitl pressure aiid a reduced temperature When they eapatid through the turhine 4a of a turbo chargei' 4. A C51 ”EG '15 2G St) riuniher oilschttenizttittztlily diselostëtl exliztiist treatrnttärit corntporierits 5 *e arrarigfiftl in theexliaust liine 3 in a riositioii downstreani of the turhine 4a. 'The exhaust treatmentcornponents 5 inay, for example, include one or setøeral of the following exliansttreatiiierit coinporieiits riarnely an tixitlzttitiri ttzttalytic converter DOG, a pztrticiilatfif tilterlïllll, a SCR catalytic converter and an aininoriia Slip catalytic converter' .ASC Theefficiency* of each exhanst treatment cornponent 5 depends on its ternperatare. Anefficient operating träinperattire of sursh exhatist ttreatnieiit coniponeirts are tisuallyaliove 2ÛÛ°C The aliility of the SCR catalyst ö to redntre riitrogeri oxides iriay heoptimal vvitliiri the temperature range EGÜÄSGOKÉ. At higher and lower ternperatares the capacity of the SCR catalyst to reduce iiitrogen oxides reduced.

A ternpeitfature sensor o serises the terntptëratniffif of the exhaast gases in :irl exhanst linesection ša located upstrearn ofthe exhanst treatrneiit components 5 and an etfaporator 7of a “ilt/'Hlš system. The upstreaiii exhatist line section 3a cornprises a first tfaltfeineniher 8 and a second valve 9. A coiíitrtil unit lll tfontrols the first Valve rnenihei" 8arid a settond valtfe 9, A terriperzttiire serisor 11 senses the terntperatuite ofthe at leastone rifthe exliaust treatment components 5. 'lhe e;f cooler l3 arranged at a front portion of the vehicle l, The coinhustioii engine 2 is cooled hy a eoolirig systern With a circulatiiig coolant. Thecooling systern eoniiirises an engine inlet line l4 protfidetl *with a coolant iitinip 15circalatiiig the coolant in ttlie cooling systern. An engine. outlet line lo reeeives tthecooltant leaving the coinbiistioii engine 2, A theririostat l7 is airrangtëtl at an enrl tiltlieeiigirie rnitlet line 16. ln case the coolant has a lovvei' temperature than the regnlatingteinperattire of the therrnostat l7, the coolant is directetl hack to the coolant pump 15via a bypass line l8. ln tsase the coolant has a higher teinperature than the regnlatingterriperattirtë of the thterinitistat l7, the ttoolztrit is directed to a ratlizttor l9 :ritniged att a,lront portion of the *vehicle l in a position hehiiirl the charge air criolei' lfš. The radiatorfan 20 and rain air protfitle a Cooling air llovv through the charge air eooler 13 and therarliator li), The coolant that lias cii"r.rula,tetl throngli the ratliator 19,, it is tliiectetlfi via atradiator oatlet line 21, hack to the engine inlet line l4 and the coolarit pump lfš. 'The C51 ”EG '15 2G St) eoo1irig systern eoiriprises a toop, The 1001) etiniiiirises a eooiant intet tine 22 iteeeisfirigeootant from the bypass Eine 18 or the radiator outtet line 21 depending on the positionof the therniostat 17. The intet 1ine leads cooiant to a condenser 23. The ioopeorrtprises an outiet 1ine 24 ieadirig the eoo1ant frorn t1te ttoniienser 23 to the erigirte intet inte 14 and the oooiaitt pump 15.

The vfehieirt is provided, vvitii a *Jflištësysteni (Waste Heat Recovery systeni). T he 'vïti R systern tttintpitfises a pinnp 25 tvtiittti r, *essuriztës artd eirttuhttes a vvorkirigmedium. The uforking inetliuni may he ethano1, 1š2451°a or other itiiid otvvorkingnieditim. The tiunifo 25 pressurizes and eircuiates the tiforking niediuin, vfia anetfaptirattii" iniet tine 26, to the efvapciratoi” 7. The vt/orhing niediuin is heated in tiieevaporztttir 7 'ray 'exhatist to a terniptëiratuite att vvthieht it etfapttirates, T1te vvoritirtgiiteditiin direeted ironi the evfarvorator 7, via an expander intet inte 27, to an erparider28. 'The pressurized and heated Working inediuni expands in the expander 28, Theexpander 28 generates a rotary motion vvhich inay he transinitted, via a suitahtemeetiartittat transmission, to a, shatt otftite (trive train of the vettiete 1, A1teitfnative1yå, theexpanfter 28 may he connected to a generator tianstläriniiig inechanieai eitergy' intoeieetricai energy: The eieetrieai energy inay he stored in e. g. a tiatteijvf. After thevtforkiiig medium has passed through the expander 28, it is directed, via an expander o ut1et hne 29 to the condeitsfifi* 23, The uftiiitiiig ineditini is ttoo1ed in the ttonttenser 23'hy the eootant in the ioop 22, 24 of the eoohrig system, 'The uforkiiig rnefhiini isdireeted from the eondenser 23, via a eondenser outtet 1ine 311, to a receiver 31.

Vv/'orrkiiig medium sutfks., via an intet 1ine 32 from thie receiver 31, to the pump 25, During operation ofthe coinhustioit engine 2, the eonti'o1 unit 1G reeeives stuhstaiitiaity'oontinuousiïv' information front the sensor 11 about the teniperattire of the exhatisttreatment, component 5. The ttontroi iinit 6 niay also receive informatioii from theseiisor 6 atnotit the exhati st terniptëiratuite iii the upstreatrit 'exhati st line seotiiori ztrtttirifoiniation from the sensor 33 ahoitt the temperature or the pressiire of the varirkingmedium in the *thfHiå system. The eontroi unit 10 *verities if the temperature of theexhautst treatment component 5 is higher than a speeititf teinperattire, The speeitit:terniperattirtë rnay he att upriei” terrtpertttiire (tia ternptëiratuie range at *vtfhittit the exhausttreatment component 5 provides a suhstaritiaiiy' optiniai treatment ofthe eahaust gases.The specific teinperatiire may he a constant temperature or a teniperattire *varying vvith other operating parameters such as the teniperatiire ofthe exhaust gases in tiie C51 ”EG 2G St) utistrtëarri exiiaost iine seetion 3a or the tenirierattirtë /presstire of the xvorking irierhitrn.in the Riv/TTR system.

During riperating eriiidititiris wheii the exiiaust treatrrient component 5 iizts a. travet'ternperatuie than a iiredeterrniiied operating temperature, the control unit ett) iiiitiate arnovenieiit ofthe first vaive member 8 and tiie second *vaive member to a tirst positionvvhitfii is shown in Pig. i. in othis case., the first vfatvre nieniher S aiid the setïond tfaiveniemher 9 direct the exiiztust gases ironi the itjnstitfeztrn. exhztitst iiiie section Sa to thetreatment component 5. in this ease, the exhaust gases may heat the treatmenteompoiierit 5. The exhatist gases ieave the exhaust treatment eonirionent 5 and enterthe interniediate exhaust iine åh. Tiie second vfative niernher 9 tiirects the exhaust gasesfront the inteifniediattf exhaust line 3h rita* the exhaust Eine 3 to the evaporattii' 7. Tiieexhaust gases heat the vvorking nieciiuin in the evoaporattär 7. The exhaust gases ieavingthe evaporator 7 are ciireeteci to the tiovviistrearn exhaust iine section 3:: ihy tiie tirst*vaive inemher 8. Consequentiy., the first vfative nifzinher S aiid the setfond valve meniher9 tiirert the exii-aust to the täxiiaost treatnierit eriiripriiierit 5 hetiii'e thirty' are direeted to the etfapor'attör 7 tvhen they are in the tirst position.

Durizng Operating conditioiis When tiie treatment component 5 iiave a higherteniiierzttitre titan the pretiettëifniitrieti tiperatirig terriperattire, the etintrtit uriit it) initiatesa rnovenieiit titthe tirst vaive niernher 8 and the second vfaive nieinher to a secondposition vifhieh seen in Fig. 2. in this case, the tirst tfaive meniher' 8 and the second*vaive inemher 9 ctiretft the exhaust. from the tipstreani exhan st line seetioii fia. tothe evaiiorattii' 7. The täxiiaost gases are ttooieti tion/ii in the etfarioiatrii* 7. The tfxiiztustgases leaving the evaptöratrir 7 are direeted to the exhaast treatment component 5 hythe second *aaive niemher 9. in this case, the exhanst have a iotver temperaturethan the temperature ofthe exhaust treatment rsoinpriritfiit 5. Consetitientiy, the exhaustgztses eooi tiie täxiiaost tiezttnierit ttoiriptiiififiit 5. Tiie exhztitst gztses ieatfirig the exhausttreatnierit component 5 are directed to the dovvnstreani exhaust iine section 7:e hyrneans of the second vaive inemher 9 and the first vaive memher 8. The first *vaiveinemher 8 and the seeond. wfatve member 9 direct the exhaust gases to the evapriraotrir" 7hetiirtë they are tiireeteti to the exhatist tezttnierit tttimpontäiit 5. in this ttase, it ispossihie to eooi the exhaust treatment eramprsnent 5 to a tower tentperature at Whichtiiey are ahie to tirovicie a stihstantiaiiy oritimai treatment of the exhanst gases.Furthermore, the exhatist gases entering the evafporator 7 may iiave a higher teinperatitre vvhicii intprtäves the etftieieney' otthe hifi-i R systern.

C51 ”EG 2G 3G iïiigs 3 aitd 4 shovvs an alternative ernhtidirnent oi the vaive arrangenieiit. 'iheenihodinierit corresporids to the enihodinierit show in Figs. i arid 2. except the existencetitian additional val fe portiori 9a oi the second vatt/e rnenttififi” 9. Vi/iien tiie vaiveinemhers S, 9 are in the tirst position in the enihodiinent in Pig. i, the exhaust gasestiotal' and the *aforhing mediuni in the iiVHiå systern are directed in the saine directionthrough the evapozrator 7. in tiiis case, the evapozrator 7 works a. parahet fiow iieattäxciiariger. Vi/iteri the tfaivtä ineniherfs 8, 9 arfe in the settoiiii position in the errihtittiirierttin Pig. 2, the exhaust tiotvc aiid the vvoihiiig rnediurit tfioiw are directed in opgfiositedirections tinotigh the evatioratoi' 7. in this case, the evariorator' 7 ttforks as a cotintertiow heat exchaiiger. A tttiunttäi* tioW heat exchangei" has tisuaiiif a higher efficiencytitan a parahei iieat extthaiiger: in :terrier to rienierijy the drawhattk vvith a pztrahei ite-atexchanger, the second valve inemher 9 is protfidefl ttfith the above rneiitioited vaiveportion 9:1 Which niakes it riossihie to change iiovw direction oi the wiforkiiig rneditini inthe evapcirator 7. Fig. 3 showifs the *valve portion 9 in the first position in vvhitsii itttitangfifs tiirectiort oi the vvoritiiig rriediiirn tiovv tiirengh the esfztporatoi* 7. Pig. 4 siiiiwvsthe cvaive poitioii 9 in the second position in iwhicit it does not citange the fiirectitin ot" the tvorking inediuni tiow through the evaporator 7.

Pig, 5 strid 6 sttow a tiirther' ernhotiinififrtt otftite valve airangeiiierit. in this case, a third*uatve nieinher 34 is coniigiirefl to aiteritativeiy flirect the exhaust gas tiow ironi theupstream exhatist iirie section Ba. to the exhaust treatment component 5 or theevaporator 7. A first intermediate exhatist iine Shi is ahie to direct exhaust gases iiroiiian ontiet oi the exhaust trezitnierit ttoiiiptiiififrtt 5 to an, iriiet liite oi the evaporztttir 7. Asecond interinediate exhaust tine Išhz is ahie to direct exhaiist gases irorn an outiet Eineof the etfaporator 7 to an iniet iine of the exhaust treatment conipoiieiit 5. A fouitiivalve nieiiiher 35 is coiiiiguied to aiiowv exhaust gas .iiov/ in one oi the intermediateexhaust hnes Éhi, åh: at the sairte tinte it hitittks tite exiianst gas iiow' in tite otheriiiterrnediate exhaust iine 3391, Bin A titth vaive ineniher 36 is contiguired toaiternativeiy direct exhaust ironi the exhatist treatment eonirionent 5 or the evaporator 7 to the doxi/nstreaiii exhatist iine section Éšc. in case the exhaust treatment component 5 has a iovvei' temperature than the sgfiecitictemperature, the control unit i Ü initiates a. iiioveinent of the Vaive iiieinhers 34, 35, 36to a. first position wxfhich is shovvii in Pig. 5. in this ttase, tiie third ifaive ineinhei" 34 directs the exhaust gas tiotvc troin the iipstreani exhaiist iine section to the eXhaiist C51 ”EG 1G treaitiitetitt eeiripettettt S, The extiattst gas tieiwv leaving the 'exhaust ttezttiïteht eteittpeiiiefiit5 is directed hy the teitrth vaive inemher 35 to tiie evaperator 'The exhaust gas tiewleaving the evaperator 7 is eiirecteti iïty the fiith *aaitfe nteinbei" 36 to the dottfnstteaniexhattst tine section Se, in ttase the exhaiist trteatrnteäiit eorntpotierit 5 has a: higherteinperatuie than the speeitie temperature, the centret itnit it) initiate a inevement ofthe tfaitfe inenihers 34, 35, 36 to a seeend position tvhieh is sitetvn in Pig. 6. in thiseaise., the third vaive: htembet 34 eiireets titt: exhattst iioti/ iieiht the upstreainexiiaust line section 3:1 to the etfettteiitfatøi” 7. The exhaiist tietv ieztvittg theevaptirater 7 is tiirecteti hy the fourtii ”tfztiwfe :member 35 te the exhaust treatmentcømpøiteiit 5. The exhatist gas tiew' ieatfing the exhatist treatment eentgferierit 5 is direeïtede hy the iifih vatt/e: htetnber 36 tet the eteiwvnstireatii exhautst iine: seetieiiít Se, 'Tiie iiiveiitieii is net restricted to the tieseriified enihefiinieiit hut ittayt he *xfetried fieeiy *within the seepe of the ciaims.

Claims (2)

1. lt) “H5 2D 11 Clairns l. A ttontiroli sysetern tor tfontrolliiig the exlianst flow in an exharrst line (3) ofattrinrliastirin errgirre (2), vvhifreitrr the 'exhaast line (3) cornprises at least riite iaxlransttreatinent component (S) and an evapräratrrr ((7) ot'a Wl-llš systern, characterizerl in thatthe control systern eonirirrises a tfalve arrangenieiit 9, 34-36) in the exhanst line (3),a tenipiziratrrre sensor confrgnreil to seirse av temperature. relaterl to the. teiriperaitrrre ofthe exhztrrst treatment eorntporrerrt (5) and a control anit (lll) rtorrtigarerl to positiont the*valve arrangeinent (8, 9, 34-35) in a tlrst riositiori when the exhanst treatmentcomponent (5) has a loiver' tenirieratnre than a specific tenrrreratrrre in vvhicli positionthe exlrarrst gases are tlirectetl to ethe exliaust treatment rroiriprriirzrit (5) before they arerliiecterl to the evaporatrir' (7) and in av siaeonrl trositiori vvherr the 'exharrst trezitnrerrtcomponent has a liighei' temperature than said specific tenirrerature in Which positionthe exliairst gases are tlirectetl to tlie evaporator' (7) before they are clirected to the exhanst tireatnient rfoiriprririäirt (5).
2. 2. A control systern accortliiig to clairir l, characterizerl in that the valve arrangerneriteoniprises a valve ineniher (ti, 34) vtfhicli alternatively direets the exlraust frontan rrpstreani exharrst line sectiori (Éia) to the exhairset treatment, component (5) and to the evfarooratrii' (7), 3. A control systern aecortliirg to clairn l or 2, cliaracterizetl in that exhaust line (3)eoniprises at least one interniiftliate exharrst line (Éêb, Éihr, 3l3g) vtfhieh tlirects exlrarrstgztses lretweerr tlre rexhtarrst treatnierrt ttornprirrifirt (S) and the etfzipoiiirtor (7) and a, valvernernher (9, 35) contigurefl to control the exharrst gas tlovv through the interinediateexhatist line (lila, šbr, åliq). 4, A corrtrol systern artcorrlirrg to any riire of the prertetlirrg clairns, clrztrzictifrierërl in thatthe valve arrangenierit cornprises a valve ineniher' (8, 9, 36) Which alternatively clirectsexhaust front the exharrst treatment coniiionent (5) and the evaporator' (7) to a iloxvnstreain exhairst line section (Éšc). 5. A control systern aecortliirg to ariy one of the preeerling clainis, cliaracterizecl in thatthe valve arrangenierit eoniprises a valve rneniher (8) vvhich, in saitl first position, eoriligrrzrecl to direct exharrst gases from arr tipsetreani exliairset line section (Ba) to the C51 ”EG 2G St) 12 exhaiist treatrneiit eornpiirient (S) znid iiorni the etfatitiiater (7) to a iiowflxristiearri exiiztust line section (Éšh). o. A ttoiitrtii systerri accoroirig to ciairri St, tiiat said varit/e rneiriher (ä)is, in said second position, ceniigiirefi te direct exhaust gases front the npstreaiiiexhatist iine section (Sa) to the etøaperatoi' (7) and front the exhaust treatment eeinpeiient (S) te the ciewnstreaini exhanst iine section (3 e). 7. A oontroi s§fstern according to anyone of the precetiiiig ciaiins, eharacterized in thatthe Valve arrangeinent eeinprises a) wait/e nieinber (9) ttfhieii, in said first position, iseentignreii te dneet exhanst gases front aan upstreain exhanst iine section (ån) te theexhaiist treatrnfifiit eiirnpiërient (5) ztriti íiforn the exiiaust treatnierit cernporierit (S) to the evaporator' (7). 8. A tttiiitirei systern aeeeirtiing to tïiaiin 7, eharacterized in that said *valve rneiiiher (9)ist in said second pesitiori, coniigiirefi te tiireet exhaiist gases íiforn the exfapoi-atei* (7)te the exhanst treatment oonipoiierit (fi) and ironi the exhatist treatment component (S) to a ciottfnstreani exhaiist iine section (30). 9. A ttoiitrtii systerri accoroirig to ariy one titithie tiifeceiiing ciaiirisi, ehiaiiracterized in thatthe eontiroi tn/steiii eonipirises a teniperatiire sensor' (e) ctiniigiirefi to sense the teniperatiire of the exhaiist gases in an iipstreani exhaust iine section (Ba). iii. A controi syfsteni zteitorfiing to any eine of the preeiätiiiig eiairns, tthzirztetfifriatëii inthat the control system ceinprises a sensor (33) ceniignred to serise the ivressare er the temperature ef the tveritiiig inedinni in the systern. i i, A controi systern zicitortiinig to any one ei the preceiiiiig ciairris, atiiarzictiäitfizeii in that the exhaust treatnient ooniporieiit (fi) is a SCR eataiyst. 12. A ttentroi sjystein atftïcirtiiiig to any one efthe iarececiing tfiainis, g:that tiie varit/e airaiigiäiiierit attinipristfs a vatt/e rnienihfifi” er a, vaive riart (Sia) coniiigiireti te change tiow direction efthe ttverking niediuin in the evaptörattör ((7). t' 4 iš. “vïehieitä cornprising a eontroi systeni aetfordiiig te any Line. of tiie preefztiing ciairni to 12. C51 ”EG 13 14. A niettied fet' enntreliing the exhattst tiew in an exhanst iiine (S) ef a eninhustieii engine (2)) in a tfehieie (i), wtfherein the exhanst iine eeniprises at ieast ene exhatrst treatriierit eerripnrierit (S) and an) eveipnrzttnr (7) titizt Vwflífïiš, a sfalve :narigeitrerit (8, 9), eharaeteiized hv the Steps efdireeting the exhattst gasen in the exhaust line te theexhattst treatnient ennigfnneiit (5) hefere they are directed te the etfaperater (7) Whenthe exhaust treatment component lias a Eeva/er ttetnperaittire than a, specific ttetnperattireaint direetitrg the exhaust gasen to the tävaptiitfater (7) hethrtë thtey are tiireettëti te theexhattst treatment ennirrnnent (5) twheii the exhaust treatment enrnptänent has a iiigiiei' temperature titan said specific ternperatttre.