EngineApplicationDepartmentofC&CTrucksCo.,Ltd.ResearchInstitute

陶兵文2015年10月

TaoBingwenOctober,20150排氣后處理系統(tǒng)簡介ExhaustSolutionSystemIntroduction

第一部分概述Chapter1Overview第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting1目錄Contents1、排氣后處理系統(tǒng)的功用：FunctionsofExhaustSolutionSystem:①保證發(fā)動機(jī)最佳性能的同時，把發(fā)動機(jī)所有燃燒廢氣安全地運(yùn)離發(fā)動機(jī)；①Toensurethebestperformanceoftheengine，combustionexhaustgasdeliveredtotheenginesafelyatthesametime；②消減發(fā)動機(jī)產(chǎn)生的排氣噪聲以滿足法規(guī)和客戶對噪音要求；②Reduceexhaustnoisegeneratedbytheenginetomeettherequirementsofregulationsandcustomers③降低或消除發(fā)動機(jī)燃燒產(chǎn)生的污染物以滿足法規(guī)和客戶要求；③Reduceoreliminatethepollutantsgeneratedbyenginecombustioninordertomeetregulationsandcustomerrequirements;2、排氣后處理系統(tǒng)的技術(shù)類型：TypesofExhaustSolutionSystem:①選擇催化還原技術(shù)簡介：選擇性催化還原是一項針對柴油發(fā)動機(jī)排氣的NOx控制技術(shù)。這個反應(yīng)需要在一個催化器里向排氣中噴入尿素（一種易于分解為氨的氮化合物）。尿素被加熱后產(chǎn)生的氨與NOx發(fā)生發(fā)應(yīng)，生成無害的氮?dú)?N2)和水(H20)。①SCR：Selective

Catalytic

ReductionIntroduction:SelectivecatalyticreductionisaNOxcontroltechniquefordieselengineexhaust.TheprocessinvolvestheinjectionofUrea(anitrogenouscompoundwhichreadilydecomposesintoammonia)intotheexhaustoveracatalystconvertor.TheammoniareactswithNOxandproducesharmlessnitrogen(N2)andwater(H20).2一、概述Chapter1Overview注意：這里所說的添藍(lán)就是指：“尿素”Note:

TheAdbluesaidhereis:"urea"3、排氣后處理系統(tǒng)的組成：ComponentsofExhaustSolutionSystem:①添藍(lán)供給裝置：如添藍(lán)罐、添藍(lán)溶液傳感器、添藍(lán)管路、添藍(lán)噴射泵等①Adbluesupplydevice:suchasadbluetank、adbluesensor、adbluehose②空氣供給裝置：如儲氣罐、油氣分離器、尼龍管等②Airsupplydevice:suchasairtank、oil&airfilter、PAhose③系統(tǒng)加熱裝置：如防凍液電磁閥、EPDM管路、添藍(lán)溶液傳感器等③Systemheatingdevice:suchascoolantcontrolvalve、EPDMhoseandadbluesensor④

排氣催化還原裝置：如催化消聲器、排氣管等④Exhaustcatalyticreductiondevice:suchasexhasutgasprocessor、exhaustpipe⑤系統(tǒng)控制裝置：如DCU、NOx傳感器、前溫度傳感器、后溫度傳感器等⑤Systemcontroldevice:suchasDCU、NOxsensor、catalystinputtemperaturesensor、catalystoutputtemperaturesensor3一、概述Chapter1Overview4、SCR后處理系統(tǒng)關(guān)鍵總成件：KeyassemblyofSCRsystem:催化消聲器Exhaustgasprocessor添藍(lán)噴嘴Ureainjectornozzle噴嘴扣壓螺母Nozzlenut添藍(lán)噴射泵UreadoserUnit防凍液電磁閥Coolantcontrolvalve油氣分離器Oil&airfilter排氣管Exhaustpipe添藍(lán)罐帶添藍(lán)溶液傳感器Ureatankwhitureasensor添藍(lán)管路Ureahoses氮氧傳感器NOxsensorSCR控制模塊Dosingcontrolunit前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor

第一部分概述Chapter1Overview第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting4目錄Contents二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction添藍(lán)供給裝置Adbluesupplydevice空氣供給裝置Airsupplydevice系統(tǒng)控制裝置Systemcontroldevice排氣裝置Exhaustcatalyticreductiondevice系統(tǒng)加熱裝置systemheatingdevice發(fā)動機(jī)Engine電源線Powerlines信號線signallines加熱管Heatlines添藍(lán)管Adbluelines空氣管AirlinesCAN線CANlines8車輛儲氣罐9油氣分離器10進(jìn)氣管11出氣管22NOx傳感器催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機(jī)廢氣流向箭頭Exhaustflowarrow19排氣尾管1.Ureatank2.UreadoserUnit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添藍(lán)供給裝置Adbluesupplydevice26蓄電池?＋－?空氣供給裝置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor排氣催化還原裝置ExhaustCatalyticreductiondevice17.Exhaustpipe18.ExhaustGasprocessor19.Exhausttailpipe系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay26.Battery27.Ignitionswitch23DCU24ECU21后溫傳感器20前溫傳感器3添藍(lán)噴嘴1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管6噴射管7添藍(lán)傳感器14進(jìn)水管15出水管12發(fā)動機(jī)13防凍液電磁閥16加熱回水管25加熱繼電器27.點火開關(guān)二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction系統(tǒng)工作原理：簡單地說，系統(tǒng)的工作原理如下：

AdBlue存放在一個安裝在底盤上的罐中。此罐向計量泵(DU)供應(yīng)溶液，后者也安裝在底盤上。DU由SCR控制模塊（DCU），DCU和發(fā)動機(jī)控制模塊(ECM)關(guān)聯(lián)通訊。DU使用來自車輛系統(tǒng)的壓縮空氣使AdBlue霧化，并通過非常精確的計量和泵送系統(tǒng)輸送到發(fā)動機(jī)排氣系統(tǒng)內(nèi)的噴嘴。DCU控制著噴入排氣中的AdBlue數(shù)量，在任何指定轉(zhuǎn)速和負(fù)載條件下，將其與發(fā)動機(jī)的NOx排放量相匹配。與熾熱的排氣一接觸，水就迅速蒸發(fā)，尿素變成氨。氨與NOx在催化轉(zhuǎn)換器內(nèi)發(fā)生發(fā)應(yīng)，這一過程的結(jié)果就是從排氣管中排放出無害的氮?dú)?N2)和水(H20)。Systemwork

principle：Brieflydescribed,thesystemfunctionsasfollows:TheAdBlueisstoredinachassismountedtank.ThetanksuppliesthesolutiontoaDosingUnit(DU)whichisalsochassismounted.TheDUiselectronicallycontrolledbytheUosingcontrolunit（DCU）whichrelatestotheenginecontrolmodule(ECM).TheDUusescompressedairsuppliedfromthevehiclesystemtoatomizetheAdBlueandbymeansofaveryaccuratepumpingandmeteringsystem,suppliesaspraynozzleintheengine’sexhaustsystem.TheamountofAdBlueinjectedintotheexhaustiscontrolledbytheDCUandmatchedtotheNOxoutputoftheengineatanygivenspeedandloadcondition.Waterevaporatesquicklyandtheureaturnsintoammoniawhenincontactwithhotexhaustgases.TheammoniareactswithNOxoverthecatalystconvertorandtheresultanttailpipeemissionfromthisprocessisharmlessnitrogen(N2)andwater(H20).二、排氣后處理系統(tǒng)—構(gòu)造Chapter2、ExhaustSolutionSystem—construction二、排氣后處理系統(tǒng)原理&構(gòu)造—添藍(lán)供給裝置Chapter2、Principle&construction—Adbluesupplydevice添藍(lán)罐Adbluetank添藍(lán)溶液傳感器Adbluesensor添藍(lán)進(jìn)液管Adbluesupplyhose添藍(lán)回液管Adbluereturnhose添藍(lán)噴射管AdbluePressurehose添藍(lán)噴射泵AdbluedoserUnit原理圖Principlefigure3添藍(lán)噴嘴1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管6噴射管7添藍(lán)傳感器1.Ureatank2.Ureadoserunit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添藍(lán)供給裝置Adbluesupplydevice車輛布置圖Vehiclelayoutfigure工作原理：添藍(lán)罐中的添藍(lán)溶液通過添藍(lán)溶液傳感器，由進(jìn)液管輸送給添藍(lán)噴射泵，然后通過噴射管送給噴嘴噴霧到排氣管中，與發(fā)動機(jī)廢氣混合；為防止泵的壓力過高，多余的添藍(lán)溶液通過回液管返回至添藍(lán)罐；Work

principle:Theureasolutioninureatankistransferredfromureasupplyhosetoureadoserunitbyureasolutionsensor，andthenthroughureapressurehosetotheexhaustpipe,wheremixwiththeengineexhaustgas;Theexcessureasolutionreturntoureatankbyreturnhose，topreventthepumppressureofureadoserunitistoohigh。8車輛儲氣罐9油氣分離器10進(jìn)氣管11出氣管空氣供給裝置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose工作原理：儲氣罐中的高壓空氣通過進(jìn)氣管進(jìn)入油氣分離器，然后輸送給添藍(lán)噴射泵，與噴射泵中的尿素溶液混合，作為尿素噴射的主要動力源。Work

principle:Thehighpressureairintheairstoragetankisusedtoentertheoil&airfilterthroughairinhose，andthentransporttoureadoserunit；Theairmixwithureainureadoserunit，whichisusedasmainpowersourceforureainjection.儲氣罐Airtank進(jìn)氣管Airinhose出氣管Airouthose油氣分離器Oil&airfilter原理圖Principlefigure車輛布置圖Vehiclelayoutfigure二、排氣后處理系統(tǒng)原理&構(gòu)造—空氣供給裝置Chapter2、Principle&construction—Airsupplydevice工作原理：當(dāng)系統(tǒng)檢測添藍(lán)溶液溫度低于0℃時，系統(tǒng)加熱功能啟動，直至添藍(lán)溶液溫度達(dá)到3℃才停止加熱。Work

principle:Theureasolutiontemperaturewillbemonitoredandifthetemperatureislessthan0degreestheheaterwillbeengaged.Theheaterwillremainonuntilthetemperatureincreasesto3degrees.發(fā)動機(jī)Engine防凍液電磁閥Engine電磁閥進(jìn)水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍(lán)溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機(jī)1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管7添藍(lán)傳感器14進(jìn)水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：當(dāng)添藍(lán)溶液傳感器探測到尿素溶液溫度低于0℃時，防凍液電磁閥閥門開啟，熱的發(fā)動機(jī)防凍液通過電磁閥進(jìn)水管流經(jīng)防凍液電磁閥，然后通過電磁閥出水管進(jìn)入到尿素傳感器加熱螺旋管，給添藍(lán)罐中的尿素溶液加熱，最后通過加熱系統(tǒng)回水管返回至發(fā)動機(jī)參與冷卻循環(huán)，如此周而復(fù)始的循環(huán)加熱尿素溶液，防止尿素溶液結(jié)冰，保證SCR系統(tǒng)尿素溶液的正常供給。Work

principle:Whentheureasolutionsensordetectureatemperatureoflessthan0degrees,

thecoolantcontrolvalveisopened,hotenginecoolantflowfromcoolantinhosetothecoolantcontrolvalve,andthenthroughthecoolantouthoseintoureasolutionsensorheatingspiraltube,soureaintankisheated，throughcoolantreturnhoseofheatingsystemtotheengineincirculatingcoolingfinally,sogoroundandbeginagain,topreventureasolutionfreeze,andensurethenormalsupplyofureasolutionforSCR.發(fā)動機(jī)Engine防凍液電磁閥Engine電磁閥進(jìn)水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍(lán)溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機(jī)1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管7添藍(lán)傳感器14進(jìn)水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：添藍(lán)溶液加熱器集成在添藍(lán)溶液傳感器中，為螺旋結(jié)構(gòu)，增大了加熱器與尿素溶液的接觸面積，提高了解凍效率。Work

principle:Inordertoimprovetheefficiencyoftheheatingprocess,ureasolutionheaterisintegratedintheureasolutionsensor,whichisaspiralstructureforincreasingthecontactareabetweentheheaterandtheureasolution.發(fā)動機(jī)Engine防凍液電磁閥Engine電磁閥進(jìn)水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍(lán)溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機(jī)1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管7添藍(lán)傳感器14進(jìn)水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice工作原理：添藍(lán)罐中的尿素溶液被加熱的同時，添藍(lán)進(jìn)液管和回液管也同時啟動電加熱功能，以保證尿素管路因結(jié)冰堵塞。添藍(lán)噴射泵自帶加熱解凍功能。Work

principle:

Theureasolutionhasbeenheatedinureasupplyhoseandureareturnhosebytheelectricheatingfunctionwhenureasolutionintankisheatedatthesametime.Theureadoserunithasaselfcontrolledheatingelementasstandard.發(fā)動機(jī)Engine防凍液電磁閥Engine電磁閥進(jìn)水管Coolantinhose電磁閥出水管Coolantouthose加熱系統(tǒng)回水管Coolantreturnhose添藍(lán)溶液傳感器Ureasensor原理圖Principlefigure車輛布置圖Vehiclelayoutfigure12發(fā)動機(jī)1添藍(lán)罐2添藍(lán)噴射泵4進(jìn)液管5回液管7添藍(lán)傳感器14進(jìn)水管15出水管13防凍液電磁閥16加熱回水管＋－化冰解凍裝置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)加熱裝置Chapter2、Principle&construction—Systemheatingdevice二、排氣后處理系統(tǒng)原理&構(gòu)造—排氣催化還原裝置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機(jī)廢氣流向箭頭Exhaustflowarrow19排氣尾管12發(fā)動機(jī)排氣催化還原裝置ExhaustCatalyticreductiondevice17.Exhaustpipe18.Exhaustgasprocessor19.Exhausttailpipe12.Engine原理圖Principlefigure車輛布置圖Vehiclelayoutfigure催化消聲器Exhaustgasprocessor排氣管Exhaustpipe排氣管尾管Exhausttailpipe發(fā)動機(jī)Engine尿素NH2CONH2加H2O后在高溫下分解成NH3和CO2過程：

蒸發(fā)：1）NH2CONH2（水溶液）->NH2-CO-NH2（融化的液態(tài)）+H2O（gas）熱分解：2）NH2-CO-NH2（融化的液態(tài)）->NH3（gas）+HNCO（gas）水解：3）NH2CONH2

（gas）+H2O（gas）->2NH3（gas）+CO2（gas）TheprocessofNH2CONH2andCO2beingdecomposedintoNH3andCO2athightemperature:Evaporation:1）NH2CONH2（Aqueoussolution）->NH2-CO-NH2（Meltedliquid）+H2O（gas）Thermaldecompositio:2）NH2-CO-NH2（Meltedliquid）->NH3（gas）+HNCO（gas）Hydrolysis:3）NH2CONH2

（gas）+H2O（gas）->2NH3（gas）+CO2（gas）二、排氣后處理系統(tǒng)原理&構(gòu)造—排氣催化還原裝置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排氣管18催化消聲器（EGP）發(fā)動機(jī)廢氣流向箭頭Exhaustflowarrow19排氣尾管12發(fā)動機(jī)原理圖Principlefigure車輛布置圖Vehiclelayoutfigure催化消聲器Exhaustgasprocessor排氣管Exhaustpipe排氣管尾管Exhausttailpipe發(fā)動機(jī)EngineNH3和排氣中的NO和NO2反應(yīng)產(chǎn)生氮?dú)夂退?）NO+NO2+2NH3->2N2+3H2O5）4NO+O2+4NH3->4N2+6H2O6）2NO2+O2+4NH3->3N2+6H2ONH3reactwithNOxinexhaustgastoproducenitrogenandwater:4）NO+NO2+2NH3->2N2+3H2O5）4NO+O2+4NH3->4N2+6H2O6）2NO2+O2+4NH3->3N2+6H2O系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍(lán)罐2添藍(lán)噴射泵7添藍(lán)傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器工作原理：DCU檢測發(fā)動機(jī)和排氣后處理系統(tǒng)的工作狀況，當(dāng)達(dá)到相應(yīng)工況條件后，SCR系統(tǒng)開始噴射尿素，SCR系統(tǒng)進(jìn)入正式催化還原工作狀態(tài)，達(dá)到降低排放污染物的要求。Workprinciple:DCUdetectstheworkconditionofengineandexhaustsolutionsystem,theSCRsystembegantosprayureasolutionwhenreachingthespecificallyconditions.theSCRsystemturnintotheformalcatalyticreductionoftheworkingstateforreducingthepollutantsofexhaustgas.原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍(lán)溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍(lán)罐2添藍(lán)噴射泵7添藍(lán)傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器SCR系統(tǒng)進(jìn)入正式催化還原工作狀態(tài)，需滿足以下7個條件：SCRsystemintotheformalcatalyticreductionoftheworkingstate,thefollowing7conditionsshouldbemet:條件1：尿素水溶液溫度至少大于7℃；Condition1:ureawatersolutiontemperatureisatleast7centigrade;條件2：氮氧傳感器狀態(tài)值為“正?！保籆ondition2:thestateofthenitrogenoxygensensoris"normal";條件3：發(fā)動機(jī)轉(zhuǎn)速大于650rpm；Condition3:enginespeedisgreaterthan650rpm;原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍(lán)溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice系統(tǒng)控制裝置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消聲器（EGP）1添藍(lán)罐2添藍(lán)噴射泵7添藍(lán)傳感器13防凍液電磁閥23DCU24ECU21后溫傳感器20前溫傳感器＋－22NOx傳感器25加熱繼電器條件4：發(fā)動機(jī)負(fù)荷大于3%；Condition4:engineloadgreaterthan3%;條件5：大氣壓力大于90kpa；Condition5:atmosphericpressuregreaterthan90kpa;條件6：排溫大于200℃；Condition6:rowtemperaturegreaterthan200;條件7：發(fā)動機(jī)水溫大于60℃。Condition7:enginewatertemperatureisgreaterthan60degrees.原理圖Principlefigure車輛布置圖Vehiclelayoutfigure控制模塊Dosingcontrolunit防凍液電磁閥Coolantcontrolvalve前溫度傳感器CatalystinputT-sensor添藍(lán)溶液傳感器Ureasensor前溫度傳感器CatalystoutputT-sensorNOx傳感器NOxsensor二、排氣后處理系統(tǒng)原理&構(gòu)造—系統(tǒng)控制裝置Chapter2、Principle&construction—Systemcontroldevice

第一部分概述Chapter1Overview

第二部分系統(tǒng)構(gòu)造與原理Chapter2SystemConstruction&OperatingPrinciple第三部分主要部件功用及工作原理Chapter3FunctionsandOperatingPrincipleofMainComponents第四部分使用注意事項Chapter4Useattention第五部分故障診斷及排除Chapter5FaultDiagnosisAndTroubleshooting19目錄Contents三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

DEF是什么？1.DEF-柴油排氣處理液（通常說的尿素，Adblue）2.32.5%的尿素水溶液3.無色，有淡淡的氨氣味，無毒4.水分蒸發(fā)后會結(jié)晶5.對碳鋼，銅，鋅等有腐蝕性6.零下11攝氏度會結(jié)冰7.詳細(xì)特性見ISO22241-1：2006或者中國標(biāo)準(zhǔn)29518-2013WhatisDEF?1.DEF–DieselExhaustFluid(a.k.a.Urea,Adblue)2.AmixofwaterandUrea(32.5%)3.Isaclearliquidsolution,faintsmellofammonia,classifiedbychemicalindustryasnon-hazardous4.Ifspilledwaterevaporatesandcrystalswillform5.Ischemicallyasaltcorrosivewhichcanattackmildsteel,brass,copperandzinc6.Startstofreezeat-11degrees7.Spec.asperDIN70070orChinaGB29518-2013尿素溶液濃度與冰點的關(guān)系Relationshipbetweenconcentrationofureasolutionandfreezingpoint

SCR后處理系統(tǒng)使用尿素質(zhì)量濃度為32.5%的尿素水溶液（AUS32）作為還原劑，其重要原因就是：尿素溶液在此濃度下結(jié)冰溫度最低（-11℃），如圖所示。

為什么車用尿素溶液量濃度要求為32.5%？Whydoesthecaruseureasolutionconcentrationrequirementis32.5%?三、主要部件功用及工作原理Three、FunctionsandOperatingPrincipleofMainComponentsUreasolutionattheconcentrationof32.5%icetemperatureminimum(-11℃),whichisthemainreasonofusingUreasolutionattheconcentrationof32.5%asareducingagentfortheSCRsystem,asshowninfig.三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

催化消聲器催化消聲器(EGP)是在密封不銹鋼殼體或“罐”內(nèi)的一個整體式催化和消聲裝置。EGP內(nèi)串聯(lián)的三個截然不同的元件分別是氨擴(kuò)散器、催化器和消聲裝置。擴(kuò)散器負(fù)責(zé)將氨均勻分散在催化器表面上。催化器負(fù)責(zé)NOx轉(zhuǎn)化的化學(xué)反應(yīng)，而消聲裝置則消減排氣系統(tǒng)的噪聲。（見圖右圖）催化器內(nèi)的化學(xué)反應(yīng)依賴于溫度（最低200°C）。ExhaustGasProcessor(EGP)Theexhaustgasprocessor(EGP)isanintegratedcatalystandacousticunitinonesealedstainlesssteelhousingor‘can’.Thethree,inseries,distinctelementsintheEGPareammoniadiffuser,catalystandacousticunit.Thediffuseractstoevenlydistributetheammoniaoverthecatalystface.ThecatalystperformsthechemicalprocessofNOxconversionandtheacousticunitmufflestheexhaustsystemnoise.(seeFigright)Thechemicalprocessinthecatalystistemperaturedependant(200oCmin.)氨擴(kuò)散器Ammoniadiffuser催化器Catalyst消聲裝置Acousticunit

催化消聲器的主要作用是催化氮氧化合物的還原反應(yīng)和降低發(fā)動機(jī)的排氣噪聲，是SCR催化器和發(fā)動機(jī)排氣消聲器的集成體。整體材料為不銹鋼，內(nèi)裝SCR催化器芯子和消聲管路，運(yùn)行過程中表面平均溫度高于200℃。法蘭面接口為入口，另一光管接口為出口。催化消聲器設(shè)計有前后兩個溫度傳感器安裝座，在催化后設(shè)計有NOx傳感器安裝座。催化器前后都要裝溫度傳感器,溫度傳感器外形如右圖所示。為防止插錯，催化器前后溫度傳感器插接件不同，前溫傳感器是圓形，后溫傳感器是方形，安裝時請辨別催化器進(jìn)出口溫度傳感器的位置。ThemainfunctionoftheEGPisthereductionofthenitrogenoxidecompoundandthereductionoftheengineexhaustnoise.ItistheintegrationoftheSCRcatalystandtheengineexhaustmuffler.Thematerialismadeofstainlesssteel,installedintheSCRcatalyticconvertercoreandmufflerpipeline,runningaveragesurfacetemperaturehigherthan200degrees.Theflangeinterfaceistheentrance,andtheotheristheoutletoftheinterface.TheEGPdesignhastwotemperaturesensorinstallation,inthecatalyticdesignofNOxsensorinstallationseat.BothbeforeandaftertheEGPhasatemperaturesensor,thetemperaturesensorconfigurationisshowninfigright.Topreventthewrong,thesensorshavedifferentconnectors，CatalystinputT-sensorisround,theCatalystoutputT-sensorissquare,pleaseidentifysensorposition.前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor前溫安裝座InputT-sensorinstallation進(jìn)氣口Exhaustinput后溫安裝座OutputT-sensorinstallation出氣口ExhaustoutletNOx安裝座Noxsensorinstallation三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

三個傳感器總成：消聲器前溫度傳感器總成消聲器前溫度傳感器總成NOx傳感器總成1.催化器上的溫度傳感器用來決定什么時間催化器達(dá)到需要溫度以實現(xiàn)化學(xué)反應(yīng)，并以此啟動尿素的計量與噴射；2.NOx傳感器實時監(jiān)測尾氣中NOx的排放量是否滿足排放要求，并反饋給DCU，用于尿素計量的計算參數(shù)之一。Threesensors:1.ThetemperaturesensorontheEGPisusedtodeterminewhattimethecatalystisneededtoachievethedesiredtemperatureinordertoachieveachemicalreaction,andtostartthemeasurementandinjectionofurea;2.NOxsensorinreal-timemonitoringofNOxemissionsintheexhaustgasemissionsrequirements,andfeedbacktotheDCU,tocalculationparametersforureameasurement.氮氧傳感器NOxsensor前溫度傳感器CatalystinputT-sensor后溫度傳感器CatalystoutputT-sensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents②添藍(lán)溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody

添藍(lán)罐總成（帶添藍(lán)溶液傳感器）主要結(jié)構(gòu)組成與功能：①通氣裝置：維持罐體內(nèi)和罐體外壓力平衡②添藍(lán)溶液傳感器：監(jiān)測尿素液位和溫度，密封添藍(lán)罐③添藍(lán)罐口蓋：密封添藍(lán)罐，便于實現(xiàn)添藍(lán)罐實時的尿素加注要求，加注口集成70μm自清潔式過濾器，以防通過加注頸管進(jìn)入的雜物損壞系統(tǒng)④液位觀察窗：人工加注尿素時，通過觀察窗口液位顯示控制尿素加注量，防止尿素加注過滿⑤排水孔：定期清理罐體中的殘渣和污垢⑥罐體：盛載尿素溶液Ureatank（integratedureasensor）Mainstructureandfunction:①Ventdevice:maintaintankinsideandoutsidepressurebalance②Ureasolutionsensor:monitoringofurealiquidlevelandtemperature,sealingUreatank③Fillingcover:sealingUreatank,itiseasytofilladblueintoUrea

tankreal-timemeetingfillingrequirements.

Thefillerneckofthetankhasafiltersizedat70microntopreventingressofmaterialwhichmaygetinviathefillerneck.④Urealevelshow:Whenmanualfillingurea,controlstheureafillingquantitythroughtheurealevelshowwindow,preventstheureafillingover⑤Drainhole:cleaningtheresidueanddirtofthetankregularly⑥Tankbody:loadingureasolution三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍(lán)罐中的關(guān)鍵總成件-添藍(lán)溶液傳感器總成監(jiān)測罐內(nèi)尿素溶液溫度，通過發(fā)動機(jī)熱水（防凍液）對罐內(nèi)尿素溶液化冰加熱，保證尿素溶液的正常供給；監(jiān)測罐內(nèi)液位高度，并按照預(yù)設(shè)液位高度向后處理系統(tǒng)控制模塊發(fā)出報警信號；

KeycomponentinUreatank-Ureasolutionsensormonitorthetemperatureofureasolutioninthetank,keeptheureasolutionnormaltemperaturebyheatingthroughenginehotcoolant,andensurethenormalsupplyofureasolutionMonitortheheightofliquidlevelintheUreatank,andsendoutthealarmsignaltotheDCUmoduleaccordingtothepresetparameter顯示液位高低原理：磁化的浮筒感應(yīng)電子管內(nèi)的磁簧管開關(guān)，改變電阻輸出的大小，通過阻值變化反應(yīng)箱體中的液體高度變化Displayliquidlevelprinciple:changethesizeoftheoutputresistancethroughtheMagneticfloatinducingthemagneticreedswitchintube;TheresistancechangedisplayliquidheightchangeintheUreatank顯示液體溫度原理：NTC熱敏電阻隨溫度變化，輸出不同阻值，通過阻值變化反應(yīng)罐內(nèi)溶液的溫度變化Displayliquidtemperatureprinciple:TheNTCthermistoroutputdifferentresistancewithdifferenttemperatureoftheUreatanksolution磁鋼浮筒Magneticfloat添藍(lán)溶液傳感器Ureasensor溫度傳感器Temperaturesensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

端口應(yīng)用Application起點From終點To管路規(guī)格HosesizeA尿素出液口Ureasupply添藍(lán)罐Ureatank噴射泵DUSAE9.49B尿素回液口Ureareturn噴射泵DU添藍(lán)罐UreatankSAE7.89C防凍液進(jìn)液口Coolantin發(fā)動機(jī)取水口Engineout添藍(lán)罐UreatankΦ14×2.5D防凍液出液口Coolantout添藍(lán)罐Ureatank發(fā)動機(jī)回水口EngineinΦ14×2.5E線束WiringABCDE三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍(lán)罐總成（帶添藍(lán)溶液傳感器）

SCR反應(yīng)所需的氨取自于質(zhì)量濃度為32.5%的尿素水溶液(AdBlue)。供應(yīng)罐的尺寸應(yīng)使AdBlue量相當(dāng)于燃油消耗量5%（歐4安裝類型）的工作用量，而對于歐5估算值約為7%。

適用的罐材料有不銹鋼、鎂鋁合金或中高密度的聚乙烯。推薦使用不透明罐，使操作員不能觀察液位。這能確保診斷顯示空罐時它仍留有足量AdBlue，以免計量泵吸入空氣。

Ureatank（Ureasensorintegrated）TheammoniarequiredfortheSCRprocessisobtainedfromasolutionof32.5%(byweight)ureainwater(AdBlue).TheUreatankshouldbesizedtosuitanoperationaluseofureaequivalentto5%offuelconsumptionforEuro4installationsandanestimated7%forEuro5.Suitabletankmaterialsarestainlesssteel,magnesiumaluminiumalloyormedium-highdensitypolyethylene.Itisrecommendedthatthetankisnon-transparentsuchthattheoperatorcannotseethelevel.Thisistoensurethatwhenthetankshowsemptydiagnostically,itwillstillhaveasignificantamountofurealefttoavoidthedosingunitdrawingair.②添藍(lán)溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添藍(lán)罐總成（帶添藍(lán)溶液傳感器）

供應(yīng)罐應(yīng)與大氣保持雙向低壓通風(fēng)，使出口接頭的液體自由流動，并排出罐內(nèi)的所有蒸汽或膨脹氣體。通氣口設(shè)計應(yīng)使其不受罐濺出或蒸發(fā)過程中生成的結(jié)晶AdBlue導(dǎo)致堵塞的影響。目前還沒有發(fā)生道路事故時車輛翻傾防濺方面的法規(guī)，但是需要關(guān)注未來法規(guī)的發(fā)展。添藍(lán)罐有一個排液孔，以便進(jìn)行定期維護(hù)。

Ureatank（Ureasensorintegrated）Theureatankshouldbeventedatlowpressurebothtoandfromatmospheretoallowfreeflowfromtheoutletconnectionandtoventanyvapourorexpansioninthetank.Theventshouldbedesignedsuchthatitisnotsusceptibletoblockagebycrystallizedureaformedduringtanksloshandevaporation.Thereisnoknownregulationonanti-spillforvehicleroll-overintheeventofaroadaccident;howeverthisneedstobemonitoredforfuturedevelopmentsinthelegislation.TheUreatankhasadrainholeforperiodicservicing.②添藍(lán)溶液傳感器Ureasensor①通氣裝置Vent③加注口蓋Fillingcover④觀察窗Levelshow⑤排水孔Drainhole⑥罐體Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

安裝孔（4個）Mountinghole（four）壓縮空氣進(jìn)口（A）CompressedAirinlet37針接頭（J1939)尿素進(jìn)液口（C）Ureainlet空氣電磁閥接口Airsolenoidvalveinterface尿素回液（D）Ureareturn尿素出液（B）Air&Ureamixoutlet添藍(lán)噴射泵總成添藍(lán)噴射泵泵(DU)是高精度裝置，用于將所需尿素溶液量噴入排氣后處理系統(tǒng)中。該部件應(yīng)輕拿輕放。如果跌落可能會損壞。由DCU控制的24V電動泵和計量系統(tǒng)與車輛壓縮空氣系統(tǒng)送來的空氣一起協(xié)作，推動霧化的尿素溶液充入排氣系統(tǒng)催化器上游的噴嘴中。應(yīng)注意空氣電磁閥是一個直接使用取自加料泵12V電源的12V裝置?？諝庀牧繛?7.5–22L/min。（標(biāo)準(zhǔn)條件）。不論是否加注AdBlue，空氣消耗都是持續(xù)的。

UreadoserUnitThedosingunit(DU)isahighaccuracyunitforinjectingtherequiredAdBluequantityintotheexhaustafter-treatmentsystem.Thiscomponentshouldbehandledwithcare.Itmaybedamagedifdropped.A24velectronicallyoperatedpumpandmeteringsystem(controlledbytheDCU)workincombinationwithairfromthevehiclecompressedairsystemtopropeltheatomizedAdBluechargethroughanozzleintotheexhaustsystemupstreamofthecatalyst.Itshouldbenotedthattheairvalvesolenoidisa12voltunitwiththe12voltpowersourcecomingfromthedosingpumpdirectly.Theairconsumptionis17.5–22litres/min.(standardconditions).ThisairconsumptioniscontinuouswhetherAdBlueisbeingdosedornot.

三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

1.空氣閥（由電磁閥控制）2.4bar壓力下的空氣壓力調(diào)節(jié)閥3.量孔4.空氣單向閥（ACV）5.背壓閥（BPV）6.混合室7.出口單向閥（彈簧承載）8.促動膜片9.進(jìn)口單向閥（彈簧承載）10.壓力開關(guān)11.空氣促動閥Ⅰ空氣裝置Ⅱ混合閥Ⅲ膜片泵A.與車輛空氣系統(tǒng)連接（壓縮空氣進(jìn)氣管）B.與添藍(lán)噴嘴連接（添藍(lán)噴射管）C.與添藍(lán)罐連接（添藍(lán)進(jìn)液管）D.與添藍(lán)罐連接（添藍(lán)回液管）ⅠⅡⅢ安裝孔（4個）Mountinghole（four）壓縮空氣進(jìn)口（A）CompressedAirinlet37針接頭（J1939)37pinconnector（J1939）尿素進(jìn)液口（C）Ureainlet空氣電磁閥接口Airsolenoidvalveinterface尿素回液（D）Ureareturn尿素出液（B）Air&Ureamixoutlet三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents1.添藍(lán)噴射泵的4種工作模式-預(yù)注模式1.FouroperatingmodesofDU—PRIMNGMODE每次發(fā)動機(jī)運(yùn)轉(zhuǎn)，添藍(lán)泵將進(jìn)入預(yù)注階段。添藍(lán)溶液通過泵循環(huán)并流回到添藍(lán)罐中，以便排空添藍(lán)系統(tǒng)中殘留的空氣與尿素溶液混合物。如果預(yù)注階段成功，將會聽到添藍(lán)泵電機(jī)全速運(yùn)轉(zhuǎn)30秒，空氣電磁閥將在本階段末工作。如果預(yù)注階段第一次不成功，空氣電磁閥將斷電，電機(jī)將再全速運(yùn)轉(zhuǎn)30秒直到預(yù)注成功。這一順序可以重復(fù)最多20次。

Everytimetheenginerunning,theDUwillcomeintoprimingmodephase.Ureasolutionthroughthecirculationpumpandflowbacktoureatank,to