重型卡车SCR排放系统中英文版 201510

EngineApplicationDepartmentofC&CTrucksCo.,Ltd.ResearchInstitute

陶兵文2015年10月

TaoBingwenOctober,20150排气后处理系统简介ExhaustSolutionSystemIntroduction

第一部分概述Chapter1Overview第二部分系统构造与原理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项Chapter4Useattention第五部分故障诊断及排除Chapter5FaultDiagnosisAndTroubleshooting1目录Contents1、排气后处理系统的功用：FunctionsofExhaustSolutionSystem:①保证发动机最佳性能的同时，把发动机所有燃烧废气安全地运离发动机；①Toensurethebestperformanceoftheengine，combustionexhaustgasdeliveredtotheenginesafelyatthesametime；②消减发动机产生的排气噪声以满足法规和客户对噪音要求；②Reduceexhaustnoisegeneratedbytheenginetomeettherequirementsofregulationsandcustomers③降低或消除发动机燃烧产生的污染物以满足法规和客户要求；③Reduceoreliminatethepollutantsgeneratedbyenginecombustioninordertomeetregulationsandcustomerrequirements;2、排气后处理系统的技术类型：TypesofExhaustSolutionSystem:①选择催化还原技术简介：选择性催化还原是一项针对柴油发动机排气的NOx控制技术。这个反应需要在一个催化器里向排气中喷入尿素（一种易于分解为氨的氮化合物）。尿素被加热后产生的氨与NOx发生发应，生成无害的氮气(N2)和水(H20)。①SCR：Selective

Catalytic

ReductionIntroduction:SelectivecatalyticreductionisaNOxcontroltechniquefordieselengineexhaust.TheprocessinvolvestheinjectionofUrea(anitrogenouscompoundwhichreadilydecomposesintoammonia)intotheexhaustoveracatalystconvertor.TheammoniareactswithNOxandproducesharmlessnitrogen(N2)andwater(H20).2一、概述Chapter1Overview注意：这里所说的添蓝就是指：“尿素”Note:

TheAdbluesaidhereis:"urea"3、排气后处理系统的组成：ComponentsofExhaustSolutionSystem:①添蓝供给装置：如添蓝罐、添蓝溶液传感器、添蓝管路、添蓝喷射泵等①Adbluesupplydevice:suchasadbluetank、adbluesensor、adbluehose②空气供给装置：如储气罐、油气分离器、尼龙管等②Airsupplydevice:suchasairtank、oil&airfilter、PAhose③系统加热装置：如防冻液电磁阀、EPDM管路、添蓝溶液传感器等③Systemheatingdevice:suchascoolantcontrolvalve、EPDMhoseandadbluesensor④

排气催化还原装置：如催化消声器、排气管等④Exhaustcatalyticreductiondevice:suchasexhasutgasprocessor、exhaustpipe⑤系统控制装置：如DCU、NOx传感器、前温度传感器、后温度传感器等⑤Systemcontroldevice:suchasDCU、NOxsensor、catalystinputtemperaturesensor、catalystoutputtemperaturesensor3一、概述Chapter1Overview4、SCR后处理系统关键总成件：KeyassemblyofSCRsystem:催化消声器Exhaustgasprocessor添蓝喷嘴Ureainjectornozzle喷嘴扣压螺母Nozzlenut添蓝喷射泵UreadoserUnit防冻液电磁阀Coolantcontrolvalve油气分离器Oil&airfilter排气管Exhaustpipe添蓝罐带添蓝溶液传感器Ureatankwhitureasensor添蓝管路Ureahoses氮氧传感器NOxsensorSCR控制模块Dosingcontrolunit前温度传感器CatalystinputT-sensor后温度传感器CatalystoutputT-sensor

第一部分概述Chapter1Overview第二部分系统构造与原理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项Chapter4Useattention第五部分故障诊断及排除Chapter5FaultDiagnosisAndTroubleshooting4目录Contents二、排气后处理系统—构造Chapter2、ExhaustSolutionSystem—construction添蓝供给装置Adbluesupplydevice空气供给装置Airsupplydevice系统控制装置Systemcontroldevice排气装置Exhaustcatalyticreductiondevice系统加热装置systemheatingdevice发动机Engine电源线Powerlines信号线signallines加热管Heatlines添蓝管Adbluelines空气管AirlinesCAN线CANlines8车辆储气罐9油气分离器10进气管11出气管22NOx传感器催化器Catalyticconverter17排气管18催化消声器（EGP）发动机废气流向箭头Exhaustflowarrow19排气尾管1.Ureatank2.UreadoserUnit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添蓝供给装置Adbluesupplydevice26蓄电池כ＋－כ空气供给装置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose化冰解冻装置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor排气催化还原装置ExhaustCatalyticreductiondevice17.Exhaustpipe18.ExhaustGasprocessor19.Exhausttailpipe系统控制装置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay26.Battery27.Ignitionswitch23DCU24ECU21后温传感器20前温传感器3添蓝喷嘴1添蓝罐2添蓝喷射泵4进液管5回液管6喷射管7添蓝传感器14进水管15出水管12发动机13防冻液电磁阀16加热回水管25加热继电器27.点火开关二、排气后处理系统—构造Chapter2、ExhaustSolutionSystem—construction系统工作原理：简单地说，系统的工作原理如下：

AdBlue存放在一个安装在底盘上的罐中。此罐向计量泵(DU)供应溶液，后者也安装在底盘上。DU由SCR控制模块（DCU），DCU和发动机控制模块(ECM)关联通讯。DU使用来自车辆系统的压缩空气使AdBlue雾化，并通过非常精确的计量和泵送系统输送到发动机排气系统内的喷嘴。DCU控制着喷入排气中的AdBlue数量，在任何指定转速和负载条件下，将其与发动机的NOx排放量相匹配。与炽热的排气一接触，水就迅速蒸发，尿素变成氨。氨与NOx在催化转换器内发生发应，这一过程的结果就是从排气管中排放出无害的氮气(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、排气后处理系统—构造Chapter2、ExhaustSolutionSystem—construction二、排气后处理系统原理&构造—添蓝供给装置Chapter2、Principle&construction—Adbluesupplydevice添蓝罐Adbluetank添蓝溶液传感器Adbluesensor添蓝进液管Adbluesupplyhose添蓝回液管Adbluereturnhose添蓝喷射管AdbluePressurehose添蓝喷射泵AdbluedoserUnit原理图Principlefigure3添蓝喷嘴1添蓝罐2添蓝喷射泵4进液管5回液管6喷射管7添蓝传感器1.Ureatank2.Ureadoserunit3.Ureainjectornozzle4.Ureasupplyhose5.Ureareturnhose6.Ureapressurehose7.Ureasensor添蓝供给装置Adbluesupplydevice车辆布置图Vehiclelayoutfigure工作原理：添蓝罐中的添蓝溶液通过添蓝溶液传感器，由进液管输送给添蓝喷射泵，然后通过喷射管送给喷嘴喷雾到排气管中，与发动机废气混合；为防止泵的压力过高，多余的添蓝溶液通过回液管返回至添蓝罐；Work

principle:Theureasolutioninureatankistransferredfromureasupplyhosetoureadoserunitbyureasolutionsensor，andthenthroughureapressurehosetotheexhaustpipe,wheremixwiththeengineexhaustgas;Theexcessureasolutionreturntoureatankbyreturnhose，topreventthepumppressureofureadoserunitistoohigh。8车辆储气罐9油气分离器10进气管11出气管空气供给装置Airupplydevice8.Airtank9.Oil&airfilter10.Airinhose11.Airouthose工作原理：储气罐中的高压空气通过进气管进入油气分离器，然后输送给添蓝喷射泵，与喷射泵中的尿素溶液混合，作为尿素喷射的主要动力源。Work

principle:Thehighpressureairintheairstoragetankisusedtoentertheoil&airfilterthroughairinhose，andthentransporttoureadoserunit；Theairmixwithureainureadoserunit，whichisusedasmainpowersourceforureainjection.储气罐Airtank进气管Airinhose出气管Airouthose油气分离器Oil&airfilter原理图Principlefigure车辆布置图Vehiclelayoutfigure二、排气后处理系统原理&构造—空气供给装置Chapter2、Principle&construction—Airsupplydevice工作原理：当系统检测添蓝溶液温度低于0℃时，系统加热功能启动，直至添蓝溶液温度达到3℃才停止加热。Work

principle:Theureasolutiontemperaturewillbemonitoredandifthetemperatureislessthan0degreestheheaterwillbeengaged.Theheaterwillremainonuntilthetemperatureincreasesto3degrees.发动机Engine防冻液电磁阀Engine电磁阀进水管Coolantinhose电磁阀出水管Coolantouthose加热系统回水管Coolantreturnhose添蓝溶液传感器Ureasensor原理图Principlefigure车辆布置图Vehiclelayoutfigure12发动机1添蓝罐2添蓝喷射泵4进液管5回液管7添蓝传感器14进水管15出水管13防冻液电磁阀16加热回水管＋－化冰解冻装置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排气后处理系统原理&构造—系统加热装置Chapter2、Principle&construction—Systemheatingdevice工作原理：当添蓝溶液传感器探测到尿素溶液温度低于0℃时，防冻液电磁阀阀门开启，热的发动机防冻液通过电磁阀进水管流经防冻液电磁阀，然后通过电磁阀出水管进入到尿素传感器加热螺旋管，给添蓝罐中的尿素溶液加热，最后通过加热系统回水管返回至发动机参与冷却循环，如此周而复始的循环加热尿素溶液，防止尿素溶液结冰，保证SCR系统尿素溶液的正常供给。Work

principle:Whentheureasolutionsensordetectureatemperatureoflessthan0degrees,

thecoolantcontrolvalveisopened,hotenginecoolantflowfromcoolantinhosetothecoolantcontrolvalve,andthenthroughthecoolantouthoseintoureasolutionsensorheatingspiraltube,soureaintankisheated，throughcoolantreturnhoseofheatingsystemtotheengineincirculatingcoolingfinally,sogoroundandbeginagain,topreventureasolutionfreeze,andensurethenormalsupplyofureasolutionforSCR.发动机Engine防冻液电磁阀Engine电磁阀进水管Coolantinhose电磁阀出水管Coolantouthose加热系统回水管Coolantreturnhose添蓝溶液传感器Ureasensor原理图Principlefigure车辆布置图Vehiclelayoutfigure12发动机1添蓝罐2添蓝喷射泵4进液管5回液管7添蓝传感器14进水管15出水管13防冻液电磁阀16加热回水管＋－化冰解冻装置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排气后处理系统原理&构造—系统加热装置Chapter2、Principle&construction—Systemheatingdevice工作原理：添蓝溶液加热器集成在添蓝溶液传感器中，为螺旋结构，增大了加热器与尿素溶液的接触面积，提高了解冻效率。Work

principle:Inordertoimprovetheefficiencyoftheheatingprocess,ureasolutionheaterisintegratedintheureasolutionsensor,whichisaspiralstructureforincreasingthecontactareabetweentheheaterandtheureasolution.发动机Engine防冻液电磁阀Engine电磁阀进水管Coolantinhose电磁阀出水管Coolantouthose加热系统回水管Coolantreturnhose添蓝溶液传感器Ureasensor原理图Principlefigure车辆布置图Vehiclelayoutfigure12发动机1添蓝罐2添蓝喷射泵4进液管5回液管7添蓝传感器14进水管15出水管13防冻液电磁阀16加热回水管＋－化冰解冻装置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor4.Ureasupplyhose5.Ureareturnhose二、排气后处理系统原理&构造—系统加热装置Chapter2、Principle&construction—Systemheatingdevice工作原理：添蓝罐中的尿素溶液被加热的同时，添蓝进液管和回液管也同时启动电加热功能，以保证尿素管路因结冰堵塞。添蓝喷射泵自带加热解冻功能。Work

principle:

Theureasolutionhasbeenheatedinureasupplyhoseandureareturnhosebytheelectricheatingfunctionwhenureasolutionintankisheatedatthesametime.Theureadoserunithasaselfcontrolledheatingelementasstandard.发动机Engine防冻液电磁阀Engine电磁阀进水管Coolantinhose电磁阀出水管Coolantouthose加热系统回水管Coolantreturnhose添蓝溶液传感器Ureasensor原理图Principlefigure车辆布置图Vehiclelayoutfigure12发动机1添蓝罐2添蓝喷射泵4进液管5回液管7添蓝传感器14进水管15出水管13防冻液电磁阀16加热回水管＋－化冰解冻装置Icethawingdevice12.Engine13.Coolantcontrolvalve14.Coolantinhose15.Coolantouthose16.Coolantreturnhose7.Ureasensor2.UreadoserUnit4.Ureasupplyhose5.Ureareturnhose二、排气后处理系统原理&构造—系统加热装置Chapter2、Principle&construction—Systemheatingdevice二、排气后处理系统原理&构造—排气催化还原装置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排气管18催化消声器（EGP）发动机废气流向箭头Exhaustflowarrow19排气尾管12发动机排气催化还原装置ExhaustCatalyticreductiondevice17.Exhaustpipe18.Exhaustgasprocessor19.Exhausttailpipe12.Engine原理图Principlefigure车辆布置图Vehiclelayoutfigure催化消声器Exhaustgasprocessor排气管Exhaustpipe排气管尾管Exhausttailpipe发动机Engine尿素NH2CONH2加H2O后在高温下分解成NH3和CO2过程：

蒸发：1）NH2CONH2（水溶液）->NH2-CO-NH2（融化的液态）+H2O（gas）热分解：2）NH2-CO-NH2（融化的液态）->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、排气后处理系统原理&构造—排气催化还原装置Chapter2、Principle&construction—Exhaustcatalyticreductiondevice催化器Catalyticconverter17排气管18催化消声器（EGP）发动机废气流向箭头Exhaustflowarrow19排气尾管12发动机原理图Principlefigure车辆布置图Vehiclelayoutfigure催化消声器Exhaustgasprocessor排气管Exhaustpipe排气管尾管Exhausttailpipe发动机EngineNH3和排气中的NO和NO2反应产生氮气和水：4）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系统控制装置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消声器（EGP）1添蓝罐2添蓝喷射泵7添蓝传感器13防冻液电磁阀23DCU24ECU21后温传感器20前温传感器＋－22NOx传感器25加热继电器工作原理：DCU检测发动机和排气后处理系统的工作状况，当达到相应工况条件后，SCR系统开始喷射尿素，SCR系统进入正式催化还原工作状态，达到降低排放污染物的要求。Workprinciple:DCUdetectstheworkconditionofengineandexhaustsolutionsystem,theSCRsystembegantosprayureasolutionwhenreachingthespecificallyconditions.theSCRsystemturnintotheformalcatalyticreductionoftheworkingstateforreducingthepollutantsofexhaustgas.原理图Principlefigure车辆布置图Vehiclelayoutfigure控制模块Dosingcontrolunit防冻液电磁阀Coolantcontrolvalve前温度传感器CatalystinputT-sensor添蓝溶液传感器Ureasensor前温度传感器CatalystoutputT-sensorNOx传感器NOxsensor二、排气后处理系统原理&构造—系统控制装置Chapter2、Principle&construction—Systemcontroldevice系统控制装置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消声器（EGP）1添蓝罐2添蓝喷射泵7添蓝传感器13防冻液电磁阀23DCU24ECU21后温传感器20前温传感器＋－22NOx传感器25加热继电器SCR系统进入正式催化还原工作状态，需满足以下7个条件：SCRsystemintotheformalcatalyticreductionoftheworkingstate,thefollowing7conditionsshouldbemet:条件1：尿素水溶液温度至少大于7℃；Condition1:ureawatersolutiontemperatureisatleast7centigrade;条件2：氮氧传感器状态值为“正常”；Condition2:thestateofthenitrogenoxygensensoris"normal";条件3：发动机转速大于650rpm；Condition3:enginespeedisgreaterthan650rpm;原理图Principlefigure车辆布置图Vehiclelayoutfigure控制模块Dosingcontrolunit防冻液电磁阀Coolantcontrolvalve前温度传感器CatalystinputT-sensor添蓝溶液传感器Ureasensor前温度传感器CatalystoutputT-sensorNOx传感器NOxsensor二、排气后处理系统原理&构造—系统控制装置Chapter2、Principle&construction—Systemcontroldevice系统控制装置Systemcontroldevice20.CatalystinputT-sensor21.CatalystoutputT-sensor22.NOxsensor23.Dosingcontrolunit24.Enginecontrolunit25.Heatingrelay催化器Catalyticconverter18催化消声器（EGP）1添蓝罐2添蓝喷射泵7添蓝传感器13防冻液电磁阀23DCU24ECU21后温传感器20前温传感器＋－22NOx传感器25加热继电器条件4：发动机负荷大于3%；Condition4:engineloadgreaterthan3%;条件5：大气压力大于90kpa；Condition5:atmosphericpressuregreaterthan90kpa;条件6：排温大于200℃；Condition6:rowtemperaturegreaterthan200;条件7：发动机水温大于60℃。Condition7:enginewatertemperatureisgreaterthan60degrees.原理图Principlefigure车辆布置图Vehiclelayoutfigure控制模块Dosingcontrolunit防冻液电磁阀Coolantcontrolvalve前温度传感器CatalystinputT-sensor添蓝溶液传感器Ureasensor前温度传感器CatalystoutputT-sensorNOx传感器NOxsensor二、排气后处理系统原理&构造—系统控制装置Chapter2、Principle&construction—Systemcontroldevice

第一部分概述Chapter1Overview

第二部分系统构造与原理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项Chapter4Useattention第五部分故障诊断及排除Chapter5FaultDiagnosisAndTroubleshooting19目录Contents三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

DEF是什么？1.DEF-柴油排气处理液（通常说的尿素，Adblue）2.32.5%的尿素水溶液3.无色，有淡淡的氨气味，无毒4.水分蒸发后会结晶5.对碳钢，铜，锌等有腐蚀性6.零下11摄氏度会结冰7.详细特性见ISO22241-1：2006或者中国标准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尿素溶液浓度与冰点的关系Relationshipbetweenconcentrationofureasolutionandfreezingpoint

SCR后处理系统使用尿素质量浓度为32.5%的尿素水溶液（AUS32）作为还原剂，其重要原因就是：尿素溶液在此浓度下结冰温度最低（-11℃），如图所示。

为什么车用尿素溶液量浓度要求为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

催化消声器催化消声器(EGP)是在密封不锈钢壳体或“罐”内的一个整体式催化和消声装置。EGP内串联的三个截然不同的元件分别是氨扩散器、催化器和消声装置。扩散器负责将氨均匀分散在催化器表面上。催化器负责NOx转化的化学反应，而消声装置则消减排气系统的噪声。（见图右图）催化器内的化学反应依赖于温度（最低200°C）。ExhaustGasProcessor(EGP)Theexhaustgasprocessor(EGP)isanintegratedcatalystandacousticunitinonesealedstainlesssteelhousingor‘can’.Thethree,inseries,distinctelementsintheEGPareammoniadiffuser,catalystandacousticunit.Thediffuseractstoevenlydistributetheammoniaoverthecatalystface.ThecatalystperformsthechemicalprocessofNOxconversionandtheacousticunitmufflestheexhaustsystemnoise.(seeFigright)Thechemicalprocessinthecatalystistemperaturedependant(200oCmin.)氨扩散器Ammoniadiffuser催化器Catalyst消声装置Acousticunit

催化消声器的主要作用是催化氮氧化合物的还原反应和降低发动机的排气噪声，是SCR催化器和发动机排气消声器的集成体。整体材料为不锈钢，内装SCR催化器芯子和消声管路，运行过程中表面平均温度高于200℃。法兰面接口为入口，另一光管接口为出口。催化消声器设计有前后两个温度传感器安装座，在催化后设计有NOx传感器安装座。催化器前后都要装温度传感器,温度传感器外形如右图所示。为防止插错，催化器前后温度传感器插接件不同，前温传感器是圆形，后温传感器是方形，安装时请辨别催化器进出口温度传感器的位置。ThemainfunctionoftheEGPisthereductionofthenitrogenoxidecompoundandthereductionoftheengineexhaustnoise.ItistheintegrationoftheSCRcatalystandtheengineexhaustmuffler.Thematerialismadeofstainlesssteel,installedintheSCRcatalyticconvertercoreandmufflerpipeline,runningaveragesurfacetemperaturehigherthan200degrees.Theflangeinterfaceistheentrance,andtheotheristheoutletoftheinterface.TheEGPdesignhastwotemperaturesensorinstallation,inthecatalyticdesignofNOxsensorinstallationseat.BothbeforeandaftertheEGPhasatemperaturesensor,thetemperaturesensorconfigurationisshowninfigright.Topreventthewrong,thesensorshavedifferentconnectors，CatalystinputT-sensorisround,theCatalystoutputT-sensorissquare,pleaseidentifysensorposition.前温度传感器CatalystinputT-sensor后温度传感器CatalystoutputT-sensor前温安装座InputT-sensorinstallation进气口Exhaustinput后温安装座OutputT-sensorinstallation出气口ExhaustoutletNOx安装座Noxsensorinstallation三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

三个传感器总成：消声器前温度传感器总成消声器前温度传感器总成NOx传感器总成1.催化器上的温度传感器用来决定什么时间催化器达到需要温度以实现化学反应，并以此启动尿素的计量与喷射；2.NOx传感器实时监测尾气中NOx的排放量是否满足排放要求，并反馈给DCU，用于尿素计量的计算参数之一。Threesensors:1.ThetemperaturesensorontheEGPisusedtodeterminewhattimethecatalystisneededtoachievethedesiredtemperatureinordertoachieveachemicalreaction,andtostartthemeasurementandinjectionofurea;2.NOxsensorinreal-timemonitoringofNOxemissionsintheexhaustgasemissionsrequirements,andfeedbacktotheDCU,tocalculationparametersforureameasurement.氮氧传感器NOxsensor前温度传感器CatalystinputT-sensor后温度传感器CatalystoutputT-sensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents②添蓝溶液传感器Ureasensor①通气装置Vent③加注口盖Fillingcover④观察窗Levelshow⑤排水孔Drainhole⑥罐体Tankbody

添蓝罐总成（带添蓝溶液传感器）主要结构组成与功能：①通气装置：维持罐体内和罐体外压力平衡②添蓝溶液传感器：监测尿素液位和温度，密封添蓝罐③添蓝罐口盖：密封添蓝罐，便于实现添蓝罐实时的尿素加注要求，加注口集成70μm自清洁式过滤器，以防通过加注颈管进入的杂物损坏系统④液位观察窗：人工加注尿素时，通过观察窗口液位显示控制尿素加注量，防止尿素加注过满⑤排水孔：定期清理罐体中的残渣和污垢⑥罐体：盛载尿素溶液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

添蓝罐中的关键总成件-添蓝溶液传感器总成监测罐内尿素溶液温度，通过发动机热水（防冻液）对罐内尿素溶液化冰加热，保证尿素溶液的正常供给；监测罐内液位高度，并按照预设液位高度向后处理系统控制模块发出报警信号；

KeycomponentinUreatank-Ureasolutionsensormonitorthetemperatureofureasolutioninthetank,keeptheureasolutionnormaltemperaturebyheatingthroughenginehotcoolant,andensurethenormalsupplyofureasolutionMonitortheheightofliquidlevelintheUreatank,andsendoutthealarmsignaltotheDCUmoduleaccordingtothepresetparameter显示液位高低原理：磁化的浮筒感应电子管内的磁簧管开关，改变电阻输出的大小，通过阻值变化反应箱体中的液体高度变化Displayliquidlevelprinciple:changethesizeoftheoutputresistancethroughtheMagneticfloatinducingthemagneticreedswitchintube;TheresistancechangedisplayliquidheightchangeintheUreatank显示液体温度原理：NTC热敏电阻随温度变化，输出不同阻值，通过阻值变化反应罐内溶液的温度变化Displayliquidtemperatureprinciple:TheNTCthermistoroutputdifferentresistancewithdifferenttemperatureoftheUreatanksolution磁钢浮筒Magneticfloat添蓝溶液传感器Ureasensor温度传感器Temperaturesensor三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

端口应用Application起点From终点To管路规格HosesizeA尿素出液口Ureasupply添蓝罐Ureatank喷射泵DUSAE9.49B尿素回液口Ureareturn喷射泵DU添蓝罐UreatankSAE7.89C防冻液进液口Coolantin发动机取水口Engineout添蓝罐UreatankΦ14×2.5D防冻液出液口Coolantout添蓝罐Ureatank发动机回水口EngineinΦ14×2.5E线束WiringABCDE三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添蓝罐总成（带添蓝溶液传感器）

SCR反应所需的氨取自于质量浓度为32.5%的尿素水溶液(AdBlue)。供应罐的尺寸应使AdBlue量相当于燃油消耗量5%（欧4安装类型）的工作用量，而对于欧5估算值约为7%。

适用的罐材料有不锈钢、镁铝合金或中高密度的聚乙烯。推荐使用不透明罐，使操作员不能观察液位。这能确保诊断显示空罐时它仍留有足量AdBlue，以免计量泵吸入空气。

Ureatank（Ureasensorintegrated）TheammoniarequiredfortheSCRprocessisobtainedfromasolutionof32.5%(byweight)ureainwater(AdBlue).TheUreatankshouldbesizedtosuitanoperationaluseofureaequivalentto5%offuelconsumptionforEuro4installationsandanestimated7%forEuro5.Suitabletankmaterialsarestainlesssteel,magnesiumaluminiumalloyormedium-highdensitypolyethylene.Itisrecommendedthatthetankisnon-transparentsuchthattheoperatorcannotseethelevel.Thisistoensurethatwhenthetankshowsemptydiagnostically,itwillstillhaveasignificantamountofurealefttoavoidthedosingunitdrawingair.②添蓝溶液传感器Ureasensor①通气装置Vent③加注口盖Fillingcover④观察窗Levelshow⑤排水孔Drainhole⑥罐体Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

添蓝罐总成（带添蓝溶液传感器）

供应罐应与大气保持双向低压通风，使出口接头的液体自由流动，并排出罐内的所有蒸汽或膨胀气体。通气口设计应使其不受罐溅出或蒸发过程中生成的结晶AdBlue导致堵塞的影响。目前还没有发生道路事故时车辆翻倾防溅方面的法规，但是需要关注未来法规的发展。添蓝罐有一个排液孔，以便进行定期维护。

Ureatank（Ureasensorintegrated）Theureatankshouldbeventedatlowpressurebothtoandfromatmospheretoallowfreeflowfromtheoutletconnectionandtoventanyvapourorexpansioninthetank.Theventshouldbedesignedsuchthatitisnotsusceptibletoblockagebycrystallizedureaformedduringtanksloshandevaporation.Thereisnoknownregulationonanti-spillforvehicleroll-overintheeventofaroadaccident;howeverthisneedstobemonitoredforfuturedevelopmentsinthelegislation.TheUreatankhasadrainholeforperiodicservicing.②添蓝溶液传感器Ureasensor①通气装置Vent③加注口盖Fillingcover④观察窗Levelshow⑤排水孔Drainhole⑥罐体Tankbody三、主要部件功用及工作原理Chapter3、FunctionsandOperatingPrincipleofMainComponents

安装孔（4个）Mountinghole（four）压缩空气进口（A）CompressedAirinlet37针接头（J1939)尿素进液口（C）Ureainlet空气电磁阀接口Airsolenoidvalveinterface尿素回液（D）Ureareturn尿素出液（B）Air&Ureamixoutlet添蓝喷射泵总成添蓝喷射泵泵(DU)是高精度装置，用于将所需尿素溶液量喷入排气后处理系统中。该部件应轻拿轻放。如果跌落可能会损坏。由DCU控制的24V电动泵和计量系统与车辆压缩空气系统送来的空气一起协作，推动雾化的尿素溶液充入排气系统催化器上游的喷嘴中。应注意空气电磁阀是一个直接使用取自加料泵12V电源的12V装置。空气消耗量为17.5–22L/min。（标准条件）。不论是否加注AdBlue，空气消耗都是持续的。

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.空气阀（由电磁阀控制）2.4bar压力下的空气压力调节阀3.量孔4.空气单向阀（ACV）5.背压阀（BPV）6.混合室7.出口单向阀（弹簧承载）8.促动膜片9.进口单向阀（弹簧承载）10.压力开关11.空气促动阀Ⅰ空气装置Ⅱ混合阀Ⅲ膜片泵A.与车辆空气系统连接（压缩空气进气管）B.与添蓝喷嘴连接（添蓝喷射管）C.与添蓝罐连接（添蓝进液管）D.与添蓝罐连接（添蓝回液管）ⅠⅡⅢ安装孔（4个）Mountinghole（four）压缩空气进口（A）CompressedAirinlet37针接头（J1939)37pinconnector（J1939）尿素进液口（C）Ureainlet空气电磁阀接口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.添蓝喷射泵的4种工作模式-预注模式1.FouroperatingmodesofDU—PRIMNGMODE每次发动机运转，添蓝泵将进入预注阶段。添蓝溶液通过泵循环并流回到添蓝罐中，以便排空添蓝系统中残留的空气与尿素溶液混合物。如果预注阶段成功，将会听到添蓝泵电机全速运转30秒，空气电磁阀将在本阶段末工作。如果预注阶段第一次不成功，空气电磁阀将断电，电机将再全速运转30秒直到预注成功。这一顺序可以重复最多20次。

Everytimetheenginerunning,theDUwillcomeintoprimingmodephase.Ureasolutionthroughthecirculationpumpandflowbacktoureatank,to