Diesel tsheb tshem tawm kev kho system
Diesel tso pa yog hais txog cov pa tso tawm los ntawm lub tshuab hluav taws xob tom qab hluav taws xob diesel, uas muaj ntau pua qhov sib txawv. Cov pa hluav taws xob no tsis yog tsuas yog tsw ntxhiab xwb, tab sis kuj ua rau tib neeg kiv taub hau, xeev siab, thiab cuam tshuam rau tib neeg txoj kev noj qab haus huv. Raws li cov kws tshaj lij los ntawm Lub Koom Haum Saib Xyuas Kev Noj Qab Haus Huv Hauv Ntiaj Teb, lub tshuab hluav taws xob siv hluav taws xob yog cov carcinogenic heev thiab tau teev tseg raws li Class A carcinogen. Cov pa phem no feem ntau muaj xws li nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO) thiab cov khoom me me, thiab lwm yam, uas feem ntau yog tawm los ntawm qhov chaw ze, thiab cov pa phem no nkag mus rau hauv lub ntsws los ntawm qhov ntswg thiab qhov ncauj, ua rau kev puas tsuaj rau tib neeg kev noj qab haus huv.
Lub ntsiab emissions ntawm diesel xyaw yog PM (particulate matter) thiab NOx, thaum CO thiab HC emissions qis dua. Kev tswj hwm lub tshuab hluav taws xob tso tawm hluav taws xob feem ntau cuam tshuam nrog kev tswj cov cim ntawm PM thiab NO, thiab txo cov pa tawm ncaj qha ntawm PM thiab NOx. Tam sim no, txhawm rau daws qhov teeb meem ntawm lub tsheb diesel, feem ntau cov kev daws teeb meem tau txais EGR + DOC + DPF + SCR + ASC system.
EGR
EGR yog cov ntawv luv ntawm Cov Hluav Taws Xob Hluav Taws Xob Recirculation. Exhaust gas recirculation yog hais txog kev xa rov qab ib feem ntawm cov pa tso pa tawm ntawm lub cav mus rau cov khoom siv manifold thiab nkag mus rau lub tog raj kheej dua nrog cov sib tov tshiab. Txij li thaum cov pa tso pa muaj ntau cov roj polyatomic xws li CO2, thiab CO2 thiab lwm cov roj hluav taws xob tsis tuaj yeem hlawv tab sis nqus tau cov cua kub ntau vim lawv lub peev xwm kub tshwj xeeb, qhov siab tshaj plaws kub ntawm cov sib tov hauv lub tog raj kheej raug txo. , yog li txo tus nqi ntawm NOx generated.
DOC
DOC lub npe tag nrho Diesel oxidation catalyst, yog thawj kauj ruam ntawm tag nrho cov txheej txheem tom qab kev kho mob, feem ntau yog thawj theem ntawm peb-theem tso pa yeeb nkab, feem ntau nrog cov hlau zoo nkauj lossis ceramics ua cov cab kuj catalyst.
Lub luag haujlwm tseem ceeb ntawm DOC yog oxidize CO thiab HC hauv cov pa tso pa, hloov mus rau hauv tsis muaj tshuaj lom thiab tsis muaj mob C02 thiab H2O. Nyob rau tib lub sijhawm, nws tseem tuaj yeem nqus tau cov organic sib xyaw thiab qee cov pa roj carbon monoxide, thiab txo qee qhov PM emissions. TSIS yog oxidized rau NO2 (NO2 kuj yog cov pa roj ntawm cov tshuaj tiv thaiv qis). Nws yuav tsum tau muab sau tseg tias kev xaiv ntawm catalyst yog ze ze rau lub diesel tso qhov kub thiab txias, thaum lub kub yog qis dua 150 ° C, lub catalyst yeej tsis ua hauj lwm. Nrog rau qhov nce ntawm qhov kub thiab txias, kev hloov pauv kev ua haujlwm ntawm cov khoom tseem ceeb ntawm cov pa tawm maj mam nce ntxiv. Thaum qhov kub thiab txias siab tshaj 350 ° C, vim qhov loj ntawm sulfate ntau lawm, tab sis ua rau kom cov particle emissions, thiab sulfate yuav npog lub nto ntawm lub catalyst kom txo tau cov kev ua thiab conversion efficiency ntawm lub catalyst, yog li ntawd yuav tsum tau.kub sensorslos saib xyuas DOC qhov ntsuas kub, thaum DOC tau txais qhov kub siab tshaj 250 ° C hydrocarbons nquag ignition, uas yog, txaus oxidation cov tshuaj tiv thaiv.
DPF
Lub npe tag nrho ntawm DPF yog Diesel Particle Filter, uas yog qhov thib ob ntawm cov txheej txheem tom qab kho thiab tseem yog ntu thib ob ntawm peb-theem tso cov yeeb nkab. Nws lub luag haujlwm tseem ceeb yog txhawm rau ntes PM hais, thiab nws lub peev xwm los txo PM yog li 90%.
Particle Filter tuaj yeem txo qhov emission ntawm cov khoom me me. Nws thawj zaug ntes cov teeb meem hauv cov pa tawm. Nyob rau tib lub sijhawm, ntau thiab ntau qhov teeb meem yuav tso rau hauv DPF, thiab qhov sib txawv ntawm DPF yuav maj mam nce. CovDifferential siab sensor tuaj yeem saib xyuas nws. Thaum qhov sib txawv ntawm qhov siab tshaj qhov pib, nws yuav ua rau DPF cov txheej txheem rov tsim dua tshiab kom tshem tawm cov khoom seem. Kev rov tsim dua tshiab ntawm cov ntxaij lim dej yog hais txog kev maj mam nce ntawm cov teeb meem hauv cov ntxiab thaum lub sijhawm ua haujlwm ntev, uas tuaj yeem ua rau muaj kev nce hauv lub cav rov qab siab thiab ua rau txo qis hauv kev ua haujlwm ntawm lub cav. Yog li ntawd, nws yog ib qho tsim nyog yuav tsum tsis tu ncua tshem tawm cov khoom seem thiab rov ua kom pom kev ua haujlwm ntawm lub cuab.
Thaum qhov kub thiab txias hauv qhov ntxiab mus txog 550 ℃ thiab cov pa oxygen ntau dua 5%, cov khoom tso tawm yuav oxidize thiab hlawv. Yog tias qhov ntsuas kub tsawg dua 550 ℃, cov av ntau dhau yuav thaiv cov ntxiab. Covkub sensor saib xyuas qhov ntsuas kub ntawm DPF. Thaum qhov kub tsis tau raws li qhov yuav tsum tau ua, lub teeb liab yuav raug pub rov qab. Lub sijhawm no, cov khoom siv hluav taws xob sab nraud (xws li lub tshuab hluav taws xob, hluav taws xob, hluav taws xob, lossis kev hloov ntawm lub cav ua haujlwm) yuav tsum tau siv los ua kom kub hauv DPF thiab ua rau cov khoom oxidize thiab hlawv.
SCR
SCR stands rau Selective Catalytic Reduction, lub ntsiab lus ntawm Selective Catalytic Reduction system. Nws kuj yog ntu kawg hauv cov yeeb nkab tso tawm. Nws siv urea ua tus txo tus neeg sawv cev thiab siv lub catalyst rau chemically react nrog NOx los hloov NOx rau hauv N2 thiab H2O.
SCR system siv lub tshuab txhaj tshuaj nrog compressed cua pab. Lub urea tov mov twj tso kua mis muaj ib tug built-in tswj ntaus ntawv uas yuav tswj lub internal urea tov mov twj tso kua mis thiab compressed cua solenoid valve ua hauj lwm raws li cov txheej txheem tsim. Tus tswj kev txhaj tshuaj (DCU) sib txuas lus nrog lub cav ECU los ntawm lub tsheb npav CAN kom tau txais lub cav ua haujlwm tsis zoo, thiab tom qab ntawd muab cov catalytic converter kub teeb liab raws li qhovkub sensor , suav cov nyiaj txhaj tshuaj urea, thiab tswj cov urea tov cov twj tso kua mis kom txhaj cov urea tsim nyog los ntawm lub tsheb npav CAN. Nyob rau hauv lub tso pa tawm. Kev ua haujlwm ntawm huab cua compressed yog nqa cov ntsuas urea mus rau lub nozzle, kom cov urea tuaj yeem ua kom tiav atomized tom qab txau los ntawm lub nozzle.
ASC
ASC Ammonia Slip Catalyst yog lub npe luv ntawm ammonia slip catalyst. Vim tias urea to thiab tsis tshua muaj cov tshuaj tiv thaiv, ammonia tsim los ntawm urea decomposition yuav raug tso tawm ncaj qha mus rau hauv cov huab cua yam tsis koom nrog cov tshuaj tiv thaiv. Qhov no yuav tsum muaj kev teeb tsa ntawm ASC cov cuab yeej los tiv thaiv ammonia khiav.
ASC feem ntau yog ntsia rau hauv qab kawg ntawm SCR, thiab nws siv cov txheej txheem catalyst xws li cov hlau muaj nuj nqis nyob rau sab hauv phab ntsa ntawm cov cab kuj los catalyze REDOX cov tshuaj tiv thaiv, uas ua rau NH3 tsis muaj mob N2.
Kub sensor
Siv los ntsuas qhov ntsuas kub ntawm qhov sib txawv ntawm cov catalyst, suav nrog qhov ntsuas kub ntawm DOC (feem ntau hu ua T4 kub), DPF (feem ntau hu ua T5 kub), SCR (feem ntau hu ua T6 kub), thiab catalyst. Qhov kub ntawm qhov cua kub (feem ntau hu ua T7 kub). Nyob rau tib lub sijhawm, cov teeb liab sib xws raug xa mus rau ECU, uas ua tiav cov txheej txheem rov tsim dua qub thiab cov tswv yim txhaj tshuaj urea raws li cov ntaub ntawv tawm tswv yim los ntawm lub sensor. Nws lub hwj chim muab hluav taws xob yog 5V, thiab ntsuas qhov ntsuas kub ntawm -40 ℃ thiab 900 ℃.
Differential siab sensor
Nws yog siv los kuaj xyuas cov pa rov qab siab ntawm DPF cua nkag thiab qhov hluav taws xob hauv lub catalytic converter, thiab xa cov teeb liab coj mus rau ECU rau kev tswj xyuas kev ua haujlwm ntawm DPF thiab OBD. Nws lub hwj chim mov voltage yog 5V, thiab qhov chaw ua hauj lwm Qhov kub yog -40 ~ 130 ℃.
Sensors ua lub luag haujlwm tseem ceeb hauv lub tshuab hluav taws xob hauv tsheb, pab saib xyuas thiab tswj cov emissions kom tau raws li ib puag ncig cov cai thiab txhim kho huab cua zoo. Cov sensors muab cov ntaub ntawv ntawm qhov kub thiab txias, siab, qib oxygen thiab nitrogen oxides (NOx), uas lub cav tswj lub cav (ECU) siv los ua kom zoo dua cov txheej txheem combustion, txhim kho roj efficiency thiab txuas ntxiv lub neej ntawm cov pa kev kho mob.
Raws li kev lag luam tsheb txuas ntxiv tsom mus rau kev txo qis emissions thiab txhim kho huab cua zoo, kev txhim kho thiab kev koom ua ke ntawm cov sensors siab heev yog qhov tseem ceeb rau kev ua tiav cov hom phiaj no.