Qhov qis-siab, qis-kub thiab qis- oxygen ib puag ncig ntawm toj siab teeb tsa cov ciam teb nruj rau kev ua haujlwm ntawm cov cav diesel. Pib los ntawm cov txheej txheem thev naus laus zis, daim ntawv no tshawb xyuas qhov cuam tshuam ntawm cov txheej txheem ntawm lub toj siab ib puag ncig ntawm cov txheej txheem combustion, turbocharging system sib piv thiab kev ntseeg tau ntawm cov khoom tseem ceeb ntawm cov cav tov diesel, thiab tshawb nrhiav kev tawm tsam.
I. Basic Theory: Alteration of Boundary Conditions in Plateau Environments
Lub tshuab hluav taws xob diesel yog "compression ignition" lub cav cua sov, thiab nws cov kev ua haujlwm tau zoo yog nyob ntawm qhov nqus cua hauv xeev. Cov kev hloov pauv tseem ceeb hauv toj siab ib puag ncig nyob hauv:
1. Atmospheric siab (P₀) thiab huab cua ceev (ρ) txo: Rau txhua txhua 1000 meters nce nyob rau hauv qhov siab, atmospheric siab poob los ntawm kwv yees li 11.5%, thiab huab cua ceev txo li ntawm 8.7% (raws li tus qauv atmospheric qauv). Ntawm qhov siab ntawm 4500 meters, qhov nqus cua kom tsawg tsuas yog 55% txog 60% ntawm qhov dej hiav txwv.
2. Txo qhov kub ib puag ncig (T₀): Rau txhua txhua 1000 meters nce siab, qhov nruab nrab ib puag ncig kub poob los ntawm 6.5 degree.
3. Kev txo qis hauv cov pa ib nrab siab: Txawm hais tias qhov ntim feem ntawm cov pa oxygen tseem tsis hloov pauv (21%), tag nrho cov kev poob siab ua rau txo qis ntawm cov pa oxygen ib nrab siab, uas yog qhov cuam tshuam ncaj qha cuam tshuam rau combustion.
Cov kev hloov pauv hauv ciam teb no tau tsim kho cov xwm txheej ua haujlwm ntawm cov tshuab diesel.
II. Qhov sib txawv hauv cov txheej txheem combustion thiab kev ua haujlwm tsis zoo
Lub combustion zoo ntawm diesel xyaw yog txiav txim los ntawm plaub yam: roj, huab cua, sib tov, thiab kub. Lub toj siab ib puag ncig systematically deteriorates tej yam.
Lub zog thiab kev lag luam attenuation
1.Theoretical voj voog ua hauj lwm txo: Raws li lub hauv paus ntsiab lus ntawm kev ua hauj lwm ntawm lub cav, nws cov hauj lwm qhia tau ncaj qha proportional rau lub voj voog kom tsawg. Qhov kev txo qis ntawm qhov nqus tau ncaj qha ua rau txo qis ntawm cov pa oxygen nkag mus rau lub tog raj kheej hauv txhua lub voj voog ua haujlwm.
2. Cov kev txwv ntawm Kev Kho Kom Zoo: Diesel cav ua haujlwm raws li kev hloov kho kom zoo, lub ntsiab lus ntawm qhov nqus cua ntim tseem nyob twj ywm, thiab lub zog yog tswj los ntawm kev sib txawv ntawm cov roj txhaj tshuaj ib lub voj voog. Ntawm qhov siab siab, cov ntsiab lus ntawm cov pa oxygen nyob rau hauv qhov nqus tau los ua ib qho kev txwv. Txhawm rau tiv thaiv cov pa luam yeeb dub hnyav thiab cov khoom siv ntau dhau, ECU yuav tsum nquag txwv cov roj txhaj tshuaj, ua rau txo qis zog thiab lub zog tso tawm. Kev kho lub zog feem ntau ua raws li cov qauv empirical:
Ne_ High Altitudes=Ne_Plain * k (qhov twg k yog qhov kho kom raug, kwv yees li 0.7 txog 1.0). Qhov tshwm sim no feem ntau hu ua "torque txo ntawm qhov siab siab".
3. Txo qis hauv kev sib xyaw ua haujlwm thiab thermal efficiency:
Diffusion combustion deterioration: Vim yog qhov tsis muaj oxygen, qhov sib xyaw ntawm cov roj txhaj nrog huab cua txo, lub sijhawm tom qab hlawv tau ntev, qhov combustion tsis tiav, thiab qhov cua kub nce.
Kev txo qis thermal efficiency: qeeb combustion ceev, txo cov cua kub tso tawm ntawm diesel, sib txawv ntawm combustion tshav kub tso qauv los ntawm qhov zoo tshaj plaws nkhaus, ua rau poob ntawm thermal - mus rau - mechanical zog conversion efficiency.
Txo cov neeg kho tshuab kev ua tau zoo: Txhawm rau tso tawm tib lub zog, yuav tsum muaj qhov qhib qhov qhib loj dua, lub cav nrawm yuav nce, thiab qhov kev faib ua feem ntawm cov twj tso kua mis thiab kev sib txhuam poob nce.
Txias pib kev sib tw ua haujlwm
1. Cov xwm txheej rau compression ignition yog cuam tshuam: Diesel cav cia siab rau qhov kub siab ntawm qhov kawg ntawm compression ua rau cov roj ignite spontaneously. Qhov kub ntawm qhov kawg ntawm compression, T_c (qhov kub ntawm qhov kawg ntawm compression)=T_a (kua cua kub) * ε^(n-1) (qhov twg ε yog qhov compression piv). Qhov ntsuas kub qis ntawm qhov siab siab ua rau txo qis hauv qhov nqus cua kub T_a. Nyob rau tib lub sijhawm, vim muaj cov yam ntxwv xws li cua sov dissipation los ntawm lub tog raj kheej phab ntsa, nws yog qhov nyuaj dua rau lub siab thiab qhov kub thiab txias thaum kawg ntawm compression kom ncav cuag qhov hluav taws xob ntawm qhov hluav taws xob ntawm diesel (feem ntau nyob ib ncig ntawm 250 degree).
Kev daws: Nws yog ib qho tsim nyog yuav tsum tau cia siab rau cov cuab yeej pib ua haujlwm xws li cov khoom siv cua preheating plugs, lub tog raj kheej liner dej preheaters, thiab siab - lub zog cia roj teeb kom ntseeg tau tias txias pib los ntawm qhov kub thiab txias thaum pib compression thiab txhim kho qhov pib ceev.
2. Deterioration ntawm emission yam ntxwv
Ib qho kev nce siab hauv cov pa paug tawm: Nyob rau hauv cov xwm txheej hnyav uas tsis muaj kev txwv roj ntau, cov pa oxygen hauv zos ua rau muaj - qhov kub thiab txias tawg ntawm cov roj, ua kom muaj kuab paug ntau thiab nquag DPF regenerations.
Ua kom muaj CO thiab HC emissions: Tsis tas li vim yog kev sib txuas tsis tiav.
III. Qhov sib txawv hauv Supercharging Systems: Los ntawm Kev Txhawb Nqa rau Lead
Nyob rau toj siab, lub turbocharger tsis yog ib qho kev txhawb zog ntxiv lawm tab sis lub neej txhawb nqa uas tswj cov kev ua haujlwm ntawm cov cav diesel.
Kev khiav hauj lwm point hloov ntawm lub turbocharger
Kev pheej hmoo Surge: Qhov qis - huab cua ceev ceev ntawm qhov siab siab ua rau lub tshuab ua haujlwm ntawm qhov taw tes kom ze rau txoj kab nce siab. Thaum tsis tshua muaj ceev thiab siab loads (xws li thaum nce toj), surging tej zaum yuav tshwm sim, tus cwj pwm los ntawm kev vibrations loj thiab txawv txav, uas yuav ua rau lub turbocharger puas.
Kev pheej hmoo ntawm overspeed: Ntawm qhov siab siab, vim qhov qis ib puag ncig siab, qhov tso tawm tsis kam txo. Nyob rau hauv siab - ceev thiab siab - load tej yam kev mob, lub turbocharger rotational ceev yuav tshaj qhov tsim txwv, ua rau lub turbine hniav tawg.
Daim ntawv thov ntawm advanced supercharging technology
Variable Geometry Turbine (VGT): Qhov no yog qhov kev daws teeb meem zoo tshaj plaws rau siab -qhov siab ntawm diesel xyaw. Los ntawm kev kho lub kaum sab xis ntawm lub nplhaib nozzle, VGT txo qhov ntws hla- ntu ntawm qhov nrawm nrawm, ua kom cov pa tawm nrawm nrawm, yog li ua kom qis dua - nrawm turbocharging teb thiab torque, zoo kov yeej lub zog lag ntawm qhov chaw siab. Thaum muaj kev kub ceev, nws ua kom loj ntawm tus ntoo khaub lig- ntu kom tiv thaiv kom tsis txhob muaj huab cua txaus, uas tuaj yeem ua rau muaj cua txias thiab dhau - nrawm ntawm lub turbocharger.
Ob -theem supercharging: Nws txais kev sib xyaw ua ke ntawm me me turbo thiab loj turbo lossis tshuab supercharging thiab turbocharging. Cov neeg kho tshuab supercharger lossis me me turbo ua kom cov lus teb ceev ceev ntawm qhov qis qis, thaum lub turbo loj yog lub luag haujlwm rau cov khoom siv hluav taws xob siab, muab kev txhawb zog txaus rau ntau yam kev ua haujlwm.
Qhov tseem ceeb ntawm turbocharging thiab intercooling: Hauv qhov siab - qhov chaw siab, qhov kub ntawm huab cua tom qab turbocharging kuj tseem siab heev. Lub intercooler tuaj yeem txo cov cua sov kom tsawg thiab ua kom cov pa kom tsawg, uas yog qhov txuas tseem ceeb hauv kev txhim kho kev ua haujlwm ntawm turbocharging.
IV. Kev daws teeb meem rau cov txheej txheem tseem ceeb thiab cov khoom tsis zoo
Roj system:
Qhov zoo ntawm qhov siab -siab txoj kev tsheb ciav hlau: Niaj hnub nimno electronically controlled common rail systems can dynamically correct the fuel injection MAP daim duab raws li cov ntaub ntawv los ntawm qhov siab sensor (los yog xam los ntawm MAP sensor), ua tiav cov roj kom muaj nuj nqis tswj thiab ntau qhov kev txhaj tshuaj (pilot txhaj, lub ntsiab txhaj tshuaj, tom qab txhaj tshuaj) kom optimize combustion thiab sib npaug ntawm lub zog siab.
Roj injectors: Tsis zoo combustion ntawm high altitudes tau yooj yim ua rau carbon deposits ntawm roj injectors thiab hnav ntawm mating qhov chaw. Nws yog ib qho tsim nyog yuav tsum tau siv cov roj zoo siab thiab cov khoom siv hluav taws xob zoo, thiab ua kom lub voj voog hloov ntawm cov lim roj.
Cua txias system:
Loj - muaj peev xwm, siab - boiling - point txias system: Siab - boiling -point antifreeze yuav tsum tau siv los tiv thaiv ntxov ntxov boiling ntawm coolant vim txo atmospheric siab. Yog tias tsim nyog, hloov mus rau qhov siab - dej twj tso kua mis thiab kiv cua radiator.
Lubrication system:
Lubrication ntawm turbochargers: turbines ua hauj lwm nyob rau hauv ntev - lub sij hawm siab - load tej yam kev mob nyob rau hauv high altitudes muaj tsis tshua muaj siab xav tau rau lub siab - kub detergency thiab shear resistance ntawm cav roj. Tsuas yog cov hluavtaws hluavtaws lossis semi-- hluavtaws hnyav- lub luag haujlwm diesel cav roj ntawm CI-4 qib lossis siab dua yuav tsum tau siv.
Intake system:
Kev saib xyuas huab cua: Vim muaj cua daj cua dub thiab xuab zeb nyob rau hauv qhov siab - thaj chaw siab, huab cua lim tau yooj yim rau kev txhaws, uas ua rau kom muaj zog tiv thaiv kab mob thiab tsim kom muaj kev sib koom ua ke ntawm qhov siab siab ntxiv rau txhaws. Nws yog ib qho tsim nyog yuav tsum tau siv cov tshuab lim cua ua haujlwm siab - thiab nquag tshuaj xyuas thiab ntxuav lawv.
Xaus thiab Outlook
High -qhov chaw ua haujlwm qhov siab ua rau qhov kev sim siab tshaj plaws rau kev siv thev naus laus zis ntawm diesel xyaw. Kev txhim kho lawv cov kev ua tau zoo yog qhov kev ua haujlwm zoo dua li kev txhim kho ntawm ib qho kev tivthaiv. Txoj kev loj hlob yav tom ntej yog nyob rau hauv:
1. "Mechanical-Electrical-Pneumatic" integrated intelligent control: Engine full-domain adaptive control strategy raws li qhov tiag -time altitude and environmental parameters.
2. Kev sib sib zog nqus ntawm cov txheej txheem txhawb nqa qib siab: Kev ua kom zoo ntxiv thiab txo tus nqi ntawm VGT thiab ob-theem boosting technologies.
3. Synergistic adaptation ntawm tom qab - kho tshuab: DPF regeneration lub tswv yim haum rau siab -altitude yam ntxwv.
Rau cov neeg siv, nkag siab txog cov hauv paus ntsiab lus no txhais tau hais tias muaj peev xwm xaiv cov qauv kev tshawb fawb ntau dua, tswj lawv kom meej dua, thiab muaj kev nyab xeeb unleash lub peev xwm muaj zog ntawm diesel xyaw hauv qhov siab - qhov chaw siab.