Ukuhlaziywa Kokushisa Kwezinjini Zokushisa Zangaphakathi
Ukuhlaziywa kokushisa kwezinjini zokushisa zangaphakathi (ama-ICE) kubalulekile ekuqondeni ukuthi amandla amakhemikhali kaphethiloli aguqulwa kanjani abe amandla omshini, kanye nendlela ukushisa okusatshalaliswa ngayo, okusetshenziswa ngayo, nokulahleka ngayo phakathi nale nqubo. Izinjini zokushisa zangaphakathi—kungakhathaliseki ukuthi zisezimotweni, kumajeneretha, noma ezisetshenziswa ezimbonini—zisebenza ngaphansi kwamazinga okushisa aphezulu kanye nokucindezela, ngakho ukusebenza kwazo, ukusebenza kahle, ukukhishwa kwegesi, kanye nokuthembeka kwezingxenye kuthonywa kakhulu izici zazo zokushisa. Ngokuhlaziywa kokushisa, onjiniyela bangenza ngcono ukwakheka kwegumbi lokushisa, amasu okupholisa, ukukhethwa kwezinto, kanye nokulawulwa kokukhishwa kwegesi.
1. Imiqondo Eyisisekelo Yamandla Nokushisa Emishinini
Empeleni, injini yokushisa yangaphakathi iguqula amandla amakhemikhali kaphethiloli abe ukushisa ngokusebenzisa ukusabela kokushisa. Lokhu kushisa kwandisa amandla angaphakathi egesi ngaphakathi kwesilinda, kudala ingcindezi esunduza i-piston (yenjini ephindiselanayo) noma eqhuba i-turbine (yenjini ye-turbine yegesi). Kodwa-ke, akuwona wonke ukushisa okuguqulwa kube umsebenzi owusizo. Iningi lakho lilahleka ngokusebenzisa:
1. Igesi yokukhipha ugesi (ukulahlekelwa ugesi): Amandla okushisa aqhutshwa ngegesi yokukhipha ugesi.
2. Uhlelo lokupholisa (ukulahlekelwa yi-coolant): Ukushisa kumuncwa yizindonga zesilinda, ikhanda lesilinda, nezinye izingxenye bese kudluliselwa ku-coolant noma emoyeni.
3. Imisebe yangaphandle kanye nokuguqulwa komoya: Ukushisa kukhishwa endaweni ezungezile kusuka ebusweni bomshini.
4. Ukulahlekelwa yimishini: Nakuba kungewona ukushisa kuphela, ukungqubuzana kudala ukushisa futhi kunciphisa ukusebenza kahle.
Ukuhlaziywa kokushisa kuzama ukudala ibhalansi yamandla: ukuthi iyiphi ingxenye yamandla kaphethiloli eba amandla amabhuleki, ukuthi kungakanani okulahlekelayo ku-coolant, kungakanani okulahlekelayo njengegesi yokukhipha ugesi, nokuthi kungakanani okulahlekelayo ngezinye izindlela.
2. Umjikelezo Ofanele We-Thermodynamic kanye Nomjikelezo Wangempela
Ukuze uqonde ukuziphatha kokushisa kwenjini, imodeli yomjikelezo efanele ivame ukusetshenziswa:
– Ibhayisikili lika-Otto lezinjini zikaphethiloli (ukushiswa kwenhlansi).
– Umjikelezo wedizili wezinjini zedizili (ukushiswa kokucindezela).
– I-Dual Cycle njengenhlanganisela yezimpawu ze-Otto ne-Diesel.
– IBrayton yama-turbine egesi.
Umjikelezo ofanele uthatha inqubo eguqukayo kanye nokusha okusheshayo, ngaphandle kokulahlekelwa ukushisa kanye nokungqubuzana. Kodwa-ke, ezinjinini zangempela, kukhona ukuphambuka okuphawulekayo, isibonelo:
– Ukusha kuthatha isikhathi (ukusha okulinganiselwe).
– Ukudluliselwa kokushisa ezindongeni zesilinda kubaluleke kakhulu.
– Kukhona ukuvuza kwegesi (ukuvuza kwegesi kudlule izindandatho zepiston).
– Inqubo yokumunca nokukhipha umoya ibangela ukulahlekelwa kokumpompa.
– Izakhiwo zokushisa zamagesi ziyashintsha ngokushisa.
Ngakho-ke, ukuhlaziywa kokushisa kwezinjini zangempela kudinga ukulungiswa—kungaba ngezindlela zokuhlola, amamodeli e-1D/3D, noma idatha yokuhlola.
3. Ukudluliselwa Kokushisa Ngesilinda
Ukudluliselwa kokushisa kusuka kumagesi okushisa kuya ezindongeni zesilinda kwenzeka ngezindlela ezintathu: ukuhanjiswa komoya, ukuhanjiswa komoya, kanye nemisebe. Ku-ICE, ukuhanjiswa komoya yikona okugqamile kakhulu, njengoba ukugeleza okuguquguqukayo ekamelweni lokushisa kusheshisa ukudluliselwa kokushisa.
Ezinye zezinto eziyinhloko ezithonya ukudluliselwa kokushisa:
– Izinga lokushisa legesi nodonga: Uma umehluko wokushisa umkhulu, izinga lokudlulisa ukushisa liba likhulu.
– I-Turbulence: Ithonywa ukwakheka kwetheku, ukuma kwepiston, ukuzungeza, ukugoba, kanye nesivinini senjini.
– Ukucindezela kwegesi kanye nobuningi: Ukwanda ngesikhathi sokucindezelwa kanye nokusha, okwandisa i-coefficient yokudlulisa ukushisa.
– Isilinganiso sokucindezela: Ngokuvamile kwandisa ukusebenza kahle kokushisa, kodwa futhi kwandisa izinga lokushisa eliphakeme ukuze umthwalo wokushisa ezingxenyeni ukhule.
Amamodeli okudlulisa ukushisa ngaphakathi kwesilinda avame ukusebenzisa ukuhlangana kwe-empirical, njenge-Woschni noma i-Hohenberg, ukulinganisa i-convection coefficient ngokusekelwe eziguquguquki zokusebenza kwenjini.
4. Ukuhlaziywa Kokushisa Kwezingxenye Ezibalulekile
Izingxenye zomshini zithola amazinga okushisa aphezulu kanye nemijikelezo yokushisa ephindaphindwayo, okungaholela ekukhathaleni kokushisa, ukuguquguquka, noma ukwehluleka kwezinto. Izingxenye ezibalulekile zifaka:
– I-Piston: Umqhele we-piston uthola ukushisa ngqo ekushiseni. Ukupholisa kufezwa ngokusebenzisa ama-jet kawoyela, amagalari okupholisa e-piston, kanye nomklamo wezinto ezibonakalayo.
– Ikhanda lesilinda namavalvu: Amavalvu okukhipha umoya kanye nendawo ezungeze izihlalo zawo athola imithwalo ephezulu kakhulu yokushisa evela kumagesi ashisayo. Izinto ezingamelani nokushisa kanye nokupholisa okuphumelelayo kubalulekile.
– I-cylinder liner: Kumelwe isuse ukushisa ngenkathi igcina ukugcotshwa futhi inciphisa ukuphambuka.
– I-Turbocharger (uma ikhona): I-turbine isebenza emazingeni okushisa aphezulu egesi yokukhipha umoya; kudingeka ukucabangela ukupholisa nokukhethwa kwama-alloy amelana nokushisa.
Ukuhlaziywa kokushisa kwezingxenye kuvame ukusebenzisa ukulingisa kokuqhuba (isb., ukuhlaziywa kwezakhi ezilinganiselwe/i-FEA) ngemingcele yegesi kanye ne-coolant convection. Umgomo ukuqinisekisa ukuthi izinga lokushisa eliphezulu lingaphansi kwemingcele yezinto ezibonakalayo nokunciphisa ukucindezeleka kokushisa.
5. Uhlelo Lokupholisa kanye Nokuphathwa Kokushisa
Ngenxa yokuthi ukushisa okuningi kumele kususwe ukuze kuvinjelwe injini ekushiseni ngokweqile, uhlelo lokupholisa luba yingxenye ebalulekile yokuhlaziywa kokushisa. Izinjini zanamuhla zisebenzisa:
– Ukupholisa uketshezi (ijakethi yamanzi) ene-radiator, ipompo yokupholisa, i-thermostat, kanye nefeni.
– Ukupholisa umoya ezinjinini ezithile (izinjini ezincane, ezinye izinjini zezithuthuthu).
Ukushintshana okubalulekile: ukupholisa ngamandla kakhulu kwehlisa izinga lokushisa lenjini futhi kunganciphisa ukusebenza kahle kokushisa ngoba ukushisa okwengeziwe kulahleka ku-coolant. Ngakolunye uhlangothi, ukupholisa okunganele kwandisa ingozi yokushayisana (kuphethiloli), ukusha ngaphambi kokushisa, ukuwohloka kukawoyela, kanye nomonakalo wezingxenye.
Imiqondo yesimanje yokuphathwa kokushisa izama ukugcina injini isezingeni lokushisa elifanele: iphakeme ngokwanele ukuze isebenze kahle futhi ikhiphe ukungcola, kodwa iphansi ngokwanele ukuze ithembeke. Amasu afaka:
– Iphampu yokupholisa eguquguqukayo.
– I-thermostat kagesi.
– Ukupholisa okuqondiswe ezindaweni ezibucayi.
– Ukulawula ukugeleza kwe-EGR (ukujikeleza kabusha kwegesi yokukhipha ugesi) ukunciphisa izinga lokushisa lokushisa kanye ne-NOx.
6. Ukusebenza Kahle Kokushisa kanye Nokulinganisela Kwamandla
Ukusebenza kahle kokushisa kwenjini kumane kuyisilinganiso somsebenzi ophelele namandla angenayo avela kuphethiloli. Ezimotweni, kuvame ukuvezwa kanje:
– Ukusebenza kahle kokushisa okubonisiwe: kusekelwe emsebenzini osesilinda.
– Ukusebenza kahle kokushisa kwamabhuleki: kusekelwe emandleni ku-output shaft.
Ibhalansi yamandla evamile yenjini evamile ikhombisa ukuthi cishe u-25–40% wamandla kaphethiloli aguqulwa abe amandla angasetshenziswa, kanti okusele kulahleka ngokukhipha umoya kanye nokupholisa. Ezinjinini zedizili zesimanje, zobuchwepheshe obuphezulu, ukusebenza kahle kungaba phezulu kakhulu, kodwa imikhawulo eyisisekelo isasele ngenxa ye-thermodynamics (isb., umkhawulo we-Carnot ofanele) kanye nemikhawulo esebenzayo (ukusha, ukungqubuzana, ukukhishwa komoya, kanye nokuqina kwezinto).
Imizamo yokuthuthukisa ukusebenza kahle kokushisa ihlanganisa:
– Khulisa isilinganiso sokucindezela (ngemikhawulo yokushisa engqongqozayo/engavamile).
– Nciphisa ukulahlekelwa ukushisa ngokusebenzisa izembozo zokushisa (izembozo zokuvimbela ukushisa).
– Ukusebenzisa amandla egesi yokukhipha umoya ngokusebenzisa i-turbocharging, i-turbocompounding, noma ukubuyisela ukushisa okulahliwe (isb., umjikelezo we-Rankine).
– Lungiselela isikhathi sokusha, i-AFR (isilinganiso somoya-uphethiloli), kanye nesu lokujova.
7. Ubudlelwano phakathi kokuhlaziywa kokushisa kanye nokukhishwa kwegesi
Izinga lokushisa lokushisa lithinta kakhulu ukwakheka kokukhishwa kwegesi:
– I-NOx iyanda emazingeni okushisa aphezulu kanye nokwanda komoya-mpilo.
– I-CO kanye ne-HC ziyanda uma ukushisa kungaphelele noma izinga lokushisa liphansi kakhulu.
– Izinhlayiya (umswati), ikakhulukazi kudizili, zithinteka ukuxubana kwendawo kanye nokushisa.
Ngakho-ke, ukuhlaziywa kokushisa akukwazi ukuhlukaniswa namasu okulawula ukukhishwa komoya. Isibonelo, i-EGR yehlisa amazinga okushisa aphezulu, ngaleyo ndlela icindezele i-NOx, kodwa ingandisa i-soot uma ingalingani ngokuxuba kahle kanye ne-oxidation.
8. Izindlela Zokuhlaziya: Ukuhlolwa Nokulingisa
Ukuhlaziywa kokushisa kwenziwa ngenhlanganisela yalokhu okulandelayo:
1. Ukuhlolwa kwenjini
Kala izinga lokushisa le-coolant, uwoyela, igesi yokukhipha umoya, kanye nezingxenye (usebenzisa ama-thermocouple, amakhamera e-IR, noma izinzwa ezikhethekile). Lolu lwazi lubalulekile ekuqinisekisweni kwemodeli.
2. Ukulingisa kwe-1D (ukulingisa umjikelezo wenjini)
Amamodeli ezinqubo ezingaphakathi kwesilinda, ukugeleza kokungenisa/ukukhipha, kanye nokushiswa komhlaba wonke. Ishesha ukuhlola amapharamitha okusebenza kanye nezilinganiso zokushisa.
3. Igumbi lokusha le-CFD 3D
Ihlola imininingwane yokuxokozela, ukuxuba, ilangabi, kanye nokusatshalaliswa kwezinga lokushisa. Iwusizo kakhulu ekwenzeni ngcono ukwakheka kwegumbi lokushisa kanye ne-injector.
4. I-FEA enesakhiwo sokushisa
Bala ukusatshalaliswa kwezinga lokushisa kanye nokucindezeleka kokushisa ezingxenyeni, ikakhulukazi ama-piston, amakhanda esilinda, ama-manifold, kanye nama-turbocharger.
Ukuhlanganiswa kwalezi zindlela kuphumela ekwakhiweni okusebenzayo nokuthembekile.
Isiphetho
Ukuhlaziywa kokushisa kwezinjini zokushisa zangaphakathi kubalulekile ekuthuthukiseni ukusebenza kahle, ukunciphisa ukukhishwa kwegesi, nokuqinisekisa ukuthembeka kwezingxenye ezindaweni zokusebenza ezishisa kakhulu. Ngokuqonda ukudluliselwa kokushisa ngaphakathi kwesilinda, izilinganiso zamandla, kanye nokuphathwa kokupholisa, onjiniyela bangenza izinqumo zokuklama ezinolwazi oluthe xaxa—kusukela ku-geometry yegumbi lokushisa kanye nezinto kuya ezinhlelweni zokupholisa kanye nokulawula ukusebenza kwenjini. Intuthuko kubuchwepheshe bokulingisa (i-CFD/FEA) kanye nezinzwa zokulinganisa ithuthukisa kakhulu amakhono okuhlaziya, okwenza kube lula ukwenza ngcono okusheshayo nokunembile ukuhlangabezana nezidingo zanamuhla zokulawula ukusebenza kahle kwamandla kanye nokukhishwa kwegesi.
Uma ufisa, ngingaguqula lesi sihloko sibe ngesezemfundo kakhulu (siphelele ngezibalo eziyisisekelo, izinkomba, kanye nezigaba ezincane zendlela yokubala) noma sisebenze kakhulu ngezinjongo zesabelo/ithisisi.
