Ukushisa okuqondile kokusha kukaphalafini

Izici eziyinhloko ze-thermophysical ze-parafini

Uphalafini i-distillate ephakathi nendawo yenqubo yokucwenga i-petroleum, echazwa njengengxenye kawoyela ongahluziwe obila phakathi kuka-145 no-300°C. Uphalafini ungatholwa ekugayweni kwamafutha ongahluziwe (uphalafini oqhutshwa ngokuqondile) noma ekuqhekekeni kwemifudlana kawoyela esindayo (uphalafini oqhekekile).

Uphalafini ongahluziwe unezakhiwo eziwenza ulungele ukuxutshwa nezithasiselo zokusebenza ezihlukahlukene ezinquma ukusetshenziswa kwawo ezintweni ezihlukahlukene zokuthengisa, okuhlanganisa amafutha okuthutha. Uphalafini ingxube eyinkimbinkimbi yezinhlanganisela zamaketango ezinamagatsha futhi aqondile ngokuvamile ezingahlukaniswa izigaba ezintathu: upharafini (55,2% ngesisindo), ama-naphthenes (40,9%) kanye nama-aromatics (3,9%).

Ukuze isebenze kahle, zonke izinhlobo zikaphalafini kufanele zibe nokushisa okukhethekile okuphezulu kakhulu okungaba khona kanye nomthamo wokushisa othize, futhi kubonakale ngebanga elibanzi kakhulu lamazinga okushisa okushisa. Emaqenjini ahlukahlukene kaphalafini, lezi zinkomba yizi:

• Ukushisa okuqondile kokuvutha, kJ/kg — 43000±1000.
• izinga lokushisa le-autoignition, ⁰C, hhayi ngaphansi - 215.
• Umthamo wokushisa othize kaphalafini ekamelweni lokushisa, J / kg K - 2000 ... 2020.

Akunakwenzeka ukucacisa ngokunembile imingcele eminingi ye-thermophysical ye-parafini, ngoba umkhiqizo ngokwawo awunawo ukwakheka kwamakhemikhali okuhlala njalo futhi kunqunywa izici zamafutha okuqala. Ngaphezu kwalokho, ukuminyana kanye ne-viscosity kaphalafini kuncike emazingeni okushisa angaphandle. Kuyaziwa kuphela ukuthi njengoba izinga lokushisa lisondela endaweni yokushiswa okuzinzile komkhiqizo kawoyela, amandla athile okushisa kaphalafini akhula kakhulu: ngo-200.⁰Ngayo kakade 2900 J / kg K, futhi at 270⁰C - 3260 J/kg K. Ngakho-ke, i-kinematic viscosity iyancipha. Inhlanganisela yale mingcele inquma ukuthungela okuhle nokuzinzile kukaphalafini.

Ukulandelana kokunquma ukushisa okuthile kokusha

Ukushisa okuqondile kokushiswa kukaphalafini kusetha izimo zokuvutha kwawo kumadivayisi ahlukahlukene - kusuka ezinjini kuya emishinini yokusika uphalafini. Esimweni sokuqala, inhlanganisela efanele yemingcele ye-thermophysical kufanele inqunywe ngokucophelela. Amashejuli ambalwa avamise ukusethwa ngayinye yezinhlanganisela zikaphethiloli. Lawa mashadi angasetshenziswa ukuhlola:

1. Isilinganiso esifanele sengxube yemikhiqizo evuthayo.
2. Izinga lokushisa le-adiabatic lelangabi lokusabela komlilo.
3. Isilinganiso sesisindo samangqamuzana semikhiqizo evuthayo.
4. Isilinganiso sokushisa esiqondile semikhiqizo evuthayo.

Le datha iyadingeka ukuze kutholwe isivinini samagesi e-exhaust aphuma enjinini, okuyiwona anquma ukusunduza kwenjini.

Isilinganiso esifanele sengxube kaphethiloli sinikeza amandla athile aphezulu kakhulu futhi siwumsebenzi wengcindezi injini ezosebenza ngayo. Injini enomfutho ophezulu wegumbi elivuthayo kanye nengcindezi ephansi yokukhipha umoya izoba nesilinganiso esiphezulu esiphezulu sengxubevange. Ngokulandelayo, ingcindezi ekamelweni elivuthayo namandla anamandla kaphethiloli kaphalafini kuncike esilinganisweni esifanele sengxube.

Emiklamweni eminingi yezinjini ezisebenzisa uphalafini njengophethiloli, kunakwa kakhulu izimo zokucindezelwa kwe-adiabatic, lapho ingcindezi nevolumu ethathwe ingxube evuthayo kusebuhlotsheni obuqhubekayo - lokhu kuthinta ukuqina kwezakhi zenjini. Kulesi simo, njengoba kwaziwa, akukho ukushintshaniswa kokushisa kwangaphandle, okunquma ukusebenza kahle okuphezulu.

Umthamo wokushisa othize kaphalafini yinani lokushisa elidingekayo ukuze kukhushulwe izinga lokushisa legremu elilodwa lento ngedigri Celsius. I-coefficient ethile yokushisa isilinganiso sokushisa okuthile ekucindezelweni okuqhubekayo kuya ekushiseni okukhethekile ngevolumu engashintshi. Isilinganiso esifanele sisethwe ekucindezelweni kukaphethiloli okunqunywe kusengaphambili ekamelweni elivuthayo.

Izinkomba eziqondile zokushisa ngesikhathi sokushiswa kukaphalafini ngokuvamile azisungulwa, njengoba lo mkhiqizo kawoyela uyingxube yama-hydrocarbon amane: i-dodecane (C).₁₂H₂₆), i-tridecane (C₁₃H₂₈), i-tetradecane (C₁₄H₃₀) kanye ne-pentadecane (C₁₅H₃₂). Ngisho nangaphakathi kweqoqo elifanayo lamafutha okuqala, isilinganiso sephesenti sezingxenye ezisohlwini asishintshi. Ngakho-ke, izici ze-thermophysical ze-parafini zihlale zibalwa ngokulula okwaziwayo nokucabangela.