Aikace-aikacen urea a cikin injin dizal

Dokokin muhalli na zamani suna sanya tsauraran iyaka akan ƙimar fitar da gurɓataccen iska a cikin iskar gas ɗin injin dizal. Wannan yana tilasta wa injiniyoyi su nemo sabbin hanyoyin magance ma'auni. Ɗaya daga cikin waɗannan shine amfani da urea don man dizal a cikin SCR (Selective Catalytic Reduction) tsarin shaye-shaye bayan magani. Injin Daimler da ke amfani da wannan fasaha su ake kira Bluetec.

Menene tsarin SCR

Yarjejeniyar muhalli ta Euro 6 tana aiki a cikin ƙasashe 28 na EU tun daga 2015. A karkashin sabon tsarin, masu kera motocin dizal suna da tsayayyen bukatu saboda injunan dizal na haifar da babbar illa ga muhalli da lafiyar dan adam, suna fitar da soot da iskar nitrogen a sararin samaniya.

Yayin da yin amfani da na'ura mai canzawa ta hanyoyi uku ya wadatar don tsaftace iskar gas na injin mai, na'urar da ta fi dacewa don kawar da mahadi masu guba a cikin iskar gas yana da mahimmanci ga injin diesel. Ingantacciyar tsaftacewa ta CO (carbon monoxide), CH (hydrocarbons) da tarkace daga iskar gas ɗin injin dizal yana ƙaruwa a yanayin zafi mai zafi, yayin da NOx, akasin haka, yana raguwa. Maganin wannan matsala ita ce shigar da wani mai kara kuzari na SCR a cikin tsarin shaye-shaye, wanda ke amfani da urea dizal a matsayin tushen bazuwar mahaɗan guba na nitrogen oxide (NOx).

Domin rage fitar da hayaki mai cutarwa, injiniyoyi sun ɓullo da tsarin tsaftace man dizal na musamman - Bluetec. Rukunin ya ƙunshi cikakken tsari guda uku, kowannensu yana tace abubuwa masu guba kuma yana rushe mahadi masu cutarwa:

• Catalyst - neutralizes CO da CH.
• Particulate tace - tarkuna soot barbashi.
• SCR catalytic Converter - Yana rage fitar da NOx tare da urea.

An yi amfani da tsarin tsaftacewa na farko akan manyan motocin Mercedes-Benz da motoci. A yau, masana'antun da yawa suna canza motocin su zuwa sabon tsarin tsaftacewa kuma suna amfani da urea a cikin injunan diesel don biyan buƙatun kula da muhalli masu tsauri.

Fasahar urea AdBlue

Ƙarshen samfurin metabolism na mammalian, urea, an san shi tun ƙarni na XNUMX. Carbonic acid diomide an haɗa shi daga mahaɗan inorganic kuma ana amfani dashi sosai a aikin gona. A cikin masana'antar kera motoci, maganin ruwa na fasaha na Adblue a matsayin wakili mai aiki a cikin tsarkakewar iskar gas mai guba daga nitrogen oxides.

Adblue shine 40% urea da 60% distilled ruwa. Ana shigar da abun da ke ciki a cikin tsarin SCR a bututun ƙarfe wanda iskar gas ke wucewa. Halin lalacewa yana faruwa, wanda nitric oxide ya rushe zuwa nitrogen mara lahani da kwayoyin ruwa.

Urea na fasaha don dizal - Adblue ba shi da alaƙa da urea urea, wanda ake amfani da shi a fannin masana'antu da masana'antu da magunguna.

Edblue a cikin injin dizal

Tsarin maganin shaye-shaye, ko mai canza SCR, rufaffiyar tsarin ne wanda shaye-shayen dizal mara-sot ke gudana. Ana zuba ruwan Adblue a cikin tanki mai ƙunshe da kai kuma a yi masa allura a cikin bututun da aka auna kafin a shigar da mai canzawa.

Gas ɗin da aka haɗe yana shiga sashin daidaitawar SCR, inda wani sinadari ke faruwa don lalata nitric oxide a cikin kuɗin ammonia a cikin urea. A hade tare da nitric oxide, kwayoyin ammonia sun rushe shi zuwa sassan da ba su da lahani ga mutane da muhalli.

Bayan cikakken sake zagayowar tsaftacewa, mafi ƙarancin adadin gurɓataccen abu yana fitowa cikin yanayi, ma'aunin fitarwa ya bi ka'idojin Euro-5 da Euro-6.

Ka'idar aiki na tsarin tsarkakewa na dizal

Cikakken injin dizal tsarin bayan magani ya ƙunshi na'ura mai canzawa, tacewa da kuma tsarin SCR. Ka'idar aiki na tsaftacewa a cikin matakai:

1. Gas masu fitar da iskar gas suna shigar da mai canzawa da kuma tacewa particulate. Ana tace sot, ana kona barbashi mai, kuma ana cire carbon monoxide da hydrocarbons.
2. Ana amfani da injector don allurar wani adadin AdBlue a cikin haɗin tsakanin matatar dizal da mai juyawa SCR catalytic. Kwayoyin Urea suna bazuwa zuwa ammonia da isocyanic acid.
3. Ammoniya ta haɗu da nitrogen oxide, mafi cutarwa bangaren man dizal da aka yi amfani da shi. Molecules sun rabu, wanda ke haifar da samuwar ruwa da nitrogen. Ana fitar da iskar gas mara lahani a cikin sararin samaniya.

Haɗin urea don dizal

Duk da sauƙaƙan ruwan injin dizal, ba shi yiwuwa a shirya urea da kanku ta amfani da taki. Tsarin kwayoyin urea (NH2) 2CO, shine a zahiri farin lu'ulu'u ne mara wari, mai narkewa a cikin ruwa da kaushi mai ƙarfi (ruwa ammonia, methanol, chloroform, da sauransu).

Ga kasuwar Turai, ana samar da ruwan ne a ƙarƙashin ikon VDA (Ƙungiyar Masana'antar Motoci ta Jamus), wacce ke ba da lasisi ga kamfanonin kera, wasu daga cikinsu suna ba da ruwa ga kasuwannin cikin gida.

A Rasha, yin jabu a ƙarƙashin alamar AdBlue ya fi 50%. Don haka, lokacin siyan urea don injin dizal ɗin da aka yi a Rasha, dole ne a yi muku jagora ta alamar "Binciken ISO 22241-2-2009".

Ribobi da fursunoni

Fa'idodin amfani da urea a bayyane suke - kawai tare da wannan reagent tsarin kula da iskar gas na injin dizal na SCR na iya cikakken aiki kuma ya dace da bukatun Euro 6 Standard.

Baya ga kare muhalli, fa'idodin tsarkakewar urea sun haɗa da abubuwa kamar haka:

• amfaninsa don motoci shine kawai 100 g a kowace kilomita 1000;
• an haɗa tsarin SCR cikin motocin diesel na zamani;
• A wasu ƙasashe ana rage harajin amfani da abin hawa idan an sanya tsarin tsaftace urea, kuma babu haɗarin tara.

Abin takaici, tsarin kuma yana da rashin amfani:

• yanayin daskarewa na urea yana kusan -11 ° C;
• bukatar man fetur na yau da kullum;
• farashin motar yana ƙaruwa;
• babban adadin ruwa na Adblue na karya;
• ƙara yawan buƙatun don ingancin man fetur;
• gyare-gyare masu tsada ga sassan tsarin.

Hadaddiyar tsarin gogewar urea da aka gina a cikin motocin diesel ya kasance hanya ɗaya tilo ta rage hayaki mai guba. Wahalhalun aiki, tsadar motocin reagents, rashin ingancin ruwa da man dizal yana nufin cewa direbobi da yawa sun zaɓi kashe tsarin da shigar da na'urori.

Duk da haka, yana da mahimmanci a fahimci cewa urea ita ce kawai sinadarai na diesel da ke hana sakin nitric oxide a cikin muhalli, wanda zai iya haifar da ciwon daji.