Gwajin fitar da dizal da mai: iri
Gwajin gwaji

Gwajin fitar da dizal da mai: iri

Gwajin fitar da dizal da mai: iri

Rikicin da ke tsakanin injinan dizal da man fetur ya kai kololuwa. Sabuwar fasahar turbo, tsarin alluran layin dogo kai tsaye sarrafawa ta hanyar lantarki, babban matsi - fafatawa yana kawo nau'ikan injuna biyu kusa… Kuma ba zato ba tsammani, a tsakiyar tsohuwar duel, sabon ɗan wasa ya bayyana kwatsam a wurin. wani wuri a ƙarƙashin rana.

Bayan shekaru da yawa na sakaci, masu zanen kaya sun sake gano babban yuwuwar injin dizal kuma sun hanzarta haɓaka ta ta hanyar ƙaddamar da sabbin fasahohi. Ya kai ga cewa rawar da yake takawa ta kusanci halayen mai gasa gas ɗin kuma ya ba da damar ƙirƙirar motocin da ba za a iya tunanin su ba kamar su Volkswagen Race Touareg da Audi R10 TDI tare da manyan burin tsere. Tarihin abubuwan da suka faru na shekaru goma sha biyar da suka gabata sananne ne ... Injin Diesel na 1936s ba su bambanta da kakanninsu ba, wanda Mercedes-Benz ya kirkira a cikin 13. Tsarin jinkirin juyin halitta ya biyo baya, wanda a cikin 'yan shekarun nan ya girma zuwa fashewar fasaha mai ƙarfi. A ƙarshen 1s, Mercedes ya sake dawo da turbodiesel na mota na farko, a ƙarshen XNUMXs, allurar kai tsaye da aka yi a cikin samfurin Audi, daga baya diesels sun sami kawunan bawul huɗu, kuma a ƙarshen XNUMXs, tsarin sarrafawa na Jirgin Ruwa na Common ya zama gaskiya. ... A halin yanzu, an gabatar da babban matsin lamba na man fetur kai tsaye a cikin injunan mai, inda matsawar matsawa a yau ta kai XNUMX: XNUMX a wasu lokuta. Kwanan nan, fasahar turbo ita ma tana fuskantar sake farfadowa, tare da ƙimar ƙimar injunan gas ɗin sun fara kusanci ƙimar ƙima na sanannen m turbo diesel. Duk da haka, a cikin layi daya da na zamani, ɗimbin ɗimbin ci gaban hauhawar farashin injin mai ya kasance ... abokan hamayyar biyu suna samun rinjaye na zahiri.

Duk da daidaituwa tsakanin halayen nau'ikan nau'ikan raka'a biyu, har yanzu akwai manyan bambance-bambance a cikin yanayi, halayya da halayyar injunan zafi biyu.

A cikin yanayin injin mai, ana samun cakuda iska da man da aka kwashe tsawon lokaci mai tsawo kuma yana farawa tun kafin fara aikin konewa. Ko ta amfani da carburetor ko tsarin allurar kai tsaye na lantarki na zamani, makasudin hadawa shine samar da uniform, cakuda mai mai kama da madaidaicin ma'aunin iskar mai. Wannan darajar yawanci tana kusa da abin da ake kira "garin stoichiometric", wanda akwai isassun kwayoyin zarra na oxygen da za su iya (a ka'ida) don haɗawa a cikin tsayayyen tsari tare da kowane hydrogen da carbon atom a cikin man fetur, samar da H20 da CO2 kawai. Saboda ma'aunin matsawa yana da ƙanƙanta don gujewa kunnawa kai tsaye ba tare da kulawa ba na wasu abubuwa a cikin man fetur saboda yawan zafin jiki mai yawa (gashin man fetur ya ƙunshi hydrocarbons tare da ƙarancin ƙawantaccen iska da zafin zafi mafi girma). kunna kai daga waɗanda ke cikin juzu'in dizal), ƙonewar cakuda yana farawa ta hanyar walƙiya kuma konewa yana faruwa a cikin hanyar gaba mai motsi a ƙayyadaddun iyaka. Abin baƙin ciki, an kafa shiyyoyin da ba su cika matakai a cikin ɗakin konewa, wanda ke haifar da samuwar carbon monoxide da barga hydrocarbons, kuma lokacin da harshen wuta ya motsa, matsa lamba da zafin jiki a gefensa yana karuwa, wanda zai haifar da samuwar nitrogen oxides mai cutarwa ( tsakanin nitrogen da oxygen daga iska), peroxides da hydroperoxides (tsakanin oxygen da man fetur). Tari na karshen zuwa mahimman dabi'u yana haifar da konewar fashewar da ba a sarrafa shi ba, don haka, a cikin gas na zamani, ana amfani da ɓangarorin ƙwayoyin ƙwayoyin cuta tare da ingantacciyar barga, da wahala-fashe sinadarai "gini" - ana aiwatar da ƙarin ƙarin matakai. a matatun mai don cimma irin wannan kwanciyar hankali. ciki har da karuwa a cikin adadin octane na man fetur. Saboda ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun mahaɗan da injunan mai ke iya aiki da su, bawul ɗin magudanar ruwa yana taka muhimmiyar rawa a cikin su, ta yadda ake daidaita nauyin injin ɗin ta hanyar daidaita yawan iska mai kyau. Duk da haka, shi, bi da bi, ya zama tushen gagarumin asara a cikin partial load yanayin, wasa da wani irin "maƙogwaro toshe" na engine.

Manufar mahaliccin dizal engine, Rudolf Diesel, shi ne don ƙara yawan matsawa rabo, sabili da haka thermodynamic yadda ya dace na na'ura. Saboda haka, yankin na man fetur jam'iyyar ragewa, da kuma makamashi na konewa ba dissipated ta cikin ganuwar Silinda da kuma sanyaya tsarin, amma "kashe" tsakanin barbashi da kansu, wanda a cikin wannan yanayin ne da yawa kusa da kowane. sauran. Idan cakuda mai da aka riga aka shirya ya shiga ɗakin konewa na irin wannan injin, kamar yadda yake a cikin injin mai, to lokacin da wani yanayi mai mahimmanci ya kai yayin aiwatar da matsawa (dangane da matsi da nau'in man fetur). ), za a fara aiwatar da tsarin kunna wutar lantarki tun kafin GMT. konewar volumetric mara sarrafawa. A saboda wannan dalili ne ake allurar man dizal a ƙarshe, jim kaɗan kafin GMT, a cikin matsanancin matsin lamba, wanda ke haifar da ƙarancin lokaci mai yawa don ƙaya mai kyau, yaduwa, haɗawa, kunna kai da buƙatar iyakar saurin gudu. wanda da wuya ya wuce iyaka. daga 4500 rpm Wannan tsarin yana tsara buƙatun da suka dace don ingancin man fetur, wanda a cikin wannan yanayin shine ɗan guntun man dizal - galibi madaidaiciya distillates tare da ƙarancin zafin jiki mai mahimmanci, tunda tsari mara ƙarfi da dogayen ƙwayoyin cuta sune buƙatu don sauƙin su. rushewa da amsawa tare da oxygen.

Wani fasalin tsarin konewa na injin dizal shine, a daya bangaren, shiyyoyi ne masu hade da arziki a kewayen ramin allurar, inda mai ya narke (fasawa) daga zafin jiki ba tare da hadawan abu ba, juyawa ya zama tushen sinadarin carbon (soot), dayan kuma. wanda babu mai a ciki kwata-kwata kuma, a ƙarƙashin tasirin zafin jiki mai yawa, nitrogen da oxygen na iska sun shiga cikin ma'amala da sinadarai, suna samar da sinadarin nitrogen. Sabili da haka, ana amfani da injunan dizal koyaushe don aiki tare da cakuda matsakaiciyar matsakaiciya (ma'ana, tare da tsananin iska), kuma ana sarrafa kayan ne kawai ta hanyar yin amfani da adadin mai da aka saka. Wannan yana gujewa amfani da maƙura, wanda shine babbar fa'ida akan takwarorinsu na mai. Don ramawa saboda wasu kurakurai na injin mai, masu zanen kaya sun ƙirƙiri injina waɗanda a cikin abin da ake kira cakuda tsarin shi ake kira "cajin madafa".

A cikin yanayin ɗaukar nauyi, mafi kyawun cakuda stoichiometric an ƙirƙira shi ne kawai a cikin kewayen wutan lantarki saboda allura ta musamman na jirgin mai mai allura, iskar iska mai sarrafawa, bayanin martaba na gaba na piston da sauran hanyoyin makamantan wannan waɗanda ke tabbatar da ƙonewa. aminci. A lokaci guda, cakuda a yawancin ƙimar ɗakin yana kasancewa mara nauyi, kuma tunda nauyin da ke cikin wannan yanayin za'a iya sarrafa shi kawai ta adadin mai da aka kawo, bawul ɗin maƙera zai iya kasancewa a buɗe. Wannan, bi da bi, yana haifar da raguwar lokaci guda na asarar da haɓaka haɓaka ingancin injin. A ka'idar komai yayi kyau, amma ya zuwa yanzu nasarar wannan nau'in injin da Mitsubishi da VW suka samar bai kasance mai kyawu ba. Gabaɗaya, ya zuwa yanzu babu wanda zai yi alfahari da cewa sun yi cikakken amfani da fa'idodin waɗannan hanyoyin fasaha.

Kuma idan kun "sihiri" hada fa'idodin nau'ikan injin guda biyu? Menene zai zama madaidaicin haɗuwa da matsawar dizal mai girma, rarraba iri ɗaya na cakuda cikin girman ɗakin konewa da kuma kunna kai tsaye a cikin ƙarar guda ɗaya? Nazarin dakin gwaje-gwaje mai zurfi na raka'a na gwaji na irin wannan a cikin 'yan shekarun nan ya nuna raguwa mai yawa a cikin iskar gas mai cutarwa a cikin iskar gas (alal misali, adadin nitrogen oxides yana raguwa har zuwa 99%!) Tare da karuwa a cikin inganci idan aka kwatanta da injunan gas . Da alama nan gaba tabbas na cikin injuna ne, wanda kamfanonin kera motoci da kamfanonin kera masu zaman kansu kwanan nan suka dunkule tare da sunan laima mai suna HCCI - Homogeneous Charge Compression Ignition Engines ko Injunan Cajin Kai na Gama.

Kamar sauran cigaban da ake ganin kamar "juyi juzu'i ne", ra'ayin kirkirar irin wannan inji ba sabon abu bane, kuma har yanzu kokarin kirkirar samfurin samfuran abin dogara har yanzu bai yi nasara ba. A lokaci guda, haɓakar ikon sarrafa lantarki na tsarin fasaha da kuma babban sassaucin tsarin rarraba gas yana haifar da kyakkyawan fata da kyakkyawan fata ga sabon nau'in injin.

A zahiri, a cikin wannan yanayin nau'ikan nau'ikan ƙa'idodi ne na aikin mai da injunan diesel. Cakuda mai haɗuwa da kyau, kamar a cikin injunan mai, ya shiga ɗakunan konewa na HCCI, amma zafi ne daga matsi. Sabon nau'in injin shima baya buƙatar bawul din motsa jiki domin yana iya aiki akan gauraya mara nauyi. Koyaya, ya kamata a sani cewa a wannan yanayin ma'anar ma'anar "siririya" ta sha bamban da ma'anar dizal, tunda HCCI ba ta da cikakkiyar sifa da wadataccen cakuda, amma nau'ikan cakuda ne mara daidaituwa. Ka'idar aiki ya kunshi kunna wuta na cakuda a lokaci guda a cikin dukkan silinda ba tare da harshen wuta mai motsi gaba daya kuma a mafi tsananin zafin jiki ba. Wannan kai tsaye yana haifar da raguwa mai yawa a cikin adadin nitrogen oxides da soot a cikin iska mai ƙarancin iska, kuma, bisa ga adadin majiyoyi masu izini, gabatarwar da yawa na HCCI mafi inganci cikin samar da kerar mota a cikin 2010-2015. Zai ceci bil adama kimanin ganga miliyan miliyan. mai kullum.

Duk da haka, kafin cimma wannan, masu bincike da injiniyoyi dole ne su shawo kan babban abin tuntuɓe a halin yanzu - rashin ingantaccen hanyar da za a iya sarrafa tsarin sarrafa kai ta hanyar amfani da ɓangarorin da ke da nau'i daban-daban na sinadarai, kaddarorin da halayen mai na zamani. Tambayoyi da yawa suna haifar da ƙunshewar matakai a nau'o'i daban-daban, juyin juya hali da yanayin zafin injin. A cewar wasu masana, ana iya yin hakan ta hanyar mayar da adadin iskar gas ɗin da aka auna daidai a cikin silinda, preheating cakuda, ko canza yanayin matsawa, ko canza yanayin matsawa kai tsaye (misali, samfurin SVC Saab) ko canza lokacin rufe bawul ta amfani da tsarin rarraba gas mai canzawa.

Har yanzu ba a bayyana yadda za a kawar da matsalar hayaniya da tasirin thermodynamic akan ƙirar injin ba saboda kunna kai na babban adadin sabo a cikin cikakken kaya. Matsala ta ainihi ita ce fara injin a cikin ƙananan zafin jiki a cikin silinda, tun da yake yana da wuya a fara kunna kai a cikin irin wannan yanayi. A halin yanzu, yawancin masu bincike suna aiki don kawar da waɗannan ƙullun ta hanyar yin amfani da sakamakon lura da samfurori tare da na'urori masu auna firikwensin don ci gaba da sarrafa lantarki da kuma nazarin ayyukan aiki a cikin cylinders a ainihin lokacin.

По мнению специалистов автомобильных компаний, работающих в этом направлении, среди которых Honda, Nissan, Toyota и GM, вероятно, сначала будут созданы комбинированные машины, которые могут переключать режимы работы, а свеча зажигания будет использоваться как своего рода помощник в тех случаях, когда HCCI испытывает трудности. Volkswagen уже реализует аналогичную схему в своем двигателе CCS (Combined Combustion System), который в настоящее время работает только на специально разработанном для него синтетическом топливе.

Ana iya kunna wutan cakuda a cikin injunan HCCI a cikin nau'i-nau'i masu yawa tsakanin man fetur, iska da iskar gas (ya isa ya kai ga zafin jiki na atomatik), kuma ɗan gajeren lokacin konewa yana haifar da karuwa mai yawa a cikin ingantaccen injin. Wasu matsaloli na sababbin nau'ikan raka'a ana iya samun nasarar magance su tare da tsarin haɗin gwiwar, kamar Toyota's Hybrid Synergy Drive - a wannan yanayin, injin konewar cikin gida ba za a iya amfani da shi ba ne kawai ta wani yanayi wanda ya fi dacewa ta fuskar gudu da nauyi. a wurin aiki, don haka ketare hanyoyin da injin ke gwagwarmaya ko ya zama mara inganci.

Busonewa a cikin injunan HCCI, wanda aka samu ta hanyar sarrafa ƙarfin zafin jiki, matsin lamba, yawa da ingancin cakuda a wuri kusa da GMT, hakika babbar matsala ce akan asalin ƙarancin wuta tare da walƙiyar walƙiya. A gefe guda, HCCI baya buƙatar ƙirƙirar matakai masu rikitarwa, waɗanda ke da mahimmanci ga mai da musamman injunan dizal, saboda yanayin girman ƙarfin motsi na lokaci ɗaya. A lokaci guda, saboda wannan dalili ne koda ƙananan karkacewar zafin jiki na iya haifar da canje-canje masu mahimmanci a cikin tafiyar motsi.

A aikace, mafi mahimmancin mahimmanci na gaba na irin wannan nau'in injin shine nau'in man fetur, kuma za'a iya samun madaidaicin ƙirar ƙirar kawai tare da cikakken ilimin halinsa a cikin ɗakin konewa. Don haka, a halin yanzu yawancin kamfanonin kera motoci suna aiki tare da kamfanonin mai (irin su Toyota da ExxonMobil), kuma galibin gwaje-gwajen da ake yi a wannan mataki ana yin su ne da man da aka kera na musamman, wanda aka ƙididdige su a gaba. Ingantacciyar amfani da man fetur da man dizal a cikin HCCI ya saba wa tunanin injunan gargajiya. Saboda high auto- ƙonewa zafin jiki na gas, da matsawa rabo a cikin su na iya bambanta daga 12:1 zuwa 21:1, da kuma dizal man fetur, wanda ignites a ƙananan yanayin zafi, ya zama in mun gwada da kananan - a kan tsari na kawai 8. :1.

Rubutu: Georgy Kolev

Photo: kamfanin

Add a comment