Usporedba rada motora s niskotlačnim i visokotlačnim EGR sustavom

undergraduate thesis

• Title (english): Comparison of performance of engine with low pressure and high pressure EGR system
• Author: Matej Buntić
• Mentor: Darko Kozarac (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2017-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Kako bi pratili sve strože ekološke norme, u vozila s motorima s unutarnjim izgaranjem ugrađuju se razni sustavi koji služe za smanjenje emisija štetnih plinova. Sustav povrata ispušnih plinova (EGR-sustav) koristi se za smanjenje štetne emisije dušikovih oksida (NOx). U praksi se uglavnom susrećemo s visokotlačnom izvedbom EGR-sustava kod koje se povrat ispušnih plinova odvaja prije turbine, ali u novije vrijeme sve se češće koristi i niskotlačna izvedba kod koje se povrat vrši iza turbine turbopunjača. U svrhu ispitivanja učinka obje izvedbe na performanse Ottovog motora nabijenog turbopunjačem s promjenljivom geometrijom turbine provedene su simulacije u računalnom programu AVL Boost. Sva ispitivanja provedena su za puno opterećenje, a položaji statorskih lopatica turbine s promjenljivom geometrijom optimirani su tako da motor daje najveću moguću indiciranu snagu. Ispitan je učinak na srednji indicirani tlak, stupanj punjenja, specifična indicirana i efektiva potrošnja, stupanj indiciranog i efektivnog djelovanja te utjecaj na tlak na ispuhu i usisu za 5, 10, 15 i 20 % za obje izvedbe EGR-a.

Abstract (english)

In order to meet the stringent emission standards, different systems are added to internal combustion engines. The exhaust gas recilcuration (EGR) system is used to reduce nitrogen oxide (NOx) emission. The high pressure loop (HPL) EGR system, in which the EGR flow is redirected before it passes the turbine, is most widely used in commercial vehicles. However, the low pressure loop (LPL) EGR system, in which the EGR flow is rerouted after it passes the turbine, is getting more and more common. In order to examine the effects of both EGR configurations on the performance of a turbocharged spark ignition engine with a variable geometry turbine (VGT), computer simulations were conducted, using the AVL Boost software. All calculations were done for full load while the positions of variable geometry turbine vanes were optimised for maximum indicated power. In addition, the effects of both EGR configurations on indicated mean effective pressure (IMEP), volumetric efficiency, indicated and brake specific fuel consumption (ISFC and BSFC), indicated and brake thermal efficiency as well as on intake and exhaust pressure were examined over the range of 5, 10, 15 and 20 % EGR.

• Keywords: sustav povrata ispušnih plinova (EGR-sustav); visokotlačni EGR-sustav; niskotlačni EGR-sustav; turbopunjač s promjenjljivom geometrijom turbine; srednji indicirani tlak; računalni program AVL Boost
• Keywords (english): exhaust gas recilcuration (EGR); high pressure loop (HPL) EGR; low pressure loop (LPL) EGR; variable geometry turbine (VGT) turbocharger; indicated mean effective pressure (IMEP); AVL Boost
• Language: croatian
• URN:NBN: urn:nbn:hr:235:552502
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 19:00:30