Proračun sastava radnog medija na početku visokotlačnog procesa temeljem sastava ispušnih plinova motora s unutarnjim izgaranjem

undergraduate thesis

• Title (english): Calculation of working fluid composition at the start of high pressure cycle of IC engine based on the exhaust gas composition
• Author: Alen Mazurek
• Mentor: Darko Kozarac (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2017-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Povrat ispušnih plinova (engl. Exhaust Gas Recirculation-EGR) kod Diesel motora služi kako bi ostali u zakonski dozvoljenim okvirima štetnih emisija odnosno smanjili emisije NOx. Kod Ottovih motora EGR se primarno rabi da se smanje gubici pumpanja, a dodatno i smanjuje emisije NOx. Da bi se bolje razumio utjecaj EGR-a na motor s unutarnjim izgaranjem, potrebno je imati model koji će točno odrediti EGR. Recirkulirani plinovi su vrući ispušni plinovi nepoznatog sastava, pa nije moguće pouzdano odrediti maseni protok kao kod zraka. Zato se određuje maseni udio EGR-a pomoću masenih protoka goriva i zraka i koncentracija plinova na usisu i ispuhu. U ovom radu je izveden matematički model za izračun EGR-a uz poznate vrijednosti koncentracije CO 2 na usisu i koncentracija plinova na ispuhu, i matematički model za izračun EGR uz masene protoke goriva i zraka i koncentraciju CO 2 na usisu. Također, izveden je približni izraz za EGR koji se često koristi u praksi, te su uspoređeni rezultati matematičkih modela. Dokazano je da se EGR ne može izračunati samo iz masenih protoka goriva i zraka i poznatih koncentracija na ispuhu.

Abstract (english)

Exhaust Gas Recirculation (EGR) is used in Diesel engines to keep emissions in allowed limit, respectively NOx limit. In Otto engines EGR is mainly used to reduce pumping losses, secondary it reduces NOx emissions. To better understand influence of EGR on internal combustion engine, precise model for EGR is needed. Recilculated gases are hot and of unknown composition, so it isn't possible to messure mass flow precissely, like that of air. That is why EGR is determined from mass flow of fuel and air and concentrations of gases in intake and exhaust. In this paper mathematical model for calculating EGR from CO 2 concentration in intake and concentrations on exhaust is derived. Mathematical model for calculating EGR from fuel and air mass flow and CO 2 concentration in intake is derived. Also, aproximate expression for EGR, which is often used in practice is derived. Results are compared. It is proven that EGR can not be calculated only from fuel and air mass flow and concentrations in exhaust.

• Keywords: EGR; CO2; usis
• Keywords (english): EGR; CO2; intake
• Language: croatian
• URN:NBN: urn:nbn:hr:235:376473
• 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 20:25:01