Simulacija rada Ottovog motora pri djelomičnim opterećenjima promjenom faktora pretička zraka

undergraduate thesis

• Title (english): Simulation of spark ignited engine operation under part load conditions by change of air excess ratio
• Author: Mario Kostanjevec
• Mentor: Momir Sjerić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Ottovi motori s pretkomorom je tehnologija koja je unaprijedila običan Ottov motor te se sve više koristi u proizvodnji automobila. Omogućuje rad na nižim temperaturama što smanjuje emisije dušikovih oksida te smanjuje potrošnju goriva u usporedbi s konvencionalnim motorima. Usporedbom dva načina rada istoga motora vidi se utjecaj faktora pretička zraka. Kod konvencionalnog motora on je u djelomičnim opterećenjima isti, dok je kod modificiranog rada motora promjenjiv. Analiza se provela preko specifičnih efektivnih i indiciranih potrošnji goriva, udjelu zaostalih produkata izgaranja, stupnju punjenja, faktoru pretička zraka, najvećem tlaku u cilindru i najvećoj temperaturi u cilindru te srednjeg indiciranog tlaka za izmjenu radnog medija . Na kraju rada provedena je analiza voznog ciklusa oba načina rada motora. Rezultati su pokazali kako modificirani način rada motora ima manju potrošnju goriva kod djelomičnih opterećenja u promatranim radnim točkama te ujedno i drastično smanjenu emisiju dušikovih oksida, a i općenito smanjenu emisiju štetnih plinova. Razlog tome je izgaranje u glavnoj komori u kojoj prevlada zrak odnosno siromašna smjesa.
Koristeći programski paket AVL BOOST uspoređivale su se i simulirale 6 različitih radnih točaka koje su podijeljene na različitim brzinama vrtnje. Početna je na 1000 min-1, a zadnja je na 6000 min-1. Uz to rad je podijeljen na 100% opterećenje i djelomična opterećenja.

Abstract (english)

Otto engines with a pre-chamber is a technology that improved the ordinary Otto engine and is increasingly used in car production. It enables operation at lower temperatures, which reduces nitrogen oxide emissions and reduces fuel consumption compared to conventional engines. By comparing the two modes of operation of the same engine, the influence of the lambda number can be seen. In the case of a conventional engine, lamba number is the same in partial loads, while it is variable in the case of modified engine operation. The analysis was carried out through the specific effective and indicated fuel consumption, the proportion of residual combustion products, charging efficiency, lambda number, the highest pressure in the cylinder and the highest temperature in the cylinder, and the average indicated pressure for changing the processing medium. At the end of the work, an analysis of the driving cycle of both modes of engine operation was carried out. The results showed that the modified operation mode of the engine has lower fuel consumption at partial loads in the observed operating points and at the same time drastically reduced emission of nitrogen oxides and generally reduced emission of harmful gases. The reason for this is combustion in the main chamber where air prevails, i.e. a lean mixture.
Using the AVL BOOST program package, 6 different operating points were compared and simulated, which were divided at different rotational speeds. The initial one is at 1000 min-1, and the last one is at 6000 min-1. Additionally, work is divided into 100% load and partial loads.

• Keywords: Ottovi motori; pretkomora; regulacija snage; vozni ciklus
• Keywords (english): Otto engines; pre-chamber; power regulation; driving cycle
• Language: croatian
• URN:NBN: urn:nbn:hr:235:852119
• 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: Embargoed access; Embargo expiration date: 2024-09-29
• Created on: 2022-09-20 12:40:10