20.500.12556/RUL-187634 Numerično modeliranje izpustov onesnažil batnega motorja avtobusa na zemeljski plin na osnovi meritev v realnem prometnem toku Numerical modelling of pollutant emissions of a natural gas bus reciprocating engine based on real-world traffic measurements Izpusti onesnažil vozil z motorji z notranjim zgorevanjem so posledica sočasnega vpliva obratovalne točke motorja, poteka zgorevanja in sistemov za naknadno obdelavo izpušnih plinov, zato je njihovo napovedovanje iz omejenega nabora obratovalnih parametrov zahtevno zlasti pri časovno spremenljivih voznih ciklih. V magistrskem delu je predstavljen podatkovno podprt pristop za napovedovanje izpustov onesnažil avtobusa na stisnjen zemeljski plin iz meritev v realnem prometnem toku. Iz izmerjenih koncentracij CO$_{2}$ , CO, NO$_{x}$ in THC je bil izdelan napovedni model, ki vsaki obratovalni točki, določeni z vrtilno frekvenco in navorom, pripiše značilne koncentracije izpustov v obliki diskretnih tabel. S poenostavljenim termičnim modelom katalitskega pretvornika je bil model razširjen na ločeni tabeli za hladno in toplo stanje ter ovrednoten na ločenem validacijskem delu cikla. Najboljše ujemanje je bilo doseženo pri CO$_{2}$ , ki je neposredno povezan s porabo goriva in obremenitvijo motorja. Pri CO, NO$_{x}$ in THC so trenutne vrednosti manj natančne, dodatno upoštevanje temperature monolita pa napovedi statistično značilno ne izboljša. Model kljub temu dobro oceni skupno količino izpustov v voznem ciklu, zato je primeren za hitro oceno skupnih izpustov in analizo voznih ciklov, ne pa za napoved trenutnih vrhov. Vehicle emissions from internal combustion engines are the result of the simultaneous influence of the engine operating point, the combustion process, and the exhaust aftertreatment systems. Consequently, predicting these emissions from a limited set of operating parameters is challenging, particularly under time-varying driving cycles. This master's thesis presents a data-driven approach for predicting pollutant emissions of a compressed natural gas bus based on real-world driving emissions measurements. Utilizing the measured concentrations of CO$_{2}$, CO, NO$_{x}$, and THC, a predictive model was developed that assigns characteristic emission concentrations to each operating point – defined by engine speed and torque – in the form of discrete tables. By incorporating a simplified thermal model of the catalytic converter, the model was extended to include separate tables for cold and warm operating states, and was subsequently evaluated on a separate validation section of the cycle. The best agreement was achieved for CO$_{2}$, which is directly linked to fuel consumption and engine load. For CO, NO$_{x}$, and THC, the instantaneous values are less accurate, and the additional consideration of the monolith temperature did not result in a statistically significant improvement in predicted accuracy. Nevertheless, the model provides a good estimation of total emissions over the driving cycle, making it suitable for a rapid assessment of cumulative emissions and driving-cycle analysis, rather than for predicting instantaneous peaks. motorji z notranjim zgorevanjem zemeljski plin izpusti onesnažil numerično modeliranje termični model katalitskega pretvornika tabele za določitev izpustov onesnažil internal combustion engines compressed natural gas emissions numerical modeling thermal model of catalytic converter emission tables true false false [J. Gerič] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-09-12 08:30:25 2026-09-12 08:30:31 2026-09-17 10:43:52 0000-00-00 00:00:00 2026 0 Ljubljana 0 XXVII, 94 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.43:004.942:519.876.5(043.2) 290296 291404035 49612.pdf 49612.pdf 1 498F5F8E9A4793724446ACE9DED869F1 65aae738b291305bb21b4396100a7b8765dc6c9763fe69ae2a917e61eb8d180a 6ce64052-ae73-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=247334 Fakulteta za strojništvo 0 0 0