Numerical modelling of the combustion process of e-fuel polyoxymethylene dimethyl ether

Abstract

Kako bi se zadovoljili propisi za smanjenje ugljičnog dioksida, ugljično neutralna sintetička goriva privlače sve više pozornosti kao alternative fosilnim gorivima. Posebna vrsta goriva koje se može primijeniti u postojeće motore s unutarnjim izgaranjem i pokazuje slične karakteristike izgaranja kao i konvencionalna goriva, je polioksimetilen dimetil eter (OME). Računalna dinamika fluida često se koristi za procjenu i ispitivanje svojstava novih goriva, uključujući sintetska goriva. U ovom radu dan je pregled sintetskih goriva i tehnologija sinteze, s naglaskom na trioksimetilen dimetil eter OME-3. Nadalje, numerička simulacija procesa izgaranja s ovim sintetskim gorivom provedena je u računalnom softveru za dinamiku fluida AVL FIRE™. Simulacija s OME-3 gorivom je uspoređena s rezultatima simulacija koje su koristile n-heptan kao gorivo i validirana eksperimentalnim podacima koje je ustupio AVL GmbH Graz. Za simulacije s OME-3 korištena je kemijska kinetika i model izgaranja za usporedbu rezultata. Dva slučaja, od kojih je jedan slučaj s jednim ubrizgavanjem, a drugi slučaj s više ubrizgavanja goriva, korištena su u 3 različita režima ubrizgavanja kako bi se procijenilo izgaranje sintetskog goriva OME-3 naspram n-heptana, koje je predstavljalo zamjenu za dizel gorivo. Promjenom profila ubrizgavanja i ubrizgane mase goriva OME-3 postignuti su rezultati u skladu s konvencionalnim gorivom.In order to meet the reductions of carbon dioxide, carbon-neutral synthetic fuels are drawing attention as an alternative to fossil fuels. One particular fuel, which can be implemented in existing internal combustion engines and shows similar combustion characteristics as conventional fuels, is polyoxymethylene dimethyl ether (OME). Computational fluid dynamics is often used to assess and test the properties of new fuels, including e-fuels. In this work, an overview of e-fuels and synthesis technologies is given, with an emphasis on OME-3. Furthermore, a numerical simulation of the combustion process with this e-fuel was conducted in the computational fluid dynamics software AVL FIRE™. The simulation was verified by comparing the simulation data for n-heptane as fuel and validated with experimental data provided by AVL GmbH Graz. For the simulations with OME-3, both chemical kinetics and a combustion model were used to compare results. Two cases, one being a single injection case, the other being a multi-injection case, were used in 3 different injection regimes to assess how e-fuel OME-3 compares to n-heptane fuel, which is a substitute for diesel fuel. By varying the injection profile and injected mass of fuel of OME-3, results which were more comparable to conventional fuel were achieved