Dynamic process modeling and simulation of electric arc furnaces

The adver­se con­di­ti­ons at the elec­tric arc fur­nace make expe­ri­men­tal inves­ti­ga­ti­ons and para­me­ter varia­ti­ons during the mel­ting pro­cess dif­fi­cult and to some extend are also asso­cia­ted with high cos­ts. For the­se reasons a dyna­mic pro­cess model is used at the IOB for theo­re­ti­cal inves­ti­ga­ti­ons and for the opti­miza­ti­on of the elec­tric arc fur­nace pro­cess. In con­trast to CFD and FEM simu­la­ti­on methods and due to sim­pli­fi­ca­ti­ons and a holi­stic view on the pro­cess the dyna­mic pro­cess model deli­vers results fas­ter with less time requi­red for com­pu­ting. It also offers a high degree of appli­ca­ti­on versatility:

  • Ana­ly­sis of dif­fe­rent pro­cess ope­ra­ti­on modes
  • Opti­miza­ti­on of pro­cess con­trol parameters
  • Inves­ti­ga­ti­on of alter­na­ti­ve EAF equi­pe­ment and EAF designs
  • Soft sens­ing
  • Ope­ra­tor training

The ana­ly­ti­cal pro­cess model is imple­men­ted using MATLAB and is based on fun­da­men­tal ther­mo­dy­na­mic and phy­si­cal equa­tions. The model published by Logar, Dovžan und Škrjanc (2012) forms the basis and has been fur­ther deve­lo­ped, espe­ci­al­ly with regard to the gas phase.

The pro­cess model con­sists of sepa­ra­te modu­les in which the ener­gy dis­tri­bu­ti­on and heat trans­fer as well as rele­vant che­mi­cal reac­tions and mass trans­fers are cal­cu­la­ted. By means of first order dif­fe­ren­ti­al equa­tions mass and tem­pe­ra­tu­re chan­ges of the sin­gle pha­ses (scrap, melt, slag, …) are cal­cu­la­ted obser­ving the laws of con­ser­va­ti­on of ener­gy and mass.

On avera­ge the pro­cess simu­la­ti­on is car­ri­ed out within one to three minu­tes depen­ding on the com­ple­xi­ty of the mode of ope­ra­ti­on. Due to the imple­men­ta­ti­on of the model for par­al­lel com­pu­ting, depen­ding on the num­ber of phy­si­cal CPU cores available, mul­ti­ple melts can be simu­la­ted at once.

The time depen­dent results of the simu­la­ti­on pro­vi­de the tem­po­ral deve­lo­p­ment of the tem­pe­ra­tu­re of all pha­ses and zones of the model, mas­ses and che­mi­cal com­po­si­ti­ons as well as heat flows during the mel­ting process.

The pro­cess model has been vali­da­ted using pro­cess data of seve­ral indus­tri­al elec­tric arc fur­naces. The model can also be used to inves­ti­ga­te alter­na­ti­ve modes of ope­ra­ti­on. The simu­la­ti­on is adapt­ed in a way, that within given boun­da­ries of mass and ener­gy inputs an auto­ma­tic con­trol of the pro­cess by the simu­la­ti­on its­elf is pos­si­ble. Due to par­al­lel com­pu­ting it is pos­si­ble to simu­la­te and eva­lua­te dif­fe­rent modes of ope­ra­ti­on and to opti­mi­ze the mel­ting pro­cess within a short peri­od of time.

Publi­ca­ti­ons
Hay, T.; Ech­ter­hof, T.; Pfei­fer, H.: EAF Pro­cess Model and Simu­la­tor, 4th Euro­pean Aca­de­mic Sym­po­si­um on EAF Steel­ma­king – EASES 2021, 16.–18. June 2021, Online event

Hay, T.; Visu­ri, V.; Aula, M.; Ech­ter­hof, T.: A Review of Mathe­ma­ti­cal Pro­cess Models for the Elec­tric Arc Fur­nace Pro­cess, Steel Rese­arch Inter­na­tio­nal, 92 (2021), Nr. 3, 2000395

Kir­schen, M.; Hay, T.; Ech­ter­hof, T.: Pro­cess Impro­ve­ments for Direct Redu­ced Iron Mel­ting in the Elec­tric Arc Fur­nace with Empha­sis on Slag Ope­ra­ti­on, Pro­ces­ses, 9 (2021), 402

Hay, T.; Her­nan­dez, J.; Roberts, S.; Ech­ter­hof, T.: Cal­cu­la­ti­on of View Fac­tors in Elec­tric Arc Fur­nace Pro­cess Mode­ling, Steel Rese­arch Inter­na­tio­nal, 92 (2021), Nr. 2, 2000341

Hay, T.; Ech­ter­hof, T.; Visu­ri, V.-V.: Deve­lo­p­ment of an Elec­tric Arc Fur­nace Simu­la­tor Based on a Com­pre­hen­si­ve Dyna­mic Pro­cess Model, Pro­ces­ses, 7 (2019), Nr. 11, 852

Hay, T.; Rei­mann, A.; Ech­ter­hof, T.: Impro­ving the Mode­ling of Slag and Steel Bath Che­mis­try in an Elec­tric Arc Fur­nace Pro­cess Model, Metall­ur­gi­cal and Mate­ri­als Tran­sac­tions B, 50 (2019), Nr. 5, S. 2377–2388

Hay, T.; Rei­mann, A.; Ech­ter­hof, T.; Pfei­fer, H.: Key­note: Dyna­mic EAF Pro­cess Model — Ther­mo­che­mis­try and Fur­ther Deve­lo­p­ment, Pro­cee­dings of the 8th Inter­na­tio­nal Con­fe­rence on Mode­ling and Simu­la­ti­on of Metall­ur­gi­cal Pro­ces­ses in Steel­ma­king (STEELSIM 2019), 13.–15. August 2019, Toron­to, Ont., Canada

Ech­ter­hof, T.; Hay, T.; Pfei­fer, H.: A Dyna­mic EAF Pro­cess Model – Sta­te of deve­lo­p­ment and out­look, 22nd IAS Steel Con­fe­rence and EXPO IAS 2018, 23.–25. Okto­ber 2018, Rosa­rio, Argentina

Mei­er, T.; Gan­dt, K.; Hay, T.; Ech­ter­hof, T.: Pro­cess Mode­ling and Simu­la­ti­on of the Radia­ti­on in the Elec­tric Arc Fur­nace, steel rese­arch inter­na­tio­nal, 89 (2018), Nr. 4, 1700487

Mei­er, T.; Gan­dt, K.; Ech­ter­hof, T.; Pfei­fer, H.: Mode­ling and Simu­la­ti­on of the Off-gas in an Elec­tric Arc Fur­nace, Metall­ur­gi­cal and Mate­ri­als Tran­sac­tions B, 48 (2017), Nr. 6, S. 3329–3344

Mei­er, T.; Hay, T.; Ech­ter­hof, T.; Pfei­fer, H.; Rekers­drees, T.; Schlin­ge, L.; Els­ab­agh, S.; Schlie­pha­ke, H.: Pro­cess Mode­ling and Simu­la­ti­on of Biochar Usa­ge in an Elec­tric Arc Fur­nace as a Sub­sti­tu­te for Fos­sil Coal, steel rese­arch inter­na­tio­nal, 88 (2017), Nr. 9, 1600458

Mei­er, T.; Ech­ter­hof, T.; Pfei­fer, H.: Inves­ti­ga­ting the Use of Bio­mass and Oxy­gen in Elec­tric Steel­ma­king by Simu­la­ti­ons Based on a Dyna­mic Pro­cess Model, 2nd ISIJ-VDEh-Jern­kon­to­ret Joint Sym­po­si­um, 12.–13. Juni 2017, Stock­holm, Schwe­den, S. 81–93

Mei­er, T.; Hassan­nia Kolag­ar, A.; Ech­ter­hof, T.; Pfei­fer, H.: Dyna­mic Pro­cess Model­ling and Simu­la­ti­on of an Elec­tric Arc Fur­nace and its Dedus­ting Sys­tem, stahl und eisen, 137 (2017), Nr. 5, S. 53–60

Mei­er, T.; Hassan­nia Kolag­ar, A.; Ech­ter­hof, T.; Pfei­fer, H.: Pro­cess mode­ling and simu­la­ti­on of an Elec­tric Arc Fur­nace for com­pre­hen­si­ve cal­cu­la­ti­on of ener­gy and mass trans­fers in com­bi­na­ti­on with a model of the dedus­ting sys­tem, 11th Euro­pean Elec­tric Steel­ma­king Con­fe­rence & Expo, 25.–27. Mai 2016, Vene­dig, Italien

Mei­er, T.; Logar, V.; Ech­ter­hof, T.; Skrjanc, I.; Pfei­fer, H.: Model­ling and Simu­la­ti­on of the Mel­ting Pro­cess in Elec­tric Arc Fur­naces – Influence of Nume­ri­cal Solu­ti­on Methods, steel rese­arch inter­na­tio­nal, 87 (2016), Nr. 5, S. 581–588

Mei­er, T.; Hassan­nia Kolag­ar, A.; Ech­ter­hof, T.; Pfei­fer, H.: Gas Pha­se Mode­ling and Simu­la­ti­on in an Elec­tric Arc Fur­nace Pro­cess Model for Detail­ed Off-Gas Cal­cu­la­ti­ons in the dedus­ting sys­tem, STEELSIM 2015 – 6th Inter­na­tio­nal Con­fe­rence on Model­ling and Simu­la­ti­on of Metall­ur­gi­cal Pro­ces­ses in Steel­ma­king, 23. – 25 Sep­tem­ber 2015, Bar­do­li­no, Italien

Mei­er, T.; Hassan­nia Kolag­ar, A.; Ech­ter­hof, T.; Pfei­fer, H.; Logar, V.; Skrjanc, I.: Model­ling and Simu­la­ti­on of the tran­si­ent Elec­tric Arc Fur­nace pro­cess, 1st Euro­pean Steel Tech­no­lo­gy & Appli­ca­ti­on Days (ESTAD) & 31st Jour­nées Sidérur­gi­ques Inter­na­tio­na­les (JSI), 7.–8. April 2014, Paris, Frankreich