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Selection of criteria to reduce the unknowns in Newton–Raphson method in the problem of finding an equilibrium composition of iron ore and fuel

P.A. Sechenov

Vestnik IGEU, 2024 issue 5, pp. 82—90

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Abstract in English: 

Background. Finding the equilibrium composition of a multicomponent system is required in various industries associated with chemical reactions. Reduction of the unknowns in the original nonlinear equation is possible if most of the unknowns receive values equal to zero as a result of the solution. This situation is typical to solve the problem of finding an equilibrium composition of iron ore and fuel, where the unknowns are the number of moles of all possible reaction products from given simple substances. The dependence of algorithmic complexity on the number of unknowns to solve a SLAEs is expressed through the function O(N3). Therefore, reduction of the unknowns will speed up the computational process. Thus, the solution to the problem of selecting criteria to reduce the number of the unknowns at each iteration of the Newton-Raphson method as applied to the problem of finding the equilibrium composition of iron ore and fuel is relevant.

Materials and methods. The matrix dimensionality reduction has been achieved using four strategies. The first three strategies involve finding a minimum threshold (removing values that most quickly tend to zero), after which the number of unknowns will decrease. The fourth strategy is associated with reducing the dimension of the original matrix.

Results. The results of numerical experiments to reduce the unknowns and speed up calculations are presented. Criteria have been found under which the calculation speed increases by 2–4 times and variables whose value is not equal to zero are not reduced.

Conclusions. The criteria to reduce the unknowns implemented in the T-Energу software package make it possible to solve the problem of finding the equilibrium composition of iron ore and fuel 2–4,2 times faster. In this case, the obtained solution for the components of the equilibrium composition with the reduction of the unknowns corresponds to the complete solution with an accuracy of 10–3. Due to acceleration at the same time, it is possible to construct equilibrium compositions over a temperature range with a temperature step that is 4 times smaller.

References in English: 

1. Zeng, Y., Man, M., Ng, Ch.K., Aitken, Z., Bai, K., Wuu, D., Lee, J.J., Ng, S.R., Wei, F., Wang, P., Tan, D.Ch.Ch., Zhang, Y.-W. Search for eutectic high entropy alloys by integrating high-throughput CALPHAD, machine learning and experiments. Materials & Design, 2024, vol. 241, pp. 112929. DOI: 10.1016/j.matdes.2024.112929.

2. Sechenov, P.A., Kozhemyachenko, V.I., Rybenko, I.A. Parallel'naya realizatsiya algoritma rascheta ravnovesnogo sostava v programmnom komplekse T-Energy [Parallel implementation of the equilibrium composition calculation algorithm in the T-Energy software package]. Vestnik Povolzhskogo gosudarstvennogo tekhnologicheskogo universiteta. Seriya: Radiotekhnicheskie i infokommunikatsionnye sistemy, 2022, no. 1(57), pp. 64–73.

3. Chernysheva, L.P., Kharitonov, D.P. Effektivnoe ispol'zovanie geterogennykh vychislitel'nykh sistem [Effective usage of heterogeneous computing systems]. Vestnik IGEU, 2012, issue 5, pp. 47–51.

4. Ivanov, V.N. Algoritmy resheniya uravneniy dvizheniya v impul'sakh Puassona sistem tverdykh tel so strukturoy dereva [Algorithms for solving the equations of motion with Poisson impulses of multibody systems with tree structure]. Vestnik Permskogo Universiteta. Matematika, Mekhanika, Informatika, 2017, issue 4(39), pp. 25–31. DOI: 10.17072/1993-0550-2017-4-25-31.

5. Sviridenko, A.B. Pryamye mul'tiplikativnye metody dlya razrezhennykh matrits. Nesimmetrichnye lineynye sistemy [Direct multiplicative methods for sparse matrices. Unbalanced linear systems]. Komp'yuternye issledovaniya i modelirovanie, 2016, vol. 8, no. 6, pp. 833–860.

6. Semushin, I.V. Eshche raz o bol'shikh obratnykh matritsakh: ot formalizmov k realizatsii [Once again about large inverse matrices: from formalisms to implementation]. Avtomatizatsiya protsessov upravleniya, 2017, vol. 50, no. 4, pp. 36–41.

7. Sechenov, P.A., Rybenko, I.A. Chislennyy metod i matematicheskaya model' nakhozhdeniya ravnovesnogo sostava termodinamicheskoy sistemy programmnogo kompleksa T-Energy [Numerical method and mathematical model for finding the equilibrium composition of the thermodynamic system of the T-Energy software package]. Vestnik Dagestanskogo gosudarstvennogo tekhnicheskogo universiteta. Tekhnicheskie nauki, 2022, vol. 49, no. 4, pp. 104–112. DOI: 10.21822/2073-6185-2022-49-4-104-112.

8. Mishchenkova, O.V., Voevodina, O.A. Primenenie LU- i QR-metodov pri reshenii zadachi o ravnovesnom sostave produktov khimicheskoy reaktsii [Application of LU- and QR-methods to solve the task on equilibrium structure of products of chemical reaction]. Vestnik IzhGTU imeni M.T. Kalashnikova, 2014, vol. 63, no. 3, pp. 172–176.

9. Kryukov, A.V., Zakaryukin, V.P., Abramov, N.A. Situatsionnoe upravlenie rezhimami sistem tyagovogo elektrosnabzheniya na osnove metodov nechetkoy klasterizatsii [Situation control of modes of railway electric supply system based on fuzzy clusterization methods]. Vestnik IGEU, 2010, issue 2, pp. 36–41.

10. Belousov, F.A., Khachatryan, N.K., Nevolin, I.V. Snizhenie razmernosti v zadache optimal'nogo upravleniya parkom gruzovykh vagonov s ispol'zovaniem bespilotnykh lokomotivov [Reduction of dimension in the problem of optimal management of a freight cars fleet using unmanned locomotives]. Biznes-informatika, 2022, vol. 16, no. 2, pp. 7–20. DOI: 10.17323/2587-814X.2022.2.7.20.

11. Lavrov, D.N., Vishnyakova, O.A., Dudyak, E.I., Lavrova, S.Yu. Komp'yuternoe modelirovanie otsenivaniya koordinat tochki besprovodnogo dostupa po izmereniyam moshchnosti prinimaemykh signalov [Computer modeling of estimating of wireless access point coordinates by measuring the received signal power]. Matematicheskie struktury i modelirovanie, 2014, vol. 30, no. 2, pp. 62–76.

Key words in Russian: 
редукция матрицы, итерационный процесс, метод Ньютона–Рафсона, задача нахождения равновесного состава
Key words in English: 
matrix reduction, iterative process, Newton–Raphson method, equilibrium composition problem
The DOI index: 
10.17588/2072-2672.2024.5.082-090
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