Сrystallization front movement control when welding polyethylene pipes at low temperatures

Аuthors

Starostin N. P., Ammosova O. A.^*

Federal Research Center “The Yakut Scientific Center of the Siberian Branch of the Russian Academy of Sciences”, Yakutsk,Russia

*e-mail: ammosova_o@mail.ru

Abstract

Existing welding machines allow connections of polyethylene pipes for gas pipelines with built-in heaters in temperatures ranging from –10 to 40 °C. In this work, we propose controlling the crystallization of the material of the weld zones and the heat-affected zone by using a built-in heater when welding at temperatures below the permitted range. We present the results of solving the inverse problem of controlling the crystallization of welded materials using temperature data at fixed points are presented. It is shown that the movement of the crystallization front in a time-varying permitted range is ensured by controlling the thermal regime.

Keywords:

thermal regime, embedded heater, crystallization, inverse problem, heat affected zone, weld zone

References

1. Starostin N.P., Ammosova O.A. Technological modes of the welding of the polyethylene pipes for gas mains under low temperature. Thermal processes in engineering, 2010, vol. 2, no. 8, pp. 377–380. (In Russ.).
2. Starostin N.P., Ammosova O.A. Upravlenie teplovym protsessom elektromuftovoi svarki polietilenovykh trub pri nizkikh temperaturakh [Control of the thermal process of electrofusion welding of polyethylene pipes at low temperatures]. Welding and Diagnostics, 2017, no. 5, pp. 21–25. (In Russ.).
3. Starostin N.P., Gerasimov A.I., Danzanova E.V., Botvin G.V., Andreev B.I. Effektivnost’ elektromuftovoi svarki polietilenovykh trub pri nizkikh temperaturakh okruzhayushchego vozdukha [Efficiency of electrofusion welding of polyethylene pipes at low ambient temperatures]. Svarochnoe Proizvodstvo, 2017, no. 11, pp. 47–49. (In Russ.).
4. Nikolaeva M.A., Starostin N.P., Danzanova E.V. Vliyanie temperaturno-vremennykh rezhimov svarki polimernykh trub pri nizkikh temperaturakh na strukturu i svoistva materialov svarnykh soedinenii. Chast’ II. Eksperimental’nye issledovaniya [Influence of temperature time conditions of polymer pipes welding at low temperatures on the structure and properties of materials of joints. Part II. Experimental studies]. Vestnik Yugorskogo Gosudarstvennogo Universiteta, 2023, no. 4, pp. 120–132. (In Russ.). DOI: 10.18822/byusu202304120-132
5. Starostin N.P., Gerasimov A.I., Danzanova E.V., Ammosova O.A. Sposob svarki polimernykh trub soedinitel'nymi detalyami s zakladnym nagrevatelem [Method of welding polymer pipes with connecting parts with an embedded heater]. Patent Rossiiskaya Federatsiya no. 2019114641 (2021).
6. Lebedev V.A., Kozyrko O.A. Sposoby i ustroistva dlya upravleniya kristallizatsiei naplavlennogo metalla pri dugovoi svarke (obzor i analiz) [Methods and devices for controlling the crystallization of deposited metal during arc welding (review and analysis)]. Zagotovitel’nye Proizvodstva v Mashinostroenii, 2015, no. 9, pp. 8–16. (In Russ.).
7. Evtushenko Y.G., Zubov V.I., Albu A.F. Optimal control of thermal processes with phase transitions. Moscow: MAKS Press, 2021, 248 p. (In Russ.). URL: https://doi.org/10.29003/m2449.978-5-317-06677-2
8. Albu A.F. Upravlenie evolyutsiei poverkhnosti razdela faz v protsesse kristallizatsii [Control of the phase boundary evolution in solidification]. Doklady akademii nauk, 2015, vol. 465, no. 1, pp. 24–27. (In Russ.).
9. Alifanov O.M., Artyukhin E.A., Rumyantsev S.V. Ekstremal’nye metody resheniya nekorrektnykh zadach [Extreme methods for solving ill-posed problems]. Moscow: Nauka, 1988, 188 p. (In Russ.).
10. Alifanov O.M. Identifikatsiya protsessov teploobmena letatel’nykh apparatov [Identification of heat transfer processes in aircraft]. Moscow: Mashinostroenie, 1979, 216 p. (In Russ.).
11. Avdonin N.A. Matematicheskoe opisanie protsessov kristallizatsii [Mathematical description of crystallization processes]. Riga: Zinatne, 1980, 180 p. (In Russ.).
12. Samarskii A.A., Vabishchevich P.N. Vychislitel’naya teploperedacha [Computational Heat Transfer]. Moscow: Editorial URSS, 2003, 784 p. (In Russ.)