TY JOUR TI Freezing Time Calculation of the Above-Ground Water Pipeline Under Conditions of Negative Temperatures KW Above-ground water pipeline KW internal icing KW freezing time KW mathematical modeling KW quasistationary approximation JO Proceedings of Petersburg Transport University AU Lapshin, V.F. PY 2023 IS 20 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"