On the prediction of local ice formation in pipes in the presence of natural convection

Pipe freezing is a pipeline maintenance technique which is used to isolate sections of a liquid-filled pipeline by freezing the contents reform a solid pressure-resistant plug. This paper describes the development of a numerical model of natural convection and solidification in a vertical water-filled pipe. The natural convection-driven flows are examined in detail and the interaction with the forming ice plug is studied The results are compared with experimental data. The numerical approach is contrasted,with a simpler one-dimensional analytical method and criteria are proposed to aid the choice of modeling technique under different conditions.