Local Freezing of Liquid Pipelines, in Order to Provide Repairs

One of the problems in repairing pipelines containing fuels or any other liquid in industrial units or public and residential buildings is impossibility of separating damaged part of the whole path for repair, avoiding waste of fluid. The present design attempts to introduce a method based on use of freezing in pipeline repairs, which, while removing pipe discharge operations locally, recommends it as a superior technique. In this method, by producing cold condition outside the pipe and on both sides of the damaged part, the fluid is frozen in the tube and creates an obstacle in the fluid flow path. The freezing operation is performed by closing a temporary refrigerant coating around the tube. Thus, the damaged part is separated from the rest of the pipeline and is repaired. In this research, the freezing equation was first calculated by numerical solution based on Simpson's integration, and the duration of freezing of the fluid in a tube with different boundary conditions (pipe diameter, type and fluid velocity, etc.) was calculated. At the end, the results of the numerical methods were compared with the results of the experiment on a device designed for this purpose.