Experimental Testing and Numerical Evaluation on Freezing for Water Hydraulics Application under Sub-Freezing Ambient Temperature Environment

摘要

The work reported in this paper explores both experimental and numerical simulations on the process of freezing of pressurized fluids in stainless steel pipes for water hydraulics systems under sub-freezing ambient temperature conditions. Preliminary experimental studies were conducted to investigate the time taken for water to freeze under sub-freezing temperature conditions and to explore ways to delay and prevent the water from freezing. A test rig was designed and tested. The results of the experiments deduced that the use of insulation would delay the time for water to freeze and the use of heating pads (heaters) mounted on the insulated piping could prevent freezing altogether. Computational Fluid Dynamics (CFD) simulation software, FLUENT, was used to identify the relevant parameters, such as the thickness of the insulation, flow velocity, pipe length, and the heat flux applied along the pipe length, which could prevent the freezing of the water throughout the solution domain with proper geometries and boundary conditions.