Development and validation of a CFD model for numerical simulation of a large natural draft wet cooling tower

Électricité de France (EDF) has commissioned the development of a CFD model, based on ANSYS Fluent v.16, which includes the specific equations (Poppe and Merkel) describing the physical phenomena occurring in a natural draft wet cooling tower (NDWCT). Heat and mass transfers between water and air, as well as drag equations for the two-phase system, are computed in specific zones such as the cooling fill, spray and rain zones. This paper presents the CFD model created and the two-step methodology implemented for the validation process: The model is first tested and set regarding thermal performance results obtained on EDF test cell Mistral located on the Bugey site. The Mistral facility includes a 7 m × 7 m counter-flow section, equipped with a large number of temperature and pressure sensors, which represents an efficient and reliable mean for cooling fill performances evaluation. Secondly, the model is fully validated thanks to acceptance tests results gathered from a large scale NDWCT refurbishment. To this end, advanced instrumentation was positioned in the tower to provide additional data for extensive validation of the model.