Use of CFD Modeling for Designing Intake and Discharge Structures in a Discharge Canal

This paper presents a computational fluid dynamics (CFD) modeling approach for designing intake and discharge structures in a discharge canal for nuclear and fossil power plants. It discusses how the CFD models are developed, what types of results can be obtained from the CFD modeling study and how the results are used for developing designs of the intake and discharge structures. The pros and cons of the CFD modeling method for this type of application are also discussed. Intake and discharge structures for a “Helper Cooling Tower South” will be added to the discharge canal of the Crystal River Energy Complex (CREC). The CFD modeling was used to confirm suitable locations for the new intake and discharge structures to minimize potential recirculation and potential loss of cooling tower efficiency, and to evaluate the erosion of the banks on the north and south side of the canal due to the flow from the discharge structure. The CFD model was developed using FLUENT for the existing and future configurations of the discharge canal that consists of the existing intake, discharges, and the new intake and discharge structures. The CFD modeling runs were performed to investigate three-dimensional flow patterns, velocities and temperatures in the discharge canal under current and future operating conditions. Current and future conditions refer to those before and after installation of the Helper Cooling Tower South Intake and Discharge structures, respectively. Comparing the CFD results (streamlines, temperature and velocity distributions, etc.) for the future conditions to those for the existing conditions, the locations and designs of the new intake and discharge structures were assessed and developed. This study demonstrates that the new intake is not impacted by the new and existing discharge structures, and the existing intake will perform similarly as it performs before the construction of the new intake and discharges. The study also identifies some sections of the canal banks and bottom that may need to be protected from erosion due to the impacts of the high velocity water from the discharge structures.