PERFORMANCE ANALYSIS OF MECHANICAL DRAFT COOLING TOWER

Conference · Tue Feb 10 04:00:00 EST 2009

OSTI ID:949871

Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT's consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

• Research Organization: SRS
• Sponsoring Organization: DOE
• DOE Contract Number: AC09-08SR22470
• OSTI ID: 949871
• Report Number(s): SRNL-STI-2009-00106
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BLOWERS
COMPUTERIZED SIMULATION
COOLING TOWERS
COUNTERFLOW SYSTEMS
FORCED CONVECTION
MATHEMATICAL MODELS
PARAMETRIC ANALYSIS
PERFORMANCE
SAVANNAH RIVER PLANT