Numerical investigation of fan performance in a forced draft air-cooled steam condenser

• Published in: Applied thermal engineering Vol. 26; no. 8; pp. 846 - 852
• Main Authors: Bredell, J.R., Kröger, D.G., Thiart, G.D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2006; Elsevier
• Subjects: Air-cooled; Applied sciences; Axial flow fan; CFD; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fan performance; Inlet flow distortion; Installations for energy generation and conversion: thermal and electrical energy; Materials and auxiliary equipments used in energy engineering; Thermal power plants; Inlet flow distortion; CFD; Axial flow fan; Air-cooled; Fan performance; Vibration; Computational fluid dynamics; Steam condenser; Thermal power plant; Water vapor; Air flow; Fan; Numerical analysis; Condenser; Performance; Axial flow
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2005.09.020

Inlet air flow distortions in a large air-cooled steam condenser (ACSC), caused by structures, wind and other fans may result in a significant reduction in fan performance, or volumetric effectiveness, as well as fan blade vibration. This phenomenon has an adverse effect on the heat rejection capacity of an ACSC due to a decrease in air mass flow rate. In this study the effect of inlet flow distortions on the flow rate through the fans in an ACSC is numerically investigated by modelling the flow field in a section of such a system using the computational fluid dynamics code, FLUENT. The effect of platform height on the volumetric effectiveness of two different types of axial flow fans is considered. The two fans have the same diameter, number of blades and rotational speed, but feature different blade designs, and hub-tip-ratios of respectively 0.153 and 0.4. Numerical simulations show all-round superior performance in terms of volume flow rate for the fan with a hub-tip-ratio of 0.4. It is furthermore confirmed that the addition of a walkway can significantly increase the flow rate through the fans located near the edge of the fan platform.