Session: 10-02 Fan Applications

Paper Number: 121702

121702 - Characterization of Windshield Effectiveness in Improving Air Cooled Condenser Performance Under High Winds and its Impact on Steam Turbine Power Output 

Large mechanical draft Air-Cooled Condensers (ACC) are increasingly preferred, as a more environmentally friendly solution than wet cooling, in the cooling processes necessary to condense the fluid vector in Rankine cycle-based power production systems. These devices are prone to a decay of efficiency and the onset of fan blade fluctuations that largely increase in case of high-speed winds and strongly depends on the wind directions.

A common and relatively simple strategy used to mitigate such wind losses is the installation, directly on the ACC structural columns, of partially porous screens made of plastic fabric that acts as wind breakers.

On top of a previous numerical study that, for a sample ACC with 3 streets and 6 rows, characterized the wind related losses for a large number of wind conditions and identified a ground installed vertical windshield in the shape of a crux as the most effective mean to recover such losses, a second numerical campaign was completed.

The same CFD model, exploiting Unsteady RANS for the modelling of the entire ACC and direct meshing of all the 108 blades, was used to characterize the windshield performance under all possible wind speeds and directions. Furthermore, the CFD results, in particular the estimate of the condenser global heat transfer coefficient, were used into a thermodynamic model of the steam cycle that permitted to compute the thermal equilibrium between steam and air side allowing the estimate of the Steam Turbine back-pressure.

Feeding the thermodynamic model with appropriate weather forecast, it was possible to compute the expected extra annual production thanks to the windshield installation that, providing reasonable installation costs and energy selling prices, permitted a reasonable estimate of the payback period for the investment. Analysing different scenarios typical for different locations around the world it was highlighted that the payback period was always less than a year and that the main driver for shortening such period is the energy price.

Presenting Author: Cosimo Bianchini Ergon Research

Presenting Author Biography: Cosimo Bianchini is executive at Ergon Research where he has been working for 9 years as CFD specialist and Engineering manager. His principal expertise is in the area of computational methods for aerodynamics and heat transfer for turbomachinery. He obtained a PhD in 2011 at the University of Florence with a thesis on advanced boundary conditions for CFD analysis of heat transfer and aeroacoustics. He started his research on the aerodynamics of Air Cooled Condenser in 2015 and since then he has completed several projects on wind effects mitigation.

Authors:

Cosimo Bianchini Ergon Research
Riccardo Da Soghe Ergon Research
Lorenzo Giannini Ergon Research
Andrew Gardner Galebreaker
Jamie Wilde Galebreaker