Thermal optimization of nacelles
As a result of Joule effect, the electrical components present in the tower and/or nacelle, generate heat that must be efficiently evacuated in order to avoid reaching high temperatures that may provoke a disruption of the wind turbine’s energy transforming system. The heat generated in large wing turbines (> 1 MW) could easily reach 50 kW, which forces to ensure a good dissipation system to prevent the emergence of high temperature zones.
Typically, the followed strategy to perform the optimization involves a gradual use, in terms of complexity, of our software capabilities:
- 0-dimensional models
- Simplified 3D models assuming laminar behavior
- High-detailed 3D geometric models using LES turbulent models
The CTTC’s optimization tools take into account the next effects:
- Natural or forced air convection of the elements inside and outside the nacelle.
- Addition of extra openings in different parts of the nacelle’s shell.
- Heat conduction among structures and shells.
- Heat exchange between the surfaces (of the elements inside the nacelle) due to thermal radiation
- Heat exchange of the outer nacelle’s surfaces by means of solar and thermal radiation with the environment.
- Coupling of the characterization of the heat generation elements and the thermo-fluidic behavior of air.
Using the mentioned tools, the group has successfully carried out the nacelle’s thermal optimization of the ECO 100, wind turbine designed by the company Ecotécnia-ALSTOM [1]
References
[1] Research Project C06619; Company: ECOTECNIA; Funding 108.000 Euros; Title: Analysis of the thermal and fluid-dynamic behaviour of the nacelle and the tower of a wind turbine. Numerical simulation, experimental validation and application to the design of a new wind turbine; Period:2006 – 2008.