Boiler inlet duct shape design optimization for combined cycle power plants
Keywords:
optimización aerodinámica, metodología de optimización, multi-atributo, búsqueda directa híbrida, parametrización geométrica, dinámica de fluidos computacional, calderas generadoras de vapor por recuperación de calor.Abstract
• A particular kind of industrial boilers, referred to as Heat
Recovery Steam Generators (HRSGs), are used in combined
cycle power plants to recover part of the heat of the exhaust
gases of a gas turbine to generate steam and power a steam
turbine. Ever since the use of HRSGs for power plants, the
shape design of the inlet duct at the entrance to these units,
one of their most critical components, has followed greatly
unchanged design guidelines. The contribution of this paper
is twofold: on the one hand, it shows that there is substantial
room for improvement in the shape design of the inlet ducts of
HRSGs, in terms of achieving a lower pressure drop, a higher
velocity uniformity and an important cost reduction of the
unit; on the other hand, it shows how the application of the
Combined Hybrid Direct Search (CHDS) algorithm, applicable in
many fields for aerodynamic shape optimization involving big
displacements, can find these improved designs, which can be
quite unconventional and non-intuitive. The CHDS algorithm
combines genetic, gradient and swarm search intelligence in
every iteration. The results obtained for the two HRSG families
presented show that there are optimum trade-off design points
with simultaneous reductions in pressure drop of up to 20-
25%, in lateral surface of up to 38% and in length of up 16%,
while having comparable velocity uniformities to the existing
designs.
• Keywords: aerodynamic optimization, optimization
methodology, multi-attribute, hybrid direct search, geometry
parameterization, computational fluid dynamics, heat recovery
steam generators
