Small Decentralized Hydropower Program National ... - Cd3wd.com

con total familiaridad con la operation de1 proyecte,
usualmente un ingeniero o alguna persona que haya
recibido entrenamiento de un ingeniero.
Diseiios de Baja Caida
Los tipos m&s comunes de turbinas de baja caida
son las de helice, de bulbo y tipo a tubo. Se han
desarrollado varios disefios de propiedad de pequenas
unidades bajo particulares marcas de fabricas, pero
en general caen en una de e&as tres categorias. El
generador de llanta es un cuarto tipo que tiene la
ventaja de que la armadura es parte de1 rotor,
eliminando asi un juego de piezas movibles y re-
quiriendo menos espacio que la turbina de tubo y el
generador asociado.
En casi todos 10s cases, una facilidad de baja Ada
sera incorporada en una represa baja. En general, e!
diseiio requerira un vertedero para acarrear el flujo
de 10s desbordes, una casa de maquinas (o por lo
menos un patio de distribution) sobre el cual montar
las unidades y la represa misma. El desaffo de1
diserio consiste en desarrollar un diseno
economicamente factible al mismo tiempo que incor-
pore seguridad.
bulkheads must be provided in order to isolate
the unit during inspection and/or repair. Most
commonly, vertical lift gates are provided on the
upsteam side. Wheel gates will be necessary if
they are to be used for turbine shutoff since
operation will be required under unbalanced
pressure. If flow is controlled by turbine wicket
gates, bulkheads can be installed both upstream
and downstream since they can then be installed
or removed under balanced pressure conditions.
Trashracks which can be cleaned readily must
always be installed upstream from these units.
Velocities through the trashracks should be held
to approximately 1 meter/second. Vibration and
failure through fatigue have been common occur-
rences in these trashracks. Designs can be
developed to prevent vibration as long as flow ap-
proaching the racks is directed normal to the
plane of the rack. A component parallel to the
face of the rack will produce vibration even at
very low velocities. Failure of trashracks can oc-
cur in hours.
Modern designs have been developed to incor-
porate spillways and turbine and generating units
Figura 6 Colocacidn Tipica de la Represa, Vertedero y Casa de Mhquinas’
Figure 6 Typical Layout of a Dam, Spillway, and Powerhouse
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