Effects of the system parameters on the extreme low pressure of the draft tube during the successive load rejection using a systematic analysis framework
Energy,
Год журнала:
2025,
Номер
unknown, С. 135130 - 135130
Опубликована: Фев. 1, 2025
Язык: Английский
Numerical study on the transient flow in a six-nozzle Pelton turbine during the load rejection process
Physics of Fluids,
Год журнала:
2025,
Номер
37(4)
Опубликована: Апрель 1, 2025
The
development
of
a
novel
electricity
system
integrating
hydropower,
wind,
solar,
and
energy
storage
requires
enhanced
rapid-response
capabilities
from
hydropower
units,
which
are
expected
to
undergo
prolonged
transitional
processes.
Pelton
turbines,
equipped
with
dual
regulation
comprising
needles
deflectors,
offer
significant
advantages
in
maintaining
stability
during
However,
the
transient
flow
hydrodynamic
characteristics
turbine
load
rejection
remain
inadequately
understood.
This
study
employs
one-dimensional
method
coupled
three-dimensional
computational
fluid
dynamics
numerically
investigate
process
turbine.
results
reveal
that
deflector-jet
interference
causes
pressure
fluctuations
water
supply
system,
maximum
amplitude
reaching
5%
gross
head.
deflector
alters
jet
direction,
simultaneously
exerts
braking
effect
on
runner's
rotation
increase
radial
force
runner,
by
an
order
magnitude.
Moreover,
peak
rotational
speed
runner
observed
at
similar
opening,
independent
initial
closure
scheme.
Язык: Английский
Hydraulic Characteristics of Pumped Storage Units from Startup to No-Load Before Synchronization Based on PID Control
Energy,
Год журнала:
2025,
Номер
unknown, С. 136747 - 136747
Опубликована: Май 1, 2025
Язык: Английский
Energy loss characteristics of pump-turbine from startup to no-load before synchronization based on PID control
Renewable Energy,
Год журнала:
2025,
Номер
unknown, С. 123667 - 123667
Опубликована: Июнь 1, 2025
Язык: Английский
Identification of Single-Blade Angle Variation in Axial Flow Pumps Based on the Variational Mode Decomposition Method
Journal of Marine Science and Engineering,
Год журнала:
2024,
Номер
12(9), С. 1586 - 1586
Опубликована: Сен. 8, 2024
Pressure
pulsations
are
crucial
data
within
the
flow
field
of
a
pump,
and
characteristics
these
can
reveal
changes
in
internal
flow.
Based
on
model
experiments,
this
paper
obtained
pressure
pulsation
under
two
blade
conditions
compared
direct
time-domain
observations,
peak-to-peak
value
changes,
VMD
decomposition
method.
The
results
show
that
even
when
it
is
known
one
condition
has
changed,
not
possible
to
determine
through
observation
changes.
indicate
special
conditions,
they
easily
affected
by
different
operating
which
interfere
with
results.
In
contrast,
method,
decomposes
signal
into
low-frequency
components,
better
display
anomalies
cycle
less
susceptible
interference
offering
some
reference
significance
for
diagnosing
main
pump.
Язык: Английский
Numerical Investigation of Symmetrical and Asymmetrical Characteristics of a Preloading Spiral Case and Concrete during Load Rejection
Symmetry,
Год журнала:
2024,
Номер
16(10), С. 1277 - 1277
Опубликована: Сен. 27, 2024
During
the
transient
process
of
load
rejection,
hydraulic
pressure
applied
to
pump-turbine
and
plant
concrete
changes
dramatically
induces
high
dynamic
stress
on
spiral
case.
The
preloading
case
has
been
widely
used
in
large-scale
pumped-storage
power
stations
due
its
excellent
load-bearing
capacity.
However,
studies
impact
structural
response
during
rejection
are
still
few
number.
In
this
paper,
3D
flow
domain
models
a
prototype
designed
analyze
characteristics
flow-induced
behavior
steel
under
different
pressures
rejection.
results
show
that
asymmetric
design
logarithmic
lines
ensures
an
axially
symmetric
potential
within
with
uniform
distribution.
Higher
provides
larger
clearance,
leading
greater
deformation
stress,
their
maximum
values
located
at
mandoor
inner
edge,
respectively.
combined
effect
asymmetrical
shape,
internal
unbalanced
force
leads
clearance
distribution,
resulting
distribution
along
axial
direction
but
symmetrical
characteristic
near
waistline
response.
Stress
variations
sections
between
share
similar
It
follows
same
trend
as
lower
pressures,
while
there
is
delayed
peak
contact
phenomenon
when
reaches
static
head.
conclusions
provide
scientific
guidance
for
optimizing
selection
stable
operation
units.
Язык: Английский