Cooling
Ponds
and
Cooling
Towers
The cooling water system is one of the most important system of power plant apd its availability predominantly decides the plant site.
The
cooling
water
requirement
in
an
open
system
is
about
50
times
the
flow
of
steam
to
the
condenser.
Even
with
closed
cooling
system
using
cooling
towers,
the
requirement
for
cooling
water
is
also
considerably
large
as
5
to
8
kg/kw-hr.
This
means
a
1000
MW
station
will
require
about
100
thousand
tons
of
circulating
water
per
day
even
with
the
use
of
cooling
towers.
This
huge
requirement
of
cooling
water
is
equivalent
to
a
requirement
of
big
city
like
Bombay.
As
the
cooling
water
takes
the
latent
heat
of
steam
in
the
condenser,
the
temperature
of
the
water
increases.The
hot
water
coming
out
the
condenser
cannot
be
used
again
in
a
closed
system
without
pre
cooling.
This
is
because,
the
hot
water
coming
out
if
used
again
will
not
be
able
to
absorb
the
heat
as
reaches
near
to
saturation
temperature
of
steam
at
condenser
pressure
and
the
condenser
vacuum
cannot
be
maintained.
Therefore
it
is
absolutely
necessary
to
pre
cool
the
water
coming
out
of
condenser
before
using
again
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