Boiler
Waste
Heat
Recovery
The present escalating costs of fossil fuels and electric power are forcing plant operators to examine the potential saving and to reduce fuel and power uses. The need for energy recovery from low and medium heat sources has gained importance due to increasing price trend of the fossil fuels.
In
the
industrial
community
millions
of
Kcals
of
heat
are
loss
for
ever
each
day.
such
waste
heat
is
typically
in
the
form
of
un
burnt
but
combustible
waste
materials,
sensible
and
latent
heat
exhausted
from
stacks.
Waste
heat
recovery
is
of
prime
importance
to
the
efficient
use
of
energy
in
the
industrial
processes
Although,
present
waste
heat
recovery
systems
have
been
non
storage
type,
future
trend
may
well
see
a
significant
increase
in
the
use
of
thermal
energy
storage.
This
will
be
necessary
in
order
to
expand
the
rational
usage
of
large
waste
heat
to
match
temporarily
the
cyclic
variations
and
to
permit
the
possibility
of
energy
cascading
and
storage
to
overcome
imbalance
in
plant
systems.
Recovery
of
heat
exhaust
from
industrial
processes
and
combustion
equipment
can
often
reduce
fuel
consumption
and
improve
thermal
efficiency
markedly.
It
may
be
used
to
generate
steam,
to
heat
air
or
water
or
fuel
depending
on
the
temperature.
pressure
and
flow
rate
of
the
exhaust.
When
the
temperature
of
the
waste
gas
exceeds
300"C. steam generation becomes most economic method of heat recovery.
Because of the growing quantities of waste heat discharged and increasing ecological concern with energy growth, energy utilization and thermal discharge problems have stimulated an examination of methods for using energy presently wasted to the environment.
In
this
regard,
ineffective
utilization,
of
energy
is
building
and
industrial
processes
constitute
a
major
component
of
the
national
energy
problem.
All
the
available
waste
heat
appears
as
low
temperature
heat.
However,
the
term
utilization
of
waste
heat
refers
to
the
performance
of
useful
functions
with
heat
before
it
is
discharged
to
the
environment.
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