Mechanical cleaning – AAON RL-240 User Manual
Page 63
63
will be removed when the heat load is less
that design.
The AAON evaporative-cooled condenser is
equipped
with
a
desuperheater.
The
desuperheater coil is located above the
eliminators. Approximately 22% of the total
heat of rejection is accomplished with the
desuperheater. Water usage of the AAON
evaporative-cooled
condenser
is
approximately 22% less than evaporative
condensers
not
equipped
with
a
desuperheater.
One method of calculating evaporation and
bleed in gallons per minute (gpm) is shown
as follows:
Evaporation Rate
=
⁄
⁄
⁄
=
⁄
⁄
Bleed Rate
=
Example:
A unit has 100 ton cooling capacity with a
compressor EER = 15
Total Heat of Rejection
= Unit Capacity in Tons Ч 12000 Ч
(
)
= 100 Ч 12000 Ч
(
)
= 1,473,040 Btu/hr
Total Full Load Heat of Rejection via
Evaporation
= Total Heat of Rejection ×
(1 – fraction of heat rejected by desuperheater)
= 1,473,040 Btu/hr × (1 – 0.22)
= 1,148,971 Btu/hr
Note that approximately 22% of the total heat of
rejection is accomplished with the desuperheater
at full load. So, the fraction of heat rejected by
the desuperheater (in the equation above) is
approximately 0.22 at full load and increases as
the ambient dry bulb decreases.
Evaporation Rate
=
⁄
⁄
⁄
= 2.19 gpm
Assuming 4 cycles of concentration:
Bleed Rate
=
= 0.73 gpm
Mechanical Cleaning
Do not attempt to mechanically clean the
copper tubing in the evaporative-cooled
condenser. Do not use wire brushes or any
other mechanical device on the copper
tubing. Severe damage may result. Contact
your
water
treatment
expert
for