Minimum Water Loop Volume For Comfort Application - Trane AquaStream2 CGAN 200 Installation Operation & Maintenance

Table 8 - Minimum water loop volume for comfort application
CGAN
CXAN
200
Water volume (l) 250
At Eurovent conditions
CG-SVX01C-E4
Installation
Minimum water volume for a
process application or for a chiller
which has to run with low ambient
temperature option.
For Process application we have to
minimize the water temperature
fluctuation at part load. In order to
avoid problem on a scroll or a
hermetic reciprocating compressor it
must run at least 2 minutes
(120 seconds) before it stops and the
minimum time between two starts is
5 minutes (300 seconds).
The water volume has to be able to
provide the cooling capacity while
the unit is shut down.
The minimum volume can be
determined by using the following
formula
Volume = Cooling capacity x Time x
highest capacity step (%) / Specific
heat / Dead band
With these values the formula
becomes
Volume = Cooling capacity X 9.56 x
highest capacity step (%)
For the CGAN running in following
conditions: Air temperature 35°C,
water 12/7°C, this gives the following
volumes. If the total water volume of
the installation is below the above
mentioned values it is necessary to
use a buffer tank.
CGAN CGAN CGAN
CXAN CXAN CXAN
250 300 400
360 360 610
CGAN CGAN CGAN
CXAN CXAN CXAN
450 490 500
640 620 370
Minimum time = 180 seconds
(300-120)
Specific heat =4.18 kJ / kg
Dead band recommended =
Function of the process
With these values the formula
becomes:
Volume = Cooling capacity x 43 x
highest capacity step (%) / Dead
band
Increasing the dead band is like
adding water volume to the loop.
CGAN CGAN CGAN
CXAN CXAN CXAN
600 700 800
370 500 650
CGAN CGAN
CXAN CXAN
900 925
760 630
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