Brine Application; Chilled Water; Condenser Water - York YK Manual

Application Data (Cont'd)
JOHNSON CONTROLS
Chilled Water – A water strainer of maximum 1/8" (3.2 mm) perforated holes must be
field-installed in the chilled water inlet line as close as possible to the chiller. If located
close enough to the chiller, the chilled water pump may be protected by the same strainer.
The strainer is important to protect the chiller from debris or objects which could block flow
through individual heat exchanger tubs. A reduction in flow through tubes could seriously
impair the chiller performance or even result in tube freeze-up. A thermal-type flow switch
is factory installed in the evaporator nozzle and connected to the OptiView™ panel, which
assures adequate chilled water flow during operation.
Condenser Water – The chiller is engineered for maximum efficiency at both design and
part load operation by taking advantage of the colder cooling tower water temperatures
which naturally occur during the winter months. Appreciable power savings are realized
from these reduced heads.
The minimum entering condenser water temperature for other full and part load conditions
is provided by the following equation:
Min. ECWT = LCHWT – C RANGE + 5°F + 12
Min. ECWT = LCHWT – C RANGE + 2.8°C + 6.6
where:
ECWT = entering condensing water temperature
LCHWT = leaving chilled water temperature
C RANGE = condensing water temperature range
at the given load condition.
At initial startup, entering condensing water temperature may be as much as 25°F (13.9°C)
colder than the standby chilled water temperature.
BRINE APPLICATIONS
Various types of brine can be used in both the evaporator and condenser in lieu of wa-
ter. The OptiView™ Control panel is programmed in the factory to allow extending the
evaporator leaving brine temperature setpoint below 36°F (2.2°C). The low evaporator
pressure cutout is factory programmed to the appropriate value depending on the percent
(%) concentration and type of brine solution.
When the chiller is not running, brine should not be run through the evaporator. However,
if there is brine running through the evaporator, there must be flow through the condenser
to prevent tubes from freezing. In brine applications the condenser pump control will
close when the condenser saturation temperature reaches 35°F (1.7°C) and the pump
will shut off when the temperature increases to 40°F (4.4°C). This is applicable if tied to
the condenser pump control.
(
%Load
100
or
(
FORM 160.75-EG1 (519)
)
)
%Load
100
41