102 TRG-TRC016-EN
notes
period four
Chiller-Plant Control
ASHRAE Guideline 3, Reducing Emission of Halogenated Refrigerants in
Refrigeration and Air Conditioning Equipment and Systems, includes a list of
recommended data points to be logged daily for each chiller. Much of this data
may be available from the display on the chiller control panel. It is also helpful
to the operator if this information is available at the chiller-plant control system
and presented in a clear format.
In addition to current status, historical operating information is valuable for
keeping the equipment operating at peak efficiency and for identifying
operating trends that signal either impending problems or a drop in system
performance. For example, the condenser approach temperature is the
temperature difference between the water leaving the condenser and the
refrigerant inside the condenser. If there has been a problem with water
treatment in the cooling tower, fouling may build up inside the tubes in the
chiller condenser. This will cause the difference between the condenser water
and refrigerant temperatures to increase, reducing chiller efficiency. By noting
an increase in this approach temperature, the operator can schedule cleaning of
the condenser tubes. By monitoring system and equipment trends, the operator
has a chance to fix minor issues before they cause operational problems.
chiller operating log
ASHRAE Guideline 3
▲ Chilled-water inlet and outlet
temperatures and pressures
▲ Chilled water flow
▲ Evaporator-refrigerant
temperature and pressures
▲ Evaporator approach
temperature
▲ Condenser-water inlet and
outlet temperatures and
pressures
▲ Condenser water flow
▲ Condenser-refrigerant
temperature and pressures
▲ Condenser approach
temperature
▲ Compressor-refrigerant suction
and discharge temperatures
▲ Oil pressures, temperature, and
levels
▲ Refrigerant level
▲ Vibration levels
▲ Addition of refrigerant or oil
Figure 110
