control or factory automation with centralized control
of an entire facility provide benefits not possible with
only local machine controllers. The following is an example
of plant control developed by Antronics.
refrigerated storage facilities are typically large plants with
many cold storage rooms and one or more engine rooms. The continuous
operation of the equipment required to maintain refrigerated
storage conditions make it an ideal plant-wide computerized
centralized control system can monitor the demand and raise
or lower engine room suction pressure dynamically to match the
need for refrigerant. Centralized control also means that the
computer can determine the optimum compressor loading to maintain
the current suction pressure set point. This not only makes
maintaining temperatures with a higher degree of accuracy easier,
but also saves money by reducing electrical energy consumption.
savings can be achieved matching discharge pressure set point
to current atmospheric conditions (humidity and temperature)
instead of using pressure switches. And like engine room compressors,
condenser fans and pumps can be matched to meet load conditions.
Adding variable frequency drives to condenser fan motors can
increase savings even further.
a centralized control system defrost times are easily coordinated
to insure that water supply, water temperatures, and refrigeration
loads are all managed as desired. Keeping track of refrigerant
float valve activity on each refrigeration zone also makes it
easier for operators to find and resolve flood back problems.
Further energy savings can be realized by adding variable frequency
drives to evaporator coil fan motors and letting the computer
control them in conjunction with the back pressure regulators
as temperatures move off of set points.
one place to view conditions throughout the plant, daily reports
and historical data makes monitoring and maintaining this type
of facility much easier.
here for a summary of these and other benefits of computerized
control for refrigeration facilities.