Patent Application of
William R. Henry
for
TITLE: METHOD TO OPTIMIZE CHILLER PLANT OPERATION
ABSTRACT
A chiller plant which
produces chilled water for airconditioning, or an industrial process and
which is comprised of chillers, cooling fluid pumps, and cooling towers
with electrical motor drives uses a substantial amount of energy. A
method that coordinates the operation of the cooling tower, cooling fluid
pumps, and refrigeration machines so that the chiller plant operates at a
higher overall efficiency thus reducing the power usage has been developed
and is presented herein. The flow rate of the cooling fluid pumps are
controlled to maintain a precise temperature difference across the
refrigerant condenser. The cooling tower fans are controlled by comparing
the cooling fluid temperature and the cooling fluid flow rate to selected
design parameters. The heat rejection rate is measured for each chiller
in the chiller plant and operating set points are established for each
operating chiller to provide the optimum operation for best energy
efficiency.
BACKGROUND - FIELD OF
INVENTION
This invention relates to a
chiller plant, and specifically methods of operation that will reduce the
power usage and improve the plants efficiency.
BACKGROUND - DISCUSSION OF
PRIOR ART.
A chiller
plant as shown in Fig. 1, includes a chiller (5), a cooling fluid pump (1),
a cooling tower (3), and a cooling fluid piping circuit (11) which
interconnects these pieces of equipment. The chiller plant produces a
chilled fluid that is distributed in a chilled fluid piping circuit (12).
The chiller plant may also include a plurality of chillers, pumps, and
cooling towers.