METHOD TO OPTIMIZE CHILLER PLANT OPERATION

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.