Cooling water process control system

Abstract

A cooling system uses a closed circuit cooling tower in series with a chiller to either lower the chiller operating point or completely cool the chill water without use of the chiller, depending on weather conditions. The process and system expands the entire function of the cooling process with a control system design that examines the power consumed by all the devices of the system, the actual load being introduced into the system, water temperatures, and weather conditions, and makes decisions based on performance criteria through the control device's program algorithms.

What is claimed is: 
     
         1 . A cooling system comprising:
 one or more chillers;   one or more closed circuit cooling towers in series with the one or more chillers; and   a controller operable to utilize the closed circuit cooling towers as a pre-cooling device to lower an operating point by reducing a heat load to the one or more chillers, the controller further operable to use only the one or more closed circuit cooling towers, shutting down the one or more chillers, when the heat load can be removed by the one or more closed circuit cooling towers.   
     
     
         2 . The cooling system of  claim 1 , further comprising a plurality of actuator driven valves receiving commands from the controller to control flow of condenser fluid and chill fluid through the cooling system. 
     
     
         3 . The cooling system of  claim 1 , wherein the controller receives input from a plurality of sensors to determine an operation state that provides optimal energy efficiency. 
     
     
         4 . The cooling system of  claim 1 , wherein the plurality of sensors include wet bulbs, entering and leaving water temperature sensors, pressure differential sensors, and weather condition sensors. 
     
     
         5 . A method for operating a cooling system, comprising:
 utilizing one or more closed circuit cooling towers in one of three operation states, a first operation state where the closed circuit cooling tower is used as a pre-cooling device to lower an operating point by reducing a heat load of chill water to one or more chillers, a second operation state where the closed circuit cooling tower is used to remove the heat load from chill water and the chill water is used directly to a load, without using the one or more chillers, and a third operation state where the closed circuit cooling tower is used to adjust water flow to have the cooling tower create a false load, allowing the one or more chillers to be adjusted to a less kilowatt per ton (kW/T) operating point; and   controlling the operation state of the one or more chillers with a controller.   
     
     
         6 . The method of  claim 5 , further comprising controlling a plurality of actuator driven valves that receive commands from the controller to control flow of condenser fluid and chill fluid through the cooling system. 
     
     
         7 . The method of  claim 5 , further comprising receiving input from a plurality of sensors to determine an operation state that provides optimal energy efficiency. 
     
     
         8 . The method of  claim 7 , wherein the plurality of sensors include wet bulbs, entering and leaving water temperature sensors, pressure differential sensors, and weather condition sensors.