Near optimization of cooling tower condenser water
AssigneeAmerican Standard Inc.
InventorsMichael C. A. Schwedler, Jon R. Hage, Dennis R. Dorman, Michael J. Stiyer
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Abstract
A method of minimizing energy use in a chiller and cooling tower system is disclosed. The method comprises the steps of: determining a measure of chiller efficiency; determining a measure of cooling tower efficiency; determining a measure of the transfer rate of heat energy between the cooling tower and the chiller; calculating a near optimal water temperature as a function of the chiller work efficiency, the cooling tower efficiency and the transfer rate; and operating the cooling tower to provide a conditioned fluid at the temperatures to produce near optimal energy consumption.
Claims25
A method of minimizing energy usage in a chiller and cooling tower system which uses a temperature conditioned fluid to exchange heat energy between the chiller and the cooling tower system comprising the steps of:
- determining a measure of chiller efficiency;
- determining a measure of cooling tower efficiency;
- determining a measure of the transfer rate of heat energy between the cooling tower and the chiller;
- calculating a near optimal water temperature as a function of the chiller work efficiency, the cooling tower efficiency and the transfer rate;
- and
- operating the cooling tower, responsive to the near optimal water temperature, to provide the temperature conditioned fluid at the near optimal temperature.
An energy efficient air conditioning system comprising:
- a load;
- a chiller for providing a conditioned fluid to control the temperature of the load;
- a chiller controller operating the chiller to maximize energy efficiency for a particular load;
- a cooling tower for transferring heat energy between ambient air and a heat transfer fluid;
- a fluid conduit carrying the heat transfer fluid and interconnecting the cooling tower and the chiller;
- a sensor for sensing the temperature of the heat transfer fluid in the cooling tower;
- a fluid temperature selector, responsive to the load and ambient conditions, for determining a near optimal fluid temperature for the fluid in the fluid conduit;
- and
- a cooling tower controller responsive to the fluid temperature selector and the fluid temperature sensor for operating the cooling tower to maximize energy efficiency.
A method for minimizing ongoing energy costs for a chiller plant comprising the steps of:
- determining actual and design loads for operational chillers in the chiller plant;
- calculating a weighted ratio for the operative chillers;
- selecting empirical constants for the operating chillers;
- calculating a near optimal temperature for cooling tower condenser water;
- controlling cooling tower fans to maintain the cooling tower condenser water supply at the calculated near optimal temperature;
- and
- operating the operating chillers to maximize their efficiency for user selected setpoints.
A method of optimizing energy usage in an air conditioning system comprising the steps of:
- calculating a near optimal condenser water temperature;
- operating a cooling tower to maintain the calculated near optimal temperature;
- circulating water cooled to said near optimal temperature from the cooling tower to a chiller;
- and
- operating the chiller to maintain a evaporator water temperature and to optimize the chiller energy efficiency.
Dependencies are inferred from the claim text.