Hierarchial control for discrete chiller units
AssigneeCarrier Corporation
InventorsPaul J. Duff, Keith G. Michaelsen
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Abstract
System and process are disclosed for the hierarchial control of a plurality of discrete chiller units each having individual dedicated controls. The system and process imposes limits on the amount of compression that can be demanded by the individual dedicated controls. These limits are selectively changed in response to whether a level of chilling has been collectively achieved. The selective changing of these limits is premised on examinations of each individual chiller unit including the recent history of any changes in compression by the unit.
Claims17
A process for selectively adding or dropping stages of compression within discrete chiller units each chiller unit having a dedicated control unit associated therewith for normally adding or dropping stages of compression in the particular chiller unit, said process comprising the steps of:
- defining a demand limit on the compression capacity in each respective chiller unit that limits the total compressor capacity that may be activated by the dedicated control unit for that respective chiller unit, each dedicated control unit thereafter independently activating stages of compression subject only to the defined demand limit;
- and
- changing the demand limit on the compression capacity of at least one chiller unit when a desired coolant temperature is not being achieved by the collective compression capacity of all discrete chiller units that have been activated by their respective control units whereby the dedicated control unit for that respective chiller unit may thereafter change the number of stages of compression in that respective chiller unit subject to the new demand limit on the compression capacity for that respective chiller unit.
Dependencies are inferred from the claim text.