Method for operating a chiller
AssigneeJohnson Controls Technology Company
InventorJeb W. Schreiber
Life of this patent
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Abstract
A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.
Claims20
A chiller system, comprising:
- a compressor configured to circulate a refrigerant through a refrigerant circuit;
- a condenser configured to place the refrigerant in thermal communication with a cooling fluid;
- an evaporator configured to place the refrigerant in thermal communication with a working fluid;
- a first sensor configured to provide first feedback indicative of a first temperature of the cooling fluid entering the condenser;
- a second sensor configured to provide second feedback indicative of a second temperature of the working fluid exiting the evaporator;
- and
- a controller communicatively coupled to the first sensor and the second sensor, wherein the controller is configured to compare the first feedback to the second feedback, to continuously operate the compressor in response to the first feedback being greater than the second feedback by a predetermined amount, to continuously operate the compressor in response to the first feedback and the second feedback being substantially equal to one another, and to operate the compressor at a minimum speed during free-cooling conditions defined by the second feedback being greater than the first feedback.
A chiller system, comprising:
- a compressor configured to circulate a refrigerant through a refrigerant circuit;
- a condenser configured to place the refrigerant in thermal communication with a cooling fluid;
- an evaporator configured to place the refrigerant in thermal communication with a working fluid;
- a first sensor configured to provide first feedback indicative of a first temperature of the cooling fluid entering the condenser;
- a second sensor configured to provide second feedback indicative of a second temperature of the working fluid exiting the evaporator;
- and
- a controller communicatively coupled to the first sensor and the second sensor, wherein the controller is configured to continuously operate the compressor in response to the first feedback being less than the second feedback.
A control system comprising memory configured to store instructions executable by a processor, wherein the instructions, when executed by the processor, are configured to:
- receive first feedback indicative of a first temperature of a cooling fluid entering a condenser;
- receive second feedback indicative of a second temperature of a working fluid exiting an evaporator;
- compare the first feedback to the second feedback;
- continuously operate a compressor in response to the first feedback being greater than the second feedback by a predetermined amount;
- continuously operate the compressor in response to the first feedback and the second feedback being substantially equal to one another;
- and
- operate the compressor at a minimum speed during free-cooling conditions defined by the second feedback being greater than the first feedback.
Dependencies are inferred from the claim text.