Method for operating a chiller
AssigneeJohnson Controls Tyco IP Holdings LLP
InventorJeb W. Schreiber
Life of this patent
Estimating the term…
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;
- and
- a controller configured to:
- receive first sensor feedback indicative of a first temperature or pressure of the cooling fluid entering the condenser;
- receive second sensor feedback indicative of a second temperature or pressure of the working fluid exiting the evaporator;
- continuously operate the compressor in response to the first sensor feedback being greater than the second sensor feedback;
- and
- operate the compressor during free-cooling conditions defined by the second sensor feedback being greater than the first sensor feedback.
A chiller system configured to circulate a refrigerant through a refrigerant circuit and to place the refrigerant in thermal communication with a cooling fluid and with a working fluid, the chiller system comprising:
- a first sensor configured to provide first feedback indicative of a first temperature or pressure of the cooling fluid entering a condenser of the chiller system;
- a second sensor configured to provide second feedback indicative of a second temperature or pressure of the working fluid exiting an evaporator of the chiller system;
- and
- a controller communicatively coupled to the first sensor and the second sensor, wherein the controller is configured to continuously operate a compressor of the chiller system 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, cause the processor to:
- receive first feedback indicative of a first fluid characteristic of a cooling fluid entering a condenser;
- receive second feedback indicative of a second fluid characteristic 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;
- and
- operate the compressor during free-cooling conditions defined by the second feedback being greater than the first feedback.
Dependencies are inferred from the claim text.