Absorption chiller control logic
AssigneeCarrier Corporation
InventorNeil Jenkins
Life of this patent
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Abstract
In an absorption chiller system, a control input for the chiller is a heat source controlled by a capacity valve, which is in turn controlled by a PI controller. The controller is controlled by a non-linear control function. During operation, a disturbance in the system is measured. A signal error is defined as a setpoint for the leaving chilled water minus the disturbance. The non-linear control function is represented as C(s)=KP0(1+b|E|)+KI/s, where where KP0 is the gain when said signal error is zero, |E| is the absolute value of the signal error, b is an adjustable constant, and KI is an integral gain.
Claims4
A method for controlling an absorption chiller system, wherein a control input for said chiller is a heat source controlled by a capacity valve, and wherein said capacity valve is controlled by a PI controller, comprising the steps of:
- measuring a disturbance in said system;
- defining a signal error as a setpoint minus said disturbance;
- and
- controlling said capacity valve based on a control function in said PI controller, wherein said control function is represented by C(s)=KP0(1+b|E|)+KI/s, where where KP0 is the gain when said signal error is zero, |E| is the absolute value of the signal error, b is an adjustable constant, and KI is an integral gain.
A control system for an absorption chiller, wherein a control input for said chiller is a heat source controlled by a capacity valve, and wherein said capacity valve is controlled by a PI controller, comprising:
- means for measuring a disturbance in said chiller;
- means for defining a signal error as a setpoint minus said disturbance;
- and
- means for controlling said capacity valve based on a control function in said PI controller, wherein said control function is represented by C(s)=KP0(1+b|E|)+KI/s, where where KP0 is the gain when said signal error is zero, |E| is the absolute value of the signal error, b is an adjustable constant, and KI is an integral gain.
Dependencies are inferred from the claim text.