METHOD AND APPARATUS FOR CAPACITY VALVE CALIBRATION FOR SNAPP ABSORPTION CHILLER

摘要

Data points are determined for an absorption chiller system which relate a position of the capacity valve to the heat input into the system. A continuous curve is determined which estimates the relationship between the position of the capacity valve and the heat input for all of the data points and all the points in between. The slope of this curve is the valve gain. The error for the system is defined as the difference between the setpoint and the leaving chilled water temperature. The leaving chilled water temperature of the system is measured to determine the actual error for the system, after which a linearizing gain derived as a function of the inverse of the valve gain is used in the system control algorithm to linearize the overall valve gain, thereby eliminating capacity valve hunting and producing an improved transient response.