Predictive and diagnostic aspects of a universal thermodynamic model for chillers

Abstract

There are fundamental aspects of chiller behavior—characterized by the chiller coefficient of performance as a function of cooling rate and coolant temperatures—that pertain to all refrigeration devices. We review, further develop, and validate against extensive experimental measurements a simple thermodynamic model that captures the universal aspects of chiller behavior. The model provides a procedure for predicting chiller performance over a broad range of operating conditions from a small number of selected measurements, as well as a diagnostic tool. The accuracy of the model is illustrated for reciprocating, centrifugal and absorption chillers. Universal aspects of chiller behavior are further illustrated with less conventional small-scale cooling devices such as thermoacoustic and thermoelectric chillers.