Centrifugal chillers: thermodynamic modelling and a diagnostic case study.

The diagnostic capability of a simple thermodynamic model for chiller performance is illustrated by a case study for a commercial, installed centrifugal chiller. Performance data were measured both prior to, and subsequent to, chiller maintenance that improved chiller efficiency. Using these experimental measurements, the authors show that the simple thermodynamic model, originally developed for reciprocating and absorption chillers, succeeds in predicting the fundamental relation between COP and cooling rate for the centrifugal chiller, and permits a clear diagnostic analysis of heat exchanger fouling on chiller performance.