Abstract
This paper describes how the performance of chillers can be predicted by the Simple Thermodynamic Model (Gordon-Ng Universal Chiller Model) at steady state conditions that span across assorted coolant temperatures. It focuses on diagnostic capabilities of the simple thermodynamic approach using the published data from a 90-ton centrifugal chiller. Five different types of degrading chiller faults (reduced condenser water flow, condenser fouling, refrigerant overcharge, noncondensable in refrigerant and excessive oil in compressor) were succinctly detected by the model based on physically meaningful parameters of chillers.