Predictive and diagnostic methods for centrifugal chillers

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, non-condensable in refrigerant and excessive oil in compressor) were succinctly detected by the model based on physically meaningful parameters of chillers. ©2008 ASHRAE.