Modification and Validation of a Universal Thermodynamic Chiller Model Used to Evaluate the Performance of Water-Cooled Centrifugal Chillers

Abstract

This paper presents modifications made to the procedure used to develop a universal thermodynamic model of chillers (Gordon and Ng, 1995). The modifications were necessary to capture physical phenomena involved when water is the coolant fluid at the condenser. The model was developed as a tool for analyzing chiller performance. It was designed to predict the coefficient of performance (COP) and the total electrical energy consumed by the compressor. The input parameters included time-series values of condenser temperatures, evaporator temperatures, and evaporator loads. The modifications were validated with data from monitoring two chillers operating at two institutional campuses: one a South Texas high school, and the other, a Northwest Arkansas university. The results showed that the average steady-state measured and predicted parameters differed by no more than 2 percent. This paper presents a literature review, model development, experimental set-ups. results, and summary and conclusions.