KHIN MAUNG AYEMECHANICAL & PRODUCTION ENGINEERING2020-09-102020-09-101999KHIN MAUNG AYE (1999). THERMODYNAMIC MODELING OF CENTRIFUGAL CHILLERS. ScholarBank@NUS Repository.https://scholarbank.nus.edu.sg/handle/10635/175658In this project, a simple thermodynamic model is developed for analysing centrifugal chillers operating in full-load and part-load conditions. Part-load operation of chillers is a significant feature of centrifugal chiller plants, which requires careful analysis so that optimum performance can be achieved. Applying the First and Second Laws of Thermodynamics, heat transfer laws and working principles of the chiller's components, a simple but yet accurate thermodynamic model is derived. It provides a linear relation between the coefficient of chiller performance (COP) and the cooling rate (Qc) in part-load conditions. The model is validated against experimental results of the chillers, which are measured in-situ at the Faculty of Medicine at the National University of Singapore. The chiller plant is totally controlled by a Building Automation System (BAS), and comprises four units of centrifugal chillers (two chillers of 900 RT each and the other two of 450 RT each). They are configured to operate in parallel and can be scheduled to operate efficiently by the BAS, simply by matching the cooling load demanded from the air-conditioning system. Only steady state performances from the measurements are considered. The results show that the predictions fit reasonably well with experimental data within experimental errors of 5%. The performance data illustrate the usefulness of the model in terms of the predictive and diagnostic capabilities.Thesis