Modelling of In-Situ Liquid Chillers

This paper presents an overview of various simulation techniques that may be useful for predicting the in-situ (dynamic) performance of vapour-compression liquid chillers over a wide range of operating conditions. Four models were considered namely steady-state and transient physical models, and steady-state and transient neural network models. Typical real-time operating data taken under various conditions including start-up, quasi-static and modulating operation were used as input to the four models. The predicted performance was then compared to the experimental data to see under what conditions each model may be suitably applied. It was found that steady-state models can give fairly accurate results under quasi-dynamic conditions with the dynamic models performing better under strongly dynamic conditions such as start-up, shutdown, and during sudden changes in load condition.