An advanced surge dynamic model for simulating ESD events and comparing different anti-surge strategies

Despite advancements in research and industry,compressors still have to operate in the stable region of thecharacteristic curves otherwise, at low flow ranges, they enteran unstable regime. The worst instability that can arise inindustrial compressors is called surge, which involves the wholesystem in view of the fact that it generates dangerous pressureand mass flow fluctuations. Thus, this phenomenon has to beprevented since it implies the deterioration of performance andleads to mechanical damage to the compressor and systemcomponents.It is clear that, currently, compression system models havea crucial role in predicting the phenomena which can occur inthe compressor and pipelines during operation.In this paper, a dynamic model, developed in theMatlab/Simulink environment, is further implemented to allowthe study of surge events caused by rapid transients, such asemergency shutdown events (ESD). The aim is to validate theexperimental data obtained in a single stage centrifugalcompressor installed in the test facility at Southwest ResearchInstitute. The test facility consists of a closed loop system and ischaracterized by a recycling circuit, and thus a recycling valve,which is opened in case of surge or driver shutdown. In thiswork, the recycling circuit is implemented in the model as well,and comparisons between recorded data and simulations werecarried out. Moreover, different actions forrecovering/preventing surge are simulated by controllingdifferent valves along the piping system and by adding a checkvalve immediately downstream the compressor.The results demonstrated the fidelity of the model and itscapability of simulating piping systems with differentconfigurations and components, also showing, qualitatively, thedifferent effects of some alternative actions which can be takenafter surge onset.