Experimental Dynamic Analysis on a T100 Microturbine Connected With Different Volume Sizes

This paper shows experimental results obtained from a T100 microturbine connected with different volume sizes. The activity was carried out with the test rig developed at the University of Genoa for hybrid system emulation. However, these results apply to all the advanced cycles where a microturbine is connected with an additional external component responsible for volume size increase. Even if the tests were performed with a microturbine, similar analyses can be extended to large size turbines. A modular vessel was used to perform and to compare the tests with different volume sizes. To highlight the volume size effect, preliminary experimental results were carried out considering the transient response due to an on/off bleed valve operation. So, the main differences between system parameters obtained for a bleed line closing operation are compared considering three different volume sizes. The main results reported in this paper are related to surge operations. To produce surge conditions in this test rig, a valve operating in the main air path was closed to generate unstable behavior for the three different volume sizes. Particular focus was devoted to the operational curve plotted on the compressor map. The vibration frequency analysis showed significant amplitude increase not only during surge events but also close to the unstable condition. In details, possible surge precursor indicators were obtained to be used for the detection of risky machine operations. The experimental data collected during these tests are analyzed with the objective of designing control systems to prevent surge conditions.