Start-up of a Test Rig for Organic Vapors

The Test Rig for Organic Vapors (TROVA) represents a novel facility built with the purpose of providing experimental data on the typical expansion ows taking place within organic Rankine cycle (ORC) turbines. The facility has been built at the Fluid-dynamics of Turbomachines Laboratory of Politecnico di Milano (Italy), in collaboration with Turboden s.r.l. [1]. It consists in a blow down facility in which an organic vapour is expanded from a high-pressure reservoir, kept at controlled supeheated or supercritical conditions, into a low-pressure reservoir, where the vapour is condensed and pumped back to the high pressure reservoir. Expansion from subsonic to supersonic speeds occurs through a converging-diverging Laval nozzle, which has been chosen as the test section for initial tests. The test rig can also accommodate liner blade cascade, as it is required by later experiments, and can operate with dierent working uids of interest for ORC applications. Within the test section the ow eld can be characterized by independent measurements of pressure, temperature, and velocity, allowing also to verify the consistency of thermodynamic models currently employed to predict the typical real-gas behaviour of ORC turbine ows. The present paper describes the commissioning of the TROVA, illustrates the test section setup and the adopted measurement techniques, and nally presents the early tests.