WP3– Bladeless expander for small scale sCO2 applications (lead UNIFI)
WP3 aims to investigate an innovative bladeless turbomachinery solution for small-scale sCO2 cycle applications (0.1-1 MWe), leveraging from the already developed know-how on Tesla turbines designed for two-phase and ORC applications, developed by (UNIFI, UNIGE).
In T3.1, in order to fully understand the potential of the Tesla turbine for sCO2 applications, the fluid dynamic assessment of the expander will be investigated, basing on operating points defined in WP1. 1D to 3D high fidelity models (i.e. using EES, Matlab-Python, Fluent, CFX, etc.) will be developed or improved from existing ones, with transfer of knowledge and methods from WP2 (POLIMI). The component models will be developed in order to define the Tesla expander optimal geometry, its on-design performance as well as off-design maps. Basing on T3.3 results, the performance models will be validated, for future design applications.
In T3.2, the adaptation of an already existing sCO2 test bench present at UNIFI premises will be carried out by UNIFI and in parallel, the modification of a sCO2 Tesla turbine prototype provided by UNIGE will be done in order to properly integrate the turbomachinery within the test bench. The integrated test rig will allow reaching the desired conditions at turbine inlet of about 100 bar and 100°C, with outlet at approx. 40bar. Flowrate, temperature, and pressure of the sCO2 at various significant sections will be measured. Preliminary start-up of the test bench coupled with the Tesla turbine prototype will be done in order to assure the stability of the system.
In T3.3, the Tesla bladeless expander prototype (UNIGE) for sCO2 will be finally run into the UNIFI CO2 test rig, providing a unique reference in the Italian and EU panorama for such kind of expander. The main outcome of this task will be the proof of concept of the bladeless expander technology in the kW power range, reaching TRL 4. The experimental results will be used also for validation of the performance models of T3.1, as well as plant thermo-economic models of T1.1.