The SERG group is involved since many years in the analysis, design and testing of microexpanders for distributed power generation, with special reference to low-temperature thermal energy conversion (solar, geothermal, industrial and residential heat recovery applications).
The modeling capabilities include most types of volumetric expanders (scroll, piston with crank mechanism, rolling vanes,...) and miniature radial inflow turbines (power range from 1 kW to 50 kWe). Recently the models have been extended to liquid expanders for pressure recovery in refrigeration systems and heat pumps (volumetric radial piston engine), and a test bench has been installed in the LINEA Laboratory of PIN in Prato.
A short summary is presented.