Caracterización y modelización de un expansor scroll de pequeña potencia. Integración en sistemas de absorción para producción de energía mecánica y refrigeración

Identifier:  TDX:1247

Handle: https://hdl.handle.net/20.500.11797/TDX1247

Authors:  Mendoza Toledo, Luis Carlos

Abstract:
This thesis presentsthe theoretical and experimental study of a small scroll expander, commerciallyavailable as a compressor, in order to integrate it into absorption systems forthe production of mechanical energy. The expander was characterized with airand ammonia to determine its performance at different operational conditions.Then the expander was modelled to predict its performance assuming that thefluid that enters into the expander carries out an isentropic expansion processfollowed by an adiabatic isochoric process. The leaks are modelled as anisentropic flow through a converging nozzle. The model calculates the netmechanical power, mass flow rate and the exhaust temperature from the supplypressure and temperature, pressure ratio and rotational speed, with a maximumdeviation between the calculated and measured variables for ammonia from ±9%,±5% and ±4 K, respectively. Also the expander model was used to calculatethe performance of other expanders of the same type but with a highervolumetric displacement (TRSA09 and TRSA012). Finally, it was performed a studyabout the integration of expansion system in absorption refrigeration systemsusing three working mixtures: ammonia/water, ammonia/sodium thiocyanate andammonia/lithium nitrate. These systems can produce up to about 29 kW ofmechanical power and 29 kW of cooling capacity at desired proportions from heatsources at low temperatures, from 80 to 130 °C and cooling at temperatures upto -10 °C.