The exploitation of low grade thermal sources is recognized as a feasible strategy in order to pursue the primary energy saving target worldwide. This concept, adaptable to a number of different applications, is aimed at exploiting low-value heat fluxes that would be wasted otherwise; additional useful electric power can be produced locally, with ORC energy systems; this is one of the most promising heat recovery solutions. In particular, the paper refers to the test bench developed in the laboratories of the University of Bologna; a prototypal micro-ORC energy system is here investigated. The micro-ORC system presents a reciprocating three-piston expander operated with refrigerant fluid. Heat is provided to the ORC from via hot water at low temperature, in order to simulate a constant low-enthalpy heat recovery process. The system rejects unused heat via a water-cooled condenser, dependent on the external ambient conditions. The test bench layout and the real-time data acquisition system, developed in the LabVIEW environment, are here described. In particular, the paper focus is on the system steady-state detection methodology. Starting from an experimental campaign, steady-state operational points are identified through an appropriate literature approach. The measured quantities and calculated performance have been post-processed in order to evaluate the influence on steady state detection, of different hot source temperature set points. Moreover, the selected steady-state detection method is suitable for real-time implementation, due to its simple formulation and the low number of variables required to be stored at time step of acquisition.

Experimental Investigation with Steady-State Detection in a Micro-ORC Test Bench

Bianchi, M.;Branchini, L.;De Pascale, A.;Ottaviano, S.;Peretto, A.;Melino, F.;
2017

Abstract

The exploitation of low grade thermal sources is recognized as a feasible strategy in order to pursue the primary energy saving target worldwide. This concept, adaptable to a number of different applications, is aimed at exploiting low-value heat fluxes that would be wasted otherwise; additional useful electric power can be produced locally, with ORC energy systems; this is one of the most promising heat recovery solutions. In particular, the paper refers to the test bench developed in the laboratories of the University of Bologna; a prototypal micro-ORC energy system is here investigated. The micro-ORC system presents a reciprocating three-piston expander operated with refrigerant fluid. Heat is provided to the ORC from via hot water at low temperature, in order to simulate a constant low-enthalpy heat recovery process. The system rejects unused heat via a water-cooled condenser, dependent on the external ambient conditions. The test bench layout and the real-time data acquisition system, developed in the LabVIEW environment, are here described. In particular, the paper focus is on the system steady-state detection methodology. Starting from an experimental campaign, steady-state operational points are identified through an appropriate literature approach. The measured quantities and calculated performance have been post-processed in order to evaluate the influence on steady state detection, of different hot source temperature set points. Moreover, the selected steady-state detection method is suitable for real-time implementation, due to its simple formulation and the low number of variables required to be stored at time step of acquisition.
Bianchi, M.; Branchini, L.; De Pascale, A.; Orlandini, V.; Ottaviano, S.; Peretto, A.; Melino, F.; Pinelli, M.; Spina, P. R.; Suman, A.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/619914
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 5
  • ???jsp.display-item.citation.isi??? 5
social impact