CONSTRUCTION AND EXPERIMENTAL INVESTIGATION OF AN ORC PLANT WITH DIFFERENT WORKING FLUIDS
Ebrahim Aeini, Stephan Kabelac, Xing Luo
Session: Poster session & Welcome drinks
Session starts: Wednesday 13 September, 17:30
Ebrahim Aeini (Institute of Thermodynamics, Leibniz University Hanover)
Stephan Kabelac (Institute of Thermodynamics, Leibniz University Hanover)
Xing Luo (Institute of Thermodynamics, Leibniz University Hanover)
The Organic-Rankine cycle (ORC) is a challenge for thermal scientists, as many different disciplines are involved, such as thermodynamics, cycle optimization, fluid property data, heat transfer, expansion power machinery and also model control strategies. The classical Clausius-Rankine cycles using water as a working fluid become less important on the global decarbonization road map, but the ORC is gaining importance and attention on this future development.
A series of experimental and theoretical investigations are carried out at an ORC test facility at the Institute of Thermodynamics of the Leibniz University of Hanover. This test rig is designed for an electric power output of 5-10 kW powered by an electric heated thermal oil circuit of 60 kW thermal power at temperatures between 150 °C< T_input <250 °C . The facility consists of a welded heat plate exchanger use as an evaporator, a rotary piston expander, a centrifugal pump and two other heat plate exchangers, which are used as a recuperator and as a condenser. The recuperator can be selectively used or deactivated depending on the chosen operating condition. In addition, it is possible to connect a subcooler into the circuit in order to decrease the temperature of the working fluid behind the condenser. In the experimental investigations the refrigerants SES36 and Solkane R365mfc are used as a working fluid. The thermal energy is removed from the system by a water cooling circuit.
The properties of the main components (heat exchanger, expander and pump) in stationary operation were modeled and compered to experimental data. Based on this stationary simulation, the feasible operating conditions and corresponding efficiencies were analyzed and discussed. The simulation show the strong influence of the recuperator on the electrical output power and the efficiency of the process.
These effects were confirmed by experimental investigations, the increase of the efficiency and the electrical output power are dependent on use of recuperator. Overall, it is attempted to find an optimal operating point in which a maximum electrical output or an optimum efficiency can be achieved.
The simulations have the aim of mapping the operational performance of the system by changing system parameters, for example with a change in the temperature of the waste heat flow or a change in the system pressure. The simulation was validated by means of experimental data and good correlations for both the individual apparatus involved and the overall cycle could be achieved. The contribution will introduce the test facility and will report on the experimental data gained from this device. The simulation results will be compared to the experimental data.