GAS TURBINE COMBINED CYCLE RANGE ENHANCER - PART 2: PERFORMANCE DEMONSTRATION

In the current energy scenario, gas turbine combined cycles (GTCCs) are considered key drivers for the transition towards fossil-free energy production. However, to meet this goal, they must be able to cope with rapid changes of power request, and to extend their operating range beyond the limits imposed by the environmental conditions in which they operate. The European H2020 project PUMPHEAT [1] aims at achieving this goal thanks to the integration of the GTCC with a heat pump (HP) and a thermal energy storage (TES). Both HP and TES are used to condition the air flow at the gas turbine compressor inlet, thus modifying the whole GTCC power output and extending its operative range. To study this setup, a dedicated cyber-physical facility was built at the University of Genova laboratories, Italy. The plant includes physical hardware, such as a 100kWel micro gas turbine, (mGT), a 10 kWel HP and a 180 kWh change phase material-based TES. These real devices are up-scaled thanks to performance maps and real-time dynamic models to emulate a full-scale heavy duty 400 MW GTCC with a cyberphysical approach. The three real key components (mGT, HP and TES) are run in the laboratory. Data collected by various sensors is monitored in real-time and used to feed both the simulated GTCC bottoming cycle model and the four-level control system. The control system determines the optimal configuration of the whole plant and the operative point of the real devices to minimize the mismatch with a real electric power demand curve. With the aim of analyzing the performance of the facility and to assess the potential of the proposed GTCC range enhancer, different operative configurations are tested: one for reducing the power production of the plant below the minimum environmental load (MEL) and two for augmenting the plant maximum power at certain ambient conditions. From the analysis of these tests it is possible to verify the effectiveness of the proposed concept and to characterize the transient behavior of the real components.