Performance map analysis of a solar-driven and fully unfired closed-cycle micro gas turbine, F. Rovense, A. Sebastián, R. Abbas, M. Romero, J. González-Aguilar, Energy, 263, 125778, 2023, Online version, https://doi.org/10.1016/j.energy.2022.125778

Abstract

This work deals with the performance maps analysis of an unfired micro gas turbine (MGT) integrated in a Concentrating Solar Power plant aimed at polygeneration applications. Particularly, this contribution explores the applicability of a MGT in a closed and unfired power cycle driven by a mass flow rate regulation system. The new layout and the system components pressure drops determine the variation of the nominal MGT working points; for that both the influence of the new operating conditions and that of the pressure drops on engine performance were analyzed. Three operational strategies were considered in which the pressure drops have been set. Furthermore, the recuperator design has been carried out and its off-design map has been obtained. The commercial MGT data were assumed, supposing it operates in a pressurized cycle with a limited turbine inlet temperature. The results show that by increasing the inlet pressure within the machinery it is possible to achieve, in highly constrained conditions, a power of almost 500 kW_e with an efficiency of 32%, while in more performing ones the peak power is approx. 570 kW_e and the efficiency is around 34%. Finally, the recuperator design results showed an effectiveness of 91.75% at these operating conditions.