Estimation of exergy-based sustainability index and performance evaluation of a novel intercooled hybrid gas turbine system

This paper contributes a novel sustainability index and modified exergy indicators for conventional gas turbines and solid oxide fuel cell integrated gas turbine (SOFC-GT) hybrid power cycles. In this work, an intercooled gas turbine (Ic-GT) cycle is considered as a base cycle, which gives an additive advantage in lowering the power required for the compressor. Moreover, on SOFC integration with Ic-GT, the qualitative and quantitative performance are examined. Numerical modeling is done using MATLAB and an exclusive comparison has been made based on energy-exergy and sustainability analysis for the system and its components. On comparing the first law efficiency at turbine inlet tem-perature, TIT 1250K and rp = 18 for Ic-GT, intercooled recuperated gas turbine (Ic-RGT), and Ic-SOFC-RGT, it is 25.82%, 36.04%, and 64.78%, respectively. Similarly, second law effi-ciency is 11.43%, 22.33%, and 61.11% and the overall sustainability index is 1.12, 1.28, and 2.57 for Ic-GT, Ic-RGT, and Ic-SOFC-RGT, respectively. Nine other modified exergy-based parameters are used to identify the role of fuel and product exergy and then compare the most affected component in three configurations. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper proposes a new sustainability index and modified exergy indicators for traditional gas turbines and solid oxide fuel cell-integrated gas turbine (SOFC-GT) hybrid power cycles. The performance of SOFC integration with intercooled gas turbine (Ic-GT) cycle is examined using numerical modeling and sustainability analysis. A comparison based on energy-exergy analysis shows that the Ic-SOFC-RGT configuration outperforms Ic-GT and Ic-RGT in terms of efficiency and sustainability. Additionally, modified exergy-based parameters are used to identify the most affected component in the three configurations.