Qualitative–quantitative comparative assessment of conventional gas turbine with fuel cell-based integrated power cycle

A conventional gas turbine has potential to generate power but suffers from significant losses in the form of exhaust. The system’s efficiency can be improved by incorporating the recuperator into the cycle, which is known as recuperated gas turbine, but only to a certain extent. Through hybridization, there are more options for improving performance. To do this, a high-temperature fuel cell known as a “solid oxide fuel cell” is combined with the traditional system to create a hybrid that offers significant improvements in both quantitative and qualitative performance. First law of thermodynamics gives the quantitative results, whereas second law of thermodynamics gives a qualitative result. This paper presents the qualitative and quantitative comparison between hybrid and non-hybrid configuration. The parametric analysis for fuel cell is shown by considering Knudsen and molecular diffusion coefficient, along with the detailed discussion of conventional system and hybrid system. Performance of hybrid system is validated with the published results. Through hybridization more than 20% efficiency is improved in recuperated gas turbine when fuel cell is installed with it. The hybrid system achieves efficiency of energy and exergy efficiency of 61.46% and 59.9%, respectively, at pressure ratio 4 and turbine inlet temperature 1250 K. A unique performance map also presented for the proposed configuration and compared the nature of the curve. Graphical abstract