LHV is the lower heating value of the fuel and ϕf is the exergy factor of Szargut and Styrylska as enunciated in Szargut et al. [24].
Table 1 Lower heating value, chemical exergy and exergy factor for different fuels (at 25 °C and 1 atm) Fuel Lower heating value (kJ/kg) Exergy factor,ϕf Fuel chemical exergy,ɛf kJ/kg) Motor gasoline 44,300 1.07 47,401 Aviation kerosene 44,100 1.07 47,187 Diesel oil 43,000 1.07 46,010 Fuel oil 40,400 1.07 40,400.
The exergy factor for liquid fuels has been taken from Table 3.4 of Szargut et al. [24].
Each component of the system is studied separately, by associating a fuel (exergy availability at the inlet of the component), a product (exergy produced by the component) and an exergy dissipation.
The product of this component is constant (constant heat flow rate exchanged with cooling water), while its fuel (exergy resource) increase.
Throughout the study, the useful energy gain and the receiver tube exergy transferred to the heat transfer fluid, the energy and exergy efficiency as well as the exergy factor were measured.
The results of energy and exergy analyses showed that 43.09% of fuel exergy was destructed and the average thermal efficiency was approximately 36.61%, and the exergetic efficiency was approximately 33.81%.
For exergetic performance analysis, the effects of operating variables such as current density, pressure, and fuel utilization factor on exergetic performances (module exergy efficiency, module exergetic performance coefficient, module exergy output and total exergy destruction rate, and components' exergy efficiencies, exergy destruction rates) are investigated.
The irreversibility losses distribution and the plant energy and exergy efficiencies are studied at different reformer temperatures (823 < T < 973 K), water to ethanol molar ratios (5 < RAE < 6.5) and fuel utilization factor (0.7 < Uf < 0.9).
Then there is the fuel factor.
