The kinetic energy produced by a turbofan engine is inseparable from the unavoidable generation of waste heat dissipated into the environment and the chemical exergy of exhaust gases. However, exergoeconomic cost analyses of these propulsion systems have focused only on the formation process of the functional product and not the cost of residue formation. In this study, symbolic thermoeconomics was applied to evaluate the impact of residue formation on the production costs of a turbofan engine and analyze the effect of component malfunctions on the fuel impact formula for diagnosing anomalies. The GE90-115B high bypass turbofan engine under takeoff conditions and a thrust requirement of 510 kN was considered as a case study. The total exergoeconomic cost of the engine was 26,754.28 USD/h: 61.04% corresponded to external resources; 0.14% and 33.07% corresponded to waste heat dissipated from the bypass and core engine, respectively; 3.28% corresponded to the chemical exergy of the exhaust gases; 2.47% corresponded to capital and operating costs. A malfunction analysis revealed that a 1% reduction in the isentropic efficiency of the compressor reduced the total kinetic exergy by −0.77 MW, increased fuel consumption by 0.49 MW, and generated irreversibility and residue of 0.80 and 0.45 MW, respectively.

Industrial liquid/solid fluidized bed heat exchangers are commonly used with particle recycling systems to allow an increased superficial velocity and higher heat transfer rates. Here, experimental results are reported on a novel helical flow channel geometry for liquid/solid fluidized beds which allow higher heat transfer rates and reduced complexity by operating below the particle transport fluid velocity. This eliminates the complexity of particle recycle systems whilst still delivering a compact heat exchanger. The qualitative character of the fluidization was studied for a range of particle types and sizes under several inclinations of the helices and various hydraulic diameters. The best fluidization combinations were further studied to obtain heat transfer coefficients and pressure drops. Improvements over the heat exchange from a plain concentric tube in an annulus were obtained to the following degree: vertical fluidized bed, 27%; helical baffles, 34 to 54%; and fluidized bed with helical baffles, 69 to 89%.

Nowadays, in Mexico, most of the installed electricity generation capacity corresponds to combined cycles, representing 37.1%. For this reason, it is important to maintain these cycles in good operating conditions, with the least environmental impacts. An exergoeconomic and environmental analysis is realized to compare the operation of the combined cycle, with and without postcombustion, with the comparison of exergoeconomic and environmental indicators. With the productive structure of the energy system, the process of formation of the final products and the residues are identified, and an allocation criterion is also used to impute the formation cost of residue to the productive components related to its formation. This criterion considers the irreversibilities generated in each productive component that participates in the formation of a residue. The compositions of pollutant gases emitted are obtained, and their environmental impact is determined. The unit exergoeconomic cost of the power output in the gas turbine is lower in the combined cycle with postcombustion, indicating greater efficiency in the process of obtaining this energy stream, and the environmental indicators of global warming, smog formation and acid rain formation are higher in the combined cycle with postcombustion, these differences being 5.22%, 5.53% and 5.30%, respectively.

Direct steam generation (DSG) is a promising technology for introducing solar energy into industrial applications, yet it still faces significant challenges. This work analyzes two critical issues associated with DSG: temperature gradients on the receiver tube wall caused by direct and concentrated radiation and flow instability resulting from the phase transition of the working fluid from liquid–vapor to vapor. These phenomena can reduce the mechanical strength of the receiver tube and lead to sudden pressure increases, deformation, or rupture, which hinder the implementation of DSG in solar thermal plants. To address these challenges, the behavior of a receiver tube composed of copper on the inside and an Al₂O₃ envelope is studied. A 50 MWe hybrid solar thermal plant is proposed for Mulegé, Baja California Sur, Mexico, including a solar field designed to analyze the production of superheated steam during peak solar irradiance hours. The effect of the Cu-Al₂O₃ ratio on the receiver tube is evaluated, with Al₂O₃ serving as a thermal regulator to reduce temperature gradients and mitigate flow instability. This combination of materials improves the receiver tube’s performance, ensuring mechanical stability and enhancing the viability of DSG systems. By reducing temperature gradients and flow instability, DSG-based plants can double thermal efficiency and significantly lower environmental impact by eliminating the need for thermal oils, which require frequent replacement. These findings demonstrate the potential for hybrid solar thermal plants to provide sustainable and efficient solutions for industrial energy needs.