International Journal of Exergy (12 papers in press)

Regular Issues

• Exergy and Energy Analysis of a Solid Oxide Fuel Cell-Gas Turbine-Supercritical CO2 Hybrid System: Economic and Environmental Assessment  
  by Divya Tiwari, Pushpraj Singh, Abhay Agrawal, Prashant Singh Chauhan 
  Abstract: As global energy demand rises due to population growth and industrialisation, efficient power generation is essential. This study develops a hybrid power system integrating a supercritical CO2 (sCO2) cycle, solid oxide fuel cell (SOFC), and gas turbine (GT). Using computational analysis, the systems energy, exergoeconomic, and environmental performance was evaluated. Results showed a 7.19% increase in efficiency and power output compared to the conventional SOFC-GT system, with a 7.39% reduction in CO2 emissions. Despite a 2.17% cost enhance, the hybrid system offers superior efficiency and sustainability. Overall, proposed hybrid system offers enhanced efficiency and environmental benefits over traditional configurations.
  Keywords: Gas turbine; Supercritical CO2 cycle; Hybrid plant; Thermo-economic analysis; CO2 emission analysis; Solid oxide fuel cell.
  DOI: 10.1504/IJEX.2025.10071468
   
  
• Energy and Exergy Analysis of Air Conditioning System with Air-Cooled and Evaporative Cooled Condenser: a Comparative Approach  
  by R. S. N. Sahai, Umais Momin 
  Abstract: This study compares the energy and exergy performance of air-conditioning systems with air-cooled condensers and evaporative-cooled condensers using cellulose, banana fibre, jute, and cotton-thread as cooling pads under varying ambient temperatures. The air-conditioning systems with evaporative-cooled condensers using a cellulose pad showed the highest COP increase upto 27.27% and lowest total exergy destruction upto 1.139 kW, achieving an exergetic efficiency range of 24.456% to 19.87%, highlighting its superior thermodynamic performance. In both systems, the condenser was the least efficient component, with the highest efficiency defect at 42.8% in the air-cooled condenser, reduced to 35% using evaporative-cooled condenser with cellulose pad.
  Keywords: air conditioning system; energy; exergy; evaporative cooling; evaporative cool condenser; evaporative cooling pad material.
  DOI: 10.1504/IJEX.2025.10071825
   
  
• Exergy-Based Improvements and Waste Exergy Emissions in Sustainable Aviation Fuels: a Pathway to Enhanced Energy Efficiency and Environmental Sustainability  
  by Sankarsan Panda, Dharmaprakash Ramasamy, Sendilkumar Subramanian, Nalini M 
  Abstract: The aviation sector will struggle to attain net-zero emissions by 2050. Sustainable aviation fuels (SAF) research is noted. We evaluated the technical performance of SAF production in a Brazilian first- and second-generation integrated sugarcane biorefinery. CO2 equivalent and renewability exergy indices assessed supply chain sustainability. One study looked at getting public transport to release less carbon dioxide. These studies examine how some of the world's biggest energy-hungry companies and industries can release less CO2.In a multi-criteria approach, we evaluated biorefinery route performance using ?B and AUEC as supplementary indicators. By 2020, S
  Keywords: Sustainable Development Goals (SDGs); municipal solid waste (MSW); The thermos electric generator (TEG); internal combustion engine (ICE); Life Cycle Assessment (LCA); Sustainable airplane Fuels.
  DOI: 10.1504/IJEX.2025.10072001
   
  
• Energy, Exergy, and Economic Exploration Analysis of LiBr-H2O and NH3-H2O Absorption Refrigeration Cycles driven by a Natural Gas Engine  
  by Victor M. Ambriz-Diaz, Carlos Rubio-Maya, Eduardo Ruiz-Casanova, Luis F. Villalón-López, Carlos R. Ramirez-Ferreira 
  Abstract: This paper presents the energy, exergy, and economic analysis of Absorption Refrigeration Cycles (ARCs) driven by a natural gas engine. The analyses are based on the laws of thermodynamics and economic indicators such as the Simple Payback Period (SPP) and the Net Present Value (NPV). Energy analysis indicates a cooling capacity and a Coefficient of Performance of the LiBr-H2O ARC that are higher by 359.3 kW and 0.36, respectively, compared to the NH3-H2O ARC. Exergy analysis shows that the NH3-H2O ARC has 5.85% more exergy destruction. Finally, the economic analysis suggests that the LiBr-H2O ACR can achieve a lower SPP.
  Keywords: absorption refrigeration cycles; NH3-H2O; LiBr-H2O; engine exhaust gases; 3-E analysis.
  DOI: 10.1504/IJEX.2025.10072007
   
  
• Entropy Generation and Irreversibility Analysis of Slip Flow in Porous Microchannel Affected by Electromagnetic Field  
  by Khaleel Al Khasawneh, Issa Zahedah, Marwan Abu Saileekc 
  Abstract: This article provided an analytical study of entropy generation and irreversibility for gaseous flow inside long planar porous-microchannel placed in electromagnetic field. Analytical expressions of total rate of entropy generation and irreversibility were provided. Effects of different parameters in entropy generation and irreversibility were investigated. This study also presented numerical results that were used as validation for the present study. The obtained results showed that rate of total entropy generation increases as Darcy number and electrical conductivity increase but decreases as porosity or thermal conductivity ratio increase. The average Bejan number increases with increasing Darcy number but decreases as Hartmann number increases. The irreversibility ratio increases as Darcy number, electric-magnetic field ratio increases but decreases as Harmann number or porosity increase. The effect of porous medium on entropy generation was smaller than electromagnetic field effect.
  Keywords: Microchannel; Slip flow; Porous medium; Electro-magnetic; Entropy generation; Irreversibility.
  DOI: 10.1504/IJEX.2025.10072015
   
  
• Exergy and Entransy Performance Analysis of an Unmodified 4-Stroke CI Engine Fuelled With CuO, Gr and Al2O3 Nano-Catalyst-Diesel Blend at Different Engine Speed  
  by Prabhat Patel  
  Abstract: This study evaluates diesel engine performance and fuel economy with copper oxide (CuO), graphene (Gr) and aluminium oxide (Al2O3) nanoparticles. Exergy and entransy analyses examined a diesel engine energy output with Al2O3, CuO and Gr) nanoparticle blends at five different concentrations. At full load, engine speed varied between 1500-2500 rpm. Nanoparticles (5 mg/l, 44 mg/l, 102 mg/l,160 mg/l, 200 mg/l) in diesel blends enhanced brake thermal efficiency by 12.35%, exergy efficiency by 7.5%, and entransy efficiency by 18.5%. Additionally, brake specific fuel consumption decreased by 11%, entropy generation by 5.5%, exergy destruction by 7.5% and entransy destruction by 18.5%. At 2100 rpm, the Gr based diesel with 160 mg/l nanocatalyst achieved maximum energy efficiency among all diesel nanocatalyst blends.
  Keywords: Exergy; Entransy; Engine Performance; Nanoparticles; Nanodiesel.
  DOI: 10.1504/IJEX.2025.10072090
   
  
• A Comprehensive Review on Advanced Exergy, Exergoeconomic, and Exergoenvironmental Analyses for Sustainable Thermal Energy Systems  
  by Uchenna Azubuike, Howard Njoku, Val Ekechukwu, Tien C. Jen 
  Abstract: Advanced exergy, exergoeconomic, and exergoenvironmental analysis (A3E) address weaknesses in conventional exergy, exergoeconomic, and exergoenvironmental methods (C3E) by evaluating system interactions and improvements. This review highlights the limited application of A3E analysis in thermal systems, with fewer than 15% incorporating these techniques. Studies on endogenous exergy destruction remain scarce, and A3E assessments are lacking. To ensure sustainability, the economic and environmental impacts of exergy destruction must be evaluated. Further research is needed, particularly in thermal power plants and other thermal systems, to enhance the application of A3E analysis.
  Keywords: exergy; advanced exergy; exergoeconomic; exergoenvironmental; sustainability; thermal systems; avoidable; unavoidable; endogenous; exogenous; environmental impact.
  DOI: 10.1504/IJEX.2025.10072212
   
  
• Energetic and exergetic assessments of a cement clinker cooler integrated poly-generation plant  
  by Faizan Khalid, Mohd Parvez, Shiv Lal, Osama Khan, Mohammad Uzair 
  Abstract: This study proposes a novel cooling method for white cement clinkers, using nitrogen and carbon dioxide as alternatives to conventional water cooling. The use of nitrogen enables recycling, while hot nitrogen can serve additional purposes, addressing water wastage in the clinker cooling process. Carbon dioxide's potential in cooling clinkers at 1,400–1,450°C is also evaluated. This approach aims to improve sustainability and resource efficiency in white cement manufacturing by reducing water consumption and introducing reusable cooling agents. The result shows that W_grid increases from 386.316 kW to 1,444.651 kW, Q_cooling rises from 585.4398 kW to 2189.2882 kW, and hydrogen production improves from 0.002723 kg/s to 0.101765 kg/s as CO₂ inlet temperature increases from 150°C to 300°C. The proposed system offers a viable solution for addressing the environmental challenges of traditional white cement clinker cooling.
  Keywords: poly-generation; vapour compression cooling cycle; rankine cycle; RC; hydrogen; freshwater.
  DOI: 10.1504/IJEX.2025.10070500
   
  
• Exergetic energy management of fuel cell electric vehicles using Tasmanian devil optimisation and recalling recurrent neural network algorithm  
  by Elango Kannan, Senguttuvan Kannan, Saravanan Kaliyaperumal 
  Abstract: This paper presents an energy management strategy (EMS) for electric and fuel cell electric vehicles (EMFCEV) using a novel TDO-RERNN approach, integrating Tasmanian devil optimisation (TDO) and recalling recurrent neural network (RERNN) algorithms. The study focuses on identifying driving conditions, calculating fuel cell output, classifying battery state of charge (SoC), and optimising power distribution among energy storage systems (ESS). Implemented and evaluated on the MATLAB platform, the proposed method demonstrates improved performance over existing methodologies, offering significant enhancements in vehicle energy efficiency and fuel consumption reduction. The TDO-RERNN approach achieves a notable 99% accuracy in predicting and optimising energy usage and distribution in FCEVs.
  Keywords: proton exchange membrane fuel cell; energy storage systems; ESS; fuel cell electric vehicles; FCEVs.
  DOI: 10.1504/IJEX.2025.10070543
   
  
• Bayesian optimisation for enhanced energy and exergy efficiency in solar multi-generation plants  
  by Seyed Saeid Razavian, Mojtaba Babaelahi 
  Abstract: This paper examines a novel concentrated solar multi-generation plant producing electricity, heating, cooling, drying, and hot water. The system employs molten salts (60% NaNO₃, 40% KNO₃) for thermal storage, enabling continuous operation through a solar tower, Rankine cycle, organic Rankine cycle, and air-based cycle. Exergy analysis revealed the solar tower and ORC evaporator contribute 47% of system losses. Using Bayesian multi-objective optimisation with Gaussian process models and expected hypervolume improvement achieved significant enhancements: 10.28% in energy efficiency, 7.50% in exergy efficiency, and 8.85% in net power output.
  Keywords: concentrated solar power; CSP; multi-generation system; energy efficiency; exergy analysis; Bayesian optimisation; Gaussian process models; molten salts.
  DOI: 10.1504/IJEX.2025.10072134
   
  
• Energy and exergy analyses of pressurised water reactors and a new model of U-tube steam generators  
  by Huseyin Emre Sahin, Harun Kemal Ozturk 
  Abstract: Energy and exergy analyses have been performed for thermodynamic performance analysis for pressurised water reactors (PWR) and a new model of U-tube steam generators (UTSG). Exergy destruction and efficiency have been obtained and compared for each component of typical PWR and all nodes of the developed UTSG model. Changes in primary inlet flow rate, feedwater inlet temperature, primary inlet temperature and U-tubes diameter ratio have been investigated and the response of the generator has been presented with the developed model. In PWR analysis, most exergy destruction rate has been in reactor (61.80%), condenser (14.27%) and turbines (8.28%). In UTSG analysis, exergy destruction rate has been greater in downcomer (47.72%) and boiling region nodes.
  Keywords: exergy; pressurised water reactors; PWR; U-tube steam generators; UTSG; two-phase heat exchangers.
  DOI: 10.1504/IJEX.2025.10071281
   
  
• Development and exergy analysis of a newly designed tower-solar collector-based combined cooling-desalination system  
  by Tawfiq Al-Mughanam 
  Abstract: This study focuses on the proposal and analysis of a new solar tower-based cogeneration system where reverse osmosis (RO) unit is connected to Kalina cycle which combines internally with absorption refrigeration cycle (ARC) aiming to produce cooling and fresh water, simultaneously. System modelling was done in EES software based on mass, energy, and exergy equations. Analysis of the results revealed that cogeneration plant yield efficiencies of 44.54% energetically and 25.81% exergetically. The results further indicated that 23.14% of the total exergy destruction occurs in central receiver. The results provide important inferences about the exergetic performance of solar-based cooling-desalination cycle.
  Keywords: tower solar collector; Kalina cycle; reverse osmosis; exergy; absorption refrigeration cycle; ARC.
  DOI: 10.1504/IJEX.2025.10071546