International Journal of Exergy (9 papers in press)

Regular Issues

• Design, Exergy Analysis, and Heat Transfer Investigation of a New Automotive Brake Disc  
  by Mohamed Ben Jamel Hadder, Ahmed Ghorbel, Fathi Djmal, Mohamed Haddar, Mounir Baccar 
  Abstract: This study investigates the thermal behaviour of four brake disc geometries using Computational Fluid Dynamics (CFD). A Standard Full Rotor (SFR), a Standard Radial Vane rotor (SRV-R), a Circular Pillar design (CP), and a novel Y-shaped disc with cooling fins are analysed under identical braking conditions. In addition to heat distribution and airflow characteristics examination, an exergy analysis is conducted to identify the most efficient configuration. Results indicate that the Y-shaped design delivers superior cooling with 20%-30% lower heat build-up and reduce exergy destruction, demonstrating its clear thermodynamic advantage for enhancing braking performance and safety.
  Keywords: Brake disc; Exergy; Heat transfer; SFR; SRV-V; CP; Y-shaped disc.
  DOI: 10.1504/IJEX.2026.10077235
   
  
• Energy, Exergy, Environmental and Economic (4E) Investigation of a SOFC Based Hybrid Power Generation System  
  by Yunis Khan, Aftab Anjum, Shashi Gandhar, Abhishek Gandhar, P.M.G Bashir Asdaque, Sukritindra Soni, Rohit Kumar Singh Gautam 
  Abstract: This work simultaneously employs the three contemporary power generation technologies in a single power generation system. The current study created a hybrid power plant that concurrently uses a gas turbine (GT), solid oxide fuel cell (SOFC), and transcritical CO2 cycle. Exergy, energy, environmental and economic (4E) analysis was performed numerically. The results showed that the proposed hybrid plant performed 7.50% better thermodynamically than that of the traditional SOFC-GT system. However, there was a 6.95% decrease in CO2 emissions per MWh of power output and overall cost of the hybrid plant went up by 6.20% in proposed plant.
  Keywords: Solid oxide fuel cell; Transcritical CO2 cycle; Hybrid energy system; Environmental analysis; Thermo-economic analysis; Gas turbine.
  DOI: 10.1504/IJEX.2026.10077780
   
  
• Modelling and Simulation of a Double-Ejector Refrigeration System: Thermodynamic Perspectives  
  by Erdem Ersayin, Leyla Ozgener 
  Abstract: Conventional single-stage ejectors suffer from pressure lift limitations under high temperature lift conditions. This study proposes a serial double ejector configuration to distribute the compression ratio across two stages. Thermodynamic and exergy analyses were conducted for R1234yf, R290, R600, and R717 at generator temperatures of 70-100C. Results show that serial staging increases the COP by up to 18% and reduces exergy destruction by 45% at temperature lifts above 30 K. Operability maps identify optimal pressure split ratios and feasible regions, demonstrating that serial staging effectively enables high lift cooling driven by waste heat.
  Keywords: double ejector refrigeration cycle; thermal performance analysis; refrigerant selection; entrainment ratio; heat driven cooling.
  DOI: 10.1504/IJEX.2026.10077792
   
  
• ISoQ: an exergy-based quality metric for residential PV/T systems  
  by Hande Gunar, Samed Dogan, Oguz Ozan Yolcan 
  Abstract: This study introduces the integrated solar conversion quality score (ISoQ) to evaluate hybrid PV/T systems by combining thermodynamic exergy with real-time demand matching. Dynamic hourly simulations were conducted for a standardised residence across five global climate zones using ten-year ERA5 data. Results reveal that Copenhagen achieved the highest ISoQ score (0.184) due to superior synchronisation between thermal generation and heating demand. Conversely, Dubai ranked lowest (0.091) despite maximal solar availability, as generated heat remained largely unutilised. The findings demonstrate that for residential applications, temporal load matching is a more critical performance driver than peak solar generation capacity.
  Keywords: hybrid PV/T; exergy analysis; ISoQ score; demand satisfaction; building energy simulation.
  DOI: 10.1504/IJEX.2026.10078182
   
  
• Energy and exergy assessment of a solar based trigeneration system  
  by Krishna Mani Mishra, Onkar Singh 
  Abstract: This study developed a trigeneration system using a Nitrogen-Brayton cycle for power, cooling, and steam generation driven by solar energy. A heat recovery steam generator and vapour absorption refrigeration system are used to produce saturated steam and cooling output, respectively. The results showed that the thermal efficiency, exergy efficiency, and power output of the overall solar plant were found to be 51.55%, 39.25% and 16,386 kW, respectively. The system delivered heating and cooling outputs of 9,666 kW and 531.90 kW, respectively. The proposed solar plant achieved a 62.20% higher thermal efficiency compared to the conventional nitrogen-based Brayton cycle.
  Keywords: solar power tower; SPT; trigeneration; exergy analysis; Brayton cycle; heat recovery steam generator; HRSG; absorption refrigeration.
  DOI: 10.1504/IJEX.2026.10078183
   
  
• Performance Evaluation of a Gasification based Trigeneration Plant Designed for Sustainable Management of Biomass Waste  
  by Abdul Khaliq, Abdullah Alhjjaji, Bandar Alzahrani, Rayed S. Alshareef 
  Abstract: This work presents a theoretical evaluation of the performance of a biomass gasification plant with the modification of minimizing the energy wastage through combined production of electricity, heating, and low temperature refrigeration. The system applies air-steam gasification of rice husk, gas-steam combined power cycle, ejector-absorption refrigeration cycle, and a process heat exchanger. A mathematical model is developed to investigate trigeneration plant’s energetic and exergetic characteristics. System modeling was done in EES software, and unlike, previous investigations, proposed research stands out for development of detailed thermo-chemical model implemented under MATLAB software considering tar formation. Proposed trigeneration plant can yield efficiencies of 74.23% energetically and 44.65% exergetically. System efficiencies are improved with the rising of SBR and declined with rise of steam turbine inlet pressure and pinch point temperature. The gasifier (25.4%), combustion chamber (15.7%), and EARC (6.4%) exhibits significant exergy destructions and hence requires special attention.
  Keywords: Biomass; Trigeneration; EARC; Exergetic efficiency; Air-steam fluidized bed gasification.
  DOI: 10.1504/IJEX.2026.10078303
   
  
• Extreme Lean Hydrogen Combustion in SI Engines: NOX Emissions and Exergy Destruction Analysis  
  by Yasin Karagöz, Saban Pusat, Emre Teksan, Erdal Tunçer, Tugba Tetik 
  Abstract: This study examines the effects of excess air coefficient (?) and late ignition timing on NOx emissions and exergy destruction in a hydrogen-fueled internal combustion engine converted from a conventional diesel engine. Experiments are conducted at 1500 rpm and 3.5 kW using two ignition timings (10
  Keywords: Hydrogen; Extreme Lean Combustion; Cold Combustion; Exergy.
  DOI: 10.1504/IJEX.2026.10078328
   
  
• Exergy and Environment Modelling for Sustainable Manufacturing Systems  
  by Gowrishankar J, Tapas Bapu B. R, Ravi Kumar, Anitha R 
  Abstract: This study examines exergy and environmental modelling for sustainable manufacturing systems to reduce environmental impact and enhance energy efficiency through multi-objective optimisation, life cycle assessment, and exergy analysis. The framework combines thermodynamic modelling, life cycle assessment (LCA), data collecting, computer simulations, and multi-objective optimisation that focuses on cost, emissions, and energy. A study of a 210 MW coal-fired thermal power plant found that the boiler was the most effective in destroying exergy, even when the turbines worked at different levels of efficiency. Improvements in exergy efficiency show that emissions, resource use, and total environmental effect are all lower. This strategy helps stakeholders make strong decisions by linking technical, financial, and environmental factors in sustainable manufacturing.
  Keywords: Exergy analysis; Sustainable manufacturing; Energy efficiency; Environmental modelling; Life cycle assessment (LCA); Exergo-environmental analysis; Thermodynamic optimization; Resource efficiency; Emi.
  DOI: 10.1504/IJEX.2026.10078498
   
  
• A Thermodynamic Evaluation of Carbon Capture and Storage with Exergy Aspects: A Critical Review  
  by Lekan Popoola, Festus Adeniyi Adeyemo, Lukumon Salami, Sunday Adekunle Adebanjo, Usman Taura, Yuli Panca Asmara, Kabir Adeola Aminu 
  Abstract: As part of the United Nation Sustainable Development Goals to attain low-carbon society, studies on ways of offsetting carbon are still imperative. This paper reviews the thermodynamics of carbon capture and storage (CCS) systems to understand the importance of CCS as a climate mitigation strategy and also explore the energy/ exergy requirements of the systems. Synergy between kinetic models and thermodynamic principles was explored to understand the mechanistic behavior of CO? transport and transformation in sorbent and storage media. Isotherm models, thermodynamic adsorption parameters, and implications for CO? sorbent design and regeneration efficiency were presented.
  Keywords: Low-carbon society; Environmental pollution; Greenhouse; Hazardous waste; Carbon offsetting.
  DOI: 10.1504/IJEX.2026.10078597