International Journal of Exergy (16 papers in press)

Regular Issues

• Thermodynamic Assessment of A Desalination System Integrated with Combined Cycle Power Plant via Throttling Process by Using a Vapour Compressor  
  by Ahmad Zikri, Muhsin Kilic 
  Abstract: This study aims to conduct a thermodynamic analysis of desalination system integrated with combined cycle power plant (CCPP), with a focus on the throttling process method combined with a steam compressor, the influence of pinch point temperature difference (PPTD) on distilled water production (specific aquadest production/SAP) and specific energy consumption (SEC). Reducing condenser pressure from 10.89 to 8.43 kPa and PPTD of 10 can increase steam turbine power by 2.18% and allow the wastewater temperature to drop to 32.5
  Keywords: electricity; freshwater; pinch point temperature difference; PPTD; specific aquadest production; SAP; specific energy consumption; SEC.
  DOI: 10.1504/IJEX.2025.10066839
   
  
• Energetic and Exergetic Analysis of Multi-Energy Hybrid System Including Geothermal, Green Hydrogen, and Cold Energy Storage  
  by Gamze Soyturk, Onder Kizilkan 
  Abstract: This research delves into a thorough examination of a multi-energy system, combining geothermal energy, hydrogen (H2) generation, and cold energy storage. The system aims to establish an eco-friendly energy infrastructure by integrating these sustainable sources and storage methods. The study evaluates the system’s energy performance, scrutinising energy inputs, outputs, losses, and conversions across various components and subsystems. Furthermore, it conducts an exergy analysis to assess the effectiveness of energy transformations within the system, pinpointing areas of irreversibility and exergy dissipation. The findings reveal that the overall energetic efficiency stands at 11.31%, while the exergetic efficiency reaches 31.69%.
  Keywords: geothermal energy; green hydrogen; cold energy storage; energy; exergy.
  DOI: 10.1504/IJEX.2025.10067147
   
  
• An Exergetic Performance Improvement Potential of a Modified Ejector-Enhanced Auto-Cascade Refrigeration Cycle  
  by Ibrahim Karacayli, Lutfiye Altay, Arif Hepbasli 
  Abstract: This study examines both conventional and advanced exergy analyses of a modified ejector-enhanced auto-cascade refrigeration (MEACR) cycle. Conventional exergy analysis shows that the proposed model significantly improves exergy efficiency compared to similar ejector-enhanced auto-cascade refrigeration cycles in the literature. Advanced exergy analysis reveals that 63.47% of the total exergy destruction is avoidable. When the components of the MEACR cycle are investigated, 56.31% of the exergy destruction is attributed to the endogenous part. The low-temperature cycle (LTC) compressor has the highest avoidable endogenous exergy destruction rate of 12.64 kW with 38.5%.
  Keywords: refrigeration; auto-cascade refrigeration; ejector; exergy analysis; advanced exergy analysis.
  DOI: 10.1504/IJEX.2025.10067148
   
  
• Exergoeconomic Analysis of the Utilisation of Microalgae Derived Biostimulants for Sustainable Agriculture  
  by Nicholas Melenek, Murilo Rampi, Jose Viriato Coelho Vargas, Gabriela Conor, Anne Oliveira, Andre B. Mariano, Juan Ordonez, Vanessa Kava 
  Abstract: This study addresses a biorefinery system that enables the production of microalgae derived biostimulants, which includes a municipal solid waste (MSW) incinerator, heat recovery steam generator (HRSG), an emissions fixation column, a photobioreactor, a flocculator, a centrifuge, and a dryer. The output is dry biomass to be utilised as fertiliser. The system technical and economic viability is investigated via an exergoeconomic analysis, which evaluates the systems performance accounting for energy consumption, exergy losses, and economic features related to each stage. The exergoeconomic evaluation established an exergetic cost of 1.022
  Keywords: agricultural practices; plant growth promoters; PGP; mathematical model; sustainability; cogeneration; exergy analysis; municipal solid waste.
  DOI: 10.1504/IJEX.2025.10067746
   
  
• Multi-Objective Optimisation of a new Multi-Generation System Integrating Waste Heat Recovery, and Geothermal Resources to produce Power, Hydrogen, Heating, and Cooling  
  by Mohammad Ali Sabbaghi, Mohammad Sefid 
  Abstract: This study investigates a new multi-generation system through the integration of geothermal energy, waste heat, organic Rankine cycle (ORC), proton exchange membrane electrolyser (PEME) and water-ammonia absorption chiller cycle. The impact of various effective parameters on system performance is evaluated and the system is optimised based on three viewpoints. The obtained results show that the turbine production power is 101.2 kW, the hydrogen production rate is 1.467 kg/h, and the amount of cooling generated in the evaporator, 65.48 kW, is determined. The heat released in the de-superheater amounts to 81.79 kW, which is utilised to operate the absorption chiller.
  Keywords: multi-generation system; absorption chiller cycle; geothermal; heat recovery; optimisation.
  DOI: 10.1504/IJEX.2025.10067934
   
  
• Exergo-economic Assessment of an Improved Combined Flash-Binary Geothermal Cycle for Hydrogen and Desalinated Water Production  
  by Mohammad Ali Sabbaghi  
  Abstract: This study proposes a combined flash-binary cycle to generate power, hydrogen, and desalinated water from geothermal wells, employing a supercritical CO2 (SCO2) cycle which is improved by a thermoelectric generator (TEG). The proposed cycle underwent analysis from energy, exergy, and economic perspectives using real data from existing geothermal wells. Results indicate energy and exergy efficiencies of 14.71% and 38.59%, respectively, with the capability of producing 0.003698 kg/s of hydrogen and 133 kg/s of desalinated water. Thermo-economic analysis reveals production costs of 3.45 $/kg for hydrogen and 39.7 cents/m3 for desalinated water, outperforming previous studies.
  Keywords: Geothermal; Supercritical CO2 cycle; Hydrogen; Desalinated water; Thermo-economic; Thermoelectric generator.
  DOI: 10.1504/IJEX.2025.10068994
   
  
• Estimation of Exergetic Behaviour of the Human Respiratory Tract  
  by Subhajit Banerjee, Sudhir Chandra Murmu, Himadri Chattopadhyay, Abhijit Dutta 
  Abstract: The present work analyses the exergetic behavior of the human respiratory system, including chemical exergy transfer during alveolar gas diffusion. The trends of entropy generation and exergy destruction in the respiratory tract due to airflow for different physical activity levels have been assessed. Furthermore, the effect of inhaled air temperature on tracheal exergy destruction has been assessed. The study for the first time extends the concept of exergetic efficiency for human respiratory tract which accounts for energy losses in the branches of the trachea. The findings indicate that human lung efficiency decreases as physical activity levels rise.
  Keywords: exergetic efficiency; respiratory system; entropy generation; lung disorder; physiological condition; Hb transfer.
  DOI: 10.1504/IJEX.2025.10068996
   
  
• Exergy Fuel Cell Micro Combined Heat and Power Systems Using COA-HDNN Hybrid Technique  
  by Rajesh G. Bodkhe, R.L. Shrivastava, Shenbagaraman S, Kanimozhi K 
  Abstract: This manuscript introduces the COA-HDNN technique, which combines Hamiltonian Deep Neural Networks (HDNN) with the Crayfish Optimization Algorithm (COA). The COA is to optimize Energy Management Systems (EMS) for micro-combined heat and power (?CHP) systems with Fuel Cells (FC) and Thermoelectric Devices (TED).HDNN predicts energy demand and system performance metrics. Implemented in MATLAB, the COA-HDNN method outperforms existing approaches, including the Salp Swarm Algorithm (SSA), Particle Swarm Optimization (PSO), and Heap Based Optimization (HBO). The results demonstrate its efficiency at 98%, cost of 2.6 x 105$, and computation time of 2.19 s, highlighting significant improvements in performance and operational efficiency.
  Keywords: Fuel Cell; Thermoelectric Device; Micro Combined Heat and Power; System; Thermoelectric Generator; Hamiltonian Deep Neural Networks; Crayfish Optimization Algorithm.
  DOI: 10.1504/IJEX.2025.10069020
   
  
• Exergetic, Economic, and Environmental Impact Assessments of a Natural Gas-Diesel Fuel Blended Internal Combustion Engine  
  by Tugba Tetik, Yasin Karagöz 
  Abstract: This study investigates the potential of dual-fuel engines using natural gas and diesel to improve performance and reduce emissions. It examines the effects of natural gas ratios and injection duration under constant load conditions. Results showed a significant reduction in carbon monoxide (CO) and smoke emissions by up to 86% and 60%, respectively. An economic analysis evaluated the feasibility of this fuel blend, calculating the internal rate of return (IRR), net present value (NPV), and payback period (PB). Additionally, an exergy analysis assessed energy conversion efficiency, while Global Warming Potential (GWP) calculations indicated a blend of 22% natural gas had the lowest GWP.
  Keywords: Dual fuel; Exergy; Natural gas; Emissions; NOx.
  DOI: 10.1504/IJEX.2025.10069139
   
  
• Consequences of Energy and Exergy Utilisation in Biological Systems  
  by Sima Kayi, Gülce Aykaç, Idil Başak Temizkan, Mustafa Ozilgen 
  Abstract: Thermodynamic consequences of energy utilisation by a volleyball player has assessed. After employing, the data that the jump-serve speed was 112 km/h and the ball travelled with 31.1 m/s of velocity for 0.4 s, the acceleration of the 270 g ball was 77.75 m/s2. It was calculated that during the jump serve, she performed five calories of work; her body released 15 calories of heat, and generated 5.2
  Keywords: Biological system; champion volleyball player; internal work performance; external work performance; energy and exergy efficiency; athlete’s performance.
  DOI: 10.1504/IJEX.2025.10069526
   
  
• Vehicle Battery Thermal Management with Exergy Considerations Using a Hybrid SHO-DRCNN Approach for Liquid Cooling  
  by S. Saravanan, N. Natarajan, R. Rajiev, C. Sathishkumar 
  Abstract: This manuscript proposes an efficient hybrid approach for liquid cooling with a Battery thermal management system (BTMS) in an electric vehicle (EV). The proposed hybrid approach is the combination of the Sea-horse optimizer (SHO) and dilated residual convolutional neural network (DRCNN), known as SHO-DRCNN approach. The main purpose of the proposed method is to provide a dependable and effective thermal management system that can successfully regulate the BP's temperature in an EV. By then, the proposed technique is implemented in the MATLAB platform and compared with other existing techniques. The proposed approach maintains the system's thermal management intact while reducing errors.
  Keywords: MC; Cooling Temperature; Battery Thermal Management System; Electric Vehicle; SH Optimizer; Dilated Residual Convolutional Neural Network.
  DOI: 10.1504/IJEX.2025.10069606
   
  
• Energy and Exergy Analysis of Novel Hybrid Active Winter Heating System  
  by Amit Shrivastava, Manoj Kumar Gaur 
  Abstract: A novel hybrid active winter heating system (HAWHS) equipped with an evacuated tube solar collector has been developed for space heating. The energy balance of the faculty room air, the evacuated tube collector, and the heat exchanger is determined using the first law of thermodynamics. Additionally, an exergy balance analysis is performed to estimate heat losses through the heating system more accurately. The average exergy efficiency of the system is 7.84%, with a corresponding sustainability index of 1.085. The maximum thermal efficiency achieved by the setup is 34.15%.
  Keywords: Winter heating system; energy balance; exergy balance; cross flow heat exchanger.
  DOI: 10.1504/IJEX.2025.10069709
   
  
• Experimental Investigation on Energy and Exergy Analyses of an Industrial Biomass Power Generation Plant  
  by Anil Badem, Hayati Olgun, Arif Hepbasli 
  Abstract: This study employs a real-time operational dataset and Engineering Equation Solver simulations to analyse an industrial biomass power plant in
  Keywords: Biomass; Energy and exergy analyses; Power generation; Sustainable energy production.
  DOI: 10.1504/IJEX.2025.10069712
   
  
• Entropy Generation in a U-Tube Flow System containing MWCNT-Fe3O4/Water Hybrid Nanofluid with Uniform and Non-Uniform Magnetic Fields  
  by Emrehan Gürsoy, Engin Gedik 
  Abstract: The study analyses entropy generation in a U-tube used in shell and tube heat exchangers, using both passive and active techniques. MWCNT-Fe3O4/water hybrid nanofluid ( = 0.001% and 0.003%) under laminar flow conditions (117.1 Dn 234.2) and magnetic fields were evaluated. Results showed that tube position did not impact irreversibility. However, MWCNT-Fe3O4/water hybrid nanofluid enhanced system efficiency, reducing total entropy generation at the rate of 13.0% and 18.0% for = 0.001% and 0.003%, respectively, at Dn = 234.2. Conversely, increasing the magnetic field raised total entropy generation, negatively impacting irreversibility.
  Keywords: Entropy generation; MHD; U-tube; Uniform and non-uniform magnetic field; MWCNT-Fe3O4/water hybrid nanofluid; Laminar flow regime.
  DOI: 10.1504/IJEX.2025.10069719
   
  
• Exergy-Energy, economic and Environmental Evaluations of a Solid Oxide Fuel Cell based Trigeneration System  
  by Yunis Khan, Pawan Kumar Singh, Aftab Anjum, K.K. Sivakumar, Shikha Gupta, Subhash Mishra 
  Abstract: This work proposes a trigeneration system based on a solid oxide fuel cell (SOFC) for power generation, steam production, and cooling effects. The results show that energy, exergy efficiency, and total cost of the trigeneration plant were enhanced by 36.51%, 4.14%, and 1.76%, respectively, as compared to the conventional SOFC-based gas turbine plant. However, the CO2 emission per MWh of output energy was reduced by 26.73%. Additionally, cooling effects of 100 kW were obtained at 5C for general-purpose applications, and heating effects of 101.4 kW were obtained by generating saturated steam through a heat recovery steam generator.
  Keywords: solid oxide fuel cell; gas turbine; hybrid system; trigeneration system; double effect vapor absorption system; heat recovery steam generation system.
  DOI: 10.1504/IJEX.2025.10069845
   
  
• Energy and Exergy Analysis of CLC based Biomass Fired Power Plants: Effect of Different Oxygen Carriers, Hydrogen and Power Co-Production  
  by Ramsagar Vooradi, Venkata Suresh P, Manohar Kakunuri, Shailesh Singh Sikarwar 
  Abstract: The depletion of fossil fuels and environmental degradation has increased interest in renewable energy harvesting. Biomass chemical looping combustion is a promising carbon-negative energy generation method. This work analyses a Chemical Looping based biomass-fired power plant integrated with an ORC cycle for electricity generation with different oxygen carriers. Sensitivity analysis is conducted on design parameters to enhance energy efficiency. Performance comparison of different oxygen carriers in terms of energy and exergy shows that blended carriers improve process economics, carbon conversion, redox characteristics, and overall plant performance. The coproduction of power and hydrogen significantly enhances energy and exergy efficiencies compared to biomass-only power production.
  Keywords: Chemical looping combustion; chemical looping hydrogen production; oxygen carriers; energy and exergy efficiencies; CO2 capture.
  DOI: 10.1504/IJEX.2025.10070031