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To reduce the irreversibility of the throttling in a dual-pressure organic flash cycle (DOFC), this study presents a modified DOFC integrating a split-flow evaporator and an ejector (EE-DOFC). In the EE-DOFC, the flow from the preheater flows into the split-flow tank (ST) and then is split into two parts. One part enters the split-flow evaporator. The other part enters the ejector and entrains the high-pressure (HP) turbine exhaust vapor. The effects of the evaporation pressure, ejector entrainment ratio, and HP turbine outlet pressure on the EE-DOFC performance are studied. The performances of the DOFC, and EE-DOFC are compared under the maximum net power output conditions. The results reveal that after the split-flow evaporator and ejector are integrated, the irreversibility of the pump and mixer decreases and the exergy losses of the ejector and heat exchanger of the EE-DOFC become lower than those of the throttling valves and heat exchanger of the DOFC. The exergy loss of the discharged water is lower in the EE-DOFC than in the DOFC. The net power output and the corresponding levelized cost of electricity (LCOE) of the EE-DOFC are higher by 10.72 % and lower by 10.92 %, respectively, compared with those of the DOFC. • Propose a modified dual-pressure DOFC integrating a split-flow evaporator and an ejector (EE-DOFC). • The component exergy losses of the DOFC and EE-DOFC were compared under the maximum net power output condition. • The maximum W net and corresponding LCOE of the EE-DOFC were 10.72 % higher and 10.92 % lower, than those of the DOFC. [ABSTRACT FROM AUTHOR]

This study aims to develop a sustainable cooling solution for refrigeration in remote areas, utilizing solely wind and solar power. Ensuring that the power generated aligns with consumption throughout the day is a critical challenge. The investigation centers on the integration of an energy storage and a compression cooling cycle to attain the desired objective. This system integrates refrigerant storage on both the evaporator and condenser sides. The storage tanks' volume is variable by time and should be adjusted automatically. The sustainability of the cooling capacity depends on the amount of input power and the type of refrigerant. Moreover, additional heat is extracted to produce hot water. The analysis includes the coefficient of performance, exergy efficiency, cooling capacity, total heating capacity, and environmental impacts for six refrigerants R134a, R22, R717, R125, R500, and R407c. The system is configured to offer a cooling capacity of 15 kW while maintaining a temperature difference of 38K. The best performance is achieved using R717 as the refrigerant with a coefficient of performance of 5.26, an exergy efficiency of 36 %, and a payback period of 2.267 in Sabzevar. Furthermore, R717 does not contribute to ozone depletion or global warming. • Presenting an eco-friendly cooling system for medical cold storage in remote areas. • Finding the maximum solar-wind cooling load during a year using the storage system. • Optimizing the refrigerant type using 4E analysis. • Finding R717 as the optimum refrigerant which produces almost 15 kW cooling load. • Comparing the results of conventional and advanced exergy analyses. [ABSTRACT FROM AUTHOR]

Improving the exergy utilization and economic performance is the core goal for the configuration optimization of the integrated energy system (IES). Achieving such a goal requires accurate evaluation of the exergy efficiency and economy. However, IES is a multisource heterogeneous and strongly coupled system. The development of reasonable exergy efficiency-economy characteristic evaluation indicators is a complex issue that limits its application in IES configuration. This article proposes a novel IES configuration optimization approach based on the concept of the equipment exergyeconomic cost coefficient. The exergyeconomic cost coefficient consists of the exergy-degradation and non-energy costs, which can quantitatively characterize the exergy efficiency and economy of the IES under a unified benchmark. A mechanism model for the equipment exergyeconomic cost coefficient, output of various equipment and total exergyeconomic cost is established. Furthermore, exergy flow attribute classification method is proposed to obtain the equipment exergyeconomic cost coefficient in the IES. The proposed method is verified in a real-world study case located in Yancheng, China. Compared to the conventional configuration method, the capacity of the renewable energy and combined heat and power generation (CHP) are enhanced, while the capacity of purchased electricity and electric boiler (EB) are reduced. It can obtain the minimum total exergyeconomic cost (TEC) for the IES. This study offers a new direction for the optimal configuration of IES. • The concept of the equipment exergyeconomic cost coefficient for IES is proposed. • Quantitative characterization of exergy efficiency and economy under a unified benchmark are considered. • A novel unified configuration optimization model for IES based on the equipment exergyeconomic cost coefficient is proposed. • The exergy-degradation cost and non-energy costs are incorporated into the objective of the configuration optimization model. • An exergyeconomic cost coefficient calculation method based on exergy flow attribute classification is proposed. [ABSTRACT FROM AUTHOR]

An innovative multi-block finned nano-enhanced phase change material (NePCM)-based photovoltaic/thermal (PV/T) system with thermal regulations through deionized water (DIW) and nanofluid at 0.25, 0.5, and 0.75 wt% is designed, fabricated, and tested in this study. The main goals are to achieve consistent heat transfer distribution, mitigate temperature stratification within each thermal energy storage block, and prevent material shrinkage at the bottom. The energy and exergy performance of the proposed PV/T-NePCM is investigated using indices such as power output, efficiency, exergy destruction, entropy generation, and sustainability index. Furthermore, environmental metrics such as CO 2 emission, carbon credit gained, and net CO 2 mitigation, as well as economic performance parameters such as energy payback time and energy cost are analyzed. The proposed system uses nanofluid as the heat transfer fluid at 1.5 l/min and 0.75 wt% NePCM, resulting in 9.26 % and 2.93 % higher energy and exergy efficiency than the DIW-based system. The economic evaluation shows that the PV/T-NePCM system has a cost of energy of 5.24 INR/kWh (0.063 USD/kWh), while the conventional PV module costs 5.64 INR/kWh (0.069 USD/kWh) with an 8 % interest rate and a 20-year lifespan. For environmental sustainability, the nanofluid-cooled PV/T-NePCM system has 637.28 kWh of embodied energy. • A novel multi-block finned NePCM-based PV/T system is introduced. • Characterization of MWCNT-enhanced PCM is performed for thermophysical properties. • Performance is assessed from energy, exergy, economic, and environmental (4E) perspectives. • PV/T-NePCM system exhibits a cost of energy amounting to 5.24 INR/kWh. • Total embodied energy of the proposed nanofluid-cooled PV/T-NePCM system amounts to 637.28 kWh [ABSTRACT FROM AUTHOR]

The integration of a thermal energy storage (TES) system is an effective way to improve the load cycling rate of coal-fired power plants (CFPPs). To evaluate the power increase potential and thermodynamic performance of CFPP supplied by heat release of the molten salt TES system, eight discharging modes for CFPP integrated with the TES system including steam injection, heater bypass, and additional turbine schemes were comparatively evaluated. The system simulation models of the integrated systems were developed and the thermodynamic performance of the proposed system were evaluated. Results show that the mode SI-HPT (high-pressure turbine steam injection) has the largest output power increase of 25.00 % under the benchmark condition of 75%THA, but the mode HB-LPH (low-pressure heater bypass) shows a very low output power increase of 2.08 %. Moreover, the power generation efficiency is changed by the external heat source through a change in the average heat absorption temperature of the Rankine cycle and the internal irreversibility of the steam/water cycle. Under the typical benchmark discharging condition of 75%THA, the power generation efficiency of the turbine in mode SI-LPT (low-pressure turbine steam injection) can be reduced from 47.41 % to 44.15 %, but it can be increased from 47.41 % to 48.86 % in mode SI-HPT. When the temperature ranges of the TES system are above 600 °C and below 450 °C, the modes SI-HPT and SI-LPT obtain the optimal comprehensive performance, respectively. This study can provide the scientific guidance for retrofit for CFPP to achieve efficient and flexible design. • Eight discharging modes of thermal energy storage system are comparatively studied. • The power increase potential and restrictions of thermal power plant are determined. • Thermodynamic performance of multiple heat sources Rankine cycle is analyzed. • The exergy destruction changes caused by external heat sources are calculated. • The optimized system for different thermal storage temperature ranges is obtained. [ABSTRACT FROM AUTHOR]

Global warming and environmental pollution are becoming increasingly severe problems due to the excessive use of fossil fuels. Recovering and utilizing waste heat from different energy systems can considered a sustainable solution to this destructive trend. This study proposes two modified Kalina cycle structures that use ejector refrigeration for combined cooling and power (CCP) generation in low-temperature waste heat. While to recover energy from a lean ammonia solution uses a two-phase expander. Thermodynamic analysis shows that the modified Kalina cycles E and F operate with a thermal efficiency of 0.3066 and 0.2557, respectively, representing a significant improvement of more than 123 % and 86 %, respectively, compared to the base cycle. Also, the exergy efficiency of the improved configurations E and F has been calculated as 0.083 and 0.089, respectively, showing an improvement of 53.8 % and 64.8 %, respectively, compared to the base cycle. The exergoeconomic analysis also revealed that the total capital cost rate for improved cycles E and F is estimated at 2.62 and 2.76 $/h, respectively. In addition, from an environmental perspective, the improved Kalina cycle F has proven to have a more eco-friendly performance with a pollution index of 0.2281 mPts/s. Moreover, a parametric study is conducted to investigate and analyze the effect of changes in significant performance parameters such as ammonia concentration, evaporator temperature, turbine inlet temperature and pressure, and turbine back-pressure for both presented modified cycles. • Compare performance of Kalina cycle with conventional ones 4E analysis are performed. • The temperature of the lean ammonia solution is optimized for maximum power output. • The ejector can reduce energy losses during the expansion of the Ammonia water fluid. • The thermal efficiency of modified Kalina cycles E and F improved to 123 % and 86 %, respectively, compared to the KCPC system. [ABSTRACT FROM AUTHOR]

The lack of studies on hybrid systems combining thermoelectric ventilation (TEV) and earth-air heat exchangers with a photovoltaic-thermoelectric generator (PV-TEG) as the power supply for the hybrid system is addressed in this research. This study aims to investigate the effectiveness and performance of such a combined system in providing the required thermal load of a building. To simulate the performance of TEV and PV-TEG systems, energy conservation equations for various components of the system were formulated for the quasi-state mode. The performance of the earth-air heat exchanger system was evaluated using the effectiveness-number of transfer units method. The resulting set of algebraic equations was then solved using a MATLAB code. Results indicated significant preheating (5.41–15.03 °C) and precooling (0.7–10.22 °C) effects during the daily hours of 15-February and 15-July, respectively. Additionally, the TEG component effectively reduced PV temperatures by 3.54 °C–16.99 °C in 15-February and 3.99 °C–21.54 °C in 15-July. The system also demonstrated a high monthly useful thermal energy output (1215–1584 kWh) in the cold months (December to March), contrasting with higher monthly useful thermal exergy (712–763 kWh) in the summer months. Furthermore, increasing the number of TEGs from 10 to 50 resulted in significant improvements in the yearly average energy and exergy proficiency indexes ( P I y a , e n and P I y a , e x ) by 164.97 % and 459.82 %, respectively. The supply air mass flow rate and the length and depth of the earth-air duct were identified as the second and third most influential parameters affecting these indexes. Moreover, the system at CPV concentration ratio of 3 provided the highest P I y a , e n and P I y a , e x of 1.512 and 14.65, respectively. • Performances of a CPV/TEG powered TEV-EAD system are assessed. • The system is able to supply the heating and cooling loads of a building. • Best energy and exergy performance occur in September and April, respectively. • Most effective parameter on system performance is number of thermoelectric coolers. [ABSTRACT FROM AUTHOR]

Dimethyl carbonate has received more and more attentions as an organic solvent in electrolytes. Aiming at the problem of high energy consumption in the process of dimethyl carbonate (DMC) production, the root of the problem was analyzed by using exergy analysis, which provides a theoretical basis for the construction of energy-saving process. Firstly, the overall process of DMC production was constructed, including propylene carbonate (PC) synthesis, DMC synthesis, azeotrope separation and propylene glycol (PG) purification processes. Secondly, the conventional and advanced exergy analyses of the four proposed processes were carried out. The distributions of exergy and exergy destruction were obtained through conventional exergy analysis. The exergy destructions were further divided through advanced exergy analysis, and the avoidable parts were focused on. Based on the above analyses, the corresponding heat integration processes were proposed. Finally, the conventional processes and the heat integration processes were evaluated with the performance indicators of the exergy destruction, total annual cost (TAC), total energy consumption (TEC) and CO 2 emissions. • The overall process of dimethyl carbonate synthesis is proposed. • Process optimization based on conventional and advanced exergy analyses. • The heat integration process presents good environmental and economic benefits. [ABSTRACT FROM AUTHOR]

This paper presents a two-stage and dual-temperature ejector auto-cascade refrigeration cycle (TEARC) driven by the waste hot water and low-pressure exhaust steam in chemical plants. In this cycle, a throttle valve is provided between the condenser outlet and separator inlet to regulate the composition and mass flow ratio of mixture refrigerant in the two evaporators. The specific enthalpies of refrigerant at the low-temperature (LT) evaporator and medium-temperature (MT) evaporator inlet are respectively reduced via the evaporative condenser and separator, leading to an enhancement in cooling capacity. Energy, exergy, and economic (3E) analyses are conducted to compare the performance between the TEARC and the basic two-stage and dual-temperature ejector refrigeration cycle (BTERC). At the basic operating condition, the TEARC has enhancements of 9.13 % and 9.95 % in COP and exergy efficiency than those of the BTERC. According to the multi-objective optimization results, it indicates that the TEARC's COP , exergy efficiency, and levelized cost of cooling are respectively improved by 8.93 % and 5.67 % and reduced by 1.22 % compared to the BTERC at optimum operating conditions. The simulation results of the proposed cycle reveal a significant performance improvement and the potential for application in waste heat-driven refrigeration. • A two-stage dual-temperature ejector auto-cascade refrigeration cycle is raised. • Using gas-gas ejector to supply superior conditioning at variable cooling loads. • TEARC's COP and exergy efficiency increased by 9.13 % and 9.95 % in the base case. • TEARC's levelized cooling cost drops by 1.22 % than BTERC at optimum conditions. [ABSTRACT FROM AUTHOR]

As an important part of the new power system, it is crucial to consider the efficiency, economy and environment of the integrated energy system simultaneously. In order to improve the efficiency of solving multi-objective optimization scheduling problems for integrated energy systems, a variable step-size approximation method is proposed in this paper. Firstly, a model of integrated energy system is constructed, and the source-side and load-side exergy equations of different energy networks are given, as well as the mathematical expressions of equipment by combining the idea of unification. Secondly, in comparison with the ergodic weights approach, the variable step-size approximation method theoretical minimum reduction percentage of solution time is deduced by mathematical methodology under the m objective functions. Finally, the results from an integrated energy system including a modified New England 30-bus system, a 6-node heat network and a 7-node gas network demonstrate that the multi-objective function proposed compromises the economy, environment and efficiency of integrated energy system compared to the traditional optimization problem. In comparison with the ergodic weights approach, the step size approximation method can save over 97 % of the solution time, and the percentage of average error can be as low as 0 % under the multi-objective functions. • A variable step-size approximation method is proposed to solve m objective functions. • The efficiency, economy and environment of integrated energy system are considered. • The number of solutions for optimization is deduced under m objective functions. • The solution time is reduced theoretically over 97 % than ergodic weights approach. • The percentage of average error from the proposed method can be as low as 0 %. [ABSTRACT FROM AUTHOR]

Biodiesel, known for its large cetane number, low pour point, and lower aromatics and sulfur content, has appeared as a promising alternative to diesel. This study focuses on testing the biodiesel extracted from Eichhornia Crassipes with TiO 2 nanoparticles at 150 ppm concentration in a diesel engine. The experiment involved varying injection timings (ITs) of the biodiesel and nanoparticle blend, with three ITs of 20, 23, 25 and 28⁰bTDC, and a standard IT of 23⁰bTDC for diesel. The engine was tested at five different engine loads, ranging from 20 % to 100 %, with an increment of 20 % after each step. The experimentation was conducted at a constant an engine speed of 1500 rpm and a compression ratio of 17.5. The result showed an enhanced performance and a decreased emissions of carbon monoxide and hydrocarbons for 20⁰bTDC of biodiesel and nanoparticle blend. However, the emission of nitrogen oxides increased for the same blend and IT of 20⁰bTDC. The study suggests that using a 150 ppm concentration of TiO 2 nanoparticles in Eichhornia Crassipes biodiesel could be an alternative to diesel for diesel engines when IT is set at 20⁰bTDC. Further, the statistical optimization using RSM suggests that the engine load around 61 % and IT of 20 ⁰bTDC gives optimum values of response variables. [Display omitted] • Four injection timings (20, 23, 25 and 28⁰bTDC) were tested for ECB-TNP nanofuel. • Exergy analysis suggests that IT of 20⁰bTDC gives highest exergetic efficiency. • Statistically optimized values are IT of 20⁰bTDC and engine load of around 61 %. • IT of 20⁰bTDC gives maximum brake thermal efficiency at all engine loads. • IT of 20⁰bTDC gives minimum emissions of CO and HC at all engine loads. [ABSTRACT FROM AUTHOR]

This paper introduces a novel method for targeting the minimum shaft work required for process electrification employing principles of Pinch Analysis and detailed heat pump performance estimations. The method deviates from conventional Pinch Analysis by dividing the grand composite curve (GCC) into net heat sink and source profiles to enable the placement of heat pumps exploiting the heat pockets of the GCC. Additionally, it employs Lorenz efficiency over exergy efficiency, offering an accurate description of heat pump performance and highlighting the importance of integration between processes. The method is applied to two case studies. The first case, milk evaporator, focused on the placement of heat pumps in the heat pockets of the GCC. The results showed that while the maximum direct heat recovery was 20,447 kW, the optimal configuration limited the heat recovery to 12,199 kW, reducing the shaft work from 1,930 kW to 1,010 kW. The second, a spray dryer case, focused on the integration of electric boilers and the partial process electrification when available excess heat is limited. In this case, 1,520 kW out of 4,640 kW were covered by an electric boiler, with a biomass boiler replacing the electric boiler to cover 3,570 kW if available. • New method for shaft work targeting based on PA and the Lorenz efficiency factor. • Available heat on the pockets of the GCC can be advantageous for HP integration. • Lorenz efficiency factor is preferred over the exergy efficiency factor. • Method is applied to two case studies, a milk evaporator and a spray drier. [ABSTRACT FROM AUTHOR]

The Organic Rankine Cycle (ORC) is a widely-used waste heat recovery approach, that converts low-grade heat into shaft work. This paper introduces a graphical methodology using Exergy-Enthalpy (Ex-H) diagrams, for evaluating and designing ORCs. ORC thermodynamics can be represented by approximate triangular exergy profiles without compromising accuracy. The exergy profile of the heat-absorbing process is crucial to ORC performance. Approximate triangular exergy profiles can be constructed for any ORC configuration to predict ORC performances, such as work output, exergy loss, and thermal efficiency. Furthermore, a systematic graphical approach is developed for integrating waste heat streams and ORCs, with step-by-step procedures outlined. The evolution procedure of the ORC exergy profile can determine working fluid selection and operating conditions. This visually intuitive yet scientifically rigorous tool clarifies the complex relationships between fluids, parameters, and system performance. Two case studies demonstrate the method's effectiveness, confirming it as a valuable tool for ORC design. • A visually intuitive and theoretically robust tool is developed for design of ORCs. • Triangular exergy profiles are constructed to predict key performance metrics. • Two cases validate the accuracy and effectiveness of the Exergy-Enthalpy Diagram. • Simplified ORC designs achieve better performance than complex literature designs. [ABSTRACT FROM AUTHOR]

Ejector refrigeration systems (ERSs) operating with carbon dioxide are notoriously challenging from both design and operation perspectives. In particular, the ejector itself gives rise to special attention since it directly affects the performance of the global system. In this study, the connections between local exergy transfers within the ejector and global cycle performance are investigated by using a novel multi-scale numerical approach. Computational Fluid Dynamics (CFD) is used to generate accurate predictions of the ejector operation with access to the local flow and heat transfer features. The exergy tube analysis is applied onto the simulation results, linking local transfers within the ejector to the results at the component- and cycle-scale. A state-of-the-art ejector thermodynamic model is then calibrated onto the CFD results, and employed to determine the physically possible operation of the ERS. In addition, the metastability impact on the exergy transfers and overall system performance is investigated by comparing the CFD results of the classical Homogeneous Equilibrium Model with those obtained with the Homogeneous Relaxation Model. Notably, it is found that at fixed ejector inlet conditions, there exits an outlet pressure that maximizes the exergy transfers from primary to secondary streams. Interestingly, this work shows for the first time that the maximum exergy gain of the secondary stream appears to correlate with the maximum coefficient of performance of the system, independently of the on- or off-design operation of the ejector. Moreover, metastability generally deteriorates the performance at both scales. The results of the present study serve to pave the way towards better ejector design objectives. • The maximum net exergy gain likely occurs in off-design regime. • The maximum theoretical COP and net exergy gain of the secondary stream coincide. • In subcritical operation, metastability lowers entrainment ratio, net exergy and COP. • Ejector design should integrate component and system scale approaches. [ABSTRACT FROM AUTHOR]

The adaptive cycle engine gains significant attention due to its variable thermodynamic cycles and multi-duct characteristics, which are utilized for thermal management to enhance engine performance. This paper explores the features of multi-duct technology in adaptive cycle engines and aims to improve engine flight performance. An analysis is conducted on the impact of duct air bleed on engine propulsion characteristics, thermodynamic cycle properties, and exhaust system infrared radiation characteristics. Initially, a component-level model of the adaptive cycle engine was established, considering CDFS duct, bypass duct, and third duct air cooling devices. This model uses the ducted cold air to cool the temperature of low-pressure turbine exit, center cone wall, and main nozzle expansion section wall. Subsequently, a method for analyzing the infrared radiation of the engine exhaust system was proposed based on the above model, and the performance of engine components and the overall engine was analyzed in terms of energy, exergy, mechanical efficiency, and thermal efficiency. Finally, the numerical simulations of the propulsion performance, thermodynamic efficiency and infrared characteristics of the adaptive cycle engine with cooling air were carried out under conditions of ground takeoff, subsonic cruise, and supersonic cruise. The simulation results show that the cooling air can effectively enhance engine performance and infrared stealth capabilities under various flight conditions. The ducted air extraction measures proposed in the paper could effectively improve the propulsion efficiency and stealth characteristics of the engine, providing important references for the development of more efficient aeroengine. • An adaptive cycle engine model with cooling air is established. • A backward infrared radiation intensity prediction method for exhaust system is proposed. • The analysis model of energy, exergy, performance, efficiency and infrared radiation for ACE is established. • Considering the impact of ACE's cooling airflows on engine performance in different flight mission stages and modes. [ABSTRACT FROM AUTHOR]

Many pumped hydro compressed air energy storage systems suffer from large head variations in the hydraulic machinery. To address this defect, this study proposes a multi-machine compensable pumped hydro compressed air energy storage system and reveals its operational, energy, exergy, and economic performances. First, the energy, exergy, and economic models of the system are established. Second, the operational characteristics of each component are analyzed. Third, the energy, exergy, and economic performances of the system are presented. Finally, the impact of operating pressure on the energy and exergy performance is analyzed. The results indicate that air pressure variations of 0.300 MPa/0.256 MPa in Tank 1 are reduced to head variations of 11.0 m/12.7 m at the hydraulic machinery, respectively. Furthermore, the round-trip efficiency, exergy efficiency, and energy storage density reached were 0.672, 0.694, and 0.038 kW·h/m3, respectively. The most significant work wastage and exergy loss occurred in Tanks 1 and 2, contributing to 48.5 % and 37.5 % of the total, respectively. As the operating pressure increases, the round-trip and exergy efficiencies decrease, and the energy storage density increases. In this study, the head amplitude at the hydraulic machinery under charging and discharging conditions was reduced by nearly 2/3 and 1/2, respectively. • A novel pumped hydro compressed air energy storage system is proposed. • Operational characteristics in each device are analyzed. • Energy, exergy and economic performances of the system are revealed. • Impact of operating pressure is compared and analyzed. [ABSTRACT FROM AUTHOR]

The establishment of traveling-wave-dominated acoustic fields within the regenerator is crucial for developing highly efficient thermoacoustic refrigeration systems. The present work introduces a novel looped, single-unit, direct-coupling thermoacoustic refrigerator, incorporating an optimally dimensioned cavity at a strategic location to maximize system performance. Central to this research is the systematic exploration of the phase modulation mechanism. This exploration involves adjusting the dimensions of the cavity structure, tracking its evolution from initial absence to full integration. The research method includes comprehensive evaluations of steady-state performance, onset characteristics, exergy loss, and axial parameter distribution analysis. The findings are visually depicted through simulations, highlighting the cavity's role in acoustic field modulation and its consequent impact on system efficiency. With the integration of an optimally sized and positioned cavity, the system's cooling efficiency improves by more than 2.5 times compared to the efficiency of a structure without cavities. A prototype replicating the proposed design was then constructed and experimentally tested. The results reveal a close correlation between the simulated and experimental data, affirming the analysis's accuracy and dependability. These studies effectively elucidate the significance of the cavity in looped single-unit thermoacoustic refrigerators and provide valuable insights for the development of more efficient phase modulation structures. • The phase modulation of cavity in thermoacoustic refrigerators is analyzed. • Cavity position is within 20%–25 % of the system wavelength. • Appropriate cavity volume is crucial for system performance. • Increasing cavity diameter significantly affects acoustic field distribution. • The experimental investigation validates the accuracy of the simulation results. [ABSTRACT FROM AUTHOR]

Goal of this paper is to highlight and place in a comprehensive historical perspective the consequential continuity between the first attempts to link the concept of monetary cost to thermodynamic principles and the latest developments that led to exergy-based cost indicators and Sustainability numeraires. This is an orientation paper, and a conscious effort was made to avoid presenting the advancements in the economic-thermodynamic paradigms by simply listing them in their chronological order: whenever possible, and on the basis of well-documented references, a "conceptual tree" is discussed that originates with the introduction of the exergy concept (the roots), grows through a trunk (cost formation theory, Techno-Economics) and main branches (Thermo-Economics, Cumulative Exergy Consumption ...) and terminates with the latest exergy-based cost theories. In Section 2 a brief recap of the concept of "cost" is provided, to clarify the different physical bases and proxies adopted in different approaches. Sections 3 and 4 contain a brief historical outline of the path that led from the recognition that exergy is a proper valuation index for energy to the initial critique to Techno-Economics and to the formulation of Monetary Thermo-Economics and to some of its initial developments. Techno-Economics, Thermo-Economics (both monetary and purely exergy-based), and other paradigms that postulated a quantifiable correlation between exergy and production cost are discussed in sections 6 through 10. Every effort has been made to provide the most relevant references for each conceptual and practical statement reported in the paper: as a result, the Reference list has grown beyond the Journal page limit, and it is available as a separate file in the Additional Material. • Provides a commented "history" of the development of Exergy Analysis into Thermo-Economics. • Discusses the coherent evolution of the Thermo-Economic paradigm into more modern models. • Suggests to use the Thermo Ecological Cost and/or the Extended Exergy Accounting as Environmental indicators. • Maintains that Thermodynamics is at the basis of Sustainability studies. [ABSTRACT FROM AUTHOR]

Addressing climate change is an urgent issue that requires effective and sustainable solutions at multiple scales from the building to the district and city scales. This study focuses on the avoidable carbon dioxide emissions responsibilities due to exergy mismatches between supply and demand at multiple scales based on the Rational Exergy Management Model. Nine key metrics for decarbonization are presented with analyses of three case studies in Glasgow, including a university campus area, and urban emissions scenarios. The existing campus district system involves 42 MW boiler capacity for heat supply and 3.35 MW electric power and heat supply with a combined heat and power system that is responsible for 80.97 kg carbon dioxide per operating hour at design conditions. The system may shift towards carbon neutrality if the combined heat and power system capacity increases to at least 27.3 MW electric power and the boiler is eventually banned. A potential expansion of the district network with solar prosumer buildings indicates that the optimum number of Exergy Stars as a new rating is four out of five when embodiments for solar prosumer buildings are considered. Urban emissions scenarios for Glasgow indicate about 20 MtCO 2 eq of urban consumption-based emissions in 2020 that are analyzed up to 2030 and 2050 under different decarbonization scenarios. Remaining urban emissions are linked to inefficiencies where exergy mismatches cause emissions responsibilities in the energy system. In comparison to the decarbonization index in the urban emissions scenarios for Glasgow, the increased exergy match at 0.87 is closest to its 2045-year value in the renewable energy based green-growth scenario. The results are useful for guiding other urban areas to embark on an effective approach for mitigation and bring society to a better balance with the planet. Districts and cities can utilize these metrics to upscale climate mitigation and minimize emissions more rapidly. • Exergy based decarbonization metrics developed at building, district, and urban scales. • Results provide a strategic roadmap based on nine main metrics for the case studies. • The three case studies in Glasgow also include university campus with district heating. • The City of Glasgow may increase the value of the main parameter from 0.11 to 0.87 • In the most ambitious scenarios, urban emissions of Glasgow reach net zero emissions. [ABSTRACT FROM AUTHOR]

The adsorption technology plays a significant role in the carbon capture domain for mitigating the CO 2 emissions, whereas the heterogeneous character is presented in practical adsorption process. In this study, a multi-node thermodynamic model is established for temperature-vacuum swing adsorption (TVSA) considering the end non-uniform adsorption. It shows superior performance for the assessment of practical TVSA cycle compared with lumped model. Through the influence analysis of different operation parameters based on multi-node model, specific exergy consumption increases from 41.6 to 62.4 kJ/mol caused by simultaneous drop of heat consumption and lift of work consumption as feed pressure raises from 1.0 to 3.0 bar. Exergy efficiency ranges between 13.8 % and 15.0 % as CO 2 concentration increases from 10 % to 20 %. However, those under ppm-level are below 0.86 %, presenting the higher exergy consumption but lower desorption capacity represented for direct air capture. The heat consumption of front half part of adsorption bed is 39.7 % higher than the latter one, proving the potential cascaded desorption of subzone heating is superior for reducing the energy consumption. Furthermore, exergy consumption is lifted due to enhancement of work consumption of vacuum pump as vacuum pressure reduces from 1.0 to 0.02 bar, resulting exergy efficiency drops from 19.6 % to 13.4 %. • A multi-node thermodynamic model considering non-uniform absorption was established. • The multi-node model showed better evaluation performance contrasted lumped model. • 39.7 % more heat was needed while desorbing the front half part of absorption bed. • Recovery raised but exergy efficiency dropped due to the reduce of vacuum pressure. [ABSTRACT FROM AUTHOR]

This study aims to develop and assess a new multigeneration system where nuclear heat is utilized as the energy source. The multigeneration system is further designed to generate power, cooling, freshwater and hydrogen. In the present multigeneration system, five main subsystems, including high-temperature gas-cooled pebble bed nuclear reactors, a Rankine cycle, a cobalt-chlorine thermochemical cycle, a multi-effect desalination system and an ammonia-water absorption refrigeration system are integrated for synchronized operation. The analyses of the present system are carried out with the approaches of energy and exergy. This integrated system uses a total of 1000 MW thermal energy that is obtained from four units of high-temperature gas-cooled pebble bed nuclear reactor. Using all the thermal energy that comes from the nuclear reactors, a total of 346.99 MW of electricity, a total of 1.59 MW of cooling, a total of 384.67 kg/s of freshwater, and a total of 0.25 kg/s of hydrogen are produced. The energetic and exergetic performance coefficients of the ammonia-water absorption refrigeration system are 0.74 and 0.83, respectively. While the energy efficiency for the overall system is calculated as 37.83%, the exergy efficiency is found to be higher as 46.32% with the multiple useful outputs which help exergetically improve the overall system. [ABSTRACT FROM AUTHOR]

The efficient use of energy is an important challenge in engineering tasks. Even with the end-of-pipe treatment method, the carbon capture process has possibilities to improve its efficiency with heat integration. Since exergy analysis helps detect the most efficient way of energy intensification, exergy investigation based on thermodynamic analysis is carried out to improve energy efficiency. Two cases for exergy destruction calculation can be considered and compared depending on the operation of the capture process: (i) the stand-alone situation, where utilities are applied, and (ii) the total site integration, where sources and sinks are available at every temperature level of the carbon capture process. Besides heat integration, the application of oxyfuel technology can further improve thermodynamic efficiencies reducing the detrimental exergy destruction. Air-combustion exhibits higher exergy destruction compared to oxyfuel-combustion, particularly at high carbon dioxide removal efficiency levels. Heat-integrated configurations nearly double thermodynamic efficiency, especially in the cases of oxyfuel technologies. Therefore, it is recommended that, for the sake of cleaner energy production, both oxyfuel technologies and heat integration should be applied to enhance carbon capture process' energy efficiency. [Display omitted] • Thermodynamic efficiencies of air and oxyfuel combustion processes are assessed. • Heat integration significantly improves thermodynamic efficiency. • The exergy destruction of oxyfuel combustion is lower than that of air combustion. • The efficiency further improves if the capture process is integrated into total site condition. [ABSTRACT FROM AUTHOR]

Auto-cascade refrigeration cycles have extensive application prospects for low-temperature refrigeration. To achieve low evaporating temperature, the cascade heat exchanger uses a significant portion of the cooling capacity, resulting in less cooling capacity entering the evaporator. A vortex tube with energy separation capability is integrated into the cycle. Then the refrigerant is further cooled, thereby reducing the cooling capacity of the cascade heat exchanger. Thus, more cooling capacity generated by the cycle is transferred to the evaporator. This paper proposes two novel auto-cascade refrigeration cycles integrating vortex tubes. The performance of novel configurations is evaluated through thermodynamic analysis. The results demonstrate that novel configurations outperform the baseline cycle in terms of energy and exergy efficiency. The coefficient of performance and exergy efficiency of cycles achieved maximum increases of 23.84 % and 11.62 %. The modified exergy analysis method distinguishes the destruction and indicates the direction of optimization. Furthermore, the economic and environmental analysis indicates that the novel cycles achieved a maximum reduction of 6.74 % in cost rate and 12.72 % in environmental impact under given conditions. Generally, the thermodynamic analysis reveal the potential of vortex tubes to enhance the performance of auto-cascade cycles.1 • Two configurations of auto-cascade cycles integrating the vortex tube are presented. • A thermodynamic analysis method is conducted to evaluate performance. • The performance of novel configurations outperforms the baseline cycle. • The modified exergy analysis method distinguishes the sources of exergy destruction. [ABSTRACT FROM AUTHOR]

Intermittence and low grade are significant barriers for the widespread application of renewable/waste energy. An absorption energy storage heat transformer with adequate energy storage and temperature lift characteristics effectively addresses this challenge. An advancement in this technology is the double-stage energy storage heat transformer (DESHT), which further enhances the range of temperature upgrade through twice temperature lifts. This paper proposes a time-dependent approach for a comprehensive study of the DESHT cycle with a working pair of LiBr/H 2 O. Firstly, the dynamic characteristics of the DESHT cycle are shown. Subsequently, the effects of discharging temperatures, charging temperatures, and solution mass ratio on cycle performance are analyzed. Results show that the DESHT cycle can achieve a temperature lift from 35 °C to 55 °C. 90 % of the total storage capacity can be reached in 60–70 % of the total charging time. The maximum discharging time per unit of charging time is achieved at a temperature lift of 45 °C. Besides, compared to the conventional double-stage absorption energy storage cycle, the DESHT cycle shows a higher exergy efficiency. Optimizing the solution mass ratio can enhance the cycle performance. These findings can serve as a valuable reference in exploring the DESHT cycle. • Time-dependent study of double-stage energy storage heat transformer is conducted. • High temperature upgrades of 35–55 °C are obtained in the investigated conditions. • Dynamic characteristics of the proposed cycle are examined comprehensively. • The concept of the ratio of discharging and charging time is proposed. [ABSTRACT FROM AUTHOR]

Efficient power generation systems are an essential way to reduce carbon emissions. To avoid the complex effects of high-pressure conditions on the solid oxide fuel cell (SOFC) and gas turbine (GT) hybrid systems, while further improving energy efficiency. A SOFC-GT hybrid system based on the reverse Brayton cycle (RBC) is proposed, in which the SOFC operates at near atmospheric pressure conditions and GT expands below atmospheric pressure. Solar energy is integrated to further enhance system performance. Rigorous assessments of the novel system and the pressurized system are conducted utilizing energy, exergy and economic analysis. The sensitivity analysis of environmental parameters on the novel system's performance is performed. The results show that the novel system generates power and efficiency better than the conventional system when the GT compression ratio is 3 and 6, respectively. The power generation and exergy efficiency of the novel system at the design point is 60.47 % and 58.57 %, respectively. The largest exergy destruction occurred in the SOFC. The lowest exergy efficient components are the parabolic dish collector (PDC) and heat exchanger 2. The novel system is more cost-effective due to the higher lifetime of the SOFC, with the levelized cost of energy (LCOE) is 0.1418 $/kWh. • The reverse Brayton cycle is applied to solid oxide fuel cell and gas turbine hybrid system. • Solar energy is coupled to further improve system performance. • The comparison between the novel system and the conventional system is analyzed. • The influence of external environmental factors on the novel system is analyzed. [ABSTRACT FROM AUTHOR]

The present study aims to develop a novel configuration of hydrogen and electricity co-production based on a small modular nuclear reactor (SMR) by synergistically integrating the Vanadium Chloride thermochemical (V–Cl) and helium-closed Brayton cycles. For the V–Cl thermochemical cycle, a steady-state simulation model is developed for the first time in the Aspen Plus environment. The entire system is assessed thermodynamically by calculating the exergy destruction rate and exergy efficiency of major components employed in different subsections (nuclear power production, clean hydrogen production, supporting Rankine cycle, hydrogen compression, and storage) of the plant. Various parametric studies are conducted to identify the scope of improvement and evaluate suitable operating parameters that exhibit optimized system performance. It is found that a maximum H 2 production rate is achieved when the VCl 4 flow is 3.6 kmol/h. A specific hydrogen production rate of 9.63 g/kWh is achieved. The reduction reactor and Deacon reactors are responsible for the highest and lowest exergy destruction with a value of 155.46 kW and 37.60 kW accounting for 49 % and 11.86 % of the overall exergy destruction within the V–Cl cycle. The share of power production from the secondary Rankine cycle in the overall hydrogen compression train is 16.48 %. The parametric study results show that with an outlet helium pressure of 15 bar, the overall work output and electrical efficiency peaked with a value of 4.6 MW and 15.64 % respectively. The overall energy and exergy efficiencies of the proposed system are found to be 16.94 % and 21.42 % respectively. • Process simulation of a four-step V–Cl thermochemical cycle is performed. • A small modular nuclear reactor is integrated. • Aspen Plus process simulator is used. • Energy and exergy efficiencies are determined. • Several sensitivity analyses are conducted under different scenarios. [ABSTRACT FROM AUTHOR]

The auto-cascade refrigeration is a critical technical approach to achieve below −40 °C. The separation efficiency of mixed refrigerant is a main factor affecting the performance. Fractionation purifies low-boiling composition but reduces refrigerant flow rate within the evaporator, which may decline the performance. This paper proposes two novel cycles combining fractionation and flash separation. The novel configurations purify the composition and increase the mass flow rate of refrigerant within the evaporator. The thermodynamic analysis results indicate that the presented cycles outperform the fractionation cycle and the basic cycle in terms of energy and exergy efficiency. Under the design condition, the mass fraction of low-boiling composition in the fractionation-enhanced cycle and the fractionation-modified cycle increased by 4.21 % and 2.97 % compared to the basic cycle. The mass flow rate within the evaporator of novel cycles increased by 25.87 % and 34.78 %. The COP and exergy efficiency of the fractionation-enhanced cycle and the fractionation-modified cycle is 42.57 % and 45.44 %, 46.61 % and 55.15 % higher than those of the basic cycle. Generally, the combination of fractionation and flash separation addresses the issues of low composition separation efficiency in the basic cycle and low flow rate of the fractionation cycle, enhancing the performance of the auto-cascade cycle. • Novel configurations of fractionated auto-cascade refrigeration cycle is proposed. • The fractionation and flash separation is applied to novel configurations. • Thermodynamic performances of four cycles are evaluated and compared. • Energy and exergy performance of proposed cycles outperforms other two cycles. [ABSTRACT FROM AUTHOR]

This research is focused on analysing the thermodynamic performance outcomes of the ammonia-fueled turbofan engine. The assessment contains exergy sustainability, economic aspects, environmental impact, and energy and exergy analysis at take-off, climb-out, climb and cruise levels. The required mathematical modelling for thermodynamic analysis of the turbofan engine was performed with Engineering Equation Solver (EES) software. Then it was calculated how much improvement could be achieved in the amount of emissions that occur in the case of using ammonia and kerosene. It was determined that the combustion chamber (CC) has the greatest improvement potential of the turbofan. The maximum productivity lack rate (83.87 %) was determined in the CC at the cruise level, minimum productivity lack rate (0.72 %) was found to be the LPC at the same level. During the take-off level, the turbofan engine had the highest energetic and exergetic fuel costs, reaching 37138.38 $/h and 34195.78 $/h, respectively. The highest specific fuel consumption (85.602 kg/kN.h), thermal efficiency (53.78 %) and thrust efficiency (40.29 %) of the turbofan engine using ammonia as fuel carried out at the take-off level. Eventually, the maximum carbon dioxide emission reduction was calculated as 43.84 tonCO 2 /h when compared to kerosene fuel. • Thermodynamic performance outputs for ammonia-fueled turbofan were evaluated. • SFC, thrust and thrust power were conducted for all altitude levels. • Exergy sustainability and economic analyses for each component were performed. • Environmental analyses for each component were investigated. • CO 2 Emission outputs were compared with the kerosene fuel. [ABSTRACT FROM AUTHOR]

The present research presents an innovative thermal integration model for a biomass-based power plant to generate power, coolant, and liquefied hydrogen. This integrated arrangement comprises biomass gasification, gas turbine cycle, organic flash-bi-evaporator refrigeration cycle, multi-effect desalination, solid oxide electrolyzer, and Claude cycle. The selection of an eco-friendly fluid for the electricity-cooling production cycle is conduced relying on a comparative analysis. The subsequent examination evaluates the economic-sustainability performance criteria through sensitivity and contour analyses. The comparative assessment identifies R1234ze(Z) as the most suitable working fluid. Four objective functions are scrutinized, and two optimization scenarios are devised based on a machine learning approach using artificial neural networks and a multi-objective gray wolf optimization technique. In Scenario A, the focused objectives are the total destructed exergy and the cost of producing liquefied hydrogen. Meanwhile, Scenario B integrates the sustainability index and the overall system cost rate as primary criteria. Scenario A exhibits more favorable operational conditions and outcomes than scenario B, showing the objectives mentioned as 9955 kW and 3.25 $/kg, respectively. In this scenario, the sustainability index, the overall investment cost rate, and the net present value are obtained to be 1.74, 236 $/h, and 205 M$, correspondingly. • Innovative biomass-driven system, producing power, coolant, and liquefied hydrogen. • Working fluid selection procedure for better eco-friendly integrated process. • Sustainability and economic evaluation/optimization using ANN-MOGWO-TOPSIS. • Scenario A is the suitable route, showing E ˙ D , tot at 9955 kW and c LH at 3.25 $/kg. • SI tot , Z ˙ tot , and NPV are found at 1.74, 236 $/h, and 205 M$, respectively. [ABSTRACT FROM AUTHOR]

Solar absorption refrigeration systems provide one of the economical options for air conditioning. In order to reduce the complexity and economic cost, a more advanced solar single-double-effect switching system is proposed. The innovation of this system is that it replaces the single-effect and high-pressure generators in previously developed single-double-effect switching system with a specific generator. The optimal heat source switching temperature of the new system was determined by the genetic algorithm to be 125.5 °C. Compared with the original single-double-effect switching system, the average coefficient of performance of the system is increased by 8.6 %, and the fluctuation of refrigeration capacity during the switching period is reduced by 48 %. The new solar single-double-effect switching system is investigated based on thermodynamic characteristics, energy, exergy, and economy aspects. The results showed that heat exchangers of the system have strong coupling. The cooling water temperature has a greater impact on the performance of the dual-effect mode. In the single-effect mode, the special-pressure generator has the largest exergy destruction (39 %), while in the double-effect mode, the absorber has the largest exergy destruction (41 %). Besides, the economic analysis demonstrated that the new system is economically viable with a payback period of 9.33 years. • An improved single-double effect switching absorption cooling system was proposed. • Operation stability of the system without single-effect generator increased by 48 %. • Thermodynamic characteristics and exergy destruction of the system were analyzed. • Thermodynamic coupling between heat exchangers in the system was strong. • The proposed system had a shorter payback period and more economy. [ABSTRACT FROM AUTHOR]

A new renewable energy-driven advanced plant is designed and developed to produce multiple useful outputs, namely electricity, heat, cooling, hydrogen, and monomethylhydrazine (as space shuttle fuel) using solar and wind energies locally available. A specific location needed for this kind of unique work is identified as the Kennedy Space Center (KSC), which is known as located on Merritt Island, in the state of Florida (USA). It is also one of the National Aeronautics and Space Administration's (NASA) ten field centers. Since December 1968, KSC has been NASA's primary launch center of American spaceflight, research, and technology. This paper presents a comprehensive analysis of the subsystems that constitute the newly proposed system potentially for KSC and highlights their complex relationships and synergies. Leveraging renewable energy sources, such as concentrated solar power (CSP) and wind energy, coupled with the subsystem uniquely, such as the regenerative Rankine cycle, multi-stage flash (MSF) desalination unit, hydrogen production process, and Li–Br absorption chiller, the KSC's system maximizes energy conversion efficiency while minimizing environmental impact. Noteworthy outcomes include daily water production of 177.63 kg/s and hydrogen production of 169.61 kg/day, alongside annual energy contributions of 212,692,688 kWh for CSP and 66,158,552 kWh for wind turbines. More than that, it produces 23.04 kg/s MMH as fuel. Additionally, the overall energy and exergy efficiencies of the system are 30.6% and 33% respectively. Despite challenges, such as low efficiencies in certain subsystems, like mono methyl hydrazine (MMH) production, ongoing research and development efforts aim to optimize processes and enhance sustainability. [ABSTRACT FROM AUTHOR]

A novel zero-carbon emission combined cooling, heating and power (CCHP) system is currently proposed. The thermal energy of the solid oxide fuel cell (SOFC) exhaust is recovered in a transcritical CO 2 (T- CO 2) power cycle. Relying on the efficient utilization of liquefied natural gas (LNG) cold energy, CO 2 capture has been achieved at low energy consumption. The thermodynamic performance is evaluated by using energy and exergy analysis methods for this hybrid process. The electrical, exergy, and CCHP efficiencies are obtained as 60.37 %, 62.83 %, and 79.09 %, respectively. The CO 2 condenser, with the largest exergy destruction ratio (18.60 %) and a low exergy efficiency (37.16 %), is regarded as the weakest point in terms of thermodynamic perfectibility. In addition, the influences of the current density, stack temperature and pressure, and fuel utilization rate have also been studied from different aspects of system performance. The current density, stack temperature, stack pressure, and fuel utilization rate are recommended as 0.3 A/cm2∼0.4 A/cm2, 900 °C, 5 bar, and 85 %, respectively. This research provides practical reference and pragmatic guidance for the integration, analysis, and optimization of SOFC-based CCHP systems. • A novel SOFC-based CCHP system is proposed, utilizing the cold energy of LNG. • The zero-carbon emission in this novel system is realized with low energy consumption. • Energy, exergy, and parametric analyses are conducted for the system evaluation. • The electrical, exergy, and CCHP efficiencies are 60.37 %, 62.83 %, and 79.09 %. • The effects of key parameters are studied from different aspects of system performance. [ABSTRACT FROM AUTHOR]

The integration of a carbon capture system is an effective way to reduce CO 2 emissions from coal-fired power plants, but the carbon capture system consumes much steam and power, which causes a high efficiency penalty. In this study, thermodynamic analyses were conducted on the coal-fired power plant integrated with carbon capture system under load cycling operation conditions. Results show that the exergy efficiency penalty increases with the decrease of power load ration, and the exergy efficiency of coal-fired power plant decreases by 8.29 and 10.02 % under 100 and 30 % load ratios with the integration of carbon capture system, respectively. The irreversibility of carbon capture system increases with the decrease of load ratio of coal-fired power plant. To enhance the performance of coal-fired power plant integrated with carbon capture system under load-cycling operation conditions, the pressure sliding operation strategy is proposed. The performance of the integrated system can be improved by increasing the absorber pressure when the load ratio is below 75 %. Moreover, decreasing the stripper pressure is beneficial to reduce the energy consumption. As a result, by pressure sliding strategy, the exergy efficiency is improved by 0.23, 0.31, 0.3, 0.37 % under 100 %, 75 %, 50 % and 30 % load ratios, respectively. • A new operation strategy of pressure sliding for carbon capture system is proposed. • The performance of CFCC under load cycling operation conditions was evaluated. • Influences of the operation pressure of key devices were quantitatively analyzed. • The exergy performance was increased by 0.3–0.37 % under low power load ratio. [ABSTRACT FROM AUTHOR]

Autocascade high-temperature heat pump (AHTHP) have the capacity for significant temperature increases, offering a promising alternative for industrial decarbonization. For a more comprehensive evaluation of the performance improvement potential of an air-source AHTHP, this work proposed a method to select refrigerant blend that has the greatest effect on the performance of an AHTHP by using an advanced exergy analysis. Subsequently, a refrigerant selection for an air-source AHTHP with steam injection technology was performed. The performance enhancement was evaluated under year-round system operating conditions, comparing the selected refrigerant with a refrigerant blend chosen using the conventional thermodynamic method. The results indicate that the refrigerant blend 0.6R245fa/0.4R1234yf, chosen through the advanced exergy analysis, exhibits a more significant capability to enhance heating capacity and output temperature in comparison to the refrigerant 0.5R1233zd(E)/0.5R1234yf, which was chosen through the conventional thermodynamic analysis. When increasing the heating capacity, the average Coefficient of performance (COP) of the refrigerant blend 0.6R245fa/0.4R1234yf at the daily maximum and minimum temperatures increased by 5.60 % and 4.07 %, respectively, while the average power consumption decreased by 6.08 % and 23.81 %, respectively. When increasing the output temperature, the COP difference between the two refrigerant blends is not significant. The average power consumption with 0.6R245fa/0.4R1234yf is 2.19 kW and 2.71 kW at the output temperature is 120 °C and 110 °C respectively, which is lower than the average power consumption with 0.5R1233zd(E)/0.5R1234yf. The results and analysis of this research could provide an effective guidance for enhancing the performance and environmental friendliness of air-source AHTHP. • An air-source AHTHP using air to generate high-temperature steam is proposed and modeled. • A methodology for refrigerant selection for air-source AHTHPs using advanced exergy analysis is presented. • The potential of air-source AHTHPs using different refrigerant blends to increase output temperature and output heating capacity is analyzed. [ABSTRACT FROM AUTHOR]

This paper investigates how to improve the utilization of solar energy in concentrated solar power plants for multi-tasked operation, including hydrogen production. In this regard, an integrated energy system with multiple power generation stages is developed to utilize heat from concentrated solar collector with molten salt thermal energy storage system. The two-stage steam Rankine cycle and organic Rankine cycle are used as power generation cycles in order to utilize heat from the molten salt at different temperature levels, which improves source utilization for power generation. Continuous energy supply is considered a crucial challenge for renewables, which can be achieved by diversifying the source or adding energy storage. The current study uses two different energy storage methods to ensure the continuous energy supply to achieve self-sufficiency as well for the community. Hydrogen energy subsystem is the second energy storage within the integrated system, which is the secondary energy storage that is used if heat is not sufficient to drive the power generation cycles. In order to make decisions for a better source utilization, ensure continuous power supply, and facilitate the operations of the components and energy storage subsystems according to the loads and source availability, an operational decision-making strategy is developed and applied within the spreadsheet model. In order to test the proposed system and the developed algorithm, a time-dependent analysis is carried out where hourly community load and hourly source data are employed. The analyses are carried out using the first and second laws of thermodynamics, primarily through energy and exergy aspects. The power cycle can generate power from heat within the temperature range of 160°C and 500°C, in between 6.12% and 37.2% of heat to power energy conversion efficiency. The overall energy and exergy efficiencies of the integrated system are found to be 31.29% and19.71% by considering the average meteorological data. • A new concentrated solar-based integrated energy system is designed. • The community demand and changing source availability are simulated. • The molten salt thermal energy and hydrogen storage options are incorporated into. • The energy and exergy efficiencies are determined annually for each hour. [ABSTRACT FROM AUTHOR]

The escalating global energy demand has prompted increased focus on the industry of liquefied natural gas (LNG), emphasizing the need for optimizing liquefaction processes to minimize capital costs. Thus, the integration between liquified natural gas LNG regasification and liquid air energy storage (LAES) to produce electricity and utilize the cold energy of LNG regasification has several interests to maximize the benefits of the process to generate power and face the challenges such as energy saving and reducing the total operations costs ... etc. Fortunately, this study introduces a novel approach that combines a single-effect mixed refrigerant (SMR) cycle with air liquefaction, incorporating regenerative Rankine cycles for enhanced efficiency. The effectiveness of the LNG-SMR-LAES process was evaluated using comprehensive energy, exergy, and economic analyses to ascertain its viability. The results showed a notable improvement in the overall net power energy by 6 % and an increase in exergy efficiency by 11.7 % compared to the base case. Energy savings of 31.6 % (470.10 kW) contributed to the process's environmental and economic feasibility. The net present value was estimated at 11,230.4 US dollars, affirming the industrial-feasible design and economic viability of the LNG-SMR-LAES process. [Display omitted] • Novel approach combines LNG-SMR-LAES to enhance process efficiency. • Proposed process achieved net power of 2462.6 kW for 12 h, increased by 6 %. • LNG-SMR-LAES process attained an electrical RTE of 168.64 % and a COP of 1.59. • Remarkable 92.03 % exergy efficiency and 31.6 % energy savings (470.10 kW) achieved. • Net present value estimated at K$11,230.4 confirming process economic feasibility. [ABSTRACT FROM AUTHOR]

Thermoelectric generators have struggled with low efficiency, limiting their widespread use. To further improve the performance of the thermoelectric generator, this paper introduces the biconical pin structure into the segmented annular thermoelectric generator, and simultaneously incorporates exergy efficiency and economic cost to evaluate its performance. Experiments are first used to verify the accuracy of the simulation model, and then the effects of the cone angle θ , leg height H , leg length ratio δ and resistance ratio ε are discussed. Finally, correlation analysis is used to obtain the weight of the impact of research parameters on thermoelectric performance, and the optimized results are obtained. The results demonstrate that the output power of the biconical segmented annular thermoelectric generator is 20.23 % higher, the exergy efficiency is 8.55 % higher, and the economic cost is reduced by 21.36 % compared to the traditional segmented annular thermoelectric generator. As the θ and H increase, the thermoelectric performance enhances. The influence of δ on thermoelectric performance is more complicated. When ε is 1.5, the thermoelectric generator has optimal thermoelectric performance. This paper provides a reference for optimizing the segmented annular thermoelectric generator structure and is of paramount importance for enhancing the efficiency of waste heat recovery. • The biconical segmented annular thermoelectric generator is proposed. • Research is conducted using exergy analysis and economic cost analysis. • The influence weight of parameters on performance is explored. • The optimal parameters of thermoelectric generator are obtained. [ABSTRACT FROM AUTHOR]

In the present research a cogeneration cycle based on a solid oxide fuel cell (SOFC), and Organic Rankine Cycle (ORC) is proposed. The cycle is fed with biogas in different molar ratios of carbon dioxide to methane (RCTC). In addition, the cycle is examined for both dry reforming (DR) and steam reforming (SR). A thermochemical model is presented for both cycles of SR–SOFC–ORC, and DR–SOFC–ORC. The model is coded in MATLAB coupled with Engineering Equation Solver software. The model was verified with both experimental and theoretical research and agreement was achieved. The energy and exergy performance of the cycle is presented and carbon deposition on the cathode due to different reactions of methane cracking, Boudouard reaction, and vapor formation are studied. The results show that for RCTC<1.2 steam reforming produces more hydrogen, while for RCTC>1.2 dry reforming is advantageous. At RCTC = 1.2 the DR and SR work the same. The overall thermal efficiency of DR-SOFC and SR-SOFC has reached 67 % and 70 %. Carbon deposition due to the Boudouard reaction, and vapor formation for both SR and DR are negligible while due to methane cracking is serious. The DR-SOFC deposits less carbon because of methane cracking due to higher operating temperatures. • A cogeneration cycle based on a biogas fueled SOFC and ORC is proposed. • The cycle is assessed with both dry and steam reforming. • The impact of different biogas compositions on cycle performance is evaluated. • Carbon deposition on the cathode is investigated. • The cycle based on steam reforming has higher efficiency. [ABSTRACT FROM AUTHOR]

Combustors of gas turbine engines have generally the highest irreversibility due to the combustion process. Therefore, to observe influence of air to fuel ratio (AFR) on combustor performance is of high importance. In this study, thermodynamic laws are employed to separately determine adiabatic flame temperature (AFT), entropy production, exergy destruction and exergy efficiency of combustor for turbojet (TJ), turbofan (TF), turboprop (TP) and turboshaft (TS) where variables are AFR, combustor inlet temperature (CIT) and combustor pressure ratio (CPR). In this regard, the higher the AFR, the lower the adiabatic flame temperature, however the higher the entropy production for related combustor. Similarly, increasing AFR leads to raise exergy destruction, thereby lowering exergy efficiency. On the other hand, as CIT increases, exergy efficiency of the combustor improves whereas slight effects of CPR on the combustor metrics are observed. Namely, due to variation of AFR, exergy destruction of combustor changes between 0.512 MW and 0.825 MW for TJ, between 1.807 MW and 2.735 MW for TS, between 28.38 MW and 40.49 MW for TF and between 3.102 MW and 4.564 MW for TP. Moreover, exergy efficiency of combustor changes between 59% and 73% for TJ, between 70% and 77% for TS, between 78% and 81% for TF and between 75% and 79% for TP engine through the determined AFR and CIT ranges. These findings indicate that combustor of each gas turbine engine demonstrates different behavior according to the mentioned variables and exergy efficiency of combustor depends on finding the optimum points of combustor variables. • Increasing AFR is prone to decreasing adiabatic flame temperature whereas the higher AFR increases exergy destruction. • To obtain maximization of exergy efficiency of combustor depends on finding out optimum points of AFR and AFT variables. • Combustor pressure ratio has a weak effect on combustor metrics in comparison with the AFR. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) is an excellent process for transforming biomass into solid fuels. Evaluating HTC's environmental benefits requires addressing substantial energy needs for reactant heating. In this regard, two innovative solar systems for powering HTC were investigated: a parabolic trough collector (PTC) that heats a heat transfer fluid (HTF) circulating through a heat exchanger surrounding a batch reactor and photovoltaic panels (PV) that powers a heating collar. Experimental results reveal that the PV system efficiently attains subcritical conditions, whereas the PTC system faces challenges. Exergetic analysis identifies heat transfer as a primary irreversibility factor, resulting in a recorded maximum entropy of nearly 100 W/K. This caused the exergy efficiency to decrease to a minimum of 0.07, dropping the accumulated exergy below 82 W. To address this issue, a validated mathematical model was employed to investigate three optimized configurations: an immersed heat exchanger, a jacketed system, and a hybrid system combining both. The results demonstrated achieving desired HTC conditions at mixing temperatures of 185 °C, 195 °C, and 230 °C, respectively. In contrast, the PV system rapidly attains 220 °C and 40 bar in 70 min. This study proposes innovative solar HTC designs for sustainable hydrochar production using PV and PTC technologies. • Innovative solar hydrothermal carbonization systems are proposed. • These systems use parabolic trough and photovoltaic panels as energy sources. • Experimental approach and energy, exergy analyses are used for evaluating the proposed systems. • A validated mathematical model used to propose other systems optimizing efficiency. [ABSTRACT FROM AUTHOR]

Gas-fired power generation, characterized by high efficiency, low carbon emissions, and flexibility, contributes significantly to the global energy transition. In the present work, a novel dual-stage intercooled and recuperative gas turbine system integrated with transcritical organic Rankine cycle (dICR-GT-tORC) was proposed. System modeling was carried out based on Thermoflex software for different configurations to evaluate the energetic and exergetic performances. It was found that the dICR-GT-tORC exhibited improved thermodynamic performance compared to the gas turbine simple cycle and dICR-GT system, with the system net energy efficiency/exergy efficiency/specific work increasing from 43.88%/41.80%/567 kJ·kg air −1 and 57.21%/54.49%/684 kJ·kg air −1 to 62.48%/59.52%/745 kJ·kg air −1, respectively. An energy utilization diagram analysis revealed that the energy cascade utilization was achieved by coupling a bottoming tORC to fully utilize the waste heat from intercoolers and the exhaust gas. Furthermore, the dICR-GT-tORC demonstrated enhanced environmental performance, reducing the CO 2 emission rate by a maximum value of 29.8%. Additionally, the impacts of key parameters, including the organic working fluid selection, the minimum temperature difference at the pinch point of recuperators and the terminal exhaust gas temperature on the system performance were investigated. It was indicated that the proposed system could be applicable in various practical scenarios from thermodynamic and environmental perspectives. • Dual-stage intercooled and recuperative gas turbine system integrated with transcritical ORC was proposed. • System modeling was conducted for energetic and exergetic performances evaluation. • The energy efficiency of the proposed gas-fired power system reached up to 62.48%. • Influence of key parameters on the system performance was analyzed quantitatively. [ABSTRACT FROM AUTHOR]

To achieve a net zero-emission society, current industries must transition to become less carbon-intensive while fulfilling the rising power demand. In this study, we present a novel multigeneration system that produces power, cooling, and solid carbon dioxide by applying cryogenic carbon capture to a gas turbine flue gas. The energy recovery concept is efficiently employed to avoid energy and exergy losses in the system. The system is simulated in Aspen Plus with the mathematical models of the exergy streams and solid-vapor equilibrium written in Matlab. The performance of the plant is assessed based on energy, exergy, economic, and environmental evaluations. Thermodynamic analysis indicates that 1.2 MJ of electricity is required to capture 1 kg of CO 2 from the gas turbine exhaust gas (which is lower compared to conventional systems) with 100 % CO 2 purity. The net generated power, energy efficiency, exergy efficiency, m ˙ CO 2 , captured , and m ˙ CO 2 , emitted for the proposed system are 179.4 MW, 41.2 %, 59.3 %, 500,000 tons annually, and 255,000 tons a year, respectively. Sensitivity analysis shows that reducing the flue gas temperature positively impacts the CO 2 content in the flue gas while having a negative effect on energy and exergy efficiency. The economic investigation shows that the system is economically profitable. [Display omitted] • The proposed system has the functions of power generation and carbon capture. • The yielded carbon dioxide purity of the proposed system is 100 %. • The energy consumption of carbon dioxide capture is only 1.2 MJ/kg. • The total exergy efficiency of the proposed system increases by 91 %. • Economic analysis results show that the proposed system has economic profitability. [ABSTRACT FROM AUTHOR]

Considering the importance of using renewable energies for human societies, it is necessary to optimize the devices used. Flat plate solar collectors play a prominent role in the domestic and industrial sectors, so it is very important to enhance their performance. Changing the structure of the collector and using minichannel flat plate collectors (MFPCs) instead of sheet and tubes conventional flat plate collectors (CFPCs) is one choice. This study examines and compares the performances of a MFPC and a CFPC based on the energy, exergy and entropy generation perspectives. The working fluid is water and the fluid flow is laminar. Both collectors have the same contact surface between the working fluid and the inner surface of the riser tubes or the minichannels. In order to solve the equations, a thermal model is developed and the engineering equation solver is used. The results show that for all of the investigated conditions, the thermal and exergy efficiencies of the MFPC are higher than those of the CFPC and the maximum energy and exergy superiorities of the MFPC are 13.8 and 14.08 %, respectively. The study of the energy performance criteria shows that the MFPC is more suitable at lower volumetric flow rates and higher inlet fluid temperatures. Investigating the entropy generation and exergy destruction indicates that for every similar case the entropy generation and exergy destruction of the MFPC are lower than those of the CFPC. These interpretations, which are based on the energy, exergy, entropy generation and exergy destruction evaluations, recommend utilization of MFPCs instead of CFPCs. • Comparative performance evaluations of a CFPC and a MFPC have been accomplished. • The energy, exergy and entropy generation perspectives have been considered. • Both collectors have a similar contact surface for the working fluid. • Thermal and exergy efficiencies of the MFPC are higher than those of the CFPC. • Entropy generation and exergy destruction of the MFPC are lower than those of the CFPC. [ABSTRACT FROM AUTHOR]

Cryogenic systems are widely used in industries but are known for their high energy consumption. Designing these systems involves numerous variables, objectives, and constraints. This study introduces an optimization approach applied to three cryogenic processes: Natural Gas Liquids (NGLs) recovery, Air Separation Unit (ASU), and propane mixed refrigerant (C3MR) liquefaction, focusing on minimizing energy input to enhance efficiency and LNG output in a mega LNG plant. Exergy analyses identified energy losses in compressors (47 %), columns (37 %), heat exchangers (10 %), and valves/mixers (5 %), highlighting the need for improved compressor design. Optimization showed that inefficiencies could be reduced by adding inter-cooled compression stages and isentropic/isothermal compression routes. The ASU optimization involved five independent variables with optimized conditions demanding 30 MW of compression power while achieving 51 % separation efficiency. Heat exchangers are the main source of exergy loss in the standalone C3MR cycle, accounting for 61.82 % of 69.0 MW followed by compressors ∼29.27 %. When simulated with utilities, total exergy loss increases to 249.0 MW, with compressors accounting for 78.34 %, exergy loss from heat exchangers drops to 17.94 %. Results affirm the practicality of the proposed method for optimizing complex cryogenic systems, providing valuable engineering insights and potential for significant energy savings. • An effective optimization methodology for complex processes. • Can be applied by various users. • Validation and insights generation are integral components. • Tested on complex cryogenic processes. • Results can be used to synthesize efficient control schemes. [ABSTRACT FROM AUTHOR]

This article introduces a new trigeneration system designed to meet the escalating energy demands by harnessing solar energy. Notably, the system features dual-mode operation and integrates ultrasound technology for hydrogen production, enabling it to adapt to varying levels of energy production by seamlessly transitioning between two modes. Through comprehensive energy, exergy, and environmental analyses, this study evaluates the system's performance and its environmental advantages. The results demonstrate that the system achieves the energy and exergy efficiencies of 58.28 % and 76.75 %, respectively. Moreover, it demonstrates that, under sunlight conditions, the system can produce hydrogen at a rate of 1 kg/h and deliver a power output of 1957 kW. During the periods utilizing a thermal energy storage option, the system is capable of generating hydrogen at 0.8 kg/h and an electrical power output of 1481.2 kW. The environmental analysis indicates that the system is eco-friendly, with the potential to reduce carbon dioxide emissions by 4.54 kg/kWh. These results underscore the system's efficiency and its contribution toward a more sustainable and environmentally friendly energy future. [ABSTRACT FROM AUTHOR]

Modern energy systems are more and more based on integrated technologies in a world evolving towards increasing concerns not only for economics but also for environmental issues with a growing focus on resources and emissions. In parallel, information technologies including advanced simulation and optimisation algorithms develop at a rapid pace. Thermoeconomics based on either the First Law or exergy, together with cost factors distributed through its equipment, also evolved during the last 30 years. However modern muti-objective evolutionary optimisation techniques, extending the capacity to tackle optimisation considering a growing number of parameters including the internalization of the costs of emissions of whole systems has also emerged. The latter is called environomics. So far, the supply of energy services was essentially dominated by fossil-based resources with a high focus on operational costs. The new trends towards renewable energies requires a growing need to consider the embedded exergies since renewable energy, like solar energy, is economically free and operational costs are inherently low. While economic factors can vary over a broad spectrum throughout the years of operation, the embedded exergies are more stable values, particularly because the systems are built in a known economic and energetic environment. A new class of methods is only emerging to deal with more complete exergy approaches to formulate more holistic exergy life cycle analyses. Those should provide a lower bound of the expected exergy payback over the lifetime of the systems to be compared with thermoeconomic or environomic optima. It is still a huge challenge ahead to provide practical tools to do it. [ABSTRACT FROM AUTHOR]

This study numerically investigated the cooling effect, energy, and exergy analyses of twisted tapes with different pitch ratios (3, 4, and 5), widths (5, 7.5, and 9.5 mm), and thicknesses (0.5, 1, and 1.5 mm) on PV/T systems between Reynolds numbers of 500 and 1900. The research revealed a positive correlation between surface temperature and both thickness and pitch, but width showed a negative correlation with surface temperature. The maximum measured PV/T surface temperature was 320.437 K, and the minimum was 307.929 K. The thermal efficiency declined as the thickness, pitch, and width increased. The maximum thermal efficiency reached 59.35%. The highest Performance Evaluation Criteria (PEC) value of 1.535 was obtained with a width of 9.5 mm, a pitch ratio of 3, a thickness of 0.5 mm, and a Reynolds number of 500. The exercise evaluations revealed the advantageous impact of including a twisted tape insert in a PV/T system. The maximum electrical efficiency of exergy was 13.77%, while the maximum thermal efficiency of exergy was 1.59%. The RSM (Response Surface Methodology) was used to analyze the 405 numerical data acquired. Based on the analyzed parameters, equations were produced that may be applied to future geometries. • In addition to performing RSM analysis, this study examined the energy, exergy, and cooling effects of twisted tapes in PV/T systems. • The maximum performance evaluation criterion (PEC) was obtained at 1.535. • The maximum thermal efficiency reached 59.35%. • Exergy had a maximum electrical efficiency of 13.77%, and a maximum thermal efficiency of 1.59%. [ABSTRACT FROM AUTHOR]

Thermally integrated pumped thermal energy storage (TI-PTES) is a flexibility option to recover low-grade heat and provide overnight storage. Common criteria when designing such systems are the power-to-power efficiency (electricity recovery), the exergy efficiency (combined heat and electricity recovery) and the energy density (storage size). However, these are generally conflicting and multi-criteria optimisation is therefore required. Design guidelines have been proposed for some specific case studies but are still lacking for the remaining wide range of possible integrations. This work therefore presents a systematic multi-criteria analysis of a TI-PTES, consisting of a vapour compression heat pump, a sensible heat storage and an organic Rankine cycle, in an extended integration domain. Results show that the storage temperature levels are key variables, as they directly influence the conflict between the performance of the heat pump and the organic Rankine cycle. Also, the intensity of the conflict between the three criteria increases with the temperature difference between the source and the sink, mainly because of the power-to-power efficiency (the density and the exergy efficiency are much less conflicting with each other). Finally, the relevance of thermal integration in TI-PTES is questioned when it leads to a sharp deterioration in exergy efficiency and density. [ABSTRACT FROM AUTHOR]

The ongoing energy transition towards renewable sources faces reliance on fossil fuels throughout their life cycle, primarily due to mining and material production for infrastructure. This study proposes the Renewable Exergy Return on Investment (RExROI) metric, which quantifies the renewable exergy obtained from each unit of non-renewable exergy invested in energy systems. It can be seen as a Renewation Index, applicable to any energy production system, indicating the degree of renewability of such technologies. Focused on silicon photovoltaic panels, the study explores five material intensities, nine scenarios based on the capacity factor and lifespan, and two alternatives for electricity used in the manufacture. Results show that material intensity increases RExROI from −0.6 MJ/MJ (non-renewable exergy is higher than electricity produced) to 5.7 MJ/MJ, increasing until 19 MJ/MJ with the best location and lifespan, and reaching 34 MJ/MJ if renewable electricity is used in manufacturing. Thus, carbon intensity can range from 734 to 7 gCO 2 eq/kWh. Furthermore, some strategies to enhance RExROI are discussed based on the (i) energy sources, (ii) materials, and (iii) production stages of photovoltaic panels. Thus, this study demonstrates the usefulness of RExROI in evaluating the energy-material-emission nexus of energy systems through exergy in the context of energy transition. [Display omitted] • RExROI compares actual renewable exergy generated with non-renewable invested. • PV panels RExROI multiplied by three with the best location lifespan. • PV panels RExROI increase in 80 % using renewable electricity in their production. • Exergy cost disaggregation is essential to analyze RExROI improvement strategies. • RExROI concept is applicable to any energy system. [ABSTRACT FROM AUTHOR]

The growing energy demand has prompted the research community to seek more efficient and sustainable resource extraction methods, particularly in the case of crude oil. Investigating the potential of nanotechnology to enhance crude-oil recovery from extra-heavy and heavy crude-oil reserves is crucial for optimizing resource utilization, improving economic viability, minimizing environmental impacts, driving technological advancement, ensuring energy security, and meeting market demands. In this study, we investigated the implementation of exergy analysis (ExA) on nanotechnology in oil-recovery processes, which has not previously been explored. This involved a life-cycle assessment (LCA) to evaluate the environmental impacts and to complement the ExA in order to optimize operations. To environmentally and thermodynamically analyze the extraction process of extra-heavy crude oil, four scenarios were evaluated: i) steam injection at 0.5 quality; ii) steam injection at 1.0 quality; iii) steam injection at 0.5 quality with 500 mg L−1 of nanoparticles; and iv) steam injection at 1.0 quality with 500 mg L−1 of nanoparticles. The nanofluids used (AlNi1 and AlNi1Pd1) consisted of 500 mg L−1 of alumina (Al 2 O 3) doped with a 1.0 % mass fraction of nickel (Ni) (i.e., AlNi1), and the same amount of alumina doped with a 1.0 % mass fraction of Ni and palladium (Pd) (i.e., AlNi1Pd1). Both nanofluids were supplemented with 1000 mg L−1 of Tween 80. The experiments were conducted in a laboratory and numerical simulation was used to upscale the different scenarios. Considering the equilibrium K-values model, a multiphase/multicomponent flow model coupled with an energy transport equation was utilized. Nanocatalyst transport, as per the experimental data, involved non-equilibrium transference between the liquid phases and the rock surface. The laboratory data were used to calibrate the model, which was then scaled up to reservoir conditions to estimate the oil recovery obtained from deploying in-situ upgrading processes at the field scale. Exergy calculations were performed on the involved flows and porous media in order to assess the crude-oil quality throughout the process. An LCA was implemented to evaluate the reduction in environmental impact achieved by using steam injection at X = 1.0 quality, with and without nanoparticles. The results of the ExA showed that using nanoparticles allowed crude oil with a higher energy quality to be obtained. Furthermore, the ExA showed that the increase in steam quality had a more significant effect on the exergy destroyed in the process than the use of nanomaterials, demonstrating the good performance of the proposed technology. Environmental analyses showed that marine ecotoxicity, urban land occupation, particulate matter formation, and global warming potential were the most-impacted categories, significantly contributing to total environmental impacts, after the fossil depletion impact category for all scenarios. In conclusion, using bimetallic nanoparticles in crude-oil extraction produces a better product with better energy and environmental performance. • Nanoparticles increase oil production during steam injection with better environmental performance. • Nanoparticles improve the energy quality of the crude oil produced during the thermal process. • An increase in steam quality had a more significant effect on exergy destruction in the process than nanoparticles. [ABSTRACT FROM AUTHOR]