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In recent years, there have been increasing concerns over the detrimental effects of irreversible linear patterns of material and energy consumption, which have led to an enormous generation of municipal solid waste (MSW). Concepts like waste-to-energy (WtE) and recycling have gained increasing recognition and support as responses to these challenges. This study assessed the exergetic potential of four WtE technologies (landfill gas-to-energy, anaerobic digestion, incineration, and plasma gasification) in the context of the MSW characteristics of Maiduguri, Borno State. The population of Maiduguri, waste generation rate, waste composition, and the ultimate and proximate analysis of the MSW were used for the assessment. Exergetic potential in the form of electrical energy generation and three exergy-based indicators (exergy efficiency, exergy defect, and improvement potential) were evaluated for each WtE option. The results reveal that anaerobic digestion and plasma gasification are viable options based on the exergetic potential and the measured exergy performance indicators. These findings offer valuable insights for policymakers and waste management authorities, facilitating informed decisions to address environmental concerns and promote resource-efficient urban development in Maiduguri and similar regions. [ABSTRACT FROM AUTHOR]

Establishing a permanent lunar base has gained increasing attention since it offers opportunities for international cooperation and the commercialization of space, forming the foundation and testing ground for a human existence independent from Earth. Essential to future missions beyond cislunar space is the exploration and in situ processing of the Moon's resources, especially the sustainable production of energetic resources and propellants. Utilizing in situ generated propellants can dramatically reduce transportation costs by removing the need to source propellants from Earth. Resources on the Moon are limited, and the extraction of available resources are energy-intensive processes demanding advanced techniques and technologies. Consequently, one of the biggest challenges lies in developing process architectures with a positive energy balance, for which comprehensive analyses are still missing. The focus currently lies on the extraction of water ice from lunar regolith and the production of hydrogen and oxygen through water electrolysis. However, alternative fuel and process options may reduce the energy cost while providing equivalent energetic revenue. In the scope of this research, the infrastructure and technologies required for extraction, refining, and storing are assumed to exist in cislunar space; therefore, only the operating cost is considered. Exergy analyses of in situ extraction methods are conducted to investigate whether the required energetic budget allows sustainable implementation. The analysis includes extraction methods and propellant options to reveal the extent to which alternatives to hydrogen are feasible. Exergy analyses determine thermodynamic losses of energy flows giving the ground for process optimization. The exergy destructed represents the margin of improvement within the process architecture and thus reflects the process's thermodynamic and economic value while allowing a more distinct examination of energy use. Assuming the availability of water and carbon dioxide ice in permanently shadowed regions, the analysis shows that choosing methane instead of hydrogen in combination with oxygen as propellants can reduce the required exergy input by up to a third. An example mission allows to directly compare the operating cost of the extraction processes for the different propellant options. The mission entails a spacecraft propelled by a liquid bipropellant engine utilizing the extracted propellant and transporting a payload of the same propellant to a depot located in lunar near-rectilinear halo orbit (NRHO). Although abundant in space, the results suggest that hydrogen may not be the only or even energetically cost-effective resource for developing cislunar and Martian space infrastructures. Likewise, sustainable extraction of propellants suitable for current and future propulsion systems will foster humanity's reach further into the solar system. • The exergy destructed represents the margin of improvement within the process propellant source on the Moon • Hydrogen may not be the only or even energetically cost-effective resource for developing cislunar and Martian space infrastructures. • Servicing a depot in a lunar NRHO can reduce the required exergetic cost by a third if methane is utilized as the propellant instead of hydrogen [ABSTRACT FROM AUTHOR]

• Detailed energy and exergy analyses are conducted on the proposed ARC. • Explore the effects of varying refrigerant mass flow rate and ammonia concentration in strong and weak solutions on key performance parameters. • Employing the GBRT machine learning method and FHO approach in the ARC is highly recommended. • The GBRT model proves to be a reliable predictive tool with strong accuracy, offering valuable insights into system performance. • The generator is the main source of exergy destruction rate (50 %). A detailed analysis of energy and exergy is conducted on a single-effect solar ammonia–water (NH 3 –H 2 O) absorption refrigeration cycle (ARC) using TRNSYS and EES software. Considering the physical and chemical exergies, the exergy destruction rate (Ė D) in each component of the system is calculated, highlighting its contribution to the overall Ė D. The study explores the effects of varying refrigerant mass flow rate (ṁ ᵣ) and ammonia concentration in strong and weak solutions (X s and X w) on key performance parameters, including coefficient of performance (COP), exergy efficiency (Ė D), and overall Ė D across a range of generator temperatures (T g). In this study, a gradient boosting regression tree (GBRT) is employed as a supervised machine-learning technique for classification and regression problems, utilizing boosting to enhance conventional decision tree predictions. The Fire Hawk Optimizer (FHO) approach is also utilized to optimize performance parameters, maximizing COP and η η E while minimizing T g and Ė D. The GBRT models are developed using available experimental and simulation data, revealing relationships between variables (ṁ ᵣ, X s , X w , and T g) and outcomes (COP, Ė D , and overall Ė D). The results revealed that the generator exhibits considerable Ė D regardless of operating conditions, underscoring its pivotal role in the ARC. It emerges as the primary Ė D contributor (50 %), followed by the evaporator (17 %) and the absorber (15 %). However, Ė D associated with the recooler, pump, and expansion valves is negligible in comparison. Optimization results reveal that, when minimizing T g and Ė D , the highest COP and Ė D at T g of 373.15 K reach 0.8081 and 0.46, respectively. [ABSTRACT FROM AUTHOR]

The development of future novel aircraft concepts requires a holistic approach to vehicle design, analysis, and optimization. Aircraft designers can no longer consider components individually as systems become more interconnected and multidisciplinary. Hence, a new approach to aircraft design and a new way to measure the performance of aircraft are needed. A novel approach to aircraft design is the use of exergy methods that can evaluate typically disparate systems using a universal measure of performance mapped to global system performance. This paper introduces a new functional and its adjoint gradient in FUN3D to determine aerodynamic exergy destruction rates. The functional is verified using the Oswatitsch relationship by comparing it to native, surface-based drag coefficients. The adjoint gradient is verified using the FUN3D native complex step method, and discrete agreement is demonstrated for flowfields and geometric derivatives. The new functional is then used for aerodynamic exergy-based analysis and optimization of the generic hypersonic vehicle. An inverse design problem is conducted first to verify the design optimization framework. Finally, a planform and airfoil aerodynamic inviscid exergy optimization of the GHV is conducted, improving exergy destruction rates by 7.1% while making substantial improvements to the cruise trim characteristics of the vehicle. [ABSTRACT FROM AUTHOR]

Power plant engineers today are primarily focused on maximizing the extraction of fuel energy. This objective involves improving the efficiencies of different thermodynamic elements and the overall cycle in terms of both first and second laws of thermodynamics. To achieve this, engineers are employing various techniques aimed at increasing these efficiencies. In the present work, one such technique being utilized is the substitution of water/steam with a different working fluid. By changing the working fluid, engineers aim to optimize the thermodynamic performance of the power plant. In this study, the analysis focuses on the utilization of an ammonia-water mixture combined with Trans critical carbon dioxide in a heat recovery vapor generator. The results of this research reveal that the highest work output and second law efficiency achieved are 1192 kJ/sec and 81.68% respectively. These optimal values are obtained when the topping cycle pressure is set to 50 bar, and the turbine inlet temperatures are 500°C and 300°C for the ammonia-water mixture and Trans critical carbon dioxide respectively. Furthermore, the maximum first law efficiency of 43.57% is observed when the topping cycle pressure is set to 50 bar, the bottoming cycle pressure is set to 160 bar, and the turbine inlet temperature is 300°C. The analysis also reveals that the heat source is responsible for the majority of energy destruction, with a maximum of 1970 kJ/sec of available energy being destroyed at a temperature of 500°C. To achieve the highest values of thermodynamic performance parameters, it is recommended to maintain low pressure in the absorber and condenser. Additionally, the analysis indicates that the cost of electricity generation reaches its peak when the condenser pressure is set at 70 bar, amounting to 0.050 USD/kWh. [ABSTRACT FROM AUTHOR]

Ever concluded whereas fractal fluctuations exhibit quantum-like chaos. Then provided a configurative description of a repeating units [from gather (unit) to transform (emergent unit)] of four conservation laws& forces in fractal organization of nature. To be proofed that Fibonacci sequence performed through Laplacian matrix normalization which technoeconophysics realm assumed as financial innovation. [ABSTRACT FROM AUTHOR]

Inclusively new to econophysics studies, herewith proposed techno-econophysics as part of techno-economy, econophysics & sociophysics to interparts description between probability and hypothesis evidently found between fractal realms and econophysics of markets, physics markets or stock markets any chaotic evidence [exergy destructive ] could present if effective & efficient criterion doesn’t complied. More precise iterative study ought to be held to configure how fractal dimension involved in techno-econophysics study of Helium Nat Gas Project which are not integer, but also proofed numerically & analytically. [ABSTRACT FROM AUTHOR]

In this work, exergy management strategies (ExMSs) for hybrid electric ground vehicles (HEVs) are developed. The main advantage of using the exergetic framework is the possibility of pursuing unconventional optimization goals that are inaccessible to the standard energy management strategy (EMS). For instance, in military applications, the critical goal of preventing thermal imaging detection from adversary units does not seem achievable with the conventional EMS. On the other hand, the exergy-based framework can be adopted to reduce the vehicle thermal emissions through the minimization of exergy terms related to heat exchange. Moreover, the overall efficiency of the vehicle can be increased through the minimization of the exergy destruction, a quantity that is not quantifiable by energy-based methods. In this paper, the exergetic model of a series hybrid electric military truck and the exergetic model of the electric induction generator are developed and used to formulate and solve two novel exergy management strategies aiming to minimize genset exergy destruction and thermal emissions, respectively. The optimal solutions to the EMS and ExMSs control problems are obtained through Dynamic Programming over two driving missions. The results show that ExMS for the minimization of exergy destruction achieves similar results to the standard EMS, while the ExMS for the minimization of thermal emissions obtains significantly lower thermal emissions compared to the EMS, effectively reducing the thermal imaging detection risk. [ABSTRACT FROM AUTHOR]

A numerical investigation was carried out in ANSYS Fluent® on a photovoltaic/thermal (PV/T) system with MXene/water nanofluid as heat transfer fluid (HTF). The interaction of different operating parameters (nanofluid mass fraction, mass flow rate, inlet temperature and incident radiation) on the output response of the system (thermal efficiency, electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency) was studied using a predictive model generated using response surface methodology (RSM). The analysis of variance (ANOVA) method was used to evaluate the significance of input parameters affecting the energy and exergy efficiencies of the nanofluid-based PV/T system. The nanofluid mass flow rate was discovered to be having an impact on the thermal efficiency of the system. Electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency were found to be greatly influenced by incident solar radiation. The percentage contribution of each factor on the output response was calculated. Input variables were optimized using the desirability function to maximize energy and exergy efficiency. The developed statistical model generated an optimum value for the mass flow rate (71.84 kgh−1), the mass fraction (0.2 wt%), incident radiation (581 Wm−2), and inlet temperature (20 °C). The highest overall energy and exergy efficiency predicted by the model were 81.67% and 18.6%, respectively. [ABSTRACT FROM AUTHOR]

Passive inserts, notably twisted turbulator inserts (TTI) and perforated twisted turbulator inserts (PTTI) loaded with water-based ternary hybrid nanofluid (THNF), are employed in plain tube heat exchangers to enhance thermal performance. The investigation focuses on how THNF replacement inserts will impact energy utilization, exergy consumption, and the environment in the decades to come. Nanoparticles of copper oxide (CuO), aluminum oxide (Al2O3), and titanium oxide (TiO2) are dissolved in water, which functions as the working fluid, and the resulting THNF is injected at three distinct concentrations (0.06, 0.09, and 0.12%). Certain aspects of the flow of a control fluid are investigated in terms of energy, exergy, and emissions. The experimental findings demonstrate that utilizing TTI and PTTI in conjunction with THNF substantially enhances the compact air heat exchanger's thermal and hydraulic efficiency. Heat transfer, friction factor, exergy change, and reversibility are greatly improved when turbulator inserts with PTTI and TTI are employed in plain tubes containing 0.12% (v/v) THNF. The CO2 discharge rises by 2.6–2.1 when PTTI or TTI turbulator inserts are inserted in the tube's core. Using PTTI with a concentration of 0.12% (v/v) THNF as the working fluid and a tube insert will provide PEC values in the range of 1.075–1.04. The thorough examination of heat transfer enhancement, friction factor, exergy efficiency, and environmental effect suggests that PTTI is a better passive device insert for heat transfer efficiency, particularly when combined with 0.12% (v/v) THNF. [ABSTRACT FROM AUTHOR]

The LNG cold energy utilization system primarily integrates additional power cycles during the gasification process to harness the cold energy released in this process efficiently. This study introduces a combined cooling and power (CCP) system, which comprises a cascade organic Rankine cycle (ORC), an air conditioning refrigeration (ACR), and a direct expansion cycle (DEC). Furthermore, the thermodynamic and economic analyses of the CCP system were evaluated, and the optimization of each influence parameters was performed by the genetic algorithms, such as the composition of the quaternary mixed working fluid (Methane: Ethane: Propane: i-Butane), condensation pressure, evaporation pressure, and the first-stage expansion pressure within the system. According to the simulation results, the suggested overall exergy destruction of the CCP system proposed by this work is reduced by 13.18% under optimized conditions, with a maximum net power generation of 230.38 kW and an exergy efficiency of 45.58%. Economic analysis reveals that the system's investment cost, annual economic benefits, and levelized energy cost are 2.02 × 106 $, 2.75 × 105 $, and 0.10 $/kWh, respectively. With the system's official operation, the investment cost will be recovered within 8.61 years. • A novel process for power generation combined with refrigeration has been proposed. • Optimized the composition of the quaternary mixed working fluid and key operation parameters. • The net out power and exergy efficiency are enhanced up to 13.40% and 7.21%, respectively. • The payback period of the system is as low as 8.61 years. [ABSTRACT FROM AUTHOR]

Increasing attention is being given to reduce the specific energy consumption in desalination processes, which translates into greater use of exergy analysis. An exergetic analysis provides relevant information related to the influence of the efficiency of a single component in the global plant performance and in the exergy cost of the product. Therefore, an exergy analysis identifies the main improvement potentials in a productive thermodynamic process. Related to desalination technologies, many previous papers deal with the calculation of the parameters involved in the exergy analysis, the exergetic efficiency of different processes, plants, and technologies among them. However, different approaches for formulating the exergetic efficiency have been suggested in the literature, often without sufficient understanding and consistency. In this work, these formulations, applied to the main desalination components and processes, are compared and critically reviewed. Two definitions of exergy efficiency are applied to the desalination components of the three main thermal desalination processes (multieffect distillation–thermal vapour compression, multistage flash distillation, and direct-contact membrane distillation). The results obtained for the exergy efficiency of the MED-TVC, MSF, and DCMD processes for the input–output approach are 21.35%, 17.08%, and 1.28%, respectively, compared to the consumed–produced approach that presented 3.1%, 1.58%, and 0.37%, respectively. The consumed–produced approach seems to better fit the thermodynamic behaviour of thermal desalination systems. [ABSTRACT FROM AUTHOR]

In this research paper, a solar air heater with triangular fins has been experimentally analysed and optimized. Initially, an experimental set-up of a solar air heater having triangular fins has been developed at the location of 28.10°N, 78.23°E. The heat transfer rate through fins and fins efficiency has been determined by the Finite Difference Method model equations. The experimental data and modeled data of response parameters have been optimized in MINITAB-17 software by the Response Surface Methodology tool. For creating the response surface design, three input parameters have been selected namely solar intensity, Reynolds number, and fin base-to-height ratio. The range of solar intensity, Reynolds number, and fin base-to-height ratio is 600 to 1000 W/m2, 4000 to 6000, and 0.4 to 0.8 respectively. The response surface design has been analyzed by calculating the outlet temperature, friction factor, Nusselt number, fin efficiency, thermal performance factor, and exergy efficiency. The optimum settings of input parameters: solar intensity is 1000 W/m2; Reynolds number is 4969.7, and the fin base to height ratio is 0.6060, on which these response: namely outlet temperature of 92.531°C, friction factor of 0.2350, Nusselt number of 127.761, thermal efficiency of 50.836%, thermal performance factor of 1.4947, and exergy efficiency of 8.762%. [ABSTRACT FROM AUTHOR]

Considering the global challenges of environmental destruction, limited fossil reserves, and the reduction of the share of energy in the final price of the product, a detailed evaluation of energy‐intensive systems is needed to improve performance. The syrup heating process is one of the basic processes in sugar factories. In this study, the syrup heating system in the purification and evaporation lines, located in the Urmia sugar plant, was evaluated, analyzed, and compared with energy and exergy analysis. Also, the subsystems of the syrup heating process were evaluated with thermodynamic analysis. Mass, energy, and exergy balances were carried out by coding in EES software, and energetic and exergetic operational parameters were extracted. The heat loss rate and exergy destruction rate in the syrup heating system of the purification line were calculated as 121.29 and 404.36 kW, respectively, and in the syrup heating system of the evaporation line as 112.70 and 238.62 kW, respectively. The recovery potential rate was 134.99 kW for the purification line and 37.70 kW for the evaporation line. The stability index and exergy efficiency for the purification line were calculated as 3.03% and 67.01% for the purification line and 6.54% and 84.71% for the evaporation line. The results of the thermodynamic analysis showed that the syrup heating process in the purification line has weaker performance from the energetic and exergetic point of view, is accompanied by large losses, and imposes a greater environmental burden. Accordingly, it is suggested that the improvement of the syrup heating performance in the purification line should be prioritized for engineering optimization and redesign in sugar processing plants. Practical applications: Monitoring the operational state of the systems and determining system losses are critical steps in food thermal processing. A practical and accurate method to evaluate the purification and evaporation lines is required to improve the thermal efficiency. According to exergy analyses, the performance of the syrup heating process in the purification line is low due to large losses and imposes a greater environmental burden. Therefore, the improvement of the syrup heating performance in the purification line should be prioritized for engineering optimization and redesign in sugar processing plants. [ABSTRACT FROM AUTHOR]

Despite the increasing use of petroleum-based fuel as a result of ever-increasing energy demands, the search for alternative fuels remains important. In this study, in a Lombardini LGW 523 brand 2-cylinder 4-stroke water-cooled engine, different volumetric ratios of methanol and gasoline fuel mixtures (M10, M20, M30, M40) were used at 4 different torque values (5, 10, 15, 20 Nm) at a constant 3000 engine speed. It is discussed. As a result of the study, engine performance, emission and energy analysis examination was carried out experimentally. [ABSTRACT FROM AUTHOR]

In internal combustion engines, operating conditions, engine design and fuel properties are closely related to efficiency. The alternative fuel used in diesel engines is expected to improve performance and emission values. Biodiesel is widely used to improve the fuel properties of alcohol and diesel. In this study, the effects of diesel, diesel-methanol, dieselbiodiesel, diesel-biodiesel-methanol mixtures are examined. Engine performance and exhaust emission tests were carried out on a three-cylinder, four-stroke diesel engine at a constant speed of 1500 rpm and five different loads: no load, 25%, 50%, 75% and 90%. Since constant speed and torque values could not be obtained in the no-load condition (T0) in the studies, the values at T0 were not used in the comparisons. As experimental data, thermal efficiency, CO, HC, CO2, NO emission values, in-cylinder pressure values and heat release rate values were examined. In experimental studies, the effects of adding different amounts of biodiesel and methanol on engine performance and emission values were compared with diesel. As a result of the comparison, positive results were obtained in the performance and gas emission values of alternative fuels compared to 100% diesel. In addition, fuel mixtures with biodiesel addition have better performance results than fuel mixtures with methanol addition. [ABSTRACT FROM AUTHOR]

The escalating challenge of waste management demands innovative strategies to mitigate environmental impacts and harness valuable resources. This study investigates waste-to-energy (WtE) technologies for municipal waste management in Kočevje, Slovenia. An analysis of available waste streams reveals substantial energy potential from mixed municipal waste, biodegradable waste, and livestock manure. Various WtE technologies, including incineration, pyrolysis, gasification, and anaerobic digestion, are compared. The results show that processing mixed municipal waste using thermochemical processes could annually yield up to 0.98 GWh of electricity, and, separately, 3.22 GWh of useable waste heat for district heating or industrial applications. Furthermore, by treating 90% of the biodegradable waste, up to 1.31 GWh of electricity and 1.76 GWh of usable waste heat could be generated annually from biodegradable municipal waste and livestock manure using anaerobic digestion and biogas combustion in a combined heat and power facility. Gasification coupled with a gas-turbine-based combined heat and power cycle is suggested as optimal. Integration of WtE technologies could yield 2.29 GWh of electricity and 3.55 GWh of useable waste heat annually, representing an annual exergy yield of 2.98 GWh. Within the Kočevje municipality, this amount of energy could cover 23.6% of the annual household electricity needs and cover the annual space and water heating requirements of 10.0% of households with district heating. Additionally, CO2-eq. emissions could be reduced by up to 20%, while further offsetting emissions associated with electricity and district heat generation by 1907 tons annually. These findings highlight the potential of WtE technologies to enhance municipal self-sustainability and reduce landfill waste. [ABSTRACT FROM AUTHOR]

This study reviews the efforts made regarding thermal desalination systems, focusing on the exergetic aspect. Each plant has a component, which limits the magnitude of thermal energy improvement; however, the target should be an effort to minimize the exergy destruction. It was found that all stand-alone systems required modification or integration with other desalination plants due to their low exergy efficiency. Furthermore, the exergy-destructive components in humidification–dehumidification (HDH) systems as a domestic desalination process, in poly-generation systems by the ability of freshwater production and energy generation, and in combined cooling–heating–power (e.g., MEE-CCPP) cycles as the recent desalination technologies were introduced. The exergy efficiency of a desalination plant increased by coupling to a solid oxide fuel cell or heat pump, using surplus low-pressure or makeup steam and optimization of the effect and stage numbers. Designing a poly-generation system capable of producing power, desalinated water, as well as liquefied natural gas heating/cooling could improve the system exergetically. Desalination systems were found to benefit from increasing the evaporation temperature caused by a Rankine cycle. Coupling the HDH system to a reverse osmosis unit or thermo-compressor vapor compression–reverse osmosis plant was found to improve the system performance exergetically. [ABSTRACT FROM AUTHOR]

In this work, the cross-linear system, a recently developed concentrated solar power technology, is investigated for process heat application to mitigate the drawback of cosine loss at higher latitudes in current concentrated solar power technologies. The mathematical model for energy and exergy analysis has been developed and validated using computational analysis and experimental work previously performed. The simulation was conducted under the average direct normal irradiance of 756.47 W/m2 considered for 8 h (Sunny hours) for April 2017. The primary goal of the thermal investigation is to identify the optimal inlet parameters for the heat transfer fluid (HTF) while considering significant value of HTF outlet temperature, energy, and exergy efficiency of the receiver. The mathematical model is developed and simulated using Engineering Equation Solver software. Following an in-depth examination of the outcome, the optimum inlet HTF temperature and mass flow rate are established with noteworthy energy and exergy efficiency. The analysis demonstrates the utilisation of the cross-linear system for process heat applications at higher latitude locations (> 30°N) to circumvent the weakness of other existing concentrated solar power technologies due to the air's wide operating temperature range as HTF. The observed results show that this system provides hot air from 180 °C to 200 °C at a thermal efficiency of 45% −50% and exergy efficiency from 25% to 30% for the low inlet temperature of 60 °C to 100 °C. Even at higher latitudes (> 30°N), the cosine effect of 0.9 for 4 h duration is a unique advantage of this system. [ABSTRACT FROM AUTHOR]

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Loop heat pipe (LHP) encased in phase change material (PCM) incorporated annular to catalytic converter (CC) is proposed to augment the performance of the "thermal energy storage" (TES). LHP are designed to extract surplus heat from the exhaust discharge, thereby reducing the amount of exhaust heat emitted into the atmosphere. A four-cylinder IC engine's CC is considered with Mg70Zn24.9Al5.1, paraffin oil as PCM and working fluid for the heat pipe are evaluated. A comparative experimental investigation was performed considering two models for CC with and without heat pipe integrated in the TES for (i) distribution of average PCM temperature (ii) energy, exergy efficiency and distribution (iii) effectiveness (iv) instantaneous waste heat recovered during heat storage. Transient cycles at 2000 r/min with varying load conditions were run considering city drive conditions. Heat storage for CC with heat pipe encased in TES was found to be 35% faster, whereas discharge time for CC without heat pipe developed in TES was found to be longer. For melt fraction 1, maximum exergy efficiencies of 71% and 69% were observed for the TES unit with and without heat pipe. Heat pipes are observed to help extract a considerable amount of surplus heat from exhaust and reduce the exhaust gas outlet temperature released into the atmosphere by nearly 130 – 40°C under various load circumstances. [ABSTRACT FROM AUTHOR]

One avenue in increasing the energy efficiency of energy systems is through utilizing the thermal energy of flue gases of industrial plants. On this thread, herein, a novel combined cascade cycle for heat recovery of flue gases of an industrial plant is proposed comprising of an organic Rankine cycle (ORC), high‐pressure transcritical CO2 cycle, transcritical CO2 cycle, and a liquefied natural gas (LNG) regasification cycle. System analysis is conducted using energy, exergy, and eco‐exergy equations. The optimization is carried out using the TOPSIS multi‐objective method. Exergy efficiency, net output work, and cost are identified as the optimization objectives. The optimization process focused on fine‐tuning variables including the vapor generator pinch point temperature, ORC turbine inlet pressure, ORC condenser pressure, and ORC condenser pinch point temperature, with optimal values gauged at 19.31°C, 29.59 bar, 1.413 bar, and 14.52°C, respectively. The preheater had the largest exergy destruction share, followed by the heat exchanger unit. The analysis showed that the ORC condenser pressure and temperature difference between two working fluids in the heat exchanger were the most critical parameters in the proposed cycle, significantly affecting the system performance. Accordingly, the exergy efficiency, net output work, and cost values in the optimal state were equal to 15.2%, 6416 kW, and 0.7457 $/s, respectively. The advantages of the proposed system include efficient heat recovery through the coupling of the multiple cycles and enhanced energy conversion pertinent to a wider range of temperatures, maximizing the overall energy extraction from the waste heat. [ABSTRACT FROM AUTHOR]

Alternate fuels are in high demand for current engines and such fuels are studied both property‐wise and tested as fuel in the current engines. In current work, diesel engines are studied for higher blend Neem (Azadirachta indica) biodiesel (NB) as fuel, and fuel additives such as n‐butanol and NiO nano additives are chosen. Experimentation was performed on the experimental stationary engine which is coupled to eddy current dynamometer for four test fuels under varying fuel injection timings. Four test fuels were chosen for experimental studies which are Diesel 90% (vol %) + n‐butanol (10%), pure Neem biodiesel, NB 90% (vol %) + n‐butanol (10%), and Neem Biodiesel 90% + 25 ppm of nickel oxide dissolved in solvent. The synthesis of nickel oxide nano additives was done using a homogenous grinding method and XRD, FESEM, and EDS characterization signifies the presence of NiO. The Neem biodiesel was derived from base catalytic process and was studied using Gas Chromatography and Mass Spectroscopy apparatus for its chemical composition. The experimentation results which were focused were on the energy, exergy derived, and expenditure at varying fuel injection timings. The exergy and energy usage were almost similar in nature and entropy produced during the chemical‐to‐mechanical energy transfer reduced with the advancement in fuel injection timing to 27° bTDC for Diesel 90% + Bt.10%, NB90 + Bt.10% and NB100 + 25 ppm of NiO by 2.2%, 2.9%, and 4.6% respectively. Also, the exergy destruction retarded when with advancement in fuel inlet timing to 27° bTDC by 2.1%, 3%, 6.2%, and 6.8% for the same fuels, respectively. [ABSTRACT FROM AUTHOR]

In this research paper, a well‐performing solar pump at the minimum cost of project life is designed and installed. Initially, the capacity of submersible pumps and discharge have been determined based on the water requirement of the crop and the size of the field. The total number of solar panels, inverter size, and motor pump system have been designed based on the law of conservation of energy. The two optimization techniques genetic algorithm (GA) and response surface methodology (RSM) have been used for analyzing the pump performance parameters and total cost. The GA tool has been used to determine the optimum tilt angle on which responses namely solar flux, solar panel efficiency, exergy, and pump efficiency should be maximum. Moreover, the performance of the solar pump at the optimum tilt angle has been compared with the 28° fixed tilt angle (latitute of location). For the experimental study solar pump experimental setup of 5 hp power has been installed in Faculty of Engineering and Technology, MJP Rohilkhand University at 28.36°N, 79.43°E. The total cost of the solar pump has been optimized with the help of RSM based on the discharge and head of the solar pump. The new optimization approach reduced the levelized cost of electricity (LCOE) from 0.041 to 0.035 $/kWh and the payback period is reduced from 4 to 3 years. The annual increment in average solar flux and overall efficiency has been recorded to be from 606 to 697 W/m2 and 11% to 14% respectively. [ABSTRACT FROM AUTHOR]

Prussian Blue Analogs (PBAs) have shown considerable prospects as the cathode materials for sodium-ion batteries (SIBs) on account of their high theoretical capacity, low cost, and easy preparation. The low practical capacity and poor cycling stability of PBAs, however, limit their wide practical deployment. To address these issues, a new strategy is deployed through introducing Fe vacancies and Cu-dopant into the PBAs frame structure, boosting the specific capacity and improving the cycling stability. On the one hand, the introduction of Fe vacancies in PBA (PBA□Fe) can provide additional storage sites and facilitate Na[sup +] diffusion kinetics, yielding a high capacity of ≈164 mAh g[sup -1] at a low current density which approaches the theoretical capacity. On the other hand, the Cu-dopant is further helpful in stabilizing the structure of PBA□Fe, thus improving the cycling stability. This work paves a new strategy that enables unlocking the capacity and improving the cycling stability of PBA materials toward high-performance SIBs. [ABSTRACT FROM AUTHOR]

The objective of this study is mainly to analyze the drying kinetic parameters, effective diffusivity, and thermodynamic performance indicators (energy, exergy, heat, and mass transfer coefficients) of tea under different drying conditions of different drying temperatures (DT) and thin layer thicknesses (TT). Experimental drying was conducted at drying temperatures of 70°C, 80°C, and 90°C with thin layer thicknesses of 10 mm, 15 mm, and 20 mm. The results show that a higher drying temperature and a lower thin layer thickness can increase evaporation moisture content and shorten drying time. By evaluating and comparing the fitting of five drying models adopted by the coefficient of determination (R2) and chi-square (χ2), it can be found that the logarithmic model is the best to describe drying behavior. The effective moisture diffusivity shows a positively correlated trend with the increase in DT and TT, with the value of activation energy ranging from 14.030 to 22.344 kJ mol-1 K-1. The specific moisture evaporation rate (SMER), energy efficiency, exergy efficiency, and sustainability index (SI) descend as the TT increases at all DT; the specific energy consumption (SEC) and improvement potential (IP) rate perform in an opposite manner, but the TT remains unchange. The conclusion drawn from the thermodynamic parameters is opposite to the aforementioned. As the TT increases, the heat and mass transfer coefficients show a significant decrease trend. In addition, the heat and mass transfer coefficients are given as functions of DT and TT, and further knowledge shows that the mass transfer coefficient is positively correlated with DT but the heat transfer coefficient is negatively correlated. In conclusion, this article provides new insights into the effects of drying characteristics, energy consumption characteristics and heat and mass transfer characteristics in the process of tea drying under different drying conditions, and provides certain theoretical reference bases for promoting the optimization of industrialized tea drying production machinery design and drying process optimization. [ABSTRACT FROM AUTHOR]

Waste heat is one of the major problems associated with the energy system. This paper discusses an energy, exergy, and emissions approach for the hybrid system by utilizing waste heat to the maximum extent. A thermoelectric generator (TEG) is incorporated to utilize the low-temperature waste heat from a hybrid model of a solid oxide fuel cell (SOFC) and a combined heat and power (CHP) system. SOFC is an electrochemical cell that generates power at high temperatures through an electrochemical reaction. The high-temperature, unutilized fuel leaves the SOFC, which is burned in the afterburner. The afterburner temperature controls the operating temperature of SOFC. Here, three recuperators are used to utilize this high-temperature waste heat to improve the performance of SOFC and simultaneously generate heat power from the water or gas recuperator. TEG is an auxiliary power production technology that converts waste heat into energy. A novel integration of TEG with SOFC–CHP hybrid system to utilize the low temperature waste heat, is employed. The main goal of this study is to analyze a novel SOFC–CHP-TEG hybrid system in terms of its thermodynamics and emissions. A Two stage TEG is integrated with the SOFC–CHP hybrid system. The simulation model of high temperature fuel cell (SOFC) is developed on MATLAB and validated with published results. This study analyses the impact of pressure ratio and afterburner temperature on the performance of SOFC–CHP-TEG. To do this, perform energy and exergy assessments using the principles of the first and second laws of thermodynamics. A novel exergy-based sustainability index with emissions analysis for the proposed SOFC–CHP is presented. The achieved overall energy efficiency is 62.54% at a pressure ratio of 12 and an afterburner temperature of 1000 K. With an increase in pressure ratio and temperature, the level of CO emissions reduces significantly. [Display omitted] • A novel energy exergy for SOFC–CHP-TEG system is presented. • Exergy based performance is compared and achieve 56.62. • Utilization of waste heat via TEG. • Energy efficiency of SOFC–CHP-TEG is 62.54% at rp = 12 and afterburner temperature of 900 K. [ABSTRACT FROM AUTHOR]

In this study, the thermodynamic performance of a real operating three-stage turbo/centrifugal type main air compressor for the air separation unit in an iron-steel industry was evaluated using both conventional and enhanced exergy analyses. Furthermore, the interaction and the potential for improvement of system components at two different airflow rates, 210,000 Nm3 h−1 and 240,000 Nm3 h−1, were investigated under real operating conditions. The results indicated that the conventional exergy analysis of the system yields efficiency rates of approximately 21.3% and 25.0% for these airflow rates, respectively. It was found that implementing operating conditions proposed by the enhanced exergy analysis could increase the system's exergy efficiency to about 40.8% and 80.7%, respectively. The primary causes of exergy destruction in the compressor are generally attributed to frictions occurring in the impeller, diffuser, and volute, as well as shock waves and air circulation during the compression process. It was observed that system efficiency could potentially increase to 80.7% with improvements in compressors and pump. The study also determined that enhanced exergy analysis is beneficial for identifying losses in system components and is seen as a tool that complements conventional exergy analysis. [ABSTRACT FROM AUTHOR]

In this study, the partial heating supercritical CO2 power cycle for waste heat recovery is investigated to understand more about the true potential of thermodynamic and economic performance improvement of each system component, as well as a more profound comprehension of the simultaneous interactions between the system components using advanced exergy and advanced exergoeconomics analysis. In addition, the affirmative or nugatory impact of the inefficiency of each component on the exogenous exergy destruction and exogenous costs in other system components separately, as well as the effect of the inefficiency combination of other components on the desired component (mexogenous effect) have been determined. The results demonstrated that according to the technological constraints in the system, the maximum exergy efficiency that can be achieved is 59.8%, and 38.4% (926.9 kW) of the total exergy destruction and 46.18% (32.52 $ h - 1 ) of the total exergy destruction cost of the system is avoidable. According to the mexogenous exergy destruction, the simultaneous interplay among other system components affects the turbine performance most. The priority of improving the components based on the highest avoidable endogenous exergy destruction cost is related to the turbine, cooler, and compressor. The results of this study revealed that 97.8% (79.73 $ h - 1 ) of the system's total cost is relevant to the endogenous part, which shows that the cost caused by the interaction among the components is very small. The turbine and compressor have the most significant cost-saving potential, while the heaters have the lowest. [ABSTRACT FROM AUTHOR]

Compared with the single-stage compression, the two-stage compression cycle shows high efficiency and application potential under both severe heating and refrigerating conditions. Therefore, to improve the performance of the two-stage vapor-compression cycle furtherly, this study introduces three ejector-assisted two-stage compression cycles (E1, E2, and E3), and a conventional two-stage vapor-compression cycles (C1) also selected as the comparison. The energetic and exergetic efficiency of the systems using various refrigerants (R152a, R1234yf, R32 and R290) is investigated and compared based on the validated theoretical model for both the severe refrigerating and heating application. The result shows that the ejector improves the system's performance significantly. Under the refrigerating mode, System E3 using R32 is recommended to be applied. Compared with Systems C1, E1, and E2, the maximum refrigerating coefficient of performance (COPR) of System E3 using R32 is improved by 16.1, 12.4, and 9.1%, respectively, with the evaporation temperature of −40 °C and condensation of 30 °C. Systems E2 and E1 using R152a are recommended under the heating mode. Compared with Systems C1 and E3, the heating coefficient of performance (COPH) of Systems E1 and E2 using R152 is improved by 3.0 and 4.5%, respectively, with the condensation temperature of 70 °C and evaporation temperature of −5 °C. The result provides a deep understanding of the potential advantages of the ejector-assisted two-stage compression cycle applied in the refrigerating and heating field. [ABSTRACT FROM AUTHOR]

Over the past decade, there has been a rapid expansion in the utilisation of process integration for incorporating renewable energy sources and energy storage systems (ESSs). Using different methods to achieve an ESS with higher efficiency is important; the originality of this study arises from two key points: initially, it proposes an inventive arrangement to harness geothermal energy for various purposes and store it in Liquid Hydrogen ( LH 2 ). Additionally, it employs cold energy from a geothermal source through a refrigeration cycle to cool down hydrogen gas prior to its entry into the liquefaction cycle. The proposed multi-generation system uses geothermal energy to produce heat (2.5 kg s - 1 hot water at 60 ℃), fresh water (41 kg s - 1 at 25 ℃), power (5200 kW) and LH 2 (79 kg h - 1 at − 253 ℃), including two-stage instant evaporation, Organic Rankine cycle, internal water heater, proton membrane electrolyser, and reverse osmosis unit. This system is analysed from the point of view of energy, exergy, and economy by focusing on the LH 2 production cycle. GA codes are utilised to optimise the LH 2 production cycle. The total annual cost of 1.74 M$ year−1 including C CAPEX,a (1.46 M$), C OPEX , a (0.25 M$), and C O & M , a (0.03 M$) is calculated for the LH 2 production cycle. Specific liquefaction cost is 2.26 $ kgLH2−1, while the minimum selling price is 2.65 $ kgLH2−1 by considering three years payback period. The LH 2 production cycle has SEC of 8.69 kWh kg Lh 2 - 1 which is less than that of similar small-scale liquefaction processes. [ABSTRACT FROM AUTHOR]

The fluid catalytic cracking (FCC) process transforms heavy wastes into lighter, more valuable (naphtha, light olefins and gases) products. However, the unit's byproducts contain a large quantity of CO 2 , which contributes to global warming. As a result, the purpose of this research was to increase the production of valuable products such as light olefins, naphtha, and hydrogen while reducing environmental impacts using the water gas shift reaction, with sensitivity analysis for three parameters (riser height, FCC feed temperature, and inlet naphtha mass flow). As a result of increasing the riser height, the output of light olefins (45%) and gases (32%) increased. Furthermore, the amount of hydrogen produced increases with a decrease in riser height (about 6%) and an increase in inlet naphtha mass flow (about 8%). Energy and exergy assessments were also carried out. It was determined that FCC had the lowest exergy destruction with a contribution of 23 MW when compared to its energy usage of 172 MW. The cooler, on the other hand, was one of the process's most energy-consuming (25%) and damaging (26%). As a result, this technique can lessen environmental effects by absorbing 125 tons of CO 2 every hour and producing 3484 kg/h of hydrogen. Economic evaluations were also undertaken, and the results revealed that the cooler has the lowest exergoeconomic factor (1%) while the FCC unit contributes the most (95%). The fractionator column is also the most expensive device in the whole process. [Display omitted] • Increasing the riser height greatly enhances the production of gases by 32% and light olefins by 45%, but decreases hydrogen production by 200 kg/h. • Increasing feed temperature, and coke production, reduce carbon dioxide emissions by 5%. • Solar energy saves 24 million tons of CO 2 emissions when compared to using gas as an energy source. • The FCC process consumes the second most energy (20%) and is the least exergy-destructive (90% efficiency) equipment within the process. • FCC unit had the greatest economic exergy factor (95%). [ABSTRACT FROM AUTHOR]

Thermoacoustic technology emerges as a sustainable and low-carbon method for energy conversion, leveraging environmentally friendly working mediums and independence from electricity. This study presents the development of a multimode heat-driven thermoacoustic system designed to utilize medium/low-grade heat sources for room-temperature cooling and heating. We constructed both a simulation model and an experimental prototype for a single-unit direct-coupled thermoacoustic system, exploring its performance in heating-only, cooling-only, and hybrid heating and cooling modes. Internal characteristic analysis including an examination of internal exergy loss and a distribution analysis of key parameters was first conducted in the hybrid cooling and heating mode. The results indicated a positive-focused traveling-wave-dominant acoustic field within the thermoacoustic core unit, enhancing energy conversion efficiency. The output system performance was subsequently tested under different working conditions in the heating-only and cooling-only modes. A maximum output heating power of 2.3 kW and a maximum COPh of 1.41 were observed in the heating-only mode. Meanwhile, a cooling power of 748 W and a COPc of 0.4 were obtained in the typical cooling condition at 7 °C when operating in cooling-only mode. These findings underscore the promising potential of thermoacoustic systems for efficiently utilizing medium/low-grade heat sources for cooling and/or heating applications in the future. [ABSTRACT FROM AUTHOR]

Supply disruptions, uncertainty, and unprecedented price rises of fossil fuels due to the recent pandemic and war have highlighted the importance of using renewable sources to meet energy demands. Solar air collectors (SACs) are major types of solar energy systems that can be utilized for space and water heating, drying, and thermal energy storage. Although there is sufficient documentation on the thermal analyses of SACs, no comprehensive reviews of the exergetic performance or qualitative insight on heat conversion are available. The primary objective of this article is to provide a comprehensive review on the optimum conditions at which the thermal performance of diverse types of solar air collectors is optimized. The effect of operating parameters such as temperature rise, flow rate, geometric parameters, solar radiation, and the Reynolds number on the thermal performance of SACs in terms of thermal hydraulic performance, energy, and exergy efficiencies has been reviewed adaptively. Beyond the operating parameters, a deep investigation is outlined to monitor fluid dynamics using analytical and computational fluid dynamics (CFDs) methodologies in the technology of SACs. In the third phase, thermodynamic irreversibility due to optical losses, thermal losses between absorber and environment, heat losses due to insulation, edge losses, and entropy generation are reported and discussed, which serve as the fundamental tools for optimization purposes. [ABSTRACT FROM AUTHOR]

The global utilization of RES, particularly geothermal energy, is rising and the inefficient nature of geothermal cycles necessitates recovering lost heat. This research proposes a combined power generation cycle that simulates integrating a trans-critical CO2 cycle with a single flash geothermal cycle, utilizing the engineering equation solver. The study contrasts the system's performance between two operating states: "Without Economizer" and "With Economizer". The investigation analyzes the impact of an economizer on key output parameters, including energy efficiency, exergy efficiency, and net power output. In the "With Economizer" operating state, the net power output experiences a noticeable increase from 201.5 kW to 204.7 kW, resulting in a 1.58% enhancement in the performance of the "With Economizer" system. The energy efficiency metric demonstrates a corresponding improvement, rising by 1.55% from 3.28% in the "Without Economizer" system to 3.331% in the "With Economizer" system, aligning with the principles of the First law of thermodynamics. Furthermore, the energy efficiency, expressed as a percentage of energy units, shows an increase from 16.3% in the "Without Economizer" system to 16.56% in the "With Economizer" system, representing a 1.595% improvement based on the Second law of thermodynamics or exergy. Regarding cost analysis, the study identifies the optimal separator pressure value for the system without an economizer, equivalent to 23. This configuration achieves a total cost rate of 01 $ per GJ. Conversely, in the system with an economizer, the optimal pressure value for the production cost rate is 322.4 kPa, resulting in a cost rate of 23.57 $ per GJ. [ABSTRACT FROM AUTHOR]

• A high-temperature heat pump steam system using single-screw compressor that recovers industrial waste heat to produce steam at 170 °C is proposed. • The feasibility and reliability of replacing a coal-fired boiler with a high-temperature heat pump steam system was evaluated using a 4E analysis. • A more advanced economic analysis model is proposed in the 4E analysis, which considers the recovery value of waste heat and CO 2 trading prices. Industrial steam is widely recognized as a valuable form of heat currency, possessing considerable social and economic significance. As the industry shifts to low carbon emissions, there is an urgent need to reduce CO 2 emissions from industrial steam generation. The analysis of a high-temperature heat pump steam system (HTHPSS), which recovers industrial waste heat to produce high-temperature steam at 170 °C, includes evaluations of its energy, exergy, economic, and environmental (4E) to determine whether it can replace a coal-fired boiler. The economic analysis considered the recovery value of waste heat and the effect of CO 2 trading prices. Optimization calculations were performed to investigate changes in the waste heat temperature and condenser outlet temperature. The study also offers recommendations for operational conditions and optimization strategies for the HTHPSS. The results indicate a positive correlation between the system coefficient of performance (COP) and the waste heat utilization rate with waste heat temperature and condenser outlet temperature. The maximum COP value is 2.73. The total exergy efficiency initially increases and then decreases as waste heat temperature increases. It also decreases as the condenser outlet temperature increases, reaching a peak value of 43.26 %. The waste heat temperature needs to be at least 59 °C to generate a net profit, with a corresponding payback period (PBP) of 4.40 years. The minimum PBP is 0.03 years, independent of waste heat temperature. The annual emission reduction increases as waste heat temperature increases and decreases as condenser outlet temperature increases. These results indicate that a HTHPSS could replace a coal-fired boiler and offer guidance for design optimization. [ABSTRACT FROM AUTHOR]

• A comparative energy, exergy and environmental (3E) analysis is performed. • Prospective low GWP and low flammable alternatives are assessed. • R-170/R-161 and R-41/R-161 show superb performance and environmental friendliness. • R-1132a/R-1234yf pair is a low flammable alternative with comparable performance. This study presents a comparative energy, exergy, and life cycle climate performance (LCCP) analysis of various refrigerants in a cascade refrigeration system (CRS). The refrigerants analyzed in the low-temperature cycle (LTC) include R-23, R-116, R-41, R-170, R-1150, and R-1132a whereas high-temperature cycle (HTC) utilizes R-404A, R-455A, R-454C, R-459B, R-161, R-290, R-1270, and R-1234yf. For the first time for CRS, LCCP analysis is conducted and fourth generation low GWP and less flammable prospective refrigerants R-1132a, R-455A, R-454C, R-459B are analyzed. The study aims to find a refrigerant pair that outperforms R-23/R-404A in terms of thermodynamic efficiency while also considering environmental impact and safety considerations. Among the 48 refrigerant groups analyzed, the study reveals that R-170/R-161 and R-41/R-161 demonstrate superior performance in terms of thermodynamic efficiency and environmental impact assessment whereas the largest exergy destruction components are HTC/LTC compressors. However, if flammability is a major concern, the recommended refrigerant pair is R-1132a/R-1234yf, as it is a suitable alternative in terms of safety considerations while still maintaining favorable thermodynamic and environmental performance. [ABSTRACT FROM AUTHOR]

In projects such as highway bridges and offshore wind farms, understanding the kinematics of soil layers and their displacement is important for accurately predicting the behavior of caissons and monopiles under lateral loads. To better predict the distribution of soil deformation around the foundations, this paper presents an extensive usage of the energy-based variational method in laterally loaded deep foundations (caissons or monopiles) with very large diameters. By adding an assumption of soil deformation in multilayered soils, the displacement distribution around the foundations can be better described. The responses of deep foundations were obtained by minimizing the potential energy and virtual work of the foundation-soil system. After that, static lateral loading tests on two caissons with the same embedment depth of 36 m and the same diameter of 6 m were performed, and the displacement field in soils and the deflection profiles of the caissons were measured. Results show that the lateral displacement and the decay distribution fields calculated from the theory in this paper agree with the measured data from the static loading tests and the corresponding finite differential method (FDM) results. At last, a series of case studies performed by MATLAB and FDM analyses were also conducted to study the influence of uz on the response of foundations, as well as the influence of foundation parameters and soil modulus on the value of ϕz. [ABSTRACT FROM AUTHOR]

This study offers a comprehensive assessment of the thermodynamic performance of a novel solar-based multigeneration system, which caters to the energy needs of a sustainable community by producing electricity, cooling, heating, and freshwater. The solar-based multigeneration system is comprised of four main components: the thermal subsystem of the parabolic trough collector (PTC) employing CO2 as a heat transfer fluid, a single-effect absorption refrigeration cycle (ARC), a supercritical CO2 (S-CO2) cycle, and an adsorption desalination (AD) cycle with heat recovery employing aluminum fumarate metal-organic framework (MOF) adsorbent material. A comprehensive parametric study was performed on the proposed solar-based multigeneration system by varying key parameters to evaluate its performance. It is found that the thermal and exergy efficiencies of a PTC were evaluated to be 68.35% and 29.88%, respectively, at a fixed inlet temperature of 225 °C and solar irradiation of 850 W/m² and also a slight reduction in the ARC cycle when examining the variation in the thermal and exergetic COPs for the generator temperature. Additionally, the thermal and exergy efficiencies of electricity, cooling, and heating were determined to be 20.41% and 21.93%, 41.34% and 3.51%, and 7.14% and 3.07%, respectively, at the operating condition. The maximum specific daily water production (SDWP) value of 12.91 m³/ton/day and a gain output ratio (GOR) of 0.64 were obtained under steady operating conditions in the AD cycle. [ABSTRACT FROM AUTHOR]

The thawing process is a common processing method used in the meat industry. To ensure provide food safety and protect meat quality, the thawing process should be carried out carefully. Ohmic thawing (OT) is one of the novel thawing methods. In this study, a custom-designed ohmic thawing prototype was set up and used to thaw frozen minced beef samples in different shapes (X: 13 × 4 × 3 cm3; Y: 13 × 6 × 2 cm3; Z: 13 cm height × 3.91 cm diameter) at 3 different voltage gradients (10–13-16 V/cm) by using 3 different electrode designs (E1, titanium foil; E2, needle type titanium electrode; E3, titanium embossed). The optimum OT condition resulting in a high-quality product with the highest process efficiency was determined. As an optimization procedure, a three-level general factorial design was performed. Thawing time, drip loss, thawing ratio, maximum temperature, ohmic power consumption, energy efficiency, and exergy efficiency values were used as responses. The cylindrical sample shape resulted in higher changes in quality and decreased performance of the process. The optimum ohmic thawing condition was a 16 V/cm voltage gradient for Y-shaped samples by using an E2 electrode design. The thawing time for the optimum condition was 2074s corresponding ohmic power consumption of 15.84 W. The drip loss during thawing was measured at 1.20%. The maximum temperature reached during the thawing process was recorded as 15.90 °C. Energy efficiency and exergy efficiency values were greater than 35%. Based on these results, the overall desirability of the ohmic thawing method was evaluated as 0.755. The obtained desirability value indicated the ohmic thawing method to be highly efficient and effective in achieving optimal thawing outcomes. The results of this study could give valuable information on the design of industrial-scale ohmic heating units to be used with solid foods, especially for thawing purposes. [ABSTRACT FROM AUTHOR]

Skin grafting is a simple and very useful surgical technique for wound repair, especially where there is difficulty in performing direct synthesis or other reconstructive techniques. low-intensity laser (LIL) has already been used successfully in cases where the graft was applied to wounds shortly after its creation. However, LIL still lacks standardization due to conflicting studies on its results. Thus, this study compared the effectiveness of continuous wave LIL with pulsed wave LIL in stimulating the healing of skin grafts, applied to newly created wounds in rabbits. For this purpose, 31 rabbits were distributed into: control group (CG, n = 10), continuous wave laser group (GLC; n = 10) and pulsed wave laser group (GLP; n = 11). Postoperative management was similar between all groups, with the exception of laser application, as indicated by the group. The GLC and GLP groups showed similar evolution, with a satisfactory healing process of the graft, unlike the GC group. These results were maintained in the microscopic evaluation, as the groups treated with laser showed less inflammation, better integration with the receptor area, greater re-epithelialization and collagenization. There was no difference in vascular density between the treatment groups on immunohistochemical analysis. The newly created wound was not able to provide nutrition for the skin graft in rabbits, but LIL is an efficient adjuvant therapy in stimulating healing between the recipient area and the graft, promoting full integration. However; although, statistically there was no difference in the form of light emission, pulsed or continuous, patients who received continuous wave LIL showed superior microscopic evolution. [ABSTRACT FROM AUTHOR]

This research applies exergy and exergoeconomic analyses to a turbocharged ethanol-fuelled engine enriched with hydrogen to operate in lean mixture conditions. Utilizing simulation data, the study examines the impacts of up to 6% of hydrogen fraction in the fuel for engine operation in the lean range from stoichiometric to fuel/air mixture equivalence ratio 0.7 are investigated. The exergy analysis revealed that hydrogen enrichment in lean operation can improve global exergy efficiency by nearly 30%. This improvement in efficiency was accompanied by significant reductions in exergy destruction and heat-based exergy transfer. The exergoeconomic evaluation indicated that hydrogen energy density and lean operation can reduce the fuel cost rate by up to 23%. The best operational scenario produced 29% decrease in specific exergoeconomic cost of electricity generation and 31% reduction in total losses. • Hydrogen addition in lean operation with ethanol reduces exergy destruction. • Global exergy efficiency is improved by nearly 70% with up to 6% hydrogen addition. • Hydrogen addition does not have a major impact on heat-based exergy transfer. • 6% hydrogen addition causes 31% reduction in exergoeconomic cost rate of total losses. • Leaner mixtures and higher hydrogen addition enhances the sustainability index. [ABSTRACT FROM AUTHOR]

Multi-Criteria Decision Making (MCDM) is a significant challenge across various domains, requiring adept resolution of conflicts arising from diverse objectives and criteria. This study proposes an innovative approach aimed at optimizing controllability, minimizing irreversibility, and maximizing overall effectiveness in control system design to address this challenge. The primary objectives of this study are to introduce a novel methodology for selecting Heat Exchanger Networks (HEN) using the well-established Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Additionally, a closeness coefficient is introduced to rank alternatives networks based on their proximity to the ideal solution. Two illustrative case studies are presented to showcase the methodology's effectiveness, adaptability, and robustness in discrete multicriteria decision-making problems, particularly in the context of HEN selection. Consistently identifying HEN configurations that fulfill controllability objectives, the methodology demonstrates its effectiveness and potential for broader applications beyond HEN optimization. The case study results affirm the adaptability and robustness of the proposed approach. In summary, this paper introduces an original and versatile approach to address the complexities of multi-criteria decision-making, specifically in the context of HEN selection. Rooted in the TOPSIS method and fortified by the closeness coefficient, the methodology holds promise for intricate decision-making processes and offers transformative possibilities for control system design. The study concludes by inviting further exploration of the proposed methodology, emphasizing its significant contribution to the field and its potential for widespread impact. Researchers and practitioners are encouraged to investigate and apply this innovative approach in diverse decision-making scenarios. The ranking results reveal that alternatives M and K is the optimum one among all the alternatives for both cases with a closeness coefficient equal to 0.651 and 0.971. [ABSTRACT FROM AUTHOR]

This study investigates the application of thermoelectric power generation devices in conjunction with cold chain logistics transport vehicles, focusing on their efficiency and performance. Our experimental results highlight the impact of thermoelectric module characteristics, such as thermal conductivity and the filling thickness of copper foam, on the energy utilization efficiency of the system. The specific experimental setup involved a simulated logistics cold chain transport vehicle exhaust waste heat recovery thermoelectric power generation system, consisting of a high-temperature exhaust heat exchanger channel and two side cooling water tanks. Thermoelectric modules (TEMs) were installed between the heat exchanger and the water tanks to use the temperature difference and convert heat energy into electrical energy. The analysis demonstrates that using high-performance thermoelectric modules with a lower thermal conductivity results in better utilization of the temperature difference for power generation. Additionally, the insertion of porous metal copper foam within the heat exchanger channel enhances convective heat transfer, leading to an improved performance. Furthermore, the study examines the concepts of exergy and entropy generation, providing insights into the system energy conversion processes and efficiency. Overall, this research offers valuable insights for optimizing the design and operation of thermoelectric generators in cold chain logistics transport vehicles to enhance energy utilization and sustainability. [ABSTRACT FROM AUTHOR]

Seawater desalination stands as an increasingly indispensable solution to address global water scarcity issues. This study conducts a thorough exergoenvironmental analysis of a multi-effect distillation with thermal vapor compression (MED-TVC) system, a highly promising desalination technology. The MED-TVC system presents an energy-efficient approach to desalination by harnessing waste heat sources and incorporating thermal vapor compression. The primary objective of this research is to assess the system's thermodynamic efficiency and environmental impact, considering both energy and exergy aspects. The investigation delves into the intricacies of energy and exergy losses within the MED-TVC process, providing a holistic understanding of its performance. By scrutinizing the distribution and sources of exergy destruction, the study identifies specific areas for enhancement in the system's design and operation, thereby elevating its overall sustainability. Moreover, the exergoenvironmental analysis quantifies the environmental impact, offering vital insights into the sustainability of seawater desalination technologies. The results underscore the significance of every component in the MED-TVC system for its exergoenvironmental performance. Notably, the thermal vapor compressor emerges as pivotal due to its direct impact on energy efficiency, exergy losses, and the environmental footprint of the process. Consequently, optimizing this particular component becomes imperative for achieving a more sustainable and efficient desalination system. [ABSTRACT FROM AUTHOR]

This study conducts both numerical and empirical assessments of thermal transfer and fluid flow characteristics in a Solar Air Collector (SAC) using a Delta Wing Vortex Generator (DWVG), and the effects of different height ratios (R = 0.6, 0.8, 1, 1.2 and 1.4) in delta wing vortex generators, which were not considered in the earlier studies, are investigated. Energy and exergy analyses are performed to gain maximum efficiency. The Reynolds number based on the outlet velocity and hydraulic diameter falls between 4400 and 22000, corresponding to the volume flow rate of 5.21–26.07 m/h. It is observed that the delta wing vortex generators with a higher height ratio yield maximum heat transfer enhancement and overall enhancement ratio. The empirical and numerical findings demonstrate that the exergy and thermal efficiencies decline in a specific range. The Nusselt number, pressure drop, energy, and exergy efficiencies enhance with rising Reynolds number, although the friction coefficient diminishes. The maximum heat transfer enhancement is 57%. According to the evaluation of exergy efficiency, the greatest efficiency of 31.2% is obtained at R = 1.4 and Reynolds number 22000. [ABSTRACT FROM AUTHOR]

The cement industry is regarded as one of the primary producers of world carbon emissions; hence, lowering its carbon emissions is vital for fostering the development of a low-carbon economy. Carbon capture, utilization, and storage (CCUS) technologies play significant roles in sectors dominated by fossil energy. This study aimed to address issues such as high exhaust gas volume, low CO2 concentration, high pollutant content, and difficulty in carbon capture during cement production by combining traditional cement production processes with cryogenic air separation technology and CO2 purification and compression technology. Aspen Plus® was used to create the production model in its entirety, and a sensitivity analysis was conducted on pertinent production parameters. The findings demonstrate that linking the oxygen-enriched combustion process with the cement manufacturing process may decrease the exhaust gas flow by 54.62%, raise the CO2 mass fraction to 94.83%, cut coal usage by 30%, and considerably enhance energy utilization efficiency. An exergy analysis showed that the exergy efficiency of the complete kiln system was risen by 17.56% compared to typical manufacturing procedures. However, the cryogenic air separation system had a relatively low exergy efficiency in the subsidiary subsystems, while the clinker cooling system and flue gas circulation system suffered significant exergy efficiency losses. The rotary kiln system, which is the main source of the exergy losses, also had low exergy efficiency in the traditional production process. [ABSTRACT FROM AUTHOR]

In response to global warming and pollution, the use of alternative fuels in diesel engines is becoming increasingly important. The purpose of this research is to evaluate the effects of hydrogen and ammonia additions to diesel fuel on carbon emissions and energy and the exergy efficiency of diesel engines and to evaluate sustainability. In this study, the effects of adding 5%, 10%, and 15% of both hydrogen and ammonia to conventional diesel fuel on specific fuel consumption, carbon emissions, energy, exergy, and sustainability index (SI) were examined parametrically. Ammonia and hydrogen fuels reduce CO2 emissions because they are carbon-free. as a result of the research, it was found that compared with ammonia addition, increasing hydrogen addition lowered specific fuel consumption while decreasing engine performance. The findings obtained show that mechanical energy and exergy values increase by 5.5% in the case of hydrogen addition and decrease by approximately 1.1% in the case of ammonia addition. The thermal efficiency and SI increased in the case of hydrogen addition and decreased in the case of ammonia addition. The exergy efficiency was estimated to be 63.37%, an increase of approximately 2.3% over pure diesel. The highest SI and exergetic performance coefficient values were determined 2.73 and 1.63, respectively. In line with the first and second law analyses, the usability of ammonia and hydrogen in diesel engines was evaluated thermodynamically. [ABSTRACT FROM AUTHOR]

Raw material with a high Al2O3 content has led to an increase in the Al2O3 content in blast furnace slag, which has affected the normal operation of a blast furnace. The exergy analysis method is an important method for studying the energy utilization of high-alumina blast furnace smelting. In this paper, to investigate the impact of slag composition on exergy efficiency and optimize exergy efficiency during the smelting process of high Al2O3 iron ore, a gray box exergy analysis model of blast furnace smelting and an objective function for minimizing the total exergy loss were developed. The results indicated that the blast furnace smelting process had an exergy efficiency (η) of 28.29% for hot metal and slag; the exergy efficiency of the blast furnace did not significantly increase with the increasing w(MgO)/w(Al2O3) and R (w(CaO)/w(SiO2)), but the exergy efficiency of the blast furnace declined with increasing w(Al2O3). The regional optimal solution for the objective function method was 7129.42 MJ with slag compositions of R = 1.295, w(MgO)/w(Al2O3) = 0.545, and w(Al2O3) = 15%. [ABSTRACT FROM AUTHOR]

The Pasco region in Peru is an area that has historically been polluted by mining activity and population growth. As a result, there is an increased production of urban wastewater and acidic water that contaminate local lakes such as Quiulacocha and Patarcocha. The construction of a treatment plant that can treat the different types of wastewaters has not yet been studied, and its sustainability has not yet been evaluated. The objective of this research was to predict the sustainability of co-treatment systems in different scenarios between urban wastewater and acidic water, expressed in terms of a ternary emergy diagram. The design of the co-treatment plant was carried out at an inflow of 10 L/s. The first scenario (Treatment I) has a primary settler for the mixture of urban wastewater and acidic water, while the second scenario (Treatment II) involves a settler and a subsurface artificial wetland, and the third scenario (Treatment IIIa and IIb) presents a settler, an electrocoagulation system and a secondary settler; this scenario differentiates between the use of urban wastewater and eutrophicated water from Patarcocha Lake. The results of the ternary diagram show the contributions of the fractions of renewable resources from Treatment I (69%), from Treatment II (65.7%), from Treatment IIIa (61.6%), and from Treatment IIIb (21.8%); the fractions of non-renewable resources in Treatment I (26.13%), Treatment II (24.13%), Treatment IIIa (23.33%), and Treatment IIIb (9.50%); and the fractions of imported inputs in Treatment I (4.84%), Treatment II (9.37%), Treatment IIIa (15.04%), and Treatment IIIb (68.72%). It is concluded that the use of a co-treatment system for urban wastewater and acidic water is sustainable in the long term when using an electrocoagulator or an artificial wetland. [ABSTRACT FROM AUTHOR]