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Hybrid solar–biomass organic Rankine cycle (ORC) systems represent a promising avenue for sustainable energy production by combining abundant but intermittent solar energy with the reliable biomass energy. This study conducts a detailed thermodynamic and economic assessment of these hybrid systems, focusing on their potential to enhance energy efficiency and reduce greenhouse gas emissions. The study also evaluates the performance of various working fluids, identifying optimal configurations for different operating conditions. A key finding is that the hybrid system, with an optimized solar–biomass ratio, achieves up to a 21 to 31% improvement in efficiency and a 33% reduction in levelized cost of electricity (LCOE) compared to solar-only systems. Additionally, the study examines case studies of real-world applications, offering insights into the scalability and cost-effectiveness of these systems in regions with high solar irradiation and biomass availability. These results underline the need for continued technological innovation and policy support to promote widespread adoption of hybrid ORC systems, particularly in the context of global decarbonization efforts. [ABSTRACT FROM AUTHOR]

The choice of refrigerant and expander is always one of the main concerns of researchers using organic Rankine cycles. The problem of using the organic Rankine cycle becomes more complicated when there are two waste heat sources with different temperatures in a system, such as exhaust gas and jacket water heat sources in an internal combustion engine. Hence, in this paper, a thermoeconomic program is developed using four types of volumetric expanders, including piston, screw, scroll and root, and eight different organic fluids in the series double cascade-evaporator organic Rankine cycle. The studied organic fluids were selected to cover a wide range of pressure levels in the series double cascade-evaporator organic Rankine cycle, including R245 FA, R123, n-pentane, acetone, n-heptane, benzene, n-octane and toluene. In the present study, 16 different pairs of expanders were examined for a cohort of 8 dissimilar fluids, resulting in an aggregate of 128 distinctive cases. In each of the 128 different cases, the important parameters, including power production, exergetic efficiency, total investment cost, net present value and levelized cost of electricity generation, are calculated. Also, the Pareto method is used to select the best organic fluid and expander pair. The results show the fluids with lower critical temperatures performed better due to the pressure ratio limit. The lowest cost of the expander compared to the total cost was 4.98%, related to the pair of root–scroll expanders, and the highest cost of 48.21% was related to the piston–screw expander pair. The lowest total investment cost was 377,478$ for the n-pentane and the piston–scroll expander pair. The screw expander costs more than other expanders, especially when in the low-pressure cycle. According to the optimization results, the optimal pair of expanders for the series double cascade-evaporator organic Rankine cycle system is scroll–scroll with n-pentane as the working fluid. Additionally, the exergetic efficiency, payback period and total investment cost values in this case are 0.3945, 4.089 years and 385,786$, respectively. [ABSTRACT FROM AUTHOR]

Türkiye is the largest cement producer of Europe and the second biggest cement exporter in the world. The industry is responsible for more than 8% of global carbon dioxide (CO2) emissions and around 15% of the primary energy consumed worldwide. In this paper, the specific energy consumption (SEC) and related emissions of a real scale cement factory currently running in Türkiye have been decreased by investigating the effects of moisture rate of the raw materials and the hot gas transfer to the grinding unit. The data has been collected in the factory site by using the monitoring equipment and real time detection over a 24-month period. Energy and exergy destructions and exergetic cost distributions are determined by using specific exergy costing method (SPECO) for all units of the factory. The specific exergetic consumption (SExC) and production (MC) costs of raw meal are calculated to be 5.05 $/GJ and 4.13 $/ton, respectively. It is investigated that the hot gas supply to the grinding unit and decreasing the moisture rate of feeding materials decreased the SPECO of raw meal, clinker and cement by 8.25%, 5.49% and 4.89% respectively. The applications provide 184.69 MJ reduction in specific energy consumption (SEC) per ton of cement produced and blocked 75,343.37 tons of CO2 emissions per year and reduced the cement production cost to 40.47 $/ton corresponding to a saving of $2.06 M per year. It has been demonstrated that it is very important to keep the moisture content of raw materials used in the cement industry as low as possible in terms of reducing energy consumption and manufacturing costs for sustainable production. [ABSTRACT FROM AUTHOR]

A state-of-art multi-generation plant integrated with a scramjet multi-cooling cycle for power, hydrogen, ammonia, and freshwater generation was analyzed from an energy, exergy, exergoeconomic as well as environmental (4E) standpoint. The coolant of the cooling cycle was the fuel of the scramjet cycle and in terms of optimizing consumed power, this cycle is benefiting from four-stage compressors. To improve the rate of hydrogen production, a methanol steam reforming procedure was employed. To provide fresh water, a reverse osmosis membrane was employed and integrated into the plant. To consider the powers of input design variables on the implementation criteria of the plant and reduce CO and CO 2 emission, an exhaustive parametric investigation was performed. The thermodynamic efficiencies, the sum unit cost of the products, the system emission rate, and the environment penalty cost rate as well as values of the products as the multi-generation plant's performance criteria were computed. Raising the hydrogen mole fraction caused an increase in the emission rate. [ABSTRACT FROM AUTHOR]

This study evaluates the potential for optimizing energy utilization and cost analysis in geothermal and solar energy-supported multigeneration systems using artificial intelligence (AI) and genetic algorithm (GA) optimization methods. Integrating renewable energy sources aims to promote sustainable energy solutions focusing on efficiency and cost-effectiveness. A cogeneration system that leverages geothermal and solar energy for electricity generation and space cooling is analyzed. The model incorporates an organic Rankine cycle (ORC) for power generation and a geothermal-solar absorption cooling cycle for space cooling, developed using Artificial Neural Networks (ANN) and optimized through thermoeconomic methods. Thermodynamic and thermoeconomic analyses guide the optimization process using an ANN-based GA method. The system, with parameters such as a 130 °C geothermal source temperature, an 85 kg/s mass flow rate, and a 600 W/m2 monthly average solar radiation intensity in Afyonkarahisar, achieves overall energy and exergy efficiencies of 19.5 % and 43.5 %, respectively. Optimization via the GA method significantly improves performance, increasing net power output from 2240 kW to 2760 kW and cooling capacity from 2720 kW to 3061 kW. Additionally, the cost of electricity decreases by 12.1 %, from 0.0165 $/kWh to 0.0145 $/kWh, while the cooling cost is reduced by 41.9 %, from 0.0745 $/kWh to 0.0525 $/kWh. Configuration of geothermal and solar energy assisted power and cooling system. [Display omitted] [ABSTRACT FROM AUTHOR]

The improvement of the overall utilization rate of compressed natural gas (CNG) engine fuel is the basis of efficient energy utilization. On the foundation of heat balance theory of internal combustion engines, this study fully considers the operation characteristics of CNG engines and systematically analyzes the distribution characteristics of different waste heat under variable working conditions. The nonlinear relationship between speed and intercooler heat source becomes evident with the increasing of intake mass flow rate. In accordance with the structural characteristics, the thermodynamic model, heat transfer model and environmental model of dual-loop organic Rankine cycle (DORC) are constructed. The system potential in full working environments is systematically evaluated. Compared with the speed, airmass flow has a significant effect on comprehensive performance of loop. The maximum power, heat transfer area and power output of per unit heat transfer area (POPA) of DORC are 36.42 kW, 23.34 m2, and 1.75 kW/m2, respectively. According to the operating characteristics of different loops, the variation laws of loop performance under the influence of multiple parameters are analyzed. The synergistic influence laws of multiple variables on system performance are also analyzed. [ABSTRACT FROM AUTHOR]

Compressed-air energy storage has been considered as a promising technology to smooth the fluctuations of renewable energy sources and improve the peak-shaving flexibility capacity of power systems. In order to improve the energy degree of compression heat and enhance the system performance, the current paper described a novel combined heating and power system that integrates compressed-air energy storage with thermochemical technology. In the proposed system, the compression heat is coupled with methanol decomposition reaction to convert the thermal energy to chemical energy (H2 and CO). A sensitivity analysis was carried out to investigate the effects of five key parameters on the system performance. The results indicated that higher values of air-to-methanol ratio, pressure ratio, and isentropic efficiency of gas turbine have positive influences on the thermodynamic performance of the proposed system. In addition, the multiobjective optimization was implemented to ascertain the optimum performance from the aspect of thermodynamics and economics. The optimal condition selected using the technique for order preference by similarity to an ideal solution (TOPSIS) method demonstrated that the exergy efficiency and levelized cost of energy of the proposed system are 39.42% and $96.58/MWh , respectively. [ABSTRACT FROM AUTHOR]

Summary: For the global future energy systems, concentrated solar power (CSP) and direct CO2 capture systems are of the most important key technologies, however, each of these systems has shortcomings. This study addresses the solar intermittency and power control complexity of the CSP systems and the substantial energy penalty of the direct oxy‐combustion (DOC) supercritical carbon dioxide (sCO2) power systems by integrating both systems. Herein, innovative power cycle configurations that integrate the CSP tower system with DOC sCO2 power cycle are introduced. The configurations include two basic cycles for comparison and validation purposes and three integrated cycles. The basic configurations are: an intercooled sCO2 power cycle driven by DOC system (S1), and a stand‐alone basic CSP tower system (S2). The integrated configurations are: CSP/DOC system where the CSP works as a preheater (S3); CSP/DOC system where the CSP works as a reheater (S4); and CSP/DOC system where each system heats part of the working fluid to drive its high‐pressure turbine (S5). The hybrid configurations reduce the fuel and the parasitic power consumptions of the basic DOC systems (S1) and reduce the capital cost associated with the conventional CSP systems (S2) by eliminating the need for thermal storage. Over practical ranges of operational parameters, comprehensive thermoeconomic, exergoeconomic, and optimization analyses for the proposed configurations are performed. Compared to the conventional CSP system, the LCOE of the hybrid system is lower by 50%. Among the hybrid configurations, the energetic and exergetic performances of S4 are the best with the lowest LCOE. According to the optimization analysis, S4 has a thermal efficiency of 55.29% at LCOEs of 7.705¢/kWh. S3, S5, S2, and S1 have thermal efficiencies of 52.90%, 48.72%, 45.56%, and 40.54% at LCOE of 7.970, 8.138, 7.864, and 6.351¢/kWh, respectively. [ABSTRACT FROM AUTHOR]

In this paper, a salinity gradient solar pond (SGSP) is used to harness the solar energy for hydrogen production through two cycles. The first cycle includes an absorption power cycle (APC), a proton exchange membrane (PEM) electrolyzer, and a thermoelectric generator (TEG) unit; in the second one, an organic Rankine cycle (ORC) with the zeotropic mixture is used instead of APC. The cycles are analyzed through the thermoeconomic vantage point to discover the effect of key decision variables on the cycles' performance. Finally, NSGA-II is used to optimize both cycles. The results indicate that employing ORC with zeotropic mixture leads to a better performance in comparison to utilizing APC. For the base mode, unit cost product (UCP), exergy, and energy efficiency when APC is employed are 59.9 $/GJ, 23.73%, and 3.84%, respectively. These amounts are 47.27 $/GJ, 29.48%, and 5.86% if ORC with the zeotropic mixture is utilized. The APC and ORC generators have the highest exergy destruction rate which is equal to 6.18 and 10.91 kW. In both cycles, the highest investment cost is related to the turbine and is 0.8275 $/h and 0.976 $/h for the first and second cycles, respectively. In the optimum state the energy efficiency, exergy efficiency, UCP, and H 2 production rate of the system enhances 42.44%, 27.54%,15.95%, and 38.24% when ORC with the zeotropic mixture is used. The maximum H 2 production is 0.47 kg/h, and is obtained when the mass fraction of R142b, LCZ temperature, pumps pressure ratio, generator bubble point temperature are 0.603, 364.35 K, 2.12, 337.67 K, respectively. • The stored heat of a salinity gradient solar pond is used for H 2 production. • Thermoelectric generators and zeotropic mixture are employed. • NSGA-II is used to find the optimum point of the system. • In optimum state η e n , η e x , UCP, and m ˙ H 2 are 6.31%, 34.63%, 44.7 $/GJ, and 0.47 kg/h. [ABSTRACT FROM AUTHOR]

n this study, energy, exergy, thermoecological, sustainability, thermoeconomic and exergoeconomic analyzes for piston-prop engines used in helicopters are explained and these analyses are applied on a pistonprop engine with 190 SHP power. Firstly, the piston-prop engine is considered as a thermodynamic system and accordingly the control volume, inlet and outlet flows, balance equations and dead state conditions of the system are determined. According to the findings, the energy efficiency of the system is found as 15.51%, while the exergy efficiency is calculated as 11%. The system’s entropy production, sustainability index, thermoecological performance coefficient, thermoeconomic parameter value, exergoeconomic parameter value due to loss exergy, exergoeconomic parameter value due to destruction exergy and total exergoeconomic parameter value are found as 2,940 W/K, 1.124, 0.161, 2.20 W/TL, 1.29 W/TL, 2.50 W/TL ve 3.79 W/TL, respectively. As a result of the analyses, it is noticed that the energy generated by the fuel entering the system is largely lost and depleted. In view of the obtained results, in addition to increasing the efficiency and performance of the engine, in order to reduce the losses and irreversibility in the system, it can be recommended to improve the cooling technologies of this type of engines [ABSTRACT FROM AUTHOR]

A growing population with depleting water resources has increased the requirement for desalination systems. Large‐scale desalination plants have seen a growth in the recent period; however, the small‐scale (SS) decentralized desalination plants' need has not been realized for the rural population. Low specific heat consumption for multieffect desalination systems makes it suitable for such decentralized operation. The challenge now lies in determining the system capacity and optimal operational range for the SS requirements. In this study, the thermoeconomic model for an SS multieffect desalination system for various configurations is developed. Optimization of the SS plant for the number of effects is performed to determine the optimal operational range of motive steam pressure, motive steam flow rate, and feed water flow rate. Total distillate production and freshwater cost are focused on objectives and constraints imposed over the input parameters with SS production. The results reveal that for a distillate production of 750 L/day, the motive steam flow requirement is estimated to be 25–35 kg/h with a pressure range of 2–5 bar. This study provided an overview for selecting the number of effects based on the commercial aspect of total production requirements. [ABSTRACT FROM AUTHOR]

To address environmental pollution effectively, it is crucial to promote the increased utilization of renewable energy sources. Furthermore, an appealing opportunity arises from enhancing the efficiency of renewable-based power plants while diversifying their product output. This study introduces a hybrid system that revolves around renewable resources, with a primary focus on evaluating power generation, hydrogen production, and freshwater extraction. The designed system seamlessly integrates a flash-binary geothermal power plant with a solar system, incorporating cutting-edge phase-change material storage technology. Hydrogen is generated through a combination of steam-methanol reforming and pressure swing adsorption processes. Freshwater is procured utilizing humidification-dehumidification and multi-effect desalination units. In terms of power generation, the system leverages the capabilities of the geothermal power plant alongside a modified Kalina cycle. The performance of this integrated system is rigorously evaluated through a combination of thermodynamic and thermoeconomic approaches. An exergy-economic optimization scenario is employed to determine the most efficient operational mode. The results of this comprehensive analysis reveal that the system can produce 0.0224 kg/s of hydrogen, 8.017 kg/s of freshwater, and generate 215.9 W of net power. Impressively, it achieves an exergy efficiency of 58.3% at a unit cost of $32.23/GJ in the base mode. Furthermore, the optimal operating state boosts efficiency to 60.59%, with a unit cost of $32.22/GJ. Notably, adjustments in the selling price of hydrogen have a significant impact on the system's financial metrics. As the price of hydrogen rises from $5 to $6/kg, the payback period reduces from 4 to 3 years, and the net present value surges from $5.81 million to $10.16 million. • A renewable-based hybrid system is proposed for power, hydrogen, and freshwater production. • Integration of geothermal power plant, solar system, and various desalination units. • Comprehensive thermodynamic and thermoeconomic analysis conducted for system evaluation. • The optimum state achieves 60.59% exergy efficiency and a unit cost of 32.22 $/GJ, with significant financial benefits. [ABSTRACT FROM AUTHOR]

Cyclohexane and sec-butyl alcohol are widely used in the pharmaceutical and chemical industries. The separation of cyclohexane/sec-butyl alcohol/water azeotropic mixture is of great significance for mitigating environmental risk, recycling solvents, and maintaining developmental sustainability. Based on the COSMO-SAC model, the infinite dilution activity coefficients of the components were calculated, and the final solvent was further obtained by relative volatility and solvent power screening. Taking the total annual cost as the objective function, the extractive distillation process is optimized based on a sequential iterative optimization algorithm. To further reduce the process energy consumption, several energy-saving processes were explored. Energy-saving processes are compared in terms of total annual cost, CO 2 emissions, and thermodynamic efficiency. It was found that the total annual cost and thermodynamic efficiency of the processes show an increasing trend, while CO 2 emissions show a decreasing trend. The results of stage-exergy indicate that the processes with heat pump are relatively small. The heat pump combined with the thermal coupling extractive distillation process exhibits better thermoeconomic and environmental performance. It provides theoretical guidance for improving the separation and recovery of value organics and energy-saving optimization of processes, which conforms to the theme of sustainable and environmental development. [ABSTRACT FROM AUTHOR]

• Hybrid PTC-TES-biomass ORC-based polygeneration system design for a commercial centre. • The system produces the annual electricity consumed in the commercial centre. • Thermoeconomic analysis provides the cost of the internal flows and final products. • Investment costs reduction leads to system economic feasibility in the medium term. • The system displaces 96.1% of the CO 2 emissions relative to a conventional system. Hybrid renewable polygeneration systems are regarded as key solutions for the sustainable energy supply of buildings. While solar heating and cooling comprises a wide range of technologies, there has been limited research on the combined production of power and cooling only, with little or no heat demand. This study designs and analyzes a hybrid solar–biomass ORC-based polygeneration system from energy, economic, and environmental viewpoints. The polygeneration system is designed to cover the electricity and cooling demands of a commercial center located in Zaragoza, Spain. A parabolic trough collector field coupled with thermal energy storage, and an auxiliary biomass boiler supply heat to an Organic Rankine Cycle (ORC), which generates electricity to cover electrical demands and to produce cooling in mechanical chillers. The biomass boiler supports the solar thermal production to ensure a stable and reliable heat supply to the ORC. The system is connected to the electric grid, so that electricity purchases and sales are possible. The equipment sizing is performed with the goal of achieving a high renewable fraction in the total electricity consumed by the commercial center. The analysis of the proposed plant includes the hourly operation throughout the year, complemented by an economic assessment, considering investment and operation costs, and an estimate of the environmental benefits of the plant. Also, a thermoeconomic analysis is developed to determine the cost formation process of the internal flows and final products of the plant. The unit cost of each flow is broken down into investment and operation cost components. Sensitivity analyses of the investment cost, interest rate, biomass price, and electricity selling price discount are made. The results show that, in economic terms, the system is not presently viable, since the cost of the electricity produced (279.07 €/MWh) is much higher than the electricity purchase price (126.70 €/MWh). In environmental terms, the system is capable of displacing 96.1% of the CO 2 emissions and 85.6% of non-renewable primary energy consumption relative to a conventional system consuming grid electricity only. [ABSTRACT FROM AUTHOR]

In this study, the effects of different nanoparticle shapes including blades, cylinders, and bricks on the thermoeconomic optimization of tubular heat exchanger (HE) networks have been studied. Boehmite alumina was used as nanoparticle and water as the base fluid. Optimal results were proposed to improve both thermal effectiveness and total annual cost simultaneously by eight design parameters. In addition, optimization was performed for four nanofluid mass flow rates, 0.5, 1, 1.5, and 2 kg/s. The results show that the application of nanoparticles was accompanied by an improvement in the thermal economic parameters of the HE network, and this improvement rate was noticeable in higher values of effectiveness. However, the results indicate a nanofluid optimal mass flow rate of 1.5 kg/s, whereas there was no significant improvement by increasing mass flow rate to 2 kg/s. The optimum results in this paper showed that the best‐studied nanoparticle shape was blade, followed by brick and cylinder shapes. For example, 9.60%, 10.68%, and 11.20% improvements in the effectiveness were obtained in cylindrical, brick, and blade forms at a fixed cost of 3000 $/year, compared with BF. These improvements are 10.40%, 11.25%, and 11.52%, respectively, for the constant value of total annual cost = 4400 $/year. [ABSTRACT FROM AUTHOR]

The Afyon Geothermal Power Plant is modeled using the Multi-Layer Feed-Forward Artificial Neural Network. The 100 × 8 data set obtained from the real Binary Geothermal Power Plant is divided into two parts: 80 × 8 training data and 20 × 8 test data. Geothermal Power Plant system modeling has been performed numerically on Matlab with three inputs and five outputs. There are ten neurons in the hidden layer in the Artificial Neural Network-based system, and the logarithmic sigmoid transfer function is used as the transfer function in each neuron. The neurons in the output layer have the purelin transfer function. As a result of the training process, the 3.06 × 10E-2 mean square error value was obtained from the ANN-based Binary Geothermal Power Plant system. The main point of the study is the optimization of the binary geothermal power plant. The genetic algorithm method with Artificial Neural Network-based is used for this purpose. The results obtained from the outputs of the Artificial Neural Network-based Binary Geothermal Power Plant system are presented. The plant's geothermal water temperature and mass flow rates are 110 °C and 150 kg/s. Energy and exergy efficiencies of the plant are calculated as 10.4% and 29.7%. The optimized simple payback period and exergy cost of the electricity generated in the plant is calculated as 2.87 years and 0.0176 $/kWh, respectively. Schematic configuration of Afyon Geothermal Power Plant. Image 1 • Modelling of Afyon Geothermal Power Plant is performed numerically based on ANN. • Geothermal temperature and mass flow rate of the plant are 110 °C, and 150 kg/s. • Energy and exergy efficiencies of the plant are calculated as 10.4%, and 29.7%. • The exergetic cost of the electricity from the plant is calculated as 0.0176 $/kWh. [ABSTRACT FROM AUTHOR]

• System-scale performance assessment is done for a two-phase immersion cooling system. • The best COP and PUE trends are found at the highest server power rate. • Exergy efficiency varies between 8.0 and 18.9% at various operation loads. • Exergy costs are found 3.25 times as higher than the energy costs. The liquid-cooling data center (DC) systems have been becoming important for the rapidly developing high-performance processors since the traditional air-cooled DC systems cannot efficiently manage them due to high heat dissipation rates. Two-phase liquid-immersion cooling is one of the promising direct liquid-cooled DC systems, but its system-scale thermal management performance has not been investigated in detail yet. This study performs the system-scale thermal management of a two-phase liquid-immersion cooling DC system under six different real-time and dynamic operation loads in the range of 3.43-9.17 kW to see the thermodynamic and thermoeconomic performances. The system includes the DC server tank, circulation pump, and dry tower. Results show that the best coefficient of performance (COP) and power usage effectiveness (PUE) values are seen at the highest operation load with 6.67 and 1.15 while the minimum COP and the highest PUE are seen at the lowest operation load with 2.5 and 1.4, respectively. In the component-based assessments, the dry tower is found as the most dominant component according to the exergy destruction ratio analysis, energy costing, and carbon-related costs. The exergy efficiency varies between 8.0% and 18.9% for different operation loads, and the operating temperatures have a crucial impact on the exergetic performances. The thermoeconomic analysis deduces that the levelized product cost is roundly 1.14 S$ · h-1 which means the exergy-related terms (e.g. destruction and loss) increase the costing trends 3.25 times as high compared to the traditional energy-based economic calculations. [ABSTRACT FROM AUTHOR]

In this study, energy, exergy, thermoecologic, sustainability, thermoeconomic and exergoeconomic analyses of solar collectors are explained and these analyses are applied to a case study. As a case study, flat plate solar collector with 8m2 area is considered. The exergy efficiency of the system is calculated as 1,99%, while energy efficiency is 52,46%. The sustainability index, thermoecologic performance coefficient, thermoeconomic parameter rate and total exergoeconomic parameter rate of the system are found as 1,02, 0,0206, 1,4 W/TL and 2,683 W/TL, respectively. The maximum energy input and exergy input are caused by the incoming solar radiation. It is seen that most of this energy/exergy is lost, and destructed due to irreversibilities. This situation is the biggest disadvantage of the flat plate solar collectors. [ABSTRACT FROM AUTHOR]

Geothermal power plants have been in operation for decades in many parts of the world. Different thermodynamic cycles can be used for producing power from geothermal resources. Binary cycle plants use the geothermal water from liquid-dominated resources at relatively low temperatures. These plants operate on a Rankine cycle with a binary working fluid (isobutane, pentane, isopentane, R-114, etc.) that has a low boiling temperature. A case study on an existing binary geothermal power plant is available in this study. Thermoeconomic performance evaluation and optimization of 2.7 MW binary organic Rankine cycle (ORC) design geothermal power plant in western Turkey is conducted using actual plant operating data, and potential improvements are identified. Afyon Geothermal Power Plant (AFJES) is thermodynamically modeled in a computer environment using current working parameters in a comprehensive way for the use of geothermal energy in electricity generation. Geothermal water temperature and mass flow rate of the plant are 110°C, and 150 kg/s, respectively. Energy and exergy efficiencies of the plant are calculated as 10.4% and 29.7%. The potential annual revenue of geothermal electricity is calculated to be 2,880,277 $/yr with a simple payback period of 3.36 years. The exergetic cost of the electricity from the plant is calculated as 0.0233 $/kWh. The optimized simple payback period and exergy cost of the electricity generated in the plant is calculated as 2.87 years and 0.0176 $/kWh, respectively. [ABSTRACT FROM AUTHOR]

• An air-conditioning system integrated with a LTES is analyzed thermoeconomically. • A novel semi-analytical solution method for phase-change process is proposed. • The proposed and numerical results are compared with one another. • The results obtained from proposed and numerical methods are in good agreement. • The performances of the overall system are compared for three types of PCMs. An air-conditioning system equipped with a latent thermal energy storage is analyzed thermodynamically and economically. A new solution method is introduced and used to solve the phase change problem. In addition, based on the 2-D modified enthalpy method, a numerical solution is carried out. The numerical results are validated using the existing experimental ones. The results obtained from the proposed method are compared with those of the numerical ones for some effective parameters. A maximum difference of 2.7% is obtained between them. By applying the proposed method, the effects of parameters such as the inlet and outlet air temperatures on the operating parameters including the coefficient of performance, exergy efficiency, total product unit cost, total investment cost, phase change material (PCM) slabs' thickness, and length are investigated. The thermodynamic and economic performances of the overall system are compared for three types of PCMs with identical melting point temperatures, namely; RT27, S27 and PureTemp27. It is shown that the total product unit cost decreases as the air temperature difference in passing through the air-conditioning system increases. This occurs in spite of the increment of investment cost because of the thermal efficiency enhancement. In the proposed method, the desired output can be obtained at any time and location with no need to previous time steps and other discretized points. This improves the optimization process for the system. The results show that, compared to the other PCM types, the PureTemp27 brings about better thermodynamic and thermoeconomic performances for the system. [ABSTRACT FROM AUTHOR]

In this research, a new ammonia-water mixture CCHP system driven by a LTHS is proposed which is a modified version of a Kalina cycle. Feasibility investigation of the recommended system is studied based on thermodynamic and thermoeconomic balance equations for performance assessment of thermal systems. the energy efficiency, exergy efficiency, and overall unit product cost are computed 49.83%, 27.68%, and 198.3 $/GJ, respectively. Also, condenser 2 is characterized as the main contributor to irreversibility of the recommended trigeneration system by exergy destruction ratio of 32.03%. Moreover, a thorough sensitivity study is carried out to attain higher energy efficiency by raising the evaporation temperature and basic NH3 concentration or by reducing the separators pressure, heating unit temperature, and terminal temperature difference (TTD) of vapour generator. From exergy perspective, it is figured out that higher exergy efficiency may be achieved by raising the separator 1 pressure, and TTD of vapour generator or by reducing the separator 2 pressure, evaporation temperature, heating unit temperature, and basic NH3 concentration. Also, it is proven that the overall cost of the cycle can be peaked with evaporation temperature, while can be maximized with separator 1 pressure and basic ammonia concentration. • A novel ammonia-water CCHP system driven by a low-grade heat source is proposed. • A comprehensive mathematical modeling of the proposed CCHP system is carried out. • The effects of some key parameters on the main performance criteria are investigated. [ABSTRACT FROM AUTHOR]

The integration of the gas turbine cycle and organic Rankine cycle with the solid oxide fuel cell for power generation is quite prevalent. However, the need is also felt for systems capable of providing power with cooling. Therefore, it is proposed to integrate solid oxide fuel cell with gas turbine cycle, vapour absorption refrigeration system and organic Rankine cycle through the heat available with fluid in the cycle. Here intercooled and reheat gas turbine cycle is integrated with solid oxide fuel cell. Heat rejected in intercooling is used in vapour absorption refrigeration system for cooling. This paper presents thermoeconomic analysis. Results show that the combination of solid oxide fuel cell-gas turbine-vapour absorption refrigeration system-organic Rankine cycle yields increase in efficiency to 68.79% as compared to 58.88% from combined solid oxide fuel cell-gas turbine cycle. The cost of electricity per unit power output is found as 1939.93 $/kW. • SOFC energy utilization for power & cooling. • Integrated SOFC, gas turbine, absorption refrigeration system and organic Rankine cycle. • Gas turbine exhaust heat recovery systems. • Intercooling heat runs vapour absorption refrigeration system. • R1233zd(E) is working fluid for organic Rankine cycle. [ABSTRACT FROM AUTHOR]

Thermal management is a critical issue in optimizing the performance of proton exchange membrane fuels cells (PEMFC). The heat balance between the heat generation in fuel cell stack (FCS) and the heat removal by coolant liquid determines the operating temperature of the PEMFC and the dehydration or flooding condition in FCS. In this study, the amount of water condensed among all the water produced during the electrochemical reaction in FCS of a hydrogen-fueled 1-kW PEMFC at various conditions was determined using a thermoeconomic method called modified productive structure analysis (MOPSA) and the calculated results were compared with observed ones. The amount of the condensed water which should be removed through the cathode channel is dependent crucially on the cooling rate of FCS, which indicates that thermal management for FCS can be done by controlling of the cooling rate of FCS. • Thermoeconomic analysis (TEA) was performed for a proton membrane fuel cell (PEMFC). • The amount of liquid water generated in fuel cell stack (FCS) was determined by TEA. • The amount of liquid water produced is dependent crucially on the cooling rate of FCS. • Thermal management of FCS can be done by controlling the cooling rate of FCS. [ABSTRACT FROM AUTHOR]

• A new sustainability index is presented for the LNG micro-cogeneration systems. • Thermoenvironmental and sustainability indicators are performed. • Interest rate does not affect significantly the best-trade off region. • High air temperature and relative humidity is proposed for the indoor operations. Liquefied natural gas (LNG), a clean fuel type mainly containing methane, has been becoming more popular amongst the other fuels for the power generation systems. Although there are a lot of thermodynamic and thermoeconomic assessments about the LNG fired power generation systems, the environmental and sustainability aspects have still lack investigation, especially on the optimization step. To minimize this gap, a multiobjective optimization study is performed for the LNG fired micro-cogeneration system. The current study considers various objective functions from thermodynamic, environmental, thermoeconomic, and sustainability aspects. A newly developed sustainability index is used as one of the objective functions in the study. The approach is defined as the complex multiobjective optimization procedure that constitutes different multiobjective optimization groups to better understand and evaluate the different objective functions together. The controllable air temperature and relative humidity are selected as the external decision variables. The best trade-off regions are identified between 300.00 K and 313.15 K at the relative humidity of 90% while they are found between 310.15 K and 313.15 K at the relative humidity of 50%. The high relative humidity and ambient air temperature present the best climatic conditions for the optimal operation of the small-scale system during the indoor operations. [ABSTRACT FROM AUTHOR]

• Energy and exergy efficiencies of the plant are 12.88% and 48.20%, respectively. • Efficiencies are higher than other plants with similar specific geofluid exergies. • Improvement potential analysis for each component in the cycle is evaluated. • Turbine-I has the highest exergy destruction ratio of 201,776 $/yr. • SUCP of the plant increases over 40% as the ambient temperature varies 30 °C. The thermodynamic and thermoeconomic performances of a 21 MW geothermal power plant with air-cooled two level binary type organic Rankine cycle was numerically investigated based on its design and operating data. The investigated plant is the Sinem Geothermal Power Plant in Germencik, Aydin, Turkey. The paper provides a detailed comparison of the exergetic performance of this plant with other eight similar type of plant units, which make use of geothermal resources with similar specific exergies. Results indicate that the exergetic efficiency of the Sinem Geothermal Power Plant is the highest with 48.2% and the others vary between 9.6% and 42.7%. This result is mainly related to the exergy losses due to suppression of heat transfer in this plant, via low temperature brine reinjection, small temperature difference in the heat exchangers and high efficiencies of the individual components. First and second law efficiencies, as well as the exergy losses and improvement potentials of each component in the plant are also calculated. In air-cooled geothermal power plants, since ambient temperature is a critical parameter for the plant performance, both thermal and economic analysis of the plant is performed based on variation in ambient air temperature. Specifically, thermoeconomic analysis of the plant is evaluated to determine the exergoeconomic factor, the relative cost difference and the sum unit cost of the product (SUCP) of the plant. The effect of ambient temperature on the SUCP of the power plant, power generation, energy and exergy efficiencies are also examined in the present study. The results showed that; when the ambient temperature increases from 5 °C to 35 °C the reduction in power generation is 6.8 MW, energy efficiency decreases from 13.7% to 9.2% while exergy efficiency decreases from 54.9% to 36.7 and SUCP of the plant increases from nearly 230 $/GJ to 330 $/GJ. [ABSTRACT FROM AUTHOR]

• The MED plant coupling increases the exergy destruction of the plant. • The RC part-load operation has a significant influence on the unit product costs. • The ambient temperature evidences only a minor effect on water costs. • The Largest MED plant sizes obtained the lowest electric and water costs. A detailed exergy cost and thermoeconomic analysis applied to a Rankine Cycle (RC) coupled to a Multi-Effect Distillation (MED) plant was performed. The aim of this work is to identify the impact of design and operating conditions on the exergy and thermoeconomic costs of the final products, electricity, and freshwater, and to assess the distribution of the destroyed exergy, the fuel, and the plant costs. The plant model considers a high disaggregation model, which includes MED plant and condenser parasitic losses, a seawater pumping system and a brine energy recovery system. It also considers solar molten salts as the RC fuel, which is the typical fluid used in solar tower plants. The impact of RC + MED plant part-load operation, ambient temperature, MED plant size, and location plant's altitude was evaluated and an analysis of operational day of the RC + MED plant was carried out. Results indicate that the plant part-load operation has a significant influence on the unit exergy and thermoeconomic product costs, while the ambient temperature evidences only a minor effect on the water costs. As well, the largest MED plant sizes (above 50,000 m3/day) offer the lowest electric and water costs, while the altitude strongly increases the water costs. [ABSTRACT FROM AUTHOR]

Summary: Small‐scale‐liquefied natural gas (LNG) cold‐utilized power generation systems are the sustainable solutions in the rural and inland areas where the large‐scale power generation is infeasible. This study investigates three different small‐scale LNG cold‐utilized power generation systems, which are called as the single, combined, and carbon dioxide (CO2)–reduced combined systems according to their design details. The assessments are done according to the life‐cycle‐based enviroeconomic and life‐cycle‐integrated thermoeconomic assessment (LCiTA) models that are recently developed and new approaches, in order to better monitor their feasibilities in real operations. The life‐cycle‐based enviroeconomic assessment shows that the combined system has the lowest environmental payback period with 7.35 years that is nearly 6 months and 1 year lower than the single and CO2‐reduced combined systems, respectively. The LCiTA study deduces that the combined system has the minimum levelized product cost while the single system has the highest values. The integration of CO2 capture components increases the levelized product cost nearly by 16.0% in the combined design, but the levelized product cost value is still found lower than the single system. Moreover, the sustainability performance of the systems is evaluated according to the improved sustainability index calculated by the life‐cycle‐integrated fuel and destruction costs. The index value of the combined system is twice that of the single system. The multiobjective optimization study is performed in cases of closed operation rooms. The best trade‐off points are found in the close ambient air temperature range between 300.50 and 302.00 K. To observe the dynamic outdoor performance, the finite sum approach is applied for the LCiTA model. The highest fluctuations are seen for the CO2‐reduced combined system while the smallest fluctuations belong to the combined system. [ABSTRACT FROM AUTHOR]

Abstract Multigeneration systems (MGSs) driven by renewable sources are proved as cutting-edge technologies for multiple productions purposes to curb greenhouse gas emissions. With this regard, a novel geothermal-based MGS is proposed to produce multiple commodities of cooling, heating, power, and hydrogen, simultaneously, using liquefied natural gas (LNG) as cold energy recovery. The system is composed of an organic Rankine cycle (ORC), an ejector refrigeration cycle (ERC), an LNG power generation system, and a proton exchange membrane (PEM) electrolyzer system. To demonstrate the feasibility of the proposed MGS, energy, exergy, and exergoeconomic analysis are employed as the most effective tools for the performance assessment of the system. It is found that the proposed MGS can produce cooling capacity, heating capacity, net output power, and hydrogen of 1020 kW, 334.8 kW, 1060 kW, and 5.43 kg/h, respectively. In this case, the thermal efficiency, exergy efficiency and total SUCP (sum unit cost of the product) of the MGS are calculated 38.33%, 28.91%, and 347.9 $/GJ, respectively. Furthermore, condenser 2 is introduced as the main source of irreversibility of the proposed MGS by exergy destruction ratio of 58.98%. Moreover, a comprehensive parametric study is carried out and it is concluded that the SUCP of the system can be optimized based on the geothermal inlet temperature. In addition, it is demonstrated that a higher thermal efficiency can be obtained by increasing the turbine 2 expansion ratio, evaporator temperature, and geothermal temperature or decreasing of the generator terminal temperature difference, turbine 1 expansion ratio, pump 3 pressure ratio, and condenser temperature. In the same vein, a higher exergy efficiency can be attained at high turbine 1 expansion ratio, turbine 2 expansion ratio, evaporator temperature, and pump 3 pressure ratio or low generator terminal temperature difference, geothermal inlet temperature, and condenser temperature. Highlights • A novel multi-generation system for cooling, heating, power, and hydrogen production is proposed. • Geothermal heat and LNG cold energy are used in the proposed system as heat source and thermal sink, respectively. • The proposed system is analyzed from thermodynamics and thermoeconomics viewpoints. • The effect of some key parameters on the main performance criteria is assessed. [ABSTRACT FROM AUTHOR]

Abstract A novel combined cooling/power cogeneration system, including a modified Kalina cycle and an absorption refrigeration cycle is proposed. The cycle uses ammonia-water as working fluid and is driven by geothermal energy. The cycle is flexible for producing different ratios of power to cooling capacities. It is observed that the ambient temperature and the split mass flow ratio at the condenser exit play major roles on the system performance. The results show that in summer time a better economic performance and also a higher cooling to power ratio is achieved. It is also seen that the overall system exergy efficiency is maximized at a specific value of the split mass flow ratio and that the total product unit cost is minimized at some specific values of the generator temperature and split mass flow ratio. The system performance is optimized considering the exergy efficiency and total product unit cost as criteria. The optimization results show that when the criterion is selected as exergy efficiency, a better economic performance is also achieved for the system. It is found that the highest exergy efficiency of the system is achieved as 33.61% and the lowest total product unit cost is obtained as $ 39.93/GJ. Highlights • A novel combined cooling and power cogeneration system is proposed. • Exergeoconomic analyses are performed in different seasons. • Exergy efficiency is maximized and unit cost is minimized at different seasons. • Effects on system performance is investigated of key parameters in proposed cycle. • Higher condenser temperature is in favor of cooling and against power outputs. [ABSTRACT FROM AUTHOR]

Highlights • Models for energetic, exergetic and economic analyses are established. • Optimization process is conducted with dual-objective Jaya algorithm. • System performances with different subcooling methods are compared. • Optimized subcooling methods are selected under different ambient conditions. Abstract The transcritical carbon dioxide vapor compression cycle is commonly used for heating and cooling applications because of the high discharge temperature and large evaporation heat. Whereas, high return water temperature is usually required by the heating demands, which significantly degrades the system performances. Nowadays, various kinds of subcooling methods have been proposed for the transcritical carbon dioxide vapor compression cycle, but a systematic comparative study based on the trade-off between the thermodynamic efficiency and economic cost is needed to analyze the applicability of these methods for large-scale district heating and cooling applications. In this work, the hot water temperature increases from 323.15 K to 343.15 K for district heating, and chilled water temperature reduces from 285.15 K to 280.15 K for district cooling. The simple single-stage transcritical carbon dioxide vapor compression cycles using subcooling methods with and without expansion work recovery, including internal heat exchanger, dedicated mechanical subcooling, cooling tower and dry cooler, are respectively modeled from the energetic, exergetic and economic perspectives. Based on the dual-objective Jaya algorithm and Technique for Order of Preference by Similarity to Ideal Solution decision-making method, the parametric study is conducted with optimized system performances to analyze the effects of different ambient conditions, namely the winter mode with ambient temperature from 248.15 K to 278.15 K and the summer mode with ambient temperature from 288.15 K to 318.15 K, and the relative humidity from 30% to 90%. Afterwards, the optimal subcooling methods under different ambient temperatures are selected based on the overall optimization and comparative study. The effects of different ambient temperatures on the system performances vary with different subcooling methods without expansion work recovery, and the dry cooler is the optimal subcooling method at the ambient temperatures from 248.15 K to 268.15 K, while the cooling tower is suggested under ambient temperatures higher than 278.15 K in spite of the performance degradation with high relative humidity. Insignificant differences of system performances using different subcooling methods can be observed with expansion work recovery, and the internal heat exchanger is selected as the optimal subcooling method for winter-mode operations, while the cooling tower is also suggested as the suitable subcooling method in the summer mode. [ABSTRACT FROM AUTHOR]

Abstract The paper presents a thermoeconomic comparison between two different solar thermal technologies, namely Linear Fresnel Reflector (LFR) and evacuated tube solar collectors (ETC), integrated into a polygeneration plant. The system produces space heating and cooling, domestic hot water and drinkable desalinated water, by means of a multi-effect distillation (MED) system. In the ETC layout, a single-effect LiBr H 2 O absorption chiller (ACH) is included; in the second layout, based on LFR collectors, a double-effect ACH is considered. An auxiliary biomass-fired heater is used to supply the additional heat required by the MED unit, in case of low availability of solar radiation. Both plants are simulated by means of a zero-dimensional dynamic simulation energy model, developed in TRNSYS environment. The model also includes detailed thermo-economic calculations. The results show that in some winter weeks, the solar fraction for freshwater production ranges between 15% and 20% for the ETC-based system, whereas is zero in case of LFR, when the MED unit is supplied only by the biomass auxiliary heater. Therefore, for the analysed case study, ETCs resulted more profitable than LFRs, achieving simple pay-back periods of about 4–5 years. Highlights • The analysed polygeneration plant produces fresh water, heat and cool. • Linear Fresnel and evacuated tubes solar collectors are compared. • Solar desalination technique is based on multi-effect distillation process. • The system is dynamically simulated in TRNSYS environment. • Evacuated solar collectors achieve lower pay back periods equal to 3.52 years. [ABSTRACT FROM AUTHOR]

A thermoeconomic analysis of a water to water heat pump are performed under different condenser and evaporator conditions. Experiments are realized for different volumetric inlet temperatures of 14.4, 17 and 19 °C and different volumetric flow rates of 50, 100, 150 lt/h for condenser cooling water. Same inlet temperatures with condenser cooling water are used for evaporator water inlet, while constant volumetric flow rate of 100 lt/h is used for each case. Modified Productive Structure Analysis (MOPSA) is used for thermoeconomic analysis. It is found that increases in inlet temperature and in volumetric flow rate cause to decrease in both the unit cost of heat delivered (H C) and the unit cost of entropy generation (S C). As a result, in the case of inT =14.4 °C and = 50 lt/h, H C and S C values are obtained to be 0.0489 $/kWh and 0.0221 $/kWh, respectively, while HC and S C values are obtained to be 0.0385 $/kWh and 0.0175 $/kWh for inT =19 °C? and = 150 lt/h, respectively. [ABSTRACT FROM AUTHOR]

Abstract Integration of biomass gasification with solid oxide fuel cell (SOFC) offers an emerging alternative for future sustainable power generation. In the present paper a comparative exergoeconomic analysis of using steam and air as two different gasification agents is performed on an integrated biomass gasification-SOFC system. The system performance is optimized based on the net output power, exergy efficiency and the unit product cost of the system. A detailed thermodynamic equilibrium model for gasification process is developed and verified by reliable available data. A parametric study is conducted to examine the effects of key operating parameters on the net output power, exergy efficiency and unit product cost of the integrated system. The results indicate that, at the optimal operating conditions when steam is used instead of air as the agent, the net output power is increased by 14.8%, the exergy efficiency is increased by 24.9% and the unit product cost of the system is decreased by 8.9%. Highlights • Comparative analysis of using steam or air is performed on a biomass gasification-SOFC system. • Energy, exergy and exergoeconomic analyses are conducted. • A comprehensive parametric study is performed to assess the effects of key operating parameters. • At the optimum operating conditions, an enhancement of 8.9% is concluded using steam instead of air. [ABSTRACT FROM AUTHOR]

Highlights • Biogas based gas turbine integrated with two organic Rankine cycles is modeled. • Thermodynamic and exergoeconomic analyses are performed. • A parametric study is done to identify the effects of important parameters. • An optimization is done to minimize the product cost and maximize the efficiency. • Exergy efficiency and overall product cost are calculated as 38.91% and 17.2 $/GJ. Abstract Biogas has been used practically as an attractive renewable energy source for various combined power plants as a recent advancement in technologies. Feasibility investigation of a modified organic Rankine cycle coupled with a gas turbine cycle fueled by biogas (60% methane +40% carbon dioxide) as a heat source is carried out in this study. Thermodynamic and thermoeconomic analysis are employed as the most powerful tools to estimate performance and cost of the system and the results are compared with the basis coupled system. Also, to investigate how the proposed systems perform under any external disturbances, a thorough sensitivity study around the basic operating input parameters was carried out. The results of the second law analysis demonstrated that among all components and for both proposed systems, the combustion chamber had the highest value of exergy destruction rate, followed by the recovery heat exchanger. The proposed combined system could produce net output electricity of 1368 kW, resulting in the thermal efficiency, exergy efficiency and overall product cost of 41.83%, 38.91%, and 17.2 $/GJ, respectively. Moreover, it is found that the thermal and exergy efficiencies of both systems could be maximized with respect to the air compressor pressure ratio and steam turbine inlet pressure, while the overall product cost of the cycles can be minimized with air compressor pressure ratio and gas turbine inlet temperature. [ABSTRACT FROM AUTHOR]

Highlights • A new thermoeconomic cost matrix is developed for a novel system. • Optimum results are obtained by Pareto-frontier in the multiobjective optimization. • The trends of captured CO 2 and condensed water contradict to each other. • The best trade-off point is found at 305 K for the closed room conditions. Abstract In the present study, a new small-scale cryogenic CO 2 capture and LNG cold utilization system is investigated through the exergetic and thermoeconomic approaches. During the system operation, the condensed water is obtained as the byproduct. The power generation rate and the exergy efficiency reach their maximum points with 27.29 kW and 28.86% at the lowest air temperature and the highest relative humidity, respectively. The minimum levelized product cost is seen as 13.10 $/s at the maximum air temperature and minimum relative humidity values. The component-based assessments show that the heat exchanger, which condenses the water vapor inside, has the highest exergy destruction ratio with the average share of 52.01% while the highest levelized destruction cost is calculated for the combustion chamber with the average value of 1.21 $/s. Also, the impact of levelized component cost is found more significant than the destruction costs. To define the best trade-off point of the proposed system, the multiobjective optimization is performed by using genetic algorithm. The exergy efficiency and the levelized product cost are selected as the objective functions, and the best trade-off points is observed at the ambient temperature of 304.88 K. To better show the advantage of the proposed design in the real environment, a Singapore case study is conducted, and the highest exergetic efficiency and CO 2 capture ratio are seen in December with 3.84 and 25.70%, respectively. On the other hand, the levelized product cost presents its minimum value in May with 14.96 $/s whereas the condensed water rate has the highest rate in May as well. [ABSTRACT FROM AUTHOR]

Humidification-dehumidification (HDH) desalination systems are popular among researchers due to their simple structure, ability to operate with low-grade and renewable energy sources, and the capacity to work with high-concentration water. This paper presents a thermodynamic and thermoeconomic analysis of an HDH system with a multi-stage bubble column dehumidifier. There was a lack of economic studies on bubble column dehumidifier systems in previous literature; also, no research had examined the impact of different geometric and temperature parameters on the entire system's performance. The fixed surface method was used to model the humidifier and dehumidifier, and the effect of mass flow rate ratio, top and bottom temperature, pipe length within each dehumidification stage, and the number of dehumidifier stages on the system's performance was studied. System performance was compared under various conditions, including gain output ratio (GOR), water production, and cost of produced freshwater. The highest GOR is obtained in the highest pipe length and the highest number of dehumidifier stages. Increasing the length of the pipe and the number of dehumidification stages increases the cost, so achieving the lowest cost of produced water is a compromise between higher cost and higher efficiency. The system achieved a GOR of 3.03, the lowest cost price of produced water is 18.29 $ m 3 , and the highest acheived exergy efficiency is 22.4 %. • An HDH system with multi-stage bubble column dehumidifier is proposed. • A thermoeconomic model has been developed to analyze this system. • A novel approach is introduced for the purchase cost of a bubble column dehumidifier. • Effects of physical and geometric parameters on system performance are investigated. • The unit cost of water production in different conditions is presented. [ABSTRACT FROM AUTHOR]

Clean energy development for multiple productions interests many countries and companies. Hence, this paper presents an innovative solar-driven trigeneration arrangement equipped with a thermal energy storage unit (TESU); the whole system comprises parabolic dish collectors, a modified Rankine cycle, and a double-effect absorption chiller. The system is designed to enhance the integrity performance compared to previous designs. Heat loss recovery is performed using an internal heat exchanger to improve the Rankine cycle's performance. The operating framework of the arrangement contains three steady modes: solar mode associated with the state without applying TESU, storage mode corresponding to the state without solar energy using TESU, and solar-storage mode capable of storing energy in addition to launching the combined cycles. The prediction of the sensitivity of the net output power, heating capacity, input energy, power to heating and cooling ratios, and energy and exergy efficiencies is conducted in solar mode. Furthermore, the thermoeconomic analysis is carried out in solar mode to determine the equipment's financial aspect. Referring to the results, the overall energy efficiencies of the modes introduced before are equal to 97.23%, 81.98%, and 40.23%, and the corresponding exergy efficiencies are 15.53%, 14.47%, and 8.58%. Also, the exergoeconomic factor of the solar subsystem is 70.77%. [Display omitted] • Modeling a CCHP system based on a modified Rankine cycle, a double absorption chiller, parabolic dish collectors and a TSU. • Improving the trigeneration system's performance by eliminating the examined models' weaknesses. • Analyzing solar dish collector systems' thermodynamic and exergoeconomic. [ABSTRACT FROM AUTHOR]

Summary: Recent research has been focused on the utilization of low‐grade waste heat, and the industrial high‐temperature heat pump can be an alternative technology because of its simplicity and outstanding performance. However, the use of carbon dioxide in vapor compression heat pumps with high‐temperature heat source is still to be optimized because of low critical temperature. In the present study, a system for waste heat recovery from the steam condenser using CO2 vapor compression cycle is modeled from the energetic, exergetic, and economic perspectives, and optimized system performances are obtained by dual‐objective Jaya algorithm. Potential optimized operating strategies for transcritical cycle are discussed by the parametric study and T‐s diagrams. The transcritical and supercritical cycles are further compared with each other considering different steam temperatures. The optimization strategies of transcritical cycle are based on the main purpose to improve the evaporation potential and achieve transcritical cycles with the critical point inside the closed region surrounded by the process curves, so lower superheating degree and minimum temperature difference of gas cooler, higher evaporating temperature, and more return water cooling should be employed in order to promote the cycle performances. In comparison with transcritical cycles performances, the supercritical operation shows superior performances, which are less sensitive to the variations of return water temperature. The use of carbon dioxide in vapor compression heat pumps for waste heat recovery from the steam condenser is optimized from the energetic, exergetic, and economic perspectives by dual‐objective Jaya algorithm. Potential optimized operating strategies for transcritical cycle are discussed by the parametric study and T‐s diagrams. The transcritical and supercritical cycles are further compared with each other considering different steam temperatures, and the supercritical operation shows superior performances, which are less sensitive to the variations of return water temperature. [ABSTRACT FROM AUTHOR]

Abstract Feasibility investigation of a humidification dehumidification (HDH) desalination system driven by an absorption-compression heat pump cycle (ACHPC) is carried out in this paper. The proposed hybrid desalination system uses both heating capacity of the discharged brine as a waste heat for the ACHPC and mechanical power of the ACHPC for the HDH system. The system's performance is investigated under different optimal design modes, using genetic algorithm (GA) as the most robust tool for optimization. A steady-state mathematical model based on the mass, energy, exergy, and exergoeconomic balance equations for components of the proposed system is developed and the predicted results are validated using the available experimental and numerical data. The results indicated that the proposed hybrid system can produce the maximum freshwater of 0.647 kg/s with the gain output ratio (GOR) and exergy-based GOR (EGOR) of 9.02 and 3.04%, respectively. In this optimal mode, the cost of produced freshwater and specific work consumption (SW) are estimated 7.13 $/l and 262.9, respectively. Furthermore, a comprehensive parametric study is conducted leading to the determination of the proposed system's behavior due to any variation in the key thermodynamic parameters. It is found that the GOR and EGOR can be maximized with the desalination top temperature, desalination mass flowrate ratio, and compression ratio, while the cost of freshwater can be minimized with the absorber terminal temperature difference and compression ratio. At last, multi-variable regression analysis is employed to correlate the main performance criteria of the system with the key thermodynamic parameters. Highlights • Performance of the HDH system is improved by combining it with the ACHPC. • Proposed hybrid desalination system is analyzed from thermodynamics and thermoeconomics viewpoints. • Single-objective optimization of the proposed hybrid desalination system is conducted, using GA. • A comprehensive parametric study of some key parameters on the main performance criteria is carried out. • Main performance criteria are correlated with the key thermodynamic parameters, using multi-variable regression analysis. [ABSTRACT FROM AUTHOR]

Three thermoeconomic methodologies, specific exergy costing (SPECO), modified productive structure analysis (MOPSA) and the Moran, were used to compare cost flows and products interactions between system components in the context of an existing binary geothermal power plant in western Turkey. With the objective of identifying advantages and disadvantages, exergy and exergoeconomic analyses were conducted using actual plant data to evaluate plant performances and thermoeconomic costs. Overall energy and exergy efficiencies of the plant were calculated as 13.5% and 47.3% and unit exergetic electricity costs were determined as 0.0436 $/kWh for MOPSA, 0.0367 $/kWh for SPECO and 0.0355 $/kWh for Moran. [ABSTRACT FROM AUTHOR]

A new cooling/power cogeneration system is proposed, analyzed and optimized from the viewpoints of thermoeconomics. The system uses geothermal water as a heat source and ammonia-water solution as a working fluid. It is an internally interacting combination of a modified Kalina and an absorption refrigeration cycles. A sensitivity analysis is performed to assess the influences of important parameters on the exergeoconomic performance of the system prior to optimizing its performance. It is shown that the mass flow division at the condenser exit plays an important role on the system performance. The optimization is performed for maximum exergy efficiency (case1), and minimum total product unit cost (case2). The results show that the total product unit cost for case 2 is around 17% lower than that for case 1 at the expense of 11.8% reduction in the second law efficiency. Similarly, it is observed that the second law efficiency for case 1 is around 13.4% higher than that for case 2 at the expense of 20.52% increase in the total product unit cost. It is found that, under studied conditions, the highest exergy efficiency and the lowest total product unit cost for system are obtained as 34.8% and $24.5/GJ, respectively. [ABSTRACT FROM AUTHOR]

The present paper deals with the thermoeconomic analysis of a CO 2 compression system using waste heat into the regenerative organic Rankine cycle. The compressor power required for CO 2 compression in the Carbon Capture and Storage has been supplied from a regenerative organic Rankine cycle which is used in thermal power plant. By using the turbine power supplied from the heat drawn and waste flue gas and the intercooler heat exchangers, 8% of the CO 2 separated from the waste flue gas compressed in the gas compressor. Thermoeconomic analysis of the system is performed by calculating thermodynamic and economic properties of the system. Energy and exergy efficiencies of cycle have been calculated as 17.2% and 51.6%. The average exergetic cost of waste heat flue gas as a fuel input in the integrated to the system is calculated to be 12.34 $/GJ or 947.5 $/h. The unit exergetic cost of electricity from the ORC system is calculated to be 17.47 $/GJ or 0.063 $/kWh. The unit exergetic cost of compressed CO 2 gas is calculated to be 84.9 $/GJ or 184.3 $/h at 310 K and 15,244 kPa. The cost of compressed CO 2 in the plant is calculated to be 18.36 $ per tonne of CO 2 . The total exergy destruction cost rate of the plant and the most destructive component of the flue gas heat exchanger is calculated to be 297.8 $/h and 219.1 $/h, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of the three thermoeconomic methodologies, SPECO (Specific exergy costing), MOPSA (Modified productive structure analysis) and Moran for an existing binary geothermal power plant in western Turkey. Exergy and exergoeconomic analyses of the Dora II binary geothermal power plant with 9543 kW net power output is carried out by using actual plant data to evaluate plant performances and thermoeconomic costs. The objective of the study is to perform the advantages and disadvantages of the presented thermoeconomic methods with respect to the one other using a binary geothermal plant data. The presented thermoeconomic methodologies are used to reveal and compare the cost flows and products interactions between the system components. The overall energy and exergy efficiencies of the plant are calculated to be 47.3% and 13.5%. The unit exergetic costs of electricity are calculated to be 0.0436 $/kWh for MOPSA method, 0.0367 $/kWh for SPECO method and 0.0355 $/kWh for MORAN method, respectively. [ABSTRACT FROM AUTHOR]

In the present study, an optimal power and freshwater cogeneration system is proposed to meet the global requirements sustainably. A Rankine cycle (RC), an organic Rankine cycle (ORC) and a reverse osmosis (RO) module are integrated to form the proposed system. The performance of the system is investigated using thermo-mathematical models allocating seven organic fluids in the bottoming ORC. A novel evolutionary algorithm-based multi-objective optimization approach is applied using thermorisk and thermoeconomic analyses. Thus, an optimal configuration is determined at both global and local scales. Finally, a flexibility analysis is performed to the optimal configuration considering probable uncertainties in the market. The optimization results showed that the total accidental risk impact and the total product cost rate improved by 2.49–48.73% and 5.67–62.41%, respectively, depending on the employed organic fluid. The highest exergetic efficiency and the minimum specific power consumption were obtained as 52.74% and 4.111 kWh/m 3 , allocating R245fa in the optimal system. The system enjoying R123 had the widest flexibility range without any increases in the optimum total product costs. [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) cold utilized micro cogeneration systems are the feasible and sustainable solutions for the inland regions where the large scale LNG cold utilization or the conventional pipeline systems are not economically applicable. The present study investigates the single and combined systems in three LNG importing countries by using the finite sum modeling which is firstly performed for the LNG cold utilization systems with the sustainability index assessment. To generate electricity, the microturbine is integrated with an LNG vaporizer and an LNG pump in the single system while the combined system includes a Stirling engine and a thermal energy storage tank in addition to the microturbine and LNG cold utilization components. Thermodynamic, environmental, thermoeconomic and sustainable analyses are performed to obtain their yearly performance maps that are extremely difficult to obtain with the conventional dynamic modeling. The yearly performance trends of the net power generation rate, exergetic efficiency, and the levelized product cost are found similar to each other while they have contrary yearly trends with the overall energetic efficiency and the Stirling engine performance parameters. The net generated power rate, the Stirling engine performance parameters, the levelized product cost, the emission rate and the sustainability index have significant changes which must be considered for the real applications while the other factors are able to be neglected during the dynamic analysis since their fluctuations are small. The most convenient time are found at 08:00 am in all the case countries though the corresponding months change for each case country. The combined system is found more feasible than the single system from the thermodynamic, thermoeconomic, environmental and sustainable viewpoints. [ABSTRACT FROM AUTHOR]

Multi-generation systems are promising technologies for multiple production applications to reduce the waste heat of the basic system. For this purpose, a novel multi-generation system using geothermal heat source is proposed which produces different commodities of cooling, heating, power and freshwater, simultaneously. The system comprises of a Kalina cycle, an absorption refrigeration cycle, a humidification-dehumidification desalination system, and a domestic water heater unit system. Exergoeconomic optimization of the proposed system is conducted, showing that the optimum thermal efficiency, exergy efficiency and total SUCP (sum unit cost of the product) can be obtained 94.84%, 47.89%, and 89.95 $/GJ, respectively. Moreover, a comprehensive parametric study showed that the Gained-Output-Ratio, freshwater, thermal efficiency and exergy efficiency can be optimized based on the desalination mass flow rate ratio. In addition, it is demonstrated that a higher thermal efficiency can be obtained by increasing vapour generator pinch point temperature difference, turbine inlet pressure, and evaporator temperature or decreasing condenser temperature, absorber temperature, basic ammonia concentration, desalination top temperature, desalination bottom temperature, and heater terminal temperature difference. Whereas, a higher exergy efficiency can be attained at high evaporator temperature, basic ammonia concentration, and desalination bottom temperature or low vapour generator pinch point temperature difference, turbine inlet pressure, condenser temperature, absorber temperature, desalination top temperature, and heater terminal temperature difference. [ABSTRACT FROM AUTHOR]

Heat recovery devices can help ventilation systems conserve energy; However, they cause a pressure drop in the system, and hence the system incurs an electricity consumption. In the present paper, the maximum allowable pressure drop of the recovery units is achieved from thermodynamic and economic points of view. The novelty of the research is that, unlike the existing criterion which does not differ for different cities, the introduced criteria can be calculated for each city with individual weather, economic, power plants, and energy conditions. Although the methods presented to calculate the criteria consider a broad range of effective parameters, there is no need to use complex energy simulation methods. Moreover, for each city, four types of criteria are introduced, which allows the city authorities to choose the best ones according to their city conditions, and then calculate the chosen criteria by the data of the city. In order to gain the criteria, modified enthalpy-hours and bin method variables are introduced to calculate sensible and latent energy consumption due to ventilation. The criteria are numerically calculated for Kerman city in Iran, and the results show that the recovery type and the chosen viewpoint has a considerable effect on the allowable pressure drop. The sensitivity of the results to different variables is analyzed in the end. [ABSTRACT FROM AUTHOR]

The mathematical model for the prediction of a novel hybrid desalination system was presented. The Hybridization of thermal and membrane desalination systems was investigated, and the efficient and appropriate arrangements were introduced. Multi-effect distillation, reverse osmosis and adsorption desalination systems were the major constituents of the novel hybrid system (MEDAD+RO). The thermodynamic and exergetic analysis was done. For economic analysis, the total revenue requirement method was used, and the thermoeconomic analysis was performed. Produced water price resulting from the thermoeconomic analysis, was $ 1.3 per cubic meter. The permeate water production in the novel system has increased to more than twice. The multi-objective optimization with genetic algorithm tool was used to obtain the optimum point of the system. The determination of best tradeoff between the permeate flow rate, price and exergetic destruction of MEDAD+RO, was the final goal of this optimization. In two-objective optimization process, the permeate water flow rate has increased 65.5%, and the price of producing water has reduced 38.4% respect to the base Plant. The optimum layout resulted of there-objective optimization led to the 59.7% increase in water production and 32.3% decrease in water production cost as compared to the first modeling. [ABSTRACT FROM AUTHOR]

In this work, a novel combined biomass based power generation system is proposed and investigated. The proposed integrated system consists of a combination of biomass gasifier, solid oxide fuel cell, gas turbine cycle and a Rankine cycle. Three different biomasses are selected: Pine Saw Dust, Municipal Solid Waste and Fowl Manure. A comprehensive thermoeconomic analysis as well as a multi-objective optimization is carried out. The effects of most important operating parameters on thermodynamic performance, unit production cost and total cost rate are investigated for the overall system and components. The operating parameters considered include biomass mass flow rate, compression ratio of air compressor, current density of solid oxide fuel cell and exit temperature of solid oxide fuel cell. The results show that the fuel mass flow rate and current density are the dominant factors affecting the variation of energy and exergy efficiencies as well as unit production cost. Moreover, the best thermodynamic and economic performances are corresponded to the Pine Saw Dust fueled system. Nevertheless, the best environmental performance is related to the Fowl Manure fueled system mainly due to the lowest content of CO 2 in flue gas leaving the system to the atmosphere. [ABSTRACT FROM AUTHOR]