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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]

In this research, thermodynamic and thermoeconomic analysis of a new multigeneration system based on the Parabolic trough collector and the photovoltaic-thermal solar collectors is carried out to produce power, cooling, hot water, hydrogen and freshwater. The proposed system includes an organic Rankine cycle, double-effect absorption refrigeration system, PEM electrolyzer and the reverse osmosis desalination unit. Analysis of energy, exergy, thermoeconomics, as well as analysis of various parameters was done by using the EES software. The results show that the energy and second law efficiency of the system is 33.49% and 13.31%, respectively. The net power produced by the system is 1271.48 kW in which ORC turbine has the maximum share. Moreover, the coefficient of performance of the cooling system is achieved to be 1.097 by considering the basic assumptions. The hydrogen and freshwater production rates are 542.3 kg/day and 4.55 kg/s, respectively. Finally, the rate of exergy destruction in each part of the system shows that the highest rate of exergy loss occurs in the PTC collector and the organic Rankine cycle with the amount of 53575 kW and 1624 kW, respectively, and in the organic Rankine cycle, the thermoelectric generator unit and evaporator have the largest share of exergy losses.

Natural gas stations require a preheating stage to prevent the formation of hydrates inside of them provoked by a sudden decompression process of the natural gas. The preheating process has been investigated to improve efficiency and to reduce costs as well. This work studies the behavior of a natural gas decompression station with a first-stage preheating process using a vortex tube and a geothermal heat exchanger, followed by a second stage involving a water bath heater (heating vat). An energetic, exergetic, and exergoeconomic study has been carried out based on a mathematical model and the theory of exergetic cost, obtaining key thermodynamic and thermoeconomic variables, including exergy flows and equipment costs. A heat flow of 26.41 kW was obtained in the geothermal preheating stage; meanwhile, a 60.43 kW heat flow was obtained in the heating vat. The results showed a saving in station fuel using only 2.046% of the natural gas in the system at the second preheating stage. Also, the system was optimized, obtaining a 15.73% reduction in the decompressed natural gas cost. These findings show the possibility of implementing these systems in zones with many geothermal resources to reach a constant, profitable natural gas supply in areas where a pipeline network does not exist. [ABSTRACT FROM AUTHOR]

In this study, the thermodynamic and thermoeconomic analysis of a multigeneration system which produces power, cooling, domestic heating, hydrogen and freshwater has been carried out. The main source of energy for this system is a solar parabolic trough collector (PTC). The working fluid applied for this solar collector is Al2O3-Therminol VP1 nanofluid. The subsystems of this multigeneration system are a steam Rankine cycle for power production, an organic Rankine cycle for power production, a double-effect absorption refrigeration system for cooling production, a domestic water heater for hot water production, a PEM electrolyzer for hydrogen production and a RO desalination unit for freshwater production. In the ORC cycle a TEG unit is applied instead of the condenser for extra power production. The system is analyzed by using the EES software. The effects of different parameters as well as the effects of nanoparticles on the performance of the proposed system were investigated. According to the results, the energy and exergy efficiency of the system are 33.81 % and 23.59 %, respectively. Among the studied working fluids in the ORC cycle, n-pentane shows the best performance. The energy and exergy efficiency of the system increases by the nanoparticle volume concentration and the solar radiation increase. Moreover, the collector inlet temperature has a negative effect on the hydrogen and freshwater production rates. Finally, it is proved that the PTC collector has the highest amount of exergy destruction rate in the studied system.

Liquefaction of natural gas (LNG) is an energy-intensive process with large CO2 emissions. This study addresses these problems by introducing a novel hybrid integration between the propane pre-cooled mixed-refrigerant (C3MR) liquefaction process and concentrated solar power (CSP), utilizing an intercooled supercritical CO2 power block. The proposed system is designed to minimize or eliminate the need for thermal energy storage (TES) and reduce CO2 emissions while providing economic benefits. These benefits are obtained mainly by recovering the cold energy of the flash-gas of the C3MR process through the precooling process of the sCO2 cycle. Then, the flash-gas is stored and combusted (using an auxiliary heater (AH)) at nighttime or when CSP is insufficient to meet the power demand. Five integration cases are evaluated from energetic, exergetic, economic, and environmental points of view: the sCO2 cycle is driven by CSP and its thermal energy storage (TES) without AH in Case-1, by CSP+TES+AH in Case-2 to Case-4 with different contribution from TES and AH, and by CSP+AH without TES in Case-5. In addition, this study optimizes the operating parameters of the hybrid system to further enhance its economic and environmental benefits. The proposed system reduces the CSP field size, minimizes or eliminates the need for TES, and reduces or eliminates CO2 emissions. The optimized results show that Case-2 and Case-5 reduced the levelized cost of electricity from 14.16¢/kWh to 10.35¢/kWh and 8.19¢/kWh, respectively, and reduced the CO2 emissions by 86% and 36%. This study contributes to the field by introducing a novel hybrid integration between the C3MR process and CSP system, providing thorough evaluations of its performance and benefits, and providing significant benefits to the decarbonization strategies of LNG and other industrial processes.

This research presents the proposal of a double ejector-two flash tank absorption refrigeration cycle, in which vapor and liquid ejectors are implemented simultaneously before the condensers and absorbers components. For the vapor ejector simulation, the shock circle approach is used. The internal environment of the vapor ejector, including the chocking phenomenon and the irreversible shock process, is also thoroughly examined. It is proposed that ejectors and flash tanks can improve the system performance. It is possible to improve the ejector entrainment ratio by incorporating a flash tank between the evaporator and condenser, which would also increase the evaporator cooling effect. Moreover, a second flash tank is installed between the generator and the absorber, which allows the generator to operate at a lower temperature and thus reduces the generator heat load. Consequently, the system's COP (coefficient of performance) increases. Furthermore, the unit cost of the final product in a wide range of operational conditions is calculated. The findings revealed up to 56.8% increase in the COP. The improvement of the maximum exergetic efficiency in the new cycle compared to the basic cycle also reaches 22.5%. Moreover, the thermoeconomic investigation show up to 34.6%. reduction in product cost.

This article presents a novel and comprehensive approach for the thermoeconomic evaluation of subcritical and supercritical isobutane cycles for geothermal temperatures of Tgeo = 100–200 °C. The isobutane cycles are optimized with respect to the maximum net power or minimum levelized cost of electricity (LCOE). Cycle optimization is also included, using a minimum superheat temperature to avoid turbine erosion, which is usually neglected in the literature. The results show that economic optimums are found in the far superheated region, while thermal optimums are obtained with dry saturated or with slightly superheated vapor at the turbine inlet (ΔTsup < 5 °C). Supercritical cycles achieve better thermal performance than subcritical cycles for Tgeo = 179–200 °C. Internal heat recuperation improves the cycle performance: the net power output increases and the LCOE decreases, but specific installation costs (SICs) increase due to the additional heat exchanger. For geothermal temperatures of Tgeo = 120 → 150 °C, the costs are LCOE = 100 → 80 USD2022/MWh and SIC = 7000 → 5250 USD2022/kW, while for geothermal temperatures of Tgeo = 150 → 200 °C, the estimated costs are LCOE = 80 → 70 USD2022/MWh and SIC = 5250 → 4600 USD2022/kW. [ABSTRACT FROM AUTHOR]

Enhancing the sustainability and diversification of Iraq's electricity system is a strategic objective. Achieving this goal depends critically on increasing the use of renewable energy sources (RESs). The significance of developing solar-powered technologies becomes essential at this point. Iraq, similar to other places with high average direct normal irradiation, is a good location for concentrated solar thermal power (CSP) technology. This study aims to recover the waste heat from the gas turbine cycle (GTC) in the Al-Qayara power plant in Iraq and integrate it with a solar power tower. A thermoeconomic analysis has been done to support the installation of an integrated solar combined cycle (ISCC), which uses concentrated solar tower technology. The results indicate that the examined power plant has a total capacity of 561.5 MW, of which 130.4 MW is due to the waste heat recovery of G.T.s, and 68 MW. is from CSP. Due to the waste heat recovery of GTC, the thermal and exergy efficiencies increase by 10.99 and 10.61%, respectively, and the overall unit cost of production is 11.43 USD/MWh. For ISCC, the thermal and exergy efficiencies increase by 17.96 and 17.34%, respectively, and the overall unit cost of production is 12.39 USD/MWh. The integrated solar combined cycle's lowest monthly capacity was about 539 MW in September, while its highest monthly capacity was approximately 574.6 MW in April. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to evaluate the thermodynamic and economic performance of using a solar chimney and wind turbine to help generate electricity in a multigeneration system. The proposed system is designed to generate power, heating, cooling, hot water, and steam. Parametric studies were conducted to evaluate the effects of various parameters such as Brayton cycle turbine inlet pressure, organic Rankine cycle turbine inlet temperature, solar radiation, wind speed, and absorption refrigeration cycle evaporator temperature on the system efficiency. The effects of these parameters on the energy, exergy, and economic efficiencies of the whole system were investigated. The results showed that the highest energy efficiency and total exergy of the multigeneration system were 22.12% and 11.4%, respectively. Also, the total power generation capacity of the studied system was calculated to be 2103 kW. The results also depicted that the highest rate of exergy destruction for the main components of the system is found in the parabolic dish solar collector. Increasing the turbine inlet pressure, the average wind velocity of the wind turbine and, evaporator temperature increasing of absorption refrigeration cycle has a positive effect on the efficiency of the proposed system.

In the current energy and environmental framework, the environmental impact of the road transport sector and the urban waste management and disposal are extremely important for highly crowded cities. This work assesses the energy, economic and environmental performance of an innovative paradigm for the full decarbonisation of the road transport sector. This problem is integrated with the management of the organic fraction of municipal solid waste. In particular, the proposed technology is based on an anaerobic digestion plant coupled with a biogas upgrading unit, for the production of biomethane. In addition, photovoltaic panels and solar thermal collectors are also considered for matching electrical and thermal demands, in order to achieve a fully-renewable system. To this scope, the system also includes suitable thermal and electric storages. The economic analysis also considers specific public funding policies, currently available for this technology. This system aims to be a novel paradigm in the energy scenario of waste disposal and road transport sector refurbishment. TRNSYS software was adopted to perform an accurate dynamic simulation for a one-year operation of the system. The anaerobic digestion model is developed by the authors in MatLab and integrated in TRNSYS, for dynamic simulation purpose. Results show that the plant is almost self-sufficient due to the integration of storage systems for both the thermal and electric energy. The photovoltaic system is able to reduce by 45% the energy dependence from the grid. Energy and environmental analyses show a Primary Energy Saving of 126% and a reduction of CO2 equivalent emissions by 112%. The economic feasibility analysis shows a promising Simple Payback period of 6 years.

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]

In this work, a natural gas assisted geothermal central heating system in northwestern Turkey utilising low enthalpy geothermal fluid and natural gas as the sources for space heating was analyzed.The study comprised energy, exergy and thermoeconomic analyses of the system under hybrid operating conditions (i.e., from 1 January 2020 to 31 March 2020). The data were collected from a basis of the facility which operates the system. The values about the heat pumps were obtained from the department of the sales company in Istanbul, Turkey and the ‘Average Values for Hybrid Case’ were determined. This work covers energetically, exergetically and thermoeconomically assessment of the system in question through its all stages. The results were found with regard to the system performance investigation. The whole system efficiencies of energy and exergy were found as 56.77% and 49.93% respectively. The exergy cost value per hour and the thermoeconomic factor were calculated as 411.242 €/h and 9.8% respectively.

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]

The maritime industry will continue to see increasing regulatory requirements to reduce carbon emissions from ships' operations. Improving the energy efficiency of ships with waste heat recovery systems based on the organic Rankine cycle (ORC) is an attractive way to meet these tightening requirements. The operational profile of a ship has a huge influence on the feasibility of installing ORC onboard as it affects the waste heat source profile from the diesel engines. However, to date, scant attention has been paid to examining the effects that the operational profile has on the marine application of ORC as it is both difficult and expensive to obtain. The present paper aims to describe a methodology that can overcome this problem by developing a generic ship speed profile that defines the ship's operational profile. This speed profile works together with a fit-for-purpose diesel engine waste heat model to derive a waste heat source profile that is used as the input to a thermoeconomic analysis that can justify the installation of ORC. The proposed methodology allows for an objective comparison of the feasibility of ORC subjected to variations in the operational profile. Furthermore, the optimum ORC design can be identified to meet payback time expectations of different shipowners. [ABSTRACT FROM AUTHOR]

The heat pumps are frequently used in domestic and industrial applications for hot water supply. The present paper aims to thermodynamically investigate the impacts of the nanoparticle-addition into the lubricants on the energetic, exergetic, and thermoeconomic aspects of a heat pump. In the experiments, air to the water heat pump is separately charged with various metal oxide-based nanoparticles (Al2O3, CuO, and TiO2)-added oils at a constant mass fraction of 0.5%. Polyolester (POE) and 134a are used as a lubricant, and refrigerant, respectively. The mass flow rates of the water passed through the condenser are varied from 10 to 25 g/s with an interval of 5 g/s. In the results, it is observed that the thermal conductivity value noteworthy increases with the presence of nanoparticles in POE. The highest increment in thermal conductivity is found to be 39% for POE + CuO in comparison with that of pure POE. Furthermore, with nanoparticles addition, it is noticed that the COP value generally improves, and the highest improvement for COP value is noticed to be 8% for POE + TiO2 nanolubricant at the mass flow of 25 g/s. Furthermore, exergy efficiency enhances by 3.6%, 1.8%, and 4.5% for POE + Al2O3, POE + CuO, and POE + TiO2, respectively. The lowest heating cost is calculated to be 3.465 ¢/kWh at 20 g/s flow rate for POE + Al2O3. In conclusion, this paper clearly reports that usage of nanoparticles along with lubricants is presenting better energetic, exergetic, and thermoeconomic results rather than the usage of lubricant alone in the heat pumps.

Evaluating Coal-Fired Power Plant (CFPP) performance is a complex process involving the determination of the turbine cycle Heat Rate (TCHR). This study focuses on determining the TCHR by developing a mathematical model. The model, which incorporates economic analysis of the plant, is developed using energy and mass balance relationships of the turbine cycle, validated using plant commissioning data from a 700MWn CFPP located in Perak, Malaysia. Actual plant data from a 700MWn CFPP is utilized to improve the accuracy and increase the confidence of the results of this study. It was found that at the nominal operating load of 729MWg, there is a Heat Rate (HR) deviation of -1,135 kJ/kWh, leading to daily losses of RM240,447 or USD 60,112. Furthermore, it is possible to utilize the developed model at lower loads as the plant is now being used to operate on "cyclic" loads. The daily losses at a lower load of 431MWg are RM125,767 or USD31,442. Thus, the model is able to compare the plant HR at various loads against commissioning data, and economic analysis is able to be carried out effectively. Valuable information for plant operations and performance engineers could be obtained using this model to determine plant HR. [ABSTRACT FROM AUTHOR]

Because of the fossil fuels crisis in recent years, increasing fossil fuel consumption and the oil crisis, energy efficiency is becoming a major concern of the twenty-first century. In this research, the combined cycle of steam Rankine and organic Rankine with the primary mover of the Allam generation cycle has been simulated. The hybrid cycle is configured in such a way that the high temperature waste heat first acts as the steam cycle evaporator and the waste heat output from the steam cycle evaporator is used as the low temperature evaporator of the organic cycle. Then, the effect of changing various parameters such as evaporator temperature and steam cycle condenser pressure on output work values, total irreversibility, energy efficiency, exergy efficiency and exergy-economic variables is investigated. The results show that the energy efficiency and exergy efficiency of the combined cycle are 0.57 and 0.66, respectively, and the amount of output work and total irreversibility are 150,125 kW and 91,237 kW, respectively. Also, according to the study results, a lot of exergy destruction takes place in the system, thus it is recommended to increase the initial price in different components in order to improve the performance of the system. Evaporators and steam cycle condensers are components that should be considered from an exergy-economic perspective, as they have the highest rate for the sum of the initial cost rate and the cost of exergy destruction. [ABSTRACT FROM AUTHOR]

Solar energy systems are widely utilized to obtain environmentally friendly and sustainable electrical and thermal energy that able to be used in many applications. Temperature-controlled solar air heater (SAH) system with a zigzag finned plate and flat plate was designed, manufactured, and tested experimentally in this study. It was determined that the set temperature was 15% higher than the flat plate SAH outlet temperature. The most important cause for this increase, the air is exposed preheating in the first collector. As the heat transfer surface area raised thanks to the zigzag fins in the second collector, the temperature of the air increases even more. SAH system's energy efficiency was found to be 71.15% on average. SAH system's maximum exergy efficiency was determined as 3.7%. The SAH system's average exergy destruction is calculated to be 651.58 W on average. According to the enviroeconomic analysis of the system, hourly CO2 mitigation was found to be 1.04 kg CO2/h and the environmental cost was 1.508 ¢/h. The energy cost was calculated as 0.0834 $/kWh, while the exergoeconomic parameter was calculated as 0.1931 kWh/$. In addition, the energy payback period was determined as 1.35 years, while the exergy payback period was determined as 45.9 years.

Because of population growth, demands for water and energy for domestic, industrial, and agricultural usages are increasing. Considerable research has been conducted in recent years to evaluate the thermodynamics and optimization of desalination systems. One important concept is the capacity to integrate power generation systems with desalination plants. The purpose of this study is to analyze the exergy and thermoeconomics of the combined desalination system (MED) and Allam power generation system. The key advantage of this proposed system is to use the heat generated in the Allam power generation system to operate the desalination system. Similarly, due to the performance of the Allam generation system, the amount of carbon dioxide produced is virtually zero. By determining the processes and solving the governing equations, the properties of the fluids passing through the combined cycle of Allam and MED are determined and thermodynamic, exergetic and thermoeconomic analysis is performed along with the thermoeconomic optimization of the system. In this research, genetic algorithm has been used for optimization and the result has been described in multi-objective optimization. Subsequently, parametric analysis and the effect of design variables on the system cost function have been accomplished. The results show that in a specific vector of decision variables, the objective functions including, the exergetic efficiency and the cost of the product produced by the system are optimized simultaneously. In conventional desalination plants, a boiler is used to supply the steam entering the desalination system. After conducting the model simulation of the desalination system, the Allam generation system is modeled as well. Thus, by combining these two systems, the heat generated by the Allam generation system can be used to evaporate water in the desalination system. In the ideal case, the price of fresh water of using the steam produced by the boiler is $1.131 per cubic meter, and by means of the steam produced by the power generation system would be $1.087 per cubic meter. Hence, the results indicate that combining the desalination system with the Allam generation system provides a 4% reduction. Reducing carbon dioxide emissions is also a significant benefit of this system. [ABSTRACT FROM AUTHOR]

In this paper, the thermoeconomic cost model of a typical gas turbine combined cycle (GTCC) system is established based on the structure theory of thermoeconomics. Because the operation strategy is the basis of the research on the design/off-design condition of GTCC unit. Therefore, the GTCC thermoeconomic performances with different strategies using the inlet guided valve (IGV) control are compared based on the GTCC cost model to analysis the influence of the main parameters on the unit thermoeconomic cost of each component. The variation rules of the thermoeconomic performances of the GTCC unit under design/off-design operating conditions influenced by the operating strategy and ambient temperature are revealed. The results show that the GTCC with the IGV T3-650-F operation strategy has the lowest thermoeconomic cost. Changing the operation strategy of gas turbine (GT) can reduce the generator (GEN) unit thermoeconomic cost. And higher GT inlet/outlet temperature is helpful to reduce the thermoeconomic cost of combined cycle under off-design conditions. The investment on the steam turbine (ST) and the irreversibility of the combustion chamber (CC) have the important influence on the thermoeconomic cost of GTCC system. Reducing the air compressor (AC) inlet air temperature can reduce the thermoeconomic cost of GTCC system.

This research work presents the assessment of the impact of the solar irradiation, the distance from the coast, and the altitude of the location for a Concentrated Solar Power + Photovoltaic + Multi-Effect Distillation (CSP + PV + MED) plant for simultaneous power generation and seawater desalination. For that, a comparative analysis of the thermoeconomic cost of electricity and water (TCE and TCW) at different locations is carried out to determine the most competitive sites where this kind of cogeneration plant can be deployed. Also, multi-objective optimization is performed to assess the optimum sizing that allows reducing the costs. The study considers four Direct Normal Irradiation (DNI) levels (from 2000 to 3500 kWh/m2-yr), six distances from the sea (from 5 to 100 km), and six altitudes (from 20 to 1000 m.a.s.l.). The results show that solar irradiation has the most significant effect on the TCE and TCW, the distance to the sea affects the TCW considerably, and the altitude has a moderate impact despite its impact is substantially lower than the other two factors. Also, cost maps of the TCE and TCW giving insights about which locations have a higher potential for developing CSP + PV + MED plants are presented. From these maps, it has been found that the potential inland locations to reach TCE and TCW under 100 $/MWh and TCW 2 $/m3 should have high DNI (at least 300 kWh/m2-yr above the coast level), distances from the coast up to 60 km, and altitudes up to 750–1000 m.

The maritime industry will continue to see increasing regulatory requirements to reduce carbon emissions from ships’ operations. Improving the energy efficiency of ships with waste heat recovery systems based on the organic Rankine cycle (ORC) is an attractive way to meet these tightening requirements. The operational profile of a ship has a huge influence on the feasibility of installing ORC onboard as it affects the waste heat source profile from the diesel engines. However, to date, scant attention has been paid to examining the effects that the operational profile has on the marine application of ORC as it is both difficult and expensive to obtain. The present paper aims to describe a methodology that can overcome this problem by developing a generic ship speed profile that defines the ship’s operational profile. This speed profile works together with a fit-for-purpose diesel engine waste heat model to derive a waste heat source profile that is used as the input to a thermoeconomic analysis that can justify the installation of ORC. The proposed methodology allows for an objective comparison of the feasibility of ORC subjected to variations in the operational profile. Furthermore, the optimum ORC design can be identified to meet payback time expectations of different shipowners.

A Plant for trigeneration of freshwater, power and cooling has been developed and optimized for higher efficiency and lower plant cost. Parabolic trough collectors with thermal energy storage are considered using thermal oil as the heat transfer fluid. Solar heat is utilized to produce power via a Toluene-based Rankine cycle for power generation and cooling via an Absorption chiller. A part of the generated power is used to run a Reverse Osmosis desalination plant. The solar data is taken from a southern city in Turkey. Exergy efficiency and plant cost rate of the system vary between 9–14% and 287–335 $/h, respectively. A multiobjective optimization study depicts that optimal exergy efficiency of %12.5 is obtainable at a plant cost rate of 328 $/h. Freshwater cost is strongly dependent on the cost of solar electricity and shows a significant fluctuation due to variable solar availability condition. The results of the studied system depict that sustainable and economical plant operation is possible in short/near terms when the investment costs of utilized technologies are competitive with those used in conventional plants.

Organic Rankine Cycle (ORC) is an effective way to recycle waste heat sources of a marine diesel engine. The aim of the present paper is to analyze and optimize the thermoeconomic performance of a Series Heat Exchangers ORC (SHEORC) for recovering energy from jacket water, scavenge air, and exhaust gas. The three sources are combined into three groups of jacket water (JW)→exhaust gas (EG), scavenge air (SA)→exhaust gas, and jacket water→scavenge air→exhaust gas. The influence of fluid mass flow rate, evaporation pressure, and heat source recovery proportion on the thermal performance and economic performance of SHEORC was studied. A single-objective optimization with power output as the objective and multi-objective optimization with exergy efficiency and levelized cost of energy (LCOE) as the objectives are carried out. The analysis results show that in jacket water→exhaust gas and jacket water→scavenge air→exhaust gas source combination, there is an optimal heat recovery proportion through which the SHEORC could obtain the best performance. The optimization results showed that R245ca has the best performance in thermoeconomic performance in all three source combinations. With scavenge air→exhaust, the power output, exergy efficiency, and LCOE are 354.19 kW, 59.02%, and 0.1150 $/kWh, respectively. Integrating the jacket water into the SA→EG group would not increase the power output, but would decrease the LCOE.

Waste-heat recovery (WHR) systems based on the organic Rankine cycle (ORC) improve the thermal efficiency of natural gas engines because they generate additional electric power without consuming more gas fuel. However, to obtain a cost-effective design, thermoeconomic criteria must be considered to facilitate installation, operation, and penetration into real industrial contexts. Therefore, a thermo-economic analyses of a simple ORC (SORC), ORC with recuperator (RORC) and a double-pressure ORC (DORC) integrated with a 2 MW Jenbacher JMS 612 GS-N. L is presented using toluene as the organic working fluid. In addition, the cost rate balances for each system are presented in detail, with the analysis of some thermoeconomics indicator such as the relative cost difference, the exergoeconomic factor, and the cost rates of exergy destruction and exergy loss. The results reported opportunities to improve the thermoeconomic performance in the condenser and turbine, because the exergoeconomic factor for the condenser and the turbine were in the RORC (0.41 and 0.90), and DORC (0.99 and 0.99) respectively, which implies for the RORC configuration that 59% and 10% of the increase of the total cost of the system is caused by the exergy destruction of these devices. Also, the pumps present the higher values of relative cost difference and exergoeconomic factor for B1 (rk = 8.5, fk = 80%), B2 (rk = 8, fk = 85%). [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]

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]

An activated carbon manufacturing process from winemaking waste is analyzed. In that way, vine shoots conversion is studied as a basis for plant designing, and mass and energy balances of hydrothermal carbonization and physical activation are fulfilled. To develop an energy-integrated plant, a network of heat exchangers is allocated to recover heat waste, and a cogeneration cycle is designed to provide electricity and remaining heat process demands. Furthermore, thermoeconomic analysis is applied to determine the thermodynamic efficiency and the economic viability of the plant. Energy balance indicates that heat exchangers energy integration covers 48.9% of the overall demands by crossing hot and cold streams and recovering heat from residual flue gas. On the other hand, the exergy costs analysis identifies combustion of pruning wood as the main source of exergy destruction, confirming the suitability of the integration to improve the thermodynamic performance. Attending to economic costs analysis, production scale and vineyard pruning wood price are identified as a critical parameter on process profitability. With a scale of 2.5 ton/h of pruning wood carbonization, a break-event point to compete with activated carbons from biomass origin is reached. Nevertheless, cost of pruning wood is identified as another important economic parameter, pointing out the suitability of wet methods such as hydrothermal carbonization (HTC) to treat them as received form the harvest and to contribute to cutting down its prices.

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]

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]

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]

To contribute to the economic viability of waste heat recovery systems application based on the organic Rankine cycle (ORC) under real operation condition of natural gas engines, this article presents a thermoeconomic optimization results using the particle swarm optimization (PSO) algorithm of a simple ORC (SORC), regenerative ORC (RORC), and double-stage ORC (DORC) integrated to a GE Jenbacher engine type 6, which have not been reported in the literature. Thermoeconomic modeling was proposed for the studied configurations to integrate the exergetic analysis with economic considerations, allowing to reduce the thermoeconomic indicators that most influence the cash flow of the project. The greatest opportunities for improvement were obtained for the DORC, where the results for maximizing net power allowed the maximum value of 99.52 kW, with 85% and 80% efficiencies in the pump and turbine, respectively, while the pinch point temperatures of the evaporator and condenser must be 35 and 16 °C. This study serves as a guide for future research focused on the thermoeconomic performance optimization of an ORC integrated into a natural gas engine.

Waste-heat recovery (WHR) systems based on the organic Rankine cycle (ORC) improve the thermal efficiency of natural gas engines because they generate additional electric power without consuming more gas fuel. However, to obtain a cost-effective design, thermoeconomic criteria must be considered to facilitate installation, operation, and penetration into real industrial contexts. Therefore, a thermo-economic analyses of a simple ORC (SORC), ORC with recuperator (RORC) and a double-pressure ORC (DORC) integrated with a 2 MW Jenbacher JMS 612 GS-N. L is presented using toluene as the organic working fluid. In addition, the cost rate balances for each system are presented in detail, with the analysis of some thermoeconomics indicator such as the relative cost difference, the exergoeconomic factor, and the cost rates of exergy destruction and exergy loss. The results reported opportunities to improve the thermoeconomic performance in the condenser and turbine, because the exergoeconomic factor for the condenser and the turbine were in the RORC (0.41 and 0.90), and DORC (0.99 and 0.99) respectively, which implies for the RORC configuration that 59% and 10% of the increase of the total cost of the system is caused by the exergy destruction of these devices. Also, the pumps present the higher values of relative cost difference and exergoeconomic factor for B1 (rk = 8.5, fk = 80%), B2 (rk = 8, fk = 85%).

Liquefied natural gas (LNG) cold utilized micro-cogeneration systems can be used as a part of small scale LNG regasification processes. The study proposes a LNG cold utilized micro-cogeneration system which combines a Stirling engine and a micro gas turbine. The combined system is compared to a conventional micro-cogeneration system the point of thermodynamic, environmental and thermoeconomic views. Parametric studies are conducted in the ranges of 288.15–313.15 K for the ambient air temperature and 3–4 for the compressor pressure ratio, respectively. Thermodynamic efficiencies and power generation rates are studied in thermodynamic analyses while carbon dioxide emission rates and the relevant emission reductions are observed in environmental analyses. An original exergy-cost matrix is produced for the combined system and thermoeconomic comparison is performed between the combined system and the conventional micro-cogeneration system. It is found that the combined system provides 7.8% higher power generation rates whereas it has 1% and 2.4% higher energetic and exergetic efficiencies, respectively at the actual pressure ratio of the micro gas turbine. Emission reductions are observed as 3.9%, 7.8% or 8% at individual pressure ratio of 3, 3.64 or 4. The unit fuel costs are calculated for the system components and it is deduced that the combined system has higher unit fuel costs at the lower pressure ratios. It is found that the single system has roundly 25% less levelized product cost than the combined system at the actual pressure ratio. A simple graphic-based thermoeconomic optimization study demonstrates that the minimum relative cost differences are at different locations for the combined cycle. [ABSTRACT FROM AUTHOR]

An approach for evaluating heat-exchanger operating efficiency using the calculated exergy efficiency (EE) that allows heat-exchanger system elements with low heat-transfer efficiency to be located and their maintenance (cleaning) to be managed according to their condition was proposed. Measurements required for the EE calculation were recorded automatically from the Automatic Process Control System databases of the application. Real-time mathematical modeling of the current mode of the facility using a computer training complex provided additional data. [ABSTRACT FROM AUTHOR]

The necessity of air-conditioning causes the enormous energy use of underground train stations. Exergy and thermoeconomic analysis is applied to the annual operation of the air-conditioning system of a large underground train station in Taiwan. The current installation and the monitored data are taken to be the base case, which is then compared to three different optimized designs. The total revenue requirement levelized cost rate and the total exergy destruction rate are used to evaluate the merits. The results show that the cost optimization objective would obtain a lower total revenue requirement levelized cost rate, but at the expense of a higher total exergy destruction rate. Optimization of thermodynamic efficiency, however, leads to a lower total exergy destruction rate, but would increase the total revenue requirement levelized cost rate significantly. It has been shown that multi-objective optimization would result in a small marginal increase in total revenue requirement levelized cost rate, but achieve a significantly lower total exergy destruction rate. Results in terms of the normalized total revenue requirement levelized cost rate and the normalized total exergy destruction rate are also presented. It has been shown by second law analysis when applied to underground train stations that lower annual energy use and lower CO2 emissions can be achieved. [ABSTRACT FROM AUTHOR]

Nowadays, gradual depletion of fossil fuels associated with emissions constraints due to greenhouse gases, leads to reuse wasted heat from power plant in order to increase the global efficiency. One of the implemented technologies for improvements is the application of combined cycles. In this scenario, the steam cycle is frequently combined with a Brayton cycle and the power plant performances and costs are competitive in the global market. Often, an energetic engineering company defines and studies the performance of the bottom steam cycle, thus it imposes operational conditions of steam turbine and heat recovery boiler and requires these components are built by two different manufacturers. For this reason, the plant cannot be globally optimized. From a steam turbines manufacturer point of view, the integration between proprietary simulation code and an energy balance code is an opportunity to simulate a complete bottom-cycle in order to define the best plant configuration. In the present paper, aone-pressure level heat recovery steam generator is studied in term of thermodynamic performance and cost analysis. The thermodynamic analysis is realized using a fixed steam turbine isentropic efficiency (as an energetic engineering company can do) and using anisentropic efficiency determined from steam turbine industrial tool, so a different best performance can be determined. Moreover, a comparison between two academic steam turbine cost correlations and steam turbine cost suggested by industrial cost is carried out. [ABSTRACT FROM AUTHOR]

Organic Rankine cycle (ORC) has been examined as an effective way to recovery waste heat from industrial manufacture. The effects of internal heat exchanger (IHE) and superheat degree on the thermoeconomic performance of ORC are presented in this paper. Zeotropic mixtures are employed in the simulation and six indicators are used to evaluate the system performance, as follows: (1) net power output, (2) thermal efficiency, (3) exergy efficiency, (4) cost per net power output (CPNPO), (5) area of the heat changers per net power output (APNPO), and (6) energy saving and emission reduction performance (ESERP). The results indicate that the more volatile pure component has a higher increasing rate of net power output when IHE is equipped. The IHE has a greater impact on thermal efficiency and exergy efficiency of the ORC with zeotropic mixtures than that of the ORC with pure fluid. For the ORC with both mixtures and pure component, the rising superheat degree results to the decline of the net power output but increase of the thermal efficiency, and exergy efficiency at the constant turbine inlet pressure. Both the basic ORC and regenerative ORC with zeotropic mixtures have a better economic performance than that with pure fluid. In addition, superheat degree has a negative effect on the economic performance of ORC with more volatile component mixtures. [ABSTRACT FROM AUTHOR]