Reduce Exergy Destruction Research Articles

Advanced Exergy Analysis for a Novel Gasoline Absorption-Stabilization Process.

The advanced exergy analysis can identify the improved potential of each component and the interaction among components of the refining processes. In this work, a new gasoline absorption–stabilization process (GASP) is proposed for better energy utilization considering the absorption process intensification, which can be further explained using exergy analysis. Both conventional and new GASPs are simulated in PRO/II, which are verified with the actual plant operation data. The energy performance of both conventional and new GASPs is evaluated through the advanced exergy analysis. The exergy efficiencies of conventional and new GASPs are 65.04 and 71.44%, respectively. In addition, the total exergy destruction rates are 7.79 and 6.01 MW, respectively. The total exergy destructions of 46.37 and 40.73% can be reduced, respectively. Though the stabilizer has the largest exergy destruction in both the processes, the air cooler for the rich gas in the new GASP has the largest potential for reducing exergy destruction, which is different from the conventional GASP. Furthermore, a sensitivity analysis of the new GASP is performed to study the effects of newly added operation and design parameters on the conventional and advanced exergy analyses of the absorber.

Analyses of yearly performance dual-temperature warm air heating system applied in different climates

To investigate the applied potential of the dual-temperature warm air heating system (DWAHS) in different climate zones, a conventional single-temperature warm air heating system (C1) and two dual-temperature warm air heating systems (C2 and C3) were compared. The dual-temperature air-source heat pump integrated with an ejector is introduced to provide two types of heat sources. The performance of the proposed systems was compared and investigated via the energetic and exergetic analysis in different climate zones. The results demonstrate that the DWAHS outperforms the conventional single-temperature warm air heating system (SWAHS) under various conditions in the selected climate zone. Under the design condition, the energy efficiency ratio (EER) of System C3 in Xi’an and Ha’erbin are the highest among the three systems, i.e., 2.75 and 1.87, respectively. In Shanghai and Chongqing, the EER of System C2 are the highest among the three systems, i.e., 2.85 and 3.10, respectively. During the entire heating season, System C2 reduces power consumption by 8.6–10.6%, System C3 reduces power consumption by 5.5–14.6% in the selected cities, and Systems C2 and C3 reduce exergy destruction by 14.2–17.6% and 13.7–18.7%, respectively.

Energy efficiency and exergy destruction of supersonic steam ejector based on nonequilibrium condensation model

With the increasing importance of the environment, energy issues have become the focus of attention. Reducing exergy destruction of the ejector during mixing can increase the entrainment ratio and improve the refrigerating system working efficiency. In this study, a wet steam model integrating a droplet nucleation and growth formulas with four categories of entropy transport equations was established to further analyze thermodynamics properties of ejector. The simulation analyzes of flow pattern, entrainment ratio and coefficient of performance COP, entropy generation and exergy destruction of dry and wet steam flows were carried out under different inlet conditions and roughness. For smooth wall, in the case of primary and secondary temperatures of 120 °C and 14 °C, the COP reaches 0.5324 with the cooling capacity of 3.103 kW. The entropy generation of wet steam flow reaches the maximum value of 1616.37 J·kg−1·K−1, and the exergy destruction also reaches the maximum of 481.68 kJ/kg. Considering the analysis of the surface roughness, the maximum of exergy destruction near critical condition point increases by 45.14 kJ/kg for the 500 μm rough wall, and exergy destruction ratio reaches the maximum value of 0.740.

Thermodynamic investigation and optimization of two novel combined power-refrigeration cycles using cryogenic LNG energy

• Develop two novel combined cycles into optimal usage of LNG cryogenic energy. • Thermodynamic analysis and optimization of two novel proposed cycles. • uncertainty analysis of two novel combined cycles. • Increasing the cold energy utilized by novel cycles compared to direct LNG evaporation. • Reducing the exergy destruction of the heat transfer process using the novel cycles. The present study aimed to introduce two novel combined power-refrigeration cycles into optimal usage of liquefied natural gas (LNG) cryogenic energy and reduce exergy destruction due to high-temperature difference in the heat transfer process. The combined cycles include a compression-ejector refrigeration cycle and two low and high-pressure Rankine cycles in which the power required to drive the compression-ejector refrigeration cycle compressor is provided by the power generated by the two low and high-pressure Rankine cycle turbines. Increasing the utilizable cooling energy of LNG is considered as the benefits of the new combined cycles compared to direct LNG evaporation. A comprehensive thermodynamic analysis, along with optimizing both novel combined power-refrigeration cycles, was performed through the first and second thermodynamics laws and the constant area model assumption for the ejector. Analyzing the design parameters demonstrated that the maximum energy efficiency, exergy efficiency, and the highest refrigeration increasing ratio (RIR) increase in both novel combined power-refrigeration cycles as increasing the pump discharge pressure and decreasing turbine outlet pressure of the low-pressure Rankine cycle. The maximum thermal efficiency and exergy efficiency were 77.3% and 23.7% in cycle І and 87.5% and 23.9% in cycle ІІ, respectively, through performing optimization in the boundary set for the design parameters. Finally, the highest obtainable cooling energy to direct the evaporation of LNG ratio in the two cycles І and ІІ was 62.6% and 73.9%, respectively.

Comparative 3-E (Energy, Exergy & Environmental) Analysis of Oxy-Coal and Air-Coal Combustion based 500 MWe Supercritical Steam Power Plants with CO2 Capture

The comparative performance study is carried out for 500 MW Supercritical (SupC) Oxy-Coal Combustion (OCC) and Air-Coal Combustion (ACC) power plants with membrane-based CO2 capture at the fixed furnace temperature. The proposed configurations are modelled using a computer-based analysis software 'Cycle-Tempo' at different operating conditions, and the detailed thermodynamic study is done by considering Energy, Exergy, and Environmental (3-E) analysis. The result shows that the net energy and exergy efficiencies of ACC power plants with CO2 capture are about 35.07 % and 30.88 %, respectively, which are about 6.44 % and 5.77 % points, respectively higher than that of OCC power plant. Auxiliary power consumption of OCC based power plant is almost 1.97 times more than that of the ACC based plant due to huge energy utilization in the Air Separation Unit (ASU) of OCC plant which leads to performance reduction in OCC plant. However, environmental benefit of OCC based power plant is more than that of ACC based power plant with respect to CO2 emission. OCC plant emits about 0.164 kg/kWh of CO2 which is approximately 16.75 times lower than the CO2 emission in ACC based power plant. It is also analyzed that the performance of the CO2 Capture Unit (CCU) for the OCC based plant is about 3.65 times higher than the ACC based power plant due to higher concentration of CO2 (nearly 80.63%) in the flue gas emitting from OCC plant. The study also reveals that the auxiliary power consumption per kg of CO2 capture of the OCC based plant is about 0.142 kWh/kg, which is approximately 0.06 times lower than the ACC based plant. The higher performance of the OCC based power plant is found at lower value of flue gas recirculation due to the fact that reduction in exergy destruction at the mixing zone of the combustor is higher than the increase in exergy destruction of the heat exchangers at higher furnace exit temperature. But the metallurgical temperature limit of boiler tube materials restricts the use of the higher value of furnace temperature. OCC based power plant with CO2 capture can be preferred over ACC based plant with CO2 capture due to higher environmental benefits towards mitigating CO2, the key greenhouse gas on earth in spite of exhibiting lesser energy and exergy efficiencies.

Exploring avoidable carbon emissions by reducing exergy destruction based on advanced exergy analysis: A case study

Abstract The energy efficiency improvement and practicable carbon emission reduction of coal chemical industry as well as other industrial systems are major concerns associated with designing feasible carbon emission reduction scheme. Based on advanced exergy analysis, this study establishes quantitative analysis between exergy destruction and direct carbon emission by three different methods to explore avoidable exergy destruction and subsequent avoidable carbon emissions in coal to synthetic natural gas (coal-to-SNG) industry. The research shows avoidable exergy destruction accounts for 57.99% of total exergy destruction and 86.07% of total exergy destruction is endogenous, so the main causes of irreversibility of units come from units’ internal operations and this coal-to-SNG system has considerable improvement potential. The avoidable carbon emissions range from 52.50 t/h (0.16kgC/ N m 3 SNG) to 165.32 t/h (0.52kgC/ N m 3 SNG) according to different assumptions. In light of the scenarios of exergy destruction reduction and available research results, the real avoidable carbon emissions may be closer to 115.95 t/h, correspondingly the carbon emission reduction potential may be 44.06%. Therefore, reducing exergy destruction by one percentage point may bring about 0.76% carbon emission reduction. This idea identifying avoidable carbon emission by avoidable exergy destruction reduction may be spread to coal chemical processes and other industrial systems.

Biodiesel as alternative additive fuel for diesel engines: An experimental and theoretical investigation on emissions and performance characteristics

ABSTRACT The use of fossil-based fuels in internal combustion engines has become a major challenge and faces with serious transformation regarding emissions. Herein, alternative fuel usage becomes prominent, thanks to a great reduction of these emissions. In this study, using 20% (B20), 50% (B50), and 100% (B100) of waste frying oil biodiesel (WFOB)–diesel blends has been experimentally and theoretically investigated on emission and performance parameters at full load conditions of 1,500–3,000 rpm ranges in the diesel engine. According to the experimental results, it has been shown that torque has not changed significantly, but brake specific fuel consumption enhanced up to 12.98% owing to the lower heating value of biodiesel. In terms of emissions, biodiesel fuels reveal different results. Whereas HC, CO2, and NOx slightly increase with B100, all emissions almost reduce with B20, including NOx and smoke opacity. Maximum reductions of B20 are obtained as 4.51% in CO2, 29.27% in CO, 39.06% in HC, 6.52% in NOx, and 25% in smoke opacity emissions. In compliance with theoretical results, usage of biodiesel reduces exergy destruction rate as up to 7.03% and increases exergetic efficiency as up to 5.86% compared to neat diesel except 2,700–3,000 rpm. Consequently, the small addition of waste frying oil biodiesel as 20% is an optimum solution under favor of minimum increase of specific fuel consumption and reduction in all emissions.

Thermodynamic analysis of a thermal barrier-coated CI engine in a dual-fuel mode using biogas

Thermodynamic investigation of a diesel engine to assess its effectiveness in the conversion of chemical energy into useful work is necessary. In this work, the engine performance has been characterised based on the exergy and energy analysis and major sources of irreversibility in various engine processes are also studied in dual-fuel mode using biogas. Yttria-stabilised zirconia (YSZ) was used as a thermal barrier coating (TBC) on the piston crown and valves to boost the performance of the dual-fuel engine. The engine with TBC showed improved thermal and exergy efficiency with a reduction in exergy destruction. The brake thermal efficiency (BTE) was 24.12% and 25.62% for diesel-alone operation in uncoated and coated engine, respectively, at full-load operation, while the BTE decreased by 23%, 29% and 34% for the uncoated engine and 10%, 12% and 19% for the coated engine with the induction of biogas at 0.6, 0.8 and 1 kg h−1, respectively.

Performance evaluation of an electric vehicle thermal management system with waste heat recovery

Widespread adoption of electric vehicles is limited by their mileage, which is severely shortened by the positive temperature coefficient (PTC) heater in cold weather. To alleviate this difficulty, an electric vehicle thermal management system (EVTMS) with waste heat recovery from motor and controller unit is presented in this study. Utilizing a simulation model, the performances of EVTMS are investigated from the aspects of energy, exergy, and thermo-economy. In addition, the effects of waste heat amount and condensation temperature on EVTMS performances are exposed and discussed. It is indicated that increasing waste heat amount and decreasing condensation temperature would contribute to EVTMS performance improvement. Results show that the EVTMS with waste heat recovery leads to, in the best case, the coefficient of performance (COP) increase of 13.2%, the exergy destruction reduction of 20.01%, and the driving mileage improvement of 33.64%. With the waste heat varying in 0–2 kW and condensation temperature varying in 30–45 °C, the COP ranges from 2.05 to 4.71 and the system exergy efficiency varies in 28.63%~40.05%. Compared with the PTC heater, EVTMS with waste heat recovery could save the annual operation cost of 162.31–249.44 €. Base on the operation cost savings, the payback period of EVTMS ranges from 4.57 to 6.77 years.

Advanced exergy analyses of modified ethane recovery processes with different refrigeration cycles

This paper presents three modified processes with different refrigeration cycles based on the recycle split vapor (RSV) process. Advanced exergy analysis is adopted to evaluate the exergy destruction forms of each component and compare exergy destruction differences among the three complex ethane recovery processes to reflect the interaction between components and identify the improvement potential of exergy destruction. The results show that avoidable endogenous exergy destruction of most equipment accounts for the highest proportion of the total exergy destruction, indicating that process improvements should focus on device performance rather than process structure. The most effective measure to reduce process exergy destruction is to improve compressor efficiency, followed by reducing the temperature approach of cold boxes and improving the separating efficiency of the columns. A sensitivity analysis shows the effects of various parameters on the four combined exergy destruction forms of demethanizer, deethanizer and refrigeration compressors, revealing opportunities for further improvement of different ethane processes to reduce exergy destruction.

Energy, exergy, exergoeconomics, and exergoenvironmental assessment of three brine recycle humidification-dehumidification desalination systems applicable for industrial wastewater treatment

Using zero liquid discharge systems is one of the efficient methods to reduce the negative environmental impact of the brines of the desalination systems and also to recycle the industrial wastewaters for reuse. Due to the simple fabrication process, low maintenance cost, intensive to inlet water quality, and the ability to use renewable and low-grade-heat, modified humidification-dehumidification systems may be a proper choice for the zero liquid discharge applications. Thus, in the present study, the energy, exergy, exergoeconomic, and exergoenvironmental assessment of three advanced brine recycle humidification-dehumidification systems for zero liquid discharge operation are comprehensively investigated. The first system is heat-driven: (1) brine recycle humidification-dehumidification system which is driven by heat and the two other systems are electricity-driven: (2) brine recycle humidification-dehumidification desalination system coupled with a heat pump in which the evaporator is as the dehumidifier, (3) brine recycle humidification-dehumidification desalination system coupled with a heat pump in which the evaporator is after the humidifier. The last system is a new proposed system in this study. The configuration of the humidification-dehumidification systems is closed-water closed-air. Operating parameters of the systems are independent of the recovery ratio of the systems. In the three considered systems, the exergoeconomic and exergoenvironmental factors are almost very low; thus, improving thermodynamic efficiencies of the components is necessary for fresh water cost and environmental impact reduction, and there is room for improvement to reduce exergy destruction without any more investment expenses. Based on the relative cost difference and the relative environmental impact difference in the systems, the dehumidifier and the evaporator are the components with the highest improvement potentials. In terms of the produced fresh water cost brine recycle humidification-dehumidification desalination system coupled with a heat pump in which the evaporator is after the humidifier system is superior to the two other systems (When heating steam price higher than 5 $/GJ); also the environmental impact of the produced fresh water in brine recycle humidification-dehumidification desalination system coupled with a heat pump in which the evaporator is after the humidifier system is lower than the two other systems. In electricity-driven systems, the water cost can be reduced by using R600 and R245fa instead of R134a.

Advanced exergy and exergoeconomic analysis for a polygeneration plant operating in geothermal cascade

This paper presents an advanced exergy and exergoeconomic analysis applied to a polygeneration plant operating in a geothermal cascade arrangement. An organic Rankine cycle (ORC), an absorption chiller and a dehydrator are the main components of the plant. The energy and exergy analysis of the polygeneration plant were carried out operating under real, unavoidable and ideal conditions. Considering real conditions, the polygeneration plant is able to reach a power output of 40 kWe, a cooling effect of 175.8 kWf and 30 kWt of useful heat for dehydration. The conventional exergy analysis shows that the component with the highest destruction of exergy of the polygeneration plant is the main heat exchanger (HX-I) having 44.05 kW, followed by the ORC with 38.58 kW. The advanced exergy analysis also indicates that 10.61 kW and 2.28 kW of exergy destruction in the HX-I and in the ORC can be avoided by improving design variables of these components. In this same context, the thermally activated refrigeration (TAR) can avoid destroying endogenously 7.36 kW while interacting with the other components of the plant operating under ideal conditions. On the other hand, the conventional exergoeconomic analysis reveals a cost of electricity production of 8.54 $/h, a cost of cooling production of 7.78 $/h and a cost of useful heat production for dehydration of 3.52 $/h. Finally, the advanced exergoeconomic analysis indicates that the heat exchanger HX-II is the component of the plant where more opportunity for reducing exergy destruction can be found.

Performance evaluation of a thermoelectric ventilation system driven by the concentrated photovoltaic thermoelectric generators for green building operations

This paper proposed one novel Thermo-Electric Ventilation (TEV) system driven by the concentrated photovoltaic-thermoelectric generator (CPV-TEG), which could use the electric power converted directly from solar energy by CPV-TEG. The effects of incident solar irradiance, number of thermoelectric generators, and ambient air temperatures on the power output of CPV-TEG have been analytically investigated through energy balance and first law of thermodynamics. Furthermore, input current and number of thermoelectric coolers were sensitively varied to optimize the performance of TEV system respectively in heating and cooling modes. Finally, an integrated theoretical and numerical approach was proposed to match the power output of CPV-TEG with the power input of TEV. Modeling results indicate that the output power from CPV-TEG could satisfy the energy demand of TEV system when the input currents of thermoelectric coolers were no more than 2.5 A and 2.8 A respectively for cooling and heating modes. Minimum energy and exergy efficiencies of the system in winter heating mode were confirmed to be 1.67 and 0.24 respectively, which were far higher than that in summer cooling mode. This research may be helpful for enhancing performance and reducing exergy destruction of thermoelectric ventilation system, simultaneously.

Advanced exergy analysis of ash agglomerating fluidized bed gasification

Exergy-based analysis is a powerful method to evaluate, understand, and improve energy conversion processes. Compared with conventional exergy analysis, advanced exergy analysis can identify the improvement potential of each component and the interactions among components of the whole system. In this paper, the ash agglomerating fluidized bed (AFB) gasification process is simulated in Aspen Plus (version 8.0). Based on the simulation results, advanced exergy analysis is carried out to study the performance of the AFB gasification process. The exergy efficiency of the AFB gasification process is 82.13% and the total exergy destruction is 4670 kW. The result shows that 54.18% of the total exergy destruction can be avoided. The AFB gasifier has the largest potential for reducing exergy destruction. In addition, sensitivity analysis is performed to research the effects of carbon conversion, pressure and temperature on the exergy destruction of the AFB gasifier.

Exergetic analysis of different R744 heat pump tumble dryer system topologies

In household heat pump tumble dryers, the commonly used refrigerant R134a has a high global warming potential and is nowadays replaced by natural refrigerant R290. Dryers with a demand for short drying time require high heating power and thus high loads of R290, which might result in additional safety measures of electronic components and installation conditions. In this study the natural refrigerant R744 as an environmentally friendly alternative for use in small commercial tumble dryers is investigated. The use of a new refrigerant for a special application requires new component design and matching system topologies. For the evaluation of different system topologies an exergy analysis is presented. The aim is to predict the possible reduction of exergy destruction e.g. caused by throttling losses. Starting point is an experimental validated system model of a heat pump tumble dryer. Additional to the standard cycle three different topologies comprising additional components like an internal heat exchanger and an ejector are investigated within simulations. Each topology is optimized with help of a multi-objective optimization algorithm to achieve comparable results. The results show that the energy consumption can be reduced by 7.2% by means of an ejector and an internal heat exchanger. For efficiency comparison simulation results with about the same drying time were chosen.

Optimizing performance in spark ignition engines with simulation metamodels

This work develops a systematic methodology able to identify the desired work points, the metamodels were evaluated varying air–fuel ratio, ignition timing, compression ratio, and combustion duration using design of computer experiments and RSM. It provide the possibility to determine optimal control parameters, according to selected objectives and operating constraints. This methodology is able to automatically identify the optimal engine calibration with less computational effort. Only in this way, the reliability of an integrated metamodel/optimizer approach can be included in a general-purpose that is to identify the engine calibration that minimizes motor vehicle emissions according to European emission standards (European Union in Off J Eur Union 50, 2007). As long as it improves mean effective pressure and reduces exergy destruction due to heat transfer and combustion process. Since, in internal combustion engines, more than 30–40 % of fuel energy wastes through the exhaust and just 12–25 % of the fuel energy converts to useful work. So, researchers are motivated to recover the heat from the waste sources in engines using the ways which not only reduce the demand of fossil fuels, but also reduce the harmful greenhouse gases and help to energy saving (Hatami et al. in Neural Comput Appl 25(7–8):2079–2090, 2014). The advantages of this contribution include the ability to study a wide range of parametric space and to independently evaluate physical and chemical processes, and detailed in-cylinder information, which is normally not available or is inaccessible in experiments. The uncertainty of the information in this unexplored design region can be quantified. Finally, the problem of optimizing involves three optimization fronts, energetic, economic and ecological (Chica and Torres in Int J Interact Des Manuf 12(1):355–392, 2018).

First and second law analyses of wastewater cooled condenser for a refrigeration system

In this study, a vapour compression refrigeration (VCR) system with a wastewater (WW) cooled condenser at a temperature range of 27-29°C was designed. The cooling capacity of the system using R134a as the refrigerant was 1.09 kW. The condenser consisted of a coaxial heat exchanger with a capacity of 1 kW. This paper dealt with energy and exergy analyses of the VCR system using WW, as a heat sink. Experiments were performed in order to evaluate the energetic and exergetic performances of the wastewater-cooled condenser (WWC) and the overall system. The convective heat transfer coefficient of WW and refrigerant in the condenser, overall heat transfer coefficient of the WWC, total amount of heat removed by WW, amount of cooling effect, coefficient of performance (COP), exergy destruction rate, and second law efficiencies of the WWC and VCR system were calculated under different WW temperatures and flowrates. Increasing volumetric flowrate of WW from 200 L/h to 400 L/h caused 4.4% improvement in COP, 12.0% reduction in exergy destruction, and 10.3% increase in exergy efficiency.

First and second law analyses of wastewater cooled condenser for a refrigeration system

In this study, a vapour compression refrigeration (VCR) system with a wastewater (WW) cooled condenser at a temperature range of 27-29°C was designed. The cooling capacity of the system using R134a as the refrigerant was 1.09 kW. The condenser consisted of a coaxial heat exchanger with a capacity of 1 kW. This paper dealt with energy and exergy analyses of the VCR system using WW, as a heat sink. Experiments were performed in order to evaluate the energetic and exergetic performances of the wastewater-cooled condenser (WWC) and the overall system. The convective heat transfer coefficient of WW and refrigerant in the condenser, overall heat transfer coefficient of the WWC, total amount of heat removed by WW, amount of cooling effect, coefficient of performance (COP), exergy destruction rate, and second law efficiencies of the WWC and VCR system were calculated under different WW temperatures and flowrates. Increasing volumetric flowrate of WW from 200 L/h to 400 L/h caused 4.4% improvement in COP, 12.0% reduction in exergy destruction, and 10.3% increase in exergy efficiency.

Optimization of mixed refrigerant system for LNG processes through graphically reducing exergy destruction of cryogenic heat exchangers

Mixed refrigerant (MR) systems are widely employed in natural gas liquefication processes due to the advantage of efficient heat transfer over pure refrigerants. An exergy destruction reduction (EDR) algorithm is proposed to optimize MR composition for energy-efficient natural gas liquefication. Exergy destruction associated with heat transfer is graphically depicted and area of the exergy destruction graph is minimized under the constraint of the minimum internal temperature approach in the heat exchanger. The EDR optimization is performed by directionally regulating individual refrigerant component responsible for decreasing the graphic exergy destruction. The C3MR process is modeled in Aspen HYSYS and the MR systems for the cryogenic heat exchangers are optimized by the programmed EDR solver run in Matlab. The EDR optimization results in 0.2515 kWh·kg−1 specific compression work with 17.7% power consumption savings as compared with the base case. In addition, the exergy destruction rate obtained from the EDR algorithm is 2.9% lower than that from the sequential quadratic programming (SQP) algorithm. The EDR algorithm based on the thermodynamic laws is efficient for optimization of liquefaction processes involving the use of MR system.

Performance analysis and multi-objective optimization of an organic Rankine cycle with binary zeotropic working fluid employing modified artificial bee colony algorithm

From a thermal point of view, zeotropic mixtures are likely to be more efficient than azeotropic fluids in low-temperature power cycles for reduction in exergy destruction occurring during heat absorption/rejection processes due to their suitable boiling characteristics. In this study, comprehensive energetic and exergetic analyses are mathematically performed for an organic Rankine cycle (ORC) system employing a potential binary zeotropic working fluid, namely R717/water. For this purpose, initially mass, energy, and exergy balance equations are derived. With regard to the similarity in molar mass of R717 (17.03 g mol−1) and water (18.01 g mol−1), there is no need to alter the size of the ORC components such as turbine and pump. In order to achieve the optimal thermal and exergy efficiencies of the ORC system, modified version a powerful and relatively new optimization algorithm called artificial bee colony (ABC) is used taking into account different effective constraints. The main motivation behind using ABC lies on its robustness, reliability, and convergence rate speed in dealing with complicated constrained multi-objective problems. Convergence rates of the algorithm for optimal calculation of the efficiencies are presented. Subsequently, due to the importance of exergy concept in ORC systems, exergy destructions occurring in the components are computed. Finally, the impacts of pressure, temperature, mass fraction, and mass flow rate on the ORC thermal and exergy efficiencies are discussed.