The Experts below are selected from a list of 1887 Experts worldwide ranked by ideXlab platform
Yekta Göksungur - One of the best experts on this subject based on the ideXlab platform.
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Exergy analysis of wine production: Red wine production process as a case study
Applied Thermal Engineering, 2017Co-Authors: Mahmut Genç, Seda Genc, Yekta GöksungurAbstract:Abstract This paper performs Exergy analysis of a red wine production line and defines the Exergy Destruction Rates to assess the system performance in terms of sustainability. A model study with necessary data is chosen for the calculations. The total Exergy Destruction Rate of the overall system was determined to be 344.08 kW while the greatest Destruction Rate of the Exergy in the whole system occurred in the open fermenter (333.6 kW). The system thermal efficiency was obtained to be 57.2% while the Exergy efficiency was calculated as 41.8%. The total Exergy Destruction Rate of the overall system increases with the increase both in the grape flow Rate and the reference temperature when the reference pressure is assumed as 101.325 kPa. Furthermore, the chemical Exergy of streams was found much higher than the physical Exergy for each stream. The Exergy results were illustRated through the Grassmann diagram. Furthermore, cumulative Exergy loss and specific Exergy loss values were determined as 2692.51 kW/1 kg/s grape processed and 5080.20 kW/kg wine, respectively.
Marc A. Rosen - One of the best experts on this subject based on the ideXlab platform.
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Technoeconomic and environmental optimization of a solar tower integRated energy system for freshwater production
Journal of Cleaner Production, 2020Co-Authors: Amir H. Keshavarzzadeh, Pouria Ahmadi, Marc A. RosenAbstract:Abstract A novel energy system consisting of a Brayton cycle, a heliostat field, an organic Rankine cycle and a multi-effect desalination-thermal vapor compression unit is proposed and investigated. Freshwater and electricity are the products of the proposed energy system. The present study proposes a sustainable renewable-based energy unit for freshwater production, and introduces a new concept of a pair plot, which can provide useful insights into the behavior of an energy system. A multi-objective optimization is conducted using NSGA-II with two objective functions (total cost and total Exergy Destruction Rate) and ten decision variables. The point on the Pareto optimal solution nearest to the ideal point has a total Exergy Destruction Rate of 4.7 MW and a total unit cost of 0.045 $/kWh. The scatter distribution and pair plot of the decision variables are illustRated and trends for each decision variable are discussed. The NSGA-II and NSGA-III performances are contrasted and compared by employing the hypervolume indicator technique. An NSGA-II genetic algorithm optimization with three objective functions is conducted and the results are discussed. The three objectives are total Exergy Destruction Rate, total unit cost and gain output ratio. Also, the impact on CO2 emissions of the heliostat field is discussed, and a thermodynamic description of each model is developed and validated with numerical and experimental data.
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A new approach for optimization of combined cycle system based on first level of Exergy Destruction splitting
Sustainable Energy Technologies and Assessments, 2020Co-Authors: R. Akbarpour Ghiasi, Mohsen Fallah, Saeed Lotfan, Marc A. RosenAbstract:Abstract A multi-objective optimization of a combined air cooled gas turbine and steam turbine system is carried out using non-dominated sorting genetic algorithm II (NSGA-II). In the optimization process, performance and environmental aspects of the system are considered, and the first level of Exergy Destruction splitting is incorpoRated. Such parameters as second law efficiency, ratio of total avoidable Exergy Destruction Rate to total Exergy Destruction Rate, and CO2 emission in exhaust gases, are considered as the objective functions. Once the model of the system is constructed in engineering equation solver (EES) software and validated, the gas turbine inlet temperature and compressor pressure ratio are considered as the decision variables based on the performed sensitivity analysis. Then, EES is coupled with MATLAB and the multi-objective optimization is performed for various values of gas turbine blade cooling air fractions. By comparing the obtained Pareto optimal points with those of the base case, considerable improvements in the values of the objective functions are observed.
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thermodynamic and exergoeconomic analyses of a novel combined cycle comprised of vapor compression refrigeration and organic rankine cycles
Sustainability, 2019Co-Authors: Nima Javanshir, S M S Mahmoudi, Marc A. RosenAbstract:In this study, a cooling/power cogeneration cycle consisting of vapor-compression refrigeration and organic Rankine cycles is proposed and investigated. Utilizing geothermal water as a low-temperature heat source, various operating fluids, including R134a, R22, and R143a, are considered for the system to study their effects on cycle performance. The proposed cycle is modeled and evaluated from thermodynamic and thermoeconomic viewpoints by the Engineering Equation Solver (EES) software. Thermodynamic properties as well as Exergy cost Rates for each stream are found sepaRately. Using R143a as the working fluid, thermal and Exergy efficiencies of 27.2% and 57.9%, respectively, are obtained for the cycle. Additionally, the total product unit cost is found to be 60.7 $/GJ. A parametric study is carried out to determine the effects of several parameters, such as turbine inlet pressure, condenser temperature and pressure, boiler inlet air temperature, and pinch-point temperature difference, on the cycle performance. The latter is characterized by such parameters as thermal and Exergy efficiencies, refrigeration capacity, produced net power Rate, Exergy Destruction Rate, and the production unit cost Rates. The results indicate that the system using R134a exhibits the lowest thermal and Exergy efficiencies among other working fluids, while the systems using R22 and R143a exhibit the highest energy and Exergy efficiencies, respectively. The boiler and turbine contribute the most to the total Exergy Destruction Rate.
Mahmut Genç - One of the best experts on this subject based on the ideXlab platform.
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Exergy analysis of wine production: Red wine production process as a case study
Applied Thermal Engineering, 2017Co-Authors: Mahmut Genç, Seda Genc, Yekta GöksungurAbstract:Abstract This paper performs Exergy analysis of a red wine production line and defines the Exergy Destruction Rates to assess the system performance in terms of sustainability. A model study with necessary data is chosen for the calculations. The total Exergy Destruction Rate of the overall system was determined to be 344.08 kW while the greatest Destruction Rate of the Exergy in the whole system occurred in the open fermenter (333.6 kW). The system thermal efficiency was obtained to be 57.2% while the Exergy efficiency was calculated as 41.8%. The total Exergy Destruction Rate of the overall system increases with the increase both in the grape flow Rate and the reference temperature when the reference pressure is assumed as 101.325 kPa. Furthermore, the chemical Exergy of streams was found much higher than the physical Exergy for each stream. The Exergy results were illustRated through the Grassmann diagram. Furthermore, cumulative Exergy loss and specific Exergy loss values were determined as 2692.51 kW/1 kg/s grape processed and 5080.20 kW/kg wine, respectively.
Mehdi Mehrpooya - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic and economic evaluation of a novel concentRated solar power system integRated with absorption refrigeration and desalination cycles
Energy Conversion and Management, 2018Co-Authors: Mehdi Mehrpooya, Bahram Ghorbani, Seyed Sina HosseiniAbstract:Abstract In this study, an innovative concentRated solar power plant integRated with desalination process and absorption refrigeration cycle aimed at supplying power, fresh water and refrigeration, was developed and exergetically assessed. The system comprised a concentRated solar thermal power plant with parabolic dish collectors and steam turbine, a multi-effect desalination process with parallel feed of seawater, and a single-stage ammonia-water absorption refrigeration system. Generally, the collectors provided 21,030 kW thermal power to the steam power plant and 4632 kW of which was converted to electrical power in steam power plant. The absorption refrigeration cycle produced 820.8 kW refrigeration and the desalination cycle provided fresh water at a Rate of 22.79 kg/s. The integRated system was simulated in Aspen Hysys and all the components of the integRated system were individually scrutinized based on the second law of thermodynamics; as well, the Exergy Destruction Rate and Exergy efficiency of each component were obtained and discussed thoroughly. According to the results, about 86% of the total Exergy Destruction Rate of the system belonged to the distillation column and heat exchangers. The overall Exergy efficiency of the cycle was 66.05%, while, the net overall thermal efficiency of the integRated system was 80.70%. The results of the economic analysis showed that the proposed integRated structure had an investment return period of 5.738 years and a net annual profit of 6.828 million US$ per year. Moreover, the impact of various factors on the performance of the integRated system was investigated using sensitivity analysis.
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Exergoeconomic evaluation of single mixed refrigerant natural gas liquefaction processes
Energy Conversion and Management, 2015Co-Authors: Mehdi Mehrpooya, Hojat AnsarinasabAbstract:Abstract Exergy and exergoeconomic analysis is performed for single mixed refrigerant Linde and Air Products and Chemicals Inc, processes, which are among the most important and popular natural gas liquefaction processes. Cost of Exergy Destruction, exergoeconomic factor, Exergy Destruction and Exergy efficiency are calculated. Results of Exergy analysis demonstRates that Exergy efficiency of Linde process is around 40.2%, and its total Exergy Destruction Rate is 93,229 kW. The Exergy efficiency and Exergy Destruction Rate for Air Products and Chemicals Inc, process are 45.0% and 72,245 kW respectively. Results of exergoeconomic analysis suggests that maximum Exergy Destruction cost for Linde process is related to E-2 heat exchanger which is 34,072 $/h and for Air Products and Chemicals Inc, process maximum Exergy Destruction cost is related to E-2 heat exchanger with the value of 4125 kW. Sensitivity of cost of Exergy Destruction and exergoeconomic factor to operating variables of the processes are studied and analyzed.
Ibrahim Dincer - One of the best experts on this subject based on the ideXlab platform.
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A comparative evaluation of OTEC, solar and wind energy based systems for clean hydrogen production
Journal of Cleaner Production, 2020Co-Authors: H. Ishaq, Ibrahim DincerAbstract:Abstract In this article, three different renewable energy methods are considered with wind, ocean thermal energy conversion (OTEC) and solar energy for clean hydrogen production, and Cu-Cl based thermochemical cycle is incorpoRated into systems to develop potential applications. In the proposed CuCl cycle configuration, the additional heat offered after the thermolysis reactor is recovered to heat the water before reaching the hydrolysis reactor. In the wind energy based hydrogen production system, the maximum Exergy Destruction Rate is found to be 48.3 kW in the wind turbine. The turbine employed to the ocean thermal energy conversion system is found to be undergoing the highest Exergy Destruction Rate of 143.3 kW. The energy and Exergy efficiencies of the solar energy based thermochemical CuCl cycle are found to be 32.7% and 33.2% and the maximum Exergy Destruction Rate of 350.69 kW is offered by the thermolysis reactor. The energetically improved configuration of the thermochemical CuCl cycle displays promising results compared to the earlier studies, such as lower heat requirements and higher efficiencies. The study indicates that there is a value to develop a clean OTEC based hydrogen production system and implement for practical applications. Furthermore, some sensitivity analyses are performed to investigate the performance of each system under different operating parameters and discussed.
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Exergy analysis of tea drying in a continuous vibro-fluidised bed dryer
2019Co-Authors: Merve Ozturk, Ibrahim DincerAbstract:In the current study, a comprehensive thermodynamic investigation through energy and Exergy analyses is performed to study and assess the performance of a three-stage tea drying system which has vibro-fluid bed dryer. Also, energy and Exergy efficiencies are, in this regard, investigated with the thermodynamic data obtained from the literature. The parametric studies are carried out to investigate the effects of varying the state properties and operating conditions on the performance of the drying system. The overall energy and Exergy efficiencies of the system are found as 42% and 7.2%, respectively. The main reason for the low Exergy efficiency is the high Exergy Destruction Rate for the components of the system. The total Exergy Destruction ratio of drying chambers is calculated as 58% of overall Exergy Destruction Rate of the system.
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energy and Exergy analyses of a biogas driven multigenerational system
Energy, 2019Co-Authors: Eren Sevinchan, Ibrahim Dincer, Haoxiang LangAbstract:Abstract In this study, energy and Exergy analyses of a biogas driven multigeneration system is conducted for performance assessment and evaluation. In this regard, the multigeneration system with a biomass digestion process is developed for this purpose. Multigeneration system consists of different subsystems, such as two-stage biomass digester, open-type Brayton cycle, Organic Rankine Cycle (ORC), single-effect absorption chiller, heat recovery, water separation unit. This multigeneration system aims to geneRate electrical power for at least 300 houses, heating power for five greenhouses, cooling power and product water from flue gas for agricultural consumption in greenhouses. The results indicate that the overall energy efficiencies of the proposed system is 72.5% with 1078 kW electrical, 198 kW heating, and 87.54 kW cooling power, and daily around 40 kg water production. However, the maximum Exergy efficiency of the multigeneration system is obtained as 30.44%, with 65% of the highest Exergy Destruction Rate in combustion chamber.
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Analysis and assessment of methanol production by integration of carbon capture and photocatalytic hydrogen production
International Journal of Greenhouse Gas Control, 2016Co-Authors: M. Almahdi, Ibrahim DincerAbstract:An integRated system for converting carbon dioxide to methanol is proposed, and four of its main components (carbon capture absorber, carbon capture stripper, photoreactor, and methanol synthesis reactor) are analyzed thermodynamically, focusing on Exergy Destruction. The carbon capture unit provides carbon dioxide extracted from industrial flue gas while the photocatalysis unit produces hydrogen from visible light via photocatalytic water splitting. Both, carbon dioxide and hydrogen are supplied to a methanol synthesis reactor at a specific feed Rate, temperature and pressure. The thermodynamic analysis shows that the largest Exergy Destruction Rate occurs in the photoreactor (706 kW). The second largest Exergy Destruction Rate occurs in the methanol synthesis reactor (24.7 kW), while the Exergy Destruction Rates are smaller in the carbon capture stripper (23.5 kW) and absorber (17.9 kW).
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Exergetic performance assessment of an integRated solar energy system
International Journal of Exergy, 2016Co-Authors: Canan Acar, Ibrahim DincerAbstract:In this study, an integRated solar absorption-cooling and heating system is taken as a basis to develop a multi-generation solar system with five outputs, namely electricity, heat, hot water, cooling, and air conditioning (humidifying/dehumidifying) for residential use. The system performance is assessed by energy and Exergy efficiencies. The present system is capable of producing 550 kW of electricity. The Exergy efficiencies and Exergy Destruction Rates are examined under the variation of ambient conditions. The results show that the maximum Exergy efficiency for the overall system is 28%. It is also found that the main sources of Exergy Destruction Rate are the solar collectors and ORC turbines and evaporators. Therefore, this study points out the importance of the selection and design of these to reduce Exergy Destruction, and as a result, increase the Exergy efficiency of the system by minimising irreversibilities.