The Experts below are selected from a list of 3141 Experts worldwide ranked by ideXlab platform
M. A. Vesaghi - One of the best experts on this subject based on the ideXlab platform.
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Design of a PCM storage system for a solar absorption chiller based on exergoeconomic analysis and genetic algorithm
International Journal of Refrigeration, 2013Co-Authors: Ali Abbasi Godarzi, Masoud Jalilian, Jalal Samimi, Ali Jokar, M. A. VesaghiAbstract:In this article, a solar absorption chiller used in MehrAbad region of Tehran, Iran is optimized with exergoeconomic principles and genetic algorithm. After optimizing, a storage system with Phase Change Material technique (PCM) is designed for this optimum configuration for supporting system when sunshine is not received adequately, especially at night. Exergoeconomic analysis is based on finding some ways to improving the performance of a thermal system considering economic constrains. In this study, the exergoeconomic optimization is applied for LiBr-water absorption. The results show that total investment cost of main system, the whole of system except storage system, has increased 2.0568% rather than the base case that system usually operates. With adding storage system to main system in optimum point, pay back period increases from 0.61 years to 1.13 years. © 2012 Elsevier Ltd and IIR. All rights reserved.
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design of a pcm storage system for a solar absorption chiller based on exergoeconomic analysis and genetic algorithm
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Ali Abbasi Godarzi, Masoud Jalilian, Jalal Samimi, Ali Jokar, M. A. VesaghiAbstract:Abstract In this article, a solar absorption chiller used in MehrAbad region of Tehran, Iran is optimized with exergoeconomic principles and genetic algorithm. After optimizing, a storage system with Phase Change Material technique (PCM) is designed for this optimum configuration for supporting system when sunshine is not received adequately, especially at night. Exergoeconomic analysis is based on finding some ways to improving the performance of a thermal system considering economic constrains. In this study, the exergoeconomic optimization is applied for LiBr–water absorption. The results show that total investment cost of main system, the whole of system except storage system, has increased 2.0568% rather than the base case that system usually operates. With adding storage system to main system in optimum point, pay back period increases from 0.61 years to 1.13 years.
Ali Abbasi Godarzi - One of the best experts on this subject based on the ideXlab platform.
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Design of a PCM storage system for a solar absorption chiller based on exergoeconomic analysis and genetic algorithm
International Journal of Refrigeration, 2013Co-Authors: Ali Abbasi Godarzi, Masoud Jalilian, Jalal Samimi, Ali Jokar, M. A. VesaghiAbstract:In this article, a solar absorption chiller used in MehrAbad region of Tehran, Iran is optimized with exergoeconomic principles and genetic algorithm. After optimizing, a storage system with Phase Change Material technique (PCM) is designed for this optimum configuration for supporting system when sunshine is not received adequately, especially at night. Exergoeconomic analysis is based on finding some ways to improving the performance of a thermal system considering economic constrains. In this study, the exergoeconomic optimization is applied for LiBr-water absorption. The results show that total investment cost of main system, the whole of system except storage system, has increased 2.0568% rather than the base case that system usually operates. With adding storage system to main system in optimum point, pay back period increases from 0.61 years to 1.13 years. © 2012 Elsevier Ltd and IIR. All rights reserved.
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design of a pcm storage system for a solar absorption chiller based on exergoeconomic analysis and genetic algorithm
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Ali Abbasi Godarzi, Masoud Jalilian, Jalal Samimi, Ali Jokar, M. A. VesaghiAbstract:Abstract In this article, a solar absorption chiller used in MehrAbad region of Tehran, Iran is optimized with exergoeconomic principles and genetic algorithm. After optimizing, a storage system with Phase Change Material technique (PCM) is designed for this optimum configuration for supporting system when sunshine is not received adequately, especially at night. Exergoeconomic analysis is based on finding some ways to improving the performance of a thermal system considering economic constrains. In this study, the exergoeconomic optimization is applied for LiBr–water absorption. The results show that total investment cost of main system, the whole of system except storage system, has increased 2.0568% rather than the base case that system usually operates. With adding storage system to main system in optimum point, pay back period increases from 0.61 years to 1.13 years.
Faramarz Ranjbar - One of the best experts on this subject based on the ideXlab platform.
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exergy and exergoeconomic assessment of hydrogen and cooling production from concentrated pvt equipped with pem electrolyzer and libr h 2 o absorption chiller
International Journal of Hydrogen Energy, 2018Co-Authors: Ehsan Akrami, Hossein Nami, Arash Nemati, Faramarz RanjbarAbstract:Abstract A novel solar based combined system is proposed to produce hydrogen and cooling. The presented cogeneration system is analyzed in detail from the viewpoints of exergy and exergoeconomic (exergy based economic analysis). The proposed system includes a concentrated PVT (CPVT), a single effect LiBr-H2O absorption chiller and proton exchange membrane electrolyzer (PEM). Produced electrical power is consumed in the PEM electrolyzer to split water into oxygen and pure hydrogen while heat removal from the CPVT is done by the absorption chiller to guarantee its better performance. Second law analysis showed that, among the three different parts of the system, the most part of exergy destruction refers to the CPVT followed by absorption chiller unit and PEM electrolyzer. Also, it is observed that, among the absorption units' components, the highest percent of exergy destruction belongs to the generator which absorbs the heat from the CPVT. Moreover, exergoeconomic analysis revealed that the most important unit from the viewpoint of economic is the CPVT with the capital investment cost of 0.08946 $/h and an exergoeconomic factor of 28.82%.
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A comprehensive thermodynamic and exergoeconomic comparison between single- and two-stage thermoelectric cooler and heater
Applied Thermal Engineering, 2017Co-Authors: Hossein Nami, Mortaza Yari, Arash Nemati, Faramarz RanjbarAbstract:Abstract Energy, exergy and exergoeconomic analysis are carried out for single- and two-stage thermoelectric devices which can be used for either heating or cooling implementation. Coefficient of performance, exergetic efficiency and unit cost of heating/cooling power are investigated as the main target of energy, exergy and exergoeconomic analysis, respectively. A comprehensive comparison between single- and two-stage thermoelectric performances has outlined in different values of current and temperature difference between hot and cold sides. An effective range of current is defined for energy (COP > 0.5 × COPmax), exergy (e > 0.5 × emax) and exergoeconomic (cC/H
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Development of an exergoeconomic model for analysis and multi-objective optimization of a thermoelectric heat pump
Energy Conversion and Management, 2016Co-Authors: Arash Nemati, Mortaza Yari, Hossein Nami, Faramarz Ranjbar, Hojjatollah Rashid KolvirAbstract:Abstract A thermoelectric heat pump (TEHP) is modeled, analyzed and optimized from the viewpoint of energy, exergy and exergoeconomic. A comprehensive parametric study is also done to clarify the effects on the energy, exergy and exergoeconomic performance of some main decision parameters. With the aim of exergetic and economic optimization, an optimization methodology based on multi-objective genetic algorithm is applied to the system and optimal values of design variables are obtained. Two objective functions are considered; exergy efficiency and unit cost of heating power. It is observed that the performance of TEHP is comparable to conventional heat pumps from the viewpoints of thermodynamic and exergoeconomic. SPECO method is applied to evaluate the exergoeconomic parameters. The results demonstrate that all decision parameters except the number of thermocouples optimize exergy efficiency and coefficient of performance of the TEHP. The obtained overall exergoeconomic factor of 60.6% illustrates that the 39.4% of total system cost relates to exergy destruction. Under optimal conditions, the unit cost of heating power and exergy efficiency are found to be 0.688 $/kW h and 14.13%, respectively.
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A comparative study on the ammonia–water based bottoming power cycles: The exergoeconomic viewpoint
Energy, 2015Co-Authors: Farzad Mohammadkhani, Faramarz Ranjbar, Mortaza YariAbstract:A comparative exergoeconomic assessment is reported for Ammonia-Water Rankine (AWR) and Ammonia-Water Recuperative Rankine (AWRR) bottoming power cycles. Through investigating temperature distributions of hot and cold fluids and pinch point location in heat exchangers, first energy and exergy analysis is performed and then cost balances and appropriate auxiliary equations are developed for components, so exergoeconomic variables are quantified. A parametric study is also performed to examine the effects on exergoeconomic performance of the cycles, of turbine inlet pressure and ammonia mass fraction in the working fluid. As a result, unit cost of electricity produced by turbine is determined to be 11.87 and 13.85 cent/kWh for the AWR and AWRR systems, respectively. Based on these values it is interesting to note that, unlike the energy and exergy analysis, the exergoeconomic viewpoint prefers the AWR system to AWRR. Also parametric study revealed that ammonia concentration has a great effect on exergoeconomic performance of the both systems. Increasing ammonia mass fraction increases total exergy destruction cost rate as well as unit cost of electricity produced by turbine in the both AWR and AWRR systems. This shows the advantage of using a binary mixture such as ammonia–water as a working fluid in these cycles.
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Comparative and parametric study of double flash and single flash/ORC combined cycles based on exergoeconomic criteria
Applied Thermal Engineering, 2015Co-Authors: Naser Shokati, Faramarz Ranjbar, Mortaza YariAbstract:In this study, double flash geothermal power cycle and single flash/ORC combined cycles with different organic fluids are used for power generation from geothermal fluid reservoir with given temperature. n-heptane, R141b, R113 and steam are selected as organic working fluids in ORC and NH3 is used as a reference working fluid in ORC in this study, as it is a common working fluid in geothermal power plants and Kalina. After energy and exergy analyses of the mentioned cycles, a comprehensive exergoeconomic analysis by developing cost balance and auxiliary equations for all components of the cycles using SPECO approach is done and all exergoeconomic parameters are calculated and these cycles are compared from thermodynamic and exergoeconomic viewpoints. Also a parametric study is performed and the effects on the thermodynamic and exergoeconomic performance of the considered cycles of such operating parameters as separator pressures in double flash geothermal power cycle and separator pressure and evaporation temperature in single flash/ORC combined cycles. The results show that although the highest values of first law efficiency and exergy efficiency among the mentioned cycles are related to single flash/ORC with steam but the minimum unit cost of produced power is related to double flash cycle. Also according to parametric study, with increasing evaporation temperature in single flash/ORC the value of CD,tot+Żtot parameters for all combined cycles except single flash/ORC with ammonia increases continuously.
Arash Nemati - One of the best experts on this subject based on the ideXlab platform.
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exergy and exergoeconomic assessment of hydrogen and cooling production from concentrated pvt equipped with pem electrolyzer and libr h 2 o absorption chiller
International Journal of Hydrogen Energy, 2018Co-Authors: Ehsan Akrami, Hossein Nami, Arash Nemati, Faramarz RanjbarAbstract:Abstract A novel solar based combined system is proposed to produce hydrogen and cooling. The presented cogeneration system is analyzed in detail from the viewpoints of exergy and exergoeconomic (exergy based economic analysis). The proposed system includes a concentrated PVT (CPVT), a single effect LiBr-H2O absorption chiller and proton exchange membrane electrolyzer (PEM). Produced electrical power is consumed in the PEM electrolyzer to split water into oxygen and pure hydrogen while heat removal from the CPVT is done by the absorption chiller to guarantee its better performance. Second law analysis showed that, among the three different parts of the system, the most part of exergy destruction refers to the CPVT followed by absorption chiller unit and PEM electrolyzer. Also, it is observed that, among the absorption units' components, the highest percent of exergy destruction belongs to the generator which absorbs the heat from the CPVT. Moreover, exergoeconomic analysis revealed that the most important unit from the viewpoint of economic is the CPVT with the capital investment cost of 0.08946 $/h and an exergoeconomic factor of 28.82%.
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A comprehensive thermodynamic and exergoeconomic comparison between single- and two-stage thermoelectric cooler and heater
Applied Thermal Engineering, 2017Co-Authors: Hossein Nami, Mortaza Yari, Arash Nemati, Faramarz RanjbarAbstract:Abstract Energy, exergy and exergoeconomic analysis are carried out for single- and two-stage thermoelectric devices which can be used for either heating or cooling implementation. Coefficient of performance, exergetic efficiency and unit cost of heating/cooling power are investigated as the main target of energy, exergy and exergoeconomic analysis, respectively. A comprehensive comparison between single- and two-stage thermoelectric performances has outlined in different values of current and temperature difference between hot and cold sides. An effective range of current is defined for energy (COP > 0.5 × COPmax), exergy (e > 0.5 × emax) and exergoeconomic (cC/H
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exergy economic and environmental impact assessment and optimization of a novel cogeneration system including a gas turbine a supercritical co2 and an organic rankine cycle gt hrsg sco2
Applied Thermal Engineering, 2017Co-Authors: Hossein Nami, S M S Mahmoudi, Arash NematiAbstract:Abstract Exergoeconomic and exergoenvironmental analyses are reported for a novel cogeneration system including a gas turbine, a heat recovery steam generator, a supercritical carbon dioxide recompression Brayton cycle and an organic Rankine cycle. A comprehensive parametric study is carried out to clarify the effects of some decision parameters on the exergoeconomic performance of the proposed system. Also, the payback period is determined for the proposed system. The sum of capital investment cost, total exergy destruction cost and environmental impact cost is considered as an objective function which is optimized with respect to the decision parameters. The variation in overall exergoeconomic factor is determined and its implication to the system design is discussed. It is observed that under the optimized condition the average product unit cost of the system (cost of produced power and steam) is decreased by 0.56 $/GJ when compared to the value obtained under a base condition.
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Development of an exergoeconomic model for analysis and multi-objective optimization of a thermoelectric heat pump
Energy Conversion and Management, 2016Co-Authors: Arash Nemati, Mortaza Yari, Hossein Nami, Faramarz Ranjbar, Hojjatollah Rashid KolvirAbstract:Abstract A thermoelectric heat pump (TEHP) is modeled, analyzed and optimized from the viewpoint of energy, exergy and exergoeconomic. A comprehensive parametric study is also done to clarify the effects on the energy, exergy and exergoeconomic performance of some main decision parameters. With the aim of exergetic and economic optimization, an optimization methodology based on multi-objective genetic algorithm is applied to the system and optimal values of design variables are obtained. Two objective functions are considered; exergy efficiency and unit cost of heating power. It is observed that the performance of TEHP is comparable to conventional heat pumps from the viewpoints of thermodynamic and exergoeconomic. SPECO method is applied to evaluate the exergoeconomic parameters. The results demonstrate that all decision parameters except the number of thermocouples optimize exergy efficiency and coefficient of performance of the TEHP. The obtained overall exergoeconomic factor of 60.6% illustrates that the 39.4% of total system cost relates to exergy destruction. Under optimal conditions, the unit cost of heating power and exergy efficiency are found to be 0.688 $/kW h and 14.13%, respectively.
Hossein Nami - One of the best experts on this subject based on the ideXlab platform.
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exergy and exergoeconomic assessment of hydrogen and cooling production from concentrated pvt equipped with pem electrolyzer and libr h 2 o absorption chiller
International Journal of Hydrogen Energy, 2018Co-Authors: Ehsan Akrami, Hossein Nami, Arash Nemati, Faramarz RanjbarAbstract:Abstract A novel solar based combined system is proposed to produce hydrogen and cooling. The presented cogeneration system is analyzed in detail from the viewpoints of exergy and exergoeconomic (exergy based economic analysis). The proposed system includes a concentrated PVT (CPVT), a single effect LiBr-H2O absorption chiller and proton exchange membrane electrolyzer (PEM). Produced electrical power is consumed in the PEM electrolyzer to split water into oxygen and pure hydrogen while heat removal from the CPVT is done by the absorption chiller to guarantee its better performance. Second law analysis showed that, among the three different parts of the system, the most part of exergy destruction refers to the CPVT followed by absorption chiller unit and PEM electrolyzer. Also, it is observed that, among the absorption units' components, the highest percent of exergy destruction belongs to the generator which absorbs the heat from the CPVT. Moreover, exergoeconomic analysis revealed that the most important unit from the viewpoint of economic is the CPVT with the capital investment cost of 0.08946 $/h and an exergoeconomic factor of 28.82%.
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A comprehensive thermodynamic and exergoeconomic comparison between single- and two-stage thermoelectric cooler and heater
Applied Thermal Engineering, 2017Co-Authors: Hossein Nami, Mortaza Yari, Arash Nemati, Faramarz RanjbarAbstract:Abstract Energy, exergy and exergoeconomic analysis are carried out for single- and two-stage thermoelectric devices which can be used for either heating or cooling implementation. Coefficient of performance, exergetic efficiency and unit cost of heating/cooling power are investigated as the main target of energy, exergy and exergoeconomic analysis, respectively. A comprehensive comparison between single- and two-stage thermoelectric performances has outlined in different values of current and temperature difference between hot and cold sides. An effective range of current is defined for energy (COP > 0.5 × COPmax), exergy (e > 0.5 × emax) and exergoeconomic (cC/H
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exergy economic and environmental impact assessment and optimization of a novel cogeneration system including a gas turbine a supercritical co2 and an organic rankine cycle gt hrsg sco2
Applied Thermal Engineering, 2017Co-Authors: Hossein Nami, S M S Mahmoudi, Arash NematiAbstract:Abstract Exergoeconomic and exergoenvironmental analyses are reported for a novel cogeneration system including a gas turbine, a heat recovery steam generator, a supercritical carbon dioxide recompression Brayton cycle and an organic Rankine cycle. A comprehensive parametric study is carried out to clarify the effects of some decision parameters on the exergoeconomic performance of the proposed system. Also, the payback period is determined for the proposed system. The sum of capital investment cost, total exergy destruction cost and environmental impact cost is considered as an objective function which is optimized with respect to the decision parameters. The variation in overall exergoeconomic factor is determined and its implication to the system design is discussed. It is observed that under the optimized condition the average product unit cost of the system (cost of produced power and steam) is decreased by 0.56 $/GJ when compared to the value obtained under a base condition.
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Development of an exergoeconomic model for analysis and multi-objective optimization of a thermoelectric heat pump
Energy Conversion and Management, 2016Co-Authors: Arash Nemati, Mortaza Yari, Hossein Nami, Faramarz Ranjbar, Hojjatollah Rashid KolvirAbstract:Abstract A thermoelectric heat pump (TEHP) is modeled, analyzed and optimized from the viewpoint of energy, exergy and exergoeconomic. A comprehensive parametric study is also done to clarify the effects on the energy, exergy and exergoeconomic performance of some main decision parameters. With the aim of exergetic and economic optimization, an optimization methodology based on multi-objective genetic algorithm is applied to the system and optimal values of design variables are obtained. Two objective functions are considered; exergy efficiency and unit cost of heating power. It is observed that the performance of TEHP is comparable to conventional heat pumps from the viewpoints of thermodynamic and exergoeconomic. SPECO method is applied to evaluate the exergoeconomic parameters. The results demonstrate that all decision parameters except the number of thermocouples optimize exergy efficiency and coefficient of performance of the TEHP. The obtained overall exergoeconomic factor of 60.6% illustrates that the 39.4% of total system cost relates to exergy destruction. Under optimal conditions, the unit cost of heating power and exergy efficiency are found to be 0.688 $/kW h and 14.13%, respectively.