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Hoseyn Sayyaadi - One of the best experts on this subject based on the ideXlab platform.

  • application of the multi objective optimization and risk analysis for the sizing of a residential small scale cchp system
    Energy and Buildings, 2013
    Co-Authors: Gholamhossein Abdollahi, Hoseyn Sayyaadi
    Abstract:

    Abstract Multi-objective optimization for sizing of a small-scale combined cooling, heating, and power generation (CCHP) system is performed. In multi-objective optimizing the s CCHP system, the three objective functions including the exergetic efficiency, total levelized cost rate of the system product and the cost rate of environmental are optimized, simultaneously. The environmental impact and thermoeconomic objective are minimized while the exegetic objective is maximized. A comprehensive emission assessment framework suitable for addressing of distributed cogeneration systems is formulated according to an electrical output-based emission factor approach and the environmental impact objective function are defined and expressed in cost terms. The economic analysis is conducted in accordance with the total Revenue Requirement ( TRR ) method. The genetic algorithm is applied to find the set of Pareto optimal solutions with respect to the aforementioned objective functions. In the present work, reliability and availability are introduced in the developed models of the system, so that redundancy is embedded in the optimal solution. In this regard, risk analysis is used as a decision-making tool for the selection of the final optimal solution from the obtained Pareto optimal frontier. The sensitivity of the optimal solution respect to variations of input parameters is analyzed.

  • multi objective optimization of a joule cycle for re liquefaction of the liquefied natural gas
    Applied Energy, 2011
    Co-Authors: Hoseyn Sayyaadi, M. Babaelahi
    Abstract:

    A LNG re-liquefaction plant is optimized with a multi-objective approach which simultaneously considers exergetic and exergoeconomic objectives. In this regard, optimization is performed in order to maximize the exergetic efficiency of plant and minimize the unit cost of the system product (refrigeration effect), simultaneously. Thermodynamic modeling is performed based on energy and exergy analyses, while an exergoeconomic model based on the total Revenue Requirement (TRR) are developed. Optimization programming in MATLAB is performed using one of the most powerful and robust multi-objective optimization algorithms namely NSGA-II. This approach which is based on the Genetic Algorithm is applied to find a set of Pareto optimal solutions. Pareto optimal frontier is obtained and a final optimal solution is selected in a decision-making process. An example of decision-making process for selection of the final solution from the available optimal points of the Pareto frontier is presented here. The feature of selected final optimal system is compared with corresponding features of the base case and exergoeconomic single-objective optimized systems and discussed.

  • a comprehensive approach in optimization of a dual nuclear power and desalination system
    Desalination, 2011
    Co-Authors: Kambiz Ansari, Hoseyn Sayyaadi, Majid Amidpour
    Abstract:

    Abstract A typical 1000 MW Pressurized Water Reactor ( PWR ) nuclear power plant coupled to a multi effect distillation desalination system with a thermo-vapor compressor (MED–TVC) is considered for optimization. The thermodynamic modeling is performed based on the energy and exergy analyses, while an economic model is developed according to the Total Revenue Requirement ( TRR ) method. The objective functions based on the thermodynamic and thermoeconomic analyses are obtained. The proposed hybrid plant with ten decision variables for power plant and six decision variables for the desalination plant is optimized in a multi-objective optimization process. This approach is applied to minimize either the cost of the system product (including the cost of generated electricity and fresh water) and/or maximize the exergetic efficiency of the system. Three optimization scenarios including thermodynamic single objective, thermoeconomic single objective and multi-objective optimizations are performed using the Genetic Algorithm (GA). In multi-objective optimization, both thermodynamics and thermoeconomic objectives are considered, simultaneously. A series of optimum solutions namely Pareto frontier is obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final optimal solution from the available optimal points on the Pareto frontier is introduced. The results obtained using the various optimization scenarios are compared and discussed.

  • multi objective optimization of a cooling tower assisted vapor compression refrigeration system
    International Journal of Refrigeration-revue Internationale Du Froid, 2011
    Co-Authors: Hoseyn Sayyaadi, Mostafa Nejatolahi
    Abstract:

    A cooling tower assisted vapor compression refrigeration machine has been considered for optimization with multiple criteria. Two objective functions including the total exergy destruction of the system (as a thermodynamic criterion) and the total product cost of the system (as an economic criterion), have been considered simultaneously. A thermodynamic model based on energy and exergy analyses and an economic model according to the Total Revenue Requirement (TRR) method have been developed. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from the Pareto frontier has been presented. The exergetic and economic results obtained for three optimized systems have been compared and discussed. The results have shown that the multi-objective design more acceptably satisfies generalized engineering criteria than other two single-objective optimized designs.

  • thermoeconomic optimization of a cryogenic refrigeration cycle for re liquefaction of the lng boil off gas
    International Journal of Refrigeration-revue Internationale Du Froid, 2010
    Co-Authors: Hoseyn Sayyaadi, M. Babaelahi
    Abstract:

    The development of the liquefaction process for the Liquefied Natural Gas (LNG) boil-off re-liquefaction plants will be addressed to provide an environmentally friendly and cost effective solution for the gas transportation. In this manner, onboard boil-off gas (BOG) re-liquefaction system as a cryogenic refrigeration cycle is utilized in order to re-liquefy the BOG and returns it to the cargo tanks instead of burning it. In this paper, a thermoeconomic optimization of the LNG-BOG liquefaction system is performed. A thermoeconomic model based on energy and exergy analyses and an economic model according to the total Revenue Requirement (TRR) are developed. Minimizing of the unit cost of the refrigeration effect as a product of BOG re-liquefaction plant is performed using the genetic algorithm. Results of thermoeconomic optimization are compared with corresponding features of the base case system. Finally, sensitivity of the total cost of the system product with respect to the variation of some operating parameters is studied.

Edward S. Rubin - One of the best experts on this subject based on the ideXlab platform.

  • A technical and economic assessment of ammonia-based post-combustion CO2 capture at coal-fired power plants
    International Journal of Greenhouse Gas Control, 2011
    Co-Authors: Peter Versteeg, Edward S. Rubin
    Abstract:

    Abstract An ammonia-based post-combustion CO2 capture system processing flue gas from a supercritical coal-fired power plant was modeled, and its estimated performance and cost were compared to an amine-based capture system. For the ammonia system the absorber CO2 capture efficiency, NH3 slip, and solids precipitation were evaluated for changes in lean solution NH3 concentration, NH3/CO2 ratio, and absorber temperature. Reductions in NH3 slip were also assessed for changes in absorber temperature and water wash flow rate. For 90% CO2 capture the levelized cost of electricity generation (annual Revenue Requirement) for the plant with ammonia-based capture was estimated at $US 105/MWh, which is comparable to the levelized cost of electricity generation for the plant with an amine-based capture system. The cost of the ammonia-based system was found to depend strongly on the fraction of CO2 captured as well as on key process design parameters such as lean solution NH3 concentration. Uncertainties in system performance and cost also were estimated probabistically. Assumptions about plant financing and utilization, as well as uncertainties in cooling costs and reaction rates that affect absorber cost were found in particular to produce a wide range of cost estimates for ammonia-based CO2 capture systems, and as a result the importance of reducing these uncertainties is emphasized.

  • technical and economic assessment of ammonia based post combustion co2 capture
    Energy Procedia, 2011
    Co-Authors: Peter Versteeg, Edward S. Rubin
    Abstract:

    Abstract The performance and cost of two ammonia-based post-combustion CO 2 capture systems operating at a new supercritical coal-fired power plant were modeled and compared to an amine-based CO 2 capture system operating at a similar plant. This assessment showed that for a fixed coal input, the plant derating of a CO 2 capture system operating with high ammonia concentrations (HighNH 3 ) was found to be 2 percentage points lower than a plant with the amine-based system. The plant derating of a CO 2 capture system operating with low ammonia concentrations (LowNH 3 ) was substantially higher. Preliminary estimates of the Revenue Requirement of the plants with HighNH 3 and LowNH 3 systems are $US 117/MWh and $US 148/MWh respectively, compared to $US 119/MWh for a plant with an amine-based system. The results from this performance assessment and preliminary cost analysis suggest that the LowNH 3 system will not be competitive and that the HighNH 3 system may have a slight energy and cost advantage over the amine system. Furthermore, a preliminary uncertainty analysis explores the critical factors that may affect the performance and cost estimates of these systems, including the potential for slow reaction kinetics to increase absorber costs, and these results are presented.

Majid Amidpour - One of the best experts on this subject based on the ideXlab platform.

  • thermoeconomic analysis with reliability consideration of a combined power and multi stage flash desalination plant
    Desalination, 2011
    Co-Authors: Seyed Reza Hosseini, Majid Amidpour, Ali Behbahaninia
    Abstract:

    Abstract This paper deals with the effects of equipment reliability consideration to thermoeconomic analysis of a combined power and multi stage flash water desalination plant. Exergy and thermoeconomic models of the considered process units are developed and presented in this work. An economic model of the system is developed according to the Total Revenue Requirement (TRR) method. This application can be very useful, either for the plant management in order to achieve a cost-effective operation, or for a better plant design. Equipment reliability using the state-space and the continuous Markov method is incorporated in thermoeconomic analysis to improve the cost values. The results show that the power and water costs with reliability consideration increased 4.1% and 6.4%, respectively. Additionally, the sensitivity analysis shows the relationship between the production cost and the system availability which can help the designer to decide how to improve the profit or competitiveness.

  • a comprehensive approach in optimization of a dual nuclear power and desalination system
    Desalination, 2011
    Co-Authors: Kambiz Ansari, Hoseyn Sayyaadi, Majid Amidpour
    Abstract:

    Abstract A typical 1000 MW Pressurized Water Reactor ( PWR ) nuclear power plant coupled to a multi effect distillation desalination system with a thermo-vapor compressor (MED–TVC) is considered for optimization. The thermodynamic modeling is performed based on the energy and exergy analyses, while an economic model is developed according to the Total Revenue Requirement ( TRR ) method. The objective functions based on the thermodynamic and thermoeconomic analyses are obtained. The proposed hybrid plant with ten decision variables for power plant and six decision variables for the desalination plant is optimized in a multi-objective optimization process. This approach is applied to minimize either the cost of the system product (including the cost of generated electricity and fresh water) and/or maximize the exergetic efficiency of the system. Three optimization scenarios including thermodynamic single objective, thermoeconomic single objective and multi-objective optimizations are performed using the Genetic Algorithm (GA). In multi-objective optimization, both thermodynamics and thermoeconomic objectives are considered, simultaneously. A series of optimum solutions namely Pareto frontier is obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final optimal solution from the available optimal points on the Pareto frontier is introduced. The results obtained using the various optimization scenarios are compared and discussed.

  • thermoeconomic optimization of a hybrid pressurized water reactor pwr power plant coupled to a multi effect distillation desalination system with thermo vapor compressor med tvc
    Energy, 2010
    Co-Authors: Kambiz Ansari, Hoseyn Sayyaadi, Majid Amidpour
    Abstract:

    Thermoeconomic optimization of a typical 1000 MW Pressurized Water Reactor (PWR) nuclear power plant coupled to a Multi Effect Distillation (MED) desalination system with thermo-vapor compressor (TVC) is performed. A thermodynamic modeling based on the energy and exergy analysis is performed while economic modeling is developed based on the Total Revenue Requirement (TRR) method. The objective function based on the thermoeconomic analysis is obtained. The proposed cogeneration plant, for simultaneous production of power and fresh water, including sixteen decision variables is proposed for thermoeconomic optimization in which the goal is minimizing the cost of system product (including the cost of generated electricity and fresh water). The optimization process is performed using a stochastic/deterministic optimization approach namely as Genetic Algorithm. It is found that thermoeconomic optimization aims at reduction of sub-components total costs by reducing either the cost of inefficiency or the cost of owning the components, whichever is dominant. For some components such as evaporators, the improvement is obtained by reducing the owning cost of the sub-system at the cost of reduction of the thermodynamic efficiency. For components like as TVC + de-superheater, improvement is achieved by increasing the thermodynamic efficiency or decreasing the inefficiency cost.

  • multi objective optimization of a vertical ground source heat pump using evolutionary algorithm
    Energy Conversion and Management, 2009
    Co-Authors: Hoseyn Sayyaadi, Emad Hadaddi Amlashi, Majid Amidpour
    Abstract:

    Thermodynamic and thermoeconomic optimization of a vertical ground source heat pump system has been studied. A model based on the energy and exergy analysis is presented here. An economic model of the system is developed according to the Total Revenue Requirement (TRR) method. The objective functions based on the thermodynamic and thermoeconomic analysis are developed. The proposed vertical ground source heat pump system including eight decision variables is considered for optimization. An artificial intelligence technique known as evolutionary algorithm (EA) has been utilized as an optimization method. This approach has been applied to minimize either the total levelized cost of the system product or the exergy destruction of the system. Three levels of optimization including thermodynamic single objective, thermoeconomic single objective and multi-objective optimizations are performed. In Multi-objective optimization, both thermodynamic and thermoeconomic objectives are considered, simultaneously. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from available optimal points on Pareto frontier is presented. The results obtained using the various optimization approaches are compared and discussed. Further, the sensitivity of optimized systems to the interest rate, to the annual number of operating hours and to the electricity cost are studied in detail.

Peter Versteeg - One of the best experts on this subject based on the ideXlab platform.

  • A technical and economic assessment of ammonia-based post-combustion CO2 capture at coal-fired power plants
    International Journal of Greenhouse Gas Control, 2011
    Co-Authors: Peter Versteeg, Edward S. Rubin
    Abstract:

    Abstract An ammonia-based post-combustion CO2 capture system processing flue gas from a supercritical coal-fired power plant was modeled, and its estimated performance and cost were compared to an amine-based capture system. For the ammonia system the absorber CO2 capture efficiency, NH3 slip, and solids precipitation were evaluated for changes in lean solution NH3 concentration, NH3/CO2 ratio, and absorber temperature. Reductions in NH3 slip were also assessed for changes in absorber temperature and water wash flow rate. For 90% CO2 capture the levelized cost of electricity generation (annual Revenue Requirement) for the plant with ammonia-based capture was estimated at $US 105/MWh, which is comparable to the levelized cost of electricity generation for the plant with an amine-based capture system. The cost of the ammonia-based system was found to depend strongly on the fraction of CO2 captured as well as on key process design parameters such as lean solution NH3 concentration. Uncertainties in system performance and cost also were estimated probabistically. Assumptions about plant financing and utilization, as well as uncertainties in cooling costs and reaction rates that affect absorber cost were found in particular to produce a wide range of cost estimates for ammonia-based CO2 capture systems, and as a result the importance of reducing these uncertainties is emphasized.

  • technical and economic assessment of ammonia based post combustion co2 capture
    Energy Procedia, 2011
    Co-Authors: Peter Versteeg, Edward S. Rubin
    Abstract:

    Abstract The performance and cost of two ammonia-based post-combustion CO 2 capture systems operating at a new supercritical coal-fired power plant were modeled and compared to an amine-based CO 2 capture system operating at a similar plant. This assessment showed that for a fixed coal input, the plant derating of a CO 2 capture system operating with high ammonia concentrations (HighNH 3 ) was found to be 2 percentage points lower than a plant with the amine-based system. The plant derating of a CO 2 capture system operating with low ammonia concentrations (LowNH 3 ) was substantially higher. Preliminary estimates of the Revenue Requirement of the plants with HighNH 3 and LowNH 3 systems are $US 117/MWh and $US 148/MWh respectively, compared to $US 119/MWh for a plant with an amine-based system. The results from this performance assessment and preliminary cost analysis suggest that the LowNH 3 system will not be competitive and that the HighNH 3 system may have a slight energy and cost advantage over the amine system. Furthermore, a preliminary uncertainty analysis explores the critical factors that may affect the performance and cost estimates of these systems, including the potential for slow reaction kinetics to increase absorber costs, and these results are presented.

Mostafa Nejatolahi - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic and thermoeconomic optimization of a cooling tower assisted ground source heat pump
    Geothermics, 2011
    Co-Authors: Hoseyn Sayyadi, Mostafa Nejatolahi
    Abstract:

    Abstract Thermodynamic and thermoeconomic optimization of a cooling tower-assisted ground source heat pump (GSHP) in a multi-objective optimization process is performed. A thermodynamic model based on energy and exergy analyses is presented, and an economic model of the hybrid GSHP (HGSHP) system is developed according to the total Revenue Requirement (TRR) method. The proposed hybrid cooling tower-assisted GSHP system, including 12 decision variables, is considered for optimization. Three optimization scenarios, including thermodynamic single objective, thermoeconomic single objective, and multi-objective optimizations, are performed. In multi-objective optimization, both thermodynamic and thermoeconomic objectives are simultaneously considered. An optimization process is performed using the genetic algorithm (GA). In the case of multi-objective optimization, an example of a decision-making process for selection of the final solution from the Pareto optimal frontier is presented. The results obtained using the various optimization approaches are compared and discussed. Further, the sensitivity of optimized systems to the interest rate, the annual number of operating hours in cooling mode, the electricity price, and the water price are studied in detail. It is shown that the thermodynamic optimization is focused on provision for the limited source of energy, whereas the thermoeconomic optimization only focuses on monetary resources. In contrast, the multi-objective optimization considers both energy and monetary. Further, it is found that thermodynamic optimization is economical when the operating time in cooling mode is long and/or the electricity price is high, and water prices variations have no marked impact on the total product cost.

  • multi objective optimization of a cooling tower assisted vapor compression refrigeration system
    International Journal of Refrigeration-revue Internationale Du Froid, 2011
    Co-Authors: Hoseyn Sayyaadi, Mostafa Nejatolahi
    Abstract:

    A cooling tower assisted vapor compression refrigeration machine has been considered for optimization with multiple criteria. Two objective functions including the total exergy destruction of the system (as a thermodynamic criterion) and the total product cost of the system (as an economic criterion), have been considered simultaneously. A thermodynamic model based on energy and exergy analyses and an economic model according to the Total Revenue Requirement (TRR) method have been developed. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from the Pareto frontier has been presented. The exergetic and economic results obtained for three optimized systems have been compared and discussed. The results have shown that the multi-objective design more acceptably satisfies generalized engineering criteria than other two single-objective optimized designs.