Multi-objective technoeconomic optimization of an off-grid solar-ground-source driven cycle with hydrogen storage for power and fresh water production (original) (raw)
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Journal of Energy Storage, 2020
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Exergetic optimization of solar collector and thermal energy storage system
International Journal of Heat and Mass Transfer, 2006
This paper deals with the exergetic optimization of a solar thermal energy system. This consists of a solar collector (SC) and a rectangular water storage tank (ST) that contains a phase change material (PCM) distributed in an assembly of slabs. The study takes into account both conduction and convection heat transfer mode for water in the SC, and also the phase change process for the PCM in the ST. An analytical solution for the melting process in the PCM is also presented. The results of the study are compared with previous experimental data, confirming the accuracy of the model. Results of a numerical case study are presented and discussed.
Solar Energy, 2009
Usual size of parabolic trough solar thermal plants being built at present is approximately 50 MW e. Most of these plants do not have a thermal storage system for maintaining the power block performance at nominal conditions during long non-insolation periods. Because of that, a proper solar field size, with respect to the electric nominal power, is a fundamental choice. A too large field will be partially useless under high solar irradiance valúes whereas a small field will mainly make the power block to work at part-load conditions. This paper presents an economic optimization of the solar múltiple for a solar-only parabolic trough plant, using neither hybridization ñor thermal storage. Five parabolic trough plants have been considered, with the same parameters in the power block but different solar field sizes. Thermal performance for each solar power plant has been featured, both at nominal and part-load conditions. This characterization has been applied to perform a simulation in order to calcúlate the annual electricity produced by each of these plants. Once annual electric energy generation is known, levelized cost of energy (LCOE) for each plant is calculated, yielding a minimum LCOE valué for a certain solar múltiple valué within the range considered.
Energies, 2022
The paper presents a design and operation analysis of an Integrated Collector Storage (ICS) solar water heater, which consists of an asymmetric Compound Parabolic Concentrating (CPC) reflector trough, while the water tank comprises two concentric cylinders. The annulus between these vessels is partially depressurized and contains a small amount of water in the bottom of the outer vessel which dominantly contributes to the heat transfer from the outer to the inner cylinder. A multi-criteria optimization algorithm is applied to re-evaluate the design specifications of the parabolic surface, thus modifying the design of the entire ICS system and predict the necessary number of units for achieving the highest possible effectiveness with minimized fabrication costs and environmental impacts. The environmental footprint of the device is assessed through Life Cycle Assessment (LCA). The produced thermal energy in conjunction with the environmental and economic results are evaluated as a fu...
Exergoeconomic assessment, parametric study and optimization of a novel solar trigeneration system
International Journal of Renewable Energy Research, 2016
An exergoeconomic analysis is performed for a solar trigeneration system in which the electric power, refrigeration power and domestic hot water are produced by a cascade organic Rankine cycle, an absorption chiller, which is accompanied by ammonia turbine, and a heat recovery cycle respectively. A parametric study is also carried out to investigate the effects of such significant parameters as degree of superheat at the turbine’s inlet of power cycle, condenser temperature of power cycle, operating pressure of the refrigerating cycle and operating fluid temperature of the main cycle on the energy and exergy efficiencies and the exergoeconomic performance of the system. Finally a multi objective optimization from the viewpoint of exergoeconomics is reported by using genetic algorithm. As a result of exergoeconomic analysis of the system, ORC Heat Exchanger (ORC Ex), Cooling Tower2 (C.T2), Absorber (Abs) and Reflux Condenser (Ref Cond) exhibit the worst exergoeconomic performance. Fo...
2016
This paper deals with a multi-objective optimization of a novel micro solar driven combined power and ejector refrigeration system (CPER). The system combines an organic Rankine cycle (ORC) with an ejector refrigeration cycle to generate electricity and cold capacity simultaneously. Major thermodynamic parameters, namely turbine inlet temperature, turbine inlet pressure, turbine back pressure, and evaporator temperature are selected as the decision variables. Three objective functions, namely the energetic efficiency, exergetic efficiency and cost rate of products are selected for optimization. NSGA-II and MOPSO are employed and compared, to achieve the final solutions in the multi-objective optimization of the system operating. It is found that the values of the energetic and exergetic efficiencies increase within 27.7% and 26.1%, respectively and the cost rate of products decreases by about 32.7% with respect to base case.
Optimization of parabolic trough solar collectors integrated with two stage Rankine cycle
2017
In this paper, detailed exergy and energy analysis of selected thermal power systems driven by parabolic trough solar collectors is presented. solar energy is used to feed a two stage steam Rankine cycle to supply domestic hot water. To determine the irreversibilities in each component and assess the system performance, a parametric study is performed to investigate the effects of varying design parameters and operating conditions such as the effects of the ambient temperature, solar radiation, and high pressure turbine pressure ratio and solar cycle mass flow rate, on the system energy and exergy efficiencies. An optimization with an evolutionary algorithm is applied to determine the best exergetic performance. This study reveals that the main source of exergy destruction is the solar collector where contributes more than 45% of total exergy destruction. In addition, heater, condenser and heat exchanger contribute to 16%, 15% and 14%, respectively. Finally, this study reveals that ...
Multi-Criteria Optimization of a solar cooling system assisted ground source Heat Pump system
2016
In this study, optimization of a solar cooling system assisted ground source Heat Pump system (GSHP) is performed. The optimization process was carried out using a multi-objective evolutionary algorithm. Three optimization scenarios, including thermodynamic single objective, thermoeconomic single objective, and multi-objective optimizations, are performed. 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. It was concluded that the multi-objective optimization considers two objectives of thermodynamic and economic, simultaneously. The results obtained using the various optimization approaches are compared and discussed. 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 money. The results showed that percentages of deviation from ideal values of thermodynamic and economic criteria for the thermodynamic optimized system were 0 % and 905 % respectively. These percentages for the economic optimized system were 104 % and 0 %, respectively. Deviation values from minimum ideal point for the multi-objective optimized design were obtained 10 % and 88 % for thermodynamic and economic criteria, respectively. It was concluded that the multi-objective design satisfies the thermodynamic and economic criteria better than two single-objective thermodynamic and economic optimized designs.
2010
Thermoeconomic analyses of any thermal system design are always based on the economic objectives. However, knowledge of economic optimization may not be sufficient for decision making process, since solutions with higher thermodynamic efficiency, in spite of small increases in total costs, may result in much more interesting designs due to changes in the energy market prices or in the energy policies. In this paper a multi-objective optimization scheme is developed and applied for an Integrated Solar Combined Cycle System (ISCCS) that produces 400 MW of electricity to find solutions that simultaneously satisfy exergetic as well as economic objectives. This corresponds to search for a set of Pareto optimal solutions with respect to the two competing objectives. The optimization process is carried out by a particular class of search algorithms known as multi-objective evolutionary algorithms (MOEAs). For such MOEAs, an example of decision-making is presented and a final optimal solution has been introduced. The final optimal solution that is selected in this analysis belongs to the region of Pareto Frontier with significant sensitivity to the costing parameters. However, the region with lower sensitivity to the costing parameter is not reasonable for the final optimum solution due to a weak equilibrium of Pareto Frontier in which a small changes in exergetic efficiency of plant due to variation of operating parameters may lead to the danger of increasing the cost rate of product, drastically. The analysis shows that optimization process leads to 3.2% increasing in the exergetic efficiency and 3.82% decreasing of the rate of product cost. Also optimization leads to the 2.73% reduction on the fuel exergy, 5.71% reductions in the total exergy destruction and also 3.46% and 7.32% reductions in the fuel cost rate and cost rate relating to the exergy destruction, respectively.