| 1. |
- Trevisan, Silvia, et al.
(författare)
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Techno-economic analysis of a solar hybrid combined cycle power plant integrated with a packed bed storage at gas turbine exhaust
- 2020
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Ingår i: AIP Conference Proceedings. - : AIP Publishing.
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Konferensbidrag (refereegranskat)abstract
- The present work performs a techno-economic analysis of an innovative solar-hybrid combined cycle composed of a topping gas turbine coupled to a bottoming packed bed thermal energy storage at the gas turbine exhaust, which runs in parallel to a bottoming steam cycle. Plant performances have been evaluated in terms of the capacity factor, the specificCO2 emissions, the capital expenditure, and the Levelised Cost of Electricity. The influence of the combustion chamber outlet temperature, solar multiple and energy storage capacity has been assessed by means of a sensitivity analysis. The present study also compares the previously listed performance against that of conventional molten salt tower ConcentratingSolar Power plants and traditional combined cycle gas turbine power plants with equivalent installed capacities and load factors. The results show that it is worth hybridizing the system, particularly at high combustion chamber outlet temperature, large storage size and solar multiple. Furthermore, plant configurations leading to a Levelised Cost of Electricity lower than 110 $/MWh can be achieved for a capacity factor of about 60%. Under these working conditions, the proposed configuration would be only 1.66 times more costly than an equivalent size CCGT. At the same time, it would yield less than half of the emissions of the latter. Simultaneously, the proposed layout is considerably cheaper than an equivalent molten salt Concentrating Solar Power plant.
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| 2. |
- Trevisan, Silvia, et al.
(författare)
-
Techno-economic analysis of an innovative purely solar-driven combined cycle system based on packed bed TES technology
- 2020
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Ingår i: AIP Conference Proceedings. - : AIP Publishing.
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Konferensbidrag (refereegranskat)abstract
- The present work performs a techno-economic analysis of a purely solar driven combined cycle composed of a solar air receiver directly connected to a topping gas turbine coupled to a bottoming packed bed thermal energy storage atthe gas turbine exhaust, which runs in parallel to a bottoming steam cycle. Capacity factor, capital expenditure, and Levelized Cost of Electricity have been considered to assess the plant performance. A sensitivity analysis has been performed in order to understand the influence of solar multiple, energy storage capacity and gas turbine expansion ratio over the plant key performance indicators. The results show that the studied solar driven combined cycle is more costly than conventional ones, and therefore it leads to higher Levelized Cost of Electricity. However, it enables a complete reduction of CO2 emissions and increased flexibility in the system with the help of the introduction of an intermediate packet bed thermal energy storage. Furthermore, large solar multiple, medium storage capacity and complete expansion ratio through the gas turbine enable enhanced system performance. Finally, further works including optimized dispatch algorithms could enable a proper evaluation of the economic profit given by the flexibility offered by the storage unit and by a potential control of the Brayton cycle recuperation level in the modified plant layouts.
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| 3. |
- Trevisan, Silvia, et al.
(författare)
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Thermo-economic optimization of an air driven supercritical CO2 Braytonpower cycle for concentrating solar power plant with packed bed thermalenergy storage
- 2020
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Ingår i: Solar Energy. - : Elsevier BV. - 0038-092X .- 1471-1257. ; , s. 1373-1391
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Tidskriftsartikel (refereegranskat)abstract
- This work presents an innovative indirect supercritical CO2 – air driven concentrated solar power plant with a packed bed thermal energy storage. High supercritical CO2 turbine inlet temperature can be achieved, avoiding the temperature limitations set by the use of solar molten salts as primary heat transfer fluid. The packed bed thermal energy storage enables the decoupling between solar irradiation collection and electricity production, and it grants operational flexibility while enhancing the plant capacity factor. A quasi steady-state thermo-economic model of the integrated concentrating solar power plant has been developed. The thermo-economic performance of the proposed plant design has been evaluated via multi-objective optimizations and sensitivity analyses. Results show that a Levelized Cost of Electricity of 100 $/MWhe and a capacity factor higher than 50%can be achieved already at a 10 MWe nominal size. Such limited plant size bounds the capital investment and leads to more bankable and easily installable plants. Results also show that larger plants benefit from economy of scale, with a 65 $/MWhe cost identified for a 50 MWe plant. The receiver efficiency is found to be the most influential assumption. A 20% decrease of receiver efficiency would lead to an increase of more than 15% of the Levelized Cost of Electricity. These results show the potential of indirect supercritical CO2 – air driven concentrated solar power plant and highlight the importance of further air receiver development. More validations and verification tests are needed to ensure the system operation during long lifetime.
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| 4. |
- Trevisan, Silvia, et al.
(författare)
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Thermodynamic analysis of a high temperature multi-layered sensible-latent thermal energy storage
- 2020
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Ingår i: AIP Conference Proceedings. - : AIP Publishing.
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Konferensbidrag (refereegranskat)abstract
- The present work provides a thorough literature review of the main high temperature sensible and latent materials suitable for a multilayered thermal energy storage system to be integrated into innovative concentrated solar power applications. Furthermore, a thermodynamic comparative analysis of six different multilayered packed-bed thermal energy storage configurations, including three selected high-temperature metallic phase change materials (Al-12.2Si, Al-20Si, andCu-Si27-Mg17) is presented. For each multilayered storage configuration, the overall impact of the phase change material layer thickness on the performance has been analyzed. As expected, the major improvements are enabled by the addition of a high-temperature phase change material at the top of the multi-layered thermal energy storage. Indeed, the discharge phase duration could be extended for 2 hours, while the energy output increases by about 5%. Furthermore, the addition of a lower melting temperature phase change material layer below the topping high temperature one grants a further slight energy output enhancement. However, this seems to be not valuable enough when considering the increased level of complexity and costs induced by such a storage unit design. The study confirms that a larger amount of phase change materials leads to a lower discharge efficiency due to a wider temperature difference between the heat transfer fluid and the storing media during phase change. The performed study reveals that the Cu-17Mg-27Si/rock multilayered thermal energy storage is worth continuing exploring, especially in terms of experimental tests to assess possible corrosion issues and different encapsulation and coating solutions that might considerably affect the lifetime of the system. Technoeconomicanalyses should be also performed to assess the economic viability of the integration of multilayered TES systems in innovative concentrated solar power plant layouts.
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| 5. |
- Trevisan, Silvia, et al.
(författare)
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Thermodynamic Analysis of an Indirect Supercritical CO2 –Air Driven Concentrated Solar Power Plant with a Packed Bed Thermal Energy Storage
- 2020
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Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP).
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Konferensbidrag (refereegranskat)abstract
- The present work assesses the thermodynamic performance of an indirect supercritical CO2 – air driven concentrated solar plant with a packed bed thermal energy storage. A specific focus has been devoted to the flexibility requirements on both air and supercritical loops, highlighting key limitations and challenges that need to be addressed prior to a fruitful development of the proposed cycles. The introduced plant design enables a supercritical CO2 turbine inlet temperature of 800°C, overcoming the temperature limits imposed by the use of solar molten salts as primary heat transfer fluid. Furthermore, the packed bed thermal energy storage permits the decoupling between thermal power collection from the sun and electricity generation. Besides, it grants operational flexibility and enlarges the plant capacity factor. Results show that the proposed indirect supercritical CO2 – air driven with a packed bed thermal energy storage concentrated solar plant leads to improved thermodynamic performance with respect to the molten salts driven design, particularly when working at high temperature, above molten salts limit. Enhancements in the power cycle efficiency and in the overall electricity production can be achieved, with a consequent increase of the capacity factor. Furthermore, the proposed system seems viable for the coupling with other power sources as PVs or secondary, low temperature, power cycles.
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