The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Kody M Powell - One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation and techno economic analysis of a concentrated solar power csp Plant Hybridized with both thermal energy storage and natural gas
Journal of Cleaner Production, 2020Co-Authors: Khalid Rashid, Kasra Mohammadi, Kody M PowellAbstract:Abstract The addition of thermal energy storage and natural gas as a complementary energy source improves the flexibility, reliability, and value of concentrated solar power (CSP) Plants. Nevertheless, due to the transient nature of solar energy, transitions from solar-only mode and natural-gas mode to Hybrid solar-natural gas mode is quite challenging, especially when the Plant is equipped with thermal storage. Thus, it is important to develop proper dynamic modeling and control schemes to accurately simulate such transitions. The objective of this study is to address this subject by demonstrating a dynamic model with reliable control schemes for a highly integrated Hybrid parabolic trough-natural gas Plant equipped with thermal energy storage. The specific goal is to study the dynamics of adding thermal storage to the Hybrid Plant. It is found that the developed control schemes assist smooth transitions between different operational modes and effective utilization of thermal storage and natural gas to maintain steady power production and steam mass flow rates under different solar conditions. The results demonstrate that the integration of storage regulates power production by solar energy and natural gas during the day time. It also enables an increase in the solar fraction of the Hybrid Plant while it causes a small decrease in thermodynamic efficiency. The analysis shows that the Hybrid Plant with the storage has a substantially lower specific CO2 emission (0.320 tonne/MWh) than single natural gas Plant (0.413 tonne/MWh) although it has a higher levelized cost of electricity ($86.32/MWh against $74.92/MWh). The Hybrid Plant with storage demonstrates a promising potential for reliable and clean production of electricity, although research and development should be conducted to lower its cost.
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designing flexibility into a Hybrid solar thermal power Plant by real time adaptive heat integration
2019Co-Authors: Khalid Rashid, Kevin Ellingwood, Seyed Mostafa Safdarnejad, Kody M PowellAbstract:Abstract This study presents the concept of flexible heat integration (FHI) applied to a concentrated solar power (CSP)-natural gas Hybrid power Plant and employing non-linear real-time optimization (RTO) to leverage the FHI concept. In a conventional CSP Plant driven by a trough collector, solar energy is dispatched in series to heat sinks at decreasing temperature. FHI dispatches solar energy to the heat sinks within the power Plant based upon ambient conditions, rather than always in series. During times of low solar activity, solar energy bypasses the steam generator and is dispatched directly to the preheater. A nonlinear optimization capitalizes on this flexible operation and establishes different collection temperature set points based upon the availability of solar power. This mechanism enables the Plant to mitigate radiative heat losses of low-grade solar power, as observed when heat is only utilized at high temperature and in series. Applying FHI and RTO increases the solar fraction by 18.2% and the solar-to-electric efficiency by 15.5%. These results indicate the potential of significant improvement of solar power production in a Hybrid Plant by leveraging the benefits of RTO and FHI. Compared to a solar only power Plant, the combination of the Hybrid design, FHI, and RTO nearly doubles the amount of solar power produced.
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leveraging energy storage in a solar tower and combined cycle Hybrid power Plant
Energies, 2018Co-Authors: Kevin Ellingwood, Khalid Rashid, Seyed Mostafa Safdarnejad, Kody M PowellAbstract:A method is presented to enhance solar penetration of a Hybrid solar-combined cycle power Plant integrated with a packed-bed thermal energy storage system. The Hybrid Plant is modeled using Simulink and employs systems-level automation. Feedback control regulates net power, collector temperature, and turbine firing temperature. A base-case Plant is presented, and Plant design is systematically modified to improve solar energy utilization. A novel recycling configuration enables robust control of collector temperature and net power during times of high solar activity. Recycling allows for improved solar energy utilization and a yearly solar fraction over 30%, while maintaining power control. During significant solar activity, excessive collector temperature and power setpoint mismatch are still observed with the proposed recycling configuration. A storage bypass is integrated with recycling, to lower storage charging rate. This operation results in diverting only a fraction of air flow to storage, which lowers the storage charging rate and improves solar energy utilization. Recycling with a storage bypass can handle larger solar inputs and a solar fraction over 70% occurs when following a drastic peaking power load. The novel Plant configuration is estimated to reduce levelized cost of the Plant by over 4% compared to the base-case Plant.
Manuel Romero - One of the best experts on this subject based on the ideXlab platform.
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optimal integration of a solid oxide electrolyser cell into a direct steam generation solar tower Plant for zero emission hydrogen production
Applied Energy, 2014Co-Authors: Javier Sanzbermejo, Jose Gonzalezaguilar, Javier Munozanton, Manuel RomeroAbstract:Abstract Steam electrolysis through Solid-Oxide Electrolysis Cell (SOEC) coupled with concentrating solar power (CSP) Plants stands for a promising system of large-scale carbon-free hydrogen production process. This study presents an energetic analysis on integration schemes of a SOEC Unit into a direct steam generation solar tower Plant. Several configurations have been analyzed aiming at minimizing the penalties of the integration over the CSP Plant, and maximizing the electrolysis performance. Atmospheric and high pressure operation modes of SOEC have been analyzed. The results show that operating the stack at atmospheric pressure, penalties over the solar Plant can be reduced by 60% if process steam is extracted from low pressure turbine section and solar Plant feed water is preheated with rejected hot streams from the electrolyser. In high pressure SOEC scenarios, although penalties over the CSP Plant are increased, the overall performance of the Hybrid Plant could be improved by 5.8%, and also oxygen could be collected as co-product if a pressure swing adsorption unit is integrated.
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coupling of a solid oxide cell unit and a linear fresnel reflector field for grid management
Energy Procedia, 2014Co-Authors: Javier Sanzbermejo, Victor Gallardonatividad, Jose Gonzalezaguilar, Manuel RomeroAbstract:Abstract Recent analyses on energy scenarios for countries with high contribution of intermittent renewables point out that electricity generation from solar and wind energy may exceed the overall electricity demand during a large number of hours per year (that include peak periods). Thus, large-scale electrical –energy storage systems are required for grid balancing. Hydrogen production through solid-oxide electrolysis cells (SOEC) stands for promising power storage systems due to its high capacity and wide variety of applications. SOEC operates with steam in the range of 600-1000 °C, which, in this work, is supplied by a concentrating solar system. Based on its simplicity and low cost of the components, a linear Fresnel reflector coupled with castable ceramic thermal energy storage system was selected. Thermal oil was retained as heat transfer fluid avoiding phase change through the solar receiver. The heat is stored during the day for later use by the SOECs. The proposed Hybrid Plant, located in Seville, Spain, is analyzed under two scenarios. In the first one, the Solid-Oxide unit is only used as steam electrolyser producing hydrogen that is directly sell to a hydrogen bus refueling station. In the second case, the device operates either as electrolyser or fuel cell, generating hydrogen that is stored and later used to produce electricity during peak periods. The capacity of the Plant operating under both scenarios has been evaluated as a function of the storage capacity.
Julio Vergara - One of the best experts on this subject based on the ideXlab platform.
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thermal power Plant efficiency enhancement with ocean thermal energy conversion
Applied Thermal Engineering, 2014Co-Authors: Rodrigo Neira Soto, Julio VergaraAbstract:Abstract In addition to greenhouse gas emissions, coastal thermal power Plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these Plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a Hybrid Plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power Plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC Plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power Plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the Plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power Plant projects regardless of the Plant location.
Fredrik Haglind - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic analysis of an integrated gasification solid oxide fuel cell Plant combined with an organic rankine cycle
Renewable Energy, 2013Co-Authors: Leonardo Pierobon, Masoud Rokni, Ulrik Larsen, Fredrik HaglindAbstract:A 100 kWe Hybrid Plant consisting of gasification system, solid oxide fuel cells and organic Rankine cycle is presented. The nominal power is selected based on cultivation area requirement. For the considered output a land of around 0.5 km2 needs to be utilized. Woodchips are introduced into a fixed bed gasification Plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations of state). A genetic algorithm is employed to select the optimal working fluid and the maximum pressure for the bottoming cycle. Thermodynamic and physical properties, environmental impacts and hazard specifications are also considered in the screening process. The results suggest that efficiencies in the region of 54e56% can be achieved. The highest thermal efficiency (56.4%) is achieved with propylcyclohexane at 15.9 bar. A comparison with the available and future technologies for biomass to electricity conversion is carried out. It is shown that the proposed system presents twice the thermal efficiency achieved by simple and double stage organic Rankine cycle Plants and around the same efficiency of a combined gasification, solid oxide fuel cells and micro gas turbine Plant.
Khalid Rashid - One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation and techno economic analysis of a concentrated solar power csp Plant Hybridized with both thermal energy storage and natural gas
Journal of Cleaner Production, 2020Co-Authors: Khalid Rashid, Kasra Mohammadi, Kody M PowellAbstract:Abstract The addition of thermal energy storage and natural gas as a complementary energy source improves the flexibility, reliability, and value of concentrated solar power (CSP) Plants. Nevertheless, due to the transient nature of solar energy, transitions from solar-only mode and natural-gas mode to Hybrid solar-natural gas mode is quite challenging, especially when the Plant is equipped with thermal storage. Thus, it is important to develop proper dynamic modeling and control schemes to accurately simulate such transitions. The objective of this study is to address this subject by demonstrating a dynamic model with reliable control schemes for a highly integrated Hybrid parabolic trough-natural gas Plant equipped with thermal energy storage. The specific goal is to study the dynamics of adding thermal storage to the Hybrid Plant. It is found that the developed control schemes assist smooth transitions between different operational modes and effective utilization of thermal storage and natural gas to maintain steady power production and steam mass flow rates under different solar conditions. The results demonstrate that the integration of storage regulates power production by solar energy and natural gas during the day time. It also enables an increase in the solar fraction of the Hybrid Plant while it causes a small decrease in thermodynamic efficiency. The analysis shows that the Hybrid Plant with the storage has a substantially lower specific CO2 emission (0.320 tonne/MWh) than single natural gas Plant (0.413 tonne/MWh) although it has a higher levelized cost of electricity ($86.32/MWh against $74.92/MWh). The Hybrid Plant with storage demonstrates a promising potential for reliable and clean production of electricity, although research and development should be conducted to lower its cost.
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designing flexibility into a Hybrid solar thermal power Plant by real time adaptive heat integration
2019Co-Authors: Khalid Rashid, Kevin Ellingwood, Seyed Mostafa Safdarnejad, Kody M PowellAbstract:Abstract This study presents the concept of flexible heat integration (FHI) applied to a concentrated solar power (CSP)-natural gas Hybrid power Plant and employing non-linear real-time optimization (RTO) to leverage the FHI concept. In a conventional CSP Plant driven by a trough collector, solar energy is dispatched in series to heat sinks at decreasing temperature. FHI dispatches solar energy to the heat sinks within the power Plant based upon ambient conditions, rather than always in series. During times of low solar activity, solar energy bypasses the steam generator and is dispatched directly to the preheater. A nonlinear optimization capitalizes on this flexible operation and establishes different collection temperature set points based upon the availability of solar power. This mechanism enables the Plant to mitigate radiative heat losses of low-grade solar power, as observed when heat is only utilized at high temperature and in series. Applying FHI and RTO increases the solar fraction by 18.2% and the solar-to-electric efficiency by 15.5%. These results indicate the potential of significant improvement of solar power production in a Hybrid Plant by leveraging the benefits of RTO and FHI. Compared to a solar only power Plant, the combination of the Hybrid design, FHI, and RTO nearly doubles the amount of solar power produced.
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leveraging energy storage in a solar tower and combined cycle Hybrid power Plant
Energies, 2018Co-Authors: Kevin Ellingwood, Khalid Rashid, Seyed Mostafa Safdarnejad, Kody M PowellAbstract:A method is presented to enhance solar penetration of a Hybrid solar-combined cycle power Plant integrated with a packed-bed thermal energy storage system. The Hybrid Plant is modeled using Simulink and employs systems-level automation. Feedback control regulates net power, collector temperature, and turbine firing temperature. A base-case Plant is presented, and Plant design is systematically modified to improve solar energy utilization. A novel recycling configuration enables robust control of collector temperature and net power during times of high solar activity. Recycling allows for improved solar energy utilization and a yearly solar fraction over 30%, while maintaining power control. During significant solar activity, excessive collector temperature and power setpoint mismatch are still observed with the proposed recycling configuration. A storage bypass is integrated with recycling, to lower storage charging rate. This operation results in diverting only a fraction of air flow to storage, which lowers the storage charging rate and improves solar energy utilization. Recycling with a storage bypass can handle larger solar inputs and a solar fraction over 70% occurs when following a drastic peaking power load. The novel Plant configuration is estimated to reduce levelized cost of the Plant by over 4% compared to the base-case Plant.
