The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
J F Hoffmann - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of a 50 mwe parabolic trough power plant integrating a Thermocline storage tank
Energy Conversion and Management, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract A simulation of a 50 MWe power plant with Thermocline tank as storage shows that there is no deterioration of the Thermocline performance with cycling (successive charges and discharges), because no temperature threshold has to be taken into account during charges. Indeed, the best control strategy when the Thermocline outlet fluid temperature increases during charge is defocusing a part of the solar field to avoid the heat transfer fluid overheating. Thus, Thermocline tank can be fully charged during summer days. During winter days, if there is not enough energy to perform a full charge, cycling effect does not occur because the remaining energy after partial discharge implies a more important state of charge for the following day. Finally, the comparison between Thermocline and two-tank technologies shows that oversizing the Thermocline tank by 11% leads to equivalent electricity production, for a lower cost (at least 22.3%).
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a temperature threshold evaluation for Thermocline energy storage in concentrated solar power plants
Applied Energy, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract Regarding energy storage in concentrated solar power plants, Thermocline technology is considered to be a cost effective but less efficient solution than conventional two-tank. However, Thermocline storage charge and discharge are usually stopped when the varying outlet temperature reaches an arbitrarily chosen value. It is shown here that the stop of the Thermocline charge depends on the overheating risk in the solar collectors, while the stop of the discharge is defined by the steam generator requirements. As a consequence, the temperature thresholds that must be defined by the experimental constraints are dynamic. Using these dynamic thresholds on an experimental setup comprising a 230 kWh Thermocline tank and a 150 kWth parabolic trough solar field led to a charge efficiency of 95.7% and a 93.5% discharge efficiency. Thus, the varying outlet temperature of a Thermocline storage system is not an issue when integrated in a concentrated solar power plant.
Thomas Fasquelle - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of a 50 mwe parabolic trough power plant integrating a Thermocline storage tank
Energy Conversion and Management, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract A simulation of a 50 MWe power plant with Thermocline tank as storage shows that there is no deterioration of the Thermocline performance with cycling (successive charges and discharges), because no temperature threshold has to be taken into account during charges. Indeed, the best control strategy when the Thermocline outlet fluid temperature increases during charge is defocusing a part of the solar field to avoid the heat transfer fluid overheating. Thus, Thermocline tank can be fully charged during summer days. During winter days, if there is not enough energy to perform a full charge, cycling effect does not occur because the remaining energy after partial discharge implies a more important state of charge for the following day. Finally, the comparison between Thermocline and two-tank technologies shows that oversizing the Thermocline tank by 11% leads to equivalent electricity production, for a lower cost (at least 22.3%).
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a temperature threshold evaluation for Thermocline energy storage in concentrated solar power plants
Applied Energy, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract Regarding energy storage in concentrated solar power plants, Thermocline technology is considered to be a cost effective but less efficient solution than conventional two-tank. However, Thermocline storage charge and discharge are usually stopped when the varying outlet temperature reaches an arbitrarily chosen value. It is shown here that the stop of the Thermocline charge depends on the overheating risk in the solar collectors, while the stop of the discharge is defined by the steam generator requirements. As a consequence, the temperature thresholds that must be defined by the experimental constraints are dynamic. Using these dynamic thresholds on an experimental setup comprising a 230 kWh Thermocline tank and a 150 kWth parabolic trough solar field led to a charge efficiency of 95.7% and a 93.5% discharge efficiency. Thus, the varying outlet temperature of a Thermocline storage system is not an issue when integrated in a concentrated solar power plant.
Quentin Falcoz - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of a 50 mwe parabolic trough power plant integrating a Thermocline storage tank
Energy Conversion and Management, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract A simulation of a 50 MWe power plant with Thermocline tank as storage shows that there is no deterioration of the Thermocline performance with cycling (successive charges and discharges), because no temperature threshold has to be taken into account during charges. Indeed, the best control strategy when the Thermocline outlet fluid temperature increases during charge is defocusing a part of the solar field to avoid the heat transfer fluid overheating. Thus, Thermocline tank can be fully charged during summer days. During winter days, if there is not enough energy to perform a full charge, cycling effect does not occur because the remaining energy after partial discharge implies a more important state of charge for the following day. Finally, the comparison between Thermocline and two-tank technologies shows that oversizing the Thermocline tank by 11% leads to equivalent electricity production, for a lower cost (at least 22.3%).
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a temperature threshold evaluation for Thermocline energy storage in concentrated solar power plants
Applied Energy, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract Regarding energy storage in concentrated solar power plants, Thermocline technology is considered to be a cost effective but less efficient solution than conventional two-tank. However, Thermocline storage charge and discharge are usually stopped when the varying outlet temperature reaches an arbitrarily chosen value. It is shown here that the stop of the Thermocline charge depends on the overheating risk in the solar collectors, while the stop of the discharge is defined by the steam generator requirements. As a consequence, the temperature thresholds that must be defined by the experimental constraints are dynamic. Using these dynamic thresholds on an experimental setup comprising a 230 kWh Thermocline tank and a 150 kWth parabolic trough solar field led to a charge efficiency of 95.7% and a 93.5% discharge efficiency. Thus, the varying outlet temperature of a Thermocline storage system is not an issue when integrated in a concentrated solar power plant.
Pierre Neveu - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of a 50 mwe parabolic trough power plant integrating a Thermocline storage tank
Energy Conversion and Management, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract A simulation of a 50 MWe power plant with Thermocline tank as storage shows that there is no deterioration of the Thermocline performance with cycling (successive charges and discharges), because no temperature threshold has to be taken into account during charges. Indeed, the best control strategy when the Thermocline outlet fluid temperature increases during charge is defocusing a part of the solar field to avoid the heat transfer fluid overheating. Thus, Thermocline tank can be fully charged during summer days. During winter days, if there is not enough energy to perform a full charge, cycling effect does not occur because the remaining energy after partial discharge implies a more important state of charge for the following day. Finally, the comparison between Thermocline and two-tank technologies shows that oversizing the Thermocline tank by 11% leads to equivalent electricity production, for a lower cost (at least 22.3%).
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a temperature threshold evaluation for Thermocline energy storage in concentrated solar power plants
Applied Energy, 2018Co-Authors: Thomas Fasquelle, Pierre Neveu, Quentin Falcoz, J F HoffmannAbstract:Abstract Regarding energy storage in concentrated solar power plants, Thermocline technology is considered to be a cost effective but less efficient solution than conventional two-tank. However, Thermocline storage charge and discharge are usually stopped when the varying outlet temperature reaches an arbitrarily chosen value. It is shown here that the stop of the Thermocline charge depends on the overheating risk in the solar collectors, while the stop of the discharge is defined by the steam generator requirements. As a consequence, the temperature thresholds that must be defined by the experimental constraints are dynamic. Using these dynamic thresholds on an experimental setup comprising a 230 kWh Thermocline tank and a 150 kWth parabolic trough solar field led to a charge efficiency of 95.7% and a 93.5% discharge efficiency. Thus, the varying outlet temperature of a Thermocline storage system is not an issue when integrated in a concentrated solar power plant.
Joseph Pedlosky - One of the best experts on this subject based on the ideXlab platform.
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Climate Variability of the Equatorial Thermocline Inferred from a Two-Moving-Layer Model of the Ventilated Thermocline*
Journal of Physical Oceanography, 2000Co-Authors: Rui Xin Huang, Joseph PedloskyAbstract:A two-moving-layer model is used to examine the structure of the equatorial Thermocline and its connection with the extratropical Thermocline. It is found that cooling (warming) in extratropics generates a low (high) potential vorticity anomaly and induces downward (upward) movement of the Thermocline, and the perturbation propagates to the equatorial Thermocline, inducing a downward (upward) movement of the Thermocline and intensification (weakening) of the undercurrent. Thus, surface cooling in the extratropics can induce warming of the equatorial Thermocline. In addition, the total mass flux in the subsurface layer in the extratropics and the equatorial undercurrent is enhanced. Although in the extratropics perturbations generated by localized cooling (warming) are confined within the characteristic cone, defined by the unperturbed trajectories of the Thermocline circulation, when these perturbations propagate into the equatorial region they are no longer confined by the characteristic cone in the meridional direction.
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Thermocline forced by annual and decadal surface temperature variation
Journal of Physical Oceanography, 1994Co-Authors: Zhengyu Liu, Joseph PedloskyAbstract:Abstract A two-layer Thermocline model is modified by adding an essentially passive mixed layer above it. The surface temperature variation is simulated by a moving outcrop line. It is found that, in contrast to a surface wind stress, a surface temperature variation causes strong variability in the ventilated zone through subducted water, while it affects the shadow zone little. Two types of buoyancy-forced solution are found. When the outcrop line moves slowly, the solutions are nonentrainment solutions. For these solutions, the surface beat flux is mainly balanced by the horizontal advection in the permanent Thermocline. The mixed layer never entrains. The time-mean Thermocline is close to the steady Thermocline with the time-mean outcrop line. When the outcrop line moves southward rapidly during the cooling season, the solutions become entrainment solutions. Now, deep vertical convection must occur because the horizontal advection in the permanent Thermocline is no longer strong enough to balance the s...
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A History of Thermocline Theory
Physical Oceanography, 1Co-Authors: Joseph PedloskyAbstract:The focus of my attention in this essay is to give the reader some insight into the development of the theoretical ideas concerning the Thermocline from the very personal point of view of someone involved in that development. It is not a review paper of the full scientific history of the subject or a detailed scientific discussion of the problem. Rather, I want to present the more personal side of the history of the attempt to reach an understanding of the phenomenon of the Thermocline. In that special sense this is a personal memoir of my involvement in that quest and I hope to capture the flavor of that experience for others. It culminated for me in the development of the theory of the Ventilated Thermocline, a theory that evolved in collaboration with Henry Stommel and Jim Luyten and so the story is one person’s view of what was a collegial effort. The presence of the Thermocline, the region of rapid increase of density with depth in the first one or two kilometers of the subtropical oceans, has been recognized for a long time. Yet looking back at the older literature it is hard to find a reference to the problem of the Thermocline, that is, in explaining the maintenance of this sharp density gradient or its cause. The Thermocline itself is bowl-shaped in the meridional plane and contains fairly entirely the wind-driven currents of the major subtropical gyres