Thermocline thermal storages are widely used in energy systems. Computational Fluid Dynamic (CFD) can be used for an accurate simulation of the physical phenomenon but its implementation in system-level annual simulations is hardly possible because of the huge computational time required. The present paper proposes a novel approach for the utilization of CFD simulation results in system-level annual simulations and optimizations. An analytical function able to represent the dimensionless vertical temperature profile inside the tank is parameterized statistically using the results of multiple simulations of a CFD model, which have been previously validated with experimental data. The reduced model obtained is then compared to other CFD simulations under highly variable conditions, showing a satisfactory degree of agreement (the mean absolute error and the error standard deviation are calculated to be 1.52 K and 1.93 K respectively). Furthermore, it is demonstrated that this approach can be conveniently adopted for the modeling of a wide range of systems with a single tank thermal energy storage, from Concentrated Solar Power to District Heating. © 2014 Elsevier Ltd.
CFD-based reduced model for the simulation of thermocline thermal energy storage systems
Donato, F.
2015-01-01
Abstract
Thermocline thermal storages are widely used in energy systems. Computational Fluid Dynamic (CFD) can be used for an accurate simulation of the physical phenomenon but its implementation in system-level annual simulations is hardly possible because of the huge computational time required. The present paper proposes a novel approach for the utilization of CFD simulation results in system-level annual simulations and optimizations. An analytical function able to represent the dimensionless vertical temperature profile inside the tank is parameterized statistically using the results of multiple simulations of a CFD model, which have been previously validated with experimental data. The reduced model obtained is then compared to other CFD simulations under highly variable conditions, showing a satisfactory degree of agreement (the mean absolute error and the error standard deviation are calculated to be 1.52 K and 1.93 K respectively). Furthermore, it is demonstrated that this approach can be conveniently adopted for the modeling of a wide range of systems with a single tank thermal energy storage, from Concentrated Solar Power to District Heating. © 2014 Elsevier Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.