TY  - JOUR
A1  - Schwager, Christian
A1  - Flesch, Robert
A1  - Schwarzbözl, Peter
A1  - Herrmann, Ulf
A1  - Teixeira Boura, Cristiano José
T1  - Advanced two phase flow model for transient molten salt receiver system simulation
JF  - Solar Energy
N2  - In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed.
KW  - Molten salt solar tower
KW  - Molten salt receiver system
KW  - Dynamic simulation
KW  - Two-phase modelling
KW  - Transient flux distribution
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.solener.2021.12.065
SN  - 0038-092X (print)
SN  - 1471-1257 (online)
VL  - 232
SP  - 362
EP  - 375
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Schwager, Christian
A1  - Angele, Florian
A1  - Nouri, Bijan
A1  - Schwarzbözl, Peter
A1  - Teixeira Boura, Cristiano José
A1  - Herrmann, Ulf
T1  - Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation
T2  - SolarPACES conference proceedings
N2  - Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted.
KW  - Process prediction
KW  - DNI forecasting
KW  - Nowcasting
KW  - Uncertainty analysis
KW  - Molten salt receiver system,
Y1  - 2024
U6  - http://dx.doi.org/10.52825/solarpaces.v1i.675
SN  - 2751-9899 (online)
N1  - 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA
IS  - Vol. 1
PB  - TIB Open Publishing
CY  - Hannover
ER  -