Transient simulation of a parabolic trough collector in EBSILON®PROFESSIONAL

Abstract

The transient effects during the start up process of a solar field play an important role for its overall performance. With the combination of sophisticated collector models and transient calculations in EBSILON®Professional, it will be possible to optimize the individual systems of a CSP-plant (thermal storage system, supplementary firing, collector field and power block) and to select the right control strategy for the system. In a first application, the new functionality is applied to the start-up procedure of a parabolic trough power plant with molten salt as heat transfer fluid. Results show that the process can be well represented by the model. Based on the generated reference start-up strategy improved strategies are going to be identified. Taking into account the transient effects of start up processes and fluctuations caused by weather conditions can also improve or verify the performance models nowadays used for annual return calculations. There are a number of issues to be solved in the near future to enable fully transient simulation capabilities. One constant heat transfer coefficient for the whole length of the tube could be replaced by a vector of automatically calculated coefficients, based on the Reynolds and Prandtl Number of each fluid element. The lack of PID-type controllers in EBSILON®Professional makes it for now very complicated to apply control strategies to the transient model.