Title Temperature homogenization of a solar trough field for performance improvement
Authors Sanchez, A. J., Gallego, A. J., ESCAÑO GONZÁLEZ, JUAN MANUEL, Camacho, E. F., ESCAÑO GONZÁLEZ, JUAN MANUEL
External publication No
Means Sol. Energy
Scope Article
Nature Científica
JCR Quartile 1
SJR Quartile 1
JCR Impact 4.67400
Area International
Web https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043277738&doi=10.1016%2fj.solener.2018.03.001&partnerID=40&md5=5e9c93c2a8cdc7940017a9cae717ca8c
Publication date 01/05/2018
ISI 000430778100001
Scopus Id 2-s2.0-85043277738
DOI 10.1016/j.solener.2018.03.001
Abstract Optimal operation of solar plant is a challenge due to the multiple disturbances affecting the plant. Research in optimal temperature set-point tracking is extensive whereas research concerning optimal power production under disturbances is not. A solar plant has to deal not only with temperature and radiation disturbances but also with dirt accumulated on the collectors which lead to a great disparity in collectors reflectivity. Cleaner collectors produce higher output temperature because of the higher reflectivity. In fact the temperature in this collector may be so high that they have to be defocused with the corresponding energy losses. The paradox is that the most efficient loops may be the one collecting less energy because of defocusing. This paper proposes a new solution based in the manipulation of the loops input valves in order to homogenize the temperatures of the different loops and avoid defocusing. The paper presents an original non linear model based optimization to homogenize the loop temperatures by manipulating the inlet valves of the loops. The nonlinear model is based on a distributed parameters model. In order to perform the optimization, temperature profiles of the loops and its reflectivities are needed. These are obtained by means of a Classification and Regression Trees (CARTs) trained with the full distributed parameters model. Simulations are carried out using a model of the Plataforma Solar de Almeria (PSA) solar trough plant to show the results of the proposed control scheme, temperature homogenization and production benefit.
Keywords Online nonlinear optimization; Model Predictive Control; Solar trough; Regression Trees
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