Hierarchical control for the start-up procedure of solar thermal fields with direct storage

Abstract Thermal energy storage tanks are habitually combined with solar thermal fields to improve the dispatchability of these facilities. From the dynamical point of view, the start-up phase is relevant since if the storage device is unloaded in terms of energy or widely stratified, the transitory regime can take long time until reaching the operating point. In this paper, an optimal real-time procedure based on a hierarchical controller for improving the start-up phase is proposed. The hierarchical controller is composed of two layers based on a Model Predictive Control (MPC) technique and Proportional Integer Derivative (PID) controllers. Real experimental tests were performed in a pilot facility located at Plataforma Solar de Almeria (Almeria, Spain). In addition, a comparison in simulation with the typical manual procedure and with two techniques proposed previously in the literature for the same plant is provided. The results demonstrate the benefits obtained by using the proposed method; since it reduces the start-up phase in 34 [min] in comparison with the manual operation, and in 26 and 6 [min] with respect to the two previous techniques.

[1]  Manuel G. Ortega,et al.  Control Óptimo Aplicado a Campos de Colectores Solares Distribuidos , 2018, Revista Iberoamericana de Automática e Informática industrial.

[2]  F. Dinter,et al.  Operability, Reliability and Economic Benefits of CSP with Thermal Energy Storage: First Year of Operation of ANDASOL 3☆ , 2014 .

[3]  Marko Bacic,et al.  Model predictive control , 2003 .

[4]  Lingai Luo,et al.  Thermal energy storage systems for concentrated solar power plants , 2017 .

[5]  L. Ricardez‐Sandoval,et al.  Optimal Start-Up Policies for a Solar Thermal Power Plant , 2018 .

[6]  M. Berenguel,et al.  Solar field control for desalination plants , 2008 .

[7]  Manuel Berenguel,et al.  Hierarchical Control of a Distributed Solar Collector Field , 2005, EUROCAST.

[8]  Torsten Fransson,et al.  Reducing the Number of Turbine Starts in Concentrating Solar Power Plants Through the Integration of Thermal Energy Storage , 2013 .

[9]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[10]  Julio Usaola,et al.  Operation of concentrating solar power plants with storage in spot electricity markets , 2012 .

[11]  Elias K. Stefanakos,et al.  Thermal energy storage technologies and systems for concentrating solar power plants , 2013 .

[12]  J. D. Gil,et al.  A feedback control system with reference governor for a solar membrane distillation pilot facility , 2018 .

[14]  Francesco Casella,et al.  Design of CSP plants with optimally operated thermal storage , 2015 .

[15]  Eduardo F. Camacho,et al.  Optimal operation in solar trough plants: A case study , 2013 .

[16]  José Domingo Álvarez,et al.  A practical NMPC with robustness of stability applied to distributed solar power plants , 2013 .

[17]  Manuel Berenguel,et al.  Gain-scheduling model predictive control of a Fresnel collector field , 2019, Control Engineering Practice.

[18]  María José Montes,et al.  Energy management in solar thermal power plants with double thermal storage system and subdivided solar field , 2011 .

[19]  Eduardo F. Camacho,et al.  Control of dead-time processes , 2007 .

[20]  José Luis Guzmán,et al.  A Multivariable Controller for the Start-up Procedure of a Solar Membrane Distillation Facility , 2018 .

[21]  A. Hepbasli,et al.  An experimental study of solar thermal system with storage for domestic applications , 2018, Journal of Mechanical Engineering and Sciences.

[22]  Anil Kumar,et al.  A review on technology and promotional initiatives for concentrated solar power in world , 2018 .

[23]  R. De Keyser,et al.  The disturbance model in model based predictive control , 2003, Proceedings of 2003 IEEE Conference on Control Applications, 2003. CCA 2003..

[24]  Guillermo Zaragoza,et al.  Efficiency in the use of solar thermal energy of small membrane desalination systems for decentralized water production , 2014 .

[25]  Manuel Berenguel,et al.  Control of Solar Energy Systems , 2012 .

[26]  Manuel Berenguel,et al.  A Robust Adaptive Dead-Time Compensator with Application to A Solar Collector Field , 1998 .

[27]  Gregory J. Kolb.  Evaluation of Annual Performance of 2-Tank and Thermocline Thermal Storage Systems for Trough Plants , 2011 .

[28]  R. Bayón,et al.  Simulation and assessment of operation strategies for solar thermal power plants with a thermocline storage tank , 2014 .

[29]  Manuel Berenguel,et al.  Optimal operation of a Solar Membrane Distillation pilot plant via Nonlinear Model Predictive Control , 2018, Comput. Chem. Eng..

[30]  Francisco Rodríguez,et al.  Thermal comfort control using a non-linear MPC strategy: A real case of study in a bioclimatic building , 2014 .

[31]  Luisa F. Cabeza,et al.  Process integration of thermal energy storage systems – Evaluation methodology and case studies , 2018, Applied Energy.

[32]  Francesco Casella,et al.  Optimal Operation of Solar Tower Plants with Thermal Storage for System Design , 2014 .

[33]  J. Ji,et al.  A novel approach to thermal storage of direct steam generation solar power systems through two-step heat discharge , 2019, Applied Energy.

[34]  Johan Löfberg,et al.  YALMIP : a toolbox for modeling and optimization in MATLAB , 2004 .

[35]  José Domingo Álvarez,et al.  Nonlinear controllers for solar thermal plants: A comparative study , 2015 .

[36]  Francisco Rodríguez,et al.  Predictive Control with Disturbance Forecasting for Greenhouse Diurnal Temperature Control , 2011 .

[37]  Julio E. Normey-Rico,et al.  A PRACTICAL APPROACH TO PREDICTIVE CONTROL FOR NONLINEAR PROCESSES , 2007 .

[38]  M. Valdés,et al.  Innovative thermal storage strategies for Fresnel-based concentrating solar plants with East-West orientation , 2018, Applied Energy.