Automated High Resolution Measurement of Heliostat Slope Errors

A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one minute per heliostat. The system is completely automated and allows the automatic measurement of an entire heliostat field during one night. It was extensively tested at the CESA-1 heliostat field at the Plataforma Solar de Almería. Comparisons of flux simulations based on the measurement results with real flux density measurements were performed. They showed an excellent agreement and demonstrated in a striking manner the high measurement accuracy and high grade of detail in the simulation achieved by this technique

AUTOMATED HIGH RESOLUTION MEASUREMENT OF HELIOSTAT SLOPE ERRORS

A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one minute per heliostat. The system is completely automated and allows the automatic measurement of an entire heliostat field during one night. It was extensively tested at the CESA-1 heliostat field at the Plataforma Solar de Almería. Comparisons of flux simulations based on the measurement results with real flux density measurements were performed. They showed an excellent agreement and demonstrated in a striking manner the high measurement accuracy and high grade of detail in the simulation achieved by this technique

Betriebsoptimierung von Turmkraftwerken: Optimierung der Heliostatzielpunkte unter Berücksichtigung des thermischen Receiververhaltens

Im Bereich der Solarforschung des DLR in Köln werden zur Analyse und Optimierung von solarthermischen Turmkraftwerken Softwarewerkzeuge entwickelt. Eine wichtige Optimierungsfrage ist die Wahl der Heliostatzielpunkte auf dem Receiver. Anhand von realistischen Simulationsszenarien wird der Einfluss der Zielpunktkonfiguration auf das Leistungsverhalten eines offenen volumetrischen Receivers untersucht

Messtechnik zur Qualitätssicherung und Betriebsoptimierung solarer Turmkraftwerke

Im Projekt SAPHIR wurden optische Messsysteme zur Unterstützung bei der Heliostat-Prototypen-Entwicklung, bei der Facetten- und Heliostat-Montage und zur Endabnahme von Heliostatenfeldern für solare Turmkraftwerke entwickelt. Diese Systeme beruhen auf photogrammetrischen und deflektometrischen Methoden. Zudem wurden zur Überwachung einer optimierten Betriebsstrategie eine neue Methode zur Flussdichtemessung auf offenen volumetrischen Receivern entwickelt und Temperaturmessungen (Infrarot-Thermografie) an einem Testreceiver durchgeführt. Zusätzlich wurde ein System zum Monitoring der Heliostat-Ausrichtung entwickelt. Ein neues Raytracing-Programm zur Verarbeitung hochaufgelöster Heliostatdaten dient sowohl zur Bewertung der Ergebnisse der optischen Messsysteme als auch zur Ermittlung optimierter Betriebsstrategien unter Berücksichtigung realer Heliostatfelddaten

Simulation solarer Turmsysteme

Solare Turmkraftwerke sind komplexe optische Systeme mit einer hohen Anzahl an Freiheitsgraden. Zur Auslegung und Optimierung werden daher computergestützte Simulationsmodelle verwendet. Die typischen Fragestellungen sind Feldauslegung und –optimierung, Receiverauslegung, Analyse des Betriebsverhaltens und Betriebsoptimierung. Im DLR wird eine Reihe von Simulationswerkzeugen verwendet, die auf unterschiedlichen Modellansätzen basieren. Die wichtigsten Eigenschaften dieser Programme und typische Anwendungsbeispiele werden präsentiert

Modeling and Simulation of a Solar Tower Power Plant with Open Volumetric Air Receiver

The start-up of the PS10 power plant in Seville, Spain, in 2007 marked the entrance of solar tower power plants into the commercial state. Questions about the right operational strategy, particularly during unsteady operation states, come to the fore, and therewith the need to carry out transient simulations of entire tower power plants including the heliostat field. Meeting this necessity, the presented simulation approach opens the way to transient full plant simulations of solar tower power plants. A detailed heliostat field model was linked to a dynamic receiver model by coupling both simulation tools. A second coupling was established to a tool hosting a control panel of the heliostat field model. With this simulation approach, a start-up procedure and a tracking stop were simulated delivering different transient behaviors of local absorber temperatures and mass flows

TRANSIENT SIMULATION OF SOLAR TOWER POWER PLANT WITH OPEN VOLUMETRIC AIR RECEIVER

The start up of the PS 10 power plant in Seville, Spain, in 2007 marked the entrance of solar power tower plants into the commercial state. Questions about the right operational strategy, particularly during unsteady operation states, come to the fore, and therewith the need to carry out transient simulations of entire power tower plants including the heliostat field. Meeting this necessity the presented simulation approach opens the way to transient full plant simulations of solar power tower plants. A detailed heliostat field model was linked to a dynamic receiver model by coupling both simulation tools. A second coupling was established to a tool hosting a control panel of the heliostat field model. With this simulation approach a startup procedure and a tracking stop were simulated delivering different transient behaviors of local absorber temperatures and mass flows

Optimization of Heliostat Aim Point Selection for Central Receiver Systems Based on the Ant Colony Optimization Metaheuristic

The optimization of the selection of heliostat aim points in a solar power tower plant with the objective of an increased overall efficiency represents a NP-hard optimization problem of high dimension. This paper presents a universal procedure for the purpose of aim point optimization based on the ant colony optimization metaheuristic that uses the principles of swarm intelligence. The applicability of the developed aim point optimization procedure to central receiver systems is demonstrated on a test case, for which the electrical power of a concentrated photovoltaic (CPV) receiver is maximized for a selected operating point. The example of a CPV receiver was chosen due to its nonlinear and nonmonotonous dependency of efficiency and flux density. It is shown that the optimization result is very close to the theoretical maximu