Solar Field Quality Control and Optimization for Solar Field Installation Parabolic Trough Collector Solar Field Eckhard Lüpfert CSP Services GmbH Concentrating Solar Power Services K.A.CARE, Riyadh, 19 th November 2013
Solar Thermal Power Plant e.g. 50 MW Parabolic Trough Field Industrial scale on-site assembly from steel parts specific components high geometry requirements to reach optical performance combination of pre-fabrication, tooling and accuracy typically 4 000-8 000 collector modules, 200 000 mirrors, 22 000 receiver tubes outcome is crucial for solar field performance
Peak efficiency of parabolic trough collector field current state of the art solar irradiance DNI cosine effects IAM shading/ blocking reflectance end losses cleanliness reflector intercept factor bellows, supports transmittance of glass cleanliness glass absorptance degradation OPTICAL EFFICIENCY Receiver thermal loss Piping thermal loss Overall Field Efficiency 100% 100% 100% 99.0% 92.1% 92.1% 91.1% 88.4% 84.9% 81.5% 80.7% 76.6% 76.6% 76.6% 71.3% 66.3% 66.3% 93% 100% 100% 100% 99% 100% 99% 97% 96% 96% 95% 93% 93% 99% 100%
Quality criterion: Total Beam Spread σ total example standard quality Mirror Shape* Beam Spread Mirror Support* Absorber Position Collector Torsion (Loads) Module Alignment Tracking Accuracy Sun 20% 7% 7% 2% 6% 17% 41% 0% σ in mrad a i σ² in mrad Mirror Shape* 2.5 25 Beam Spread 0.2 0.04 Mirror Support* 1.6 10.24 Absorber Position 2 4 Collector Torsion (Loads) 1 1 Module Alignment 2 4 Tracking Accuracy 2 4 Sun 3.5 12.25 Total 7.8 60.53 Intercept Factor 96.0%
Quality criterion: Total Beam Spread σ total example high quality Mirror Shape* Beam Spread Mirror Support* Absorber Position Collector Torsion (Loads) Module Alignment Tracking Accuracy Sun 32% 3% 6% 2% 6% 10% 41% 0% σ in mrad a i σ² in mrad Mirror Shape* 2 16 Beam Spread 0.2 0.04 Mirror Support* 1 4 Absorber Position 1.5 2.25 Collector Torsion (Loads) 1 1 Module Alignment 1.5 2.25 Tracking Accuracy 1 1 Sun 3.5 12.25 Total 6.24 38.79 Intercept Factor 98.7%
Intercept function EuroTrough collector 1.00 Intercept factor γ 0.95 0.90 0.85 0.80 0.75 0 2 4 6 8 10 12 14 σ total in mrad σ 2 total = σ 2 sun + σ 2 optical
Concentrator Specification Performance depends on optical and geometric properties under operating conditions. Optical parameters (e.g. reflectance, absorptance) are well known specifications with increasing level of harmonization for components. Geometric properties and their effect on optical efficiency (intercept factor) at component level distances, angular tolerances, mirror shape accuracy, tracking accuracy. Geometric specifications, influences of assembly accuracy, loads during operation and tracking deviations reasonably range of 1-3 mrad Individual effects can be treated as independent and often normal distributed, which allows classic statistical approaches for optimization and quality control strategies.
Quality Control for Collector Geometry Collector components (series products, require specifications/ standards and regular controls) curved mirrors vacuum receivers Collector design (to be checked on prototypes / test installations) geometry, mechanical properties, mechanical components Steel parts with relevance for geometry mirror support arms etc. Assembly steps collector module module alignment to drive center of gravity
Relevant Criteria in Checking Procedure Module reference mirror alignment receiver alignment Collector reference alignment between modules and drive in all collector angles receiver torque transfer reflector
Testing options production integrated in collaboration with contractor photogrammetric or laser tracker (before mirror assembly) deflectometric (with mirrors) final quality control shape measurements in solar field includes all components, assembly and alignment requires specific manual measurements (expert team) checking frequency can be adapted to needs high frequency at beginning, decreasing if good results
Test performance focusing quality in mm (FDx) from: Deflectometry (TARMES) and Receiver Alignment Additional measurement of module alignment collector torsion over operation range Evaluation criteria shape quality parameter (SDx, FDx) intercept factor Final control flux maps thermal performance
Requirement for effective quality control specifications for the contractor preparation time quality control plan possible inline controls search for the unexpected actions, corrections if required collaboration with contractor
Quality Assurance of Concentrator Structures: CSPS Photogrammetric Measurement System QFoto Automatic in-line production quality assurance of collector structures with QFoto Based on close-range photogrammetry Including evaluation and assessment software (failed/passed) to optimize and document production quality Database allows for timeline evaluations and statistics of all collectors produced
QFoto Photogrammetry in Trough Production Line Quality Control Sheet Example
Production Quality Assurance of Concentrator Mirrors: Deflectometric Measurement System QDec Automatic production quality assurance of concentrator mirrors with QDec High-resolution, optical measurement system based on deflectometry Including evaluation and assessment software (failed/passed) to optimize and document production quality
QDec Deflectometric Measurement System Quality Control in Mirror and Module Production Automatic production quality assurance of concentrator mirrors with QDec High-resolution, optical measurement system based on deflectometry Including evaluation and assessment software (fail/pass) to optimize and document production quality
QDec Flexible Application for all Types of Concentrator Dishes Heliostats Panels (Fresnel, Dishes, Parabolic Trough)
Trough Modules Shape Measurement in Field with Deflectometry Slope Deviation in mrad Local Intercept Factor in %
CSP Services/DLR Quality Control Experience References 2004-2013 EuroTrough PSA SkalET, LS3 at KJC Andasol 1-3 Abengoa Sevilla Solnova, PSSM, Helioenergy, Helios, Shams, Solana, Mojave, Godawari, South Africa, Iberdrola Kuraymat, Ain Beni Mathar, Hassi R Mel Gossamer Samca Elecnor Solarlite Sener Siemens Shikun Binui FPL Nextera Fichtner, Lahmeyer Flabeg, Rioglass, Saint-Gobain, Guardian, TG, SynergX
Quality control after successful optimization