1. www.DLR.de Chart 1> IRES 2012> Breuer > 14.11.2012 Development of a solar driven tube receiver to superheat steam for the high temperature electrolysis Stefan Breuer, Dennis Thomey DLR Institute for Solar research

2. Content www.DLR.de Chart 2> IRES 2012> Breuer > 14.11.2012 1.Overview 2.Designstudy 3.Thermal balancing 4.Constructing and assembling the receiver 5.Outlook

3. Overview Overall Process Development and experimental analysis of a solar receiver in the DLR high flux solar simulator Techno-economic analysis: Flowsheeting and simulation of a MW-scale facility. 2012-14 2011-14 www.DLR.de Chart 3> IRES 2012> Breuer > 14.11.2012

4. Overview Motivation (HTE) www.DLR.de Chart 4> IRES 2012> Breuer > 14.11.2012 -Electrical energy demand drops -Heat demand rises -Total demand rises very few -Overall efficiency improves at higher temperature

5. www.DLR.de Chart 5 Overview Solarsimulator -Solar Simulator in Cologne -10 Xenon Lamps -Max. peak power output at 36 kW -90% radiation hits target of 9 cm -Max solar flux density ~5 MW/m² -Implementing a shutter system for flux control > IRES 2012> Breuer > 14.11.2012

6. www.DLR.de Chart 6 Designstudy volumetric and tubular differences > IRES 2012> Breuer > 14.11.2012 Volumetric ReceiverTubular Receiver Open system: window needed Sealing problems with window Extrusion of monolith structure SiSiC Structure Closed system: no window needed Lots of tube connectors Use of standard parts (tubes) High temperature steel/alloy

7. www.DLR.de Chart 7 Thermal balancing geometrical layout - integral calculation > IRES 2012> Breuer > 14.11.2012 1 2 3

8. www.DLR.de Chart 8 -Segmentation into 10 ringelements -View factors calculated by MATLAB ® -Wall temperature calculation via ray tracing (OptiCAD ® ) -Convectional heat transfer onto fluid per ringelement -Radiation heat exchange calculation -Implementing a flux-density controller (shutter-system) Thermal balancing thermal layout - differential calculation > IRES 2012> Breuer > 14.11.2012 1 2.12.22.32.42.n 3 2

9. www.DLR.de Chart 9 -Raytracing executed by OptiCAD -Implemented solar simulator data -Division of wall into 10 ringelements with each 40 segments -Summation of incoming power per ringelement -Focus distance variation for optimized usage of incoming radiation Thermal balancing calculation methods - ray tracing > IRES 2012> Breuer > 14.11.2012

10. www.DLR.de Chart 10 Thermal balancing Thermal balancing - focus variation for incoming power > IRES 2012> Breuer > 14.11.2012

11. www.DLR.de Chart 11 Thermal balancing calculation methods - heat transfer > IRES 2012> Breuer > 14.11.2012

12. www.DLR.de Chart 12 Designing a test receiver for use in the Thermal balancing - variation of mass flow (example calculation) > IRES 2012> Breuer > 14.11.2012

13. www.DLR.de Chart 13 -Construction was carried out in a 3D CAD system -Material research for high temperature steel (1.4841) -Insulation material used for building the cavity (Al 2 O 3 ) -Implementing the measurement sensors for temperature & pressure -Programming a controlling system with LabView ® Constructing and assembling Engingeering - construction & development > IRES 2012> Breuer > 14.11.2012

14. www.DLR.de Chart 14 Constructing and assembling Engingeering - assembling the receiver for solar simulator > IRES 2012> Breuer > 14.11.2012 Solar radiation Steam inlet Steam outlet Thermocouples Pressure measurement

15. www.DLR.de Chart 15 -Thermal test campains will be executed in november and december -Bilancing of the existing system with experimental data -Optimizing the system with experimental results -Build a full high temperature electrolysis cycle -Improve the receiver and rebuild it with newly adapted data Outlook > IRES 2012> Breuer > 14.11.2012

16. www.DLR.de Chart 16 Thank you for your attention! Solar driven tubular heat exchanger > IRES 2012> Breuer > 14.11.2012