www.dlr.de chart 1> ires 2012> breuer > 14.11.2012 development of a solar driven tube...
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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
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
OverviewOverall 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
HT-Elektrolysis
Solar-receiver
Steam600-700 °C
H2
O2
Heat recovery
H2O
H2
O2
OverviewMotivation (HTE)
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- Electrical energy demand drops
- Heat demand rises
- Total demand rises very few
- Overall efficiency improves at higher temperature
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OverviewSolarsimulator
- 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
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Designstudyvolumetric and tubular differences
> IRES 2012> Breuer > 14.11.2012
Volumetric Receiver Tubular Receiver
Open system:
window neededSealing problems with
window
Extrusion of
monolith structureSiSiC Structure
Closed system:
no window needed
Lots of tube connectors
Use of standard parts
(tubes)High temperature steel/alloy
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- Calculation of an integral system
- Front (1) is open
- Assumption of wall temperature
- Calculate the radiation of side (2) and back (3) to the front
- Viewfactor calculation by VDI-Heatatlas
- Calculation of needed power for backradiation and fluid heating
- Cylinder has good radiation and constructing properties
Thermal balancinggeometrical layout - integral calculation
> IRES 2012> Breuer > 14.11.2012
1
2
3
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- 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 balancingthermal layout - differential calculation
> IRES 2012> Breuer > 14.11.2012
1
2.1 2.2 2.3 2.4 2.n
3
2
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- 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 balancingcalculation methods - ray tracing
> IRES 2012> Breuer > 14.11.2012
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Thermal balancingThermal balancing - focus variation for incoming power
> IRES 2012> Breuer > 14.11.2012
1 2 3 4 5 6 7 8 9 100
500
1000
1500
2000
2500
3000
-20 mm
-10 mm
0 mm
10 mm
20 mm
40 mm
60 mm
80 mm
Ringelement [-]
inco
min
g p
ow
er
[W]
1 2 3 4 5 6 7 8 9 100
500
1000
1500
2000
2500
3000
-20 mm
-10 mm
0 mm
10 mm
20 mm
40 mm
60 mm
80 mm
Ringelement [-]
inco
min
g p
ow
er
[W]
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- Convectional heat transfer calculation by Nusselt-correlation VDI-HA
- Logarithmic average temperature depends on walltemperature
- Wall temperature depends on incoming power and radiation
- Radiation heat transfer
Thermal balancingcalculation methods - heat transfer
> IRES 2012> Breuer > 14.11.2012
-1 1 3 5 7 9 113.5E+02
4.5E+02
5.5E+02
6.5E+02
7.5E+02
8.5E+02
9.5E+02
1.1E+03
Fluid outlet temperature
1 kg/h
2 kg/h
3 kg/h
4 kg/h
5 kg/h
6 kg/h
7 kg/h
Ringelements [-]
Tem
per
atu
re [
K]
0 2 4 6 8 100.0E+00
2.0E+01
4.0E+01
6.0E+01
8.0E+01
1.0E+02
1.2E+02
1.4E+02
1.6E+02
1.8E+02
Heat transfer coefficient
1 kg/h
2 kg/h
3 kg/h
4 kg/h
5 kg/h
6 kg/h
7 kg/h
Ringelements [-]
hea
t tr
ansf
er c
oef
fici
ent
[W/m
²K]
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Designing a test receiver for use in the Thermal balancing - variation of mass flow (example calculation)
> IRES 2012> Breuer > 14.11.2012
0 2 4 6 8 107.0E+02
8.0E+02
9.0E+02
1.0E+03
1.1E+03
1.2E+03
1.3E+03
Lateral wall temperature
1 kg/h
2 kg/h
3 kg/h
4 kg/h
5 kg/h
6 kg/h
7 kg/h
Ringelements [-]
Tem
per
atu
re [
K]
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- Construction was carried out in a 3D CAD system
- Material research for high temperature steel (1.4841)
- Insulation material used for building the cavity (Al2O3)
- Implementing the measurement sensors for temperature & pressure
- Programming a controlling system with LabView®
Constructing and assemblingEngingeering - construction & development
> IRES 2012> Breuer > 14.11.2012
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Constructing and assemblingEngingeering - assembling the receiver for solar simulator
> IRES 2012> Breuer > 14.11.2012
Solar radiation Steam inletS
team outlet
Thermocouples
Pressure measurement
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- 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
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Thank you for your attention!
Solar driven tubular heat exchanger
> IRES 2012> Breuer > 14.11.2012