Solar Thermal Power System for Lunar ISRU Processes

Transcription

1 VG Solar Thermal Power System for Lunar ISRU Processes T. Nakamura and C.L. Senior Physical Sciences Inc. Presented at Space Technology and Applications International Forum STAIF 2005 February 2005 Physical Sciences Inc. 20 New England Business Center Andover, MA 01810

2 Lunar ISRU Processes VG Oxygen propellant fuel cell life support system Metals structural materials storage vessels powdered metal for propulsion Construction materials ceramics, glass concrete radiation shielding building blocks

3 Solar Energy for Lunar Material Processing: Previous Concept VG Difficult to achieve ideal heating of process materials uneven heating uncontrolled heat flux Difficult to modularize limited scaling non-ideal process configuration

4 Optical Waveguide (OW) Solar Energy System VG

5 OW Solar Energy System: Features VG High concentration of solar flux (~10-4 suns) can be transmitted via flexible OW lines directly into thermal reactor Solar intensity or spectra can be tailored to specific material processing steps Provide solar energy inside of enclosures The system can be modularized and can be easily transported to and deployed at the lunar base The system can be applied to many material production processes

6 The Ground Test Model of the OW Solar Thermal Power System VG

7 Thermal Reactor for Hydrogen Reduction of JSC-1 VG

8 Thermal Reactor with Optical Fiber Cables VG

9 Inside of Thermal Reactor VG

10 Material Processing Container VG

11 Material Processing Experiment VG Hydrogen reduction of iluminite: FeTiO 3 + H 2 Fe + TiO 2 + H C ~ 1100 C Material sample: Lunar soil simulant (JSC-1) containing 3 wt% of iluminite Reaction detection: Absorption of a water line at 1.36 µm

12 Thermal Reactor Temperature versus Solar Power 1000 VG Temperature (ºC) /18/96 3/19/96 3/23/96, moly rad shields added 3/26/96 4/13/96, moly sleeve insert added 4/27/96 4/29/96 5/9/96 0 least square fit Power Input (W) D-3092

13 Hydrogen Reduction of Ilmenite (FiTiO 3 ) VG Reactor Temperature: 697 C Reactant: Ar+5%H 2 MassFlowRate: slpmatt=0 Sample Weight: 20 gram 5 4 Reactor Temperature: 775 C Reactant: Ar+5%H 2 Mass Flow Rate: 0.25 slpm at t=0 Sample Weight: 20 gram Water Vapor (ppm) Thousands 3 2 Water Vapor (ppm) Thousands Time (min) D-2470z Time (min) D-2471z

14 Hydrogen Reduction of JSC-1 VG Water Vapor (ppm) Thousands Extrapolation from NASA/JSC Data Reactor Temperature: 832 C Reactant: Ar+5%H 2 Sample Weight: 20 gram Mass Flow Rate: 0.25 slpm at t=0 Dotted Line: Least Squares Curve Fit D-2473a Time (min)

15 System Efficiency of the Engineering Model and the Future Space Based System VG Engineering Model Results Space- Based Operational System Improvement Measures Primary concentrator Reflectivity Intercept factor Reflectivity enhancing coating Intercept factor in space will be higher Concentrator fiber coupling Front-end Fresnel reflection Fiber fill factor Improve fiber cable front termination design for higher fill factor Optical fiber cable transmission (10 meter) Fiber transmission Back-end Fresnel reflection Use low-oh fiber for higher transmission efficiency System efficiency ~0.380 ~0.724

16 Achievable Temperature versus Solar Flux Intensity 4000 VG Receiver Temperature (K) Single Fiber Test Data (1999) NA = 0.44 NA = 0.37 Phase II Projection Phase I Data (2003) Material Processing Exp. Results (1996) Space System Projection NA = 0.37 NA = 0.48 Solar Thermal Propulsion Program Effective AM0 Concentration Ratio G-1837b

17 Optical Fiber Cables Emitting Solar Power VG

18 High Temperature Processes for Lunar ISRU VG Class Description Examples Temperature [K] 1 Pyrolysis O 2 production at low to medium pressure Chemical Process Recovery 2 3 Gas-solid reactions Gas-liquid or threephase reactions Reduction of regolith to produce O 2 Reduction of magma to produce O 2, silicates Desorption of solids Solar wind volatiles, drying Hot liquid processing Metal/basalt casting, glass processing Manufacturing 6 7 Sinter forming Composite forming Powder metallurgy, refractory sintering Fibers, whiskers, flakes in matrix Welding/Glass blowing Power Operations 9 Thermal energy storage In fused basalt < 1400

19 Pyrolysis of Regolith for Oxygen Recovery VG

20 Hydrogen Reduction of Ilminite VG

21 Solar Wind Volatile Recovery VG

22 Basalt Melting for Glass Production VG

23 Brick Sintering Oven VG

24 Brick Joining Oven VG

25 Lunar-Based Solar Material Processing Plant VG

26 Plan View of a 100 kw Process Plant (2 m Concentrators) VG

27 Plan View of a 100 kw Process Plant (4 m Concentrators) VG

28 Solar Power System Weight VG Weight per kwth Thermal Size 1 ~ 10 kwth 10 ~ 100 kwth Cable length 2 m 4 m 6 m 8 m 10 m Cable 0.96 kg 1.9 kg 2.9 kg 3.8 kg 4.8 kg Conc. + Cable 2.2 kg 3.1 kg 4.1 kg 5.1 kg 6.0 kg Conc. eff = 0.86 Conc. sys. weight (with support and tracking) = 1.2 kg/m 2 Optical fiber cable weight = sun

29 Conclusions VG The optical waveguide system is capable of collection, concentration, and transmission of solar energy for in-situ resource utilization The overall system efficiency for the engineering model was 38%. Much higher efficiency (~72%) can be achieved for a space-based operation system The system can be applied to a variety of high temperature chemical processes, manufacturing processes, and power generation and storage Technology issues for the future includes: lightweight concentrator system lightweight and efficient optical fiber cable material processing solar reactor