Next Generation OBIGGS Developments at Phyre Technologies Santosh
Next Generation OBIGGS: Developments at Phyre Technologies Santosh Y. Limaye Phyre Technologies, Inc. November 2, 2005 Atlantic City, NJ Presented at International Aircraft Systems Fire Protection Working Group Meeting
The Concept l l l Treat the ullage from the fuel tank to create inert gas Inexpensive catalytic system Avoid the use of bleed air This concept resulted from liquid fuel de-oxygenation system development
High Heat Sink Fuels: Enable Advanced Propulsion Filamentous Heat sink relative to JP-8 Amorphous Condensation 14 >1300 F 12 Deposition is The Significant Challenge for High Heat Sink Fuels 10 pyrolytic deposits thermal-oxidative deposits 8 6 Combustor 900 F 4 2 325 F 425 F 550 F 300 0 JP-8+100 JP-8+225 JP-900 Endo JP Near term Mid - Term 400 200 JP-8 500 600 300 JP-8+100 JP-8+225 700 800 400 Fuel Flow 900 1000 500 JP-900 1100 600 Fuel Temperature, F Fuel Temperature, C Endothermic fuels High Heat Sink Fuels Benefits • Increase Thrust-to-weight – enables higher T 41 • Reduce take-off gross weight – reduce fuel recirculation & ram air HX wt • Reduce component operating temp. – higher heat sink capability • Improve SFC – enables higher T 3 and P 3
Quick Review of De-Oxygenation System Inert Gas Contaminated Fuel Gas Contactor Removing dissolved oxygen in fuel De-Oxygenated Fuel Gas prevents Separator Fuel premature oxidation; a primary cause of coking. Inert Gas + O 2 + Fuel Vapor Pump Oxygen free gas For Recycling Gas Treatment System
Mass Transfer Issue Mass Transfer Region O 2 Concentration Gradient Diesel Droplet in N 2 Gas N 2 Bubble in Diesel
Does it work? - O 2 Concentration (ppm) 60 YES! Fuel O 2 = 57. 9 ± 5. 4 ppm 50 40 N 2 flow: 2. 5 Liter/Min; lpm 30 O 2 = 5 ppm 20 10 0 0 0. 5 1 1. 5 2 Fuel Flow (lpm) 2. 5 3 3. 5 4
Results from Testing at AFRL Run 75 Run 79/81 Baseline JP-8 Run 80 PADS Deox JP-8 (Catalyst) P A D S D e O x Run 76 PADS Deox JP-8 (Nitrogen) J P 8 JP-8+100
OBIGGS
10 5 urge 15 Inert Air P Hydrocarbon Vapor Volume Fraction (%) OBIGGS Considerations Dil utio n Critical 5 wit Dilution h. A ir with Ai r Flammability Region 10 15 Oxygen Volume Fraction (%) 20
Catalytic Inerting System (CIS): Next Generation OBIGGS Concept Make up air to consume hydrocarbon vapor and pressure equalization safety device Pump Air + Fuel Vapor Fuel PATENT PENDING Water trap <10% oxygen + Fuel vapor + CO 2 H 2 O + N 2 21% oxygen + Fuel vapor + N 2 Catalytic Gas Treatment System
CIS System Description Reverse Flow Valve Low Temp. air to air Heat Exchangers Inlet Oxygen Sample Port Blower Heat Exchanger & Heaters Reverse Flow Valve Catalyst Bed, 5” Dia x 4. 5”length Inlet Size: 12”x 40” Capacity: 150 CFM # of passes to 10% O 2 : 3 Outlet Control Unit Power Water Drain Oxygen Sensors Support Systems Automatic Moisture Drain Valves Optional, High Removal Rate, Vapor Fuel Control
CIS Catalytic Chemistry l Saturated vapor phase of fuel vapor : C 9 H 20 (Nonane) l l l As per DOT/FAA/AR-04/8 report (page 12), the precise composition is C 9. 05 H 18. 01 Vapor pressure of Nonane is estimated to be 8000 ppmv at 70 F Stoichiometric Reaction of 8000 ppmv Nonane will consume 112, 000 ppmv (or 11. 2%) oxygen to provide 70, 000 (7%) and 40, 000 (4%) ppmv of CO 2 and H 2 O Vapor Pressure of Nonane (Jet Fuel) TC TK VP Pa Atmospheres -46. 8 226. 35 1 0. 00001 -26 247. 15 10 0. 00010 0 273. 15 100 34 307. 15 1, 000 80. 8 353. 95 10, 000 0. 09709 150. 3 423. 45 100, 000 0. 97087 Stoichiometric Reaction C 9 H 20 + 14 O 2 + 52. 67 N 2 9 CO 2 + 10 H 2 O + 52. 67 N 2 0. 00097 . 008 @ 70 F 0. 00971
Oxygen Removal Rate Corrected O 2 Ratio Corrected/Uncorrected 13. 82 14. 02 1. 01 2 9. 09 9. 45 1. 04 3 5. 98 6. 44 1. 08 4 3. 94 4. 46 1. 13 Pass # O 2 % 0 21. 00 1 1. If H 2 O is removed from the product, additional fresh air is needed to compensate the gas pressure in the reactant. 2. The corrected O 2 column shows new concentration based on fresh addition of air to replace water molecules. 3. Three passes will ensure reduction of O 2 below 10%.
CSR Model: Oxygen Depletion Rate For 450 Cu. Ft. Ullage
Experimental Schematic Pump Moisture trap Post Catalyst O 2 Conc. Ullage O 2 Conc. Catalyst Downstream Temp. CDT Catalyst Controller for heater Oxygen Sensor* Ullage Volume VU Fuel Volume VF Flow Rate FR Flow Meter Experimental limitations: l l l Catalyst Temp. CT Pressure gage Fuel Tank l Heater Very small ullage volume Limited flow rate control l l Limitations on catalyst volume (smallest 1. 2 cc) Delayed response due to long oxygen sensor lines Objective was proof of concept to validate theoretical calculations
Initial Results – Experiment #1
Conclusion Benefits þ No need for bleed air, eliminate ozone destruction device þ Low temperature process þ Only power necessary: blower operation þ Smaller foot-print, lighter weight, lower cost þ Closed loop system þ Ability to reduce oxygen level as well as fuel vapor level Other Concerns Addressed C Use of fuel vapor phase means no sulfur contamination, no corrosion C Instead of purging the fuel vapor, it is consumed in the process, hence no VOC emissions from the tank C Ability to precisely control gas partial pressures Next Steps l l l Prototype Development Testing Phase Strategic Partnership Development
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