Presented by: Bill Leach, Code 4.3.5.1 NAVAIR Fire Protection Team Leader
description
Transcript of Presented by: Bill Leach, Code 4.3.5.1 NAVAIR Fire Protection Team Leader
NAVAL AVIATION SYSTEMS
oo MAET MAET MAET
RETROFIT OPPORTUNITY FOR HFC-125
IN AIRCRAFT ENGINE SYSTEMS
Presented 19 November 1998 to:
The International Aircraft Fire and Cabin Safety Research Conference
Presented by: Bill Leach, Code 4.3.5.1
NAVAIR Fire Protection Team Leader
NAVAL AVIATION SYSTEMS
oo MAET MAET MAET NAVY RESPONSIBLE USE POLICY
• Stockpile– Halon Usage Factors & Aircraft Attrition Rates
• Minimize Use – Recycle
– Reduce Non-Fire Discharges & False Alarms
• Alternative R&D– Corporate Efforts
• TDP: Technology Development Program• NGP: Next Generation Program
– Navy Efforts• Gas Generator Technology• Water Mist Technology
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oo MAET MAET MAET NAVAIR HALON POLICIES
• In-Service Aircraft (Pre - 1993)– U.S. DOD Halon Stockpile
• New Aircraft Programs (Post - 1993)– Non-Halon System
– No Reliance on Stockpile
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oo MAET MAET MAET NAVAIR HALON POLICIES
• Old Retrofit Solution:– None Needed
– None Available
• New Retrofit Opportunity:– Enhanced (and Growing) Pressures on Stockpile
– Unexpected Forward Fit Solution (F/A-18E/F)
HIGH POTENTIAL FOR RETROFIT SOLUTION
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oo MAET MAET MAETFORWARD FIT SOLUTION (F/A-18E/F)
• E/F Specification Requirement– No Halon
– Better than or equal to C/D System• C/D System: 5.5 # of Halon 1301
• Same Bottle Compartment as C/D– No Growth Provision for New Agent Cylinder
• E/F Solution: HFC-125 (~ 6 pounds)
F/A-18E/F Solution Seems to Contradict Industry Knowledge
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oo MAET MAET MAET HALON ALTERNATIVE TECHNOLOGY DEVELOPMENT PROGRAM
• 1992 Start, 4 Year Effort• DOD Program w/ FAA Participation• Only “Corporate” Effort to Identify Chemical
Alternative for Halon– Extinguishing Performance; Toxicity; Material
Compatability; Agent Stability; Availability • TDP Answer: HFC-125
Predictions of 200 - 300% System Growth Required
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oo MAET MAET MAET F/A-18E/F PATH TO SUCCESS
Technology Technology DevelopmentDevelopment
F/A-18E/FF/A-18E/F
SolutionSolution
Baseline: Gas Generator–Thermal Extremes–Insensitive Munitions–Resulted in High Risk
New Baseline: HFC-125–Four Nozzle Distribution–Equal to or Better than Halon
Alternate Agents–Gas Generator–CF3I–Dry Chemical–HFC-125
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oo MAET MAET MAET F/A-18E/F TESTING
• Detailed Airflow Analyses– High Fidelity Engine Nacelle Simulator
• Agent Distribution Testing– Optimize Plumbing Scheme
• Fire Testing– Baselined to Halon Defeat Point
• Relight Condition
– Confirm Equivalence with Halon
NAVAL AVIATION SYSTEMS
oo MAET MAET MAETF/A-18E/F TEST ARTICLE
NAVAL AVIATION SYSTEMS
oo MAET MAET MAET
1998 HOTWC
HFC-125
EVALUATED DISTRIBUTION OPTIONS
N1
N2
N3
N4
N5N6
N1N2
N3
. N5
N6xx
F-18 Ext. BottlePres: 600 - 1800 psig
Exhaust
Exhaust
Air In
Nozzle Configuration Definition
Nozzle Opening (diam, inches) or [area in2]
Configuration N1 N2 N3 N4 N5 N6
EMD Open n/a n/a Open Open n/a(0.19”) (0.25”) (5/8”)
LRIP Open n/a n/a Open n/a Open(0.19”) (0.25”) (5/8”)
3 Nozzle Open Open Open Open n/a n/a(0.19”) (1/2”) [5/8] (0.25”)
4 Nozzle Open Open Open Open n/a Open(0.19”) (1/2”) [5/8] (0.25”) (5/8”)
LRIP + Open n/a Open Open n/a Open(0.19) [5/8] (0.25) (5/8”)
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oo MAET MAET MAET
Nozzle Placement(s)
“Agent”
To AMAD ENGINE AFT
E/F 4 Nozzle
(Outb”d)
( HFC-125 ImprovedDistribution)
“Agent”
5.6 lb @ 600 psi
( HALON )5.5 lb min @ 600 psi
“Agent”
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oo MAET MAET MAET GENERAL SYSTEM INSTALLATIONGENERAL SYSTEM INSTALLATION
FIREX BOTTLE
NAVAL AVIATION SYSTEMS
oo MAET MAET MAETHFC-125 TEST RESULTS
Optimized HFC-125 is Competitive With HALON 1301
0
15
10
5
HALON 1301(5.5#)
HFC-125
EMD LRIP EMD LRIP 3Noz 4Noz
“Fir
e O
ut”
Tim
e ~
(Sec
)
Target Min
5.6#
ImproveDistribution
ImprovePerformance
6.3#
Baseline
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oo MAET MAET MAET F/A-18E/F TEST RESULTS
• HFC-125 System Proven to Meet or Exceed Halon Performance– HFC-125 Always Put Out the Fire– Several HFC-125 Test Points with No Relight
• Defined System Details for Production– Optimized 4 Nozzle Arrangement– 6.0 # Agent Minimum– 600 psi Nitrogen (Maintain Cold Temp Performance)
• HFC-125 System Selected to Enter Qualification Testing (End FY99)
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oo MAET MAET MAET HFC-125
• 1998 F/A-18E/F Engine Testing
VolumetricConcentration
Agent Mass(Pounds)
Design EquationPrediction(per TDP)
18.51% 4.87
Fire Test Data 8 – 9% 5.6
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oo MAET MAET MAET HFC-125 DESIGN EQUATIONS
• Application– Any New Use of HFC-125– Requirement: Concentration– Guidance: Mass– Some Level of Conservatism
• Option to Design Equations– Fire Testing– Less Agent Likely– Smaller, Lighter Solution for New Aircraft– Retrofit Possible
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oo MAET MAET MAET FIRE PROTECTION TRUTHS
• Halon 1301 is a Very Efficient Fire Extinguishing Chemical
• HFC-125 is a Less Efficient Fire Extinguishing Chemical than Halon 1301
• Halon 1301 Discharge Plumbing is Very Inefficient (Most In-Service Aircraft)
• By Addressing the Plumbing, HFC-125 Systems Can Be Made As Efficient as Halon 1301 Systems
System Equivalence is the True Goal!
NAVAL AVIATION SYSTEMS
oo MAET MAET MAET FIRE PROTECTION TRUTHS
• HFC-125 is a Retrofit Option, NOT A DROP-IN!– Agent Discharge Plumbing Must be Optimized
• Detailed Airflow Analyses• Agent Concentration Measurement• Fire Testing
• Even Better Retrofit Opportunity on Helos and Other Cross-Plumbed Systems– Redundant Halon Bottles (Primary & Secondary)
– Couple Bottles for Single Discharge• 200% Growth Immediately Attainable• Possibility of Meeting Design Equations