Post on 19-Sep-2020
transcript
Updated Experimental Investigation of the
NexGen and Propane Burner
Fire Test Center
University of Cincinnati, Cincinnati, OH, USA
May 10th, 2017
Samir Tambe, Ryan Hasselbeck, and San-Mou Jeng
Project Overview
● Project Objective:
– Quantify the effect of fuel flow rate on burn-through and back side temperature
– Draw comparisons between the NexGen and Propane burner, for various test
article sizes and test conditions.
● Previously Presented Work
– Effect of Burner setup and calibration TC size
– Sensitivity of Burner to air and fuel flow rates and temperatures
– Effect of burner orientation on performance
– Comparison of fire test results between NexGen and Gas burners
● Recent Developments
– Study of Flame Retention Heads (FRH) and Delavan fuel nozzles
– Burner sensitivity to operating conditions
– Burner sensitivity to assembly tolerances
– Sensitivity to inclination and test set-up
– Study of ignitorless stator configuration, comparison with FRH configuration
Effect of Fuel Flow Rate on Burn-Through
and Back Side Temperature
Overview
• Two fuel nozzles tested:
• Delevan, 80 Degree, Type W, 2.5 GPH
• Delevan, 80 Degree, Type W, 2.0 GPH
• Two nozzles were used to reach a larger range of fuel flow rates (1.75 – 2.8 gph)
than is achievable from one nozzle alone.
1.5
1.7
1.9
2.1
2.3
2.5
2.7
50 70 90 110 130
Flo
w R
ate
(gp
h)
Fuel Pressure (psi)
Flow Rate vs Pressure - 2.0 vs 2.5 GPH Nozzle
2.0 GPH Nozzle
2.5 GPH Nozzle
2.5 GPH Nozzle – Flow Rate Variation
• Temperature decreases, as expected, with
a decreasing fuel flow rate.
• Burn-Through time increases with a
decreasing fuel flow rate, as expected. The
trend is not linear.
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Tim
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1" Temperature vs Fuel Flow Rate - 2.5 GPH Nozzle
2.00 gph
2.15 gph
2.25 gph
2.50 gph
2.70 gph
2.80 gph
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600
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Burn Through Time vs Fuel Flow Rate -2.5 GPH Nozzle
2.00 gph
2.15 gph
2.25 gph
2.50 gph
2.70 gph
2.80 gph
0
500
1000
1500
0 60 120
Tem
per
atu
re (
F)
Test Time (s)
2.50 GPH Nozzle Comparison, Various Flow Rates
2.0 GPH
2.15 GPH
2.25 GPH
2.5 GPH
2.7 GPH
2.8 GPH
2.0 GPH Nozzle – Flow Rate Variation
• Temperature decreases, as expected, with
a decreasing fuel flow rate.
• Burn-Through time increases with a
decreasing fuel flow rate, as expected. The
trend is not linear.
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1" Temperature vs Fuel Flow Rate - 2.0 GPH Nozzle
1.75 gph
2.00 gph
2.15 gph
2.25 gph
670
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500
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Burn Through Time vs Fuel Flow Rate - 2.0 GPH Nozzle
1.75 gph
2.00 gph
2.15 gph
2.25 gph
0
500
1000
1500
0 60 120
Tem
per
atu
re (
F)
Test Time (s)
2.0 GPH Nozzle Comparison, Various Flow Rates
1.75 GPH
2.0 GPH
2.15 GPH
2.25 GPH
2.5 vs 2.0 GPH Nozzle Comparison
• Fuel pressure of different nozzles has an
observable effect on performance,
regardless if flow rates are equivalent.
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Burn Through Time -- 2.0 GPH Flow
2.0 GPH Nozzle
2.5 GPH Nozzle
0
500
1000
1500
2000
Tim
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1" Temperature -- 2.0 GPH Flow
2.0 GPH Nozzle
2.5 GPH Nozzle
0
200
400
600
800
1000
1200
0 120 240
Tem
per
atu
re (
F)
Test Time (s)
Backside Temperature -- 2.0 GPH Flow
2.0 gph nozzle
2.5 gph nozzle
2.0 GPH nozzle operated at 116 psi
2.5 GPH nozzle operated at 65 psi
2.5 vs 2.0 GPH Nozzle Comparison
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500
1000
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1" Temperature -- 2.25 GPH Flow
2.0 GPH Nozzle
2.5 GPH Nozzle
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75
150
225
300
Tim
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Burn Through Time -- 2.25 GPH Flow
2.0 GPH Nozzle
2.5 GPH Nozzle
• This effect of fuel pressure is repeatable
over a range of fuel flow rates.0
500
1000
1500
0 120 240
Tem
per
atu
re (
F)
Test Time (s)
Backside Temperature -- 2.25 GPH Flow
2.0 gph nozzle
2.5 gph nozzle
2.0 GPH nozzle operated at 142 psi
2.5 GPH nozzle operated at 86 psi
Side Study: Burner Cone Age
• Burner operated at same fuel pressure and
flow rate.
• As a burner cone is ‘broken in’, the fuel flow
required to reach 2000 degrees decreases
some.
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Burn Through Time vs Burner Cone
Old Cone
New Cone
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1" Temperature vs Burner Cone
Old Cone
New Cone
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1" Heat Flux vs Burner Cone
Old Cone
New Cone
Summary
• Burner performance is highly dependent on fuel flow rate. Calibration
temperature, back-side temperature rise, and burn-through time are all impacted
by fuel flow rate, though the impact is not linear.
• Fuel nozzles of different flow ratings will not perform equivalently, when operated
at equivalent fuel flow rates.
• Though burn-through times are not effected by the cone alone, the calibration of
the burner (rather, the fuel input required to achieve 2000 F) will depend on the
age of the cone.
• Note: A burn-through time of 5 minutes was achieved at fuel flow input of 2.15
GPH (2.5 GPH Nozzle).
NexGen and Propane Comparison
Overview of Set-Up
NexGen Burner: Panel Set-Up
8x8x0.125” 12x12x0.125”
24x24x0.125”
Propane Burner: Panel Set-Up
8x8x0.125” 24x24x0.125”
12x12x0.125”
Burnthrough Results
8” Panels
Burnthrough Comparison
Burner Temperature (F) Heat Flux (BTU/ft*s) Burnthrough (s)
Propane 2067 9.8 295
NexGen (55 psi) 1712 9.7 445
NexGen (100 psi) 1910 13.4 147
8" Panels
• Flame is fully able to wrap
around panel, for both the
NexGen and Propane
burners.
• When heat flux is
matched, NexGen burner
takes significantly longer
for burnthrough. Likely an
effect of gravity (panel is
horizontal for vertical
propane burner, vs vertical
panel for horizontal
NexGen).
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Bu
rnth
rou
gh T
ime
(s)
Propane NexGen (55 psi) NexGen (100 psi)
8” Panels
Propane Burner NexGen Burner
55 psiNexGen Burner
100 psi
12” Panels
Burnthrough Comparison• Flame is unable to wrap
around for either
NexGen or Propane
burner.
• When heat flux is
matched, NexGen
burner takes
significantly longer for
burnthrough, as with the
8” panels.
• Burnthrough time with
the NexGen burner
does not increase
linearly with increasing
fuel pressure.
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Bu
rnth
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ime
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Propane NexGen (55 psi) NexGen (85 psi) NexGen (100 psi)
Burner Temperature (F) Heat Flux (BTU/ft*s) Burnthrough (s)
Propane 2057 9.6 445
NexGen (55 psi) 1696 9.7 908
NexGen (100 psi) 1909 12.3 143
NexGen (85 psi) 1850 11.5 174
12" Panels
12” Panels
NexGen Burner
55 psi
Propane BurnerNexGen Burner
100 psi
24” Panels
Burnthrough Comparison
• Flame is unable to wrap
around for either
NexGen or Propane
burner.
• When heat flux is
matched, burn-through
time with the NexGen
burner closely matches
that of the propane
burner. 464 438 120
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400
500
Bu
rnth
rou
gh T
ime
(s)
24" Panel Comparison
Propane NexGen (55 psi) NexGen (100 psi)
Burner Temperature (F) Heat Flux (BTU/ft*s) Burnthrough (s)
Propane 2069 9.8 464
NexGen (55 psi) 1717 9.2 438
NexGen (100 psi) 1934 12.7 120
24" Panels
24” Panels
Propane Burner
NexGen Burner
Vertical NexGen vs Propane Burner
Comparison
Vertical NexGen Burner Set-Up
Panels were suspended 4” above the burner cone and
sandwiched around the edges, exactly as they were using the
propane burner.
Burn-Through Results
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Burner Comparison - Vertical Orientation
Propane
NexGen
8" Panels 12" Panels 24" Panels
• Temperature and Heat
Flux were matched
between both burners
as closely as was
possible.
• For all test article sizes,
the NexGen burner
yielded significantly
lower burn-through
times.
• Note: for both burners,
the flame was able to
wrap around the 8”
panels. Burner (Vertical) Temperature (F) Heat Flux (BTU/ft*s) Burn-Through (s)
Propane 2067 9.8 295
NexGen 1981 10.8 171
Propane 2057 9.6 445
NexGen 2014 10.7 174
Propane 2069 9.8 464
NexGen 1993 10.8 125
8" Panels
12" Panels
24" Panels
Post Test Pictures
8x8x0.125”12x12x0.125”24x24x0.125”
Summary
• With the larger 24x24” panels, when the heat flux is closely matched, the
burn-through performance of both burners is nearly equivalent.
• With both burners operated vertically, and at similar calibration results, the
NexGen burner is more severe than the propane burner.