Get documents about "Timken
Shared by: xiaoyounan
-
Stats
- views:
- 45
- posted:
- 12/30/2011
- language:
- English
- pages:
- 45
Document Sample
FIA|TECH ENERGY WORKSHOP 2010
Energy Savings Initiatives
The Timken Company’s Steel Business
Mike Seifert and Nathan Abboud
March 24, 2010
1
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Outline of Topics to be Discussed
• Overview of Energy Savings at Timken over the Years
• Heat Treat Furnace Energy Savings Projects
1. Reducing the number of burners
2. Installing high velocity burners
• Rotary Furnace Energy Savings Projects
1. Tuning on-line billet temperature model and level 2 control system
2. Optimizing on-line billet temperature model and level 2 control system
3. Replacing conventional burners in the high fired zones with
regenerative ones
4. Redesigning recuperator by adding more surface area
5. Increasing oxygen enrichment
2
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Alloy Steel - US
Faircrest Steel Plant MCF per Shipped Ton
HSP Continuous Caster
HSP Continuous Mill
CI
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
1980s ~ 40% improvement 1990s ~ 17% improvement 2000s ~ 45% improvement (excl. 2009)
3
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Heat Treat
Roller Hearth Furnaces
• Historically the furnaces were designed for production & quality
• Energy efficiency was not the primary driver
• Team of Manufacturing, Process Improvement, Combustion, & Met
QA was formed
4
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Heat Treat
Roller Hearth Furnaces
An idea was generated that we may be able to reduce the number
of burners
Numerous trials were run monitoring temperature profiles of the
product and the furnace
Product samples were cut and examined to assure no impact to
the product properties
5
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Heat Treat
Roller Hearth Furnaces
Trials supported reducing burners in the soak zones
Results:
No impact to product quality
Significant fuel savings
6
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Reducing the number of burners
Control Char t
Individual Measur ement of 7RMCF/ton
4. 50
4. 00
UCL =3. 89 61
7RMCF/ton
3. 50
3. 00 Avg=3. 092 7
2. 50
LCL=2. 28 93
2. 00
02/01/2005
04/01/2005
06/01/2005
08/01/2005
10/01/2005
12/01/2005
02/01/2006
04/01/2006
06/01/2006
08/01/2006
Date
This control chart shows the Results
Net reduction of 25%
7
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Heat Treat
Car Furnaces
One of our car furnaces had lower velocity 1950 vintage burners
Another car had a higher mix 1979 vintage burner
8
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Heat Treat
Car Furnaces
These two car furnaces at GSP were rebuilt with high velocity
burners to improve throughput in addition to energy
9
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Installing high velocity burners
Before
4 Car MCF/ton changes
3.50
3.25
3.00
2.75
2.50
2.25
2.00
1.75 4 car
1.50
1.25
1.00
0.75 After
0.50 changes
0.25
0.00
09
l
l
07
08
Ju
Ju
n-
Ja
Ja
Ja
As high as 33% savings for some heat treat cycles
10
Heat Treat Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
MCF /Ton
Other projects:
Reduced Cycle Times
Improved Furnace Pressure
Control
Shut down Zones
Added Insulation
Better Control of Air/Fuel
…
11
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Outline of Topics to be Discussed
• Overview of Energy Savings at Timken over the Years
• Heat Treat Furnace Energy Savings Projects
1. Reducing the number of burners
2. Installing high velocity burners
• Rotary Furnace Energy Savings Projects
1. Tuning on-line billet temperature model and level 2 control system
2. Optimizing on-line billet temperature model and level 2 control system
3. Replace conventional burners in the high fired zones with regenerative ones
4. Redesign recuperator by adding more surface area
5. Increase oxygen enrichment
12
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Key factors for success:
• Projects needed dedicated resources
• Finite element analysis knowledge was essential
• DOE (Design of Experiment) expertise was required
• Commitment from operations for the trials was needed
• Trials were designed to run within standard operating ranges
13
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Outline of Topics to be Discussed
• Overview of Energy Savings at Timken over the Years
• Heat Treat Furnace Energy Savings Projects
1. Reducing the number of burners
2. Installing high velocity burners
• Rotary Furnace Energy Savings Projects
1. Tuning on-line billet temperature model and level 2 control system
2. Optimizing on-line billet temperature model and level 2 control system
3. Replace conventional burners in the high fired zones with regenerative ones
4. Redesign recuperator by adding more surface area
5. Increase oxygen enrichment
14
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
• True knowledge of billet temperatures allows optimum pre-heat conditions
to be set
• Scale layer minimized so mill yields increase
• Areas of non-uniform heating that cause eccentricity of tubing identified
• Vital information for verification of mathematical furnace models
15
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
Making Thermod billet temperature calculation closer to actual temperature.
Attaching a logger to the billet with thermocouples recording temperatures
every 5 seconds.
16
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
17
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
18
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
19
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
20
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
21
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
22
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
• Design of experiment goal was to run a minimum number of trials to
identify the variables causing the most amount of error between
calculated and actual billet temperature.
• These trials were later analyzed and used to refine the model and
reduce the error.
23
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
• Assuming:
– The error from factor interactions is negligible
– Only diameter spacing and time are the main factors
• DOE half factorial predicts the main effects of 3 control factors with
a total of 6 runs
RUN DIA SPACING TIME (MPI)
1 10.5 1.25 15
2 6 1.25 15
3 6 0.25 15
4 10.5 0.25 15
5 6 1.25 25
6 6 0.25 25
24
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
• Zone temperature range is 1700°F to 2350°F. It varies
within the same run. Thus, its effect was captured.
• Time usually varies from 15 MPI TO 25 MPI. Only 6” billet
was tested at 15 MPI and 25 MPI. The 10.5” billet can not
be tested at 25 MPI due to Datapaq limitations
• View factor is a function of spacing. Only spacing was
tested.
• Emissivity varies with scale thickness and scale thickness
varies with time. Only time was tested.
• According to DEFORM model already developed, material
type has negligible effect.
25
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
Material type effect is negligible
Material Type Effect, 10.5" Billet, 15 mpi
2500
2400
2300
2200
2100
2000
1900
1800
1700
1600
1500 zone
1400
T (F)
1300 top_1026
1200
1100 bot_1026
1000
900 top_52100
800
700 bot_52100
600
500 top_1090
400
300 bot_1090
200
100
0
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
8000
8500
9000
500
0
t (s)
26
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
Predicted temperature was off by over 400°F at times
BILLET OD: 6", BILLET SPACING: 1.5", TIME IN FURNACE: 15 MPI
2300
2200
2100
2000
1900
1800
1700
1600
1500
1400
Thermod_zone
1300
Datapaq_zone
1200
Thermod_top
1100
Datapaq_top1
1000
Datapaq_top2
900
Thermod_center
800
Datapaq_center1
700
Datapaq_center2
600
Thermod_bottom
500
Datapaq_bottom1
400
Datapaq_bottom2
300
200
100
0
0
180
360
540
720
900
1080
1260
1440
1620
1800
1980
2160
2340
2520
2700
2880
3060
3240
3420
3600
3780
3960
4140
4320
4500
4680
4860
5040
5220
5400
27
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Tuning on-line billet temperature model and level 2 control system
New view factors were calculated to account for furnace geometry and
billet spacing variations
Furnace thermocouples were relocated to reflect true zone temperature
Difference between actual billet temperature and calculated billet
temperature was significantly reduced
28
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Outline of Topics to be Discussed
• Overview of Energy Savings at Timken over the Years
• Heat Treat Furnace Energy Savings Projects
1. Reducing the number of burners
2. Installing high velocity burners
• Rotary Furnace Energy Savings Projects
1. Tuning on-line billet temperature model and level 2 control system
2. Optimizing on-line billet temperature model and level 2 control system
3. Replace conventional burners in the high fired zones with regenerative ones
4. Redesign recuperator by adding more surface area
5. Increase oxygen enrichment
29
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Quality
Production
Energy Savings
30
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
If the billet temperature is non-uniform, the tube is eccentric.
Eccentric tubes often result in an out-of-tolerance wall size.
31
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
Furnaces are slightly pressurized in order to reduce cold air infiltration
Cold air infiltration negatively affects billet temperature uniformity
32
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
• Billet spacing
• Zone #4 excess air
• Zone #5 excess air
• Enthalpy Profile
• Furnace pressure
Responses were:
Eccentricity (P)
Fuel Consumption (S)
Productivity (S)
33
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
• A resolution 5 fractional factorial design of experiment with center
points was conducted using JMP
• Ran a four month trial
• Towards the end of the trial, results started to show that lower
eccentricity can be achieved with , increased spacing, increased
excess air, and higher furnace pressure
34
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
• The trial was augmented with additional settings in order to determine the
optimal settings for this process.
• The trial was continued to completion with these additional runs.
• Optimal spacing was determined (Greater than normal practice)
• We optimized excess air (which was a higher setting)
• Furnace pressure was not changed
35
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
36
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Optimizing on-line billet temperature model and level 2 control system
• In Summary:
• A design of experiment using JMP (statistical software) was conducted to
optimize furnace settings and achieve uniformly heated billets.
• Since then, eccentricity has been at a record low. Tubes concentricity
significantly improved allowing us to process new orders with a tighter wall
size tolerance.
• Monitoring fuel, we did see a reduction in fuel.
• Productivity was maintained
37
Energy Savings Initiatives
The Timken Company’s Steel Business
FIA|TECH ENERGY WORKSHOP 2010
Outline of Topics to be Discussed
• Overview of Energy Savings at Timken over the Years
• Heat Treat Furnace Energy Savings Projects
1. Reducing the number of burners
2. Installing high velocity burners
• Rotary Furnace Energy Savings Projects
1. Tuning on-line billet temperature model and level 2 control system
2. Optimizing on-line billet temperature model and level 2 control system
3. Replace conventional burners in the high fired zones with regenerative ones
4. Redesign recuperator by adding more surface area
5. Increase oxygen enrichment
38
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Replace conventional burners in the high fired zones with regenerative ones
Regeneration uses a pair of burners which cycle to alternately
heat the combustion air or recover and store the heat from the
furnace exhaust gases.
Replaced 21 burners with 9 burners at #4 Rotary in 2006
Air preheat temperatures within 300°F - 500°F of the furnace are
achieved resulting in exceptionally high thermal efficiency.
Result was 32% in natural gas saving
39
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Replace conventional burners in the high fired zones with regenerative ones
Regenerative Burners Cycle A
Gas
Hot air
Hot POC
Courtesy of Bloom Eng.
Warm POC 40
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Replace conventional burners in the high fired zones with regenerative ones
Regenerative Burners Cycle B
Courtesy of Bloom Eng.
41
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Redesign recuperator by adding more surface area
A recuperator is a special purpose counter-flow heat exchanger used
to recover waste heat from exhaust gases. Optimization of heat
recuperator size for heat recovery applications is extremely significant in
order to get maximum savings from these systems.
Courtesy US Department of Energy Efficiency
42
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Increase oxygen enrichment
Substitution of commercial oxygen for combustion air, which contains
only 20.9% O2, reduces the volume of heat-absorbing nitrogen flowing
through the combustion process and therefore reduces the flue gas loss.
2005: 3% enrichment
2006: 7% enrichment
Result was 10% in natural gas saving
43
Rotary Furnace Energy Savings Projects
FIA|TECH ENERGY WORKSHOP 2010
Other projects:
Shut down Zones
Added Insulation
Better Control of Air/Fuel
…….
44
FIA|TECH ENERGY WORKSHOP 2010
45
Questions?
