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Arvind AtreyaDepartment of Mechanical Engineering
University of Michigan, Ann Arbor [email protected] , (734) 647 4790
DOE–ITP’s Programs at Michigan
GACCOM - Detroit || 6/23/09 || 1
Presentation Outline• Overview of ITP & other programs at Michigan• Programs available free for industry to increase
energy efficiency, productivity and profitability.• Integrated delivery of Service, Education,
Research & Development from Michigan.• Examples and case studies.
– Simple measures.– More complicated measures (use of DOE tools). – CHP example– Measures with great potential but requiring R&D.
• ConclusionsGACCOM - Detroit || 6/23/09 || 2
Supply104
Quads
Domestic67%
Imports33%
Industrial31.98
Consume100
Quads
Nuclear 8%Renewable 6%
Fossil86%
~ 1640 MMtons of ‘CO2’ emissions/yr~ $320 billion
1 Quad = 1015 BTU = 1.05 Exajoules= 1015 BTU $10/106BTU
= $10 billion
U.S. Energy Flow, 2005 (Quads)Note: Industrial usage > Transportation
GACCOM - Detroit || 6/23/09 || 3
Range of Programs at MichiganPurpose: To increase energy efficiency,
productivity and profitability.
1. Industrial Assessment Center (IAC) – ITP
2. Michigan Industrial Energy Center (MIEC) – ITP
3. Industry-University Research Center for: Thermal Technology – NSF (new)
GACCOM - Detroit || 6/23/09 || 4
• Energy audit and industrial assessment
• No cost to small/medium manufacturerswithin 150 miles of a Center
• Conducted by university-based team of engineering faculty/students
• Confidential report sent to plant within 60 days from site visit
• 26 participating universities across the country
• 240 students in training each year
• 650 Assessment Days of service provided to manufacturers
• Average savings per assessment: $55,000/yr
Industrial Assessment Centers (IACs)
GACCOM - Detroit || 6/23/09 || 5
New Michigan Industrial Energy Center (MIEC)
GACCOM - Detroit || 6/23/09 || 6
State of Michigan Energy OfficeProject Director: Roger Doherty
Primary Participants: University of Michigan (UM)
Shephard Advisors (SA)Renewable Energy Systems (RES)
Website & Outreach
Shephard AdvisorsWeb resources
Training lectures Discussion boards
with Q&A
Local Training Center
Univ. of MichiganShort course on
Industrial Energy + DOE-ITP Training. Obtain DOE-UM
certification.
SEN Energy Assessments
Univ. of Michigan3-day assessments of
larger facilities.Local Training of Energy Managers
New Technology Implementation
RES and UMNew technology demonstration
Long-term help in implementing new
technology
New NSF Industry/University Cooperative Research Center for Thermal Technology
GACCOM - Detroit || 6/23/09 || 7
University Michigan(Deans office)Governed by:
Industrial Advisory Board & NSFCenter Director: Arvind Atreya
R&D Project – 1of industry interest
UM Faculty & Industry
Representative +
Graduate Student
R&D Project – 2of industry interest
UM Faculty & Industry
Representative +
Graduate Student
R&D Project – 3of industry interest
UM Faculty & Industry
Representative +
Graduate Student
… etc.
30K/project from industry, rest NSF + University
Industrial Energy Work at Michigan
GACCOM - Detroit || 6/23/09 || 8
Process Heating 38%
Steam 35%
Other4%
Electro-chemical 2%
ProcessCooling
1%
Motor Systems
12%
Facilities 8%
Combustion of fossil fuels. Either in boilers or furnaces.
Manufacturing Energy Used by Plant Size and System Type (%)
Plant Size: % Total Energy Use
4,014 Large Plants
58%MIEC &
NSF I/UCRC
Small 5%(MIEC training)
112,398Mid-SizePlants 37%
IAC & MIEC
System Type: % Total Energy Use
GACCoM - Detroit || 6/23/09 || 9
• To be completed before assessment visit
• Gather plant data including product type, annual sales levels, production levels, operating hours
• Study processes and plant layout
• Analyze utility billing data
• Identify key energy systems
• Develop assessment day strategy
Pre-Assessment
• Conduct engineering and financial analyses of priority recommendations
• Develop first order estimates of implementation costs
• Document results in “GOLD Standard” format assessment report
• Upload report data into IAC database
• Deliver report to plant within 60 days from plant visit
Analysis & Repor ting
• Conduct follow up discussions with plant, 6-9 months following assessment visit
• Identify implemented energy savings
• Upload implementation data into the IAC database
Follow Up
• Duration: One Day
• Meet with plant management team
• Present details of pre-assessment analysis
• Tour plant
• Collect operating data
• Conduct diagnostic testing
• Discuss preliminary assessment findings with management
• Prioritize potential recommendations for further analysis
Assessment Visit
Components of the IAC Assessment
GACCOM - Detroit || 6/23/09 || 10
• $74,000/yr in recommended energy savings +
• $58,000/yr in recommended non-energy savings
• Implementation rates between 45% and 50%
• 5,900 MMBtu/yr per plant savings, additional replicated and spin-off savings of 1,260MMB/yr
• 4-8% of annual IAC plant energy consumption
Typical IAC Assessment
GACCOM - Detroit || 6/23/09 || 11
• Publicly Available• Contains data:
– Facility – Recommendations– Implementation
• Searchable by:– Size (in energy usage,
employees, etc…)– Industry type (NAICS or SIC)– Location– Recommendation type
• Updated in real time as the assessments are completed
IAC Database
GACCOM - Detroit || 6/23/09 || 12
http://www1.eere.energy.gov/industry/bestpractices/iacdatabase.html
Search Examples– What are the most common
recommendations for Forest Product manufacturers?
– What is the average savings for replacing a boiler?
– What are the top ten most common energy recommendations?
GACCOM - Detroit || 6/23/09 || 13
Recommendations # of times
Ave.Sav / pay back-yr
Reduce illumination to minimum level 53 $5,000 / 0.5Use high efficiency lamps and ballasts 238 $7,000 / 2.5Install occupancy sensors 71 $2,000 / 1Use radiant heater for spot heating 25 $18,000 / 2Reduce building air ventilation by air filtering 21 $8,000 / 0.5Proper A/F ratio for boilers and furnaces ~3% O2 in flue gas 58 $13,000 /
0.5Eliminate compressed air leaks 166 $6,000 / 0.5Optimize Plant Power Factor 33 $11,000 / 1Compressor Air Intakes In Coolest Locations 155 $2,000 / 1
Simple Energy Saving MeasuresExamples: – you really don’t need us for these
More complicated measures (PHAST)
Furnace Heat Input
Heat in Flue Gases
Available Heat = (Furnace Heat Input – Heat in flue gases)
In a typical high temp. furnace Largest heat loss is flue gas enthalpyIf a furnace heats products to 1,500 F Flue gases cannot be cooled below this
temperature without using external equipment.
At 1,500 F Flue gas loss ~ 50%.
At 2,000 F (stoichiometric)
Flue gas loss ~ 55%
At 2,000 F (20% excess air)
Flue gas loss ~ 62%
External waste-heat recovery devices: • Recuperators • Regenerators
GACCOM - Detroit || 6/23/09 || 14
Excess air (improper pressure control) Al melting furnace – use of PHAST
GACCOM - Detroit || 6/23/09 || 15
Savings flue gas control $867,248/Yr + $248,577/YrSavings covering the well 162,797/Yr
Excess air (improper pressure control) Example – 903 Melting Furnace
Preheat to 800F2,963,099
GACCOM - Detroit || 6/23/09 || 16
GACCOM - Detroit || 6/23/09 || 17Thermal Energy
Ele
ctri
cal P
ower
Needed Power
Needed Heat
Prime mover characteristics
Combined Heat & PowerIdentifying the Need
GACCOM - Detroit || 6/23/09 || 18
Combined Heat & Power (many options)
Waste Heat Boiler
Power generation – primary consideration
Process Heat– primary consideration
Raw Material:Particle Board
Laminator
Size Cutting
Routing Boards
Secondary Operations:e.g. Drilling hole patterns
Inspection, PackagingShipping
Scrap BoardSaw DustScrap Part
Boiler
Example: Wood Furniture Manufacturer
GACCOM - Detroit || 6/23/09 || 19
• 8,380,800 kWh/yr – Cost: $311,539/yr
• 2,032 kW demand – Cost: $143,188/yr
• Total Electrical Costs: $456,188/yr
• NO NATURAL GAS COSTS
• Steam is generated by wood waste– Used for heating in winter
– Heat is rejected in summer
Energy Usage by the Plant
GACCOM - Detroit || 6/23/09 || 20
• Install 170 kW unit• Generate power
during the summer• Use steam for heating
in winter
• Install 170 kW unit• Generate power year
round• Use natural gas
booster boilers for heatingCosts:
Installation Cost: Same for both optionsAnnual operating costs: $10,000/yr obtained from steam turbine manufacturers assumed same for both options
CHP Options
GACCOM - Detroit || 6/23/09 || 21
• 12 month Option= $67,654 - $13,750 - $10,000 = $43,904/yr
• 6 month Option= $33,862 - $10,000 = $23,862/yr
• Same implementation and O&M costs.• Better utilization of existing equipment with
the 12 month operation• The two options are equal if natural gas
costs increase to $12.87/MMBtu
CHP Options Comparison
GACCOM - Detroit || 6/23/09 || 22
• Average Cost of Steam Turbine from Equipment Manufacturers and Dealers* = $73,000
• Cost of Installation varied*: $35,000 to $75,000
• Total estimated implementation cost = $148,000
Simple Payback on 12 months option = 3.4 years*Much help is now available to obtain these estimates:• Midwest CHP Center: www.chpcentermw.org• Use boiler program – SSAT• Cogen Pro from San Diego IAC
Implementation
GACCOM - Detroit || 6/23/09 || 23
New Technology Measures New flameless (homogeneous) or low-gradient combustion:
• Flameless Oxidation (FLOX),
• High Temperature Air Combustion (HiTAC), and
• Low temperature gradient (MILD) combustion.
The essential conditions for achieving these are:a) Air & gas mixture temperatures are above the auto ignition
temperature (~ 1200K), and
b) Fuel and oxidant must be sufficiently diluted before they react.
Usually this is accomplished by highly diluting the air by hot flue gases which results in flameless combustion. O2% ↓, thus peak T↓ & ‘T’ becomes more uniform. However, radiation may actually go down.
GACCOM - Detroit || 6/23/09 || 24
Known Facts, Problems and SolutionsWell-Known Facts:
• Air preheat & O2-enrichment increase furnace efficiency.– Also ↑ temperatures, NOx & other pollutants.
• Primary mode of heat transfer in a furnace is radiation.– High level of uniform radiation increases furnace productivity.
• High radiation energy transfer from the reaction zone. – Reduces flame temperature Intense radiation is desirable.
• Radiation is a volumetric phenomenon.– Volumetric or homogeneous or flameless combustion ↑ radiation.
A beneficial combination:– Air + hot flue gases (→ flameless combustion) + O2+ radiation.
How to do it?
GACCOM - Detroit || 6/23/09 || 25
Expected Improvements in Efficiency, Productivity and Emissions
Industries such as Steel, Glass, Aluminum, Petrochemical, etc. use large amounts of energy for process heating.
In high Temp furnaces, the useful portion is typically < 50%
The new technology presented here can provide >50% improvement in energy efficiency and reduce NOx & GHGs.
This is done by reducing the loss of flue gas enthalpy. At 1,500°F flue gas temperature flue gas energy loss ~ 50%.
While combustion air preheat & O2-enrichment are traditionally used to reduce flue gas losses, the proposed method is less expensive & low maintenance.
It also offers additional benefits of fuel flexibility, high productivity, and ultralow emissions by enabling Radiative Homogeneous (or Flameless) Combustion (RHC).
GACCOM - Detroit || 6/23/09 || 26
Benefits of Highly Radiative O2-enriched CombustionCalculations for CO2 and NO – for the same amount of CH4
burning in “air” with different O2% & radiation heat loss
NO
(ppm
) / H
eat l
oss r
atio
GACCOM - Detroit || 6/23/09 || 27
Increasing flame radiation:
• Increases productivity for the same fuel consumption.
• Decreases CO2 production by a factor of 5 and NO by five orders of magnitude for the same fuel use.
• Fuel preheat will increase radiation through soot formation as well as, increase furnace efficiency.
Highly Radiative, O2-enriched, Homogeneous (flameless) Combustion has substantial benefits for furnace operation.
Summary: Benefits of Highly Radiative O2-enriched Homogeneous (flameless) Combustion
GACCOM - Detroit || 6/23/09 || 28
O2 Enrichment + Preheating: Al furnace example
Benefits:• Much cheaper to implement• Low maintenance • Beneficial for NOx reduction• We must consider O2 cost
650oC exhaustto atmosphere
AluminumMelting Furnace
Example
High Temperature Recuperator
22oC dilution airHigh pressure 22oC
ambient air
Exhaust 1100oC ± 1” wc. 900oC
Combustion air @ 400oC & 20”wc. Flow ≈ 277.8 SCF/s = 331.61 gmol/s of air (69.67 gmol/s O2 + 261.94 gmol/s N2)
Hot bleed (X)
Make up oxygen
(Y)
700 oC air at 21% O2
CH4
Oxygen balance2
2
0.21 [ ( / ) ( / )](% ) ; 0.2461
X gmol s of bleed Y gmol s O added O in exhaust X Y or Y X
× += × + = ×Energy balance
( / ) 42.74( / ) (1100 700)33 (700 22) (331.61 ) (700 400)
X gmol s J gmolK Y X Y
⋅ ⋅ − =⋅ ⋅ − + − − ⋅ −
X = 137.305 ; Y = 33.79 ; & air = 160.515 gmol/s.
GACCOM - Detroit || 6/23/09 || 29
Fuel Savings – O2 enrichment + air preheat
0
10
20
30
40
50
60
70
20 30 40 50 60 70 80 90 100
% F
uel s
avin
gs
% Oxygen in combustion air
Calculations using DOE - PHAST program.DOE claims that it is accurate to within 5%
Furnace exhaust temperature 2000oF Combustion air preheat in oF
100
20001800
1600
1400 1200
1000 800
600 400
200
It is important to note that the proposed system provides fuel savings due to both preheat and
O2%.
Maximum
GACCOM - Detroit || 6/23/09 || 30
Experiment Results – NOx
NO Emission
0
3
6
9
12
15
18
1 2 3 4 5 6 7 8 9 10 11 12Case No.
PPM
GACCOM - Detroit || 6/23/09 || 31
Steel Furnace Example
Plate Mill or Hot
Mill Furnaces
Recuperator
70FExhaust: flow rate @ 1900 F, with 2% wet O2
Pressure: ~0.8” WC ~1000F
Combustion air at 750F, 21% O2
25” WCGas flow rate
Make up O2
By ~1/3 EGR + O2, the temp. increases to 1100 F. Savings:
(1) Plate Mill furnaces $2,114,070
(2) Hot Mill furnaces $4,797,764
Does not include O2 cost Low maintenance Much cheaper to implement Beneficial for NOx reduction
GACCOM - Detroit || 6/23/09 || 32
CONCLUSIONSIAC, new MIEC and NSF-I/UCRC can help to:1. Significantly reduce energy costs.2. Reduce greenhouse gas emissions.3. Reduce NOx and other pollutant emissions.4. Increase in productivity.5. Help use low calorific value inexpensive fuels.6. Multi-fuel capability.7. Oxygen-free atmosphere to prevent oxidation.8. Potential for in situ incineration of volatile
organic compounds.
GACCOM - Detroit || 6/23/09 || 33
Thank You!
Questions
GACCOM - Detroit || 6/23/09 || 34
GACCOM - Detroit || 6/23/09 || 35
Technology for TodayBestPractices
Steel Mining Petroleum
Aluminum
Metalcasting
Forest Products
Glass
AgricultureChemicals
Technologyfor theFuture
ITP Strategy for Today & Tomorrow
GACCOM - Detroit || 6/23/09 || 36
Industrial Systems Requiring more Knowhow:
• Process Heating Systems (PHAST)
• NOx and Energy Assessment Tool (NxEAT)
• Steam Systems (SSAT)
• Insulation Systems (3E Plus)
• Compressed Air Systems (AirMaster+)http://www1.eere.energy.gov/industry/bestpractices/software.html
Also: http://www1.eere.energy.gov/industry/about/brochures.html
Software available from ITP
GACCoM - Detroit || 6/23/09 || 37
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
1200 1400 1600 1800 2000 2200 2400 2600 2800
Temperature (K)
CO M
ole f
ract
ion
21% O225% O230% O235% O240% O2
Φ=1.0, Residence Time=0.5 sec
CO – A strong function of temperature
Perfect mixingGRI-Mech. 3.0 calculations
GACCOM - Detroit || 6/23/09 || 38
0.000
0.002
0.004
0.006
0.008
0.010
1200 1400 1600 1800 2000 2200 2400 2600 2800
Temperature (K)
NO
Mol
e fr
actio
n21% O2 25% O2 30% O2
35% O2 40% O2
Φ=1.0, Residence Time=0.5 sec
NO – Even stronger function of temperature
Perfect mixingGRI-Mech. 3.0 calculations
GACCOM - Detroit || 6/23/09 || 39
Some well-known facts: Benefits of Air Preheating
0
5
10
15
20
25
30
35
40
45
50
55
60
65
0 200 400 600 800 1000 1200Combustion air temperature oC
1500oF
2200oF
2550oF
Flue gas temperature oF
~ 50% savings are possible if combustion air could be preheated to 1800oF from flue gases at 2200oF
Currently possible with recuperators & regenerators
% R
educ
tion
in F
uel C
onsu
mpt
ion
by A
ir Pr
ehea
ting
GACCOM - Detroit || 6/23/09 || 40
Well known facts: Furnace efficiency for various O2% without air preheating
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000 1200 1400 1600 1800 2000Flue gas temperature oC
Eff
icie
ncy %
21% O2 35% O2 50% O2 100% O2
At 21% O2 & flue gas temperature of 1100 oC the furnace eff. is only 50%, whereas, at 100% O2 eff. is ~ 80% because of lower mass flow.
GACCOM - Detroit || 6/23/09 || 41
Oxygen Enrichment
50%
60%
70%
80%
90%
100%
21% 31% 41% 51% 61% 71% 81% 91% 101%% Oxygen in air
% F
uel C
onsu
mpt
ion
2000 1900 1800 1700 1600 1500 1400 1300 1200
1100 1000 900 800 700 600 500
Benefits of oxygen enrichment increase with the flue gas temperature
Oxygen Enrichment – Economic Analysis
GACCOM - Detroit || 6/23/09 || 42
IFRF - Boston || 6/08/09 || 43
FurnaceHigh temp. Exhaust at
1 ” wcExhaust
Optional high temp. recuperator
High pressure ambient air
Preheated high pressure combustion air
Hot bleed
Make up oxygen
HighTempair @21% O2
Schematic of the arrangement
High Temperature Recuperator
Preheatedair
OPTIONAL RECUPERATION
Red
uce
dex
haus
tto
air
o rre
cup
e rat
o r
Dil u
ti on
c ont
rolle
dby
jetl
e ngt
h&
mom
e ntu
m
To burner
80Froom air
o
Exhaust
High
tem
pera
ture
&hi
ghve
loci
tyflu
ega
sdi
lute
dai
ren
riche
dby
O2
Exhaust from the
furnace at ~ 1” wc
1
2
3
4
5
6
External Implementation –vertical orientation
0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
800.00
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
1 1.5 2 2.5 3 3.5 4
Mas
s flo
w R
ate
(kg/
s)
Pressure (bar)
SONIC
SC
FM
GACCOM - Detroit || 6/23/09 || 44R
educ
ed e
xhau
st
flow
rate
Dilu
tion
cont
rolle
d by
jet l
engt
h &
mom
entu
m
.
To burner
�
High pressure oxygen-enriched air
Hig
h te
mp
& h
igh
velo
city
flue
ga
s di
lute
d ai
r
.
1
2
3
4
6
Red
uced
exh
aust
flo
w ra
te
Dil u
tion
cont
rolle
d by
jet l
engt
h &
mom
entu
m.
To burner
�
Pressurized fuel gas or liquid or both
Hea
ted
dilu
ted
and
vapo
rized
fu
el g
ases
.
1
2
3
4
6
Ideal External Implementation
Possible Implementation
Preheated & diluted Fuel
Furnace Walls
Furnace Walls
Slot Injection of Fuel & Air to Create a Large
Volume Highly RadiativeCombustion Zone
GACCOM - Detroit || 6/23/09 || 45