Burner Retrofits:

Opportunities Yielding Worthwhile Paybacks

Norbert Hennrich

March 9, 2016

High Efficiency Burners

Agenda

• Boiler Efficiency

• Efficiency Losses

• Combustion Basics

• Tune-Up

• Turndown Ratio

• Key Factors for Maximum Efficiency

• Boiler Project Examples

Existing Boiler Market

• Boiler Population ≅ 400,000 units of commercial & industrial

boilers in North America

• Consumes 25% of the world’s energy

Existing Boiler Market

Boiler Age < 20 Years Old

(40%)

> 20 Years Old

(60%)

Efficiency (Based on HHV) Better than 75%

(40%)

Between 70-75%

(60%)

Potential Savings By increasing combustion efficiency by 10% there is a potential to save 400 million

barrels of oil equivalent per year.

15 billion $US wasted per year.

∆ barrel oil = 35 $US

Boiler Efficiency

1. Combustion Efficiency

• Higher levels of combustion efficiency can only be achieved when

fuel and air are properly mixed.

2. Flue Gas Temperature

• Dependent on boiler’s ability to absorb heat as well as on excess air

• Cleanliness of heat exchanger = big factor

3. Turn Down Ratio

• Equipment needs to be sized for the actual needed capacity to

eliminate unnecessary cycling (purging of air through the system.)

Efficiency Losses in a Boiler System

1%

100%

76% 20%

3%

Efficiency Losses in a Boiler System

• Radiant Losses (approx. 4%)

• Insulation of boiler jacket and insulation of pipes and valves

helps reduce radiant losses!

• Stack Losses (approx. 20%)

• Stack Temperature

• 35-40 ˚F increase equals approx. +1% in energy loss

• Combustion Efficiency

• Oxygen not used in combustion process = additional losses

• Turndown Ratio of Burner Equipment

• Purging & Boiler Cycling

Combustion Efficiency

Combustion Efficiency

Combustion

Chamber

Pressure

Air Pressure Air Temperature

To prevent a shortage of air being caused by external

factors, excess air is used for combustion

Excess air

+15…20%

Excess air = inert particles loss of heat

Fan Contamination Chimney Draught

Some Burners Use More than 100% Excess Air

Combustion Efficiency

Combustion with 15% Excess Air Combustion with 50% Excess Air

O2 Content: 3%

CO2 Content: 10%

Loss of Heat: Low

O2 Content: 7%

CO2 Content: 8%

Loss of Heat: High

Excess Air vs. Oxygen

Boiler Efficiency — Tune Up

Boiler HP Fuel Cost

$0.75 $1.00 $1.50 $2.00

100 $3,635 $4,847 $7,271 $9,694

200 $7,271 $9,694 $14,541 $19,389

300 $10,906 $14,541 $21,812 $29,083

500 $18,177 $24,236 $36,354 $48,471

800 $29,083 $38,777 $58,166 $77,554

Possible savings per year with a 5% improvement in boiler efficiency

(based on 3,000 hours per year of operation)

Although stack losses are unavoidable, an equipment tune-up using combustion analysis

data can often significantly reduce this source of heat loss and save fuel costs by

improving fuel efficiency.

Source: EPA.gov

Boiler Efficiency — Tune Up • The Usual Conclusion:

• Service and clean boiler/heat exchanger on a regular basis.

• Tune-up the burner to reduce excess air to the minimum of what the

boiler can use.

• What Else Can Be Done?

• A burner retrofit or boiler changeout!

• Why?

• To further increase the combustion efficiency through tighter 02

settings.

• Increase in Turndown Ratio (overall operating range of boiler

system.)

Boiler Efficiency — Turndown Ratio

• What is Turndown Ratio?

• Turndown is the burner’s ratio of capacity at

full fire compared to its lowest firing point

before shutdown.

• Boilers with a wider Turndown Ratio are

typically more efficient at meeting variable

loads.

• A properly sized boiler operation with a high

Turndown Ratio eliminates almost all purge

cycles.

Boiler Efficiency — Purge Cycles

• What are Purge Cycles?

• Boilers must run a purge cycle at the start of each on-cycle

to assure that there is no accumulation of explosive gases in

the fire box.

• By Code, enough air must be blown through the boiler to

perform an air exchange of 4x the volume of the fire box.

• This purging with cold air also removes heat from the boiler!

• Flames tend to be the most unstable and heat transfer is

at its lowest at start-up.

• Reducing the number of on-cycles increases boiler efficiency

and the life of the existing boiler by eliminating stress on the

boiler vessel.

Heating Loss Due to Purge Cycles

Number of Cycles/Hour Percentage of Energy Loss

2 2%

5 8%

10 30%

Source: Boiler Efficiency Institute

Key Factors for Maximum Efficiency

• Accurately sized equipment*

• Regular tune-up/service for maximum efficiency

• Operation range/turndown ratio*

• Excess air levels during entire operating range – combustion efficiency*

*Limitations which can only be overcome by a burner retrofit or

equipment change-out.

Linkage Controls vs. Linkageless Controls

One stepping motor for

air and fuel connected

via Linkages (Rods).

Differential is prone to

drift over time.

Linkage Controls vs. Linkageless Controls

• A linkageless control system

provides precise matching of

fuel and air via designated

stepping motors (no drifts.)

• The burner can be precisely

commissioned per the individual

boiler application.

• Result: Highest turndown and

lowest excess air.

Burner Retrofit Rational —

600 HP/20,085 Boiler

Efficiency

Gain = 10%

Payback = 4 years

$350,000

Purchase new

boiler/burner package

$200,000

Remove old boiler

$30,000

Install new boiler

$120,000

Burner Retrofit Rational —

600 HP/20,085 Boiler

• Net result of high efficient burner retrofit versus

boiler replacement:

• Capital cost reduced by $230,000

• Continuous fuel savings of 7%

• < 2 year payback

Retain existing boiler

$0

Retrofit w/ high efficient

burner: $ 60,000

$120,000 Efficiency gain = 7%

Payback = 2 years

Install burner

$60,000

In Summary

• Great Candidates for Burner Retrofits:

• Boiler/Burner installations with:

• High average excess air levels (> 5% excess air)

• High runtimes (Therms usage) (>3,500 hrs per year)

• Large load swings (turndown ratio < 6-1)

• Oversized equipment (potential of additional savings

by de-rating equipment)

Backup

Hospital Customer A

Retrofitted with high efficiency/high

turndown burner

Outcomes:

• Natural Gas Saves $29,770 annually

• $35,822 Ameren Illinois Incentive

• 1.5 Year Payback

Hospital Customer B

Weishaupt WM-GL30 Duel Fuel Burner

for use with new Hurst boiler

Integration with Building Automation

System

Outcomes:

• Saves 19,762 Therms annually

• $23,715 Ameren Illinois Incentive

Large Food Manufacturer

Existing register-style burners could

not produce the 65,000 pounds of

steam per hour they said they could

Retrofitted with high efficiency burners

that could produce 65,000 pounds of

steam per hour

Outcomes:

• Saves 342,206 Therms/Year with

Added Capacity

• $480,000 Ameren Illinois Incentive

• 2 Year Payback

Ameren Illinois Energy Efficiency Program Incentives:

28

• 12% customer bonus added to gas incentives

• Project must be submitted on or after Jan. 13, 2016 (no equipment/materials could have been purchased prior to Jan. 13)

• Project must be completed by May 31, 2016

• Potential gas-saving project ideas include:

• Steam traps

• Mechanical insulation

• Ozone laundry systems

• Commercial kitchen equipment

• HVAC controls

• Visit ActOnEnergy.com/GasBonus for details

Ameren Illinois Energy Efficiency

Program Energy Advisors

Call 1.866.800.0747

to request a consultation with an

Energy Advisor

1. Chad Whitehead Chad.Whitehead@gdsassociates.com 309.620.6333 2. Steven Smith Steven.L.Smith@leidos.com 309.212.5831 3. Rod Rhoads Rod.Rhoads@gdsassociates.com 217.649.8897 4. Mark Steinmetz Mark.Steinmetz@gdsassociates.com 217.670.9606 5. John Strode John.Strode@gdsassociates.com 309.370.0062 6. Fred Joshu Fred.M.Joshu@leidos.com 309.433.4316 7. Larry Erwin Lawrence.F.Erwin@leidos.com 309.838.2340

Questions?