1. Energy Efficiency
in Industrial Heating
Systems
‫גרדאן וולקאן‬ Volkan GERDAN
Mechanical Engineer
Energy Manager (Buildings and Industry)

2. An Indian Proverb
Only when the last tree is cut.
Only when the last river is polluted.
Only when the last fish is caught.
Only then will they realize that
you cannot eat money.

3. Energy Efficiency
• Energy Efficiency – Energy Saving
• Two phrases that are most confusing.
• Energy Saving
is reduction of energy consumption
with one or multiple measures,
resulting in foreseen reduction or change in
quality, quantity, comfort, safety etc.
• Energy Efficiency
is reduction of energy consumption
while producing the same quantity
in the same quality.
(…or more in higher quantity)

4. First Step into Energy Efficiency
10 - 5 - 2 - 1 - 0.5 - 0.1 %
What is more important?
Leaking
Tap Visible!
Dropping
Leaking
Energy Invisible!
Dropping

5. First Step into Energy Efficiency

6. First Step into Energy Efficiency

7. Energy in the Industry
• Energy is used in two major forms in the industry:
• Electricity
• Heat
• Many of the electricity consuming processes
are heat sources by themselves.
• A good portion of electricity consumption is
caused by heat production or distribution.
So there’s no possibility of a real reduction of energy intensity
without taking both into consideration.

8. Energy in the Industry
• Energy intensity
• It’s basically the ratio of energy consumption with production.
• Calculated as TOE of energy consumed per 1,000 USD sales revenues.
• As example: Energy intensity of several countries
e
OECD 0.17
North America 0.20
Europe 0.14
Asia 0.17
EU27 0.12
Germany 0.11
UK 0.09
Japan 0.09
Switzerland 0.06
Israel 0.14

9. Energy in the Industry
• Efficiency Increasing Projects (EIPs)
4R
o Reduce
o Reuse
o Recycle
o Rethink

10. Energy in the Industry
• Efficiency Increasing Projects (EIPs)
Optimization Projects:
With no or limited investment costs
easily applicable by the industrial facility itself.
Example:
Temperature setting in an office:
1°C means 10%

11. Energy in the Industry
• Efficiency Increasing Projects (EIPs)
Improvement Projects:
With low investment costs
implemented on the existing process.
Example:
Heat insulation of the existing
pipes:
Payback times less than half a
year are possible.

12. Energy in the Industry
• Efficiency Increasing Projects (EIPs)
Upgrading Projects:
With varying investment costs
resulting in higher, sustainable energy efficiency changes.
Example:
Economizer integration to an
existing steam boiler:
5% or more saving can
be achieved without
further costs.

13. Efficiency Increasing Projects
• Heat Recovery
• It’s one of the most applicable methods of energy efficiency increase.
• Anything carrying excess heat is the source disregarding its
temperature:
• Discharged hot water from any process heater
• Ovens (heat-recovery from multiple points possible)
• Condensate return of the steam system
• Boiler’s flue gases

14. Efficiency Increasing Projects
• Economizers

15. Efficiency Increasing Projects
• Economizers
• Fuel savings 5% or more
• Pre-heating of the boiler’s feedwater
• Pre-heating of any other circuit is possible
Steam Chimney
at 10 bar Flue-gas Heavy Oil
184°C temperature ~160°C
>200°C
Economiser with Gas
integrated by-pass ~120°C

16. Efficiency Increasing Projects
• Economizers
• Stand alone versions allow
• Implementation to any steam boiler
• Gas, light oil or heavy oil

17. Efficiency Increasing Projects
• Ovens and Drying
• Optimization project: Change of temperature setting (Rethink!)
• Heat-recovery options:
• Air recirculation
15 – 40% efficiency increase
• Air pre-heating
15 – 25% efficiency increase

18. Efficiency Increasing Projects
• Case Study: Paper Mill
Air
Economizer Exhaust
Paper Mill:
2.0 t/day of 300 g/m2 paper increased to 3.1 t/day
Fresh-Air
from from
from
Flash Steam
CHP Plant
steam Boiler
810 kW out of 3,370 kW recovered !!!
Implementation of heat recovery system to an existing paper mill:
24% increase of energy efficiency
50% increase of production without increase of energy consumption
Investment amount: Annual Savings: Payback Period
220,000 EUR 7,806,000 kWh – 200,000 EUR Less than 1.5 years

19. Efficiency Increasing Projects
• Using the “high” calorific value of the fuel
via condensation technology
Condensing Boiler
High
Low Calorific Value Used Heat Heating
Calorific
System
Value
Condensation
Vapor

20. Efficiency Increasing Projects
What is
Condensation
Technology?

21. Efficiency Increasing Projects
• Summary of Heating
Air (O2) Losses
Fuel Heating
Natural gas, Fuel-oil,
Diesel-oil etc.
Energy
(C,H,O …)
+ CO2 + H20

22. Efficiency Increasing Projects
• Heat Losses and Recoveries
Chimney Heat Losses
Very Low Flue Gas
Temperatures
Losses of Energy Due To
The Latent Heat In Water
Vapor
Condensation

23. Efficiency Increasing Projects
• Is 110% efficiency possible?
miles/h km/h
100 miles/h > 100 km/h

24. Efficiency Increasing Projects
• Is 110% efficiency possible?
Lower Heating Value Hs Higher Heating Value Hi
The latent heat in water vapor is not The latent heat in water vapor is
taken into consideration and the rest taken into account and the total is
is accepted to be 100%. accepted to be 100%.
For natural gas:
8.250 kcal/m3 9.155 kcal/m3
100 units of energy 111 units of energy

25. Efficiency Increasing Projects
• Is 110% efficiency possible?
Chimney Heat Losses
LT Boiler 6 – 9%
Condensing Boiler 1 – 2%
Heat Recovery 5 – 7%
Condensation
LT Boiler 0%
Condensing Boiler 0 – 10%
Heat Recovery 0 – 10%
Total Heat Recovery of Condensing Boiler: 5 – 17%

26. Efficiency Increasing Projects
• Condensing boilers

27. Efficiency Increasing Projects
• Condensing boilers

28. Efficiency Increasing Projects
• Losses of a boiler
• Chimney losses
• Cooling losses
• Chimney losses occur only when the burner is running.
• Cooling losses occur
• Stand-by losses:
During stand-by on a fixed temperature
(when the burner is off)
• Radiation losses:
During the operation
(when the burner is running)

29. Efficiency Increasing Projects
• Radiation losses are relative to
• Dimensions
• Water volume
• Weight
Stand-by and
radiation losses Chimney losses
Fuel losses

30. Efficiency Increasing Projects
• The cooling losses are the sum of radiation and stand-by losses.
Burner running : Radiation losses 1,2%
Burner off : Stand-by losses 0,8%
Total cooling losses are
2% in average.
• During the operation of the burner, combustion and chimney losses are
happening.
Chimney losses : 7%
Combustion losses : 7%

31. Efficiency Increasing Projects
• Stand-by losses are depending on stand-by duration
• No stand-by means
• No stand-by losses.
• They are less than chimney losses.
Stand-by losses are in positive relation with boiler outshell area per kW
power
Higher boiler power has relatively less area.
• The ratio between chimney and stand-by losses:
in 70 kW 1:3
in 1000 kW 1:5

32. Efficiency Increasing Projects
• Combustion can affect both chimney and stand-by losses.
• In best way, the combustion is realized without any interruptions while
changing the capacity: Modulation
On – Off Operation Operation with modulation

33. Efficiency Increasing Projects
• Capacity modulation
• Boilers and burners are selected for the peak load.
• Normally they are running on lower capacities.
• In case of an on/off controlled burner, partial loads cause
very high cycling frequency!

34. Efficiency Increasing Projects
• Every cycling (on/off) causes
Reduction of burner economic life
A swap away period of the fan
Air sent to the chimney together with the rest heat
A period of bad combustion conditions
(with very low efficiency)
Loss of unused fuel
Stand-by (cooling) losses
• Annual losses via cycling
On-off burners: ~ 5%
Modulating burners: ~ 1%

35. Efficiency Increasing Projects
• How to control the combustion?
Chimney draught (Pa) = h x (r1-r2)
h = Height of the chimney (m)
r1= Density of outdoor air (kg/m3)
r2= Density of flue-gas (kg/m3)
Boilers with jet burners
Burner’s blower and chimney run as two fans in serial
connection.
Combustion air is under effect of ambient conditions.

36. Efficiency Increasing Projects
• How to control the combustion?
Start-Up / Colder Day Warmer Day
Maintenance Day To = 5°C To = 30°C
To= 20oC
Higher draught and Lower draught and
Higher air surplus Lower air surplus
Low Efficiency Low Efficiency and Soot

37. Efficiency Increasing Projects
• Choosing the right burner is an energy increasing project!
• One staged burners
• Two staged burners
• Modulating burners
• Modulating burners
with pneumatic mixing (soot-free burners)
• Larger capacities:
• Frequency controlled (> 2,000 kW)
• Oxygen controlled (> 3,000 kW)

38. Efficiency Increasing Projects
• Combined Heat and Power Generation
• Cannot be understood in the scope of energy efficiency.
• On the other hand it’s an important method of cost reduction.
• CHP basically allows to switch
from one energy source
to another.
• Important primary energy savings
and reduction of CO2 emissions
are generated

39. Efficiency Increasing Projects
• Combined Heat and Power Generation
• Is a CHP system applicable in my industrial facility?
• If a facility needs
• Heat
• Electricity
then the answer is “YES”.
For CHP, heat is always the prior demand.

40. Efficiency Increasing Projects
• Combined Heat and Power Generation
Thermal
Losses
68%
Fuel Electricity
100% 32%
Thermal & Mechanical
Losses
20% Electricity
Steam
Fuel Useful
Hot water
100% 80%
Hot air
CHP Plant Chilled water

41. Efficiency Increasing Projects
• Case Study: Plaster Factory
• Implementation of CHP’s heat recovery system to the existing tunnel
ovens as hot-air
• Feed-in of excess electricity
Investment amount: Annual Savings: Annual Income via Feed-In: Payback Period
910,000 EUR 180,000 EUR 240,000 EUR 2.2 years
Annual Primary Energy Savings: 1,480,000 kWh
Annual Reduction of CO2 Emissions: > 11,600 t eq

42. Other Topics of Energy Efficiency
• Compressed air systems: Up to 80% efficiency increase opportunities
• Implementation of renewable energy resources
• Thermal insulation
• Temperature settings
• Thermal storage
• Green buildings (factories)
• Recycling and waste management
• Energy monitoring (You cannot reduce if you cannot monitor!)

43. ‫תודה רבה‬