הרצאת וולקן גרדן - לדיקו גרין

Energy Efficiency

in Industrial Heating

Systems

וולקאן גרדאן Volkan GERDAN

Mechanical Engineer

Energy Manager (Buildings and Industry)

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.

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)

First Step into Energy Efficiency

10 - 5 - 2 - 1 - 0.5 - 0.1 %

What is more important?

Leaking

DroppingTap Visible!

Leaking

DroppingEnergy Invisible!



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.

• 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


• Efficiency Increasing Projects (EIPs)

4Ro Reduceo Reuseo Recycleo Rethink



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%



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.



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.

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


• Economizers


• Economizers

• Fuel savings 5% or more

• Pre-heating of the boiler’s feedwater

• Pre-heating of any other circuit is possible

Steam

at 10 bar

184°C

Economiser with

integrated by-pass

Chimney

Flue-gas

temperature

>200°C

Heavy Oil

~160°C

Gas

~120°C


• Economizers

• Stand alone versions allow

• Implementation to any steam boiler

• Gas, light oil or heavy oil


• 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

Air

EconomizerExhaust

Fresh-Air

from

CHP Plant

from

Flash

steam

from

Steam

Boiler


• Case Study: Paper Mill

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

Paper Mill:

2.0 t/day of 300 g/m2 paper increased to 3.1 t/day

810 kW out of 3,370 kW recovered !!!


• Using the “high” calorific value of the fuel

via condensation technology

Condensing Boiler

Vapor

High

Calorific

Value

Low Calorific Value

Condensation

Heating

System

Used Heat


What is

Condensation

Technology?


Heating

Energy

+ CO2 + H20

FuelNatural gas, Fuel-oil,

Diesel-oil etc.

(C,H,O …)

Air (O2) Losses

• Summary of Heating


Chimney Heat Losses

Losses of Energy Due To

The Latent Heat In Water

Vapor

Very Low Flue Gas

Temperatures

Condensation

• Heat Losses and Recoveries

D:/Ekin/Desktop/Yoğuşmalı Sunum/MOV00564.mpg


• Is 110% efficiency possible?

km/hmiles/h

100 miles/h > 100 km/h


Lower Heating Value Hs

The latent heat in water vapor is not

taken into consideration and the rest

is accepted to be 100%.

Higher Heating Value Hi

The latent heat in water vapor is

taken into account and the total is

accepted to be 100%.

For natural gas:

8.250 kcal/m3 9.155 kcal/m3

100 units of energy 111 units of energy



Total Heat Recovery of Condensing Boiler: 5 – 17%

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%



• Condensing boilers


• Condensing boilers


• 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)


• Radiation losses are relative to

• Dimensions

• Water volume

• Weight

Stand-by and

radiation losses Chimney losses

Fuel losses


• 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%


• 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


• 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


• 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!


• 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%

Boilers with jet burners

Burner’s blower and chimney run as two fans in serial

connection.

Combustion air is under effect of ambient conditions.

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)


• How to control the combustion?

• How to control the combustion?


Start-Up /

Maintenance Day

To= 20oC

Colder Day

To = 5°C

Warmer Day

To = 30°C

Higher draught and

Higher air surplus

Low Efficiency

Lower draught and

Lower air surplus

Low Efficiency and Soot


• 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)


• 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



• 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.



Fuel

100%

Thermal

Losses

68%

Electricity

32%

Fuel

100%

Thermal & Mechanical

Losses

20%

CHP Plant

Electricity

Steam

Hot water

Hot air

Chilled water

Useful

80%


• 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

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!)

תודה רבה

הרצאת וולקן גרדן - לדיקו גרין

Documents

efficiency

energy efficiency

power generation

water vapor

energy consumption

energy intensity

annual savings

temperature