hovalwerk ag 01.09.2002 1 gas condensing technology h2oh2o director - marketing und development...

Hovalwerk AG 01.09.2002 1

Gas Condensing Technology

H2O

Director - Marketing und DevelopmentHeating Technology Division

Markus Telian



Physical basics

Combustion

Efficiency

State of the art in boiler technology

Content



HHC C C C C C C C C CHH

HH HH HH HH HH HH HH HH HH HH

HH HH HH HH HH HH HH HH HH HH

HH

HH

C

C

C

C

C

C

C

C

HH

HH

C

C

C

C

C

C

C

C

C

C

C

C

C C

C C

HH

HH HH

HH

HH HH

HH HH

CHH

HH

HH

HH

C C C

HH HH HH

HHHH

HH HH HH

HHC C C C

HH HH HH HH

HH

HH HH HH HH

coalCoronen H:C = 0.5 : 1

oilDecan H:C = 2 : 1 Natural gas

Methan H:C = 4 : 1

Propane C3H6

Butane C4H8

Energy sources and their carbon / hydrogen ratio



natural gas

oil

coalwood

lignite

0.40 0.36 0.33 0.26 0.20

in kg in kg COCO2 2 / kWh / kWh fuel inputfuel input

COCO22-formation of different energy sources-formation of different energy sources



COCO22- production by comparison old or new- production by comparison old or new

0,40

0,31 0,29

0,220,18

100%old

combustion engineering

48% optimized

combustion engineering

oldOil

ges = 0.65

oldN.Gas

ges = 0.65

newN.Gas

ges = 0.90

newGas

Condensingges = 1.09

newOil

ges = 0.90

... in kg CO2 / kWh useful energy

0,25

newOil

Condensingges = 1.04



FuelsPhysical basics for condensation firing fuel oil or gas

Gross calorific value(Ho)

net calorific value (Hu)

theoretical condensingppower generationower generation (Ho-Hu)

theoreticalaccrual condensing wateraccrual condensing water

steam dew pointsteam dew pointat Lambda 1.2

acidity - pH-value

12.56 kWh/kg

11.80 kWh/kg

0.76 kWh/kg

1,3 kg HEL

47°C

~ 2 - 4

11.14 kWh/m3

10.06 kWh/m3

1.08 kWh/m3

1.6 m3/ Erdgas H

56°C

~3 - 5

FuelOil

NaturalGas



Schematic representation

Chemical reactions:

COO OO = CO2 (carbon dioxid)

H HOO = H2O (water vapour)

gasCH4 C H

H

H

H

OO OOS = SO2 (sulphur dioxid)

CO2+ 2H2OAfter the combustion

Combustion of 1m3 natural gas



Wherein lie the most important savings of energy?

a) Lowering the flue gas temperature Conventional boiler: flue gas temperature 140 °C up to 190 °C

Condensing boiler: flue gas temperature 5 K up to 20 K above return temp.

approxmimate value:

Reduction of the flue gas temperature by 20K gives an increase of the

efficiency of 1%.

b) Condensation fo the water steam in the flue gas (latent heat: 0.66 kWh/kg condensate)



(Hu)

HH22OO

""vaporousvaporous""

(Ho)

HH22OO

„fluid"„fluid"

Gai

ned

qu

antit

y of

he

at a

t ful

lco

mbu

stio

n

2.)

1.)

net & gross calorific valuenet & gross calorific value

1.111.091.081.061.06

10.06 kWh/m3

25.88 kWh/m3

34.32 kWh/m3

11.80 kWh/kg10.08 kWh/l

11.14 kWh/m3

28.11 kWh/m3

37.17 kWh/m3

12.56 kWh/kg10.68 kWh/l

Natural Gas H*PROPANE BUTANE HEIZÖL EL**HEIZÖL EL

gross (Ho) net (Hu) relation Ho / Hu

fuels

2) Referred efficiency determination on Hu (100 %)

* russian natural gas** Specifikation ÖMV "Futura"

1) the larger the difference between gross and net calorific value the larger the energy gain!

Influence and characteristicsggross calorific valueross calorific value

netnet calorific value calorific value



Return

Flow

Condensate Drain

Flue Gas

Fuel and Combustion Air

1200 - 1600 °C

First part of the heat exchanger

Second part of the heat exchanger

120 - 180 °C

~ 40 °C

< 35 °C

Burner Design:

Atmospheric Burner, Premix Burner, Pressure Jet Burner

Schematic picture of a condensing boiler

Temperatures are examples!



Bo

iler

Sh

ellDew point

Flue Gas 52 - 57 °C

Boiler WaterFlue Gas

Combustion

COCO22Fuel Dew Point specific amount

of condensationTheor. max.CO2-Content *)

Natural Gas ~ 56°C

~ 52°C

~ 51°C

~ 47°C

0.16 kg/kWh

0.12 kg/kWh

0.12 kg/kWh

0.09 kg/kWh

11.8 %

13.7 %

14.1 %

15.3 %

PROPANE

BUTANE

Fuel Oil EL*) ÖNORM M7510,T2



60

50

40

30

20

10

4

6

8

10

12

14

16

Dew

po

int

°C

CO

2-C

on

ten

t V

ol.

-%

05 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Water Contnet (Vol.-%)

Natural GasNet CV = 10,04 kWh/m3

CO2max = 12,0 %

ColeNet CV = 7,91 kWh/kgCO2max = 20,6 %

FuelOil ELNet CV = 11,86 kWh/kgCO2max = 15,3 %

Dew pointin dependenceof thefuel and theCO2-content


Gas Condensing TechnologyE

ffic

ien

cy %

Amount of Condesateg/kWh

20 30 5040 600

30

60

90

120

1020

4050

7080

100110

Return Temperature °C

air ratio 1.1

natural gas H

95

110

105

100

90

1

Efficiency

Condensate

3

.... Depends on the temperature

difference in the boiler shell

2

Amount of condensate and efficiency in dependence of the return temperature

Condensate in real (Theory = 100%): ~70-75 %

~60-65 %

~45-50 %

naturalgas



UltraGas® efficiency -comparison ( )

Available heat

90 % gross

100 % net

93 % net87 % gross

91 %net85 % gross

Radiation losses

Not usedcondensationheat

Fluegas losses

100 % gross

111 % net

109 % net98 % gross

108 % net97 % gross

Low temperature-boiler Condensing boiler-gasCondensing boiler-oil

100 %gross

106 % net

104 % net98 % gross

103 % net 97 % gross

gross (GCV)

net (LCV)

Radiation losses Radiation losses

Fluegas losses Fluegas losses



gross (GCV) gross (GCV)

net (LCV)net (LCV)

Available heat Available heat



UltraGas® efficiency comparison ( ) acc. to DIN 4702 - 8

75 / 60 °C75 / 60 °C

40 / 30 °C

LT-boiler Condensing boiler

86 % (gross)95 % (net)

95 % (gross)105 %(net)

98 % (gross)109 % (net)

The efficiency calculated according to DIN 4702 - 8 is an objective and comparable figure for boilers (heating mode)



A single pass, natural gas down fired, firetube boiler.

Fully condensing capable, hot water boiler.

boiler sizes with capacity range of 50kW through 650kW single and from 250kW to 1300kW as double unit available.

UltraGas®

State of the art in boiler technology



General plan of types modulating ratio power range at 40/30°C

UltraGas® (50) 13 - 52 kWUltraGas® (60) 13 - 62 kWUltraGas® (80) 21 - 82 kWUltraGas® (100) 21 - 101 kW UltraGas® (125) 25 - 125 kWUltraGas® (150) 32 - 150 kWUltraGas® (200) 44 - 202 kWUltraGas® (250) 49 - 250 kWUltraGas® (300) 55 - 300 kWUltraGas® (350) 55 - 350 kWUltraGas® (400) 99 - 400 kWUltraGas® (450) 99 - 450 kWUltraGas® (500) 99 - 500 kWUltraGas® (650) 94 - 650 kW



General plan of types modulating ratiopower range at 40/30°C

UltraGas® (250D) 25 - 246 kW UltraGas® (300D) 32 - 300 kWUltraGas® (400D) 44 - 404 kWUltraGas® (500D) 49 - 500 kWUltraGas® (600D) 55 - 600 kWUltraGas® (700D) 55 - 700 kW UltraGas® (800D) 99 - 800 kWUltraGas® (900D) 99 - 900 kWUltraGas® (1000D) 99 - 1000 kWUltraGas® (1300D) 94 - 1300 kW



Optimised stratification, a counter flow heat exchanger design to provide optimal heat transfer Heavy Polymer flue gas collection box prevents acidic corrosion.

Design



The extended heating surface design provides the ideal solution for the demands of a condensing boiler and helps to recover virtually all the latent heat of the flue gas.

The tube consists of an outer stainless steel 1.4571 (316 Ti) tube (waterside) and an aluminium profile on the flue gas side.

The Clearfire is also qualified for the use of inhibitors. I.e. used in heating systems with oxygen diffusion.

aluFer®



Aluminium has a ten times higher heat conductivity compared to stainless steel.

The complex aluminium profile with fins and micro structures produce a huge heat transfer surface.

The micro structure causes a complex turbulent flow pattern and intensities the heat transfer.

The vertical position of the tubes enables a self-cleaning effect. A reduction in efficiency due to deposits on the surface is avoided.

each aluFer® tube is divided into eight flow channels.

As a result, turbulent flue gas flow is created and a hot core stream is avoided

aluFer®



extremely clean combustion

turn down ratio 1 : 6.5

low noise

minimum electrical power consumption

Ultraclean®- burner system



schematic diagram

Gas valve

Air

Gas

Fan

Burner

Venturi

p Ignition

Ultraclean®



The Clearfire®-premix burner is made of a high temperature resistant Fecralloy metal fibre

almost flameless combustion of thehomogeneous gas / air mixture.

The solid body radiation of the burner surface cools the flame and enables extremely low emissions.

The flexible metal fabric prevents thermal stresses, resulting in a long lifetime of the

Ultraclean®-premix burner. Ultra Low NOx Performance

Ultraclean®



UltraGas® (300,350,600D,700D) emissions

NOX and CO in relation to the burner load (dry, 3 % O2)

01020304050607080

0 10 20 30 40 50 60 70 80 90 100

burner load [%]

NO

x / C

O in

[m

g/m

]3

NO(x) UltraGas® (300,350,600D,700D) CO UltraGas® (300,350,600D,700D)



Summary

Condensation

Maximum efficiency

Saves money

Less primary energy used

Less CO2 (approx 42%)

Protects the Environment

hovalwerk ag 01.09.2002 1 gas condensing technology h2oh2o director - marketing und development...

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