Gas Condensing Technology

busyicicleMechanics

Feb 22, 2014 (3 years and 5 months ago)

91 views

Hovalwerk AG






01.09.2002





1

Gas Condensing Technology

H
2
O

Director
-

Marketing und Development

Heating Technology Division

Markus Telian

Hovalwerk AG






01.09.2002





2

Gas Condensing Technology




Physical basics



Combustion



Efficiency



State of the art in boiler technology

Content

Hovalwerk AG






01.09.2002





3

Gas Condensing Technology


H


C


C


C


C


C


C


C


C


C


C


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


H


C


C


C


C


C


C


C


C


H


H


C


C


C


C


C


C


C


C


C


C


C


C


C


C


C


C


H


H


H


H


H


H


H


H


C


H


H


H


H


C


C


C


H


H


H


H


H


H


H


H


H


C


C


C


C


H


H


H


H


H


H


H


H


H

coal

Coronen H:C =
0.5 : 1

oil

Decan H:C =
2 : 1

Natural gas

Methan H:C =
4 : 1

Propane


C
3
H
6


Butane


C
4
H
8


Energy sources and their carbon / hydrogen ratio


Hovalwerk AG






01.09.2002





4

Gas Condensing Technology

natural gas

oil

coal

wood

lignite

0.40

0.36

0.33

0.26

0.20

in kg
CO
2
/ kWh
fuel input

CO
2
-
formation of different energy sources

Hovalwerk AG






01.09.2002





5

Gas Condensing Technology

CO
2
-

production by comparison old or new

0,40

0,31


0,29

0,22

0,18

100%

old
combustion
engineering

48%
optimized
combustion
engineering

old

Oil

h
ges

= 0.65

old

N.Gas

h
ges

= 0.65

new

N.Gas

h
ges

= 0.90

new

Gas
Condensing

h
ges

= 1.09

new

Oil

h
ges

= 0.90

... in kg CO
2
/ kWh useful energy


0,25

new

Oil
Condensing

h
ges

= 1.04

Hovalwerk AG






01.09.2002





6

Gas Condensing Technology

Fuels

Physical
basics

for

condensation

firing

fuel
oil

or

g
as

Gross calorific value
(H
o
)


net
calorific value (H
u
)


theoretical

condensing

p
ower generation

(H
o
-
H
u
)


theoretical

accrual condensing water


steam dew point

at

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/m
3



10.06 kWh/m
3





1.08 kWh/m
3





1.6 m
3
/

Erdgas H




56
°
C




~3
-

5


Fuel

Oil


Natural

Gas

Hovalwerk AG






01.09.2002





7

Gas Condensing Technology

Schematic representation

Chemical reactions:


C


O


O

=

CO
2
(carbon dioxid)


H


H


O

=

H
2
O


(water vapour)


gas

CH
4


C


H


H


H


H


O


O


S

=

SO
2

(
sulphur

dioxid)

CO
2
+ 2H
2
O

After the combustion

Combustion of 1m
3

natural gas

Hovalwerk AG






01.09.2002





8

Gas Condensing Technology

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)

Hovalwerk AG






01.09.2002





9

Gas Condensing Technology

(H
u
)

H
2
O

"
vaporous
"

(H
o
)

H
2
O

„fluid"

Gained quantity of heat at full

combustion

2.)

1.)

net & gross calorific value

1.11

1.09

1.08

1.06

1.06

10.06 kWh/m
3

25.88 kWh/m
3

34.32 kWh/m
3

11.80 kWh/kg

10.08 kWh/l

11.14 kWh/m
3

28.11 kWh/m
3

37.17 kWh/m
3

12.56 kWh/kg

10.68 kWh/l

Natural Gas H*

PROPANE

BUTANE

HEIZÖL EL**

HEIZÖL EL

gross (H
o
)

net (H
u
)

relation


H
o

/ H
u

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 characteristics

g
ross calorific value

net

calorific value

Hovalwerk AG






01.09.2002





10

Gas Condensing Technology

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!

Hovalwerk AG






01.09.2002





11

Gas Condensing Technology

Boiler Shell

Dew point

Flue Gas 52
-

57
°
C

Boiler Water

Flue Gas

Combustion

CO
2

Fuel

Dew Point

specific amount

of condensation

Theor. max.

CO
2
-
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

Hovalwerk AG






01.09.2002





12

Gas Condensing Technology

60

50

40

30

20

10

4

6

8

10

12

14

16

Dew point
°
C

CO
2
-
Content Vol.
-
%

0

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Water Contnet (Vol.
-
%)

Natural Gas

Net CV = 10,04 kWh/m
3

CO
2max

= 12,0 %

Cole

Net CV = 7,91 kWh/kg

CO
2max

= 20,6 %

FuelOil EL

Net CV = 11,86 kWh/kg

CO
2max

= 15,3 %

Dew point

in dependence

of the

fuel and the

CO
2
-
content


Hovalwerk AG






01.09.2002





13

Gas Condensing Technology

Efficiency %

Amount of Condesate

g/kWh

20

30

50

40


60

0

30

60

90

120

10

20

40

50

70

80

100

110

Return Temperature
°
C

air ratio 1.1

natural gas H

95

110

105

100

90

1

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 %


natural

gas

Hovalwerk AG






01.09.2002





14

Gas Condensing Technology

UltraGas
®



efficiency
-
comparison (


)

Available heat


90 % gross

100 % net

93 % net

87 % gross

91 %net

85 % gross

Radiation losses

Not used

condensation

heat

Fluegas losses

100 % gross

111 % net

109 % net

98 % gross

108 % net

97 % gross

Low temperature
-
boiler

Condensing boiler
-
gas

Condensing boiler
-
oil

100 %gross

106 % net

104 % net

98 % gross


103 % net


97 % gross

gross (GCV)

net (LCV
)

Radiation losses

Radiation losses

Fluegas losses

Fluegas losses

Not used

condensation

heat

Not used

condensation

heat

gross (GCV)

gross (GCV)

net (LCV
)

net (LCV
)

Available heat

Available heat

Hovalwerk AG






01.09.2002





15

Gas Condensing Technology

UltraGas
®


efficiency comparison

(


) acc. to DIN 4702
-

8

75 / 60
°
C

75 / 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)

Hovalwerk AG






01.09.2002





16

Gas Condensing Technology


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


Hovalwerk AG






01.09.2002





17

Gas Condensing Technology


General plan of types modulating ratio







power range at 40/30
°
C



UltraGas
®

(50)



13
-

52 kW


UltraGas
®

(60)



13
-

62 kW


UltraGas
®

(80)



21
-

82 kW


UltraGas
®

(100)



21
-

101 kW


UltraGas
®

(125)



25
-

125 kW


UltraGas
®

(150)



32
-

150 kW


UltraGas
®

(200)



44
-

202 kW



UltraGas
®

(250)



49
-

250 kW



UltraGas
®

(300)



55
-

300 kW



UltraGas
®

(350)



55
-

350 kW



UltraGas
®

(400)




99
-

400 kW



UltraGas
®

(450)




99
-

450 kW



UltraGas
®

(500)




99
-

500 kW


UltraGas
®

(650)




94
-

650 kW

Hovalwerk AG






01.09.2002





18

Gas Condensing Technology


General plan of types

modulating ratio







power range at 40/30
°
C




UltraGas
®

(250D)




25
-

246 kW


UltraGas
®

(300D)



32
-

300 kW



UltraGas
®

(400D)




44
-

404 kW



UltraGas
®

(500D)




49
-

500 kW



UltraGas
®

(600D)




55
-

600 kW


UltraGas
®

(700D)




55
-

700 kW



UltraGas
®

(800D)




99
-

800 kW


UltraGas
®

(900D)




99
-

900 kW


UltraGas
®

(1000D)





99
-

1000 kW



UltraGas
®

(1300D)





94
-

1300 kW


Hovalwerk AG






01.09.2002





19

Gas Condensing Technology

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


Design

Hovalwerk AG






01.09.2002





20

Gas Condensing Technology


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
®

Hovalwerk AG






01.09.2002





21

Gas Condensing Technology




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
®

Hovalwerk AG






01.09.2002





22

Gas Condensing Technology



extremely clean combustion




turn down ratio 1 : 6.5




low noise




minimum electrical power consumption

Ultraclean
®
-


burner system

Hovalwerk AG






01.09.2002





23

Gas Condensing Technology

schematic diagram

Gas valve

Air

Gas

Fan

Burner

Venturi

p

Ignition

Ultraclean
®


Hovalwerk AG






01.09.2002





24

Gas Condensing Technology


The
Clearfire
®
-
premix burner

is made of

a high
temperature resistant Fecralloy metal fibre


almost flameless combustion of the

homogeneous gas / air mixture.


The solid body radiation of the burner

surface

cools the flame and enables

e
xtremely low
emissions.


The flexible metal fabric prevents thermal

stresses, resulting in a long lifetime of the


Ultraclean
®
-
premix burner
.


Ultra Low NOx Performance


Ultraclean
®

Hovalwerk AG






01.09.2002





25

Gas Condensing Technology

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

NO
X

and CO in relation to the burner load (dry, 3 % O
2
)

0

10

20

30

40

50

60

70

80

0

10

20

30

40

50

60

70

80

90

100

burner load [%]

NO
x

/ CO in [mg/m]

3

NO(x) UltraGas
®

(300,350,600D,700D)

CO UltraGas
®

(300,350,600D,700D)

Hovalwerk AG






01.09.2002





26

Gas Condensing Technology

Summary

Condensation

Maximum efficiency

Saves money

Less primary energy used

Less CO
2
(approx 42%)

Protects the Environment