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WORLD-GENERATION NOVEMBER/DECEMBER 2016
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FINSPANG, SWEDEN - Siemens
believes 3-D printing can transform turbine
manufacturing and recently opened its
Finspang factory to showcase its progress.
Incremental improvements in gas
turbine performance are becoming harder
and harder to achieve, but technological
advances have opened up the potential for
large gains in turbine production.
Siemens is investing millions of dollars
in 3-D printing, or additive manufacturing
(AM), as it is often called in an industrial
setting.
In August Siemens added to its AM
portfolio with the acquisition of an 85%
stake in Materials Solutions Ltd., a U.K.
company that pioneered the use of
Selective Laser Melting (SLM), which is
used to melt or “weld” powdered metal
compounds used in additive manufacturing.
Siemens began using AM for plastics in
1989 and began using it in power
generation in 2009. The company now has
three facilities for additive manufacturing,
the newly acquired facility in Britain, a site
in Berlin for large gas turbines, and its
largest AM site, in Finspang.
Finspang is a town of about 12,400
inhabitants roughly 92 miles (147
kilometers) southwest of Stockholm. It
would seem to be in the middle of nowhere,
but it has a history of turbine
manufacturing dating back to 1913. So
when Siemens acquired it in 2003, it
already had the tool shops and other
infrastructure needed for heavy
manufacturing.
Finspang is where Siemens
manufactures five of the 18 turbines in its
portfolio, including its best selling SGT-800
turbine, which ranges in capacity from 48
MW to 54 MW, and packages another three
turbines. In all, nearly half of the company’s
gas turbine fleet passes through Finspang.
Finspang is also on the leading edge of
Siemens’ AM efforts with capabilities that
run from design and development to
manufacturing and testing. The company
has been using AM in Finspang since 2009
and shipping turbines with AM components
from Finspang since 2013.
PUTTING AMTO WORK
The Finspang facility produces three
AM products for Siemens. The company
uses AM to make a fuel swirler for its SGT-
750, its newest gas turbine.
The swirler is a small cylinder about
one-and-a-half inches in diameter that is
hollow and fluted. It mixes fuel and air and
was designed specifically for the SGT-750.
All seven SGT-750s that have been shipped
have swirlers made using AM.
Other turbines have swirlers, but not of
the complexity of the one in the SGT-750.
That could only be done using AM, says
Vladimir Navrotsky, chief technology
officer in Siemens’ distributed generation
service division.
Siemens also uses AM to manufacture
a small clip that is used to control the
amount of cooling air going into the turbine
blade. The goal is to have AM produced
clips in all of the SGT-800 turbines. AM
chips have been in serial production since
2015, and Siemens uses AM to repair and
replace burner tips on burners that go into
turbines. In the past, the tip was cut off
along with some of the body of the burner
and a new tip was welded in place. Using
AM, the company is able to cut off the
burner tip closer to where it meets the
body of the burner. The body of the burner
is then put in the 3-D printer and the new
burner tip is built in place. Siemens is using
AM to repair burner tips for both its SGT-
700 and SGT-800 turbines and says AM can
do the job about 60% faster than is possible
using conventional methods.
But Siemens is looking to get the most
value out of AM by expanding it to larger
components, such as the entire burner. The
burner is a critical component of a gas
turbine. It sits between the compressor
blades and the turbine combustor blades
where it mixes air and gas and burns the
fuel at temperatures up to 1,500 degrees
Celsius.
A burner for a SGT-700 or a SGT-800 is
about 700 millimeters long and weighs as
much as 20 kilograms. It includes flanges
or vanes for mixing air into the fuel mix, as
well as nozzles for fuel and, at the end of
the unit, the burner tip.
AM also eliminates the welding needed
to put together the parts of a conventional
burner. Siemens says AM will enable it to
use up to 63% less material and to design
some elements into the burner tip rather
than add them on at a later stage. For
instance, conventional burners require
external tubing for fuel. With AM, the
tubing is incorporated into the design and
runs inside the walls of the combustors like
veins.
AM also allows flexibility in the design
of the burner tips. Different types of lattices
can be manufactured into the fuel nozzles
of the burner tips. Different lattice patterns
allow the burners to burn different fuel
mixes, such as biomass or natural gas
mixed with other reactive fuels or with
hydrogen. Siemens says the wider array of
fuel mixes opens the potential for turbines
to operate with lower emission levels.
In early September, during a tour of the
Finspang facility, Thorbjoern Fors, CEO of
distributed generation service in Siemens’
power generation services division, said the
new fully printed burners would be “ready
in weeks.”
Next on the horizon for Siemens is the
3-D printing of turbine blades. Like
burners, turbine blades live in a harsh
environment with high temperatures, but
are also subjected to high centrifugal forces
and velocities that can reach the speed of
sound.
At present the AM materials are not
sufficiently developed to handle 3-D
printing of turbine blades, Novrotsky says,
but Siemens is using AM for rapid
prototyping of blades and eventually hopes
to use AM for the commercial production
of blades.
Using AM for turbine blades could reap
even more benefits. Engineering better
built-in cooling features into the design and
manufacture of the blades and making the
PERSPECTIVE
HEAVY INDUSTRY IS MOVINGTOTHE CLOUD
BY PETER MALONEY
(continued page 21)