Power Plants in northern Germany – Project
examples for optimizing intakes and outfalls
Oliver Stoschek
DHI – Coastal Engineering
Head of branch office, DHI-WASY Germany
Agenda
•
•
•
•
•
•
© DHI
Scope
Method
Coastline Example - Wilhelmshaven
Brackish Environment – Brunsbüttel
Tidal River – Stade
Summary
01.
Scope
© DHI
Scope
• EIA for 15 Power Plants from 2006 to 2012
EIA criteria (Heat Capacity Plan):
ΔT < 3K @ max. 500m radius,
3K < 25% cross section,
T < 28°C (peak 30°C),
< 0.3 m/s at intake (fish)
>80% oxygen at outfall
must be fulfilled.
• Only 2 locations are realised
Adaption of local structures
to optimize costs.
© DHI
02.
Method
© DHI
Method
Proof the setup – revise the setup – proof it again
• Numerical 3-D models were used (MIKE3 & Ecolab & Particle
Tracking & Sediment & Transport – DHI, OpenFoam (CFD))
• Worst case situations were studied:
summer time, characterized by high temperatures and low upstream
discharge (as far as applicable)
Optimize the layout to stay
within the EIA criteria and have
an optimised output
© DHI
Method / Location
1. Wilhelmshaven can be found at the German
coastline without any influence from upstream
discharges.
2. Brunsbüttel is located in the estuary of the
River Elbe, a specific brackish environment
with 3-dimensional currents.
3. Stade is located inside the Elbe River in a
tidal environment. It is dominated by tides and
upstream discharge. Low oxygen content and
nature reserve areas are driving the design.
All examples: tidal range up to 4m
© DHI
03.
Coastline Example - Wilhelmshaven
© DHI
Wilhelmshaven
• Longshore current
• Existing plant near by
• … and a new port
-> no longshore current
-> additional sedimentation
• Optimize the position of the outfall to obtain
the least impact on the existing plant and
minimize the recirculation (MIKE 3)
• Assess sediment transport (MT/ST)
• Optimize the intake (CFD)
© DHI
Model Area
Wilhelmshaven
30 m³/s @ ΔT of 7K
-> Position 3 was chosen
Pos. 1 has higher impact
on neighboring plant
Pos. 4 and 5 have an
significant impact on
recirculation
© DHI
Optional Locations
Wilhelmshaven
A diffusor was chosen as a first choice
-> High sedimentation occurs
-> New solution needed
© DHI
Diffusor
Wilhelmshaven
• A single point outfall was chosen
• The intake design was optimised (<0.3m/s)
Outfall
Intake
© DHI
Wilhelmshaven
mean temperature increase
© DHI
max temperature increase
04.
Brackish Environment – Brunsbüttel
© DHI
Brunsbüttel
• Longshore current > 1.5 m/s
• Existing plants near by
• Optimize the position of the
outfall to obtain the least impact
on the existing plants and
minimize the recirculation
(MIKE 3)
• Deliver long term 3D-HD data
for a habitat model (1 year)
Mittelwert
mean
• Impact on O2 (Ecolab)
© DHI
Model Area
Temperature (July/August) near bottom
Wassertemperatur [°C]
2002
2003
2004
2005
2006
20.3
21.2
19.6
19.6
22.1
minimum
Minimum
17.0
18.0
16.7
17.5
18.9
maximum
Maximum
23.6
24.7
22.8
21.4
25.2
Brunsbüttel
Intake upstream or downstream?
• 40.000m³/s tidal discharge
• full vertical mix of cooling water in
riverine water
intake downstream, outfall upstream
(1b)
• Less impact on NPP
• Less recirculation (deeper water)
• No EIA criteria will be violated
© DHI
Temperature increase ΔT (K)
Brunsbüttel
Location / Variant
Max.
Mean
Intake NPP Var. 1a
2.4
0.4
Intake NPP Var. 1b
1.0
0.3
Intake SWS Var. 1a
1.3
0.4
Intake SWS Var. 1b
0.9
0.3
Temperature increase (vertical average) at the planned SWS coal fired power
plant (CFPP) in Brunsbüttel (variant 1b)
© DHI
Brunsbüttel
© DHI
05.
Tidal River – Stade
© DHI
Stade
•
•
•
•
No significant longshore current
Low O2 values
Nature reserve area near by
6.000m³/s tidal discharge / 150
to 3.500m³/s river discharge
• Pier is blocking cross currents
• Optimize the position, water
deth and length of the pier to
stay in EIA criteria (MIKE 3)
• Impact on O2 (Ecolab)
© DHI
Stade
Current speed during flood
period at the surface
Current speed during ebb period
at the surface
© DHI
Stade
maximum exceedance of
3°C excess temperature
(sliding 6 hour mean value)
© DHI
06.
Summary
© DHI
Summary
• Three examples for intake and outfall designs at the northern
German coast were shown.
• Each example was adapted to the local situation. Numerical 3D
hydraulic models were used to optimize the shape, size and location
of the structures.
• All examples show the clear demand of on-site investigations to
optimize the design for intake and outfall structures
– not one design for all, not only heat is driving the design.
• In all shown cases optimization was needed to stay within the
environmental criteria, e.g. the size of the mixing zone
© DHI
Thank you
Oliver Stoschek
© DHI
About DHI
DHI are the first people you should call when you have a tough
challenge to solve in a water environment.
In the world of water, our knowledge is second-to-none, and we strive
to make it globally accessible to clients and partners.
So whether you need to save water, share it fairly, improve its quality,
quantify its impact or manage its flow, we can help. Our knowledge,
combined with our team’s expertise and the power of our technology,
hold the key to unlocking the right solution.
© DHI