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Double Reheat Technology
The next step to optimized efficiency
Answers for energy.
Modern Steam Power Plants:
On the Path to Increased Efficiency
The requirements of power suppliers for their modern steam power plants
have changed considerably in the past few years. The increasing demand for
reliable base load supply, combined with resource scarcity and environmental
regulations, drives the need for greater efficiency.
Technologies on test
A cost-intensive solution
One possible route to greater efficiency in modern steam
power plants is the so-called 700°C technology. And efficiency can indeed be increased through this innovative
solution. However, increased efficiency normally means
higher steam parameters. And as the required pressures
and temperatures increase, so does the stress on materials, inducing additional risks and maintenance costs.
To increase efficiency with steam temperatures beyond
700°C more resistant turbines are required. Materials
with higher resistances could therefore be the solution.
However this technology is still in its infancy and therefore expensive.
1981
1996
2009
> 2020
SPP Bergkamen
747 MW
SPP Boxberg
906 MW
Wai Gao Qiao III
2x1000 MW
700°C technology
39%*
SPP efficiency
190 bar / 530 / 530°C
43%*
SPP efficiency
47%*
SPP efficiency
> 50%*
SPP efficiency
260 bar / 540 / 580°C
270 bar / 600 / 600°C
350 bar / 700 / 720°C
*Net efficiency achievable with this technology – project-specific efficiency may vary.
Intelligent Optimization:
Double Reheat Technology
Siemens is tackling the issue of steam power plant efficiency optimization:
DRH technology is one smart step towards achieving 50% efficiency.
How DRH works
Expertise based on experience
The steam is reheated in two loops, thus entering the
different turbine modules with optimized parameters.
Siemens DRH technology has a long track record, stretching from the very first projects in the 1960s to the latest
state-of-the-art solutions. Today Siemens provides applications which can be used in steam power plants with an
output up to 1350 MW.
Benefits of DRH technology
In contrast to the 700°C technology the realization of a DRH
application is based on proven technology such as existing
turbine modules as well as known materials. This means
maximized overall efficiency with modest investment
costs at a high level of profitability and controllable risks.
DRH technology
vs.
700°C technology
50.2%
49.5%
3.2%
2.5%
47.0%
SRH with
state-of-the-art
technology
47.0%
Improvement
through DRH
technology
DRH with
state-of-the-art
technology
SRH with
state-of-the-art
technology
Improvement
through 700°C
technology
SRH with
700 °C
technology
Performance Counts:
Application Range for DRH Technology
Siemens DRH technology is the optimal solution for applications used
in steam power plants with an output between 600 and 1350 MW.
The double reheating of steam can be realized in two different ways.
HP turbine
Siemens DRH technology: benefits at a glance
•
•
•
•
•
Combined axial th
radial journal bea
Increasing efficiency up to 49.5%
Optimal use of resources
Consistent reduction of CO2 emissions
Lower operating risk compared to 700°C technology
Compliance with highest safety standards
Application range for DRH technology
DRH applications can be used in steam power plants with an output between 600 and 1350 MW.
600 MW
1000 MW
Tandem-compound configuration
The tandem-compound configuration
For smaller power output values the tandem-compound
configuration will apply. In this solution all modules are
mounted on one turbine-generator train. This configuration needs only one electrical generator.
H80
I50
I50
L2 x 12.5
L2 x 12.5
L2 x 12.5
* Third low-pressure turbine for output above 1000 MW, depending on project-specific parameters
LP turbines
2nd IP turbine
1st IP turbine
hrust and
aring
1200 MW
1350 MW
Cross-compound configuration
The cross-compound configuration
For higher power output values the cross-compound configuration is required. By splitting the steam turbine package into two separate turbine-generator trains it reduces
harmful mechanical stress on the rotor. Additional benefits: Increasing overall plant efficiency while at the same
time reducing CO2 emissions.
I50
H80
I50
I50
L2 x 12.5
L2 x 12.5
L2 x 12.5
Publisher and Copyright © 2014:
Siemens AG
Energy Sector
Freyeslebenstraße 1
91058 Erlangen, Germany
For more information,
please contact our
Customer Support Center.
Phone: +49 180 524 84 37
Fax:
+49 180 524 24 71
(Charges depending on the provider)
E-mail: support.ic@siemens.com
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Trademarks mentioned in this document are the
property of Siemens AG, its affiliates, or their
respective owners.
Subject to change without prior notice.
The information in this document contains general
descriptions of the technical options available,
which may not apply in all cases. The required
technical options should therefore be specified in
the contract.