Abstracts - VGB PowerTech Journal 10/2008

The Development of Porous Multi-layer Systems for the 700 °C Steam Turbine Technology

Dieter Bohn

The development of thermally highly loaded, open-porous and cooled multi-layer systems for combined cycle power plants is aiming at the establishment of the technical and scientific fundamentals in order to achieve total efficiencies of 65 % in future combined cycle power plants as of the year 2025. This requires gas turbine entrance temperatures of 1350 °C (ISO) and steam turbine temperatures of 650 to 690 °C. These temperatures can be achieved through the development of new materials in connection with effusion cooling.

Steam Turbine Operation and Damage after Long Service Time

Stefan Thumm, Martin Eckel and Bruno Metzner

Allianz Global Corporate & Specialty AG, the industrial insurance carriers of Allianz Group and AZT Risk & Technology GmbH, have a lot of experience and a comprehensive database about damage of industrial steam turbines and large-scale power generation turbosets. Sound maintenance concepts are the main loss prevention measure, which will be presented and discussed in detail. Some modifications and additions to existing maintenance concepts are also provided.

Strength Test on a 920 MW Steam Boiler – Replaced by Non-destructive Testing

Jens Winkler and Peter Lange

Following legal regulations, a 920 MW boiler in the Lippendorf power plant was to be subjected to recurrent strength test for the first time in the year 2007. Therefore, Vattenfall Europe Generation AG & Co. KG entrusted TÜV SÜD Industrie Service GmbH, NL Leipzig with the selection of equivalent non-destructive procedures. In Germany it was the first time that a hydrostatic test of a steam generator of this size was replaced completely by equivalent non-destructive testing.

Automated Inspection of Monobloc Rotors Using Ultrasound Phased Array Technique

Andreas Nowi

Since 1975 is has been recommended to subject turbine rotors after extended operation to recurrent ultra-sound- and crack testing within the scope of standard inspection routines. Alstom developed an innovated, automated testing process on the basis of the ultra-sound phased-array-technology to cut testing time and to increase accuracy and reproducibility of results.

Turbine Inspection in an Industrial Power Plant – Results from the Renunciation of Manufacturer's Competence

Lutz Dümmel

In 2007 it was the first time that a service company instead of the original equipment manufacturer (OEM) inspected a two-casing extraction/condensing turbine with a capacity of 20 MW constructed in 1964. Important experience was gained from the first co-operation with an external service company.

New Low-pressure Exhaust Modules for the MAN Steam Turbine Product Line – High-performance Bladings for Highest Efficiency Levels

Mark Andre Schwarz, Klaus Behnke and Hartmut Klemm

Currently it can be observed that in the case of generator drives as well as “mechanical drives” smaller units are demanded with a steam turbine capacity of up to 150 MW and clearly higher efficiencies. MAN TURBO is meeting the challenge through realisation of a comprehensive development project aiming at the extension of the application range of the current steam turbine series.

Integration of Direct Solar Steam Collectors in Steam Cycle Power Plants

Robert Pitz-Paal, Markus Eck and Tobias Hirsch

For solar thermal power plants, the temperature stability of the synthetic heat transfer oil that is circulated in parabolic trough collectors limits the life steam temperatures in the steam cycle to about 375 °C To overcome this limit, direct steam generation in the absorber tubes themselves is subject to research activities within the last years. The article gives an overview about the concept of direct steam generation in parabolic trough collectors and summarises the operating experiences obtained so far.

Growth of Oxide Scales during Steam Oxidation at 650 °C

Reinhard Knödler and Stefan Straub

Future steam power plants will operate at considerably higher temperatures than today because of the necessity of higher efficiencies and of lower or nearly zero emission rates. One issue with respect to material requirements is the increasing oxidation rate of steels, which can induce damage of the steel itself. This paper deals with aspects of the growth and morphologies of oxide scales at higher temperatures up to 650 °C. Laboratory tests can give only a first indication or ranking about the steam oxidation or corrosion behaviour of the steels.

Concept and Operational Results of a Conversion to Enhance the Performance of Steam Generators for the Combustion of Refinery Residues

Roland Bräcker, Hans-Ulrich Thierbach and Uwe Rähder

Two natural circulation steam generators fired with refinery residual oils with a design capacity of 620 t/h, which had been commissioned at the end of the 90s, were upgraded at PCK Schwedt in order to increase their capacity to 750 t/h. Technical details of the upgrade, measures guaranteeing trouble-free operation and first operating results are presented. Experience clearly demonstrates that minor boiler fouling and high full-load availability of the boiler are achieved using HSC-R as fuel.

First Operating Experiences with the Flue Gas Cleaning Plant of TEV Neumünster

Winfried Notter, Wei Xi, Jürgen Gottschalk and Reenhard Gerdes

In 2005 Stadtwerke Neumünster started operation of the new Refuse Derived Fuel (RDF) plant. The new plant has a capacity of about 150,000 tonnes of RDF per year which is produced in the mechanical-biological separation stage. Since the chloride content of RDF and coal – to be used optionally – is highly differing, the chemistry of the flue gas cleaning plant has to be able to react quickly to keep the emissions safely below specified limit values. The special flue gas cleaning concept is being presented and first experience made with commissioning and initial operating phase are being described.

Data Mining and Statistical Process Control for Condition Bases Maintenance

Peter Deeskow, Urs Steinmetz and Martin Hay

Optimum, condition-based maintenance should balance the commercial consequences of an efficiency loss or a component failure and the cost of maintenance. This requires an early and highly reliable detection of abnormalities of the component/unit behaviour. For this purpose key performance indicators (KPIs) can be used which are online calculated from operational measurements and which solely depend on the component condition and do not depend on other influencing factors such as operation mode, load or ambient conditions. Software tools using data mining methods can facilitate the definition and calculation of such KPIs.

Lusatian Lignite – Decisions for the Future

Detlev Dähnert and Wolfgang Ketzmer

In the year 2007, the four active open-cast mines in Lusatia produced about 60 million tonnes of raw lignite and supplied the power plants of Vattenfall Europe Generation, the lignite refining plant “Schwarze Pumpe” and additional consumers. A number of important decisions have been made for the future of the Lusatian lignite area. In this connection the focus is on the long-term mining and power plant development and the overall development of the entire region which is important for reasons of economy and employment policy.

Stressors at Modern Workplaces – “Technology-induced Stress” – Investigations in Power Plants

Annette Hoppe, Sven Binkowski and Dietmar Haake

The status analyses of power plant control rooms from the viewpoint of ergonomics and psychology is focussing on scientific analyses of stressors at highly complicated work places in order to gain further knowledge on the issue of “technology-induced stress” and to a practical assessment of work places for the estimation of stresses. A guideline is to be developed supporting design of modern control rooms.
The Development of Porous Multilayer Systems for the 700 °C Steam Turbine Technology.