Abstracts - VGB PowerTech Journal 8/2012

A nearly perfect removal of steam turbine generator unit

Tomi Dewes, T. Vuorinen and M. Hietela

With this project, Fortum was challenged with dismantling a second-hand 20-year old steam turbine/generator unit in France and transporting it to its new operating location in Sweden. To ensure future reliable long-term operation, the unit required thorough reconditioning and inspection which also included comprehensive modernisation of I&C

Modernisation of steam turbines and condensers at coal-fired power plant Ibbenbüren

John Walsh and Roland Sommer

In 2009, the high-pressure-, intermediate-pressure-, and the two-low pressure turbines as well as the two condensers - all commissioned in 1985 - of the RWE Ibbenbüren coal-fired power plant were modernised by Siemens with latest turbine and condenser technology. Prior to the project, the plant was assessed in detail jointly with RWE. Once the retrofit was completed and the unit returned to operation, the performance increased by 86 MW.

Laser measurement on turbine parts

Martin Breindl

Exact knowledge of geometry is needed for spare parts supply and complex remodelling of turbines. However, determination of geometry requires time and organisation. In 2007 TMS discovered the laser tracker for determining geometry. In 2008 TMS started the pilot project “Laser measurement on turbine parts” within the scope of remodelling a steam turbine. The paper describes areas of application, technique, measurement method, data processing, examples, and resulting advantages.

Analysis and improvement of vibrational behaviour on the ND37 A last stage blade

Pierre-Alain Masserey, Ivan McBean and Huascar Lorini

This paper gives a detailed description of the intensive investigation conducted by Alstom to determine the root cause of isolated blade root cracking on the ND37 fleet and the resulting mitigating actions which were developed. An operational “risk zone” was defined to prevent flutter until the permanent solution of stage “mistuning” could be implemented. The affected units have been modified during major overhauls and returned to operation with the risk of flutter fully eliminated.

Fly ash in power plant construction - Concrete works for the block 9 of the Mannheim power plant

Rolf Scheinost

Grosskraftwerk Mannheim Aktiengesellschaft (GKM) is planning to build one of the most modern hard coal-fired power plant units. Altogether about 160.000 m³ of concrete are to be used for unit No. 9. An expected amount of 16.500 m³ of fly ash will be used for the different concretes. The fly ash employed is a by-product of GKM which has produced certified fly ash for 25 years. Fly ash characteristics make its employment technically as well as economically appropriate especially for use in power plant construction.

Regulations for the utilisation of fly ash in concrete - Today, tomorrow and the day after tomorrow!

U. Wiens and Hans-Joachim Feuerborn

The report deals with revision of the European product standard for fly ash in concrete EN 450-1 and of the European and national rules of application. The rules of application in the European standard for concrete EN 206 are being revised. In addition to the k-value concept, the principles of the equivalent concrete performance concept as well as the principles of the equivalent performance combinations concept will be described.Furthermore, the impacts of the new construction product regulation on the CE marking of fly ash will be described and an overview of the work on harmonised test procedures for the emission of regulated dangerous substances from construction products will be given.

Determination of ash concentration and caloric values of coal directly on the conveyor belt

Jürgen Wess

Among the multi-element methods of instrumental analyses, the neutron activation analysis takes a special position. The method is able to penetrate even thick layers of samples and covers whole mass flows online, like on conveyor belts. A new technique of pulsed excitation allows the reduction of undesired components of analytical gamma-rays, which allows the determination of carbon, oxygen and hydrogen. Therefore, the ash content, based on the ash containing elements, and the calorific values, based on calculation models, can be measured in one process.

From river Main water to boiler feedwater

Ivonne Haferland

Infraserv Höchst operates the water demineralisation plant (DIW) for the Industriepark Höchst near Frankfurt. Additionally pressurized steam produced by the power plant is also used for heat transfer purposes, or in its unaltered liquid state, for production processes. Triggered by significant development of the on-site production facilities, it was necessary to design and build a new DIW plant in 2009, strictly dedicated to the treatment of roughly pre-filtered water from the local river Main, used in conjunction with its immanent substantial seasonal quality changes.

Experiences with treatment of the water-steam-cycle in the RDF heating and power plant Nehlsen Stavenhagen with film-forming amines

Bernd Kolander, André de Bache and Wolfgang Hater

For more than four years, the water-steam cycle of the refuse-derived fuel (RDF) heating and power plant Nehlsen Stavenhagen has been treated with a conditioning agent, based on film-forming amines. The water and steam parameters are in accordance with the guidelines, except for acid conductivity in the steam, which drives the extraction condensing turbine. In order to understand the reasons for the increased acid conductivity, laboratory studies were carried out, as well as studies on-site of the direct conductivity, acid conductivity and degassed acid conductivity. The treatment of the water-steam cycle was judged to be very satisfactory.

A successful cleaning concept for Germany’s biggest reverse osmosis plant

Hermann Kempen and Ronald Zierau

During the last years, new developments for membrane material and also for treatment chemicals have resulted in higher efficiency and reliability of reverse osmosis (RO) plants. Nevertheless, especially RO plants receiving raw water from surface waters with open intake or from waste water streams are facing problems with fouling on membranes during operation. In such cases, the efficient cleaning of membranes is mandatory to ensure long-term supply of permeate in high quality and sufficient quantity. New cleaning concepts with proprietary cleaning products are gaining in importance. The successful application of such a cleaning concept at Germany’s biggest RO plant is described in this paper.

Long-term experiences with reverse osmosis membranes in three different process water plants

Peter Sehn

Reverse osmosis (RO) membranes with fouling-resistant (FR) properties have been used for more than ten years for the production of high-purity process water from river water. The operational experience gained during this period is being discussed by examples of three different installations. Although in all three cases similar raw water and pre-treatment are used, significant differences in the fouling behaviour and in the useful lifetime membranes are observed. The reasons are presented and discussed.

Experience with polyamines in the high pressure steam system of naphtha cracker - From new to proven treatment

Roy van Lier, Mark Gerards and Jo Savelkoul

Following a decade of operational experience with film-forming amine products at lower pressures at the Geleen (petro)chemical site in the Netherlands, the ammonia/morpholine treatment of the 125 bar steam system of one of SABIC’s Dutch naphtha crackers was successfully converted to a polyamine programme in November, 2005. The paper is an update to mark over six years of - generally positive - experience with polyamine treatment. In our view, such treatment is now also proven for high-pressure steam cycle in olefins plants.