Abstracts - VGB PowerTech Journal 12/2004

VGB Congress "Power Plants 2004"

The VGB Congress "Power Plants 2004" took place in Cologne/Germany from 6th to 8th October 2004. This year's motto was "Ensuring investment - How can we fill the generation gap?". About 1000 participants from Germany and abroad attended the plenary and technical lectures that were dealing with topics like "Market and Competition" as well as "Technology, Operation and Environment". Special lectures were dealing with further subjects like nuclear energy in Europe, consumers´ requirements to be met by the energy industry, operating experience, new materials, application of renewables and issues of climate protection. A comprehensive side programme and technical visits rounded off the Congress.

Current State of the Construction Works of the Thermal Waste Treatment Plant in Lauta

E. Eich

A thermal waste treatment plant is being built in Lauta/Saxony. This plant is to be part of the general waste concept of the regional waste organisation Upper Lusatia, Lower Silesia (RAVON). The construction was decided in 1993 by RAVON, and the European-wide invitation to tender was issued in 1995. The corresponding contracts with a period of 25 years were signed in 1997 between a consortium of VEAG/STEAG and RAVON. The Lauta incineration plan comprises two identical combustion lines with a furnace capacity of 37.5 MW each and a combustion capacity of a total of 2225000 Mg waste/a.

New Automation Concepts Increase the Profitability of Power Plant Concepts and Experiences from four Plants including "Consumption-controlled Start-up"

St. Leibbrandt and B. Meerbeck

Before implementing an improvement measure, profitability has to be determined in addition to technical feasibility. That requires close co-operation between process and instrumentation and control (I&C) specialists from the power plant and the I&C supplier.
This paper takes four plants to demonstrate the tangible benefits gained from I&C system improvements. The fourth example describes the "Consumption-controlled start-up".

Lifetime Assessment of the Electrical Installation, Steps towards the Long-term Working of Power Stations

J. Paetzold

The determination of life expenditure and residual life assessment have become major issues of utilities and their engineering departments. It is essential to possess the means needed to sufficiently and accurately make assessments. Some of these means are described for the electrical items generator, transformer/station-service transformer, switchgear/cable. It also has to be taken into account that certain electrical items are prone to aging.

Changed Life Cycles of Software and Hardware Components in Power Plants "Upgrades" and "Updates" Seen from the Aspect of Profitability
Reporting of Experience Gained from Both a Customer and Supplier Viewpoint

P. Pankau, J. Holzapfel and Th. Rosch

It is really only a few years back now that process control systems for power plants - these systems consisting of an automation level (with programmable logic controllers a distinguishing feature) and the operation and monitoring level, the so-called human-machine interface - were basically installed as "monolithic" systems with an anticipated service life of about 15 years. The lifetime expectations of power plant owner/operators for these system generations were essentially founded on their proprietary hardware and software, which was subject to very different innovation cycles than those, which apply for modern system. Modern process control systems with PC-based HMI-solutions feature far higher functionality and their distinguishing feature is that they are based on international standards for their hardware and software. This paper uses a practical example, upgrade of the power plant I&C as performed in Gemeinschaftskraftwerk Kiel, to show how tailored update/upgrade strategies can assure system maintainability over the long-term and how these strategies can be exploited to enable power plant owner/operators to reap the benefits of increased functionality.

Operating Experience Leads to Simple Solutions

F. W. Albert

The operation of waste-to-energy-plants is challenging. This is also due to the fact that reliable and reproducible knowledge concerning materials and designs of the steam generator is only partly available. It has proven to be very valuable to overcome this lack through free discussions among experts of different disciplines. Hypotheses on the theoretical fouling mechanisms of waste-fired boilers are presented and materials are discussed.

Rubbing Damage at Turbo Machines, Reasons and Effects

St. Thumm and B. Metzner

Rubbing damage at turbo machines occurs still today with relatively moderate influence up to the loss of the turbine. Several investigations in the last years show, that technical problems, which are fundamentally controllable, are often responsible for these phenomena. Damage investigations show again and again, that an explanation for a rubbing damage is difficult on account of missing data or is even impossible. The most important steps for explanation of a rubbing damage are summarised.

Experience in Backfitting of the Water Treatment System in the Waste-to-energy Plant at Essen-Karnap
E. Müller and Th. Badewitz
RWE Power AG operates a waste incineration plant in Essen-Karnap that incinerates up to 745.000 t domestic waste and domestic waste like industrial refuse. Raw water for plant operation is taken from the Rhein-Herne canal and is processed for process water, cooling water and boiler feedwater in three steps. As of 31st May 2002, discharge of gravel filter backwash containing more than 50 mg/l suspended solids was not allowed anymore. These altered conditions of water laws required a modification of the water treatment plant.

Long-term Stability of 9-12%Cr Steels - Current Understanding and Future Perspectives

J. Hald

In the last 25 years creep rupture strength of 9-12%Cr steels for steam tubes and turbines has been doubled by the development of new alloys. Newly developed steam tube steels are based on modifications of well-established steels like the X20CrMoV121. Mechanisms increasing strength by the addition of Mo and W are being discussed. Oxidation by steam and creep resistance have to be taken into account upon the development of chromium steels for steam temperatures up to 650 °C.

Online Cleaning of the Combustion Chamber of the Kassel Waste Incineration Plant

H.-P. Themann

Different cleaning devices are used in order to achieve the guaranteed operating hours of waste incineration plants. Cleaning of the heating surfaces with the known systems did not produce the desired results. After having compared the cleaning possibilities water lance blowers (WLB) were installed in the boiler. According to the current experience, the fouling tendency is safely controlled with WLB.

Determining the Water Content in Transformers - Possibilities and Application Limits of Moisture Distribution Curves

I. Höhlein and U.Thiess

Modern electric measurement procedures for determining the water content in the solid insulation of oil-cooled power transformers can lead to results that differ significantly from those obtained by the application of equilibrium curves for moisture in oil/moisture in solid insulation, especially in the case of highly aged oils. A possible solution to this problem would be to determine the water saturation in aged oils in the laboratory, with an adaptation of the equilibrium curves. The objective is to obtain a classification of aged industrial oils.

Managing the Bolting of Couplings of High Power Throughput Confidently

N. Schneider

This paper deals with bolted joints on couplings with high power throughput and shows weak spots of existing tightening methods. Multi jackbolt tensioning systems offer a low cost alternative. Due to their high pre-load capabilities they reduce the risk of failure. Also, susceptibility to maintenance as well as costs can be decreased. Some typical applications are documented in support of these claims.

Qualification of Power Plant Personnel in Eastern Europe by Organisations in North Rhine-Westphalia

J. Liebhardt, G. Schlegel, R. Tschiedel and R. Wiengarn

For the new states of the European Union the admission into the EU means the acceptance of European Community Law. The training of personnel plays an important role in this transformation process, therefore, the personnel training needs were defined and the required qualification modules designed in a concept study financed by the state of North Rhine-Westphalia. The KWS has developed tentative training objectives and designed modular training concepts. This provides a good basis for creating modular advanced training measures.