Abstracts - VGB PowerTech Journal 4/2007

New Vattenfall Projects in Germany

Reinhardt Hassa, Axel Rademacher

We are facing the challenge to leave a liveable environment for future generations. This objective can be achieved by reducing the emissions of CO2. For the next years, power generation will still depend on fossil fuels. Vattenfall is willing to beat this challenge and we will expand our generation capacity, which is already on a technologically advanced level, by using different types of fuel in our modern, up-to-date and efficient power plants.

Clean Coal Technologies –- International Activities

John Topper, Adolf Aumüller, Colin Henderson, Hans-Joachim Meier

Power generation must rely considerably on coal for some time. Clean coal technologies (CCTs) developments will address short-to-medium term conventional emission concerns, while for the longer term, technologies are emerging to achieve systems with CO2 capture and storage. These will be most attractive if they also achieve near-zero emissions of conventional pollutants. This paper reviews emissions targets, the main coal-fired technologies, and strategies for developing CCTs to reach near-zero emissions technologies (ZETs). (EN)

Establishment and Certification of Integrated Work Safety Management Systems for the Conventional Power Stations of the EnBW Kraftwerke AG

Frank-Peter Kirschning

This paper presents the basics of a work safety management system, and describes the preparatory work for the implementation of such a system in the EnBW Kraftwerke AG. The basis of the concept was a process analysis at the conventional locations of the EnBW Kraftwerke AG, which finally resulted in an action catalogue. In addition to measures for technical and organisational optimisation, the action catalogue deals in particular with topics surrounding the man-machine interface. Essential characteristics of AMS are the indicator-supported, process-oriented approach, which supports a process of continual improvement in the area of work safety, and the inclusion of findings from occupational medicine and psychology in the relevant risk assessments.

Prevention Activities for the Energy Industry by the BGFE

Reinhard Lux

Several consultant activities by the prevention inspectors represent the basis of the German Trade Association for Precision Mechanics and Electrical Engineering (BGFE)-services to each power plant. The co-ordination of typical prevention tasks for power plants is subject of the department of machinery and energy supply systems – special consultant activities are offered, e. g. by the department of electrical engineering and the department of hazardous substances.

Prevention as a Part of Hazard Assessment at RWE Power AG

Udo Matzka

In co-operation with the German Trade Association for Precision Mechanics and Electrical Engineering (BGFE), RWE Power has developed an innovative, intranet-capable data processing system for hazard assessment at major enterprises. The focus of development has been on user friendliness, high flexibility and a uniform, systematic structure. Comparable hazards of similar installations and the measures developed can be exchanged across operations.

Stadtwerke Leipzig's First Biomass-fired Power Plant with Circulating Fluidised Bed Combustion and Reheating

Frank Beckert, Heinrich Schaarschuch

In 2005 Stadtwerke Leipzig in the Eichsfeld/Thuringia put into operation their first power plant with 20 MW according to EEG law (law on the use of renewables). 22 month after contracting, the plant was connected to the local grid. Unfortunately the trial operation started-up five months later. With about 37 % gross electrical efficiency a record level in the range up to 20 MW for biomass was achieved. First in Germany an EEG-plant with 20 MW was built without waste wood fraction in the fuel. Fraction logging by-products are used as main fuel.

Modernisation of the CHP Plant Barmen – Experience during Project Realisation and First Operational Experience

Volker Leonhard, Uwe Herrmann

Wuppertaler Stadtwerke AG replaced at the Barmen CHP plant a hard coal-fired unit and also a combined cycle gas turbine (CCGT) by a modern CCGT plant. Under the influence of the conditions of a liberalised energy market and the Combined Heat and Power Generation Law (KWKG) the project examinations, preliminary planning, assignment and relisation of the modernisation measure were accomplished. The project was realised as a turn-key order by a general contractor. The new CCGT plant was integrated into an existing building and consists of two new gas turbines, each with one unfired heat recovery steam generator.

Run an Offshore Wind Farms like a Power Plant – Experience from Nysted and Horns Rev

Claus Bjerge, Jesper Runge Kristoffersen

This paper describes the two Danish Offshore wind farms, Nysted and Horns Rev and the operational experience controlling the active and reactive power from the wind farms. The Horns Rev wind farm was built in 2002 by the Danish utility group Elsam, and has now been in regular operation for a long period. The wind farm was the first to be equipped with advanced centralised control of both active and reactive power. The Nysted wind farm was built in 2003 by the Danish utility group ENERGI E2. (EN)

Economic Analysis of Geothermal Electricity Generation in Germany

Martin Kaltschmitt

Geothermal energy is due to its existing large resources in Germany an option which can noteworthy contribute to the future energy provision. The amendment of the EEG law (law on the use of renewables) therefore draws much more interest to geothermal electricity generation. Against this background, the objective of this article is to identify the main cost drivers and risks of a geothermal power and heat generation under the geological conditions in Germany and derives the resultant recommendations.

Realisation of a Non-leakage GGH System for the FGD Circuit in Italy's Most Modern Coal-fired Power Plant under Construction at Torrevaldaglia North

Pietro Dolfi, Frank Adamczyk

Presently the utility ENEL is beginning to retrofit its power stations so that the previous main energy sources oil and gas are replaced by hard coal. In this connection various power station sites are being retrofitted and/or completely new power stations are being built at the existing power station sites. This is the case at the Torrevaldaliga North site (3 units each 660 MWel). For the selection of the heat displacement system (GGH) around the flue gas desulphurisation plant (FGD) ENEL decided in favour of the leakage-free ECOGAVO system which has been proven successful for many years. (EN)

The Oxyfuel Process – Boiler Design Considerations and Possibilities for the Minimisation of CO2 Impurities

Alfons Kather, Christian Hermsdorf, Mathias Klostermann

The Oxyfuel process is a power plant process where nitrogen is removed from the combustion air prior to combustion to raise CO2 concentration in the flue gas up to approximately 90 % vol. (dry). In order to limit the temperature inside the furnace to the levels corresponding to the air, approximately two thirds of the cooled-down flue gases need to be recycled. The paper will discuss the boundary conditions to be considered for the entire process and the target values as well as possible solutions.

Damage Analysis at the Tube Bend of a Steam Generator

Dirk Bettge, Christian Klinger, Dietmar Klingbeil

A heat exchanger was designed for the supply of process steam in a petrochemical plant. Severe leakages in the superheater and in the evaporator modules were identified during the test phase; the commissioning was stopped. On the basis of these analyses, the damaged components were either repaired or exchanged by new components with improved design.

Corrosion Mechanisms of Refractory Materials in Waste Incineration Plants

Ulrich Hohmann

In most waste incineration plants, silicon carbide (SiC) mixes were used until the nineties as a tried and tested material for vessel linings. However, due to altering waste compositions and combustion loads, the lifetimes of these linings has decreased drastically. In the following years several refractory systems were tested in waste incineration boilers. The most common refractories have been investigated by the Allianz Centre for Technology (AZT). These are particularly high and low cement castables (HCC and LCC), refractory mortars and silicon nitride bonded silicon carbide tiles. All of the investigated materials showed signs of corrosion in the binding matrices. The deduced corrosion mechanisms are always similar: during operation vapours of alkali, earth alkali and zinc chlorides diffuse through the open pores into the refractories and react in a specific way with the binding matrices. These corrosions cause temperature cycling cracks which eventually lead to the complete failure of the refractory system.

Fluoroplastics as Corrosion Protection in Flue Gas Desulphurisation Units

Gregor Bueche, Klaus Hackel

Quadrant EPP offers an extensive portfolio of semi-finished fluoroplastics under the brand name SYMALIT® that are used as corrosion protection or non-adhesive linings in the chemical industry. The demands made on corrosion protection systems in flue gas applications in power plants at high temperatures are no special challenge to SYMALIT® products in terms of chemical resistance. About a dozen plants have already been successfully lined in Europe and Asia. (EN)

(EN) paper in the English language!