Abstracts - VGB PowerTech Journal 7/2006

Can Waste-to-energy make a Substantial Contribution to Energy Supply?

Grundmann, Jan; May, Frank

In Germany there is a general potential to cover theoretically 5 % of the existing demand in electrical energy by usage of waste fuels in waste incineration. High-temperature chlorine corrosion in waste boilers requires operation under moderate steam parameters, causing low electrical efficiency. Due to that fact waste fuels are preferably used for combined heat and power production the existing lack of capacity in waste incineration in Germany will soon be covered by new projects. These projects are developed in close co-operation with industrial energy customers, looking for long-term stable energy costs. Increasing the capacities for co-incineration in power plants and cement kilns will be limited in future.

One Year Implementation of the Technical Instruction on Municipal Waste

Radde, Claus-André

With the implementation of the Ordinance on Waste Dumping and Landfilling on 1 June 2005, the ban on landfilling of untreated wastes was enforced and became irreversible. The treatment of domestic and bulky wastes has been ensured and should soon stabilise following completion of new waste treatment capacities. Only the energy recovery of high-calorific wastes from mechanical-biological treatment plants is not yet possible. However, we cannot expect the situation to be noticeably improved before 2007.

Flexible Waste Management at the Augsburg Waste Incineration Plant

Stenzel, Michael; Stephan, Martin

Since June 2005 the further use of landfills has been prohibited in Germany. For the duration of a planned outage of the Augsburg waste incineration plant, the incoming waste had to be redirected, i.e. it had to be partitioned and packed at the plant site for further transport to a nearby interim storage. Consequently all related waste streams had to be supervised and to be recorded with an IT solution that was flexible enough to adapt quickly to this changed situation.

Optimisation of the MSW Incinerator in Bremen and Operation Experiences

Klasen, Thomas; Görner, Klaus; Auel, Werner; Sudau, Bernd

The lines 2 and 3 of the MSW incinerator in Bremen, which have been in operation since 1969, were modified in order to increase plant availability. Apart from the adjustment of components like grate firing system, ash removal system, combustion control, air system for primary air as well as secondary air and feeding devices, the replacement of the existing roller grate at the boilers 2 and 3 by a new water-cooled moving-grate firing system was one of the main issues of the retrofit activities. The MSW incinerator was modernised based on a simulation study with CFD optimisation. The first measured values showed already very good combustion results. The predicted values for the end-concept, e.g. low CO-concentrations, were confirmed.

Maintenance Planning and Documentation with the WIS System

Griedl, Rainer ; Buschart, Rufus

WIS is the German abbreviation for “knowledge integration for maintenance services”. The principal goal of the WIS concept is to provide all information relevant for maintenance decision-making and maintenance planning through, for example, the systematic documentation and analysis of maintenance activities. The WIS System supplies technical data and documents describing the maintenance histories of the plant components as well as information obtained from condition monitoring equipment. In view of the highly positive experience gained from applying the WIS program it is planned to extend use of the WIS System to other power plants and service providers, as well.

General Interface-free Overhaul of the 110-MW-Railway Power Turboset at the Lünen STEAG Power Plant

Fink, Harald; Frense, Stephan

Regarding the optimisation of plant performance, STEAG AG’s Lünen power plant has chosen the tried and tested overhaul cycle, in line with the unit’s operating mode which is continuously monitored by plant staff. The general turboset overhaul from 1st April to 5th August illustrates how the teamwork between customer and service supply company including all specialist divisions can ensure a smooth and interface-free performance – from planning to commissioning and documentation.

Thermal Spray Coatings to Reduce Corrosion and Erosion

Schülein, Rüdiger W.; Born, Manfred; Korb Jürgen

Resistant coatings with guaranteed sufficient service times are most effective to protect boiler tubes from corrosion and erosion. Cladding is well known and the most common solution. Alternative processes are interesting in terms of loads and costs. Due to high thermal loading of the parts by this process, limitations of corrosion resistance of the material above temperatures of 450° C and high cost requires. Coating of highly loaded parts like boiler tubes and turbines by thermal spray coating is a well-known and established alternative. Different processes and the most important characteristics of thermal spray coatings are described.

On-site Evaluation of Fouling Release Coatings for the Protection of Cooling Circuits against Macro Organism

Verelst, Lieve; Girasa, Emmanuel und De Vries, Tjerk

Biofouling control in power plants has generally been focused on the use of biocides and especially chlorine. Other chemical treatments (e.g. ozone, chloramines, quaternary ammonium, isothiazolones etc.) and physical methods (e.g. thermal shocks, fine filtration, application of antifouling coatings etc.) receive more and more interest and are valuable alternatives. Thanks to the development of non-toxic, fouling release coatings, a preventive, environmentally-friendly and cost-effective technique now exists to prevent the colonisation of cooling circuits. Since 2002 Laborelec has undertaken a test series with five different commercially available coatings (EN).

Perennial Operating Experience with Dead End Ultra-filtration for Treating of Surface Water

Nagel, Rolf; Will, Thomas

Ultra-filtration is gaining in importance for the pretreatment upstream of reverse osmosis systems, especially when surface waters or similar waters are used. The retention of different constituents like e.g. TOC is being considered. The influence of pre-treatment on the downstream reverse osmosis is explained in comparison to conventional technology with ultra-filtration. The findings are based on operational results.

Spray Attemperators – Potential Problems and Solutions

Boroumandi, Behzad

Spray attemperation is one of the most efficient and commonly used methods for controlling superheater and reheater temperature in power boilers. In this paper, results of experiences gained about spray attemperators and their potential problems are discussed and two case studies have also been presented. At the end of the paper recommendations about inspections have been made. (EN)

Practical Application of Fracture Mechanics in Power Plant Engineering

Theilig, Holger

The operational experiences with power plants show that occurring damage and defects at components can influence the safety and availability considerably. Technically well-founded statements concerning exchange, repair or temporary further operation of faulty components are therefore indispensable part of a sure and economic management. The paper shall promote the application of fracture mechanical concepts at the planning of the maintenance of power plants.

Occupational Safety and Health Protection in Modern Power Plant Operation - New Contents in the Apprenticeship of a Power Plant Master Craftsman

Kettler, Eckhard; Bieder; Markus

Liberalisation on the electricity market and the resulting competition are challenging utilities in particular. This process of change affects occupational safety and health protection in power plant operation as well. Regarding large utilities, today this objective is not in contradiction to corporate targets but integral part of leading culture.