Abstracts - VGB PowerTech Journal 1-2/2011

Sustainable energy for Europe: Towards 2020 and beyond - Addressing the challenges facing the European electricity industry

Hans ten Berge

The European electricity sector is currently facing a number of important challenges with the ultimate objective of achieving a carbon-neutral, secure and integrated European electricity market. After 61 CEOs signed a declaration in 2009 setting out their objective of carbon-neutral electricity by 2050, the subsequent analysis within EURELECTRIC's "Power Choices study" demonstrated that this goal was technically and economically feasible, provided the right economic and policy framework is put in place. The process has paved the way for the power industry's latest document "20 Steps Towards 2020".

Facing the challenges - New structures in the energy business

Bernhard Fischer, Matthias Neubronner and Torsten Röglin

The utility sector is facing big challenges over the short, mid and long term. All utilities have to meet three challenges, a so-called trilemma: They must optimise between security of supply, profitability and the environment while dealing with the liberalisation and the parallel integration of energy markets as well as the huge need for modernisation and investment in the asset base. The role of the utility sector in climate protection is evident. The same applies to the European-wide need for modernisation of grid and generation assets. The possible answer for integrated utilities could be a structural change with a turn to cross-regional focussing along the whole value chain.

Renewable energies in Europe - Opportunities and challenges

Fritz Vahrenholt and Holger Gassner

Renewable energies will play an important role in the future European energy supply. Europe and its member states have agreed on challenging targets concerning increasing application of renewables, reduction of greenhouse gas emissions and energy efficiency. Being more successful by fulfilling the last two targets, the faster the share of renewable energies will rise relatively. Therefore, not only the growth targets of renewable energies have to be taken seriously. As much important as new capacities for increasing renewable energies are the improvement and development of the energy infrastructure, the insurance of security of supply under increasing volatility, cost efficiency and public and political acceptance.

Perspectives for the generation portfolio of the future

Frank-Detlef Drake

The climate discussion remains the decisive driver in the change process of the European energy industry. Three levers are indispensable to achieve a significant reduction in carbon emissions: "increased efficiency", "more electricity" and a "low-CO2 electricity mix". A low-CO2 electricity mix can be achieved by 2050 via several paths: The "short bridge" with a swift transition to nearly 100 % renewables or the "long bridge" with a mix of renewables, nuclear power, gas and coal equipped with CCS as an intermediate step towards an energy supply that is sustainable in the long term. However, only the "long bridge" seems to be realistic for reasons of cost efficiency, supply security and feasibility.

Nuclear energy and renewables - Technical flexibility to balance stochastic infeed

Alfred Voß, Matthias Hundt, Rüdiger Barth and Ninghong Sun

One opinion in the current discussion about energy policy is that the extension of nuclear power will impede renewables-based supply because nuclear power and renewable energies would be incompatible within the integrated electricity network. A technical-economic analysis of the electricity generating system with high shares of electricity generation from renewables shows that this assertion cannot be supported from a technical and operational perspective. In terms of lower electricity prices and climate protection a nuclear phase-out might even be counterproductive.

Areva's thermo-hydraulic platform qualified as test and inspection body

Ingo Ganzman, Wolfgang Herr, Holger Schmidt, Willi Stecher, Dirk Walter, Klaus Umminger, Achim Beisiegel, Michael Wich, Philippe Dolleans and Thierry Muller

Areva runs an internationally unique test and qualification infrastructure for power plant components. The associated thermo-hydraulic platform has been certified as test and inspection body according to ISO 17025 and ISO 17020. It comprises integral test loops for pressurised water reactors and boiling water reactors. The maximum operational parameters of the test loops in the thermo-hydraulic platform are heating capacities of up to 22 megawatts, electrical currents of up to 80 kilo amperes, pressures of up to 300 bar and temperatures of up to 600 °C. The accreditation thereby covers tests and assessments as well as expert concept evaluations with appropriate support programmes.

The Danish cell project - Status and perspective of a smart grid demonstration

Nis Martensen, Per Lund, Holger Kley, Eckehard Tröster and Thomas Ackermann

There is a trend all over Europe towards power generation in the distribution network using wind, photovoltaic, and combined heat and power plants. The Danish power system can be considered a leader: already today more than 50 % of the total production capacity consists of distributed generation, mainly wind and combined heat and power plants. As a consequence of this development, it has become more difficult to predict and to control the total electricity generation. This article describes the Danish cell project, a new development for optimal management of distribution grids (cells) with large amount of distributed generation.

VDMA contribution to functional safety of turbomachinery - Required risk reduction by safety functions for steam turbines

Bernhard Wüst, Matthias Zelinger, Jürgen Havemann and Christian Potten

Turbomachinery in power plants and industrial plants has to satisfy high safety standards. To meet these requirements, mechanical, hydraulic and electromechanical components have been used, most of them well-established already for decades. In recent years new standards for functional safety have been developed which address different target groups (IEC 61 528/511 for process industry IEC 62061 and ISO 13849 for mechanical engineering). The Working Panel "Functional Safety of Turbomachinery" of VDMA defines rules for turbomachinery that will be presented with their background.

Material and process improvements in condenser tubing

Lodoic de Kerret and Pascal Gerard

The reliability of the surface condenser is a key factor in plant performance level and maintenance cost optimisation. Two important parameters must be taken into account when attempting to optimise the quality and the reliability of condenser tubing: appropriate material according to the cooling water corrosion level and manufacturing of the tubing product itself. The importance of proper material selection is being explained.

Experience with on-line partial discharge measurements of synchronous generators

Jan Pedersen, Karsten Kabel and Christian Sanddal Nielsen

DONG Energy Power decided to install on-line partial discharge (PD) monitoring on the majority of its generators. This paper presents the PD system installed, the basic methods for interpretation of the measurements as well as the experience obtained from several case studies where the on-line PD measurements successfully identified stator winding problems. In two cases the generators in question were rewound before a failure occurred. In both of these cases findings from visual inspections and from the rewind process are compared to the conclusions based on the on-line PD results.

Experiences with fires in silos for coal storage in the Tiefstack CHP

Claus Rosner and Hauke Röpell

Since 1996 there have been two coal silos on the site of the CHP Hamburg-Tiefstack close to the inner city of Hamburg. Now there is a lot of experience with the storage of several types of imported coals. The special design of the silos allows an effective fight against exothermal spontaneous heating of the stored coal. There are several possibilities to stop  spontaneous heating and to discharge the coal from the silo to the power plant without creating any problems for power plant operation. The paper discusses several different measures to prevent smouldering fire, to handle warm coal, to empty the silos and to cool down coal.

Cleaning of cladded boiler tubes in waste-to-energy plants

Christian Grasser

The cleaning of cladded boiler tubes in waste-to-energy plants has not been discussed yet. The deposits on the surfaces of water wall tubes seriously influence maintenance and operation of a waste-to-energy plant. The diploma thesis was to show options to optimise the cleaning process from the technical viewpoint on the one hand and from the economical point of view on the other. The main focus of this study is blast cleaning. With these results the best terms for blast cleaning have been identified.

Operational tests to optimise the SNCR unit of waste incineration plants

Martin Mineur and Wolfgang Schmidt

In future more stringent emission limits for nitrogen oxides (NOx) will apply to waste incineration plants. With the amendment of the 17th Federal Immission Control Ordinance (17th BImSchV) a limit of 100 mg/Nm3 for NOx as annual average value will be introduced. This applies to all plants which go into operation from 1st January 2013 or will be changed significantly and with a rated thermal input greater than 50 MW. With regard to the intensification of the NOx limits, operational tests were carried out at the waste incineration plants which both use the SNCR technique.

Quality improvements at combustion air dampers for the optimisation of operating efficiency

Dirk Pfeiffer, Tobias Kühnle, Thorsten Strunz, Thomas Sabel and Martin Käß

Rising demands on the operation of power stations in terms of load variation and operating efficiency require constant optimisation and quality control. In service the process performance of a firing system is directly correlated to the distribution of combustion air where the right amount of air is dispensed to the dosed fuel at every operational stage. Measures taken at the level of combustion air dampers can result in improvements here. The optimisation process will be outlined using the example of a 550 MW coal-fired unit.