Abstracts - VGB PowerTech Journal 3/2013

The role of hydro power in the European power supply system

Thomas Leitl, Herfried Harreiter and Kathrin Schmelter

Hydro power is still the major electricity generation technology from renewable energy sources in Europe. Pumped storage plants are another important factor in achieving the ambitious European targets regarding renewable energy sources. Pumped storage plants support the system stability by providing flexibility and enable the integration of volatile renewable energy sources in the power supply system. Due to the existing environmental legislation and the water framework directive, current and future hydro power projects are associated with high efforts. The European energy and environmental policy should be harmonised and licensing procedures should be simplified for a sustainable development of the available hydro power potential.

Can we still be rescued? Energy and climate change as a key issue of the future security

Franz-Josef Radermacher

Revised version of the festive lecture given by Franz Josef Radermacher at the VGB Congress “Power Plants 2012“, held in Mannheim/Germany, October 10 to 12, 2012. Franz Josef Radermacher is professor for computer science at the Ulm University and head of the department for data bases/artificial intelligence. Within the scope of the “Global Marshall Plan Initiative”, he supports the balance model in a globalised world, i.e. innovative eco-social and economically sensitive, sustainable economising trying to take into account the complexity of current market and growth conditions.

PT schemes - An instrument of quality assurance in power plant chemistry

Bernhard Ruchti

The international standard ISO/IEC 17025 defines the requirements that testing laboratories have to meet if they wish to obtain accreditation. These requirements include among others the regular participation in proficiency testing programmes (“PT schemes”). In cooperation with members of the VGB Working Panels “PWR- and BWR-Chemistry” a PT scheme was developed that meets the specific requirements of the nuclear power plant industry in water chemistry. Due to the good experiences made, new projects are planned in the sector of conventional power plant chemistry.

The influence of start/stop operation on the water steam-cycle

Jan Soons, Frank de Vos and Marga van Deelen

More and more power plants operate as start/stop units. Some units are even started-up almost every day. These frequent start-ups will influence the water/steam chemistry and therefore the integrity of the systems. During start-up, for most plants not the water chemistry but the temperature will be the guiding parameter. As a consequence, water quality is lacking when systems are started-up and it has to be assured that this period when the water quality is off specification is as short as possible in order to prevent negative effects on the system. It was found that in practice no direct evidence was discovered that start/stop operation has a direct negative effect on the systems. However, the possible effects on the water/steam cycle have not been investigated yet.

Modified combustion chamber for biomass- and agrarmass-fired CFB boilers

Rafal Kobylecki, Robert Zarzycki, Zbigniew Bis, Marek Pawlik, Jozef Zyla and Kazimierz Szynol

The new design of a circulating fluidised bed (CFB) furnace is presented. The CFB boiler was intended to be fired exclusively with blends of wood chips and various agromass types. The maximum content of agromass in the fuel mixture was assumed at 25 wt%. The boiler was designed to match these fuels. The boiler modification has been patented and is currently implemented into an CFB boiler in Poland.

Demanding fuel combustion - Metso CFB multi-fuel boiler experience in Stora Enso Ostroleka

Rafal Kulesza

Stora Enso Poland erected a combined cycle power plant for supplying its Ostroleka mill with power and heat. The central component is a circulating fluidised bed combustion (CFB) boiler designed for multi-fuel combustion like biomass and residues of the paper mill. The thermal rat-ing of the CFB boiler amounts to 164 MW and two turbines supply up to 43 MW of power.

Comparison of four steam generators regarding the decomposition products of amines

Anke Söllner, Wolfgang Glück, Kathrin Höllger, Wolfgang Hater and André de Bache

Different water chemistry treatments are used in power plants. For combined cycle power plants Siemens employs the all volatile treatment. In order to gain experience with organic treatment, four power plants using film-forming and alkalising amines as organic treatment, were examined. Research shows that the organic treatment is a sufficient corrosion protection method for power plants with steam extraction combined with a complex and widely ramified steam condensate system. To minimise the risk of corrosion, it is recommended to monitor the iron content in the water steam cycle more frequently.

Experimental results of ammonia operated condensate polishing plants in combined cycle power plants

Christian Ochsmann, Henrik Jahr, Wolfgang Glück, Stefan Neumann and Hans-Jürgen Wedemeyer

Modern combined cycle power plants with once-through boilers require highly pure boiler feedwater. Typically a condensate polishing plant (CPP) is used as “salt sink” in the water-steam cycle, with a combination of cation and anion exchanger resin in a mixed bed filter. Ammonia ions are removed which reduces the lifetime of CPP. An alternative is the so-called “ammonium form operation” which is being presented and discussed. This mode was investigated. The experimental results show that the “ammonium form operation” is an attractive technology, which offers reduced operating costs and therefore meets economical expectations of power plant operators.

Integrated flue gas cleaning system for a CO2 purification process appli-cable in an oxyfuel power plant

Stephanie Tappe, Jinying Yan, Helge Kaß, Vince White and Andrew Wright

Since 2009 Vattenfall has been operating a 30 MWth research plant at the Schwarze Pumpe site in order to perform comprehensive investigations focussing on new power plant components as well as process related aspects like the oxyfuel technology. In addition, a further pilot plant was erected in 2010 by the international gas supplier Air Products for the investigation of an alternative CO2 purification process. Within a common research agreement, numerous tests have been performed focussing on the characterisation of the integrated flue gas cleaning process.

Degassing by membranes - The future in IEX-demin plants?

Dieter Mauer

IEX demineralisation plants need a degassing function when operated by carbonic acid containing raw water. Typically blowers are used. Other disadvantages due to atmospheric open construction occur, e.g. sump-pump, sump level control, pollution by e.g. microbiological germs as well as size and noise. On the other hand the apparatus itself is simple and cheap disregarding the additional pumps. Membrane degassers do not have these disadvantages, but show a higher price at high flow rates. Nevertheless, promising advantages show up above the simple comparison of CO2 removal. The paper assesses and discussed such advantages with their possibly far-reaching impacts.

Three-phase current transformer rectifier sets - High-voltage power supplies for difficult ESP conditions

Josef von Stackelberg

The precipitation rate of electrostatic precipitators (ESP) highly depends on the consistency of waste gas. Among other things, electrical conductivity plays an important role as well as the ability of particles to be electrically charged or ionised. Within certain limits, common ESPs are able to clean waste gas satisfactorily. If the dust attributes exceed these limits, more sophisticated technical solutions are required in the ESP to meet the demands for the gas cleaning equipment. In these cases, a three phase transformer rectifier system offers an alternative to the con-ventional single phase system, as it delivers a smooth direct current voltage over a wide voltage range.

Two years after the tsunami and the Fukushima accident - Worldwide consequences

Ludger Mohrbach

The damage of four units of the nuclear power plant Fukushima-Daiichi caused by the tsunami on March 11, 2011 has had considerable effects on energy politics - in Germany. Extensive safety reviews of nuclear power plants all over the world have, in the meantime, shown that out-side Japan no other country had to shut down its plants because of de-sign deficits comparable to those in Fukushima-Daiichi (not even tempo-rarily). Worldwide, countries that have the technology and use nuclear power will continue to operate their plants until the technical operating life of at least 40, in most cases even 60 years, has ended. The majority of these plants will be replaced or expanded. At least seven more coun-tries have decided to start using nuclear power.