Abstracts - VGB PowerTech Journal 4/2015

New hydro possibilities in Europe and worldwide

Herfried Harreiter and Herwig Rabitsch

Hydropower is the largest single renewable electricity source today. In industrialised countries, especially in Europe, growth will be considerably low due to the current market distortions, most of the growth will come from large projects in emerging economics and developing countries in Africa, Asia and Latin America. Due to these projects, the IEA roadmap foresees by 2050 a doubling of global capacity. Upgrading or redevelopment of existing plants or innovative applications can also deliver additional benefits.

Baltic 2 offshore wind farm: Challenges and solutions during design and erection of a 288 MW offshore wind power plant

Georg-Nikolaus Stamatelopoulos, Stefan Kansy, John Michael Hannibal and Björn Frettlöhr

Offshore wind offers a great potential for reliable power supply with markedly less future costs. However, offshore also means special requirements related to transport and installation at sea. Even if these requirements alone are very stringent, they are not the only ones that apply. Meeting these challenges requires project organisation comparable to other major projects.

Cost performance improvements by hydropower-specific benchmarking

Klaus Engels, Christoph Müser, Bernhard Möstl and Clemens Griebel

European hydropower operators are facing major challenges in today’s business environment. Therefore, a thorough understanding of the absolute and relative cost positions of their assets is essential for maintaining competitive advantage. Pöyry Management Consulting together with E.ON and other participants developed a customised approach which neutralises hydropower-specific cost drivers by systematically accounting for structural and technical differences of the plants in order to extract real performance gaps only.

Reduction of the minimum generator power output of hard coal-fired power plants through control and process engineering

Hendrik Lens and Michael Nolte

The development of the European electricity market requires more flexibility from utilities operating conventional power plants. This includes coverage of a larger load range than in the past. It is possible to reduce the load of hard coal-fired power plants below their present minimum. However, numerous effects on the power plant process need to be considered. For successful implementation, measures in the field of process engineering and control are needed.

Increasing flexibility of lignite-fired power plants

Günter Heimann

Due to the change in the German energy system with high shares of renewable energy production, the flexibility of existing lignite-fired power plants needs to be increased to secure the best possible system integration of fluctuating renewable energies and to fulfil the requirements set by the TSO. The current challenges of the power generation market in Germany and the existing possibilities to increase the flexibility of lignite-fired power plants are outlined. It is shown that lignite-fired power plants already make a significant contribution as partner of renewables.

Experimental results of minimum load tests obtained from 920 MW units at the Lippendorf lignite power plant

Steffen Lysk, Stephanie Tappe and Peter Lange

The German turnaround in energy policy poses new challenges especially on lignite-fired base load power plants of Vattenfall Europe Generation. One possibility is the extension of the load range by decreasing the minimum load of a power plant unit in order to increase the load and control range. This reduces the number of shutdown and start-up procedures and enables more flexible and gentle operation of the power plant. In order to demonstrate the approach, measures taken at the Lippendorf power plant will be described in detail as an example.

The induction machine as excitation system for large turbine generators

Stefan Schmülling and Ana Joswig

Compared to common excitation systems, the induction machine as exciter for large turbine generators has the advantage of providing an excitation current at standstill without the use of brushes and collector rings. The energy for the excitation current is delivered through a transformer, which is directly connected to the generator’s terminal and therefore with the grid. This makes an additional permanent magnet rotor expendable and leads to a shortened shaft. Static excitation systems can be replaced with such an exciter.

Retrofit of an ECO bypass to reduce minimum load of a 750 MW hard coal-fired power plant

Bernhard Michels and Heike Kotzan

Due to the new requirements of the energy market, created by the German “Energiewende”, a more efficient ECO bypass was retrofitted to unit 3 of Mehrum power plant in order to reduce minimum load which was limited at 250 MW (net about 36.2 %) by the flue gas temperature. At relatively low cost and temporal expense, the minimum load was reduced to 120 MW (net about 17.4 %) by installing an ECO bypass.

Advanced and state-of-the-art preservation of combined cycle power plants

Frank Udo Leidich

Due to deregulation of the energy market and the increase in gas price, many combined cycle power plants in Europe cannot be operated economically in base load. Therefore, a lot of these plants only run in peaking operation with frequent standstills of variable lay-up time. To assure that the intended lifetime of the power plant is not negatively impacted during lay-up time, a tailor made, plant specific preservation concept needs to be elaborated.

Centralised multivariable feedback control of steam drums in combined cycle power plants

Ahmed Elguindy, Fabian Nickel and Kai Michels

The deregulation of the energy market and integration of renewable energy resources into the electrical grid have led to dramatic changes in the power industry, which rapidly resulted in new challenges that cannot be met by classical control structures employed in conventional power plants. This paper presents the implementation of a modern multivariable control technique aiming at optimisation of the water level control performance of the low-pressure steam drum unit in the 450 MW CCHPP (combined-cycle heat and power plant) München Süd. The new multivariable control strategy significantly improves the closed-loop performance.

Hybrid cooling towers without plume

Hans Ruscheweyh, Reiner Windhövel and Frank Werner

The public often judges a power plant by the huge plume of the natural draught cooling towers. Lower cooling towers have less visual impact on the environment, but can cause fog formation, high humidity and icing of the ground at low ambient temperatures. These problems are to be solved by converting cell cooling towers into so-called hybrid cooling towers which help to increase the acceptance of power plants by avoiding cooling tower plumes and the aforementioned problems related to cell cooling towers.

Successful first use of electronic documentation at Knapsack II power plant

Harald Hümmer, Anke Kunze, Christiane Lammel, Wolfgang Ernst und Peter Kapinus

Whenever a completed power plant project is handed over to the customer, it includes a documentation set, which is vital to ensuring proper operation and maintenance. This “technical documentation” is used today as product for power plant operations which is being increasingly altered and shaped by the demands of modern operation management systems. In its Standard VGB-R 171, first issued in 2003 and completely revised in 2010, VGB PowerTech has defined the content, structure and form of power plant technical documentation and adapted this documentation to changing use and user behaviour. For the first time ever, the plant supplier of Knapsack II power plant in Germany used this Standard as a basis to generate the plant’s complete technical documentation entirely in electronic form, intelligently linking data and documents.