Abstracts - VGB PowerTech Journal 11/2016

How services are affected by digitalisation

Markus John

Given the fact that we are undergoing the fourth industrial revolution, it is becoming increasingly important for companies to develop solutions that help their customers to increase efficiency and reduce costs. On the one hand, technology is advancing in leaps and bounds; on the other, consumer and user behaviour have also changed. The preparation of mass data (Big Data) from system networks and control systems; intelligent sensors and drives; flexible regulation of our demand for electricity in order to optimise costs, taking into account electric and thermal storage; as well as increasing cyber-security requirements are just some of the technical factors driving the market today.[more...]

Energy transition and ageing power plants as change process – challenges and solutions for insurer

Martina Pösl, Stefan Thumm and Martin Eckel

Due to increased pressure of competition in the scope of the energy transition, the profitability of conventional energy production decreases. Maintenance budgets are critically reviewed and time periods between overhauls are being stretched as far as possible. At the same time, technical requirements in terms of flexibility of the plants increase significantly. Affected by that is also a large number of old power plants with high operating hours. This leads to a change of risk exposure of these assets, which has to be reconsidered and newly evaluated by the insurer. The lecture will outline criteria of risk considerations. The influence of the altered and increased requirements and constraints on steam turbines shall be illustrated as example. Focus of the lecture are, furthermore, current trends of maintenance concepts.

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Steam turbines subject to flexible operation

Frank Biesinger, Huáscar Lorini and Hans-Holger Knauf

Due to the “Energiewende”, the load and operating behaviour of many power plants in service has changed from base-load to more flexible operation. Numbers of starts, operating hours per annum and ramp rates have all changed dramatically. An increased lifetime consumption of the steam turbine components due to faster start up, longer standstill and frequent low load operation is often the consequence. In order to assess the capabilities for flexible operation in future, the current life time status of the critical steam turbine components has to be determined. Consequently a re-allocation of remaining life time for a flexible future load regime is possible. Finally, the implementation of a state-of-the-art thermal stress control system allows the adjustment of the stress calculator settings to the needs of the re-allocated remaining life.

Evaluation of transient operation for steam turbines with flexible analytical calculation approach

Wolfgang Beer and Lukas Propp

Requirements for flexible operation of steam turbines have been increasing in the past years and continue to rise. Therefore tools for designing and evaluating of transient operations are necessary. These tools have to calculate start-up and shut-down operations and load change operations. In addition they must be able to reliably predict the consequences of these transient operations on the life time of the turbine. In these work an analytical calculation approach is presented which allows fast and flexible calculation of start-up procedures and load change operations. In addition, validation calculations based on FEA are presented. The practical use of this approach is demonstrated with three examples.

Optimisation of industrial heat and power generating plants

Helmut Steinmetz

Industrial heat and power generation plants are built for decades. Most of them have been designed for a save operation in connection with a constant electrical output. Today a constant electrical output is less important than the delivery of energy in accordance with the demand of the production plant. This article describes how to prepare an optimization of industrial heat and power generating plants and the possibilities of their optimization. In this article simple measures of optimization are described, to be implemented as single measure or as a combination of measures (under considerations to be includes).

Preservation of combined cycle power plant Knapsack 1 and 2 with film forming amine Octadecylamin (ODA) – Experience after one year of operation

Ronny Wagner, Erwin Czempik and Elmar Arent

Statkraft Markets GmbH operates two combined cycle power plants (CCPP) in Hürth near Cologne. Even with a low number of operating hours, both power plants have to be available at short notice to deliver their power to the grid immediately in case of demand. For better protection from idle corrosion, the boilers stays filled after a cycle of operation and is topped with a nitrogen blanket. Since January 2015, the preservation procedure with the film forming amine Octadecylamine (ODA) is used additionally in the unit 1 of the Knapsack CCPP.

Is a retrofit a very substantial modification? VDMA 4315-2 Existing Plants

Bernhard Hoffmann and Bernhard Wüst

According to the EU guideline a product to which important changes have been made after commissioning may be considered as a new product. This has to be decided on a case-by-case basis. Part 2 of the VDMA 4315 series of specifications answers the question “very substantial modification?” on the basis of concrete decision guidance. Reconstruction scenarios which occur most frequently will be present in a case-specific way. VDMA 4315-2 shows of how to proceed with renovating of protective functions of old equipment with regards of the functional safety requirements and provides clear tips on usage. As the reconstruction of existing equipment is primarily covered by European and local work usage regulations, VDMA 4315-2 has been provided with a uniform interpretation in joint meetings between manufactures (VDMA) and operating organizations (VGB), so that the assessment provided here conveys the shared view of manufactures and operating organizations.

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Optimisation of flue gas cleaning processes by utilisation of the performance profile of PTFE and modified PTFE in heat exchanger and lining applications

Michael Schlipf and Katja Widmann

Due to its excellent resistance to all chemicals being present in the chemical mix of flue gases, Polytetrafluoroethylene (PTFE) and modified PTFE turn out to be the material of choice for various applications in flue gas systems of coal-fired power plants. They are resistant as well under dry as under wet conditions and therefore no measures have to be undertaken for preservation during short- and long-term shut down periods. The high specific heat cp of PTFE, twice as high as that of steel, makes it an ideal material for corrosion resistant heat transfer elements in Ljungström® heat exchangers. Weight reduction of the moving rotor and ease of cleaning due to the non-stick surface of PTFE are further benefits of the polymer material concept.

Primary NOx reduction technology development – The road to IED compliance

John Goldring and Gerry Riley

The progress is outlined which was made from the original first generation Low NOx burners (LNBs) to the current, state-of-the-art, Ultra-Low NOx Burners (ULNBs) that are achieving IED-compliance or near-compliance using primary NOx-reduction methods only, when firing Coal, Biomass, Oil or Gas. SCR is such an expensive option that it is thought to be uneconomic by many generators. However, with the advent of RJM’s Ultra low NOx technology, SCR is no longer the only option for IED compliance.

Thermal damage to the forced draught due to flue gas discharging via cooling tower

Bernhard Persigehl, Konrad Fertl and Martin Fricke

At the new-built coal power plant Trianel in Lünen/Germany the forced draught was damaged due to thermal overloading. The reason was hot air flowing back from the vessel over the secondary air path. The air entered the vessel as cooling air and heated up during a trip following a blockage within the air heater. An operational data analysis showed that this backflow was not caused by the blockage within the air heater or the chosen valve positions, because it also occurred during hot banking operation. Based on the results of the investigation different protective measures have been implemented to prevent future damages.

Optimisation of industrial heat and power ‘ generating plants –The impact of German CO2 reduction targets on the European electricity market

Dietmar Lindenberger

The topic “CO reduction within the electric power system” should actually be preceded by a more general remark on the efficiency of energy policy from a macroeconomic perspective. An efficient and effective energy policy necessitates that the primary targets of such an energy policy, namely safeguarding a sustainable energy supply as well as considering environmental and climate objectives, are attained at the lowest possible costs. This corresponds to the general economic principle according to which given goals are to be achieved with relatively little effort and/or investments. That is beyond doubt because it means nothing else than to avoid any unnecessary waste of resources in order to reach such objectives.

New guideline ruling on the future of the Rhenish mining area

Michael Eyll-Vetter

Lignite is important in Germany for helping ensure a continuous supply of the market with electricity and heat. More than any other energy source, it stands for security of supply and affordability. Besides economic determinants, it is political conditions, in particular, that are increasingly being brought to bear on the extraction and use of coal. With the object of dispensing with further resettlements of townships after 2030, North Rhine-Westphalia’s state government in spring 2014 triggered the process for drawing up a new guideline ruling on the Garzweiler opencast mine. The bottom line is that the guideline ruling, adopted on 05.07.2016, now confirms, on the one hand, that the Garzweiler mine will be needed for the long-term energy supply while, on the other, limiting the extraction field to such an extent that considerable losses of the deposit occur.

From the Cottbus-Nord opencast mine to the “Cottbuser Ostsee”

Birgit Schroeckh

The Cottbus-Nord opencast mine was the first of the 5 mines in the Lusatian lignite mining region that shut down production as scheduled at the end of 2015. The opencast mine is currently in “shift change” from an active mine to the “shaping of the post-mining landscape”. The development of the Cottbus-Nord opencast mine shows how wise decisions in approving can be successfully implemented beyond political legislative periods. The successful implementation of the measures are preconditions to give the “go ahead” for the water from autumn 2018 to fill the “Cottbuser Ostsee” within a period of 5 to 6 years.