Abstracts - VGB PowerTech Journal 1-2/2021

Transmission system operators prevent blackout – Decisive contribution by dispatchable power plants

Dr Oliver Then

As a result of the separation, there was a power deficit of approx. 6,300 MW in the north-west region, combined with a frequency drop to 49.74 Hertz, and a power surplus of approx. 6,300 MW in the south-east region, combined with a frequency increase to 50.6 Hertz. After only 15 seconds, the frequency deviations initially stabilised at 49.84 and 50.3 Hertz.[more...]

Flexibilisation – Analysis of the effects by evaluation of the VGB database KISSY

J. Aydt, M. Bader, J. Bareiß, R. Mohrmann, I. Pfaff, S. Prost, R. Uttich and H. Wels

The operating regime of fossil conventional thermal power plants has changed due to the increased use of renewable energies such as wind power and photovoltaics. The resulting increase in power generation capacity in the power grid also leads to increased downtimes and reduced operating times under full load for the conventional power plants. As a result, these power plants are subject to increased flexible operation.

Basically, the question must be asked whether the changed operating mode has also led to increased lifetime consumption of plant components. In terms of materials technology, the relationship between cyclic loading, such as that caused by start-ups and shutdowns, and increased service life consumption for thick-walled components is well known. It was unclear whether other unexpected damage had occurred in the plants in addition to the recorded service life consumption on selected components and whether this was clearly related to the change in operating mode. To clarify these issues, all relevant boiler, turbine, and generator components were considered.

For statistical data analysis, the data set of the VGB-KISSY database was used. The data originate from 129 hard coal and lignite-fired power plants as well as from 33 combined cycle and gas turbine power plants of VGB members over a period of 10 years (2005 to 2019). The data were anonymized before analysis and evaluated as an annual time series considering precise VGB definitions for planned and unplanned unavailability.

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Characterization of the long-term behavior of 600/620 °C turbine materials

Johanna Marie Haan, Torsten-Ulf Kern, Yang Wang, Christian Kontermann, Florian Kauffmann and Sabine Polenz

In addition, LCF tests with holding time were able to provide evidence of the functionality of the materials in relation to the changed requirements by flexible power plant operation and higher operating temperatures. Comparisons were also made regarding the deformation and fatigue behavior compared to currently established materials and their application temperature limits.

In summary, it is confirmed that the development of advanced 9-10Cr steels has produced three reliable materials that form a stable alloy concept for 600-620 °C power plant application.

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Attack detection systems in the OT environment at operators of critical infrastructures

Stefan Loubichi

The new IT Security Act 2.0 obliges the operators of German critical infrastructures to implement systems for attack detection. If they fail to do so or if they think it is not necessary they face severe penalties of up to EUR 10,000,000. The question naturally arises as to whether this was really necessary. According to a research report by the Criminological Institute in Lower Saxony, only 20 percent of industrial companies use Intrusion Detection Systems. Normally this should be a good reason why it is necessary to implement such systems. In the area of anomaly detection and intrusion detection in particular, the German Bundesamt für Sicherheit in der Informationstechnik (BSI) gives a lot of assistance on what to consider. The selection of the suitable system depends on the budget available, the infrastructural requirements and whether the company has dealt with OT security beforehand. It is important that the manufacturers of these components of critical infrastructure must issue a guarantee for their components. For German manufacturers this shouldn’t be critical, for manufacturers outside the EU the BSI will certainly be critical.

KKS and RDS-PP® – VGB speaks the language of power plant technology

Andreas Böser and Sabine Kuhlmann

Regardless of the degree of industrialization, power generation is undoubtedly one of the most important and complex tasks of any society. The reliable supply of energy and thus the successful operation of each individual power plant – regardless of the primary energy used – requires an identification system for the consistent identification of plant components and processes. KKS and RDS-PP® provide these capabilities from planning to orderly dismantling. Starting with project planning, through operation of the plant and up to the planned end of operation, all process participants speak the same “VGB language” and can thus communicate with each other nationally and also internationally without any problems. Thanks to this VGB power plant language, data can be exchanged irrespective of manufacturer and operator and enable power plant operators to operate and maintain their plants independently and, in the end, to dismantle them in compliance with laws and standards.

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EffEfficient energy technology for many applications: Combined heat and power iKWK

Stefanie Reil

The German coal phase-out law opens up completely new opportunities for combined heat and power (CHP). This is because the associated amendment to the CHP Act (KWKG) promotes greater flexibility in the technology and thus opens up innovative business models for CHP plants. Until now, these have served almost exclusively as base-load generators in continuous operation. But the sharp increase in volatile power generation from the sun and wind is making more and more residual load necessary: This is precisely where CHP has a great opportunity to demonstrate its market credentials for the future. However, the new flexibility also increases the complexity of CHP-based energy concepts. To ensure that the respective application (business case) remains economically viable, sound project development and planning are essential. Here, Gammel Engineering (GE) is already prepared for complex and flexible concepts due to its decades of know-how in project development for decentralized energy systems and CHP. This is currently being demonstrated again in the planning of an iKWK system in Bad Reichenhall. The project, jointly developed by Stadtwerke Bad Reichenhall and Gammel Engineering, was awarded the contract in the first iKWK tender round in 2018. Full commissioning is planned for June 2021. Currently, the municipal utilities are already advertising it with the slogan: “Saalach heat from renewable, innovative, CO2-saving CHP plant”.

New method for fully automated deter­mination of the concentration of legionella in a water sample within a few hours

Holger Ohme, Jennifer Becker, Pascal Jahn and Dirk Heinecke

The hygienic necessity to control the concentration of legionella in technical water systems from which aerosols can be discharged leads to the problem that the cultivation method (ISO 11731-2017) used for this purpose only provides reliable results after a delay of 7-12 days. On this basis, necessary measures can only be taken and controlled with a considerable time delay. Rapid tests currently available on the market either do not correlate reliably with the accredited cultivation method or require (time-)consuming preparation steps. Some rapid tests provide highly specific detection for single Legionella species, but not for all Legionella species in a water sample (Legionella spp. = species pluralis). The newly developed measuring device INWATROL L.nella+ is based on the method of measuring the metabolic activity of living cells and reliably determines the parameter Legionella spp. from a water sample within a few hours. The measuring device is directly connected to the technical water system with automatic and self-disinfecting sample feed, including self-disinfection of the water contained in the measuring cell after the measurement is completed. This enables the plant operator to determine the hygienic water quality continuously and safely. In addition to the direct control of the success of the measures carried out, it is also possible to control e.g. biocides according to requirements.

Energy consumption in Germany 2020


Energy consumption in Germany in 2020 fell by 8.7 percent compared to the previous year, reaching a historic low of 11,691 petajoules (PJ) or 398.8 million tonnes of hard coal equivalent (MtCE). Compared to 2006, the year with the highest energy consumption in Germany so far since reunification, the decline amounts to about 21 per cent, reports the Working Group on Energy Balances. As a result of the decline in consumption and further shifts in the energy mix in favour of renewables and natural gas, the AG Energiebilanzen expects a decrease in energy-related CO2 emissions in the order of about 80 million tonnes. This corresponds to a reduction of around 12 percent compared to the previous year.