Abstracts - VGB PowerTech Journal 11/2020

The Corona challenges

The Corona/Covid 19 crisis continues to have a firm grip on the world. Whereas in the middle of the year, with falling infection number and illnesses, there was hope that this pandemic was coming to an end, this hope was dashed at the end of the year. The number of infections and illnesses rose again, not only regionally, but across all regions and countries, and in some cases rapidly. Accordingly, measures to contain this development were again necessary, i.e. both private and public life were and are being restricted. [more...]

Digitalization in the Energy Sector – Status-quo, outlook and need for action

Paul Weigel and Klaus Görner

Digitalization and Industry 4.0 will have a far-reaching impact on the energy sector. For stakeholders of all value stream steps and generation technologies, new opportunities and chances as well as new challenges arise. The VGB project DigiPoll@Energy (VGB P428) analyzes the view on digitalization as well as the current status and the expected development among ordinary VGB members with the objective to prepare the ground for joint research projects and support activities by VGB for its members.

Therefore, an online survey was launched in December 2019. Extensive answers were submitted by 35 participants. Subsequently deep dive interviews with 5 interview partners were conducted to clarify questions and go into more detail.

The survey reveals that companies are well aware of the upcoming changes, both on the benefit as well as the risk side. Although some first steps have been taken, a substantial need to further drive digitalization measures becomes apparent. There are indications that the implementation and use of actual digital applications follows the implementation of digitalization measures with a time lag, hence swift action is recommended. Besides the current low implementation level of applications many companies are at present experimenting with new applications, thus a significant future impact can be expected. One of the biggest challenges for many companies appears to be to connect different systems and devices into a central network and database.

This article is a summarized version of the full DigiPoll@Energy documentation!

Digitalization possibilities and the potential of the Digital Twin for steam supply systems

Lukas Kasper, Thomas Bacher, Felix Birkelbach and René Hofmann

Digitalization is more and more becoming part of industrial processes and opens up completely new application areas. The visions of Industry4.0 and Energy4.0, as summarized in this article, both paint a picture of an unprecedented level of interconnectedness of devices and smart services in the Internet of Things. Systems and products will be created that have a high degree of networking, flexibility and automation. Because of these features, they have a huge potential for reducing cost, energy consumption and for improving economic sustainability.

In this article, as an excerpt from the VGB research project DigiSteam, the most promising possibilities offered by digitalization are evaluated with special focus on the steam supply sector. The connection with the concept of reference architectures, such as RAMI4.0, is discussed and the Digital Twin is introduced. Based on these theoretical fundamentals, an adaption of a five-dimensional Digital Twin model to a steam generator is presented. It consists of physical steam generator, communication model, virtual steam generator, data model and service model. A holistic Boiler Prognostics and System Health Management is outlined and with use cases, it is shown that system monitoring, prediction and optimization can be greatly improved by employing this Digital Twin.

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Flexibilization of a combined cycle gas turbine by integration of a P2F synthesis

Florian Möllenbruck, Emmanouil Kakaras and Klaus Görner

By integrating an appropriately dimensioned Power-to-X plant into an existing power plant process, the power range of the power plant can be significantly increased. However, providing the required operating media for the Power-to-X plant has a significant impact on the power plant process. The thermal power requirement results essentially from the capturing of CO2 (desorption of the solvent). This leads to an average reduction in gross output of about 11 MWel. The electrical power requirement of the Power-to-X system is dominated by electrolysis (96%). The integration of the Power-to-X plant into the power plant process continues to lead to a partly significant change in the mechanical shaft power. While the HD turbine remains virtually unaffected, the shaft performance of the LP turbine drops significantly. The reduction results essentially from the reduction of the mass flow and the resulting reduction in the inlet pressure.

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Gas turbine combustors with constant volume heat addition

Friedrich Hala and Reinhard Willinge

Around of the beginning of the twentieth century gas turbines underwent important changes, one of them being in the field of combustion, which in turn developed in two different ways: the constant pressure combustion and the constant volume heat addition, which yields higher thermodynamic efficiency. This paper describes the development of the latter method.

By the middle of the 20th century, further research was carried out, using detonations for the burning fuel. Again there were two approaches, both of them in combination with a turbine stage, namely “pulsed detonation engines (PDE)” and by the “continuously rotating detonation engine (CDRE)”. Either method will be described here in brief.

In the various investigations, it was shown that gas turbines with combustion chambers in which the heat supply is isochoric can achieve better efficiency than with isobaric combustion. In particular, this applies to combustion chambers that work with detonations.

Rotating detonation (RDE) combustors are considered to be advantageous as they are able to provide a near constant exhaust gas flow. However, it is limited that much work is still required for optimisation, such as with regard to the stability of the initiation of the detonation processes, fuel supply, protection against overheating and vibrations. With successful further development taking these points into account, continuous operation would be possible. A combustor (PDE or RDE) for high-power gas turbines, it seems, will require some research and development work in the future

Highlights of the World Nuclear Performance Report 2020

Jonathan Cobb

The 2020 edition of the World Nuclear Performance Report, published by World Nuclear Association, combines the Association’s own data and analysis with data from the International Atomic Energy Agency’s PRIS database. The report looks at long term trends in nuclear performance as well as progress in new nuclear build. The full report, available from the Association’s website also includes five case studies and interviews, looking at individual examples of excellent performance in the nuclear industry. While this year’s report details the performance of nuclear reactors globally in 2019, over much of 2020 our focus has been on the impacts of the COVID-19 pandemic. Throughout the pandemic, operators have worked with great commitment to ensure that their reactors have continued to provide electricity and support grid stability. Staff working at reactors have had to adapt to working in COVID-safe conditions whilst ensuring continuity. With the dramatic drop in electricity demand seen in some regions, reactors have had to demonstrate greater flexibility in operation. While many renewable generators have been cushioned from the impacts of the pandemic by obligations to purchase their electricity, nuclear operators have had to vary the output of their plants to support both intermittent generation and changes in demand. In 2020 the nuclear industry has been an essential part of the response to the coronavirus pandemic. Prior to this, 2019 proved to be one of the most significant for nuclear generation, with near-record levels of generation. Nuclear reactors generated a total 2657 TWh of electricity in 2019, up 95 TWh from 2563 TWh in 2018, and second only to the 2661 TWh generated in 2006. This is the seventh successive year that nuclear generation has risen, with output 311 TWh higher than in 2012