Abstracts - VGB PowerTech Journal 3/2021
Hydrogen as an energy carrier plays an important role in achieving climate neutrality and in the success of the energy transition. Hydrogen, the energy industry and energy technology can look back on a long history and thus also have extensive experience in handling and using it. Hydrogen has been studied and used in science and technology for more than 200 years. [more...]
A method for the consideration of relaxation effects in the assessment of stresses and bearing loads of high temperature piping systems
Continuous monitoring of the piping and hanger systems of modern coal-fired power plants is essential. Because of high steam parameters creep exhaustion as well as stress relaxation due to creep deformation play crucial roles (e.g. with respect to the pipe stresses) and the stress reserves are low. An increased number of start-ups and shut-downs moreover evokes low cycle fatigue of the piping components. Thus, continuous assessment of the degrees of exhaustion due to creep damage and low cycle fatigue has to be performed for the most critical parts. Therefore, among other things it must be checked, whether the pipe stresses are in an admissible range. This is quite challenging, since during operation the piping system is subjected to relaxation effects. According to calculation standards it is assumed, that these effects uniformly lower the operating stresses throughout the pipe over time. Actual operational measurements of rigid support forces show however, that the relaxation is non-uniform throughout the pipe and may thus at some locations even increase the load. Therefore, this contribution provides a method of how these relaxation effects can be reflected in a pipe statics analysis, based on actual measurements during operation.
Wind energy: continued operation often pays off
The end of the design life of a wind turbine does not have to mean immediate dismantling. It is often more economical to exploit the lifetime reserves and continue to operate the turbine for a few more years. TÜV SÜD shows what is needed to achieve this. There is much to be said for operating existing wind turbines (WTGs) beyond the estimated operating life of 20 years in most cases. The prerequisite is a coherent marketing concept. The topic is particularly relevant for operators of German wind farms, as state subsidies for a large part of the plants will expire in the coming years. For the next five years alone, this will affect wind turbines with a total capacity of 2.5 gigawatts per year. However, the alternatives after expiry of the estimated operating life are the same everywhere: dismantling, repowering or continued operation. TÜV SÜD has developed methods to reliably determine the lifetime reserves of wind turbines. The report shows exactly which specific maintenance measures are required. This enables operators to reliably calculate the necessary investments and thus the profitability.
Hydropower indispensable for secure power supply in Europe
Peter Bauhofer and Mario Bachhiesl
On January 8, 2021, Europe was on the verge of a blackout. Once again, the significant contribution of hydropower in stabilizing the European power systems in critical situations was demonstrated impressively. Thanks to the reserve it is able to maintain and the balancing power, hydropower is indispensable for the security of energy supply in Europe. A frequency drop caused by the tripping of an overcurrent protection in a substation in Croatia on January 8, 2021, nearly led to a large-scale blackout in the European power grid. However, a blackout was avoided by targeted countermeasures on due time. Given the underfrequency in the northwestern subgrid, large power plants of all generation types made up for the generation deficit after the initial interception by the flywheels of the rotating machine sets (Synchronous Inertia) with rapid increase in output. In addition, contracted loads, i.e. industrial consumers with a total capacity of 1.7 GW, were taken off the grid, primarily in France and Italy. Automatic and manual countermeasures were also activated in the southeastern subgrid due to the increase in frequency. On the one hand, excess power was reduced by withdrawing generation and shutting down of generation plants, and on the other hand, forced pumping operation in pumped storage power plants was initiated for this region in order to take energy out of the system. ENTSOE’s recently published interim report on this event gives evidence on the substantial contribution of hydropower plants in managing this critical system situation.
Data protection in times of pandemic: Claim, reality and practical aids
The Corona pandemic has led to a new (probably permanent) emphasis on home office, video conferencing and remote control. Germany is currently characterised by a reform backlog and an overbearing bureaucracy that does not stop at digitalisation. Not only did digital tracking in Corona also fail in Germany because of data protection, but in the areas of home office, videoconferencing and remote control, data protection prevents as well sustainable innovation. The Emotet malware attack on the Kammergericht in Berlin has shown that the German capital in particular does not take information security and data protection very seriously. Nevertheless, more and more hurdles are being erected by Berlin‘s data protection commissioner when it comes to video conferencing. In this example, we use MS Teams to show that this tool can be operated in a legally compliant manner despite the concerns of the Berlin authorities. The new „Double Key Encryption“ procedure from Microsoft, which is now used with Microsoft 365 E5, plays an important role in this paper. The process uses two keys to access protected content, one held by Microsoft and the other by the E5 user. The technical implementation is described in this essay. Finally, this paper will argue why the new draft of the Telecommunications Act would be a step in the wrong direction and would harm the competitiveness of German companies. Quite apart from that, the new Telecommunications Act would also not be an improvement of data protection in Germany.
Development of safety case data claimed for laser cutting operations in nuclear decommissioning
Howard Chapman, Julian Spencer, Stephen Lawton, Andrew Gale and Matthew Clay
Laser cutting for size reduction of redundant vessels and pipework in nuclear facilities is considered to be a novel process to most decommissioning engineers, yet is a widely used technique elsewhere in other manufacturing industries. The use of laser cutting in the nuclear industry requires demonstrable quantified solutions to overcome subjective safety concerns in order for end users to adopt the technology for decommissioning purposes. The National Nuclear Laboratory (NNL) has undertaken a research programme to address these safety concerns to understand the damage that can be done by a direct or stray laser beam, if it illuminates a variety of different materials commonly found in a nuclear decommissioning environment. NNL is currently developing a new National Nuclear User Facility for Hot Robotics (NNUF-HR) which will support the United Kingdom by applying robotics to develop cheaper and faster nuclear decommissioning systems, nuclear new-builds, advanced modular fission reactors and future fusion power plants. It is concluded that innovations in data processing, analytics and retrieval for laser cutting will offer a significant improvement in problem solving capabilities in design and safety case development for future nuclear decommissioning challenges.
Studies on performance and degradation stability of chemically degraded nuclear graded ion exchange materials by application of radio analytical technique
Pravin U. Singare
In the present investigation attempts was made to study the stability and performance of chemical degraded nuclear grade resins Purolite NRW505 (R1) and Purolite NRW400 (R2) based on kinetics and thermodynamics of ion-isotopic exchange reactions performed by using fresh and degraded resins. For the reactions performed by equilibrating resins with 0.200M radioactive labeled bromide ion solution at 30.0 oC, the values of specific reaction rate k (min-1) for fresh R1 (0.428 min-1) and R2 (0.356 min-1) resins decreases to 0.420 and 0.330 min-1 respectively for the reactions performed by using resins degraded in 20% H2O2 medium; which further decreases to 0.415 and 0.298 min-1 respectively for the reactions performed by using resins degraded in 30% H2O2 medium. Similarly trend was observed for the resins degraded in 0.010 M HClO4 medium. The higher k values for the R1 resin indicate their better performance stability even under stringent degradation conditions.
City of Essen establishes H2 advisory board
Top companies and research jointly drive the hydrogen economy forward
As the energy capital of Europe, Essen is home to top companies and research institutions that represent a complete hydrogen ecosystem. Now the city is bringing them together in an H2 advisory board. The aim is to combine forces at the highest level, develop projects together and actively implement them. The founding of the H2 Advisory Board of the City of Essen took place today as an online event with high-ranking representatives from Brenntag SE, con|energy AG, Evonik Industries AG, Gas- und Wärme-Institut Essen e.V., MESSE ESSEN GmbH, Open Grid Europe GmbH, RAG-Stiftung, Ruhrbahn GmbH, RWE AG, Stadtwerke Essen AG, thyssenkrupp Industrial Solutions AG, TRIMET ALUMINIUM SE and Westenergie AG. Concrete projects were presented at the founding event - and Essen was established as the headquarters of the hydrogen makers.