Abstracts - VGB PowerTech Journal 7/2020

Power supply in times of Corona and COVID-19

Christopher Weßelmann

The worldwide spread of the Corona virus and the direct and indirect consequences and effects associated with it have been affecting our lives since the spring of this year. The pandemic and Covid 19 diseases have triggered a global health and economic crisis unprecedented for our modern society. The coronavirus, first noticed in the early days of this year in Wuhan, China, with a local outbreak, according to current knowledge, determines private, social, economic and political life.[more...]

Technical risk management of hydropower plants

Wolfgang Hamelmann, Klaus Engels and Peter Struckmann

When operating and maintaining a large portfolio of hydropower assets, the challenge for the owner and operator is to decide which risk mitigation investments and maintenance activities should come first, and when. This is especially true when resources in personnel and budgets are limited, and the profitability of the plants must be optimized. The situation requires an efficient and rational prioritization of activities and corresponding allocation of budgets. But how can the right criteria and investment principles be determined, if the overall target is safe, reliable, compliant and economical operation of plants? This article outlines how an asset risk management system can assist in this determination.

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Optimised maintenance strategies in thermal waste utilisation
Artificial intelligence and high quality key performance indicators increase availability

Mariusz Maciejewski and Harald Moosandl

Currently, thermal waste treatment plants are virtually used to capacity, mostly operating at maximum utilization capacity. After technical optimizations in recent years, in most cases a further increase in the throughput can only be achieved by increasing the hours of operation and thus reducing the downtimes. First of all, these goals can be achieved by means of optimized strategies like a predictive and thus condition-based maintenance. An innovative system of STEAG Energy Services GmbH (SES) that MVV Umwelt, one of Europe’s leading companies of the industry, uses in their plants, already shows how innovative and powerful methods can be used in practice. A fundamental prerequisite for this is a continuous process quality and condition monitoring of plants and components in thermal waste treatment plants. Here a central challenge consists in the task to reliably identify abnormalities and also creeping changes from the vast amount of process data provided by modern control systems in order to react early and thus in time. Methods for the physical modeling in predictive maintenance create a crucial basis for this. Moreover, groundbreaking technologies like Big Data and machine learning in combination with AI methods allow to largely automate the procedures for the modeling and thus the determination of reference values for the real-time monitoring of thermal waste treatment plants. After all, especially the users and thus the operation management and maintenance in thermal waste treatment plants benefit from such developments.

Refractory linings under thermomechanical aspects

Holger Leszinski and Martin Breddermann

The design of refractory structures is usually based on requirements that must be matched to the expected furnace atmosphere: Tightness, thermal and chemical compatibility, minimization of heat losses, etc. In this respect, the experience of the constructor and heat transfer calculations on the regular layer structure are supposed to ensure that the completed system can be relied upon. In contrast, comparatively little attention is paid to thermomechanical processes. Often it is constraint stresses – during operation caused by hindrance of temperature deformation and sometimes many times higher than stresses due to dead loads or internal furnace pressure – which can “bring furnace components to their knees”. Even after the occurrence of such failures, the causes are often sought in the wrong direction, among other things because the thermomechanical interactions of the individual structural components are not known or are underestimated. Of course, it is only possible to approximate the complex of refractory construction with its innumerable imponderables, also from a thermomechanical point of view; for this, in the given article the basic mechanisms are explained, exemplary thermomechanical considerations of various design examples are shown, and the possibilities for optimizing safety and service life that can be concluded from this are presented.

Thermal turbomachinery
Consulting services for the plant operator

Gerald Kulhanek, Michael Schwaiger, Dominik Franzl and Leonhard Franz Pölzer

Thermal turbomachines are the core component of many industrial plants. After the occurrence of damage, during revisions/overhauls, in the case of large revamp/retrofit projects or for new acquisitions, plant operators are often interested in obtaining consulting services from external consulting companies for a limited period of time. In recent years and decades, the turbomachinery market has been characterized by major changes. Turbine manufacturing plants have been shut down or restructured and tasks have become more and more challenging due to new regulations and laws. At the same time, it is becoming increasingly difficult for turbine manufacturers and plant operators to retain or attract skilled workers and experts. This creates a demand for independent technical consulting services in the field of thermal turbomachinery. This paper defines and describes the essential requirements that a turbomachinery consulting team should meet in order to ensure a sustainable partnership with a plant operator. Based on many years of practical experience, the range of tasks for which the use of consulting services in the field of thermal turbomachinery has proven its worth is presented, as well as the developed solution methods.

Statement on the IT Security Act 2.0

Stefan Loubichi

The threat situation in IT/OT-security as well as cyber-security in the energy sector remains high. We don´t know who exactly the cyber terrorist / cyber criminals are, what they are planning and that their next goals are. We only know from the annual cyber attacks in Ukrainian power grids or SCADA systems worldwide that they could realize a blackout. With the IT-security law (published in 2015) our government took a courageous step in 2015 to protect our critical infrastructure. Unfortunately, in Germany we have lost leadership in this area in terms of IT-/OT-security and have not adopted an audit program for energy producers until now. In this article the draft of the ITR-security law 2.0, published in May 2020, is presented. It is anticipated that the draft will enter into force with slight changes by the end of the year. Operators as well as manufacturer of core components have to deal with new (legal) requirements for their IT-/OT-systems. What they have to do and which consequences they have to expect if they do not implement the requirements are presented in this article. Of course, there is still room for improvement in our IT-security law 2.0. But the new IT-security law 2.0 will help us to achieve security for tomorrow.

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The Biofficiency Project Part 1: Handling ash-related challenges in biomass-fired cogeneration plants

Lynn Hansen, Thorben de Riese, Richard Nowak Delgado, Timo Leino, Sebastian Fendt, Pedro Abelha, Hanna Kinnunen, Partik Yrjas, Flemming Frandsen, Bo Sander, Frans van Dijen and Hartmut Spliethoff

The EU funded project Biofficiency developed a blueprint for the next generation of biomass-based cogeneration plants using difficult fuels while assuring a secure and nearly carbon-neutral power generation. In this first part of a series of two publications, a summary of the activities handling ash-related challenges in biomass boilers is provided. Three thermochemical pre-treatment technologies, torrefaction, hydrothermal carbonisation and steam explosion proved suitable for upgrading residual biomass feedstock by increasing energy densities and improving storage as well as handling properties. In combustion tests, both in pulverised fuel (PF) and fluidised bed (FB) systems ash-related problems, namely deposit build-up, fine particle formation and corrosion were examined. Deposit tests in PF boilers showed that the additives have a pronounced effect on deposit propensity, the additive amount being of greater importance than the type of additive. The use of additives also showed positive influence on aerosol formation. In FB firing, an optimisation of the additive composition and insertion was performed, where elemental sulphur was found to be the most cost-effective additive for this case. It was demonstrated that pre-treating straw by torrefaction combined with a washing step requires a substantially lower amount of additive to be added during combustion. Biomass ashes from different sources were classified based on their composition and possible utilisation pathways with the goal to avoid landfilling were developed. Innovative utilisation options were identified such as utilisation in construction materials or recovery of valuable elements.

A journey through 100 years VGB | Hydropower

  • Development Potential of Hydro-electric Power
    E. Göde
  • Hydro-power: Challenges in Europe
    Michel Vogien and Hans Peter Sistenich
  • Maintaining Know-how and Assuring Quality in Hydro Power Plants
    Josef F. Ciesiolka and Hans-Christoph Funke