Abstract - VGB PowerTech Journal 12/2019

Power for the future of digitalisation

Christopher Weßelmann

Today, it is impossible to imagine our everyday life and our lives without the Internet. The Internet follows us at every turn. At home, in the household, when the Internet accompanies us with information via television, radio or PC, or even in far-away places around the world, when it provides information on what is happening at home via networked devices.[more...]

An integrated approach to risk informed decision management

Howard Chapman, Maria Cormack, Caroline Pyke, John-Patrick Richardson and Reuben Holmes

The nuclear industry presents a unique combination of challenges in the planning and deployment of both large and small projects. The requirements of the regulatory framework, diverse stakeholders, cost effectiveness of investment, and the management of actual and perceived risks all contribute to the complexity of decisionmaking. Pragmatic decisions must be made to balance all of these and any other factors. The best solution to solve a problem today might not be the best solution tomorrow. The challenge is to understand uncertainty from the decision-making process and demonstrate that decisions are made transparently. This paper examines a solution to decision-making in the nuclear industry to help prevent lack of stakeholder buy-in due to the complexity of the problem. The method encourages communication with all stakeholders before during and after the decision-making process and conveys the output in a simple and highly visual way that satisfies all their different interests and points of view.

Problems, solutions and new construction of a bed ash cooling system with a fluidized ash cooler

Joachim Plackmeyer, Adlan Omer and Georg Saarmann

In circulating fluidized bed combustors maintaining an adequate particle size distribution is essential. Failing this often leads to problems within the combustor and subsequently to problems in the bed ash drain and the bed ash cooling system. Preliminary the effects of different bed ash particle sizes on internal and external ash circulation and on combustion are shown. This results in the need for targeted and consistent care for the bed ash through efficient ash removal. The peculiarities of a fluidized ash cooler are described in a specific example. The occurring problems, their causes and solutions are depicted. The problems were sintering, formation of large ash lumps and clogging with retroactive effects on the required power plant operation. A new design of a bed ash cooler, highlighting the most important details, as well as the operating experience are described.

Perspective development of electricity generation in Europe

Stefan Ulreich und Hans-Wilhelm Schiffer

The European power plant park will experience a paradigm shift between 2025 and 2030 due to the technical lifetime of conventional plants. The foreseeable change will be intensified by the increasing efforts in recent years to shut down nuclear and coal-fired power plants before they reach the end of their technical and economic life. The declining generation capacity from conventional power plants can be compensated by the addition of renewable energies. However, in order to maintain stability in the grid, it must be ensured that the necessary secure capacity is available at all times. Conventional power plants, which have so far provided most of the secured capacity, will only be available to a significantly reduced extent in future. For this reason, renewable energies and flexibility options such as storage and demand response will have to make strongly growing contributions to secure capacity from this period onwards in order to achieve the usual level of security of supply. To illustrate the upcoming challenges, this article looks at the death line of the conventional power plant park of the EU-28 .

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Energy Supply Without Nuclear: Winter 2022/23 is Coming

Roman Martinek

Only three and a few years are left in Germany before the scheduled shutdown of the country’s last nuclear power plants: by December 31, 2022, Isar, Neckarwestheim and Emsland NPPs (one reactor at each) will be disconnected from the grid. This raises the question which energy sources will be used in Germany in the future national power supply. This is closely linked to the question of compliance with the goals of the Paris Climate Agreement and the achievement of the targets promised by the German government. On the one hand, it is quite obvious that, given the current level and scope of renewable energy production, it will not be possible to replace the nuclear power capacities to be decommissioned with solar and wind energy immediately after 2022. In other words, replacement capacity and generation must be provided.

Counter-current flow division for heat absorption from two isothermal parallel plates

M. Goodarzi, N. Eshghabadi and R. Sadeghi

A particular counter-current flow division for heat absorption from two parallel plates has been introduced to improve the thermo-hydraulic performance. The new counter-current channel was constructed with inserting two zero thickness and impermeable plates within the basic parallel-plate geometry to establish a central sub-channel and two external ones. The total flow rate has been divided to two ones supplying to the central and external constructed sub-channels in counter-current directions. The effect of the cross section ratio on the thermal and hydraulic performances have been investigated compared to the single-pass arrangement. Two regimes of the flow division also have been considered for each geometrical cases. The obtained results showed that a better thermal performance would be enhanced when the cross section of the central sub-channel was greater than the external ones, for both flow regimes. Besides, the overall performance, which regarded the hydraulic performance in addition to the thermal one, was better for second flow regime at high Graetz number.

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CFD simulation of flow characteristics and thermal performance in circular plate and shell oil coolers

Ya-jie Shen, Yong-heng Gao and Yong-jie Zhan

Circular plate and shell heat exchangers were gradually applied as oil coolers. Hence, it was necessary to investigate their performance at low Reynolds number with high viscous oil. This paper provides a CFD simulation of flow characteristic and thermal performance in circular plate and shell oil cooler with different plate parameters, such as plate angle β, ratio of plate pitch to height p/h and corrugation styles. The friction factor f and Colburn factor j were investigated for the various plate parameters. The numerical results showed that f increased with increasing β, and both increased as p/h decreased. When β<60°, j increased with increasing β, but when β≥60°, j keep nearly equal. f and j increases with decreasing p/h, and the comprehensive performance of p/h=3.3 is the best. It was also found that there was no difference between inclination corrugation and chevron corrugation in terms of flow characteristics and thermal performance. In order to achieve optimum performance, the following parameters should be used: β=45° and p/h=3.3.

100 Years VGB: 150 years of electrical engineering – a review and future prospects for power plant construction

H. Böhm

The development of power plant construction both in the last 150 years and also relative to the deduced major trends for the future is illustrated by the important milestones. In this respect, the important role of modern power stations is very prominent in ensuring enduring economic development.

100 Years VGB: Electricity and water for life in the desert – Al Taweelah Power Station in Abu Dhabi

G. Silbermann and R. Koerdt

Al Taweelah Power Station comprises a power plant section with six units and a desalination section also with six lines. Daily, the plant can supply about 17.5 million kWh of electricity and about 350 000 m3 of drinking water. This paper describes, in addition to the installation of the plant, the project management, ten partner companies with their numerous suppliers and subcontractors had to co-ordinate their plans precisely with each other. From June 1996, the six units were commissioned with an interval of one to two months between each. The entire plant is currently operating in the guarantee period. It has fulfiled the expectations of the client.

100 Years VGB: Joint research as a supernational task – 25 years of VGB RESEARCH FOUNDATION

G. Häßler

Along with numerous and major research-, development and demonstration projects effected by the utilities, VGB’s Joint Research has successfully installed its function over 25 years. Attractive by its benefit-cost ratio, Joint Research aims at improving the state-of-the-art technology in a neutral, noncommercial way. University research makes a significant contribution. Due to the extension of the VGB member community all over Europe, the utility-based Joint Research may become a partner of the EU.