Abstracts - VGB PowerTech Journal 11/2017
The potential of digitisation
Dipl.-Ing. Christopher Weßelmann
The realignment of the power industry is one of the major challenges of the new millennium. It comprises two central components: the new energy supply structures, known as the “energy turnaround” – it is a new structure in energy supply that differs markedly be-tween the extremes of 100 % renewables and business-as-usual strategies, which more or less favour conventional generation. The second component concerns digitisation, often referred to as “Industry 4.0”. Irrespective of the way in which the objectives are de-fined, it affects all types of power production and ultimately also the consumer, because one factor is the digital coupling of production and consumption. [more...]
Enhancement of fuel flexibility of industrial gas turbines by development of innovative combustion systems
Nurettin Tekin, Atsushi Horikawa and Harald Funke
For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilisation with gas turbine/gas engine for electricity supply. In the developments of hydrogen gas turbine, key technology is stable and low NOx hydrogen combustion, especially, Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large difference in the physical properties of hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fuelled gas turbines.
Constant volume combustion in gas turbines – Research in the chairs of fluid dynamics and combustion kinetics of the TU Berlin
Panagiotis Stathopoulos and C. Oliver Paschereit
The efficiency of gas turbine power plants has experienced a steady increase in the last decades. Novel cooling technologies and materials made higher turbine inlet temperatures possible and led to higher system efficiencies. However, this trend has an upper limit due to various financial, technological and environmental factors. A way to solve this problem is to apply alternative system configurations and novel cycles. Constant volume combustion (CVC) cycles are such a solution, if the technological challenges accompanying them could be addressed and solved. Two thermodynamic cycles have been used so far in the open literature to represent the behaviour of gas turbines that operate with constant volume combustion, namely the Humphrey and the ZND cycle. While the first considers purely constant volume combustion, the second refers to the use of detonations as a way to approach CVC.
The new BAT Reference Document for Large Combustion Plants – anticipated impacts on OCGT and CCGT for power and heat supply
Martin Ruhrberg
The review of the Reference Document on Best Available Techniques for Large Combustion Plants (BREF LCP) has started in 2011. Key objective of the review process is the revision of the Best Available Techniques (BAT) for emission abatement and energy efficiency. The publication of the legally binding new BAT conclusions is envisaged for the second half of 2017. The BAT conclusions will contain a number of ambitious BAT associated emis-sion levels (BAT-AEL) for nitrogen oxide emissions for both open cycle (OCGT) and combined cycle gas turbines (CCGT) as well as indicative emission performance values for carbon monoxide. Furthermore, the document will establish additional monitoring requirements and new procedures for assessing compliance with the emission values. The document will also include performance levels for energy efficiency expressed as design values. In Germany, the BAT conclusions will be implemented in the form of general binding rules through a major review of the 13th Federal Immission Ordi-nance. In the presentation, the most relevant new requirements for OCGT and CCGT will be identified and potential approaches for implementation of the new requirements presented. The presentation will close with an assessment of the potential impact on the existing German gas turbine fleet and the new plants to be built in the forthcoming years.
Modelling the operational performance of water-cooled surface condensers using the single-tube condenser model according to VGB-S-130
Francisco Blangetti, Wolfgang Czolkoss and Lucas Borobia
The former VGB guideline VGB-R 130 „Acceptance Test Measurements and Operational Monitoring of Water-Cooled Surface Condensers” (1994) pro-vided information on the implementation and evaluation of measurements on turbine condensers. This guideline was a valuable tool for manufacturers and operators in determining the condenser performance from the measured values and the comparison with nominal values. The VGB guideline has now been revised and updated and published with the same title as the new VGB-Standard VGB-S-130-00. The new VGB-Standard includes an advanced calculation program for turbine condensers. It can be applied for the design of turbine condensers as well as for acceptance tests and for the operational monitoring of the condenser performance.
Current topics in the “Entsorgungshandbuch für Energiedienstleister”
Kerstin Fetsch and Thomas Eck
The disposal manual „Entsorgungshandbuch für Energiedienstleister“ is worked out and written by an integrated project group of the German Associa-tion of Energy and Water Industries (BDEW) and the international technical association for generation and storage of power and heat (VGB PowerTech e.V.). The loose leaf collection, which is updated once a year and published as CD and book, gives information about the typical questions on waste disposal and waste management within companies of the energy sector. It presents the state and the current legal development of national and Euro-pean waste legislation. Practical recommendations to questions on disposal topics are given. The structure and content of the disposal manual are described and an outlook on the future main topics is given. In this context the current changes in waste legislation, which are dealt with in the last and the next supplement delivery of our loose leaf collection, are pointed out.
Phosphorus recycling from sewage water via fluidised bed sludge combustion
Georg Hiller and Joachim Werther
Sewage sludges from municipal waste water treatment plants contain a considerable amount of phosphorus. The amendment to the German Sewage Sludge Ordinance of August, 2017 is a first step into comprehensive phosphorus recycling from sewage sludges or ashes from sewage sludge incinera-tion, where the focus is on the usage of the phosphorus for fertilising purposes. In the present work experience at the Waste Water Treatment Plant Ulm is reported with the production of an ash obtained by fluidised bed combustion which satisfies the specifications of the German Fertiliser Ordinance and thus can be marketed as a fertiliser. The efficiency of the phosphorus recovery from the water into the ash is above 97 %. In 2016 8,408 tons of phosphate ash was brought to market as a phosphate fertiliser. This is equivalent to a mass of recycled phosphate of about 1,400 t P2O5 or 610 t of phosphorus.
Analysis of single droplet evaporation to realise a fast spray modelling approach for online SNCR enhancement
Tobias Widder, Michael Beckmann, Fabian Geltz, Philip Reynolds and Wolfgang Schüttenhelm
A proven method for reducing nitrogen oxide emissions in thermal power plants is the SNCR process. It is cost-efficient and enables to match current legal emission limits. To tap the full potential of the SNCR process, an almost process-synchronous computed reducing agent and nitrogen oxide distri-bution in the firing provided by a fast spray modeling approach is required. We recommend such an approach based on the postulate, that it is feasible to determine the reducing agent spray as a sum of single droplet trajectories. Each droplet trajectory is interrelated with the time-dependent droplet evaporation behavior and the resulting release of reducing agent. Whereas the droplet trajectory can be defined by an ordinary differential equation considering relevant appearing forces and the main flue gas flow, detailed evaporation behavior is significant more complex. Subsequently after achieving evaporation experiments in an ultrasonic levitator, the in this case verifiable appropriate D²-law for droplet evaporation was merged with the single droplet trajectories and implemented in a spray model program code. The reducing agent distribution as well as the NO distribution – using a simple global NO calculation approach – were computed for a German MWISP. Comparing the results with measured total values and the operating experiences yields a good approximation at computation times lower than 1 second.
The Triple Effect of Carbon Dioxide
Eike Roth
Carbon dioxide (CO2) affects the atmosphere in three ways: it absorbs radiation and thus adds energy to the atmosphere (heat), it emits radiation and thus dissipates (heat) energy from the atmosphere, both of which are important for the climate on Earth, and the CO2 also has a non-climate effects on life on Earth. In principle, these effects can have considerable consequences if anthropogenic CO2emissions influence the CO2 concentration in the atmosphere. This article point out that many questions remain unanswered with regard to the exact size of the individual effects and that the consequences, in some cases, are not yet clear and cannot yet be sufficiently quantified. This would be necessary for responsible decisions, however, and there is an urgent need for action.