Abstracts - VGB PowerTech Journal 9/2004

RWE Innogy's Business Risk - Assessment Process

Chr. J. Elston

RWE Innogy developed the Business Risk Assessment Process (BRAP) with the aim of maximising the commercial performance of power plant in de-regulated markets. BRAP is a suite of processes that together form a balanced view of all risks associated with the plant: market risk; environmental risk; major engineering risk; plant condition; operational factors and human competence.

Ultrafiltration - A Safe and Cost-effective - Process for the Production of Boiler Feedwater

W. Ruppricht and Th. Müllrick

Ultrafiltration is an economical process for treating surface water from rivers, lakes and seas. In comparison to conventional water treatment, ultrafiltration is a nearly chemical-free process, which can be highly automated and provides a constant water quality independent of changes in the raw water. Because of the reliable separation of colloids, turbidity, bacteria and viruses, ultrafiltration is very well suited as a pre-treatment before reverse osmosis.

Four Years Experience with a New Chlorine Dosing Regime against Macro Fouling

H.A. Jenner, H.J.G. Polman and R. van Wijck

KEMA developed in 1998 a new method of chlorination called Pulse-Chlorination® in order to combat macro fouling in cooling systems. The chlorination method uses short successive periods of chlorination, alternating with periods without chlorine. The full-scale tests on site between 1999 and 2003 resulted in extremely clean condensers and thus a better performance of the cooling water system (K-value) and therefore less maintenance.

On-line Monitoring of Corrosive - Tendencies of Cycle Fluid
Part Two: Measurement of the Concentration of Suspended Ferric/Ferrous Oxides/Hydroxides by Use of Turbidity

H.J. Bettenworth, E.V. Maughan and H.D. Pflug

This paper presents a method, which is suitable for the on-line monitoring of the concentration of suspended iron oxides/hydroxides by use of scattered light turbidity (nephelometry). Together with the continuous measurement of concentration of dissolved ferrous ions in plant cycles this method allows the monitoring of the corrosion tendency
of cycle fluid.

Pilot Tests on Raw Water Treatment for the Production of Fully Demineralised Water

H. Schley, D. Mauer, Adelja Markert, Inge Lehmann and O. Piepenbring

In the Lippendorf power plant the following effect was observed in the water-steam cycle: immediately after feeding the demin water into the water-steam cycle, a clearly increase of the specific conductivity is observed downstream of the highly acid cation exchanger. The organic constituents occurring in the process of demin water production were systematically investigated. Several variants were tested that can reliably retain the DOC and in combination with a fully demineralisation plant and/or mixed bed exchanger produce suitable demin water. A plant concept was developed.

Automation of Analytical Systems in Power Cycles

R. Germann

Acid conductivity is taken as an example to discuss concrete automation of analytics. It is the objective of automation to convert a reliable, "verified" measured value. It is necessary to consider the entire chain from sampling up to signal exchange. The entire process is aiming at automated secured quality of analytics that permits more efficient plant operation on the basis of reliable measured data.

Quo Vadis Power Plant Chemistry II - Automated Monitoring of Cooling Cycle Systems

H. Prenzel, S. Neuhaus, Annette Ewald and A. Gerk

The development of the activities in the field of power plant chemistry is outlined. A precise and general forecast is not possible from a present point of view because not every single approach can be taken into account here. However, it is becoming increasingly apparent that the automation of monitoring and control processes will have a growing impact on the field of chemistry.

Influence of Flow and Chemical Reactions in Flue Gas Caused Fouling on Superheater Tubes in Waste-to-energy Plants

R. Warneke

Corrosion is an electro-chemical process. Therefore, the reaction limits are determined by thermodynamics. The development of the products will be described by kinetics. Reactions take place within this different complex. Such reactions lead to new species on the one hand and on the other to changes in Gibbs' enthalpy with release or absorption of energy. It can be seen that these energies can have a significant influence on the fouling and corrosion processes.

Status and Perspectives of Energy Storage Systems

Chr. Kölsch, B. Heyder and W. Münch

Capacity control and keeping-up of voltage in the power grids is among the core issues of electricity supply companies. Electrical storage systems can make their contribution to operate electrical networks safely. Important energy storage systems are introduced and their perspectives for future development are outlined.

Replacement of Process Control System and Upgrade of Plant Systems for Units D and E at Reuter West Power Station

R. Redetzky, M. Schönwälder and G. Prawdzik

The Reuter West power plant was taken into operation in the mid-80ies. It was realized that the demands of the year 2000 could not be met with 1980s technology. Operating cycles at the Reuter West power station were closely reviewed, and strategies for significant improvements were developed. The two units were modified and retrofitted in 2002 and 2003. The core of these measures was the replacement of process control.

Development of Creep Damage at Components Made of X 10 CrMoVNb 9-1 (P 91)

M. Rauch, K. Maile, P. Seliger and A. Reuter

This paper describes the relation between the deformability under uniaxial condition as well as multiaxial stress states and the cavity density of modern martensitic heat resistant steels and of the ferritic steel 14MoV6-3. Particular attention is paid to the manner how the relation between cavity density, deformation and the grade of multiaxiality can be stated using the results of smooth and notched hollow cylinder specimens under combined loading of internal pressure and axial tension.
This relation, which can be described mathematically, can be used for inelastic finite element calculations. This makes it possible to consider not only the already possible deformation calculation but
also damage prediction and its interaction with the creep behaviour.

Crack Growth Tests on a Ferritic Reactor Pressure Vessel Steel under the Simultaneous Influence of Simulated BWR Coolant and Irradiation

H. Hoffmann et al.

Crack growth tests under constant load with initial in-situ cycling were performed on the low alloy reactor pressure vessel (RPV) steel 22 NiMoCr 3 7 (A 508 Cl. 2) with the goal to determine crack growth rates of irradiated and non-irradiated steel under the simultaneous influence of simulated BWR coolant and irradiation. The tests were performed under conditions as near as possible to operational conditions in a commercial BWR reactor. The research results are summarized and are compared with international data.