Small hydro potential… with Ossberger

All over Germany there is much potential for small hydro power. Wehra basin is the lower basin of a pumped storage plant owned by Schluchseewerk. At each level in the basin the inflow needs to be redirected to the original river bed. Discharge is made through a tunnel outlet structure. Within the barrage plant, part of the discharge is used for energy production. As inflows and heads fluctuate strongly, the installation of a double-cell, cross-flow turbine was economically justified. The installed power is 1135kW.

The optimal utilisation of the existing flow distribution demanded a turbine with an efficiency curve that was as flat as possible throughout the whole flow range, and with acceptable efficiencies even at extreme variations of the head. So a two-cell Ossberger turbine was selected, equipped with a draft tube and a 1m runner diameter.

The casing of the turbine takes up the precision bearing inserts to support the guide vanes. The regulating shafts with shrunk, hardened steel bushings run in maintenance-free DEVA friction bearings. This permits an easier guide vane mounting and dismounting towards radial direction.

va-tech-hydro… works on Germany’s largest hydro project

VA Tech Hydro is working on the largest hydro power project in Germany, the Goldisthal 1060MW underground pumped storage power plant. In addition to the complete hydraulic steel structures and penstocks, the company is also supplying and installing four new pump turbines and motor generators (approximately 340MVA), two of which operate with variable speed.

The current project extension comprises equipping these pumped storage sets with Diatech, an extensive monitoring and diagnosis system. Goldisthal is scheduled to go into operation progressively between 2002 and 2004.

In December 2000, the 200th compact bulb turbine weighing more than 30 tons was dispatched from the VA Tech Escher Wyss Ravensburg factory. The turbine has been installed in a power station located in the Chiemsee region in Bavaria and, since commissioning in February 2001, the station has provided power for over 600 households. In addition to the turbine, the company has also supplied the generator and all required electrical equipment.

Also, in Bavaria, the first compact axial turbine (CAT) from VA Tech Escher Wyss has been successfully commissioned in the Sylvenstein dam power station, which was built in 1958 to help with flood protection.

PERI on form for Europe’s longest canal bridge

There has been a waterway connecting the Rhine with the Oder since 1934, but it was only after the reunification of Germany that the link became more important for new trade with Eastern Europe. However, the waterway is not a viable passage all year round. Fluctuating levels of the Elbe mean that differences of up to 7.5m often bring shipping to a standstill. A cost-effective and modern upgrade for the waterway would entail building Europe’s longest canal bridge and a double lock with economising basins at Hohenwarthe, and a lock with economising basins at Rothensee.

Construction of the 900m long canal bridge is the joint responsibility of the Bilfinger and Berger consortium of Magdeburg and Dillinger Stahlbau of Saarlouis. It will directly link the Elbe-Havel canal with the Mittelland canal. The structure comprises two main parts: a 690m long and 34m wide approach section, resting on 17 piers shaped like the bow of a ship, and the 228m long section on two pairs of piers carrying the waterway over the Elbe.

Despite complicated approach pier geometry, Bilfinger and Berger Schalungsbau of Roxheim planned the formwork in conjunction with formwork specialist PERI Germany of Stuttgart, to maximise the proportion of standard components for the mighty wall sections.

DSD-Noell hydromechanical equipment

Over the last 50 years, DSD Dillinger Stahlbau – with a steel construction division based in Saarlouis and an industrial plants construction division in Düsseldorf – has developed from a medium-sized company with mainly regional activities into a global organisation.

In 1997 DSD became a wholly-owned subsidiary of Ferrostaal AG Essen, which in turn is a member of the MAN Group, one of the largest industrial groups in Germany. Since mid 2000, when DSD Dillinger Stahlbau took over Noell Hydro-mechanical Equipment, the companies have been combining their know-how and experience in the field of hydraulic engineering. DSD-Noell offers a range of hydromechanical equipment from design to commissioning. This includes all types of gates, stoplogs, trashracks, penstocks, steel linings and valves, as well as the appurtenant hydraulic drives and electrical control systems.

Recently DSD has supplied and installed the hydromechanical equipment for the Rothensee lock in Germany, one of the largest projects of this type in Europe. Other major projects in Germany include the large ship lock on the river Weser at Bremen and the tide lock at Emden. The fishing port lock in Bremerhaven is scheduled for commissioning later this year. This project comprises 5000 tons of steel structures.

Internationally the works for hydro power plants – Platanovryssi (Greece) and Garafiri (Guinea) – have recently been successfully completed. Currently DSD is involved in the construction of the Kukule Ganga (Sri Lanka), Dhauliganga (India), Kali Gandaki A (Nepal) plants as well as the Batang Hari and Batu Tegi dam projects in Indonesia. In Egypt the works for the New Zifta lock, for which DSD has supplied the hydraulic steel work, are under construction.

WKV’s factory of the future

WKV Wasserkraft Wolk of Gutach, near Freiburg, has been producing and installing hydro stations up to 10MW for over 22 years. The company’s product range includes Pelton, Francis, Turgo and Crossflow turbines but its speciality is the design and manufacture of governing systems for speed, level and discharge control.

WKV has recently moved to a new production site, which staff refer to as the Future Factory. Built in 1999/2000, this is the first energy autarkic and greenhouse gas emission-free heavy engineering plant in Germany. Two WKV Francis turbines with a combined output of 320kW provide energy for the factory, with excess being fed into the local grid. Heating is accomplished via 30m of sun collectors, three heat pumps utilising energy from ground water flow and the waste heat from the two generators.

The first large order to be produced in the new factory comprised two single 2MW jet Pelton turbines, which were shipped to Sri Lanka in December 2000 and are now being commissioned. Another 2.1MW twin jet Pelton turbine is entering production now to be delivered to Ecuador by the end of November 2001. WKV’s scope of supply will include the turbine, generator, governor, low and medium voltage switchgear and transformers. Located at the eastern slope of the Andes at an altitude of over 3400m, this installation is due to be commissioned around Easter 2002.

WKV has completed more than 500 projects, including providing a 206kW axial turbine to produce energy from drinking water at a water treatment plant in Sulzfeld, and three 3.5MW Turgo turbines to power the Kasese cobalt mine in Uganda.

A self-financing emergency power unit at the newly-built Goldisthal pumped storage plant in Germany is a mini hydro station at the outlet works of the main dam. It is used for economic utilisation of the required compensation flow. All the energy produced by the 670kW WKV crossflow turbine will be fed into Goldisthal’s own supply grid. Its second task is to provide an emergency power supply to ensure safe operation of the main equipment in case of supply grid failure.

Naue-Fasertechnik simplifies underwater installation

During the 1997 and 1998 construction seasons, the first underwater installation of Bentofix geosynthetic clay liner (GCL) was approved by the Wasser-und schifffahrtsverwaltung (Water and Waterway regulating agency) as a pilot project along a 1km long section of the Havel-Oder waterway. The design incorporated a layer of Bentofix GCL overlain with a separate, protective sand ballast layer of Terrafix Sandmat.

Based upon the success of the Havel-Oder project, the installation of an improved Bentofix product was approved for use in the Dortmund-Ems canal. Along a 500m section of the canal, this installation featured Bentofix GCL BZ 13-B, a multi-layer composite that incorporates both the GCL and sand ballast elements into a single lining. Bentofix BZ 13-B is basically a combination of a natural sodium bentonite sealing layer and an overlying sand ballast layer, separated as well as encapsulated by layers of geotextile – resulting in a robust five-layer, pre-ballasted GCL composite which simplifies underwater installation into a single step process.

voith-siemens Hydro Power Generation…German perspectives

Voith Siemens Hydro Power Generation aims to deliver tailor-made products and services, from single component supply to complete plant management. The company has installed one-third of the world’s hydro capacity. A global network of engineering, manufacturing and service organisations offers complete equipment, installations and services for hydro plants; plus service, modernisation and rehabilitation of existing hydro plants amongst others.

With approximately 75% of the technical hydro power potential in Germany being exploited, 4.3% of electrical energy has been generated using hydro power plants.

About 5000 hydro power plants can be found in Germany, with 450 of them having a capacity of 1MW or more, generating more than 90% of the total hydro power. The service market in Germany (modernisation, rehabilitation, upgrading, uprating) has dropped to one-third of its average volume in recent years, starting with liberalisation of the energy market. Voith Siemens Hydro is still holding a 30% share of this reduced market (the latter being approximately 20M Euro per year) New plants are very rare. The Goldisthal pumped storage scheme (4 x 269MW), awarded in 1997, was the last big project to date, and may well be for many years to come.

Voith Siemens Hydro is supplying a share of 47% of the pump turbines including the hydraulic design and the electrical (digital) and hydraulical governors (VA Tech has 39%, including basic engineering; and CKD Blansko Engineering the remaining 14%). The contract for automation equipment for the plant was also awarded to Voith Siemens Hydro in 1999.

The company’s latest new project, which was awarded in June 2001, is Hiltenfingen – a 1 x 0.9MW plant on the river Wertach (an EPC contract).

Concrete pump logistics at Ems storm dam

To improve storm protection and maintain flow in the river Ems for large shipping vessels, the Ems storm dam is being constructed at Ganderum. The dam comprises northern and southern connection dikes along with the edge piers, six water piers and seven pointing sills in the river bed, four lift and two swivel segment gates as well as an operational tunnel and the operational buildings. The contract for concrete pump logistics was awarded to Messrs Betonlift from Hamburg. The contract also comprises the setting up and operation of an 8m3 double shaft mixer trough below a mobile concrete mixer plant; the installation and cleaning of two delivery lines laid parallel to each other; the operation of two super sound-insulated stationary pumps, as well as a long reach boom truck-mounted concrete pump which is operated from a pontoon.

The concrete is made in the mixing plant on the northern bank of the Ems. A Jumbo mixer trough is set up below the mixing plant and is continually and automatically fed by the two stationary Putzmeister concrete pumps. To dampen the noise level of the machines, Putzmeister has installed the stationary pumps in sound-proofed containers which lower the operating noise from 86dB (A) to 78dB (A).

The Ems storm dam will, on its completion in autumn 2002, be operated and maintained by the Niedersachsen Department for Water Resources and Coastal Protection.

Hunger hydraulic cylinders

Over the last three decades more than 130 large dams have been equipped with Hunger hydraulic systems to ensure the correct functioning of radial, slide and wheel-mounted dam gates and the reliable control of turbines.

In spring of this year Hunger supplied 21 hydraulic cylinders to the Lower Colorado River Authority project in the US. These were pressure cylinders for actuating dam gates and feature several special components.

The piston rods are protected from corrosion, mechanical damage and wear by the Ceraplate 2000 metal oxide coating. Ceraplate 2000 is made of a metallic Ni/Cr basic layer and a Cr2O3/TiO2 top coat. The CIPS incremental measuring system is integrated in the coating structure of Ceraplate 2000 and measures the stroke of the piston rod with a resolution of 1mm without any contact whatsoever. To improve their long term reliability, the cylinders are equipped with the EVD sealing system, which can be adjusted from the outside, in addition to the primary sealing system. With the EVD it is possible to compensate wear and loss of prestress of the seal from the outside without dismantling the cylinders. In conjunction with flexible bellows these frames seal the cylinders against the water that flows past them so that only the piston rods are in the water.