Partenstein storage power plant
| Partenstein storage power plant | ||
|---|---|---|
 |
||
| location | ||
|
||
| Coordinates | 48 ° 26 '1 " N , 13 ° 59' 10" E | |
| country |
 Austria
|
|
| Waters | Big mill | |
| power plant | ||
| owner | Energy AG | |
| construction time | 1919-1924 | |
| Start of operation | 1924 | |
| technology | ||
| Bottleneck performance | 33.8 megawatts | |
| Average height of fall |
176.2 m | |
| Expansion flow | 26 m³ / s | |
| Standard work capacity | 102 million kWh / year | |
| Turbines | 2 Francis turbines , 1 Kaplan turbine , 2 Pelton turbines | |
| Generators | 3 synchronous generators, 2 asynchronous generators | |
| Others | ||
The Partenstein storage power plant is Austria's first large-scale power plant . It is located in the Mühlviertel , in the southern municipal area of the municipality of Kleinzell in the Mühlkreis , near the confluence of the Große Mühl in the Danube . After its completion in 1924, it set standards in early electrification due to its high performance for the time. Despite a later increase in output, it now ranks far behind in the list of the most powerful power plants in Austria.
history
In 1924, the power plant was put into operation after a five-year construction period. At that time, the power plant was the largest power plant in Austria with an output of around 29.5 MW and a standard energy capacity of 88 GWh per year. The two cast Francis spiral turbines with vertical shaft were supplied and installed by Voith St. Pölten. The two air-cooled Siemens synchronous generators sat above and were permanently coupled to the turbine.
The power station buildings, consisting of the machine house and the 110 kV switch house, were built in an economical half-timbered concrete construction in the late Art Nouveau style according to plans by Mauriz Balzarek . The baroque fountain west of the power station and a statue of St. John Nepomuk next to the bridge come from the former Langhalsen Castle , which was flooded by the reservoir.
When in 1962–1964 the Danube level was dammed up by the newly built Aschach power plant by around 10 m, the Francis turbines had to be renewed and raised. The third machine set was also installed as a downstream switchgear. The power plant output increased to 33.8 MW with a standard energy capacity of 102 GWh per year.
Since 1997, the entire power plant including the weir and shut-off devices in the surge tank with all its components has been equipped with control technology. The automated remote operation took place from the control room of the Ranna pumped storage power plant until the beginning of 2012 . Today the Partenstein power plant, like all hydropower plants operated by Energie AG, is controlled from the "hydropower control center" in Gmunden .
Dam wall and reservoir Langhalsen / Neufelden
During the construction period from 1919 to 1924, a reservoir had to be created for the storage power plant. ( Location ) For this purpose, a 17 meter high gravity dam with a crown length of 117 m was built in the valley of the Große Mühl north of the town of Neufelden to damm the river. The wall consists of quarry stone masonry with cuboid granite blocks and is equipped with two weir fields for flood relief as well as a bottom outlet.
The Langhalsen reservoir , also known as the Neufelden reservoir , is named after the small town of Langhalsen , which, together with Langhalsen Castle , had to be demolished in 1923/24 except for one house because it was located in the reservoir area. It serves as a weekly storage facility and has a storage volume of 736,000 m³. The lake extends in the valley of the Große Mühl between Neufelden and Pürnstein Castle .
Water tunnel and penstock
The inlet structure on the south bank of the reservoir is followed by an underground, accessible and circular headrace rock tunnel with a total length of 5.6 km and a diameter of 2.8 m. This initially runs in a southerly direction below the town of Neufelden, but then emerges again in a short pipe bridge over the Mühltal. The tunnel then runs below the town of Kleinzell to an edge of the terrain above the power station, where the Mühlviertel highlands, which are around 550 m high, suddenly drop by around 170 m to the level of the cut Danube valley. Here the so-called surge tank has to absorb pressure surges, such as those that occur when the turbine is shut down quickly, for example when the turbine is shut down, and shut off the water flowing into the downstream pressure pipeline in the direction of the power house in the event of a malfunction.
The welded (not riveted) steel pressure pipeline, built for the first time in Austria, overcomes most of the usable gradient in a swath of the steep, wooded flanks of the Große Mühl valley and ends in the machine house by the turbines or their upstream ball valves on the turbine floor below the generators. The pipeline is 371 m long and has a diameter of 2.80 m in front of or 1.70 m clear width from the pants branch in the machine house. The pipeline laid above ground in the steep terrain is protected against corrosion inside and outside and anchored to the ground in many places. Before the drive water reaches the nacelle, service water is taken geodetically 30 m above the main turbines via an extraction valve for cooling purposes. The expansion water volume of the power plant is 26 m³ / s with a raw head of 176.2 m and a nominal head of 165.5 m.
Turbines and machine sets
Main level M1 / M2
The main machine set consists of two Francis spiral turbines with a vertical shaft with 19.6 MW each and the two three-phase synchronous generators with 21.5 MVA each.
The turbines, each with an upstream spherical valve , drive the generators in the upper generator floor from the turbine floor by means of a shaft flange connection. The excitation machines of the respective generators are in turn seated on the upper end shields. The nominal speed is 600 min −1 . The operating voltage is 5.5 kV. Air is used for cooling.
The energy is dissipated from the machine terminal box directly with bare aluminum busbars and by means of ceramic wall bushings to the nearby 5.5 kV switchgear, in which the neutral point treatment, required for generator protection purposes (Bütow transformer for winding earth fault detection), takes place. The power is transported from this switchgear in the direction of the 110 kV network via a six-fold parallel single-conductor cable connection to the substation.
Turbine functionality: The newly installed Francis spiral turbines , supplied by the Voith St. Pölten company, have a design feature that is worth mentioning.
The water is usually fed tangentially into the horizontal spiral housing with a vertical shaft , exits the spiral housing and thus at the same time radially enters the diffuser. The streamlined, pivotable guide vanes deflect the inlet jet approx. 45 degrees to the tangent in the direction of rotation of the impeller in order, in cooperation with the peripheral speed, to steer the resulting relative speed into the blades, which are inclined to the tangent at the point of entry, so that it enters the impeller without bumps , so that the water enters the blade channels, the space between two blades, completely undisturbed. The water now flows through the blade channel in a curved path, partly still radially, but already with an axial component towards the end of the blade channel in an upward direction. Here, the angles and the not inconsiderable water outlet speed as well as the circumferential speed of the inner diameter of the impeller are coordinated in such a way that suddenly every radial component has disappeared from the three vectors and only a column of water flowing smoothly up into the suction pipe results. The amount of loss is with
sufficient to move the water to the end of the suction pipe, where a continuous suction pipe expansion (diffuser) still enables energy to be gained. Only here does the water have the desired minimum low-energy speed, which, however, is just enough to make room for the water flowing in. Should a turbine have to achieve 100% efficiency , the water flowing out would have to be standing at the suction pipe outlet, then it would no longer have any energy in it. Since this is not possible, even the best calculated and manufactured turbine is never 100% in the yield of the existing potential, the water of the reservoir. In addition, there are unavoidable pressure losses when the process water flows through the hydrodynamically shaped diffuser and the spatially curved blade channels of the impeller itself - one speaks of the impeller loss height in meters of water column at the nominal flow. The hydraulic efficiency of the turbine should be around 90–91%. Losses in height in the circular rock tunnel and the steel pressure pipeline differ depending on the operating mode (power) and are not taken into account in the mentioned turbine efficiency. The losses of a hydraulic system vary from the nominal efficiency at 100% load to the respective partial load efficiency. In the case of run-of-river power plants, depending on the water supply, this is not the case with storage power plants, because there the outputs are mostly constant in the nominal range, except when starting up and shutting down.
The special design feature of the two main turbines is that the turbine shaft runs coaxially in the suction pipe going upwards until the shaft passes through the outer bend of the 90 ° suction pipe bend attached to it. The turbine shaft is, so to speak, inclined in the intake manifold flow, unfavorable in terms of flow, but taken into account when choosing the intake manifold cross-section. Any existing and possibly promoted cavitation tendency is eliminated by blowing in compressed air.
When exiting, the water from these turbines does not flow downwards, as is normally the case, but in this case upwards and then through a 90 ° bend horizontally into an overflow basin. In order to fully utilize the remaining gradient to the Danube backwater, the water is then fed to the Kaplan downstream switchgear.
Downstream switchgear M3
When the turbine was renewed in 1964, a Kaplan bulb turbine with an output of 2192 kW was also installed. This is housed in a cavern 30 m southwest of the machine house. It is supplied from the overflow basin and is used to use the remaining gradient of approx. 10 m. The water then flows through the underwater duct - a 240 m long pressure tunnel - into the river bed near the mouth of the Great Mühl, which has been dammed back from the Danube. The usable residual gradient therefore depends on the water level of the Danube, which was back-dammed from the Aschach power plant .
If the Kaplan turbine M3 is not operational, the water flows after the main turbines over the weir crown-like upper edge of the overflow basin directly into the river bed of the Große Mühl.
Self-service system M4
Since it must be possible to carry out a black start when the machines are at a standstill and the 110 kV network fails at the same time , the power plant in a basement room has had a new machine set with 400 kVA rated power since 1997 . A single-jet Pelton turbine takes the process water from the pressure pipe with Hn = 153 m via a gate valve and discharges it into the overflow basin behind the turbine. The Pelton impeller, which is attached directly to the generator shaft, is housed in a welded turbine housing. The nozzle needle is adjusted by means of an electric servo motor , the jet deflector in the housing of the impeller below the injection nozzle is also operated by a servo motor and a fast-working mechanical weight drive for turbine quick-action by means of a jet deflector.
The synchronous generator has four poles and is designed for a turbine speed of 1,500 min −1 . The entire machine control and monitoring is carried out by an industrial computer built into the machine control cabinet. The energy generated with 3 × 400 V at cos φ = 0.8 (320 kW) is conducted to the distribution board via two parallel cables YY 4x185 (Cu). This in turn is connected to a 400 kVA transformer, 30kV / 400V, of the substation.
In order to be less sensitive to shock loads from various consumers and to avoid the necessity of not going through in the event of sudden relief, a flywheel with a diameter of approx. 1.6 m and 100 mm thick is attached to the generator shaft opposite the generator output side. This flywheel is a prerequisite for a stand-alone power supply for all auxiliary systems of the two large machine sets M1 and M2 necessary for operation.
The centrifugal mass of the generator enables the speed to run slowly through the rated speed range when starting up, in order for the automatic synchronization unit to record the time required to measure the generator line-to-line voltage and the reference voltage of the auxiliary power distributor as well as the more important frequency of the generator voltage before the synchronization is switched on. The time required to connect the machine to the covered self-service distributor is approx. 1 to 2 minutes. In the event of a total failure of the power grid, a synchronization process is not necessary, a reference voltage of the failed grid is not available or zero volts. The computer is supplied with power via a 220VDC / 230VAC inverter , which in turn is supplied from the 220 V lead station battery . The servomotors for the power control and for the beam deflector are supplied via separate inverters.
In connection with the automatic voltage regulation, it should also be mentioned with regard to the generator that the efficiency of a generator also falls with increasing sin φ or falling cos φ. The selected single-nozzle Pelton high-pressure turbine is the most suitable turbine for this application.
The original turbine installed in 1924, including the open salient pole generator, was in operation until 1997. Then it had to give way to the machine set described above.
Cooling water turbine
The extraction rate of around 50 l / s required for cooling purposes is fed to a small 55 kW Pelton turbine, expanded from H = 135 m, passed through a filter device and fed to the circuit for water cooling of the generator plain bearings in the machine house. The energy gained by means of an asynchronous generator is fed into the 400 V power distributor via cable . With the exception of the technically unavoidable power consumption for auxiliary services, such as oil pressure generation for bearing lubrication and turbine control, no energy is lost.
Substation and grid connection
The 110 kV indoor switchgear is located in the switch house to the east of the machine building. In 1924 it made it possible for the first time to transport energy over a new 110 kV high-voltage transmission line via Linz-Wegscheid to Vienna to supply the federal capital with energy.
Today the 110 kV overhead lines lead to the Ranna pumped storage power plant and the Ottensheim-Wilhering power plant . The power plant is also connected to the regional 30 kV medium-voltage network.
Technical description of the switchgear:
The two 5.5kV / 110kV machine transformers , each with 20 MVA output, are only separated from the switchgear building by a short rail connection that allows transformers and equipment to be transported to the open-air switchgear behind.
Then Al-stranded is fed into the switchgear to the low-oil circuit breakers . These are set up in a switch box closed off with sheet steel swing gates. They are supplied with 220 V DC for the spring-loaded storage drive elevator motor via automatic distributors , each equipped with a single coil and two separate protective trip coils for transformer differential protection and backup protection. The latter, fed by a separate triggering energy self-sufficient automatic distributor from a DC distributor, to supply the overcurrent time relay.
The energy is fed from the circuit breaker via current transformers to the disconnectors on the upper floor of the building.
The ceramic supports of the 50 mm aluminum pipe busbar are suspended from the ceiling cross struts of the building. The individual busbar disconnectors are driven by 220V DC drive motors with spindle gears and mechanical coupling rods with intermediate, corrosion-free 30 mm steel shafts and drive levers that have a powerful effect via 90 ° deflections on the base of the rotating column. The motors are supplied with power from the respective control cabinet.
The last stage of the kinematics of the drive ends with the drive lever of the ball-bearing ceramic rotating columns, which carry the cutting blades with silver-plated copper current paths at the contact points. Then the lines lead out to the overhead line .
Web links
- Film excerpt about the power plant construction in the media wien film archive: Hans Glück: The technology in battle with nature. Landesbildstelle, 1923, accessed on December 1, 2013 .
- Information from Energie AG with technical details about the power plant
- Document with technical data for the power plant (PDF; 1.7 MB)
literature
- Valentin E. Wille: The founding power plants of the state producers. Architecture of former large power plants. Published in: Robert Stalla et al .: Architecture and Monument Preservation. Studienverlag, Innsbruck-Wien-Bozen 2012, ISBN 3-7065-5129-2 .
Individual evidence
- ↑ Energie AG press release about the new control center ( memento of the original from November 12, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Fritz Bertlwieser: Mills - hammers - saws - Upper Mühlviertel, Bohemian Forest, Bavarian Forest. Haslach 1999, p. 244.
