Walchensee Hydroelectric Power Station
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The Walchenseekraftwerk is a 1924 Taken in Kochel am See in operating high-pressure storage power plant in Bavaria. It was built by the Cementbaugeschäft Rudolf wool. It is with an installed capacity of 124 MW until today one of the largest of its kind in Germany and is one of the EWK GmbH in Landshut.
Description
The Walchenseekraftwerk uses hydropower with a natural gradient of about 200 m between the " upper basin " acting Walchensee (801 m above sea level. NN ) and the " lower basin " Lake Kochel (600 m above sea level. NN ) to produce electricity. During operation of the power plant, the water level of Walchensee may be reduced by about 6 m, which corresponds to an available storage space of 110 million m³. It is thus a storage power station, but no pump storage power plant, since no water is pumped back into the Walchensee. It was originally built for general power supply, but is now used as peak load power plant.
Water storage and inflows
The natural inflows of Walchensee not sufficient to provide enough water for the operation of the storage plant. The Walchenseekraftwerk is therefore the central plant of a wide-ranging network of weirs, canals, tunnels and power plants. With the Isar conduction and conduction Rißbach the Walchensee is supplied with the required additional water and used the leveraging existing gradient to generate electricity. The natural flow of Walchensee at Niedernach - on the Jachen the Isar - is blocked by a weir. In order to keep the water level of Lake Kochel stable as possible, its outflow is regulated in a lock canal at Kochel. In order to protect the flat Loisachtal and Wolfratshausen from flooding by water from the power plant, the Loisach Isar- channel ensures additional runoff into the Isar.
Through the power plant operation and the resulting highly fluctuating water levels both lakes freeze in the winter hardly. Therefore, the ice sheets are thin in the various bays and may not be accessed.
Isar Reconciliation
Coming from the catchment area of Walchensee water quantities are not sufficient for the operation of the power plant. Therefore, it was planned from the start to lead the water of the river Isar in the Walchensee. The Isar comes as a whitewater river from the Austrian part of the Karwendel Mountains. It was through the weir Krün by five meters to the Isar River Reservoir ( 870 m) accumulated between Mittenwald and Krün at river kilometer 251.5 and transferred from there to an almost complete Walchensee. Since 1990, however, a minimum amount of water in the original river course must remain ( depending on the season 3 to 4.8 m³ / s). In order to take advantage of the slope of the residual water from 5 m at the weir to generate electricity, there is a small hydroelectric power plant was built in 1990. The transferred Isar water first flows in an open channel through Kruen to Wallgau. On this route the channel the water of the wreath and the Finzbachs is fed into underground pipes. Before Wallgau crosses the canal in a culvert State Road 11 and the mostly dry bed of Finzbaches and is of Wallgau through a tunnel to Sachensee ( 867 m) out. The Sachensee is also slightly dammed by a weir and regulated. Originally, the water flowed through the Obernachkanal over several steep steps ( the so-called Isar case ) to the north, crossed the grounds of the Laboratory of Hydraulics and Water Resources at the Technical University of Munich and culminated in Einsiedl in the Walchensee. In the 1950s it was decided to also use the gap between Sachensee and Walchensee and built the power plant Obernach, which was taken 1955. Since then, some of the available on Sachensee water is directed into a 3.9 -kilometer-long pressure tunnel to the hidden in the mountain water castle and from there to the two turbines of the power plant Obernach, opens its outlet in the Walchensee. By the Isar Reconciliation maximum of 25 m³ / s of water can be directed into the Walchensee.
Rißbach conduction
The Rißbach comes from the northern part of the Karwendel Mountains, where in the maple floors the water flows to the smaller streams. Below the border between Tyrol and Bavaria and immediately after the opening of the Fermersbaches is the water-rich stream at the Oswald hut on the road Vorderriß ( Bavaria ) - Hinterriß (Tirol ) jammed ( 838 m above sea level. ) And in the total of nearly 7 km long Rißbachstollen initiated. The Rißbachstollen is divided into the 3,647 m-long tunnel Grasberg, in to about halfway the water flowing to Rißbach Fischbachs will be initiated. The Grasberg tunnel leads to a culvert by which the bed of the river Isar and the next current toll road will pass under above Vorderriß or just above ox seat. The subsequent 3313 m long high head studs ends above Niedernach the Alpine stream weir ( 821 m above sea level. NN ), with the well whose water is directed into the Walchensee. From the Alps Bach weir a nearly 150 m long tunnel and an approximately 215 m long channel leading to the intake structure, from which the water is passed through a pressure pipe on a slope of 21 m to Laufwasserkraftwerk Niedernach at the southeast end of Walchensee. Excess water runs from the intake structure on a wide canal staircase next to the power plant in the lake. By Rißbach conduction maximum of 12 m³ / s water can flow into the Walchensee. The power plant has been in operation since 1951.
Technical Operations
The Walchenseekraftwerk receives its water from the intake structure at Urfeld am Walchensee that is largely hidden behind a road bridge and a rake in the rock. Over a 1,200 m long, 4.80 m high and 4.60 m wide pressure tunnel of concrete, whose sole is 10 meters below the normal water level of the lake, the water through the boiler mountain flows into the highly visible, high above the power plant water tower. Its huge, 10,000 m³ comprehensive and 10 m deep pool of water compensates for the pressure fluctuations in the pressure tubes, which produced during start, rules or stopping of the turbines. In order to withstand the water pressure in the pelvis, the outer wall like a dam is constructed with a downwardly increasing thickness of up to 15 m. The moated castle also contains an upstream slide gate valve of the house leading to the power plant pipes including overhead crane for maintenance and repair work.
Six 430 -meter-long pressure pipes with a slightly downwardly decreasing average diameter of 2 m let the water flow to the eight turbines in the power house. The diameter of the tubes increases from initially 2.25 m to 1.85 m below the top of the nacelle from. The wall thickness of the tubes is above 10 mm and below 27 mm. The 100 m long nacelle is positioned laterally to the tube sheet to be not damaged in an eventual break of a pipe as possible from the shooting down of water.
Four tubes propel each one of the four Francis turbines, while the remaining two tubes drive two Pelton turbines with two wheels each. The Francis turbines run at a speed of 500 min -1, the Pelton turbines with 250 min -1. All turbines together can add up to 84 m³ / s of water. The Francis turbines can be booted in about 30 seconds at full load from idling at a standstill, not completely filled turbine, the process takes about three minutes. Below the turbines is the outlet, which opens into a canal in Lake Kochel.
The Francis turbines are connected to three-phase generators with a maximum capacity of 18 MVA and 6.6 kV at the frequency of 50 Hz. The Pelton turbines are connected to single-phase generators, which are designed for the extraction of traction power with the original standard 16 2/ 3 Hz (which is tolerated by the current system at 16.7 Hz). The total power generated is divided into 72 MW electricity and 52 MW rotational traction power. The control of work per year is about 300 million kWh. During the construction of the power plant orders for the generators were evenly distributed among the former manufacturer, so that four manufacturers supplied two generators.
From the generators of the power to the transformer house beyond the court is directed to where the generator voltage is transformed from 6.6 kV to the mains voltage of 110 kV. About the switchgear front of the transformer house, the current is then fed into the overhead lines.
In the courtyard between the machine hall and transformer house a decommissioned wheel of a Pelton turbine with two wheels was placed on a shaft, which weighs about 30 tons. The wheel was replaced because an evolved form of the vanes resulted in a higher efficiency.
Special
The Federal Highway 11 from the town of Walchensee to Urfeld runs along the steep slope of the Duke stand on the north shore. The waters of Walchensee exerts pressure on the banks, which prevents slipping of the road. In winter, when the water level drops due to consumption by the Walchenseekraftwerk, the use of the road is restricted by a weight limit for trucks. At an appropriate time in the spring E.ON is under threat of a penalty obliged to raise the water level so that the traffic restriction - can be reversed - mainly because of tourism. Therefore, the energy company informed in winter on the snow conditions in the catchment area in order to be able to calculate how much meltwater is likely to meet the demand available.
History
The idea for the Walchenseekraftwerk was born in 1900 in Munich. They wanted to exploit the height difference of 200 m between Walchensee and Kochelsee for obtaining electrical energy. Oskar von Miller was the mastermind and planner for the construction of the Walchenseekraftwerk work. He wanted to advance the electrification of the Bavarian Railway (see also Mittenwaldbahn ) and the State of Bavaria. Already in the autumn of 1903 - disguised as search and rescue a missing family - investigated by divers in the background of Walchensee. About the same time the preliminary planning to build a full path Tölz- Lenggries - Jachenau - Mittenwald - frontier were known. A connection with the planning of the power plant from today's perspective obviously, but a substitute for the show flowed removal of the wood had to be created from the mountains. In the 267th meeting of the Bavarian Chamber of Deputies on April 25, 1914, the topic was discussed in detail Walchenseekraftwerk " as a matter of honor of the Bavarian people." In this case, however, the question was asked whether any sufficient number of customers would be found for the electricity generated. The Department of Transportation, in contrast to the Ministry of the Interior, forced strangely enough the Walchensee project not because you had doubts about the viability of electric railway operation there.
After much preliminary work of the Bavarian state parliament decided on 21 June 1918 ( five months before the end of World War I ) power plant construction. The construction work started in December 1918. For the operation of numerous electrically powered machinery specially the power plant boiler Bach was built in the vicinity of the construction site. However, it could cover only about one- third of the demand, the other two thirds were so produced with traction engines with steam- powered generators. The number of workers increased from initially 120 to 2000 at the time of highest operation. On 5 January 1921, the state Walchensee Werk AG was Founded in Munich, which will continue to build and finish and should take over the operation of the power plant. The April 5th, 1921, founded, also state Bavaria Werk AG to take over the wide distribution of the current. For the first time dined a turbine on January 24, 1924 energy into the grid, the other seven turbines followed in the next few months.
After the Bavaria factory, the factory Walchensee A. G. Had 1942/43, finally accepted and was privatized in 1994 and in turn taken over by the VIAG that worked in the E.ON again in 2000, the power plant hydropower GmbH is now operated by energy company E.ON.
Tourism
2001, the power plant operator EWK opened a new visitor center, the industrial monument is visited annually by nearly 100,000 visitors.