Rüchlig power plant

Rüchlig power plant
Power plant before renovation in 2012
location
Coordinates	646130  /  250073
country	Switzerland  Aargau
place	Aarau
Waters	Aare
Height upstream	363.75  m above sea level M.
power plant
owner	Axpo
construction time	1882-1883
Start of operation	1884
technology
Bottleneck performance	8.8 megawatts
Average height of fall	3.4 m
Expansion flow	360 m³ / s
Standard work capacity	54 million kWh / year
Turbines	Main power plant: 4  bulb turbines Doping power plant : 1 bulb turbine
Generators	Main power plant: 4 × 2.3 MW Doping power plant: 1 × 1.26 MW
Others
Website	axpo.com
was standing	2020

The power plant Rüchlig is a low-pressure - hydropower plant on the river Aare in Aarau in Switzerland , which was put into operation 1884th The power station used by Jura-Cement-Fabriken was taken over by Axpo in 2002 and completely renovated in 2014.

history

Rüchlig power plant on the Siegfried map from 1896 (left). On the right the Chocolat Frey power plant .

First power plant

In 1882 the builder Daniel Schmuziger-Oberlin bought land in Scheibenschachen from the local community of Aarau for the construction of a cement factory. This also included the concession to use the hydropower of the Aare. The first Rüchlig power plant was built by the Zurlinden cement factory between 1882 and 1883 and commissioned on January 9, 1884. It was located on a one-kilometer-long works canal that was diverted from the Aare about 260 m below the chain bridge without a dam . The power plant used an island in the Aare, whose branch of the river north of the island had silted up. The silted arm was dredged for the construction of the power plant and used as a works sewer, with the machine house 800 m below the chain bridge. The power transmission from the only Jonval turbine to the cement mills to be driven took place via a transmission . The turbine processed 4.9 m³ of water per second and had an output of 102 hp. The end of the underwater canal was in the Widler ^{▼ area} on the border between Aarau and Küttigen - the canal was only extended to Rüchlig in the 1910s. The construction of a weir in the Aare failed due to the opposition from the population - it was only realized in the 1920s. In 1896, the canal inlet was improved, so that 7 m³ of water per second could be used and the power of the turbine was increased to 155 hp.

First expansion

Rüchlig power plant 1906. The inlet structure of the canal is visible.

In 1897, the conversion of the Zurlinden & Co. cement factory into a stock corporation resulted in the Jura-Cement-Fabriken, which also included the Wildegg plant. They bought in 1902 from the Aare island from the Ortsbürgergemeinde Aarau, which from now on and after the original cement factory Zurlinden Co. as Zurlindeninsel was called.

The power plant was expanded and provided with two additional Francis turbines , each with an output of 250 hp. In 1906 the works channel was provided with an inlet structure consisting of an inlet sluice and a tentacle. The lower and upper water channels were also dredged so that 25 cubic meters of water could be used per second.

Second expansion

Rüchlig power plant on the Siegfried map, data from 1913. The extended underwater canal and the correction of the Aare can be seen

On May 1, 1907, the cement factories asked to use the slope of the Aare as far as Biberstein , but were not granted a license for the time being, as others were also trying to obtain this license. In the years 1910 and 1911, the Jonval turbine from the beginning was replaced by a Francis turbine with an output of 775 hp, whereby a later extension and deepening of the underwater canal was already taken into account.

In 1912, the cement factories received the permit to extend the underwater canal as part of the simultaneous correction of the Aare in the Rüchlig area. The construction work took place between 1912 and 1916. An old cut-off river course was used to extend the underwater canal of the power plant, which increased the usable net gradient to 2.8 to 3.6 m depending on the flow of the Aare. The first two Francis turbines were removed and replaced by new ones from the Bell machine works in Kriens , each with an output of 600 hp. The usable amount of water rose to 58 m³ / s.

All turbines worked with gears on a common transmission shaft, which mechanically drove the machines. These included two two-phase generators, each of which could deliver 500 hp. A Lenix belt transmission transmitted the power to the generators. The arrangement allowed a large translation in a small space and was provided with an automatic tensioning device. The energy generated was used in the cement factory to drive engines and for lighting. The electrochemical factory in Elfa was also supplied with an output of 370 kW. It made hydrogen peroxide , which was used as a bleach in straw processing - the region was known for making straw hats . The electrical system part of the power plant would have been able to generate up to 10 million kWh annually.

• 

  Power plant from the upstream side, approx. 1926

• 

  Machine room, transmission in the foreground, 1916

Third expansion

Rüchlig power station on the Siegfried map, data from 1931. The widened underwater canal can be seen

Extended power plant in 1929.

In the following ten years there was a dispute over the expansion of hydropower. The Motor Corp. struck a power plant before that the distance from Rüchlig to Brugg before, making the task of your power plant would have meant in Wildegg for the JCF. The JCF then proposed the expansion of the locations they already used in Aarau and Wildegg. Another Motor AG project suggested an expansion, which would also have fallen victim to the JCF plant in Aarau, which resulted in the JCF again proposing a larger expansion of Aarau in December 1916.

The SBB also showed interest in the water power of the Aare. It proposed a power plant in that the distance of the mouth of the Suhre, ^▼ at the same time the community boundary between Aarau and tube formed to the mouth ^▼ front of the underwater channel of the power plant in JCF Wildegg. An investigation by the Aargau Construction Department gave this project priority over the other projects, which would have caused the two JCF power plants to go under. The JCF's negotiating position was particularly bad because the JCF's documents for the concession for the second expansion could still be found at the authorities. The Aargau authorities thereupon judged the use of hydropower by the JCF in Aarau as illegal, but issued the JCF a provisional order in April 1919, which tolerated the use of 58 m³ / s. In contrast, the license granted in 1902 for the use of 27 m³ / s was still considered valid by the authorities. In contrast, the SBB received the concession to use the entire route from Aarau to Wildegg. However, the railway did not begin immediately with the construction of the power station, but worked out a new plan that provided for a reservoir that would have made the JCF quarries unusable and would have destroyed a lot of cultivated land. Large sections of the population resisted this project.

The dispute over the use of water took a turn when the documents believed to be missing about the second expansion stage were found again in 1925 and the authorities issued a valid concession for the second expansion in September of the same year, whereupon the SBB withdrew its construction project. At the request of the government council, the JCF's concession was immediately increased to 260 cubic meters of water per second, whereupon opposition from the city of Aarau reported that it was planning to use the incline with its own power station on the right bank of the river. The Great Council rejected the recommendation of the Governing Council use by two power plants from, would have though a larger minority preferred the allocation of water rights to the public sector, which on 14 September 1926, the JCF the concession for the expansion of the existing power plant to 260 m³ / s which was valid for 85 years until 2011.

The concession included the construction of a weir in the natural river bed of the Aare 930 m below the chain bridge approximately at the level of the machine house, which began in January 1927. With the concession, the JCF undertook to complete the expansion within the set deadlines. The JCF was also ordered to use the energy only for the operation of its own plants in Aarau and Wildegg, with the exception of the energy to be given to Chocolat Frey as a replacement, which could no longer use its power plant due to the expansion. Excess energy could be delivered to the electricity works of the city of Aarau, whereby at least 1200 kW had to be delivered in the winter half-year. The JCF was also obliged to build public footbridges over the Aare and the upper water canal that could be used by pedestrians and cyclists and should be located about 400 m below the chain bridge.

Work on widening the existing works sewer began in January 1927. Two propeller turbines from Escher Wyss were installed in the extension of the nacelle , each driving a screen generator for three-phase alternating current . The two existing generators were also replaced by a three-phase generator . The expansion was completed in March 1929. The suction capacity of the system was 150 m³ / s.

Fourth expansion

The fourth expansion phase was delayed because the need for building materials decreased during the Second World War and the JCF therefore had no need for additional energy. The canton therefore granted the JCF an extension of the deadline for the full expansion of the facility specified in the license. The building permit for the expansion of the facility was granted in June 1943, but the work was postponed due to a lack of material. After the end of the war, the demand for cement increased again, so that the expansion of the works channel was started, which was made possible by the demolition of the cement factory building after production was concentrated in Wildegg. Originally it was planned to install two more turbines, in the end only a Kaplan turbine from Bell was installed because there was not enough space for a second turbine. The work was carried out in 1950 and 1951. The capacity of the system rose to 190 m³ / s.

Fifth expansion

In 1959 and 1960 the underwater canal was widened and deepened. The three old Francis turbines from the 1910s were replaced by three bulb turbines - a design that was hardly known in Switzerland at the time. The maximum amount of water that can be processed rose to 346 m³ / s and the annual energy production to 55 million kWh.

Sixth expansion

Axpo took over the power plant in 2011 and renewed it in the following years, although it did not generate any electricity from July 2012 to the end of 2014. The old power plant was demolished for 131 million and a new plant was built. Four bulb turbines are housed in the very flat nacelle, each with an output of 2.3 MW. The generators can deliver a maximum of 8.8 MW. so that an annual production of up to 64 million kWh should be possible. With the expansion, the concession was also renewed, which is valid until 2074. It also included improving the fish ascent and descent aid. Furthermore, the weir was adapted so that even the floods of the Aare of the century with runoffs of up to 1,400 cubic meters per second can be safely discharged. The weir was equipped with a doping power plant that processes the 30 to 40 m³ / s that are released into the Aare.

Technical specifications

Expansion stage	Years of construction	Commissioning taking	Swallowing capital (m³ / s)	Turbines	Power output		Rule- working capital (Million kWh)	Type of current
					mechanically	electric
0	1882-83	1884	4.9	1 Jonval turbine	102 hp	-
	1896		7th		155 hp
1	1902		25th	1 Jonval turbine 2 Francis turbine n	155 hp 2 × 250 hp
2a	1910-1911	1911	20th 25th	1 Francis turbine 2 Francis turbines	775 hp 2 × 250 hp
2 B	1912-1916	1916	58	1 Francis turbine 2 Francis turbines	1100 hp	1000 hp	10	Two-phase alternating current
3	1927-1929	1929	150	1 Francis turbine 2 Francis turbines 2 propeller turbines	-	1 × 800 hp 2 × 600 hp 2 × 2100 hp		Three phase alternating current
4th	1950-1951	1951	190	1 Francis turbine 2 Francis turbines 2 propeller turbines 1 Kaplan turbine		1 × 800 hp 2 × 600 hp 2 × 2100 hp 1 × 1835 hp
5	1959-1963	1963	346	3 bulb turbines 2 propeller turbines 1 Kaplan turbine		8 MW	55
6th	2011-2015	2014	360	3 bulb turbines		11 MW	64

literature

• Axpo (ed.): Hydraulic power plant Rüchlig . Factsheet. November 2016 ( axpo.com [PDF]).
• Hugo Marfurt: The "Rüchlig" power plant of the Jura-Cement-Farbiken Aarau . 1964, p. 36-48 , doi : 10.5169 / SEALS-559004 .

Individual evidence

1. ↑ ^{a b} Hugo Marfurt, p. 37
2. ↑ ^{a b c} Othmar Birkner: Aarau . In: Inventory of the newer Swiss architecture (INSA) . tape 1 , 1984, Rüchlig. Cement factory, S. 156 , doi : 10.5169 / SEALS-1273 .
3. ↑ ^{a b} Statistics of hydropower plants in Switzerland . January 1, 1914, Appendix No. 23, p. 270-271 ( admin.ch ).
4. ↑ Geoserver of the Swiss Federal Administration ( information )
5. ↑ ^{a b c d} Hugo Marfurt, p. 38
6. ^ Hugo Marfurt, p. 39
7. ↑ ^{a b c d} Aarau, power station of the Jura cement factories . In: Schweizerischer Wasserwirtschaftsverband (Ed.): Guide through the Swiss water management . tape 1 . Zurich 1926, p. 117-118 .
8. ↑ About newer belt drives. In: Polytechnisches Journal . tape 320 , 1905, pp. 436–440 ( hu-berlin.de [accessed June 28, 2020]).
9. ^ History. In: ELFA event hall. Retrieved June 28, 2020 (Swiss Standard German). 
10. ^ Hugo Marfurt, p. 41
11. ^ Hugo Marfurt, p. 42
12. ^ Hugo Marfurt, p. 43
13. ↑ ^{a b} Hugo Marfurt, p. 44
14. ^ Hugo Marfurt, p. 45
15. ↑ Hugo Marfurt, pp. 47-48
16. ↑ Axpo. Factsheet

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