E ISSN 1987 - 8257

Sunday, 25 October 2009 19:40
Zhinvali hydroelectric (generation) complex was put into operation in 1985. The area of water collection in the power site is 1900 km2, the annual average consumption is 43, 8 m3/sec, and annual average water intake – 1384 million m3.

The scheme of Zhinvali hydroelectric (generation) complex envisages building a seasonal storage reservoir with the capacity of 520 million m3 for meeting the needs of energy, water supply and irrigation.

The hydroelectric (generation) complex includes:
Earth-and-rock-fill dam with the central loamy nucleus with the height of 101 m, the water intake, idle bottom culvert for the water flow of 1000 m3/sec (it may be used for the operation of Zhinvali reservoir).

The intake structure (the height is 55 m) represents a quadrangle reinforced concrete tower on the hard rock and is equipped with a small rack, flat wheel shield and grab bucket.

The water runs from the water inlet through tunnel conduit with the length of 650 m to the turbines of underground power station.

The power station is located behind the dam at the depth of 70 m under the riverbed. In the turbine room there are 4 hydroelectric generators with the capacity of 32, 5 thousand kW each. The power generated by the generators is transmitted to the open transformer yard of 110 and 220 kW at the downstream dam slope. The annual generation is 390 million kWh.

The tailrace tunnel is gravity for passing 115 m3/sec of water. It consists of 8, 6 km tunnel area and 1, 0 km tail-race at the end of which there is a compensating basin located in the tail-water for supplying the customers with water during the stoppage of hydro power as well as for the relaxation of rate of rise of water discharge in the riverbed of Aragvi with the sharp rate of loading at the hydro power.

The capacity of compensating basin (1 million m3) is defined from the conditions of daily operation.

The compensating basin is filled up at the expense of backwater of the river at 5 m, which is formed by 6, 5 m dam and embankments dumped of floodplain pebbles.

In order to avoid silting the waters of the river Aragvi are drained bypassing the compensating basin through by-channel.

The water outlet is envisaged in the compensating basin for 400 m3/sec consumption through which the part of the water comes for supplying of water of the tail-water (low-water discharge is 10 m3/sec).

The water consumers of natural flow of the river are the following: Mukhrani and Saguramo irrigation systems and springs of Aragvi group water supply of Tbilisi which is fed by filtrates of the River Aragvi.

Part of the water (11, 6 m3/sec) runs to the main conduit of domestic and potable waters which are combined with irrigation facilities.

Part of the water (7, 0 m3/sec) is used for irrigation and is thrown to Tbilisi Sea and some part is used for water supply of Tbilisi.

The ingress of part of Aragvi water in Tbilisi Sea enables to use the Iori river in Kvemo Samgori irrigation system.

The length of domestic and potable water aqueduct is 36,7 km. 18,64 km is open aqueduct of precast reinforced –concrete pipes with the diameter of 3,3 m; 11,4 km – five tunnels, 6,7 km – four branches of metal aqueduct with the diameter of 1,4 m. At the end of aqueduct the water is distributed for water supply and irrigation with the splitter.
The water used for water supply undergoes treatment in the treatment plant which is a part of Zhinvali hydroelectric (generation) complex.

Tetrikhevi Hydro plant with the installed capacity of 12 MW was put into operation in 1955. The water runs from Sioni reservoir to the Hydro plant. The length of the pressure piping is 1100 m, the design water flows is 13 m3. Tetrikhevi Hydro plant has a 35/6 kW. In 2008 Hydro Plant became deregulated (and the generated power may be sold at free tariff). The Hydro Plant average generation is 25 million kWh.   
Last Updated on Sunday, 25 October 2009 19:50
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