Arzninskaya hydroelectric station

Arzninskaya hydroelectric power station (Arzniy hydroelectric power station) is a hydroelectric power station on the Hrazdan River, near the Armenian village of Arzni . It is part of the Sevan-Hrazdan cascade , being its fourth stage (located between the Gyumush and Kanaker hydroelectric stations ). The first hydropower unit was launched in 1956. The capacity of the hydroelectric power station is 70.6 MW, the average annual design is 300 million kWh , and the actual output in recent years is 80 million kWh. ^[one]

Arzninskaya hydroelectric station
Output Portals of Arzninskaya HPP
A country	Armenia
River	Handed out
Cascade	Sevan-Hrazdan
Owner	CJSC International Energy Corporation
Status	acting
Years of input units	1956
Main characteristics
Annual electricity production, mln kWh	300 (80)
Kind of power plant	derivational
Design head , m	121
Electric power, MW	70.6
Equipment specifications
Type of turbines	radial axial
Number and brand of turbines	3x
Flow through turbines, m³ / s	23.7
Number and brand of generators	3 × GFS 441/26
Power of generators, MW	3 × 23.52
Main facilities
Dam type	gravity concrete
Gateway	not
Outdoor switchgear	110 kV
On the map

Structurally, it is a derivational hydroelectric power station with a head reservoir, pressureless derivation and an underground building of a hydroelectric power station. The composition of hydroelectric power plants: ^[1]

• head waterworks;
• derivation;
• pressure pool;
• blank spillway (rapid flow);
• pressure pipeline;
• hydroelectric building;
• Switchgear.

The head waterworks serves to draw water from the Hrazdan River, consists of a massive concrete dam with a dull spillway, a water inlet with two openings, overlapped by flat gates and two washing galleries. The dam forms a small reservoir with a volume of 150 thousand m³. The water intake is interfaced with a pressureless derivation of 8 km long, running along the Hrazdan coast and consisting of two tunnels with a total length of 4.1 km and two canals with a total length of about 3.8 km with two aqueducts. From the derivation, water is supplied to the pressure basin, equipped with an automatic siphon idle spillway, a water outlet to the Arzni-Shamiramsky irrigation canal and a hole for the pressure pipe with an anterior chamber. The combined pressure head pipeline consists of an elevated metal part, a surge tank, and a vertical shaft 100 m deep. After the shaft there are three horizontal adits (water conduits) that feed water directly to the turbines. The building is an underground type hydroelectric station, located at a depth of 100 m, connected to the surface by a horizontal adit overlooking the gorge slope. Three vertical radial-axial hydraulic units with a capacity of 23.5 MW each, operating at a design pressure of 118 m, are located in the HPP building. Turbine and generator manufacturers are Austrian branches of Voith and Siemens Schukkert. The switchgear is also located in the underground room ^[1] .

The owner of the station is CJSC International Energy Corporation, 90% of the shares of which belong to the Russian OJSC RusHydro . The equipment of the hydroelectric station is outdated, its replacement and reconstruction is required.