Operating and Under Construction Hydroelectric Power Plants on the Ardon River

The Zaramag hydroelectric power plants are a Russian cascade of operating and under construction hydroelectric power plants on the Ardon River in the Alagir district of North Ossetia, which is an interconnected complex of two hydroelectric power plants - the Main HPP with a capacity of 10 MW and the Zaramagskaya HPP-1 with a capacity of 342 MW. Construction of the hydroelectric power plant began in 1976, the completion of construction is scheduled for 2013, so the total duration of construction will be at least 37 years.






Transcaucasian Highway



Soil embankment dam on the Ardon River. The maximum height of the dam is 39 m, the length is 300 m, the volume of the embankment is 1.586 million m³ of soil. The dam is filled out of pebbly-gravelly soils, has an anti-seepage core of loam. During the construction, the initial design of the dam was changed - the height of the dam was reduced (according to the original project, it was supposed to be 79 m with an embankment volume of 3726 thousand m³ of soil), the embankment of pebble-gravelly soils in thrust prisms was partially replaced by a mound of ordinary stone from mountain scree, which significantly increased the reliability of the dam. A feature of the dam is the dam crest elevation (1708 m at the reservoir level of 1690.6 m; thus, the dam margin is 17.4 m higher than the normal water level in the reservoir), which ensures the safety of the dam in the event of a collapse of a large landslide or landslide in the reservoir. In addition, the design of the dam provides the possibility of increasing its height if such a decision is made.



The building of the Main HPP is of an open type, coastal.



General view of the Main HPP. From left to right: the building of the head hydroelectric power plant (turbine hall), the dam, the future spillway.



Segment-type shutter. Due to the sanitary spillway, it is slightly ajar.



Downstream. On the right is the station building.



Before entering the turbine hall, I expected to see there, judging by its size, several GAs. I was very surprised when there was only one GA. The head HPP is designed to generate electricity from the water pressure created by the dam. The HPP building has one four-blade rotary-blade hydraulic turbine with a pre-turbine butterfly valve, which drives the hydrogenerator.



Do you see the people on the left? On the hull of the GA there is a five-ruble coin on the edge. Not only does it not fall, it is generally immobile! Here is a clear illustration of the absence of vibration on the HA.



A feature of the hydroelectric unit is the possibility of a significant increase in its capacity (up to 33 MW) in the event of a decision to increase the height of the dam; In this case, the design of the impeller provides for the possibility of its reconstruction with an increase in the number of blades from 4 to 8. In the foreground of the photo is a crooked box. They said that this is turbine braking equipment and why it is needed in the main hall is not clear. "Soon we will remove it downstairs to the technical floor, so that it does not spoil the view here."



The diameter of the impeller of the hydro turbine is 3.5 m, the weight of the impeller is about 30 tons. With a design head of 18.6 m, the hydroelectric unit develops a capacity of 15 MW (in the isolated operation mode of the Main HPP; when working together with the Zaramagskaya HPP-1, the power is reduced to 10 MW).



This is an inlet pipe with water in front of the HA.



Technical floor. At the bottom, in the recess, there is an inlet pipe. On the right, you can see a pipeline that can be used to supply water to the derivation of the Zaramagskaya HPP-1 bypassing the Golovnaya HPP.





The water spent at the hydroelectric unit is either discharged into the Ardon River bed (during the operation of the Main HPP before the launch of the Zaramagskaya HPP-1), or is fed into the diversion tract of the Zaramagskaya HPP-1.



This is where the distribution of water discharge takes place. Now it is being discharged into the Ardon River. Then, when GES-1 is started, the discharge path to the Ardon River is blocked by a gate. The water level in the chamber rises and discharges into the diversion tunnel. You can see its beginning on the left. Such a rounding of concrete is the lower part of the portal.



View of the station from the dam.



To the right of the mountain is Nizhny Zaramag. In 2009, 10 people lived in it.



A water intake through which water is supplied to the civil aviation system.



Entrance portal of the construction and operational spillway. At first, the height of these spillways is surprising, but remembering that the project provides for the filling of the dam to a height of 79 meters (now the height is 39 m.), this becomes clear. Although I may be wrong.





The construction of the hydroelectric power plant has been carried out since 1976, the project of the hydroelectric power plant has been repeatedly revised, the customers and contractors of the construction have changed several times, and the pace of construction work has changed. Currently, the launch of the Golovskaya HPP took place on September 18, 2009, the launch of the Zaramagskaya HPP-1 is tentatively scheduled for 2012.