Upgrading layout and design solutions in the course of design and construction of the Chirkeiskaya hydroelectric plant

Abstract

The author describes innovation engineering solutions used in the construction and assembly works of a hydroelectric power plant, which reduce labor consumption and construction time.The Chirkeiskaya hydroelectric power plant (HPP), which is the largest in the Northern Caucusus with an installed capacity of 1000 MW and an arch dam 232.5 m high, has a long history.The Sulak River on which this HPP is located is the largest waterway in mountainous Daghestan. Its total power potential including its tributaries is estimated at 21 billion kW × h. Allowing for a minimal damage to economics and the environment, it is advisable to use up to 80% of this potential.The Chirkeiskaya hydrosystem operated since 1974 include the following structures:-the double-curvature arch dam of height 232 m. The height of the arch part is 184 m, the base width is 30 m, the crest length is 333 m, and the proportion coefficient is 0.16. The height of the wedge-shaped plug is 48 m high, its base width is 82 m, and its width at the contact with the arch is 33 m. The concrete masonry volume is 1320 thousand m 3 . The turbine water conduits of diameter 5.5 m are taken out from the dam body onto the downstream face. The inclined water-intake, 60 m high, is directly adjacent to the upstream face of the dam;-the HPP building next to the dam with two rows of turbogenerator units. The building width is 56.6 m, its length 80 m, and its height 54.6 m. Four turbogenerator units with RO-230 turbines (impeller diameter 4.5 m) are installed in two engine rooms.-the maximum estimated flow rate through the turbine is 170 m 3 /sec, the maximum head 212 m, and the estimated head 170 m. Production buildings Nos. 1 and 2 linked by a cable passage and transformer chambers are located on the roof of the HPP building. The assembly site is located inside the HPP building; -the service spillway, i.e., a non-pressure tunnel conduit, is intended for a flow rate of 2400 m 3 /h and consists of an open concrete spillway, a 150-m sloping segment, a horizontal tunnel 350 m length, and a discharge (flume-like) channel with a spring board and a side spillway of a total length of 281 m;-the provisional spillway intended for the start-up of the first generator unit and the hydroelectric power plant under decreased levels (with a head of 130 m); -DS 330 kW and the HPP control building; -the cable well with the upper cable passage to the control building, the lower cable tunnel, and the passage to production buildings Nos. 1 and 2; -a set of structures for reinforcing the left bank; -cementation and ventilation wells with four tiers of cementation and drainage adits at the edges where the dam is cut into the banks; -Tishiklinskaya dam with a conduit spillway intended for a flow rate of 10 m 3 /sec.