Hes inside
Theoretically, everything is clear with hydroelectric power plants - water goes from the upstream to the lower one, it turns the turbine wheel. The turbine rotates a generator, and it produces electricity ...
Details are interesting.
To a hostess on a note: to receive 1 kilowatt-hour of the electric power, it is necessary to lower 14 tons of water from height of 27 meters.
(Details were checked during the visit to nine different hydropower plants).
')
To paraphrase a classic: all thermal power plants are alike, each hydroelectric power plant is arranged in its own way. In other words, typical hydroelectric power plants do not exist, all hydroelectric power plants are different. Each has its own water flow, head, topography, soil, climate, proximity to the sea, the volume of the reservoir ...
Here, for example, seems to be the usual machine room of the station. Except that all the windows in it are artificial, with lighting.
That's because the machine room is located in the rock at a depth of 76 meters.
This is the first underground hydroelectric power station in the USSR , four water lines with a diameter of 6 m come to it from the surface. And this is a mine, also cut down in a rocky foundation, to extract equipment from the deep-well chamber in case of repair / replacement:
Ideally, all the water should go through the turbines and give energy. But it is not always possible.
Part of the water has to be dumped past the hydroelectric station:
- in the repair of hydraulic units;
- during spring floods, if there is no multi-year regulation reservoir (and it is often not);
- it happens that in the cascade of hydropower stations (stations located on one river) the capacity of the upper station is greater than the lower one; then the bottom must let some of the water out past the turbines, otherwise it will simply flood it;
- sometimes open idle spill at the request of fish factories for the passage of fry downstream;
- etc.
The idle spillway of the White Sea Hydroelectric Power Plant is three shutters.
Quite a lot of attention is paid to the issue of reserving, because not being able to lower the level in the reservoir in time is fraught. Any of the valves here can be lowered / raised with a gantry crane, two of the three with electric winches. In extreme cases, it is possible and manually (with a speed of, however, 3 cm / min).
The shutter is raised, there is an idle discharge for the water intake of the city of Belomorsk, located downstream:
Induction heating is used to combat the icing of valves. For example, 150 kW is required for heating this instance:
Sometimes bubbling is done for the same reason - air is passed from the depth along the gate; see the compressed air hose:
The discharge includes measures to quench the kinetic energy of the flow - water wells, collision flows, steps, or, as here, at the Volkhov hydroelectric station - water stove with dampers:
A special fish pass for salmon was made at the Nizhnetulomskaya HPP , which spawns upstream. The design imitates a half-kilometer mountain stream with stones at the bottom, zigzag passages and places for the rest of the fish.
Interestingly, during the period of spawning at hydroelectric power stations, the 4th hydraulic unit closest to the fish passage is disconnected, so that the salmon can hear the noise of the fish passage and head there.
At the Verkhnetulomsky station, the fish pass was made in the form of a 2-kilometer backlit tunnel and a special fish-lift, but this design was unsuccessful, the fish did not go. From the situation out - the tunnel was turned into a fish factory and allowed warm water into it from the cooling of the generators. And the fry are good, and energy efficiency is evident. From where in the generator warm water - see below.
Let me remind you that during the accident of 2009, after the breakthrough of water into the turbine room at the Sayano-Shushenskaya HPP, power supply of the station’s own needs was quickly lost, as a result of which the closures on the water inlets had to be manually reset. In the wake of this incident, hydropower stations were actively engaged in backup power supply - emergency diesel generators, batteries.
This is also an element of safety - aeration pipes in the upper part of the conduits of the Kondopoga hydroelectric station :
The thickness of the steel walls of the conduits is relatively small - 12 mm. Rings of conduits are designed for high internal pressure or low vacuum. But if you close the upper valves and the water line dramatically empty, then a deep vacuum will arise inside them, and the pipes may be deformed. Aeration pipes let in air when emptying, and everything will be fine.
Remains of a wooden water conduit of the 1930s:
In case the turbine water line breaks during operation, a protective wall is provided (in the center of the frame):
Thanks to her, the water will not go to the right - to the administrative building, but bypass the station to the left and go along the excavation to the lower pool.
Now we are between the turbine and the generator and observe the shaft connecting them. On the left you can see the diagram of the hydraulic unit with the gauges displayed on it showing the pressure in the lubrication system.
Under the legs - hydraulic drives of the guide vane:
More options can be seen in the engine room.
Water and air temperatures, water levels in pools:
Mnemonic on display.
This hydraulic unit does not work (power 0 MW, guide vanes closed, rotor speed 0%).
It is clearly seen how water is drawn from the spiral chamber of the turbine (below) and is fed to the generator coolers (it is in the center, red, coolers A and B) and for lubricating the thrust bearing, upper (VGP) and lower (NGP) generator bearings. Yes, yes, they are oiled. From here, warm water is taken for the fish factory.
In the right side, a red oil tank is visible - this is the hydraulic control system of the guide vane. It also shows the pressure, flow rates and levels of all liquids.
Vibration Information:
In brackets: the fatigue failure of the turbine cap mounting studs was officially called the destruction of the hydraulic unit on the same Sayano-Shushenskaya due to vibrations occurring when the hydraulic unit passes through the “forbidden zone” range (there are other opinions , but this is not the case).
Where is the "forbidden zone", we will see on the central control panel of the HPP:
Hydraulic units G1, G3, G4 in operation, G2 stopped. On a black background is the power that generators generate 38.1 / 38/38 MW, respectively. The G3 and G4 columns are red, because they are working at full capacity, the G1 still has a reserve. The red zone is visible behind the bars - this is precisely the range of power in which the hydraulic unit is undesirable to work and which must be quickly passed through when starting / stopping.
By the way, a knowledgeable person outside the building will say which of the hydraulic units is not working:
The second pair of counterweights raised - so the valves on the turbine conduits unit number 2 is omitted.
Very actively implement remote control.
So, for example, this 60 MW station operates around the clock, but the staff on it happens only during the day and on workdays, the rest of the time it is controlled by telemechanics from the head hydroelectric station:
HPPs work on dispatch order, which regulates when and how much station to issue electricity. Since hydroelectric power plants are the most maneuverable energy sources (they start up quickly and stop quickly), they serve to cover peak loads and their production varies depending on the time of day and the day of the week. Unlike thermal and nuclear power plants, which provide the basic part of consumption and operate in a relatively stable mode.
Dispatch instruction on the screen (sorry for the cosmic image quality; on the x-axis - the clock, on the y-axis - power):
The dispatch task takes into account the mutual influence of hydroelectric power stations in a cascade, the water levels in their reservoirs, consumers' demands for water and electricity, etc. and on the basis of this distributes the energy production between the stations. It is curious that on the Paz River, on the border between Norway and Russia, there are 5 Russian and 2 Norwegian hydropower stations, and the river itself flows out of a Finnish lake. And nothing, somehow agreed.
Details are interesting.
To a hostess on a note: to receive 1 kilowatt-hour of the electric power, it is necessary to lower 14 tons of water from height of 27 meters.
(Details were checked during the visit to nine different hydropower plants).
')
To paraphrase a classic: all thermal power plants are alike, each hydroelectric power plant is arranged in its own way. In other words, typical hydroelectric power plants do not exist, all hydroelectric power plants are different. Each has its own water flow, head, topography, soil, climate, proximity to the sea, the volume of the reservoir ...
Here, for example, seems to be the usual machine room of the station. Except that all the windows in it are artificial, with lighting.
That's because the machine room is located in the rock at a depth of 76 meters.
This is the first underground hydroelectric power station in the USSR , four water lines with a diameter of 6 m come to it from the surface. And this is a mine, also cut down in a rocky foundation, to extract equipment from the deep-well chamber in case of repair / replacement:
Closures and waste structures
Ideally, all the water should go through the turbines and give energy. But it is not always possible.
Part of the water has to be dumped past the hydroelectric station:
- in the repair of hydraulic units;
- during spring floods, if there is no multi-year regulation reservoir (and it is often not);
- it happens that in the cascade of hydropower stations (stations located on one river) the capacity of the upper station is greater than the lower one; then the bottom must let some of the water out past the turbines, otherwise it will simply flood it;
- sometimes open idle spill at the request of fish factories for the passage of fry downstream;
- etc.
The idle spillway of the White Sea Hydroelectric Power Plant is three shutters.
Quite a lot of attention is paid to the issue of reserving, because not being able to lower the level in the reservoir in time is fraught. Any of the valves here can be lowered / raised with a gantry crane, two of the three with electric winches. In extreme cases, it is possible and manually (with a speed of, however, 3 cm / min).
The shutter is raised, there is an idle discharge for the water intake of the city of Belomorsk, located downstream:
Induction heating is used to combat the icing of valves. For example, 150 kW is required for heating this instance:
Sometimes bubbling is done for the same reason - air is passed from the depth along the gate; see the compressed air hose:
The discharge includes measures to quench the kinetic energy of the flow - water wells, collision flows, steps, or, as here, at the Volkhov hydroelectric station - water stove with dampers:
About fish
A special fish pass for salmon was made at the Nizhnetulomskaya HPP , which spawns upstream. The design imitates a half-kilometer mountain stream with stones at the bottom, zigzag passages and places for the rest of the fish.
Interestingly, during the period of spawning at hydroelectric power stations, the 4th hydraulic unit closest to the fish passage is disconnected, so that the salmon can hear the noise of the fish passage and head there.
At the Verkhnetulomsky station, the fish pass was made in the form of a 2-kilometer backlit tunnel and a special fish-lift, but this design was unsuccessful, the fish did not go. From the situation out - the tunnel was turned into a fish factory and allowed warm water into it from the cooling of the generators. And the fry are good, and energy efficiency is evident. From where in the generator warm water - see below.
Security
Let me remind you that during the accident of 2009, after the breakthrough of water into the turbine room at the Sayano-Shushenskaya HPP, power supply of the station’s own needs was quickly lost, as a result of which the closures on the water inlets had to be manually reset. In the wake of this incident, hydropower stations were actively engaged in backup power supply - emergency diesel generators, batteries.
This is also an element of safety - aeration pipes in the upper part of the conduits of the Kondopoga hydroelectric station :
The thickness of the steel walls of the conduits is relatively small - 12 mm. Rings of conduits are designed for high internal pressure or low vacuum. But if you close the upper valves and the water line dramatically empty, then a deep vacuum will arise inside them, and the pipes may be deformed. Aeration pipes let in air when emptying, and everything will be fine.
Remains of a wooden water conduit of the 1930s:
In case the turbine water line breaks during operation, a protective wall is provided (in the center of the frame):
Thanks to her, the water will not go to the right - to the administrative building, but bypass the station to the left and go along the excavation to the lower pool.
Management and control
Now we are between the turbine and the generator and observe the shaft connecting them. On the left you can see the diagram of the hydraulic unit with the gauges displayed on it showing the pressure in the lubrication system.
Under the legs - hydraulic drives of the guide vane:
More options can be seen in the engine room.
Water and air temperatures, water levels in pools:
Mnemonic on display.
This hydraulic unit does not work (power 0 MW, guide vanes closed, rotor speed 0%).
It is clearly seen how water is drawn from the spiral chamber of the turbine (below) and is fed to the generator coolers (it is in the center, red, coolers A and B) and for lubricating the thrust bearing, upper (VGP) and lower (NGP) generator bearings. Yes, yes, they are oiled. From here, warm water is taken for the fish factory.
In the right side, a red oil tank is visible - this is the hydraulic control system of the guide vane. It also shows the pressure, flow rates and levels of all liquids.
Vibration Information:
In brackets: the fatigue failure of the turbine cap mounting studs was officially called the destruction of the hydraulic unit on the same Sayano-Shushenskaya due to vibrations occurring when the hydraulic unit passes through the “forbidden zone” range (there are other opinions , but this is not the case).
Where is the "forbidden zone", we will see on the central control panel of the HPP:
Hydraulic units G1, G3, G4 in operation, G2 stopped. On a black background is the power that generators generate 38.1 / 38/38 MW, respectively. The G3 and G4 columns are red, because they are working at full capacity, the G1 still has a reserve. The red zone is visible behind the bars - this is precisely the range of power in which the hydraulic unit is undesirable to work and which must be quickly passed through when starting / stopping.
By the way, a knowledgeable person outside the building will say which of the hydraulic units is not working:
The second pair of counterweights raised - so the valves on the turbine conduits unit number 2 is omitted.
Very actively implement remote control.
So, for example, this 60 MW station operates around the clock, but the staff on it happens only during the day and on workdays, the rest of the time it is controlled by telemechanics from the head hydroelectric station:
HPPs work on dispatch order, which regulates when and how much station to issue electricity. Since hydroelectric power plants are the most maneuverable energy sources (they start up quickly and stop quickly), they serve to cover peak loads and their production varies depending on the time of day and the day of the week. Unlike thermal and nuclear power plants, which provide the basic part of consumption and operate in a relatively stable mode.
Dispatch instruction on the screen (sorry for the cosmic image quality; on the x-axis - the clock, on the y-axis - power):
The dispatch task takes into account the mutual influence of hydroelectric power stations in a cascade, the water levels in their reservoirs, consumers' demands for water and electricity, etc. and on the basis of this distributes the energy production between the stations. It is curious that on the Paz River, on the border between Norway and Russia, there are 5 Russian and 2 Norwegian hydropower stations, and the river itself flows out of a Finnish lake. And nothing, somehow agreed.
Source: https://habr.com/ru/post/365973/
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