DE202011000798U1 - Canal as a pumped storage power plant - Google Patents

Abstract

Pumped storage power plant for converting renewable energy into potential energy, comprising: a. a source of renewable energy, in particular a wind turbine, b. a descent structure comprising a first lower and a second upper step, c. at least one pump, the pump, driven by the regenerative energy, pumping water from the first lower stage into the second upper stage.

Description

The invention relates to a pumped storage power plant for converting renewable energy into potential energy, the pumped storage power plant comprising a source of regenerative energy, a descent structure, and at least one pump, the pump driven by the regenerative energy pumping water from the first lower to the second upper level ,

Renewable energies are energies from sources that either renew themselves at short notice or whose use does not contribute to the depletion of the source. These are sustainably available energy resources, which include hydropower, wind energy, solar radiation (solar energy), geothermal energy and tidal energy.

The use of wind power has been known for centuries. In the past, the use of mechanical energy (windmills) was common, today the focus is on the generation of electrical energy. Wind power refers to the conversion of the horizontal kinetic energy (kinetic energy) of the air masses of the earth into electrical energy. The original source of energy for wind power is radiated light energy of the sun, which causes differences in the radiation budget of the earth. The resulting energy gradients express themselves as differences in air pressure and lead to mass air movements to compensate for the energy gap.

The rotor blades of a wind turbine convert the kinetic energy of the air particles into rotational energy. This energy, which is thus available on the rotating axis, is converted into electrical power by means of a generator.

Modern wind turbines largely operate on the principle of buoyancy, with aerodynamically shaped rotor blades, as they are used in aircraft, are used. Compared with these buoyancy rotors, resistance rotors reach a maximum of a performance coefficient of about 35%, since the rotor surfaces must be guided against the wind on the way back. The rotor blades of a wind turbine use the buoyancy principle to convert kinetic energy into mechanical energy. This principle, which develops its force due to pressure differences in the windward and leeward side when flowing around bodies, has always been used in sailing and for a long time in aviation. The difference in the use of wind power is that the rotor blades rotate as centered lever arms around its own axis and thus exert a torque whose force can be transmitted to a generator. The buoyancy is the resultant of two forces, the buoyancy force and the resistance force. Both forces depend significantly on the angle of the rotor blade to the wind direction. In this respect, the quotient of buoyancy force to resistance force can be formed for each angle of attack (center line of the profile to the wind direction). This so-called glide ratio is a measure of the achievable energy yield.

Along with this principle, today's wind turbines are usually equipped with horizontal axis rotors, which must be tracked to the wind direction. They require the installation of the generator in the spire. In contrast, vertical axis rotors enable a ground-level installation of the generator and do not require wind tracking. However, they have lower efficiencies and sometimes require a start-up aid. Known as vertical systems are the Savonius rotor and the Darrieus rotor.

The most common is the classification of wind turbines according to their installed capacity, whereby so far in small systems (<70 kW, about 25 m high), medium systems (70-750 kW, about 40-65 m high) and large systems (> 750 kW , about 60-100 m high) was distinguished. It can not be ruled out that this classification will be overhauled in the future. The "megawatt class" has already established itself among new plants, and an end to this development can not be defined, especially in connection with offshore installations.

There are various systems available for power control. The simplest method is unscrewing from the wind, which can be used as coarse control for high wind speeds. The stall control also represents a relatively coarse control according to the principle of stall, energetically favorable is the pitch control, which is made by stepless control of the angle of attack of the rotor blades. To reduce torque surges as the wind passes through the tower shadow, the horizontal axis of the rotor is usually tilted slightly to increase the distance between the lower rotor blades and the tower.

• • Mast: Die Masten weisen üblicherweise eine Höhe von 10 m bis 100 m auf, wobei mit zunehmender Höhe nicht nur der Energieertrag steigt, sondern auch die Errichtungskosten aufgrund der aufwendigeren Statik. Die Masten werden aus Stahl oder Beton (Holz nur bei sehr kleinen Masten) errichtet und dienen der Aufnahme von Gondel, Rotor, Getriebe und Generator.
• • Gondel: Die Gondel bildet Grundrahmen, Träger und Verkleidung zur Aufnahme und Befestigung von Getriebe und Generator. Sie dient der Aufnahme aller an der Mastspitze auftretender Kräfte und Momente.
• • Rotorblätter: Die Anzahl der Rotorblätter ist für den energetischen Wirkungsgrad unbedeutend. Je weniger Blätter eingesetzt werden, um so höher ist die Drehzahl der Anlage, um in gleicher Zeit die gleiche Fläche nutzen zu können. Zur Mitte hin sind die Rotorblätter meist als Holmverbindung ohne aktive Fläche konstruiert, da das Verhältnis zwischen Nutzen (Hebelarm, Strömungsfläche) und Aufwand nach innen deutlich ungünstiger wird. Die modernen Rotorblätter werden aus Kunststoff (GFK, CFK) gefertigt.
• • Getriebe: Das Getriebe sorgt für die Übersetzung der vergleichsweise geringen Rotordrehzahl auf die installierte Nenndrehzahl des Generators.
• • Rotorwelle: Die Rotorwelle stellt die Verbindung zwischen Rotor und Getriebe dar.
• • Generator: Als Generatoren sind sowohl Synchron- als auch Asynchron-Generatoren einsetzbar.
• • Steuerfahnen: Die Steuerfahne bewirkt die automatische Einstellung des Winkels zwischen Gondel/Rotor und Windrichtung.

A wind turbine usually consists of the following components:

• • Mast: The masts usually have a height of 10 m to 100 m, with increasing height not only increases the energy yield, but also the construction costs due to the more complex static. The masts are made of steel or concrete (wood only on very small masts) and serve to accommodate nacelle, rotor, gearbox and generator.
• • Gondola: The gondola forms the base frame, girder and fairing for receiving and attaching the gearbox and generator. She serves the Recording of all forces and moments occurring at the top of the mast.
• • Rotor blades: The number of rotor blades is insignificant for the energy efficiency. The fewer blades are used, the higher the speed of the system, in order to use the same area in the same time. Towards the center, the rotor blades are usually designed as a spar connection without active surface, since the ratio between benefits (lever arm, flow area) and effort inside is much less favorable. The modern rotor blades are made of plastic (GFK, CFK).
• • Transmission: The transmission translates the comparatively low rotor speed to the installed rated speed of the generator.
• • Rotor shaft: The rotor shaft represents the connection between rotor and gearbox.
• • Generator: Both synchronous and asynchronous generators can be used as generators.
• • Control vanes: The control lug automatically adjusts the angle between the nacelle / rotor and wind direction.

Even at high wind speeds, the rotor speed is too low to drive a normal generator. The power is transmitted from the rotor blades via the hub to the "slow wave" (rotor shaft) and from there to the gearbox. It increases the speed via gears and transmits this energy to the "fast shaft" (generator drive shaft), which drives the generator. But today there are also gearless generators, which offers the advantage of an overall simpler system. In the generator metal coils are mounted on the longitudinal axis; this is the so-called rotor. In the housing of the generator, a strong magnetic field is generated. The rotating motion of the metal coils in the fixed magnetic field causes the electrons to flow in one direction through the coil. This creates electrical current and thus also voltage. The generator produces electricity.

Since electrical energy can be stored only with difficulty and with losses, it is provided by a power plant management by technical and organizational measures according to the needs. In Germany, the so-called base load and medium load have so far mainly been covered by lignite and nuclear power plants or, above all, hard coal-fired power plants. The peak load mainly came from gas and pumped storage power plants. With increasing shares of electricity from renewable energies, a changed power plant management is necessary. Although geothermal power plants can cover base load and hydroelectric power plants, biomass power plants and biogas plants base load and / or peak load. Power generation from solar energy and wind, however, is subject to strong fluctuations. However, these partly correlate with the daily or annual load profile. Thus, power from solar energy is provided at peak times. Electricity generated by wind energy increases more in winter and can compensate for the reduced yields of solar systems at the time.

Up to now pumped storage power plants or - for small amounts of energy or short-term fluctuations in demand - accumulators or high-capacitive capacitors are used for the storage of electrical energy.

The object of the invention is to provide means which enable a storage of energy, in particular regenerative energy.

The task is solved by the independent claim. Preferred embodiments will be apparent from the dependent claims.

• a. eine Quelle regenerativer Energie, insbesondere eine Windkraftanlage,
• b. ein Abstiegsbauwerk, umfassend eine erste untere und eine zweite obere Stufe,
• c. mindestens eine Pumpe,

wobei die Pumpe, angetrieben durch die regenerative Energie, Wasser von der ersten unteren in die zweite obere Stufe pumpt.It was completely surprising that a pumped storage power plant could be deployed to convert renewable energy into potential energy, allowing for the use and storage of renewable energy. The pumped storage power plant comprises:

• a. a source of renewable energy, in particular a wind turbine,
• b. a descent structure comprising a first lower and a second upper level,
• c. at least one pump,

wherein the pump, driven by the regenerative energy, pumps water from the first lower to the second upper stage.

The pumped storage power plant according to the invention (also referred to as pumped storage plant in the context of the invention) is a form of storage power plant and serves to store electrical energy by pumping up water, which can be converted back into electrical power via turbines in the opposite way. The electrical energy is thus stored by converting it into potential energy from water and fed back into the grid by converting this potential energy into electrical energy.

In the sense of the invention, the potential energy (also altitude or position energy) is in particular an energy form inherent to a body due to its position or position in a conservative force field (such as a gravitational field or electric field). A certain, arbitrarily chosen place in this field serves as a reference point, in the gravitational field of the earth, this can be, for example, the earth's surface. The amount of energy changes only by change of position relative to the reference point and can only be stated with reference to this.

The person skilled in the art knows that a pumped storage power plant is not a power plant in the conventional sense, since on balance it does not generate electricity but always consumes electricity because of the losses in efficiency associated with the intermediate storage. It is a necessary for grid control energy storage. The ability of the pumped storage power plants to both absorb and deliver energy can be used to control the power grid. It was completely surprising that it can serve in particular for the storage of the electricity which is obtained by regenerative energies. The power of the power plant is available within a matter of minutes, if required, and can be flexibly regulated in a wide range. This is an advantage over conventional thermal power plants, whose performance can only be adjusted over a period of several hours. Also, the pumping operation can be flexibly adapted to different power surpluses in the network when two separate riser and downpipes are present. This control energy can be used both to catch demand peaks and to catch sudden consumption drops.

It is preferred that the pumped storage power plant has a reversible plant operation. Advantageously, it comprises a turbine, a motor-generator and a pump which are mounted on a shaft and preferably form a unit.

For the purposes of the invention, pumps are working machines which preferably convey incompressible fluids. These include liquid-solid mixtures, pastes and liquids with low gas content. The drive energy is preferably provided by one or more plants for the production of renewable energy. The drive energy is then converted by the pump into the kinetic energy of the medium.

The pumped storage power plant preferably has at least two modes of operation: when power is needed, the motor-generator operates as a generator and, powered by the turbine, supplies electrical power. The water flows from the upper stage to the lower stage and provides the drive power. In the second mode of operation, electrical energy provided by regenerative energy plants is used to operate the motor generator as an electric motor so that the pump is driven to pump water back to the second stage.

It may be preferred that the pump is equipped with pump turbines. In the sense of the invention, the pump turbine is, in particular, a turbomachine, which can be flowed through in both directions and, depending on the direction of rotation, works as a pump or turbine.

In order to ensure optimum control of the modes of operation, the turbine preferably has closure caps, with closure flaps being mounted in front of the endloading lines. The end load line is preferably made through pipes. Furthermore, at least one turbine and tubes are mounted in the direction of the first stage, so that an efficient discharge of the water through the turbine can be achieved.

It is preferred that the descent structure is a sluice or hoist which is advantageously located on a federal waterway. It was completely surprising that federal waterways for storing energy, preferably regenerative energy, particularly preferably wind energy, can be used by means of the pumped-storage power plant according to the invention. In Germany, the length of the federal waterways amounts to about 2000 km and a width of 20 to 50 m, whereby it is preferred that only channels are used. The federal waterways, like wind energy, concentrate on regions in northern and central Germany.

The federal waterways can be used advantageously as composite storage for regenerative energies with decentralized Energieeinspeisoption. Wherever descent structures (in particular locks and / or elevators) are present, pumped storage power plants can be installed which preferentially convert wind energy into potential energy, i. H. Water is pumped from the first lower stage (or channel holding) to the second upper stage. To generate the energy, it is preferable to place branches with shutters in front of the pump shutters of the pumps, with turbines and pipes being mounted in the lower stage or channel holding direction. Advantageously, the pumped storage power plant may comprise means for control and energy delivery lines. It has been found that high building costs can be saved by the means according to the invention, since the construction of reservoir and the descent structures such as lifts and locks omitted. Only the pumps in the descent structures are to be converted.

The pumped storage power plant according to the invention can be realized by low installation costs, which in turn has economic and business advantages, such. B. the omitted need for the shutdown of wind turbines result. If more power is generated by wind energy than is currently needed, it may be preferable for the pumped storage power plant to pump water from a channel (eg a first stage) counter to the direction of flow of a weir into a second stage by means of the wind stream. In the second stage, the water can be used as a carrier of potential energy, so that the water is brought by a turbine back into the lower stage or channel basin at the next peak current and thereby converted into electrical energy.

The invention also relates to a device for storing regenerative energy as potential energy, wherein a pump by energy, in particular electrical energy generated by wind turbines, pumps water in a federal waterway from a first lower stage to a second upper stage of a descent structure, the pump in particular before pump closure flaps branches, in particular pipes with flaps and pump closure flaps are arranged in front of the pump.

The invention will be explained in the following with reference to a figure by way of example, but without being limited to these. It shows:

1 Schematic structure and operation of a pumped storage power plant

1 shows a schematic structure and the operation of a pumped storage power plant. The storage of energy is easily solved at the pumped storage power plant. There is usually a storage tank for water down the pumped storage power plant itself and a reservoir for water above the pumped storage power plant. The upper reservoir of the hydroelectric power plant is often 2 meters or much higher above the pumped storage power plant and can also be referred to as the upper stage according to the invention, wherein the reservoir below the pumped storage are referred to as the lower stage. In the pumped storage hydroelectric power plant itself are usually several turbines and at the respective turbine a permanently connected generator for generating electricity. The turbines in the pumped storage hydropower plant are also used in opposite flow direction as pumps and therefore called pump turbines and the generator then becomes the electric motor for the pump turbine in the pumped storage hydroelectric power plant. The pumps are preferably powered by energy (electricity) derived from renewable energy, such as wind energy. Often overnight, when the electricity grid is lightly loaded and the electricity is cheaper, the water can be pumped from the lower reservoir of pumped storage hydropower plants via the electrically operated pump turbine and water pipes in the upper reservoir of pumped storage hydropower plants. There the water remains. Now, if additional power is required for the electricity grid at the pumped storage hydroelectric power station, the barriers in the water pipes are opened and the water shoots back into the valley with enormous water power and is pumped through the pumped storage hydropower plants. The pump turbines are connected to the generator via fixed shafts and turn the generator. Similar to a bicycle dynamo, electricity is generated as green electricity within the generator in the hydroelectric power plant. The electricity as green electricity is converted into a network and then fed into the electricity grid. The water that has passed through the turbine of the pumped-storage hydropower plant is collected in the lower reservoir, to be pumped up again at the next opportunity for the pumped storage power plant. The diameter of the pump turbines in the pumped storage hydropower plant is several meters, depending on the power plant output. The control flow can be designed as follows:

control flow

• a.) a.) Das Oberbecken ist noch nicht bis zur maximalen Höhe gefüllt.
• b.) b.) Das Stromnetz des vorgeschalteten EVU,s hat (Leistungsüberschuß) von der Windenergie. Das heißt das Netz verbraucht negative Regelenergie.

Pumping from underwater into the upper water depends on 2 parameters

• a.) a.) The upper basin is not yet filled to its maximum height.
• b.) b.) The power grid of the upstream power supply company, s has (power surplus) of the wind energy. This means that the network consumes negative control energy.

• c.) a.) Das Oberbecken ist noch nicht soweit abgelassen bis zur min Grenze.
• d.) b.) Das Stromnetz des vorgeschalteten EVU,s braucht Leistung (Positive Regelenergie)

The drawing of the water from the upper water into the underwater via the turbine depends on 2 parameters.

• c.) a.) The upper basin is not yet drained to the minimum limit.
• d.) b.) The power grid of the upstream utility, s needs power (positive control energy)

The respective criteria described under a.) Are determined only by the operator of the sewer (water and ship's office)

The criteria described under b.) Are only determined by the upstream RU.

The energy dissipation succeeds over the same network from which the pump (pumps) are supplied.

Claims (11)

Pumped storage power plant for converting renewable energy into potential energy, comprising: a. a source of renewable energy, in particular a wind turbine, b. a descent structure comprising a first lower and a second upper step, c. at least one pump, wherein the pump, driven by the regenerative energy, pumps water from the first lower to the second upper stage. Pumped storage power plant according to claim 1, characterized in that the pumped storage power plant comprises at least one turbine. Pumped storage power plant, according to claim 1 or 2, characterized in that it comprises at least one generator. Pumped storage power plant, according to one or more of the preceding claims, characterized in that it comprises at least one pump with pump closure flaps. Pumped storage power plant, according to one or more of the preceding claims, characterized in that in front of the pump closure flaps are mounted. Pumped storage power plant, according to one or more of the preceding claims, characterized in that turbine and tubes are mounted in the direction of the first stage. Pumped storage power plant, according to one or more of the preceding claims, characterized in that the descent structure is a lock or lift. Pumped storage power plant, according to one or more of the preceding claims, characterized in that the descent structure is arranged on a federal waterway. Pumped storage power plant, according to one or more of the preceding claims, characterized in that it comprises means for control. Pumped storage power plant according to one or more of the preceding claims, characterized in that it has energy delivery lines. Apparatus according to one or more of the preceding claims for storing regenerative energy as potential energy, wherein a pump by energy, in particular electrical energy generated by wind turbines, pumps water in a federal waterway from a first lower stage to a second upper stage of a relegation structure Pump shutter valves are arranged in front of the pump.

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