Energy conversion device

Abstract

The invention relates to an energy conversion device, in particular a fluid power plant device, comprising a fluid reservoir (14a; 14b) for storing a fluid (100a; 100b), a gravity line (20a; 20b) connected to the fluid reservoir (14a; 14b), a turbine (22a; 22b) downstream of the gravity line (20a; 20b) and designed to convert the kinetic energy of the fluid (100a; 100b), which can be supplied from the fluid reservoir (14a; 14b) to the turbine (22a; 22b) via the gravity line (20a; 20b), into a rotational motion of an output shaft of the turbine (22a; 22b), and a generator (48a; 48b) designed to generate the rotational motion of the output shaft. to convert it into electrical energy.It is proposed that the energy conversion device comprises a pressure vessel (30a; 30b), which is designed in particular differently from a housing of the turbine (22a; 22b), in which a gas (102a; 102b) is arranged at an overpressure above the ambient air pressure, in particular of at least 0.2 bar, and the turbine (22a; 22b) is arranged at least partially.

Description

State of the art

[0001] The invention relates to an energy conversion device.

[0002] An energy conversion device, in particular a fluid power plant device, has already been proposed, comprising a fluid reservoir for storing a fluid, a gravity pipe connected to the fluid reservoir, a turbine downstream of the gravity pipe designed to convert the kinetic energy of the fluid, which can be supplied from the fluid reservoir to the turbine via the gravity pipe, into a rotational motion of an output shaft of the turbine, and a generator designed to convert the rotational motion of the output shaft into electrical energy.

[0003] German publication DE 372 326 C discloses a turbine system with a turbine arranged in a turbine housing, wherein the turbine and the turbine housing are arranged below a water level, wherein when the turbine is switched off the water initially rises to a tongue, thereby creating a separation between the outside atmosphere and the inside of the turbine housing and the turbine housing in which the turbine is arranged is pressurized when the turbine is switched off.

[0004] Patent application US 2013 / 0 043 681 A1 discloses a generator system for integration into a building, which is specifically designed to extract kinetic energy from water supplied to the building and convert it into an electric current, wherein during operation the water rises in a casing in which the turbine is arranged and compresses a gas in the casing, wherein, by gas pressure and gravity, the water is forced out of the casing at a constant pressure through an outlet pipe connected to a lower end of the casing, so that the water can be used in the building.

[0005] The object of the invention is, in particular, to provide a generic device with improved efficiency characteristics. This object is achieved according to the invention by the features of claim 1, while advantageous embodiments and further developments of the invention can be found in the dependent claims. Advantages of the invention

[0006] The invention relates to an energy conversion device, in particular a fluid power plant device, comprising a fluid reservoir for storing a fluid, a gravity line connected to the fluid reservoir, a turbine downstream of the gravity line and designed to convert the kinetic energy of the fluid, which can be supplied from the fluid reservoir to the turbine via the gravity line, into a rotational movement of an output shaft of the turbine, and a generator designed to convert the rotational movement of the output shaft into electrical energy, with a pressure vessel, in particular designed differently from a turbine housing, in which a gas with an overpressure relative to the ambient air pressure, in particular of at least 0.2 bar, and the turbine are at least partially arranged.

[0007] It is proposed that the energy conversion device has a return section through which the fluid can be conveyed from the pressure vessel back into the fluid reservoir, and has a compressor and / or mixing unit designed to mix the fluid to be returned with a compressed conveying gas in the return section, wherein the return section has several individual lines that are connected downstream of and fed by a mixing valve.

[0008] An "energy conversion device" is preferably understood to be a device designed to convert the potential energy (gravitational potential energy) of a fluid, preferably water, stored in a fluid reservoir, into electrical energy and / or thermal energy. The energy conversion device is preferably designed as a heat pump device, intended to convert the potential energy of a fluid stored in a fluid reservoir into thermal energy for temperature control of a system, for example, a heating system. When designed as a heat pump device, the energy conversion device is preferably intended for continuous operation.In an operating state, the energy conversion device, designed as a heat pump device, is intended to convert a potential energy of the fluid into electrical energy and to use the generated electrical energy simultaneously to return the fluid to the fluid reservoir, whereby any thermal energy generated in the process is intended for temperature control of a system.

[0009] Preferably, the energy conversion device is also designed as an energy storage device intended for converting the potential energy of a fluid stored in a fluid reservoir into electrical energy for feeding into an electrical grid. When configured as an energy storage device, the energy conversion device is preferably designed for two-stage operation. In a first operating state, the energy conversion device, configured as an energy storage device, is designed to convert the potential energy of the fluid into electrical energy. In a second operating state, the energy conversion device, configured as an energy storage device, is designed to use electrical energy to pump the fluid back into the fluid reservoir, i.e., to convert electrical energy into the potential energy of the fluid.In principle, it would also be conceivable for an energy conversion device, designed as an energy storage device, to operate continuously, with the fluid flowing from the fluid reservoir through the turbine into the pressure vessel and simultaneously being pumped back from the pressure vessel into the fluid reservoir via the return path. In this process, energy would be "drawn" from the environment, particularly through the compression of the conveying gas (which is ambient air), and used to pump the fluid back into the fluid reservoir. This allows the return pumping of the fluid to be carried out with a particularly low electrical energy consumption, thus making it energy-efficient.

[0010] A "fluid reservoir" is preferably understood to be a storage device for a fluid intended to drive the turbine. The fluid reservoir is designed as a storage device capable of holding a volume of fluid. The fluid reservoir can be designed as an open or closed fluid reservoir. Preferably, a fluid reservoir designed as a closed fluid reservoir can be a tank. A fluid reservoir designed as a tank preferably has a capacity of at least 0.005 m³. In principle, fluid reservoirs designed as tanks with a capacity of 0.1 m³, preferably 1 m³, or more than 1.5 m³ are also conceivable. Preferably, a fluid reservoir designed as an open fluid reservoir can be a lake, for example, a reservoir, in particular a mountain lake, which has a significantly larger capacity.Preferably, the energy conversion device has only one fluid reservoir. However, it is also conceivable that the energy conversion device has several fluid reservoirs, which are preferably coupled together.

[0011] The fluid for driving the turbine is a liquid, preferably an incompressible liquid. Preferably, the fluid for driving the turbine is water. In principle, it would also be conceivable for the fluid for driving the turbine to be a different liquid, for example, a coolant. It would also be conceivable for the fluid to be a refrigerant. Likewise, it is conceivable for the fluid to be an antifreeze or to contain an antifreeze.

[0012] The fluid reservoir is located above the turbine. The fluid reservoir is at a geodetic height relative to the turbine. The fluid reservoir is designed to store a fluid that is supplied to the turbine for energy conversion. The size of the fluid reservoir can vary depending on the size of the energy conversion device. The fluid reservoir can be designed as a fluid tank, for example, mounted on a building or other structure. A fluid reservoir designed as a fluid tank can, for example, have a capacity of 0.005 cubic meters to 2000 cubic meters. Preferably, the fluid reservoir can also be designed as a reservoir. For larger energy conversion devices, such as energy storage devices, particularly energy storage power plants, the fluid reservoir can advantageously be designed as a reservoir.For the energy conversion device to function as an energy storage device, the fluid reservoir is preferably designed as a large water reservoir, such as a reservoir. For the energy conversion device to function as a heat pump device, the fluid reservoir is preferably designed as a fluid tank.

[0013] The fluid reservoir can have different geodetic heights relative to the turbine depending on the configuration of the energy conversion device. Preferably, the fluid reservoir has a geodetic height of at least 5 m relative to the turbine. In a configuration of the energy conversion device as a heat pump, the fluid reservoir preferably has a height of at least 5 m relative to the turbine. Preferably, the geodetic height at which the fluid reservoir is arranged relative to the turbine in a configuration as a heat pump is between 7 m and 800 m, preferably between 10 m and 600 m, and in a particularly advantageous configuration between 80 m and 200 m. In a configuration of the energy conversion device as an energy storage device, the fluid reservoir preferably has a height of at least 5 m relative to the turbine.Preferably, the geodetic height at which the fluid reservoir is arranged relative to the turbine is between 10 m and 2000 m in an embodiment as an energy storage device, preferably between 50 m and 1500 m and in a particularly advantageous embodiment between 100 m and 1000 m.

[0014] A "downpipe" is preferably understood to be a pipe through which a fluid can be supplied to a higher-level fluid reservoir of the turbine. The downpipe can consist of a single pipe or several individual pipes. The diameter of the downpipe depends on the design of the energy conversion device and, in particular, on the quantity of fluid to be supplied to the turbine during operation. For a configuration of the energy conversion device as a heat pump, the downpipe preferably has a diameter of 0.5–5000 cm, more preferably 1–1000 cm, and most advantageously 2–20 cm. For a configuration of the energy conversion device as a heat pump, the downpipe is preferably designed as a single pipe.For the energy conversion device to function as an energy storage device, the downpipe preferably has a diameter of 0.1–15 m, more preferably 1–10 m, and most advantageously 2–5 m. The diameter is dimensioned according to the required flow rate of the fluid to be conveyed, so that, in particular, the friction losses between the fluid and the pipe are as low as possible.

[0015] A "turbine" is understood to be a turbomachine that converts the kinetic energy of a flowing fluid into mechanical rotational energy, which is then transmitted via a turbine output shaft. The turbine preferably has several impellers arranged in at least one fluid stream, which, by flowing around the fluid, absorb the fluid's kinetic energy and convert it into rotational energy. In principle, it would be conceivable for the turbine to be driven by a single fluid stream from a single nozzle. Preferably, the turbine has multiple nozzles that direct several fluid streams onto the turbine, particularly onto its impellers. Preferably, the turbine is designed as a Pelton turbine. In principle, it would also be conceivable for the turbine to be designed as a Kaplan turbine, a Francis turbine, or any other turbine design deemed suitable by those skilled in the art.

[0016] The term "generator" is preferably understood to mean an electrical machine designed to convert kinetic energy, in particular rotational energy, into electrical energy. The generator can be, for example, an alternating current generator or a direct current generator.

[0017] A "pressure vessel" is preferably understood to be a sealable container in which pressure can be maintained. The pressure vessel is preferably pressure-tight. The pressure vessel preferably has at least one fluid inlet opening through which a fluid can flow into the pressure vessel via the discharge pipe at an inlet pressure, and at least one fluid outlet opening through which a fluid can be discharged from the pressure vessel. The fluid inlet opening is preferably located below a maximum fluid fill level of the pressure vessel. A fluid inlet opening above the fluid fill level is also conceivable. The fluid outlet opening is located below a minimum fluid fill level in the pressure vessel. Preferably, all openings in the pressure vessel, i.e., all openings for fluid lines or electrical lines, are located below the minimum fluid fill level.Preferably, all fluid inlet openings, fluid outlet openings, and openings through which, for example, electrical cables are routed into the pressure vessel are arranged below the minimum fluid fill level. This eliminates the need for complex seals against gases, particularly helium. This also advantageously seals the pressure vessel against leakage of the pressurized gas. Preferably, the pressure vessel is designed to maintain a pressure of 0.2 bar to 200 bar.

[0018] The term "gas" is preferably understood to mean a pure gas or a gas mixture. Preferably, the gas or gas mixture has a lower density than ambient air. Preferably, the gas or gas mixture is not ambient air.

[0019] The term "overpressure in the pressure vessel" refers to a pressure within the pressure vessel that is higher than the ambient pressure immediately outside the vessel. Preferably, the overpressure in the pressure vessel is in the range of 0.2 bar to 200 bar relative to the ambient pressure immediately outside the vessel. The overpressure in the pressure vessel is particularly dependent on the geodetic height of the fluid reservoir located above the pressure vessel. The pressure vessel is constantly under overpressure. The pressure vessel is under overpressure when the energy conversion device is in operational condition. The pressure vessel is under overpressure during operation of the turbine located within the pressure vessel.In particular, the overpressure in the pressure vessel is not only present during a specific operating state of the energy conversion device, for example a switched-off state of the energy conversion device, but especially continuously during an operational state.

[0020] The phrase "the turbine is at least partially arranged in the pressure vessel" preferably means that preferably a main part, and particularly preferably the entire turbine, is completely arranged in the pressure vessel. However, in an alternative embodiment, it is also conceivable that only a part of the turbine, for example, only a turbine outlet, is arranged in the pressure vessel, and the remaining part of the turbine is connected to the pressure vessel and / or integrated into a gravity pipe. The turbine is operated in the pressurized pressure vessel. "Provided for" is understood to mean, in particular, specially designed and / or equipped. The phrase "an object is provided for a specific function" is understood to mean, in particular, that the object fulfills and / or performs this specific function in at least one application and / or operating condition.This allows the overpressure within the pressure vessel to be advantageously used to return the fluid to the fluid reservoir. By utilizing the overpressure within the pressure vessel, the fluid is advantageously pressurized and forced out of the pressure vessel through a fluid outlet, thus forcing the fluid in a return path towards the fluid reservoir. This can advantageously improve the efficiency of returning the fluid to the fluid reservoir.

[0021] It is further proposed that the gas have a density of less than 1.2 kg / m³, and in particular be helium. The term "density of a gas" preferably refers to the density of the gas measured under laboratory conditions. A gas with a density of less than 1.2 kg / m³ is preferably helium. In principle, it would also be conceivable for the gas to be hydrogen, illuminating gas, methane, or ammonia. Furthermore, it would be conceivable for the gas to consist of a mixture of different gases. This would allow for an advantageously high overpressure to be provided in the pressure vessel, resulting in advantageously low frictional resistance for a turbine located within the pressure vessel. By using a suitable gas, the friction of the turbine in the pressurized pressure vessel can be advantageously reduced, thereby advantageously increasing the efficiency of the energy conversion device.

[0022] Furthermore, it is proposed that the turbine be designed as a Pelton turbine. A "Pelton turbine" is preferably understood to be a free-jet turbine comprising at least one turbine wheel with multiple turbine blades, driven by a fluid jet exiting from at least one nozzle. This allows the turbine to be designed with a particularly advantageous high efficiency.

[0023] A "return section" is preferably understood to be a part of the energy conversion device designed to return a fluid, particularly one used to drive the turbine, from the pressure vessel back to the fluid reservoir. Preferably, the return section is free of a fluid pump device, such as a water pump, that pumps the fluid directly back into the fluid reservoir. The return section is preferably at least partially made of a thermally conductive material, such as copper. Preferably, the return section is largely made of a thermally conductive material. Preferably, by designing the return section with a thermally conductive material, particularly advantageous heat conduction from the surroundings to the fluid mixture conveyed in the return section can be achieved.This allows heat energy from the environment to be supplied particularly well to the transported gas expanding in the return section.

[0024] A "compressor and / or mixing unit" is preferably understood to be a unit comprising at least one compressor unit or one mixing unit, but preferably both. A "compressor unit" is preferably understood to be a unit designed for compressing and conveying a gas, in particular a conveying gas. The compressor unit is preferably designed as a compressor. The compressor unit is preferably designed to compress a conveying gas to a pressure of 0.1 bar to 250 bar. Depending on the delivery head over which the fluid to be conveyed must be conveyed, the compressor unit is designed to deliver the conveying gas to a different pressure. Preferably, the compressor unit can be driven by an electric motor. In principle, it would also be conceivable for the compressor unit to be driven by another means.For example, it would be conceivable that the compressor unit is driven by a rotational movement generated by the turbine. In this case, a direct drive of the compressor's drive shaft by the turbine's output shaft would be possible. It would also be conceivable that the compressor's drive shaft could be driven indirectly via a gearbox, for example, a planetary gearbox. It would also be conceivable that the compressor unit is located within the pressure vessel. Preferably, the conveying gas is air, in particular ambient air. It would also be conceivable that the conveying gas is a gas or gas mixture. Other gases could be used as the conveying gas, which would be considered appropriate by those skilled in the art.It would be advantageous to also seal the fluid reservoir and for the energy conversion device to have a return line through which the conveyed gas collecting in the fluid reservoir can be conveyed back to the compressor.

[0025] A "mixing unit" is preferably understood to be a unit designed to mix two fluids, in particular the return fluid (which is a liquid) and a conveying gas. The mixing unit is designed to adjust the ratio of two volume flows, in particular the volume flow of the return fluid and the volume flow of the conveying gas. The mixing unit is designed to mix the return fluid (which is a liquid) and the conveying gas in such a way that a defined quantity of the return fluid and a defined quantity of the conveying gas are alternately discharged from at least one outlet of the mixing unit. The mixing unit is designed to mix the volume flows of the return fluid and the conveying gas in such a way that separate volumes of the return fluid and the conveying gas are alternately discharged from one outlet.The return fluid, which is a liquid, and the conveyed gas are not miscible in the sense that they form a single fluid. The mixing unit is not designed to form a homogeneous fluid or emulsion from the return fluid and the conveyed gas. Preferably, the mixing unit has at least one mixing valve for mixing the return fluid with the conveyed gas. It is also conceivable that the mixing unit has several mixing valves connected in parallel for mixing the return fluid with the conveyed gas. A mixing valve of the mixing unit can preferably be a simple 3 / 2-way valve, a rotary valve, or another type of valve that would be suitable to a person skilled in the art, having at least one inlet for the fluid to be conveyed, at least one inlet for the conveyed gas, and at least one outlet for the mixture of the fluid to be conveyed and the conveyed gas.The mixing valve is designed to alternately discharge a defined volume of return fluid and a defined volume of conveying gas from its outlet. This allows the fluid to be conveyed particularly easily and efficiently along the conveying path to the higher-level fluid reservoir via the conveying gas.

[0026] As the conveying gas rises in the return section, it expands due to the decreasing pressure. This expansion work of the conveying gas during its ascent in the return section facilitates the efficient conveying of the fluid. This expansion cools the conveying gas, causing it to absorb heat energy from its surroundings, particularly from the return section. Energy, especially heat energy, is thus extracted from the surroundings to transport the fluid back into the system. This energy is then used to pump the fluid back into the system and is subsequently converted into potential energy, then mechanical energy, and finally, by the turbine, into electrical energy.The energy conversion device can therefore preferably extract energy, in particular heat energy, from the environment and convert it at least partially into electrical energy.

[0027] It is further proposed that the return section includes a compressor and / or mixing unit with a mixing valve designed to mix the return fluid with the compressed delivery gas. The mixing valve is designed to mix the return fluid, which is a liquid, preferably water, with the delivery gas, in such a way that a defined volume of return fluid and a defined volume of delivery gas flow alternately in a line downstream of the mixing valve. The downstream line preferably has such a small diameter that the delivery gas cannot bypass it in the upward-leading line. The pressurized delivery gas is designed to draw the liquid delivery fluid upwards in the line downstream of the mixing valve by means of its buoyancy force.The pressurized conveying gas is designed to fill as much of the pipe diameter as possible and to act according to the principles of plug flow, piston flow, or bubble flow. As the pressurized conveying gas rises in the upward-directed pipe, it expands due to the decreasing pressure, thereby accelerating the conveyance of the fluid. This allows the return section to be designed particularly advantageously for returning the fluid.

[0028] Furthermore, it is proposed that the return section includes a compressor and / or mixing unit with a mixing valve designed to mix the return fluid and a compressed conveying gas in a ratio ranging from 30:1 to 1:30. The mixing valve is particularly preferably designed to mix the return fluid and the compressed conveying gas in a ratio ranging from 20:1 to 1:20, more preferably from 10:1 to 1:10, and most preferably from 5:1 to 1:5. In a particular embodiment, the mixing valve is designed to mix the return fluid and the compressed conveying gas in a 1:1 ratio. This allows for the conveying of the fluid to be pumped using the conveying gas to be particularly advantageous.

[0029] It is further proposed that the energy conversion device comprises a compressor and / or mixing unit, which includes a mixing valve with a variable mixing ratio. The term "variable mixing ratio" preferably means that the mixing ratio of the mixing valve can be changed within a defined range by an adjustment mechanism, preferably during operation. Preferably, the mixing ratio is adjustable within a range of 30:1 to 1:30. The adjustment mechanism can preferably be manually adjustable by an operator or automatically. This allows for particularly advantageous adjustment of the fluid recirculation and adaptation to external environmental influences.

[0030] The multiple individual lines of the return path, which are connected downstream of the mixing valve, are all connected in parallel. The individual lines of the return path are at least partially, preferably largely, and particularly preferably entirely made of a material with advantageous thermal conductivity, such as copper or a material with a comparable thermal conductivity. The return path has a varying number of individual lines depending on the fluid flow rate per minute; this number is determined during the design of the energy conversion device. Preferably, the return path has at least 10 individual lines, more preferably at least 50 individual lines, and particularly preferably more than 100 individual lines.In principle, it would also be conceivable that the return path has several mixing valves, with each bundle of parallel connected individual lines connected downstream of a mixing valve.

[0031] Preferably, at least 10 individual lines are connected downstream of a mixing valve. Preferably, a single mixing valve is connected downstream of a maximum of 100 individual lines. This allows a return section to be provided in which a mixture of the return fluid (in liquid form) and the conveying gas can be conveyed particularly advantageously and in large volumes.

[0032] Preferably, individual conductors could split into several smaller conductors along their length, preferably in the upper third. For example, each individual conductor could split into two or three further individual conductors in the upper third. In principle, each of the split individual conductors could split again into one or two further individual conductors in the upper quarter of the return path. These individual conductors could have the same inner diameter as the other individual conductors.

[0033] It is further proposed that each of the multiple individual lines has an inner diameter of less than 100 mm. The inner diameter of the individual lines determines the flow cross-section available to a fluid flowing through them, in particular the mixture formed from the fluid to be returned and the conveying gas. Preferably, the inner diameter is less than 80 mm, more preferably less than 50 mm, and in advantageous embodiments less than 20 mm. The inner diameter of the individual lines is selected during the design of the energy conversion device depending on the fluid volume to be conveyed per minute, the delivery head, and the pressure in the pressure vessel. In an advantageous embodiment, the inner diameter of the individual lines is, preferably by way of example, 6 mm.This allows the individual lines to be advantageously designed so that a conveying gas and a fluid to be conveyed, which is in the form of a liquid, can flow separately and the conveying gas cannot flow past the fluid to be conveyed, which is in the form of a liquid.

[0034] Furthermore, it is proposed that the electric generator driven by the turbine be arranged inside the pressure vessel. This allows the pressure vessel to be designed advantageously simply and cost-effectively to be pressure-tight, since no moving parts, such as a rotatable shaft, need to extend from the pressure vessel to the outside, which would require complex seals.

[0035] It is further proposed that the generator have electrical leads that exit the pressure vessel below a minimum fluid level. A "minimum fluid level" is preferably understood to be the level to which the return fluid remains in the pressure vessel during normal operation. This allows for a simple and advantageous sealing of the outlet where the electrical leads exit the pressure vessel, thus providing a simple and advantageous seal for the pressure vessel itself.

[0036] Furthermore, it is proposed that the return section include a compressor and / or mixing unit comprising a compressor designed to compress a conveying gas and connected upstream of a mixing valve. This allows a conveying gas intended for conveying the returned fluid to be advantageously pressurized for conveying purposes before being mixed with the fluid.

[0037] It is further proposed that the return section includes a heat exchanger arranged between a compressor unit and a mixing valve, designed to extract thermal energy from a compressed delivery gas. A "heat exchanger" is preferably understood to be a device designed to transfer thermal energy from at least one first volume flow to at least one second volume flow. Preferably, the heat exchanger is designed to extract thermal energy from a first volume flow, in particular the compressed delivery gas, and transfer this thermal energy to a further volume flow, preferably water, for storage or further transfer. Preferably, the heat exchanger is designed as a separate component downstream of the compressor unit.In principle, it would also be conceivable for the heat exchanger to be at least partially integrated into the compressor unit. It would be possible for the compressor unit to incorporate an integrated heat exchanger. This would allow heat generated during the compression of the conveyed gas to be extracted and utilized to its advantage.

[0038] Furthermore, it is proposed that the return section include a heat exchanger located in the upper third of the return section, which, in at least one operating state, is designed to supply thermal energy to the flowing conveying gas. An "upper section" is understood to be a section facing the fluid reservoir. Preferably, the upper section comprises an upper third, more preferably an upper quarter, and most advantageously an upper fifth of the return section facing the fluid reservoir. Preferably, thermal energy is supplied to the conveying gas, which has expanded and thus cooled in the return section, via the heat exchanger so that the conveying gas can continue to expand.Preferably, thermal energy is supplied to the conveying gas via the heat exchanger in the upper part of the return section only if the thermal energy absorbed from the surroundings of the return section is insufficient for the conveyed fluid to expand sufficiently to convey the fluid to be conveyed. Preferably, the heat exchanger in the upper third of the return section can be supplied with the thermal energy extracted from the fluid flow by the heat exchanger immediately downstream of the compressor.

[0039] Furthermore, according to the invention, a method for operating an energy conversion device is proposed, wherein in one process step a fluid is pumped back from a pressure vessel into the fluid reservoir by means of a pressure prevailing in the pressure vessel and by a mixture with a pressurized conveying gas. This allows the fluid, which is in liquid form, to be pumped back into the fluid reservoir particularly efficiently.

[0040] It is further proposed that, in a process step, thermal energy generated during the compression of a conveying gas be extracted from the compressed conveying gas for further use. This allows heat generated during the compression of the conveying gas to be used advantageously. Drawings

[0041] Further advantages will become apparent from the following description of the drawings. The drawings illustrate two exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0042] They show: Fig. 1 A schematic representation of a first embodiment of an energy conversion device, designed as a heat pump and attached to a building; Fig. 2 A further schematic representation of the energy conversion device designed as a heat pump; Fig. 3 A schematic representation of a second embodiment of an energy conversion device, designed as an energy storage device and arranged on a mountain; and Fig. 4 A further schematic representation of the energy conversion device designed as a heat pump. Description of the exemplary implementations

[0043] The Figure 1 and 2 Figure 1 shows a schematic representation of an energy conversion device 10a according to the invention. Figure 1 and 2Figure 1 shows an energy conversion device 10a according to the invention in a first embodiment. The energy conversion device 10a is designed as a fluid power plant device. The energy conversion device 10a is designed as a heat pump device. The energy conversion device 10a designed as a heat pump device is intended to provide thermal energy. The thermal energy provided by the energy conversion device 10a is preferably intended to be supplied to another device, for example, a heating circuit.

[0044] The energy conversion device 10a is shown attached to a building 12a. In this example, building 12a has a height of 140 meters. However, it is also conceivable that building 12a could have a different height. The energy conversion device 10a has a fluid reservoir 14a for storing a fluid 100a. The fluid 100a is intended for operating the energy conversion device 10a. The fluid 100a is preferably approximately incompressible. The fluid 100a is a liquid. Preferably, the fluid 100a is water. However, it is also conceivable that the fluid 100a, being liquid, could be a refrigerant or water containing a refrigerant. The fluid reservoir 14a is a tank. The fluid reservoir 14a, being a tank, is located on the roof of building 12a.The fluid reservoir 14a, designed as a tank, is preferably arranged in the building at least at a reservoir height of 145 m. The fluid reservoir 14a has a capacity of 0.2 m³. In principle, it would be conceivable for the fluid reservoir to have a capacity of 0.1 m³ to 1 m³. The fluid reservoir 14a has a fluid outlet 16a. The fluid 100a, which is liquid, can exit the fluid reservoir 14a through the fluid outlet 16a. The fluid reservoir 14a has a fluid inlet 18a. The fluid 100a, which is liquid, can be pumped back into the fluid reservoir 14a through the fluid inlet 18a.

[0045] The energy conversion device 10a has a downpipe 20a. The downpipe 20a is connected to the fluid reservoir 14a. The downpipe 20a is connected to the fluid outlet 18a of the fluid reservoir 14a. The fluid 100a can flow from the fluid reservoir 14a through the downpipe 20a. The downpipe 20a runs vertically. The downpipe 20a does not necessarily have to run parallel to the vertical. The downpipe 20a leads from the reservoir level to a region located vertically below it. The fluid 100a, which is liquid, flows through the downpipe 20a solely due to gravitational acceleration, i.e., in particular, the force of gravity. The downpipe 20a is preferably designed as a single pipe. The downpipe 20a is preferably made of a pressure-resistant pipe. However, the downpipe 20a can also have several individual pipes.In principle, it would also be conceivable that the energy conversion device 10a has further downpipes 20a leading away from the fluid reservoir 14a.

[0046] The energy conversion device 10a has a fluid valve 94a arranged in the downpipe 20a. The fluid valve 94a is preferably located at an upper end of the downpipe 20a, facing the fluid reservoir 14a. The fluid valve 94a is designed to control the flow rate of fluid 100a flowing from the fluid reservoir 14a through the downpipe 20a. The fluid valve 94a is designed to open and close the downpipe 20a. In a closed state, the fluid valve 94a seals the downpipe 20a. In an open state, the fluid valve 94a releases a flow cross-section of the downpipe 20a, allowing fluid 100a to flow from the fluid reservoir 14a through the downpipe 20a. Preferably, the fluid valve 94a is infinitely adjustable.The flow rate of the fluid valve 94a can be continuously adjusted between the closed position and the fully open position.

[0047] The energy conversion device 10a includes a turbine 22a. The turbine 22a is connected downstream of the gravity pipe 20a. The turbine 22a is designed to convert the kinetic energy of the fluid 100a, which is supplied to the turbine 22a from the fluid reservoir 12a via the gravity pipe 20a, into rotational energy. The turbine 22a is located vertically below the fluid reservoir 14a. The turbine 22a is located in a basement of building 12a. The turbine 22a is located 145 meters below the fluid reservoir 14a, measured vertically. The vertical distance between the turbine 22a and the fluid reservoir 14a represents the geodetic height that the fluid 100a stored in the fluid reservoir 14a has relative to the turbine 22a. The turbine 22a is designed as a free-jet turbine. Preferably, the turbine 22a is designed as a Pelton turbine. The turbine 22a has a turbine wheel 24a with several impeller wheels 26a.The impellers 26a are preferably each formed by two approximately hemispherical half-blades separated from each other by a sharp edge. The turbine 22a has an output shaft. The output shaft is connected to and driven by the turbine wheel 24a. The turbine 22a has at least one nozzle 28a, which is designed to direct the fluid 100a in a jet onto the impellers 26a of the turbine 22a. The nozzle 28a is oriented tangentially to a circumference of the turbine wheel 24a. The nozzle 28a is designed to direct the fluid 100a, which flows from the discharge pipe 20a, at high velocity onto the impellers 26a of the turbine 22a, thereby driving the turbine wheel 24a. Preferably, the turbine 22a has several nozzles 28a oriented tangentially to the circumference of the turbine wheel 24a.In principle, it would also be conceivable that turbine 22a is designed as a different turbine, for example as a different free-jet turbine.

[0048] The energy conversion device 10a includes a pressure vessel 30a. The pressure vessel 30a is distinct from the housing of the turbine 22a. The pressure vessel 30a is designed to collect the fluid 100a after it has driven the turbine 22a. The pressure vessel 30a forms a closed interior. The pressure vessel 30a is preferably designed in two parts. The pressure vessel 30a has a lower shell 32a and an upper shell 34a. The lower shell 32a forms only the lower part of the pressure vessel 30a. The lower shell 32a preferably extends only below a minimum fluid level 36a of the pressure vessel 30a. A connection area in which the upper shell 34a is connected to the lower shell 32a is arranged below the minimum fluid level 36a. The pressure vessel 30a is preferably made of a metal, for example, steel.In principle, it would also be conceivable for the pressure vessel 30a to be made of a different material, such as a fiber-reinforced plastic. The pressure vessel 30a has a capacity of 0.2 m³. In principle, it would also be conceivable for the pressure vessel 30a to have a capacity of 0.1 m³ to 0.5 m³. The exact size of the pressure vessel 30a depends in particular on the size of the entire energy conversion device 10a, especially on the geodetic height of the fluid reservoir 14a relative to the turbine 22a and the volume of fluid 100a to be circulated per minute. For the exemplary embodiment, it would be conceivable, for example, that 450 liters per minute flow from the fluid reservoir 14a into the pressure vessel 30a, thereby driving the turbine 22a.

[0049] The pressure vessel 30a has a fluid inlet 38a. The downpipe 20a leads into the pressure vessel 30a through the fluid inlet 38a. A fluid 100a can enter the pressure vessel 30a through the downpipe 20a via the fluid inlet 38a. Preferably, the fluid inlet 38a is located below a fluid fill level 36a, more preferably below a minimum fluid fill level 36a. The fluid 100a, which is under pressure from the fluid reservoir 14a via the downpipe 20a, can flow through the fluid inlet 38a into the pressure vessel 30a to the turbine 22a. Alternatively, a nozzle 28a of the turbine 22a could be located directly at the fluid inlet 38a of the pressure vessel 30a, with the fluid inlet 38a being at the same level as the turbine 22a. The pressure vessel 30a has a fluid outlet 40a. Fluid 100a collected in pressure vessel 30a can be discharged from pressure vessel 30a through fluid outlet 40a.Fluid outlet 40a is located in a base area of ​​pressure vessel 30a. Fluid outlet 40a is located below the minimum fluid level 36a. Alternatively, fluid outlet 40a could also be located in the base of pressure vessel 30a. Fluid outlet 40a discharges the fluid 100a collected in pressure vessel 30a. All lines leading into pressure vessel 30a are located below the minimum fluid level.

[0050] Pressure vessel 30a is designed to be pressurized in an operating state. Pressure vessel 30a is under pressure in an operating state. Pressure vessel 30a is under a pressure higher than the immediate ambient air pressure. Pressure vessel 30a is under a pressure higher than the immediate ambient air pressure during a ready-for-operation state. Pressure vessel 30a is under a pressure higher than the immediate ambient air pressure during normal operation of the energy conversion device. Pressure vessel 30a is under a pressure higher than the immediate ambient air pressure during operation of the turbine 22a located in pressure vessel 30a. The pressure in pressure vessel 30a is 3 bar.The overpressure maintained in the pressure vessel 30a depends in particular on the geodetic height at which the fluid reservoir 14a is located above the turbine 22a. The overpressure in the pressure vessel 30a is intended to force the fluid 100a collecting in the pressure vessel 30a out of the pressure vessel 30a through the fluid outlet 16a. The overpressure in the pressure vessel 30a is preferably 22% lower than the fluid pressure of the fluid 100a in the downpipe 20a at the level of the turbine 22a. The fluid pressure of the fluid 100a in the downpipe 20a must be greater than the overpressure in the pressure vessel 30a so that the fluid 100a can flow from the downpipe 20a through the nozzle 28a into the pressure vessel 30a, and in particular onto the impellers 26a of the turbine 22a. Depending on the geodetic height at which the fluid reservoir 14a is located above the turbine 22a, the overpressure can be between 0.2 bar and 100 bar above the ambient pressure.

[0051] To generate overpressure in pressure vessel 30a, a gas 102a is arranged within the pressure vessel 30a. The gas 102a is designed as a pressurized gas intended to generate pressure in the pressure vessel 30a. The gas 102a has a density of less than 1.2 kg / m³. Preferably, the gas 102a has a density of approximately 0.1785 kg / m³. The gas 102a is preferably helium. The gas 102a can be pure helium or a helium mixture. It would also be conceivable, in principle, for the gas 102a to be another gas or gas mixture with a density of less than 1.2 kg / m³.By using a gas 102a with a density of less than 1.2 kg / m³, particularly a gas such as helium, the frictional resistance within the pressure vessel 30a for moving parts, especially the turbine wheel 24a, can be advantageously kept low despite the increased pressure. By using a gas 102a with a density of less than 1.2 kg / m³ to generate the overpressure in the pressure vessel 30a, the frictional resistance between the rotating turbine wheel 24a and its impeller blades 26a and the surrounding gas 102a can also be kept low at high overpressures in the pressure vessel 30a. By using the gas 102a to generate overpressure, the efficiency of the turbine 22a can be advantageously increased, particularly by reducing the flow resistance of the turbine wheel 24a, especially at increased pressures.Flow losses at the turbine 22a due to increased flow resistance as a result of the overpressure in the pressure vessel 30a can thus be advantageously minimized.

[0052] To generate and maintain overpressure in pressure vessel 30a, the energy conversion device 10a includes a gas reservoir 42a. The gas reservoir 42a is designed as a gas tank in which gas 102a is stored. The gas reservoir 42a is connected to pressure vessel 30a via a supply line 44a. A gas inlet 46a, through which the supply line 44a leads into pressure vessel 30a, is located below the minimum fluid fill level 36a. A valve (not shown) is located in the supply line 44a. This valve can be opened to change the pressure in pressure vessel 30a, allowing gas 102a to enter or escape from pressure vessel 30a. In the closed position, the valve is sealed, and no gas 102a can escape from pressure vessel 30a via the supply line 44a.In principle, it would also be conceivable that the energy conversion device 10a does not have a gas reservoir 42a permanently connected to the pressure vessel 30a, but that the pressure vessel 30a is only filled with gas 102a during assembly and that gas 102a is replenished in the pressure vessel when a required overpressure is undershot in the form of maintenance.

[0053] The energy conversion device 10a includes a generator 48a. The generator 48a is designed as an electric generator. The generator 48a is intended to convert the rotational motion of the output shaft of the turbine 22a into electrical energy. The generator 48a is arranged in the pressure vessel 30a. The generator 48a is preferably directly connected to the output shaft of the turbine 22a. The generator 48a has electrical conductors 50a through which an electric current generated by the generator 48a can flow. The electrical conductors 50a of the generator 48a exit the pressure vessel 30a below the minimum fluid level 36a.

[0054] The energy conversion device 10a has a return section 52a. The return section 52a is designed to convey the fluid 100a collected in the pressure vessel 30a back into the fluid reservoir 14a. The return section 52a is designed to convey the fluid 100a above the geodetic height at which the fluid reservoir 14a is located above the pressure vessel 30a. The return section 52a is designed without a liquid pump. The return section 52a does not have a pump that directly pumps the fluid 100a back into the fluid reservoir 14a. The return section 52a is designed to convey the fluid 100a solely by the pressure in the pressure vessel 30a and a pressurized conveying gas 104a from the pressure vessel 30a into the fluid reservoir. The return section 52a is designed, for example, to pump 450 liters per minute from the pressure vessel 30a back into the fluid reservoir 14a.

[0055] The return line 52a has a first line section 54a. The first line section 54a is directly connected to the pressure vessel 30a. The first line section 54a is connected to the fluid outlet 40a of the pressure vessel 30a. The first line section 54a preferably consists of a single line. The first line section 54a is, for example, designed as a pipe or a hose. The return line 52a has a compressor and mixing unit 56a. The compressor and mixing unit 56a is designed to provide a compressed conveying gas 104a. The conveying gas 104a is ambient air. The compressor and mixing unit 56a has a compressor 58a. The compressor 58a is designed as a compressor. The compressor 58a is designed as a compressor to draw in and compress ambient air.Compressor 58a is designed to convert ambient air into compressed conveying gas 104a. Compressor 58a is designed to compress the ambient air into conveying gas 104a at a pressure of 3 bar. Compressor 58a compresses the conveying gas 104a to a pressure of 3 bar. The pressure to which compressor 58a compresses the conveying gas 104a depends on the geodetic height over which the fluid 104a must be conveyed from pressure vessel 30a to fluid reservoir 14a. Depending on the geodetic height at which fluid reservoir 14a is located above pressure vessel 30a, the pressure to which compressor 58a must bring the conveying gas 104a can range between 0.2 bar and 100 bar. In principle, it would also be conceivable that the compressor and mixing unit 56a has several compressors 58a, or that the compressor and mixing unit 56a has additional components.The compressor and mixing unit 56a has a delivery gas line 60a. The delivery gas line 60a is connected to an outlet of the compressor 58a. The delivery gas line 60a is designed to convey the pressurized delivery gas 104a away from the compressor 58a. The compressor 58a is preferably electrically driven. The compressor 58a is preferably driven by the current generated by the generator 48a of the turbine 22a. The compressor 58a is supplied with electrical current via the lines 50a of the generator 48a. In principle, it would also be conceivable for the compressor 58a to be driven by the rotational movement of the turbine 22a itself via a mechanical coupling.

[0056] The compressor and mixing unit 56a is designed to mix the return fluid 100a with the compressed delivery gas 104a. The compressor and mixing unit 56a includes a mixing valve 62a. The mixing valve 62a is designed to mix the return fluid 100a with the compressed delivery gas 104a. The mixing valve 62a is arranged between the first line section 54a of the return line 52a and the delivery gas line 60a. The mixing valve 62a is designed as a 3 / 2-way valve. The mixing valve 62a has a first fluid inlet 64a for the return fluid 100a. The second end of the first line section 54a is connected to the first fluid inlet 64a of the mixing valve 62a. The mixing valve 62a has a second fluid inlet 66a. The second fluid inlet 66a directs the conveying gas 104a into the mixing valve 62a.The delivery gas line 60a of the compressor and mixing unit 56a is connected to the second fluid inlet 66a of the mixing valve 62a. The compressor 58a is located upstream of the mixing valve 62a. The mixing valve 62a has a fluid outlet 68a. The fluid outlet 68a is designed to discharge a mixture of the fluid 100a to be pumped and the delivery gas 104a. During operation, the fluid 100a mixed with the delivery gas 104a in the mixing valve 62a flows through the fluid outlet 68a. During operation, a defined volume of fluid 100a and a defined volume of delivery gas 104a flow alternately through the fluid outlet 68a.

[0057] The mixing valve 62a is designed to mix the return fluid 100a with the compressed delivery gas 104a. The mixing valve 62a is designed to alternately connect the first fluid inlet 64a and the second fluid inlet 66a to the fluid outlet 68a. During operation, the mixing valve 62a alternately directs the fluid 100a from the first fluid inlet 64a to the fluid outlet 68a and the delivery fluid 104a from the second fluid inlet 66a to the fluid outlet 68a. The mixing valve 62a has a first switching position in which the first fluid inlet 64a is fluidly connected to the fluid outlet 68a. The mixing valve 62a has a second switching position in which the second fluid inlet 66a is fluidly coupled to the fluid outlet 68a. In a factory, the mixing valve 62a is designed to switch back and forth alternately between the first and second switching positions.In principle, it would also be conceivable that the mixing valve 62a has a third switching position in which neither of the two fluid inlets 64a, 66a is coupled to the fluid outlet 68a and the mixing valve 62a is closed. The third switching position could be interposed between the first and second switching positions during operation.

[0058] The mixing valve 62a is designed to mix the return fluid 100a and a compressed delivery gas 104a in a mixing ratio ranging from 30:1 to 1:30. Advantageously, the mixing valve 62a is designed to mix the return fluid 100a and the compressed delivery gas 104a in a 1:1 ratio during operation. Depending on the volume of fluid 100a to be delivered, the mixing valve 62a can preferably also be designed to mix the return fluid 100a and the compressed delivery gas 104a in a different mixing ratio. For this purpose, the switching times of the first and second switching positions of the mixing valve 62a are varied. Preferably, the mixing valve 62a is designed to be adjustable during operation. The mixing valve 62a is preferably designed so that the switching times for the first and second switching positions are adjustable, preferably during operation.The mixing valve 62a is designed so that the mixing ratio of the return fluid 100a and the conveying gas 104a can be variably adjusted. The mixing ratio can preferably be variably adjusted during operation within a range of 30:1 to 1:30. This is preferably achieved by varying the switching times for the first and second switching positions of the mixing valve 62a. A switching time for a switching position is specifically defined as the time during which the mixing valve 62a remains in the corresponding switching position.

[0059] The return line 52a has a second line section 70a. The second line section 70a is arranged between the mixing valve 62a and the fluid reservoir 14a. The second line section 70a is arranged between the compressor and mixing unit 56a and the fluid reservoir 14a. The second line section 70a is designed to convey the fluid 100a and the conveying gas 104a from the compressor and mixing unit 56a to the fluid reservoir 14a. During operation, the mixture of the fluid 100a to be conveyed and the conveying gas 104a flows from the compressor and mixing unit 56a to the fluid reservoir 14a via the second line section 70a.

[0060] The return line 52a has several individual lines 72a, 74a. The individual lines 72a, 74a are connected downstream of the mixing valve 62a. The individual lines 72a, 74a are fed by the mixing valve 62a. The several individual lines 72a, 74a form the second line section 70a. The return line 52a here exemplarily has 84 individual lines 72a, 74a. In principle, it would also be conceivable for the return line 52a to have a different number of individual lines 72a, 74a. The number of individual lines 72a, 74a depends in particular on the volume of fluid 100a to be returned per minute in a process. Preferably, the number of individual lines 72a, 74a that the return line 52a has is between 20 and 1000. In principle, depending on the size of the energy conversion device 10a, a significantly larger number of individual lines 72a, 74a would also be conceivable, for example 600 individual lines 72a, 74a.Fourteen of the individual lines 72a, 74a are each bundled together and guided within a pipe element 76a, 78a, 80a, 82a, 84a, 86a. The fourteen individual lines 74a, 76a bundled together are each surrounded by one of the six pipe elements 76a, 78a, 80a, 82a, 84a, 86a shown as examples in this embodiment and are held together by it. In principle, it would also be conceivable for a different number of individual lines 72a, 74a to be bundled together and guided within a pipe element 76a, 78a, 80a, 82a, 84a, 86a. Preferably, it would be conceivable for a number of 5 to 200 individual lines 72a, 74a to be bundled together.

[0061] The individual lines 72a, 74a each have an inner diameter of less than 100 mm. Preferably, the individual lines 72a, 74a have an inner diameter of 6 mm. The inner diameter of the individual lines 72a, 74a is preferably selected to be so small that a conveying gas 104a flowing in the individual lines 72a, 74a cannot flow past the return fluid 100a flowing upstream, which is a liquid. The inner diameter of the individual lines 72a, 74a is selected such that the surface tension of the return fluid 100a, which is a liquid, prevents the conveying gas 104a from flowing past the fluid 100a in the individual lines 72a, 74a. The return section 52a, in particular the line sections 54a, 70a, are made of a thermally conductive material. The return path 52a, in particular the conductor sections 54a, 70a are preferably made of copper.In particular, the individual conductors 72a, 74a are made of a material with good thermal conductivity, especially copper.

[0062] The return section 52a includes a heat exchanger 88a. The heat exchanger 88a is integrated into the compressor and mixing unit 56a. The heat exchanger 88a forms part of the compressor and mixing unit 56a. The heat exchanger 88a is located between the compressor 58a and the mixing valve 62a. The heat exchanger 88a is designed to extract thermal energy from the compressed delivery gas 104a. The delivery gas 104a, compressed by the compressor 58a, is heated by the compression process within the compressor 58a. The compressed delivery gas 104a, heated by the compression, flows through the delivery gas line 60a to the mixing valve 62a. The heat exchanger 88a is located on the delivery gas line 60a. The heat exchanger 88a is designed to extract thermal energy, in particular heat, from the delivery gas 104a flowing in the delivery gas line 60a. The heat exchanger 88a includes a heat transfer medium.The heat transfer medium is designed to extract thermal energy from the compressed delivery gas 104a flowing in the delivery gas line 60a. The heat transfer medium is designed to supply this thermal energy to another system. The heat exchanger 88a is designed to supply the thermal energy extracted from the delivery gas 104a to another system, in particular a heating system. For example, the heating system can be configured as a heating system 90a for building 12a. The heating system 90a can, for example, be designed to provide hot water and / or heating energy for building 12a. The heating system 90a is preferably configured as a heating system for building 12a known from the prior art.

[0063] The return section 52a includes a further heat exchanger 98a. The heat exchanger 98a is integrated into the return section 52a. The heat exchanger 98a is located in an upper region of the return section 52a, facing the fluid reservoir 14a. The heat exchanger 98a is designed to supply thermal energy to the fluid mixture flowing through the return section 52a, in particular to the conveyed fluid. The heat exchanger 98a is preferably supplied with thermal energy from the first heat exchanger 88a. The heat exchanger 98a is preferably only activated in an operating condition in which the thermal energy that can be transferred from the environment to the conveyed gas is no longer sufficient to heat the conveyed gas 104a sufficiently for it to expand in order to convey the fluid 100a.The heat exchanger 98a allows additional thermal energy to be supplied to the conveying gas 104a, which is needed for volume work, i.e. for expanding the conveying gas 104a and thus for conveying the fluid 100a to be conveyed.

[0064] The energy conversion device 10a includes a control unit 92a. The control unit 92a is intended for operating the energy conversion device 10a. A method for operating the energy conversion device 10a will be briefly described below. The control unit 92a controls the energy conversion device 10a. The control unit 92a regulates the flow of fluid 100a, which is supplied from the fluid reservoir 14a to the turbine 22a via the flow line 20a, through the fluid valve 94a. The fluid 100a exits the nozzle 28a of the turbine 22a at the end of the flow line 20a and strikes the impellers 26a of the impeller 26a. Due to the geodetic height that the fluid reservoir 14a has relative to the turbine 22a, the fluid 100a has a high pressure in the area of ​​the nozzle 28a and flows at a high speed onto the impeller wheels 26a of the turbine wheel 24a.The pressure of fluid 100a at nozzle 28a is greater than the pressure in pressure vessel 30a, which is created by the pressurized gas 102a contained within it. The jet of fluid 100a exiting nozzle 28a drives turbine 22a and thus generator 48a. In this operating state, generator 48a produces an electric current through the rotation of turbine 22a. This electric current can be supplied to an energy storage unit or used directly to drive compressor 58a. After driving turbine 22a, fluid 100a collects at the bottom of pressure vessel 30a, in which turbine 22a is located. Due to the overpressure in pressure vessel 30a, fluid 100a is forced through fluid outlet 40a into the first line section 54a. The fluid 100a is forced upwards in the return section 52a by the pressure of 3 bar in the interior of the pressure vessel 30a.The compressor 58a is driven, preferably by means of the electric current generated by the generator 48a of the turbine 22a. The compressor 58a draws in ambient air and compresses it into a compressed delivery gas 104a. The compressed delivery gas 104a is discharged via the delivery gas line 60a of the compressor and mixing unit 56a. The heat exchanger 88a extracts thermal energy from the delivery gas 104a flowing in the delivery gas line 60a. The thermal energy extracted by the heat exchanger 88a is supplied to the heating system 90a.

[0065] The mixing valve 62a of the compressor and mixing unit 56a mixes the fluid 100a flowing from the first line section 54a and the pressurized delivery gas 104a flowing from the delivery gas line 60a. The fluid 100a and the delivery gas 104a are mixed by the mixing valve 62a in a 1:1 ratio. A defined volume of fluid 100a and an equal volume of delivery gas 104a flow alternately from the fluid outlet 68a of the mixing valve 62a. During operation, the mixing ratio of the mixing valve 62a can be adjusted by means of the control unit 92a. The mixture of pressurized fluid 100a and pressurized delivery gas 104a flows into the second line section 70a, specifically into the individual lines 72a and 74a. In the individual lines 72a, 74a, a volume of fluid 100a and a volume of conveying gas 104a flow alternately.In individual lines 72a and 74a, the fluid 100a flows with pockets of conveying gas 104a enclosed between it. The fluid 100a and the conveying gas 104a flow in the return section 52a, which leads upwards towards the fluid reservoir 14a, in individual lines 72a and 74a. The pressure in the pressure vessel 30a, acting on the returned fluid 100a, forces it to a defined height. In individual lines 74a and 74a, the conveying gas 104a, which is enclosed between volumes of fluid 100a, pushes the fluid 100a upwards in individual lines 72a and 74a of the second line section 70a due to its buoyancy. The conveyed fluid 104a cannot flow past the liquid fluid 100a being conveyed due to the narrow inner diameter of the individual lines 72a and 74a. As it rises in the individual lines 72a and 74a, the conveyed gas 104a expands due to the decreasing pressure.The incompressible fluid 100a to be pumped does not expand. As a result, the fluid 100a is pumped faster as it progresses further up the individual lines 72a and 74a of the second line section 70a due to the expansion of the conveying gas 104a. The expanding and rising conveying gas 104a carries the fluid 100a back down through the individual lines 72a and 74a to the fluid reservoir 14a. There, the fluid 100a is collected again and can be fed back to the turbine 22a via the gravity line 20a, where the process described above is repeated.

[0066] The conveying gas 104a flowing in the return section 52a, particularly in the individual lines 72a and 74a downstream of the compressor and mixing unit 56a, expands due to the decreasing pressure as it rises towards the fluid reservoir 14a. This expansion of the conveying gas 104a as it rises in the individual lines 72a and 74a further reduces its temperature. In an advantageous embodiment, the individual lines 72a and 74a of the second line section 70a of the return section 52a can be used for cooling. For this purpose, heat exchangers could be integrated into each of the second line section, supplying thermal energy to the conveying gas 104a flowing in the individual lines 72a and 74a, thereby, for example, providing cool air to an air conditioning system for building 12a.The conveyed gas 104a in the return section 52a expands because the pressure on the individual conveyed gas bubbles decreases towards the top and / or work is performed. As a result, the conveyed gas 104a cools down. If the conveyed gas 104a cools below the temperature of the fluid 100a being conveyed, heat exchange occurs between the fluid 100a being conveyed and the conveyed gas 104a. Heat exchange also occurs via the material of the individual lines 72a, 74a of the return section 52a if the conveyed gas 104a and / or the fluid 100a being conveyed is colder than the environment outside the return section 52a. Thus, energy, in particular thermal energy, is transferred. Therefore, when work is performed, i.e., when the conveyed gas 104a expands, energy is continuously supplied as the conveyed gas 104a cools down accordingly.This cools the fluid 100a being pumped, which is in constant contact with the conveying gas 104a, and the individual lines 72a and 74a of the return section 52a. The individual lines 72a and 74a of the return section 52a are heated by the outside of the individual lines 72a and 74a, for example, by the ambient air. Optionally, as described previously, additional thermal energy can be supplied in the upper section of the return section 52a via the heat exchanger 98a. This heats the fluid 100a being pumped and the conveying gas 104a. The conveying gas 104a can then expand further. Thus, some of the energy required for the work done in the volume is transferred to the system in the return section 52a. This increases the potential energy.Because the energy for the volume work in the first section of the return section 52a is supplied from the environment and from the stored energy in the fluid being pumped, and is almost completely supplied at the appropriate velocity within the return section 52a over a corresponding period of time, a virtually isothermal expansion occurs. A certain temperature difference must always be present for heat exchange to take place. This is still available through the heat exchanger 88a and its extraction of thermal energy after compression. This thermal energy can be supplied to the return section 52a in the final section via the further heat exchanger 98a. The previously exhausted potential of the volume work and its isothermal expansion, which was powered by external thermal energy, now has an even higher temperature potential available.When the fluid / gas mixture is heated, additional energy is supplied to the return section 52a. This causes the temperature of the conveyed gas 104a to rise, leading to further expansion. Some of this supplied heat energy remains as a higher fluid temperature. The remaining energy is absorbed by the conveyed gas 104a if the expansion has not completely absorbed it. Otherwise, this energy is also fully utilized during the expansion and is reflected in the increased potential energy for the fluid reservoir 14a. Through this process, energy in the form of heat is converted into potential energy. Consequently, ambient heat can be converted into mechanical and then into electrical energy.

[0067] In principle, it would also be conceivable that the conveying gas 104a, instead of being drawn from ambient air, could be configured as a refrigerant. This would allow a particularly large amount of thermal energy to be transferred from the environment when the conveying gas 104a, configured as a refrigerant, evaporates before or after the mixing valve 62a, since the conveying gas 104a cools down significantly, resulting in a very high temperature gradient between the conveying gas 104a and the environment. This would have a particularly positive effect on the volume work, i.e., on the expansion of the conveying gas 104a, and thus improve the conveying of the fluid 100a.

[0068] Alternatively, the pressure vessel 52a, with its components, could be located not in a basement room of building 12a, but at the bottom of a shaft provided for the energy conversion device. This shaft could be located in the ground, preferably directly beneath or adjacent to building 12a. The shaft is preferably more than 10 meters deep, and preferably more than 50 meters deep. A depth of more than 100 meters is also conceivable. The compressor and mixing unit 56a is located at the bottom of the shaft together with the pressure vessel 52a. The mixing valve 62a is also located at the bottom of the shaft. The compressor 58a is also preferably located at the bottom of the shaft together with the pressure vessel 52a.Advantageously, the pressure vessel 52a, the compressor and mixing unit 52a (i.e., the mixing valve 62a), and / or the compressor 58a would be designed as a single assembly module that can be lowered into the shaft together. The corresponding lines, i.e., the return line 52a, as well as the downpipe 20a and electrical lines 50a, are routed within the shaft to the respective components, i.e., the pressure vessel 52a and the compressor and mixing unit 52a.

[0069] In the Figures 3 and 4 A further embodiment of the invention is shown. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby, with regard to identically designated components, in particular components with the same reference numerals, reference is also generally made to the drawings and / or the description of the other embodiments, in particular the Fig. 1 and 2, can be referenced. To distinguish the embodiments, the letter a is the reference numeral of the embodiment in Fig. 1 and 2 recreated. In the exemplary embodiment of the Fig. 2 and 3 The letter a is replaced by the letter b.

[0070] The Figures 3 and 4 Figure 1 shows a second embodiment of the energy conversion device according to the invention. The energy conversion device 10b is designed as a fluid power plant device. The energy conversion device 10b is designed as an energy storage device. The energy conversion device 10b designed as an energy storage device is intended to store energy in the form of potential energy of a fluid 100b in a fluid reservoir 14b and to convert it into electrical energy when required. The energy conversion device 10b is shown, by way of example, mounted on a mountain 96b.

[0071] The energy conversion device 10b includes the fluid reservoir 14b for storing the fluid 100b. The fluid 100b is provided for operating the energy conversion device 10b. The fluid 100b is preferably approximately incompressible. The fluid 100b is a liquid. Preferably, the fluid 100b is water. The fluid reservoir 14b is designed as a reservoir. The fluid reservoir 14b is arranged on the mountain 96b. The fluid reservoir 14b is preferably arranged at least at a reservoir height of 2000 m on the mountain. The fluid reservoir 14b has, by way of example, a capacity of 10,000 m³.

[0072] Fluid reservoir 14b has a fluid inlet 18b. The fluid 100b, in liquid form, can be pumped back into fluid reservoir 14b through the fluid inlet 18b. The energy conversion device 10b has a drop line 20b. The drop line 20b is connected to fluid reservoir 14b. The drop line 20b is connected to the fluid outlet 18b of fluid reservoir 14b. The fluid 100b can flow out of fluid reservoir 14b via the drop line 20b. The energy conversion device 10b has a fluid valve 94b, which is arranged in the drop line 20b.

[0073] The energy conversion device 10b includes a turbine 22b. The turbine 22b is connected downstream of the gravity pipe 20b. The turbine 22b is designed to convert the kinetic energy of the fluid 100b, which is supplied to the turbine 22b from the fluid reservoir 14b via the gravity pipe 20b, into rotational energy. The turbine 22b is located vertically below the fluid reservoir 14b. The turbine 22b is located in a basement of building 12b. The turbine 22b is located 2000 meters below the fluid reservoir 14b, measured vertically.

[0074] The energy conversion device 10b includes a pressure vessel 30b. The pressure vessel 30b is distinct from the turbine housing 22b. The pressure vessel 30b is designed to collect the fluid 100b after it has driven the turbine 22b. The pressure vessel 30b forms a closed interior space. The pressure vessel 30b has a capacity of 100 m³. In principle, it would be conceivable for the pressure vessel 30b to have a capacity of 30 m³ to 1000 m³. The exact size of the pressure vessel 30b depends in particular on the size of the entire energy conversion device 10b, especially on the geodetic height of the fluid reservoir 10b relative to the turbine 22b and the volume of fluid 100b to be processed per minute. The pressure vessel 30b is designed to be pressurized during operation. The pressure vessel 30b is under overpressure in an operating state.Pressure vessel 30b is under a higher overpressure than the immediate ambient air pressure. The overpressure in pressure vessel 30b is 40 bar. Depending on the geodetic height at which the fluid reservoir 14b is located above the turbine 22b, the overpressure can range between 10 bar and 200 bar above ambient pressure.

[0075] To generate the overpressure in the pressure vessel 30b, a gas 102b is arranged in the pressure vessel 30b. The gas 102b has a density of less than 1.2 kg / m³. Preferably, the gas 102b has a density of approximately 0.1785 kg / m³. The gas 102b is preferably helium. To generate and maintain the overpressure in the pressure vessel 30b, the energy conversion device 10b has a gas reservoir 42b.

[0076] The energy conversion device 10b includes a generator 48b. The generator 48b is designed as an electric generator. The generator 48b is intended to convert a rotational motion of the output shaft of the turbine 22b into electrical energy. The generator 48b is arranged in the pressure vessel 30b. The generator 48b has electrical conductors 50b through which an electric current generated by the generator 48b can flow. The electrical conductors 50b of the generator 48b extend from the pressure vessel 30b below a minimum fluid level 36b.

[0077] The energy conversion device 10b has a return section 52b. The return section 52b is designed to pump the fluid 100b collected in the pressure vessel 30b back into the fluid reservoir 14b. The return section 52b is designed to pump the fluid 100b above the geodetic height at which the fluid reservoir 14b is located above the pressure vessel 30b. The return section 52b is designed without a liquid pump. The return section 52b has a first line section 54b. The first line section 54b is directly connected to the pressure vessel 30b.

[0078] The return section 52b includes a compressor and mixing unit 56b. The compressor and mixing unit 56b is designed to provide a compressed conveying gas 104b. The conveying gas 104b is ambient air. The compressor and mixing unit 56b includes a compressor 58b. The compressor 58b is designed as a compressor. The compressor 58b is designed to compress the ambient air into a conveying gas 104b at a pressure of 40 bar. The compressor 58b compresses the conveying gas 104b to a pressure of 40 bar. Depending on the geodetic height at which the fluid reservoir 14b is located above the pressure vessel 30b, the pressure to which the compressor 58b must bring the conveying gas 104b can be between 10 bar and 200 bar. A delivery gas line 60b is connected to an outlet of the compressor 58b. The delivery gas line 60b is designed to convey the pressurized delivery gas 104b away from the compressor 58b.

[0079] The compressor and mixing unit 56b is designed to mix the return fluid 100b with the compressed delivery gas 104b. The compressor and mixing unit 56b includes a mixing valve 62b. The mixing valve 62b is designed to mix the return fluid 100b with the compressed delivery gas 104b. The mixing valve 62b is located between the first line section 54b of the return line 52b and the delivery gas line 60b. The mixing valve 62b is designed to mix the return fluid 100b and the compressed delivery gas 104b in a mixing ratio ranging from 30:1 to 1:30. The mixing valve 62b is advantageously designed in an operation to mix the return fluid 100b and the compressed conveying gas 104b in a mixing ratio of 1:1.

[0080] The return line 52b has a second line section 70b. The second line section 70b is arranged between the mixing valve 62b and the fluid reservoir 14b. The second line section 70b is arranged between the compressor and mixing unit 56b and the fluid reservoir 14b.

[0081] The return line 52b has several individual lines 72b, 74b. The individual lines 72b, 74b are connected downstream of the mixing valve 62b. The individual lines 72b, 74b are fed by the mixing valve 62b. The return line 52b has 1000 individual lines. Preferably, the number of individual lines 72b, 74b in the return line 52b is between 600 and 100,000. In principle, depending on the size of the energy conversion device 10b, a significantly larger number of individual lines would also be conceivable, for example, 1,000,000 individual lines 72b, 74b.

[0082] The individual conductors 72b, 74b each have an inner diameter that is less than 100 mm. Preferably, the individual conductors 72b, 74b have an inner diameter of 20 mm.

[0083] The energy conversion device 10b, designed as an energy storage device, includes a control unit 92b. The control unit 92b is intended for operating the energy conversion device 10b. A method for operating the energy conversion device 10b will be briefly described below. In particular, the differences between this method and the first embodiment will be described. Essentially, the operation of the energy conversion device 10b, designed as an energy storage device, is the same as for the first embodiment. The main difference is that the potential energy of the fluid 100b is not to be converted into thermal energy, but into electrical energy. The electrical energy generated by the turbine 22b is intended to be fed into a power grid.The energy conversion device 10b, designed as an energy storage device, operates in a two-phase system. In a first operating state, electrical energy is generated by draining the fluid 100b from the fluid reservoir 14b into the pressure vessel 30b, where the fluid 100b drives the turbine 22b. This electrical energy is fed into an electrical circuit. In a second operating state, following the first, the fluid 100b is pumped back into the fluid reservoir 14b. The compressor 58b is operated using electrical energy from a power grid, and the fluid 100b is thus pumped back into the fluid reservoir 14b by means of the compressed conveying gas 104b. The basic function is the same as in the first embodiment. Reference sign 10 Energy conversion device 58 compressor 12 Building 60 Gas pipeline 14 Fluid reservoir 62 Mixing valve 16 Fluid outlet 64 Fluid inlet 18 Fluid inlet 66 Fluid inlet 20 Case management 68 Fluid outlet 22 turbine 70 Pipe section 24 Turbine wheel 72 Individual line 26 paddle wheel 74 Individual line 28 nozzle 76 Pipe element 30 Pressure vessel 78 Pipe element 32 lower shell 80 Pipe element 34 upper shell 82 Pipe element 36 Fluid fill level 84 Pipe element 38 Fluid inlet 86 Pipe element 40 Fluid outlet 88 Heat exchanger 42 gas reservoir 90 heating system 44 Supply line 92 Control and regulation unit 46 Gas inlet 94 Fluid valve 48 generator 96 Mountain 50 Line 98 Heat exchanger 52 Return route 100 Fluid 54 Pipe section 102 gas 56 Compressor and mixing unit 104 Gas

Claims

1. Energy conversion device, in particular fluid power plant device, having a fluid reservoir (14a; 14b) for a storage a fluid (100a; 100b), having a fall pipe (20a; 20b) that is connected to the fluid reservoir (14a; 14b), having a turbine (22a; 22b) which is connected downstream of the fall pipe (20a; 20b) and is configured to convert a kinetic energy of the fluid (100a; 100b), which can be supplied to the turbine (22a; 22b) from the fluid reservoir (14a; 14b) via the fall pipe (20a; 20b), into a rotational movement of an output shaft of the turbine (22a; 22b), and having a generator (48a; 48b) which is configured to convert the rotational movement of the output shaft into an electrical energy, having a pressure vessel (30a; 30b), which is in particular realized differently from a housing of the turbine (22a; 22b) and in which a gas (102a; 102b) with an overpressure relative to the ambient air pressure, in particular of at least 0.2 bar, and the turbine (22a; 22b) are arranged at least partially, characterized by a reconveying section (52a; 52b) via which the fluid (100a; 100b) can be conveyed from the pressure vessel (30a; 30b) back into the fluid reservoir (14a; 14b), and wherein the energy conversion device further comprises a compressing and / or mixing unit (56a; 56b) configured to mix the fluid (100a; 100b) that is to be recirculated in the reconveying section (52a; 52b) with a compressed conveying gas (104a; 104b), wherein the reconveying section (52a; 52b) comprises a plurality of individual conduits (72a, 74a; 72b, 74b) which are connected downstream of a mixing valve (62a; 62b) and are supplied by the latter.

2. Energy conversion device according to claim 1, characterized in that the gas (102a; 102b) has a density of less than 1.2 kg / m3, and is in particular embodied as helium.

3. Energy conversion device according to claim 1 or 2, characterized in that the turbine (22a; 22b) is realized as a Pelton turbine.

4. Energy conversion device according to any one of the preceding claims, characterized in that the compressing and / or mixing unit (56a; 56b) comprises the mixing valve (62a; 62b), which is configured to mix the fluid (100a; 100b) that is to be reconveyed with the compressed conveying gas (104a; 104b).

5. Energy conversion device according to any one of the preceding claims, characterized in that the compressing and / or mixing unit (56a; 56b) comprises the mixing valve (62a; 62b), which is configured to mix the fluid that is to be reconveyed (100a; 100b) and the compressed conveying gas (104a; 104b) in a mixing ratio that lies in a range from 30:1 to 1:30.

6. Energy conversion device according to any one of the preceding claims, characterized in that the compressing and / or mixing unit (56a; 56b) comprises the mixing valve (62a; 62b), the mixing ratio of which is variably adjustable.

7. Energy conversion device according to any one of the preceding claims, characterized in that the plurality of individual lines (72a, 74a; 72b, 74b) each have an inner diameter that is smaller than 100 mm.

8. Energy conversion device according to any one of the preceding claims, characterized in that the electric generator (48a; 48b) driven by the turbine (22a; 22b) is arranged inside the pressure vessel (30a; 30b).

9. Energy conversion device according to any one of the preceding claims, characterized in that the generator (48a; 48b) comprises electric lines (50a; 50b), which are guided out of the pressure vessel (30a; 30b) below a minimum fluid filling level (36a; 36b).

10. Energy conversion device according to any one of the preceding claims, characterized in that the compressing and / or mixing unit (56a; 56b) comprises a compressor (58a; 58b), which is configured to compress the compressed conveying gas (104a; 104b) and is connected upstream of the mixing valve (62a; 62b).

11. Energy conversion device according to any one of the preceding claims, characterized in that the reconveying section (52a; 52b) comprises a heat exchanger (88a), which is arranged between a compressor (58a) and a mixing valve (62a; 62b) and is configured to extract thermal energy from the compressed conveying gas (104a; 104b).

12. Energy conversion device according to any one of the preceding claims, characterized in that the reconveying section (52a; 52b) comprises a heat exchanger (98a), which is arranged in an upper region, in particular an upper third of the reconveying section (52a; 52b), and is configured, in at least one operation state, to supply thermal energy to the flowing conveying gas (104a; 104b).

13. Method for operating an energy conversion device according to any one of the preceding claims, characterized in that in one method step, a fluid (100a; 100b) is reconveyed from the pressure vessel (30a; 30b) into the fluid reservoir (14a; 14b) by a pressure prevailing in the pressure vessel (30a; 30b) and by mixing with a conveying gas (104a; 104b) that is under pressure.

14. Method according to claim 13, characterized in that in one method step, a thermal energy produced during compression of the conveying gas (104a; 104b) is extracted from the compressed conveying gas (104a; 104b) for further utilization.

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