WO2023109987A1

WO2023109987A1 - Bulk battery

Info

Publication number: WO2023109987A1
Application number: PCT/CZ2022/050085
Authority: WO
Inventors: Daniel Gelnar; Jan Diviš; Jiří ZEGZULKA; Jan Nečas
Original assignee: Vysoká Škola Báňská - Technická Univerzita Ostrava
Priority date: 2022-09-02
Filing date: 2022-09-02
Publication date: 2023-06-22

Abstract

The invention relates to a bulk battery for a reversible conversion of electrical energy into a combination of potential and kinetic energy of bulk material, comprising a support structure (1) comprising at least one upper hopper (3) for storing the bulk material, positioned above at least one lower hopper (2) for storing the bulk material. Each lower hopper (2) has a lower discharge cap (6) at its lower part and each upper hopper (3) has an upper discharge cap (7) at its lower part. In the direction of circulation of the bulk material, at least one conveying device (5), which is connected to a power source and suitable for conveying the bulk material from the lower hopper (2) to the upper hopper (3) and for converting electrical energy into a combination of potential and kinetic energy of the bulk material, is arranged between at least one lower hopper (2) and at least one upper hopper (3). Further, in the direction of circulation of the bulk material, at least one generator (4, 10, 11, 12, 13), which is connected to a power grid or a battery and suitable for converting the combination of potential and kinetic energy of the bulk material into electrical energy, is arranged between at least one upper hopper (3) and at least one lower hopper (2). The lower discharge cap (6), the upper discharge cap (7), the conveying device (5) and the generator (4, 10, 11, 12, 13) are connected to a control unit (14). The invention further relates to a method of converting electrical energy into a combination of potential and kinetic energy of bulk material, a method of converting a combination of potential and kinetic energy of bulk material into electrical energy, a method for preheating and/or drying material to be torrefied, a method for heating an external torrefaction reactor (17), use of the bulk battery for torrefying bulk material, and a corresponding computer program [product], a computer-readable storage medium, and a data carrier signal.

Description

Bulk battery

The present invention relates to a bulk battery, in particular a bulk battery suitable for incorporation into a material torrefaction process. The newly proposed device falls by its design into the field of transport and storage equipment and by its use into the field of power generation, actively complementing in particular solar, wind and other power plants.

The prior art described below relates to various technologies, namely bulk storage, energy storage and thermal material processing.

Hoppers are generally devices that are used to store various materials. In practice, these devices are well known and widespread in various industries such as construction, agriculture, food processing, etc. They are usually placed above the ground level by means of beam structures and the earth's gravity is used to empty them, which allows, if the storage device is properly designed and set up, the spontaneous discharge of the material without the supply of additional energy. At the bottom of the hopper, there is a discharge cap equipped with a device for opening and closing the output. When the material is discharged from the hopper, the material has kinetic energy which is not currently used in these devices. Thus, the primary use of hoppers in the prior art is to store bulk material, which can then be returned to the production and use processes.

In addition, there is another problem with solar and wind power generation technology, namely that they generate renewable energy depending on the weather at a time when it is usually not needed to be distributed to customers. This surplus energy needs to be stored somewhere until the time of consumption, thus protecting the distribution system from overloading in times of surplus energy.

Furthermore, low-temperature pyrolysis, also called torrefaction (roasting), can be included among the technologies of material torrefaction and pyrolysis, which is a thermal treatment of input material in an inert atmosphere, i. e. heating the material without access of air. In the field of design and technology, plants are known with different types of reactors with a stationary layer (batch), continuous, where the input material is fed into the technology where continuous processing as well as a continuous production of products over time occurs. Different types of integration into the technological process are also known, where for example, hoppers and discharge and dosing equipment are installed before the actual input into the technology. From a design point of view, this is always a device which includes, among other things, a hopper and a storage section where the material is stored and transported to the reactor itself.

The Czech patent CZ 307918 B6 describes a device for reducing the effects of abrasive flow of bulk material, which includes a paddle wheel. Said device is a modular system wherein at least one paddle wheel, at least one torque sensor and speed sensor are disposed in a housing on at least one shaft, wherein at least one output of the speed sensor and one output of the torque sensor are coupled to at least one first input of a control unit. For a larger number of paddle wheels, these may be placed side by side and/or one on top of another in the housing. Further, a coupling is provided in the housing on at least one of said shafts to connect said shaft to at least one shaft of at least one brake torque generator which is located outside the housing. The brake torque generator has the function of converting the rotational motion of the paddle wheel into electrical and/or thermal energy, and also has the function of controlling the dynamic flow of the bulk material by resistively braking the generator. In addition, holes are formed in the walls of the housing for mounting the bearing housings, which are attached to the housing by means of bolted connections. The shaft of the paddle wheel passes through the bearing housings, and at the same time the brake torque generator is fixed to the outside of the housing wall by screw brackets.

The disadvantage of the invention disclosed in CZ 307918 B6 is that it does not allow reversible conversion of electrical energy into a combination of potential and kinetic energy of the bulk material, but only unidirectional conversion of the combination of potential and kinetic energy of the bulk material into electrical energy by gravity of the bulk material through the paddle wheel generator.

Thus, in the prior art, there is a need to provide a device and method for reversible conversion of electrical energy into a combination of potential and kinetic energy of bulk material, i. e. for storing unused electrical energy in a structurally and materially inexpensive battery.

It is an object of the present invention to provide a device and method for storing unused electrical energy in a structurally and materially inexpensive battery.

The object of the invention is achieved by a bulk battery for a reversible conversion of electrical energy into a combination of potential and kinetic energy of bulk material, the bulk battery comprising a support structure comprising at least one upper hopper for storing the bulk material, positioned above at least one lower hopper for storing the bulk material. Each lower hopper has a lower discharge cap at its lower part, and each upper hopper has an upper discharge cap at its lower part. In the direction of circulation of the bulk material, at least one conveying device, which is connected to a power source (e.g., a renewable or non-renewable energy source) and suitable for conveying the bulk material from the lower hopper to the upper hopper and for converting electrical energy into a combination of potential and kinetic energy of the bulk material, is arranged between at least one lower hopper and at least one upper hopper. Further, in the direction of circulation of the bulk material, at least one generator, which is connected to a power grid or a battery and suitable for converting the combination of potential and kinetic energy of the bulk material into electrical energy, is arranged between at least one upper hopper and at least one lower hopper. The lower discharge cap, the upper discharge cap, the conveying device and the generator are connected to a control unit, allowing remote and programmable control of the entire bulk battery and downstream systems.

To clarify the basic principle of energy conversion, kinetic energy means mechanical energy of moving bulk material relative to other parts of the bulk battery (e. g. relative to the generator) and potential energy means mechanical energy of bulk material located in the potential field of the gravitational force. With respect to the law of conservation of mechanical energy, there is a reversible transformation of kinetic and potential energy of bulk material, which includes the term of combination of the potential and kinetic energy of the bulk material.

The lower hopper may comprise at least one lower weight sensor connected to the control unit, and/or the upper hopper may comprise at least one upper weight sensor connected to the control unit. The weight sensors are used to record the amount of bulk material in each hopper at a given time.

The conveying device may be a circulation conveyor.

The generator may be selected from a group consisting of a paddle wheel generator, a bucket generator, a belt generator, a lift generator, a rotary storage generator, or a combination thereof. These generators are functionally equivalent.

The bulk battery may comprise at least two generators placed side by side and/or one on top of another to generate more power.

The bulk battery may comprise a bulk material input, preferably for a material to be torrefied, in the lower part of the conveying device, and a bulk material output, preferably for a material to be torrefied, under the lower discharge cap of at least one lower hopper, allowing the bulk battery to be incorporated into a method of torrefying bulk material.

The bulk battery may comprise a first heat exchanger between the conveying device and the generator, which allows waste heat generated by the operation of the conveying device to be transferred by means of the first heat exchanger to the bulk material passing through the generator, thereby preheating and/or drying the bulk material (e. g. bulk material to be torrefied).

The bulk battery may comprise a second heat exchanger between the conveying device and an external torrefaction reactor, allowing waste heat generated by operation of the conveying device to be transferred to the external torrefaction reactor by means of the second heat exchanger, thereby torrefying the bulk material to be torrefied.

The object of the invention is also achieved by a method of converting electrical energy into a combination of potential and kinetic energy of bulk material, using the bulk battery as described above, wherein at least one conveying device connected to a power source is powered by electrical energy and transports bulk material from a lower hopper with an open lower discharge cap to an upper hopper with a closed upper discharge cap, thereby converting electrical energy into a combination of potential and kinetic energy of the bulk material.

The object of the invention is also achieved by a method of converting a combination of potential and kinetic energy of bulk material into electrical energy, using the bulk battery as described above, wherein at least one generator connected to a power grid or a battery generates electrical energy and, with the participation of gravity fall of the bulk material, transports the bulk material from an upper hopper with an open upper discharge cap to a lower hopper with a closed lower discharge cap, thereby converting the combination of potential and kinetic energy of the bulk material into electrical energy.

In the context of the torrefaction process, the object of the invention is also achieved by a method for preheating and/or drying material to be torrefied, using the bulk battery comprising a bulk material input in the lower part of the conveying device, a bulk material output under the lower discharge cap of at least one lower hopper, a first heat exchanger between the conveying device and the generator, and optionally a second heat exchanger between the conveying device and the external torrefaction reactor. In this method, at least one conveying device and at least one generator are in operation, wherein waste heat generated by the operation of the conveying device is transferred by means of the first heat exchanger to the bulk material passing through the generator, whereby the bulk material is preheated and/or dried.

In the context of the torrefaction process, the object of the invention is also achieved by a method for heating an external torrefaction reactor, using the bulk battery comprising a bulk material input in the lower part of the conveying device, a bulk material output under the lower discharge cap of at least one lower hopper, a first heat exchanger between the conveying device and the generator, and a second heat exchanger between the conveying device and the external torrefaction reactor. In this method, at least one conveying device and at least one generator are in operation, wherein waste heat generated by the operation of the conveying device is transferred to the external torrefaction reactor by means of a second heat exchanger, whereby the bulk material to be torrefied is torrefied.

In the context of the torrefaction process, the object of the invention is also achieved by use of the bulk battery comprising a bulk material input in the lower part of the conveying device, a bulk material output under the lower discharge cap of at least one lower hopper, optionally a first heat exchanger between the conveying device and the generator, and optionally a second heat exchanger between the conveying device and the external torrefaction reactor, for torrefying bulk material.

The object of the invention is also achieved by a computer program [product] comprising instructions to cause the bulk battery as described above to execute the steps of the above-described method of converting electrical energy into a combination of potential and kinetic energy of bulk material, or the steps of the above-described method of converting a combination of potential and kinetic energy of bulk material into electrical energy.

In the context of the torrefaction process, the object of the invention is also achieved by a computer program [product] comprising instructions to cause the bulk battery comprising a bulk material input in the lower part of the conveying device, a bulk material output under the lower discharge cap of at least one lower hopper, optionally a first heat exchanger between the conveying device and the generator, and optionally a second heat exchanger between the conveying device and the external torrefaction reactor, to execute the steps of the above-described method for preheating and/or drying material to be torrefied or the steps of the above-described method for heating the external torrefaction reactor.

The object of the invention is also achieved by a computer-readable storage medium having stored thereon the above-described computer program [product], or a data carrier signal carrying the above-described computer program [product].

The bulk battery is a supplementary device in the production of electrical energy and is used to store energy not currently used. The device has a support structure in which at least two identical storage hoppers are arranged one above the other. Further, there is at least one generator between said hoppers, which converts kinetic energy into electrical energy. These hoppers are connected to each other by at least one conveying device, which provides circulation of the bulk material between the hoppers. The hopper discharges are fitted with discharge caps to control the flow of the bulk material. Furthermore, the hoppers are equipped with at least three weight sensors for determining the quantity of material inside the hopper. At least one conveying device, at least two discharge caps, at least one generator, at least two weight sensors are connected to a control unit which is further connected to a power generation and to a distribution electrical grid or an electrical battery for storing electrical energy.

At least one lower hopper is filled with circulating bulk material, such as sand. If surplus energy is produced in power plants and needs to be stored, the bulk material is moved from at least one lower hopper to at least one upper hopper by means of at least one conveying device, based on the evaluation of the control unit. If the energy from the power plants is to be distributed to customers, the bulk material is discharged from at least one upper hopper to at least one lower hopper by means of at least one generator for converting kinetic energy to electrical energy and the control unit passes this electrical energy on to the distribution network.

The proposed device is therefore used to store such surplus energy in the bulk material. This surplus energy powers a conveying device (a circulating conveyor) that transports the bulk material to the upper hopper(s), and at times of electrical demand, this bulk material is discharged from the upper hopper(s) and the kinetic energy of this bulk material is converted into electrical energy during the flowing process via the generator. The device therefore serves to store unconsumed energy produced and protects the distribution system from overloading in times of surplus energy.

In the proposed device, the primary function is not to store and return the bulk material back into the process, but to use it as a circulating medium for energy storage. The energy stored in the bulk material is converted from kinetic energy to electrical energy when it is discharged back from the hopper by the generator located below the hopper.

The main advantage of this invention is the innovative way of storing electrical energy in the bulk material, which brings new possibilities for extending the applicability of, for example, solar or wind power generation systems. These systems do not always produce electricity when it is needed, and it is therefore important to store this energy. The surplus electrical energy produced also threatens the distribution grid when it is saturated, and this problem is also addressed by the proposed device that extracts this energy and stabilises the whole process of distributing electricity to consumers. Another advantage is the modular design of the device.

When transporting bulk material, a certain amount of waste heat is generated on the conveyors. This heat can be transferred by a first heat exchanger to the generator to partially dry the bulk material, and some of the heat can also be also transferred by a second heat exchanger to preheat an external torrefaction reactor.

The material in the bulk battery is therefore not only used to store energy as such, but also serves as a reservoir of material for torrefaction, where this material is also pre-dried (reducing moisture content) by the waste heat generated and thus saving on the energy required to conduct the torrefaction process. Otherwise, the material would have to be held longer in the torrefaction reactor or heated to a higher temperature.

The underlying idea of the invention is further explained by exemplary embodiments, which are described using the accompanying drawings.

Fig.1

shows a block diagram of an exemplary device when being charged by renewable power according to example 1.

Fig.2

shows a block diagram of an exemplary device when being charged by a distribution network according to example 1.

Fig.3

shows a structure of an exemplary device when being discharged according to example 1.

Fig.4

Fig.5

shows a diagram of an exemplary device according to example 1.

Fig.6

shows a diagram of an exemplary device according to example 2.

Fig.7

shows a diagram of an exemplary device according to example 3.

Fig.8

shows a diagram of an exemplary device according to example 4.

Fig.9

shows a diagram of an exemplary device according to example 5.

Fig.10

shows a block diagram of an exemplary device when being charged by renewable power according to example 6.

Fig.11

shows a block diagram of an exemplary device when being charged by a distribution network according to example 6.

Fig.12

shows a structure of an exemplary device when being discharged according to example 6.

Fig.13

Fig.14

shows a diagram of an exemplary device according to example 6.

Fig.15

shows a diagram of an exemplary device according to example 7.

Fig.16

shows a diagram of an exemplary device according to example 8.

Fig.17

shows a diagram of an exemplary device according to example 9.

Fig.18

shows a diagram of an exemplary device according to example 10.

Examples

The invention will be further explained by reference to exemplary embodiments with reference to the relevant drawings.

Example 1

The device for storing electrical energy in bulk material according to example 1 (figures 1 to 5) comprises a support frame 1 to which are attached, via brackets with at least three lower weight sensors 8, at least one lower hopper 2 fitted with a lower discharge cap 6 below the lower hopper and, via brackets with at least three upper weight sensors 9, at least one upper hopper 3 fitted with an upper discharge cap 6 below the upper hopper. At least one paddle wheel generator 4 is connected to the output of the upper hopper 3 and the input of the lower hopper 2. At least one circulation conveyor 5 is connected to the output of the lower hopper 2 and the input of the upper hopper 3.

During charging of the device (figures 1 and 2), the lower discharge cap 6 of the lower hopper 2 is opened by a signal from the control unit 14 and the bulk material from the lower hopper 2 is conveyed by the circulation conveyor 5, supplied with energy from external sources, to the upper hopper 3 until the lower weight sensors 8 of the lower hopper 2 measure an empty state.

During discharging of the device (figures 3 and 4), the upper discharge cap 7 of the upper hopper 3 is opened by a signal from the control unit 14 and the bulk material is flown from the upper hopper 3 by gravity through the paddle wheel generator 4 into the lower hopper 2 until the upper weight sensors 9 of the upper hopper 3 measure an empty state. The flow of the bulk material over the paddles of the generator 4 consumes the kinetic energy of the flow of the bulk material as the rotation of the paddle wheel generator 4 generates electrical energy and supplies it to the electrical distribution network during the discharge process.

Example 2

The device according to example 2 ( ) differs from the device described in example 1 in that the paddle wheel generator 4 is replaced by a bucket generator 10.

Example 3

The device according to example 3 ( ) differs from the device described in example 1 in that the paddle wheel generator 4 is replaced by a belt generator 11.

Example 4

The device according to example 4 ( ) differs from the device described in example 1 in that the paddle wheel generator 4 is replaced by a lift generator 12.

Example 5

The device according to example 5 ( ) differs from the device described in example 1 in that a rotary storage generator 13 is combined with and added to the paddle wheel generator 4. The paddle wheel generator 4 may be located above and/or below the rotary storage generator 13.

Example 6

The device for storing electrical energy in bulk material, according to example 6 (figures 10 to 14), differs from the device described in example 1 only by the addition of a first heat exchanger 15 between the conveying device 5 and the paddle wheel generator 4 for transferring the waste heat generated by the operation of the conveying device 5 to the bulk material passing through the paddle wheel generator 4, whereby the bulk material can be preheated and/or dried, and further by the addition of a second heat exchanger 16 between the conveying device 5 and the external torrefaction reactor 17 for transferring the waste heat generated by the operation of the conveying device 5 to the bulk material to be torrefied and located in the external torrefaction reactor 17, whereby the bulk material can be torrefied.

Example 7

The device according to example 7 ( ) differs from the device described in example 6 in that the paddle wheel generator 4 is replaced by a bucket generator 10.

Example 8

The device according to example 8 ( ) differs from the device described in example 6 in that the paddle wheel generator 4 is replaced by a belt generator 11.

Example 9

The device according to example 9 ( ) differs from the device described in example 6 in that the paddle wheel generator 4 is replaced by a lift generator 12.

Example 10

The apparatus according to example 10 ( ) differs from the device described in example 6 in that a rotary storage generator 13 is combined with and added to the paddle wheel generator 4. The paddle wheel generator 4 may be located above and/or below the rotary storage generator 13.

The device described above is applicable in energy industry wherever electricity is generated and needs to be stored in times of surplus and non-usability and distributed in times of need. The device can also be used for the validation and calibration of DEM dynamic process simulations (DEM = discrete element method), which are useful for the improvement of bulk generators.

1 support structure

2 lower hopper

3 upper hopper

4 paddle wheel generator

5 conveying device, circulating conveyor

6 lower discharge cap

7 upper discharge cap

8 lower weight sensor

9 upper weight sensor

10 bucket generator

11 belt generator

12 lift generator

13 rotary storage generator

14 control unit

15 first heat exchanger

16 second heat exchanger

17 external torrefaction reactor

18 bulk material input

19 bulk material output

Claims

A bulk battery for a reversible conversion of electrical energy into a combination of potential and kinetic energy of bulk material, characterized in that it comprises a support structure (1) comprising at least one upper hopper (3) for storing the bulk material, positioned above at least one lower hopper (2) for storing the bulk material, each lower hopper (2) having a lower discharge cap (6) at its lower part and each upper hopper (3) having an upper discharge cap (7) at its lower part, wherein in the direction of circulation of the bulk material, at least one conveying device (5), which is connected to a power source and suitable for conveying the bulk material from the lower hopper (2) to the upper hopper (3) and for converting electrical energy into a combination of potential and kinetic energy of the bulk material, is arranged between at least one lower hopper (2) and at least one upper hopper (3), wherein in the direction of circulation of the bulk material, at least one generator (4, 10, 11, 12, 13), which is connected to a power grid or a battery and suitable for converting the combination of potential and kinetic energy of the bulk material into electrical energy, is arranged between at least one upper hopper (3) and at least one lower hopper (2), wherein the lower discharge cap (6), the upper discharge cap (7), the conveying device (5) and the generator (4, 10, 11, 12, 13) are connected to a control unit (14).
The bulk battery according to claim 1, characterized in that the lower hopper (2) comprises at least one lower weight sensor (8) connected to the control unit (14), and/or the upper hopper (3) comprises at least one upper weight sensor (9) connected to the control unit (14).
The bulk battery according to claim 1 or 2, characterized in that the conveying device (5) is a circulation conveyor (5).
The bulk battery according to any of the preceding claims, characterized in that the generator (4, 10, 11, 12, 13) is selected from the group consisting of a paddle wheel generator (4), a bucket generator (10), a belt generator (11), a lift generator (12), a rotary storage generator (13), or a combination thereof.
The bulk battery according to any of the preceding claims, characterized in that it comprises at least two generators (4, 10, 11, 12, 13) placed side by side and/or one on top of another.
The bulk battery according to any of the preceding claims, characterized in that it comprises a bulk material input (18), preferably for a material to be torrefied, in the lower part of the conveying device (5), and a bulk material output (19), preferably for a material to be torrefied, under the lower discharge cap (6) of at least one lower hopper (2).
The bulk battery according to any of the preceding claims, for preheating or drying bulk material, characterized in that it comprises a first heat exchanger (15) between the conveying device (5) and the generator (4, 10, 11, 12, 13).
The bulk battery according to any of the preceding claims, for heating an external torrefaction reactor (17), characterized in that it comprises a second heat exchanger (16) between the conveying device (5) and the external torrefaction reactor (17).
A method of converting electrical energy into a combination of potential and kinetic energy of bulk material, using the bulk battery according to any of the preceding claims, characterized in that at least one conveying device (5) connected to a power source is powered by electrical energy and transports bulk material from a lower hopper (2) with an open lower discharge cap (6) to an upper hopper (3) with a closed upper discharge cap (7), thereby converting electrical energy into a combination of potential and kinetic energy of the bulk material.
A method of converting a combination of potential and kinetic energy of bulk material into electrical energy, using the bulk battery according to any of the preceding claims, characterized in that at least one generator (4, 10, 11, 12, 13) connected to a power grid or a battery generates electrical energy and, with the participation of gravity fall of the bulk material, transports the bulk material from an upper hopper (3) with an open upper discharge cap (7) to a lower hopper (2) with a closed lower discharge cap (6), thereby converting the combination of potential and kinetic energy of the bulk material into electrical energy.
A method for preheating and/or drying material to be torrefied, using the bulk battery according to claim 7 dependent on claim 6, or according to claim 8 dependent on claims 6 and 7, characterized in that at least one conveying device (5) and at least one generator (4, 10, 11, 12, 13) are in operation, wherein waste heat generated by the operation of the conveying device (5) is transferred by means of the first heat exchanger (15) to the bulk material passing through the generator (4, 10, 11, 12, 13), whereby the bulk material is preheated and/or dried.
A method for heating an external torrefaction reactor (17), using the bulk battery according to claim 8 dependent on claims 6 and 7, characterized in that at least one conveying device (5) and at least one generator (4, 10, 11, 12, 13) are in operation, wherein waste heat generated by the operation of the conveying device (5) is transferred to the external torrefaction reactor (17) by means of a second heat exchanger (16), whereby the bulk material to be torrefied is torrefied.
Use of the bulk battery according to any of claims 6 to 8 for torrefying bulk material.
A computer program [product] comprising instructions to cause the bulk battery according to any of claims 1 to 8 to execute the steps of the method of claim 9 or 10, or to cause the bulk battery according to any of claims 6 to 8 to execute the steps of the method of claim 11 or 12.
A computer-readable storage medium having stored thereon the computer program [product] according to claim 14, or a data carrier signal carrying the computer program [product] according to claim 14.