EP3710758A1

EP3710758A1 - Heating module for a fluid heat exchanger and device for energy storage

Info

Publication number: EP3710758A1
Application number: EP18818977.3A
Authority: EP
Inventors: Dieter Schluckebier
Original assignee: B and S Entwicklungsgesellschaft Mbh
Current assignee: B and S Entwicklungsgesellschaft Mbh
Priority date: 2017-11-16
Filing date: 2018-11-02
Publication date: 2020-09-23
Also published as: WO2019096344A1; DE102017126959A1

Abstract

The invention relates to a heating module for a fluid heat exchanger, comprising alternating field generating means for generating an electromagnetic alternating field, a coupling element (4) for inductive coupling to the electromagnetic alternating field and a heat transfer volume (19) for heating the fluid heat exchanger, characterized in that at least one heat transfer element (5) is electrically connected in series with the coupling element (4) and is arranged within the heat transfer volume (19). The invention further relates to a device for energy storage, comprising a heat storage medium (9) and at least one circuit (12, 13) for a fluid heat exchanger, wherein the at least one circuit (12, 13) of the heat exchanger is designed such that the heat storage medium flows around and/or through the heat exchanger in order to supply heat into the heat storage medium (9) and/or to extract heat from the heat storage medium (9), characterized by a heating module (1) of the aforementioned type for heating the heat exchanger.

Description

Heating module for a fluid heat exchanger and device for energy storage

The invention relates to a heating module for inductive heating of a fluid according to the preamble of claim 1 and to a device for energy storage according to the preamble of claim 11.

The increasing use of renewable energies, such as solar or wind energy, poses major challenges to the energy system, in particular due to the fluctuating availability of these energy sources. It is tried, the temporally strongly fluctuating energy demand and the strongly fluctuating

Availability of renewable energy sources through intelligent networking

compensate. Intelligent networking to control power generators and electrical consumers in as large a geographical area as possible, such as Europe, can help secure energy supplies. However, energy storage is essential - especially with increasing share of renewable energy sources. Pumped storage are proven, but are not available anywhere and not in any extent available. Thus, additional storage capacities are required. Storage facilities based on

Battery technology is fundamentally an alternative, as plants up to 40 MWh have already been built and larger capacities are planned. However, battery systems are costly and polluting, especially because of the required raw material extraction. After their lifetime, batteries usually form toxic

Special waste containing heavy metals such as mercury, cadmium and lead. In addition, there is a certain operating hazard, as explosions, leaks and unwanted chemical reactions are difficult to exclude completely.

For a further alternative form of energy storage, a thermoelectric approach is followed, in which excess electrical energy is induced by induction in

Heat energy is converted and stored in a heat storage. An operating according to this principle device for energy storage of the type mentioned above and a heating module suitable for this purpose are known from EP 28330290 B1. There, an energy storage device is disclosed, which at least one coupling element includes, which is inductively heated by means of a transformer circuit. A fluid heat exchanger, for example air, is heated directly in or on the coupling element and releases the absorbed heat to a heat storage medium, for example stones. The heat storage medium is in a thermally insulated

Storage that allows medium-term storage of heat content. The

Heat storage medium can be brought to a temperature of 1000 ° C and more, for example.

In a withdrawal cycle is over the same or another fluid

Heat exchanger, the heat removed from the memory and a consumer, for example, a heat-power coupling in the form of a steam turbine, supplied when a corresponding energy demand is detected at a consumer or in a connected power grid.

For purposes of heat input EP 2833092 B1 discloses, the

Revelation content is included in full extent, in a variant

arranged outside the memory heating module and a device for

Energy storage of the type mentioned. In the known heating module, an alternating electromagnetic field is generated in a primary coil and a

Coupling element is guided as a secondary winding around a magnetic core. The coupling element, for example in the form of a metallic tube, is also part of the circuit for the fluid heat exchanger and provides the

Heat transfer volume for heating the fluid heat exchanger for

Available. The heating takes place directly through the contact of the fluid

Heat exchanger with the walls of the coupling element.

The invention concerned here is the technical problem underlying a

Heating module of the aforementioned type and a device for

To provide energy storage of the type mentioned above, which have an improved over the prior art efficiency. In a heating module of the type mentioned, the technical problem with the characterizing features of claim 1 and in the device of the type mentioned above with the characterizing features of claim 11 is achieved.

The dependent claims relate to advantageous developments of

Invention.

Thus, to heat a fluid heat transfer medium, e.g. is provided for heating a heat storage medium, a heating module is used, which alternating field generating means for generating an electromagnetic

Alternating field, a coupling element for inductive coupling to the

electromagnetic alternating field and a heat transfer volume for heating the fluid heat exchanger comprises. According to the invention, the heating module has at least one heat transfer element, which is electrically connected in series with the coupling element and arranged within the heat transfer volume. Thus, the at least one heat transfer element is heated by means of the ohmic resistance of an electric current supplied via the coupling element. in the

Heat transfer volume flows around the fluid heat exchanger to the at least one heat transfer element and is heated in this way. Thus, a very effective heating of the heat exchanger can be achieved with high efficiency.

The heat transfer volume may be communicated to a fluid conduit system, e.g. With

Fluid line elements of a fluid circuit, be connected and surrounds the at least one heat transfer element, preferably with lateral walls, which extend between an inlet opening and an outlet opening for the fluid heat exchanger. Inlet opening and outlet opening may be smaller than the cross section in the cross-section perpendicular to the main direction of flow of the heat exchanger

Have heat transfer volume or even an equal or larger cross-sectional area. In the main flow direction is the beginning of the

Heat transfer volume defined by the cross section at which the

Heat exchanger can first hit the heat transfer element or at least one of the heat transfer elements. The end of the heat transfer volume is then defined accordingly by the cross section at which the heat exchanger can not touch the heat transfer element or at least one of the heat transfer elements for the first time.

The heating module according to the invention can be designed such that the alternating field generating means and at least one part of the coupling element at least partially circulating the alternating field generating means outside of the

Heat transfer volume are arranged. It is thus given a spatial separation between at least a part of the coupling element and the at least one heat transfer element. The coupling element is at least not exposed in its full extent to the fluid heat exchanger and can be operated at relatively low temperatures, whereby the specific resistance can be kept correspondingly low.

It is advantageous if the surface of the at least one heat transfer element is large in relation to the heat transfer volume. It is therefore proposed that in an advantageous embodiment of the heating module according to the invention

Heat transfer element or the heat transfer elements is dimensioned such that the ratio of all provided for the contact with the fluid surfaces of the heat transfer element or the heat transfer elements to the

Heat transfer volume at least 100 m ² / m ³ , preferably at least 150 m ² / m ³ .

In this way, a high efficiency of heat transfer in a small space can be achieved with high power transmission. This highly efficient way of converting electrical energy into thermal energy can be used particularly advantageously for the storage of energy, e.g. of energy from regenerative

Energy sources, such as Solar systems or wind power.

The heating module according to the invention can be designed such that the alternating field generating means generates an electromagnetic alternating field

Have primary winding and an associated coil core and the

Coupling element is guided around at least part of the magnetic coil core. In this case, the coupling element forms a secondary winding, which may for example consist of a single turn or partial turn.

In an advantageous embodiment of the heating module, the coupling element is band-shaped, thus has a large width compared to its thickness.

For example, the coupling element could have a width of 1000 mm and a thickness of 5 to 10 mm and be made of an electrically conductive metal, e.g. Copper exist. In the width direction, the coupling element, as well as the

Heat transfer elements, be divided into separate segments to

Problems of thermal expansion to meet.

The heating module according to the invention can be designed so that at least two heat transfer elements are provided. At least two of the

Heat transfer elements are electrically connected in series with each other. In an advantageous embodiment, at least 10, more advantageously at least 15, 20, 25, 40, 50, 100 or 150 heat transfer elements are arranged in the heat transfer volume.

In particular, it may be advantageous if the heating module according to the invention is designed such that the at least one heat transfer element is plate-shaped or cup-shaped. Accordingly, a heat transfer element on flat sides, which are dimensioned perpendicular to its thickness direction by at least an order of magnitude larger than the thickness. In a plate-shaped heat transfer element, the flat sides are flat, while in a shell-shaped heat transfer element, the flat sides can be curved one or more times.

The at least one heat transfer element can also have perforations and / or be structured on its flat sides, for example by ribs or dents, in order to further increase the heat transferring surface.

Other forms of heat transfer elements, e.g. Tubes are also conceivable.

In the case of tubes, the fluid may alternatively flow through the tubes to flow around the outsides. The tubes may e.g. at their circumferences in the axial direction

directly, or indirectly by intermediate pieces, be fixed to each other, for example by Welding. In this case, a plurality of welded together tubes, for example, each form a wall-like structure, wherein the current flows perpendicular to the axial direction of the tubes over the peripheries of the tubes. The wall-like structures can in turn be connected in series and arranged such that adjacent wall structures are passed in opposite directions from the stream.

It may be advantageous to design the heating module according to the invention such that at least two of the heat transfer elements are arranged with their flat sides facing each other. In this way, gaps are formed between the heat transfer elements, through which the heat exchanger can flow. The

Gap thicknesses and thus the distances between adjacent heat transfer elements perpendicular to the flat sides may preferably be at most 30 mm, not more than 25 mm, not more than 20 mm, not more than 15 mm or not more than 10 mm. The gap thicknesses can also have different values depending on the requirement. It may be advantageous if the flat sides with each other facing heat transfer elements are aligned parallel to each other. This can be uniform

Gap thickness can be achieved.

With the illustrated structures, very high efficiencies can be achieved. The use of the electromagnetic induction in the heating module according to the invention is particularly characterized in that the conversion of electricity to heat can be achieved almost lossless. This is made possible on the one hand by the high ohmic resistance in the series-connected heat transfer elements. In an arrangement of the heat transfer elements, in which the current direction of adjacent heat transfer elements is in opposite directions, for example meandering, the induced magnetic fields largely cancel each other out and the inductive resistance is negligible. Together, assuming a close to zero ohmic resistance and zero inductive resistance, a power factor of 1 results. For sinusoidal current through the alternating field generating means, this also means an effective factor in reality (ratio of active power to apparent power). of cos F «1, which is associated with a high electrical efficiency of about 99%. The inductive technique used in this way makes it possible, in particular together with the achievable high density of heat transfer elements, high power densities and power transfers in the heating module, which can be used as heat exchangers and air in large quantities. For previously known from the prior art variants, such as a resistance heating of fluids by means mounted in pipes heating coils, comparatively high power densities have not been considered feasible. The ratio of all provided for the contact with the fluid surfaces to the surrounding heat transfer volume is according to the known from the prior art variants usually up to 10 m ² / m ³ .

Gases, e.g. Air as a heat exchanger increase the operational safety, as they can be used non-toxic, environmentally friendly and otherwise unproblematic. In addition, gases with high storage temperatures of up to 1,000 ° C possible, which in turn has a positive effect on the efficiency of a power plant, which can use the stored heat as a source.

In a device for energy storage, comprising a heat storage medium and at least one circuit for a fluid heat exchanger, wherein the at least one circuit of the heat exchanger is designed such that the

Heat input into the heat storage medium and / or for heat removal from the heat storage medium of the heat transfer medium flows around the heat storage medium and / or flows through, it is proposed a for heating the

Heat exchanger serving heating module according to one of the above

to use embodiments of the invention. Because of the high efficiency of the heating module can be achieved over the prior art, a significant increase in the efficiency of the device for energy storage.

The device according to the invention can be designed such that the

Heat storage medium has a solid. The solid may comprise, for example, mineral substances, in particular stones, which are characterized by a high

Characterize heat capacity. Advantageously, the device according to the invention can be designed so that for the heat input into the

Heat storage medium and / or for heat removal from the Heat storage medium of the heat exchanger directly contacted the heat storage medium. This also allows the efficiency of the device can be significantly increased.

The following are exemplary embodiments of the invention

Heating module and the device for energy storage illustrated by figures.

It shows schematically

Fig. 1: the basic structure of a heating module and

Fig. 2: a device for energy storage with three heating modules, a

Heat storage and a heat-power coupling.

Fig. 1 shows the basic structure of a heating module 1 in the form of a

Transformer circuit with a arranged in a transformer space 22 coil 2 as a primary winding, a magnetic core 3 and serving as a secondary winding coupling element 4, which is band-shaped and with a variety of as

Heat transfer elements serving heating plates 5 is electrically connected in series.

For the sake of clarity, Fig. 1 shows a relatively small number of heating plates 5, the number of which is preferably greater in actual systems, e.g. 40 to 150. The electrical contacting of the heating plates 5 with each other is shown schematically in the figure by semicircles. In fact, the heating plates 5 can also be integrally connected to each other in this way, so that there is a single meandering body that forms the heating plates 5.

The coupling element 4 is electrically contacted at transition points 18 on the outermost heating plates 5. The heating plates 5 have a depth of eg 1 m or 1.5 m measured relative to the illustration in FIG. 5, measured perpendicular to the image plane. The band-shaped coupling element 4 may preferably have the same or a similar depth or bandwidth measured in the same direction. The heating plates 5 and / or the coupling element 4 can also be seen perpendicular to the image plane Segments of, for example, 200 mm or 250 mm wide may be subdivided to counteract problems associated with thermal length change. The beaten by the coupling element 4 to the coil 2 and the magnetic core 3 semicircle may, for example, have a diameter of about 1 m.

The heating plates 5 are arranged within a heat transfer volume 19, which in the image plane has a cross-section of, for example, 1 m ² and is surrounded by side walls 20 and a demarcation wall 21. The demarcation wall 21 is used for spatial demarcation with respect to the transformer room 22 and is - like the

Sidewalls 20 also - thermally insulating. The heat transfer volume 19 can be connected to fluid line elements 6 of a fluid circuit 13. With regard to the fluid circuit 13 and the fluid line element 6, reference is made to the description of FIG. 2. The region of the transition points 18 is - unlike in Figure 1 shown for clarity - preferably also largely thermally insulating and preventing or at least aggravating a mass transfer, e.g. through an insulation material. The heating plates 5 can - as in other than the concrete embodiment of the heating module 1 described here - be arranged standing or hanging.

By means of the coil 2 and the magnetic core 3 is an electromagnetic

Alternating field in the coupling element 4 generates a heating current, which heats due to the given in the heating plates 5 high ohmic resistance. The heating plates 5 in turn serve to heat a fluid, not shown here

Wärmeüberträgers, which preferably flows along the heating plates 5 perpendicular to the plane of the drawing. It is also conceivable to allow the transformer space 22 to flow through a fluid in order to cool the coupling element 4, e.g. by means of a separate fluid circuit, not shown here. It may also be the still cool fluid heat exchanger, which can already be heated by it. The transformer space 22 preferably has thermally insulating walls 23.

The heating plates 5 are dimensioned and arranged in the heat transfer volume 19 such that the ratio of the total area of the heating of the fluid provided flat sides of the heating plates 5 to the heating plates 5 receiving heat transfer volume 19 at least 100 m ² / m ³ , preferably at least 150 m ² / m ³ . In this way it is possible to heat the fluid to be heated, preferably air, to 1000 ° C. or more.

The aforementioned exemplary dimensions have been given by way of example and may be advantageous in connection with a device for energy storage, which is shown in more detail in FIG. But in this context, other dimensions are of course possible. In fact, that can

Heating module according to the invention can also be used for other purposes to heat fluids. Then, depending on the temperature or power requirement entirely different dimensions may be useful. Also, the heat transfer elements need not be formed as a heating plate 5. Other forms, e.g. Pipes are in the

Presentation introduction shown.

Fig. 2 shows schematically the structure of a device for energy storage with three in terms of the fluid flow in series heating modules 1, a

Heat storage 7 and a heat-power coupling 8. The heating modules 1 are shown here only symbolically and can the heating module 1 shown in FIG

correspond.

In the heat-insulated heat storage 7, a heat storage medium 9, for example, stones in a bed, arranged. The heat storage medium 9 is to be heated to a maximum temperature, for example 1000 ° C, by means of the heat transfer fluid, preferably air. The fluid itself is brought by means of the heating modules 1 to a corresponding temperature. The heating modules 1 are over

Power lines 25 with electrical power from a power grid or a specific power source, for example, one or more wind turbines 24 supplied.

In particular, this electric power can be provided, which is not used in the power grid, that is excess, is.

For loading the heat accumulator 7, the fluid in a first circuit 13 by means of a first fan 10 through the fluid conduit elements 6 through the Heat transfer volumes 19 (see Figure 1) of the heating modules 1 and the heat storage 7 out. The fluid line elements 6 each go via at least one input and output not shown here in the heat transfer volume 19 of

connected heating module 1 via. The fluid is finally brought in the heating modules 1 to a heating temperature, for example 1000 ° C, and then contacted in the heat storage 7, the heat storage medium 9, preferably immediately. This took place until the heat storage medium over the entire height of the

Medium fill has reached its maximum temperature.

For discharging the heat accumulator 7, the fluid is guided by means of a second fan 11 in a second circuit 12 via the heat accumulator 7 and a heat exchanger 14. The heat exchanger 14 is part of the heat e-power coupling 8, by means of which a turbine 15 electrical power is generated, which is the power grid or an immediate consumer (not shown here) is provided.

In the second circuit 12, the fluid in the heat storage 7 by the direct contact with the heat storage medium 9 to the maximum temperature, for example, 1000 ° C, brought. In the heat exchanger 14, an operating fluid contained in a piping 16, e.g. Air, heated for the heat-power coupling 8. 2, a gas turbine power plant is shown by way of example as a heat-power coupling 8. Alternatively, e.g. a steam turbine power plant or a combination of

Gas turbine power plant and steam turbine power plant can be used for energy production. The gas turbine power plant shown in Fig. 2 densified by means of a

Compressor 17, the operating fluid, such as air coming from the environment, and it leads by means of the pipe 16 via the heat exchanger 14 to the turbine 15, where the cooled operating fluid is then supplied to the environment or used for further use. LIST OF REFERENCE NUMBERS

1 heating module

2 coil

3 magnetic core

4 coupling element

5 heating plate

6 fluid line element

7 heat storage

8 heat-power coupling

9 heat storage medium

10 first fan

11 second fan

12 second cycle

13 first cycle

14 heat exchangers

15 turbine

16 pipeline

17 compressors

18 transition point

19 heat transfer volume

20 sidewall

21 demarcation wall

22 transformer room

23 wall

24 pinwheel

25 power lines

Claims

Heating module for a fluid heat exchanger and device for energy storage claims

A heating module for a fluid heat exchanger, comprising

a) alternating field generating means for generating an electromagnetic

Alternating field

b) a coupling element (4) for inductive coupling to the electromagnetic alternating field and

c) a heat transfer volume (19) for heating the fluid heat exchanger, characterized in that

d) at least one heat transfer element (5) with the coupling element (4) electrically connected in series and disposed within the heat transfer volume (19).

2. Heating module according to claim 1, characterized in that the

Alternating field generating means and at least one part of the coupling element (4) at least partially surrounding the alternating field generating means outside the

Heat transfer volume (19) are arranged.

3. Heating module according to claim 1 or 2, characterized in that the heat transfer element (5) or the heat transfer elements (5) is dimensioned such that the ratio of all provided for the contact with the fluid

Areas of the heat transfer element (5) or the heat transfer elements (5) to the heat transfer volume (19) is at least 100 m ² / m ³ , preferably at least 150 m ² / m ³ .

4. Heating module according to one of the preceding claims, characterized in that the alternating field generating means comprises an electromagnetic alternating field generating primary winding (2) and an associated coil core (3) and the coupling element (4) around at least a portion of the magnetic coil core (3). is guided.

5. Heating module according to one of the preceding claims, characterized in that the coupling element (4) is strip-shaped.

6. Heating module according to one of the preceding claims, characterized

characterized in that at least two heat transfer elements (5) are provided.

7. Heating module according to claim 6, characterized in that the at least two of the heat transfer elements (5) are electrically connected in series with each other.

8. Heating module according to one of the preceding claims, characterized

characterized in that the at least one heat transfer element (5) is plate-shaped or cup-shaped.

9. Heating module according to claim 7 and 8, characterized in that at least two of the heat transfer elements (5) are arranged with their flat sides facing each other.

10. heating module according to claim 9, characterized in that the flat sides with each other facing the heat transfer elements (5) are aligned parallel to each other.

11. Energy storage device comprising

a heat storage medium (9) and

at least one circuit (12, 13) for a fluid heat exchanger, wherein the at least one circuit (12, 13) of the heat exchanger is designed such that for heat input into the heat storage medium (9) and / or for heat removal from the heat storage medium (9) Heat exchanger flows around the heat storage medium and / or flows through,

marked by

a heating module (1) for heating the heat exchanger according to one of claims 1 to 10.

12. The device according to claim 11, characterized in that the

Heat storage medium (9) has a solid.

13. The apparatus of claim 11 or 12, characterized in that for heat input into the heat storage medium (9) and / or for heat removal from the heat storage medium (9) of the heat transfer medium, the heat storage medium (9) contacted directly.