EP3538831A1

EP3538831A1 - Method for storing thermal energy, heat reservoir, and steam power plant

Info

Publication number: EP3538831A1
Application number: EP17800368.7A
Authority: EP
Inventors: Heimo WALTER; Markus Haider; Karl SCHWAIGER; Martin Hämmerle
Original assignee: Technische Universitaet Wien
Current assignee: Technische Universitaet Wien
Priority date: 2016-11-09
Filing date: 2017-11-09
Publication date: 2019-09-18
Also published as: WO2018085872A1

Abstract

The invention relates to a method and a heat reservoir (1) for storing thermal energy, comprising the steps of: - arranging a bed (8) in a first storage vessel (9); - conveying the bed from the first storage vessel (10) into a fluidised bed module (7); - fluidising the bed (8) in the fluidised bed module (7); - exchanging heat between the bed (8) in its fluidised state and a first fluid flow inside a first heat exchange element (20); - and conveying the bed (8) from the fluidised bed module (7) into the second storage vessel (10), wherein - said bed (8) comprises micro-capsules (17) that have a phase change material (18).

Description

Method for storing heat energy, heat storage and

Steam power plant

The invention relates to a method for storing

Heat energy with the steps:

- placing a bed in a first storage tank;

- Transporting the bed of the first storage tank in a fluidized bed module;

- Fluidizing the bed in the fluidized bed module;

- Heat exchange between the bed in the fluidized

Condition and a first fluid flow within a first heat exchanger element;

- Transporting the bed of the fluidized bed module in the second storage container.

Furthermore, the invention relates to a heat storage having

- a pile;

- a fluidized bed module;

- Means for introducing a fluidizing gas in the fluidized bed module to the bed in a

to put fluidized state;

- A first storage container for the bedding;

- A second storage container for the bed, wherein the second storage container is connected via the fluidized bed module with the first storage container;

- A first heat exchanger element, which in the

Fluidized bed module is guided.

Finally, the invention relates to a steam power plant with a steam generator and with a heat storage.

In the prior art fluidized beds have long been used for the treatment and handling of solid beds. The fluidized bed is a bed of solid particles

denoted by an upward flow of a Fluidizing gas is placed in a fluidized state. In such fluidized bed reactors, a nozzle bottom is provided, through which the fluidizing gas from an underlying

Windbox is introduced into the reactor room to go through there

Raising the solids bed to produce the fluidized bed (see AT 515 810 AI).

With this technology, fluidized bed heat exchangers

be realized, in which heat exchanger elements in the

Fluidized bed are immersed in the fluidized

Heat storage medium by heat exchange with the working fluid within the heat exchanger elements to heat or cool. In the prior art are as heat transfer and

Heat storage medium used fine solid particles. Sand is used especially frequently.

DE 10 2013 208 973 AI discloses a latent heat storage system with two containers, which are connected to each other via a pipe. Between the containers, a phase change material is conveyed via the pipeline (for example, directly with a screw conveyor or as a suspension in a transport fluid), wherein a heat transfer device thermal energy between the phase change material and a

Heat transfer material is transferred. In such dimensionally stable PCM, however, there is no encapsulation of the phase change material as in the subject invention. In addition, such

Polymers only melting temperatures in the range up to about 150 ° C.

WO 2013/089678 A1 shows a different cooling device for a heat-generating component of a computer (for example a processor).

In contrast, the object of the present invention is to improve a method and a heat accumulator of the kind set forth in such a way that the storage of heat with higher efficiency can be accomplished.

This task is performed by a method with the characteristics of

Claim 1, a heat accumulator with the features of claim 8 and a steam power plant with the features of claim 15 solved. Preferred embodiments of the invention are specified in the dependent claims 2 to 7 and 9 to 14, respectively.

According to the invention, the bed has microcapsules with a

Phase change material on.

In the prior art, various versions of latent heat storage devices have already been proposed, in which the in

Compared to sensitive heat storage media higher

Heat absorption capacity of phase change materials ("Phase Change Materials", short PCM) are used

Latent heat storage use the enthalpy change of

Phase change material, which absorbs high amounts of heat energy during melting, which are discharged again as solidification heat during discharge of the latent heat storage. An example of such a latent heat storage is shown in DE 10 2010 060 717. In this embodiment of the latent heat storage, a heat transfer medium is supplied through a pipe, which is received within a heat spreader in the form of an extruded profile. The extruded profile has a base body, on which ribs are fixed, which are in rib branches and rib branches

are split. The heat spreader is arranged in a heat storage, inside which a phase change material is provided.

Furthermore, Amin et al. in "Effective thermal conductivity for melting in PCM encapsulated in a sphere", Applied Energy 122: 280-287, June 2014, proposed to provide spherical containers with inclusions of the phase change material. These

Spherical containers are arranged in a storage container in which a heat transfer fluid for flowing around the spherical container is introduced.

However, the embodiments of the latent heat accumulator explained above have the common disadvantage that the heat output can not be separated from the storage capacity.

An approach to the separation of heat output from the

Storage capacity was reported by Zipf et al. in "high temperature

latent heat storage with a screw heat exchanger: Design of

prototype ", Applied energy 109 (2013) 462-469, whereby the phase change material is analyzed by means of a

Transported worm heat exchanger. However, this design is structurally complex and not very efficient.

In DE 3038723 a different heat storage mass in the form of a hollow sphere has been disclosed in which a

Phase change material in pores of an outer shell of a

Support material is included. The hollow spheres can be used in a fluidized bed heat exchanger. With the well-known

Hollow balls, however, the existing storage volume can only

insufficiently exploited. This would lead to a much larger design of the storage tank and the fluidized bed module at the same power. In principle, the hollow spheres must be substantially larger than the microparticles according to the invention

be executed. Another disadvantage is that significantly higher auxiliary energies would be necessary for the transport of the hollow spheres.

Finally, the hollow spheres cause a poorer heat transfer due to the larger volume.

In addition, microencapsulated phase change materials (cf. for example DE 10 2006 055 707 A1) is known per se in the prior art. However, such microcapsules have hitherto been used only for remote uses. For example, a so-called slurry flow (with phase change material in a liquid) was used for cooling machine components (EP 2 949 422 A1).

According to the invention microcapsules, ie particles with a

Outside diameter in the micrometer range, in the fluidized state, preferably substantially in the horizontal plane, transported along the fluidized bed module. The fluidized bed module is between a first storage container and a second

Storage container arranged. When the microcapsules are transported in the one horizontal direction, from the first storage container via the fluidized bed module into the second storage container, the microcapsules absorb heat from the first fluid flow of the first

Heat exchange medium, so that the microcapsules in one

State of higher heat energy in the second storage container reach, in which the microcapsules in the state of higher

Heat energy can be collected. This process corresponds to the Einspeicherbetriebszustand. Conversely, the microcapsules, when transported in the other horizontal direction, from the second storage tank via the fluidized bed module into the first storage tank, heat to the first fluid flow of the

Deliver heat exchange medium, so that the microcapsules in the first storage tank in a state of lower heat energy reach the first storage tank. Depending on the design, a single fluidized bed module for the Einspeicher- and the Ausspeichervorgang be provided. However, it can also be provided in the form of fluidized bed modules, two heat exchangers, so that a reversal of direction of the flow in the respective

Heat exchanger is not necessary. In this embodiment, the one heat exchanger for storing and the other heat exchanger for the storage of the heat energy is set up. The microcapsules contain a phase change material, which during transport through the fluidized bed module in heat exchange with the first fluid flow of the heat exchange medium the

Can change state of aggregation, so that latent heat in the

Microcapsules is stored or latent heat of the

Microcapsules is dispensed. Preferably that works

Phase change material of the microcapsules during transport from the first storage container into the second storage container within the fluidized bed module from the solid phase to the liquid phase, whereby high amounts of melting energy can be absorbed. Accordingly, when transporting the microcapsules in the other direction, from the second storage container via the

Fluidized bed module in the first storage tank, a solidification of the phase change material of the microcapsules instead, whereby the previously stored heat is released in the form of solidification heat to the first fluid flow of the heat exchange medium. This design brings significant benefits. On the one hand, the heat transfer is particularly efficient. In particular, the

Phase change at substantially constant temperature of

Microcapsules. Furthermore, particularly high amounts of heat can

get saved. The transport between the first and second storage container via the fluidized bed is therefore particularly advantageous because a decoupling of heat output and

Storage capacity can take place. The fluidized bed also allows a very good heat transfer between the microcapsules and the heat exchange medium. The microcapsules can

advantageously with low energy consumption in the

be brought fluidized state.

In the method according to the invention for storing heat, the further steps are preferred:

- Heat exchange between the bed in the fluidized

Condition and a second fluid flow within a second heat exchanger element, preferably also - Heat exchange between the bed in the fluidized state and a third fluid flow within a third heat exchanger element

carried out .

In this embodiment, therefore, a second fluid flow of a heat exchange medium, in particular also a third

Fluid flow of a heat exchange medium, in the

Fluidized bed module out to independently allow each heat exchange with the fluidized microcapsules. Advantageously, therefore, the same fluidized bed of microcapsules can be used in the

Einspeicherbetriebszustand receive heat from the first and second fluid flow and deliver the stored heat to the first and the second fluid flow in Ausspeicherbetriebszustand.

According to a preferred disclosed embodiment is in a

Einspeicherbetriebszustand the phase change material of

Microcapsules heated by heat absorption of the first fluid flow in the solid state, wherein in the

Einspeicherbetriebszustand the phase change material of

Microcapsules by heat absorption from the second fluid flow from the solid state to the liquid state

is transferred.

In this embodiment, the heat of the first

Fluid flow to be used, the sensible heat, d.

with a temperature change accompanying heat, the

Phase change material to increase in the solid state. in the

Discharge mode becomes the phase change material

solid state of aggregation with heat release to the first

Cooled fluid flow. Furthermore, the heat of the second fluid flow during charging of the heat accumulator can be converted into heat of fusion of the phase change material of the microcapsules. Accordingly, the transition from the liquid to the solid state of aggregation of

Phase change material when unloading the heat accumulator can be used to provide the heat for the evaporator of the steam generator.

The material of the shell of the microcapsules remains solid

Aggregate state, when the phase change material of the microcapsules by heat absorption from the second fluid flow from the solid

State of aggregation is transferred to the liquid state of aggregation.

According to a further preferred embodiment, the form of FIG

Einspeicherbetriebszustand the phase change material of

Microcapsules heated by heat absorption of the third fluid flow in the liquid state.

In this embodiment, the heat of the third

Fluid flow to increase the sensible heat of the

Accordingly, the phase change material is cooled during discharge of the heat accumulator in the liquid state of aggregation with heat release the third fluid flow.

When charging the energy store, it is therefore preferable to use both the sensitive area of the phase change material of the microcapsules in the solid state, the latent heat of the phase change material in the transition from the solid state to the liquid state, and the sensible heat of the phase change material in the liquid state.

In a preferred application of the method according to the invention, the first fluid flow between a steam generator, in particular a steam power plant, and the first

Promoted heat exchanger element. In this embodiment, the heat from the first fluid flow of the steam generator to the

Fluidized bed of microcapsules are discharged, which is formed in the fluidized bed module between the first storage tank and the second storage container.

Due to the steady expansion of renewable energies, both overcapacities and undercapacities of electrical power can occur over time. The fluctuations are compensated with the help of conventional power plants. For this fossil-fired power plants, especially coal power plants, are often used with steam generators, which, however, bring the disadvantage that the output power to the power grid can not be changed to any extent and fast enough.

By the heat exchange between the first fluid flow of the steam generator and the microcapsules in the fluidized bed module is an intermediate storage of energy of the steam power plant

allows, when the need for electrical energy currently available less than that provided by the steam power plant

Energy is. If the demand for electrical energy increases, the energy stored in the microcapsules can be returned to the water-steam cycle of the steam power plant.

It is particularly preferred in this case if the first fluid flow between a preheater of the steam generator and the first

Heat exchanger element is conveyed, wherein in one

Einspeicherbetriebszustand the phase change material of

Microcapsules is heated by heat absorption from the first fluid flow in the solid state. At this

Embodiment variant, the heat of the first fluid flow from the preheater of the steam generator can be used to the sensible heat, ie the heat associated with a temperature change, of the phase change material in the solid state. In the Ausspeicherbetriebszustand the phase change material in the solid state state with heat release to the first

Cooled fluid flow. Advantageously, the sensitive area of the phase change material in the solid state of aggregation on the temperatures of the heat exchange medium in the preheater of

Steam generator tuned.

According to a particularly preferred embodiment, the second fluid flow is conveyed between an evaporator of a steam generator and the second heat exchanger element, wherein in a

Einspeicherbetriebszustand the phase change material of

is transferred. Accordingly, the heat of the second fluid flow during charging of the heat storage in heat of fusion of the

Phase change material of the microcapsules are converted.

Advantageously, the phase change of the microcapsules

efficient on the properties of the second fluid flow

matched, which of the evaporator of the steam generator

is derived. Accordingly, the transition from the liquid state to the solid state of the phase change material in the

Discharging the heat accumulator can be used to provide the heat for the evaporator of the steam generator.

Finally, it is preferably provided that the third

Fluid flow between a superheater of a steam generator and the third heat exchanger element is promoted, wherein in

Einspeicherbetriebszustand the phase change material of

Microcapsules is heated by heat absorption of the third fluid flow in the liquid state. At this

Variant may be the heat of the superheater

derived third fluid flow used to increase the sensible heat of the phase change material in the liquid state become. Accordingly, the phase change material is cooled during discharge of the heat accumulator in the liquid state of aggregation with release of heat to the third fluid flow. Advantageously, the sensitive area of the phase change material is in the liquid

State of aggregation matched to the temperatures of the heat exchange medium in the superheater of the steam generator.

In a particularly preferred embodiment, when the energy store is charged, both the sensitive area of the energy storage device and the energy storage device are charged

Phase change material of the microcapsules in the solid state, the

Latent heat of the phase change material in the transition from the solid state to the liquid state and the sensible heat of the

Phase change material used in the liquid state. For this purpose, the first, second and third heat exchanger element are provided, which with the preheater, evaporator or superheater of the

Steam generator are connected. Advantageously, the

Heat exchange between the microcapsules and the first, second and third fluid flow in individual longitudinal sections of the

Fluid bed module take place so that forms a temperature profile along the fluidized bed.

In a preferred embodiment, the microcapsules each have a core of the phase change heat storage material and a shell enclosing the core on all sides. The shell is made of a different material than the phase change thermal storage material of the core.

As the phase change material of the microcapsules, for example, a nitrate salt may be provided. The shell, however, preferably consists of a plastic, such as polyimide. The microcapsules have the advantage that the required auxiliary energy for the

Fluidized bed is smaller, but the heat transfer coefficient is greater than in the case of the hollow spheres used in the prior art, which in addition, assuming the same weight and the same material, have a larger volume and therefore require larger storage tank required. Accordingly, the microcapsules allow a particularly economical operation of the heat storage.

On the one hand to allow a high heat output and

on the other hand, the fluidization of the microcapsules in the

To facilitate fluidized bed, it is beneficial if the

Microcapsules each having a diameter of 50 to 500 microns, in particular from 50 to 100 microns. Preferably, similar microcapsules are provided, each in the

Have substantially the same diameter.

In a preferred embodiment is a second

Heat exchanger element, preferably also a third

Heat exchanger element, led into the fluidized bed module. The second heat exchanger element, optionally also the third

Heat exchanger element, leads to a heat exchange medium to

Heat exchange with the microcapsules in the fluidized bed module. For this purpose, the first, second, and optionally also the third, heat exchanger element are connected to a heat source or heat sink. First and / or second and / or third

Each heat exchanger element is preferably a tube bundle

intended .

In a particularly preferred embodiment, the first heat exchanger element and the second heat exchanger element are

preferably also the third heat exchanger element, in

Seen longitudinally of the fluidized bed module from each other

are spaced. In this embodiment, the first, second and optionally the third heat exchanger element, in

Flow direction of the microparticles (based on the

Injection mode), in successive

Longitudinal sections of the fluidized bed module arranged. As a result, at the individual longitudinal sections of the fluidized bed module different heat states of the microcapsules are formed,

In a preferred application of the energy store, the first heat exchanger element is connected to a steam generator. Of the

Steam generator is in particular part of a steam power plant. In this embodiment, the heat generated in a steam boiler can be at least partially stored in the heat storage when the demand for electrical energy to the respective

Time is lower than the heat provided by the boiler is. This can advantageously be a balance of

Fluctuations in electricity demand are created, creating a

particularly efficient operation of the steam power plant is made possible.

In particular, it is advantageous if the first heat exchanger element with a first customer, in particular a preheater of a

Steam generator, and / or the second heat exchanger element with a second consumer, in particular an evaporator of the steam generator, and / or the third heat exchanger element with a third

Customer, in particular a superheater of the steam generator,

is connected or are.

The invention will be described below with reference to a preferred

Embodiment, to which it should not be limited, further explained.

Fig. 1 shows schematically a heat storage for use in a steam power plant, wherein in the illustrated

Storage Mode Microcapsules with phase change material core in the fluidized state in the horizontal direction

transported to receive the heat of fluid flows from a steam generator;

Fig. 2 shows the heat storage of Fig. 1 in one

Ausspeicherbetriebszustand, wherein the microcapsules of the Fluidized bed can be transported in opposite directions to transfer the previously stored heat to the fluid flows of the

Deliver steam generator; and

Fig. 3 shows schematically a microcapsule with a core

Phase change material and a shell.

Fig. 1, 2 show a heat storage 1, which in the embodiment shown from management part of a steam power plant 2 is. The steam power plant 2 may have a conventional structure, wherein in the following only the essential for the invention

Components are explained. In the embodiment shown, the heat accumulator 1 with a water-steam cycle of

Steam power plant 2 connected. For the sake of simplicity, only one steam generator 3 of the water-steam cycle is shown. The steam generator 3 has a preheater 4 for preheating

Feed water, an evaporator 5 for generating water vapor from the feed water and a superheater 6 for heating the

Water vapor on. The steam generator 3 is connected to a steam turbine (not shown), which is connected to a generator (not shown).

As can be seen from Fig. 1, 2, the heat or

Energy storage 1 a fluidized bed heat exchanger module (hereinafter referred to as: fluidized bed module) 7 for generating a fluidized bed of a bed 8, which consists of heat storage particles. The fluidized-bed module 7 is provided with a first storage container 9 for the bed 8 at one end region and with a second storage container 10 for the bed 8 at the other end region

connected. In the embodiment shown is a first

Shut-off device 11 between the first storage tank 9 and the fluidized bed module 7 and a second shut-off device 12 between the second storage tank 9 and the fluidized bed module 7 is provided. The first shut-off device 11 and the second Shut-off device 12 can each be transferred between an open state and a closed state. In the open state of the first 11 and second shut-off device 12, the bed of the first 9 and second storage container 10 can flow under the action of gravity in the fluidized bed module 7. In the closed state of the first 11 and second

Shut-off device 12 is the passage of the first 9 or

second storage container 10 is shut off in the fluidized bed module 7. In the drawing, the first 11 and second shut-off device 12 are exemplified as a slider. The

Fluidized-bed module 7 has a device 13 for introducing a fluidizing gas (see arrows 14) into the bottom side (with reference to the operating state shown)

Fluidized bed module 7 on. Due to the upward flow of the fluidizing gas, a fluidized bed with the

Heat storage particles of the bed 8 generates. Thus, the heat storage particles of the bed 8 are placed in the fluidized bed module 7 in a fluidized state. The device 13 may have a nozzle base known in the prior art. The

Fluidized bed module 7 has at the top a ceiling 7a, in which at least one outlet opening 15 for the

Fluidizing gas is formed. The outlet opening 15 can be provided with a valve, in particular a control valve, for adaptation of the exiting fluidizing gas flow (compare arrow 16).

In the embodiment shown, the bed 8 is formed of microcapsules 17, each consisting of a core

Phase change material 18 and one the core on all sides

enclosing sheath 19 exist. Thus, the microcapsules 17 are substantially free of voids. The microencapsulated

Phase materials or microcapsules 17 each have one

Diameter of 50 to 500 microns. For storing heat in the heat accumulator 1 or for

Discharge of heat from the heat accumulator 1 are in the

shown embodiment, a first heat exchanger element 20, a

second heat exchanger element 21 and a third

Heat exchanger element 22 is provided which each project in sections in the fluidized bed module 7. The first heat exchanger element

20 carries a first fluid flow, the second heat exchanger element

21 carries a second fluid flow and the third

Heat exchanger element 22 carries a third fluid flow of a

Heat exchange medium, here water vapor. The first

Heat exchanger element 20 is connected to the preheater 4, the second

Heat exchanger element 21 is connected to the evaporator 5 and the third heat exchanger element 22 is connected to the superheater 6 of the

Steam generator 3 connected.

In Fig. 1, the Einspeicherbetriebszustand of the heat accumulator 1 is shown, wherein the microcapsules 17 of the fluidized bed in

fluidized state due to the difference in height between the first storage tank 9 and the fluidized bed module 7 in the one horizontal direction 23 along the fluidized bed module 7 flow. As will be explained in detail below, the

Microcapsules 17 by the contact with the first 20, second 21 and third heat exchanger element 22 in a higher state

Heat energy brought. In the embodiment shown, the

Microcapsules 17 after passing through the fluidized bed module 7 via a closable first outlet opening 24a in a first

Between bunker 24 b out. Thereafter, the microcapsules 17 by means of a first transport device 25, which in the

is shown in the form of a bucket elevator, transported in the second storage container 10. in the

Injection mode, i. when loading the heat accumulator 1, the first shut-off device 11 is in the open

Condition, whereas the second shut-off device 12 in

closed state is located. To form individual heat exchange zones, the first heat exchanger element 20, the second heat exchanger element 21 and the third heat exchanger element 22 are arranged in the transport direction 23 of the microcapsules 17 (in relation to the injection operating state) at successive longitudinal positions of the fluidized bed module 7.

When loading the heat accumulator 1, the first fluid flow from the preheater 4 of the steam generator 3 via the first

Heat exchanger element 20 promoted. This is the

Phase change material of the microcapsules 17 is heated by heat absorption of the first fluid flow in the solid state. The first fluid flow of the heat exchange medium in the

Heat exchanger element 20 is cooled accordingly. The second fluid flow is from the evaporator 5 via the second

Heat exchanger element 21 promoted. Due to the heat exchange between the microcapsules 17 and the second fluid flow, the phase change material of the microcapsules 17 from the solid

State of aggregation transferred to the liquid state of aggregation.

Finally, the third fluid flow is conveyed by the superheater 6 via the third heat exchanger element 22, wherein in

Einspeicherbetriebszustand the phase change material of

Microcapsules is heated by heat absorption of the third fluid flow in the liquid state.

2 shows the Ausspeicherbetriebszustand the heat accumulator 1. For unloading the heat accumulator 1, the second

Shut-off device 12 is opened, whereas the first

Shut-off device 11 is closed. This allows the

Microcapsules 17 with the stored heat from the second

Storage tank 10 enter the fluidized bed module 7. There, the microcapsules 17 flow in the fluidized state in the other horizontal direction 26 (opposite to the direction 23 in FIG Injection mode) along the fluidized bed module 7. In heat exchange with the first, second and third fluid flows, the microcapsules 17 release the previously stored heat.

Due to the third heat exchanger element 22 is a

Cooling of the phase change material in the liquid state. The second heat exchanger element 21 effects a phase transition of the phase change material from the liquid to the solid state. By the contact with the first heat exchanger element 20 is the

Phase change material cooled in the solid state. The first, second and third fluid flows absorb the heat given off by the microcapsules. Finally, the microcapsules 17 pass through a second outlet opening 27a of the fluidized-bed module 7 into a second intermediate bunker 27b, which has a second intermediate bunker 27b

Transport device 28, in the embodiment shown again a bucket elevator, with the first storage container 9 is connected. Depending on the design, the same transport device for transporting the microcapsules 17 from the first intermediate bunker 24b into the second storage container 19 and for transporting the microcapsules 17 from the second intermediate bunker 27b into the first storage container 9 may also be provided. Of course, it is not necessary for the invention to ensure the horizontal transport of the microcapsules 17 by an increased arrangement of the first 9 and second storage container 10 relative to the fluidized bed module 7. Other transport means for the horizontal transport of the microcapsules 17 along the fluidized-bed module 7 may also be provided.

Fig. 3 shows the microcapsules 17, which in the

Fluidized bed module or fluidized bed tank 7 in the

be fluidized state.

In summary, with the illustrated heat accumulator 1, a method for intermediate storage of heat, in particular in a steam power plant 2, can be carried out, which comprises at least the following steps: - Provide a bed 8 in a first storage container 9, wherein the bed 8 microcapsules 17 with a

Phase change material 18;

- Transporting the bed of the first storage container 10 in a fluidized bed module 7;

- Fluidizing the bed 8 in the fluidized bed module 7;

- Transporting the bed 8 in the fluidized state in a substantially horizontal direction along the

Fluidized bed module 7;

- Heat exchange between the bed 8 in the fluidized

Condition and a first fluid flow within a first heat exchanger element 20, wherein the first fluid flow preferably between the heat exchanger element 20 and a

Steam generator 3 is promoted;

- Transporting the bed 8 of the fluidized bed module 7 in the second storage container 10th

Claims

Claims:

1. Method for storing heat energy with the steps:

- Arranging a bed (8) in a first storage container

(9);

- Transporting the bed of the first storage container

(10) in a fluidized bed module (7);

- Fluidizing the bed (8) in the fluidized bed module (7);

Heat exchange between the bed (8) in the fluidized state and a first fluid flow within a first heat exchanger element (20);

- Transporting the bed (8) of the fluidized bed module (7) in the second storage container (10),

characterized in that

- the bed (8) microcapsules (17) with a

Phase change material (18).

2. The method according to claim 1, characterized by the further step:

- Heat exchange between the bed (8) in the fluidized state and a second fluid flow within a second heat exchanger element (21), wherein in one

Einspeicherbetriebszustand the phase change material (18) of the microcapsules (17) by heat absorption from the first

Fluid flow in the solid state is heated and wherein in the Einspeicherbetriebszustand the

Phase change material (18) of the microcapsules (17)

Heat absorption from the second fluid flow from the solid

State of aggregation is transferred to the liquid state of aggregation.

3. The method according to claim 2, characterized by the further step:

- Heat exchange between the bed in the fluidized Condition and a third fluid flow within a third heat exchanger element (22), wherein in

Einspeicherbetriebszustand the phase change material (18) of the microcapsules (17) by heat absorption from the third

Fluid flow is heated in the liquid state.

4. The method according to any one of claims 1 to 3, characterized

characterized in that the first fluid flow between a

Steam generator (3), in particular a steam power plant (2), and the first heat exchanger element (20) is conveyed.

5. The method according to claim 4, characterized in that the first fluid flow between a preheater (4) of the

Steam generator (3) and the first heat exchanger element (20) is conveyed, wherein in a Einspeicherbetriebszustand the phase change material (18) of the microcapsules (17)

Heat absorption from the first fluid flow in the solid

Aggregate state is heated.

6. The method according to claim 4 or 5, characterized in that the second fluid flow between an evaporator (5) of a

Steam generator (3) and the second heat exchanger element (21) is conveyed, wherein in a Einspeicherbetriebszustand the phase change material (18) of the microcapsules (17)

Heat absorption from the second fluid flow from the solid

State of aggregation is transferred to the liquid state of aggregation.

7. The method according to any one of claims 4 to 6, characterized

characterized in that the third fluid flow is between a

Superheater (6) of a steam generator (3) and the third

Heat exchanger element (22) is conveyed, wherein in

Fluid flow is heated in the liquid state.

8. heat storage (1) having

- a bed (8);

- A fluidized bed module (7);

- means (13) for introducing a fluidizing gas into the fluidized bed module (7) to place the bed (8) in a fluidized state;

- A first storage container (9) for the bed (8);

- A second storage container (10) for the bed, wherein the second storage container via the fluidized bed module (7) is connected to the first storage container (9);

- A first heat exchanger element (9), which in the

Fluidized bed module (7) is guided,

characterized in that

- the bed (8) microcapsules (17) with a

Phase change material (18).

9. heat storage (1) according to claim 8, characterized in that the microcapsules (17) each have a core of the phase change heat storage material (18) and the core on all sides

enclosing envelope (19).

10. heat storage (1) according to claim 8 or 9, characterized

characterized in that the microcapsules (17) each have a

Diameter of 50 to 500 microns, especially from 50 to 100 microns.

11. Heat storage (1) according to one of claims 8 to 10, characterized in that a second heat exchanger element (21), preferably also a third heat exchanger element (22), is guided in the fluidized bed module (7) or are.

12. Heat storage (1) according to claim 11, characterized in that the first heat exchanger element (20) and the second Heat exchanger element (21), preferably also the third

Heat exchanger element (22), in the longitudinal direction of

Fluidized bed module (7) are seen spaced from each other.

13. Heat storage (1) according to one of claims 8 to 12, characterized in that the first heat exchanger element (20) with a

Steam generator (3) is connected.

14. Heat storage (1) according to one of claims 11 to 13, characterized in that the first heat exchanger element (20) with a first consumer, in particular a preheater (4) of a

Steam generator (3), and / or the second heat exchanger element (21) with a second consumer, in particular an evaporator (5) of the

Steam generator (3), and / or the third heat exchanger element (22) with a third customer, in particular a superheater (6) of the

Steam generator (3), is connected or are.

15. steam power plant (2) with a steam generator (3) and with a heat storage (2), characterized in that the heat accumulator (1) is designed according to one of claims 1 to 14.