WO2025103840A1 - Latent heat storage means for stationary heat supply - Google Patents

Abstract

The present invention relates to a storage means, preferably a latent heat storage means, comprising a storage means casing, which defines the storage means volume and is designed such that the storage means casing suppresses tendency for spontaneous crystallization of at least one phase-change medium accommodated in the storage means and preferably present as a subcooled melt.

Description

Latent heat storage for stationary heat supply

The present invention relates to a latent heat storage device for stationary heat supply.

Currently, numerous applications, such as the provision of hot water in buildings, are known for which heat storage is advantageous and therefore desirable. For example, it is known to store heat generated by solar radiation during the day so that it can be used later when solar radiation is absent or comparatively low.

The present invention is based on the object of creating an advantageously operating heat storage system. A particular focus is placed on the design of the storage device, in particular a latent heat storage device in which a phase change medium is accommodated or can be accommodated.

The present invention is based on the object of mitigating or even completely eliminating the disadvantages of the prior art. This object is achieved by the subject matter of the independent claims, and the dependent claims specify advantageous developments.

Against this background, the present invention relates to a storage device, preferably a latent heat storage device, with a storage casing which defines the storage volume limited and designed in such a way that the storage shell suppresses the tendency towards spontaneous crystallization of at least one phase change medium accommodated in the storage, which is preferably present in the supercooled melt.

A storage tank according to the invention can further be equipped with a heat exchanger, preferably a tube-bundle-plate heat exchanger, which is modular in design and has a number of preferably identical sub-units. The dimensions of the tube-bundle-plate heat exchanger can be flexibly adapted to the dimensions of the storage tank by selecting the number of sub-units. In this way, cover systems for storage tanks of various dimensions can be flexibly configured.

The basic structure of a heat storage system according to the invention is shown, for example, in Fig. 1. The present disclosure preferably relates to a single latent heat storage device, described as a cluster in the context of the description of Fig. 1. This latent heat storage device comprises, for example, a container and several plate-and-tube bundle heat exchangers that are hydraulically interconnected via a cover system. The storage device/cluster is filled with a latent heat storage medium/phase change medium. A trigger mechanism is preferably installed to control the phase change from latent to crystalline.

A storage device according to the invention preferably provides an efficient system for storing and providing any heat energy supplied or demanded for high and continuous outputs. It offers particular advantages in terms of load adjustments and load shifts, as well as storage density and space consumption. The phase change medium used preferably allows for control of the subcooled melt and ensures the long-term stability of the heat storage material.

At least one tube bundle plate heat exchanger of a storage device according to the invention can have at least one connecting component which is is connected or connectable in a locking and/or form-fitting manner to at least one tube of the tube bundle, preferably a plurality of the tubes of the tube bundle.

The connecting component can have at least one cutout, preferably a star-shaped cutout, into which a tube of the tube bundle is inserted or can be inserted. This ensures optimal heat transfer between the tube and the connecting component, in particular a plate.

In an embodiment according to the invention, expanding the tubes is preferably no longer necessary. Thus, at least one tube, preferably all of the tubes in the tube bundle, can have a cylindrical shape with a constant diameter and/or not be expanded at least locally to form a frictional connection with the connecting component. This simplifies production.

In a storage tank according to the invention, preferably at least one tube, preferably all of the tubes of the tube bundle, is/are designed as a single-tube (LI) tube, which is preferably connected or connectable at both ends to the connecting component, or a plate, of the tube bundle/plate heat exchanger. This eliminates the need for additional soldering, and corrosion protection is ensured throughout the service life.

Preferably, the tube bundle plate heat exchanger comprises at least two heat exchanger plates (also referred to as “plates”), the spacing of which is selected such that a volume and/or mass segmentation of the phase change medium contained in the storage is ensured and/or the tendency towards spontaneous crystallization of at least one phase change medium contained in the storage is suppressed.

A storage device according to the invention can further be equipped with at least one cover and/or a cover system which is designed to form a hyd- to provide a hydraulic connection of at least one tube bundle of a tube bundle plate heat exchanger to at least one energy source and at least one energy sink and/or is designed to provide a forward-return connection of the at least one tube bundle.

Preferably, one or more trigger mechanisms are arranged on the lid and/or lid system for the targeted triggering of a phase transition in the phase change medium accommodated in the storage device on or in the lid or lid system.

Furthermore, the present invention relates to a heat storage system, preferably a latent heat storage system with at least one storage device according to the present invention.

Furthermore, the present invention relates to a building or mobile unit, such as caravans, motor vehicles and the like, with at least one heat storage system according to the present invention.

A trigger mechanism which can be used in the context of the present invention is described in more detail below.

For example, a trigger mechanism for triggering a phase transition in a phase change medium can be provided, wherein the trigger mechanism triggers the phase transition by a targeted introduction of seed crystals and/or a targeted, preferably local, temperature reduction of the phase change medium.

For example, such a triggering mechanism can be used in a latent heat storage system with multiple storage containers (hereinafter also referred to as a cluster), which is particularly suitable for stationary long-term storage and consumption-based provision of heat. The latent heat storage system can have any number of storage containers. tern (clusters). A salt hydrate is preferably used as the latent storage medium. These salt hydrates are melted, and the long-term storage of the thermal energy occurs in the supercooled melt. This melt is long-term stable. For controlled heat release, it is necessary to manipulate the supercooled salt melt in such a way that the rehabilitation process is initiated with heat release. This is achieved via appropriate trigger mechanisms, such as those that are the subject of the present invention. At the same time, it must be ensured that spontaneous initiation of crystallization is excluded and that no passivation of the trigger mechanism occurs.

In an exemplary embodiment of the invention, a storage unit comprises a hybrid tube heat exchanger with two independent and separate hydraulic circuits. The cluster is filled with a salt hydrate via a closed system. The salt hydrate is preferably melted via a solar heat exchanger. Once the salt hydrate is in the supercooled melt (below 30°C), the stored heat can be stored for any length of time. This allows, among other things, solar heat yields to be transferred from the summer half of the year to the winter half of the year. The following trigger mechanisms can be used according to the invention to provide heat as needed:

• Pneumatic-mechanical release, and/or

• Electromechanical triggering, and/or

• Cooling of the salt hydrate to below -12°C, preferably by means of at least one Peltier element, and/or

• Seeding using seed crystals, preferably using a mechanical grinder

A trigger mechanism according to the invention can have an introduction mechanism for the targeted introduction of seed crystals into a phase change medium, which is designed to introduce seed crystals into the phase change medium by means of a pneumatic-mechanical process and/or by means of an electro-mechanical process. The insertion mechanism can comprise a movable plunger, at the tip of which, facing the phase change medium, the seed crystals are arranged, and a pneumatic-mechanical and/or electromechanical actuator designed to bring the plunger into contact with the phase change medium and preferably to immerse the plunger into the phase change medium to a defined depth. A trigger mechanism with such a plunger is shown, for example, in Figures 6 and 7.

The defined depth to which the plunger is immersed or can be immersed in the phase change medium is preferably adjustable by means of an input unit.

Alternatively or additionally, the trigger mechanism can be equipped with a trigger chamber designed to accommodate a volume of phase-change medium. Furthermore, a temperature reduction mechanism, preferably comprising at least one Peltier element, can be provided, which is designed to reduce the volume of phase-change medium accommodated in the trigger chamber to a temperature below -10°C, preferably below -12°C, and in particular to a temperature between -25°C and -12°C. This temperature reduction initiates a phase transition. A trigger mechanism with such a trigger chamber is shown, for example, in Figure 8.

The triggering chamber is preferably connected and/or connectable by means of a channel to a volume of phase change medium accommodated in a storage device, preferably a latent heat storage device, so that a phase transition initiated in the triggering chamber can continue through the channel in the volume of phase change medium accommodated in the storage device.

Alternatively or additionally, a trigger mechanism according to the present invention can be equipped with a container for seed crystals, from which seed crystals can be selectively fed into a phase change medium as needed, preferably by gravity. A trigger mechanism with such a container is shown, for example, in Figure 9. A grinder is preferably arranged downstream of the container, by means of which the seed crystals can be ground to a desired size, preferably adjustable by means of an input unit.

A vapor barrier can also be provided at the inlet for the seed crystals into a storage tank containing the phase-change medium, shielding the trigger mechanism from moisture penetration. This prevents, for example, clumping of the crystals.

The phase change medium is preferably a salt hydrate and/or a salt melt.

Further features of a memory according to the invention are described below.

For example, the invention relates to a storage device, in particular a latent heat storage device, with at least one chamber for receiving a phase change medium, wherein at least one triggering mechanism according to the invention is assigned to the chamber with the at least one phase change medium.

A storage device according to the invention may comprise a plurality of chambers for accommodating a phase change medium, wherein each of the chambers is associated with at least one trigger mechanism according to the present invention.

A memory used in the present invention is described in detail below.

A storage device according to the invention can further be equipped with at least one cover and/or a cover system, wherein the triggering mechanism or the triggering mechanisms are arranged on or in the cover or cover system. A lid or lid system used in the present invention is described in detail below.

Furthermore, the invention relates to a heat storage system, preferably a latent heat storage system with at least one triggering mechanism according to the present invention and/or at least one storage device according to the present invention.

A heat storage system used in the context of the present invention is described in detail below and is shown as an example in Fig. 1.

Another aspect of the present invention relates to a building or mobile unit, such as caravans, motor vehicles and the like, having at least one heat storage system according to the present invention.

A memory in which one or more trigger mechanisms according to the invention can be used is described below.

According to the invention, a storage device, preferably a latent heat storage device, is provided, comprising at least two separate chambers, in each of which a preferably different phase change medium is or can be accommodated.

In this way, the advantages of different phase change media can be combined in one storage device.

Preferably, a storage device according to the invention has a storage casing which limits the storage volume and is preferably designed such that the storage shell suppresses the tendency for spontaneous crystallization of at least one phase change medium in the supercooled melt.

For example, the storage shell is designed differently in different chambers of the storage tank, so that the material of the storage shell is adapted to the phase change medium contained in the respective chamber and its tendency to spontaneous crystallization in the supercooled melt.

The storage tank may further comprise a heat exchanger, preferably a tube bundle plate heat exchanger, which is of modular construction and preferably comprises a number of sub-units, the number of which can be adapted to the size of the storage tank used.

In this way, the shell-and-tube plate heat exchanger can be flexibly adapted to storage tanks of different sizes, for example, by adding or removing sub-units. Alternatively or additionally, the number of shell-and-tube plate heat exchangers can also be adjusted. For example, each chamber can be equipped with a shell-and-tube plate heat exchanger. The shell-and-tube plate heat exchanger is just one example; any other heat exchanger can also be used.

For example, there can be at least two tube bundle plate heat exchangers, each of which is arranged in a separate chamber, separated by partition walls in a media-tight manner.

Alternatively or additionally, at least two sub-units of a tube bundle plate heat exchanger may be present, each of which is arranged in a separate chamber, separated by partition walls in a media-tight manner.

According to a preferred embodiment, the storage device has at least four separate chambers, in each of which a different phase change medium is accommodated or can be accommodated. At least one chamber or a number of chambers can be filled with at least two different phase change media, wherein the phase change media preferably have the same high storage densities in the phase change and/or different phase change temperatures.

Furthermore, at least one tube-bundle plate heat exchanger can be present, which is connected to the associated energy source and the associated energy sink via a hydraulically connected cover system of the storage tank, which is preferably designed to ensure the tightness and the supply-return connection of the tube bundles. A cover system used in the context of the present invention is described in detail below.

A trigger mechanism for initiating a phase change of the associated phase-change medium is preferably present in or on the lid system for each of the chambers. The trigger mechanism triggers, for example, a phase transition, in particular a crystallization, of the phase-change medium by inoculating the phase-change medium with crystals.

Preferably, a reservoir according to the invention does not have any additional and/or designated hydraulic interconnection for accessing the individual chambers with the different phase change media. In other words, the hydraulic interconnection for accessing the individual chambers with the different phase change media preferably takes place exclusively via the reservoir's cover system, in particular its hydraulic line system.

A latent heat storage system (storage) according to the invention provides an efficient system for storing and providing any available or demanded heat energy for high and continuous performance. The use of multiple phase change media offers particular advantages when used in conjunction with heat pumps. The first phase change medium, for example, has a melting point of approximately 32°C and thus covers the load range of underfloor heating, while a second phase change medium in this temperature range is, for example, crystalline but does not have a high storage density or is in the “supercooled” melt.

If higher supply temperatures are required, for example for hot water supply, the second phase change medium can be triggered via the trigger mechanism and, if it is sodium acetate trihydrate, for example, can provide a supply temperature of 58°C.

With the storage tank according to the invention, the operating point of a heat pump can be optimally controlled, for example by heating the storage tank to a drinking water temperature of approximately 60°C once a day. In the last third of the heating process, the performance factor and efficiency decrease depending on the heat pump used. Performance factors of 2.5 to 3.5 are achievable. This process takes a maximum of 30 minutes per storage unit per day, depending on the output of the connected heat pump. For the remaining operating time, the heat pump can operate at the lower temperature level corresponding to the connected heat distribution system, i.e., generate heat with the highest efficiency. In this way, performance factors of more than 4.5 and high efficiencies can be achieved.

Another application can be efficiently developed, namely the regeneration of near-surface heat extraction systems for heat pumps.

The phase change medium used or the combination of phase change media used allows control of the subcooled melt and ensures the long-term stability of the heat storage material. In practice, a latent heat storage device according to the invention, preferably with several phase change media, usually has a cover which interacts, for example, with a heat exchanger (e.g. a tube bundle plate heat exchanger).

Exemplary embodiments of a lid or lid system used within the scope of the present invention are explained below.

For example, a cover for a latent heat storage device is provided, wherein the cover is designed to be arranged on a tube bundle plate heat exchanger and to provide a fluidic connection of the tube bundles of the tube bundle plate heat exchanger.

Preferably, the cover connects the individual tube bundles and supplies them with heat transfer medium, such as water. The cover can thus enable circulation of the heat transfer medium within the heat exchanger.

Preferably, the cover has a sealing system or clamp-type sealing system for sealing the tube bundles, or this is integrated into the cover. In other words, the cover can be designed such that the cover, preferably exclusively the cover or the sealing system arranged on it, seals the tube bundles of the heat exchanger to the outside.

According to one embodiment, the cover is designed to provide a hydraulic connection between the tube bundles in a supply and/or return line. The cover can have an inlet, an outlet, and a lumen for conducting heat transfer medium. The cover can thus preferably be fluidically and/or hydraulically coupled to the tube bundle.

The lid can be made of polymer and/or metal. For example, the lid can be made of a polymer at least partially coated with a metal, in particular aluminum. The lid preferably has an inlet and an outlet for fluid, preferably liquid.

In order to connect the cover to the tube bundle, the cover can have a number of connections which are designed to be connectable or connected to a corresponding number of tubes arranged parallel to one another, so that a parallel flow through the tubes with liquid, in particular heat exchange medium, is ensured, preferably according to a Tichelmann system.

The cover may, for example, have two connections, each of which can be connected to a distribution system that supplies fluid to a plurality of pipes or returns fluid from a plurality of pipes in a bundled manner.

Preferably, a cover according to the invention with a tube bundle heat exchanger with parallel flow tubes (Tichelmann system) is used, since this allows a particularly high efficiency to be achieved.

The cover can seal the tube bundle plate heat exchanger preferably completely, but also only partially.

Depending on the size of the latent heat storage device used, a lid system of variable size is required. A lid according to the invention is therefore preferably designed in a modular manner, allowing multiple lids to be connected to flexibly adapt the size of the lid system to the heat storage device.

In order to connect several covers to one another, these preferably have at least one, preferably several coupling elements for fluidically coupling the cover to another cover, so that the cover can be coupled modularly to another cover. The at least one coupling element can, for example, comprise a form-locking element, a frictional engagement element, and/or a force-locking element and can preferably be configured as a plug-in connection, a snap-in connection, or a screw connection. For example, a connecting piece can be provided that can be inserted into a corresponding connecting piece.

In order to ensure fluid circulation in the entire cover system, the at least one coupling element is preferably at least partially fluid-permeable and preferably has a cavity or lumen through which fluid, preferably heat transfer medium, can flow.

One aspect of the present invention thus relates to a system with at least two covers according to the present invention, wherein the at least two covers are preferably coupled by means of their coupling elements. In principle, it is also conceivable for the coupling elements to be provided separately from the covers as a set; for example, separate connecting parts can be supplied.

Preferably, a system according to the invention or a cover according to the invention can be operated or used without maintenance.

The system or a cover according to the invention can be designed in such a way that seals arranged on the system and/or the tube bundle of the plate heat exchanger are accessible and/or replaceable at any time, preferably without tools.

Another aspect of the invention relates to a heat storage system, preferably a latent heat storage system with a lid according to the invention and/or a lid system according to the invention. Another aspect relates to a building or mobile unit, such as caravans, motor vehicles and the like, with at least one heat storage system according to the present invention.

A heat storage system, preferably a latent heat storage system, is described below, which can be used together with at least one latent heat storage device according to the invention and/or a cover or cover system described above.

The heat storage system, for example, features a tube-bundle plate heat exchanger. A cover system as described above is used for the hydraulic connection of the tube bundles.

The heat storage system can be designed with a plurality of storage containers in which a latent heat storage medium is located, as well as with a line system with supply lines for supplying heat into the storage containers and with discharge lines for discharging heat from the storage containers, wherein the line system has one or more valves by means of which at least one supply line to at least one of the storage containers and/or at least one discharge line from at least one of the storage containers can be shut off or the flow can be changed, as well as with a control unit which is connected to the valve(s) and is designed in such a way that it controls them in a suitable manner, preferably depending on demand and/or depending on the heat available for loading.

Preferably, the heat storage system comprises a plurality of storage containers containing a latent heat storage medium, for example, a salt hydrate or preferably another medium that crystallizes upon heat dissipation. Heat can be supplied to the latent heat storage devices via the supply lines, and heat can be removed from them via the discharge lines as needed. The supply and removal of heat is controlled or regulated by a control unit that acts on valves that control or regulate the supply of heat or a heat transfer medium or the removal of heat or the heat transfer medium.

Furthermore, a heat storage system can be provided, comprising one or more storage containers in which a latent heat storage medium is located, wherein the heat storage system is designed such that it can be operated in a first operating mode in which sensible heat of the latent heat storage medium is used, and that it can be operated in a second operating mode in which the heat of fusion of the latent heat storage medium is used.

"Sensible heat" refers to the heat or heat content of the latent heat storage medium that can be extracted without a phase change occurring. According to this embodiment of the invention, the heat storage system can be operated in the first operating mode or in the second operating mode, or in both operating modes. The selection of the operating mode can preferably be predetermined by a control unit, which, depending on the heat requirement, operates the heat storage system in the first or second or both operating modes, for example, simultaneously or sequentially.

Preferably, several or all of the storage tanks can be individually controlled via valves. This makes it possible to selectively control one or more of the storage tanks, i.e., to "load" them with heat or to extract heat from them.

The terms “loaded” and “charging” or “discharged” and “discharge” used in this description mean the supply of heat to the latent heat storage medium or the removal of heat from the latent heat storage medium. In a further embodiment, it is provided that the selection of the operating mode takes place automatically and/or that the operating modes can be selected independently of one another.

For example, it is conceivable that the first operating mode or the second operating mode or both operating modes can be set automatically depending on the heat requirement.

In a further embodiment, it is provided that the heat storage system has one or more heat circuits or is connected to them, via which heat from the storage container(s) can be supplied to one or more heat consumers.

It is conceivable that the heat storage system has at least one heat circuit or is connected to at least one heat circuit in which at least one heat exchanger is provided for heating domestic water. For example, it is conceivable to use the heat stored in the latent heat storage media to heat domestic water, for example, in the home.

In a further embodiment, the heat storage system comprises or is connected to at least one heat circuit that serves as a heating circuit. This makes it possible to use the heat stored in the latent heat storage media to heat, for example, a building.

In a further embodiment, it is provided that the control unit is connected to at least one sensor which emits a signal representative of the heat demand of at least one consumption point and/or of the heat content of at least one storage container, and that the control unit controls the valve(s) of the line system of the storage containers as a function of the at least one sensor signal. In a further embodiment of the invention, it is provided that in the first operating mode at least one storage container is switched on if the amount of sensitive heat of the storage containers already switched on is not sufficient.

Furthermore, it can be provided that switching from the first to the second operating mode takes place when the sensitive heat of the latent heat storage medium is exhausted and/or that the control unit is designed in such a way that, when loading the storage containers, it first supplies heat to the storage container(s) with the lowest or a comparatively low heat content and, after its/their loading, preferably after its/their complete loading, switches to one or more further storage containers so that heat is supplied to this/these.

In a further embodiment of the invention, the storage container has a width or depth or diameter of < 50 cm, preferably < 30 cm, and particularly preferably in the range of 5 cm to 15 cm. These small dimensions allow the latent heat storage system, or at least the storage container(s), to be integrated into walls in a space-saving manner for stationary, i.e., stationary, operation, or to be implemented in a pre-wall installation.

As explained, the latent heat storage medium is preferably a storage medium that crystallizes when heat is removed and changes into the liquid state when heat is added.

Furthermore, it can be provided that the heat storage system is connected to a heat source, in particular a solar system, a burner for burning wood, wood pellets, oil or gas, etc., or includes such a heat source. This heat source is connected to the piping system and serves to supply the heat generated in this way to the storage container(s) as needed. The invention further relates to a building or a mobile unit, such as a caravan, motor vehicle and the like, with at least one heat storage system according to the present invention.

At this point, it should be noted that the present disclosure is not limited to the explicitly mentioned combinations of features, but features can be combined and claimed in any way or even in isolation.

Further details and advantages of the invention are explained in more detail with reference to the embodiments shown in the drawings.

Figure 1 shows a heat storage system as it can be used according to the invention with a cover (system) according to the invention, in a schematic view.

The heat storage system according to the present invention comprises a plurality of storage containers 1, referred to below as clusters 1. These clusters 1 are particularly suitable for stationary long-term storage of heat as well as for the consumption-based provision of heat. The latent heat storage unit consists of any desired number of storage containers or clusters 1, as shown in the figure.

The individual clusters 1 are filled with a latent heat storage medium.

The heat storage system according to the present invention further comprises a central control unit 10 with necessary sensors and heat circuits for loading and unloading the latent heat storage media with heat.

As can be seen from the figure, each of the clusters 1 can be individually controlled via valves combined in a valve block 2, ie heat can be selectively supplied to each cluster 1 or heat can be selectively removed from each cluster 1. This follows by appropriate switching of the valves located in the valve block 2, which in turn are controlled by the control unit 10.

As further shown in the figure, the heat of the latent heat storage media located in the clusters 1 can be used to operate a heating circuit, which is designated in the figure by reference numeral 6. This heating circuit is controlled by switching corresponding valves in the valve block 3.

Additionally, a further heat circuit is provided, which includes the plate heat exchanger 4, which serves to provide hot water for domestic use. The hot water connection, for example, of a house, is designated by reference numeral 5.

This additional heat circuit can also be controlled by corresponding valves in valve block 3. The valves in valve block 3, like the pumps of both heat circuits, are controlled by control unit 10.

As further shown in the figure, each cluster 1 comprises a tubular structure filled with the latent heat storage medium, preferably salt hydrate. A pipe runs through this pipe, which is filled with, or through which, water or another heat transfer medium flows, so that the water or another heat transfer medium, such as the latent heat storage medium itself, either releases heat to the latent heat storage medium located in cluster 1 or absorbs it, depending on the operating mode.

After being fully charged, the latent heat storage units or clusters 1 preferably release the stored heat in two separate modes. The disadvantages of an "either-or" mode of operation are thus avoided, although such an operation is also encompassed by the invention. The independent use of sensible heat and melting heat enables both short-term and long-term heat provision.

While the sensible heat is preferably stored for a short time and, according to the embodiment shown here, is mainly available for domestic water heating, the melting or latent heat can be made available for a long time and can be used, for example, to operate a heating system.

The operating behavior regarding short-term heat storage corresponds to the storage technology commonly available on the market. However, instead of a hot water tank, the example shown here uses a plate heat exchanger. This prevents the risk of contamination or Legionella infestation from the outset. Furthermore, energy losses are eliminated by preventive measures such as increasing the temperature to kill germs.

Cluster 1 and its latent heat storage media can be charged using any available heat source. Examples include solar thermal systems, wood pellets, fireplaces, oil or gas burners, etc.

The loading and unloading process, i.e. the supply of heat to the clusters 1 and the removal of heat from the clusters 1, is controlled and regulated via the integrated central control 10.

It can be provided that individual clusters 1 are selected and loaded or unloaded in an intelligent and proactive manner.

The sensible heat can also be selected and provided as required via the control 10. The long-term storage of heat preferably takes place in the form of the supercooled melt of the salt hydrate or another suitable latent heat storage medium. This storage is long-term and temperature-stable. It is conceivable to carry out the heat demand in 1 kWh clusters 1. It is conceivable to carry out the heat demand as well as the heat supply via the central control system 10. In this case, it can be provided that the heat demand with regard to the stored heat of fusion is carried out by a trigger mechanism 8 on cluster 1 initiating the recrystallization process of the salt hydrate. The salt hydrate in cluster 1 heats up to 58 °C, and the heat can be provided via the heat cycle. Of course, this value is only an example value that does not limit the invention. The trigger mechanism 8 is preferably activated automatically and particularly preferably by the control system 10.

As indicated in the figure, the clusters 1 are preferably tubular. In the illustrated embodiment, they have a diameter of 10 cm. They can thus be integrated into walls for space-saving installation, for example, or installed in front of the wall. This system is therefore particularly suitable for installation in buildings, where it can be used, for example, for heating domestic water and/or as part of or for operating the heating system.

Cluster 1 is charged from a heat source (not shown in detail) via corresponding controls of the valves of valve block 2. Preferably, solar thermal heat is supplied. The central control unit 10 selects a fully discharged cluster 1. The operating state is detected by a sensor 7 on cluster 1. The selected cluster 1 is then hydraulically selected via the installed valve blocks 2 and 3 and connected in the heat circuit in such a way that it can be "charged" with heat. The loading process continues until the sensor 7 located on or in cluster 1 detects the complete dissolution of the latent heat storage medium. After that, the loading process is complete.

If additional heat is available from a heat source, another cluster 1 is selected and its loading can be carried out as described.

After loading is complete, the latent heat storage medium is heated to a temperature of approximately 70 °C to 80 °C. Due to the thermal insulation, the sensitive heat can be stored temporarily and used for hot water production.

If hot water is requested, the control unit 10 detects this via the sensors on the heat exchanger 4 and selects a cluster 1. This cluster is then connected to the plate heat exchanger 4 via the valve blocks 2 and 3 or via the valve position of the valves located therein. By dissipating the sensitive heat using a heat transfer medium, the latent heat storage medium of the correspondingly selected cluster 1 is cooled and, depending on the amount of heat dissipated, is then, for example, in the state of a subcooled melt.

Since the crystallization process has not yet begun, the stored heat of fusion is still available.

If the heat quantity of one cluster 1 is not sufficient to cover the hot water demand, additional clusters 1 can be connected. If the storage tank is exhausted in relation to the sensitive heat quantity of all clusters 1, the additional demand can be covered by discharging the melting heat, as described below. The supercooled melt can store thermal energy for any length of time. When this stored heat is needed to meet demand, the central control unit 10 selects one or more clusters 1.

The crystallization process of the latent heat storage medium is initiated via the illustrated trigger mechanism 8. Cluster 1 is hydraulically connected via valve blocks 2 and 3 and connected to the demand source. The demand source can be either the plate heat exchanger 4, i.e., heat required to provide domestic hot water, or a heating circuit 6. Other heat consumers are also possible.

Thus, it is conceivable that one cluster 1 at a time is selected to extract heat from it. It is also conceivable that the charging and/or discharging of the clusters 1 occurs in groups, meaning that more than one cluster 1 is charged and/or discharged simultaneously.

As further shown in the figure, the piping system for the heat transfer medium located in cluster 1 can comprise a heat exchanger 9, which primarily serves to provide hot water. This heat exchanger, or the heat transfer medium located therein or flowing through it, primarily utilizes the sensible heat of the latent heat storage medium located in cluster 1.

In the exemplary embodiment presented above, the heat of fusion of the salt hydrate was requested after the sensible heat of the latent heat storage media was exhausted. In principle, it is of course also conceivable to perform these processes simultaneously rather than sequentially. For example, it is conceivable to use one or more clusters for domestic hot water preparation or for a heat sink for which the sensible heat is sufficient, and one or more other clusters for heating or for a heat sink for which the heat released by the phase change is required. It is particularly advantageous if the unloading processes as well as the loading process of the cluster(s) are carried out fully automatically by the controller 10.

A latent heat storage system is described above with reference to Fig. 1. A latent heat storage device according to the invention can be a single latent heat storage device described above as a cluster.

Such a latent heat storage device comprises, for example, a container and several plate-and-tube bundle heat exchangers, which can be hydraulically connected or are connected via a cover system as described above and shown in Figs. 2-4. The latent heat storage device (also referred to simply as the storage device) is preferably provided with partition walls that allow the use of multiple phase-change media. This achieves an advantageous spread of the phase-change temperature plateaus. To control the phase change from latent to crystalline, a trigger mechanism is preferably attached to each chamber of the storage device.

Fig. 2 shows a sectional view through a cover that can be used with a latent heat storage device according to the invention and, in this illustration, covers a tube bundle. Fig. 2 illustrates the sealing function of the cover.

The cover 11 provides a hydraulic connection between the supply and return lines. The cover 11 is connected to a tube 12 of the tube bundle and seals it. The tube 12 is equipped with an O-ring 13.

The cover 11 has a first (upper) clamping plate 14 and a second (lower) clamping plate 15. The tube 12 extends at least partially between the clamping plates 14 and 15 and is fluidly connected to the cover 11. The second clamping plate 15 has a depression, for example, with an inclination of 45°, for receiving the O-ring 13. The cover 11 also has a cover seal 16. Fig. 3 shows in the upper panel a view from below and in the lower panel a side view of a cover 11 according to the invention.

The cover 11 has an inlet 17 for the supply line, through which fluid can flow into the cover. The cover 11 also has an outlet 18 for the return line, through which fluid can flow out of the cover. A collecting channel 19, 20 is assigned to both the supply line and the return line. Furthermore, the cover 11 has screw connection points 21 for clamping screws.

Fig. 4 illustrates the principle of the basic, modular expandability of the cover system; a pair of covers 11 can be extended, for example, using T-pieces or connecting pieces. Sealing is preferably achieved at the ends of the strands with end caps.

As shown in Fig. 4, the collecting channels 19 and 20 can be connected to each other by means of connecting pieces/connecting elements.

Fig. 5 shows a latent heat storage device (storage device) according to the invention. The storage device is, for example, in a storage container designated cluster 1.

The reservoir is divided into two separate chambers 24, 25 by two partition walls 22, 23, each containing a phase change medium (phase change medium a or phase change medium b). In this example, two different phase change media are used.

Each chamber 24, 25 is equipped with at least one heat exchanger, in particular a tube bundle plate heat exchanger 26 and/or a trigger mechanism for triggering a phase transition of the respective phase change medium.

Fig. 6 illustrates a trigger mechanism for pneumatic-mechanical triggering. The basic principle of this mechanism is to cause the supercooled salt melt to spontaneous crystallization mechanically by changing the surface tension and introducing seed crystals by means of a pestle 27, using a pestle containing seed crystals.

Due to direct contact with the molten salt, new seed crystals immediately adhere to the plunger 27 after crystallization. This solution regenerates the trigger mechanism.

A seal 28 of the ram chamber 29 prevents the mechanism from becoming passivated during the melting phase. In this embodiment, the ram movement is controlled pneumatically via compressed air.

In this example, the trigger plunger 27 is actuated by spring force. For this purpose, a spring 30 is preloaded and maintained under tension by compressed air. The spring preload is adjusted using a pressure reducer.

The pressure reducer is connected upstream of the compressed air valves 31, 32, 33, and 34 (four solenoid valves in this variant). Valves 31, 32, 33, and 34 are controlled by thermostats, for example, so that the trigger mechanism can be activated preferably based on temperature.

In the example shown in Fig. 6, for example, a first thermostat controls M-valve 31, a second thermostat controls M-valves 32 and 33, and a third thermostat controls M-valve 34. A 2-out-of-3 excitation avoids false excitation, making the circuit single-fault proof.

In Fig. 6, the piston 35 is in the uppermost position and the plunger 27 of the trigger mechanism is in a parked position, i.e. it is not in contact with the phase change medium 36. In Fig. 7, the piston 35 is in the lower position and the plunger 27 of the trigger mechanism is in an active position, i.e. it is in contact with the phase change medium 36, so that the seed crystals located at the tip of the plunger 27 trigger a phase change of the phase change medium 36.

The change in surface tension and the introduction of seed crystals cause the supercooled molten salt to spontaneously crystallize. Contact between the plunger and the phase-change medium causes new crystals to adhere to the plunger immediately after crystallization, which can be used as seed crystals. In this way, the trigger mechanism regenerates itself without maintenance.

In the example shown in Fig. 7, the M valves 31 to 34 are energized, so that the lack of compressed air in the lower piston chamber causes the piston 35 to move downward. The spring 30 relaxes, and the plunger 27 is moved into the phase change medium 36.

In other words, for example, the activation of the first to third thermostats energizes all M valves, redirecting the compressed air. This relieves the pressure in the lower piston chamber via valves 31 and 32, allowing spring 30 to relax. This immerses the plunger 27 into the surface of the molten salt, thus initiating the crystallization process.

Sealing the plunger chamber prevents the mechanism from becoming passivated during the melting phase.

The ram movement, for example, is controlled pneumatically via a servo unit with an electric motor.

The plunger's immersion depth into the medium is preferably adjustable. The applied energy is determined by the spring force and is therefore preferably also adjustable. Fig. 8 shows a triggering mechanism that specifically and locally cools the phase change medium to a temperature below -12 °C, for example using a Peltier element.

The basic principle of this mechanism is to use a small insulated trigger chamber 37 filled with a phase change medium, such as salt hydrate, to specifically and locally cool the phase change medium to a temperature below -12 °C in order to trigger a phase transition.

The small insulated chamber 37 is connected to the phase-change medium in the heat storage unit via a small crystallization channel 38. Thus, the phase transition simulated in the small chamber 37 continues throughout the entire volume of the phase-change medium.

A corresponding arrangement is shown, for example, in Fig. 8. If a phase transition is to be triggered, the Peltier element 39 is activated via a control unit. The cold side of the Peltier element 39 is connected to the cooling plate 40, and the warm side is connected to the heat sink 41.

Heat is extracted from the salt hydrate in the subcooled melt via the heat conducting mandrel on the cooling plate 40. The melt is cooled in chamber 37 to less than/cooler than -12°C. Upon reaching at least -12°C, spontaneous crystallization of the salt melt in chamber 37 is initiated. The crystal formation process is further conducted via the crystallization channel 38, causing the salt hydrate present in the subcooled melt to crystallize and release its stored thermal energy as desired.

When melting the salt hydrate, it should preferably be ensured that the crystals in the trigger chamber 37 are also completely melted. The thermal insulation component 42, which is intended to limit the heat load on the Peltier element, ensures that the salt crystals in the Triggering chamber 37 is not possible. For this purpose, the Peltier element 39 is preferably briefly controlled via the control unit with the polarity reversed at the end of the melting process. The temperature in the triggering chamber 37 should briefly exceed 80°C to completely melt the salt hydrate.

Fig. 9 shows another embodiment of a trigger mechanism. This one uses a grinder. The basic principle of this mechanism is to introduce salt crystals into the phase-change medium, e.g., the supercooled molten salt, using a small grinder.

As shown in Fig. 9, the motor 43 drives the small grinder 44 via the drive shaft 45. Salt crystals are collected from the salt crystal container 46 and crushed in the grinder 44. These crystals fall directly into the molten salt via the collecting and filling funnel 47. The vapor barrier is intended to prevent condensate formation in the entire system during the melting phase.

The vapor barrier is to be installed below the collecting and filling funnel. Various designs are possible. A sealing lip with a slider, which opens during the release process and then closes again, meets these requirements.

Fig. 10 shows another latent heat storage device (storage device) according to the invention. The storage device is, for example, a storage container designated as cluster 1 in Fig. 1.

The storage tank has a storage shell 48 with which the storage tank is lined. The storage tank also has a cover system 49, to which the tubes of the tube bundle 51 are anchored by means of a clamping system 50.

The cover system 49 has a connection 52 for the flow and a connection 53 for the return. The storage tank can be filled with phase change medium via a filling nozzle 54. The storage tank has empty pipes 55 for a temperature sensor, which can be used to measure the temperature of the phase change medium in the storage tank.

For example, based on the measured values of the temperature sensors, a trigger mechanism can be activated by means of a control unit to trigger a phase transition in the phase change medium.

As shown in Fig. 10, the trigger mechanism comprises, for example, a servo motor 56 which is connected via a coupling with a coupling rod 57 to a trigger plate 58 immersed in the phase change medium.

To improve heat exchange through a larger surface area, fins 59 are provided.

List of reference symbols

1 : Storage tank

2: Valve block

3: Valve block

4: Heat exchanger

5: Hot water connection

6: Heating circuit

7: Sensor technology

8: Trigger mechanism

9: Heat exchanger

10: Control

11 : Cover with hydraulic forward-return connection

12: Tube bundle

13: O-ring

14: Upper clamping plate

15: Lower clamping plate with 45° countersink for O-ring

16: Cover seal

17: Admission Preliminary Round

18: Outlet return with connection piece

19: Collecting channel flow

20: Collecting channel return

21 : Screw connection points clamping screws

22: Partition wall

23: Partition wall

24: Chamber

25: Chamber

26: Shell and tube plate heat exchanger a, b: Phase change medium

27: Piston extended from salt 28: Sealing

S: Salt container

30: Spring

F1 : Spring tensioned

D1 : Compressed air switched through

M1 : M-valves de-energized 2 of 3 excitation

K: Piston in upper end position

36: Salt filling

M2: M-valves energized and controlled and release piston is relieved

F2: Spring is relaxed

D2: Compressed air is shut off

A: Trigger plunger is shot into the surface of the salt

37: Trigger chamber

38: Crystallization channel

39: Peltier element

40: Refrigeration plate with dome

41 : Heat sink

42: Insulation component

BS: Tank wall storage

43. Engine

44: Grinder

45: Drive shaft

46: Salt crystal container

47: Collecting and filling funnel with vapor barrier

CB: Cluster storage tank wall

US: Supercooled molten salt

48: Storage case

49: Lid system

50: Clamping system

51 : Tube bundle

52: Connection Vorlaut

53: Return connection : Filling nozzle . Empty pipes for temperature sensors : Servo motor Release mechanism : Coupling Coupling rod Release mechanism: Release plate : Slats

Claims

Claims 1. Storage device, preferably a latent heat storage device, with a storage shell which limits the storage volume and is designed such that the storage shell suppresses the tendency towards spontaneous crystallization of at least one phase change medium accommodated in the storage device, which phase change medium is preferably present in the supercooled melt. 2. Storage according to claim 1, further comprising a heat exchanger, preferably a tube bundle plate heat exchanger, which is of modular design and has a number of preferably identical sub-units, wherein the dimensions of the tube bundle plate heat exchanger can be flexibly adapted to the dimensions of the storage by selecting the number of sub-units. 3. Storage according to claim 2, characterized in that the tube bundle plate heat exchanger has at least one connecting component which is or can be connected in a force-fitting and/or form-fitting manner to at least one tube of the tube bundle, preferably to a plurality of the tubes of the tube bundle. 4. Storage tank according to claim 3, characterized in that the connecting component has at least one punched-out portion, preferably a star-shaped punched-out portion, into which a pipe of the pipe bundle is inserted or can be inserted. 5. Storage device according to one of claims 2 to 4, characterized in that at least one tube, preferably all the tubes, of the tube bundle have a cylindrical shape with a constant diameter and/or are not at least locally widened in order to enter into force-locking engagement with the connecting component. 6. Storage tank according to one of claims 2 to 5, characterized in that at least one tube, preferably all of the tubes, of the tube bundle is designed as an LI tube, which is preferably connected or connectable at both ends to the connecting component of the tube bundle plate heat exchanger. 7 Storage according to one of claims 2 to 6, characterized in that the tube bundle plate heat exchanger has at least two heat exchanger plates, the distance between which is selected such that a volume and/or mass segmentation of the phase change medium contained in the storage is ensured and/or the tendency towards spontaneous crystallization of at least one phase change medium accommodated in the storage is suppressed. 8. Storage tank according to one of the preceding claims, further comprising at least one cover and/or a cover system which is designed to provide a hydraulic connection of at least one tube bundle of a tube bundle plate heat exchanger to at least one energy source and at least one energy sink and/or is designed to provide a forward-return connection of the at least one tube bundle. 9. Storage device according to one of the preceding claims, further comprising at least one cover and/or a cover system, wherein one or more triggering mechanisms are provided for the targeted triggering of a phase transition in the phase change medium accommodated in the storage is/are arranged on or in the cover or cover system. 10. Heat storage system, preferably latent heat storage system with at least one storage device according to one of claims 1 to 9. 11. A building or mobile unit, such as a caravan, motor vehicle, or the like, having at least one heat storage system according to claim 10.