EP3126768A1 - Heat accumulation system and method of operating same - Google Patents

Abstract

The invention relates to a heat accumulation system comprising an inner storage tank, an inner thermal insulation layer that surrounds at least part of the inner storage tank, a device which is disposed on the side of the thermal insulation layer facing away from the inner storage tank in order to transfer a waste heat flow that is emitted by the inner storage tank and penetrates the inner thermal insulation layer to a heat transfer fluid, and a heat pump that includes an evaporator, the device being hydraulically connectable to the evaporator of the heat pump.

Description

 Heat storage arrangement and method for operating such

The present invention relates to a heat storage arrangement and a method for operating such. In this case, the heat storage arrangement contains an inner storage tank, an inner heat-insulating layer at least partially surrounding the inner storage tank, a device for transferring a heat loss layer passing through the inner heat-insulating layer of the inner storage tank to a heat transfer fluid and a heat pump containing an evaporator. The device for transmitting the heat flow is hydraulically connectable to the evaporator of the heat pump.

In the area of building energy supply and thermal solar energy use, solar thermal combined systems are systems that serve both domestic water heating and heating support. These plants usually have at least one hot water tank, which is provided with thermal insulation in order to heat lessen the memory. The term "heat losses of the storage" or in short "storage losses" is understood here to mean the self-discharge of the storage due to the heat flow through the thermal insulation to the environment. Typical combination storage tanks according to the prior art have a heat loss rate of about 4 W / K at a volume of 1,000 liters. In a medium

Temperature difference to an unheated installation room of 35 K and a heating period of 8 months (September to April), these heat losses add up to about 800 kWh. In combi systems come, especially with respect to the domestic water heating, various memory versions are used, of which the most important of Peuser (FA Peuser, K.-H. Remmers and M. Schnauss: long-term experience solar thermal, Solarpraxisverlag, ISBN 3-934595-07-3, 2001 ) to be discribed. With regard to the classification of thermal energy storage is always to sensitive heat storage, so heat through

Increase the temperature of a medium (without phase change). Since the storage medium here is water throughout, it can immediately serve as a heat carrier fluid through which heat exchangers (for example radiators) flow.

In recent years, more and more concepts are being worked on in order to increase the solar coverage of the total heat demand of a building in combination plants. This is compared to today typical combination systems both an increase in the collector surface and an increase in the heat capacity of the memory required. The concept of the "Solar-Active-House" relies on very large storage volumes for hot water storage systems, whereby the long-term goal is to develop new types of thermochemical heat storage with a higher energy density compared to hot water storage by a factor of 8. Another approach to building energy supply that has been increasingly pursued in recent years is the combination of thermal solar energy use with electric heat pumps.

In latent heat storage, a phase change (usually solid) is used to increase the usable heat capacity in a given temperature interval. The phase change material (PCM, eg water / ice, salt hydrates or paraffin) can either be an unencapsulated substance directly fill a storage tank into which a heat exchanger is integrated, or the phase change material can be integrated into a composite (eg a graphite matrix to increase the thermal conductivity) are formed from the shaped body such as plates, which are brought into heat exchange with a heat transfer fluid. An encapsulation of the phase change material in macrocapsules or microcapsules is also known, wherein the macrocapsules can be introduced directly into a storage container, so that a heat transfer fluid can flow between the capsules. Phase change slurries (PCS) are also known which consist of a suspension of PCM microcapsules in a heat transfer fluid or of an emulsion. The use of PCS in a heat accumulator for buildings is described in EP 1 798 487 B1. Furthermore, sorption storage and thermochemical storage are known.

The main problems of the sorption reservoirs to date are high costs, not yet available sorption materials with regard to the requirement of the application (in particular storage density and long-term stability) and not yet mature concepts for system integration in building energy systems.

The most important goals in the further development of thermal storage are the increase of the usable energy density and, if necessary, the heat transfer performance of the storage (if the storage medium is not also heat transfer fluid) and the increase in storage efficiency, which is defined as the energy usable in the storage discharge in relation to the Storage charge spent energy. To increase storage efficiency, the reduction of heat loss plays a key role in sensitive and latent heat storage. An important approach here is improved thermal insulation (eg by evacuated highly porous insulating materials such as perlite or fumed silica, so-called vacuum super insulation). For a given storage capacity, there is a close relationship between energy density and storage efficiency, since a storage with a higher energy density can be realized in a smaller volume and thus with a smaller surface, so that the heat losses are reduced with the same quality of thermal insulation. Since latent heat storage (and especially sorption and thermochemical storage) are significantly more expensive than water storage due to the material costs in the production and also in most known designs, the heat transfer performance is a limiting factor, was looking for opportunities, the benefits of latent - or Sorptionsspeichern (high energy density or significantly reduced heat losses) with those of water storage (cost-effective, high heat transfer performance) to combine. As a result of these efforts, various combination memories are known. For example, EP 2204618 A2 describes a hot water storage tank that contains a jacket around the water tank in the upper area, which is filled with a PCM.

Furthermore, thermal storage are known, which are used in combination with solar and heat pump systems. For example, in DE 20 2006 012 871 Ul a water / ice storage is described, the

 Uniformization of the heat supply of a heat pump is used and is located in the flow of the heat pump evaporator.

The combination of an absorption refrigerating machine / heat pump with a latent storage is described in WO 2006/100047 A2. Here is the

Latent heat storage integrated into the condenser circuit of the absorption heat pump.

In large hot water storage tanks according to the state of the art, as required for combination systems with high solar coverages, the heat losses to the environment represent a hitherto unavoidable disadvantage. According to the standard DIN EN 12977-1 (2012), the heat loss rate of hot water storage tanks in W / K is not greater than 0.16 x _Λ / ϊ ^ with the nominal volume V _n in liters. For a storage volume of 10 m ³ , according to this formula, the heat loss rate is 16 W / K and the heat losses / day at

ΔΤ = 35 K is 13 kWh. For a typical small combi system with a 1 m ³ solar storage tank, permissible heat losses of 4.3 kWh / day result under the same conditions. These heat flows are disadvantageous in that they increase the heating energy requirement of the building (in particular the proportion not covered by the solar system) when the storage is located outside the insulated building envelope. Is he inside Although these heat flows cover part of the heating load in winter, they can contribute to the building overheating in summer or increase the need for cooling. Overall, the state of development is thermal storage for solar thermal

Combination systems with high solar coverages still unsatisfactory. The concept of the "Solar Active House" with a very large hot water storage tank (from approx. 5 m ³ ) addresses only one niche market (almost exclusively in the new building sector), as the storage is located within the insulated building envelope due to the large heat losses should and in the

Only rarely build old buildings.

However, there is a need for improved systems for the thermal solar energy use because of the great potential for the substitution of fossil energy carriers, especially in old buildings. Here are the attractive ways to

Reduction of heating demand in the course of a refurbishment is often limited, be it due to facades worth preserving or due to only very costly recoverable thermal bridges, lack of space for the roof truss and basement ceiling insulation etc. The use of highly efficient compression heat pumps is often difficult in the refurbishment of existing buildings

Soil as a heat source can not be developed or only with great effort and possibly unreasonable burdens on the building users. However, electric heat pumps that use air as a source of heat can usually achieve little more than the primary efficiency of gas fired boilers in the building stock - with annual work figures of 2.6.

When retrofitting thermal storage in old buildings, there is often a problem regarding the accessibility of the installation rooms (eg basement rooms). The recoverable storage volume is often limited by the dimensions of the access ways (doors, stairs). This problem can be solved either by a construction of a storage container on site in the installation room or by a modular storage concept. For example, EP 2532940 A2 describes a pressure-loadable segment memory which can be designed in such a way that the individual segments need not be pressure-resistant at their contact surfaces. The hydraulic connection between The individual segments can be realized by means of pipe grommets that seal when filling the memory under pressure due to the pressure resulting from the pressure to the outside.

As is known from DE 20 2006 012871 U1, it is advantageous to connect a buffer store upstream of the evaporator of a heat pump when a solar collector is the only heat source for the heat pump. There, however, the use of the heat loss of a further heat storage is not described. The buffer is designed as water / ice storage. Such is not readily available for sorption heat pumps that use water as a working fluid, since usually the evaporator of the heat pump must be kept at temperatures above 0 ° C to prevent its freezing.

For solar thermal combined systems (domestic hot water and heating support) with high solar cover levels (based on the total heat demand), there are so far no mature concepts for the integration of sorption heat pumps as an alternative heat source. Furthermore, it would be desirable to be able to set up the required large hot water tank outside the insulated building envelope. However, there is no system for recovering the then during the heating period occurring heat losses of this memory.

Object of the present invention is therefore to provide a heat storage arrangement that significantly increases the total energy efficiency of the system with low cost in solar thermal combined systems with a heat pump as an alternative heating system. In particular, the heat storage arrangement should be advantageously usable in cases where the solar heat storage is outside the insulated building envelope, as is often the case with energetically renovated existing buildings. Furthermore, the solution according to the invention should be so executable that a temporal flexibilization of the heat pump operation (load displacement / load decoupling) is made possible according to aspects that are independent of the current heat demand of the building and the current solar radiation offer.

This object is related to a heat storage arrangement with the Characteristics of claim 1 and with respect to a method for operating a heat storage arrangement having the features of claim 15. The respective dependent claims are advantageous developments.

According to the invention, a heat storage arrangement is specified which comprises an inner storage tank, an inner heat-insulating layer at least partially surrounding the inner storage tank, a device disposed on the side of the thermal-barrier layer facing away from the inner storage tank for transferring a heat loss layer of the inner storage tank passing through the inner heat-insulating layer to a heat - Includes meträgerfluid and a heat pump containing an evaporator. The device for transmitting the waste heat flow is hydraulically connectable to the evaporator of the heat pump.

According to the invention it was recognized that for solar thermal combined systems (for hot water and heating support), which use a heat pump as an alternative heat source, the waste heat flows can be used by the storage insulation in large parts in a simple manner, and that this to a significant increase in the solar coverage of the

Systems and a corresponding primary energy savings. By means of the heat storage arrangement according to the invention, the loss heat flow of an insulated heat accumulator can be absorbed at a low temperature level and supplied to the evaporator of a heat pump.

For the energetic refurbishment of existing buildings, the system according to the invention has the advantage that heat storage of solar thermal combined systems can be arranged outside the insulated building envelope, without the heat flow is lost to the heating system through the thermal insulation of the memory. By the system according to the invention, therefore, the primary energy cost of the heating system compared to solar thermal combination systems according to the prior art can be reduced with the same collector and memory size.

Also compared with solar thermal technology already known from the prior art. Combi systems in conjunction with a heat pump reduce the primary energy costs or increase the solar coverage. This is achieved by utilizing the heat losses of the accumulator to raise the temperature level in the evaporator circuit of the heat pump, so that the heat pump can achieve a higher annual operating efficiency.

A preferred embodiment provides that the device for transmitting a heat flow is designed as a sheath storage, wherein the sheath memory, a fluid or a phase change material (PCM), which may be in thermal contact with the heat transfer fluid contains.

A further preferred embodiment provides that the device for transmitting a heat flow is designed as a heat exchanger and contains no further memory elements.

In a further preferred embodiment of the heat storage arrangement according to the invention, an outer heat-insulating layer is disposed on the side of the inner heat-insulating layer facing away from the device, wherein the heat transfer resistance of the inner thermal barrier coating is greater than the heat transfer resistance of the outer thermal barrier coating. Due to the outer heat-insulating layer, a condensation of atmospheric moisture on the outside of the storage arrangement can be avoided since the water vapor contained in the ambient air can not reach the cold surfaces of the heat storage arrangement. In this case, relatively diffusion-tight (closed-cell) insulating materials can be used as the outer thermal barrier coating.

Furthermore, it is preferred that the device formed as a sheath storage is formed by at least two, preferably made of plastic, hollow body, each having an outer wall and an inner side and an outer side, wherein the shape of the at least two hollow body adapted to the surface of the inner thermal barrier coating is and each two adjacent hollow body of the at least two hollow bodies have a common contact surface. The at least two hollow bodies are in this case substantially form-fitting around the arrangement of inner storage container and inner thermal barrier coating arranged around. Advantage of such a modular, consisting of several hollow sheath storage is its easier Einbringbarkeit in rooms with narrow accesses (as typically cellar rooms in the renovation of buildings). It can be here in a given room with a narrow access (door, stairs) can be introduced effective

Storage capacity compared to a water reservoir according to the prior art can be significantly increased. For the hollow body, extrusion blow molding offers a cost-effective production process. A further preferred embodiment provides that in each case one of the at least two hollow bodies, and in each case a part of the inner thermal barrier coating and optionally each part of the outer thermal barrier coating is integrated in each one of at least two prefabricated elements, wherein the at least two prefabricated elements substantially form - Are arranged around the inner storage container around.

A further preferred embodiment of the heat storage arrangement according to the invention provides that the inner thermal barrier coating consists of a hard foam and substantially positively abuts a wall of the inner storage container, also the outer wall of the at least two hollow body and / or optionally the outer thermal barrier coating is made hard enough, in order to limit a deformation of the outside of the hollow body, and the at least two hollow bodies are held in position by at least one tensile structure, preferably a steel drawstring, wherein the at least one tensile structure on an outer periphery of the assembly comprising the inner storage container inner heat-insulating layer, which is arranged at least two hollow body and optionally the outer thermal barrier coating. This arrangement prevents the hollow bodies from bulging too much at the common contact surfaces. Furthermore, by the support on the inner

Storage tank and the drawstrings of the sheath storage are operated at a higher pressure. An annular arrangement of the hollow body offers the advantage over an alternative linear arrangement that the pressure-stable end plates required for a linear arrangement are not required. Furthermore, it is preferred that the at least two hollow bodies are designed such that they have at least one fluid passage at each contact surface to an adjacent hollow body, which is sealed by a pressure applied via the zugbelastbare structure contact pressure to the outside, and the at least two hollow body in addition a total of two more Have fluid connections on its outer side, so that on the at least two hollow bodies, a fluid circuit is constructed, through which all existing hollow body can be flowed through. Particularly preferably, the at least two hollow bodies are designed so that they have two fluid passages at different heights at each contact surface to an adjacent hollow body and also each have a tensile structure in the respective height of these two fluid passages. In this way, the contact pressure can be maximized. In addition, if two fluid passages are present at different heights, a thermal stratification in the hollow bodies can occur as a result of the buoyancy forces.

In a further preferred embodiment, the at least two prefabricated elements are designed so that heat-conducting planar elements rest in the regions on the inner heat-insulating layer, in which a heat flow from the inner storage container to the at least two

Hollow bodies could get past the environment of the heat storage arrangement, and the heat-conducting sheet-like elements have an overlap surface with the inside of the at least two hollow body, at least partially umzulei- the heat flow to the at least two hollow bodies, wherein the heat-conducting sheet-like elements are preferably metal sheets. By this embodiment, an even more efficient recovery of the heat losses of the inner storage container, in particular at the lid and bottom area, can be achieved. Furthermore, it is preferred that the sheath storage contains at least one phase change material (PCM), which has a melting point between -5 ° C and 30 ° C. The PCM is preferably ice here if the refrigerant used in the heat pump allows operation below 0 ° C. This is the case, for example, with sorption heat pumps with ammonia or methanol as refrigerant and with almost all compression heat pumps. In a further preferred embodiment, the jacket reservoir contains at least one phase change slurry (PCS) which is pumpable and can be used to transfer heat to the heat pump evaporator, the PCS containing at least one phase change material (PCM) having a melting point between 5 ° C and 30 ° C. The phase change fluid here is preferably an ice slurry.

It is further preferred that the melting point of the at least one phase change material (PCM) is between 4 ° C and 20 ° C. Here, the refrigerant used in the heat pump is preferably water.

A further preferred embodiment of the heat storage arrangement according to the invention provides that the evaporator of the heat pump in addition to the shell memory with at least one other heat source is connected, at least a serial flow of the further heat source, the shell memory and the evaporator of the heat pump with the heat transfer fluid allows in this order becomes. In this way, a temporal flexibility of the heat pump operation (load displacement / load decoupling) can be made possible.

Furthermore, it is preferred that the heat pump is a sorption heat pump, in which water is preferably used as the refrigerant. In the event that the heat pump is a thermally driven heat pump (in particular sorption heat pump), the temporal flexibility is relevant if the heat source of the heat pump is coupled to a power generator (cogeneration). Due to the high mass-specific heat of evaporation of water, the highest (annual) operating figures can be achieved with water as the refrigerant for sorption heat pumps, provided that suitable low-temperature heat sources are available.

The present invention is also directed to a method for operating a heat storage arrangement according to the invention, wherein heat from a heat source, preferably a solar thermal system, introduced into the inner storage tank and used after removal to cover a heating and / or hot water demand, wherein the heat - Additional heat pump is also used to cover the heating and / or hot water demand, characterized in that when the heat of the inner storage tank in a foreseeable future time, preferably within the next two to four days, probably not alone Cover heat and / or hot water requirements, the heat pump is switched on before a complete discharge of the inner storage container periodically to cover the heating and / or hot water demand in the way that on average over the storage period of the device for transmitting a heat flow of the evaporator the heat pump receives at least the waste heat flow from the inner storage tank.

Whether the heat of the inner storage tank alone can cover the heating heat and / or hot water demand in a specific time can be assessed, for example, by means of a predictive control.

If the device for transmitting a heat flow is designed as a sheath storage, this is preferably operated in a temperature range between 0 ° C and 20 ° C. The volume of the jacket storage is then preferably dimensioned so that the heat flow from the inner storage tank over a period of 8 hours at most leads to a temperature increase of 10 K in the shell memory. This achieves a temporal flexibility with regard to the heat pump operation, which can be used, for example in the case of compression heat pumps, to take electricity grid loads and fluctuating electricity prices into account.

If the heat pump is an electric heat pump, it is possible to use the sheath accumulator for charging the inner storage container with high power, preferably in times of favorable electricity supply.

A further preferred variant of the method according to the invention provides that the heat pump is a thermally driven heat pump, preferably a sorption heat pump, and drive heat for the heat pump is provided by an additional heat source, preferably a burner or a CHP plant. A further preferred variant of the method according to the invention provides that, when falling below a first threshold temperature in the inner storage tank, the heat and / or hot water demand is primarily covered by the heat from the heat pump when a second threshold temperature is exceeded in the heat flow transfer apparatus. and the coverage of the heating heat demand otherwise takes place primarily by the heat from the inner storage tank.

In a further preferred variant of the method according to the invention, the inner storage tank is used as a layer heat storage, wherein the heat pump additionally introduces heat into a central region of the inner storage tank. In this way, the annual yield of the solar system can be increased.

The present invention will be explained in more detail with reference to the following figures, without restricting the invention to the specifically illustrated embodiments and parameters.

Fig. 1 shows a detail of a cross section through a part of a heat storage arrangement according to the invention. An inner storage container 1 is surrounded by an inner thermal barrier coating 2. On the side facing away from the inner storage tank 1 side of the thermal barrier coating 2 is a device 3 for transmitting a passing through the inner thermal barrier coating 2 heat loss of the inner storage tank 1 to a heat transfer fluid, which is designed as a shell memory. On the side facing away from the inner thermal barrier coating 2 side of the designed as a shell memory device 3, an outer thermal barrier coating 5 is arranged. In this case, the jacket store is made up of a plurality of hollow bodies which have been produced by extrusion blow molding from a suitable plastic (for example HDPE). The individual hollow bodies are shaped so that they can be positively arranged around the inner storage container 1 and the inner thermal insulation layer 2.

2 shows a part of a device 3 for transferring a heat loss stream passing through the inner thermal barrier coating 2 of the inner storage tank 1 onto a heat transfer fluid from various perspectives. ven. The device 3 is designed as a sheath storage and is constructed from hollow bodies. The connection of the hollow body is made by a quick connection system with flexible hose pieces 6 and prefabricated on the hollow body attached fittings 7. Such quick connectors are known from solar thermal collectors and are usually realized there because of the high temperature requirements with stainless steel corrugated pipes. From the heating technology are also tool-free mountable quick connectors for plastic / metal composite pipes known that may be suitable here (eg plug-in fittings). In the region of the connecting pieces 7 are on the hollow bodies indentations or recesses, which allow a connection of the elements in a form-fitting arrangement around the inner storage container 1 around. The entirety of the hollow body is connected by a Tichelmann interconnection in order to achieve the most uniform possible flow through the elements. To further favor this, perforated tubes 9 are arranged within the storage elements between the connecting pieces 7, which together with the connecting pieces represent the distributor and collector of the Tichelmann interconnection.

Claims

Patent claims Heat storage arrangement containing an inner storage container (1), an inner thermal insulation layer (2) which at least partially surrounds the inner storage container (1), a device (3) arranged on the side of the thermal insulation layer (2) facing away from the inner storage container (1) for transmitting a through the inner thermal insulation layer (2) passing through the heat loss flow of the inner storage container (1) onto a heat transfer fluid and a heat pump (4) containing an evaporator, the device (3) being hydraulically connectable to the evaporator of the heat pump (4). Heat storage arrangement according to the preceding claim, characterized in that the device (3) for transmitting a heat flow is designed as a jacket storage, the jacket storage containing a fluid or a phase change material (PCM) which can be in thermal contact with the heat transfer fluid. Heat storage arrangement according to claim 1, characterized in that the device (3) for transmitting a heat flow is designed as a heat exchanger and does not contain any further storage elements. Heat storage arrangement according to claim 2, characterized in that an outer thermal insulation layer (5) is arranged on the side of the device (3) designed as a jacket storage layer facing away from the inner thermal insulation layer (2), the heat transfer resistance of the inner thermal insulation layer (2) being greater than the heat transfer resistance the outer thermal insulation layer (5). Heat storage arrangement according to one of claims 2 or 4, characterized in that the front is designed as a jacket storage Direction (3) is formed by at least two hollow bodies, preferably made of plastic, each of which has an outer wall as well as an inside and an outside, the shape of the at least two hollow bodies being adapted to the surface of the inner thermal insulation layer (2) and each two adjacent hollow bodies of the at least two hollow bodies have a common contact surface. Heat storage arrangement according to the preceding claim, characterized in that one of the at least two hollow bodies, as well as a part of the inner thermal insulation layer (2) and optionally a part of the outer thermal insulation layer (5) are integrated into one of at least two prefabricated elements, whereby the at least two prefabricated elements are arranged essentially in a form-fitting manner around the inner storage container (1). Heat storage arrangement according to one of the two preceding claims, characterized in that the inner thermal insulation layer (2) consists of a rigid foam and rests essentially in a form-fitting manner on a wall of the inner storage container (1), as well as the outer wall of the at least two hollow bodies and/or optionally the outer thermal insulation layer (5) is made hard enough to limit deformation of the outside of the hollow bodies, and the at least two hollow bodies are held in position by at least one tensile structure, preferably a tension band made of steel, the at least one tensile structure on one outer circumference of the arrangement comprising the inner storage container (1), the inner thermal insulation layer (2), which is arranged at least two hollow bodies and optionally the outer thermal insulation layer (5). Heat storage arrangement according to the preceding claim, characterized in that the at least two hollow bodies are designed so that they have at least one fluid passage through each contact surface to an adjacent hollow body a contact pressure that can be applied via the tensile structure is sealed to the outside, and the at least two hollow bodies additionally have a total of two further fluid connections on their outside, so that a fluid circuit is built on the at least two hollow bodies through which all existing hollow bodies can flow. Heat storage arrangement according to one of the two preceding claims, characterized in that heat-conducting flat elements rest on the inner thermal insulation layer (2) in the areas in which a heat flow from the inner storage container (1) passes the at least two hollow bodies to the surroundings of the heat storage arrangement could, and the heat-conducting flat elements have an overlap surface with the inside of the at least two hollow bodies in order to at least partially redirect the heat flow to the at least two hollow bodies, the heat-conducting flat elements preferably being metal sheets. Heat storage arrangement according to one of claims 2 or 4 to 9, characterized in that the jacket storage contains at least one phase change material (PCM) which has a melting point between -5 ° C and 30 ° C. Heat storage arrangement according to one of claims 2 or 4 to 9, characterized in that the jacket storage contains at least one phase change fluid (Phase Change Slurry, PCS) which is pumpable and can be used for heat transfer to the evaporator of the heat pump (4), the PCS contains at least one phase change material (PCM) which has a melting point between -5 °C and 30 °C. Heat storage arrangement according to the preceding claim, characterized in that the melting point of the at least one phase change material (PCM) is between 4 °C and 20 °C. Heat storage arrangement according to one of claims 2 or 4 to 11, characterized in that the evaporator of the heat pump (4) can be connected to at least one further heat source in addition to the jacket storage, at least one being serial Flow through the further heat source, the jacket storage (3) and the evaporator of the heat pump (4) with the heat transfer fluid is made possible in this order. Heat storage arrangement according to one of the preceding claims, characterized in that the heat pump (4) is a sorption heat pump, in which water is preferably used as the coolant. Method for operating a heat storage arrangement according to one of the preceding claims, wherein heat from a heat source, preferably a thermal solar system, is introduced into the inner storage container (1) and, after removal, is used to cover heating and/or hot water requirements, with the heat pump ( 4) additional heat given off is also used to cover the heating and/or hot water requirements, characterized in that if the heat of the inner storage container (1) is not expected to occur in a foreseeable future period, preferably within the following two to four days alone can cover the heating heat and/or hot water requirement, the heat pump (4) is switched on periodically before the inner storage container (1) is completely discharged to cover the heating heat and/or hot water requirement in such a way that, on average over time, over the storage period the device (3) for transmitting a heat flow, the evaporator of the heat pump (4) absorbs at least the lost heat flow from the inner storage container (1). Method according to the preceding claim, characterized in that the heat pump (4) is a thermally driven heat pump, preferably a sorption heat pump, and by an additional heat source, preferably a burner or a CHP system, drive heat for the heat pump (4) is provided. 17. The method according to one of the two preceding claims, characterized in that when the temperature falls below a first threshold temperature in the inner storage container (1), the heating and/or hot water requirements are covered primarily by the heat from the heat pump (4) when in the device (3) a second threshold temperature is exceeded in order to transfer a heat flow, and the heating requirement is otherwise primarily covered by the heat from the inner storage container (1). 18. The method according to any one of claims 15 to 17, characterized in that the inner storage container (1) is used as a layered heat storage, the heat pump (4) additionally introducing heat into a central region of the inner storage container (1).