Heat and cold storage unit having a countercurrent heat exchanger

Abstract

A heat storage unit and heat exchanger has a first fluid line, a second fluid line, a heat exchanger and a storage container. The heat exchanger is designed to transfer heat between the first fluid line and the second fluid line. The storage container is designed to receive a thermal storage medium. At least a portion of the heat exchanger is arranged in the storage container in order to allow heat transfer between the heat exchanger and the thermal storage medium.

Description

Heat and cold storage with counterflow heat exchanger AREA

[0001] The invention relates to the technical field of thermal energy storage and in particular to a heat or cold storage device with an integrated counterflow heat exchanger and to a system with a heat storage device and a cold storage device. BACKGROUND

[0002] The energy absorbed by a building's roof is usually sufficient to cover the building's energy needs, at least on average, throughout the year. A photovoltaic system with photovoltaic modules can be used to generate electricity and / or a photothermal system can be used to generate hot water. The energy generated can be supplied to consumers in the building.

[0003] Furthermore, additional variable energy sources can be available for use in a building, such as waste heat from a chiller or electricity generated by a wind turbine. Heat pumps of various designs are regularly used, for example, in single-family and multi-family homes, to make even low-temperature heat sources usable.

[0004] However, in all of the aforementioned cases, the problem is that corresponding (renewable) energy generation and energy consumption by private households or industrial complexes often diverge both in the short term and seasonally. In particular, the potential for renewable energy generation is regularly higher in summer than in winter, e.g., through photovoltaics or photothermal energy, even though energy consumption is significantly higher in winter, especially for space heating and domestic hot water.

[0005] One way to decouple energy consumption and generation is through thermal energy storage. These can temporarily store the generated energy in cold or heat storage systems for short- to long-term periods in order to compensate for different times of energy generation and consumption.

[0006] Conventional heat (or cold) storage systems comprise multi-zone storage systems, with a heat exchanger extending through the central area to transfer heat (or cold). Spatially separated from this are the outer areas at different heights. several heat exchangers are arranged to extract the heat (or cold) in the heat storage (or cold storage). OVERVIEW

[0007] The heat storage (or cold storage) devices known from the prior art are not optimized for use in a system with a photovoltaic system and / or a heat pump. It is an object of the invention to provide a heat storage (or cold storage) device optimized for use in a system with a photovoltaic system and / or a heat pump.

[0008] This object is achieved according to the invention by a heat accumulator and exchanger having the features of claim 1, a use of the heat accumulator and exchanger having the features of claim 11 or 12, a system having the features of claim 13 or 18, a method having the features of claim 19 or 25, a computer program having the features of claim 29, a local heating network having the features of claim 30, and a local heating network system having the features of claim 32. Embodiments of the invention are specified in the dependent claims.

[0009] According to a first aspect, a heat storage and exchanger comprises a first fluid line, a second fluid line, a heat exchanger, and a storage container. The heat exchanger is configured to transfer heat between the first fluid line and the second fluid line. The storage container is configured to accommodate a thermal storage medium. At least a portion of the heat exchanger is arranged in the storage container to enable heat transfer between the heat exchanger and the thermal storage medium.

[0010] This creates a highly integrated heat storage and exchanger that allows heat from a solar thermal system and, if currently in operation, a heat pump to be transferred into the storage tank via the heat exchanger. If the heat pump is not currently in operation, the heat storage and exchanger can continue to operate unchanged to continue transferring heat from the solar thermal system to the heat storage and exchanger.

[0011] For this purpose, the solar system or heat pump can be connected to the first or second fluid line, respectively. This avoids the need for further adjustments, for example, regarding electrical connections. [oi2] Furthermore, the heat exchanger, as a result of its arrangement in the storage tank, can enable effective heat transfer between the first and second fluid lines, for example, between the photovoltaic system and a cold side of the heat pump. The effective heat transfer is particularly a result of the generous space available in the storage tank, due to which the heat exchanger can be designed, for example, as a double-pipe heat exchanger, with a large contact area between the first and second fluid lines. In conventional systems, however, no heat exchanger is usually provided that would enable direct and effective heat transfer between the first and second fluid lines or between the heat pump and the photovoltaic system.

[0013] In some embodiments, the heat exchanger is arranged largely within the storage tank. For example, the heat exchanger can be arranged within the storage tank for at least half, at least two-thirds, or at least three-quarters of its length. Alternatively or additionally, the heat exchanger can be arranged within the storage tank for at least half, at least two-thirds, or at least three-quarters of its volume.

[0014] The thermal storage medium may comprise or be a liquid, particularly at room temperature. For example, the thermal storage medium may comprise water, for example, in a volume fraction of at least half, at least two-thirds, or at least three-quarters.

[0015] However, those skilled in the art will understand that various thermal storage media can be used, which need not be limited to heat storage through temperature changes of the solid / liquid storage medium. For example, the storage container can also contain a phase-change material for storing thermal energy as latent energy, thermochemical storage media, or a salt dehydration storage system for insulation-free long-term storage.

[0016] In some embodiments, the heat exchanger is designed as a counterflow heat exchanger.

[0017] In appropriate embodiments, the effectiveness of heat transfer between the first and second fluid lines or between the heat pump and the photovoltaic system can be further improved.

[0018] The heat exchanger may comprise or be designed as a multi-tube heat exchanger, a double-tube heat exchanger, a plate heat exchanger or a tube bundle heat exchanger.

[0019] The first fluid line and the second fluid line may be in direct contact in the heat exchanger and / or over a range of at least 0.5 m or of at least 1 m or of at least 2 m.

[0020] In appropriate embodiments, the effectiveness of heat transfer between the first and second fluid lines, or between the heat pump and the photovoltaic system, can be further improved. Such embodiments can be made possible by arranging the heat exchanger in the storage tank.

[0021] In some embodiments, the storage tank is a cistern storage tank. Alternatively or additionally, the storage tank can have a volume for the thermal storage medium of at least 1 m 3or of at least 2 m 3 or at least 3 m 3 Alternatively or additionally, the storage tank may be designed for underground installation.

[0022] In particular, the heat storage and heat exchanger can be configured to be installed at least partially in the ground as a single piece, i.e., with the heat exchanger arranged therein. After partial installation in the ground, connections for the first and second fluid lines can protrude upwards from the ground and be available for connecting the photovoltaic system and heat pump, so that an integrated system can be implemented quickly, efficiently, and cost-effectively.

[0023] In appropriate embodiments, the storage tank can provide a sufficiently large storage capacity to store enough heat (or cold) to cover fluctuations in the demand of a building over periods of months, in particular seasonal fluctuations.

[0024] In some embodiments, the first fluid line and / or the second fluid line is configured to pass through an upper surface of the thermal storage medium at least once or at least twice when the thermal storage medium is arranged in the storage container. Alternatively or additionally, the first fluid line and / or the second fluid line can pass through the storage container at least once or at least twice in the uppermost quarter of its height, especially in the uppermost fifth of its height or at its top.

[0025] Corresponding embodiments can simplify the connection of the heat storage and exchanger to other components of the system, in particular when the heat storage and exchanger is arranged in the ground, where, for example, the top quarter, the top fifth or the top of the storage tank protrudes from the ground.

[0026] In some embodiments, the heat storage and exchanger is located in an outdoor area (i.e., relative to a building), for example, above ground or underground in the vicinity of a neighboring building. In other words, the heat exchanger may not be located within a building.

[0027] The heat accumulator and exchanger can be coupled to an associated heat storage unit located in a building. For example, in embodiments in which the heat accumulator and exchanger is configured as an ice storage unit or latent heat storage unit, the associated heat storage unit can be a cold storage unit. Alternatively or additionally (additionally, for example, in embodiments in which the heat accumulator and exchanger forms a second heat accumulator and exchanger), the associated heat storage unit can be a multi-zone storage unit.

[0028] In some embodiments, the first fluid line and / or the second fluid line is configured for evaporation and / or condensation of a refrigerant therein.

[0029] In some embodiments, the heat storage and exchanger comprises at least one additional heat exchanger.

[0030] The at least one additional heat exchanger can be configured for thermal coupling to the thermal storage medium and / or arranged in the storage container, in particular spatially separated from the heat exchanger.

[0031] The additional heat exchanger can enable heat transfer between the storage tank or the thermal storage medium arranged therein and a consumer, or heat transfer between the storage tank or the thermal storage medium arranged therein and another heat source or heat storage device such as a geothermal collector.

[0032] In some embodiments, the at least one additional heat exchanger has at least one supply / discharge line or at least two supply / discharge lines.

[0033] The at least one supply / discharge line or the at least two supply / discharge lines can be configured to pass through an upper surface of the thermal storage medium when the thermal storage medium is arranged in the storage container.

[0034] The at least one supply / discharge line or the at least two supply / discharge lines can or can pass through the storage tank in the uppermost quarter of its height, in particular in the uppermost fifth of its height or at its top.

[0035] Corresponding embodiments can simplify the connection of the heat storage and exchanger to other components of the system, in particular when the heat storage and exchanger is arranged in the ground, where, for example, the top quarter, the top fifth or the top of the storage tank protrudes from the ground.

[0036] A geothermal collector can be thermally coupled to the heat storage and exchanger. In some such embodiments, the geothermal collector can be spatially separated from the heat storage and exchanger and thermally coupled to the heat storage and exchanger, for example, by a fluid line.

[0037] In particular, an additional heat exchanger of the at least one additional heat exchanger can be coupled to the geothermal collector, in particular in order to thermally couple the geothermal collector to the heat storage and exchanger.

[0038] A geothermal collector comprises heat transfer pipe loops, which typically run essentially horizontally in the near-surface ground to exchange heat between the adjacent ground and a heat transfer medium. Accordingly, thermal energy can be stored or extracted from the geothermal collector by flowing a heat transfer medium through the heat transfer pipe loops, depending on the respective temperatures.

[0039] The geothermal collector can be arranged laterally to the storage tank.

[0040] The storage tank can represent an energy-storing component with a high energy storage density, which can be thermally charged and discharged with comparatively rapid response. Heat losses from the storage tank can increase the temperature of the surrounding soil, which can also be used as an energy source thanks to the geothermal collector arranged on the side. Accordingly, the insulation requirements for the storage tank can be comparatively low, allowing it to be constructed using simple structural measures. For example, the storage tank can be provided by a concrete boundary, while heat transfer loops can be laid in the surrounding soil.

[0041] In preferred embodiments, the heat storage and exchanger comprises a valve arrangement for selectively guiding a heat transfer medium through the storage tank in a first position or for connecting the storage tank and the geothermal collector in series in a second position, wherein a control device is configured to switch the valve arrangement from the first position to the second position when a stored amount of energy in the storage tank is above an energy threshold value.

[0042] The heat storage and exchanger can have at least two or at least three additional heat exchangers.

[0043] The at least two or at least three additional heat exchangers can be arranged at different heights in the storage tank.

[0044] In corresponding embodiments, the heat storage and exchanger can form a multi-zone heat storage system. In other words, the multiple heat exchangers at different heights can provide, for example, heating water and domestic water at different temperatures.

[0045] A multi-zone heat storage system can be particularly advantageous for storing heat provided at high temperatures, i.e., as a high-temperature heat storage system. For example, a multi-zone heat storage system can make it possible to provide a temperature of at least 60°C in the upper zone, which prevents the formation of Legionella bacteria and enables the provision of domestic hot water.

[0046] The storage tank can be set up as an ice storage tank.

[0047] For example, the storage container may have a pressure equalization vessel. In particular, the gas volume of the pressure equalization vessel may be at least 8% of the volume of the storage container for the thermal storage medium, for example, if the thermal storage medium is in the liquid state.

[0048] Alternatively or additionally, the heat storage and exchanger can comprise a circulation device, such as a circulation pump and / or an agitator, designed to circulate the thermal storage medium in the storage container. The circulation device can be arranged in the thermal storage container. The circulation device can be designed to generate a flow, particularly in the region of the heat exchanger.

[0049] The heat storage and exchanger can have a flow channel. The flow channel can be arranged in the thermal storage container. The flow channel can be arranged such that it defines a direction toward the heat exchanger for the flow generated by the circulation device and / or limits it. The flow channel can enclose at least a portion of the generated flow and / or the heat exchanger and / or the circulation device.

[0050] The flow channel may have a first tube, for example an outer tube.

[0051] The first tube may enclose a portion of the heat exchanger and / or a portion of the generated flow and / or the circulation device; in particular, to limit the generated flow outward and / or to direct it toward the heat exchanger. The first tube may enclose at least a portion of the generated flow and / or the heat exchanger and / or the circulation device. The first tube may be concentric with the double-tube heat exchanger.

[0052] The flow channel may have a second tube, e.g., an inner tube. The second tube may limit the generated flow inward, in particular to specify its direction toward the heat exchanger. The second tube may be enclosed by at least a portion of the generated flow and / or the heat exchanger. The second tube may be concentric with the heat exchanger and / or with the first tube.

[0053] Embodiments for use as ice storage, e.g. with pressure compensation vessel, circulation pump and / or agitator, can be used in a particularly advantageous manner for storing thermal energy or heat at low temperatures, ie as a low-temperature heat storage device. Corresponding embodiments can further increase the storage capacity of the heat storage and exchanger by utilizing the latent heat during the phase transition of the thermal storage medium from the liquid state to ice. In particular, the cold storage capacity can be increased by the ice. Furthermore, the storage container can be installed underground without any risk of damage to the storage container due to a change in the volume of the thermal storage medium in the event of frost or ice formation.

[0054] The storage vessel may have an upper shell region and a lower shell region.

[0055] The upper shell area can have stronger thermal insulation between the inside and outside of the storage tank than the lower shell area.

[0056] Corresponding embodiments may make it possible to thermally couple the lower region of the storage tank to the surroundings of the storage tank, in particular to the surrounding soil, while thermally insulating the upper region of the storage tank. In particular, if the heat storage tank is designed as a multi-zone heat storage tank, this allows the storage capacity to be increased at a lower temperature associated with the lower region of the storage tank, for example, for heating water. At the same time, a higher temperature associated with the upper region can be maintained, for example, for domestic water. Thus, corresponding embodiments may be particularly advantageous for use as a high-temperature heat storage tank.

[0057] In some embodiments, the upper shell region has a height that is at least one half of a height of the storage container.

[0058] In some designs, the lower shell area has a height that is at least one fifth of the height of the storage tank.

[0059] In some embodiments, the thermal storage medium is arranged in the storage container, and the thermal storage medium has a freezing point of at most -1°C or of at most -2°C, in particular in embodiments for use as a low-temperature heat storage device.

[0060] With appropriate designs, it can be ensured that when the temperature drops below 0°C, water in the environment of the storage tank, particularly in the soil surrounding the storage tank, freezes before the thermal storage medium freezes. This means that latent heat from the water in the surrounding area, particularly in the soil, can be used to further increase the thermal storage capacity of the heat storage and exchanger. Furthermore, the risk of the storage tank being damaged by a change in the volume of the thermal storage medium in the event of frost or ice formation can be reduced, particularly at temperatures just below freezing. By keeping the thermal storage medium in its liquid state, the thermal conductivity of the thermal storage medium and / or the heat transfer between the thermal storage medium and the heat exchanger (e.g., by convection) can be improved.

[0061] An expansion fluid can be arranged in the pressure equalization vessel.

[0062] The expansion fluid may have a freezing point that is lower than the freezing point of the thermal storage medium.

[0063] In corresponding embodiments, it can be ensured that the expansion fluid is in the liquid state when the thermal storage medium freezes (or melts) and the pressure compensation vessel can thus compensate for the volume change when the thermal storage medium freezes (or melts).

[0064] The modifications described as particularly advantageous for high-temperature heat storage and those described as particularly advantageous for low-temperature heat storage can be implemented on separate heat storage and exchangers, or on the same heat storage and exchanger. Typically, a system can be provided with multiple heat storage and exchangers, one of which can be optimized for use as a high-temperature heat storage unit and one as a low-temperature heat storage unit. This allows the heat storage and exchangers to be optimized for their respective applications. A single model of heat storage and exchanger can be provided that is configured for use as both a high-temperature heat storage unit and a low-temperature heat storage unit (for example, to save development costs).

[0065] A second section of the heat exchanger may have thermal insulation from the thermal storage medium. [o66] By thermally insulating the second section of the heat exchanger from the thermal storage medium, it can provide a stronger thermal coupling between the first fluid line and the second fluid line than between the thermal storage medium and either fluid line. Thus, the temperatures of fluids in the two fluid lines at one end of the second section can be more closely aligned to each other than to the temperature of the thermal storage medium.

[0067] For example, one of the fluid lines may be coupled to a solar system to be cooled, and the other fluid line to a cold side of a heat pump, and the second section may allow the temperature of the cooling fluid for the solar system to be reduced below the temperature of the thermal storage medium.

[0068] The second section may be arranged at an end region of the heat exchanger.

[0069] The second section can in particular be arranged at an end region of the heat exchanger from which the first fluid line leads to a heat pump. By means of the corresponding second section, the fluid in the first fluid line can be heated (or cooled) more strongly than would otherwise be the case (i.e. without the corresponding second section) in the heat storage and exchanger before it is led to the heat pump. For example, the first fluid line can lead from the end region of the heat exchanger to the cold side of the heat pump, and the temperature of the first fluid line (or the fluid therein) in the end region can be brought closer to the temperature of the second fluid line (or the fluid therein), wherein, for example, the second fluid line comes from a solar system and has a temperature which exceeds that of the thermal storage medium.

[0070] By heating the fluid in the first fluid line more before it is fed to the cold side of the heat pump (or cooling it more before it is fed to the warm side of the heat pump), a temperature difference between the fluids arriving at the warm and cold sides of the heat pump, i.e., between the first fluid line and the second fluid line (or the fluids therein) at the heat pump, can be minimized. This can improve the efficiency of the heat pump.

[0071] A portion of the first fluid line may have thermal contact (e.g., direct contact) with the thermal storage medium to transfer heat between the portion of the first fluid line and the thermal storage medium. Alternatively or additionally, the section of the first fluid line can be arranged in a region of the storage container for the thermal storage medium, in particular in an uppermost section of the region of the storage container for the thermal storage medium.

[0072] The thermal contact of the section of the first fluid line with the thermal storage medium can exceed the thermal contact of the section of the first fluid line with the second fluid line, for example, in terms of magnitude or by a factor of 2, 3, or 5, for example with regard to the respective thermal conductivities. In other words, the section of the first fluid line can be thermally insulated from the second fluid line.

[0073] In particular, a heat storage and exchanger for use as a high-temperature heat storage device may have a corresponding section of the first fluid line.

[0074] Corresponding embodiments can particularly advantageously promote the introduction of heat from the first fluid line directly into the thermal storage medium. This can be particularly advantageous for a multi-zone heat storage device or for a high-temperature heat storage device, for example if the first fluid line coming from a warm side of a heat pump is designed to introduce the heat from the heat pump (i.e. from its warm side) into the multi-zone heat storage device or the high-temperature heat storage device. For example, the corresponding section of the first fluid line can be arranged in the uppermost region of the storage container immediately after the first fluid line enters the storage container. Thus, the fluid coming from the heat pump through the first fluid line can release heat to the uppermost region of the storage container immediately after entering the storage container, i.e. at its highest possible temperature.This allows the temperature (e.g. of the thermal storage medium) in the uppermost area of ​​the storage tank to be effectively maximized and thus a high-temperature domestic water supply to be ensured.

[0075] The portion of the first fluid line may be at least partially arranged in the thermal storage container.

[0076] The section of the first fluid line can be arranged at an end region of the heat exchanger, in particular directly adjoining the end region of the heat exchanger.

[0077] The storage container can form a closed vessel for the thermal storage medium. Alternatively or additionally, the storage container can be configured to hold a liquid thermal storage medium.

[0078] Corresponding embodiments can ensure that the thermal storage medium is held in the storage container and thus the heat present in the thermal storage medium can be stored, for example in order to compensate for long-term or seasonal fluctuations in energy demand and / or supply.

[0079] The thermal storage medium can be arranged in the storage container. The thermal storage medium can be configured to provide an electrolyte for an electrochemical cell. The heat storage and exchanger can be configured to provide the thermal storage medium to the electrochemical cell in a fluid-coupled manner.

[0080] A second aspect concerns the use of the heat storage and exchanger described above as an underground heat storage facility.

[0081] The second aspect may include the use of the above-described heat storage and exchanger as an underground heat storage unit for cooling a photovoltaic system. Alternatively or additionally, the second aspect may include the use of the above-described heat storage and exchanger as an underground heat storage unit for absorbing heat during an evaporation process of a coolant of a heat pump.

[0082] The second aspect may include the use of the above-described heat storage and exchanger as an underground heat storage for storing condensation heat of a heat pump refrigerant.

[0083] A third aspect concerns the use of the heat storage and exchanger described above as a counterflow heat exchanger.

[0084] The counterflow heat exchanger can be used in particular for heat exchange between a refrigerant of a heat pump and a liquid heat transfer medium, wherein the liquid heat transfer medium thermally couples the first or the second fluid line to a photovoltaic system.

[0085] According to a fourth aspect, a system comprises a heat accumulator and exchanger as described above, and at least one control unit. The at least one control unit is configured to control a fluid flow through the first fluid line depending on a first parameter, wherein the first parameter is linked to the availability of electrical power.

[0086] The at least one control device can be configured to output a control signal for a heat pump depending on the first parameter.

[0087] Corresponding embodiments can enable the operation of the heat pump when electrical power is highly available, for example when a photovoltaic system produces high electrical power, for example measured against its peak power, or when the photovoltaic system produces a surplus of electrical power, for example compared to consumption associated with a building. In this situation, the high or surplus electrical power can be stored as thermal energy in the heat storage and exchanger by means of the heat pump in order to be available for times of low heat or energy availability. Thus, a demand for heat or energy can be met during times of low availability without having to resort to an additional (for example, expensive or limited) energy source, such as natural gas.In particular, thermal energy can be stored at a low temperature, and the temperature can be raised to a required level at a later time using a heat pump. The low storage temperature allows heat to be harnessed at a correspondingly low temperature (e.g., from photothermal energy under otherwise unfavorable conditions). Furthermore, losses during storage can be reduced.

[0088] The heat exchanger may comprise a double-pipe heat exchanger.

[0089] The first fluid line may comprise an inner tube of the double-tube heat exchanger.

[0090] The first fluid line can be configured to be coupled to the heat pump, in particular the first fluid line can be coupled to the heat pump.

[0091] The first parameter can be linked to electrical power provided by a photovoltaic system.

[0092] The at least one control device may comprise or be at least one electrical control device, in particular at least one electrical control device that is configured to receive and / or output electrical control signals.

[0093] In some embodiments, the at least one control device is a purely electrical control device, in particular without a mechanical device such as a valve or a pump.

[0094] In other embodiments, the at least one control unit comprises at least one mechanical device configured to control a fluid flow, such as a valve or a pump. In particular, the at least one control unit may comprise several or all mechanical devices for controlling the fluid flow.

[0095] The at least one control device can further be configured to control a fluid flow through the second fluid line in dependence on a second parameter.

[0096] The second parameter can be linked to a first temperature difference.

[0097] In corresponding embodiments, the control unit can enable temperature control (i.e., heating or cooling) of a component connected to the second fluid line. For this purpose, the fluid flow through the second fluid line can be switched on when the second parameter indicates a temperature or a temperature difference within a target range suitable for temperature control. The fluid flow through the second fluid line can be switched off when the second parameter lies outside the target range. The component to be temperature controlled can be a solar thermal system.

[0098] In the context of this description, a solar system may comprise a photovoltaic system and / or a photothermal system. In particular, a solar system may comprise a combined solar and photothermal system.

[0099] A first temperature of the first temperature difference can be linked to the storage tank and / or the thermal storage medium. [oioo] A second temperature of the first temperature difference may be associated with a solar system and / or a device thermally coupled to the second fluid line. In particular, the solar system may include the photovoltaic system.

[0101] The system can be configured to optionally couple the storage tank and / or the thermal storage medium to a geothermal collector.

[0102] The optional coupling may refer to a coupling whose coupling strength, in particular thermal coupling strength, is controllable, in particular by controlling a fluid flow, for example by means of a pump or a valve.

[0103] The at least one control device can be configured to selectively couple the storage tank and / or the thermal storage medium to the geothermal collector depending on a third parameter.

[0104] The third parameter can be linked to a second temperature difference.

[0105] A first temperature of the second temperature difference may be linked to the storage container and / or the thermal storage medium.

[0106] A second temperature of the second temperature difference can be linked to the geothermal collector.

[0107] Corresponding embodiments can make it possible to selectively transfer heat from the storage tank or thermal storage medium to the geothermal collector or extract it from it. Thus, the geothermal collector can be used, on the one hand, as an extension of the heat storage system. On the other hand, especially in the event of a change, particularly an increase, in the outside temperature, the heat available can be transferred into the storage tank or thermal storage medium via the geothermal collector and thus utilized.

[0108] The system may further comprise a second heat storage and exchanger. The second heat storage and exchanger may comprise a first fluid line, a second fluid line, and a storage container. The storage container may be configured to accommodate a thermal storage medium.

[0109] The second heat storage and exchanger can be configured to enable heat to be transferred between the first fluid line and the thermal storage medium and between the second fluid line and the thermal storage medium.

[0110] The at least one control device can be configured to control a fluid flow through the first fluid line of the second heat accumulator and exchanger together with the fluid flow through the first fluid line of the heat accumulator and exchanger.

[0111] Corresponding embodiments can provide an optimized system for the long-term storage of heat or cold in combination with a heat pump. For this purpose, the first fluid line of the heat storage and exchanger can be coupled to one, e.g., cold, side of the heat pump, and the first fluid line of the second heat storage and exchanger can be coupled to the second, e.g., warm, side of the heat pump.

[0112] Heat pump systems generate the same amount of cooling energy when generating heat. Heat pump systems generate the same amount of heat energy when used as a cooling system, i.e., when generating cold. With conventional heat generation (conventional use as an air conditioning system), the cooling energy (heat energy) is released into the environment as a waste product, e.g., air or groundwater.

[0113] In addition to heat generation, e.g., for heating or domestic hot water, many buildings also require a cooling system, e.g., for air conditioning / building cooling or photovoltaic cooling. However, the demand for heat (e.g., in winter) and cold (e.g., for cooling in summer) often differs in time (e.g., depending on the season). By using two heat storage and exchangers and combining them in the system, the cold during heat generation (or the heat when used as a cooling system) is stored and made available for use as needed.

[0114] By utilizing cold energy for heat generation and thermal energy for cooling, energy efficiency can be doubled compared to conventional solutions. This dual use can be achieved both locally, using suitable storage media, and at the neighborhood level by feeding it into heating and cooling networks.

[0115] By jointly controlling the fluid flows through the two first fluid lines, in such embodiments, a heat transfer from the heat storage and - exchanger to the second heat storage and exchanger. In other words, the thermal storage medium of the heat storage and exchanger is cooled, while the thermal storage medium of the second heat storage and exchanger is heated (or vice versa). With appropriate design of the heat storage and exchangers (e.g., their volumes), this can enable the storage of heat or cold for months or seasons.

[0116] The storage tank (or the thermal storage medium contained therein) and / or the geothermal collector thermally coupled to the heat storage and exchanger can be configured as an energy-storing component of the heat storage and exchanger, or can provide such an energy-storing component, or can be designated as such.

[0117] In other words, the heat storage and exchanger can include an energy-storing component. The energy-storing component can include or be the storage tank and / or the geothermal collector thermally coupled to the heat storage and exchanger.

[0118] In other words, the storage tank can be the energy-storing component of the heat storage and exchanger, or the geothermal collector thermally coupled to the heat storage and exchanger can be the energy-storing component of the heat storage and exchanger, or both (i.e., jointly) can be the energy-storing component of the heat storage and exchanger.

[0119] A geothermal collector (e.g. an additional one or one spatially separated from the geothermal collector thermally coupled to the heat storage and exchanger) can be thermally coupled to the second heat storage and exchanger.

[0120] The second heat storage and exchanger may comprise an energy-storing component, for example having properties similar to the above-described properties of the energy-storing component of the heat storage and exchanger, but related to the second heat storage and exchanger rather than to the heat storage and exchanger.

[0121] In some embodiments, a thermally insulating partition wall separates earth regions, in particular adjacent earth regions, from one another. The thermally insulating partition wall can be at least partially, in particular to a large extent (e.g. (according to their vertical extent) below the earth's surface. The mutually delimited earth regions can each be assigned to a geothermal collector. In particular, one of the delimited earth regions can be assigned to the earth collector that is thermally coupled to the (first) heat storage and exchanger, and another of the delimited earth regions can be assigned to the earth collector that is thermally coupled to the second heat storage and exchanger.

[0122] In preferred embodiments, the energy-storing component of the first heat storage and exchanger (in particular its geothermal collector) adjoins the energy-storing component of the second heat storage and exchanger (in particular its geothermal collector) and is laterally separated from the energy-storing component of the second heat storage and exchanger (in particular its geothermal collector) by a thermally insulating partition wall embedded in the ground.

[0123] For example, adjacent ground sections can each be equipped with geothermal collectors, and the thermally insulating partition wall can be embedded in the ground between the heat transfer loops of the geothermal collector, which is thermally coupled to the first heat storage and exchanger, and the geothermal collector, which is thermally coupled to the second heat storage and exchanger, so that different temperatures can be provided in the energy-storing component of the first heat storage and exchanger (in particular in its geothermal collector) and the energy-storing component of the second heat storage and exchanger (in particular in its geothermal collector).

[0124] In preferred embodiments, the energy-storing component of the heat storage and exchanger (in particular its geothermal collector) is separated laterally from the surrounding soil by the thermally insulating partition wall.

[0125] A laterally surrounding insulating partition wall can allow a higher temperature level to be maintained in the energy-storing component of the heat storage and exchanger (in particular its geothermal collector) for longer and / or with lower energy losses, thus providing seasonal storage of thermal energy in the energy-storing component of the heat storage and exchanger (in particular its geothermal collector) at an increased storage temperature. The thermally insulating partition wall can extend vertically over the lower end of the energy-storing component of the heat storage and exchanger (in particular over the lower end of its geothermal collector). heat collector) extend downward into the ground to define an insulated section of the energy-storing component (especially its geothermal collector). The insulated section may be open at the bottom to utilize the thermal capacity of the underlying soil.

[0126] The energy-storing component of the heat storage and exchanger (in particular its geothermal collector) can be adjacent to the energy-storing component of the second heat storage and exchanger (in particular its geothermal collector) and separated from it by the thermally insulating partition wall. The thermally insulating partition wall should have a reduced thermal conductivity compared to the ground, in particular a thermal conductivity of less than 1 W / (m*K), preferably less than 0.5 W / (m*K), more preferably less than 0.2 W / (m*K). The insulation can be perimeter insulation, which can be provided by panels in the ground, for example made of Styrodur, and / or can comprise sections of loose-fill insulation material, such as foam glass granules. In some embodiments, the thermally insulating partition wall is separated from the energy-storing components on both sides by the ground.

[0127] In some embodiments, the system further comprises an upper partition wall forming an upper boundary of the energy-storing component of the heat storage and exchanger (in particular, its geothermal collector) to thermally insulate the energy-storing component of the heat storage and exchanger (in particular, its geothermal collector) in the vertical direction. For example, the upper partition wall can be arranged below a floor slab of a building to reduce heat losses from the energy-storing component into the building.

[0128] In preferred embodiments, the system further comprises a lower partition wall which forms a lower boundary of the energy-storing component of the heat storage and exchanger (in particular of its geothermal collector) in order to thermally insulate the energy-storing component of the heat storage and exchanger (in particular of its geothermal collector) in the vertical direction from the underlying soil.

[0129] The lower partition wall can improve insulation of the energy-storing component of the heat storage and exchanger (especially its geothermal collector), so that its temperature level can be maintained for longer and / or with lower energy losses.

[0130] The system may include the heat pump.

[0131] The fluid flow through the first fluid line of the heat storage and exchanger can be configured to thermally couple the heat storage and exchanger to one side, e.g., a hot or cold side, of the heat pump.

[0132] The fluid flow through the first fluid line of the second heat storage and exchanger can be configured to thermally couple the second heat storage and exchanger to one side, e.g., to a complementary cold or warm side, of the heat pump.

[0133] The heat pump can be designed to provide an output of at least 3 kW or at least 5 kW.

[0134] The system may include a solar system.

[0135] The heat storage and exchanger of the system can have at least one additional heat exchanger, wherein one of the at least one additional heat exchanger is designed to thermally couple the solar system to the storage tank and / or the thermal storage medium of the heat storage and exchanger, in particular in series with a geothermal collector.

[0136] An additional heat exchanger of the second heat storage and exchanger can be configured to thermally couple the solar system to the storage tank and / or the thermal storage medium of the second heat storage and exchanger.

[0137] The second heat storage and exchanger may have one or all of the features described above in connection with the heat storage and exchanger of the first aspect.

[0138] In a fifth aspect, a system comprises a first heat storage and exchanger, a second heat storage and exchanger, a heat pump, and a control unit. The first heat storage and exchanger comprises a first fluid line, a second fluid line, a heat exchanger, and a storage container. The heat exchanger is configured to transfer heat between the first fluid line and the second fluid line. The storage container is configured to receive a thermal storage medium. At least a portion of the heat exchanger is arranged in the storage container to form a To enable heat transfer between the heat exchanger and the thermal storage medium. The first heat storage and exchanger has a volume for its thermal storage medium of at least 2 m 3and is arranged at least partially underground. The second heat storage and exchanger has a first fluid line, a second fluid line, and a storage container configured to accommodate a thermal storage medium. The second heat storage and exchanger is configured to enable heat to be transferred between its first fluid line and its thermal storage medium, and between its second fluid line and its thermal storage medium. The heat pump is configured to provide an output of at least 5 kW. A fluid flow through the first fluid line of the first heat storage and exchanger or the second heat storage and exchanger is configured to thermally couple the first heat storage and exchanger to a cold side of the heat pump.The fluid flow through the first fluid line of the other heat accumulator and exchanger is configured to thermally couple the other heat accumulator and exchanger to a warm side of the heat pump. The control unit is configured to jointly control an operating state of the heat pump, the fluid flow through the first fluid line of the first heat accumulator, and the fluid flow through the first fluid line of the second heat accumulator as a function of a first parameter, wherein the first parameter is linked to an electrical power provided by a photovoltaic system. The second fluid line of the first heat accumulator and exchanger and / or the second heat accumulator and exchanger is coupled to a solar system.

[0139] The other heat storage and exchanger may refer to the heat storage and exchanger or to the second heat storage and exchanger; in particular to the one of the two in which the fluid flow through its first fluid line is not arranged to thermally couple it to the cold side of the heat pump.

[0140] The thermal storage medium of the second heat storage and exchanger can be arranged in the storage container of the second heat storage and exchanger. The thermal storage medium arranged in the storage container of the second heat storage and exchanger can be configured to provide a second electrolyte for the electrochemical cell. The second heat storage and exchanger can be configured to provide the thermal storage medium to the electrochemical cell in a fluid-coupled manner.

[0141] The system may comprise the electrochemical cell, wherein the thermal storage medium of the first heat storage and exchanger and the thermal storage medium of the second heat storage and exchanger are fluidly coupled to the electrochemical cell; in particular, wherein the thermal storage medium of the first heat storage and exchanger and the thermal storage medium of the second heat storage and exchanger are fluidly coupled to different half-cells of the electrochemical cell.

[0142] According to a sixth aspect, a method for creating an underground heat storage device comprises arranging at least a portion of a heat storage and exchanger in the ground. The heat storage and exchanger has a first fluid line, a second fluid line, a heat exchanger, and a storage container. The heat exchanger is configured to transfer heat between the first fluid line and the second fluid line. The storage container is configured to accommodate a thermal storage medium. At least a portion of the heat exchanger is arranged in the storage container to enable heat to be transferred between the heat exchanger and the thermal storage medium.

[0143] The method may further comprise thermally coupling the heat storage and exchange to the ground.

[0144] The method may further comprise setting up the heat exchanger as a counterflow heat exchanger.

[0145] The method may further comprise coupling the first fluid line to a heat pump.

[0146] The method may further comprise thermally coupling the heat storage and exchanger to a first heating network, in particular to a first district heating network, in order to selectively store heat or cold from the heat storage and exchanger in the district heating network or to extract it from the district heating network into the heat storage and exchanger. In particular, the heat storage and exchanger can be coupled in series with the geothermal collector and / or with the ground to the first heating network, in particular to the first district heating network.

[0147] The method may further comprise coupling a first fluid line of a second heat storage and exchanger to the heat pump.

[0148] The second heat storage and exchanger may have one or all of the features described above in connection with the second heat storage and exchanger of the fourth aspect.

[0149] The method may further comprise coupling the second heat storage and exchanger to a second heating network, in particular to a second local heating network, in particular wherein the second (local) heating network has an average lower temperature than the first (local) heating network. In particular, the second heat storage and exchanger can be coupled in series with its geothermal collector and / or with the surrounding soil to the second heating network, in particular to the second local heating network.

[0150] For example, the first (local) heating network may be a high-temperature (local) heating network, and the second (local) heating network may be a low-temperature (local) heating network (in other words, a (local) cooling network).

[0151] Thermal insulation, in particular a thermally insulating partition wall, can be arranged between a region of the first (local) heating network (e.g., the high-temperature (local) heating network) and a region of the second (local) heating network (e.g., the low-temperature (local) heating network or the (local) cooling network). In particular, the thermal insulation can be arranged at least partially underground, or the thermally insulating partition wall can be an underground thermally insulating partition wall. For example, the thermal insulation or the thermally insulating partition wall can be arranged between a geothermal collector (or an underground fluid line) of the first (local) heating network (e.g., the high-temperature (local) heating network) and a geothermal collector (or an underground fluid line) of the second (local) heating network (e.g., the low-temperature (local) heating network or the (local) cooling network).

[0152] The method may further comprise coupling the second fluid line to a solar system.

[0153] The method may further comprise setting up a controller to receive or determine a first parameter, wherein the first parameter is linked to an availability of electrical power.

[0154] The method may further comprise setting up the at least one control device to control a fluid flow through the first fluid line in dependence on the first parameter.

[0155] The heat storage and exchanger may have at least one additional heat exchanger.

[0156] The method may further comprise coupling a heat exchanger of the at least one additional heat exchanger to a geothermal collector.

[0157] The at least one additional heat exchanger may have one or all of the features of the at least one additional heat exchanger described above in connection with the heat storage and exchanger of the first aspect.

[0158] In embodiments in which the method comprises coupling the first fluid line to a heat pump, the method may further comprise coupling a first fluid line of a second heat accumulator and exchanger to the heat pump. In particular, in corresponding embodiments, the first fluid line of the heat accumulator and exchanger may be coupled to a cold side of the heat pump, and the first fluid line of the second heat accumulator and exchanger may be coupled to a warm side of the heat pump. Alternatively, the first fluid line of the heat accumulator and exchanger may be coupled to the warm side of the heat pump, and the first fluid line of the heat accumulator and exchanger may be coupled to the warm side of the heat pump.

[0159] The method may further comprise performing one or all of the method steps relating to the heat storage and exchanger, correspondingly on the second heat storage and exchanger.

[0160] According to a seventh aspect, a method for operating a system comprising a heat accumulator and exchanger has at least two operating modes, and the method comprises selectively executing one of the at least two operating modes. The first operating mode comprises operating the heat pump at a first heat pump output and generating a fluid flow through the first fluid line to transfer heat between the heat pump and the thermal storage medium. The second operating mode comprises operating the heat pump at a second heat pump output that is at most one-quarter of the first heat pump output and generating a stronger fluid flow through the second fluid line than through the first fluid line to transfer heat via the second fluid line. The heat accumulator and exchanger can have one or all of the features of the heat accumulator and exchanger of the first aspect.

[0161] In some embodiments, when selectively executing one of the at least two operating modes, a selection between the first and second operating modes is performed automatically based on a first parameter. In particular, the first parameter can be linked to the availability of electrical power.

[0162] The method may comprise selectively guiding the fluid flow through the second fluid line to a solar system, to a geothermal collector, or to the solar system and the geothermal collector.

[0163] The method may further comprise, in the first and / or second operating modes, controlling the strength of the fluid flow through the second fluid line as a function of a first temperature difference. In particular, a first temperature of the first temperature difference may be linked to the storage container and / or the thermal storage medium. In particular, a second temperature of the first temperature difference may be linked to a solar system.

[0164] The method may further comprise selectively extracting heat from the heat storage and exchanger or a geothermal collector coupled to the heat storage and exchanger, in particular depending on a temperature associated with the storage container and / or the thermal storage medium; and / or depending on a temperature associated with the geothermal collector.

[0165] The method may further comprise controlling a thermal coupling between the geothermal collector and the storage tank and / or the thermal storage medium as a function of a second temperature difference. In particular, a first temperature of the second temperature difference may be linked to the storage tank and / or the thermal storage medium; and / or a second temperature of the second temperature difference may be linked to the geothermal collector.

[0166] The system may include a second heat storage and exchanger.

[0167] The second heat storage and exchanger may have one or all of the features described above in connection with the second heat storage and exchanger of the fourth aspect.

[0168] The method may further comprise performing the method steps relating to the heat accumulator and exchanger correspondingly on the second heat accumulator and exchanger. In particular, in corresponding embodiments, the first fluid line of the heat accumulator and exchanger may be coupled to a cold side of the heat pump; and the first fluid line of the second heat accumulator and exchanger may be coupled to a warm side of the heat pump. Alternatively, the first fluid line of the first heat accumulator and exchanger may be coupled to the warm side of the heat pump, and the first fluid line of the second heat accumulator and exchanger may be coupled to the warm side of the heat pump.

[0169] According to an eighth aspect, a computer program is arranged to cause an electronic control system to carry out the method according to the seventh aspect.

[0170] According to a further aspect, a local heating network comprises a first heat storage and exchanger, a second heat storage and exchanger and a geothermal collector.

[0171] The first heat storage and exchanger is a heat storage and exchanger as described above in connection with the first aspect. Alternatively, the district heating network comprises a system as described above, and the first heat storage and exchanger is the heat storage and exchanger of the system.

[0172] The second heat storage and exchanger is a heat storage and exchanger as described above in connection with the first aspect. Alternatively, the district heating network comprises a system as described above, and the first heat storage and exchanger is the heat storage and exchanger of the system. The second heat storage and exchanger is spatially separated from the first heat storage and exchanger, for example, by at least 50 m, by at least 100 m, or by at least 200 m.

[0173] The geothermal collector is thermally coupled to the first heat storage and exchanger and the second heat storage and exchanger, and is designed to store heat or cold in the surrounding ground and to extract at least part of the stored heat or cold from the ground at a later time.

[0174] The downstream heating network may further comprise a conduit configured to thermally couple the first heat storage and exchanger and the second heat storage and exchanger. A first portion of the conduit may have thermal insulation. A second portion of the conduit may have less or no thermal insulation to form the geothermal collector.

[0175] According to a further aspect, a district heating network system comprises a district heating network as described above, and further a second district heating network.

[0176] The second district heating network comprises the following: a first low-temperature heat storage tank, a second low-temperature heat storage tank and a second geothermal collector.

[0177] The first low-temperature heat storage unit is a heat storage unit and exchanger as described above in connection with the first aspect. Alternatively, the district heating network comprises a system as described above, and the first low-temperature heat storage unit is the second heat storage unit and exchanger of the system.

[0178] The thermal storage medium of the first low-temperature heat storage unit has a lower temperature than the thermal storage medium of the first heat storage unit and exchanger.

[0179] The second low-temperature heat storage unit is a heat storage unit and exchanger as described above in connection with the first aspect. Alternatively, the district heating network comprises a system as described above, and the first low-temperature heat storage unit is the second heat storage unit and exchanger of the system.

[0180] The second low-temperature heat storage unit is spatially separated from the first low-temperature heat storage unit, for example by at least 50 m or by at least 100 m or by at least 200 m.

[0181] The thermal storage medium of the second low-temperature heat storage unit has a lower temperature than the thermal storage medium of the second heat storage unit and exchanger.

[0182] The second geothermal collector is thermally coupled to the first low-temperature heat storage unit and the second low-temperature heat storage unit, and is configured to store second heat or cold in a surrounding soil and to extract at least a portion of the stored second heat or cold from the soil at a later time.

[0183] In some embodiments, the district heating network system further comprises a thermally insulating partition wall configured to thermally insulate a region of the district heating network from a region of the second district heating network. In particular, the thermally insulating partition wall can be arranged at least partially underground. SHORT DESCRIPTION OF THE CHARACTERS

[0184] The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings. The figures show, in schematic representation:

[0185] Fig. 1: a heat storage and exchanger according to an example;

[0186] Fig. 2a: a heat storage and exchanger according to another example;

[0187] Fig. 2b: a heat storage and exchanger according to another example;

[0188] Fig. 3: a heat storage and exchanger according to another example;

[0189] Fig. 4: a system with a heat storage and exchanger according to an example;

[0190] Fig. 5a: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to an example;

[0191] Fig. 5b: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0192] Fig. 5c: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0193] Fig. 5d: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0194] Fig. 5e: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0195] Fig. 5f: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0196] Fig. 5g: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0197] Fig. 5h: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0198] Fig. 5i: a system with a heat storage and exchanger and an operating mode of a method for operating the system according to a further example;

[0199] Fig. 6a - Fig. 6e: a system with a heat storage and exchanger coupled to a district heating network;

[0200] Fig 7a: a heat storage and exchanger according to another example;

[0201] Fig 7b: a heat storage and exchanger according to another example;

[0202] Fig 7c: a heat storage and exchanger according to another example;

[0203] Fig 7d: a heat storage and exchanger according to another example;

[0204] Fig 7e: a heat storage and exchanger according to another example;

[0205] Fig 8: a heat storage and exchanger according to another example;

[0206] Fig. 9a: a district heating network with an electrochemical cell according to an example; and

[0207] Fig. 9b: a district heating network system with an electrochemical cell according to a Example. DESCRIPTION OF THE CHARACTERS

[0208] Fig. 1 shows a heat storage and exchanger 100 according to a first embodiment.

[0209] The heat storage and exchanger 100 has a storage container 106 for a thermal storage medium 108, as well as a heat exchanger 104, which is partially arranged in the storage container 106.

[0210] Thanks to the integrated heat exchanger 104, the heat storage and exchanger 100 is particularly suitable for retrofitting existing systems.

[0211] The storage tank 106 is sufficiently large to accommodate such a large quantity (e.g., volume) of the thermal storage medium 108 that it provides a heat capacity to cover the heat demand of a building over a longer period of time, such as several days, weeks, or months. For example, the storage tank 106 can be designed for the heat demand of a single-family home, and its volume, depending on the size of the single-family home, can be approximately 2 m 3 , 5 m 3 , 10 m 3 , 15 m 3 or 20 m 3In alternative embodiments, a larger storage tank 106 or a plurality of storage tanks 106 are provided for a larger single building or building complex.

[0212] Thus, the storage tank 106 with the thermal storage medium 108 contained therein makes it possible to fully or partially cover the heat demand of a building during a period of poor availability (at night, in winter, or during periods of cold and / or sunny weather) using energy in the form of heat that is stored during times of good availability (during the day, in summer, or during periods of warm and / or sunny weather).

[0213] The storage tank 106 is designed to be buried underground. Accordingly, its walls are made of an opaque, liquid-tight, and preferably corrosion-resistant material such as steel. Alternatively or additionally, a concrete wall is provided to mechanically reinforce the walls.

[0214] The storage container 106 provides an area for the thermal storage medium 108. For example, the storage container 106 provides a target fill level 116 for the thermal storage medium 108.

[0215] Fluid lines 102a, 102b extend above the area of ​​the storage container 106 for the thermal storage medium 108, ie above the target filling level 116. In other words, areas of the fluid lines 102a, 102b that are outside the storage area container 106 are arranged (e.g. supply / discharge lines or connecting elements of the fluid lines 102a, 102b), higher in the vertical direction than the area of ​​the storage container 106 for the storage medium 108 or higher than the desired filling level 116. Thus, the fluid lines 102a, 102b are accessible from above and also above ground when the storage container 106 is arranged underground.

[0216] The underground arrangement does not necessarily mean that the entire storage tank 106 is located below the earth's surface. In some embodiments, only the lower region of the storage tank 106 is located below the earth's surface, for example, the lowest 60%, 70%, 80%, 90%, or 95% of its vertical extent. Preferably, the top of the storage tank 106 is flush with the earth's surface or is located slightly above the earth's surface, so that the supply / discharge lines or connecting elements of the fluid lines 102a, 102b are accessible above ground.

[0217] In the embodiment shown, the regions of the fluid lines 102a, 102b that are arranged outside the storage container 106 (e.g., supply / discharge lines or connection elements of the fluid lines 102a, 102b) are higher in the vertical direction than the entire storage container 106.

[0218] The storage tank 106 is designed for use in the storage tank 106 due to its dimensions (min. 1 m 3 , especially 2 m 3 for the thermal storage medium) and material composition (opaque, liquid-tight and preferably corrosion-resistant) hereinafter also referred to as cistern storage 106.

[0219] In the storage container 106 of Fig. 1, the cross-sectional area is always the same in horizontal planes at different heights (ie, across the entire vertical extent of the storage container 106). In alternative embodiments, the cross-sectional area decreases toward the top. In any case, the cross-sectional area does not increase significantly toward the top.

[0220] This allows the heat storage and exchanger 100 to be conveniently lowered into a pit, particularly for an underground arrangement.

[0221] In the illustrated storage tank, the cross-sectional area is round; in alternative designs, it is elliptical. The absence of corners, protrusions, or bulges in the cross-sectional area further facilitates lowering into the pit.

[0222] Due to its underground arrangement, the heat storage and exchanger 100 minimizes its footprint (i.e., the floor space required) in the building to be supplied with heat or on the property where it is installed. As an underground heat storage and exchanger 100, the heat storage and exchanger can, for example, form a retrofit component for an existing system.

[0223] The heat exchanger 104 of the embodiment of Fig. 1 is designed as a double-tube heat exchanger. The second fluid line 102b is arranged coaxially around the first fluid line 102a. The first fluid line 102a and the second fluid line 102b are thus in thermal contact via a common wall. In alternative embodiments, the heat exchanger 104 is a plate heat exchanger or a shell-and-tube heat exchanger or a multi-tube heat exchanger with more than two coaxial lines, with the outermost two lines serving as the first fluid line 102a and the second fluid line 102b.

[0224] The arrangement of the heat exchanger 104 in the storage tank 106 enables a large tube length of the (particularly double-tube) heat exchanger, and thus an effective heat transfer between the first and second fluid lines 102, 102b. In particular, the space available in the storage tank 106 is larger than with a conventional arrangement of a heat exchanger in a heat pump. Instead of a double-tube heat exchanger, a multi-tube heat exchanger (i.e., with more than two lines arranged coaxially in thermal contact with one another), a plate heat exchanger, or a tube bundle heat exchanger can be installed in order to also benefit from the larger space available. In the illustrated embodiment, the double-tube heat exchanger 104 is spiral-shaped with a height of 2 m and a diameter of 0.5 m, but diameters of 1 m, 2 m, 3 m, or 4 m are possible (adapted to the annual energy requirement of the building to be supplied).

[0225] A first section 144 of the heat exchanger 104 is arranged below the desired filling level 116 (i.e., is arranged in the region of the storage tank 106 for the thermal storage medium 108) and is in thermal contact with the region of the storage tank 106 for the thermal storage medium 108 via its outer wall, which simultaneously forms the outer wall of the second fluid line 102b. The region of the storage tank 106 for the thermal storage medium 108 surrounds the second fluid line 102b, and in embodiments with a double-pipe heat exchanger, the first fluid line 102a. In other words, the arrangement of the heat exchanger 104 (in particular its first section 144) in the storage tank 106 (in particular in the region of the storage tank 106 for the thermal storage medium 108) results in a triple heat exchanger consisting of the first fluid line 102a, second fluid line 102b and storage container 106 (in particular the area of ​​the storage container 106 for the thermal storage medium 108 or below the desired fill level 116). This arrangement enables the exchange of heat between a fluid in the first fluid line 102a, a fluid in the second fluid line 102b, and the thermal storage medium 108.

[0226] The arrangement of the heat exchanger 104 in the storage container 106 also enables effective heat transfer during heat transfer between the second fluid line 102b (and indirectly the first fluid line 102a) and the thermal storage medium 108, as described above in connection with the heat transfer between the first fluid line 102a and the second fluid line 102b.

[0227] The heat exchanger 104 extends upwards through the area of ​​the storage tank 106 for the thermal storage medium 108 to above the target filling level 116 of the storage tank 106 for the thermal storage medium 108. Thus, a first area 144 (e.g. below the target filling level 116 of the storage tank 106 for the thermal storage medium 108) of the heat exchanger 104 is in thermal contact with the thermal storage medium 108, while a second area 138 (e.g. above the target filling level 116 of the storage tank 106 for the thermal storage medium 108) of the heat exchanger 104 is not in thermal contact with the thermal storage medium 108 (or the area of ​​the storage tank 106 provided for this purpose), i.e. is spaced apart from it or is insulated from it by air. The first section 144 corresponds to the central region of the heat exchanger 144, the second region 138 corresponds to the two end regions 138 of the heat exchanger 104.

[0228] The thermal conductivity between the first fluid line 102a and the second fluid line 102b can be considered as a reference value for the presence or absence of thermal contact between a section of the heat exchanger 104 and the thermal storage medium 108. If the thermal conductivity between the section of the heat exchanger 104 and the thermal storage medium 108 is lower (e.g., per length) (e.g., simply lower, or lower by a factor of 2, 3, 5, or 10) than the thermal conductivity between the first fluid line 102a and the second fluid line 102b, then thermal contact is not present. This results in the temperatures of fluids in the first fluid line 102a and the second fluid line 102b becoming more similar to one another than (e.g., each) to the temperature of the thermal storage medium 108.

[0229] Since in the illustrated embodiment the heat exchanger 104 in its middle area 144 (ie in its first section 144) is connected to the thermal storage medium io8 is in thermal contact, the temperature of fluids flowing through the fluid lines 102a, 102b largely adapts there to the temperature of the thermal storage medium 108. In at least one end region 138 (ie in its second section 138), however, the heat exchanger 104 is not in thermal contact with the thermal storage medium 108. Consequently, the temperature of a fluid flowing through one of the fluid lines 102a, 102b, after flowing through the central region 144 of the heat exchanger 104, approaches the temperature of the fluid in the other fluid line 102a, 102b in this end region 138.

[0230] Preferably, the heat exchanger 104 is operated as a counterflow heat exchanger. Thus, in the end region 138, the temperature of the outflowing fluid in one fluid line 102a, 102b equalizes to the temperature of the inflowing fluid in the other fluid line 102a, 102b. Typically, the temperature spread between these fluids is greater than the temperature difference between the outflowing fluid and the thermal storage medium 108. Thus, the outflowing fluid in the end region 138 of the heat exchanger 104 is cooled or heated more significantly without thermal contact with the thermal storage medium 108 than would be the case if the heat exchanger 104 were in thermal contact with the thermal storage medium 108 over the entire length of the heat exchanger 104.In exemplary embodiments, the outflowing fluid from the second fluid line 102b is directed to a photovoltaic system for cooling, while the inflowing fluid into the first fluid line 102a, coming from the cold side of a heat pump, provides the required cooling. In such embodiments, the end region 138 of the heat exchanger 104 achieves a lower temperature of the outflowing fluid from the second fluid line 102b, thus improving the cooling of the photovoltaic system.

[0231] The extent of temperature equalization of the fluid lines 102a, 102b (or the fluids contained therein) in the end region 138 of the heat exchanger can be controlled by controlling the flow velocity of at least one of the fluids (in particular both fluids) in its fluid line 102a, 102b (in particular in the two fluid lines 102a, 102b). A high flow velocity prevents significant temperature equalization between the fluid lines 102a, 102b (or the fluids contained therein). The outflowing fluid essentially has the temperature of the thermal storage medium 108. A low flow velocity causes significant temperature equalization between the fluid lines 102a, 102b (or the fluids contained therein), and the outflowing fluid essentially has the temperature of the other fluid line (or the fluid contained therein). A temperature sensor is preferably for detecting the temperature of the outflowing fluid, and the flow rate of one of the fluids (or both fluids) through the associated fluid line(s) 102a, 102b is regulated with respect to the temperature detected by the temperature sensor (in particular to achieve a predetermined target temperature).

[0232] The thermal storage medium 108 consists largely (for example, in terms of its volume) of water. It also contains an antifreeze, so that the freezing point of the thermal storage medium 108 is below that of water, for example, at most -1° or at most -2°. 0For low-temperature applications, even below -20°C or -35°C. In alternative embodiments, particularly for use as high-temperature heat storage devices, thermal storage media 108 are used that have a melting point in the range of 10°C to 70°C (e.g., 10°C, 20°C, or 30°C), such as paraffins. This allows the heat capacity of the storage medium 108 to be increased by utilizing its latent heat at the phase transition, even when used as a high-temperature heat storage device.

[0233] In some embodiments, the wall of the storage tank 106 enables thermal coupling of the thermal storage medium 108 to a medium surrounding the thermal storage tank 106. Specifically, the storage tank 106 is arranged in the ground, which forms the surrounding medium.

[0234] The antifreeze contained in the thermal storage medium 108 and its freezing point below that of water ensure that when the temperature drops (in particular below the freezing point of water), water in the surrounding medium freezes first before the thermal storage medium 108 freezes. Thus, the thermal storage medium 108 is effectively protected from freezing, or the storage container 106 is protected from frost damage due to volume expansion of the thermal storage medium 108 upon freezing.

[0235] To provide even greater frost protection, in some embodiments, an antifreeze such as glycol is included in the thermal storage medium 108 at a concentration of up to 50% to further lower the freezing point of the thermal storage medium 108, such as to -20°C or -35°C.

[0236] Preferably, the heat storage and exchanger 100 (or the heat exchanger 104) is used as a counterflow heat exchanger, ie a fluid flow through the first fluid line 102a is directed opposite to a fluid flow through the second fluid line 102b. This further improves the effectiveness of heat transfer between the first fluid line 102a and the second fluid line 102b.

[0237] Fig. 2a shows a heat accumulator and exchanger 100 according to a second embodiment, which is similar to that of Fig. 1. Corresponding elements are designated by the same reference numerals; a repeated description is omitted. The heat accumulator and exchanger 100 of Fig. 2a is formed with a number of modifications. According to different embodiments, a heat accumulator and exchanger 100 is formed with only one or a combination of the described modifications.

[0238] The height h of the region of the storage tank 106 provided for the thermal storage medium (not shown) is similar to the corresponding height in the heat accumulator and exchanger 100 of Fig. 1 and is approximately 2 m. In addition, the storage tank 106 of Fig. 2a has a region 142 (referred to as dome 142 in the context of this disclosure) above the region provided for the thermal storage medium, which is not provided for the thermal storage medium but provides space for other elements, in particular the first fluid line 102a and the second fluid line 102b. In the illustrated embodiment, the first fluid line 102a and the second fluid line 102b pass through the dome 142 in a straight line in the vertical direction. The supply / discharge lines 112, 114 are thus arranged above the dome 142.In alternative embodiments, the first fluid line 102a and the second fluid line 102b bend sideways (in the horizontal direction) within the dome from below. In corresponding embodiments, the supply / discharge lines 112, 114 are arranged laterally of the dome 142.

[0239] To use the heat storage and exchanger 100 as an underground heat storage unit, the area of ​​the storage tank 106 intended for the thermal storage medium is arranged underground, while the dome 142 is arranged at least partially above ground. Thus, the fluid lines 102a, 102b are accessible above ground for connection.

[0240] In the storage tank 106 of Fig. 2a, an additional heat exchanger 118 with supply / discharge lines 120 for a fluid is arranged.

[0241] The additional heat exchanger 118 enables an effective and controllable thermal coupling of the heat storage and exchanger 100 or the thermal storage medium arranged therein to a medium surrounding the storage tank 106, specifically to the ground in the case of an underground arrangement of the storage tank 106. For this purpose, a geothermal collector is arranged in the ground, and a fluid line of the geothermal collector is connected to the supply / discharge lines 120. A valve and / or a circulation pump controls the flow of a fluid (e.g., brine) through the additional heat exchanger 118 and serially through the fluid line of the geothermal collector, thus thermally coupling the heat storage and exchanger 100 to the ground.

[0242] In the illustrated embodiment, the fluid line of the additional heat exchanger 118 passes laterally through the storage tank 106. In other words, the supply / discharge lines 120 are arranged laterally of the storage tank 106. In alternative embodiments, the fluid line of the additional heat exchanger 118 passes upwards (like the fluid lines 102a, 102b) through the storage tank 106. In such embodiments, the supply / discharge lines 120 are arranged above the area of ​​the storage tank 106 intended for the thermal storage medium 108. Corresponding to the supply / discharge lines 112, 114 described above, they can run partially horizontally above the storage medium 108. A corresponding arrangement can facilitate the connection of the supply / discharge lines 120 to the geothermal collector.

[0243] The heat exchanger 104 of Fig. 2a has a thermal insulation 140 in one of its end sections 138. This is designed as a casing for at least one of the fluid lines 102a, 102b with a thermally insulating material, in particular a porous material and / or one with a vacuum-sealed region. In the illustrated embodiment with the double-pipe heat exchanger 104, the two fluid lines 102a, 102b are casings.

[0244] The thermal insulation 140 thus defines the end region 138 of the heat exchanger 104 without thermal contact with the thermal storage medium 108, with the effects and advantages described in connection with the exemplary embodiment of Fig. 1. One difference between the two embodiments is that in the exemplary embodiment of Fig. 1, the end region 138 of the heat exchanger without thermal contact with the thermal storage medium 108 is defined by that region of the heat exchanger 104 that is arranged outside the region of the storage container 106 for the thermal storage medium 108 (e.g., above the desired filling level 116).

[0245] By providing the thermal insulation 140, the extent and position of the end region 138 of the heat exchanger 104 can be adjusted in a targeted manner and independently of the course of the fluid lines 102a, 102b without thermal contact with the thermal storage medium 108 (and thus the temperature adjustment of the fluid lines 102a, 102b or the fluids contained therein). In the illustrated embodiment, an end region 138 of the heat exchanger has the thermal insulation 140. In alternative embodiments, both end regions 138 are equipped with the thermal insulation.

[0246] The heat storage and exchanger 100 of Fig. 2a also comprises a pressure equalization vessel 130a, 130b, 130c.

[0247] The pressure equalization vessel 130a, 130b, 130c has a pressure equalization bag 130a for an expansion fluid 136, a riser pipe 130b and a pressure equalization tank 130c.

[0248] During operation, the pressure equalization bag 130a is filled with the expansion fluid 136 when the thermal storage medium is in the liquid state. In this state, the pressure equalization vessel 130c provides a gas volume that at least corresponds to the volume increase of the thermal storage medium upon freezing (e.g., 8% in the case of water).

[0249] If the thermal storage medium freezes during operation, its volume increases, in the case of water by approximately 8%. The thermal storage medium compresses the pressure equalization bag 130a and a portion of the expansion fluid 136 previously contained therein through the riser pipe 130b into the pressure equalization tank 130c. The expansion fluid 136 displaces the gas in the gas volume. As a result, the thermal storage medium can expand without any risk of damaging the storage tank 106.

[0250] The heat storage and exchanger 100 of Fig. 2a is therefore particularly suitable for use as a low-temperature heat storage or as a cold storage.

[0251] As illustrated in Fig. 2b, in some embodiments, the heat storage and exchanger 100 (particularly for use as a low-temperature heat storage or cold storage device) comprises a circulation device 150, for example, a circulation pump 150 or an agitator 150. This circulates the storage medium 108 in the storage container 106 when the temperature of the storage medium 108 reaches or falls below its freezing point. In some embodiments (not shown), the heat storage and exchanger 100 comprises the circulation device 150 in addition to the pressure equalization vessel 130a, 130b, 130c.

[0252] The circulation device 150 reduces ice formation and improves heat conduction in the storage tank 106. The circulation device 150 delays a stratification reversal that would otherwise occur when using a water-containing (i.e., aqueous) thermal storage medium and its temperature passes through 4°C. Since the density of the aqueous thermal storage medium reaches its maximum at 4°C, at an (e.g., average) temperature of the storage tank (or the thermal storage medium contained therein) at temperatures above or below 4°C, warmer or colder thermal storage medium is located in the upper region of the thermal storage tank. In contrast, the lower region of the thermal storage tank contains colder or warmer thermal storage medium. The stratification reversal occurs when the temperature passes through 4°C.The circulation device 150 reduces stratification of the thermal storage medium, thus delaying the stratification reversal and ultimately reducing ice formation.

[0253] The heat storage and exchanger 100 of Fig. 2b also has a flow channel 146, 148 arranged in the thermal storage container 106. The flow channel 146, 148 is arranged such that it defines a direction for the flow 152 generated by the circulation device 150 toward the heat exchanger 104 and / or limits it; for this purpose, it encloses at least a portion of the generated flow 152.

[0254] In the illustrated embodiment, the flow channel 146, 148 is formed by two mutually concentric tubes 146, 148.

[0255] The outer tube 148 encloses a portion of the heat exchanger 104, as well as a portion of the generated flow 152 and the circulation device 150 itself. Thus, it confines the generated flow 152 outward and directs it toward the heat exchanger 104 by preventing the flow 152 from straying too far from the heat exchanger 104. The outer tube 148 is concentric with the double-tube heat exchanger 104.

[0256] In the illustrated embodiment, the flow channel 146, 148 also includes an inner tube 146, however, this is optional and is omitted in some embodiments. The inner tube 146 further confines the generated flow 152, namely inward, and thus also directs it toward the heat exchanger 104. The inner tube 146 is concentric with the double-tube heat exchanger 104 and also with the outer tube 148.

[0257] The flow channel 146, 148 improves the effectiveness of the circulation device 150 by directing the flow 152 generated by it toward the heat exchanger 104, i.e., by limiting it and specifying its direction toward the heat exchanger 104. This improves the heat transfer between the heat exchanger 104 and the storage tank or thermal storage medium in all embodiments; accordingly, the circulation device 150 and optionally the flow channel 146, 148 can be provided in conjunction with all described embodiments.

[0258] In addition, the circulation device can particularly effectively delay or prevent ice formation on the heat exchanger 104. Ice formation is particularly undesirable on the heat exchanger 104, as it can lead to reduced heat conduction (particularly between the heat exchanger 104 and the thermal storage tank 106 or the thermal storage medium) or even to frost damage on the heat exchanger 104.

[0259] The heat storage and exchanger 100 of Fig. 2b, like the heat storage and exchanger 100 of Fig. 2a, is thus particularly well suited for use as a latent heat storage device or as an ice storage device, as well as for use at temperatures around freezing point. To further improve the suitability of the heat storage and exchanger 100 of Fig. 2b, one or all of the features described in connection with Fig. 2a can optionally be provided.

[0260] Fig. 3 shows a heat accumulator and exchanger 100 according to a third embodiment, which is similar to that of Fig. 1, Fig. 2a, and Fig. 2b. Corresponding elements are designated by the same reference numerals, and a repeated description is omitted. The heat accumulator and exchanger 100 of Fig. 3 is formed with a number of modifications. According to different embodiments, a heat accumulator and exchanger 100 is formed with only one or a combination of the described modifications.

[0261] The heat storage and exchanger 100 of Fig. 3 is designed as a multi-zone heat storage.

[0262] The heat storage and exchanger 100 of Fig. 3 has three additional heat exchangers 118, 122, 126, which are arranged at different heights.

[0263] The thermal storage medium 108 in the storage tank 106 of the heat storage and exchanger 100 has a temperature profile in which the temperature increases from bottom to increases at the top (temperature stratification). Thus, the different heights at which the additional heat exchangers 118, 122, 126 are arranged in the storage tank 106 correspond to different temperatures of the thermal storage medium 108 in the storage tank 106.

[0264] The lowest additional heat exchanger 118 serves for thermal coupling to a geothermal collector or to the surrounding soil.

[0265] The middle additional heat exchanger 122 serves to extract heat at a first, lower temperature, for example for a heating system.

[0266] The upper additional heat exchanger 126 is used to extract heat at a second, higher temperature, for example for domestic water.

[0267] In the illustrated embodiment, the additional heat exchangers 118, 122, 126 or their supply / discharge lines 120, 124, 128 are guided laterally out of the storage tank 106. In alternative embodiments, the additional heat exchangers 118, 122, 126 or their supply / discharge lines 120, 124, 128 are guided upwardly out of the storage tank 106, as described in connection with the embodiments of Fig. 1, Fig. 2a, Fig. 2b for the first fluid line 102a and the second fluid line 102b. This can simplify the connection of further elements to the supply / discharge lines 120, 124, 128, particularly if the storage tank 106 is arranged largely underground (for example, in terms of its vertical extent), but its upper side protrudes from the ground.

[0268] In some embodiments, the end region 138 of the heat exchanger has thermal insulation 140, as described above. During operation, a fluid in the first fluid line 102a flows through this end region 138 to the supply / discharge line 114 from the storage tank 106 (upward in Fig. 3), for example, to the warm side of a heat pump. Its temperature is adjusted to that of a fluid flowing in the second fluid line 112b in the end region 138 from the supply line 112 into the storage tank 106 (downward in Fig. 3), for example, coming from a geothermal collector. If the temperature of the outflowing fluid in the first fluid line 102a is higher than that of the inflowing fluid in the second fluid line 102b, the outflowing fluid in the first fluid line 102a is further cooled (heat is removed from it), and the inflowing fluid in the second fluid line 102b is heated (absorbs heat). This allows the heat The heat transfer in the heat storage and exchanger 100 can be further improved, and the efficiency (e.g. a performance factor such as the annual performance factor) of the heat pump can be further improved.

[0269] The heat storage and exchanger 100 also has, in the uppermost section of the storage container 106, a section 138' of the first fluid line 102a (not shown), which is thermally coupled to the region of the storage container 106 for the thermal storage medium 108, but is thermally insulated from the second fluid line 102b. The double-pipe heat exchanger 104 is not formed in this region. Rather, the first fluid line 102a is in direct thermal contact with the thermal storage medium 108 and forms a heat exchanger with it, but is thermally insulated from the second fluid line 102b. For this purpose, the first fluid line 102a and the second fluid line 102b are spaced apart from one another in this section 138' (e.g., by an insulating material or by the thermal storage medium 108).Preferably, the first fluid line 102a and the second fluid line 102b are guided separately from one another in the section 138' by one of their supply / discharge lines 112, 114 into the storage tank, and are only brought together in the storage tank 106 to form the heat exchanger 104.

[0270] Accordingly, the first fluid line 102a transfers the heat contained therein (or in the fluid carried by it) directly after its entry into the storage tank 106 to the thermal storage medium 108 in the uppermost region of the storage tank 106. Typically, the first fluid line 102a carries a fluid in this region 138' that flows into the storage tank 106 from the warm side of a heat pump. Thus, the heat transfer takes place at maximum temperature, i.e. essentially at the temperature of the warm side of the heat pump or at the temperature at which the fluid flows into the storage tank from the heat pump; in particular, without any significant temperature loss due to heat transfer from the first fluid line 102a to the second fluid line 102b.

[0271] An upper region 132a of the shell surface (upper shell region) of the storage container 106 has thermal insulation 134. The thermal insulation is absent in a lower region 132b of the shell surface (lower shell region) of the storage container 106. In other words, the upper shell region 132a is more thermally insulated from a medium surrounding the storage container 106 than the lower shell region 134a, typically at least three times more (i.e., with a thermal conductivity at least three times lower).

[0272] The height extension hi of the upper shell region 132a is approximately twice as large as the height extension h2 of the lower shell region 132b. In other words, the height extension hi (I12) of the upper (or lower) shell region 132a (132b) is approximately two-thirds (approximately one-third) of the height extension h of the region of the storage container 106 intended for the thermal storage medium.

[0273] The weaker or substantially nonexistent thermal insulation of the lower shell region 132b results in a thermal coupling of the lower shell region 132b to the medium surrounding the storage vessel 106, typically to the soil surrounding the storage vessel 106.

[0274] Thus, the medium or soil surrounding the storage tank 106 is made usable as an additional thermal storage medium for heat at low temperatures.

[0275] However, the upper region of the storage tank 106, in which the thermal storage medium has a higher temperature, is thermally insulated by the upper jacket region 132a and the insulation 134 in order to ensure a sufficiently high temperature in the upper region of the storage tank 106, for example for domestic water.

[0276] The heat storage and exchanger 100 of Fig. 3 is particularly suitable for use as a high-temperature heat storage device (e.g. due to its design as a multi-zone heat storage device).

[0277] Fig. 4 shows a system 200 with a heat storage and exchanger 100 according to a first embodiment.

[0278] The system 200 comprises the heat storage and exchanger 100, a second heat storage and exchanger 210, a control unit 202, a heat pump 204, and a solar system 206, 208.

[0279] The heat storage and exchanger 100 is similar to that of Fig. 1, Fig. 2a, Fig. 2b or Fig. 3.

[0280] According to the illustration in Fig. 4, the second heat storage and exchanger 210 is also similar to that of Fig. 1, Fig. 2a, Fig. 2b or Fig. 3. In other embodiments, however, the second heat storage and exchanger 210 is constructed differently or more simply. Various embodiments are possible, as long as the second heat storage and exchanger 210 comprises a storage container 220, a first fluid line 212a, and a second fluid line 212b, and is configured to enable heat transfer between the first fluid line 212a and the storage container 220 (or a thermal storage medium arranged therein) and between the second fluid line 212b and the storage container 220 (or the thermal storage medium arranged therein). In the illustrated embodiment, this is achieved by a single heat exchanger 222; however, in alternative embodiments, multiple heat exchangers may be provided.

[0281] In alternative embodiments, the second heat storage and exchanger 210 is similar to at least one of the heat storage and exchangers 100 of Fig. 1, Fig. 2a, Fig. 2b, or Fig. 3. The heat storage and exchanger 100 of Fig. 4 may be of simpler construction as long as it has the features described above in connection with the second heat storage and exchanger 210.

[0282] The system 200 is operated, at least temporarily (e.g., during summer or winter), such that one of the heat storage units and exchangers 100, 210 is operated as a low-temperature heat storage unit (i.e., as a cold storage unit), and the other heat storage unit and exchanger 100, 210 is operated as a high-temperature heat storage unit. With such use, the temperature difference between the cold storage unit and the high-temperature heat storage unit is kept as large as possible, e.g., by discharging heat from the heat pump 204 into the high-temperature heat storage unit and cold into the cold storage unit when the heat pump 204 is in operation. By using the two heat storage units and exchangers 100, 210 in the system 200 as heat and cold storage units, as described above, the efficiency of the system 200 is improved compared to a conventional heat recovery system in which the cold energy released by the heat pump is released as a waste product into the environment, e.g., air or groundwater.Likewise, the efficiency of the 200 system is improved compared to a conventional air conditioning system, in which the heat energy emitted by the heat pump is released into the environment as a waste product.

[0283] The system 200 also allows for temporary use of both heat storage units and exchangers 100, 210 as cold storage units or (high-temperature) heat storage units, particularly during the transition from winter to summer or from summer to winter. Towards the end of winter, as much cold as possible is introduced into both heat storage units and exchangers 100, 210 in order to be available for cooling in the summer. Towards the end of summer, as much cold as possible is Heat is introduced into both heat storage and exchangers 100, 210 to be available for heating during the winter.

[0284] The heat storage and exchanger 100 is thermally coupled to a cold side 214 of the heat pump 204 by means of the first fluid line 102a.

[0285] The heat storage and exchanger 100 is thermally coupled to the solar system 206, 208 by means of the second fluid line 102b.

[0286] The heat storage and exchanger 100 is thermally coupled to a geothermal collector 224 in the ground 230 by means of the additional heat exchanger 118. Alternatively or additionally, the thermal coupling between the heat storage and exchanger 100 and the ground 230 is achieved through the wall of the heat storage and exchanger 100.

[0287] Alternatively or in addition to the thermal coupling of the heat storage and exchanger 100 to the geothermal collector 224 and / or the ground 230, the additional heat exchanger 118, in some embodiments, couples the heat storage and exchanger 100 to a (particularly local) heating network. For this purpose, the additional heat exchanger 118 is coupled directly to the (local) heating network (i.e., instead of to the geothermal collector 224 and / or the ground 230), or in series with the geothermal collector 224 and / or the ground 230. The latter embodiment is particularly advantageous for implementing a (local) heating network across several buildings or properties that are located in proximity to one another, i.e., in a district. A system 200 is installed in each building or on each property to supply it. The heat storage and exchangers 100 of the systems are connected by means of the (e.g.,connected in series with the associated geothermal collectors 224 to create a common heat storage unit (in particular a low-temperature heat storage unit or cold storage unit) of large capacity. Accordingly, the heat storage units and exchangers 210 of the systems 200 are connected to each other by means of the associated geothermal collectors 228 to create another common heat storage unit (in particular a high-temperature heat storage unit) of large capacity.

[0288] The second heat storage and exchanger 210 is thermally coupled to a warm side 216 of the heat pump 204 by means of its first fluid line 212a.

[0289] The second heat storage and exchanger 210 is thermally coupled to the solar system 206, 208 by means of its second fluid line 212b.

[0290] The illustrated solar system 206, 208 consists of a photovoltaic system 206 and a photothermal system 208. In alternative embodiments, the solar system does not have a photovoltaic system 206 or photothermal system 208, or it has multiple photovoltaic systems 206 or photothermal systems 208. The photovoltaic system 206 and the photothermal system 208 can be integrated with each other as a monolithic unit (e.g., a single system can function as both photovoltaic system 206 and photothermal system 208) or can be spatially separated from each other.

[0291] Optionally, the second heat storage and exchanger 210 is thermally coupled to a geothermal collector 228 in the ground 232 by means of the additional heat exchanger 218. Alternatively or additionally, the thermal coupling between the second heat storage and exchanger 210 and the ground 232 is effected by the wall of the heat storage and exchanger 100, preferably by a lower shell region of the storage tank 220, as described accordingly in connection with Fig. 3.

[0292] In addition to the fluid lines shown as solid lines, the system 200 includes control lines that connect the control unit 202 to the other components. The control lines are shown as dashed lines. The control lines are configured to transmit electrical signals, thereby enabling the control unit 202 to control the components connected to the control unit 202.

[0293] In particular, the control unit 202 is connected to the photovoltaic system 206 and the heat pump 204.

[0294] Through its connection to the photovoltaic system 206, the control unit 202 receives information regarding the electrical power currently produced by the photovoltaic system 206.

[0295] Through its connection to the heat pump 204, the control unit 202 controls the operating state of the heat pump 204, i.e., the current output of the heat pump. In particular, the control unit 202 can switch the heat pump 204 on or off.

[0296] The control unit 202 also provides an input for receiving further information regarding the availability of electrical power in addition to the electrical power currently produced by the photovoltaic system 206. This information relates, among other things, to the availability of electrical power from wind power.

[0297] Optionally, the information relates to a consumption of electrical power, for example, in a building associated with the system 200. In such embodiments, the availability of electrical power refers to the difference between the electrical power provided, for example, by the photovoltaic system 206 and / or a wind turbine, and the consumption of electrical power.

[0298] The control unit 202 also provides an input to receive information regarding a heat demand, for example regarding a building or building complex to be supplied with heat.

[0299] In addition, the control unit 202 is connected to temperature sensors that determine the temperature of the photovoltaic system 206, the photothermal system 208, the soil 230, the soil 232, the (particularly thermal storage medium of) the heat storage and exchanger 100, and the (particularly thermal storage medium of) the second heat storage and exchanger 210 and transmit it to the control unit 202. If a heat storage and exchanger is designed as a multi-zone heat exchanger, it has several temperature sensors that are configured to determine the temperature at different heights of its storage tank and transmit it to the control unit 202.

[0300] In addition, the control unit 202 is connected to valves and flow regulators, which are shown as circles at connection points between the fluid lines. The control unit uses the valves and flow regulators to regulate the direction and flow of the fluid flow through the respective fluid line. Furthermore, the control unit 202 controls circulation pumps (not shown) and thereby also controls the fluid flow through the fluid lines.

[0301] In particular, the control unit 220 controls the flow (e.g., the flow velocity) through at least one of the fluid lines 102a, 102b to control the temperature of a fluid as it flows out of one of the two fluid lines 102a, 102b, for example, as described in connection with the end region 138 of Fig. 1, Fig. 2a, and Fig. 2b. Similarly, the control unit 220 controls the flow (e.g., the flow velocity) through at least one of the fluid lines 212a, 212b to control the temperature of a fluid as it flows out of one of the two fluid lines 212a, 212b.

[0302] Fig. 5a shows a system according to another embodiment, which is similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals; a repeated description is omitted. Furthermore, Fig. 5a illustrates a first operating mode 500a of a method for operating the system according to an example.

[0303] In the first operating mode 500a of Fig. 5a, the control unit 202 controls the heat pump 104 and the fluid flows through the fluid lines such that a closed fluid flow is generated through the solar system 206, 208, the second fluid line 102b and the heat exchanger 104; that the heat pump 204 is in the switched-on operating state; that a closed fluid flow is generated through the cold side 214 of the heat pump 204 and the first fluid line 102a; and that a closed fluid flow is generated through the warm side 216 of the heat pump 204 and the first fluid line 212a.

[0304] This first operating mode is particularly advantageous when the solar system 206, 208 has a higher temperature than the heat storage and exchanger 100 or its thermal storage medium. In this case, heat is transferred from the solar system 206, 208 to the heat storage and exchanger 100. The solar system thus serves as a photothermal system 208. Furthermore, the heat storage and exchanger 100 cools the solar system 206, 208, which increases the efficiency of the photovoltaic system 206.

[0305] The cooling of the photovoltaic system 206 is further improved in that the fluid that reaches the photovoltaic system 206 through the second fluid line 102b is in effective heat exchange in the heat exchanger 104 with the cold fluid from the cold side 214 of the heat pump 204, which flows through the first fluid line 102a.

[0306] Since the heat exchanger 104 has a region at its end (from the perspective of the fluid flow through the second fluid line 102b) that is thermally insulated from the thermal storage medium of the heat storage and exchanger 100, the fluid flow through the second fluid line 102b is cooled below the temperature of the (in particular thermal storage medium of) the heat storage and exchanger 100, which further improves the cooling of the photovoltaic system 206.

[0307] In the illustrated embodiment, the warm side 216 of the heat pump is thermally coupled to the second heat storage and exchanger 210, in particular to its first fluid line 212a. Thus, the heat from the warm side 216 of the heat pump 204 is stored in the second heat storage and exchanger 210 and made available for periods of low availability.

[0308] Thus, this first operating mode is particularly advantageous when the availability of electrical power for operating the heat pump 204 is good, in particular when the electrical power currently provided by the photovoltaic system 206 exceeds a predefined critical value or when electrical power is readily available according to another of the criteria described above.

[0309] Here and below, operating modes in which the heat pump 204 is in the switched-on operating state are referred to as active. Active operating modes are characterized, for example, by the heat pump operating at a power of at least 10%, at least 20%, or at least 30% of its maximum power, or by the heat pump operating at a power of at least 10%, at least 20%, or at least 30% of a peak power of the photovoltaic system 206.

[0310] In all operating modes, an active operating mode is always selected when the availability of electrical power for operating the heat pump 204 is good (as described above for the first operating mode), in particular when the electrical power currently provided by the photovoltaic system 206 exceeds a current electrical energy consumption and / or a predefined critical value. Thus, energy is stored as heat in the second heat storage and exchanger 210 when it is particularly readily available as electrical power or even in excess. Alternatively, the active operating mode is selected when electrical power is readily available according to another of the criteria described above.

[0311] Fig. 5b shows a system according to another embodiment, which is similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals; a repeated description is omitted. Furthermore, Fig. 5b illustrates a second operating mode 500p of a method for operating the system according to an example.

[0312] In the second operating mode 500p of Fig. 5b, the control unit 202 controls the heat pump 104 and the fluid flows through the fluid lines such that a closed fluid flow is generated through the solar system 206, 208, the second fluid line 102b, and the heat exchanger 104; and that the heat pump 204 is in the off operating state.

[0313] In other words, the closed fluid flow through the second fluid line 102b in the second operating mode corresponds to that in the first operating mode, however However, when the heat pump 204 is switched off. In other words, the second operating mode 500p as a passive operating mode corresponds to the first operating mode 500a as an active operating mode.

[0314] As an alternative to the illustrated embodiment, in which the fluid flow is directed through the first heat accumulator and exchanger 100, in a further embodiment (not shown), the fluid flow is directed through the second heat accumulator and exchanger 210. This can be achieved by switching the valves 508a, 508b.

[0315] Here and below, operating modes in which the heat pump 204 is in the off operating state are referred to as passive. Passive operating modes are characterized, for example, by the heat pump being operated at a power level that corresponds to no more than half, no more than one-third, no more than one-quarter, or no more than one-fifth of the power level in the corresponding active operating mode. For example, the heat pump is operated at a power level of no more than 9%, no more than 6%, or no more than 3% of its maximum power, or at a power level of no more than 9%, no more than 6%, or no more than 3% of the peak power of the photovoltaic system 206.

[0316] In the second operating mode, as well as in all other operating modes, a passive operating mode is always selected when the availability of electrical power for operating the heat pump 204 is poor, in particular when the electrical power currently provided by the photovoltaic system 206 falls below a current electrical energy consumption and / or a second predefined critical value. Thus, the power consumption of the heat pump 204 is kept low when electrical power is poorly available.

[0317] Like the first operating mode 500a, this second operating mode 500p is particularly advantageous when the solar system 206, 208 has a higher temperature than the heat storage and exchanger 100 or its thermal storage medium in order to achieve the advantages described above in connection with the first operating mode.

[0318] Furthermore, the second operating mode is advantageous when the temperature of the solar system 206, 208 is equal to or below the freezing point of water, while the temperature of the heat storage and exchanger 100 or its thermal storage medium is above this. At such temperatures, snow or ice can form on the solar system 206, 208. By operating the system in the second operating mode, for example, at regular intervals, snow or ice can be thawed. This allows more light to reach the solar array 206, 208 and it can provide more electrical power and / or heat.

[0319] Fig. 5c shows a system according to another embodiment, similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals; a further description is omitted. Furthermore, Fig. 5c illustrates the first operating mode 5ooa' of the method for operating the system according to another example.

[0320] The first operating mode 500a' according to the embodiment of Fig. 5c is similar to the first operating mode 500a according to the embodiment of Fig. 5a. However, the control unit 202 regulates such that the closed fluid flow through the photovoltaic system 206, the photothermal system 208, the second fluid line 102b and the heat exchanger 104 also passes in series through the geothermal collector 224.

[0321] In corresponding embodiments, the geothermal collector 224 or the soil 230 can thus be used as an additional heat storage device.

[0322] In the illustrated embodiment, the fluid passes through the geothermal collector 224 before passing through the upper region of the storage tank 106. This is particularly advantageous if the temperature of the fluid upon feeding into the geothermal collector 224 or after passing through the solar system 206, 208 (flow temperature) exceeds the temperature in (particularly the upper region of) the storage tank 106. Accordingly, the control unit 202 receives information about the flow temperature and the temperature in (the upper region of) the storage tank 106. If the flow temperature exceeds the temperature in (the upper region of) the storage tank 106, the control unit 202 selects operating mode 5ooa', and this is executed.

[0323] In alternative embodiments (not shown), the fluid passes through the geothermal collector 224 after passing through the lower region of the storage tank 106. Such embodiments are advantageous when the temperature of the geothermal storage tank is below the temperature of (especially the lower region of) the storage tank 106. The control unit 202 selects such an operating mode, and it is executed when the flow temperature is below the temperature in (especially the lower region of) the storage tank 106.

[0324] Fig. 5d shows a system according to a further embodiment, which is similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals, a further description is omitted. Furthermore, Fig. 5d illustrates a third operating mode 530 of a method for operating the system according to an example.

[0325] In the third operating mode 530, the control unit 202 controls the heat pump 204 and the fluid flows through the fluid lines such that the heat pump 204 is in the switched-on operating state; that a closed fluid flow is generated through the cold side 214 of the heat pump 204 and the first fluid line 102a; and that a closed fluid flow is generated through the warm side 216 of the heat pump 204 and the first fluid line 212a.

[0326] The third operating mode 510 thus allows heat to be transferred from the heat storage and exchanger 100 to the heat storage and exchanger 210. This ensures a sufficiently high temperature of the second heat storage and exchanger 210 or its thermal storage medium, particularly in its upper region, where the heat exchanger 126 extracts heat for domestic water. The temperature for domestic water is thus regularly sufficiently high to prevent the formation of Legionella bacteria.

[0327] In the illustrated embodiment, heat from the warm side 216 of the heat pump 204 or cold from the cold side 214 of the heat pump 204 is transferred to a building 502 via the fluid line in 506b in order to heat or cool it. In alternative embodiments, the heat transfer or cold transfer to the building 502 is omitted. Whether heat or cold, or neither, should be transferred to the building 502 is determined by the control unit 202 based on an actual temperature of the building 502 and a target temperature for the building 502 that a user sets. In other words, the system serves to heat or cool depending on the target temperature and actual temperature of the building. The control unit 202 controls the execution of the operating mode accordingly.

[0328] A corresponding heat or cold transfer to the building 502 is optionally possible in all other active operating modes, for example in the operating modes described above in connection with Fig. 5a and Fig. 5c.

[0329] The third operating mode is an active operating mode that is executed when the availability of electrical power to operate the heat pump 204 is good. The availability of electrical power is determined by the control unit 202 as described above.

[0330] Fig. 5e shows a system according to another embodiment, which is similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals; a repeated description is omitted. Furthermore, Fig. 5e illustrates a fourth operating mode 520 of a method for operating the system according to an example.

[0331] In the fourth operating mode 520, the control unit 202 controls the heat pump 204 and the fluid flows through the fluid lines such that a closed fluid flow is generated through the solar system 206, 208 and the cold side 214 of the heat pump 204; that the heat pump 204 is in the switched-on operating state; and that a closed fluid flow is generated through the warm side 216 of the heat pump 204 and the first fluid line 212a.

[0332] In this operating mode, heat or cold is optionally transferred to the building 502, as described above in connection with the operating mode of Fig. 5d.

[0333] The fourth operating mode 520 enables the provision of heat from the solar system 206, 208 for heating the building 502 or for storage in the second heat storage and exchanger 210. Alternatively to storage in the second heat storage and exchanger 210, the heat can be stored in the heat storage and exchanger 100.

[0334] As an alternative to (in particular exclusively) storing the heat in the storage medium of the second heat storage and exchanger 210, the second heat storage and exchanger 210 can be connected in series with the geothermal collector 228 so that the heat is stored in the geothermal collector 228 and the second heat storage and exchanger 210.

[0335] Accordingly, when storing in the heat storage and exchanger 100, the geothermal collector 224 can be connected in series.

[0336] In the illustrated embodiment of the fourth operating mode 520, the heat is taken from the solar system 206, 208 as the heat source. In alternative embodiments, the heat is taken from one of the geothermal collectors 224, 228 as the heat source. In such embodiments, a closed fluid flow is generated through the geothermal collector 224 or 228 and the cold side 214 of the heat pump 204, instead of the Closed fluid flow through the solar system 206, 208 and the cold side 214 of the heat pump 204. Preferably, either the geothermal collector 224, the geothermal collector 228, or the solar system 206, 208 is used as the heat source, depending on which of these elements has the highest temperature. The selection is made automatically by the control unit 202 based on temperature sensors linked to these elements.

[0337] In the illustrated embodiment, the heat is supplied to the building 502 through the fluid line 506a by means of the heat pump 204 and the fluid line 506b. In alternative embodiments, the heat is instead supplied to the building 502 through the fluid line 504, i.e., without using the heat pump 204 (and the fluid lines 506a, 506b). Such alternative embodiments provide a passive operating mode that otherwise corresponds to the active operating mode shown. The passive operating mode is advantageous when the temperature of the solar system 206, 208 (or the temperature of one of the geothermal collectors in 224, 228) exceeds the temperature of the heat storage and exchanger 100, or its storage medium, and / or when the availability of electrical power is poor.

[0338] Fig. 5f shows a system according to another embodiment, similar to that of Fig. 4. Corresponding elements are designated by the same reference numerals; a repeated description is omitted. Furthermore, Fig. 5t illustrates a fifth operating mode 530 of a method for operating the system according to an example.

[0339] In the fifth operating mode 530, the controller 202 controls the fluid flows through the fluid lines such that a closed fluid flow is created through the heat exchanger 126 and the building 502.

[0340] Accordingly, heat for the building 502, for example for domestic water, can be taken from the second heat storage and exchanger 210.

[0341] In alternative embodiments of the fifth operating mode 530, the heat for the building 502 is extracted from the second heat storage and exchanger 210 by means of the heat exchanger 122, or from the heat storage and exchanger 100 by means of the heat exchanger 118, or from the ground 230 or 232 by means of the geothermal collector 224, or from the ground 230 or 232 by means of the geothermal collector 228.

[0342] Which heat exchanger 118, 122, 126 or geothermal collector 224, 228 is used is determined by the control unit 202 based on temperatures at the respective heat exchangers 118, 122, 126 and a requested temperature, as well as the selection of an active or passive operating mode.

[0343] First, the control unit 202 determines whether an active or passive operating mode should be selected based on the availability of electrical power.

[0344] If a passive operating mode is selected or if electrical power is poorly available, the control unit 202 selects the heat exchanger 118, 122, 126 or geothermal collector 224, 228 whose temperature exceeds the requested temperature by the smallest amount. If no heat exchanger 118, 122, 126 or geothermal collector 224, 228 is found whose temperature exceeds the requested temperature, the control unit 202 selects the heat exchanger 118, 122, 126 or geothermal collector 224, 228 with the highest temperature or switches to an active operating mode.

[0345] When an active operating mode is selected or when electrical power is readily available, the control unit 202 selects the heat exchanger 118, 122, 126 or geothermal collector 224, 228 and couples it to the cold side of the heat pump 204, in which the warm side 216 of the heat pump 204 exceeds the requested temperature by the smallest amount during operation (in particular with the readily available electrical power).

[0346] This procedure ensures that heat is extracted from the heat exchanger 118, 122, 126 or geothermal collector 224, 228 at the lowest possible temperature and thus improves the energy efficiency of the system.

[0347] Examples of corresponding variants 530", 530", 530'" of the fifth operating mode 530 are shown in Fig. 5g, Fig. 5h and Fig. 5!.

[0348] In the example 530' of Fig. 5g, electrical power is readily available due to intense solar radiation on the photovoltaic system 206. The thermal storage medium of the heat storage and exchanger 100 has a temperature of around -2 0 corresponding to its freezing point, and the thermal storage medium of the second heat storage and exchanger 210 has a temperature of 60° in the upper area and 20° in the lower area. The soil 230 or 232 has a temperature of 5 0 or 6°. Such a situation can occur during the day at the end of winter or the beginning of spring.

[0349] An underfloor heating system in the building requests a temperature of 35° from the control unit 202 based on a user selection.

[0350] In the example 530', an active operating mode is selected due to the good availability of electrical power.

[0351] In the example shown, the electrical power provided by the photovoltaic system 206 is not sufficient to generate sufficient heat when the heat pump 204 is operated with this power and a fluid from the storage tank 106 with a temperature of -2 0 on the cold side 214 of the heat pump 204, the warm side 216 is heated to the target temperature of 35 0 However, the electrical power provided by the photovoltaic system 206 is sufficient to heat the ground when the heat pump 204 is operated at this power and with a fluid from the ground 230 at a temperature of 5 0 on the cold side 214 of the heat pump 204, the warm side 216 is heated to the target temperature of 35 0 to heat.

[0352] Thus, the control unit 202 selects the geothermal collector 224 and couples it to the cold side 214 of the heat pump 204. The building 502 is heated from the warm side 216 of the heat pump 204.

[0353] In the example 530" of Fig. 5h, electrical power is poorly available due to low solar radiation on the photovoltaic system 206. The thermal storage medium of the heat storage and exchanger 100 has a temperature of 11 0 , and the thermal storage medium of the second heat storage and exchanger 210 has a temperature of 75 0 and in the lower range of 40°. The soil 230 or 232 has a temperature of 13 0 or 18°. Such a situation can occur on a summer night.

[0354] An underfloor heating system in the building requests a temperature of 18° from the control unit 202 based on a user selection.

[0355] In the example 530, a passive operating mode is selected due to the poor availability of electrical power.

[0356] In the illustrated embodiment, neither the temperature of the heat storage and exchanger 100 nor the temperature of the ground 230 is sufficient to provide the target temperature of 18°C. However, the temperature of the ground 232 is sufficient to provide the target temperature of 18°C.

[0357] Thus, the control unit 202 selects the geothermal collector 228 and couples it to the building 502 for heating.

[0358] In the example 530'" of Fig. 5!, electrical power is poorly available due to low solar radiation on the photovoltaic system 206. The thermal storage medium of the heat storage and exchanger 100 has a temperature of 8°, and the thermal storage medium of the second heat storage and exchanger 210 has a temperature of 70° in the upper region and 40° in the lower region. The soil 230 or 232 has a temperature of 7 0 or 14 0Such a situation may occur on a night in late summer or autumn, after the outdoor temperature has dropped seasonally compared to that of the example in Fig. 5h.

[0359] An underfloor heating system in the building requests a temperature of 25 0 at the control unit 202.

[0360] In the example 530, a passive operating mode is selected due to the poor availability of electrical power.

[0361] In the illustrated embodiment, neither the temperature of the heat storage and exchanger 100 nor the temperature of the ground 230, 232 is sufficient to achieve the target temperature of 25 0 However, the temperature of the second heat storage and exchanger 210 is sufficient to achieve the target temperature of 25 0 to provide.

[0362] Thus, the control unit 202 selects the second heat storage and exchanger 210 and couples it to the building 502 for heating.

[0363] When heating in a passive operating mode from one of the heat storage and exchangers 100, 210, the geothermal collector 224, 228 associated with the heat storage and exchanger 100, 210 is preferably connected upstream of the heat storage and exchanger 100, 210, in particular when the temperature of the associated geothermal collector 224, 228 is above the return temperature of the fluid from the building 502.

[0364] Accordingly, in the example shown, the geothermal collector 228 is connected upstream of the second heat storage and exchanger 210. This results in preheating of the fluid from the building before it is passed through the second heat storage and exchanger 210. The fluid thus extracts part of the heat for heating the building 502 from the system at a lower temperature (from the geothermal collector 228) instead of at a higher temperature. (from the second heat storage and exchanger 210). Extracting heat at a lower temperature further improves the system's energy efficiency.

[0365] Those skilled in the art will understand that the above examples are intended merely to illustrate various modes of operation of the system, without any intention of limiting the teachings. For example, in exemplary embodiments, different thermal storage devices can be combined, e.g., by mixing liquid heat-conducting media that are thermally coupled to different thermal storage devices, in particular by means of a mixing valve, to provide a requested temperature.

[0366] Fig. 6a shows a district heating network system 600 with a district heating network and a second district heating network. The district heating network and the second district heating network are each based on heat storage and exchangers 100 and systems 200, respectively. The heat storage and exchangers 100 may be similar to those of Fig. 1, Fig. 2a, Fig. 2b, or Fig. 3. The systems 200 may be similar to those of Fig. 4, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5se, Fig. 5t, Fig. 5g, Fig. 5h, or Fig. 5i.

[0367] The local heating network (or the second local heating network) serves to store heat or cold with a greater heat capacity than that provided by a single heat storage and exchanger 100 or a single system 200. The local heating network (or the second local heating network) is therefore also referred to below as a storage system (or complementary storage system).

[0368] The district heating network (ie storage system) comprises a plurality of systems 200. Each of the systems 200 is assigned to a building or property 602, e.g., arranged in or on it.

[0369] The systems 200 comprise a heat storage and exchanger 100 and optionally a second heat storage and exchanger 210, e.g., a second heat storage and exchanger 210 as described above in connection with Fig. 4.

[0370] Optionally, the systems 200 comprise geothermal collectors 224 assigned to one of the heat storage and exchangers 100, 210 or two geothermal collectors 224, 228 assigned to the two heat storage and exchangers 100, 210.

[0371] The heat storage and exchangers 100 are connected to a storage system by means of the lines 604, optionally in series with the geothermal collectors 224. Thus, the Heat storage capacity of the storage system is increased compared to that of the individual systems 200. Depending on the embodiments, the storage system is a low-temperature storage system (cold storage system) consisting of low-temperature heat storage units 100 (cold storage units 100), for example, as shown in Fig. 2a or Fig. 2b, or a high-temperature storage system consisting of high-temperature heat storage units, for example, as shown in Fig. 3-

[0372] A corresponding high-temperature storage system is, in some embodiments, operated as an anergy network or as a cold heat network, ie at temperatures of the thermal storage medium in the range of 1°C to 40°C, preferably in the range of 10°C to 25°C.

[0373] Each of the systems 200 has a pump (not shown) which is configured to drive a fluid flow in the lines 604 and / or in the lines 606, for example a hydraulic pump. The pump is preferably controlled by the control unit 200 described above, i.e. switched on or off as needed. Alternatively, a separate control unit can be provided which is coupled to the control unit 200. The provision of the pumps for the fluid flow in the lines 604 and / or in the lines 606 in a decentralized manner in the systems 200 enables the use of comparatively low-performance, cost-effective pumps, compared to a conventional system in which a central pumping station is provided or a few pumping stations are provided.In addition, the pressure distribution in the district heating network can be controlled across the entire area, for example by increasing the current pumping capacity of one of the pumps in order to compensate for a local pressure drop in the district heating network (e.g. due to a local bottleneck, for example in one of the lines 604, 604).

[0374] Thus, each of the plots 602 can be supplied with heat (or cooling) from the local heating network even if the capacity of the local heat storage and exchanger 100 arranged on the plot 602 would already be exhausted due to a temporarily increased heat (or cooling) demand on the plot 602 or due to a reduced energy or heat generation (e.g. a failure of the solar system) on the plot 602.

[0375] The geothermal collectors 224, which are arranged in the vicinity of the heat storage and exchangers 100 and thermally coupled thereto, further increase the heat storage capacity of the storage system. In some embodiments, additional geothermal collectors 224, 224" are arranged at a distance from the heat storage and exchangers 100, e.g. between the properties 602 or away from the properties 602, and connected to the storage system by means of the lines 604.

[0376] The additional geothermal collector 224' is implemented as a section of the line 604 with reduced thermal insulation, compared to other sections of the line 604, which are designed with full thermal insulation, in order to enable the transport of heat or cold with as little loss as possible. Due to the reduced thermal insulation, the line 224', 604 is thermally coupled to the surrounding ground, thus implementing the geothermal collector 224'.

[0377] The additional geothermal collector 224" is similar to the geothermal collectors 224, 228 described in connection with Fig. 4. By means of valves, it is optionally coupled to the line 604, and thus optionally coupled to the storage system.

[0378] According to the described (i.e., low-temperature or high-temperature) storage system, the second heat storage units and exchangers 210 are connected by means of the lines 606 to a second local heating network, i.e., to a complementary (i.e., high-temperature or low-temperature) storage system, in order to realize a complementary storage system with increased heat storage capacity. The second heat storage units and exchangers 210 can be similar to the heat storage units and exchangers 100 of Fig. 1, Fig. 2a, Fig. 2b, or Fig. 3. Alternatively, instead of the second heat storage units and exchangers 210, a system 200 can be provided that is similar to one of the systems 200 of Fig. 4, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5e, Fig. 5t, Fig. 5g, Fig. 5h, or Fig. 5l.

[0379] As described for the heat storage and exchanger 100 and the geothermal collector 224, in some embodiments, the second heat storage and exchanger 210 is coupled to a geothermal collector 228. In Figure 6, the geothermal collector 228 for the property is shown at the bottom left. In some embodiments, additional geothermal collectors (not shown) are also connected to the complementary storage system. For this purpose, these additional geothermal collectors are coupled to the lines 606, corresponding to the coupling of the additional geothermal collectors 224', 224" to the lines 604 described above.

[0380] In some embodiments, thermally insulating partition walls 608 are also provided to thermally insulate the second heat storage and exchanger 210 from the heat storage and exchanger 100 and / or the geothermal collector 224, as for the Plot shown at the top right in Fig. 6a. Alternatively or additionally, in some embodiments, thermally insulating partition walls 608 are also provided to thermally insulate the geothermal collector 228 from the heat storage and exchanger 100 and / or the geothermal collector 224, as shown for the plot at the bottom left in Fig. 6a. Further thermally insulating partition walls 608 thermally insulate lines 604, 606 of the local heating network and the second local heating network from one another, as shown in Fig. 6a for the lines 604, 606 between the two left-hand plots 602. Preferably, the thermally insulating partition walls 608 are arranged at least partially underground, in particular in embodiments in which the heat storage and exchangers 100, 210 are arranged at least partially underground.

[0381] In preferred embodiments, corresponding thermally insulating partition walls are used to define the geothermal collector 224 or the geothermal collector 228. In such embodiments, a laterally circumferential thermally insulating partition wall laterally delimits the geothermal collector 224 (or the geothermal collector 228). Optionally, an upper and / or lower thermally insulating partition wall delimits the geothermal collector 224 (or the geothermal collector 228) in its vertical extent.

[0382] In preferred embodiments of the system 200 of Fig. 4, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5e, Fig. 5t, Fig. 5g, Fig. 5h or Fig. 5! and the district heating network system 600 of Fig. 6a, the geothermal collector 224 adjoins the geothermal collector 228 and is laterally separated from the geothermal collector 228 by a thermally insulating partition wall embedded in the ground.

[0383] In preferred embodiments, at least one of the systems 200 includes a solar array 206, 208. In some embodiments, a locally limited (e.g., on one of the properties 602 or away from the properties 602) solar array 206, 208 is provided, which provides sufficient peak power to supply multiple properties 602. In alternative embodiments, the solar arrays 206, 208 are distributed, i.e., each of the systems 200 includes a solar array 206, 208.

[0384] Fig. 6b, Fig. 6c, Fig. 6d, and Fig. 6e show the coupling of a heat accumulator 100 to a storage system 600 according to various embodiments. The heat accumulator is preferably a heat accumulator 100 as previously described in connection with Fig. 1, Fig. 2a, Fig. 2b, or Fig. 3 or the system 200 of Fig. 4, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5e, Fig. 5t, Fig. 5g, Fig. 5h, or Fig. 5!. The storage system is similar to that of Fig. 6a. The heat storage device 100 may be a high-temperature heat storage device 100 or a low-temperature heat storage device; in particular, a high-temperature heat storage device 100 coupled to a high-temperature storage system or a low-temperature heat storage device coupled to a low-temperature storage system.

[0385] In Fig. 6b, Fig. 6c, the heat storage device 100 is purely thermally coupled to the storage system. With such a coupling, no material exchange takes place between the thermal storage medium 108 in the storage container 106 and the storage system (or a medium in the line 604 of the storage system). In other words, there is no fluid coupling between the storage container 106 and the storage system (or a line 604 of the storage system). Corresponding embodiments have the advantage that the respective fluid circuits are separate and their composition can be individually controlled. Contamination of one of the fluid circuits does not affect the other fluid circuit.

[0386] In some embodiments, the geothermal collector 230 is selectively thermally coupled to the storage system, as shown in Fig. 6b, Fig. 6c. The selective thermal coupling between the storage system and the geothermal collector 230 can also be purely thermal in the sense described above, particularly if the thermal coupling between the storage tank 106 and the storage system is purely thermal. In some embodiments, it is formed in series with the storage system and the geothermal collector 230.

[0387] In Fig. 6d, Fig. 6e, the heat storage device 100 is fluidly coupled to the storage system. With such a coupling, a material exchange takes place between the thermal storage medium 108 in the storage container 106 and the storage system (or a medium in the line 604 of the storage system). In other words, a fluid flows through the storage container 106 and the line 604 during operation. In other words, there is a fluid coupling between the storage container 106 and the storage system (or the line 604 of the storage system). Corresponding embodiments have the advantage that the entire storage system can operate not only as a thermal storage system, but also as an electrochemical storage system. This is made possible by the exchange of the storage medium 108 and the electrolyte contained therein in the storage system.

[0388] In some embodiments, the geothermal collector 230 is selectively fluid-coupled to the storage system, as shown in Fig. 6d, Fig. 6e. The selective fluid coupling between the storage system and the geothermal collector 230 can be configured in particular if The storage tank 106 and the storage system are fluidly coupled. In some embodiments, it is formed in series with the storage system and the geothermal collector 230.

[0389] Fig. 7a, Fig. 7b, Fig. 7c, Fig. d, and Fig. e show possible arrangements of a heat storage and exchanger 100 relative to a building 700 to which the heat storage and exchanger 100 is assigned. The heat storage and exchanger 100 may be similar to those of Fig. 1, Fig. 2a, Fig. 2b, or Fig. 3.

[0390] In Fig. 7a, the heat storage and exchanger 100 is arranged within the building 700. This enables simple and cost-effective installation. Furthermore, the heat storage and exchanger 100 is protected from the elements, improving its service life.

[0391] In Fig. 7b, the heat storage and exchanger 100 is arranged outside the building 700. Such an arrangement is particularly advantageous when the heat exchanger 104 contains a refrigerant that is highly flammable or toxic. Arranging the heat storage and exchanger 100 outside the building 700 reduces the resulting hazards for the residents of the building 700.

[0392] In Fig. 7c, the heat storage and exchanger 100 is arranged underground outside of the building 700. The underground arrangement makes the area above the heat storage and exchanger 100 usable. The heat storage and exchanger 100 is protected from the effects of the weather. Furthermore, the heat storage and exchanger 100 can be effectively thermally coupled to the surrounding ground, creating a geothermal collector. An (at least partially) underground arrangement is also possible below the building 700.

[0393] The arrangement of the heat storage and exchanger 100 in Fig. d corresponds to that in Fig. 7c. Alternatively, an above-ground arrangement of the heat storage and exchanger 100 is possible, as shown in Fig. 7b.

[0394] The heat storage and exchanger 100 of Fig. d is associated with a heat storage unit 702, to which the heat storage and exchanger 100 is thermally coupled (e.g., via one of the heat exchangers 104, 118, 122, 126). The associated heat storage unit 702 is arranged in the building 700.

[0395] Fig. 7e shows a particularly advantageous preferred arrangement with two heat storage and exchangers 100a, 100b, each arranged underground. One of the two heat storage and exchangers 100a, 100b is designed as a low-temperature heat storage (i.e., cold storage), for example, as described in connection with the heat storage and exchanger 100 of Fig. 2a or Fig. 2b, and the other as a high-temperature heat storage 100, for example, corresponding to the heat storage and exchanger 100 of Fig. 3.

[0396] One of the heat storage and exchangers 100a is coupled to the associated heat storage 702, as described above. In particular, the high-temperature heat storage (or the low-temperature heat storage) is coupled to the associated heat storage 702 to ensure optimization for heating (or cooling) of the building 700.

[0397] The associated heat storage unit 702 is arranged in the building 700 and is preferably designed as a multi-zone heat storage unit.

[0398] A thermally insulating partition wall 608 is arranged between the heat storage and exchangers 100a, 100b, in particular between their storage containers 106. In the illustrated embodiment, the thermally insulating partition wall 608 between the heat storage and exchangers 100a, 100b is also arranged underground in the ground. In alternative embodiments (not shown), the heat storage and exchangers 100a, 100b are arranged adjacent to one another and / or in a common housing, without any soil between them. In corresponding embodiments, the thermally insulating partition wall 608 is also arranged in the common housing and thus preferably at least partially underground. In embodiments in which the system has the geothermal collectors 224, 228 associated with the heat storage and exchangers 100a, 100b, as described, for example, in connection with Fig.4, as an alternative to the illustrated partition wall 608 or in addition thereto, a thermally insulating partition wall 608 is arranged between the geothermal collectors 224, 228.

[0399] The thermally insulating partition wall 608 enables effective thermal insulation of the heat storage and exchanger units 100a, 100b and / or the geothermal collectors 224, 228, even in confined spaces. This is particularly advantageous in residential areas with high land prices, for example, for single-family or terraced houses, or in the vicinity of small or medium-sized businesses, since the system with the thermally insulated partition wall 608 can also be installed in a smaller courtyard, for example.

[0400] The combination of the heat storage and exchanger 100 with the associated heat exchanger 702 improves, for example, the alternating use of the heat storage and exchanger 100 as a heat storage unit (e.g., during the winter) and as a cold storage unit (e.g., at the transition from winter to summer), as described above. In winter, the heat storage and exchanger 100 and the associated heat exchanger 702 can be kept at the highest possible temperature. At the transition from winter to summer, the heat storage and exchanger 100 can be kept at the lowest possible temperature, and, for example, can also freeze (i.e., be used as an ice storage unit), while the associated heat exchanger 702 is kept at a higher temperature, for example, for domestic water and / or heating water for the building 700. In corresponding embodiments, the storage of cold in the heat storage and exchanger 100 is improved by utilizing the latent heat at the phase transition.

[0401] In alternative embodiments (not shown), the heat accumulator and exchanger 100 and the associated heat accumulator 702 of Fig. d are interchanged, ie the heat accumulator and exchanger 100 is arranged in the building 700 and the associated heat accumulator 702 outside the building 700. In corresponding embodiments, the improved cold storage as described above can also be achieved, wherein the associated heat accumulator 702 can freeze (ie be used as an ice accumulator).

[0402] Fig. 8 shows a system 200 with a heat storage and exchanger 100 and a second heat storage and exchanger 210. The system 200 is similar to that of Fig. 4, Fig. 5a, Fig. 5b, Fig. 5c, Fig. 5d, Fig. 5e, Fig. 5t, Fig. 5g, Fig. 5h, or Fig. 5! and may include one or all of the elements described therein. Accordingly, the following description is limited to additional elements.

[0403] In some embodiments, the heat storage and exchanger 100 is similar to that of Fig. 2a or Fig. 2b, and the second heat storage and exchanger 210 is similar to the heat storage and exchanger 100 of Fig. 3.

[0404] In the system 200 of Fig. 8, the thermal storage media of the heat storage and exchangers 100, 210 are electrolytes for a redox flow battery, and the system 200 further comprises an electrochemical cell 800.

[0405] Preferably, the electrolyte comprises redox-active chemical compounds, in particular ions of a metal compound, preferably ions of a vanadium, sodium, zinc, or iron compound, and / or redox-active organic compounds, preferably viologens, quinones, lignins or lignin sulfates.

[0406] For example, the electrolytes can be provided by vanadium oxide ions dissolved in water or by a saline solution in combination with aminoxyl radicals, such as 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO), and a viologen. However, those skilled in the art will understand that the aforementioned examples are merely exemplary and that other electrolytes may be used.

[0407] Pumps arranged in the heat storage and exchangers 100, 210, the electrochemical cell 800, or in electrolyte lines 802a, 802b therebetween flow the electrolytes from the heat storage and exchangers 100, 210 through the electrolyte lines 802a, 802b to the electrochemical cell 800. The internal structure (not shown) of the electrochemical cell 800 comprises several electrochemical half-cells, a membrane therebetween, and electrodes associated with the electrochemical half-cells. The electrolyte lines 802a, 802b lead to different electrochemical half-cells separated by the membrane, i.e., the electrolytes are flowed through these different electrochemical half-cells by means of the electrolyte lines 802a, 802b. Generated current can be drawn from the associated electrodes.

[0408] The electrochemical cell 800 is thermally coupled to at least one of the heat storage and exchangers 100, 210. In the illustrated embodiment, the coupling is selectively effected by means of the valves 806 to the fluid lines 808a, 808b and thus selectively to the heat storage and exchangers 100, 210. In alternative embodiments, however, only the coupling to one of the heat storage and exchangers 100, 210 is present, in particular the coupling via the fluid line 808b to the high-temperature heat storage 210.

[0409] In the illustrated embodiment, the fluid lines 808a, 808b couple the electrochemical cell 800 directly to the heat storage and exchanger 100, 210. In alternative embodiments, the coupling is optionally effected by means of the heat pump 204, i.e., the fluid lines 808a, 808b are optionally coupled to the cold side 214 of the heat pump 204 instead of to the heat storage and exchanger 100, 210. If the coupling to the cold side 214 of the heat pump 204 is selected, the warm side 216 of the heat pump 204 is thermally coupled to the heat storage and exchanger 100, 210.

[0410] In detail, the thermal coupling is achieved by means of a heat exchanger 804 thermally coupled to the electrochemical cell 800. This heat exchanger can be thermally coupled externally to at least one of the electrochemical half-cells. However, the heat exchanger 804 is preferably arranged in at least one of the electrochemical half-cells. In some embodiments, partial heat exchangers are arranged in several electrochemical half-cells, and the partial heat exchangers are interconnected to form the heat exchanger 804, for example, in series.

[0411] In the illustrated embodiment, the electrochemical cell 800 is spatially separated from the heat storage and exchangers 100, 210. However, in alternative embodiments (not shown), the electrochemical cell 800 is arranged within the heat storage and exchanger 100 or the heat storage and exchanger 210, thus providing a highly integrated system for quick and cost-effective assembly.

[0412] By doubly coupling at least one of the heat storage and exchangers 100, 210 to the electrochemical cell 800, on the one hand via the electrolyte line 802a, 802b, and on the other hand via the thermal coupling through the fluid line 808a, 808b, the system 200 utilizes the electrochemical cell 800 in two ways. On the one hand, it serves to generate electricity using the electrolytes of the heat storage and exchangers 100, 210. On the other hand, the waste heat generated in the electrochemical cell 800 is stored in the heat storage and exchanger 100, 210 for (e.g., later) use. Conversely, the system uses the heat storage and exchanger 100, 210 or the thermal storage medium contained therein twice, on the one hand as an electrolyte for the electrochemical cell 800, and on the other hand as an energy storage device for absorbing the waste heat generated by the electrochemical cell 800.

[0413] Should the temperature of the electrolyte in the storage tank be expected to reach temperatures outside the optimal operating temperatures of the electrochemical cell 800, thermal coupling can also be established between the electrolyte lines and / or the supply lines with heat consumers, such as heating lines, in order to maintain suitable operating temperatures in the electrochemical cell 800. Alternatively or additionally, the maximum storage temperature of the storage tank can be limited to a compatible electrolyte temperature, for example, if chemical processes above the maximum storage temperature would prevent effective storage of electrical energy, and the control system can limit the operation of the heat pump accordingly.

[0414] Alternatively to the electrolytic cell or in addition thereto, the heat storage and exchanger or the system described above further comprises, in some embodiments (not shown), a thermoelectrochemical cell which can be coupled to the (first) heat storage and exchanger 100 and / or the second heat storage and exchanger 210 for generating electrical energy.

[0415] A thermoelectrochemical cell can utilize a temperature difference between two electrodes to convert thermal energy into electrical energy. For example, the thermoelectric cell can be based on a temperature-dependent redox couple, such as a ferric / ferrocyanide couple, so that different temperature levels at the electrodes, such as 20 °C and 60 °C, can be used to generate electricity.

[0416] A corresponding electrolyte solution for operating the thermoelectric cell can be stored in the storage container of the first heat storage and exchanger 100 and / or the second heat storage and exchanger 210, or the thermoelectrochemical cell can be coupled to the first heat storage and exchanger 100 and / or the second heat storage and exchanger 210 via heat exchangers.

[0417] For example, the electrodes of the thermoelectrochemical cell can be coupled to the first and second heat storage and exchangers 100, 210, respectively, to generate a temperature difference in the thermoelectrochemical cell. This temperature difference can then generate a potential difference that can be tapped at the electrodes. Thus, the different temperature levels maintained by the heat storage and exchangers 100, 210 can be used to generate electricity in the thermoelectrochemical cell.

[0418] Furthermore, the stored thermal energy in the (first) heat storage and exchanger 100 can also be used to regenerate an electrolyte solution to generate electricity, for example, according to the operating principle of thermally regenerable electrochemical cycles (TREC) or thermally regenerable batteries (TRB). In other words, the system can comprise a TREC cell or a thermally regenerable battery, and the controller can be configured to selectively couple the TREC cell or the thermally regenerable battery to the heat pump or the (first) heat storage and exchanger 100, depending on the availability of electrical energy, in order to regenerate the TREC cell or the thermally regenerable battery.

[0419] Figs. 9a and 9b show local heating networks 610a, 610b and a local heating network system 600, respectively, with an electrochemical cell 800 according to two embodiments. The local heating networks 610a, 610b and the local heating network system 600 are similar to the local heating network and local heating network system 600 previously described in connection with Figs. 6a-6e, respectively, and can be configured with additional elements described therein, although these are not shown in Figs. 9a and 9b to avoid repetition. The electrochemical cell 800 is similar to that of the embodiment of Fig. 8.

[0420] In the embodiment of Fig. 9a, the heat storage units and exchangers 100 of the local heating network 610a are fluidly coupled to or through the line(s) 604a, as described in detail in connection with Figs. 6d and 6e. The heat storage units and exchangers 100 of the local heating network 610b are similarly fluidly coupled to or through the line 604b. The thermal storage media of the heat storage units and exchangers 100 are electrolytes as described in connection with Fig. 8. The local heating networks 610a, 610b are fluidically decoupled from each other (separated from each other) and preferably also thermally decoupled from each other.

[0421] An electrochemical cell 800 is selectively fluidically coupled to the lines 604a, 604b, to the heat storage and exchangers 100, and to the district heating networks 610a, 610b via the valves 612 and the electrolyte lines 802a, 802b. In particular, one half-cell of the electrochemical cell 800 is selectively fluidically coupled to the district heating network 610a (or to its line 604a or to its heat storage and exchanger 100). Another half-cell of the electrochemical cell 800 is selectively fluidically coupled to the district heating network 610b (or to its line 604b or to its heat storage and exchanger 100).

[0422] Thus, each of the local heating networks 610a, 610b serves as an electrochemical storage system for one of the half-cells, or the local heating networks 610a, 610b as a whole serve as an electrochemical storage system for the electrochemical cell 800.

[0423] In the embodiment of Fig. 9b, the heat storage units and exchangers 100 of the district heating network system 600 are fluidly coupled to or through the line(s) 604, as described in detail in connection with Fig. 6d, Fig. 6e. In some embodiments, the corresponding heat storage units and exchangers 100 serve as high-temperature heat storage units of the district heating network system 600. The heat storage units and exchangers 210 of the district heating network system 600 are fluidly coupled to or through the line 606, as described in detail in connection with Fig. 6d, Fig. 6e. In some embodiments, the corresponding heat storage units and exchangers 210 serve as low-temperature heat storage units of the local heating network system 600. Alternatively, the heat storage units and exchangers 100 serve as low-temperature heat storage units and the heat storage units and exchangers 210 serve as high-temperature heat storage units of the local heating network system 600.

[0424] An electrochemical cell 800 is selectively fluidically coupled to the lines 604, 606 and to the heat storage and exchangers 100, 210 by the valves 612 and the electrolyte lines 802a, 802b. One half-cell of the electrochemical cell 800 is selectively fluidically coupled to the heat storage and exchangers 100, and another half-cell of the electrochemical cell 800 is selectively fluidically coupled to the heat storage and exchangers 210. Furthermore, the function and advantages correspond to those described in connection with Fig. 9a, whereby the two district heating networks of the district heating network system 600 (or their corresponding components) replace the district heating networks 610a, 610b of Fig. 9a (or their corresponding components).

[0425] In the embodiments of Fig. 9a, Fig. 9b, the electrochemical cell 800 is preferably fluid-coupled to a local heating network 610a, 610b or a local heating network of the local heating network system 600 (or to its line 604, 604b, 606, 606b or to its heat storage and exchanger 100, 210) that is operated frost-free, for example at a temperature of at least 1°C, at least 10°C, at least 15°C, or at least 20°C. In some embodiments, the two half-cells of the electrochemical cell 800 described in connection with Fig. 9a, Fig. 9b are each fluid-coupled to a corresponding local heating network (or a corresponding component thereof).

[0426] In the embodiments of Fig. 9a, Fig. 9b, in addition to the fluid coupling of the electrolyte cell 800 to at least one of the local heating networks 610a, 610b or the local heating networks of the local heating network system 600 (or to its line 604, 604b, 606, 606b or to its heat storage and exchanger 100, 210), a thermal coupling (not shown) of the electrolyte cell 800 to at least one of the heat storage and exchanger 100, 210 of the local heating network is optionally provided, as described in connection with the embodiment of Fig. 8. This thermal coupling is spatially separated from the aforementioned fluid coupling, for example, using at least one separate fluid line 808a, 808b (as described in Fig. 8, not shown in Fig. 9a, 9b) that is fluidically separated from the electrolyte lines 802a, 802b. In some embodiments, the electrolyte cell 800 includes a heat exchanger 804, similar to that shown in Fig.8, and this heat exchanger 804 is thermally coupled to at least one of the storage vessels 100, 210, and in some embodiments purely thermally coupled (ie, fluidly separated). LIST OF REFERENCE SYMBOLS 100, 100a, 100b heat storage and exchangers 102a, 102b first, second fluid line 104 heat exchangers 106 storage tanks 108 thermal storage medium 110 dashed highlighted area (with internal structure of the heat exchanger) 112 Supply / discharge of the first fluid line 114 Supply / discharge of the second fluid line 116 Target filling level of the storage tank for the thermal storage medium 118, 122, 126 additional heat exchanger 120, 124, 128 Supply / discharge line of the additional heat exchanger 130a, 130b, 130c Pressure equalization tank upper shell area 132b lower mantle area 134, 140 thermal insulation 138 second area of ​​the heat exchanger, end area of ​​the heat exchanger 142 Cathedral 144 first area of ​​the heat exchanger 146, 148 flow channel, pipes 150 Circulation device 152 flow generated by the circulation device 200 systems 202 control unit 204 heat pump 206 photovoltaic system (solar system) 208 solar thermal system (solar system) 210 second heat storage 212a first fluid line of the second heat accumulator 212b second fluid line of the second heat accumulator 214 cold side of the heat pump 216 warm side of the heat pump 218 additional heat exchanger of the second heat storage 220 storage tank of the second heat storage 222 Heat exchanger of the second heat storage tank 224, 228 Geothermal collector 230, 232 soil 500a, 500a' first operating mode 502 buildings 504 Fluid lines to / from building 506a Fluid lines to / from heat pump 508a, 508b valves 500p second operating mode 512 valves 510 third operating mode 520 fourth operating mode 530, 530', 530", 53o"'fifth operating mode 600 local heating network 602 buildings, land 604, 606 lines 6o8 thermally insulating partition wall 224', 224“ additional geothermal collector 700 buildings 702 assigned heat storage 800 electrochemical cell 802a, 80b Electrolyte line 804 Heat exchanger of the electrochemical cell 806 Flow control (valve or circulation pump) 808a, 808b Fluid line 610a, 610b local heating network, additional local heating network 612 valve

Claims

Claims 1. A heat storage and exchanger (100), comprising: a first fluid line (102a) and a second fluid line (102b); a heat exchanger (104) configured to transfer heat between the first fluid line (102a) and the second fluid line (102b); and a storage container (106) configured to accommodate a thermal storage medium (108); wherein at least a portion of the heat exchanger (104) is arranged in the storage container (106) to enable heat to be transferred between the heat exchanger (104) and the thermal storage medium (108).

2. Heat storage and exchanger (100) according to one of the preceding claims, wherein the first fluid line (102a) and the second fluid line (102b) are in direct contact in the heat exchanger (104) and / or over a region of at least 0.5 m or of at least 1 m or of at least 2 m.

3. Heat storage and exchanger (100) according to one of the preceding claims, wherein the second fluid line (102b) is thermally coupled to a solar system (206, 208); and / or wherein the first fluid line (102a) is thermally coupled to a cold side (214) of a heat pump (204).

4. Heat storage and exchanger (100) according to one of the preceding claims, wherein the heat exchanger (104) comprises a double-pipe heat exchanger.

5. Heat storage and exchanger (100) according to claim 4, wherein the first fluid line (102a) comprises an inner tube of the double-tube heat exchanger, and wherein the first fluid line (102a) is coupled to a heat pump (204) or is coupled to the cold side (214) of the heat pump (204).

6. Heat storage and exchanger (100) according to one of the preceding claims, wherein the storage container (106) is a cistern storage and / or is designed for an underground arrangement and / or has a volume for the thermal storage medium (108) of at least 1 m 3 or of at least 2 m 3 or at least 3 m 3 .

7. Heat storage and exchanger (100) according to one of the preceding claims, wherein the first fluid line (102a) and / or the second fluid line (102b) is configured to pass through an upper surface (116) of the thermal storage medium (108) at least once or at least twice when the thermal storage medium (108) is arranged in the storage container (106); and / or the first fluid line (102a) and / or the second fluid line (102b) passes through the storage container (106) at least once or at least twice in the uppermost fifth of its vertical extent.

8. Heat storage and exchanger (100) according to one of the preceding claims, which has at least two or at least three additional heat exchangers (118, 122, 126), wherein the at least two or at least three additional heat exchangers (118, 122, 126) are arranged at different heights in the storage container (106).

9. Heat storage and exchanger (100) according to one of the preceding claims, wherein the storage container (106) is configured as an ice storage container; and / or the storage container (106) comprises a circulation device configured to circulate the thermal storage medium in the storage container, in particular, wherein the storage container (106) further comprises a flow channel arranged in the thermal storage container (106) such that it predetermines a direction towards the heat exchanger for the flow generated by the circulation device and / or limits it; and / or the storage container (106) has a pressure equalization vessel (130a, 130b, 130c), wherein a gas volume (130c) of the pressure equalization vessel is at least 8% of a volume of the storage container (106) for the thermal storage medium (108), in particular when the thermal storage medium (108) is in the liquid state.

10. Heat storage and exchanger (100) according to one of the preceding claims, wherein the storage container (106) has an upper shell region (132a) and a lower shell region (132b), and wherein the upper shell region (132a) has a stronger thermal insulation (134) between the inside and outside of the storage container (106) than the lower shell region (132b), in particular wherein the lower region of the storage container is thermally coupled to a surrounding soil.

11. Heat storage and exchanger (100) according to one of the preceding claims, wherein the thermal storage medium (108) is arranged in the storage container (106), and wherein the thermal storage medium (108) has a freezing point of at most -1°C or of at most -2°C or of at most -20°C, in particular wherein the storage container is thermally coupled to a surrounding soil.

12. Heat storage and exchanger (100) according to one of the preceding claims, wherein the thermal storage medium (108) is arranged in the storage container (106) and wherein the thermal storage medium (108) is configured to provide an electrolyte for an electrochemical cell (800), in particular wherein the heat storage and exchanger (100) is configured to provide the thermal storage medium (108) of the electrochemical cell (800) in a fluid-coupled manner.

13. Heat storage and exchanger (100) according to one of the preceding claims, wherein a second section (138) of the heat exchanger (104) has no thermal contact with the thermal storage medium (108) and / or has thermal insulation (140) with respect to the thermal storage medium (108) and / or is arranged above a desired filling level (116) of the storage container (106) for the thermal storage medium (108). 14- Heat storage and exchanger (100) according to one of the preceding claims, which is arranged for a fluid coupling of the storage container (106) and / or the thermal storage medium (108) to a line (604, 606) external to the storage container (106).

15. Use of a heat storage and exchanger (100) according to one of the preceding claims as an underground heat storage.

16. Use of a heat storage and exchanger (100) according to one of the preceding claims as a countercurrent heat exchanger.

17. System (200) comprising a heat accumulator and exchanger (100) according to one of the preceding claims and at least one control device (202), wherein the at least one control device (202) is configured to control a fluid flow through the first fluid line (102a) as a function of a first parameter, wherein the first parameter is linked to an availability of electrical power and / or is linked to an electrical power provided by a photovoltaic system (206).

18. The system of claim 17, wherein the at least one control device (202) is further configured to output a control signal for a heat pump (204) depending on the first parameter, wherein the heat exchanger (104) comprises a double-pipe heat exchanger, wherein the first fluid line (102a) comprises an inner pipe of the double-pipe heat exchanger, and wherein the first fluid line (102a) is configured to be coupled to the heat pump (204) or is coupled to the heat pump (204).

19. System according to one of claims 17 to 18, wherein the second fluid line (102b) is thermally coupled to a solar system (206, 208) and / or wherein the system comprises the solar system (206, 208).

20. The system of any one of claims 17 to 19, further comprising a second heat storage and exchanger (210), the second heat storage and exchanger (210) comprising: a first fluid line (212a) and a second fluid line (212b); and a storage container (210) configured to accommodate a thermal storage medium (108); wherein the second heat accumulator and exchanger (210) is configured to enable heat to be transferred between the first fluid line (212a) and the thermal storage medium (108) and between the second fluid line (212b) and the thermal storage medium (108); wherein the at least one control device (202) is configured to control a fluid flow through the first fluid line (212a) of the second heat accumulator and exchanger (210) together with the fluid flow through the first fluid line (102a) of the heat accumulator and exchanger (100).

21. The system of claim 20 in combination with claim 18, wherein the system comprises the heat pump (204), and wherein the fluid flow through the first fluid line (102a, 212a) of the heat accumulator and exchanger (100) or the second heat accumulator and exchanger (210) is configured to thermally couple this heat accumulator and exchanger (100, 210) to a cold side (214) of the heat pump (204), and the fluid flow through the first fluid line (102a, 212a) of the other heat accumulator and exchanger (100, 210) is configured to thermally couple the other heat accumulator and exchanger (100, 210) to a warm side (216) of the heat pump (204).

22. The system of claim 21, wherein the heat pump (204) is configured to provide a power of at least 3 kW or at least 5 kW.

23. A system comprising: a first heat storage and exchanger (100) and a second heat storage and exchanger (210), wherein the first heat storage and exchanger (100) has: a first fluid line (102a) and a second fluid line (102b); a heat exchanger (104) configured to transfer heat between the first fluid line (102a) and the second fluid line (102b); and a storage container (106) configured to receive a thermal storage medium (108); wherein at least a portion of the heat exchanger (104) is arranged in the storage container (106) to enable heat to be transferred between the heat exchanger (104) and the thermal storage medium (108); and wherein the first heat storage and exchanger (100) has a volume for its thermal storage medium (108) of at least 2 m 3and is arranged at least partially underground; and wherein the second heat storage and exchanger (210) comprises: a first fluid line (212a) and a second fluid line (212b); and a storage container (210) configured to receive a thermal storage medium (108); wherein the second heat storage and exchanger (210) is configured to enable heat to be transferred between the first fluid line (212a) and the thermal storage medium (108) and between the second fluid line (212b) and the thermal storage medium (108);a heat pump (204) configured to provide an output of at least 5 kW, wherein a fluid flow through the first fluid line (102a) of the first or second heat accumulator and exchanger (100, 210) is configured to thermally couple this heat accumulator and exchanger (100, 210) to a cold side (214) of the heat pump (204), and a fluid flow through the first fluid line (212a) of the other of the first and second heat accumulators and exchangers (100, 210) is configured to thermally couple the other heat accumulator and exchanger (100, 210) to a warm side (216) of the heat pump (204);and a control device (202) configured to jointly control an operating state of the heat pump (204), the fluid flow through the first fluid line (102a) of the first heat accumulator (100) and the fluid flow through the first fluid line (212a) of the second heat accumulator (210) as a function of a first parameter, the first parameter being linked to an electrical power provided by a photovoltaic system (206); wherein the second fluid line (102b) of the first heat storage and exchanger (100) and / or the second heat storage and exchanger (210) is coupled to a solar system (208).

24. A method for producing an underground heat storage facility, the method comprising: Arranging at least a portion of a heat storage and exchanger (100) in the ground (230), wherein the heat storage and exchanger (100) comprises: a first fluid line (102a) and a second fluid line (102b); a heat exchanger (104) configured to transfer heat between the first fluid line (102a) and the second fluid line (102b); and a storage container (106) configured to receive a thermal storage medium (108); wherein at least a portion of the heat exchanger (104) is arranged in the storage container (106) to enable heat to be transferred between the heat exchanger (104) and the thermal storage medium (108).

25. The method of claim 24, further comprising: thermally coupling the heat storage and exchanger (100) to a geothermal collector (224) and / or to the ground (230).

26. The method according to claim 24 or 25, further comprising: thermally coupling the heat storage and exchanger (100) to a local heating network (600) in order to selectively store heat or cold from the heat storage and exchanger (100) in the local heating network (600) or to extract it from the local heating network (600) into the heat storage and exchanger (100); in particular in series with the geothermal collector (224) and / or with the ground (230); in particular, wherein the geothermal collector (224) is coupled to a further heat storage and exchanger (100).

27. A method according to any one of claims 24 to 26, further comprising: Setting up the heat exchanger (104) as a counterflow heat exchanger.

28. A method according to any one of claims 24 to 27, further comprising: Coupling the first fluid line (102a) to a heat pump (204).

29. The method of claim 28, further comprising: Coupling a first fluid line (212a) of a second heat accumulator and exchanger (210) to the heat pump (204), wherein the second heat accumulator and exchanger (210) comprises: a first fluid line (212a) and a second fluid line (212b); and a storage container (210) configured to receive a thermal storage medium (108); wherein the second heat accumulator and exchanger (210) is configured to enable heat to be transferred between the first fluid line (212a) and the thermal storage medium (108) and between the second fluid line (212b) and the thermal storage medium (108); wherein the first fluid line (102a, 212a) of the heat accumulator and exchanger (100) or of the second heat accumulator and exchanger (210) is coupled to a cold side of the heat pump (204); and wherein the first fluid line (102a, 212a) of the other heat storage and exchanger (100, 210) is coupled to a warm side of the heat pump (204).

30. A method according to any one of claims 24 to 29, further comprising: Fluid coupling of the storage tank (106) and / or the thermal storage medium (108) to a line (604, 606) external to the storage tank (106) and / or to a local heating network.

31. A method for operating a system (200) comprising a heat storage and exchanger (100), wherein the heat storage and exchanger (100) comprises: a first fluid line (102a) and a second fluid line (102b), wherein the first fluid line (102a) is coupled to a heat pump (204); a heat exchanger (104) configured to transfer heat between the first fluid line (102a) and the second fluid line (102b); and a storage container (106) configured to receive a thermal storage medium (108); wherein at least a portion of the heat exchanger (104) is arranged in the storage container (106) to enable heat to be transferred between the heat exchanger (104) and the thermal storage medium (108); wherein the method has at least two operating modes, the method comprising: selectively executing one of the at least two operating modes; wherein the first operating mode comprises: Operating the heat pump (204) with a first heat pump output; and Generating a fluid flow through the first fluid line (102a) to transfer heat between the heat pump (204) and the thermal storage medium (108); and wherein the second operating mode comprises: Operating the heat pump (204) with a second heat pump output which is at most one quarter of the first heat pump output; and Generating a stronger fluid flow through the second fluid line (102b) than through the first fluid line (102a) to transfer heat by means of the second fluid line (102b).

32. The method according to claim 31, wherein, in the selective execution of one of the at least two operating modes, a selection between the first and the second operating mode is carried out automatically based on a first parameter, the first parameter being linked to an availability of electrical power. 33- Method according to one of claims 31 or 32, wherein the second fluid line (102b) is thermally coupled to a solar system (206, 208) and the method further comprises: Operating the system (200) in the second operating mode when the temperature of the solar system (206, 208) is equal to or below the freezing point of water, while the temperature of the heat storage and exchanger (100) or its thermal storage medium is above the freezing point of water.

34. A method according to any one of claims 31 to 33, further comprising: Controlling a flow of a fluid through the first fluid line 102a or the second fluid line 102b; to reduce a temperature difference between a first fluid flowing out of one of the first fluid line 102a and the second fluid line 102b and a second fluid flowing into the other of the first fluid line 102a and the second fluid line 102b; and to further increase a temperature difference between the outflowing first fluid and the thermal storage medium 108.

35. Method according to one of claims 31 to 34, wherein the heat storage and exchanger (100) has a fluid coupling of the storage container (106) and / or the thermal storage medium (108) to a line (604, 606) external to the storage container (106) and / or to a local heating network, and wherein the method further comprises: Transport of electrolyte through said fluid coupling.

36. The method according to any one of claims 31 to 35, wherein the system further comprises a second heat storage and exchanger (210), wherein the second heat storage and exchanger (210) comprises: a storage container (210) configured to receive a thermal storage medium (108); and a first fluid line (212a) and a second fluid line (212b); wherein the second heat storage and exchanger (210) is configured to transfer heat between the first fluid line (212a) and the thermal storage medium (108) and between the second fluid line (212b) and the thermal storage medium (108); the method further comprising: Carrying out the method steps relating to the heat accumulator and exchanger (100) correspondingly at the second heat accumulator and exchanger (216); wherein the first fluid line (102a, 212a) of the first or second heat accumulator and exchanger (100, 214) is coupled to a cold side of the heat pump (204); and wherein the first fluid line (102a, 212a) of the other of the first and second heat accumulators and exchangers (100, 216) is coupled to a warm side of the heat pump (204).

37. A computer program configured to cause an electronic control system to carry out a method according to any one of claims 25 to 28.

38. A local heating network, comprising: a first heat storage and exchanger (100), wherein the first heat storage and exchanger (100) is a heat storage and exchanger (100) according to any one of claims 1 to 10; or a system according to any one of claims 13-18, wherein the first heat storage and exchanger (100) is the heat storage and exchanger (100) of the system according to any one of claims 13-18; a second heat storage and exchanger (100), wherein the second heat storage and exchanger (100) is a heat storage and exchanger (100) according to any one of claims 1 to 10; or a further system according to any one of claims 13-18, wherein the second heat storage and exchanger (100) is the heat storage and exchanger (100) of the further system; wherein the second heat storage and exchanger (100) is spatially separated from the first heat storage and exchanger (100), for example by at least 50 m or by at least 100 m or by at least 200 m;and a geothermal collector (224) which is thermally coupled to the first heat storage and exchanger (100) and the second heat storage and exchanger (100) and which is configured to store heat or cold in a surrounding ground (230) and; to extract at least part of the stored heat or cold from the ground (230) at a later time.

39. The district heating network of claim 38, further comprising: a conduit (604, 606) configured to thermally couple the first heat storage and exchanger (100) and the second heat storage and exchanger (100); wherein a first portion of the conduit (604, 606) has thermal insulation, and wherein a second portion of the conduit (604, 606) has less or no thermal insulation to form the geothermal collector (224).

40. A district heating network according to claim 38 or 39, further comprising an electrochemical cell (800) fluidly coupled to the first heat storage and exchanger (100) and to the second heat storage and exchanger (100).

41. Local heating network according to claim 40, wherein the first heat storage and exchanger (100) and the second heat storage and exchanger (100) are fluidly coupled to a half-cell of the electrochemical cell (800), and wherein another half-cell of the electrochemical cell (800) is fluidly coupled to a further local heating network (610b) according to one of claims 38 to 40, wherein the further local heating network (610b) is thermally and / or fluidically decoupled from the local heating network (610a).

42. District heating network according to one of claims 38 to 41, further comprising: a fluid coupling between the first heat storage and exchanger (100) and the second heat storage and exchanger (100), and / or a fluid coupling between the first heat storage and exchanger (100) and the geothermal collector (224), and / or a fluid coupling between the second heat storage and exchanger (100) and the geothermal collector (224).

43. District heating network according to claim 42, wherein said fluid coupling(s) is / are arranged to transport electrolyte. 44- A local heating network system (600) comprising a local heating network according to any one of claims 38 to 43, and further comprising a second local heating network, the second local heating network comprising: a first low-temperature heat storage device, the first low-temperature heat storage device being a heat storage and exchanger (100) according to any one of claims 1 to 10; or a system according to any one of claims 15 or 18, the second low-temperature heat storage device being the second heat storage and exchanger (100) of the system; and the thermal storage medium of the first low-temperature heat storage device having a lower temperature than the thermal storage medium of the first heat storage and exchanger (100); a second low-temperature heat storage device, the second low-temperature heat storage device being a heat storage and exchanger (100) according to any one of claims 1 to 10;or a further system according to one of claims 15 or 18, wherein the second low-temperature heat accumulator is the second heat accumulator and exchanger (100) of the further system; wherein the second low-temperature heat accumulator is spatially separated from the first low-temperature heat accumulator, for example by at least 50 m or by at least 100 m or by at least 200 m; and wherein the thermal storage medium of the second low-temperature heat accumulator has a lower temperature than the thermal storage medium of the second heat accumulator and exchanger (100); a second geothermal collector (228) which is thermally coupled to the first low-temperature heat accumulator and the second low-temperature heat accumulator, and which is configured to store second heat or cold in a surrounding soil (232) and to extract at least a portion of the stored second heat or cold from the soil (232) at a later time;and optionally a thermally insulating partition wall (608) which is designed to thermally insulate a region of the local heating network from a region of the second local heating network, in particular wherein the thermally insulating partition wall (608) is arranged at least partially underground; 45. Local heating network system (600) according to claim 44, comprising an electrochemical cell (800), wherein a half cell of the electrochemical cell (800) is connected to the first heat storage and exchanger (100) and / or to the second heat storage and exchanger (loo) is fluid-coupled, and wherein another half-cell of the electrochemical cell (800) is fluid-coupled to the first low-temperature heat storage device and / or to the second low-temperature heat storage device.

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