LATENT HEAT STORAGE SYSTEM HAVING A LATENT HEAT STORAGE DEVICE AND METHOD FOR OPERATING A LATENT HEAT STORAGE SYSTEM

Abstract

A latent heat storage system includes at least one latent heat storage device which contains a storage medium with latent heat, at least one heat pump coupled to the latent heat storage device, at least one extraction circuit which has a first heat carrier medium and with which, during normal operation, in accordance with the intended purpose, heat can be extracted from the storage medium and supplied to the heat pump on the input side, and an extraction heat exchanger which is in contact with the storage medium, wherein the extraction heat exchanger is connected to the extraction circuit. Between the extraction heat exchanger and the heat pump, a coupling device is arranged in a connection line, which at least temporarily supplies a second heat carrier medium, which can be heated by at least one heat source, into a section of the connection line. A method for operating a latent heat storage system is also provided.

Claims

1. A latent heat storage system comprising at least one latent heat storage device which contains a storage medium with latent heat, at least one heat pump coupled to the latent heat storage device, at least one extraction circuit which has a first heat carrier medium and with which, during normal operation, in accordance with the intended purpose, heat can be extracted from the storage medium and supplied to the heat pump on the input side, and an extraction heat exchanger which is in contact with the storage medium, wherein the extraction heat exchanger is connected to the extraction circuit, wherein, between the extraction heat exchanger and the heat pump, a coupling device is arranged in a connection line, which at least temporarily supplies a second heat carrier medium, which can be heated by at least one heat source, into a section of the connection line.

2. The latent heat storage system according to claim 1, wherein the section into which the second heat carrier medium is admixed is arranged between coupling device and heat pump.

3. The latent heat storage system according to claim 1, wherein at least one regeneration circuit is provided with the second heat carrier medium, with which, during normal operation, in accordance with the intended purpose, heat can be supplied to the storage medium from at least one heat source, wherein the at least one latent heat storage device comprises a regeneration arrangement within the storage medium, wherein the regeneration arrangement is connected to the regeneration circuit.

4. The latent heat storage system according to claim 3, wherein the coupling device fluidically connects the regeneration circuit to the heat pump and the regeneration device is at least partially bypassed.

5. The latent heat storage system according to claim 3, wherein extraction circuit and regeneration circuit are temporarily in fluidic connection by connection lines, wherein a first connection line connects a section of the extraction circuit downstream or upstream of a conveyance means to a connection line between regeneration device and heat source of the regeneration circuit, and a second connection line connects the coupling device to a section of the regeneration circuit downstream or upstream of a conveyance means in the regeneration circuit.

6. The latent heat storage system according to claim 1, wherein the coupling device comprises an element that can be closed-loop and/or open-loop controlled.

7. The latent heat storage system according to claim 1, wherein a closed-loop control and/or open-loop control device is provided, which actuates the coupling device depending on at least one operating parameter of the latent heat storage device and/or of the latent heat storage system.

8. The latent heat storage system according to claim 1, wherein the at least one regeneration circuit has an air-source collector as heat source.

9. The latent heat storage system according to claim 1, wherein the regeneration device has a heat exchanger arranged in the storage medium.

10. The latent heat storage system according to claim 1, wherein the regeneration device has one or more inflows and outflows in the latent heat storage device, and the storage medium circulates at least partially in the regeneration circuit.

11. A method for operating a latent heat storage system according to any one of the preceding claims, wherein the latent heat storage system comprises at least one latent heat storage device which contains a storage medium with latent heat, at least one heat pump coupled to the latent heat storage device and at least one extraction circuit which has a first heat carrier medium and with which, during normal operation, in accordance with the intended purpose, heat is extracted from the storage medium and supplied to the heat pump on the input side, wherein the at least one latent heat storage device comprises at least one extraction heat exchanger in contact with the storage medium, which is connected to the extraction circuit, wherein at least temporarily a second heat carrier medium, which is heated by at least one heat source, is supplied into a section of the connection line.

12. The method according to claim 11, wherein, via at least one regeneration circuit with the second heat carrier medium, during normal operation, in accordance with the intended purpose, heat is supplied into the storage medium from at least one heat source, wherein the at least one latent heat storage device comprises a regeneration arrangement within the storage medium, which is connected to the regeneration circuit.

13. The method according to claim 11, wherein the second heat carrier medium is supplied with variable volume flow, in particular wherein the volume flow of the second heat carrier medium is set depending on a feed temperature of the heat pump.

14. The method according to claim 11, wherein the second heat carrier medium is supplied when a predetermined icing degree of the latent heat storage device with respect to a volume f capable of freezing in accordance with the intended purpose has been reached.

15. The method according to claim 11, wherein the second heat carrier medium is supplied when a temperature of the first heat carrier medium of the extraction circuit is less than or equal to 1 C.; and the second heat carrier medium of the at least one heat source is hotter than the first heat carrier medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Additional advantages result from the following description of the drawing. In the drawings, embodiment examples of the invention are represented. The drawings, the description and the claims contain numerous features in combination. Advantageously, the person skilled in the art will also consider the features individually and combine them into appropriate additional combinations.

[0039] In the drawings, in an exemplary manner:

[0040] FIG. 1 shows a latent heat storage system according to an embodiment example of the invention with a regeneration arrangement having a heat exchanger in the storage medium;

[0041] FIG. 2 shows a latent heat storage system according to an embodiment example of the invention having an open regeneration arrangement in the storage medium;

[0042] FIG. 3 shows a flow chart for the operating procedure of a latent heat storage system according to an embodiment example of the invention.

DETAILED DESCRIPTION

[0043] In the figures, identical or equivalent components are numbered with identical reference numerals. The figures merely show examples and are understood to be non-limiting.

[0044] Direction terminology used below with terms such as left, right, top, bottom, in front of, behind, after, and the like are only used to improve the understanding of the figures and are never intended to represent a limitation of the generality. The represented components and elements as well as their design and use can vary depending on the considerations of a person skilled in the an and can be adapted to the respective applications.

[0045] FIG. 1 represents a latent heat storage system 100 according to an embodiment example of the invention. The latent heat storage system 100 comprises a latent heat storage device 10 which contains a storage medium 20 with latent heat, for example, water. Furthermore, the latent heat storage system 100 comprises an extraction circuit 30 which, during normal operation, in accordance with the intended purpose, extracts heat from the storage medium 20, and a regeneration circuit 40 by means of which, during normal operation, according to the intended purpose, heat is supplied into the storage medium 20.

[0046] During normal operation, no fluid connection between extraction circuit 30 and regeneration circuit 40 is provided.

[0047] The latent heat storage device 10 comprises an extraction heat exchanger 32 in contact with the storage medium 20, in particular immersed therein, which is arranged in the extraction circuit 30, and a regeneration arrangement 42 within the storage medium 20, which is arranged in the regeneration circuit 40. The latent heat storage device 10 comprises a surrounding wall 12, for example, a housing, which is preferably provided or arranged in the ground and which is filled with the storage medium 20. Optionally, the storage medium 20 can also be provided directly in the ground, for example, as a pond installation or cavern. A region 14 of the ground which acts thermally on the latent heat storage device 10 by heat supply or heat absorption is indicated with a double dashed line. The latent heat storage device 10 itself can here act as a geothermal probe.

[0048] In the extraction circuit 30, the extraction heat exchanger 32 is connected via lines 112, 114 to a heat pump 104. The heat pump 104 raises the temperature level of the heat carrier medium 34 and supplies a consumer 130 with heat at a correspondingly higher level.

[0049] The heat carrier medium 34 is circulated in the extraction circuit 30 with a feed pump 106. By means of a circuit not designated in further detail, the heat pump 104 supplies the consumer 130, for example, a building, a residence or the like, with heat and conveys a corresponding heat carrier medium with a conveyance means 110, for example, a feed pump.

[0050] In the regeneration circuit 40, the regeneration arrangement 42 is connected via lines 116, 118 to a heat source 102. For example, the regeneration arrangement 42 is provided in the form of a regeneration heat exchanger 46 which is connected, for example, to an air-source collector as heat source 102, which absorbs heat of the environmental air. The heat carrier medium 44 in the regeneration circuit 40 is circulated with a feed pump 108. Alternatively or additionally, other heat sources can also be provided, for example, exhaust air devices and the like.

[0051] In the regeneration arrangement 42 with the regeneration heat exchanger 46, the heat carrier medium 44 circulates, which preferably corresponds to the heat carrier medium 34 from the extraction circuit 30, for example, a sol or a water-glycol mixture.

[0052] During normal operation, the extraction heat exchanger 32 extracts heat from the storage medium 20 and cools said storage medium in the process. Preferably, heat can be extracted until the thermal unloading of a predetermined region 36 around the extraction heat exchanger 32. This is the case during normal operation, for example, during the winter. From the beginning of the cold season to the end of the cold season, the volume 36 here solidifies gradually around heat exchange pipes of the extraction heat exchanger 32. When water is used as storage medium 20, a monolithic ice block forms in a controlled manner, which, in the completely unloaded state of the storage medium 20, maximally assumes the volume 36 in which the extraction heat exchanger 32 is embedded. The maximum volume 36 results substantially from the design of the extraction heat exchanger 32.

[0053] The heat transfer from the storage medium 20 into the heat carrier medium 34 in the extraction heat exchanger 32 occurs via the monolithic ice block. In the extraction circuit 20, the extraction heat exchanger 32 is connected to the heat pump 104, which raises the extracted heat to a higher temperature level which can be used by the consumer 130. A typical heat carrier medium 20 in the extraction circuit 30 can be, for example, a sol or a glycol-water mixture.

[0054] During normal operation, the regeneration arrangement 42 releases heat into the storage medium 20 and in the process it heats said storage medium. Due to the heat supply, the thermally unloaded latent heat storage device 10 can be thermally loaded and/or the unloading of the latent heat storage device 10 can be delayed. Preferably, during the thermal loading of the latent heat storage device 10, storage medium 20 which has solidified around the extraction heat exchanger 32 is thawed again. This is the case during normal operation, for example, during the summer. Preferably, from the beginning of the warm season to the end of the warm season, the solidified storage medium 20 on the extraction heat exchanger 32 gradually in a controlled manner liquefies again due to the heat supply, wherein the extraction heat exchanger 32 embedded therein is exposed again. In the case in which water is used as storage medium 20, the monolithic ice block is thawed in a controlled manner. The heat contribution of the heated storage medium 20 into the heat carrier medium 34 in the extraction heat exchanger 32 occurs via the melting monolithic ice block. If, after completed melting of the ice block, additional heat is supplied via the regeneration arrangement 42 into the latent heat storage device 10, the temperature of the storage medium 20 rises correspondingly.

[0055] Extraction circuit 30 and regeneration circuit 40 are strictly separated hydraulically during normal operation due to their different functions.

[0056] Due to the limited heat transfer between the heat exchanger pipes of the extraction heat exchanger 32, in the case of strongly frozen storage medium 20, the heat carrier medium 34 in the extraction heat exchanger 32 is rapidly supercooled and then supplies an insufficient feed temperature on the heat pump 104. According to the invention, a coupling device 50 is arranged in the connection line 112 from the extraction heat exchanger 32 to the heat pump 104, which at least temporarily supplies heat carrier medium 44 of the regeneration circuit 40, which can be heated by at least one heat source 102, into a section 113 of the connection line 112, which is provided downstream of the coupling device 50.

[0057] The coupling device 50 establishes a fluid connection between the regeneration circuit 40 and the heat pump 104, so that the regeneration arrangement 42 is at least partially bypassed.

[0058] Extraction circuit 30 and regeneration circuit 40 are in fluidic connection via two connection lines 66, 68. The first connection line 66 connects a section 115 of the extraction circuit 30 downstream of the feed pump 106 to a section 117 of the connection line 116 between regeneration arrangement 42 and heat source 102 of the regeneration circuit 40. The second connection line 68 connects the coupling device 50 to a section 119 of the connection line 118 of the regeneration circuit 40 upstream of the feed pump 108 in the regeneration circuit 40.

[0059] Thereby, a circuit 48 is formed, in which the heat carrier medium circulates in sections 113, 115 of the connection lines 112, 114 of the extraction circuit 30, in the connection lines 66, 68 and sections 117, 119 of the lines 116, 118 of the regeneration circuit 40, in the heat pump 104 and in the heat source 102. Advantageously, the feed pump 108 in the regeneration circuit 40 can be stopped when the coupling device 50 admixes a volume flow of the second heat carrier medium 44 into the first heat carrier medium 34.

[0060] The coupling device 50 is preferably designed as a mixing element 52 that can be closed-loop or open-loop controlled, so that the second heat carrier medium 44 from the regeneration circuit 40 can be admixed with variable volume flow.

[0061] A closed-loop and/or open-loop control device 60 is provided, which actuates the coupling device 50 depending on at least one operating parameter of the latent heat storage device 10 and/or of the latent heat storage system 100. In particular, the at least one operating parameter can be an icing degree of the latent heat storage device and/or a temperature of the first heat carrier medium.

[0062] The closed-loop and/or open-loop control device 60 can advantageously be in connection with various additional components and sensors of the latent heat storage system 100, for example, with the conveyance means 106, 108, temperature sensors which are not represented, which are associated with the heat pump 104 and the heat source 102, and the like, which is indicated with dashed double arrows in the closed-loop and/or open-loop control device 60.

[0063] FIG. 2 shows a latent heat storage system 100 according to an embodiment example of the invention. The arrangement corresponds broadly to the embodiment example in FIG. 1, so that, to avoid unnecessary repetitions, preferably differences between the two embodiment examples are discussed.

[0064] In the embodiment example in the figure, the regeneration arrangement 42 of the regeneration circuit 40 is designed as an open system and, instead of a heat exchanger 46 (FIG. 1), it comprises inflows 47 which are open toward the storage medium 20 and outflows 49 in the latent heat storage device 10.

[0065] The regeneration circuit 40 comprises two sections 43, 45, a section 43 close to the heat source and a section 45 close to the latent heat storage device, which are separated by a heat exchanger 82. In the section 45, a conveyance means 120, for example, a pump, conveys the heat carrier medium 20 which, in this region forms the heat carrier medium of the regeneration circuit 40; in section 43, the conveyance means 108 conveys the second heat carrier medium 44 of the regeneration circuit 40. In the section 45, the storage medium 20 circulates as second heat carrier medium 44; in the section 43, preferably the same medium as in the extraction circuit 30 circulates as second heat carrier medium 44.

[0066] For example, the inflows 47 and outflows 49 can be formed by annular lines in the non-icing region of the latent heat storage device 10, which comprise, along their circumference, openings for the passage of the storage medium 20 which represents the heat carrier medium 44 of the section 45.

[0067] The heat exchanger 82 also represents a separation of the circuits into the section 45 of the open regeneration arrangement 42 and the circuit 48 with lines 113, 115, 106, 66, 117, 119, 66.

[0068] If the beat exchange medium 44 from the section 43 of the regeneration circuit 40 is admixed via the coupling device 50 into the feed line to the heat pump 104, the conveyance means 120 can be shut down in the section 45 of the regeneration circuit 40 close to the latent heat storage device.

[0069] FIG. 3 shows a flow chart of the operating procedure of a latent heat storage system 100, as represented in FIGS. 1, 2, according to an embodiment example of the invention. Below, reference is made to the latent heat storage systems 100 in FIGS. 1, 2.

[0070] The method for operating the latent heat storage system 100 provides that a second heat carrier medium 44 which is heated by at least one heat source 102 is supplied at least temporarily into a section 113, arranged downstream of a coupling device 50, of a connection line 112 to a heat pump 108 in the extraction circuit 30 with a first heat carrier medium 32, and in particular is admixed with the first heat carrier medium 32. This can advantageously occur with variable volume flow of the second heat carrier medium 44, in particular, the volume flow of the second heat carrier medium 44 can be set independently of a feed temperature of the heat pump 104.

[0071] The second heat carrier medium 44 is preferably supplied when a predetermined icing degree of the latent heat storage device 10 with respect to a volume 36 capable of freezing in accordance with the intended purpose has been reached, preferably starting from an icing degree of at least 90% with respect to a volume 36 of the latent heat storage device 10, capable of freezing in accordance with the intended purpose.

[0072] In particular, the second heat carrier medium 44 can be supplied when a temperature of the first heat carrier medium 34 of the extraction circuit 30 is less than or equal to 1 C., preferably less than or equal to 0 C., and the second heat carrier medium 44 of the at least one heat source 102 is hotter than the first heat carrier medium 32.

[0073] In S100, on the open-loop and/or closed-loop control unit 60 of the latent heat storage system 100, a demand for heating a consumer 130 is present. The latent heat storage device 10 is almost unloaded, and the temperature of the heat carrier medium 34 in the extraction circuit 30 is low, for example, close to 0 C. In S102, ACTUAL values are compared between the heat source 102 and the latent heat storage device 10. The heat source 102 can be a roof collector. Additionally or alternatively, other heat sources can optionally be coupled to the regeneration circuit 40.

[0074] In S104, the heat pump 104 is supplied with the heat carrier medium 32, 44 of the hotter of the two energy sources, latent heat storage device 10 and heat source 102. If, during operation, the temperature of the heat carrier medium 34 or 44 in question remains higher than the temperature of the other heat carrier medium 44 or 34, in S106, the heating process with this source is continued as long as this temperature is higher than the other temperature. The heat pump 104 thus receives the highest possible feed temperature of the latent heat storage system 100.

[0075] However, if the temperature of the heat carrier medium 34 or 44 in question drops below the temperature of the other so far colder heat carrier medium 44 or 34, in S108, the volume flows from heat source 102 and extraction heat exchanger 32 are mixed by means of the coupling device 50, until, in the latent heat storage system 100, the highest possible temperature of the mixture of the heat transfer media 34, 44 is reached. The system can also switch from S106 into this path when the temperature of the hotter heat carrier medium 34 or 44 drops too much.