Heat exchanger as solar module and circuit for solar thermal cooling

Abstract

The invention relates to a heat exchanger (2), in particular as a solar module, with a heat transfer area (12), with a first collection box (13) and with a second collection box (14), wherein the first collection box (13) is arranged on one side of the heat transfer area (12) and the second collection box (14) is arranged opposite the first collection box (13) on a second side of the heat transfer area (12), wherein the first collection box (13) has a first collection area (15) and wherein the second collection box (14) has a third collection area (16), wherein the first collection box (13) is fluidly connected to the heat transfer area (12) via first openings (17) with the first collection area (15) and the second collection box (14) is fluidly connected to the heat transfer area (12) via its third collection area (16) via second openings (18), wherein optional tubes (22) are further arranged.which cross the heat transfer area (12), the first collection area (15) and the second collection area (23), wherein adsorbents (21) are arranged distributed in the heat transfer area (12), wherein the heat transfer area (12) is designed to be box-shaped and can be directly flowed through by a first fluid.

Description

[0001] The invention relates to a heat exchanger, in particular as a solar module, and a circuit for operating a solar thermal cooling process and such a solar thermal cooling process.

[0002] Cooling rooms and equipment consumes ever-increasing amounts of energy worldwide, to the point that more energy is already used for cooling than for heating. This is a global trend, particularly in light of climate change, and is likely to intensify in the coming years.

[0003] Cooling via the Linde process using a compressor requires a power source and high electrical consumption. If the electrical energy is to be generated via photovoltaics, it must be considered that photovoltaics have a low efficiency of less than 10%. To generate a cooling capacity of approximately 5 kW, a solar irradiance of 0.8 to 1 kW / m² is required. 2 With a photovoltaic efficiency of approximately 8-10%, very large areas of photovoltaic solar collectors are required, which makes the solar system equipped with it for generating cold very expensive and also requires a very large amount of space, which cannot always be provided.

[0004] Nevertheless, it makes sense to want to use solar radiation for the generation of cold in order to achieve regenerative cooling.

[0005] The task is therefore to create a heat exchanger, particularly in the form of a solar module, with which solar radiation can be used to generate cooling. It is also a task to create a cycle for operating a solar thermal cooling process and to implement such a solar thermal cooling process itself.

[0006] The problem with the heat exchanger is solved by the features of claim 1.

[0007] One embodiment relates to a heat exchanger, in particular as a solar module, with a heat transfer area, a first collection box, and a second collection box, wherein the first collection box is arranged on one side of the heat transfer area and the second collection box is arranged opposite the first collection box on a second side of the heat transfer area, wherein the first collection box has a first collection area and wherein the second collection box has a third collection area, wherein the first collection box is fluidly connected to the heat transfer area via first openings with its first collection area and the second collection box is fluidly connected to the heat transfer area via second openings with its third collection area, wherein optional pipes are further arranged which cross the heat transfer area, the first collection area, and the second collection area.Adsorbents are distributed throughout the heat transfer zone, which is enclosed in a box-like structure and through which a first fluid can flow directly. This creates a heat exchanger that can be used in a closed loop for solar-powered cooling, allowing for solar-powered cooling, particularly where it is needed due to solar energy. The ends of the pipes protrude, for example, from the first and third collection zones and are thus exposed to airflow, enabling a defined cooling effect.

[0008] In one embodiment, it is advantageous if the first collection box has a first collection area and a second collection area, and the second collection box has a third collection area and a fourth collection area, wherein the pipes are fluidically connected to the second collection area of ​​the first collection box on one side and to the fourth collection area of ​​the second collection box on the other, and wherein a second fluid can flow through the pipes. In this way, a second fluid can be used to cool the heat exchanger in the pipes as needed.

[0009] In one embodiment, it is also advantageous to have a fluid connection for the first fluid at the first collection area of ​​the first collection box and a fluid connection for the first fluid at the third collection area of ​​the second collection box, and / or a fluid connection for the second fluid at the second collection area of ​​the first collection box and a fluid connection for the second fluid at the fourth collection area of ​​the second collection box. This allows a first fluid and a second fluid to flow through the heat exchanger, with the first fluid serving the refrigeration circuit for generating cold and the second fluid circuit serving to generate heat and cool the heat exchanger.

[0010] It is also advantageous that the heat transfer area is enclosed to the outside by a first outer cover and a second outer cover between the two collection boxes, with the second outer cover being positioned opposite the first. Thus, the first and second covers between the collection boxes enclose the space and form a flow-through volume for the refrigerant, in which the adsorber is also located.

[0011] It is particularly advantageous if at least the first outer cover and / or the second outer cover is at least partially soldered, welded, and / or glued to at least one or all of the pipes and / or at least one or both of the collection boxes. This creates a very stable structure that remains permanently stable even under fluctuating thermal conditions and temperatures.

[0012] Furthermore, it is advantageous if at least the first outer cover is coated with a light-absorbing material, especially black. This improves light absorption and allows the heat exchanger to heat up better and faster.

[0013] It is also advisable for at least the first outer cover to be coated with a light-absorbing material, particularly black, by soldering on a solderable material. This coating can, for example, be a so-called Blackbraze material, where a solderable material is applied and soldered, resulting in a stable black coating after soldering.

[0014] It is also advantageous if at least the second outer cover is equipped with at least one cooling fin. This allows the heat exchanger to be cooled more efficiently by an airflow around it.

[0015] It is also advantageous if activated carbon is used as the adsorbent, in particular if activated carbon elements are arranged, especially if they are designed as cuboid elements. The adsorbent can also be provided as a packed bed.

[0016] Furthermore, it is also advisable to glue the activated carbon elements in place, particularly on the inside of one of the covers and / or on the pipes. This ensures a stable and secure design.

[0017] It is also particularly advantageous if finned elements are arranged between the pipes. These finned elements provide stability and improve heat transfer.

[0018] It is also advantageous if a refrigerant, particularly methanol, can be used as the first fluid and / or a cooling fluid, particularly a water-based cooling fluid, can be used as the second fluid. This allows the refrigerant to be used to generate the cooling, while the coolant serves to cool the heat exchanger when needed and desired.

[0019] In another embodiment, it is also advantageous to operate the heat exchanger as a solar thermal collector. This allows the heat exchanger to be specifically exposed to the sun in order to utilize solar radiation to generate cooling via the refrigerant circuit.

[0020] The problem related to the cycle is solved by the features of claim 14.

[0021] One embodiment relates to a circuit for operating a solar thermal cooling process with a heat exchanger according to the invention, which is further equipped with a condenser and an evaporator with cold storage.

[0022] In one embodiment, it is also advantageous for the first fluid, a refrigerant, particularly methanol, to circulate in the circuit. This methanol can be adsorbed into the adsorbent as needed and desorbed again as needed.

[0023] The problem with the cooling method is solved by the features of claim 16.

[0024] One embodiment relates to a solar thermal cooling process with a cycle according to the invention, including a heat exchanger according to the invention. In the evaporator, refrigerant evaporates and charges a cold storage unit with cold. The evaporated refrigerant is then directed into the heat exchanger, where it is adsorbed, generating heat. This heat is then dissipated. In a further step, the refrigerant is desorbed from the adsorber by solar heating and, as hot refrigerant vapor, is directed from the heat exchanger to the condenser. In the condenser, the refrigerant vapor is cooled and then directed back to the evaporator, where it evaporates again. This allows for solar-induced cooling within a single cycle, which is very efficient compared to alternative methods.

[0025] It is particularly advantageous if the cold storage system uses a cooling medium. This allows the cold to be stored in a defined quantity and later extracted from the cold storage medium and used for cooling purposes when needed.

[0026] It is also advantageous if the evaporator is circulated by a third fluid, which is cooled by the refrigerant evaporator, whereby the cooled third fluid flows through the cold storage medium and cools the cold storage medium, and / or if the cold storage medium is cooled directly by the evaporator. This allows for effective cooling of the cold storage medium.

[0027] It is also advantageous if the cold storage unit is connected to a cooling circuit through which a fourth fluid flows, which is cooled by the cold storage unit. This cooled fourth fluid is used to cool room air and / or equipment, and / or can itself be the air to be cooled. In this way, the cold can be efficiently transported to another location where it can be used for cooling, for example, for air conditioning.

[0028] It is particularly advantageous if the cold storage unit is charged with cold by evaporating the refrigerant, especially intermittently, cyclically, and / or particularly before sunrise. This allows the cold to be generated while sunlight is still not shining on the heat exchanger, and the stored cold can then be used later, for example, when the sun heats a building or the room air. It is also possible to generate cold intermittently or cyclically.

[0029] It is also advantageous if the heat exchanger, especially after sunrise, is illuminated by solar light, thereby heating the refrigerant in the adsorber and facilitating its desorbation. If the adsorber is fully charged before sunrise, the desorption process can be carried out using solar power after sunrise, saving additional energy for this process.

[0030] It is therefore particularly advantageous if the heat exchanger, for example after the refrigerant has been desorbed, is actively shaded by means of a shading device in order to cool the heat exchanger. The shading can also be used to control the amount of light reaching the heat exchanger and thus also the desorption process.

[0031] The invention is explained in more detail below based on exemplary embodiments and the figures in the drawings.

[0032] They show: Fig. 1 a schematic view of an embodiment of a cycle according to the invention for a solar thermal cooling process, Fig. 2 a further schematic view of an embodiment of a heat exchanger according to the invention, and Fig. 3 another schematic view of the embodiment of the heat exchanger according to the invention.

[0033] The Fig. Figure 1 shows a schematic view of an embodiment of a circuit 1 according to the invention for a solar thermal cooling process to explain the solar thermal cooling process.

[0034] The circuit 10 for operating a solar thermal cooling process is equipped with a heat exchanger 2, and furthermore includes a condenser 3 and an evaporator 4 with a cold storage tank 5. A first expansion and / or control valve 6 and a second expansion and / or control valve 7 are also provided. The first expansion and / or control valve 6 is arranged between the condenser and the evaporator, and the second expansion and / or control valve 7 is arranged between the evaporator 4 and the heat exchanger 2.

[0035] In the illustrated embodiment, the heat exchanger 2 has a controllable shading device 8, with which the heat exchanger 2 can be shaded in a controlled manner in order to cool it. If the shading device 8 is controlled to the state of exposing the heat exchanger 2 to sunlight, the heat exchanger 2 is exposed to sunlight and heated.

[0036] In circuit 10, the first fluid circulating is a refrigerant, in particular methanol.

[0037] The condenser 3 is preferably fluid-cooled and provided with a fluid inlet 9 and a fluid outlet 11, wherein the refrigerant coming from the heat exchanger 2 is cooled and preferably also liquefied again by means of the fluid in the heat transfer.

[0038] Heat exchanger 2 is also in the Fig. 2 and Fig. Figure 3 is shown by way of example and schematically. The heat exchanger 2 is, as shown in Fig. 1. Recognizable, especially suitable as a solar module.

[0039] The heat exchanger 2 has a heat transfer area 12 and a first collection box 13 as well as a second collection box 14.

[0040] The first collection box 13 is arranged on one side of the heat transfer area 12, and the second collection box 14 is arranged opposite the first collection box 13 on a second side of the heat transfer area 12, as shown in Fig. 2 can be seen.

[0041] The first collection box 13 has a first collection area 15 and the second collection box 14 has a third collection area 16.

[0042] The design of the heat exchanger 2 is chosen such that the first collection box 13 with the first collection area 15 is fluidly connected to the heat transfer area 12 by means of first openings 17 and the second collection box 14 with its third collection area 16 is fluidly connected to the heat transfer area 12 by means of second openings 18.

[0043] Furthermore, a fluid connection 19 for the first fluid is provided on the first collection area 15 of the first collection box 13, and a fluid connection 20 for the first fluid is provided on the third collection area 16 of the second collection box 14. Thus, the first fluid can flow into the first collection box 13 through the fluid connection 19, flow through the first collection area 15 into the heat transfer area 12, and from there flow out of the heat exchanger 2 through the third collection area 16 of the second collection box 14 and the fluid connection 20.

[0044] Adsorbents 21 are distributed throughout the heat transfer area 12. These adsorbents 21 serve for the controlled adsorption and desorption of the refrigerant.

[0045] In the illustrated embodiment of the Fig. 2 and Fig. 3. The heat transfer area 12 is designed as a box-shaped enclosure and is directly permeable to a first fluid, the refrigerant. The refrigerant flows over the adsorbent, also called the adsorber, and can be adsorbed by it and desorbed again upon heating by solar radiation.

[0046] For improved heat transfer and for cooling the heat exchanger 2 as needed, optional pipes 22 are also arranged, which cross the heat transfer area 12, the first collection area 15 and the third collection area 16. In this way, the pipes 22 can absorb heat and conduct it to the outside, where it can be dissipated.

[0047] In an alternative and only indicated embodiment, the first collection box 13 has a first collection area 15 and a second collection area 23, and the second collection box 14 has a third collection area 16 and a fourth collection area 24. The pipes 22 are fluidly connected to the second collection area 23 of the first collection box 13 and to the fourth collection area 24 of the second collection box 14, and a second fluid can flow through the pipes 22. This provides a fluid-cooled alternative. In this case, a fluid connection 25 for the second fluid would be provided on the second collection area 23 of the first collection box 13, and a fluid connection 26 for the second fluid would be provided on the fourth collection area 24 of the second collection box 14.

[0048] Furthermore, in Fig. 3 to recognize that the heat transfer area 12 is enclosed to the outside by a first outer cover 27 and by a second outer cover 28 between the two collection boxes 13, 14, wherein the second outer cover 28 is arranged opposite the first outer cover 27.

[0049] In an advantageous embodiment, at least the first outer cover 27 and / or the second outer cover 28 is at least partially soldered, welded, and / or glued to at least one or all of the pipes 22 and / or at least one or both of the collection boxes 13, 14. It may be sufficient if the respective cover is connected to a pipe base of the collection box 13, 14.

[0050] It is particularly advantageous if at least the first outer cover 27 is coated with a light-absorbing material, especially black. This coating 31 can be applied, for example, using the so-called "Blackbraze" process, i.e., by means of a stable, black, soldered coating 31. This ensures that at least the first outer cover 27 is coated with a light-absorbing material, especially black, by soldering a solderable material.

[0051] In Fig. Figure 3 also shows that at least the second outer cover 28 is provided with at least one cooling fin 29. This cooling fin 29 may be soldered, glued or otherwise attached.

[0052] According to the exemplary embodiment, activated carbon 21 is provided as the adsorbent. This activated carbon is provided, in particular, as activated carbon elements which are arranged. These activated carbon elements are, for example, designed as cuboid-shaped elements. The activated carbon elements can be glued on, in particular to an inner side of one of the covers 27, 28 and / or to the tubes 22.

[0053] It can also be advantageous if 22 rib elements (not shown) are arranged between the tubes.

[0054] The first fluid can be a refrigerant, in particular methanol, and / or the second fluid can be a cooling fluid, in particular a water-based cooling fluid.

[0055] The described heat exchanger 2 can be operated as a solar thermal collector, in particular in the solar thermal cooling process described below.

[0056] The solar thermal process according to the invention is carried out with a cycle 1 described above and a heat exchanger 2 described above.

[0057] In this process, refrigerant, in particular methanol, is circulated in circuit 1. The refrigerant is evaporated in the evaporator 4, causing it to cool down and thereby charging a cold storage unit 5 with cold via heat transfer.

[0058] The evaporated refrigerant is directed from the evaporator 4 into the heat exchanger 2. In the heat exchanger 2, the refrigerant is adsorbed, thereby generating heat, which is then dissipated, for example via the pipes 22 and / or the cooling fin 29 and / or the air flowing around the heat exchanger 2 or the second fluid.

[0059] In a further step, solar heating warms the heat exchanger 2 and the adsorbent, causing the refrigerant to desorb from the adsorber and be directed as hot refrigerant vapor from the heat exchanger 2 to the condenser 3. In the condenser 3, the refrigerant vapor is cooled and directed back to the evaporator 4, where the refrigerant evaporates again.

[0060] In an advantageous embodiment, the cold storage unit 5 has a cold storage medium which can be cooled.

[0061] The evaporator 4 can also be permeated by a third fluid, which is cooled by the evaporator 4 through evaporation of the refrigerant, whereby the cooled third fluid flows through the cold storage medium 5 and cools the cold storage medium and / or the cold storage medium is cooled directly by the evaporator 4.

[0062] It is also advantageous if the cold storage unit 5 is connected to a cooling circuit 30, which is circulated by a fourth fluid which is cooled by the cold storage unit 5, wherein the cooled fourth fluid serves to cool room air and / or units and / or is itself air to be cooled.

[0063] The process can be carried out cyclically, intermittently, or in response to specific events. For example, before sunrise, the cold storage unit 5 can be charged with cold by evaporating the refrigerant. Alternatively, the cold storage unit can also be charged cyclically, for example, in regular cooling cycles or on demand. When the heat exchanger 2 is exposed to sunlight, it can also be shaded to cool it down; see the shading device 8.

[0064] The heat exchanger 2 can also be illuminated by solar light after sunrise, thereby heating up and causing the refrigerant in the adsorber to desorb.

[0065] It is also advantageous if the heat exchanger 2 is actively shaded by means of a shading device 8 after the desorption of the refrigerant in order to cool the heat exchanger 2. Reference symbol list 1 cycle 2 heat exchangers 3 Capacitor 4 evaporators 5 cold storage units 6 Expansion and / or control valve 7 Expansion and / or control valve 8 Shading device 9 Fluid inlet 10 Circulation 11 Fluid outlet 12 Heat transfer area 13 Collection boxes 14 collection boxes 15 Collection area 16 Collection area 17 Opening 18 Opening 19 Fluid connection 20 Fluid connection 21 Adsorbents 22 pipes 23 Collection area 24 Collection area 25 Fluid connection 26 Fluid connection 27 Cover 28 Cover 29 cooling fins 30 Cooling circuit 31 Coating

Claims

[1] Heat exchanger (2), in particular as a solar module, comprising a heat transfer area (12), a first collection box (13) and a second collection box (14), wherein the first collection box (13) is arranged on one side of the heat transfer area (12) and the second collection box (14) is arranged opposite the first collection box (13) on a second side of the heat transfer area (12), wherein the first collection box (13) has a first collection area (15) and wherein the second collection box (14) has a third collection area (16), wherein the first collection box (13) is fluidly connected to the heat transfer area (12) via first openings (17) and the second collection box (14) is fluidly connected to the heat transfer area (12) via its third collection area (16) via second openings (18), wherein optional tubes (22) are further arranged which connect the heat transfer area (12),the first collection area (15) and the second collection area (23), wherein adsorbents (21) are arranged distributed in the heat transfer area (12), wherein the heat transfer area (12) is designed to be box-shaped and can be directly flowed through by a first fluid. [2] Heat exchanger (2) according to claim 1, characterized by , that the first collection box (13) has the first collection area (15) and a second collection area (23) and the second collection box (14) has the third collection area (16) and a fourth collection area (24), wherein the pipes (22) are fluidly connected on the one hand to the first collection box (13) with the second collection area (23) and on the other hand to the second collection box (14) with the fourth collection area (24), wherein the pipes (22) are capable of being permeated by a second fluid. [3] Heat exchanger (2) according to claim 1 or 2, characterized by, that a fluid connection (19) for the first fluid is provided on the first collection area (15) of the first collection box (13) and a fluid connection (20) for the first fluid is provided on the third collection area (16) of the second collection box (14) and / or a fluid connection (25) for the second fluid is provided on the second collection area (23) of the first collection box (13) and a fluid connection (26) for the second fluid is provided on the fourth collection area (24) of the second collection box (14). [4] Heat exchanger (2) according to claim 1, 2 or 3, characterized by , that the heat transfer area (12) is enclosed to the outside by a first outer cover (27) and by a second outer cover (28) between the two collection boxes (13,14), wherein the second outer cover (28) is arranged opposite the first outer cover (27). [5] Heat exchanger (2) according to claim 4, characterized by, that at least the first outer cover (27) and / or the second outer cover (28) is or are at least partially soldered, welded and / or glued to at least one or all of the pipes (22) and / or at least one of the collection boxes (13,14) or both collection boxes (13,14). [6] Heat exchanger (2) according to claim 4 or 5, characterized by , that at least the first outer cover (27) is coated with a light-absorbing material, in particular black. [7] Heat exchanger (2) according to claim 6, characterized by , that at least the first outer cover (27) is coated with a light-absorbing material, in particular black, by soldering a solderable material. [8] Heat exchanger (2) according to claim 4, 5, 6 or 7, characterized by , that at least the second outer cover (28) is provided with at least one cooling fin (29). [9] Heat exchanger (2) according to any one of the preceding claims, characterized by, that activated carbon is provided as an adsorbent (21), in particular activated carbon elements are arranged, which are in particular designed as cuboid elements. [10] Heat exchanger (2) according to any one of the preceding claims, characterized by that the activated carbon elements are glued on, in particular to an inside of one of the covers (27,28) and / or to the tubes (22). [11] Heat exchanger (2) according to any one of the preceding claims, characterized by , that rib elements are arranged between the tubes (22). [12] Heat exchanger (2) according to any one of the preceding claims, characterized by that the first fluid can be a refrigerant, in particular methanol, and / or the second fluid can be a cooling fluid, in particular a water-based cooling fluid. [13] Heat exchanger (2) according to any one of the preceding claims, characterized by , that the heat exchanger (2) is operated as a solar thermal collector. [14] Circuit (1,10) for operating a solar thermal cooling process with a heat exchanger (2) according to one of the preceding claims, further comprising a condenser (3) and an evaporator (4) with cold storage. [15] Circuit (1,10) according to claim 14, characterized by , that in the cycle (1,10) the first fluid, a refrigerant, in particular methanol, circulates. [16] Solar thermal cooling method with a cycle (1, 10) according to one of claims 14 or 15 with a heat exchanger (2) according to one of the preceding claims 1 to 13, wherein in the evaporator (4) refrigerant is evaporated and charges a cold storage unit (5) with cold, the evaporated refrigerant is directed into the heat exchanger (2), in the heat exchanger (2) the refrigerant is adsorbed and thus generates heat, wherein the heat is dissipated, wherein in a further step the refrigerant is desorbed from the adsorber by solar heating and is directed as hot refrigerant vapor from the heat exchanger (2) to the condenser (3), in the condenser (3) the refrigerant vapor is cooled and directed back to the evaporator (4), where the refrigerant evaporates again. [17] Solar thermal cooling method according to claim 16, characterized by , that the cold storage unit (5) has a cold storage medium which can be cooled. [18] Solar thermal cooling method according to claim 17, characterized by , that the evaporator (4) is traversed by a third fluid which is cooled by the evaporator (4) of the refrigerant, wherein the cooled third fluid flows through the cold storage (5) and cools the cold storage medium and / or that the cold storage medium is cooled directly by the evaporator (4). [19] Solar thermal cooling method according to claim 17 or 18, characterized by , that the cold storage unit (5) is connected to a cooling circuit (30) through which a fourth fluid flows, which is cooled by the cold storage unit (5), wherein the cooled fourth fluid serves to cool room air and / or units and / or is itself air to be cooled. [20] Solar thermal cooling method according to one of claims 16 to 19, characterized by, that the cold storage unit (5) is charged with cold by evaporating the refrigerant, in particular temporarily, cyclically and / or especially before sunrise. [21] Solar thermal cooling method according to one of claims 16 to 20, characterized by , that the heat exchanger (2), especially after sunrise, is illuminated by solar radiation and is thereby heated, and the refrigerant in the adsorber is thereby heated and desorbed. [22] Solar thermal cooling method according to one of the preceding claims, characterized by , that the heat exchanger (2), in particular after the desorption of the refrigerant, is actively shaded by means of a shading device (8) in order to cool the heat exchanger (2).

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