Refrigeration device and heat exchanger as well as refrigerant circuit for a refrigeration device

Abstract

A heat exchanger for a refrigeration device comprises a first heat exchanger tube for conducting refrigerant, a second heat exchanger tube for conducting refrigerant, which is arranged adjacent to the first heat exchanger tube in a first direction and is connected to the first heat exchanger tube, a plurality of first fins which are in heat-conducting contact with the first heat exchanger tube and are arranged at a distance from one another in a second direction running transversely to the first direction, and a plurality of second fins which are in heat-conducting contact with the second heat exchanger tube and are arranged at a distance from one another in the second direction. An intermediate throttle element is arranged between the first and second heat exchanger tubes and connects the first and second heat exchanger tubes. The first fins are arranged at a first distance from one another in the second direction.The second slats are spaced apart from each other in the second direction at a second distance that is greater than the first distance.

Description

TECHNICAL FIELD

[0001] The present invention relates to a heat exchanger for a refrigeration appliance, a refrigerant circuit containing the heat exchanger, and a refrigeration appliance, in particular a household refrigeration appliance such as a refrigerator, a freezer or a freezer chest or a fridge-freezer combination. STATE OF THE ART

[0002] In household refrigeration appliances, a refrigerant circuit is provided to extract heat from a storage chamber by evaporating refrigerant in an evaporator and releasing it into the environment by condensing the refrigerant in a condenser. The evaporator is thermally coupled to the storage chamber. In so-called NoFrost appliances, the evaporator is located in an evaporator chamber that is fluidly connected to the storage chamber, with a fan circulating an air flow between the evaporator chamber and the storage chamber.

[0003] The evaporator is typically a heat exchanger comprising a heat exchanger tube and a plurality of fins thermally connected to the heat exchanger tube. The fins are arranged at a predetermined distance from one another, defining flow channels through which the air conveyed by the fan is transported. Due to the low temperatures at the evaporator and the fact that the air flowing between the fins may contain a certain amount of moisture, condensation forms on the evaporator and, over time, typically leads to icing.

[0004] Icing typically does not occur evenly across the evaporator, but rather occurs more frequently in the coldest areas. Especially in the refrigerant circuits used in household refrigeration appliances, it is difficult to precisely adjust the temperature distribution within the evaporator. To ensure reliable airflow through the evaporator despite localized icing, the spacing between the fins is typically relatively large.

[0005] DE 10 2015 218 452 A1 describes a household refrigeration appliance with multiple storage chambers, each of which is assigned an evaporator. The evaporators are connected in series and connected by a capillary tube to set a lower vapor pressure in the downstream evaporator than in the upstream evaporator. SUMMARY OF THE INVENTION

[0006] One of the objects of the present invention is to provide improved solutions for a heat exchanger of a refrigeration device. In particular, it is an object of the invention to provide a heat exchanger that can be used as an evaporator, in which ice formation is limited to a limited area as much as possible, thereby increasing the efficiency of the evaporator.

[0007] This object is achieved according to the invention by an evaporator having the features of claim 1, a refrigerant circuit having the features of claim 11 and a refrigeration device having the features of claim 14.

[0008] Advantageous embodiments and further developments arise from the subclaims which refer back to the independent claims in conjunction with the description.

[0009] According to a first aspect of the invention, a heat exchanger for a refrigeration appliance, in particular for a household refrigeration appliance, comprises a first heat exchanger tube for conducting refrigerant, a second heat exchanger tube for conducting refrigerant, which is arranged adjacent to the first heat exchanger tube in a first direction and is connected to the first heat exchanger tube, a plurality of first fins, which are in heat-conducting contact with the first heat exchanger tube and are arranged spaced from one another in a second direction extending transversely to the first direction, so that first flow channels extending in the first direction are formed between the first fins, and a plurality of second fins, which are in heat-conducting contact with the second heat exchanger tube and are arranged spaced from one another in the second direction,such that second flow channels extending in the first direction are formed between the second fins. An intermediate throttle member is arranged between the first and second heat exchanger tubes and connects the first and second heat exchanger tubes. The intermediate throttle member is designed to expand the refrigerant coming from the first heat exchanger tube. The first fins are arranged at a first distance from one another in the second direction. The second fins are arranged at a second distance from one another in the second direction, which is greater than the first distance.

[0010] According to a second aspect of the invention, a refrigerant circuit for a refrigeration appliance, in particular for a household refrigeration appliance, comprises an evaporator which is formed by a heat exchanger according to the first aspect of the invention, a compressor for compressing gaseous refrigerant with a suction connection which is connected to the second heat exchanger tube and a pressure connection for expelling compressed gaseous refrigerant, an evaporator with an inlet which is connected to the pressure connection of the compressor and an outlet which is connected to the first heat exchanger tube, and a main throttle element which is arranged between the outlet of the evaporator and the first heat exchanger tube and is designed to expand the refrigerant.

[0011] According to a third aspect of the invention, a refrigeration appliance, in particular a household refrigeration appliance, such as a refrigerator, a freezer or chest freezer, or a fridge-freezer combination, is provided. The refrigeration appliance comprises a storage chamber for accommodating refrigerated goods and a refrigerant circuit according to the second aspect of the invention, wherein the evaporator is thermally coupled to the storage chamber in order to extract heat therefrom by evaporating refrigerant in the first heat exchanger tube and the second heat exchanger tube, and the condenser is thermally coupled to the environment in order to release heat to the environment by condensing refrigerant.

[0012] One of the ideas underlying the invention is to divide the heat exchanger into a first region and a second region, wherein in the first region there is a higher vapor pressure in the heat exchanger tube than in the second region, and to arrange the fins in the second region at a greater distance from one another than in the first region. Because the vapor pressure in the second region is lower than in the first region, the second region is colder than the first region, which promotes ice formation there. A large fin spacing is therefore provided in this region. Since ice formation predominantly occurs in the second region, a significantly smaller fin spacing and thus a larger heat transfer surface can be achieved in the first region.

[0013] In order to achieve different vapor pressures in the two heat exchanger sections, the heat exchanger is designed according to the invention with a first heat exchanger tube and a second heat exchanger tube, which are connected by an intermediate throttle element. The intermediate throttle element is designed to expand the refrigerant flowing from the first heat exchanger tube into the second heat exchanger tube in order to generate a lower vapor pressure in the second heat exchanger tube than in the first heat exchanger tube.

[0014] The first and second heat exchanger tubes are spaced apart in a first direction. For example, the heat exchanger tubes can each have linearly extending sections, wherein the linearly extending sections of the first heat exchanger tube and the linearly extending sections of the second heat exchanger tube are spaced apart from one another in the first direction. An outlet of the first heat exchanger tube is connected to the inlet of the second heat exchanger tube by the intermediate throttle element.

[0015] A plurality of first fins are thermally conductively connected to the first heat exchanger tube, each extending in the first direction and spaced apart in the second direction. A plurality of second fins are thermally conductively connected to the second heat exchanger tube, each extending in the first direction and spaced apart in the second direction. As explained, the second fins are arranged at a greater distance from one another than the first fins.

[0016] An advantage of the invention is that, when used as an evaporator, the heat exchanger ices up primarily in the area of ​​the second fins and the second heat exchanger tube due to the lower vapor pressure in the second heat exchanger tube. This largely prevents ice formation in the area of ​​the first heat exchanger tube and the first fins, allowing the first fins to be arranged with relatively close spacing. This allows for a significant increase in the heat transfer surface and consequently improves the efficiency of the heat exchanger.

[0017] According to some embodiments, the first fins may be longer in the first direction than the second fins. Accordingly, the second, cooler region of the heat exchanger can be designed to be more compact than the first, warmer region. Thus, the heat transfer surface can be increased even further.

[0018] According to some embodiments, the intermediate throttle element can be formed by a capillary that connects the first and second heat exchanger tubes. The advantage of a capillary is that it can be implemented cost-effectively and ensures high operational reliability of the heat exchanger. Optionally, the main throttle element of the refrigerant circuit can also be designed as a capillary, with the capillary forming the intermediate throttle element having a larger flow diameter than the capillary forming the main throttle element. This advantageously prevents refrigerant from accumulating upstream of the capillary forming the intermediate throttle element.

[0019] According to some embodiments, the first and second fins can be separated from one another. In particular, the first and second fins can be implemented as separate components, which are, for example, spatially separated from one another. This prevents thermal coupling between the first and second heat exchanger tubes via the fins, allowing ice formation to be even more effectively limited to the area of ​​the second fins and the second heat exchanger tube.

[0020] According to some embodiments, the first and second fins may be spaced apart from one another in the first direction, such that a gap is formed between the first fins and the second fins in the first direction. This further improves thermal separation between the first and second fins and limits ice formation even more effectively to the area of ​​the second fins and the second heat exchanger tube.

[0021] According to some embodiments, it can be provided that the first distance between the first slats is in a range between 1 mm and 7 mm.

[0022] According to some embodiments, it can be provided that the second distance between the second slats is in a range between 8 mm and 15 mm.

[0023] According to some embodiments, it can be provided that the second distance is at least 1.1 times, preferably at least 1.5 times, the first distance.

[0024] According to some embodiments, the heat exchanger may include a first retaining plate extending in the first direction, to which both the first and second heat exchanger tubes are connected, and a second retaining plate extending in the first direction, which is arranged at a distance from the first retaining plate in the second direction and to which both the first and second heat exchanger tubes are connected. The retaining plates are thus connected to both heat exchanger tubes, which improves the mechanical stability of the heat exchanger and thus facilitates assembly.

[0025] According to some embodiments, the first fins and the second fins can be arranged between the first and second retaining plates, respectively, with respect to the second direction. The retaining plates can thus form the outermost boundaries of the first and second fins with respect to the second direction. This facilitates the assembly of the heat exchanger and improves the mechanical stability of the heat exchanger.

[0026] According to some embodiments, it can be provided that a holder for attaching a sensor and / or switching device, such as an overheating monitor, is formed on the first and / or the second holding plate.

[0027] According to some embodiments, it can be provided that the first heat exchanger tube has an inlet for injecting coolant and an outlet, and extends between the inlet and the outlet in a meandering manner through recesses formed in the first fins, and that the second heat exchanger tube has an inlet connected to the outlet of the first heat exchanger tube by the intermediate throttle element and an outlet for discharging the coolant, and extends between the inlet and the outlet in a meandering manner through recesses formed in the second fins. The heat exchanger tubes can, for example, each bear against the circumference of the respective recess, so that a thermally conductive contact is formed between the fins and the heat exchanger tubes.

[0028] The meandering course can be realized, for example, by the respective heat exchanger tube having several linear first tube sections, and two first tube sections each being connected to one another by an arcuate second tube section. The first tube sections can extend, in particular, along the second direction. The linear first tube sections thus run transversely to the fins. For example, two first tube sections each can extend through a recess in a respective fin designed as an elongated hole. This advantageously allows a relatively long heat exchanger tube to be installed in a small volume.

[0029] According to some embodiments, the refrigerant circuit may include a fan arranged and configured to generate an air flow that first flows through the second flow channels and then through the first flow channels of the heat exchanger. Accordingly, the air flows through the heat exchanger along the first direction such that the air first flows through the region of the second heat exchanger tube and the second fins and then through the region of the first heat exchanger tube and the first fins. In this way, icing of the heat exchanger can be more reliably limited to the region of the second heat exchanger tube and the second fins, since the possibly humid air first encounters the colder region of the heat exchanger.

[0030] According to some embodiments, it can be provided that a suction side of the fan faces the first fins of the heat exchanger, or a pressure side of the fan faces the second fins of the heat exchanger.

[0031] According to some embodiments, the refrigeration device may have an evaporator chamber fluidically connected to the storage chamber, in which the heat exchanger forming the evaporator is arranged. The fan is arranged and configured to circulate air between the evaporator chamber and the storage chamber. The refrigeration device may thus be implemented as a NoFrost device.

[0032] The features and advantages disclosed herein in connection with one aspect of the invention are also disclosed for the other aspect and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 a simplified, schematic sectional view of a refrigeration device according to an embodiment of the invention; Fig. 2 shows a simplified hydraulic circuit diagram of a refrigerant circuit according to an embodiment of the invention; and Fig. 3 a perspective view of a heat exchanger according to an embodiment of the invention.

[0034] In the figures, the same reference symbols denote identical or functionally identical components, unless otherwise stated. DETAILED DESCRIPTION OF EMBODIMENTS

[0035] Fig. 1 shows an example of a refrigeration device 300 in the form of a refrigerator. The invention will be described below by way of example with reference to the Fig. 1, but is not limited thereto. For example, the invention can also be used in other household refrigeration appliances, such as a freezer or chest freezer or a refrigerator-freezer combination, or in refrigeration appliances in general.

[0036] As in Fig. As shown schematically in Figure 1, the refrigeration appliance 300 has a body 302, which defines a storage compartment or storage chamber 310 for accommodating refrigerated goods, such as food, beverages, medications, or the like. A machine compartment 312, separate from the storage compartment 310, can optionally also be defined at least partially by the body 302.

[0037] As in Fig. 1, the refrigeration device 300 has a refrigerant circuit 200. A hydraulic circuit diagram of the refrigerant circuit 200 is shown in Fig. 2 schematically shown. As shown in the Fig. 1 and Fig. 2, the refrigerant circuit 200 comprises an evaporator 210, a compressor 220, a condenser 230 and a main throttle element 240 ( Fig. 2), e.g. in the form of a capillary 241. Optionally, the refrigerant circuit 200 additionally has a fan 250 ( Fig. 1).

[0038] The evaporator 220 is thermally coupled to the storage compartment 310 to extract heat therefrom by evaporating refrigerant. For example, the evaporator 210, as shown in Fig. 1 purely by way of example and shown only schematically, can be arranged in an evaporator chamber 315 fluidly connected to the storage compartment 310, and the fan 250 can be arranged and configured to circulate air between the evaporator chamber 315 and the storage compartment 310. The fan 250 thus draws in warm air from the storage compartment 310, directs it through or over the evaporator 210, where the air transfers heat to the refrigerant located in the evaporator 210, and then expels the air back into the storage compartment 310.

[0039] The evaporator 210 has an outlet 212, which is connected to a suction port 221 of the compressor 220. The compressor 220 compresses the gaseous refrigerant coming from the evaporator 210 and feeds it via a pressure port 222 to an inlet 231 of the condenser 230. In the condenser 230, the refrigerant condenses, releasing heat to the environment. An outlet 232 of the condenser 230 is connected to an inlet 211 of the evaporator 210, with the main throttle element 240 being arranged between the condenser 230 and the evaporator 210 and expanding the refrigerant. As shown in Fig. 1 purely schematically, the compressor 220 can be arranged, for example, in the machine room 212. The condenser 230 is in Fig. 1 is also shown purely schematically and can be arranged, for example, on an outer wall of the body 202 or in the machine room 212.

[0040] The refrigerant circuit 220 is generally designed to extract heat from the storage compartment 210 by evaporating refrigerant and to release this heat to the environment by condensing refrigerant.

[0041] Fig. 3 shows an example of a heat exchanger 100 which is used in the Fig. 1 and Fig. 2 is used as an evaporator 210. The heat exchanger 100 has a first region 101 and a second region 102 spatially separated therefrom. The first region 101 has a first heat exchanger tube 1 and a plurality of first fins 4. The second region 102 has a second heat exchanger tube 2 and a plurality of second fins 5. Furthermore, the heat exchanger 100 has an intermediate throttle element 3, which connects the first and second heat exchanger tubes 1, 2 to one another.

[0042] The first and second regions 1, 2 may be spaced apart from one another in a first direction X1, as shown in Fig. 3 is shown as an example. Generally, the first and second heat exchanger tubes 1, 2 are spaced apart from each other in the first direction X1.

[0043] The first heat exchanger tube 1 has an inlet 11 for injecting refrigerant and an outlet 12. The inlet 11 of the first heat exchanger tube 1 forms the inlet 211 of the evaporator 210. Between the inlet 11 and the outlet 12, the first heat exchanger tube 1 can extend in a meandering manner. As shown in Fig. 3, the first heat exchanger tube 1 can have a plurality of linearly extending first tube sections 14, which extend in a second direction X1 running transversely to the first direction X1, and second, curved tube sections 16, wherein in each case two first tube sections 14 are connected to one another by an arcuate second tube section 16.

[0044] The second heat exchanger tube 2 has an inlet 21 and an outlet 22 for discharging the refrigerant. The outlet 22 forms the outlet 212 of the evaporator 210. Between the inlet 21 and the outlet 22, the second heat exchanger tube 2 can extend in a meandering manner. As shown in Fig. 3, the second heat exchanger tube 2 can, for example, have a plurality of linearly extending first tube sections 24 extending in the second direction X1, and second, curved tube sections 26, wherein in each case two first tube sections 24 are connected to one another by an arcuate second tube section 26.

[0045] The inlet 21 of the second heat exchanger tube 2 is connected to the outlet 12 of the first heat exchanger tube 1 via the intermediate throttle element 3. The intermediate throttle element 3 can be designed, for example, as a capillary. In this case, the capillary 3 forming the intermediate throttle element 3 can have a larger flow diameter than the capillary 241 forming the main throttle element 240. The intermediate throttle element 3 expands the refrigerant coming from the first heat exchanger tube 1, so that a lower vapor pressure prevails in the second heat exchanger tube 2. The second region 102 of the heat exchanger 100 thus has a lower temperature than the first region 102 during the flow of refrigerant.

[0046] The first lamellae 4 each extend in the first direction X1 and are spaced apart from one another in the second direction X2 by a first distance d1. Thus, a first flow channel 40 extending in the first direction X1 is formed between two adjacent first lamellae 4. The first distance d1 can, for example, be in a range between 1 mm and 7 mm. As shown in Fig. As shown by way of example in Figure 3, the first slats 4 can be designed, for example, as rectangular plates. The slats 4 can be made, for example, from a metal sheet.

[0047] As in Fig. As further shown in Figure 3, the first fins 4 can each have recesses 41 through which the first heat exchanger tube 1 extends. For example, the recesses 41 can each be designed as an elongated hole, with two first tube sections 14 each extending through a recess 41. The first fins 4 are in heat-conducting contact with the first heat exchanger tube 1. For example, the heat exchanger tube 1 can rest against the circumference of the respective recess 41. The second slats 5 each extend in the first direction X1 and are arranged at a second distance d2 from one another in the second direction X2. Thus, between each two adjacent second slats 5, a second flow channel 50 extending in the first direction X1 is formed. The second distance d2 can, for example, be in a range between 8 mm and 15 mm. Generally, the second distance d2 between the second slats 5 is greater than the first distance d1 between the first slats 4. For example, the second distance d2 can be at least 1.1 times, preferably at least 1.5 times, the first distance d1.

[0048] As in Fig. As shown by way of example in Figure 3, the second slats 5 can be designed, for example, as rectangular plates. The slats 5 can be made, for example, from a metal sheet.

[0049] As in Fig. As further shown in Figure 3, the second fins 5 can each have recesses 51 through which the second heat exchanger tube 2 extends. For example, the recesses 51 can each be designed as an elongated hole, with two first tube sections 24 each extending through a recess 51. The second fins 5 are in heat-conducting contact with the second heat exchanger tube 2. For example, the heat exchanger tube 2 can rest against the circumference of the respective recess 51.

[0050] The first and second slats 4, 5 can be physically or spatially separated from each other, i.e., as separate components. For example, the first and second slats 4, 5 can be positioned spaced apart from each other in the first direction X1, such that a gap 45 is formed between the first slats 4 and the second slats 5 in the first direction X1, as shown in Fig. 3 is shown as an example.

[0051] As in Fig. 3 further shown by way of example, the heat exchanger 100 can optionally have a first holding plate 61 and a second holding plate 62. The holding plates 61, 62 can each extend in the first direction X1 and can, for example, be rectangular. Furthermore, both the first and the second heat exchanger tube 1, 2 are connected to the first holding plate 61. For example, the first holding plate 61 can each have recesses 63, e.g. in the form of elongated holes, through which the respective heat exchanger tube 1, 2 runs. For example, the respective heat exchanger tube 1, 2 can be fixed in a respective recess 63 of the first holding plate. Similarly, both the first and the second heat exchanger tube 1, 2 are connected to the second holding plate 62. For example, the second holding plate 62 can each have recesses 64, e.g. in the form of elongated holes, through which the respective heat exchanger tube 1, 2 runs.For example, the respective heat exchanger tube 1, 2 can be fixed in a respective recess 64 of the first holding plate.

[0052] The holding plates 61, 62 are arranged spaced apart from each other in the second direction. As shown in Fig. 3, the first slats 4 and the second slats 5 can be arranged between the first and the second holding plate 61, 62 with respect to the second direction X2.

[0053] As in Fig. 3, the end regions of the holding plates 61, 62 can optionally protrude in the first direction X1 beyond the ends of the second slats 5 facing away from the first slats 4. In this end region, the holding plates 61, 62 can each have a holding recess 67, which can be used to hold a defrost heater (not shown). Fig. Figure 3 also shows, by way of example, that the first holding plate 61 has a bracket 65 in the form of a clamp. This bracket 65 can be used to secure a sensor and / or an overheating monitor.

[0054] The heat exchanger 100 can be subjected to an air flow by means of the fan 250, e.g., when the heat exchanger 100 is arranged as an evaporator 210 in the evaporator chamber 315 of the refrigeration device 300. The fan 250 is preferably arranged in such a way as to generate an air flow that first flows through the second flow channels 50 and then through the first flow channels 40 of the heat exchanger 100. This is shown in Fig.3 is schematically represented by the arrow S. Air thus flows through the heat exchanger 100 along the first direction X1, with the air flow first flowing through the second region 102 through the flow channels 50 formed between the second fins 5 and then through the first region 101 through the flow channels 40 formed between the first fins 4. Since the second region 102 has a lower temperature than the first region 101, icing occurs predominantly in the second region 101. In particular, since the moisture from the air coming from the storage compartment 310 can be predominantly separated in the cold second region 102, it is possible to largely avoid icing in the first region 101. The first fins 4 can thus advantageously be positioned at a relatively small distance d1 from one another.

[0055] To direct the air flow through the heat exchanger 100 as described above, a suction side of the fan 250 can be positioned facing the first fins 4 of the heat exchanger 100. Alternatively, a pressure side of the fan 250 can face the second fins 5 of the heat exchanger 100.

[0056] Although the present invention has been explained above using exemplary embodiments, it is not limited thereto but can be modified in a variety of ways. In particular, combinations of the above embodiments are also conceivable. REFERENCE SYMBOL 1 first heat exchanger tube 2 second heat exchanger tube 3 Intermediate throttle organ 4 first slats 5 second slats 11 Inlet of the first heat exchanger tube 12 Outlet of the first heat exchanger tube 14 first pipe sections of the first heat exchanger pipe 16 second pipe sections of the first heat exchanger pipe 21 Inlet of the second heat exchanger tube 22 Outlet of the second heat exchanger tube 24 first pipe sections of the second heat exchanger pipe 26 second pipe sections of the second heat exchanger pipe 30 capillaries 40 first flow channels 41 recesses of the first slats 45 gap 50 second flow channels 51 recesses of the second slats 100 heat exchangers 101 first area of ​​the heat exchanger 102 second area of ​​the heat exchanger 200 Refrigerant circuit 210 evaporator 211 Evaporator inlet 212 Evaporator outlet 220 compressors 221 Compressor suction connection 222 Compressor pressure connection 230 condenser 231 Condenser inlet 232 Condenser outlet 240 Main throttle organ 241 capillaries 250 fans 300 refrigeration unit 302 Corpus 310 Storage chamber or storage compartment 312 Engine room 315 Evaporator chamber S Arrow X1 first direction X2 second direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2015 218 452 A1

[0005]

Claims

[1] Heat exchanger (100) for a refrigeration device (300), in particular for a household refrigeration device, comprising: a first heat exchanger tube (1) for passing refrigerant; a second heat exchanger tube (2) for passing refrigerant, which is arranged adjacent to the first heat exchanger tube (1) in a first direction (X1) and is connected to the first heat exchanger tube (2); a plurality of first fins (4) which are in heat-conducting contact with the first heat exchanger tube (1) and are arranged at a distance from one another in a second direction (X2) extending transversely to the first direction (X1), so that first flow channels (40) extending in the first direction (X1) are formed between the first fins (4); and a plurality of second fins (5) which are in heat-conducting contact with the second heat exchanger tube (2) and are arranged at a distance from one another in the second direction (X2), so that second flow channels (50) extending in the first direction (X1) are formed between the second fins (5); characterized by , that an intermediate throttle element (3) is arranged between the first and the second heat exchanger tube (1, 2), the first slats (4) are arranged in the second direction (X2) at a first distance (d1) from each other, and the second slats (5) are arranged spaced from one another in the second direction (X2) at a second distance (d2) which is greater than the first distance (d1). [2] Heat exchanger (100) according to claim 1, wherein the intermediate throttle member (3) is formed by a capillary (30) which connects the first and the second heat exchanger tube (1, 2) to each other. [3] Heat exchanger (100) according to claim 1 or 2, wherein the first and second fins (4, 5) are separated from each other. [4] Heat exchanger (100) according to one of the preceding claims, wherein the first and second fins (4, 5) are spaced apart from each other in the first direction (X1) such that a gap (45) is formed between the first fins (4) and the second fins (5) in the first direction (X1). [5] Heat exchanger (100) according to one of the preceding claims, wherein the first distance (d1) of the first fins (4) from one another is in a range between 1 mm and 7 mm. [6] Heat exchanger (100) according to one of the preceding claims, wherein the second distance (d2) of the second fins (5) from one another is in a range between 8 mm and 15 mm. [7] Heat exchanger (100) according to one of the preceding claims, wherein the second distance (d2) is at least 1.1 times, preferably at least 1.5 times, the first distance (d1). [8] Heat exchanger (100) according to one of the preceding claims, additionally comprising: a first holding plate (61) extending in the first direction (X1), to which both the first and the second heat exchanger tubes (1, 2) are connected; and a second holding plate (62) extending in the first direction (X1), which is arranged at a distance from the first holding plate (61) in the second direction (X2) and to which both the first and the second heat exchanger tube (1, 2) are connected. [9] Heat exchanger (100) according to claim 8, wherein the first fins (4) and the second fins (5) are arranged between the first and the second holding plate (61, 62) with respect to the second direction (X2), respectively. [10] Heat exchanger (100) according to one of the preceding claims, wherein the first heat exchanger tube (1) has an inlet (11) for injecting refrigerant and an outlet (12) and extends between the inlet (11) and the outlet (12) in a meandering manner through recesses (41) formed in the first fins (4), and wherein the second heat exchanger tube (2) has an inlet (21) connected to the outlet (12) of the first heat exchanger tube (1) by the intermediate throttle element (3) and an outlet (22) for discharging the refrigerant and extends between the inlet (21) and the outlet (22) in a meandering manner through recesses (51) formed in the second fins (5). [11] Refrigerant circuit (200) for a refrigeration device (300), in particular for a household refrigeration device, comprising: an evaporator (210) formed by a heat exchanger (100) according to one of the preceding claims; a compressor (220) for compressing gaseous refrigerant having a suction port (221) connected to the second heat exchanger tube (2) and a pressure port (222) for discharging compressed gaseous refrigerant; an evaporator (230) having an inlet (231) connected to the pressure connection (222) of the compressor (220) and an outlet (232) connected to the first heat exchanger tube (1); and a main throttle element (240) which is arranged between the outlet (232) of the evaporator (230) and the first heat exchanger tube (1) and is designed to expand the refrigerant. [12] Refrigerant circuit (200) according to claim 11, insofar as it is dependent on claim 2, wherein the main throttle element (240) is designed as a capillary (241), and wherein the capillary (3) forming the intermediate throttle element (3) has a larger flow diameter than the capillary (241) forming the main throttle element (240). [13] Refrigerant circuit (200) according to claim 11 or 12, additionally comprising: a fan (250) which is arranged and designed to generate an air flow flowing first through the second flow channels (50) and then through the first flow channels (40) of the heat exchanger (100). [14] Refrigeration appliance (300), in particular household refrigeration appliance, comprising: a storage chamber (310) for receiving refrigerated goods; and a refrigerant circuit (200) according to one of claims 11 to 13; wherein the evaporator (221) is thermally coupled to the storage chamber (310), in order to extract heat therefrom by evaporating refrigerant in the first heat exchanger tube (1) and in the second heat exchanger tube (2), and wherein the condenser (223) is thermally coupled to the environment in order to release heat to the environment by condensing refrigerant. [15] Refrigeration device (300) according to claim 14, insofar as it is dependent on claim 13, additionally comprising: an evaporator chamber (315) fluidically connected to the storage chamber (310), in which the heat exchanger (100) forming the evaporator (221) is arranged; wherein the fan (250) is arranged and designed to circulate air between the evaporator chamber (315) and the storage chamber (310)

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