Heat exchanger and air conditioning device

Abstract

The heat exchanger comprises a plurality of flat tubes through which a refrigerant flows, and a plurality of fins arranged between the flat tubes to transfer the heat of the refrigerant flowing through the flat tubes. The fins have a flat portion with an opening formed in part of it, and louvers that form the opening in the flat portion, and slits are formed in the part of the flat portion that comes into contact with the end of the flat tube to drain water that accumulates in the flat portion.

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger including flat tubes and fins, and an air conditioning apparatus. [Background technology]

[0002] Conventionally, heat exchangers including flat tubes and fins have been known. Patent Document 1 discloses a heat exchanger including a plurality of flat tubes and a corrugated fin provided with a plurality of louvers. Patent Document 1 discloses a corrugated fin heat exchanger in which a slit is formed in the center of the corrugated fin. As such, the slit is formed in a portion furthest from each of the upstream end and downstream end of the flat tube in the air flow direction. As a result, Patent Document 1 aims to suppress freezing by using the slit to release the freezing load even if the surface temperature drops below the freezing point and there is a possibility of freezing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-183908 Summary of the Invention [Problem to be solved by the invention]

[0004] When the heat exchanger functions as an evaporator when the outside air temperature is low, the accumulation of condensed water on the fins may reduce the heating capacity. Although Patent Document 1 has slits, it does not take drainage into consideration. There is a need for a heat exchanger that can efficiently drain the water that forms on the fins.

[0005] The present disclosure has been made to solve the above-mentioned problems, and provides a heat exchanger and an air conditioner that efficiently discharge water. [Means for solving the problem]

[0006] A heat exchanger according to the present disclosure includes a plurality of flat tubes through which a refrigerant flows, and a plurality of fins provided between the flat tubes to transfer heat of the refrigerant flowing through the flat tubes, the fins having a planar portion with an opening formed in a part thereof and louvers forming the opening in the planar portion, the planar portion extending further upwind than the end of the flat tubes, and a slit formed in a portion of the fin that contacts the end of the flat tube on the upwind side to drain water that accumulates in the planar portion. The slit opens in a normal direction of the flat surface, and the flat surface is located on the windward side of the slit. . [Effects of the Invention]

[0007] According to the present disclosure, slits are formed in the flat portions of the fins at the portions where they come into contact with the ends of the flat tubes to drain water that accumulates on the flat portions. When condensation occurs on the fins, the water is drained through the slits. The water that passes through the slits is guided to the ends of the flat tubes, where it falls downward without accumulating on the fins, etc. Therefore, water can be efficiently drained. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a circuit diagram showing an air conditioner according to a first embodiment. [Figure 2] 1 is a front view showing a heat exchanger according to a first embodiment. [Figure 3] 1 is a top view showing a heat exchanger according to a first embodiment. [Figure 4] 1 is a side view showing a heat exchanger according to a first embodiment. [Figure 5] 1 is a top view showing a heat exchanger according to a first embodiment. [Figure 6] FIG. 10 is a top view showing a heat exchanger according to a second embodiment. [Figure 7] FIG. 10 is a top view showing a heat exchanger according to a third embodiment. [Figure 8] FIG. 10 is a top view showing a heat exchanger according to a fourth embodiment. [Figure 9] FIG. 10 is a top view showing a heat exchanger according to a fifth embodiment. [Figure 10] FIG. 10 is a top view showing a heat exchanger according to a sixth embodiment. [Figure 11] FIG. 13 is a top view showing a heat exchanger according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of a heat exchanger and an air conditioning apparatus according to the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below. In addition, the dimensional relationships between components in the following drawings, including FIG. 1, may differ from the actual relationships. In addition, in the following description, terms indicating directions are used as appropriate to facilitate understanding of the present disclosure, but these terms are used for the purpose of explaining the present disclosure and do not limit the present disclosure. Examples of terms indicating directions include "up," "down," "right," "left," "front," and "rear." Note that hatching in cross-sectional views has been partially omitted in some of the drawings.

[0010] Embodiment 1 Fig. 1 is a circuit diagram showing an air conditioner 1 according to embodiment 1. As shown in Fig. 1, the air conditioner 1 is a device that adjusts the air in an indoor space, and includes an outdoor unit 2 and an indoor unit 3 connected to the outdoor unit 2. The outdoor unit 2 is provided with a compressor 6, a flow path switching device 7, a heat exchanger 8, an outdoor blower 9, and an expansion section 10. The indoor unit 3 is provided with an indoor heat exchanger 11 and an indoor blower 12.

[0011] A compressor 6, a flow switching device 7, a heat exchanger 8, an expansion section 10, and an indoor heat exchanger 11 are connected by refrigerant piping 5 to form a refrigerant circuit 4 through which a refrigerant, which is a working gas, flows. The compressor 6 draws in refrigerant in a low-temperature, low-pressure state, compresses the drawn refrigerant, and discharges it as a high-temperature, high-pressure refrigerant. The flow switching device 7, which is, for example, a four-way valve, switches the direction in which the refrigerant flows in the refrigerant circuit 4. The heat exchanger 8 exchanges heat between, for example, outdoor air and the refrigerant. The heat exchanger 8 acts as a condenser during cooling operation and as an evaporator during heating operation.

[0012] The outdoor fan 9 is a device that sends outdoor air to the heat exchanger 8. The expansion section 10 is a pressure reducing valve or expansion valve that reduces the pressure of the refrigerant to expand it. The expansion section 10 is, for example, an electronic expansion valve whose opening degree is adjustable. The indoor heat exchanger 11 is, for example, a device that exchanges heat between the indoor air and the refrigerant. The indoor heat exchanger 11 acts as an evaporator during cooling operation and as a condenser during heating operation. The indoor fan 12 is a device that sends indoor air to the indoor heat exchanger 11.

[0013] (Operation mode, cooling operation) Next, the operating modes of the air conditioner 1 will be described. First, cooling operation will be described. In cooling operation, the refrigerant drawn into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 6 passes through the flow switching device 7 and flows into the heat exchanger 8, which functions as a condenser. In the heat exchanger 8, the refrigerant exchanges heat with outdoor air sent by the outdoor fan 9, condensing and liquefying. The condensed liquid refrigerant flows into the expansion section 10, where it expands and is decompressed to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant then flows into the indoor heat exchanger 11, which functions as an evaporator. In the indoor heat exchanger 11, the refrigerant exchanges heat with indoor air sent by the indoor fan 12, evaporating and gasifying. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated refrigerant in a gaseous state at a low temperature and pressure passes through the flow switching device 7 and is sucked into the compressor 6.

[0014] (Operation mode, heating operation) Next, heating operation will be described. In heating operation, the refrigerant drawn into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 6 passes through the flow switching device 7 and flows into the indoor heat exchanger 11, which functions as a condenser. In the indoor heat exchanger 11, the refrigerant exchanges heat with indoor air sent by the indoor blower 12, condensing and liquefying. At this time, the indoor air is heated, and heating is performed indoors. The condensed liquid refrigerant flows into the expansion section 10, where it expands and is decompressed to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant then flows into the heat exchanger 8, which functions as an evaporator. In the heat exchanger 8, the refrigerant exchanges heat with outdoor air sent by the outdoor blower 9, evaporating and gasifying. The evaporated low-temperature, low-pressure gas refrigerant passes through the flow switching device 7 and is drawn into the compressor 6.

[0015] The air conditioner 1 does not necessarily have to have the flow path switching device 7. In this case, the air conditioner 1 becomes a dedicated cooling machine or a dedicated heating machine.

[0016] FIG. 2 is a front view showing the heat exchanger 8 according to the first embodiment. Next, the heat exchanger 8 will be described in detail. As shown in FIG. 2, the heat exchanger 8 is, for example, a parallel flow type heat exchanger 8. The heat exchanger 8 may also be a fin tube type heat exchanger 8. The heat exchanger 8 includes flat tubes 20, fins 30, and a header 40.

[0017] (Flat tube 20) The flat tubes 20 are tubes through which a refrigerant flows, and are arranged in multiple rows and made of, for example, aluminum or an aluminum alloy. The multiple flat tubes 20 are arranged at intervals so that their longitudinal axes face each other, and fins 30 are provided between the flat tubes 20. The flat tubes 20 may also be made of a clad material with an aluminum core. The flat tubes 20 have, for example, multiple flow paths formed in a row through which the refrigerant flows. The flat tubes 20 extend with their height direction as the longitudinal direction.

[0018] (Fin 30) The fins 30 are components that transfer heat from the refrigerant flowing through the flat tubes 20, and are, for example, corrugated fins that are bent and arranged between the flat tubes 20. The width of the fins 30 is equal to the distance between adjacent flat tubes 20. The fins 30 have inclined surfaces that are inclined with respect to the horizontal direction and are alternately folded back. In other words, the fins 30 can be described as strip-shaped members that are alternately folded back and arranged in multiple rows in the height direction. Between the fins 30 and the flat tubes 20, ventilation channels 31 are formed through which air flows. The fins 30 are made of, for example, aluminum. The fins 30 may also be plate fins.

[0019] (Header 40) The header 40, through which the refrigerant flows and which divides the refrigerant into the connected flat tubes 20, is made of, for example, aluminum. As described above, the header 40 may be made of the same material as the fins 30 and the flat tubes 20, or a different material may be used. The header 40 includes a header 40 that connects one ends of the flat tubes 20 and a header 40 that connects the other ends of the flat tubes 20. The interior of the header 40 may be configured so that the space through which the refrigerant flows is partitioned by one or more partitions. A refrigerant pipe 5 is connected to one of the headers 40, and the header 40 is connected to the flow path switching device 7 via the refrigerant pipe 5. A refrigerant pipe 5 is connected to the other header 40, and the header 40 is connected to the expansion section 10 via the refrigerant pipe 5. The header 40 may be made of the same material as the flat tubes 20.

[0020] (Plane part 32) Fig. 3 is a top view showing the heat exchanger 8 according to the first embodiment. As shown in Fig. 3, the fins 30 have a flat portion 32 and a plurality of louvers 33. The flat portion 32 is a plate-like member that extends at an angle along the longitudinal direction of the flat tubes 20. The flat portion 32 has a rectangular opening 32a (see Fig. 4) that extends along the longitudinal direction of the flat tubes 20 in a part of the center, excluding both end portions adjacent to the flat tubes 20.

[0021] (Luba 33) Fig. 4 is a side view showing the heat exchanger 8 according to the first embodiment. As shown in Fig. 4, the louvers 33 form openings 32a in the flat surface portion 32. A plurality of louvers 33 are provided for each opening 32a. The louvers 33 are formed by cutting and raising a portion of the flat surface portion 32, and are inclined in a side view. In a side view, one end of the louvers 33 is higher than the flat surface portion 32 and the other end is lower than the flat surface portion 32.

[0022] (Slit 35) As shown in FIG. 3 , slits 35 for discharging water 50 accumulated in the flat portion 32 are formed in the portions of the flat portion 32 that come into contact with the ends of the flat tubes 20. Here, the ends of the flat tubes 20 refer to the ends of the flat tubes 20 in the longitudinal direction. In this manner, the slits 35 are formed in the flat portion 32 so as to be continuous with the ends of the flat tubes 20. The slits 35 are also formed in the flat portion 32 of the fins 30 that face the vicinity of the center of the flat tubes 20 in the longitudinal direction. The slits 35 extend in the direction in which the flat tubes 20 face each other. That is, the slits 35 extend along the minor axis direction of the flat tubes 20. In the first embodiment, the slits 35 are rectangular, but are not limited to a rectangular shape.

[0023] As shown in Fig. 3, the slits 35 are formed on the upwind side, which is the upstream side in the air flow, of the flat surface portion 32 of the fin 30. The opening area of ​​the multiple slits 35 is larger on the upwind side of the fin 30 than on the downwind side. In the first embodiment, the slits 35 are formed only on the upwind side, but the slits 35 may also be formed on the downwind side. Furthermore, the slits 35 are formed only on the upwind end side of the flat tube 20, but they may also be formed on the downwind end side of the flat tube 20.

[0024] 4, a plurality of louvers 33 are provided, and the louvers 33 located on both ends of the slit 35 are inclined line-symmetrically with respect to the slit 35. The louvers 33 located on one end of the slit 35 are inclined while gradually descending toward the slit 35, and the louvers 33 located on the other end of the slit 35 are also inclined while gradually descending toward the slit 35. In other words, the inclination directions of the louvers 33 located on both ends of the slit 35 are different from each other.

[0025] FIG. 5 is a top view showing the heat exchanger 8 according to the first embodiment. Next, the positions of the slits 35 in the bent fins 30 adjacent in the height direction will be described. In FIG. 5, the fin 30 on the left side is the upper fin 30, the fin 30 in the middle fin 30, and the fin 30 on the right side is the lower fin 30. Also, in FIG. 5, the upper side is the upwind side and the lower side is the downwind side. As shown in FIG. 5, the slits 35 are offset from one another in the height direction. Although FIG. 5 illustrates an example in which the lengths of the slits 35 in the minor axis direction of the flat tubes 20 are the same, they may be different.

[0026] Furthermore, the offset of the slits 35 may be periodic or non-periodic. If the slits 35 are periodic, the manufacturing process is simplified. Furthermore, when no slits 35 are formed in any of the flat tubes 20, as in the fins 30 in the center and on the right side of FIG. 5, the bonding strength between the flat tubes 20 and the fins 30 is higher. By periodically offsetting the positions of the slits 35 in the height direction, as in the first embodiment, it is possible to achieve both high drainage performance and high bonding strength.

[0027] According to the first embodiment, slits 35 for draining water accumulated on the flat surface portions 32 are formed in the portions of the flat surface portions 32 of the fins 30 that come into contact with the ends of the flat tubes 20. When condensation occurs on the fins 30, the water is drained through the slits 35. The water that passes through the slits 35 is guided to the ends of the flat tubes 20, and falls downward without remaining on the fins 30, etc. Therefore, the water can be drained efficiently. This improves the heating capacity.

[0028] The slits 35 extend in the direction in which the flat tubes 20 face each other. This increases the bonding area between the flat tubes 20 and the fins 30. This increases the bonding area between the flat tubes 20 and the fins 30 while ensuring drainage. The slits 35 of the fins 30, which are aligned vertically, are offset from one another in the vertical direction. This allows droplets adhering to the fins 30 to fall through the upper slits 35, strike the lower flat surface 32, flow along the inclined flat surface 32, and then fall through the slits 35. This means that droplets are less likely to accumulate on the fins 30. This allows for a balance between bonding strength and low-temperature heating capacity.

[0029] The slits 35 are formed on the upwind side of the fins 30. The opening area of ​​the multiple slits 35 is larger on the upwind side of the fins 30 than on the downwind side. This allows for improved drainage on the upwind side, where the amount of frost and dehumidification is greater. This, in turn, improves the heating low-temperature capacity. Furthermore, the louvers 33 located on both ends of the slits 35 are inclined downwardly and symmetrically with respect to the slits 35. This allows water generated on the louvers 33 to pass through the inclined surfaces of the louvers 33 and be guided to the slits 35, where it is discharged. This allows for improved drainage.

[0030] Embodiment 2 6 is a top view showing a heat exchanger 8 according to embodiment 2. Embodiment 2 differs from embodiment 1 in that multiple rows of flat tubes 20 are provided. In embodiment 2, parts common to embodiment 1 are given the same reference numerals and description thereof will be omitted, and the description will focus on the differences from embodiment 1.

[0031] As shown in Fig. 6, the flat tubes 20 are arranged in multiple rows in the longitudinal direction of the fins 30. In the second embodiment, two rows of the flat tubes 20 are illustrated, but three or more rows may be provided. Here, the spaces between the multiple rows of flat tubes 20 are referred to as inter-row portions 32b. The slits 35 are portions of the planar portion 32 that come into contact with the ends of the flat tubes 20, and are formed in the inter-row portions 32b.

[0032] The inter-row portions 32b have a large portion that is not in contact with the flat tubes 20 compared to the other planar portions 32, and therefore do not have a high heat exchange capacity. According to the second embodiment, the slits 35 are formed in the inter-row portions 32b between the multiple rows of flat tubes 20, and therefore, drainage can be improved without reducing the heat exchange capacity.

[0033] Embodiment 3 7 is a top view showing a heat exchanger 8 according to embodiment 3. Embodiment 3 differs from embodiment 2 in the position where the slits 35 are formed. In embodiment 3, parts common to embodiments 1 and 2 are given the same reference numerals and description thereof will be omitted, and the description will focus on the differences from embodiments 1 and 2.

[0034] 7, the slits 35 are formed in all of the portions of the inter-row portions 32b that come into contact with the ends of the flat tubes 20. As described above, the inter-row portions 32b have many portions that do not come into contact with the flat tubes 20 compared to the other planar portions 32, and therefore do not have high heat exchange capacity. According to the third embodiment, the slits 35 are formed in all of the portions of the inter-row portions 32b that come into contact with the ends of the flat tubes 20, and therefore, it is possible to further improve drainage without reducing heat exchange capacity.

[0035] Embodiment 4 8 is a top view showing a heat exchanger 8 according to embodiment 4. Embodiment 4 differs from embodiment 1 in that slits 35 are formed on the upwind side and downwind side of fins 30. In embodiment 4, parts common to embodiments 1 to 3 are given the same reference numerals and description thereof will be omitted, and the following description will focus on the differences from embodiments 1 to 3.

[0036] As shown in FIG. 8, the slits 35 are formed on the windward and leeward sides of the fins 30. This allows water to be discharged using all of the ends of the flat tubes 20. The water that passes through the slits 35 is guided to the ends of the flat tubes 20, and falls downward without accumulating on the fins 30, etc. This allows water to be discharged efficiently. Furthermore, because the water is guided along the ends of the flat tubes 20, rapid drainage is achieved. This further improves heating capacity.

[0037] Embodiment 5. 9 is a top view showing a heat exchanger 8 according to embodiment 5. Embodiment 5 differs from embodiment 4 in that the slits 35 are formed only in the portions of the planar portion 32 that come into contact with the ends of the flat tubes 20. In embodiment 5, parts that are common to embodiments 1 to 4 are given the same reference numerals and description thereof will be omitted, and the following description will focus on the differences from embodiments 1 to 4.

[0038] As shown in Fig. 9, the slits 35 are formed only in the portions of the flat portion 32 that contact the ends of the flat tubes 20. That is, the slits 35 are not formed in the flat portion 32 of the fins 30 that are joined to the flat tubes 20. This makes it possible to improve drainage without reducing heat exchange capacity as much as possible. Furthermore, because water is guided along the ends of the flat tubes 20, rapid drainage is achieved.

[0039] Embodiment 6 10 is a top view showing a heat exchanger 8 according to a sixth embodiment. In this sixth embodiment, the opening area of ​​the slits 35 differs between the inter-row portion 32b and the portion other than the inter-row portion 32b. In this sixth embodiment, the same parts as those in the first to fifth embodiments are denoted by the same reference numerals and their description will be omitted, and the following description will focus on the differences from the first to fifth embodiments.

[0040] 10, the opening area of ​​the slits 35 is larger in the inter-row portions 32b than in other portions. This improves drainage without reducing heat exchange capacity as much as possible. Furthermore, because water is guided along the ends of the flat tubes 20, rapid drainage is achieved.

[0041] Embodiment 7 11 is a top view showing a heat exchanger 8 according to embodiment 7. This embodiment 7 differs from embodiments 1 to 6 in the opening area of ​​the slit 35. In this embodiment 7, parts that are common to embodiments 1 to 6 are given the same reference numerals and description thereof will be omitted, and the following description will focus on the differences from embodiments 1 to 6.

[0042] As shown in Fig. 11, the flat surface portion 32 is formed with slits 35 whose opening area is larger on the upwind side of the fin 30 than on the downwind side. This improves drainage on the upwind side, where the amount of frost and dehumidification is greater, thereby improving the heating low-temperature capacity. [Explanation of symbols]

[0043] 1 air conditioning unit, 2 outdoor unit, 3 indoor unit, 4 refrigerant circuit, 5 refrigerant piping, 6 compressor, 7 flow path switching device, 8 heat exchanger, 9 outdoor blower, 10 expansion section, 11 indoor heat exchanger, 12 indoor blower, 20 flat tube, 30 fin, 31 ventilation duct, 32 flat section, 32a opening, 32b inter-row section, 33 louver, 35 slit, 40 header, 50 water.

Claims

1. a plurality of flat tubes through which a refrigerant flows; a plurality of fins provided between the flat tubes and configured to transfer heat of the refrigerant flowing through the flat tubes; The fins are a planar portion having an opening formed in a part thereof; a louver that forms the opening in the planar portion, The flat portion extends further upwind than the end of the flat tube, and a slit is formed in a portion of the fin that contacts the end of the flat tube on the upwind side to drain water that accumulates in the flat portion, The slit opens in a normal direction of the flat surface, and the flat surface is located on the upwind side of the slit. heat exchanger.

2. A slit is further formed in the flat portion between both ends in the longitudinal direction of the flat tube. The heat exchanger of claim 1.

3. The slit is The flat tubes extend in a direction facing each other.

3. The heat exchanger according to claim 1 or 2.

4. The flat tube extends with the height direction as the longitudinal direction, The fins are arranged in a plurality in the height direction, The slits of the fins arranged in the height direction are offset from each other in the height direction.

3. The heat exchanger according to claim 1 or 2.

5. The opening areas of the plurality of slits are The windward side of the fin is larger than the leeward side.

3. The heat exchanger according to claim 1 or 2.

6. The flat tubes are provided in several rows with spaces between them in the longitudinal direction of the fin, The slit is formed in inter-row portions between the plurality of rows of flat tubes 3. The heat exchanger according to claim 1 or 2.

7. A plurality of flat tubes through which a refrigerant flows; a plurality of fins provided between the flat tubes and configured to transfer heat of the refrigerant flowing through the flat tubes; The fins are a planar portion having an opening formed in a part thereof; a louver that forms the opening in the planar portion, The flat portion extends further upwind than the end of the flat tube, and a slit is formed in a portion of the fin that contacts the end of the flat tube on the upwind side to drain water that accumulates in the flat portion, The flat tubes are provided in several rows with spaces between them in the longitudinal direction of the fin, The slit is formed in inter-row portions between the plurality of rows of the flat tubes, The flat tubes are formed in all of the inter-row portions in contact with the ends of the flat tubes. heat exchanger.

8. A plurality of flat tubes through which a refrigerant flows; a plurality of fins provided between the flat tubes and configured to transfer heat of the refrigerant flowing through the flat tubes; The fins are a planar portion having an opening formed in a part thereof; a louver that forms the opening in the planar portion, The flat portion extends further upwind than the end of the flat tube, and a slit is formed in a portion of the fin that contacts the end of the flat tube on the upwind side to drain water that accumulates in the flat portion, The flat tubes are provided in several rows with spaces between them in the longitudinal direction of the fin, The slit is formed in inter-row portions between the plurality of rows of the flat tubes, The inter-row portion is formed in a portion in contact with both ends of the flat tubes that face each other in the longitudinal direction. heat exchanger.

9. The opening area of ​​the slit is The inter-row portion is larger than the portion other than the inter-row portion. The heat exchanger according to claim 6.

10. The slit is formed on the windward and leeward sides of the fin 3. The heat exchanger according to claim 1 or 2.

11. A plurality of flat tubes through which a refrigerant flows; a plurality of fins provided between the flat tubes and configured to transfer heat of the refrigerant flowing through the flat tubes; The fins are a planar portion having an opening formed in a part thereof; a louver that forms the opening in the planar portion, The flat portion extends further upwind than the end of the flat tube, and a slit is formed in a portion of the fin that contacts the end of the flat tube on the upwind side to drain water that accumulates in the flat portion, The slit is The flat portion is formed only on a portion of the flat portion that comes into contact with the end of the flat tube. heat exchanger.

12. The louvers are provided in plurality, The louvers arranged on both ends of the slit are inclined downwardly and symmetrically with respect to the slit.

3. The heat exchanger according to claim 1 or 2.

13. The heat exchanger according to claim 1 or 2 An air conditioning device comprising:

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