Heat exchanger and air conditioner

Abstract

This heat exchanger comprises a plurality of flat tubes inside of which refrigerant flows, and a plurality of fins that are provided between the flat tubes and transmit the heat of the refrigerant flowing through the flat tubes. The fins each have a plane part in which an opening is formed in a portion thereof, and a louver that opens and closes the opening of the plane part. A louver removal space in which a position connected to the end part of the louver is notched is formed in the plane part.

Description

Heat exchanger and air conditioning device

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

[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 with a plurality of louvers. Patent Document 1 discloses a corrugated fin heat exchanger in which a plurality of slit drainage holes are formed close to each other, thereby improving heat transfer performance and fin strength and smoothly draining condensed water that adheres to the surface of the fin when used as an evaporator. Patent Document 1 also aims to improve heat exchange efficiency by improving drainage.

[0003] Japanese Patent Application Laid-Open No. 2020-153540

[0004] However, in the case of a heat exchanger such as that disclosed in Patent Document 1, in which corrugated fins are provided across multiple rows of flat tubes, the ends of the louvers are cut and raised directly from the flat surface of the fins to form the inclined portions of the louvers. As a result, liquid droplets that flow down along the inclined portions of the louvers accumulate on the flat surface. Even if the ends of the louvers do not directly form the inclined portions of the louvers from the flat surface of the fins, condensed water accumulates because the gap between the flat surface and the louvers is narrow.

[0005] The present disclosure has been made to solve the above-mentioned problems, and provides a heat exchanger and an air conditioning apparatus that prevent water from accumulating at the ends of louvers.

[0006] The heat exchanger of the present disclosure comprises a plurality of flat tubes through which a refrigerant flows, and a plurality of fins arranged between the flat tubes to transfer heat from the refrigerant flowing through the flat tubes, the fins having a planar portion with an opening formed in part of it, and louvers that open and close the opening in the planar portion, and a louver removal space is formed in the planar portion by cutting out a position connected to the end of the louver.

[0007] According to the present disclosure, a louver removal space is formed by cutting out the flat portion at a position connected to the end of the louver. Therefore, water that accumulates at the end of the louver is discharged through the louver removal space. Therefore, it is possible to prevent water from accumulating at the end of the louver.

[0008] Fig. 1 is a circuit diagram showing an air conditioning apparatus according to embodiment 1. Fig. 2 is a front view showing a heat exchanger according to embodiment 1. Fig. 3 is a perspective view showing a heat exchanger according to embodiment 1. Fig. 4 is a schematic view showing fins according to embodiment 1. Fig. 5 is a top view showing a heat exchanger according to embodiment 1. Fig. 6 is a side view showing a heat exchanger according to embodiment 1. Fig. 7 is a top view showing a heat exchanger according to a modified example of embodiment 1. Fig. 8 is a perspective view showing a heat exchanger according to embodiment 2. Fig. 9 is a top view showing a heat exchanger according to embodiment 3.

[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. Furthermore, in the following drawings, including FIG. 1, the dimensional relationships between components may differ from the actual relationships. Furthermore, in the following description, terms indicating directions are used as appropriate to facilitate understanding of the present disclosure. However, these terms are 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. Figure 1 is a circuit diagram showing an air conditioner 1 according to embodiment 1. As shown in Figure 1, the air conditioner 1 is a device that conditions 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 (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 of refrigerant flow in the refrigerant circuit 4. The heat exchanger 8 exchanges heat between, for example, outdoor air and the refrigerant. The heat exchanger 8 functions 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 Modes, Cooling Operation) Next, the operation 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 low-temperature, low-pressure gas state passes through the flow switching device 7 and is sucked into the compressor 6 .

[0014] (Operation Mode, Heating Operation) Next, the heating operation will be described. In the 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 in the room. The condensed liquid refrigerant flows into the expansion section 10, where it expands and decompresses 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 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. The heat exchanger 8 may also be a fin tube type heat exchanger. The heat exchanger 8 includes flat tubes 20, fins 30, and a header 40.

[0017] (Flat Tubes 20) The flat tubes 20 are tubes through which a refrigerant flows. A plurality of flat tubes 20 are arranged side by side and are made of, for example, aluminum or an aluminum alloy. The plurality of 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, a plurality of 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] (Fins 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 fins 30 have inclined surfaces that are inclined with respect to the horizontal direction and are alternately folded. In other words, the fins 30 can be described as strip-shaped components that are alternately folded 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 allows the refrigerant to flow therethrough and distributes the refrigerant to the connected flat tubes 20. The header 40 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 end of the flat tubes 20 and a header 40 that connects the other end of the flat tubes 20. The interior of the header 40 may be configured such 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] (Flat surface portion 32) Fig. 3 is a perspective view showing the heat exchanger 8 according to the first embodiment. As shown in Fig. 3, the fin 30 has a flat surface portion 32 and a plurality of louvers 33. The flat surface portion 32 is a plate-shaped member that extends at an angle along the longitudinal axis direction of the flat tubes 20. A rectangular opening 32a extending along the longitudinal axis direction of the flat tubes 20 is formed in part of the central portion of the flat surface portion 32, excluding both end portions adjacent to the flat tubes 20.

[0021] (Louvers 33) FIG. 4 is a schematic diagram showing the fin 30 according to the first embodiment. As shown in FIG. 4, the louvers 33 open and close the openings 32a formed in the planar 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 planar portion 32 and are inclined in a side view. In a side view, one end of the louvers 33 is higher than the planar portion 32 and the other end is lower than the planar portion 32. In the first embodiment, there is no portion connected to the planar portion 32 that serves as an inclined portion of the louvers 33. This portion serves as a louver-removed space 34. If there were no louver-removed space 34, there would be a portion connected to the planar portion 32 that serves as the louvers 33. The length of this louver 33 is half that of the other louvers 33 to align it with the height of the other louvers 33 (see the dashed line in FIG. 4). The plurality of louvers 33 that open and close one opening 32a are referred to as a louver group 33a.

[0022] (Louver-removed space 34) A louver-removed space 34 is formed in the flat portion 32. As shown in FIG. 3 , the louver-removed space 34 is formed by cutting out a portion of the flat portion 32 that is connected to the ends of the multiple louvers 33. While FIG. 3 illustrates an example in which the louver-removed space 34 is offset in the minor axis direction of the flat tube 20 with respect to the opening 32a formed in the flat portion 32, the louver-removed space 34 may not be offset, or the offset may vary. As shown in FIG. 4 , the louver-removed space 34 is formed at the end of the opening 32a formed in the flat portion 32 in the major axis direction of the flat tube 20. In other words, the louver-removed space 34 can be said to be a space in which a portion where the louvers 33 are provided (see dashed line in FIG. 4 ), which would normally be half the length, is cut out.

[0023] FIG. 5 is a top view showing the heat exchanger 8 according to the first embodiment. Next, the position of the louver-removed spaces 34 in the bent fins 30 adjacent in the vertical direction will be described. In FIG. 5, the fin 30 on the left side is the upper fin 30, the fin 30 in the center is 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 louver-removed spaces 34 are offset in the vertical direction. While FIG. 5 illustrates an example in which the lengths of the flat tubes 20 in the minor axis direction in the louver-removed spaces 34 are the same, they may be different. Furthermore, the offset of the louver-removed spaces 34 may be periodic or non-periodic. If the louver-removed spaces 34 are periodic, the manufacturing process is simplified.

[0024] Fig. 6 is a side view showing the heat exchanger 8 according to the first embodiment. When the louver-removed spaces 34 are misaligned in the height direction, as shown in Fig. 6, water adhering to the fins 30 falls downward without remaining in one place. This makes it difficult for droplets 50 to remain on the fins 30. Note that drainage is further improved when the louver-removed spaces 34 reach the bottom of the inclined portions of the fins 30, which are the portions where the fins 30 and the flat tubes 20 are joined.

[0025] (Modification) Fig. 7 is a top view showing a heat exchanger 8 according to a modification of the first embodiment. In Fig. 7, the longitudinal length of the fins 30 is considerably longer than the longitudinal length of the flat tubes 20, and the fins 30 protrude outward from both ends of the flat tubes 20. As shown in Fig. 7, one of the two louver-removed spaces 34 is formed in the fins 30 protruding outward from both ends of the flat tubes 20. In this way, the louver-removed space 34 does not have to face the flat tubes 20.

[0026] According to the first embodiment, a louver removal space 34 is formed by cutting out a position in the flat portion 32 that is connected to the end of the louver 33. Therefore, water that accumulates at the end of the louver 33 is discharged through the louver removal space 34. Therefore, it is possible to prevent water from accumulating at the end of the louver 33.

[0027] Furthermore, the flat tubes 20 extend with the height direction as the longitudinal direction, and multiple fins 30 are arranged in the height direction, with the louver removal spaces 34 of the fins 30 arranged in the height direction being offset from one another in the height direction. As a result, droplets adhering to the fins 30 fall through the louver removal spaces 34 located above, hit the flat surface portions 32 located below, flow along the inclined flat surface portions 32, and then fall through the louver removal spaces 34. In other words, droplets are less likely to remain on the fins 30.

[0028] Second Embodiment Fig. 8 is a perspective view showing a heat exchanger 8 according to a second embodiment. In this second embodiment, the dimensions of the louver-removed space 34 are specified. In this second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and their description is omitted, and the description will focus on the differences from the first embodiment.

[0029] As shown in Figure 8, the width T of the flat tubes 20 in the longitudinal direction in the louver-removed space 34 is 1 / 3 to 2 / 3 of the width W of the louvers 33. This allows for improved drainage without impairing heat exchange capacity. In other words, it is possible to achieve both heat exchange capacity and drainage. Furthermore, it is more preferable that the width T of the flat tubes 20 in the longitudinal direction in the louver-removed space 34 is 1 / 2 of the width W of the louvers 33. This simplifies the manufacturing process because it is only necessary to remove the portion where the louvers 33 are to be installed, which would otherwise be half the length.

[0030] Embodiment 3. Figure 9 is a top view showing a heat exchanger 8 according to embodiment 3. Embodiment 3 differs from embodiments 1 and 2 in that slits 35 are formed in the fins 30. In embodiment 3, parts common to embodiments 1 and 2 are assigned the same reference numerals and description thereof will be omitted, and the following description will focus on the differences from embodiments 1 and 2.

[0031] As shown in Figure 9, the fin 30 has slits 35 formed therein to drain water accumulated in the flat portion 32. The slits 35 are not adjacent to the louvers 33. Figure 9 illustrates a case in which multiple slits 35 are formed and, like the louver-removed spaces 34, are offset from one another in the height direction. Note that a single slit 35 may be formed, or the slits may be aligned in the height direction. In this way, in the third embodiment, the slits 35 are formed in addition to the louver-removed spaces 34, thereby further improving drainage performance.

[0032] REFERENCE SIGNS LIST 1 Air conditioning device, 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 channel, 32 Planar section, 32a Opening, 33 Louver, 33a Louver group, 34 Louver removal space, 35 Slit, 40 Header, 50 Droplets.

Claims

1. A heat exchanger comprising: a plurality of flat tubes through which a refrigerant flows; and a plurality of fins disposed between the flat tubes to transfer heat from the refrigerant flowing through the flat tubes, wherein the fins have flat portions with openings formed in some parts thereof, and louvers that open and close the openings in the flat portions, and wherein the flat portions are formed with louver-removed spaces cut out at positions connected to the ends of the louvers.

2. A heat exchanger according to claim 1, wherein the louver-removed space is offset from the end of the louver in the minor axis direction of the flat tubes.

3. The heat exchanger according to claim 2, wherein the flat tubes extend with the height direction as the longitudinal direction, the fins are arranged in a plurality in the height direction, and the louver-removed spaces of the fins arranged in the height direction are offset from each other in the height direction.

4. A heat exchanger according to any one of claims 1 to 3, wherein the width of the flat tubes in the longitudinal direction in the louver-removed space is 1 / 3 to 2 / 3 of the width of the louvers.

5. A heat exchanger according to any one of claims 1 to 4, wherein the fins are formed with slits for discharging water that accumulates in the flat surface portions.

6. The heat exchanger according to claim 5, wherein the flat tubes extend with their longitudinal direction being in the height direction, the fins are arranged in multiple rows in the height direction, and the slits of the fins arranged in the height direction are offset from one another in the height direction.

7. An air conditioner equipped with a heat exchanger according to any one of claims 1 to 6.

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