Heat exchanger, air conditioner equipped with heat exchanger, and method for manufacturing heat exchanger

Abstract

This heat exchanger comprises: a plurality of flat heat-transfer tubes that each have a flow passage through which a refrigerant flows formed therein, that are disposed with spaces therebetween in the right-left direction perpendicular to both the up-down direction, which is the direction of extension of the tubes, and the front-rear direction, which is the direction of airflow, and that are aligned in two rows in the front-rear direction; and corrugated fins that are disposed between two rows of flat heat-transfer tubes adjacent in the right-left direction, that are joined to the two right-left rows of flat heat-transfer tubes as traversing the up-down direction, and that have a projecting portion that projects more forward than the front end portions of the flat heat-transfer tubes in the front row. The position of the front end portions of the flat heat-transfer tubes in the front row is not uniform in the up-down direction, and the length of each projecting portion in the front-rear direction is not uniform in the up-down direction.

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger including flat heat transfer tubes and corrugated fins, an air conditioner equipped with the heat exchanger, and a method for manufacturing the heat exchanger. [Background technology]

[0002] Conventionally, corrugated fin tube type heat exchangers equipped with flat heat transfer tubes and corrugated fins have been widely used.

[0003] In air conditioners equipped with this corrugated fin tube heat exchanger in their outdoor units, the heat exchanger functions as an evaporator during heating operation. However, when the outdoor temperature drops below freezing, moisture in the air forms frost on the evaporator, causing frost formation. When frost forms on the heat exchanger, the heat transfer area of the corrugated fins decreases and the ventilation passages become narrower, resulting in a decrease in heating capacity. To address this issue, a heat exchanger has been proposed in which the front ends of the corrugated fins protrude further forward than the front ends of the flat heat transfer tubes, i.e., the windward end of the corrugated fins protrudes further upwind than the windward end of the flat heat transfer tubes, thereby suppressing frost formation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6165360 Summary of the Invention [Problem to be solved by the invention]

[0005] The heat exchanger described in Patent Document 1 improves frost resistance by having the front ends of the corrugated fins protrude further forward than the front ends of the flat heat transfer tubes. However, during defrosting operation, heat from the high-temperature, high-pressure gas refrigerant is difficult to transfer to the protruding parts of the corrugated fins that protrude further forward than the front ends of the flat heat transfer tubes, making defrosting difficult once frost forms on the protruding parts of the corrugated fins. In addition, because the protruding parts of the corrugated fins protrude further forward than the front ends of the flat heat transfer tubes, there is a problem in that the strength of the protruding parts is reduced.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a heat exchanger that improves defrosting performance without reducing frost resistance and that improves the strength of corrugated fins, an air conditioner equipped with a heat exchanger, and a method for manufacturing a heat exchanger. [Means for solving the problem]

[0007] The heat exchanger of the present disclosure has a flow path formed therein through which a refrigerant flows, and is equipped with flat heat transfer tubes arranged in a plurality of rows spaced apart from each other in a left-right direction perpendicular to the up-down direction and the front-to-back direction, which is the ventilation direction, in the vertical direction, and arranged side by side in two rows in the front-to-back direction, and corrugated fins arranged between the two rows of flat heat transfer tubes adjacent to each other in the left-to-right direction, joined to the two rows of flat heat transfer tubes in the left and right direction in the vertical direction, and having protruding portions that protrude further forward than the front ends of the flat heat transfer tubes in the front row, wherein the position of the front ends of the flat heat transfer tubes in the front row is not uniform in the vertical direction, and the length of the protruding portions in the front-to-back direction is not uniform in the vertical direction.

[0008] An air conditioner according to the present disclosure is equipped with the above-described heat exchanger.

[0009] a step of arranging a plurality of the flat heat transfer tubes in the rear row on a reference plane along the left-right direction; a step of arranging spacers above the flat heat transfer tubes in the rear row to ensure a gap between the flat heat transfer tubes in the rear row and the flat heat transfer tubes in the front row; a step of arranging a plurality of the flat heat transfer tubes in the front row on the spacers along the left-right direction; a step of arranging the corrugated fins between each of the two rows of flat heat transfer tubes adjacent to each other in the left-right direction; a step of compressing the corrugated fins arranged between the two rows of flat heat transfer tubes adjacent to each other in the left-right direction; a step of attaching headers to the ends of the flat heat transfer tubes; and a step of joining the headers to the flat heat transfer tubes, and the corrugated fins to the flat heat transfer tubes by brazing. [Effects of the Invention]

[0010] In the heat exchanger according to the present disclosure, the corrugated fins have protruding portions that protrude forward beyond the front ends of the flat heat transfer tubes in the front row. The length of the protruding portions in the front-to-rear direction is not uniform in the up-to-down direction. That is, the protruding portions have some long and some short portions relative to the longitudinal direction of the flat heat transfer tubes. This improves defrosting performance without reducing frost resistance, and also improves the strength of the corrugated fins. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view schematically illustrating a configuration of a heat exchanger according to a first embodiment. [Figure 2] 1 is a perspective view schematically showing the arrangement relationship between flat heat transfer tubes and corrugated fins in a heat exchanger according to a first embodiment. FIG. [Figure 3] 1 is a diagram showing the configuration of an air conditioner equipped with a heat exchanger according to a first embodiment. [Figure 4] 1 is a schematic plan view of a heat exchanger according to a first embodiment. [Figure 5]3 is a flowchart showing a manufacturing process of the heat exchanger according to the first embodiment. [Figure 6] FIG. 3 is a perspective view schematically showing the arrangement of flat heat transfer tubes and corrugated fins in the manufacturing process of the heat exchanger according to the first embodiment. [Figure 7] 7 is a schematic plan view of the flat heat transfer tubes and the corrugated fins shown in FIG. 6, viewed from a first direction. FIG. [Figure 8] FIG. 4 is a schematic plan view of a case where angled spacers are used in the method for manufacturing the heat exchanger according to the first embodiment. [Figure 9] FIG. 10 is a perspective view schematically showing the arrangement relationship between flat heat transfer tubes and corrugated fins in a heat exchanger according to a second embodiment. [Figure 10] FIG. 10 is a schematic plan view of a heat exchanger according to a second embodiment. [Figure 11] FIG. 10 is a schematic plan view showing an example of a method for manufacturing a heat exchanger according to a second embodiment. [Figure 12] FIG. 10 is a schematic plan view of a case where angled spacers are used in a manufacturing method of a heat exchanger according to a second embodiment. [Figure 13] FIG. 10 is a perspective view schematically showing the arrangement relationship between flat heat transfer tubes and corrugated fins in a heat exchanger according to a third embodiment. [Figure 14] FIG. 10 is a schematic plan view of a heat exchanger according to a third embodiment. [Figure 15] FIG. 10 is a perspective view schematically showing the arrangement relationship between flat heat transfer tubes and corrugated fins in a heat exchanger according to a fourth embodiment. [Figure 16] FIG. 10 is a schematic plan view of a heat exchanger according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below. Also, the size relationships of the components in the drawings may differ from those in reality.

[0013] Embodiment 1 Fig. 1 is a perspective view schematically showing the configuration of a heat exchanger 1 according to the first embodiment. Fig. 2 is a perspective view schematically showing the arrangement relationship between flat heat transfer tubes 2 and corrugated fins 3 in the heat exchanger 1 according to the first embodiment. Note that arrows AF in Fig. 1 indicate the ventilation direction of air supplied to the heat exchanger 1, arrow X indicates a first direction, arrow Y indicates a second direction, and arrow Z indicates a third direction, and this also applies to drawings described later.

[0014] 1, the heat exchanger 1 according to the first embodiment is a corrugated fin tube type heat exchanger. The heat exchanger 1 includes a plurality of flat heat transfer tubes 2, a plurality of corrugated fins 3, row headers 4, a first header 51, and a second header 52.

[0015] As shown in FIG. 2, the flat heat transfer tube 2 has a flat cross section, multiple refrigerant flow paths formed therein, and has a flat portion 2A and a curved portion 2B. The flat heat transfer tube 2 is preferably made of a metal with good heat conductivity, such as aluminum. As shown in FIG. 1, the flat heat transfer tubes 2 are arranged at intervals in a first direction (hereinafter also referred to as a left-right direction) perpendicular to the second direction and a third direction (hereinafter also referred to as a front-rear direction), which is the direction of ventilation, with the second direction (hereinafter also referred to as a vertical direction) as the tube extension direction. The flat heat transfer tubes 2 do not necessarily need to be arranged at intervals in a direction strictly perpendicular to the second and third directions, but may be arranged at intervals in a direction approximately perpendicular to the second and third directions. The flat heat transfer tubes 2 are also arranged in two rows in a third direction perpendicular to the first and second directions, i.e., the ventilation direction. Here, the flat heat transfer tubes 2 do not have to be arranged in two rows in a direction strictly perpendicular to the first direction and the second direction, but may be arranged in two rows in a direction approximately perpendicular to the first direction and the second direction. In the following, the flat heat transfer tubes 2 arranged in the first row, which is the front row on the upwind side, will be referred to as the front flat heat transfer tubes 21, and the flat heat transfer tubes 2 arranged in the second row, which is the rear row on the downwind side, will be referred to as the rear flat heat transfer tubes 22.

[0016] As shown in Fig. 2, the corrugated fin 3 is formed by repeatedly folding a plate-like member in a mountain direction and a valley direction, and has a flat portion 3A and a curved portion 3B. The curved portion 3B of the corrugated fin 3 is joined to the flat portion 2A of the flat heat transfer tube 2 by brazing. The corrugated fin 3 is disposed between the front flat heat transfer tube 21 and the rear flat heat transfer tube 22 that are adjacent in the left-right direction, and is joined to the left-right front flat heat transfer tube 21 and the rear flat heat transfer tube 22 in the up-down direction, thereby transferring heat to the front flat heat transfer tube 21 and the rear flat heat transfer tube 22. The corrugated fin 3 is preferably made of a metal with good heat conductivity, such as aluminum.

[0017] As shown in FIG. 1 , the first header 51 is a header into which the lower ends of the front flat heat transfer tubes 21 are inserted. A refrigerant pipe 61 is connected to one end of the first header 51. The first header 51 distributes the refrigerant flowing in from the refrigerant pipe 61 to the front flat heat transfer tubes 21. The first header 51 also combines the refrigerant flowing out from the front flat heat transfer tubes 21 and causes it to flow out to the refrigerant pipe 61. The second header 52 is a header into which the lower ends of the rear flat heat transfer tubes 22 are inserted. The refrigerant pipe 62 is connected to one end of the second header 52. The second header 52 distributes the refrigerant flowing in from the refrigerant pipe 62 to the rear flat heat transfer tubes 22. The second header 52 also combines the refrigerant flowing out from the rear flat heat transfer tubes 22 and causes it to flow out to the refrigerant pipe 62. The row-to-row header 4 is a header into which the upper ends of the front flat heat transfer tubes 21 and the rear flat heat transfer tubes 22 are inserted. The row transfer header 4 bridges the refrigerant between the front flat heat transfer tubes 21 and the rear flat heat transfer tubes 22, and merges the refrigerant flowing out from one of the front flat heat transfer tubes 21 and the rear flat heat transfer tubes 22, and distributes the refrigerant to the other tube before flowing out.

[0018] Fig. 3 is a diagram showing the configuration of an air conditioner equipped with a heat exchanger 1 according to the first embodiment. As shown in Fig. 3, the air conditioner includes an outdoor unit 200 and an indoor unit 100, which are connected by refrigerant piping 300 to form a refrigerant circuit. Note that the air conditioner according to the first embodiment includes one outdoor unit 200 and one indoor unit 100, but is not limited to this, and there may be two or more outdoor units 200 and two or more indoor units 100.

[0019] The outdoor unit 200 has a compressor 201, a flow path switching device 202, an outdoor heat exchanger 203, and an outdoor fan 204. Here, the heat exchanger 1 according to the first embodiment is used as the outdoor heat exchanger 203. The heat exchanger 1 is arranged so that the front flat heat transfer tube 21 is on the upwind side and the rear flat heat transfer tube 22 is on the downwind side.

[0020] The compressor 201 draws in a low-temperature, low-pressure refrigerant, compresses the drawn refrigerant, and discharges a high-temperature, high-pressure refrigerant. The compressor 201 is, for example, an inverter compressor whose capacity, which is the amount of refrigerant discharged per unit time, is controlled by changing its operating frequency. The flow path switching device 202 is, for example, a four-way valve, which switches between cooling operation and heating operation by switching the direction of the refrigerant flow. Note that the flow path switching device 202 may be a combination of a two-way valve and a three-way valve instead of a four-way valve.

[0021] The outdoor heat exchanger 203 functions as an evaporator or a condenser, and exchanges heat between the air and the refrigerant to evaporate and gasify the refrigerant or condense and liquefy the refrigerant. The outdoor heat exchanger 203 functions as an evaporator during heating operation and as a condenser during cooling operation. The outdoor fan 204 is provided near the outdoor heat exchanger 203 and supplies outdoor air to the outdoor heat exchanger 203.

[0022] The indoor unit 100 has an indoor heat exchanger 101, an indoor fan 102, and a throttling device 103. The indoor heat exchanger 101 functions as an evaporator or a condenser, exchanging heat between air and a refrigerant to evaporate and gasify the refrigerant or condense and liquefy the refrigerant. The indoor heat exchanger 101 functions as a condenser during heating operation and as an evaporator during cooling operation. The indoor fan 102 is provided near the indoor heat exchanger 101 and supplies indoor air to the indoor heat exchanger 101. The throttling device 103 reduces the pressure of the refrigerant to expand it. The throttling device 103 is, for example, an electronic expansion valve whose throttle opening can be adjusted. By adjusting the opening, the pressure of the refrigerant flowing into the indoor heat exchanger 101 during cooling operation and the pressure of the refrigerant flowing into the outdoor heat exchanger 203 during heating operation are controlled.

[0023] Next, operation modes of the air conditioner according to the first embodiment will be described. First, heating operation will be described. In heating operation, as shown by the solid line in FIG. 3 , the flow path switching device 202 is switched so that the discharge side of the compressor 201 is connected to the indoor heat exchanger 101. The high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 201 passes through the flow path switching device 202 and flows into the indoor heat exchanger 101. The gas refrigerant that flows into the indoor heat exchanger 101 condenses and liquefies by exchanging heat with air in the space to be air-conditioned, supplied from the indoor fan 102, in the indoor heat exchanger 101. The liquefied refrigerant is decompressed as it passes through the expansion device 103, and becomes a two-phase gas-liquid state. The two-phase gas-liquid refrigerant flows into the outdoor heat exchanger 203, where it evaporates and gasifies by exchanging heat with outdoor air supplied from the outdoor fan 204. The gasified refrigerant passes through the flow path switching device 202 and is sucked into the compressor 201 again.

[0024] Next, cooling operation will be described. In cooling operation, as shown by the dashed line in FIG. 3 , the flow path switching device 202 is switched so that the discharge side of the compressor 201 is connected to the outdoor heat exchanger 203. The high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 201 passes through the flow path switching device 202 and flows into the outdoor heat exchanger 203. The gas refrigerant that flows into the outdoor heat exchanger 203 condenses and liquefies by exchanging heat with outdoor air supplied by the outdoor fan 204 in the outdoor heat exchanger 203. The liquefied refrigerant is decompressed as it passes through the expansion device 103 and becomes a two-phase gas-liquid state. The two-phase gas-liquid refrigerant flows into the indoor heat exchanger 101, where it evaporates and gasifies by exchanging heat with air in the space to be air-conditioned supplied by the indoor fan 102. The gasified refrigerant passes through the flow path switching device 202 and is drawn into the compressor 201 again.

[0025] Here, for example, in the heat exchanger 1, if the first header 51 is a liquid header through which a liquefied refrigerant flows and the second header 52 is a gas header through which a gasified refrigerant flows, during cooling operation, the refrigerant that flows into the second header 52 passes through the rear flat heat transfer tubes 22, the row-to-row header 4, and the front flat heat transfer tubes 21, and flows out of the first header 51. In the front flat heat transfer tubes 21, heat exchange occurs between the refrigerant that has undergone heat exchange in the rear flat heat transfer tubes 22 and air that has not undergone heat exchange. In addition, in the rear flat heat transfer tubes 22, heat exchange occurs between the refrigerant that has not undergone heat exchange and the air that has undergone heat exchange in the front flat heat transfer tubes 21. Therefore, the heat exchanger 1 according to the first embodiment can maintain a temperature difference that allows effective heat exchange between the refrigerant and the air, thereby improving heat transfer performance.

[0026] Furthermore, when the heat exchanger 1 functions as an evaporator, the surfaces of the flat heat transfer tubes 2 and the corrugated fins 3 are at a temperature lower than the air passing through the heat exchanger 1. Therefore, moisture in the air condenses on the surface of the evaporator, forming condensed water. When heating operation is performed in low outdoor air temperatures below freezing, moisture in the air can cause frost to form on the evaporator. For this reason, the air conditioner performs defrosting operation when the outdoor air temperature reaches a constant temperature. Here, defrosting operation refers to an operation in which hot gas (high-temperature, high-pressure gas refrigerant) is supplied from the compressor 201 to the heat exchanger 1 to prevent frost from forming on the heat exchanger 1 functioning as an evaporator.

[0027] Fig. 4 is a schematic plan view of the heat exchanger 1 according to the first embodiment. As shown in Fig. 4, the corrugated fin 3 has protruding portions 31 that protrude forward of the front ends of the front flat heat transfer tubes 21, i.e., protrude upwind of the windward ends of the front flat heat transfer tubes 21. Here, L1 is the length in the airflow direction of the protruding portions 31 at the upper part of the corrugated fin 3. L3 is the length in the airflow direction of the protruding portions 31 at the lower part of the corrugated fin 3. L2 is the length in the airflow direction of the protruding portions 31 at the center between the upper and lower parts of the corrugated fin 3.

[0028] In the heat exchanger 1 according to the first embodiment, the length L1 of the protruding portions 31 at the upper portion of the corrugated fin 3 and the length L3 of the protruding portions 31 at the lower portion of the corrugated fin 3 are smaller than the length L2 of the protruding portions 31 at the center of the corrugated fin 3. This is because the length of the corrugated fin 3 in the front-rear direction and the position of its front end are uniform in the up-down direction, whereas the front flat heat transfer tubes 21 are bent downwind (particularly the most at the center), and the positions of their front ends are not uniform in the up-down direction. By satisfying L2 > L1 and L2 > L3, heat from the high-temperature, high-pressure gas refrigerant is more easily transferred from the upper and lower portions of the flat heat transfer tubes 2 to the protruding portions 31 of the corrugated fin 3 during defrosting operation than in the conventional case, thereby improving the defrosting capacity of the corrugated fin 3. Furthermore, the strength of the corrugated fin 3 can be improved in the areas where the protruding portions 31 are short. Furthermore, the protruding portion 31 at the center of the corrugated fin 3 can protrude a sufficient amount, which does not reduce the frost resistance of the corrugated fin 3. In this way, in the first embodiment, the defrosting capacity of the corrugated fin 3 can be improved without reducing the frost resistance of the corrugated fin 3.

[0029] Fig. 5 is a flowchart showing the manufacturing process of the heat exchanger 1 according to the first embodiment. Fig. 6 is a perspective view schematically showing the arrangement of the flat heat transfer tubes 2 and the corrugated fins 3 in the manufacturing process of the heat exchanger 1 according to the first embodiment. Fig. 7 is a schematic plan view of the flat heat transfer tubes 2 and the corrugated fins 3 shown in Fig. 6, viewed from a first direction. Fig. 8 is a schematic plan view when an angled spacer 600 is used in the manufacturing method of the heat exchanger 1 according to the first embodiment.

[0030] The heat exchanger 1 according to the first embodiment is formed through the manufacturing process shown in FIG. 5. As shown in FIG. 6, first, a predetermined number of rear flat heat transfer tubes 22 are arranged on a reference plane at predetermined intervals along a first direction (S001). Here, the reference plane is a plane parallel to the first direction and the second direction. Next, spacers 500 for maintaining a gap between the rear flat heat transfer tube 22 and the front flat heat transfer tube 21 are arranged on both ends of the rear flat heat transfer tube 22 (S002). Next, a predetermined number of front flat heat transfer tubes 21 are arranged on the spacers 500 at predetermined intervals along the first direction (S003). Next, corrugated fins 3 are arranged between the front flat heat transfer tube 21 and the rear flat heat transfer tube 22 adjacent to each other in the first direction, and the corrugated fins 3 arranged between the adjacent front flat heat transfer tube 21 and the rear flat heat transfer tube 22 are compressed (S004). In this state, the row headers 4, the first header 51, and the second header 52 are attached to the ends of the front flat heat transfer tubes 21 and the rear flat heat transfer tubes 22. Finally, in this assembled state, the headers and the flat heat transfer tubes 2, and the corrugated fins 3 and the flat heat transfer tubes 2 are joined by brazing, thereby forming the heat exchanger 1 (S005).

[0031] At this time, if the upper surface of the spacer 500 is parallel to the reference plane, the front flat heat transfer tube 21 will bend due to its own weight, as shown in Fig. 7. Therefore, the amount of deflection is the length L2 of the protruding portion 31 at the center of the corrugated fin 3. However, the rear flat heat transfer tube 22 is disposed on the reference plane, so no deflection occurs.

[0032] In the manufacturing process of the heat exchanger 1, a spacer 600 having an upper surface angled at an angle θ with respect to the reference plane may be used instead of the spacer 500, as shown in Fig. 8. In this case, by increasing the angle θ of the upper surface of the spacer 600, the deflection of the front flattened heat transfer tube 21 can be increased. In other words, the length L2 of the protruding portion 31 at the center of the corrugated fin 3 can be increased.

[0033] As described above, the heat exchanger 1 according to the first embodiment has a flow path formed therein through which a refrigerant flows, and is provided with flat heat transfer tubes 2 arranged in two rows in the front-to-back direction, with the tube extension direction being the up-to-down direction and the left-to-right direction perpendicular to the up-to-down direction and the front-to-back direction which is the ventilation direction, and the flat heat transfer tubes 2 arranged side by side in two rows in the front-to-back direction, and corrugated fins 3 arranged between the two rows of flat heat transfer tubes 2 adjacent in the left-to-right direction and joined to the two rows of flat heat transfer tubes 2 in the left and right direction in the up-to-down direction, and having protruding portions 31 that protrude further forward than the front ends of the flat heat transfer tubes 2 in the front row, wherein the position of the front ends of the flat heat transfer tubes 2 in the front row is not uniform in the up-to-down direction, and the length of the protruding portions 31 in the front-to-back direction is not uniform in the up-to-down direction.

[0034] In the heat exchanger 1 according to the first embodiment, the corrugated fins 3 have protruding portions 31 that protrude forward beyond the front ends of the flat heat transfer tubes 2 in the front row. The length of the protruding portions 31 in the front-to-rear direction is not uniform in the up-down direction. That is, the protruding portions 31 have some long and some short lengths relative to the longitudinal direction of the flat heat transfer tubes 2. This allows heat from the high-temperature, high-pressure gas refrigerant to be more easily transferred from the upper and lower parts of the flat heat transfer tubes 2 to the protruding portions 31 of the corrugated fins 3 during defrosting operation in the short protruding portions 31. This improves the defrosting capacity of the corrugated fins 3 and the strength of the corrugated fins 3. Furthermore, the protruding length can be secured in the long protruding portions 31, preventing a decrease in the frost resistance of the corrugated fins 3. As a result, the defrosting performance can be improved without a decrease in the frost resistance, and the strength of the corrugated fins 3 can be improved. Furthermore, the positions of the front ends of the flat heat transfer tubes 2 in the front row are not uniform in the vertical direction, but this is because the flat heat transfer tubes 2 in the front row are warped during the manufacturing process of the heat exchanger 1. By utilizing this warping of the flat heat transfer tubes 2 to make the front-to-rear length of the protruding portions 31 not uniform in the vertical direction, the heat exchanger 1 can be manufactured more easily and at a lower cost than when the warping of the flat heat transfer tubes 2 is not utilized, that is, when the positions of the front ends of the flat heat transfer tubes 2 in the front row are uniform in the vertical direction and the length of the corrugated fins 3 is changed in the vertical direction to make the front-to-rear length of the protruding portions 31 not uniform in the vertical direction.

[0035] The air conditioner according to the first embodiment is equipped with the heat exchanger 1 described above.

[0036] According to the air conditioner of the first embodiment, the same effects as those of the heat exchanger 1 described above can be obtained.

[0037] Moreover, the manufacturing method of the heat exchanger 1 according to Embodiment 1 is the above-described manufacturing method of the heat exchanger 1, and includes a step of arranging a plurality of flat heat transfer tubes 2 in the rear row on a reference plane along the left-right direction, a step of arranging a spacer 500 on the upper side of the flat heat transfer tubes 2 in the rear row to secure a gap between the flat heat transfer tubes 2 in the rear row and the flat heat transfer tubes 2 in the front row, a step of arranging a plurality of flat heat transfer tubes 2 in the front row on the spacer 500 along the left-right direction, a step of arranging corrugated fins 3 between two adjacent rows of flat heat transfer tubes 2 in the left-right direction, a step of compressing the corrugated fins 3 arranged between two adjacent rows of flat heat transfer tubes 2 in the left-right direction, a step of attaching headers to the ends of the flat heat transfer tubes 2, and a step of joining the headers and the flat heat transfer tubes 2, and the corrugated fins 3 and the flat heat transfer tubes 2 by brazing.

[0038] According to the manufacturing method of the heat exchanger 1 according to Embodiment 1, the same effects as those of the above-described heat exchanger 1 can be obtained.

[0039] Moreover, the manufacturing method of the heat exchanger 1 according to Embodiment 1 is a manufacturing method that uses a spacer 600 angled on the upper surface with respect to the reference plane.

[0040] According to the manufacturing method of the heat exchanger 1 according to Embodiment 1, by angling the upper surface of the spacer 600 and increasing the angle, the deflection of the front flat heat transfer tube 21 can be increased. That is, the length L2 of the protruding portion 31 at the center of the corrugated fin 3 can be increased.

[0041] Moreover, in the heat exchanger 1 according to Embodiment 1, when the length in the ventilation direction of the protruding portion 31 at the upper part of the corrugated fin 3 is L1, the length in the ventilation direction of the protruding portion 31 at the center of the corrugated fin 3 is L2, and the length in the ventilation direction of the protruding portion 31 at the lower part of the corrugated fin 3 is L3, the relationship L1 < L2 and L3 < L2 is satisfied.

[0042] In the heat exchanger 1 according to the first embodiment, by satisfying L2 > L1 and L2 > L3, heat from the high-temperature, high-pressure gas refrigerant is more easily transferred from the upper and lower parts of the flat heat transfer tubes 2 to the protruding portions 31 of the corrugated fins 3 during defrosting operation than in the past, thereby improving the defrosting capacity of the corrugated fins 3. Furthermore, the strength of the corrugated fins 3 can be improved where the protruding portions 31 are short. Furthermore, the protruding amount can be secured where the protruding portions 31 are long, so the frost resistance of the corrugated fins 3 is not reduced. In this way, in the first embodiment, the defrosting capacity of the corrugated fins 3 can be improved without reducing the frost resistance of the corrugated fins 3.

[0043] Embodiment 2 The second embodiment will be described below, but explanations of parts that overlap with those of the first embodiment will be omitted, and parts that are the same as or equivalent to those of the first embodiment will be given the same reference numerals.

[0044] The difference between the heat exchanger 1 according to the first embodiment and the heat exchanger 1 according to the second embodiment is the bending direction of the flat heat transfer tubes 2. In the first embodiment, the flat heat transfer tubes 2 are bent toward the downwind side, whereas in the second embodiment, the flat heat transfer tubes 2 are bent toward the upwind side.

[0045] Fig. 9 is a perspective view schematically showing the arrangement relationship between the flat heat transfer tubes 2 and the corrugated fins 3 in the heat exchanger 1 according to the second embodiment. Fig. 10 is a schematic plan view of the heat exchanger 1 according to the second embodiment.

[0046] As shown in FIGS. 9 and 10, in the heat exchanger 1 according to the second embodiment, the length L1 of the protruding portion 31 at the upper part of the corrugated fin 3 and the length L3 of the protruding portion 31 at the lower part of the corrugated fin 3 are larger than the length L2 of the protruding portion 31 at the central part of the corrugated fin 3. Thus, by setting L2 < L1 and L2 < L3, it is possible to suppress the corrugated fin 3 from falling during the manufacture or transportation of the heat exchanger 1. Also, at the location where the protruding portion 31 is short, the strength of the corrugated fin 3 can be improved. Further, compared with the prior art, during the defrosting operation, the heat of the high-temperature and high-pressure gas refrigerant is more likely to be transmitted from the upper and lower parts of the flat heat transfer tube 2 to the protruding portion 31 of the corrugated fin 3, so that the defrosting ability of the corrugated fin 3 can be improved. Also, at the location where the protruding portion 31 is long, the protruding amount can be ensured, so that the frosting resistance of the corrugated fin 3 is not reduced. Thus, in the second embodiment, the defrosting ability of the corrugated fin 3 can be improved without reducing the frosting resistance of the corrugated fin 3, and further, the strength of the corrugated fin 3 can be improved.

[0047] FIG. 11 is a schematic plan view showing an example of a manufacturing method of the heat exchanger 1 according to the second embodiment. FIG. 12 is a schematic plan view in the case of using the angled spacer 800 in the manufacturing method of the heat exchanger 1 according to the second embodiment.

[0048] Next, a manufacturing method of the heat exchanger 1 according to the second embodiment will be described with reference to FIGS. 5 and 11. First, a predetermined number of rear flat heat transfer tubes 22 are arranged on a reference plane at predetermined intervals along the first direction (S001). Here, the reference plane is a plane parallel to the first direction and the second direction. Next, as shown in FIG. 11, spacers 500 for maintaining a gap between the rear flat heat transfer tube 22 and the front flat heat transfer tube 21 are arranged on both ends of the rear flat heat transfer tube 22. Furthermore, a spacer 700 for maintaining a gap between the rear flat heat transfer tube 22 and the front flat heat transfer tube 21 is arranged on the center of the rear flat heat transfer tube 22 (S002). In this case, when the length of the spacer 500 in the third direction is L500 and the length of the spacer 700 in the third direction is L700, the relationship L700 > L500 holds. Note that the greater the difference between L700 and L500, the smaller the length L2 of the protruding portion 31 at the center of the corrugated fin 3. Next, a predetermined number of front flat heat transfer tubes 21 are arranged on the spacers 500, 700 at predetermined intervals along the first direction (S003). Next, two corrugated fins 3 are arranged between each of the front flat heat transfer tubes 21 and rear flat heat transfer tubes 22 adjacent to each other in the first direction, with the spacer 700 sandwiched between them, and the corrugated fins 3 arranged between the adjacent front flat heat transfer tubes 21 and rear flat heat transfer tubes 22 are compressed (S004). In this state, the row-to-row headers 4, the first header 51, and the second header 52 are attached to the ends of the front flat heat transfer tubes 21 and rear flat heat transfer tubes 22. Finally, in this assembled state, the headers and the flat heat transfer tubes 2, and the corrugated fins 3 and the flat heat transfer tubes 2 are joined by brazing, respectively, to form the heat exchanger 1 (S005).

[0049] Note that, as shown in FIG. 12, instead of using the spacers 500 and 700, a spacer 800 with an angle θ on the upper surface with respect to the reference plane may be used. At this time, by increasing the angle θ of the upper surface of the spacer 800, the deflection of the front flat heat transfer tube 21 can be increased. That is, the length L2 of the protruding portion 31 at the center of the corrugated fin 3 can be decreased. In the case of such a manufacturing method, since the spacer 700 is not disposed above the center of the rear flat heat transfer tube 22, the corrugated fin 3 disposed between the front flat heat transfer tube 21 and the rear flat heat transfer tube 22 adjacent to each other in the first direction can be made into one.

[0050] As described above, for the heat exchanger 1 according to the second embodiment, when the length in the ventilation direction of the protruding portion 31 at the upper part of the corrugated fin 3 is L1, the length in the ventilation direction of the protruding portion 31 at the center of the corrugated fin 3 is L2, and the length in the ventilation direction of the protruding portion 31 at the lower part of the corrugated fin 3 is L3, the relationship of L1 > L2 and L3 > L2 is satisfied.

[0051] According to the heat exchanger 1 according to the second embodiment, by setting L2 < L1 and L2 < L3, it is possible to suppress the corrugated fin 3 from falling during the manufacture or transportation of the heat exchanger 1. Further, at the location where the protruding portion 31 is short, the strength of the corrugated fin 3 can be improved. Further, compared with the prior art, during the defrosting operation, the heat of the high-temperature and high-pressure gas refrigerant is likely to be transmitted from the upper and lower parts of the flat heat transfer tube 2 to the protruding portion 31 of the corrugated fin 3, so that the defrosting ability of the corrugated fin 3 can be improved. Further, at the location where the protruding portion 31 is long, the protruding amount can be ensured, so that the frosting resistance of the corrugated fin 3 is not decreased. Thus, in the second embodiment, it is possible to improve the defrosting ability of the corrugated fin 3 without decreasing the frosting resistance of the corrugated fin 3, and further, the strength of the corrugated fin 3 can be improved.

[0052] Embodiment 3. Hereinafter, the third embodiment will be described, but explanations of parts that overlap with the first and second embodiments will be omitted, and parts that are the same as or equivalent to the first and second embodiments will be given the same reference numerals.

[0053] Fig. 13 is a perspective view schematically showing the positional relationship between the flat heat transfer tubes 2 and the corrugated fins 3 in a heat exchanger 1 according to a third embodiment. Fig. 14 is a schematic plan view of the heat exchanger 1 according to the third embodiment. As shown in Figs. 13 and 14, in the heat exchanger 1 according to the third embodiment, the length L1 of the protruding portions 31 at the upper part of the corrugated fin 3 is longer than the length L3 of the protruding portions 31 at the lower part of the corrugated fin 3, and the length of the protruding portions 31 gradually decreases from the upper part to the lower part of the corrugated fin 3.

[0054] Because the lower part of the heat exchanger 1 is the last part to receive hot gas during defrosting operation, frost may remain unmelted at the lower part of the heat exchanger 1. However, the length L3 of the lower protruding portions 31 of the corrugated fins 3 is set shorter than the length L1 of the upper protruding portions 31 of the corrugated fins 3. This allows heat from the high-temperature, high-pressure gas refrigerant to be more easily transferred from the lower part of the flat heat transfer tubes 2 to the protruding portions 31 of the corrugated fins 3, thereby improving the defrosting capacity of the corrugated fins 3 and reducing the amount of unmelted frost. Furthermore, because the protruding length can be secured in the longer portions of the upper protruding portions 31 of the corrugated fins 3, the frost resistance of the corrugated fins 3 is not reduced. In this way, in the third embodiment, the defrosting capacity of the corrugated fins 3 can be improved without reducing the frost resistance of the corrugated fins 3.

[0055] As described above, in the heat exchanger 1 of embodiment 3, when the length in the ventilation direction of the protruding portion 31 at the upper part of the corrugated fin 3 is L1 and the length in the ventilation direction of the protruding portion 31 at the lower part of the corrugated fin 3 is L3, the relationship L1>L3 is satisfied, and the length of the protruding portion 31 gradually decreases from the upper part to the lower part of the corrugated fin 3.

[0056] According to the heat exchanger 1 of the third embodiment, heat from the high-temperature, high-pressure gas refrigerant is easily transferred from the lower part of the flat heat transfer tubes 2 to the protruding portions 31 of the corrugated fins 3, thereby improving the defrosting capacity of the corrugated fins 3 and reducing residual frost. Furthermore, since the protruding length can be secured in the long portions of the protruding portions 31, the frost resistance of the corrugated fins 3 is not reduced. Thus, in the third embodiment, the defrosting capacity of the corrugated fins 3 can be improved without reducing the frost resistance of the corrugated fins 3.

[0057] Embodiment 4 Hereinafter, the fourth embodiment will be described, but the description of the same parts as those in the first to third embodiments will be omitted, and the same parts as or corresponding parts to those in the first to third embodiments will be given the same reference numerals.

[0058] Fig. 15 is a perspective view schematically showing the positional relationship between the flat heat transfer tubes 2 and the corrugated fins 3 in the heat exchanger 1 according to the fourth embodiment. Fig. 16 is a schematic plan view of the heat exchanger 1 according to the fourth embodiment. As shown in Figs. 15 and 16, in the heat exchanger 1 according to the fourth embodiment, the length L1 of the protruding portions 31 at the upper part of the corrugated fin 3 is smaller than the length L3 of the protruding portions 31 at the lower part of the corrugated fin 3, and the length of the protruding portions 31 gradually increases from the upper part to the lower part of the corrugated fin 3.

[0059] The upper part of the heat exchanger 1 has a large aerodynamic force and a high heat exchange capacity. Therefore, when the length L1 of the protruding portion 31 at the upper part of the corrugated fin 3 arranged at the upper part of the heat exchanger 1 is smaller than the length L3 of the protruding portion 31 at the lower part of the corrugated fin 3, the ventilation resistance of the heat exchanger 1 can be reduced. As a result, the energy required to rotate the outdoor fan 204 becomes smaller, and the performance of the air conditioner can be improved. Also, since the protruding amount can be ensured at the location where the protruding portion 31 at the lower part of the corrugated fin 3 is long, the frost resistance of the corrugated fin 3 is not reduced. Thus, in Embodiment 4, the performance of the air conditioner can be improved without reducing the frost resistance of the corrugated fin 3.

[0060] As described above, for the heat exchanger 1 according to Embodiment 4, when the length in the ventilation direction of the protruding portion 31 at the upper part of the corrugated fin 3 is L1 and the length in the ventilation direction of the protruding portion 31 at the lower part of the corrugated fin 3 is L3, the relationship L1 < L3 is satisfied, and the length of the protruding portion 31 gradually increases from the upper part to the lower part of the corrugated fin 3.

[0061] According to the heat exchanger 1 according to Embodiment 4, the ventilation resistance of the heat exchanger 1 can be reduced, the energy required to rotate the outdoor fan 204 becomes smaller, and the performance of the air conditioner can be improved. Also, since the protruding amount can be ensured at the location where the protruding portion 31 is long, the frost resistance of the corrugated fin 3 is not reduced. Thus, in Embodiment 4, the performance of the air conditioner can be improved without reducing the frost resistance of the corrugated fin 3.

Explanation of Reference Numerals

[0062] 1 heat exchanger, 2 flat heat transfer tube, 2A flat portion, 2B curved portion, 3 corrugated fin, 3A flat portion, 3B curved portion, 4 row header, 21 front flat heat transfer tube, 22 rear flat heat transfer tube, 31 protrusion portion, 51 first header, 52 second header, 61 refrigerant piping, 62 refrigerant piping, 100 indoor unit, 101 indoor heat exchanger, 102 indoor fan, 103 throttling device, 200 outdoor unit, 201 compressor, 202 flow path switching device, 203 outdoor heat exchanger, 204 outdoor fan, 300 refrigerant piping, 500 spacer, 600 spacer, 700 spacer, 800 spacer.

Claims

1. a plurality of flat heat transfer tubes, each having a flow path formed therein through which a refrigerant flows, the flat heat transfer tubes being arranged at intervals in a left-right direction perpendicular to the up-down direction and the front-rear direction, which is the direction of ventilation, and arranged in two rows in the front-rear direction; a corrugated fin disposed between two rows of the flat heat transfer tubes adjacent to each other in the left-right direction, joined to the two rows of the flat heat transfer tubes in the left-right direction in the up-down direction, and having a protruding portion protruding forward beyond the front ends of the flat heat transfer tubes in the front row, The positions of the front ends of the flat heat transfer tubes in the front row are not uniform in the vertical direction, The length of the protruding portion in the front-rear direction is not uniform in the up-down direction. heat exchanger.

2. When the length in the front-rear direction of the protruding portion at the upper part of the corrugated fin is L1, the length in the front-rear direction of the protruding portion at the center part of the corrugated fin is L2, and the length in the front-rear direction of the protruding portion at the lower part of the corrugated fin is L3, Satisfy the relationships L1<L2 and L3<L2 The heat exchanger of claim 1 .

3. When the length in the front-rear direction of the protruding portion at the upper part of the corrugated fin is L1, the length in the front-rear direction of the protruding portion at the center part of the corrugated fin is L2, and the length in the front-rear direction of the protruding portion at the lower part of the corrugated fin is L3, Satisfy the relationships L1>L2 and L3>L2 The heat exchanger of claim 1 .

4. When the length of the protruding portion at the upper part of the corrugated fin in the front-rear direction is L1 and the length of the protruding portion at the lower part of the corrugated fin in the front-rear direction is L3, The relationship L1>L3 is satisfied, and The length of the protruding portion gradually decreases from the top to the bottom of the corrugated fin. The heat exchanger of claim 1 .

5. When the length of the protruding portion at the upper part of the corrugated fin in the front-rear direction is L1 and the length of the protruding portion at the lower part of the corrugated fin in the front-rear direction is L3, The relationship L1<L3 is satisfied, and The length of the protruding portion gradually increases from the top to the bottom of the corrugated fin. The heat exchanger of claim 1 .

6. A device equipped with the heat exchanger according to any one of claims 1 to 5. Air conditioner.

7. A method for manufacturing a heat exchanger according to any one of claims 1 to 5, a step of arranging a plurality of the flat heat transfer tubes in the rear row on a reference plane along the left-right direction; a step of arranging a spacer above the flat heat transfer tubes in the rear row to ensure a gap between the flat heat transfer tubes in the rear row and the flat heat transfer tubes in the front row; arranging a plurality of the flat heat transfer tubes in a front row on the spacer along the left-right direction; a step of disposing the corrugated fins between the two rows of the flat heat transfer tubes adjacent to each other in the left-right direction; compressing the corrugated fins disposed between the two rows of flat heat transfer tubes adjacent to each other in the left-right direction; attaching headers to the ends of the flat heat transfer tubes; and joining the header and the flat heat transfer tube, and the corrugated fin and the flat heat transfer tube by brazing. A method for manufacturing a heat exchanger.

8. Use the spacer with its upper surface angled relative to the reference surface A method for manufacturing the heat exchanger according to claim 7.

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