HEAT EXCHANGER

TECHNICAL FIELD

The present disclosure relates to a heat exchanger including a fin provided to a heat transfer tube.

BACKGROUND

There is a heat exchanger in which a heat-transfer-enhancement part is provided in a heat transfer plate that forms a fin provided to a heat transfer tube. The heat-transfer-enhancement part is a slit part, a cut and bent-up part, or a louver. The heat transfer plates are each located on the corresponding one of an upwind side and a downwind side of the heat transfer tube. The heat-transfer-enhancement part is provided in the heat transfer plate on the upwind side of a heat exchange part (see, for example, Patent Literature 1).

PATENT LITERATURE

Patent Literature 1: International Publication No. WO 2019/026243 (see FIG. 18)

However, the heat exchanger has a problem with the fin disclosed in Patent Literature 1 in that air bypasses the heat-transfer-enhancement part, which is provided in the heat transfer plate on the upwind side and has high pressure loss, and consequently the airflow concentrates on a flat part of the heat transfer plate, resulting in an insufficient heat transfer coefficient between gas and the fin.

SUMMARY

The present disclosure has been made in view of the above circumstances, and it is an object of the present disclosure to provide a heat exchanger including a fin that can improve a heat transfer coefficient between gas and the fin.

A heat exchanger according to an embodiment of the present disclosure includes: a heat transfer tube that extends in a second direction that crosses a first direction in which gas flows, and a fin that is provided to the heat transfer tube and has a surface that extends in the first direction and the second direction. The fin has a first extension part and a second extension part, the first extension part has a first heat-transfer-enhancement area that is located further upstream in a flow of the gas than the heat transfer tube in the first direction and improves a heat transfer coefficient, and the second extension part has a second heat-transfer-enhancement area that is located further downstream in the flow of the gas than the heat transfer tube in the first direction and improves a heat transfer coefficient.

According to an embodiment of the present disclosure, the first heat-transfer-enhancement area is provided in the first extension part of the fin located upstream in the flow of the gas, while the second heat-transfer-enhancement area is provided in the second extension part of the fin located further downstream in the flow of the gas than the first extension part. It is therefore possible to provide the heat exchanger in which the first heat-transfer-enhancement area and the second heat-transfer-enhancement area can improve a heat transfer coefficient between the fin and the gas passing through the fin.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating a refrigeration cycle apparatus according to Embodiment 1.

FIG. 2 is a perspective view illustrating an outdoor heat exchanger in FIG. 1.

FIG. 3 illustrates a heat transfer part of the heat exchanger according to Embodiment 1.

FIG. 4 illustrates a modification of a method for attaching a fin to a heat transfer tube in the heat exchanger according to Embodiment 1.

FIG. 5 illustrates a heat transfer part of the heat exchanger according to Embodiment 2.

FIG. 6 illustrates a heat transfer part of the heat exchanger according to Embodiment 3.

FIG. 7 illustrates a heat transfer part of the heat exchanger according to Embodiment 4.

FIG. 8 illustrates a modification of the heat transfer part of the heat exchanger according to Embodiment 4.

FIG. 9 illustrates a heat exchange part of the heat exchanger according to Embodiment 5.

FIG. 10 illustrates a modification of the heat exchange part of the heat exchanger according to Embodiment 5.

FIG. 11 illustrates the arrangement of first heat-transfer-enhancement parts and second heat-transfer-enhancement parts, which are formed in a fin in Comparative Example.

FIG. 12 illustrates a relationship between a slit area rate and air-side heat transfer performance.

DETAILED DESCRIPTION

Hereinafter, an air-conditioning apparatus according to an embodiment will be described with reference to the drawings. Note that the same constituent elements in the drawings are denoted by the same reference signs, and redundant explanation will be omitted appropriately. The present disclosure may include all combinations of configurations that can be combined among the configurations explained in embodiments described below. In addition, the relationship of sizes of the components in the drawings may differ from that of actual ones. The forms of the constituent elements described throughout the entire specification are merely examples, and do not intend to limit the constituent elements to the forms described in the specification. In particular, the combination of constituent elements is not limited to only the combination in each embodiment, and the constituent elements described in one embodiment can be applied to another embodiment. In the embodiments below, in a case where a plurality of identical constituent elements are provided, these identical constituent elements may be denoted by the same reference sign followed by an underscore and a different number to distinguish the constituent elements from each other. However, when the plurality of identical constituent elements are collectively described, or when one of the identical constituent elements is described as a typical example, an underscore and a different number may not be placed after the reference sign.

Embodiment 1

FIG. 1 is a schematic configuration diagram illustrating a refrigeration cycle apparatus according to Embodiment 1. In Embodiment 1, the refrigeration cycle apparatus is used as an air-conditioning apparatus 1. The air-conditioning apparatus 1 includes a compressor 2, an outdoor heat exchanger 3, an expansion valve 4, an indoor heat exchanger 5, and a four-way valve 6. In this example, the compressor 2, the outdoor heat exchanger 3, the expansion valve 4, and the four-way valve 6 are provided in an outdoor unit, while the indoor heat exchanger 5 is provided in an indoor unit.

The compressor 2, the outdoor heat exchanger 3, the expansion valve 4, the indoor heat exchanger 5, and the four-way valve 6 are connected to each other through refrigerant pipes, forming a refrigerant circuit through which refrigerant can circulate. In the air-conditioning apparatus 1, when the compressor 2 operates, refrigeration cycle is performed in which the refrigerant circulates through the compressor 2, the outdoor heat exchanger 3, the expansion valve 4, and the indoor heat exchanger 5 while the refrigerant changes in phase.

The outdoor unit is provided with an outdoor fan 7 configured to force outside air to pass through the outdoor heat exchanger 3. Through the outdoor heat exchanger 3, refrigerant exchanges heat with an airflow of the outside air generated by operation of the outdoor fan 7. The indoor unit is provided with an indoor fan 8 configured to force room air to pass through the indoor heat exchanger 5. Through the indoor heat exchanger 5, refrigerant exchanges heat with an airflow of the room air generated by operation of the indoor fan 8.

The air-conditioning apparatus 1 is capable of switching the operating mode between cooling mode and heating mode. The four-way valve 6 is a solenoid valve configured to switch refrigerant flow passages in response to the switching of the operating mode of the air-conditioning apparatus 1 between cooling mode and heating mode. During operation in cooling mode, the four-way valve 6 guides refrigerant flowing from the compressor 2 to the outdoor heat exchanger 3 and also guides refrigerant from the indoor heat exchanger 5 to the compressor 2. During operation in heating mode, the four-way valve 6 guides refrigerant flowing from the compressor 2 to the indoor heat exchanger 5 and also guides refrigerant flowing from the outdoor heat exchanger 3 to the compressor 2. In FIG. 1, the refrigerant flow direction during operation in cooling mode is illustrated by the dotted arrow, while the refrigerant flow direction during operation in heating mode is illustrated by the solid arrow.

During operation of the air-conditioning apparatus 1 in cooling mode, refrigerant compressed by the compressor 2 is delivered to the outdoor heat exchanger 3. At the outdoor heat exchanger 3, the refrigerant transfers heat to the outside air and thus condenses. Thereafter, the refrigerant is delivered to the expansion valve 4, is reduced in pressure by the expansion valve 4, and is then delivered to the indoor heat exchanger 5. Thereafter, the refrigerant receives heat from the room air at the indoor heat exchanger 5 and thus evaporates, and then flows back to the compressor 2. Therefore, during operation of the air-conditioning apparatus 1 in cooling mode, the outdoor heat exchanger 3 serves as a condenser, while the indoor heat exchanger 5 serves as an evaporator.

During operation of the air-conditioning apparatus 1 in heating mode, refrigerant compressed by the compressor 2 is delivered to the indoor heat exchanger 5. At the indoor heat exchanger 5, the refrigerant transfers heat to the room air and thus condenses. Thereafter, the refrigerant is delivered to the expansion valve 4, is reduced in pressure by the expansion valve 4, and is then delivered to the outdoor heat exchanger 3. Thereafter, the refrigerant receives heat from the outside air at the outdoor heat exchanger 3 and thus evaporates, and then flows back to the compressor 2. Therefore, during operation of the air-conditioning apparatus 1 in heating mode, the outdoor heat exchanger 3 serves as an evaporator, while the indoor heat exchanger 5 serves as a condenser.

FIG. 2 is a perspective view illustrating the outdoor heat exchanger 3 in FIG. 1. The outdoor heat exchanger 3 includes a heat exchanger 11 through which an airflow A passes. The airflow A is generated by operation of the outdoor fan 7. The heat exchanger 11 includes a first header tank 12, a second header tank 13, and a plurality of heat exchange parts 14 connecting the first header tank 12 and the second header tank 13. In the heat exchanger 11, either a refrigerant pipe extending from the expansion valve 4 or a refrigerant pipe extending from the four-way valve 6 is connected to the first header tank 12, while the other refrigerant pipe is connected to the second header tank 13.

The first header tank 12 and the second header tank 13 are each located horizontally. The second header tank 13 is located above the first header tank 12. The first header tank 12 and the second header tank 13 are located parallel to each other in a third direction, which is the z-direction in FIG. 2.

While the first header tank 12 and the second header tank 13 each have a cuboid outer shape in FIG. 2, their outer shape is not limited. The first header tank 12 and the second header tank 13 may have, for example, a circular cylindrical outer shape or an elliptical cylindrical outer shape. It is also possible to change the cross-sectional shape appropriately. The first header tank 12 and the second header tank 13 may also employ, for example, a cylindrical body structure with opposite ends of the cylindrical body closed, or a layered structure of plate-like bodies on which slits 21 are formed. In each of the first header tank 12 and the second header tank 13, a refrigerant port is formed through which refrigerant can flow into and out from the header tank.

The plurality of heat exchange parts 14 are spaced apart from each other in the longitudinal direction of the first header tank 12 and the second header tank 13, that is, in the z-direction in FIG. 2. The plurality of heat exchange parts 14 are arranged parallel to each other. The plurality of heat exchange parts 14 extend longitudinally in the y-direction, which is a second direction that crosses the z-direction in FIG. 2. The y-direction is an up-down direction in the present embodiment. In this example, the longitudinal direction of each heat exchange part 14 is perpendicular to the longitudinal direction of the first header tank 12 and the longitudinal direction of the second header tank 13. In this example, any part is not allowed to be located in a space between the plurality of heat exchange parts 14. This prevents any part from connecting to any of the opposite surfaces of the adjacent heat exchange parts 14 in this example.

The airflow A generated by operation of the outdoor fan 7 passes through gaps between the plurality of heat exchange parts 14. In this example, the airflow A passes through the gaps between the plurality of heat exchange parts 14 in a direction that crosses the longitudinal directions of the first header tank 12, the second header tank 13, and each heat exchange part 14, that is, in the x-direction, which is a first direction in FIG. 2. In the example in FIG. 2, the x-direction is perpendicular to the y-direction in which the heat exchange parts 14 extend longitudinally.

FIG. 3 illustrates the heat exchange part 14 of the heat exchanger 11 according to Embodiment 1. In FIG. 3, the heat exchange part 14 illustrated in FIG. 2 is viewed in the z-direction. In FIG. 3, the open arrow shows the direction in which gas flows. FIG. 3 illustrates only one of the plurality of heat exchange parts 14 illustrated in FIG. 2 as an example.

The heat exchange part 14 includes a heat transfer tube 15 and a fin 16.

As illustrated in FIG. 2, the heat transfer tubes 15 are spaced apart from each other at predetermined intervals in the z-direction. Each of the heat transfer tubes 15 is a circular tube or a flat tube. As illustrated in FIG. 3, the heat transfer tube 15 extends in the y-direction and connects the first header tank 12 and the second header tank 13. The heat transfer tube 15 extends in the y-direction, that is, in the up-down direction. Refrigerant flowing into the heat transfer tube 15 from the first header tank 12 or the second header tank 13 flows inside the heat transfer tube 15 in the up-down direction.

As illustrated in FIG. 3, the fin 16 has a surface extending in the x-direction and the y-direction. The fin 16 is provided to the heat transfer tube 15 such that the fin 16 extends longitudinally in the y-direction. The fin 16 has a first extension part 16_1 and a second extension part 16_2.

The first extension part 16_1 and the second extension part 162 are positioned on the outer side of the heat transfer tube 15 in the x-direction. In the example in FIG. 3, the first extension part 16_1 and the second extension part 16_2 have equal size and are provided to the heat transfer tube 15 such that the first extension part 161 and the second extension part 16_2 extend longitudinally in the y-direction. The first extension part 16_1 and the second extension part 16_2, which are formed separately, are attached to the respective sides of the heat transfer tube 15 extending in the y-direction.

The first extension part 16_1 has a rectangular shape when viewed in the z-direction with one of the longer sides provided on the heat transfer tube 15. The shorter sides of the first extension part 16_1 are located to extend in the x-direction toward the upwind side. The first extension part 16_1 has a first heat-transfer-enhancement area 17_1, which is located upstream in a flow of gas passing through the fin 16 and improves a heat transfer coefficient between the gas and the first extension part 16_1.

The first heat-transfer-enhancement area 17_1 has a plurality of first heat-transfer-enhancement parts 17_1_1, which are located upstream in a flow of gas passing through the fin 16 and improve a heat transfer coefficient between the gas and the first extension part 16_1. The plurality of first heat-transfer-enhancement parts 17_1_1 are arranged in the y-direction. The first heat-transfer-enhancement area 17_1 further has a first flat part 17_1_2 positioned between the first heat-transfer-enhancement part 17_1_1 located on the upper side in the y-direction and the first heat-transfer-enhancement part 17_1_1 located on the lower side in the y-direction. In the example in FIG. 3, a plurality of first flat parts 17_1_2 are provided in the first heat-transfer-enhancement area 17_1. The first heat-transfer-enhancement parts 17_1_1 and the first flat parts 17_1_2 are alternately arranged in the y-direction.

In each of the first heat-transfer-enhancement parts 17_1_1, three slits 21 are arranged parallel to each other in the x-direction. The slits 21 are openings penetrating through the fin 16. Instead of the slits 21 formed in the first heat-transfer-enhancement part 17_1_1, a cut and bent-up part, a louver, or an uneven part may be provided. The cut and bent-up part is formed by bending up a portion between two parallel slit-like cuts provided in the face of the fin 16 in the z-direction. As a consequence of provision of the cut and bent-up part, an opening of the same shape as the cut and bent-up part is provided in the fin 16. The cut and bent-up part protrudes from the face of the fin 16 in the z-direction. The louver is formed by slanting a portion between two slits formed in the face of the fin 16 from the face of the fin 16. As a consequence of formation of the louver, an opening of the same shape as the louver is provided in the fin 16. The uneven part protrudes or is recessed from the face of the fin 16 in the z-direction. It is also allowable in Embodiment 2 and other embodiments that the first heat-transfer-enhancement part 17_1_1 is a cut and bent-up part, a louver, or an uneven part.

The first flat part 17_1_2 is a rectangular-shaped flat area of the fin 16 between the first heat-transfer-enhancement parts 17_1_1. The first flat part 17_1_2 has a smaller length in the y-direction than the length of the first heat-transfer-enhancement part 17_1_1 in the y-direction.

The second extension part 16_2 has a rectangular shape when viewed in the z-direction with one of the longer sides provided on the heat transfer tube 15. The shorter sides of the second extension part 16_2 are located to extend in the x-direction toward the downwind side. The second extension part 16_2 has a second heat-transfer-enhancement area 17_2, which is located downstream in the flow of gas passing through the fin 16 and improves a heat transfer coefficient between the gas and the second extension part 16_2.

The second heat-transfer-enhancement area 17_2 has a plurality of second heat-transfer-enhancement parts 17_2_1, which are located downstream in the flow of gas passing through the fin 16 and improve a heat transfer coefficient between the gas and the second extension part 16_2. The plurality of second heat-transfer-enhancement parts 17_2_1 are arranged in the y-direction. The second heat-transfer-enhancement area 17_2 further has a second flat part 17_2_2 positioned between the second heat-transfer-enhancement part 17_2_1 located on the upper side in the y-direction and the second heat-transfer-enhancement part 17_2_1 located on the lower side in the y-direction. In the example in FIG. 3, a plurality of second flat parts 17_2_2 are provided in the second heat-transfer-enhancement area 17_2. The second heat-transfer-enhancement parts 17_2_1 and the second flat parts 17_2_2 are alternately arranged in the y-direction.

In each of the second heat-transfer-enhancement parts 17_2_1, three slits 21 are arranged parallel to each other in the x-direction. The slits 21 are openings penetrating through the fin 16. Instead of the slits 21 formed in the second heat-transfer-enhancement part 17_2_1, a cut and bent-up part, a louver, or an uneven part may be provided. The cut and bent-up part is formed by bending up a portion between two parallel slit-like cuts provided in the face of the fin 16 in the z-direction. As a consequence of provision of the cut and bent-up part, an opening of the same shape as the cut and bent-up part is provided in the fin 16. The cut and bent-up part protrudes from the face of the fin 16 in the z-direction. The louver is formed by slanting a portion between two slits formed in the face of the fin 16 from the face of the fin 16. As a consequence of formation of the louver, an opening of the same shape as the louver is provided in the fin 16. The uneven part protrudes or is recessed from the face of the fin 16 in the z-direction. It is also allowable in Embodiment 2 and other embodiments that the second heat-transfer-enhancement part 17_2_1 is a cut and bent-up part, a louver, or an uneven part.

The second flat part 17_2_2 is a rectangular-shaped flat area of the fin 16 between the second heat-transfer-enhancement parts 17_2_1. The second flat part 17_2_2 has a smaller length in the y-direction than the length of the second heat-transfer-enhancement part 17_2_1 in the y-direction.

In the second heat-transfer-enhancement area 17_2 downstream of the first heat-transfer-enhancement part 17_1_1 in a flow of gas in the x-direction, the second flat part 17_2_2 is located. In the second heat-transfer-enhancement area 17_2 downstream of the first flat part 17_1_2 in the flow of gas in the x-direction, the second heat-transfer-enhancement part 17_2_1 is located. That is, the heat exchange part 14 has an area where the first heat-transfer-enhancement part 17_1_1 and the second flat part 17_2_2 are arranged side by side in the x-direction, and an area where the first flat part 17_1_2 and the second heat-transfer-enhancement part 17_2_1 are arranged side by side in the x-direction. In the example in FIG. 3, an area is further provided where the first heat-transfer-enhancement part 17_1_1 and the second heat-transfer-enhancement part 17_2_1 are arranged side by side in the x-direction.

In the heat exchanger 11 according to Embodiment 1, an airflow entering the heat exchanger 11 flows over the surface of the first heat-transfer-enhancement area 17_1 of the fin 16 in the x-direction. In the first heat-transfer-enhancement area 17_1, the slits 21 formed in the first heat-transfer-enhancement parts 17_1_1 enhance heat transfer from or to portion of the airflow. An airflow entering the first flat parts 17_1_2 and another airflow bypassing the first heat-transfer-enhancement parts 17_1_1 flow over the surfaces of the first flat parts 17_1_2 in the x-direction.

Subsequently, the airflow passes through the surface of the heat transfer tube 15, then exchanges heat with refrigerant flowing inside the heat transfer tube 15, and thereafter flows over the surface of the second heat-transfer-enhancement area 17_2 in the x-direction. In the second heat-transfer-enhancement area 17_2, the slits 21 formed in the second heat-transfer-enhancement parts 17_2_1 enhance heat transfer from or to portion of the airflow. An airflow entering the second flat parts 17_2_2 and another airflow bypassing the second heat-transfer-enhancement parts 17_2_1 flow over the surfaces of the second flat parts 17_2_2 in the x-direction.

FIG. 4 illustrates a modification of the method for attaching the fin 16 to the heat transfer tube 15 in the heat exchanger 11 according to Embodiment 1. In FIG. 4, the heat transfer tube 15 and the fin 16 are viewed in the y-direction. In the above explanation, the example has been described in which the first extension part 16_1 and the second extension part 16_2 of the fin 16 are separately attached to the heat transfer tube 15. However, as illustrated in FIG. 4, the first extension part 16_1 and the second extension part 16_2 may be integrally formed into a single piece. The same applies to the other embodiments including Embodiments 2, 3, 4, and 5.

The fin 16 has the first extension part 16_1, the second extension part 16_2, and a main body part 16_3. The fin 16 illustrated in FIG. 4 is formed by integrating the first extension part 16_1 and the second extension part 16_2 with the main body part 16_3 into a single piece. The main body part 16_3 is bent to be brought into contact with the heat transfer tube 15. The bent main body part 16_3 is then attached to the heat transfer tube 15. Even in this attachment mode, it is still possible to form the heat exchange part 14 of the present embodiment.

It is also possible to position the first extension part 16_1 and the second extension part 16_2 to the heat transfer tube 15 in the z-direction in the following manner. For example, as illustrated in FIG. 4, the first extension part 16_1 and the second extension part 16_2 are arranged in alignment with the center of the heat transfer tube 15 in the z-direction. This arrangement is also applicable to a mode in which the first extension part 16_1 and the second extension part 16_2 are separately attached to the heat transfer tube 15. It is allowable that the first extension part 16_1 and the second extension part 16_2 are not exactly aligned with the center of the heat transfer tube 15 in the z-direction. The first extension part 16_1 and the second extension part 16_2 may be located within the width of the heat transfer tube 15 in the z-direction. Note that although not illustrated, the first extension part 16_1 and the second extension part 16_2 may also be located flush with an end face of the heat transfer tube 15 in the z-direction.

As described above, the heat exchanger 11 according to Embodiment 1 includes the heat transfer tube 15, which extends in the second direction, which crosses the first direction in which gas flows, and the fin 16, which is provided to the heat transfer tube 15 and has a surface that extends in the first direction and the second direction. The fin 16 has the first extension part 16_1 having the first heat-transfer-enhancement area 17_1, which is located further upstream in a flow of the gas than the heat transfer tube 15 in the first direction and improves a heat transfer coefficient to the gas. The fin 16 has the second extension part 16_2 having the second heat-transfer-enhancement area 17_2, which is located further downstream in the flow of the gas than the heat transfer tube 15 in the first direction and improves a heat transfer coefficient to the gas. In the heat exchanger 11 in Embodiment 1, the first heat-transfer-enhancement area 17_1 is located upstream of the heat transfer tube 15, while the second heat-transfer-enhancement area 17_2 is located downstream of the heat transfer tube 15, so that the heat transfer coefficient between the fin 16 and the gas passing through the fin 16 can improve.

When gas is delivered toward the heat transfer tube 15, the gas flows around the surface of the heat transfer tube 15 extending in the x-direction, while bypassing the heat transfer tube 15. The gas is thus unlikely to flow to an upstream end and a downstream end of the heat transfer tube 15 in a direction in which the gas flows (the left and right end portions of the heat transfer tube 15 on the drawing of FIG. 4 illustrated as an example). However, in the present embodiment, the first extension part 16_1 and the second extension part 16_2, which extend in the x-direction in which gas flows are located respectively upstream and downstream of the heat transfer tube 15. The first extension part 16_1 is provided with the first heat-transfer-enhancement area 17_1, which improves a heat transfer coefficient to the gas. The second extension part 162 is provided with the second heat-transfer-enhancement area 17_2, which improves a heat transfer coefficient to the gas. It is therefore possible to improve the heat transfer coefficient between the fin 16 and the gas flowing in the x-direction.

The second flat parts 17_2_2 are located in the second heat-transfer-enhancement area 17_2 and arranged side by side with the first heat-transfer-enhancement parts 17_1_1 in the x-direction. The second heat-transfer-enhancement parts 17_2_1 are located in the second heat-transfer-enhancement area 17_2 and arranged side by side with the first flat parts 17_1_2 in the x-direction. With this configuration, even when gas flowing in the x-direction flows through the first flat parts 17_1_2 on the upstream side, this gas still flows easily through the second heat-transfer-enhancement parts 17_2_1 on the downstream side. After having flowed around the first heat-transfer-enhancement parts 17_1_1 on the upstream side, gas flows through the first flat parts 17_1_2 on the downstream side. It is therefore possible to improve the heat transfer coefficient in the fin 16. With this configuration, it is possible to increase the path length for an airflow to pass across the fin 16 in its entirety through the first flat parts 17_1_2 or the second flat parts 17_2_2, and thus increase the substantial heat-transfer area of the fin 16.

In the first heat-transfer-enhancement area 171, the first heat-transfer-enhancement parts 17_1_1 and the first flat parts 17_1_2 are alternately arranged in the second direction, which is the y-direction. In the second heat-transfer-enhancement area 17_2, the second heat-transfer-enhancement parts 17_2_1 and the second flat parts 17_2_2 are alternately arranged in the second direction, which is the y-direction. Due to this arrangement, with reference to a pressure-loss distribution across the fin 16 in its entirety, pressure loss of airflow in the y-direction shows almost a uniform distribution. Therefore, the volume of airflow that passes through the first flat parts 17_1_2 and the second flat parts 17_2_2 is reduced. This results in an improvement in the heat transfer coefficient between the airflow and the fin 16.

Embodiment 2

The heat exchange part 14 of the heat exchanger 11 according to Embodiment 2 is different in size of the first flat parts 17_1_2 and the first flat parts 17_1_2 from the heat exchange part 14 of the heat exchanger 11 according to Embodiment 1.

FIG. 5 illustrates the heat exchange part 14 of the heat exchanger 11 according to Embodiment 2. In FIG. 5, the open arrow shows the direction in which gas flows. FIG. 5 illustrates only one of the plurality of heat exchange parts 14 illustrated in FIG. 2 as an example.

As illustrated in FIG. 5, in Embodiment 2, the first heat-transfer-enhancement part 17_1_1, the first flat part 17_1_2, the second heat-transfer-enhancement part 17_2_1, and the second flat part 17_2_2 each have an equal length in the x-direction, while each having an equal length in the y-direction. Note that it is allowable that the first heat-transfer-enhancement part 17_1_1, the first flat part 17_1_2, the second heat-transfer-enhancement part 17_2_1, and the second flat part 17_2_2 each have an equal length only in the y-direction.

The first heat-transfer-enhancement parts 17_1_1 are arranged in the y-direction at the same positions as the second flat parts 17_2_2 in the second heat-transfer-enhancement area 17_2 in the y-direction. The first flat parts 17_1_2 are arranged in the y-direction at the same positions as the second heat-transfer-enhancement parts 17_2_1 in the second heat-transfer-enhancement area 17_2 in the y-direction.

That is, the first heat-transfer-enhancement parts 17_1_1 and the second heat-transfer-enhancement parts 17_2_1, which are formed in the fin 16 in the heat exchanger 11 according to Embodiment 2, are staggered in position from each other in the y-direction. Likewise, the first flat parts 17_1_2 and the second flat parts 17_2_2 are staggered in position from each other in the y-direction.

As described above, the heat exchanger 11 according to Embodiment 2 includes the heat transfer tube 15, which extends in the second direction, which crosses the first direction in which gas flows, and the fin 16, which is provided to the heat transfer tube 15 and has a surface that extends in the first direction and the second direction. The fin 16 has the first extension part 16_1 having the first heat-transfer-enhancement area 17_1, which is located further upstream in a flow of the gas than the heat transfer tube 15 in the first direction and improves a heat transfer coefficient to the gas. The fin 16 has the second extension part 16_2 having the second heat-transfer-enhancement area 17_2, which is located further downstream in the flow of the gas than the heat transfer tube 15 in the first direction and improves a heat transfer coefficient to the gas. In the heat exchanger 11 in Embodiment 1, the first heat-transfer-enhancement area 17_1 is located upstream of the heat transfer tube 15, while the second heat-transfer-enhancement area 17_2 is located downstream of the heat transfer tube 15, so that the heat transfer coefficient between the fin 16 and the gas passing through the fin 16 can improve.

In Embodiment 2, the first heat-transfer-enhancement part 17_1_1, the first flat part 17_1_2, the second heat-transfer-enhancement part 17_2_1, and the second flat part 17_2_2 each have an equal length in the x-direction, while each having an equal length in the y-direction. Due to this configuration, when the fin 16 is manufactured, it is possible to form the first heat-transfer-enhancement parts 17_1_1 and the second heat-transfer-enhancement parts 17_2_1 in the fin 16 by use of progressive pressing.

Embodiment 3

The heat exchange part 14 of the heat exchanger 11 according to Embodiment 3 does not have the first flat parts 17_1_2 or the second flat parts 17_2_2 differently from the heat exchange part 14 of the heat exchanger 11 according to Embodiment 1.

FIG. 6 illustrates the heat exchange part 14 of the heat exchanger 11 according to Embodiment 3. In FIG. 6, the open arrow shows the direction in which gas flows. FIG. 6 illustrates only one of the plurality of heat exchange parts 14 illustrated in FIG. 2 as an example.

As illustrated in FIG. 6, in Embodiment 3, the first heat-transfer-enhancement area 17_1 has a plurality of first heat-transfer-enhancement parts 17_1_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas. The second heat-transfer-enhancement area 17_2 has a plurality of second heat-transfer-enhancement parts 17_2_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas.

Each of the first heat-transfer-enhancement parts 17_1_1 has one slit 21. The slits 21 provided in the first heat-transfer-enhancement parts 17_1_1 adjacent to each other in the y-direction are at positions displaced from each other in the x-direction. It is allowable that a plurality of slits 21 are formed in the x-direction in each of the first heat-transfer-enhancement parts 17_1_1.

As illustrated in FIG. 6, in the first extension part 16_1, three slits 21 are formed one by one in the y-direction at positions displaced from each other in the x-direction. This formation pattern is repeated.

Each of the second heat-transfer-enhancement parts 17_2_1 has one slit 21. The slits 21 provided in the second heat-transfer-enhancement parts 17_2_1 adjacent to each other in the y-direction are at positions displaced from each other in the x-direction. It is allowable that a plurality of slits 21 are formed in the x-direction in each of the second heat-transfer-enhancement parts 17_2_1.

As illustrated in FIG. 6, in the second extension part 16_2, three slits 21 are formed one by one in the y-direction at positions displaced from each other in the x-direction. This formation pattern is repeated.

In Embodiment 3, the sum of a count of slits 21 formed in the first heat-transfer-enhancement part 17_1_1 in the x-direction and a count of slits 21 formed in the second heat-transfer-enhancement part 17_2_1 in the x-direction is constant.

According to Embodiment 3, the plurality of first heat-transfer-enhancement parts 17_1_1 and the plurality of second heat-transfer-enhancement parts 17_2_1 are provided in the y-direction in the fin 16. The sum of the count of slits 21 formed in the first heat-transfer-enhancement part 17_1_1 in the x-direction and the count of slits 21 formed in the second heat-transfer-enhancement part 17_2_1 in the x-direction is constant. That is, a plurality of sets of equal count of slits 21 provided in the x-direction (two slits in the example of FIG. 6) are arranged in the y-direction. It is therefore possible to obtain a uniform pressure-loss distribution of airflow in the y-direction. This allows the fin 16 in the heat exchanger 11 to improve its heat transfer coefficient.

Embodiment 4

In the heat exchange part 14 of the heat exchanger 11 according to Embodiment 4, a first pattern of arrangement of the slits 21 formed in the first heat-transfer-enhancement parts 17_1_1, and a second pattern of arrangement of the slits 21 formed in the second heat-transfer-enhancement parts 17_2_1 are displaced from each other in the x-direction.

FIG. 7 illustrates the heat exchange part 14 of the heat exchanger 11 according to Embodiment 4. In FIG. 7, the open arrow shows the direction in which gas flows. FIG. 7 illustrates only one of the plurality of heat exchange parts 14 illustrated in FIG. 2 as an example.

As illustrated in FIG. 7, in Embodiment 4, the first heat-transfer-enhancement area 17_1 has a plurality of first heat-transfer-enhancement parts 17_1_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas. The second heat-transfer-enhancement area 17_2 has a plurality of second heat-transfer-enhancement parts 17_2_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas.

In the plurality of first heat-transfer-enhancement parts 17_1_1, the slits 21 are formed in the first pattern. In the first pattern, in the first heat-transfer-enhancement parts 17_1_1, two slits 21 arranged side by side in the x-direction, and one slit 21 provided adjacent to the two slits 21 in the y-direction are formed in succession in the y-direction. In the example in FIG. 7, at the intermediate position between the two slits 21 arranged side by side in the x-direction, one slit 21 adjacent to these two slits 21 in the y-direction is located.

In the plurality of second heat-transfer-enhancement parts 17_2_1, the slits 21 are formed in the second pattern. In the second pattern, one slit 21 provided in the x-direction in the second heat-transfer-enhancement part 17_2_1, and two slits 21 located below the one slit 21 in the y-direction and on respective opposite sides of the one slit 21 are formed in succession in the y-direction.

As illustrated in FIG. 7, the first pattern of arrangement of the slits 21 and the second pattern of arrangement of the slits 21 are displaced from each other in the y-direction. In the x-direction, the sum of the count of slits 21 formed in the first heat-transfer-enhancement part 17_1_1 and the count of slits 21 formed in the second heat-transfer-enhancement part 17_2_1 is constant at three.

Note that the first pattern and the second pattern are not limited to the example illustrated in FIG. 7, and various patterns with different counts of slits 21 can be employed. As an example of the arrangement pattern, a combination of three slits 21 arranged side by side in the x-direction with only one slit 21 provided in the x-direction is repeatedly formed in the y-direction.

FIG. 8 illustrates a modification of the heat exchange part 14 of the heat exchanger 11 according to Embodiment 4.

As illustrated in FIG. 8, the first flat part 17_1_2 is located below the first heat-transfer-enhancement part 17_1_1 in the y-direction. The first heat-transfer-enhancement parts 17_1_1 are arranged in the y-direction with each of the first flat parts 17_1_2 interposed between the first heat-transfer-enhancement parts 17_1_1.

In a plurality of first heat-transfer-enhancement parts 17_1_1, square-shaped uneven parts 22 are formed in a first pattern. In the first pattern, two uneven parts 22 arranged side by side in the x-direction in the first heat-transfer-enhancement part 17_1_1 and one uneven part 22 provided in the first heat-transfer-enhancement part 17_1_1 adjacent to the two uneven parts 22 in the y-direction are formed in succession in the y-direction with the first flat part 17_1_2 interposed between these first heat-transfer-enhancement parts 17_1_1.

In a plurality of second heat-transfer-enhancement parts 17_2_1, square-shaped uneven parts 22 are formed in a second pattern. In the second pattern, two uneven parts 22 arranged side by side in the x-direction in the second heat-transfer-enhancement part 17_2_1 and one uneven part 22 located in the second heat-transfer-enhancement part 17_2_1 below the two uneven parts 22 in the y-direction and located between the two uneven parts 22 are formed in succession in the y-direction with the second flat part 17_2_2 interposed between these second heat-transfer-enhancement parts 17_2_1.

In FIG. 8, the first pattern of arrangement of the uneven parts 22 and the second pattern of arrangement of the uneven parts 22 are also displaced from each other in the second direction, which is the y-direction. In the x-direction, the sum of the count of uneven parts 22 formed in the first heat-transfer-enhancement part 17_1_1 and the count of uneven parts 22 formed in the second heat-transfer-enhancement part 17_2_1 is constant at three.

Note that in FIG. 8, it is allowable that the first flat parts 17_1_2 and the second flat parts 17_2_2 are not provided.

As described above, according to Embodiment 4, the first pattern of arrangement of the slits or uneven parts provided in the first heat-transfer-enhancement parts, and the second pattern of arrangement of the slits or uneven parts provided in the second heat-transfer-enhancement parts are displaced from each other in the second direction. It is therefore possible to narrow the pressure-loss distribution of airflow in the y-direction. This allows the fin 16 in the heat exchanger 11 to improve its heat transfer coefficient.

The first pattern of the first heat-transfer-enhancement parts 17_1_1 and the second pattern of the second heat-transfer-enhancement parts 17_2_1 are displaced from each other. This makes it possible to form the first pattern and the second pattern by use of progressive pressing.

Embodiment 5

Next, the heat exchanger 11 according to Embodiment 5 is described.

FIG. 9 illustrates the heat exchange part 14 of the heat exchanger 11 according to Embodiment 5. In FIG. 9, the open arrow shows the direction in which gas flows. In FIG. 9, at least two lines of the plurality of heat exchange parts 14 illustrated in FIG. 2 are provided in the x-direction. FIG. 9 illustrates only a heat exchange part 14_1 on the first line and a heat exchange part 14_2 on the second line as an example.

As illustrated in FIG. 9, the fin 16 is provided to a first heat transfer tube 15_1 and extends in the y-direction, which is a vertical direction. The first heat transfer tube 15_1 is provided between a first header tank 12_1 and a second header tank 13_1. The fin 16 has the first extension part 16_1 and the second extension part 16_2.

The first extension part 16_1 of the fin 16 has a rectangular shape and is located with one of the longer sides attached to the first heat transfer tube 15_1 in the y-direction, and with the shorter sides extending in the x-direction toward the upwind side.

The second extension part 16_2 of the fin 16 has a rectangular shape and is located with one of the longer sides attached to the first heat transfer tube 15_1 in the y-direction, and with the shorter sides extending in the x-direction toward the downwind side.

The first extension part 16_1 is located upstream in a flow of gas passing through the fin 16. The first extension part 161 has a rectangular shape when viewed in the z-direction with one of the longer sides located on the first heat transfer tube 15_1. The first extension part 16_1 is provided with the first heat-transfer-enhancement area 17_1, which improves a heat transfer coefficient of the first extension part 16_1 to the gas. The first heat-transfer-enhancement area 17_1 has a plurality of first heat-transfer-enhancement parts 17_1_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas, and a plurality of first flat parts 17_1_2, which are arranged in the y-direction. The first heat-transfer-enhancement parts 17_1_1 and the first flat parts 17_1_2 are alternately arranged in the y-direction.

In each of the first heat-transfer-enhancement parts 17_1_1, three slits 21 are arranged parallel to each other in the x-direction. The first flat part 17_1_2 is a rectangular-shaped flat area of the fin 16 between the first heat-transfer-enhancement parts 17_1_1. The first flat part 17_1_2 has a length in the y-direction equal to the length of the first heat-transfer-enhancement part 17_1_1 in the y-direction.

The second extension part 16_2 is located downstream in the flow of gas passing through the fin 16. The second extension part 16_2 has a rectangular shape when viewed in the z-direction with one of the longer sides located on the first heat transfer tube 15_1. The second extension part 16_2 is provided with the second heat-transfer-enhancement area 17_2, which improves a heat transfer coefficient of the second extension part 16_2 to the gas. The second heat-transfer-enhancement area 17_2 has a plurality of second heat-transfer-enhancement parts 17_2_1, which are arranged in the y-direction and improve a heat transfer coefficient to the gas, and a plurality of first flat parts 17_1_2, which are arranged in the y-direction. The second heat-transfer-enhancement parts 17_2_1 and the second flat parts 17_2_2 are alternately arranged in the y-direction.

In each of the second heat-transfer-enhancement parts 17_2_1, three slits 21 are arranged parallel to each other in the x-direction. The second flat part 17_2_2 is a rectangular-shaped flat area of the fin 16 between the second heat-transfer-enhancement parts 17_2_1. The second flat part 17_2_2 has a length in the y-direction equal to the length of the second heat-transfer-enhancement part 17_2_1 in the y-direction.

The second heat-transfer-enhancement part 17_2_1 is located side by side with the first heat-transfer-enhancement part 17_1_1 in the x-direction. The second flat part 17_2_2 is located side by side with the first flat part 17_1_2 in the x-direction.

The fin 16 is provided to a second heat transfer tube 15_2 and extends in the y-direction. The second heat transfer tube 15_2 is provided between the first header tank 12_1 and the second header tank 13_1. The fin 16 has the first extension part 16_1 and the second extension part 162.

The first extension part 16_1 of the fin 16 has a rectangular shape and is located with one of the longer sides attached to the second heat transfer tube 15_2 in the y-direction, and with the shorter sides extending in the x-direction toward the upwind side.

The second extension part 16_2 of the fin 16 has a rectangular shape and is located with one of the longer sides attached to the second heat transfer tube 15_2 in the y-direction, and with the shorter sides extending in the x-direction toward the downwind side.

The second heat-transfer-enhancement parts 17_2_1 are formed in the fin 16 provided to the first heat transfer tube 151 at positions different in the y-direction from the positions of the first heat-transfer-enhancement parts 17_1_1 formed in the fin 16 provided to the second heat transfer tube 15_2.

FIG. 10 illustrates a modification of the heat exchange part 14 of the heat exchanger 11 according to Embodiment 5. In FIG. 10, the open arrow shows the direction in which gas flows. In Embodiment 5, three lines of the plurality of heat exchange parts 14 illustrated in FIG. 2 are provided in the x-direction with the plurality of heat exchange parts 14 spaced apart from each other in the z-direction. FIG. 10 illustrates only the heat exchange part 14_1 on the first line, the heat exchange part 14_2 on the second line, and a heat exchange part 14_3 on the third line as an example.

The first heat-transfer-enhancement parts 17_1_1 and the first flat parts 17_1_2, which are formed in the fin 16 provided to each of the first, second, and third heat transfer tubes 15_1, 152, and 15_3 are identical to those illustrated in FIG. 5.

As illustrated in FIG. 10, the second heat-transfer-enhancement parts 17_2_1 are provided to the first heat transfer tube 151 at positions different in the second direction from the positions of the first heat-transfer-enhancement parts 17_1_1 provided to the second heat transfer tube 15_2. The second heat-transfer-enhancement parts 17_2_1 are provided to the second heat transfer tube 15_2 at positions different in the y-direction from the positions of the first heat-transfer-enhancement parts 17_1_1 provided to the third heat transfer tube 15_3.

According to Embodiment 5, the first heat-transfer-enhancement parts 17_1_1 of the adjacent heat transfer tubes 15 are formed at different positions in the second direction. Therefore, a uniform pressure-loss distribution of airflow in the y-direction is obtained, and the volume of airflow that passes through the first flat parts 17_1_2 and the second flat parts 17_2_2 is reduced. This results in an improvement in the heat transfer coefficient between the airflow and the fin 16.

Even when an airflow passes through the first flat parts 17_1_2 and the second flat parts 17_2_2, a plurality of fins 16 are arranged in the x-direction, which is a direction of the airflow, increases the path length for the airflow, and thus can still increase the substantial heat-transfer area of the fins 16.

Effects In a case where the heat transfer tube 15 is a circular tube or a flat tube, air is unlikely to flow to the upstream side and downstream side of the heat transfer tube 15. Thus, originally there is not such a technical concept that the fin 16 is provided with both the first heat-transfer-enhancement area 17_1 and the second heat-transfer-enhancement area 17_2 as described in Embodiments 1 to 5. Further, there is not such a technical concept that a heat-transfer effect is to be enhanced by arrangement or combination of the first heat-transfer-enhancement parts 17_1_1 in the first heat-transfer-enhancement area 17_1 and the second heat-transfer-enhancement parts 17_2_1 in the second heat-transfer-enhancement area 17_2.

In the heat exchanger 11 in Embodiments 1 to 5, the first heat-transfer-enhancement parts 17_1_1 are formed in the fin 16 extending toward the upwind side, while the second heat-transfer-enhancement parts 17_2_1 are formed in the fin 16 extending toward the downwind side. This exerts a significant influence on heat-conduction efficiency of the fin 16.

It has been described in Embodiments 1 to 5 that the first heat-transfer-enhancement parts 17_1_1 and the second heat-transfer-enhancement parts 17_2_1 can be formed by any one or more of a cut and bent-up part, a slit, a louver, and an uneven part. In a case where the cut and bent-up part, the slit, or the louver is employed, the fin 16 is provided with openings. This results in a reduction in the area of planar portion of the fin 16, that is, a reduction in the heat exchange area with gas. In a heat exchanger in a different mode from Embodiments 1 to 5, the heat transfer tube 15 penetrates through the fin 16 and is in contact on its entire outer circumferential surface with the fin 16. Heat thus conducts from the heat transfer tube 15 to the fin 16 in 360-degree directions when the heat transfer tube 15 is viewed in cross section. Therefore, only a limited influence is exerted on the reduction in the heat exchange area due to the openings provided in the fin 16. However, in the heat exchanger in Embodiments 1 to 5, the fin 16 is connected to the sides of the heat transfer tube 15 extending in the y-direction, or is connected to the x-y plane (FIG. 4) of the heat transfer tube 15. This limits the direction of heat conduction from the heat transfer tube 15 to the fin 16. Therefore, in Embodiments 1 to 5, a more significant influence is exerted on the reduction in the heat exchange area due to the openings provided in the fin 16, compared to the heat exchanger in the mode in which the heat transfer tube penetrates through the fin. In view of the above, the opening area of the fin 16, and the arrangement of the first heat-transfer-enhancement parts 17_1_1 and the second heat-transfer-enhancement parts 17_2_1 in Embodiments 1 to 5 are described below.

FIG. 11 illustrates the arrangement of first heat-transfer-enhancement parts 17_1_1 and second heat-transfer-enhancement parts 17_2_1, which are formed in the fin 16 in Comparative Example. FIG. 11 illustrates the first heat transfer tube 15_1 and the second heat transfer tube 15_2, which are spaced apart from each other in the x-direction. As illustrated in FIG. 11, each of the second heat-transfer-enhancement parts 17_2_1 is located side by side with the corresponding one of the first heat-transfer-enhancement parts 17_1_1 in the x-direction. Each of the second flat parts 17_2_2 is located side by side with the corresponding one of the first flat parts 17_1_2 in the x-direction.

FIG. 12 illustrates a relationship between a slit area rate and air-side heat transfer performance. The “SLIT AREA RATE” refers to slit area/area of the fin 16. The “AIR-SIDE HEAT TRANSFER PERFORMANCE” refers to air-side heat transfer area of the fin 16×air-side heat conductivity.

In FIG. 12, g_1 shows characteristics of the slit area rate and the air-side heat transfer performance of the heat exchanger 11 illustrated in FIG. 11. g_2 shows characteristics of the slit area rate and the air-side heat transfer performance of the heat exchanger 11 illustrated in FIG. 9. g_3 shows characteristics of the slit area rate and the air-side heat transfer performance of the heat exchanger 11 illustrated in FIG. 5 when two lines of the heat exchangers 11 are provided in the x-direction. g_4 shows characteristics of the slit area rate and the air-side heat transfer performance of the heat exchanger 11 illustrated in FIG. 8 when two lines of the heat exchangers 11 are provided in the x-direction.

As illustrated in FIG. 12, provided that the slit area rate is almost the same, the fin 16 illustrated in FIG. 8 exhibits the highest air-side heat transfer performance. The fin 16 illustrated in FIG. 5 and the fin 16 illustrated in FIG. 9 exhibit the second and third highest air-side heat transfer performance, respectively. The fins 16 illustrated in FIGS. 5, 8, and 9 exhibit higher air-side heat transfer performance than the air-side heat transfer performance of the fin 16 illustrated in FIG. 11 as Comparative Example. The other fins 16 described in Embodiments 1 to 5 also exhibit higher air-side heat transfer performance than the air-side heat transfer performance of the fin 16 illustrated in FIG. 11 as Comparative Example.

As illustrated by g_2 in FIG. 12, the heat exchanger 11 having the configuration of FIG. 9 exhibits higher air-side heat transfer performance when the slit area rate is 7.5% than the air-side heat transfer performance when the slit area rate is 15%. It is therefore desirable to set the slit area rate to 7.5% when the heat exchanger 11 employs the configuration of FIG. 9. As illustrated by g_1 in FIG. 12, a peak of the air-side heat transfer performance appears when the slit area rate is 7.5%. In any of the patterns in Embodiments 1 to 5, it is desirable to set the slit area rate to 5 to 10%. The reasons for limiting the slit area rate to 5 to 10% are to prevent a decrease in heat conductivity that is ease of heat transfer across the fin 16 to improve a heat transfer coefficient of the first heat-transfer-enhancement parts 17_1_1 and the second heat-transfer-enhancement parts 17_2_1.

In Embodiments 1 to 5, the first heat-transfer-enhancement parts 17_1_1 may have a shape different from a shape of the second heat-transfer-enhancement parts 17_2_1. For example, each of the first heat-transfer-enhancement parts 17_1_1 may be formed into the slit 21, while each of the second heat-transfer-enhancement parts 17_2_1 may be formed into an uneven shape. To avoid frost formation, a smaller count of slits 21 may be formed in the first heat-transfer-enhancement part 17_1_1 than the count of slits 21 to be formed in the second heat-transfer-enhancement part 17_2_1.

The first heat-transfer-enhancement parts 17_1_1 may also have different shapes from each other. For example, the first heat-transfer-enhancement parts 17_1_1 may include the slits 21 and louvers. Likewise, the second heat-transfer-enhancement parts 17_2_1 may also have different shapes from each other. For example, the second heat-transfer-enhancement parts 17_2_1 may include the slits 21 and uneven shapes.

Embodiments 1 to 5 are merely described as examples, and are not intended to limit the scope of the claims. The embodiments can be implemented in various other forms. Various omissions, replacements, and changes can be made without departing from the gist of the embodiments. These embodiments and modifications of these embodiments are included in the scope and gist of the embodiments.

HEAT EXCHANGER

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