ES2877582T3 - Heat exchanger and refrigeration cycle device - Google Patents

Abstract

Heat exchanger (1), comprising: a first fin (11) having a first end (11c) and a second end (11d) in a lateral direction; a second fin (21) having a third end (21c) and a fourth end (21d) in the lateral direction, the third end (21c) being positioned to face the second end (11d); a first heat transfer tube (15) positioned away from the first end (11c) by a first predetermined interval and passing through the first fin (11); and a second heat transfer tube (25) positioned away from the third end (21c) by a second predetermined interval and passing through the second fin (21), the first heat transfer tube (15) having a first flat or curved upper surface (15a) and a first flat lower surface (15c), the second heat transfer tube (25) having a second flat or curved upper surface (25a) and a second flat lower surface (25c), and the heat exchanger being characterized in that: when the first upper surface (15a) is defined as a first surface in a case where the first upper surface (15a) has a flat shape, a tangent plane (17) of the first surface upper surface (15a) is defined as a first surface in a case where the first upper surface (15a) has a curved shape, the second upper surface (25a) is defined as a second surface in a case where the second the upper surface (25a) has a flat shape, and a tangent plane (27) of the second upper surface (25a) is defined as a second surface in a case where the second upper surface (25a) has a curved shape, and when the first heat transfer tube (15) and the second heat transfer tube (25) are viewed such that the first bottom surface (15c) is horizontal, in a vertical cross section perpendicular to a direction in that the first heat transfer tube (15) passes through the first fin (11), the first surface sloping down towards the first end (11c), the second surface sloping down towards the third end (21c), an upper end of the second heat transfer tube (25) being located higher than the first bottom surface (15c), an intersection point A being located at which the second surface intersects or an extension line of the second surface and an extension line of the first lower surface (15c) closer to the second heat transfer tube (25) than an intersection point B where the second surface or the extension line of the second surface intersect and a line of extension of the second lower surface (25c).

Description

DESCRIPTION

Heat exchanger and refrigeration cycle device

Technical field

The present invention relates to a heat exchanger in which both the drainage performance and the heat transfer performance are improved and to a refrigeration cycle apparatus including the same.

Previous technique

An existing heat exchanger has been known in which two or more fin and tube type heat exchange parts are arranged in parallel along a flow direction of air blown in a lateral direction from a fan. More specifically, each of the heat exchange parts of this heat exchanger includes a plurality of fins extending in an up-down direction and a plurality of heat transfer tubes. The plurality of fins are arranged parallel to a predetermined interval in the lateral direction substantially perpendicular to the direction of the air flow. The plurality of heat transfer tubes are arranged in parallel at a predetermined interval in the up-down direction and pass through the fins along a direction of arrangement of these fins. The ends of each of the heat transfer tubes are connected to distribution pipes or manifolds to form refrigerant conduits that include these heat transfer tubes. In the heat exchanger, heat is exchanged between the air flowing into the gaps between the fins and the refrigerant flowing through the heat transfer tubes.

Also proposed is the heat exchanger configured as described above in which a flat tube is used as the heat transfer tube. The flat tube is a heat transfer tube having, for example, an elliptical sectional shape in which the width is greater than the height in a cross-sectional view perpendicular to the flow direction of the refrigerant. Compared with the heat exchanger including the circular tubes, the heat exchanger including the flat tubes can ensure a large heat transfer area of the tubes and reduce the air vent resistance. Therefore, compared with the heat exchanger including the circular tubes, the heat exchanger including the flat tubes can provide improved heat transfer performance. In contrast, when the heat exchanger including the flat tubes is used as an evaporator, its drainage performance is lower than that of the heat exchanger including the circular tubes. This is because water droplets easily stay on the top surfaces of flat tubes.

For example, when in an air conditioner and a refrigeration cycle apparatus such as a freezer, the heat exchanger for an outdoor unit is used as a low temperature evaporator of the outdoor air, the water in the air is condensed and frost forms on the heat exchanger. The formation of frost leads to an increase in the resistance to ventilation, a deterioration in the heat transfer performance and damage to the heat exchanger. To avoid these problems, a normal refrigeration cycle apparatus has a defrost mode of operation to melt the frost that adheres to the heat exchanger. As described above, the water droplets easily stay on the heat exchanger that includes the flat tubes. When the water droplets stay in the heat exchanger, the water droplets freeze and form a large volume of frost. That is, the heat exchanger that includes the flat tubes requires a longer period of defrosting operation, which results in a deterioration in comfort and a reduction in the average heating capacity.

Patent literature 1 discloses that in a heat exchanger in which two fin and tube type heat exchange parts using flat tubes having an elliptical sectional shape are arranged in parallel along a direction of air flow blown in a lateral direction from a fan, the flat tubes are arranged in such a way that the upper surfaces of the flat tubes are inclined.

List of references

Patent bibliography

Patent Bibliography 1: Unexamined Japanese Patent Application Publication No. 2007-183088

JP2005114308A discloses a heat exchanger to reduce ventilation resistance and improve evaporation performance in case of using a heat exchanger as an evaporator.

WO2014091536A1 discloses a flat tube heat exchange apparatus which is capable of being aligned in a zigzag arrangement, even if a row of the flat tube heat exchange apparatus is identically arranged in a plurality of rows, and wherein the positions of the end portions of the fins are not irregular. The flat tube heat exchange apparatus combines a plurality of rows of a single row flat tube heat exchange apparatus having: flat tubes that have a cross-sectional shape that is a rectangle that has a large aspect ratio and rounded corners, and into which a heat exchange medium flows heat; and a plurality of plate-shaped fins into which the flat tubes are inserted, and which combine with the flat tubes in the orthogonal direction. The flat tubes are arranged at a regular pitch in the direction of passage of the fins. If the pitch of the flat tube direction of passage is defined as Dp and the coefficient of Dp is defined as k, and if 0 <k <0.5 or 0.5 <k <1, the distance between one end of fin on one side in the fin passing direction, and a flat tube is kDp, and the distance between a fin end on the other side in the fin passing direction, and a flat tube is (1-k ) Dp. The second row of single row flat tube heat exchange apparatus is arranged to be opposite in the direction of passage to the first row of single row flat tube heat exchange apparatus. Document WO2014091536 discloses a heat exchanger according to the preamble of claim 1. Document JPH1089870A discloses a heat exchanger for improving a close match between heat exchange pipes and plate-shaped fins of an exchanger heat and allow its assembly operation to be carried out easily.

Summary of the invention

Technical problem

In the heat exchanger disclosed in Patent Literature 1, the top surface of each of the flat tubes is tilted to make the condensed water droplets stay on the top surfaces of the flat tubes to be easily drained down the drain. gravity. Accordingly, the heat exchanger disclosed in the patent literature 1 can reduce the period of the defrosting operation. In contrast, the heat exchanger disclosed in patent literature 1 cannot exert sufficient heat transfer performance, which is an advantage of flat tubes.

More specifically, the air that has flowed into the heat exchanger reaches the leading edge of the flat tube and splits into two directions, that is, the direction along the upper surface and the direction along the lower surface of the tube. flat tube. On the surface facing the air flow, air flows along the tube wall and passes through the heat exchanger while maintaining the air velocity relatively high. On the other hand, on the surface that is not oriented towards the air flow, the air hardly flows along the wall of the tube, thus causing stagnation of the air flow, that is, a region of stagnant water. When the heat exchanger disclosed in the patent literature 1 is viewed in the direction of the air flow, the flat tubes of the heat exchange part located downstream in the direction of the air flow are arranged behind the region of standing water from the flat tubes of the upstream heat exchange part. Consequently, a sufficient amount of air does not flow in the vicinity of the surfaces of the flat tubes of the heat exchange part located downstream in the direction of the air flow, thus causing a reduction in the air velocity at a position of this type. As a result, the heat exchanger disclosed in patent literature 1 cannot exert sufficient heat transfer performance, which is an advantage of flat tubes.

As a method of solving the problem, it is proposed that the arrangement positions of the flat tubes located downstream in the direction of the air flow are changed in such a way that the flat tubes located downstream are not located behind the flat tubes located downstream. up when the heat exchanger is viewed in the direction of the air flow. That is, it is proposed that the downstream flat tubes are arranged without overlapping with the upstream flat tubes when the heat exchanger is viewed in the direction of the air flow. However, in the heat exchanger thus configured, the ventilation resistance of the heat exchanger increases, thus causing a deterioration in the heat transfer performance.

An object of the present invention is to provide a heat exchanger in which both the drainage performance and the heat transfer performance are improved and a refrigeration cycle apparatus including the same.

Solution to the problem

A heat exchanger of an embodiment of the present invention is provided according to claim 1.

Advantageous effects of the invention

An embodiment of the present invention provides a heat exchanger in which both the drainage performance and the heat transfer performance are improved and a refrigeration cycle apparatus including the same. It should be noted that Embodiments 3 and 4 are used merely for a better understanding of the present application and do not form part of the invention.

Brief description of the drawings

[Fig. 1] Fig. 1 is a diagram illustrating a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

[Figure 2] Figure 2 is a front view illustrating a heat exchanger according to Embodiment 1 of the present invention.

[Figure 3] Figure 3 is an enlarged view (front view) illustrating a finned main part of the heat exchanger according to Embodiment 1 of the present invention.

[Figure 4] Figure 4 is a cross-sectional view illustrating a heat transfer tube of the heat exchanger according to Embodiment 1 of the present invention.

[Figure 5] Figure 5 is an enlarged view of a main part of a part of figure 2.

[Figure 6] Figure 6 is a front view illustrating a heat exchanger according to Embodiment 2 of the present invention.

[Figure 7] Figure 7 is an enlarged view (front view) illustrating a finned main part of the heat exchanger according to Embodiment 2 of the present invention.

[Figure 8] Figure 8 is an enlarged view of a main part of a part of Figure 6.

[Figure 9] Figure 9 is a front view illustrating a heat exchanger according to Embodiment 3.

[Fig. 10] Fig. 10 is an enlarged-scale view (front view) illustrating a finned main part of the heat exchanger according to Embodiment 3.

[Figure 11] Figure 11 is an enlarged view of a main part of a part of Figure 9.

[Figure 12] Figure 12 is a front view illustrating a heat exchanger according to Embodiment 4.

[Figure 13] Figure 13 is an enlarged view (front view) illustrating a finned main part of the heat exchanger according to Embodiment 4.

[Figure 14] Figure 14 is an enlarged view of a main part of a part of figure 12. Description of embodiments

Hereinafter, embodiments of a heat exchanger and a refrigeration cycle apparatus according to the present invention will be described with reference to the drawings.

Embodiment 1

Fig. 1 is a diagram illustrating a refrigerant circuit of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

A refrigeration cycle apparatus 100 includes a compressor 200, a condenser 300, an expansion mechanism 400, and an evaporator 500. These components of the refrigeration cycle apparatus 100 are connected sequentially through the refrigerant pipes.

Compressor 200 is configured to draw in refrigerant and compress the drawn in refrigerant into a high-pressure, high-temperature gas refrigerant. Condenser 300 is configured to exchange heat between the refrigerant flowing through condenser 300 and air or other heat exchange target. The condenser 300 is, for example, a fin tube type heat exchanger. A fan 301 configured to supply the air that serves as a heat exchange target to the condenser 300 is provided in the vicinity of the condenser 300. The expansion mechanism 400 is, for example, an expansion valve, and is configured to decompress and expand the coolant. Evaporator 500 is configured to exchange heat between the refrigerant flowing through evaporator 500 and air or other heat exchange target. Condenser 500, according to Embodiment 1, is a finned tube type heat exchanger. A fan 501 configured to supply the air that serves as the heat exchange target to the evaporator 500 is provided in the vicinity of the evaporator 500. The fan 501 is, for example, a propeller fan.

In the refrigeration cycle apparatus 100 according to claim 1, a heat exchanger 1 having the following configuration is used as the evaporator 500 to improve both the drainage performance and the heat transfer performance of the evaporator 500.

Fig. 2 is a front view illustrating a heat exchanger according to Embodiment 1 of the present invention. Fig. 3 is an enlarged view (front view) illustrating a finned main part of the present heat exchanger. Fig. 4 is a cross-sectional view illustrating a heat transfer tube of the present heat exchanger. Figure 5 is an enlarged view of a main part of a part of Figure 2.

Figure 2 illustrates heat transfer tubes 15 and 25 in cross section. A blank arrow shown in each of Figure 2 and Figure 5 represents a flow direction of air to be supplied to heat exchanger 1 from fan 501. That is, in Embodiment 1, fan 501 is configured to supply air to the heat exchanger 1 in a substantially horizontal direction. In other words, a rotary shaft of the fan 501, which is a propeller fan, is positioned in the substantially horizontal direction. In each of Figures 2, 3 and 5, this air flow direction is also represented by an arrow X. An arrow Z shown in each of Figures 2, 3 and 5 represents the direction of gravity.

In the heat exchanger 1, a plurality of fin and tube type heat exchange parts are arranged in parallel along the air flow direction. In Embodiment 1, the description focuses on an example in which the heat exchanger 1 includes a first heat exchange part 10 located upstream of the air flow direction, and a second heat exchange part 20 located downstream of the air flow direction. The first heat exchange part 10 and the second heat exchange part 20 have a similar configuration.

More specifically, the first heat exchange part 10 includes a plurality of plate-shaped fins 11 that extend in the up-down direction. These fins 11 are arranged in parallel to a predetermined fin pitch (interval) in a lateral direction perpendicular to the direction of the air flow (a direction perpendicular to the paper plane of Figure 2). A plurality of notches 12 are cut at a downstream end 11d of each of the fins 11 at a predetermined level pitch (gap) in the up-down direction. These notches 12 are cut so that the respective heat transfer tubes 15 are to be inserted into the notches, and have a shape that corresponds to an external shape of the heat transfer tube 15. An upstream end 12a of each of the notches 12 is positioned away from an upstream end 11c of the fin 11 by a predetermined interval (a first predetermined interval). Each of the notches 12 is shaped such that a distance between an upper edge and a lower edge of the notch 12 gradually increases from the upstream end 12a to an opening 12b. Consequently, the heat transfer tubes 15 can be easily inserted into the respective notches 12.

Herein, fin 11 corresponds to a first fin of the present invention. The upstream end 11c corresponds to a first end of the present invention. The downstream end 11d corresponds to a second end of the present invention.

The first heat exchange part 10 includes a plurality of heat transfer tubes 15 inserted into respective notches 12 in each of the fins 11. That is, the heat transfer tubes 15 are arranged in parallel at a pitch of default level in the up-down direction. Each of the heat transfer tubes 15 is provided to pass through the fins 11 in an arrangement direction of these fins 11. The fins 11 and the heat transfer tubes 15 are firmly integrated with each other by brazing. Each of these heat transfer tubes 15 has a width greater than the height in a cross-sectional view perpendicular to the direction of flow of the refrigerant. Each of the heat transfer tubes 15 houses a plurality of partitions that define a plurality of refrigerant conduits 16 within the heat transfer tube 15.

The shape of the heat transfer tube 15 will be described later in detail. The heat transfer tube 15 has a flat top surface 15a and a flat bottom surface 15c. A distance between the upper surface 15a and the lower surface 15c gradually increases from the upstream end 15b towards the downstream end 15d. In other words, the distance between the upper surface 15a and the lower surface 15c gradually increases from the upstream end 11c towards the downstream end 11d of the fin 11. Such a heat transfer tube 15 is made of, for example, aluminum or an aluminum alloy, and is manufactured by, for example, extrusion molding. Thus, in embodiment 1, the heat transfer tube 15 houses partitions, which define a plurality of refrigerant conduits 16 within the heat transfer tube 15, such that the upper surface 15a and the lower surface 15c are substantially symmetrical to a plane that includes a bisector of an angle formed by the upper surface 15a and the lower surface 15c. This shape can easily ensure the manufacturability in extrusion molding of the heat transfer tube 15. The heat transfer tube 15 can be manufactured by, for example, extrusion molding to have an elliptical section shape and then be transformed into a final shape by an additional procedure such as a press. The wall surfaces of the refrigerant conduits 16, that is, the inner wall surfaces of the heat transfer tube 15, may have grooves. This structure increases the contact area between the surfaces of the internal walls of the heat transfer tube 15 and the refrigerant. Consequently, the efficiency of heat exchange is improved.

Herein, any one of the heat transfer tubes 15 corresponds to a first heat transfer tube. The upper surface 15a of the heat transfer tube 15 corresponding to the first heat transfer tube corresponds to a first surface of the present invention.

As described above, the upstream ends 12a of the respective notches 12, into which the respective heat transfer tubes 15 are to be inserted, in each of the fins 11 are positioned away from the upstream end 11c of the fin 11 using the default interval (the first default interval). Accordingly, in a state where the heat transfer tubes 15 fit into the fin 11, the upstream ends 15b of the respective heat transfer tubes 15 are also positioned away from the upstream end 11c of the fin 11. using the default interval (the first default interval). Such an arrangement allows each of the fins 11 to have a first area 11a and a second area 11b. The first area 11a is an area in which a plurality of notches 12 are cut in a longitudinal direction corresponding to the direction of gravity (represented by the arrow Z), and the heat transfer tubes 15 are provided. The second area 11b is an area in which heat transfer tubes 15 are not provided in the longitudinal direction (represented by arrow Z), and it is a water drainage area for draining the water adhering to the fin 11. The second area 11b is positioned upstream of the first area 11a in the flow direction (represented by arrow X) of the air serving as the heat exchange fluid. The boundary between the first area 11a and the second area 11b is a virtual straight line connecting the upstream ends 12a of the respective notches 12 arranged in parallel in the up-down direction, in other words, a virtual straight line connecting the upstream ends 15b of the respective heat transfer tubes 15 arranged in parallel in the up-down direction.

In the state in which the heat transfer tubes 15 fit into the fin 11, each of the upper surfaces 15a of the respective heat transfer tubes 15 slopes downwardly from the downstream end 11 d towards the end upstream 11c of the fin 11, in other words, towards the second area 11b, which is the water drainage area. That is, the upper surface 15a of the heat transfer tube 15 slopes downward towards the upstream end 11c of the fin 11. In Embodiment 1, the upper surface 15a of the heat transfer tube 15 slopes by an angle 0 with respect to the horizontal surface. On the other hand, in the state in which the heat transfer tubes 15 are fixed on the fin 11, each of the lower surfaces 15c of the respective heat transfer tubes 15 is substantially horizontal.

The second heat exchange part 20 includes a plurality of plate-shaped fins 21 extending in the up-down direction. These fins 21 are arranged parallel to a predetermined fin pitch (interval) in a lateral direction perpendicular to the direction of the air flow (a direction perpendicular to the paper plane of Figure 2). A plurality of notches 22 are cut at a downstream end 21d of each of the fins 21 at a predetermined level pitch (gap) in the up-down direction. These notches 22 are cut so that the respective heat transfer tubes 25 are to be inserted into the notches 22, and have a shape that corresponds to an external shape of the heat transfer tube 25. An upstream end 22a of each one of the notches 22 is positioned away from an upstream end 21c of each of the fins 21 by a predetermined interval (a second predetermined interval). Each of the notches 22 is shaped such that a distance between an upper edge and a lower edge of the notch 22 gradually increases from the upstream end 22a to an opening 22b. Consequently, the heat transfer tube 25 can be easily inserted into the corresponding notch 22.

Herein, fin 21 corresponds to a second fin of the present invention. The upstream end 21c corresponds to a third end of the present invention. The downstream end 21d corresponds to a fourth end of the present invention.

The second heat exchange part 20 includes a plurality of heat transfer tubes 25 inserted into respective notches 22 in each of the fins 21. That is, the heat transfer tubes 25 are arranged in parallel at a pitch of default level in the up-down direction. Each of the heat transfer tubes 25 is provided to pass through the fins 21 in an arrangement direction of these fins 21. The fins 21 and the heat transfer tubes 25 are firmly integrated with each other by brazing. Each of these heat transfer tubes 25 has a width greater than the height in a cross-sectional view perpendicular to the direction of flow of the refrigerant. Each of the heat transfer tubes 25 houses a plurality of partitions that define a plurality of refrigerant conduits 26 within the heat transfer tube 25.

The shape of the heat transfer tube 25 will be described later in detail. The heat transfer tube 25 has a flat top surface 25a and a flat bottom surface 25c. A distance between the upper surface 25a and the lower surface 25c gradually increases from the upstream end 25b towards the downstream end 25d. In other words, the distance between the upper surface 25a and the lower surface 25c gradually increases from the upstream end 21c towards the downstream end 21d of the fin 21. Such a heat transfer tube 25 is made of, for example, aluminum or an aluminum alloy, and is manufactured by, for example, extrusion molding. Therefore, in Embodiment 1, the heat transfer tube 25 houses partitions that define a plurality of refrigerant conduits 26 within the heat transfer tube. heat transfer 25 such that upper surface 25a and lower surface 25c are substantially symmetrical to a plane that includes a bisector of an angle formed by upper surface 25a and lower surface 25c. This shape can easily ensure the manufacturability in extrusion molding of the heat transfer tube 25. The heat transfer tube 25 can be manufactured by, for example, extrusion molding to have an elliptical section shape and then be transformed into a final shape by an additional procedure such as a press. The wall surfaces of the refrigerant conduits 26, that is, the inner wall surfaces of the heat transfer tube 25, may have grooves. This structure increases the contact area between the inner wall surfaces of the heat transfer tube 25 and the refrigerant. Consequently, the efficiency of heat exchange is improved.

Herein, the heat transfer tube 25 laterally adjacent to the heat transfer tube 15 corresponding to the first heat transfer tube corresponds to a second heat transfer tube of the present invention. The upper surface 25a of the heat transfer tube 25 corresponding to the second heat transfer tube corresponds to a second surface of the present invention.

As described above, the upstream ends 22a of the respective notches 22, into which the respective heat transfer tubes 25 are to be inserted, in each of the fins 21 are positioned away from the upstream end 21c of the fin 21 using the default interval (the second default interval). Accordingly, in a state where the heat transfer tubes 25 fit into the fin 21, the upstream ends 25b of the respective heat transfer tubes 25 are also positioned away from the upstream end 21c of the fin 21. using the default interval (the second default interval). Such an arrangement allows each of the fins 21 to have a first area 21a and a second area 21b. The first area 21a is an area in which a plurality of notches 22 are cut in a longitudinal direction corresponding to the direction of gravity (represented by arrow Z), and heat transfer tubes 25 are provided. The second area 21b is an area in which heat transfer tubes 25 are not provided in the longitudinal direction (represented by arrow Z), and it is a water drainage area for draining the water adhering to the fin 21. The second Area 21b is positioned upstream of the first area 21a in the flow direction (represented by arrow X) of the air serving as the heat exchange fluid. The boundary between the first area 21a and the second area 21b is a virtual straight line connecting the upstream ends 22a of the respective notches 22 arranged in parallel in the up-down direction, in other words, a virtual straight line connecting the upstream ends 25b of the respective heat transfer tubes 25 arranged in parallel in the up-down direction.

In the state in which the heat transfer tubes 25 fit into the fin 21, each of the upper surfaces 25a of the respective heat transfer tubes 25 slopes downwardly from the downstream end 21d towards the downstream end. up 21c of the fin 21, in other words, towards the second area 21b, which is the water drainage area. That is, the upper surface 25a of the heat transfer tube 25 slopes downward toward the upstream end 21c of the fin 21. In Embodiment 1, the upper surface 25a of the heat transfer tube 25 slopes by an angle 0 with respect to the horizontal surface. On the other hand, in the state in which the heat transfer tubes 25 are fixed on the fin 21, each of the lower surfaces 25c of the respective heat transfer tubes 25 is substantially horizontal.

The first heat exchange part 10 and the second heat exchange part 20 configured as described above are arranged in such a way that the downstream ends 11d of the respective fins 11 of the first heat exchange part 10 and the Upstream ends 21c of the respective fins 21 of the second heat exchange part 20 are oriented towards each other. Even when the fins 11 of the first heat exchange part 10 and the fins 21 of the second heat exchange part 20 are displaced relative to each other in the direction perpendicular to the paper plane of Fig. 2, in Embodiment 1, the Downstream ends 11d of the respective fins 11 of the first heat exchange part 10 are each interpreted as facing the corresponding one of the upstream ends 21c of the respective fins 21 of the second heat exchange part 20.

In the heat exchanger 1 according to embodiment 1, the heat transfer tubes 15 of the first heat exchange part 10 and the heat transfer tubes 25 of the second heat exchange part 20, the transfer tubes being tubes 25 laterally adjacent to the respective heat transfer tubes 15, are provided in an arranged relationship as illustrated in Figure 5, illustrating a vertical cross section perpendicular to the direction in which the heat transfer tubes 15 pass through fins 11, in other words, as illustrated in figure 5, illustrating a vertical cross section perpendicular to the direction in which heat transfer tubes 25 pass through fins 21 To describe this layout relationship in detail, the intersection points A and B are defined below. An intersection point at which an extension line of the s intersect The second surface of the present invention (the upper surface 25a of the heat transfer tube 25 in embodiment 1) or the second surface and an extension line of the lower surface 15c of the heat transfer tube 15 is defined as the point of intersection A. An intersection point at which the extension line of the second surface of the present invention (the upper surface 25a of the heat transfer tube 25 in Embodiment 1) or the second surface and an extension line of the present invention intersect. the bottom surface 25c of the heat transfer tube 25 is defined as the point of intersection B.

More specifically, the upper end (a point C in Figure 5) of the heat transfer tube 25 is positioned higher than the bottom surface 15c of the heat transfer tube 15 laterally adjacent to the heat transfer tube 25. The point intersection A in which the upper surface 25a of the heat transfer tube 25 and the extension line of the lower surface 15c of the heat transfer tube 15 intersect is located closer to the heat transfer tube 25 which is in the point of intersection B at which the extension line of the upper surface 25a and the extension line of the lower surface 25c of the heat transfer tube 25 intersect. That is, the point of intersection A is located downstream of the point of intersection B in the direction of the air flow. In such an arrangement relationship, the heat transfer tube 15 of the first heat exchange part 10 and the heat transfer tube 25 of the second heat exchange part 20, the heat transfer tube being 25 laterally adjacent to the heat transfer tube 15, overlap each other when the heat exchanger 1 is viewed in the direction of the air flow. In the arrangement relationship between the heat transfer tube 15 and the heat transfer tube 25 overlapping each other when the heat exchanger 1 is viewed in the direction of the air flow, the heat exchange tube 25 is slightly lower than heat transfer tube 15.

Next, the operation of the heat exchanger 1 according to Embodiment 1 will be described.

First, the heat exchange action between the air supplied from the fan 501 and the refrigerant flowing in the heat transfer tubes 15 and 25 will be described.

As described above, the fan 501 is, for example, a propeller fan, and the rotary axis of the fan 501 is positioned in the substantially horizontal direction. As represented by the blank arrow in each of Figures 2 and 5, the air supplied from the fan 501 flows in the substantially horizontal direction towards the heat exchanger 1 from the upstream end 11c of the fin 11 of the first heat exchange part 10. This air flows into the first heat exchange part 10 and then flows out through the second heat exchange part 20.

More specifically, the air supplied from the fan 501 flows into gaps between the fins 11 of the first heat exchange part 10 from the upstream ends 11c of the respective fins 11. When this air reaches the upstream end 15b of the exhaust tube heat transfer 15, the air is divided into two directions, that is, the direction along the upper surface 15a and the direction along the lower surface 15c.

As described above, the upper surface 15a of the heat transfer tube 15 slopes downward towards the upstream end 11c of the fin 11. That is, the upper surface 15a of the heat transfer tube 15 faces the air flow. Therefore, air can flow along the upper surface 15a through most of the heat transfer tube 15 in the width direction. Therefore, the air flow without significant separation can facilitate the heat exchange between the air and the heat transfer tube 15, and can also reduce the resistance to ventilation.

As described above, the lower surface 15c of the heat transfer tube 15 is substantially horizontal. That is, the direction of the lower surface 15c of the heat transfer tube 15 substantially coincides with the direction of the air flow. Thus, air can flow along the bottom surface 15c through substantially the entire heat transfer tube 15 in the width direction. Therefore, the air flow without significant separation can facilitate the heat exchange between the air and the surface of the heat transfer tube 15 and can also reduce the resistance to ventilation.

When the focus is on the heat transfer tubes 15 adjacent to each other in the up-down direction, a gap between the lower surface 15c of the upper heat transfer tube 15 and the upper surface 15a of the heat transfer tube 15 downstream narrows in the downstream direction of the air flow. This configuration can reduce the creation of a low air velocity region (a region of standing water) between the upper surface and the lower surface due to the expansion of the air passage, and can facilitate heat exchange between the air and the surface of the first heat exchange part 10.

The air that has flowed around the heat transfer tubes 15 flows out of the first heat exchange part 10 from the downstream ends 11d of the respective fins 11. Herein, in each of the transfer tubes of heat 15 of the first heat exchange part 10, the upper surface 15a slopes downwardly towards the upstream end 11c and the lower surface 15c is substantially horizontal. Air flowing between heat transfer tubes 15 adjacent to each other in the up-down direction flows more upward than in the horizontal direction.

The air that has flowed out of the first heat exchange part 10 flows into gaps between the fins 21 of the second heat exchange part 20 from the upstream ends 21c of the respective fins 21.

When this air reaches the upstream end 25b of the heat transfer tube 25, the air splits into two directions, that is, the direction along the upper surface 25a and the direction along the lower surface 25c.

The upper surface 25a of the heat transfer tube 25 is located behind the downstream end 15d of the heat transfer tube 15 located upstream of the heat transfer tube 25, in the direction of the air flow. That is, according to an existing technique, the upper surface 25a of the heat transfer tube 25 is located behind the region of stagnant water, which causes that a sufficient amount of air cannot flow through the upper surface 25a, reducing thus the air velocity and the efficiency of heat exchange. However, in Embodiment 1, the air flowing into the gaps between the fins 21 flows more upward than the horizontal direction and reaches the upstream ends 25b of the respective heat transfer tubes 25. Therefore, as shown By means of an arrow W illustrated in Figure 5, a part of the air that has reached the upstream end 25b of the heat transfer tube 25 can flow along the upper surface 25a. This configuration can facilitate heat exchange between the air and the upper surface 25a. In Embodiment 1, the upstream end 25b of the heat transfer tube 25 is positioned slightly lower than the heat transfer tube 15. Therefore, the amount of air flowing along the upper surface 25a of the heat transfer tube 25 can be increased, thereby facilitating heat exchange between the air and the upper surface 25a.

On the other hand, since the air that has reached the upstream end 25b of the heat transfer tube 25 flows more upward than the horizontal direction, the lower surface 25c of the heat transfer tube 25 is oriented towards the air flow. Accordingly, air can flow along the lower surface 25c of the heat transfer tube 25. This configuration can facilitate heat exchange between the air and the lower surface 25c.

Next, the water draining action to drain the water droplets adhering to the heat exchanger 1 will be described.

The water draining action of the first heat exchange part 10 is described below.

The water droplets adhering to the first area 11a of each of the fins 11 of the first heat exchange part 10 flow along the surface of the fin 11 which is in the first area 11a to fall. These water droplets reach the upper surface 15a of each of the heat transfer tubes 15. The water droplets that have reached the upper surface 15a of the heat transfer tube 15 flow along the upper surface 15a towards the upstream end 15b due to the influence of gravity. Most of the water droplets that have reached the upstream end 15b flow towards the second area 11b using the momentum of the water droplets that flow along the upper surface 15a, and flow towards the bottom of the first part. heat exchange 10. As the second area 11b does not include heat transfer tubes 15, the water droplets flow along the surface of the fin 11, reach the bottom of the first heat exchange part 10 and they drain without stopping. That is, the first heat exchange part 10 can provide the improved drainage performance even while using the heat transfer tubes 15 which have a width greater than the height in a cross-sectional shape.

Some of the water droplets that have not flowed from the first area 11a to the second area 11b flow along the upstream end 15b of the heat transfer tube 15 towards the lower surface 15c. The water droplets that have flowed towards the lower surface 15c of the heat transfer tube 15 remain and grow on the lower surface 15c of the heat transfer tube 15, while surface tension, gravity, static friction force and others forces balance. The water droplets expand downward and become more susceptible to gravity as the water droplets grow. When the gravity in the water droplets exceeds the component of the forces including the surface tension in the direction opposite to the direction of gravity, the water droplets are unaffected by the surface tension and leave the lower surface 15c of the tube. heat transfer 15. The water droplets that have left the lower surface 15c of the heat transfer tube 15 flow down along the first area 11a again and reach the upper surface 15a of the lower heat transfer tube 15 . Then the water droplets repeat the operations described above and finally drain towards the bottom of the first heat exchange part 10.

The water draining action of the second heat exchange part 20 is also similar to that of the first heat exchange part 10.

That is, the water droplets that adhere to the first area 21a of each of the fins 21 of the second heat exchange part 20 flow along the surface of the fin 21 that is in the first area 21a to fall. These water droplets reach the upper surface 25a of each of the heat transfer tubes 25. The water droplets that have reached the upper surface 25a of the heat transfer tube 25 flow along the upper surface 25a towards the upstream end 25b due to the influence of gravity. Most of the water droplets that have reached the upstream end 25b flow into the second area 21b using the momentum of the water droplets flowing along the upper surface 25a, and flowing towards the bottom of the second heat exchange part 20. As the second area 21b does not include heat transfer tubes 25, the water droplets flow along the surface of the fin 21, reach the bottom of the second heat exchange part 20, and drain without stopping. That is, the second heat exchange part 20 can provide the improved drainage performance even while using the heat transfer tubes 25 which have a width greater than the height in a cross-sectional shape.

Some of the water droplets that have not flowed from the first area 21a to the second area 21b flow along the upstream end 25b of the heat transfer tube 25 towards the lower surface 25c. The water droplets that have flowed towards the lower surface 25c of the heat transfer tube 25 remain and grow on the lower surface 25c of the heat transfer tube 25, while surface tension, gravity, static friction force and others forces balance. The water droplets expand downward and become more susceptible to gravity as the water droplets grow. When the gravity in the water droplets exceeds the component of the forces including the surface tension in the opposite direction to the direction of gravity, the water droplets are unaffected by the surface tension and leave the lower surface 25c of the tube. heat transfer 25. The water droplets that have left the lower surface 25c of the heat transfer tube 25 flow down along the first area 21a again and reach the upper surface 25a of the lower heat transfer tube 25 . Afterwards, the water droplets repeat the operations described above and finally drain towards the bottom of the second heat exchange part 20.

As described above, the heat exchanger 1 according to embodiment 1 includes the fins 11 each having the upstream end 11c and the downstream end 11d in the lateral direction, the fins 21 each having the upstream end 21c and the downstream end 21d in the lateral direction, the upstream end 21c being positioned to face the downstream end 11d, the heat transfer tubes 15 positioned each away from the upstream end 11c by the first predetermined interval and passing to through fins 11 and heat transfer tubes 25 each positioned away from upstream end 21c via the second predetermined interval and passing through fins 21. Heat transfer tube 15 has flat top surface 15a and the flat bottom surface 15c. The heat transfer tube 25 has the flat top surface 25a and the flat bottom surface 25c. Herein, the top surface 15a and the top surface 25a will be defined as a first surface and a second surface, respectively. When the heat transfer tube 15 and the heat transfer tube 25 are viewed such that the lower surface 15c is horizontal, in vertical cross section perpendicular to the direction in which the heat transfer tube 15 passes to Through the fins 11, the first surface slopes down towards the upstream end 11c, the second surface slopes downwards towards the upstream end 21c, the upper end of the heat transfer tube 25 is positioned higher than the lower surface 15c, and the point of intersection A at which the second surface and the extension line of the lower surface 15c intersect is situated closer to the heat transfer tube 25 than the point of intersection B at which the line intersect extension line of the second surface and the extension line of the lower surface 25c.

Accordingly, the heat exchanger 1 according to Embodiment 1 can provide the improved drainage performance even while using the heat transfer tubes 15 and 25 each having a width greater than the height in a cross-sectional shape. In the heat exchanger 1 according to Embodiment 1, the arrangement relationship between the heat transfer tube 15 located upstream of the air flow and the heat transfer tube 25 located downstream of the air flow overlapping each other When the heat exchanger 1 is viewed in the direction of the air flow it can also facilitate heat exchange in the heat transfer tube 25, as described above. Therefore, in the heat exchanger 1 according to Embodiment 1, both the drainage performance and the heat transfer performance are improved.

In embodiment 1, the lower surface 15c, 25c of the heat transfer tube 15, 25 is positioned to be horizontal. However, without being limited to this arrangement, the lower surface 15c, 25c of the heat transfer tube 15, 25 can be positioned to tilt with respect to the horizontal plane. When the upper surface 15a, 25a of the heat transfer tube 15, 25 slopes down towards the second area 11b, 21b, the drainage performance can be improved as described above. In addition, when air is supplied from the fan 501 to the heat exchanger 1 so that the air flows along the lower surface 15c of the heat transfer tube 15, the heat transfer performance can be improved as shown. described above. However, when the lower surface 15c, 25c of the heat transfer tube 15, 25 is positioned to slope downward from the upstream end 15b, 25b towards the downstream end 15d, 25d, the water droplets that have reached the upstream end 15b, 25b from the upper surface 15a, 25a of the heat transfer tube 15, 25 easily flow to the lower surface 15c, 25c. Accordingly, the improved drainage performance described above is slightly reduced. Therefore, it is preferable that the lower surface 15c, 25c of the heat transfer tube 15, 25 is positioned to be horizontal or to slope downward from the downstream end 15d, 25d towards the upstream end 15b, 25b. In other words, it is preferable that the lower surface 15c, 25c of the heat transfer tube 15, 25 is positioned to be horizontal or to slope downward from the downstream end 11d, 21d towards the water end. top 11c, 21c of fin 11, 12.

In Embodiment 1, the heat transfer tubes 15 and 25 are fixed in the respective notches 12 and 22 of each of the fins 11 and 21, but the fins 11 and 21 may have through holes in the fins 11 and 21 of so that the heat transfer tubes 15 and 25 are inserted into the respective through holes. This configuration of the heat exchanger 1 allows both the drainage performance and the heat transfer performance to be improved.

In Embodiment 1, fin 11 and fin 21 are formed independently, but fin 11 and fin 21 can be integrally formed to form a fin piece. In this case, only the heat exchanger 1 is required to be manufactured with respect to the virtual straight line extending in the up-down direction at the position away from the upstream end 25b of the heat transfer tube 25 by the predetermined interval ( the second predetermined interval) as the downstream end 11d of the fin 11 and the upstream end 21c of the fin 21. This configuration of the heat exchanger 1 allows both the drainage performance and the heat transfer performance to be improved.

Embodiment 2

In Embodiment 1, the inclination of the lower surface 15c of the heat transfer tube 15 is the same as that of the lower surface 25c of the heat transfer tube 25. However, without being limited to this configuration, the inclination of the bottom surface 15c of the heat transfer tube 15 may be different from the bottom surface 25c of the heat transfer tube 25 to configure the next heat exchanger 1. It should be noted that the elements not particularly described in embodiment 2 are similar to those of Embodiment 1 and the same functions or configurations are described with the same reference signs.

Fig. 6 is a front view illustrating a heat exchanger according to Embodiment 2 of the present invention. Fig. 7 is an enlarged-scale view (front view) illustrating a finned main part of the present heat exchanger. Figure 8 is an enlarged view of a main part of a part of Figure 6.

Figure 6 illustrates heat transfer tubes 15 and 25 in cross section. A blank arrow shown in each of Figure 6 and Figure 8 represents a flow direction of air to be supplied to heat exchanger 1 from fan 501. That is, in Embodiment 2, fan 501 is configured to supply air to the heat exchanger 1 in a substantially horizontal direction. In other words, the rotary axis of the fan 501, which is a propeller fan, is positioned in the substantially horizontal direction. In each of Figures 6 to 8, this air flow direction is also represented by an arrow X. An arrow Z shown in each of Figures 6 to 8 represents the direction of gravity.

Also in the heat exchanger 1 according to embodiment 2, the heat transfer tubes 15 of the first heat exchange part 10 and the heat transfer tubes 25 of the second heat exchange part 20, the tubes being heat transfer 25 laterally adjacent to the respective heat transfer tubes 15, are arranged in such a way that the upper end of the heat transfer tube 25 and the intersection points A and B are located in the same way as in the embodiment 1 in a vertical cross section perpendicular to the direction in which the heat transfer tubes 15 pass through the fins 11, in other words, in a vertical cross section perpendicular to the direction in which the heat transfer tubes heat 25 pass through fins 21.

More specifically, the upper end (a point C in Figure 8) of the heat transfer tube 25 is positioned higher than the bottom surface 15c of the heat transfer tube 15 laterally adjacent to the heat transfer tube 25. The point intersection A in which the upper surface 25a of the heat transfer tube 25 and the extension line of the lower surface 15c of the heat transfer tube 15 intersect is located closer to the heat transfer tube 25 which is in the point of intersection B at which the extension line of the upper surface 25a and the extension line of the lower surface 25c of the heat transfer tube 25 intersect. That is, the point of intersection A is located downstream of the point of intersection B in the direction of the air flow. Therefore, also in the heat exchanger 1 according to embodiment 2, the heat transfer tube 15 of the first heat exchange part 10 and the heat transfer tube 25 of the second heat exchange part 20, being the heat transfer tube 25 laterally adjacent to the heat transfer tube 15, overlap each other when the heat exchanger 1 is viewed in the direction of the air flow in the same way as in embodiment 1. In the relation of arrangement between heat transfer tube 15 and heat transfer tube 25 overlapping each other when heat exchanger 1 is viewed in the direction of air flow, the upstream end 25b of heat transfer tube 25 it is located slightly lower than the lower surface 15c of the heat transfer tube 15.

The heat exchanger 1 according to embodiment 2 differs from that of embodiment 1 in that the lower surface 25c of the heat transfer tube 25 slopes downward from the downstream end 21 d towards the upstream end 21c of the fin 21, In other words, towards the second area 21b, which is a drainage area of Water. That is, the lower surface 25c of the heat transfer tube 25 slopes downward toward the upstream end 21c of the fin 21.

Also in the heat exchanger 1 according to embodiment 2 configured in this way, the water droplets that have reached the upper surface 15a, 25a of the heat transfer tube 15, 25 can drain into the second area 11b, 21b which does not include heat transfer tubes 15, 25 due to the influence of gravity, in the same way as in embodiment 1. Furthermore, in heat exchanger 1 according to embodiment 2, the lower surface 25c of heat transfer tube 25 it also slopes down towards the second area 21b. Consequently, the water droplets adhering to the lower surface 25c of the heat transfer tube 25 flow along the lower surface 25c towards the upstream end 25b due to the influence of gravity. Most of the water droplets that have reached the upstream end 25b are drained into the second area 21b using the momentum of the water droplets flowing along the lower surface 25c. Therefore, the heat exchanger 1 according to embodiment 2 can provide a further improved drainage performance compared to the heat exchanger 1 according to embodiment 1.

The heat exchanger 1 according to embodiment 2 can provide a further improved heat transfer performance compared to the heat exchanger 1 according to embodiment 1. More specifically, in the heat transfer tube 25 according to embodiment 2, both the upper surface 25a and lower surface 25c are arranged to be inclined downward in the upstream direction of the air flow. Accordingly, a plane including a bisector of an angle formed by the upper surface 25a and the lower surface 25c is inclined downward in the upstream direction of the air flow. In other words, a center line of the cross section of the heat transfer tube 25 is inclined downward in the upstream direction of the air flow in the cross section perpendicular to the direction in which the heat transfer tubes 25 pass through the fins 21. Herein, as described in Embodiment 1, the air flowing into gaps between the fins 21 of the second heat exchange part 20 flows more upward than the horizontal direction and reaches the upstream ends 25b of the respective heat transfer tubes 25. That is, the heat exchanger 1 according to embodiment 2 is configured such that the center line of the cross-section of the heat transfer tube 25 is at along the air flow compared to the heat exchanger 1 according to embodiment 1. Therefore, in the heat exchanger 1 according to embodiment 2, the resistance to wind nthylation when air flows around the heat transfer tube 25 can be further reduced, compared to the heat exchanger 1 according to embodiment 1. Thus, in the heat exchanger 1 according to embodiment 2, the heat exchange in the Heat transfer tube 25 can be further provided and the heat transfer performance can be further improved, compared to the heat exchanger 1 according to Embodiment 1.

Embodiment 3

In Embodiment 1 and Embodiment 2, the intersection point A is located closer to the heat transfer tube 25 than the intersection point B. Embodiment 3, which is not part of the invention, will be described by illustrating an example in that the arrangement positions of the heat transfer tubes 25 in the heat exchanger 1 according to embodiment 1 are shifted upwards so that the intersection point A coincides with the intersection point B. It should be noted that the elements do not described particularly in Embodiment 3 are similar to those of Embodiment 1 or Embodiment 2 and the same functions or configurations are described with the same reference signs.

Fig. 9 is a front view illustrating a heat exchanger according to Embodiment 3. Fig. 10 is an enlarged-scale view (front view) illustrating a finned main part of the present heat exchanger. Figure 11 is an enlarged view of a main part of a part of Figure 9.

Figure 9 illustrates heat transfer tubes 15 and 25 in cross section. A blank arrow shown in each of Figure 9 and Figure 11 represents an air flow direction to be supplied to heat exchanger 1 from fan 501. That is, in Embodiment 3, fan 501 is configured to supply air to the heat exchanger 1 in a substantially horizontal direction. In other words, the rotary axis of the fan 501, which is a propeller fan, is positioned in the substantially horizontal direction. In each of Figures 9 to 11, this air flow direction is also represented by an arrow X. An arrow Z shown in each of Figures 9 to 11 represents the direction of gravity.

In the heat exchanger 1 according to embodiment 3, the intersection point A at which the extension line of the upper surface 25a of the heat transfer tube 25 and the extension line of the lower surface 15c of the transfer tube intersect of heat 15 coincides with the point of intersection B where the extension line of the upper surface 25a and the extension line of the lower surface 25c of the heat transfer tube 25 intersect. Also in embodiment 3, the upper end (a point C in Figure 11) of the heat transfer tube 25 is positioned higher than the bottom surface 15c of the heat transfer tube 15 laterally adjacent to the heat transfer tube 25 in the same manner as in Embodiment 1 and Embodiment 2. The other configurations of the heat exchanger 1 according to Embodiment 3 are similar to Embodiment 1.

When the arrangement positions of the heat transfer tubes 25 in the heat exchanger 1 according to embodiment 1 are shifted upwards such that the intersection point A coincides with the intersection point B as in the heat exchanger 1 according to Embodiment 3, the heat transfer tube 15 and the heat transfer tube 25, which are laterally adjacent to each other, overlap each other when the heat exchanger 1 is viewed in the direction of air flow, from the same as in Embodiment 1. In the heat transfer tube 15 and the heat transfer tube 25 overlapping each other when the heat exchanger 1 is viewed in the direction of the air flow, the position in the up direction -Down the bottom surface 25c of the heat transfer tube 25 coincides with the position in the up-down direction of the bottom surface 15c of the heat transfer tube 15.

When the arrangement positions of the heat transfer tubes 25 in the heat exchanger 1 according to embodiment 2 are shifted upward so that the intersection point A coincides with the intersection point B, the heat transfer tube 15 and the heat transfer tube 25, which are laterally adjacent to each other, overlap each other when the heat exchanger 1 is viewed in the direction of the air flow, in the same way as in Embodiment 2. In the tube of heat transfer 15 and heat transfer tube 25 overlapping each other when heat exchanger 1 is viewed in the direction of air flow, the upstream end 25b of heat transfer tube 25 is positioned slightly higher than the lower surface 15c of the heat transfer tube 15.

Also in the heat exchanger 1 configured as in embodiment 3 the water droplets that have reached the upper surface 15a, 25a of the heat transfer tube 15, 25 can drain into the second area 11b, 21b which does not include transfer tubes of heat 15, 25 due to the influence of gravity, in the same way as in Embodiment 1 and Embodiment 2. Therefore, the heat exchanger 1 according to Embodiment 3 can provide the improved drainage performance in the same way than in embodiment 1 and embodiment 2.

In the heat exchanger 1 according to Embodiment 3, the arrangement and orientation of the heat transfer tubes 15 which are adjacent to each other in the up-down direction in the first heat exchange part 10 are the same as in the Embodiment 1 and Embodiment 2. Accordingly, the air flowing into the gaps between the fins 21 of the second heat exchange part 20 flows more upward than the horizontal direction and reaches the upstream ends 25b of the respective transfer tubes. heat exchanger 25. Therefore, even when the heat exchanger 1 is configured as in embodiment 3, a sufficient amount of air can flow along the upper surfaces 25a of the respective heat transfer tubes 25 of the second heat exchange part 20. Therefore, in the heat exchanger 1 configured as in embodiment 3, the heat transfer performance can also be improved.

That is, in the heat exchanger 1 according to Embodiment 3, both the drainage performance and the heat transfer performance can also be improved in the same way as in Embodiment 1 and Embodiment 2.

When the arrangement positions of the heat transfer tubes 25 in the heat exchanger 1 according to Embodiment 1 are shifted upward such that the intersection point A coincides with the intersection point B, a degree of overlap between the tube heat transfer tube 15 and heat transfer tube 25 which are laterally adjacent to each other when the heat exchanger 1 viewed in the direction of the air flow becomes the largest as illustrated in figure 11 or others figures. For example, when heat transfer tubes having the same shape are used as heat transfer tube 15 and heat transfer tube 25, the heat transfer tube 25 is completely hidden behind the heat transfer tube. heat 15 when the heat exchanger 1 is viewed in the direction of the air flow as illustrated in Figure 11 or other figures. Consequently, when the arrangement positions of the heat transfer tubes 25 in the heat exchanger 1 according to Embodiment 1 are shifted upward such that the intersection point A coincides with the intersection point B, the resistance to Ventilation can be reduced by increasing the degree of overlap between the heat transfer tube 15 and the heat transfer tube 25, and the heat transfer performance can be improved by reducing the amount of the ventilation resistance.

Embodiment 4

In embodiment 1 to embodiment 3 the heat transfer tube 15, 25 having the flat top surface 15a, 25a is used. Embodiment 4 discloses an example using the heat transfer tube 15, 25 having a curved upper surface 15a, 25a. It should be noted that the elements not particularly described in embodiment 4 are similar to those in any of embodiment 1 to embodiment 3 and the same functions or configurations are described with the same reference signs.

Fig. 12 is a front view illustrating a heat exchanger according to the embodiment that is not part of the present invention. Figure 13 is an enlarged view (front view) illustrating a main part fins of the present heat exchanger. Figure 14 is an enlarged view of a main part of a part of Figure 12.

Figure 12 illustrates heat transfer tubes 15 and 25 in cross section. A blank arrow shown in each of Figure 12 and Figure 14 represents an air flow direction to be supplied to heat exchanger 1 from fan 501. That is, in Embodiment 4, fan 501 is configured to supply air to the heat exchanger 1 in a substantially horizontal direction. In other words, the rotary axis of the fan 501, which is a propeller fan, is positioned in the substantially horizontal direction. In each of Figures 12 to 14, this air flow direction is also represented by an arrow X. An arrow Z shown in each of Figures 12 to 14 represents the direction of gravity.

In embodiment 1 to embodiment 3, a plurality of notches 12, into which the respective heat transfer tubes 15 are to be inserted, are cut into each of the fins 11 of the first heat exchange part 10 at a default level crossing (space) in the up-down direction. On the other hand, in embodiment 4, a plurality of through holes 13, into which the respective heat transfer tubes 15 are to be inserted, are provided in each of the fins 11 of the first heat exchange part 10 to a predetermined level crossing (space) in the up-down direction. Each of the through holes 13 has a shape that corresponds to an external shape of the heat transfer tube 15. The upstream end 13a of the through hole 13 is positioned away from the upstream end 11c of the fin 11 by the predetermined interval (the first default interval). The downstream end 13b of the through hole 13 is also positioned away from the downstream end 11d of the fin 11 by the predetermined interval.

Each of the heat transfer tubes 15 according to embodiment 4 is inserted into the corresponding through hole 13 in each of the fins 11 and is provided to pass through the fins 11 in an arrangement direction of these fins 11. The fins 11 and the heat transfer tubes 15 are firmly integrated with each other by brazing. Each of these heat transfer tubes 15 has a width greater than the height in a cross-sectional view perpendicular to the direction of flow of the refrigerant.

The shape of the heat transfer tube 15 will be described later in detail. The heat transfer tube 15 has an upwardly projecting curved upper surface 15a and a flat lower surface 15c. A distance between the upper surface 15a and the lower surface 15c gradually increases from the upstream end 11c towards the downstream end 11d of the fin 11 in a part (a part of the fin 11 that is close to the upstream end 11c) that it is upstream of the lateral center position in the air flow, when the heat transfer tube 15 is viewed in a cross-sectional view perpendicular to the flow direction of the refrigerant. In other words, when a tangent plane of the upper surface 15a is defined as a tangent plane 17, a distance between the tangent plane 17 and the lower surface 15c gradually increases from the upstream end 11 c towards the downstream end 11d of the fin 11. It should be noted that the lower surface 15c of the heat transfer tube 15 is substantially horizontal. That is, the tangent plane 17 slopes downward towards the upstream end 11c of the fin 11.

Herein, tangent plane 17 corresponds to a first surface of the present invention.

As described above, the upstream end 13a of the through hole 13 of the fin 11 into which the heat transfer tube 15 is to be inserted is positioned away from the upstream end 11c of the fin 11 by the predetermined interval (the default first interval). The downstream end 13b of the through hole 13 of the fin 11 into which the heat transfer tube 15 is to be inserted is positioned away from the downstream end 11d of the fin 11 by the predetermined interval. In the state where the heat transfer tube 15 fits into the fin 11, the upstream end 15b of the heat transfer tube 15 is also positioned away from the upstream end 11c of the fin 11 by the predetermined interval ( the first default interval). In the state where the heat transfer tube 15 fits into the fin 11, the upstream end 15d of the heat transfer tube 15 is also positioned away from the downstream end 11d of the fin 11 by the predetermined interval.

Therefore, in embodiment 4, the second area 11b in which there are no heat transfer tubes 15 is positioned in each of a part near the upstream end 11c and a part near the downstream end 11d of the fin 11 The boundary between the first area 11a and the second area 11b that is close to the upstream end 11c is a virtual straight line connecting the upstream ends 13a of the respective through holes 13 provided in parallel in the up-down direction, said otherwise, a virtual straight line connecting the upstream ends 15b of the respective heat transfer tubes 15 arranged in parallel in the up-down direction. Furthermore, the boundary between the first area 11a and the second area 11b that is close to the downstream end 11d is a virtual straight line connecting the downstream ends 13b of the respective through holes 13 provided in parallel in the up-down direction, in other words, a virtual straight line connecting the downstream ends 15d of the respective heat transfer tubes 15 arranged in parallel in the up-down direction.

The second heat exchange part 20 according to embodiment 4 has a similar configuration to that of the first heat exchange part 10 according to embodiment 4. More specifically, a plurality of through holes 23, into which the respective Heat transfer tubes 25 are provided on each of the fins 21 of the second heat exchange part 20 at a predetermined level pitch (gap) in the up-down direction. Each of the through holes 23 has a shape that corresponds to an external shape of the heat transfer tube 25. The upstream end 23a of the through hole 23 is positioned away from the upstream end 21c of the fin 21 by the predetermined interval (the second default interval). The downstream end 23b of the through hole 23 is also positioned away from the downstream end 21d of the fin 21 by the predetermined interval.

Each of the heat transfer tubes 25 according to embodiment 4 is inserted into the corresponding through hole 23 in each of the fins 21 and is provided to pass through the fins 21 in an arrangement direction of these fins 21. The fins 21 and the heat transfer tubes 25 are firmly integrated with each other by brazing. Each of these heat transfer tubes 25 has a width greater than the height in a cross-sectional view perpendicular to the direction of flow of the refrigerant.

The shape of the heat transfer tube 25 will be described later in detail. The heat transfer tube 25 has an upwardly projecting curved upper surface 25a and a flat lower surface 25c. A distance between the upper surface 25a and the lower surface 25c gradually increases from the upstream end 21c towards the downstream end 21d of the fin 21 in a part (a part of the fin 21 that is close to the upstream end 21c) that it is upstream of the lateral center position in the air flow, when the heat transfer tube 25 is viewed in a cross-sectional view perpendicular to the flow direction of the refrigerant. In other words, when a tangent plane of the upper surface 25a in a part (a part of the fin 21 that is near the upstream end 21c) that is upstream of the lateral center position in the air flow is defined as a tangent plane 27, a distance between the tangent plane 27 and the lower surface 25c gradually increases from the upstream end 21c towards the downstream end 21 d of the fin 21. It should be noted that the lower surface 25c of the heat transfer tube 25 is substantially horizontal. That is, the tangent plane 27 slopes downward toward the upstream end 21c of the fin 21.

Herein, tangent plane 27 corresponds to a second surface of the present invention.

As described above, the upstream end 23a of the through hole 23 of the fin 21, into which the heat transfer tube 25 is to be inserted, is positioned away from the upstream end 21c of the fin 21 by the predetermined interval ( the second default interval). The downstream end 23b of the through hole 23 of the fin 21 into which the heat transfer tube 25 is to be inserted is positioned away from the downstream end 21d of the fin 21 by the predetermined interval. In the state where the heat transfer tube 25 fits into the fin 21, the upstream end 25b of the heat transfer tube 25 is also positioned away from the upstream end 21 c of the fin 21 by the predetermined interval. (the second default interval). In the state where the heat transfer tube 25 fits into the fin 21, the upstream end 25d of the heat transfer tube 25 is also positioned away from the downstream end 21d of the fin 21 by the predetermined interval.

Therefore, in embodiment 4, the second area 21b in which heat transfer tubes 25 are not provided is positioned in each of a part near the upstream end 21c and a part near the downstream end 21d of the fin. 21. The boundary between the first area 21a and the second area 21b that is close to the upstream end 21c is a virtual straight line connecting the upstream ends 23a of the respective through holes 23 provided in parallel in the up-down direction, in other words, a virtual straight line connecting the upstream ends 25b of the respective heat transfer tubes 25 arranged in parallel in the up-down direction. Furthermore, the boundary between the first area 21a and the second area 21b that is close to the downstream end 21 d is a virtual straight line connecting the downstream ends 23b of the respective through holes 23 provided in parallel in the up-down direction. In other words, a virtual straight line connecting the downstream ends 25d of the respective heat transfer tubes 25 arranged in parallel in the up-down direction.

In the heat exchanger 1 configured in this way, the water droplets that have reached the upper surface 15a, 25a of the heat transfer tube 15, 25 can drain into the second areas 11b, 21b that do not include heat transfer tubes. 15, 25 due to the influence of gravity, in the same way as in Embodiment 1 to Embodiment 3. Therefore, the heat exchanger 1 according to Embodiment 4 can also provide the improved drainage performance in the same way as in embodiment 1 to embodiment 3.

The tangent plane 17 described above of the heat transfer tube 15 of the first heat exchange part 10 is positioned to have the same inclination as the upper surface 15a of each of embodiment 1 to embodiment 3, and the tangent plane 27 described above of the heat transfer tube 25 of the second heat exchange part 20 is positioned to have the same inclination as the upper surface 25a of each of Embodiment 1 to Embodiment 3. Thus, the performance of drainage can be improved in the same way as in embodiment 1 to embodiment 3.

That is, only the tangent plane 17, 27 of the heat transfer tube 15, 25 is required to slope downward from the downstream end 11d, 21d towards the upstream end 11c, 21c of the fin 11, 21. Only The upper end (a point C in Figure 14) of the heat transfer tube 25 is required to be positioned higher than the bottom surface 15c of the heat transfer tube 15 laterally adjacent to the heat transfer tube 25. Only requires that an intersection point A where the tangent plane 27 of the heat transfer tube 25 and the extension line of the lower surface 15c of the heat transfer tube 15 intersect to coincide with an intersection point B where they intersect the tangent plane 27 and the extension line of the lower surface 25c of the heat transfer tube 25, or is located closer to the heat transfer tube 25 than the point of intersection B.

Such a configuration allows the arrangement positions of the heat transfer tubes 15 and 25 to be similar to those of embodiment 1 to embodiment 3. The air flow in the first heat exchange part 10 and the second heat exchange part 20 may also be similar to that of embodiment 1 to embodiment 3. More specifically, the air supplied from the fan 501 towards the first heat exchange part 10 in the substantially horizontal direction flows in the substantially horizontal direction along the lower surface 15c in the vicinity of the lower surface 15c of the substantially horizontally positioned heat transfer tube 15. The air flows more upward than the horizontal direction in the vicinity of the upper surface 15a in a part that is upstream from the lateral center position in the air flow. Accordingly, the air flowing into gaps between the heat transfer tubes 15 adjacent to each other in the up-down direction flows more upward than the horizontal direction as in embodiment 1 to embodiment 3. Therefore, air flowing into gaps between the fins 21 of the second heat exchange part 20 flows more upward than the horizontal direction and reaches the upstream ends 25b of the respective heat transfer tubes 25. As in Embodiment 1 through In embodiment 3, a sufficient amount of air can flow in the vicinity of the upper surface 25a of the heat transfer tube 25 located at a position behind the stagnant water region. In the case of an existing technique, the air velocity is reduced in the vicinity of the upper surface 25a of the heat transfer tube 25, which is located behind the region of standing water. This air flow can facilitate heat exchange between the air and the upper surface 25a.

List of reference signs

1 Heat exchanger, 10 first heat exchange part, 11 fin, 11 a first area, 11 b second area, 11c upstream end, 11d downstream end, 12 notch, 12a upstream end, 12b opening, 13 through hole , 13a upstream end, 13b downstream end, 15 heat transfer tube, 15a upper surface, 15b upstream end, 15c lower surface, 15d downstream end, 16 refrigerant conduit, 17 tangent plane, 20 second exchange part heat, 21 fin, 21a first area, 21 b second area, 21c upstream end, 21d downstream end, 22 notch, 22a upstream end, 22b opening, 23 through hole, 23a upstream end, 23b downstream end , 25 heat transfer tube, 25a upper surface, 25b upstream end, 25c lower surface, 25d downstream end, 26 refrigerant conduit, 27 tangent plane, 100 refrigeration cycle apparatus, 200 compressor, 300 condenser, 301 vent ilator, 400 expansion mechanism, 500 evaporator, 501 fan

Claims (1)

Heat exchanger (1), comprising: a first fin (11) having a first end (11c) and a second end (11d) in a lateral direction; a second fin (21) having a third end (21c) and a fourth end (21d) in the lateral direction, the third end (21c) being positioned to face the second end (11d); a first heat transfer tube (15) positioned away from the first end (11c) by a first predetermined gap and passing through the first fin (11); Y a second heat transfer tube (25) positioned away from the third end (21c) by a second predetermined gap and passing through the second fin (21), the first heat transfer tube (15) having a first flat or curved upper surface (15a) and a first flat lower surface (15c), the second heat transfer tube (25) having a second flat or curved top surface (25a) and a second flat bottom surface (25c), and the heat exchanger being characterized in that: When the first upper surface (15a) is defined as a first surface in a case where the first upper surface (15a) has a flat shape, a tangent plane (17) of the first upper surface (15a) is defined as a first surface in a case where the first upper surface (15a) has a curved shape, the second upper surface (25a) is defined as a second surface in a case where the second upper surface (25a) has a flat shape , and a tangent plane (27) of the second upper surface (25a) is defined as a second surface in a case where the second upper surface (25a) has a curved shape, and when the first heat transfer tube (15) and the second heat transfer tube (25) are viewed such that the first bottom surface (15c) is horizontal, in a vertical cross section perpendicular to a direction in which the first heat transfer tube (15) passes through the first fin (11), the first surface sloping down towards the first end (11c), the second surface sloping down towards the third end (21c), an upper end of the second heat transfer tube (25) being positioned higher than the first lower surface (15c), an intersection point A where the second surface or an extension line of the second surface and an extension line of the first lower surface (15c) intersect closer to the second heat transfer tube (25) than a point intersection line B where the second surface or the extension line of the second surface and an extension line of the second lower surface (25c) intersect. Heat exchanger (1) according to claim 1, wherein when the first heat transfer tube (15) and the second heat transfer tube (25) are viewed such that the first bottom surface (15c) is horizontal, the second lower surface (25c) slopes downward toward the third end (21c). Refrigeration cycle apparatus (100), comprising: the heat exchanger (1) of claim 1 or 2; Y a fan (501) configured to supply air to the heat exchanger (1) from the first end (11c) along the first bottom surface (15c), the heat exchanger (1) being installed in such a way that the first surface slopes downwards towards the first end (11c) and the second surface slopes downwards towards the third end (21c). Refrigeration cycle apparatus (100) according to claim 3, in which the heat exchanger (1) is installed such that the first lower surface (15c) is horizontal or slopes down towards the first end ( 11c).