JP2022040969A - Heat exchanger and air conditioner using that heat exchanger - Google Patents

Abstract

To provide a heat exchanger in which a heat transfer tube in a flat shape passes through a plurality of fins, where the heat exchanger secures a drainage performance of condensed water retained on a surface of the heat transfer tube while improving a heat transfer rate, and further suppresses increase in ventilation resistance.SOLUTION: A heat exchanger 100 comprises a heat transfer tube 1 in a flat shape and a plurality of fins 2 provided to the heat transfer tube 1, where a refrigerant flowing inside the heat transfer tube 1 exchanges heat with air flowing between the plurality of fins 2. Each fin 2 comprises: a heat transfer expansion surface 21 comprising a peak portion 21x and a valley portion 21y provided along an air flow direction; and a drain structure 22 provided to overlap the heat transfer expansion surface 21.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat exchanger and an air conditioner using this heat exchanger.

In recent years, in order to reduce the refrigerant of air conditioners, the diameter of heat transfer tubes of heat exchangers has been reduced, and as a part of this, as shown in Patent Document 1, a flat tube having a large number of holes is formed. A so-called flat multi-hole tube, which is a member, is used as a heat transfer tube.

By the way, when the heat exchanger of the outdoor unit works as an evaporator during the heating operation, condensed water is generated on the heat transfer surface of this heat exchanger, and the condensed water collects on the heat transfer tube. Therefore, when the above-mentioned flat tube is used as the heat transfer tube, water tends to collect on the surface (particularly the upper surface) of the heat transfer tube and the drainage property deteriorates as a result, as a result, as compared with the case where the heat transfer tube of the circular tube is used. It causes an increase in resistance and frost formation, and causes a decrease in the performance of the outdoor unit.

For this reason, it is not possible to adopt a shape in which condensed water easily collects as the shape of the fin. For example, a fin shape having a cut surface such as a louver or a slit is expected to have a heat transfer promoting effect, but the cut surface has a cut surface. It is difficult to use because condensed water tends to collect. As described above, although the effect of promoting heat transfer is to be improved by devising the fin shape, the fin shape is restricted from the viewpoint of drainage of condensed water.

Within such restrictions on the fin shape, a shape in which a mountain portion and a valley portion are provided along the air flow direction can be mentioned as a shape expected to have a heat transfer promoting effect without providing a cut surface. .. With such a configuration, the speed of the air flowing along the fins is improved in the peaks and valleys, the heat transfer coefficient is improved, and the heat transfer area is improved, so that the amount of heat transfer can be increased. Moreover, the drainage property of condensed water is better than that provided with a cut surface.

However, the fins provided with the peaks and valleys in this way have a narrower and longer air flow path than the flat fins, so that the ventilation resistance increases. When the change in the direction of air flow is large, the heat transfer coefficient is greatly improved, but the ventilation resistance is also greatly increased. Therefore, if the direction of air flow changes significantly, the performance of the outdoor unit may be deteriorated.

Japanese Unexamined Patent Publication No. 2013-245884

Therefore, the present invention has been made to solve the above-mentioned problems at once, and in a heat exchanger in which a flat heat transfer tube penetrates a plurality of fins, the heat transfer coefficient is improved while improving the heat transfer coefficient. The main issue is to ensure the drainage of condensed water accumulated on the surface of the heat transfer tube and to suppress the increase in ventilation resistance.

That is, the heat exchanger according to the present invention includes a flat heat transfer tube and a plurality of fins provided in the heat transfer tube, and is between the refrigerant flowing inside the heat transfer tube and the plurality of fins. In a heat exchanger configured to exchange heat with the flowing air, the fins have a heat transfer expanding surface having peaks and valleys provided along the direction of the air flow, and the heat transfer. It is characterized by having a drainage structure provided so as to overlap the enlarged surface.

With such a configuration, since it has a heat transfer expansion surface having peaks and valleys, the heat transfer coefficient is improved and a drainage structure is provided so as to overlap the heat transfer expansion surface, so that the heat transfer tube is provided. It is also possible to improve the drainage property of the condensed water that collects on the surface of the. Moreover, by superimposing the drainage structure on the heat transfer expansion surface where the air velocity is high, the air flow can be greatly disturbed, so that the ventilation resistance is increased compared to the case where the peaks and valleys are simply provided. The heat transfer coefficient can be significantly improved while suppressing the heat transfer coefficient. Specific data showing the relationship between the magnitude of the change in the direction of air flow, the improvement of the heat transfer coefficient, and the increase in ventilation resistance will be described later.

It is preferable that the drainage structure has an uneven shape provided on the heat transfer expansion surface.
With such a configuration, the condensed water accumulated on the surface of the heat transfer tube can flow along the unevenness, and the drainage property can be sufficiently exhibited.

As a more specific embodiment of the drainage structure, dimples or beads provided on the heat transfer expansion surface can be mentioned.

The plurality of heat transfer tubes are arranged in multiple stages up and down so that the flat surface faces up and down, and the fins extend in the up and down direction and form a long shape through which the plurality of heat transfer tubes penetrate. A notch is formed in one long side portion of the fin at a portion corresponding to the plurality of heat transfer tubes, and the other long side portion of the fin is linear from the upper end portion to the lower end portion. It is preferable that the drainage structure is configured to drain water droplets generated on the surface of the heat transfer tube toward the other long side portion.
With such a configuration, the water droplets drained by the drainage structure flow down along the long side extending linearly of the fins, and conversely, it is difficult for them to collect in the notch, so that the drainage property of the condensed water is further improved. Can be made to.

By the way, when the heat transfer expansion surface having the mountain part and the valley part and the drainage structure are overlapped, the material of the overlapping part is stretched and thinned in the mountain part and concentrated and thickened in the valley part. Fins are more likely to crack or break in the valleys.
Therefore, in view of the workability of the fins, it is preferable that the height of the portion of the drainage structure overlapping the mountain portion is lower than the height of the portion overlapping the valley portion.
With such a configuration, it is possible to alleviate the elongation of the material during processing at the part overlapping the mountain part of the drainage structure, and also to alleviate the concentration of the material at the part overlapping the valley part of the drainage structure, resulting in cracking or breakage. Can be prevented.

The fin is a corrugated fin in which the peaks and valleys are alternately and repeatedly formed, and the corrugated angle is preferably 5 ° or more and 24 ° or less.
If this is the case, it is possible to suppress an increase in ventilation resistance, and it is possible to achieve both improvement in drainage property and improvement in heat exchanger performance. The specific data will be described later.

By the way, in the heat exchanger shown in Patent Document 1 described in the background art, condensed water is transmitted to fins through which heat transfer tubes provided in multiple stages penetrate in order to improve the drainage property of water accumulated on the surface of the flat tube. It is configured to drain water.

However, even if the condensed water is transmitted to the fins in this way, if there are two or more rows of heat transfer tubes arranged in multiple stages, the condensed water may move to the adjacent heat transfer tube and continue to stay without being drained. In reality, the drainage property cannot be sufficiently improved.

Therefore, the present invention has been made to solve the above-mentioned problems at once, and in a heat exchanger in which two or more rows of flat heat transfer tubes are arranged, the drainage property of condensed water accumulated on the surface of the heat transfer tubes is improved. The main issue is to improve it more than before.

That is, the heat exchanger according to the present invention has a first heat exchange portion in which a plurality of flat first heat transfer tubes provided in multiple stages penetrate the first fin, and a flat plate provided in multiple stages. A plurality of second heat transfer tubes having a shape are provided with a second heat exchange section formed by penetrating the second fin, and the first heat exchange section and the second heat exchange section form each of the heat transfer tubes. In the heat exchangers arranged adjacent to each other in the width direction, the distance between the first heat transfer tube and the second heat transfer tube adjacent to each other is the distance between the first heat transfer tube or the second heat transfer tube. It is characterized in that it is larger than 40% of the width dimension, and the distance from the first fin to the second heat transfer tube is larger than 20% of the width dimension of the second fin.

With a heat exchanger configured in this way, the distance between the first heat transfer tube and the second heat transfer tube and the distance between the first fin and the second heat transfer tube are wide, so the heat exchanger can travel through the gap. Condensed water can be drained off, and drainage can be improved more than before. The specific data will be described later.

As an embodiment for sufficiently widening the distance between the first heat transfer tube and the second heat transfer tube, the first heat transfer tube is located on one side in the width direction from the center of the first fin in the width direction. The second heat transfer tube is arranged on the other side in the width direction from the center portion in the width direction of the second fin, and the other side in the width direction of the first fin and the second one. An embodiment in which one side of the fin in the width direction is interposed between the first heat transfer tube and the second heat transfer tube can be mentioned.

As a more specific configuration, the first fin has a notch formed on one side in the width direction for inserting the first heat transfer tube, and the other side in the width direction is continuous over the longitudinal direction. The second fin is provided continuously over the longitudinal direction on one side in the width direction, and a notch for inserting the second heat transfer tube on the other side in the width direction. Is preferably formed.
With such a configuration, the condensed water can be drained off through the portions of the first fin and the second fin that are continuously provided in the longitudinal direction.

In another embodiment for sufficiently widening the distance between the first heat transfer tube and the second heat transfer tube, the widthwise both ends of the first heat transfer tube are the widthwise both ends of the first fin. It can be mentioned that both ends in the width direction of the second heat transfer tube are located inside the second heat transfer tube and are located inside the both ends in the width direction of the second fin.

Further, as another aspect, the first heat transfer tube and the second heat transfer tube may be arranged in a staggered manner along the longitudinal direction orthogonal to the width direction.

In order to improve the heat exchange efficiency, it is preferable that the first fin or the second fin is provided with a plurality of rows of the first heat transfer tube or the second heat transfer tube.

As described above, in the heat exchanger shown in Patent Document 1 described in the background art, condensed water is applied to the fins through which the heat transfer tubes provided in multiple stages penetrate in order to improve the drainage property of the water accumulated on the surface of the flat tube. It is configured to be transmitted and drained.

However, even if the condensed water is transmitted to the fins in this way, if the pitch of the plurality of fins (hereinafter, also referred to as fin pitch) is too small, a bridge of condensed water is formed between the fins adjacent to each other. It becomes easy to be drained, and sufficient drainage cannot be obtained. However, if the fin pitch is too large, the heat exchange efficiency cannot be guaranteed. Further, regarding the width dimension of the heat transfer tube, if it is too large, the amount of condensed water that stays on the heat transfer tube increases, and sufficient drainage cannot be obtained. If it is too small, the heat exchange efficiency is guaranteed. Can't.

Therefore, the present invention has been made to solve the above-mentioned problems at once, and in a heat exchanger in which a flat heat transfer tube penetrates a plurality of fins, the heat transfer tube is ensured while ensuring heat exchange efficiency. The main task is to improve the drainage property of the condensed water that collects on the surface of the water pipe.

That is, the heat exchanger according to the present invention is a heat exchanger in which flat heat transfer tubes are arranged side by side at a predetermined fin pitch and penetrate a plurality of fins, and the width dimension of the heat transfer tubes is the fins. It is characterized in that it is 4 times or more and 7 times or less the pitch.

With the heat exchanger configured in this way, the width dimension of the heat transfer tube is 4 times or more and 7 times or less of the fin pitch, so that the heat exchange efficiency (fin efficiency) is ensured and the drainage property deteriorates. It can be suppressed and drainage can be improved more than before. The specific data will be described later.

As a more specific embodiment, an embodiment in which the width dimension of at least a part of the heat transfer tube is 10 mm or less can be mentioned.

Further, the air conditioner according to the present invention is characterized by including the above-mentioned heat exchanger, and the above-mentioned effects can be exhibited by such an air conditioner.

According to the present invention configured in this way, in a heat exchanger in which a flat heat transfer tube penetrates a plurality of fins, while improving the heat transfer coefficient, drainage of condensed water accumulated on the surface of the heat transfer tube is performed. It is possible to guarantee the property and suppress the increase in ventilation resistance.

The schematic diagram which shows the whole structure of the heat exchanger in 1st Embodiment. The schematic diagram which shows the structure of the drainage structure in the same embodiment. The schematic diagram which shows the corrugated angle of the fin in the same embodiment. The graph which shows the effect by the drainage structure in the same embodiment. The schematic diagram which shows the structure of the drainage structure in another embodiment. The schematic diagram which shows the structure of the drainage structure in another embodiment. The schematic diagram which shows the structure of the mountain part and the valley part in another embodiment. A photograph showing cracks in the processed parts of the mountains and valleys. The schematic diagram which shows the structure of the drainage structure in another embodiment. A photograph showing the effect of the drainage structure in another embodiment. The schematic diagram which shows the structure of the fin which examined in the middle in consideration of the assembling property of a heat transfer tube. The schematic diagram which shows the structure of the fin in another embodiment. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in the same embodiment. The graph which shows the correlation between the heat transfer tube interval / heat transfer tube width, and the amount of stagnant water. Schematic diagram of fins with notches formed. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in another embodiment. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in another embodiment. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in another embodiment. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in another embodiment. The schematic diagram which shows the arrangement of a heat transfer tube and a fin in another embodiment. The schematic diagram which shows the correlation between the fin pitch and the amount of condensed water in the same embodiment. The schematic diagram which shows the correlation between the width of a heat transfer tube and the amount of condensed water in the same embodiment. The graph which shows the correlation between the ratio of a heat transfer tube width and fin pitch in the same embodiment, and drainage property. The schematic diagram which shows the structure of the heat transfer tube in another embodiment. The schematic diagram which shows the structure of the heat transfer tube and fin in another embodiment. The schematic diagram which shows the structure of the heat transfer tube and fin in another embodiment.

<First Embodiment>
Hereinafter, the first embodiment of the heat exchanger according to the present invention will be described with reference to the drawings.

The heat exchanger 100 according to the present embodiment is an air exchanger including a compressor, an outdoor heat exchanger, a throttle mechanism, and a refrigerant circuit to which an indoor heat exchanger is connected, and is the outdoor heat exchanger or the indoor heat exchange. It is used for at least one of the vessels.

Specifically, as shown in FIG. 1, the heat exchanger 100 is a so-called fin-and-tube heat exchanger, in which a plurality of heat transfer tubes 1 in which a refrigerant flows inside and a plurality of heat transfer tubes 1 provided in these heat transfer tubes 1 are provided. It is provided with a number of fins 2.

The heat transfer tube 1 has a flat shape and has a plurality of internal flow paths through which the refrigerant flows, and is referred to as a multi-hole flat tube. The heat transfer tube 1 of the present embodiment is arranged so that the flat surface faces up and down, that is, the flat surface is horizontal, and the heat transfer tube 1 is provided so that the refrigerant flows along the horizontal direction inside the heat transfer tube 1. There is.

Such heat transfer tubes 1 are arranged in multiple stages above and below in parallel with each other, for example, at equal intervals. In this embodiment, a row consisting of a plurality of first heat transfer tubes 1A and these first heat transfer tubes 1A in the width direction are provided. A row of a plurality of second heat transfer tubes 1B adjacent to each other is provided. More specifically, the first heat transfer tube 1A and the second heat transfer tube 1B adjacent to each other are arranged so as to be at the same height here. The heat transfer tubes 1 are not limited to two rows, but may be provided in three or more rows, or may be in one row.

The fin 2 has a long shape extending in the vertical direction, and is penetrated by a plurality of heat transfer tubes 1 provided in multiple stages. The fins 2 are arranged at a predetermined fin pitch along the extending direction of the heat transfer tube 1, and are arranged at equal intervals here. As a result, heat exchange is performed between the air flowing along the width direction of the fins 2 and the refrigerant flowing in the internal flow path of the heat transfer tube 1.

Similar to the number of rows of the heat transfer tube 1, the plurality of fins 2 arranged along the extending direction of the heat transfer tube 1 are provided with, for example, two or more rows, and here, the first heat transfer tube 1A is provided. A row consisting of a plurality of first fins 2A penetrating and a row consisting of a plurality of second fins 2B penetrating the second heat transfer tube 1B are provided. The fins 2 are not limited to two rows, but may be provided in three or more rows, or may be provided in one row.

According to the above-described configuration, the heat exchanger X of the present embodiment has the first heat exchange section A in which a plurality of first heat transfer tubes 1A provided in multiple stages penetrate the plurality of first fins 2A. , A plurality of second heat transfer tubes 1B provided in multiple stages are provided with a second heat exchange section B formed by penetrating a plurality of second fins 2B, and these first heat exchange sections A and The second heat exchange section B is arranged adjacent to each other in the width direction of the heat transfer tubes 1A and 1B.

Here, the first heat transfer tube 1A and the second heat transfer tube 1B have the same dimensions, and when they are not distinguished below, these heat transfer tubes 1A and 1B are referred to as heat transfer tubes 1. Further, the first fin 2A and the second fin 2B have the same dimensions, and when they are not distinguished below, these fins 2A and 2B are referred to as fins 2.

Therefore, as shown in FIG. 2, the fin 2 of the present embodiment has a heat transfer expansion having a mountain portion 21x and a valley portion 21y provided along the air flow direction, in other words, along the width direction of the fin 2. A surface 21 and a drainage structure 22 provided so as to overlap the heat transfer expansion surface 21 are provided.

First, the heat transfer expansion surface 21 will be described.
The heat transfer expansion surface 21 is formed by processing a flat plate-shaped fin 2, and expands the heat transfer area of the fin 2.

The heat transfer expansion surface 21 has a mountain portion 21x formed by folding a flat plate-shaped fin 2 into a mountain portion and a valley portion 21y formed by folding the fin 2 into a valley portion, and these peak portions 21x and valleys. The portion 21y is formed as a crease portion extending along the longitudinal direction (vertical direction) of the fin 2.

More specifically, as shown in FIG. 3, the fin 2 of the present embodiment is a corrugated fin. Here, the corrugated angle, which is the angle at which the fin 2 is bent during corrugated processing, is set to 5 degrees or more and 24 degrees or less, and the mountain portion 21x and the valley portion 21y having this corrugated angle are alternately and repeatedly formed in the width direction of the fin 2. There is.

Next, the drainage structure 22 will be described.
The drainage structure 22 is for draining the condensed water generated when the heat exchanger 100 of the outdoor unit acts as a condenser during the heating operation from the surface of the heat transfer tube 1 and the surface of the fin 2, and particularly the heat transfer tube 1. It prevents the condensed water from staying on the flat surface.

Specifically, in this drainage structure 22, the surface of the fin 2 is recessed from the mountain portion 21x side toward the valley portion 21y side, and the surface of the fin is expanded from the valley portion 21y side toward the mountain portion 21x side. It is a convex part that is made to come out. As shown in FIG. 2, the drainage structure 22 here is a bead-shaped or rib-shaped ridge 22 formed elongated in the width direction of the fin, and its surface is from the valley portion 21y side to the mountain portion 21x side. It is a bulging curved surface.

The drainage structure 22 is provided so as to overlap the heat transfer expansion surface 21 described above. More specifically, the drainage structure 22 overlaps at least one of the creases formed as the mountain portion 21x or the valley portion 21y described above, and here, a plurality of mountain portions 21x and valleys adjacent to each other. It is provided so as to straddle the portion 21y.

In the present embodiment, the plurality of heat transfer tubes 1 are arranged in multiple stages up and down so that the flat surface faces up and down as described above, and the fins 2 extend in the up and down direction to penetrate the plurality of heat transfer tubes 1. It has a long shape. Then, as shown in FIG. 2, a notch 2z is formed in a portion corresponding to a plurality of heat transfer tubes 1 on one long side portion 2p of the fin 2, and the fin 2 is formed through the notch 2z. The heat transfer tube 1 can be fitted. On the other hand, the other long side portion 2q of the fin 2 is not provided with a notch and extends linearly from the upper end portion to the lower end portion.

In such a configuration, the drainage structure 22 of the present embodiment is provided so as to drain the condensed water generated when the heat exchanger 100 acts as a condenser toward the other long side portion 2q of the fin 2.

More specifically, as shown in FIG. 2, in the elongated ridge 22 which is a drainage structure 22, one end portion 22a located on one long side portion 2p side of the fin has an end portion 22a which is located on the other long side portion of the fin 2. It is provided at a position higher than the other end 22b located on the 2q side, and is inclined so as to descend from one end 22a toward the other end 22b. As a result, the condensed water flows down along the ridge 22 toward the other long side portion 2q of the fin 2, and then falls down along the long side portion 2q.

The fin 2 of the present embodiment has a plurality of the above-mentioned ridges 22 as a drainage structure. Specifically, at least one ridge 22 is provided between each of the plurality of heat transfer tubes 1 provided in multiple stages above and below.

Subsequently, the graph of FIG. 4 shows the data obtained by experimenting with the action and effect of the above-mentioned configuration.
In this graph, the corrugated angle of the fin 2 is taken on the horizontal axis, and the ratio of the improvement rate of the heat transfer coefficient to the increase rate of the ventilation resistance (hereinafter referred to as a heat exchanger performance index) is taken on the vertical axis. In addition, this vertical axis sets 100% as the heat exchanger performance index when the above-mentioned ridge 22 is not provided on the fin 2 at each corrugated angle.

Here, when the above-mentioned drainage structure is provided on the flat plate-shaped fins that have not been corrugated, the rate of increase in ventilation resistance is larger than the rate of improvement in the heat transfer coefficient due to this drainage structure. As a result, the drainage property is improved, but the performance of the heat exchanger is deteriorated. This proof is the case where the corrugated angle in the graph of FIG. 4 is 0 degrees, and it can be seen that the heat exchanger performance index is less than 100%.

On the other hand, as shown by the curve in the graph of FIG. 4, the heat exchanger performance index becomes 100% by providing the drainage structure 22 in the fin 2 and setting a corrugated angle of 5 degrees or more and 24 degrees or less. It can be seen that the improvement in drainage performance and the improvement in heat exchanger performance are achieved at the same time.

To explain this in more detail, when the drainage structure 22 is superposed on the region where the air flow direction changes due to the corrugated processing, that is, the region where the mountain portion 21x and the valley portion 21y are formed by the corrugated processing, the air thereof. The improvement rate of the heat transfer coefficient and the improvement rate of the ventilation resistance change according to the flow direction (corrugated angle) of.

Then, by setting the corrugated angle to 5 degrees or more and 24 degrees or less as described above, the improvement rate of the heat transfer coefficient exceeds the increase of the ventilation resistance, and the heat exchanger performance index exceeding 100% can be obtained.

According to the heat exchanger 100 configured as described above, since the fin 2 has the heat transfer expanding surface 21 having the peak portion 21x and the valley portion 21y, the heat transfer coefficient can be improved, and the heat transfer rate can be improved. Since the drainage structure 22 is provided so as to overlap the enlarged surface 21, the drainage property of the condensed water collected on the surface of the heat transfer tube 1 can be improved. Moreover, since the corrugated angle is set to 5 ° or more and 24 ° or less, the air flow can be greatly disturbed, so that the increase in ventilation resistance is suppressed as compared with the case where the mountain portion 21x and the valley portion 21y are simply provided. At the same time, the heat transfer coefficient can be improved, and as a result, both the improvement of drainage property and the improvement of heat exchanger performance can be achieved at the same time.

Further, one long side portion 2p of the fin 2 is provided with a notch 2z, and the other long side portion 2q is configured to extend linearly. Since the generated water droplets are configured to be drained toward the other long side portion 2q, the water droplets flow down along the long side portion 2q, and conversely, the notch of one long side portion 2p. Since 2z is less likely to accumulate, the drainage property of condensed water can be further improved.

<Modified example of the first embodiment>
The present invention is not limited to the first embodiment.

For example, in the first embodiment, one drainage structure 22 is provided between heat transfer tubes 1 adjacent to each other in the vertical direction, but as shown in FIG. 5, a plurality of drainage structures are provided between these heat transfer tubes 1. 22 may be provided. In this example, as in the first embodiment, a plurality of ridges 22 extending diagonally downward from one long side portion 2p of the fin 2 toward the other long side portion 2q are formed as a drainage structure. The ridges 22 include those having different lengths from each other and those having bulging directions opposite to each other.

Further, the drainage structure 22 is a bead-shaped or rib-shaped convex strip in the above embodiment, but as shown in FIG. 6, it may be a concave portion or a convex portion formed by, for example, dimple processing. In this example, the concave and convex portions of the drainage structure 22 are hemispherical, but may be columnar or conical, for example.

Further, in the above embodiment, the case where the mountain portion 21x and the valley portion 21y are formed by corrugated processing has been described, but as shown in FIG. 7, for example, the mountain portion 21x and the valley portion 21y may be formed by drawing processing. .. That is, the mountain portion 21x may be a portion where the surface of the fin 2 rises in the air flow direction, and the valley portion 21y may be a portion where the surface of the fin 2 sinks in the air flow direction. The specific shape may be changed as appropriate.

By the way, when the heat transfer expansion surface 21 having the mountain portion 21x and the valley portion 21y and the drainage structure 22 are overlapped with each other, the material of the overlapping portion becomes thin in the mountain portion 21x and concentrates in the valley portion 21y, so that the mountain portion 21x The fin 2 is liable to crack or break at the valley portion 21y (see FIG. 8).
Therefore, in view of the workability of the fin 2, as shown in FIG. 9, the height of the portion of the drainage structure 22 overlapping the mountain portion 21x may be lower than the height of the portion overlapping the valley portion 21y. The "height" here is the distance from the surface of the fin 2 where the drainage structure 22 is not provided to the surface of the drainage structure 22.
More specifically, as shown in FIG. 9, in the drainage structure 22, the height of the portion overlapping the mountain portion 21x is Ht, the height of the portion overlapping the valley portion 21y is Hb, the mountain portion 21x and the valley. Assuming that the height of the central portion between the portions 21y is Hm, Hb>Hm> Ht is satisfied.
With such a configuration, it is possible to alleviate the elongation of the material during processing at the portion overlapping the mountain portion 21x of the drainage structure 22, and alleviate the concentration of the material at the portion overlapping the valley portion 21y of the drainage structure 22. , Can prevent cracking and breakage (see FIG. 10).

Here, in order to improve the heat exchange efficiency between the fin 2 and the heat transfer tube 1 inserted into the notch 2z of the fin 2, the fin 2 is configured as a notch 2z as shown in FIG. An intermediate configuration was considered having a contact surface 23 formed by bending the inner peripheral edge of the above in the arrangement direction of the fins.
With such a configuration, the contact area between the contact surface 23 and the outer peripheral surface of the heat transfer tube 1 can be widened, so that the heat exchange efficiency can be improved.

However, if the above-mentioned contact surface 23 is provided on the fin 2 having the peak portion 21x and the valley portion 21y, when the heat transfer tube 1 is inserted into the notch 2z, the back side of the contact surface 23 (the back side in the insertion direction of the heat transfer tube 1). ) Stress is concentrated on the end, and the fin 2 may break at that point.

Therefore, as shown in FIG. 12, the fin 2 here has a stress dispersion portion 24 that disperses stress at the inner end portion of the contact surface 23. Specifically, the stress dispersion portion 24 is formed by cutting out the mountain portion 21x or the valley portion 21y located at the innermost end of the mountain portion 21x and the valley portion 21y overlapping the notch 2z in the height direction. It is a thing.
According to such a configuration, the stress applied to the inner end portion when the heat transfer tube 1 is inserted into the notch 2z can be dispersed by the stress dispersion portion 24, and the fin 2 can be prevented from breaking at this portion. Can be done.

Further, in the intermediate configuration shown in FIG. 11, when the heat transfer tube 1 is inserted into the notch 2z, the moment acting in the direction in which the fin 2 breaks becomes large, and the fin 2 may break.
Therefore, as shown in FIG. 12, the dimension Lx of the contact surface 23 in the mountain portion 21x in the bending direction (here, the arrangement direction of the fins 2) is set to the bending direction of the contact surface 23 in the valley portion 21y (here, the arrangement of the fins 2). It is smaller than the dimension Ly in the direction).
With such a configuration, since the dimension Lx in the bending direction of the mountain portion 21x where the moment is the largest is reduced, it is possible to prevent the fin 2 from bending.

<Second Embodiment>
Next, a second embodiment of the heat exchanger according to the present invention will be described with reference to the drawings. In FIGS. 13 to 20 referred to in the following description, the description of the heat transfer expansion surface and the drainage structure of the fins is omitted for convenience of explanation.

In the present embodiment, the distance between the heat transfer tubes 1 adjacent to each other and the distance between the fins 2 and the heat transfer tube 1 are characteristic, and this point will be described in detail.

That is, in the present embodiment, as shown in FIG. 13, the distance between the first heat transfer tube 1A and the second heat transfer tube 1B adjacent to each other (hereinafter referred to as the heat transfer tube interval D1) is set to the first heat transfer tube 1A. Alternatively, it is made larger than 40% of the width dimension of the second heat transfer tube 1B (hereinafter referred to as the heat transfer tube width W).
The heat transfer tube spacing D1 here is the width direction end a of the second heat transfer tube 1B side of the width direction ends of the first heat transfer tube 1A and the width direction end of the second heat transfer tube 1B. It is a separation distance from the widthwise end portion b on the first heat transfer tube 1A side of the portions.
Further, the heat transfer tube width W here is a separation distance between both ends of the heat transfer tubes 1A and 1B in the width direction.

Here, the graph shown in FIG. 14 shows the surface of the heat transfer tube 1 when there is no gap between the first heat transfer tube 1A and the second heat transfer tube 1B, that is, when the heat transfer tube spacing D1 = 0. It shows the correlation between the heat transfer tube interval D1 / heat transfer tube width W and the stagnant water amount when the stagnant water amount is 100%.

As can be seen from this correlation, according to the heat exchanger X of the present embodiment, as described above, the heat transfer tube interval D1 / heat transfer tube width W> 0.4, so that the amount of retained water is the first transfer. It is less than 80% when there is no gap between the heat pipe 1A and the second heat transfer tube 1B, and it can be seen that almost the maximum high drainage property is obtained.

Further, in the present embodiment, the distance from the first fin 2A to the second heat transfer tube 1B (hereinafter referred to as fin heat transfer tube distance D2) is set to the width dimension of the second fin 2B (hereinafter referred to as the second fin width L2). It is intended to be larger than 20%, more preferably larger than 30%.
The fin heat transfer tube spacing D2 here is from the long side portion L on the second heat transfer tube 1B side of the first fin 2A to the first heat transfer tube among the widthwise end portions of the second heat transfer tube 1B. It is a distance along the width direction to the end portion b in the width direction on the 1A side.

Here, for example, as shown in FIG. 15, when a notch X is provided in the long side portion L of the first fin 2A and the second fin 2B in order to improve the assembling property, the long side is provided by the notch X. The portion L becomes discontinuous, and the portion of the notch X hinders drainage. As a result, even if the heat transfer tube spacing D1 is largely secured, high drainage may not be obtained.

On the other hand, in the present embodiment, the heat transfer interval D1 / heat transfer tube width W> 0.4 is set as described above, and the fin heat transfer interval D2 is larger than 20% of the second fin width L2. More preferably, it is made larger than 30%, so that a sufficient area for water transfer on the drainage route can be secured.

<Modified example of the second embodiment>
The present invention is not limited to the second embodiment.

For example, the first fin 2A and the second fin 2B may be configured as shown in FIG. 16B.
That is, the first fin 2A has a notch X formed on one side in the width direction for inserting the first heat transfer tube 1A, and the other side in the width direction is continuous in the longitudinal direction (vertical direction). It is provided and
Further, the second fin 2B is continuously provided on one side in the width direction over the longitudinal direction (vertical direction), and a notch X for inserting the second heat transfer tube 1B is provided on the other side in the width direction. It was formed.

More specifically, in the first fin 2A, a notch X is formed intermittently along the longitudinal direction on one long side portion, and the other long side portion is formed from the upper end portion to the lower end portion. It extends linearly over.
Further, in the second fin 2B, one long side portion extends linearly from the upper end portion to the lower end portion, and the other long side portion is intermittently cut out along the longitudinal direction X. Is formed.

In the above-described configuration, as shown in FIG. 16B, the first heat transfer tube 1A is arranged on one side in the width direction from the center in the width direction of the first fin 2A, and the second heat transfer tube 1A is arranged. The heat pipe 1B may be arranged on the other side in the width direction from the center portion in the width direction of the second fin 2B.
Then, the other side in the width direction of the first fin 2A and the other side in the width direction of the second fin 2B may be arranged so as to be interposed between the first heat transfer tube 1A and the second heat transfer tube 1B. ..
In other words, the notch X of the first fin 2A and the notch X of the second fin 2B are formed so as to face opposite to each other, and the first fin 2A is formed from the upper end to the lower end. A long side portion extending linearly and a long side portion extending linearly from the upper end portion to the lower end portion of the second fin 2B may be provided adjacent to each other.
With such a configuration, the heat transfer tube interval D1 can be made larger than the configuration shown in FIG. 16A, and condensed water is placed between the first heat transfer tube 1A and the second heat transfer tube 1B. I can tell you. However, the heat exchanger 100 of the present invention may have the configuration shown in FIG. 16A.

Further, as shown in FIG. 17B, the arrangement of the first heat transfer tube 1A with respect to the first fin 2A and the arrangement of the second heat transfer tube 1B with respect to the second fin 2B are the first heat transfer tube 1A. The widthwise ends of the second heat transfer tube 1B are located inside the widthwise ends of the first fin 2A, and the widthwise ends of the second heat transfer tube 1B are located inside the widthwise ends of the second fin 2B. May be located inside.
With such a configuration, the heat transfer tube spacing D1 can be made larger than that shown in FIG. 17A, and condensed water is placed between the first heat transfer tube 1A and the second heat transfer tube 1B. I can tell you. However, the heat exchanger 100 of the present invention may have the configuration shown in FIG. 17 (a).

The first heat transfer tubes 1A and the second heat transfer tubes 1B that are adjacent to each other are arranged so as to have the same height as each other in the above embodiment, but the heights may be different from each other, for example, FIG. 18 (b). As shown in, it may be arranged in a staggered manner along the longitudinal direction orthogonal to the width direction.
Also in this case, the heat transfer tube spacing D1 is the width direction end portion of the first heat transfer tube 1A on the second heat transfer tube 1B side and the width direction end portion of the second heat transfer tube 1B. It can be the distance from the widthwise end of the first heat transfer tube 1A side.
With such a configuration, the heat transfer tube interval D1 can be made larger than the configuration shown in FIG. 18A, and condensed water is placed between the first heat transfer tube 1A and the second heat transfer tube 1B. I can tell you. However, the heat exchanger 100 of the present invention may have the configuration shown in FIG. 18A.

In the above embodiment, the first fin 2A and the second fin 2B are provided with one row of the first heat transfer tubes 1A arranged in multiple stages and the second heat transfer tubes 1B arranged in multiple stages, respectively. However, a plurality of rows of the first heat transfer tube 1A and the second heat transfer tube 1B may be provided for the first fin 2A and / or the second fin 2B, respectively. That is, two rows of heat transfer tubes 1A and 1B may be provided for one row of fins 2A (2B).

As shown in FIG. 19A, the first heat transfer tube 1A and the second heat transfer tube 1B may have different width dimensions (W1 and W2).
Further, the first fin 2A and the second fin 2B may have different width dimensions (L1 and L2) from each other as shown in FIG. 19B.
Further, as shown in FIG. 19 (c), the heat transfer tube spacing D1 in the portion where the condensed water stays much may be wider than the heat transfer tube spacing in the portion where the condensed water stays less.

By the way, as described in the explanation of FIG. 15, if the notch X is provided in the long side portion L of the first fin 2A and the second fin 2B, the drainage property is deteriorated.
Therefore, as shown in FIG. 20A, a notch X is provided in the long side portion L of the first fin 2A, and the long side portion L'of the second fin 2B adjacent to the notch X is cut. The shape may be along the notch X.
Further, as shown in FIG. 20B, a notch X is provided in the long side portion L of the first fin 2A, and the long side portion L'of the second fin 2B adjacent to the notch X is cut. It may be arranged so as to overlap the notch X.
With these configurations, the drainage route can be expanded to the discontinuous portion caused by the notch X, and the drainage property can be improved.

<Third Embodiment>
Next, a third embodiment of the heat exchanger according to the present invention will be described with reference to the drawings. In FIGS. 21 to 26 referred to in the following description, the description of the heat transfer expansion surface and the drainage structure of the fins is omitted for convenience of explanation.

In this embodiment, the relationship between the width dimension of the heat transfer tube and the fin pitch is characteristic, and this point will be described in detail.

First, the fins 2 of the present embodiment are arranged at a predetermined fin pitch along the extending direction of the heat transfer tube 1, and are arranged at equal intervals here.

In the configuration in which the flat heat transfer tube 1 penetrates the plurality of fins 2 in this way, as shown in FIG. 21, if the fin pitch P of the plurality of fins 2 is too small, the fins 2 adjacent to each other are between the fins 2. Bridges of condensed water are likely to be formed, and sufficient drainage cannot be obtained. However, if the fin pitch P is too large, the heat exchange efficiency cannot be guaranteed.
The fin pitch P here is a separation distance along the same stretching direction of the fins 2 adjacent to each other in the stretching direction of the heat transfer tube 1.

Further, as shown in FIG. 22, if the width dimension W of the heat transfer tube 1 (hereinafter, also referred to as the heat transfer tube width W) is too large, the amount of condensed water staying on the heat transfer tube 1 increases by that amount, which is sufficient. It is not possible to obtain a good drainage property, and if it is too small, the heat exchange efficiency cannot be guaranteed.
The heat transfer tube width W here is a separation distance from one end in the width direction to the other end in the width direction of the heat transfer tube 1.

Therefore, it is preferable that the heat transfer tube width W is 4 times or more and 7 times or less the fin pitch P.

More specifically, the heat transfer tube width W of the present embodiment is at least a part of 10 mm or less, and here, the total length in the longitudinal direction is 10 mm or less.

Here, the graph shown in FIG. 23 shows the correlation between the heat transfer tube width W / fin pitch P and the drainage property. As shown in FIG. 23, even if the heat transfer tube width W / fin pitch P <4.0 is not expected to improve the drainage property, the surface of the heat transfer tube 1 when the heat transfer tube width W / fin pitch P = 4.0 is set. The drainage property of is 100%.

As can be seen from this correlation, according to the heat exchanger 100 of the present embodiment, as described above, since the heat transfer tube width W / fin pitch P ≧ 4 times, the heat exchange efficiency can be ensured. Moreover, since the heat transfer tube width W / fin pitch P ≦ 7 times, the deterioration of drainage can be suppressed to about 10%.

The present invention is not limited to the third embodiment.

For example, in the above embodiment, one row of heat transfer tubes 1 is provided for one row of fins 2, but as shown in FIG. 24, one row of fins 2 is provided side by side along the width direction. Two or more rows of heat transfer tubes 1 may be provided through the gap. In FIG. 24, the pair of heat transfer tubes 1 arranged side by side in the width direction have the same width dimension W, but they may have different width dimensions.
With such a configuration, since two or more rows of heat transfer tubes 1 are provided, heat exchange efficiency almost equal to that when one row of heat transfer tubes having a width dimension obtained by adding the widths of these heat transfer tubes W is provided is ensured. At the same time, since the heat transfer tube width W in each row can be shortened, the amount of width condensed water accumulated on the heat transfer tube 1 can be reduced.

Further, as shown in FIG. 25, the heat exchanger 100 may be configured such that the heat transfer tube width W / fin pitch P differs depending on the stage of the heat transfer tube 1.
In this way, by changing the heat transfer tube width W according to the size of the fin pitch P, the drainage property can be equalized.

Further, as shown in FIG. 26, the width W1 between the heat transfer tubes in the portion where the condensed water stays much may be wider than the heat transfer tube width W2 in the portion where the condensed water stays less.

In addition, the present invention is not limited to each of the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ・ ・ ・ Heat exchanger 1 ・ ・ ・ Heat transfer tube 2 ・ ・ ・ Fin 21 ・ ・ ・ Heat transfer expansion surface 21x ・ ・ ・ Mountain part 21y ・ ・ ・ Tani part 22 ・ ・ ・ Drainage structure 2z ・ ・ ・ Notch

Claims (15)

A flat heat transfer tube and a plurality of fins provided in the heat transfer tube are provided, and heat is exchanged between the refrigerant flowing inside the heat transfer tube and the air flowing between the plurality of fins. In a heat exchanger configured as
The fins
A heat transfer expansion surface having peaks and valleys provided along the direction of air flow,
A heat exchanger characterized by having a drainage structure provided so as to overlap the heat transfer expansion surface. The heat exchanger according to claim 1, wherein the drainage structure has an uneven shape provided on the heat transfer expansion surface. The heat exchanger according to claim 2, wherein the drainage structure is a dimple or a bead provided on the heat transfer expansion surface. A plurality of the heat transfer tubes are arranged in multiple stages up and down so that the flat surface faces up and down.
The fins extend in the vertical direction and form a long shape through which the plurality of heat transfer tubes penetrate.
A notch is formed on one long side of the fin at a position corresponding to the plurality of heat transfer tubes.
The other long side of the fin extends linearly from the upper end to the lower end.
The heat exchanger according to any one of claims 1 to 3, wherein the drainage structure is configured to drain water droplets generated on the surface of the heat transfer tube toward the other long side portion. .. The heat exchanger according to any one of claims 1 to 4, wherein the height of the portion of the drainage structure overlapping the mountain portion is lower than the height of the portion overlapping the valley portion. The heat according to any one of claims 1 to 5, wherein the fin is a corrugated fin in which the peaks and valleys are alternately and repeatedly formed, and the corrugated angle is 5 ° or more and 24 ° or less. Exchanger. A first heat exchange section in which a plurality of flat first heat transfer tubes provided in multiple stages penetrate the first fin, and a plurality of flat second heat transfer portions provided in multiple stages. The heat transfer tube is provided with a second heat exchange section formed by penetrating the second fin, and the first heat exchange section and the second heat exchange section are adjacent to each other in the width direction of each heat transfer tube. In the heat exchanger that is located
The distance between the first heat transfer tube and the second heat transfer tube adjacent to each other is larger than 40% of the width dimension of the first heat transfer tube or the second heat transfer tube.
The invention according to any one of claims 1 to 6, wherein the distance from the first fin to the second heat transfer tube is larger than 20% of the width dimension of the second fin. Heat exchanger. The first heat transfer tube is arranged on one side in the width direction with respect to the center portion in the width direction of the first fin.
The second heat transfer tube is arranged on the other side in the width direction from the center in the width direction of the second fin.
The heat exchanger according to claim 7, wherein the other side in the width direction of the first fin and one side in the width direction of the second fin are interposed between the first heat transfer tube and the second heat transfer tube. The first fin has a notch formed on one side in the width direction for inserting the first heat transfer tube, and the other side in the width direction is continuously provided over the longitudinal direction.
The second fin is continuously provided on one side in the width direction over the longitudinal direction, and a notch for inserting the second heat transfer tube is formed on the other side in the width direction. The heat exchanger according to claim 8. The widthwise ends of the first heat transfer tube are located inside the widthwise ends of the first fin.
The heat exchanger according to any one of claims 7 to 9, wherein both ends in the width direction of the second heat transfer tube are located inside the both ends in the width direction of the second fin. The heat exchange according to any one of claims 7 to 9, wherein the first heat transfer tube and the second heat transfer tube are arranged in a staggered manner along a longitudinal direction orthogonal to the width direction. vessel. The invention according to any one of claims 7 to 11, wherein a plurality of rows of the first heat transfer tube or the second heat transfer tube are provided for the first fin or the second fin. Heat exchanger. In a heat exchanger in which the flat heat transfer tubes are arranged side by side at a predetermined fin pitch and penetrate through a plurality of the fins.
The heat exchanger according to any one of claims 1 to 12, wherein the width dimension of the heat transfer tube is 4 times or more and 7 times or less the fin pitch. 13. The heat exchanger according to claim 13, wherein at least a part of the heat transfer tube has a width dimension of 10 mm or less. An air conditioner comprising the heat exchanger according to any one of claims 1 to 14.

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