WO2020084786A1

WO2020084786A1 - Heat exchanger and refrigeration cycle device using same

Info

Publication number: WO2020084786A1
Application number: PCT/JP2018/039965
Authority: WO
Inventors: 綾河島
Original assignee: 三菱電機株式会社
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2020-04-30
Also published as: JP7112053B2; JPWO2020084786A1; CN211290633U

Abstract

The present invention comprises: a plurality of plate-shaped fins disposed so as to be arranged side by side in the front and rear directions at preset intervals; and a plurality of heat transfer tubes that have flat-shaped cross sections and are disposed so as to be arranged side by side in the long-side direction of the fins at preset intervals with respect to the fins. The heat transfer tubes have been subjected to a surface treatment for retaining hydrophilicity on the outer peripheral surfaces thereof. The fins have groove sections which extend in the long-side direction and which are composed of uneven shapes provided so as to be adjacent in the short-side direction that is orthogonal to the long-side direction, and the fins have been subjected to a surface treatment for retaining hydrophilicity. This makes it possible to improve heat exchange performance while ensuring drainage characteristics, even if the heat transfer tubes are flat shapes.

Description

Heat exchanger and refrigeration cycle apparatus using the same

The present invention relates to a heat exchanger and a refrigeration cycle device using the heat exchanger.

As this type of heat exchanger, a plurality of plate-shaped fins arranged so as to be stacked at a preset interval, and a plurality of heat transfer tubes penetrating along the direction in which these fins are arranged in parallel And a fin-and-tube type heat exchanger having

The heat transfer tubes used in such heat exchangers have, for example, a perfect circular cross section or a flat shape such as an elliptical shape or an oval shape. On the other hand, a plurality of openings such as through holes or notches corresponding to the shape of the heat transfer tube are formed in the plurality of fins, and the heat transfer tube is inserted into these openings. As a result, the plurality of heat transfer tubes are assembled with the fins penetrating along the direction in which the fins are arranged in parallel.

Further, fins are formed with fin collars that are cut and raised perpendicularly to the heat transfer tubes, and the fin collars are brazed in the furnace or adhered to the heat transfer tubes by using an adhesive to form heat transfer tubes. Adhesion with the fin can be improved.

Also, the end of each heat transfer tube is connected to a distribution pipe or header that forms a refrigerant flow path together with the heat transfer tube. Then, in the heat exchanger, heat is exchanged between the heat exchange fluid such as air or gas flowing between the fins and the heat exchanged fluid such as water or refrigerant flowing in the heat transfer tube.

In addition, a heat exchanger in which a cut-and-raised part called a slit or a louver that opens in the direction in which air mainly flows is formed, or a scratch or a waffle that protrudes in the direction in which air mainly flows. Heat exchangers are known in which so-called protrusions are formed. In such a heat exchanger, the cut-and-raised portion or the protruding portion is provided to increase the surface area for heat exchange, thereby improving the heat exchange performance.

Furthermore, heat exchangers in which a plurality of flow paths are formed inside the heat transfer tube, or heat exchangers in which grooves are formed on the inner surface of the heat transfer tube are known. Even in such a heat exchanger, the heat exchange performance is improved by providing a plurality of flow paths or grooves to increase the surface area for heat exchange.

By the way, when the heat exchanger is used as an evaporator, water in the air adheres to the heat exchanger as condensed water. Therefore, the condensed water adhering to the heat exchanger travels along the surfaces of the fins and the heat transfer tubes, hangs down in the longitudinal direction, and is discharged below the heat exchanger. At this time, since condensed water adheres to the fins, ventilation resistance increases and heat exchange performance deteriorates. Therefore, it is necessary to quickly discharge the condensed water adhered to the fins in the longitudinal direction.

Also, when the heat exchanger is installed in an outdoor unit and used as an evaporator, water in the air becomes frost and adheres to the heat exchanger. Therefore, in an air conditioner or a refrigerator including a heat exchanger, the frost adhering to the heat exchanger is melted by performing a defrosting operation, and the frost that has been melted into water droplets is removed from the surface of the fins and the heat transfer tubes. Then, it is hung down in the longitudinal direction and discharged below the heat exchanger.

When the defrosting operation is finished and the water droplets remain after the heating operation is started, the water droplets are frozen again and grow, which causes the increase of ventilation resistance and the deterioration of the heat exchange performance as described above. Therefore, these water drops must be reliably removed. On the other hand, in such a heat exchanger, by extending the time of the defrosting operation in order to reliably drain the water droplets, the average heating capacity is reduced in a certain time during which the defrosting operation is performed, so the drainage time is shortened. It is necessary to plan.

Therefore, for example, in Patent Document 1, a heat exchanger is proposed in which the entire fin region except for the annular portion formed around the insertion hole through which the heat transfer tube is inserted has a wave shape including peaks and valleys extending in the vertical direction. There is.

Japanese Patent Laid-Open No. 6-82189

However, in the heat exchanger of Patent Document 1, when a flat heat transfer tube is used, there is a problem in that drainage is stagnant at the upper and lower portions of the heat transfer tube, making it difficult to quickly and reliably perform drainage. .

That is, when a flat heat transfer tube is used in the heat exchanger of Patent Document 1, condensed water adhering to the fins or water droplets such as melted frost fall on the upper surface of the flat heat transfer tube, and the outer circumference of the heat transfer tube After wrapping around along the bottom surface of the heat transfer tube, it hangs down to the upper surface of the heat transfer tube arranged below. As described above, in the flat heat transfer tube, a flat portion, which does not exist in the perfect circular heat transfer tube, exists on the outer circumference of the heat transfer tube, so that water droplets attached to the outer circumference of the heat transfer tube are prevented from moving in the longitudinal direction. Will have a region that becomes. For this reason, with a flat heat transfer tube, not only the drainage rate of water droplets adhering to the outer periphery of the heat transfer tube decreases, but also the amount of water droplets that are not drained and stagnant on the upper and lower surfaces of the heat transfer tube increases, resulting in heat exchange. There was a problem that performance deteriorated.

The present invention is to solve the above-mentioned problems, and even if the heat transfer tube has a flat shape, it is possible to improve the heat exchange performance while ensuring drainage, and a heat exchanger using the same. It is an object of the present invention to provide a refrigeration cycle device that has been used.

A heat exchanger according to the present invention and a refrigeration cycle apparatus using the heat exchanger are inserted into a plurality of plate-shaped fins arranged side by side in a front-back direction at preset intervals, and insertion holes formed in the fins. And a plurality of heat transfer tubes each having a flat cross section and arranged side by side in the longitudinal direction of the fins at predetermined intervals with respect to the fins, and the heat transfer tubes retain hydrophilicity on the outer peripheral surface. A surface that has been subjected to a surface treatment, the fin has an uneven shape provided adjacent to each other in the lateral direction orthogonal to the longitudinal direction, has a groove portion extending in the longitudinal direction, and retains hydrophilicity. It has been processed.

According to the heat exchanger and the refrigeration cycle apparatus using the same according to the present invention, by collecting the water droplets adhering to the fin surface in the groove portion of the fin, the water droplet can be promptly guided downward in the longitudinal direction to be drained. it can. In addition, the water droplets that have accumulated on the upper surface of the heat transfer tube wet and spread, so that even with a flat heat transfer tube, the water droplets can be guided downward in the longitudinal direction and drained without water droplets accumulating on the upper surface of the heat transfer tube. Becomes Therefore, even in the heat exchanger using the flat heat transfer tube, the water droplets on the fin surface can be quickly and surely drained, and thus the heat exchange performance can be improved while ensuring drainage. .

It is a refrigerant circuit diagram showing an example of a refrigerating cycle device concerning Embodiment 1 of the present invention. It is a perspective view showing an example of the outdoor heat exchanger in the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a principal part enlarged view in the outdoor heat exchanger of FIG. FIG. 4 is a sectional view showing an AA section of FIG. 3. FIG. 3 is a perspective view illustrating a main part of the outdoor heat exchanger of FIG. 2, which is used for explaining a step of inserting a heat transfer tube and fins. 5 is an enlarged view of a main part of the heat exchanger according to Comparative Example 1. FIG. 5 is an enlarged view of a main part showing water droplets on the surface of the heat exchanger according to Comparative Example 1. FIG. 6 is an enlarged view of a main part of a heat exchanger according to Comparative Example 2. FIG. 6 is an enlarged view of a main part showing drainage of water droplets on the surface of the heat exchanger according to Comparative Example 2. FIG. FIG. 3 is an enlarged view of a main part showing drainage of water droplets on the surface of the heat exchanger according to the first embodiment. It is a principal part enlarged view of the heat exchanger which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the BB cross section of FIG. It is a principal part enlarged view in the heat exchanger of FIG. It is a principal part enlarged view in the modification 1 of the heat exchanger which concerns on Embodiment 2 of this invention. It is a principal part enlarged view in the modification 2 of the heat exchanger which concerns on Embodiment 2 of this invention. It is a principal part enlarged view in the heat exchanger which concerns on Embodiment 3 of this invention. FIG. 17 is a cross-sectional view showing a CC cross section of FIG. 16. It is a principal part enlarged view which shows the drainage of the water droplet of the surface in the heat exchanger which concerns on Embodiment 3 of this invention. It is a principal part enlarged view which shows the drainage of the water droplet of the surface in the heat exchanger which concerns on Embodiment 3 of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are the same or equivalent to each other, and this is common to all the texts in the specification. Further, in the cross-sectional views, hatching is omitted as appropriate in view of visibility. Further, the forms of the constituent elements shown in the entire specification are merely examples and are not limited to these descriptions. Further, as the outdoor unit, an outdoor unit installed in an air conditioner, a low temperature device, a hot water supply device or the like can be widely applied.

Embodiment 1.
<Structure of refrigeration cycle apparatus 1>
First, the refrigeration cycle apparatus 1 according to Embodiment 1 of the present invention will be described. FIG. 1 is a refrigerant circuit diagram showing an example of a refrigeration cycle device according to Embodiment 1 of the present invention. In addition, in FIG. 1, the flow of the refrigerant during the cooling operation is indicated by a dashed arrow, and the flow of the refrigerant during the heating operation is indicated by a solid arrow.

As shown in FIG. 1, the refrigeration cycle apparatus 1 includes a compressor 2, a four-way valve 3, an indoor heat exchanger 4, an indoor fan 5, an expansion device 6, an outdoor fan 7, and an outdoor heat exchanger 10. The compressor 2, the four-way valve 3, the indoor heat exchanger 4, the expansion device 6, and the outdoor heat exchanger 10 are connected by a refrigerant pipe to form a refrigerant circuit.

The compressor 2 compresses the refrigerant. The refrigerant compressed by the compressor 2 is discharged and sent to the four-way valve 3. The compressor 2 can be configured by, for example, a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or the like.

The indoor heat exchanger 4 functions as a condenser during heating operation and as an evaporator during cooling operation. The indoor heat exchanger 4 is, for example, a fin-and-tube heat exchanger, a microchannel heat exchanger, a shell-and-tube heat exchanger, a heat pipe heat exchanger, a double-tube heat exchanger, or a plate heat exchanger. It can be configured with a container or the like.

The expansion device 6 expands and decompresses the refrigerant that has passed through the indoor heat exchanger 4 or the outdoor heat exchanger 10. The expansion device 6 can be composed of, for example, an electric expansion valve capable of adjusting the flow rate of the refrigerant. As the expansion device 6, not only an electric expansion valve, but also a mechanical expansion valve having a diaphragm as a pressure receiving portion, a capillary tube, or the like can be applied.

The outdoor heat exchanger 10 functions as an evaporator during heating operation and as a condenser during cooling operation. The outdoor heat exchanger 10 will be described in detail later.

The four-way valve 3 switches the flow of refrigerant between heating operation and cooling operation. That is, the four-way valve 3 connects the discharge port of the compressor 2 to the indoor heat exchanger 4 and the refrigerant flow so as to connect the suction port of the compressor 2 to the outdoor heat exchanger 10 during the heating operation. Switch. Further, the four-way valve 3 connects the discharge port of the compressor 2 with the outdoor heat exchanger 10 and the refrigerant flow so as to connect the suction port of the compressor 2 with the indoor heat exchanger 4 during the cooling operation. Switch.

The indoor fan 5 is attached to the indoor heat exchanger 4 and supplies air, which is a heat exchange fluid, to the indoor heat exchanger 4.
The outdoor fan 7 is attached to the outdoor heat exchanger 10 and supplies air as a heat exchange fluid to the outdoor heat exchanger 10.

<Operation of Refrigeration Cycle Device 1>
Next, the operation of the refrigeration cycle apparatus 1 will be described together with the flow of the refrigerant. First, the cooling operation performed by the refrigeration cycle apparatus 1 will be described. The flow of the refrigerant during the cooling operation is indicated by the broken line arrow in FIG. Here, the operation of the refrigeration cycle apparatus 1 will be described, taking as an example the case where the heat exchange fluid is air and the heat exchanged fluid is a refrigerant.

As shown in FIG. 1, by driving the compressor 2, the high-temperature and high-pressure gas-state refrigerant is discharged from the compressor 2. Hereinafter, the refrigerant flows according to the broken line arrow. The high-temperature and high-pressure gas refrigerant (single phase) discharged from the compressor 2 flows into the outdoor heat exchanger 10 functioning as a condenser via the four-way valve 3. In the outdoor heat exchanger 10, heat is exchanged between the flowing high-temperature and high-pressure gas refrigerant and the air supplied by the outdoor fan 7, the high-temperature and high-pressure gas refrigerant is condensed, and the high-pressure liquid refrigerant (single Phase).

The high-pressure liquid refrigerant sent from the outdoor heat exchanger 10 becomes a two-phase refrigerant of low-pressure gas refrigerant and liquid refrigerant by the expansion device 6. The two-phase state refrigerant flows into the indoor heat exchanger 4 that functions as an evaporator. In the indoor heat exchanger 4, heat is exchanged between the two-phase state refrigerant that has flowed in and the air supplied by the indoor fan 5, and the liquid refrigerant of the two-phase state refrigerant evaporates to form a low-pressure gas. It becomes a refrigerant (single phase). Due to this heat exchange, the inside of the room is cooled. The low-pressure gas refrigerant sent from the indoor heat exchanger 4 flows into the compressor 2 via the four-way valve 3, is compressed into a high-temperature high-pressure gas refrigerant, and is discharged from the compressor 2 again. Hereinafter, this cycle is repeated.

Next, the heating operation performed by the refrigeration cycle apparatus 1 will be described. The flow of the refrigerant during the heating operation is shown by the solid arrow in FIG.

As shown in FIG. 1, by driving the compressor 2, the high-temperature and high-pressure gas-state refrigerant is discharged from the compressor 2. Hereafter, the refrigerant flows according to the solid arrow.

The high-temperature and high-pressure gas refrigerant (single phase) discharged from the compressor 2 flows into the indoor heat exchanger 4 functioning as a condenser via the four-way valve 3. In the indoor heat exchanger 4, heat is exchanged between the flowing high-temperature and high-pressure gas refrigerant and the air supplied by the indoor fan 5, and the high-temperature and high-pressure gas refrigerant is condensed to form a high-pressure liquid refrigerant (single-phase). )become. The heat exchange heats the room.

The high-pressure liquid refrigerant sent from the indoor heat exchanger 4 becomes a two-phase refrigerant of low-pressure gas refrigerant and liquid refrigerant by the expansion device 6. The two-phase refrigerant flows into the outdoor heat exchanger 10 that functions as an evaporator. In the outdoor heat exchanger 10, heat exchange is performed between the two-phase refrigerant that has flowed in and the air supplied by the outdoor fan 7, and the liquid refrigerant of the two-phase refrigerant evaporates to form a low-pressure gas. It becomes a refrigerant (single phase).

The low-pressure gas refrigerant sent from the outdoor heat exchanger 10 flows into the compressor 2 via the four-way valve 3, is compressed into a high-temperature and high-pressure gas refrigerant, and is discharged from the compressor 2 again. Hereinafter, this cycle is repeated.

During the above-described cooling operation and heating operation, if the refrigerant flows into the compressor 2 in a liquid state, liquid compression occurs, causing a failure of the compressor 2. Therefore, it is desirable that the refrigerant flowing out from the indoor heat exchanger 4 during the cooling operation or the outdoor heat exchanger 10 during the heating operation is a gas refrigerant (single phase).

Here, in the evaporator, when heat exchange is performed between the air supplied from the fan and the refrigerant flowing inside the heat transfer tube forming the evaporator, water in the air is condensed and evaporated. Water drops form on the surface of the vessel. The water droplets generated on the surface of the evaporator travel along the surfaces of the fins and the heat transfer tubes and are dropped downward, and are discharged as drain water below the evaporator.

Also, since the outdoor heat exchanger 10 functions as an evaporator during heating operation in a low outdoor temperature state, moisture in the air may frost on the outdoor heat exchanger 10. Therefore, the refrigeration cycle apparatus 1 performs the “defrosting operation” for removing frost when the outside air has a certain temperature (for example, 0 ° C.) or less.

The "defrosting operation" is to supply hot gas (high-temperature high-pressure gas refrigerant) from the compressor 2 to the outdoor heat exchanger 10 in order to prevent frost from adhering to the outdoor heat exchanger 10 that functions as an evaporator. It is driving. The defrosting operation may be executed when the duration of the heating operation reaches a predetermined value (for example, 30 minutes). In addition, the defrosting operation may be performed before the heating operation when the outdoor heat exchanger 10 has a constant temperature (for example, -6 ° C) or less. The frost and ice attached to the outdoor heat exchanger 10 are melted by the hot gas supplied to the outdoor heat exchanger 10 during the defrosting operation.

For example, a bypass refrigerant pipe (not shown) is provided between the outlet of the compressor 2 and the outdoor heat exchanger 10 so that hot gas can be directly supplied from the compressor 2 to the outdoor heat exchanger 10 during the defrosting operation. ) May be used for connection. Further, the discharge port of the compressor 2 is connected to the outdoor heat exchanger 10 via a refrigerant flow path switching device (for example, a four-way valve 3) so that hot gas can be supplied from the compressor 2 to the outdoor heat exchanger 10. It may be configured to.

<About the outdoor heat exchanger 10>
FIG. 2 is a perspective view showing an example of the outdoor heat exchanger in the refrigeration cycle device according to Embodiment 1 of the present invention. FIG. 3 is an enlarged view of a main part of the outdoor heat exchanger of FIG. FIG. 4 is a sectional view showing an AA section of FIG. FIG. 5 is a perspective view showing a main part of the outdoor heat exchanger of FIG. 2 and is used for explaining a step of inserting the heat transfer tubes and the fins.
In FIG. 2 and subsequent figures, the x direction is the depth direction of the outdoor heat exchanger 10, and indicates the width direction that is short in the fins 11 of the outdoor heat exchanger 10. Further, the y direction is the width direction of the outdoor heat exchanger 10, and shows the direction in which the fins 11 that are the depth (thickness) direction in the fins 11 are arranged in parallel. Furthermore, the z direction is the longitudinal direction (vertical direction) of the outdoor heat exchanger 10, and represents the height direction of the fins 11. The white arrow K represents the ventilation direction of the air supplied from the outdoor fan 7 to the outdoor heat exchanger 10. As can be seen from FIG. 2, the outdoor heat exchanger 10 according to the first embodiment is supplied with air from the outdoor fan 7 shown in FIG. 1 in the ventilation direction K (x direction of the fins 11). Further, FIG. 3 shows a main part when the outdoor heat exchanger 10 is observed in the y direction. Further, FIG. 4 shows an AA cross section in the fin 11 of FIG.

The outdoor heat exchanger 10 is, for example, a two-row structure heat exchanger, and includes a windward heat exchanger 10A and a leeward heat exchanger 10B. The windward side heat exchanger 10A and the leeward side heat exchanger 10B are fin-and-tube type heat exchangers, and the ventilation direction K of the air supplied from the outdoor fan 7 shown in FIG. 1, that is, the outdoor heat exchanger 10 is shown. Are juxtaposed along the depth x direction. The windward side heat exchanger 10A is arranged on the windward side in the ventilation direction K of the air supplied from the outdoor fan 7, and the leeward side heat exchanger 10B is the leeward side in the ventilation direction K of the air supplied from the outdoor fan 7. It is located in. One end of the heat transfer pipe 12 of the windward heat exchanger 10A is connected to the windward header collecting pipe 10C. One end of the heat transfer pipe 12 of the leeward heat exchanger 10B is connected to the leeward header collecting pipe 10D. The other end of the heat transfer tube 12 of the windward heat exchanger 10A and the other end of the heat transfer tube 12 of the leeward heat exchanger 10B are connected to the inter-row connection member 10E.

That is, in the outdoor heat exchanger 10 according to the first embodiment, one of the windward heat exchanger 10A and the leeward heat exchanger 10B is transferred from one of the windward header collecting pipe 10C and the leeward header collecting pipe 10D. The refrigerant is distributed to the heat pipe 12. Then, the refrigerant distributed to the one heat transfer tube 12 of the upwind heat exchanger 10A or the downwind heat exchanger 10B passes through the inter-row connection member 10E, and the downwind heat exchanger 10B or the upwind heat exchanger 10A. Flows into the other heat transfer tube 12. After that, the refrigerant flowing into the other heat transfer pipe 12 of the leeward heat exchanger 10B or the windward heat exchanger 10A merges with the other of the leeward header collecting pipe 10D or the leeward header collecting pipe 10C, and the compressor 2 It flows toward the suction port or the throttling device 6.

In the first embodiment, the windward heat exchanger 10A and the leeward heat exchanger 10B have the same configuration. Therefore, the windward heat exchanger 10A will be described below as a representative of both. Hereinafter, the windward heat exchanger 10A and the leeward heat exchanger 10B are simply referred to as the heat exchanger 13. In addition, when the heat exchange load of the outdoor heat exchanger 10 can be covered by one of the windward side heat exchanger 10A or the leeward side heat exchanger 10B, only one of the windward side heat exchanger 10A and the leeward side heat exchanger 10B can be used to generate the outdoor heat. The exchanger 10 may be configured.

As shown in FIGS. 3, 4, and 5, the heat exchanger 13 includes a plurality of fins 11 and a plurality of heat transfer tubes 12. The fins 11 are rectangular plate-shaped members extending in the longitudinal direction (z direction), and as shown in FIG. 5, the fins 11 are arranged in the same outdoor heat exchanger 10 in the front-back direction at predetermined intervals. It is arranged. In the case of the first embodiment, the fins 11 are arranged in the same outdoor heat exchanger 10 side by side in the y direction at a prescribed fin pitch interval FP.

Further, a plurality of insertion holes 14 into which the heat transfer tubes 12 are inserted are formed in the fins 11 above and below in the longitudinal direction of the fins 11 at predetermined intervals. Then, the fin 11 has a plurality of concavo-convex shapes provided adjacent to each other along the ventilation direction K of the air from the outdoor fan 7 in a region excluding the insertion holes 14, and has a groove portion 15 extending in the longitudinal direction. . In the case of the first embodiment, the region excluding the insertion hole 14 of the fin 11 is the entire region excluding the insertion hole 14 including the first region P where the insertion hole 14 does not exist in the longitudinal direction. The air flow direction K of the air from the outdoor fan 7 indicates the same direction as the x direction as the lateral direction orthogonal to the z direction as the longitudinal direction.

At this time, the extending direction of the uneven shape is parallel to the longitudinal direction, and as shown in FIG. 4, the uneven space RSm is preferably 5 mm or less. This is because, as a result of the study, it is clear that when the diameter of the water droplets is about 5 mm, the water droplets are dropped in the longitudinal direction by its own weight, and the effect of aggregating the water droplets due to the uneven shape is expected to be 5 mm or less. Further, the unevenness height Ra is preferably about 1/3 of the fin pitch interval FP (FIG. 5) in order to prevent the fins from contacting each other. Such a concavo-convex shape can be formed by a method of imparting a concavo-convex shape to a press or rolling roll and transferring the roll. Although not shown here, after forming a concavo-convex shape on the surface of the fin 11, a cut-and-raised portion or a protruding portion may be further formed to increase the surface area for heat exchange and improve the heat exchange performance. .

Regarding a plurality of heat transfer tubes, in FIGS. 3 and 5, two heat transfer tubes 12 located above and below in the z direction are shown as representatives. As shown in FIG. 3, the upper heat transfer tube 12 and the lower heat transfer tube 12 are inserted into the insertion holes 14 formed in the fin 11, and the length of the fin 11 is increased at predetermined intervals with respect to the fin 11. They are arranged side by side.

As shown in FIG. 5, the heat transfer tube 12 extends in the y direction, which is the direction in which the plurality of fins 11 are arranged in parallel, and the end portions of the insertion holes 14 formed in the plurality of fins 11 are formed. 14a is inserted in the x direction. Thereby, the plurality of fins 11 hold the heat transfer tube 12 in a state where the heat transfer tube 12 penetrates the insertion hole 14. The heat transfer tube 12 is a flat tube whose cross section orthogonal to the longitudinal direction has a flat shape.

Furthermore, the fins 11 and the heat transfer tubes 12 according to the first embodiment are subjected to a treatment for keeping their surfaces hydrophilic. The contact angle between the surfaces of the fins 11 and the heat transfer tubes 12 is preferably 30 ° or less. Further, it is desirable that the fins 11 have higher hydrophilicity than the heat transfer tubes 12. In order to maintain the hydrophilicity on the surfaces of the fins 11 and the heat transfer tubes 12, the surface of the fins 11 and the heat transfer tubes 12 is made hydrophilic by post-coating with a flux or a hydrophilic agent used when brazing the fins 11 and the heat transfer tubes 12. A conductive coating can be formed.

<Frosting action and drainage action of the outdoor heat exchanger 10>
Subsequently, the frosting action and the drainage action of the heat exchanger 13 according to the first embodiment will be described. In addition, in order to facilitate understanding of the effect of the heat exchanger 13 according to the first embodiment, in the following, first, the comparative example 1, the comparative example 2, and the example 1 using the first embodiment will be described in this order. The frosting action and the drainage action of the outdoor heat exchanger 10 according to the first embodiment will be described.

<Comparative Example 1>
FIG. 6 is an enlarged view of a main part of the heat exchanger 100 according to Comparative Example 1. The contact angle between the surfaces of the fin 101 and the heat transfer tube 102 of Comparative Example 1 is about 80 °. The heat exchanger 100 is different from the heat exchanger 13 according to the first embodiment in that the heat exchanger 100 does not have the groove portion 15 formed on the surface of the fin 11 shown in FIG. It is not hydrophilic. 7: is a principal part enlarged view which shows the water droplet of the surface of the heat exchanger 100 which concerns on the comparative example 1. FIG. In the heat exchanger 100 of Comparative Example 1, as shown in FIG. 7, condensed water or water droplets H melted in the defrosting operation are held on the upper and lower surfaces of the heat transfer tube 102 in the insertion hole 104, and further on the surface of the fin 101. Also remains as water drops H and cannot be completely drained.

<Comparative example 2>
FIG. 8 is an enlarged view of a main part of the heat exchanger 110 according to Comparative Example 2. FIG. 9 is an enlarged view of an essential part showing drainage of water droplets on the surface of the heat exchanger 110 according to Comparative Example 2. The contact angle between the surfaces of the fin 111 and the heat transfer tube 112 of Comparative Example 2 is about 10 °. The heat exchanger 110 is different from the heat exchanger 13 according to the first embodiment in that it does not have the groove portion 15 formed on the surface of the fin 11 shown in FIG. 3. In the heat exchanger 110 of Comparative Example 2, as shown in FIG. 9, since the surfaces of the fins 111 and the heat transfer tubes 112 are hydrophilic, the water droplets H drained to the upper surfaces of the heat transfer tubes 112 in the insertion holes 114 are transferred. It spreads along the outer peripheral surface of the heat transfer tube 112 without accumulating on the upper surface of the heat tube 112. The water droplets H on the upper surface of the heat transfer tube 112 flow to the lower surface of the heat transfer tube 112 along the outer peripheral surface of the heat transfer tube 112, are guided by the hydrophilic fins 111, and are drained to the upper surface of the lower heat transfer tube 112. Then, the water droplet H is drained to the lower side of the heat exchanger 110 by repeating the draining process of flowing to the lower surface of the heat transfer tube 112 along the outer peripheral surface of the heat transfer tube 112 (FIG. 9). Therefore, although it takes time, the residual water in the heat exchanger 110 can be made smaller than that in Comparative Example 1. However, the water droplets H on the upper surface of the heat transfer tube 112 wet and spread along the outer peripheral surface of the heat transfer tube 112 to the lower surface "whole area" of the heat transfer tube 112, and are further drained to the upper surface "whole area" of the heat transfer tube 112. Therefore, the drainage path is longer than that of the heat exchanger 13 of the first embodiment described later, and it takes time to drain the heat exchanger 110 below the heat exchanger 110.

<Example 1>
As shown in FIG. 3 and FIG. 4, in the heat exchanger 13 according to the first embodiment, the contact angle of the surfaces of the fins 11 and the heat transfer tubes 12 is about 10 °, and the unevenness interval RSm is 0.5 mm. The height Ra is 0.3 mm (FP = 1.0 mm). In the case of the first embodiment, in the first region P where the insertion hole 14 does not exist in the longitudinal direction of the fin 11, water droplets H melted by the defrosting operation are collected in the groove portion 15 formed on the surface of the fin 11, It was confirmed that the water was quickly drained along the groove 15.

Further, since the surfaces of the fins 11 and the heat transfer tubes 12 are each hydrophilic, the water droplets H collected on the upper surface of the heat transfer tubes 12 spread along the outer peripheral surface of the heat transfer tubes 12 without accumulating on the upper surfaces of the heat transfer tubes 12. . Then, the water droplets H are guided to the groove portion 15 by the hydrophilic property of the fins 11 and then drained downward along the groove portion 15 in the longitudinal direction.

At this time, most of the water droplets H drained from the upper surface of the heat transfer tube 12 are, as shown in FIG. 10, the water droplets H on the heat transfer tube 12 among the plurality of groove portions 15 of the fin 11 drain downward in the longitudinal direction. The water is drained along the groove portion 15A that first intersects in the drainage path. FIG. 10 is an enlarged view of an essential part showing drainage of water droplets on the surface of the heat exchanger according to the first embodiment. Since the insertion hole 14 is formed in a region of the fin 11 where the heat transfer tube 12 exists in the longitudinal direction, the groove portion 15 is cut off at the position of the insertion hole 14. Therefore, it is difficult for the water droplets H to directly propagate to the lower surface of the heat transfer tube 12 and the upper surface of the lower heat transfer tube 12, and the groove portion of the first region P where the insertion hole 14 (that is, the heat transfer tube 12) does not exist in the z direction. Drainage is mainly performed at 15A. Therefore, the retention state of the water droplets H on the upper surface and the lower surface of the heat transfer tube 12 which is of particular concern in the drainage of the heat exchanger 13 using the flat heat transfer tube 12 is minimized, and the drainage is facilitated in the first region P. It becomes possible to actively carry out drainage.

<Effect of Embodiment 1>
As described above, in the refrigeration cycle device 1 according to the first embodiment, the water droplets H attached to the surfaces of the fins 11 can be collected in the groove portions 15 and quickly drained downward in the longitudinal direction of the heat exchanger 13. it can. Further, by allowing the water droplets H accumulated on the upper surface of the heat transfer tube 12 to spread, the water droplets H do not accumulate on the upper surface of the heat transfer tube 12 even if the heat transfer tube 12 has a flat shape, and the water droplets H move downward in the longitudinal direction. It can be led to and drained. At this time, the water droplets H accumulated on the upper surface of the heat transfer tube 12 can be mainly drained in the first region P where drainage is easy in the longitudinal direction of the fin 11 without the insertion hole 14. Therefore, the condensed water of the entire heat exchanger 13 or the water droplets H such as dissolved water due to the defrosting operation can be drained much more rapidly. Therefore, even in the heat exchanger 13 using the flat heat transfer tube 12, the water droplets H on the surfaces of the fins 11 can be quickly and surely drained, thus improving drainage and heat exchange performance. Can be planned.

Embodiment 2.
Next, a refrigeration cycle apparatus 1 (FIG. 1) according to Embodiment 2 of the present invention will be described. Specifically, in the above-described first embodiment, the case where the groove portion 15 is provided on the entire surface of the fin 11 in the x direction has been described (see FIGS. 3 to 5, 10 and the like). On the other hand, in the refrigeration cycle apparatus 1 according to the second embodiment, as shown in FIG. 11 described later, the fins 21 of the heat exchanger 20 have different regions in which the groove portions 25 extending in the longitudinal direction are provided, The other configurations are the same. For this reason, in the second embodiment, a specific configuration of the heat exchanger 20 will be described, and other redundant description will be omitted.

FIG. 11 is an enlarged view of a main part of the heat exchanger 20 according to Embodiment 2 of the present invention. FIG. 12 is a cross-sectional view showing a BB cross section of FIG. FIG. 13 is an enlarged view of a main part of the heat exchanger 20 of FIG. As shown in FIG. 11, in the heat exchanger 20 according to the second embodiment, the groove portion 25 is provided in the area where the heat transfer tube 22 (insertion hole 24) does not exist in the z direction on the surface of the fin 21.

Specifically, the fin 21 is located on the first region P where the insertion hole 24 does not exist in the longitudinal direction and on the center side in the lateral direction of the first region P in the longitudinal direction, and in the lateral direction of the insertion hole 24. The groove portion 25 is provided in the second region Q including the end portion 24a on the side of the first region P in. Here, the second region Q includes the vicinity of the boundary between the groove 24 and the end 24 a of the heat transfer tube 22 on the first region P side in the insertion hole 24.

More specifically, as shown in FIG. 11 and FIG. 13, the second region Q has an RSm of RSm from the end 24a on the first region P side of the insertion hole 24 toward the center side of the insertion hole 24 in the lateral direction. It is desirable that the area is twice as wide. Here, the second area Q is an area having a width twice as large as RSm from the end portion 24a on the first area P side of the insertion hole 24 toward the center side of the insertion hole 24 in the lateral direction. This is to secure the groove portion 25 that functions as a drainage path for the water droplets H attached to the upper surface of the. That is, a width of one RSm corresponds to either a concave portion or a convex portion of the unevenness forming the groove 25, and makes the groove function as a drainage path for the water droplets H attached to the upper surface of the heat transfer tube 22. 25 cannot always be secured. Therefore, by making the region twice the width of RSm, it is possible to surely hold the groove portion 25 that has both the concave and convex shapes that form the groove portion 25 and that functions as the drainage path of the water droplets H.

<Effect of Embodiment 2>
As described above, in the heat exchanger 20 according to the second embodiment, the same effect as that of the first embodiment can be obtained by only providing the groove portion 25 extending in the longitudinal direction only in the first region P and the second region Q. Obtainable. That is, in the heat exchanger 20 according to the second embodiment, the water droplets H accumulated on the surfaces of the fins 21 and the upper surfaces of the heat transfer tubes 22 are moved downward in the longitudinal direction via the groove portions 25 of the first region P and the second region Q. It is possible to drain water quickly and surely. Therefore, not only the heat exchange performance can be improved while ensuring the drainage property of the heat exchanger 20, but the formation region of the groove 25 in the fin 21 can be reduced to simplify the configuration.

<Modification of Second Embodiment>
The heat exchanger 20 according to the second embodiment is not limited to the above-mentioned configuration. FIG. 14 is an enlarged view of a main part in the first modification of the heat exchanger 20 according to the second embodiment of the present invention. As shown in FIG. 14, a third region R, which is on the center side in the lateral direction with respect to the second region Q and is a flat face in which the insertion hole 24 exists in the longitudinal direction of the fin 21, projects from the flat face. The cut-and-raised portion 26, the protruding portion 27, or both may be provided.
In this case, the heat exchange performance can be further improved by increasing the surface area of the fin 21 for heat exchange.

In addition, in the heat exchanger 20 according to the second embodiment, as shown in FIG. 11, the opposite end of the end 24a on the first region P side in the insertion hole 24 is formed in a notched state. However, the present invention is not limited to this.

FIG. 15 is an enlarged view of a main part in the second modification of the heat exchanger 20 according to the second embodiment of the present invention. For example, as in the heat exchanger 200 shown in FIG. 15, the end portion on the opposite side of the end portion 24a on the first region P side of the insertion hole 240 formed in the fin 210 may not be in the notched state. In this case, the fin 210 of the heat exchanger 200 has an insertion hole 240 corresponding to the heat transfer tube 220 opened at the center of the fin 210. The insertion hole 240 includes an end portion 240a on the first region T side located upstream of the air ventilation direction K and an opposite end portion 240b located downstream of the air ventilation direction K opposite thereto. Has a flat shape corresponding to the heat transfer tube 220 without being cut out. At this time, the region corresponding to the first region P is the first region T, the region corresponding to the second region Q is the second region U, the region corresponding to the third region R is the third region V, and the insertion The holes 240 are formed symmetrically in the lateral direction around the hole 240.

In the heat exchanger 200 as described above, like the heat exchanger 20 described above, water droplets (not shown) accumulated on the surfaces of the fins 210 and the upper surfaces of the heat transfer tubes 220 are formed in the groove portions of the first region T and the second region U. Through 250, it is possible to quickly and surely drain downward in the longitudinal direction. Moreover, the groove 250 is not provided in the entire area of the surface of the fin 210 in the x direction, but is provided in the first region T and the second region U to the minimum necessary. Can be simplified. Further, since the insertion hole 240 is opened in the center of the fin 210 in a flat shape corresponding to the heat transfer tube 220 without notching the opposite end portion 240b, it is remarkably compared with the case having the notch. The heat transfer tube 220 can be stably held.

Embodiment 3.
Next, a refrigeration cycle apparatus 1 (FIG. 1) according to Embodiment 3 of the present invention will be described. Specifically, in the above-described first embodiment, the case where the extending direction of the groove portion 15 on the surface of the fin 11 is parallel to the upper and lower sides in the longitudinal direction has been described (see FIGS. 3 to 5, 10 and the like). On the other hand, in the refrigeration cycle apparatus 1 according to the third embodiment, as shown in FIGS. 16 to 19 described later, the extending direction of the groove 35 in the fin 31 of the heat exchanger 30 is the longitudinal direction of the fin 31. Other than that the point is inclined with respect to the direction, the others are configured similarly. For this reason, in the third embodiment, the specific configuration of the heat exchanger 30 will be described, and other redundant description will be omitted. The region corresponding to the first region P in the above-described first embodiment is the first region Pa, and the end portion 14a of the insertion hole 14 on the first region P side is the first region Pa side in the insertion hole 34. End portion 34a.

FIG. 16 is an enlarged view of a main part of the heat exchanger 30 according to the third embodiment of the present invention. FIG. 17 is a cross-sectional view showing a CC cross section of FIG. As shown in FIGS. 16 and 17, in the heat exchanger 30 of the third embodiment, in the z direction on the surface of the fin 31, when the groove portion 35 is arranged with the longitudinal direction facing up and down in the gravity direction, the groove portion is arranged. The inclining direction of 35 inclines downward toward the first region Pa. In other words, in the heat exchanger 30 according to the third embodiment, the groove portion 35 extends in a state in which the groove 35 is inclined in the downward direction opposite to the ventilation direction K of the air flowing between the fins 31. .

FIG. 18 is an enlarged view of an essential part showing drainage of water droplets on the surface of the heat exchanger 30 according to the third embodiment of the present invention. FIG. 19 is an enlarged view of an essential part showing drainage of water droplets on the surface of the heat exchanger 30 according to Embodiment 3 of the present invention. In this case, in the heat exchanger 30 according to the third embodiment, the water droplets H accumulated on the upper surface of the heat transfer tube 32 in the insertion hole 34 spread wet along the outer peripheral surface of the hydrophilic heat transfer tube 32, and the heat transfer tube 32. The water is drained along the groove 35A on the surface of the fin 31 that first intersects with the upper drainage path. At this time, since the groove portion 35A extends toward the end of the fin 31 on the side of the first region Pa, the drained water droplet H does not come into contact with the heat transfer pipe 32 below and the first region Pa where drainage is easy. Be led up to.

Further, in the heat exchanger 30 of the third embodiment, the condensed water on the groove 35B is guided to the first region Pa without accumulating on the upper surface of the heat transfer pipe 32. At this time, each groove 35 is arranged such that the height position of the one groove 35 on the surface of the fin 31 on the first region Pa side where the heat transfer tube 32 does not exist is lower than the height position on the insertion side of the heat transfer tube 32. Has been extended.

<Effect of Embodiment 3>
As described above, in the heat exchanger 30 according to the third embodiment, the extending direction of the groove portion 35 provided on the surface of the fin 31 is defined as the ventilation direction K of the air flowing between the fins 31 in the z direction. Tilts in the opposite downward direction. Thereby, it becomes possible to further promote the drainage in the first region Pa where the drainage is easy, and the drainage can be carried out much more rapidly than in the first embodiment described above.

1 refrigeration cycle device, 2 compressor, 3 four-way valve, 4 indoor heat exchanger, 5 indoor fan, 6 expansion device, 7 outdoor fan, 10 indoor heat exchanger, 10A windward heat exchanger, 10B leeward heat exchanger 10C leeward header collecting pipe, 10D leeward header collecting pipe, 10E inter-row connecting member, 11, 21, 31, 101, 111, 210 fins, 12, 22, 32, 102, 112, 220 heat transfer pipes, 13, 20, 30, 100, 110, 200 heat exchanger, 14, 24, 34, 104, 114, 240 insertion hole, 14a, 24a, 34a, 240a, 240b end, 15, 15A, 25, 35, 35A, 35B , 250 groove part, 26 cut and raised part, 27 protruding part, H water drop, K air ventilation direction, P, Pa, T first area, Q, U second area , R, V third region.

Claims

A plurality of plate-shaped fins arranged side by side in the front and back direction at a preset interval,
A plurality of heat transfer tubes that are inserted into the insertion holes formed in the fins and have a flat cross section arranged side by side in the longitudinal direction of the fins at preset intervals with respect to the fins;
The heat transfer tube, the outer peripheral surface is subjected to a surface treatment for maintaining hydrophilicity,
The fins are
A heat exchanger, which is formed of concavo-convex shapes adjacent to each other in the lateral direction orthogonal to the longitudinal direction, has a groove portion extending in the longitudinal direction, and is subjected to a surface treatment for maintaining hydrophilicity.
The fins are
As the region having the groove,
A first region in which the insertion hole does not exist in the longitudinal direction of the fin,
A second region that is closer to the center in the lateral direction than the first region in the longitudinal direction of the fin, and includes an end portion on the first region side in the lateral direction of the insertion hole,
The heat exchanger according to claim 1, further comprising:
The fins are
A cut-and-raised portion or a protruding portion protruding from the flat surface is provided in a third area, which is on the center side in the lateral direction with respect to the second area and is formed of a flat surface in which the insertion hole exists in the longitudinal direction. The heat exchanger according to claim 2, which is provided.
The fins are
The heat exchanger according to any one of claims 1 to 3, wherein the extending direction of the groove is inclined with respect to the longitudinal direction.
The fins are
When the longitudinal direction is arranged vertically in the direction of gravity,
The heat exchanger according to claim 4, wherein the groove is inclined in a downward direction toward the first region.
A refrigeration cycle apparatus comprising the heat exchanger according to any one of claims 1 to 5, and using the heat exchanger as an evaporator.