WO2020245982A1

WO2020245982A1 - Heat exchanger and refrigeration cycle device

Info

Publication number: WO2020245982A1
Application number: PCT/JP2019/022556
Authority: WO
Inventors: 龍一永田; 真哉東井上; 前田　剛志; 繁佳松井
Original assignee: 三菱電機株式会社
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2020-12-10
Also published as: JPWO2020245982A1; JP7292389B2

Abstract

Provided are a heat exchanger in which retention of refrigerator oil is reduced and with which it is possible to improve quality, and a refrigeration cycle device in which the heat exchanger is used. The heat exchanger and the refrigeration cycle device according to the present invention are provided with: a plurality of heat transfer tubes in which the tube axes extend in the vertical direction, the plurality of heat transfer tubes being arranged next to each other in the horizontal direction; and a header connecting the upper end parts of the plurality of heat transfer tubes to each other. The header is provided with a partition member that partitions the interior into an insertion space, into which the upper end parts of the plurality of heat transfer tubes are inserted, and an upper space located above the insertion space. The partition member is provided with through-holes via which the insertion space and the upper space communicate with each other.

Description

Heat exchanger and refrigeration cycle equipment

The present invention relates to a heat exchanger and a refrigeration cycle device including the heat exchanger, and particularly to a header structure.

A heat exchanger that functions as a condenser mounted on an indoor unit in an air conditioner that is a refrigeration cycle device is known. The liquid refrigerant condensed by this heat exchanger is depressurized by the expansion device, and becomes a gas-liquid two-phase state in which the gas refrigerant and the liquid refrigerant are mixed. Then, the refrigerant in the gas-liquid two-phase state is converted into a low-pressure gas refrigerant by evaporating the liquid refrigerant among the refrigerants in the gas-liquid two-phase state in a heat exchanger that functions as an evaporator mounted on the outdoor unit. After that, the low-pressure gas refrigerant sent out from the heat exchanger flows into the compressor mounted on the outdoor unit, is compressed, becomes a high-temperature and high-pressure gas refrigerant, and is discharged from the compressor again. Hereinafter, this cycle is repeated (see, for example, Patent Document 1).

In such an air conditioner, that is, the refrigerant circuit of the refrigerating cycle device, the refrigerating machine oil that lubricates the sliding part of the compressor is circulated together with the refrigerant. For example, when the heat exchanger operates as a condenser, the gas refrigerant and the refrigerating machine oil flow into the upper header, the refrigerant flows through the heat transfer tube while changing the phase, and flows into the lower header as a liquid refrigerant.

Here, in the conventional heat exchanger, especially when the heat transfer tube has a flat multi-hole tube structure, when the gas refrigerant mixed with the refrigerating machine oil flows into the header, the refrigeration mixed in the gas refrigerant is performed. Machine oil is separated. Then, the separated refrigerating machine oil flows into the heat transfer tube together with the gas refrigerant. At this time, since the holes in the heat transfer tube are fine, it is difficult for the refrigerating machine oil to flow into the heat transfer tube, and there is a problem that the refrigerating machine oil stays in the header.

Therefore, in the heat exchanger described in Patent Document 1, a pipe having a protruding length shorter than the protruding length of the heat transfer tube protruding in the upper header is provided. As a result, the refrigerating machine oil in the header is returned to the lower header via the pipe provided in the upper header, and the refrigerating machine oil is suppressed from staying in the upper header.

Japanese Unexamined Patent Publication No. 2005-24188

However, in the heat exchanger of Patent Document 1, the above-mentioned piping is arranged between a part of a plurality of adjacent heat transfer tubes protruding in the header. Therefore, the refrigerating machine oil is discharged from the pipes in the area between the heat transfer pipes on both sides where the pipes are arranged, but the refrigerating machine oil is discharged between the adjacent heat transfer pipes in the area where the pipes are not arranged. There was a risk of staying without.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide a heat exchanger capable of reducing the retention of refrigerating machine oil and improving the quality, and a refrigeration cycle apparatus including the heat exchanger. ..

The heat exchanger according to the present invention includes a plurality of heat transfer tubes whose tube shafts extend in the vertical direction and are arranged side by side in the horizontal direction, and a header for connecting the upper ends of the plurality of heat transfer tubes. The header includes a partition member that partitions the inside into an insertion space into which the upper end of the plurality of heat transfer tubes is inserted and an upper space located above the insertion space, and the partition member is the insertion space. It is provided with a communication hole for communicating between the upper space and the upper space.

Further, the refrigeration cycle device according to the present invention includes a refrigerant circuit having at least a compressor, a condenser, an expansion device and an evaporator, and is equipped with the heat exchanger as the condenser or the evaporator.

According to the present invention, since the header is partitioned up and down by a partition member and the partition member is provided with a communication hole, the flow velocity of the refrigerant passing through the communication hole in the header can be increased. The refrigerant with increased flow velocity collides with the refrigerating machine oil staying inside the header, scatters the refrigerating machine oil, and winds it up to send the refrigerating machine oil to the downstream side of the refrigerant circuit along with the flow of the refrigerant, and the refrigeration stays in the heat exchanger. Machine oil can be reduced.

It is a schematic diagram which shows the refrigerant circuit 5 of the air conditioner 1 which concerns on Embodiment 1. FIG. It is a schematic diagram which shows an example of the heat exchanger 100 mounted on the air conditioner 1 which concerns on Embodiment 1. FIG. It is a front view of the heat exchanger 1100 which is a comparative example of the heat exchanger 100 which concerns on Embodiment 1. FIG. FIG. 5 is an enlarged cross-sectional view of the upper header 20 of the heat exchanger 100 according to the first embodiment. This is a modification of the communication hole 22 provided in the upper header 20 of the heat exchanger 100 according to the first embodiment. It is an enlarged sectional view of the upper header 220 of the heat exchanger 200 which concerns on Embodiment 2. FIG. It is an enlarged sectional view of the upper header 320 of the heat exchanger 300 which concerns on Embodiment 3. FIG. This is a modification of the partition member 321 of the upper header 320 of the heat exchanger 300 according to the third embodiment. This is a modification of the partition member 321 of the upper header 320 of the heat exchanger 300 according to the third embodiment. It is a schematic diagram which shows an example of the heat exchanger 400 mounted on the air conditioner 1 which concerns on Embodiment 4. FIG. It is a schematic diagram which shows an example of the heat exchanger 500 mounted on the air conditioner 1 which concerns on Embodiment 5. FIG. FIG. 5 is an enlarged cross-sectional view of the upper header 520 of the heat exchanger 500 according to the fifth embodiment. This is a modification of the communication hole 22 provided in the upper header 520 of the heat exchanger 500 according to the fifth embodiment.

Hereinafter, embodiments will be described based on the drawings. It should be noted that, in each figure, those having the same reference numerals are the same or equivalent thereof, which are common in the entire text of the specification. In addition, the forms of the components shown in the entire specification are merely examples, and are not limited to these descriptions. Further, in the drawings below, the relationship between the sizes of the constituent members may differ from the actual one.

Embodiment 1.
<Configuration of air conditioner 1>
The air conditioner 1 as a refrigeration cycle device to which the heat exchanger 100 according to the first embodiment is applied will be described with reference to FIG. The heat exchanger 100 according to the first embodiment is configured as at least one of the outdoor heat exchanger 12 and the indoor heat exchanger 14 of the air conditioner 1.

FIG. 1 is a schematic diagram showing a refrigerant circuit 5 of the air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 according to the first embodiment performs cooling or heating by transferring heat between the outside air and the indoor air via a refrigerant. The air conditioner 1 is for air conditioning indoors, and has an indoor unit 2 and an outdoor unit 3.

Examples of the refrigerant flowing through the air conditioner 1 include various refrigerants such as R32 refrigerant, R290 refrigerant which is a low GWP refrigerant, the above-mentioned mixed refrigerant containing R32 refrigerant as a main component, and mixed refrigerant containing R290 refrigerant as a main component. Refrigerant can be applied. Further, a refrigerant having a smaller gas density than an R32 refrigerant or an R410A refrigerant such as an olefin-based refrigerant, propane or DME (dimethyl ether) has a higher refrigerant flow velocity per capacity, and therefore has a great effect of improving performance by reducing pressure loss. Examples of the olefin-based refrigerant include HFO1234yf, HFO1234ze (E), and the like. Further, refrigerating machine oil is circulated together with the refrigerant in the refrigerant circuit 5 of the air conditioner 1. The refrigerating machine oil is for lubricating the components of the compressor 10, and normally circulates inside the compressor 10, but a part of the refrigerating machine oil is discharged to the refrigerant circuit 5 together with the refrigerant.

In the air conditioner 1, the indoor unit 2 and the outdoor unit 3 are connected by pipes via the

refrigerant pipes

4, 4a and 4b to form a refrigerant circuit 5 in which the refrigerant circulates. The refrigerant circuit 5 is provided with a compressor 10, a flow path switching device 11, an outdoor heat exchanger 12, an expansion device 13, and an indoor heat exchanger 14, and these are connected via

refrigerant pipes

4, 4a, and 4b. There is.

The outdoor unit 3 has a compressor 10, a flow path switching device 11, an outdoor heat exchanger 12, and an expansion device 13. The compressor 10 compresses and discharges the sucked refrigerant. Here, the compressor 10 may include an inverter device. When the inverter device is provided, the operation frequency can be changed by the control unit 6 to change the capacity of the compressor 10. The capacity of the compressor 10 is the amount of refrigerant delivered per unit time.

The flow path switching device 11 is, for example, a four-way valve, which switches the direction of the refrigerant flow path. The air conditioner 1 can realize a heating operation or a cooling operation by switching the flow of the refrigerant by using the flow path switching device 11 based on the instruction from the control unit 6. The outdoor heat exchanger 12 exchanges heat between the refrigerant and the outdoor air. Further, the outdoor heat exchanger 12 is provided with an outdoor blower 15 in order to improve the efficiency of heat exchange between the refrigerant and the outdoor air. An inverter device may be attached to the outdoor blower 15. In this case, the inverter device changes the rotation speed of the fan by changing the operating frequency of the fan motor 16 which is the drive source of the outdoor blower 15. The outdoor blower 15 is not limited to this as long as the same effect can be obtained. For example, the type of fan may be a sirocco fan or a plug fan. Further, the outdoor blower 15 may be a pushing type or a pulling type.

Here, the outdoor heat exchanger 12 functions as an evaporator during the heating operation, and exchanges heat between the low-pressure refrigerant flowing in from the refrigerant pipe 4b side and the outdoor air to evaporate the refrigerant and vaporize it. And let it flow out to the refrigerant pipe 4a side. Further, the outdoor heat exchanger 12 functions as a condenser during the cooling operation, and the refrigerant compressed by the compressor 10 flowing in from the refrigerant pipe 4a side via the flow path switching device 11 and the outdoor air. Heat exchange is performed between the refrigerants to condense and liquefy the refrigerant, and the refrigerant flows out to the refrigerant pipe 4b side. Although the case where the outdoor air is used as the external fluid has been described here as an example, the external fluid is not limited to the gas containing the outdoor air, and may be a liquid containing water.

The expansion device 13 is a throttle device that controls the flow rate of the refrigerant, and adjusts the pressure of the refrigerant by adjusting the flow rate of the refrigerant flowing through the refrigerant pipe 4 by changing the opening degree of the expansion device 13. During the cooling operation, the expansion device 13 expands the high-pressure liquid state refrigerant into the low-pressure gas-liquid two-phase state refrigerant to reduce the pressure. The expansion device 13 is not limited to this, and an electronic expansion valve, a capillary tube, or the like may be used as long as the same effect can be obtained. For example, when the expansion device 13 is composed of an electronic expansion valve, the opening degree is adjusted based on the instruction of the control unit 6.

The indoor unit 2 includes an indoor heat exchanger 14 that exchanges heat between the refrigerant and the indoor air, and an indoor blower 17 that adjusts the flow of air that the indoor heat exchanger 14 exchanges heat with.

The indoor heat exchanger 14 acts as a condenser during the heating operation, exchanges heat between the refrigerant flowing in from the refrigerant pipe 4a side and the indoor air, condenses the refrigerant and liquefies it, and causes the refrigerant pipe. Let it flow out to the 4b side. Further, the indoor heat exchanger 14 functions as an evaporator during the cooling operation, and exchanges heat between the refrigerant brought into a low pressure state by the expansion device 13 flowing in from the refrigerant pipe 4b side and the indoor air. The refrigerant takes heat from the air, evaporates and vaporizes it, and flows out to the refrigerant pipe 4a side. Although the case where the indoor air is used as the external fluid has been described here as an example, the external fluid is not limited to the gas containing the indoor air and may be a liquid containing water.

The operating speed of the indoor blower 17 is determined by the user's setting. It is preferable to attach an inverter device to the indoor blower 17 and change the operating frequency of the fan motor 18 to change the rotation speed of the fan. The indoor blower 17 is not limited to this as long as the same effect can be obtained. For example, the type of fan may be a sirocco fan or a plug fan. Further, the indoor blower 17 may be a pushing type or a pulling type.

<Operation example of cooling and heating operation of air conditioner 1>
Next, the operation of the cooling operation will be described as an operation example of the air conditioner 1. The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 10 flows into the outdoor heat exchanger 12 via the flow path switching device 11. The gas refrigerant that has flowed into the outdoor heat exchanger 12 is condensed by heat exchange with the outside air blown by the outdoor blower 15, becomes a low-temperature refrigerant, and flows out of the outdoor heat exchanger 12. The refrigerant flowing out of the outdoor heat exchanger 12 is expanded and depressurized by the expansion device 13 to become a low-temperature low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the indoor heat exchanger 14 of the indoor unit 2, evaporates by heat exchange with the indoor air blown by the indoor blower 17, becomes a low-temperature low-pressure gas refrigerant, and becomes an indoor heat exchanger. Outflow from 14. At this time, the indoor air that has been endothermic and cooled by the refrigerant becomes harmonized air (blow-out air) and is blown out from the indoor unit 2 into the room that is the air-conditioning target space. The gas refrigerant flowing out of the indoor heat exchanger 14 is sucked into the compressor 10 via the flow path switching device 11 and is compressed again. In the cooling operation of the air conditioner 1, the above operation is repeated (indicated by the solid arrow in FIG. 1).

Next, the operation of the heating operation will be described as an operation example of the air conditioner 1. The high-temperature and high-pressure gas refrigerant compressed and discharged by the compressor 10 flows into the indoor heat exchanger 14 of the indoor unit 2 via the flow path switching device 11. The gas refrigerant flowing into the indoor heat exchanger 14 is condensed by heat exchange with the indoor air blown by the indoor blower 17, becomes a low-temperature refrigerant, and flows out from the indoor heat exchanger 14. At this time, the indoor air that has been warmed by receiving heat from the gas refrigerant becomes conditioned air (blown air) and is blown out from the indoor unit 2 into the room. The refrigerant flowing out of the indoor heat exchanger 14 is expanded and depressurized by the expansion device 13 to become a low-temperature low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 12 of the outdoor unit 3, evaporates by heat exchange with the outside air blown by the outdoor blower 15, becomes a low-temperature low-pressure gas refrigerant, and becomes the outdoor heat exchanger 12. Outflow from. The gas refrigerant flowing out of the outdoor heat exchanger 12 is sucked into the compressor 10 via the flow path switching device 11 and is compressed again. In the heating operation of the air conditioner 1, the above operation is repeated (indicated by the broken line arrow in FIG. 1).

If the refrigerant flows into the compressor 10 in a liquid state during the cooling operation and the heating operation described above, liquid compression occurs, which causes a failure of the compressor 10. Therefore, it is desirable that the refrigerant flowing out from the outdoor heat exchanger 12 during the cooling operation or the indoor heat exchanger 14 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 constituting the evaporator, the moisture in the air is condensed and evaporated. Water droplets form on the surface of the vessel. The water droplets generated on the surface of the evaporator are dropped downward along the surfaces of the fins and the heat transfer tube, and are discharged as drain water below the evaporator.

<About heat exchanger 100>
Next, the heat exchanger 100 mounted on the air conditioner 1 according to the first embodiment will be described. The heat exchanger 100 is applied to at least one of the outdoor heat exchanger 12 and the indoor heat exchanger 14 shown in FIG. 1, but it is particularly preferable to apply the heat exchanger 100 to a heat exchanger used as a condenser.

FIG. 2 is a schematic view showing an example of the heat exchanger 100 mounted on the air conditioner 1 according to the first embodiment. FIG. 2A is a front view of the heat exchanger 100. FIG. 2B is a cross-sectional view of the heat exchanger 100, and shows a cross-sectional view of a portion AA of FIG. 2A. FIG. 2C is a top view of the heat exchanger 100. In FIGS. 2 and 2, the x direction is the width direction of the heat exchanger 100, the extension direction of the header 20 of the heat exchanger 100, the thickness direction of the flat tube 50 which is a flat heat transfer tube, and the flat tube 50. It shows the direction of parallelization. Further, the y direction is the height direction of the heat exchanger 100, and indicates the pipe axis direction of the flat tube 50, that is, the direction in which the refrigerant is along the flow. Further, the x direction is the depth direction of the heat exchanger 100, and indicates the horizontal direction intersecting the x direction, which is the extension direction of the header 20, that is, the width direction of the flat tube 50. The AF indicated by the white arrow indicates the ventilation direction of the air supplied from the outdoor blower 15 (see FIG. 1) to the outdoor heat exchanger 12, and the RF indicated by the arrow is supplied to the heat exchanger 100. It represents the flow direction of the refrigerant.

As shown in FIG. 2, the heat exchanger 100 according to the first embodiment is configured by arranging a plurality of flat tubes 50 in a row in the horizontal direction. The plurality of flat tubes 50 are arranged with their pipe axes oriented in the vertical direction, a header 20 is connected to an upper end portion, and a header 30 is connected to a lower end portion. The header 20 connects the upper ends of the plurality of flat tubes 50 to each other, and the header 30 connects the lower ends of the plurality of flat tubes 50 to each other. That is, the plurality of flat tubes 50 are arranged between the header 20 and the header 30. The header 20 may be referred to as an upper header, and the header 30 may be referred to as a lower header.

The plurality of flat tubes 50 are heat transfer tubes having a multi-hole tube structure having a flat cross section, and in the first embodiment, the tube axes are provided so as to rise in the vertical direction, that is, in the y direction. The plurality of flat tubes 50 are arranged side by side in the horizontal direction, that is, in the x direction at preset intervals between the upper and

lower headers

20 and 30. Further, in the case of the first embodiment, the heat transfer member such as the corrugated fin that connects the side surfaces of the flat tubes 50 is not arranged in the gap 80 between the adjacent flat tubes 50. However, the heat exchanger 100 may be provided with a heat transfer member as needed. Although the heat exchanger 100 includes a flat tube 50, a heat transfer tube having a cross-sectional shape such as a circular cross section may be used instead.

The upper and

lower headers

20 and 30 are each formed in a hollow rectangular parallelepiped shape, and are provided with insertion holes so that the ends of a plurality of flat tubes 50 can be inserted. In the upper header 20, a plurality of upper end portions 51 of the flat tubes 50 are inserted from below.

Here, in the upper and

lower headers

20 and 30, generally, the connection strength between the plurality of flat pipes 50 and the

headers

20 and 30 is secured, and the brazing material used for the connection flows into the refrigerant flow path in the flat pipe 50. The flat tube 50 is projected into the

headers

20 and 30 by a predetermined size for the purpose of preventing quality deterioration.

Further, the header 20 is provided with a partition member 21 inside, and the inside is partitioned into two upper and lower spaces. The space in which the upper end 51 of the plurality of flat tubes 50 is inserted is referred to as an insertion space S1, and the space located above the insertion space S1 is referred to as an upper space S2. The upper surface 23 on the upper space side of the partition member 21 faces the upper space S2, and the lower surface 24 on the insertion space side of the partition member 21 faces the insertion space S1.

The insertion space S1 and the upper space S2 are communicated with each other by a communication hole 22 which is a through hole provided in the partition member 21. As shown in FIG. 2C, the communication hole 22 is circular and is arranged between the plurality of flat tubes 50 in the top view, that is, from the viewpoint in the pipe axis direction.

(Action of heat exchanger 100)
FIG. 3 is a front view of the heat exchanger 1100, which is a comparative example of the heat exchanger 100 according to the first embodiment. In the heat exchanger 1100 according to the comparative example, the upper header 120 is connected to the upper end 51 of the plurality of flat tubes 50 and the lower header 120 is connected to the lower end 52, similarly to the heat exchanger 100 according to the first embodiment. 30 is connected. However, the internal structure of the upper header 20 is different from that of the heat exchanger 100 according to the first embodiment, and the upper header 120 of the heat exchanger 1100 of the comparative example is not divided into two internal spaces.

The refrigerant circulates in the refrigerant circuit 5 of the air conditioner 1 and the refrigerating machine oil 90 discharged from the compressor 10 circulates. Therefore, the refrigerating machine oil 90 flows into the upper header 120 of the heat exchanger 1100 together with the refrigerant from the outflow port. Then, the refrigerating machine oil 90 adheres to the inner wall of the upper header 120 and gradually stays in the lower part of the upper header 120. The end face 53 through which the refrigerant flow paths of the plurality of flat pipes 50 are open is located at a position higher than the bottom surface 126 of the upper header 120 by a predetermined height. Therefore, the refrigerating machine oil 90 retained in the heat exchanger 1100 is not discharged from the upper header 120 unless it reaches the end faces 53 of the plurality of flat tubes 50. Therefore, in the heat exchanger 1100 of the comparative example, the refrigerating machine oil 90 continues to stay inside the upper header 120.

On the other hand, the heat exchanger 100 according to the first embodiment can discharge the refrigerating machine oil 90 staying in the upper header 20 by the action described below. As shown in FIGS. 2A and 2B, there is a refrigerating machine oil 90 staying in the header 20 in the lower region of the insertion space S1. In the heat exchanger 100, the refrigerant flows into the header 20. The refrigerant that has flowed into the upper space S2 of the header 20 passes through the communication hole 22 of the partition member 21 and moves to the insertion space S1. At this time, since the refrigerating machine oil 90 flows into the insertion space S1 together with the refrigerant, the refrigerating machine oil 90 stays in the lower part of the insertion space S1.

FIG. 4 is an enlarged cross-sectional view of the upper header 20 of the heat exchanger 100 according to the first embodiment. FIG. 4 is an enlarged view of the periphery of the upper header 20 of FIG. 2 (b). The white arrows shown in FIG. 4 schematically represent an example of the flow of the refrigerant. A plurality of communication holes 22 are formed in the partition member 21 provided inside the upper header 20 of the heat exchanger 100. The refrigerant that has flowed into the upper header 20 flows into the upper space S2 of the upper header 20 at a predetermined pressure. When the refrigerant moves from the upper space S2 to the insertion space S1, it passes through the communication hole 22 having a smaller cross-sectional area than the upper space S2. Therefore, the refrigerant passing through the communication hole 22 flows into the insertion space S1 in a state where the flow velocity is increased. That is, the communication hole 22 is a condensing hole that reduces the cross-sectional area of the flow of the passing fluid and increases the flow velocity. The flow of the refrigerant accelerated by passing through the communication hole 22 collides with the liquid level of the refrigerating machine oil 90 staying in the lower part of the insertion space S1, and the refrigerating machine oil 90 is scattered in the insertion space S1 and wound up. The scattered droplets of the refrigerating machine oil 90 flow into the flat pipe 50 from the end face 53 together with the refrigerant. As a result, the refrigerating machine oil 90 staying in the upper header 20 can be reduced.

As shown in FIGS. 2A and 2C, a plurality of communication holes 22 are provided in the partition member 21. Therefore, in the refrigerating machine oil 90 located below the plurality of communication holes 22, the flow of the refrigerant collides with the liquid surface, and the refrigerating machine oil 90 is scattered in the insertion space S1 and wound up. In the first embodiment, the communication hole 22 is arranged between the plurality of flat pipes 50, and is provided at one place for every two of the gaps 80 between the plurality of flat pipes 50. However, the number of communication holes 22 installed is not limited to that shown in FIG.

FIG. 5 is a modified example of the communication hole 22 provided in the upper header 20 of the heat exchanger 100 according to the first embodiment. The upper header 20 does not have to be in the form of providing one communication hole 22 for each of the gaps between the plurality of flat tubes 50 as shown in FIG. 2C. The upper header 20a of the modified example is provided with, for example, a plurality of communication holes 22a having a cross-sectional area smaller than that of the communication holes 22 at positions corresponding to the gaps 80 of the plurality of flat pipes 50. With this configuration, the communication hole 22a can be installed even when the distance between the plurality of flat tubes 50 is narrow. Further, the cross-sectional shape of the communication holes 22 and 22a is not limited to a circle, and may be an oval, an ellipse, a rectangle, or the like.

Further, the insertion space S1 and the upper space S2 of the upper header 20 are limited to a form partitioned by a partition member 21 arranged perpendicularly to the pipe axis direction of the flat pipe 50, as shown in FIG. is not. For example, the partition member 21 may be installed at an angle in FIG. 4, and may be configured so that the flow of the refrigerant passing through the communication hole 22 collides with the liquid surface of the retained refrigerating machine oil 90.

When the heat exchanger 100 is used as a condenser in the refrigerant circuit 5 shown in FIG. 1, gas refrigerant flows in from the outflow port 29. In this case, since the refrigerating machine oil 90 of the compressor 10 flows into the upper header 20 together with the gas refrigerant, the refrigerating machine oil 90 tends to adhere to the inside of the upper header 20 and stay there. However, according to the heat exchanger 100, the refrigerating machine oil 90 can be scattered and flowed into the plurality of flat pipes 50 by the above configuration, so that the retention of the refrigerating machine oil 90 can be suppressed. The heat exchanger 100 may be incorporated in the refrigerant circuit 5 so that the upper header 20 and the discharge side of the compressor 10 are connected when used as a condenser.

The air conditioner 1 to which the heat exchanger 100 is applied can prevent the compressor 10 from stopping due to seizure or the like by returning the discharged refrigerating machine oil 90 to the compressor 10, and the compressor 10 can be prevented from stopping. It is possible to suppress deterioration of quality such as shortening the life of the air conditioner. Thus, it is possible to realize the heat exchanger 100 and the air conditioner 1 using the heat exchanger 100, which can reduce the retention of the refrigerating machine oil 90 and improve the quality.

Embodiment 2.
Next, the heat exchanger 200 according to the second embodiment will be described. The heat exchanger 200 according to the second embodiment is a modification of the shape of the partition member 21 provided on the upper header 20 according to the first embodiment.

FIG. 6 is an enlarged cross-sectional view of the upper header 220 of the heat exchanger 200 according to the second embodiment. The upper header 220 of the heat exchanger 200 according to the second embodiment includes a partition member 221. The partition member 221 includes an inclined surface 223a inclined in the direction of gravity toward the communication hole 22 on the upper surface 223 on the upper space S2 side.

The partition member 221 is inclined so that both the left and right ends are high and the central part is low in the cross section shown in FIG. As a result, when the refrigerating machine oil 90 that has flowed into the upper space S2 together with the refrigerant adheres to the wall surface or the upper surface 223 and stays there, the refrigerating machine oil 90 moves to the communication hole 22 along the inclined surface and is inserted through the communication hole 22. Move to S1. Thereby, the heat exchanger 200 can reduce the refrigerating machine oil 90 staying in the upper space S2.

The refrigerating machine oil 90 that has moved from the upper space S2 to the insertion space S1 is scattered by the flow of the refrigerant accelerated by the communication hole 22 and flows into the plurality of flat pipes 50 as described in the first embodiment. The heat exchanger 200 according to the second embodiment has an advantage that the refrigerating machine oil 90 staying in the upper space S2 can be further reduced while obtaining the effect of the heat exchanger 100 according to the first embodiment.

In the second embodiment, the partition member 221 has the cross-sectional shape shown in FIG. 6 in each cross section in the x direction. However, the shape of the partition member 221 is not limited to this, and an inclined surface inclined in the direction of gravity toward the communication hole 22 may be provided in a mortar shape around the communication hole 22. Further, the partition member 221 has different thicknesses at the left and right end portions and the central portion of the cross section shown in FIG. 6, but may be formed to have a uniform thickness. For example, the flat plate may be bent at the central portion where the communication hole 22 is provided to form the partition member 221.

Embodiment 3.
Next, the heat exchanger 300 according to the third embodiment will be described. The heat exchanger 300 according to the third embodiment is a modification of the shape of the partition member 21 provided on the upper header 20 according to the first embodiment.

FIG. 7 is an enlarged cross-sectional view of the upper header 320 of the heat exchanger 300 according to the third embodiment. The upper header 320 of the heat exchanger 300 according to the third embodiment includes a partition member 321. The partition member 321 is provided with a plurality of hemispherical protrusions 325 on the lower surface 324 on the insertion space S1 side.

As described in the first embodiment, the flow of the refrigerant through the communication hole 22 collides with the liquid level of the refrigerating machine oil 90 staying in the lower part of the upper header 320, and the refrigerating machine oil 90 scatters. The scattered refrigerating machine oil 90 may not only flow into the plurality of flat pipes 50 together with the refrigerant, but may also adhere to the lower surface 324 of the partition member 321. However, since the lower surface 324 of the partition member 321 is provided with the plurality of protrusions 325, the refrigerating machine oil 90 adhering to the lower surface 324 is aggregated on the top of the protrusions 325 due to surface tension, and easily falls from the lower surface 324. The refrigerating machine oil 90 that has fallen from the lower surface 324 stays in the lower part of the insertion space S1 and is scattered again by the refrigerant, or is scattered by the flow of the refrigerant during the fall and flows into the plurality of flat pipes 50 together with the refrigerant.

As described above, the heat exchanger 300 according to the third embodiment adheres to the lower surface 324 of the partition member 321 inside the upper header 320 while obtaining the effect of the heat exchanger 100 according to the first embodiment. There is an advantage that the refrigerating machine oil 90 is also reduced.

8 and 9 are modified examples of the partition member 321 of the upper header 320 of the heat exchanger 300 according to the third embodiment. The partition member 321a according to the modified example has a protrusion 325a extending in the x direction and is formed as a ridge. Further, in the partition member 321b according to the modified example, hemispherical protrusions 325b are arranged side by side in two rows. As described above, the shape and arrangement position of the protrusion 325 may be changed. Further, when the protrusion 325 has a sharp tip, the agglutination of the refrigerating machine oil 90 is promoted. For example, the protrusion 325 may be formed in a conical shape.

Further, the partition member 321 can aggregate and drop the refrigerating machine oil 90 by forming minute irregularities by roughening the surface of the lower surface 324.

Embodiment 4.
Next, the heat exchanger 400 according to the fourth embodiment will be described. The heat exchanger 400 according to the fourth embodiment is a modification of the shape of the communication hole 22 of the partition member 21 provided in the upper header 20 according to the first embodiment.

FIG. 10 is a schematic view showing an example of the heat exchanger 400 mounted on the air conditioner 1 according to the fourth embodiment. FIG. 10A is a front view of the heat exchanger 400. 10 (b) is a cross-sectional view of the heat exchanger 400, and shows a cross-sectional view of a portion AA of FIG. 10 (a). FIG. 10 (c) is a top view of the heat exchanger 400. The upper header 420 of the heat exchanger 400 according to the fourth embodiment includes a partition member 421. The partition member 421 includes a communication hole 422 long in the x direction. The communication holes 422 are arranged so as to straddle the plurality of flat tubes 50 in a plan view.

In the heat exchanger 100 according to the first embodiment, the distance between the plurality of flat tubes 50 may be narrow. In this case, it is difficult to provide the communication hole 22 provided in the partition member 21 at a position corresponding to the gap 80 of the plurality of flat pipes 50. When the communication hole 22 is located above the flat pipe 50, the refrigerant directly collides with the end surface 53 of the flat pipe 50 from the communication hole 22. In this case, there is a concern that the area where the flow of the refrigerant from the communication hole 22 collides with the liquid surface of the refrigerating machine oil 90 where it has accumulated becomes smaller, and the effect of scattering the refrigerating machine oil 90 becomes smaller. Further, since the accelerated flow of the refrigerant directly collides with the end surface 53 of the flat pipe 50, it becomes difficult to evenly distribute it to a plurality of flow paths inside the flat pipe 50, and the heat exchange performance of the heat exchanger 100 is improved. There is a concern that it will decline.

On the other hand, as in the heat exchanger 400 according to the fourth embodiment, by arranging the communication holes 422 so as to straddle the flat pipes 50 in a plan view, the freezing that reliably stays between the plurality of flat pipes 50. The refrigerant from the communication hole 422 can collide with the liquid surface of the machine oil 90. At this time, the cross-sectional area s of the communication hole 422 may be set as small as possible with respect to the area S of the upper surface 423 of the partition member 421. By reducing the cross-sectional area s, the flow velocity of the refrigerant passing through the communication hole 422 is increased, and the effect of scattering the refrigerating machine oil 90 is enhanced.

As shown in FIG. 10C, the length of the communication hole 422 in the x direction may be set larger than the distance between the communication holes 422 and the adjacent communication holes 422. By increasing the length of the communication hole 422 in the x direction, the effect of increasing the flow velocity of the refrigerant can be obtained while reducing the pressure loss when the refrigerant passes through the communication hole 422.

Embodiment 5.
Next, the heat exchanger 500 according to the fifth embodiment will be described. The heat exchanger 500 according to the fifth embodiment is a modification of the arrangement of the plurality of flat tubes 50 according to the first embodiment. Accordingly, the structure of the upper header 520 of the heat exchanger 500 is different from that of the upper header 20 of the heat exchanger 100.

FIG. 11 is a schematic view showing an example of the heat exchanger 500 mounted on the air conditioner 1 according to the fifth embodiment. FIG. 11A is a front view of the heat exchanger 500. 11 (b) is a cross-sectional view of the heat exchanger 500, and shows a cross-sectional view of a portion AA of FIG. 11 (a). FIG. 11C is a top view of the heat exchanger 500. The heat exchanger 500 according to the fifth embodiment includes a plurality of

flat tube groups

550a and 550b. The first flat tube group 550a and the second flat tube group 550b are arranged in series along the flow of a fluid such as air passing through the heat exchanger 500. Each of the first flat tube group 550a and the second flat tube group 550b is arranged in parallel in the horizontal direction with the tube axes facing up and down like the plurality of flat tubes 50 of the heat exchanger 100 according to the first embodiment. ..

A lower header 30a is connected to the lower end 52 of the first flat tube group 550a. A lower header 30b is connected to the lower end 52 of the second flat tube group 550b. The lower header 30a is connected to the refrigerant circuit 5 and the refrigerant flows into the lower header 30a. The inflowing refrigerant flows into the upper header 520 via the respective flat pipes 50a of the first flat pipe group 550a, and flows into the lower header 30b from the upper header 520 via the respective flat pipes 50b of the second flat pipe group 550b. To do. The lower header 30b is connected to the refrigerant circuit 5, and the refrigerant flows out from the outflow port.

As shown in FIG. 11B, the upper header 520 is divided into upper and lower internal spaces by a partition member 521 to form an upper space S2 and an insertion space S1. Further, the insertion space S1 is divided into a first insertion space S1a into which the upper end 51 of the first flat tube group 550a is inserted and a second insertion space S2b into which the upper end 51 of the second flat tube group 550b is inserted. It is partitioned. A partition portion 526 is joined to the lower surface 524 of the partition member 521, and the partition portion 526 partitions the insertion space S1 in the direction in which a plurality of

flat tube groups

550a and 550b are arranged.

FIG. 12 is an enlarged cross-sectional view of the upper header 520 of the heat exchanger 500 according to the fifth embodiment. The heat exchanger 500 of the fifth embodiment scatters the stagnant refrigerating machine oil 90 as follows and sends it to the downstream side. The flow of the refrigerant in the first insertion space S1a is indicated by a black arrow and a white arrow in the figure. Refrigerant flows into the upper header 520 from the first flat tube group 550a. The refrigerant R flowing out from the end surface 53 of the first flat tube group 550a hits the lower surface 524 of the partition member 521, changes the direction of flow, flows downward so as to convect in the first insertion space S1a in the vertical direction, and stays therethrough. It hits the liquid level of the refrigerating machine oil 90 and flows upward again. At this time, the refrigerant scatters the refrigerating machine oil 90, passes through the communication hole 22, and flows into the upper space S2.

The refrigerant that has flowed into the upper space S2 from the first insertion space S1a flows into the second insertion space S1b from the communication hole 22 that communicates with the second insertion space S1b. The communication hole 22 communicating with the second insertion space functions in the same manner as the communication hole 22 provided in the upper header 20 of the heat exchanger 100 according to the first embodiment, and the refrigerant flowing in from the communication hole 22 functions. , The refrigerating machine oil 90 staying in the lower part of the second insertion space S1b is scattered and flows into the second flat tube group 550b together with the refrigerant.

When the heat exchanger 500 according to the fifth embodiment is used as a condenser in the air conditioner 1, the refrigerant that has passed through the first flat tube group 550a is condensed and used as a gas-liquid two-phase refrigerant in the first insertion space S1a. Inflow to. Therefore, not only the refrigerating machine oil 90 but also the liquid phase refrigerant may stay in the lower part of the first insertion space S1a and the second insertion space S2b of the upper header 520. In the heat exchanger 500 according to the fifth embodiment, the staying liquid-phase refrigerant and the refrigerating machine oil 90 are sent downstream by the above action, and the staying liquid-phase refrigerant and the refrigerating machine oil 90 are sent to the inside of the upper header 520. The effect of reducing is obtained. Even when the heat exchanger 500 is used as an evaporator, the effect of reducing the amount of the liquid phase refrigerant and the refrigerating machine oil 90 that stays due to the above action can be obtained.

FIG. 13 is a modified example of the communication hole 22 provided in the upper header 520 of the heat exchanger 500 according to the fifth embodiment. The communication hole 22 provided in the partition member 521 of the upper header 520 can have the same shape as the communication hole 422 of the upper header 420 according to the fourth embodiment. Further, the communication hole 22 may be the communication hole 22a shown in FIG.

Although the embodiments have been described above, the present invention is not limited to the above-described embodiments. For example, each embodiment may be combined as appropriate. Further, in the first to fifth embodiments, the plurality of heat transfer tubes included in the

heat exchangers

100, 200, 300, 400, and 500 have been described as flat tubes 50, but heat transfer tubes having a circular cross section may be used. good. The

flat tubes

50, 50a, 50b, the first flat tube group 550a, and the second flat tube group 55b may be referred to as a heat transfer tube, a first heat transfer tube group, and a second heat transfer tube group, respectively.

1 air conditioner, 2 indoor unit, 3 outdoor unit, 4 refrigerant pipe, 4a refrigerant pipe, 4b refrigerant pipe, 5 refrigerant circuit, 6 control unit, 10 compressor, 11 flow path switching device, 12 outdoor heat exchanger, 13 Inflator, 14 indoor heat exchanger, 15 outdoor blower, 16 fan motor, 17 indoor blower, 18 fan motor, 20 (upper) header, 20a upper header, 21 partition member, 22 communication hole, 22a communication hole, 23 upper surface, 24 lower surface, 29 outflow port, 30 (lower) header, 30a lower header, 30b lower header, 50 flat tube, 50a flat tube, 50b flat tube, 51 upper end, 52 lower end, 53 end face, 80 gap, 90 refrigerating machine oil, 100 heat exchanger, 120 upper header, 126 bottom, 200 heat exchanger, 220 upper header, 221 partition member, 223 upper surface, 300 heat exchanger, 320 upper header, 321 partition member, 321a partition Member, 321b partition member, 324 lower surface, 325 protrusion, 325a protrusion, 325b protrusion, 400 heat exchanger, 420 upper header, 421 partition member, 422 communication hole, 423 upper surface, 500 heat exchanger, 520 upper header, 521 partition member , 524 lower surface, 526 partition, 550a (first) flat tube group, 550b (second) flat tube group, 1100 heat exchanger, R refrigerant, S area, S1 insertion space, S1a first insertion space, S1b second Insertion space, S2 upper space, S2b second insertion space, s cross-sectional area.

Claims

Multiple heat transfer tubes with tube axes extending in the vertical direction and arranged side by side in the horizontal direction,
A header for connecting the upper ends of the plurality of heat transfer tubes is provided.
The header is
A partition member for partitioning the inside into an insertion space into which the upper end of the plurality of heat transfer tubes is inserted and an upper space located above the insertion space is provided.
The partition member is
A heat exchanger provided with a communication hole for communicating between the insertion space and the upper space.
The partition member is
The heat exchanger according to claim 1, wherein the upper surface on the upper space side is provided with an inclined surface that is inclined in the direction of gravity toward the communication hole.
The partition member is
The heat exchanger according to claim 1 or 2, wherein a protrusion is provided on the lower surface on the insertion space side.
The communication hole is
The heat exchanger according to any one of claims 1 to 3, which is located between the plurality of heat transfer tubes from a viewpoint in a direction along the tube axis.
The communication hole is
The heat exchanger according to any one of claims 1 to 3, which is located across the plurality of heat transfer tubes from a viewpoint in a direction along the tube axis.
The length of the communication hole is
The heat exchanger according to claim 5, which is longer than the distance between the adjacent communication holes.
The plurality of heat transfer tubes
The first heat transfer tube group located on the upstream side of the flow of air flowing into the plurality of heat transfer tubes, and
It is equipped with a second heat transfer tube group located on the downstream side.
The header is
The insertion space is divided into a first insertion space into which the upper end of the first heat transfer tube group is inserted and a second insertion space into which the upper end of the second heat transfer tube group is inserted. With a part
Each of the first heat transfer tube group and the second heat transfer tube group
The lower ends of the plurality of heat transfer tubes are connected to each other by a lower header.
The lower header
The heat exchanger according to any one of claims 1 to 6, further comprising an outflow port for a refrigerant.
A refrigeration cycle apparatus including a refrigerant circuit having at least a compressor, a condenser, an expander, and an evaporator, and equipped with the heat exchanger according to any one of claims 1 to 7 as the condenser or the evaporator. ..