JP7292389B2 - Heat exchanger and refrigeration cycle equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat exchanger and a refrigeration cycle apparatus having the heat exchanger, and more particularly to the structure of a header.

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

In a refrigerant circuit of such an air conditioner, that is, a refrigeration cycle apparatus, refrigerating machine oil for lubricating sliding parts of a compressor and the like is mixed with refrigerant and circulated. For example, when the heat exchanger operates as a condenser, gas refrigerant and refrigerating machine oil flow into the upper header, the refrigerant flows through the heat transfer tubes while changing phases, and flows into the lower header as liquid refrigerant.

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

Therefore, in the heat exchanger described in Patent Literature 1, a pipe having a projection length shorter than the projection length of the heat transfer pipe projecting into the upper header is provided. As a result, the refrigerating machine oil in the header is returned to the lower header through the piping provided in the upper header, thereby suppressing the refrigerating machine oil from accumulating in the upper header.

JP 2005-24188 A

However, in the heat exchanger of Patent Literature 1, the above-described piping is arranged between some of the plurality of adjacent heat transfer tubes projecting into the header. Therefore, the refrigerating machine oil is discharged from the piping in the area between the heat transfer tubes on both sides where the piping is arranged, but the refrigerating machine oil is discharged between the adjacent heat transfer tubes in the area where the piping is not arranged. There was a risk of staying without a trace.

An object of the present invention is to solve the above-described problems, and to provide a heat exchanger capable of reducing stagnation of refrigerating machine oil and improving quality, and a refrigerating cycle apparatus equipped with the heat exchanger. .

A heat exchanger according to the present invention includes a plurality of heat transfer tubes arranged horizontally with tube axes extending in the vertical direction, and an upper header connecting upper ends of the plurality of heat transfer tubes. , the upper header includes a partition member that partitions the interior into an insertion space into which the upper end portions of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space, wherein the partition member a communication hole that communicates between the insertion space and the upper space ; and an inclined surface that is inclined in the direction of gravity toward the communication hole on the upper surface of the upper space, wherein the inclined surface In a cross section perpendicular to the direction in which the heat tubes are arranged side by side, both end portions are high and the center portion is inclined so that the communication holes are located in the direction along the tube axis of the plurality of heat transfer tubes. It is located between and increases the flow velocity of the coolant flowing into the insertion space through the communication hole.
Further, a heat exchanger according to the present invention includes a plurality of heat transfer tubes arranged in parallel in a horizontal direction with a tube axis extending in the vertical direction, an upper header connecting upper end portions of the plurality of heat transfer tubes, wherein the upper header includes a partition member that partitions the interior into an insertion space into which the upper end portions of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space, wherein the partition member is a communication hole communicating between the insertion space and the upper space; to increase the flow velocity of the coolant passing through and flowing into the insertion space.
Further, a heat exchanger according to the present invention includes a plurality of heat transfer tubes arranged in parallel in a horizontal direction with a tube axis extending in the vertical direction, an upper header connecting upper end portions of the plurality of heat transfer tubes, wherein the upper header includes a partition member that partitions the interior into an insertion space into which the upper end portions of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space, wherein the partition member is , a communication hole communicating between the insertion space and the upper space, the communication hole being positioned between the plurality of heat transfer tubes when viewed in a direction along the tube axis, and passing through the communication hole to increase the flow velocity of the refrigerant flowing into the insertion space, and the plurality of heat transfer tubes are arranged in a first heat transfer tube group positioned upstream of the flow of air flowing into the plurality of heat transfer tubes, and a first heat transfer tube group positioned downstream of the flow of air flowing into the plurality of heat transfer tubes The upper header divides the insertion space into the first insertion space into which the upper end of the first heat transfer tube group is inserted and the second heat transfer tube group of the A partition part is provided to partition the upper end part into a second insertion space into which the first heat transfer tube group and the second heat transfer tube group are inserted, and the lower end parts of the plurality of heat transfer tubes are arranged downward. They are connected by side headers, and the lower header is provided with inlets and outlets for the refrigerant.

A refrigeration cycle apparatus 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, the header is vertically partitioned by the partition member, and the partition member is provided with the communication hole. Therefore, the flow velocity of the refrigerant passing through the communication hole in the header can be increased. The increased flow velocity of the refrigerant collides with the refrigerating machine oil that remains inside the header, causing the refrigerating machine oil to scatter and roll up. Machine oil can be reduced.

2 is a schematic diagram showing a refrigerant circuit 5 of the air conditioner 1 according to Embodiment 1. FIG. 1 is a schematic diagram showing an example of a heat exchanger 100 mounted in an air conditioner 1 according to Embodiment 1. FIG. 2 is a front view of heat exchanger 1100, which is a comparative example of heat exchanger 100 according to Embodiment 1. FIG. 4 is an enlarged cross-sectional view of upper header 20 of heat exchanger 100 according to Embodiment 1. FIG. This is a modification of the communication hole 22 provided in the upper header 20 of the heat exchanger 100 according to Embodiment 1. FIG. FIG. 8 is an enlarged cross-sectional view of upper header 220 of heat exchanger 200 according to Embodiment 2; FIG. 11 is an enlarged cross-sectional view of upper header 320 of heat exchanger 300 according to Embodiment 3; This is a modification of the partition member 321 of the upper header 320 of the heat exchanger 300 according to Embodiment 3. FIG. This is a modification of the partition member 321 of the upper header 320 of the heat exchanger 300 according to Embodiment 3. FIG. FIG. 10 is a schematic diagram showing an example of a heat exchanger 400 mounted on the air conditioner 1 according to Embodiment 4. FIG. FIG. 10 is a schematic diagram showing an example of a heat exchanger 500 mounted in the air conditioner 1 according to Embodiment 5. FIG. FIG. 12 is an enlarged cross-sectional view of upper header 520 of heat exchanger 500 according to Embodiment 5; This is a modification of the communication hole 22 provided in the upper header 520 of the heat exchanger 500 according to Embodiment 5. FIG.

Embodiments will be described below with reference to the drawings. In each figure, the same reference numerals denote the same or corresponding parts, which are common throughout the specification. Also, the forms of the constituent elements shown in the entire specification are merely examples and are not limited to these descriptions. Furthermore, in the drawings below, the size relationship of each component may differ from the actual size.

Embodiment 1.
<Configuration of air conditioner 1>
An air conditioner 1 as a refrigeration cycle device to which a heat exchanger 100 according to Embodiment 1 is applied will be described with reference to FIG. Note that the heat exchanger 100 according to Embodiment 1 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 an air conditioner 1 according to Embodiment 1. FIG. As shown in FIG. 1, the air conditioner 1 according to Embodiment 1 performs cooling or heating by transferring heat between outside air and indoor air via a refrigerant. The air conditioner 1 performs indoor air conditioning, and has an indoor unit 2 and an outdoor unit 3 .

As the refrigerant flowing through the air conditioner 1, for example, various refrigerants such as R32 refrigerant, R290 refrigerant which is a low GWP refrigerant, mixed refrigerant containing R32 refrigerant as a main component, or mixed refrigerant containing R290 refrigerant as a main component. A refrigerant can be applied. In addition, refrigerants with lower gas density than R32 or R410A refrigerants, such as olefinic refrigerants, propane, or DME (dimethyl ether), have a high refrigerant flow rate per capacity, and therefore have a large effect of improving performance by reducing pressure loss. In addition, HFO1234yf or HFO1234ze(E) etc. are mentioned as an olefinic refrigerant|coolant. Refrigerant oil circulates 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 part of it 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 pipe-connected via 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, which are connected via refrigerant pipes 4, 4a, and 4b. there is

The outdoor unit 3 has a compressor 10 , a channel 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 an inverter device is provided, the capacity of the compressor 10 can be changed by changing the operating frequency with the control unit 6 . Note that the capacity of the compressor 10 is the amount of refrigerant sent out per unit time.

The channel switching device 11 is, for example, a four-way valve, and is a device that switches the direction of the coolant channel. The air conditioner 1 can realize heating operation or cooling operation by switching the refrigerant flow using the flow path switching device 11 based on an instruction from the control unit 6 . The outdoor heat exchanger 12 exchanges heat between refrigerant and outdoor air. In addition, the outdoor heat exchanger 12 is provided with an outdoor fan 15 in order to increase the efficiency of heat exchange between the refrigerant and the outdoor air. An inverter device may be attached to the outdoor fan 15 . In this case, the inverter device changes the operating frequency of the fan motor 16, which is the driving source of the outdoor fan 15, to change the rotational speed of the fan. 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 of a pushing type or a pulling type.

Here, the outdoor heat exchanger 12 functions as an evaporator during heating operation, and performs heat exchange between the low-pressure refrigerant flowing from the refrigerant pipe 4b side and the outdoor air to evaporate the refrigerant. and flow out to the refrigerant pipe 4a side. In addition, the outdoor heat exchanger 12 functions as a condenser during cooling operation, and the refrigerant that has been compressed by the compressor 10 and has flowed through the flow path switching device 11 from the refrigerant pipe 4a side and the outdoor air. Heat is exchanged between them, the refrigerant is condensed and liquefied, and flowed out to the refrigerant pipe 4b side. Although the case where outdoor air is used as the external fluid has been described here as an example, the external fluid is not limited to gas containing outdoor air, and may be liquid containing water.

The expansion device 13 is an expansion 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 degree of opening of the expansion device 13 . The expansion device 13 expands a high-pressure liquid state refrigerant into a low-pressure gas-liquid two-phase state refrigerant to reduce the pressure during cooling operation. The expansion device 13 is not limited to this, and may be an electronic expansion valve, a capillary tube, or the like as long as the same effect can be obtained. For example, when the expansion device 13 is composed of an electronic expansion valve, the degree of opening is adjusted based on instructions from the controller 6 .

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

The indoor heat exchanger 14 functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing from the refrigerant pipe 4a side and the indoor air, condenses and liquefies the refrigerant, and the refrigerant pipe It is made to flow out to the 4b side. In addition, the indoor heat exchanger 14 functions as an evaporator during cooling operation, and performs heat exchange between the refrigerant that has been brought into a low pressure state by the expansion device 13 flowing from the refrigerant pipe 4b side and the indoor air, The refrigerant takes the heat of the air, evaporates, and flows out to the refrigerant pipe 4a side. Although the case where indoor air is used as the external fluid has been described as an example, the external fluid is not limited to gas containing indoor air, and may be liquid containing water.

The operating speed of the indoor fan 17 is determined by user settings. 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 the fan may be a sirocco fan or a plug fan. Further, the indoor blower 17 may be of a pushing type or a pulling type.

<Example of Cooling and Heating Operation of Air Conditioner 1>
Next, the cooling operation will be described as an example of the operation of the air conditioner 1. FIG. 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 fan 15 , becomes a low-temperature refrigerant, and flows out of the outdoor heat exchanger 12 . The refrigerant that has flowed out of the outdoor heat exchanger 12 is expanded and decompressed 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 fan 17, and becomes a low-temperature, low-pressure gas refrigerant in the indoor heat exchanger. It flows out from 14. At this time, the indoor air that has been cooled by absorbing heat by the refrigerant becomes conditioned air (blowing air), and is blown from the indoor unit 2 into the room that is the space to be air-conditioned. The gas refrigerant that has flowed out of the indoor heat exchanger 14 is sucked into the compressor 10 via the flow switching device 11 and compressed again. In the cooling operation of the air conditioner 1, the above operations are repeated (indicated by solid arrows in FIG. 1).

Next, the operation of the heating operation will be described as an example of the operation of the air conditioner 1. FIG. 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 switching device 11 . The gas refrigerant that has flowed into the indoor heat exchanger 14 is condensed by heat exchange with indoor air blown by the indoor blower 17 , becomes a low-temperature refrigerant, and flows out of the indoor heat exchanger 14 . At this time, the indoor air heated by receiving heat from the gas refrigerant becomes conditioned air (blowing air) and is blown out from the indoor unit 2 into the room. The refrigerant that has flowed out of the indoor heat exchanger 14 is expanded and decompressed 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 fan 15, and becomes a low-temperature low-pressure gas refrigerant in the outdoor heat exchanger 12. flow out from The gas refrigerant that has flowed out of the outdoor heat exchanger 12 is sucked into the compressor 10 via the flow switching device 11 and compressed again. In the heating operation of the air conditioner 1, the above operations are repeated (indicated by the dashed arrow in FIG. 1).

During the cooling operation and the heating operation described above, if the refrigerant flows into the compressor 10 in a liquid state, liquid compression occurs, which causes the compressor 10 to malfunction. Therefore, it is desirable that the refrigerant flowing out of the outdoor heat exchanger 12 during cooling operation or the indoor heat exchanger 14 during heating operation is gas refrigerant (single-phase).

Here, in the evaporator, when heat is exchanged between the air supplied from the fan and the refrigerant flowing inside the heat transfer tubes that make up the evaporator, moisture in the air condenses and evaporates. Water droplets form on the surface of the vessel. Water droplets generated on the surface of the evaporator drip downward along the surfaces of the fins and heat transfer tubes and are discharged as drain water below the evaporator.

<Regarding heat exchanger 100>
Next, the heat exchanger 100 mounted on the air conditioner 1 according to Embodiment 1 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, and is particularly preferably applied to a heat exchanger used as a condenser.

FIG. 2 is a schematic diagram showing an example of the heat exchanger 100 mounted on the air conditioner 1 according to Embodiment 1. As shown in FIG. FIG. 2(a) is a front view of the heat exchanger 100. FIG. FIG. 2(b) is a cross-sectional view of the heat exchanger 100, showing a cross section taken along line AA of FIG. 2(a). FIG. 2(c) is a top view of the heat exchanger 100. FIG. 2 and later, 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 tubes 50 that are flat heat transfer tubes, and the direction of the flat tubes 50. It shows the direction to be aligned. The y-direction is the height direction of the heat exchanger 100 and indicates the axial direction of the flat tubes 50, that is, the direction along which the refrigerant flows. Furthermore, the x direction is the depth direction of the heat exchanger 100 and indicates the horizontal direction intersecting with the x direction, which is the extension direction of the header 20 , that is, the width direction of the flat tubes 50 . AF indicated by a white arrow represents the ventilation direction of air supplied from the outdoor fan 15 (see FIG. 1) to the outdoor heat exchanger 12, and RF indicated by an 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 Embodiment 1 is configured by arranging a plurality of flattened tubes 50 in a row in the horizontal direction. The plurality of flat tubes 50 are arranged with their tube axes directed in the vertical direction, and have upper ends connected to the headers 20 and lower ends connected to the headers 30 . The header 20 connects the upper ends of the flat tubes 50 together, and the header 30 connects the lower ends of the flat tubes 50 together. That is, the flat tubes 50 are arranged between the headers 20 and 30 . Note that the header 20 may be called an upper header, and the header 30 may be called a lower header.

The plurality of flat tubes 50 are heat transfer tubes having a multi-hole structure with a flat cross section, and in the first embodiment, the tube axes are erected in the vertical direction, that is, in the y direction. A plurality of flat tubes 50 are arranged side by side at predetermined intervals in the horizontal direction, ie, the x direction, between the upper and lower headers 20 and 30 . Further, in the case of Embodiment 1, a heat transfer member such as a 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 necessary. Although the heat exchanger 100 includes the flat tubes 50, heat transfer tubes 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 the shape of a hollow rectangular parallelepiped and have insertion holes so that the ends of a plurality of flat tubes 50 can be inserted. Upper end portions 51 of a plurality of flat tubes 50 are inserted into the upper header 20 from below.

Here, in the upper and lower headers 20 and 30, in general, the connection strength between the plurality of flat tubes 50 and the headers 20 and 30 is ensured, and the brazing material used for connection flows into the refrigerant flow path in the flat tubes 50. For the purpose of preventing deterioration in quality, the structure is such that the flat tube 50 protrudes into the headers 20 and 30 by a predetermined dimension.

Moreover, the header 20 has a partition member 21 inside, and the inside is partitioned into two upper and lower spaces. A space in which the upper end portions 51 of the plurality of flat tubes 50 are inserted is called an insertion space S1, and a space located above the insertion space S1 is called an upper space S2. The upper space side upper surface 23 of the partition member 21 faces the upper space S2, and the insertion space side lower surface 24 of the partition member 21 faces the insertion space S1.

The insertion space S<b>1 and the upper space S<b>2 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. 2(c), the communication holes 22 are circular and arranged between the plurality of flat tubes 50 in a top view, that is, from the perspective of the tube axis direction.

(Action of heat exchanger 100)
FIG. 3 is a front view of heat exchanger 1100, which is a comparative example of heat exchanger 100 according to the first embodiment. Heat exchanger 1100 according to the comparative example has upper headers 120 connected to upper ends 51 of a plurality of flat tubes 50 and lower headers 120 connected to lower ends 52 in the same manner as heat exchanger 100 according to the first embodiment. 30 are 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 internal space of the upper header 120 of the heat exchanger 1100 of the comparative example is not divided into two.

Refrigerant oil 90 discharged from the compressor 10 circulates in the refrigerant circuit 5 of the air conditioner 1 along with the refrigerant. Accordingly, the refrigerant oil 90 flows into the upper header 120 of the heat exchanger 1100 from the inlet and outlet together with the refrigerant. 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 faces 53 of the plurality of flat tubes 50 where the coolant channels are open are positioned higher than the bottom surface 126 of the upper header 120 by a predetermined height. Therefore, the refrigerating machine oil 90 remaining in the heat exchanger 1100 is not discharged from the upper header 120 unless it reaches the end surfaces 53 of the 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 Embodiment 1 can discharge the refrigerating machine oil 90 remaining in the upper header 20 by the action described below. As shown in FIGS. 2(a) and 2(b), there is refrigerating machine oil 90 remaining in the header 20 in the area below the insertion space S1. Refrigerant flows into the header 20 of the heat exchanger 100 . The coolant that has flowed into the upper space S2 of the header 20 passes through the communication holes 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 upper header 20 of heat exchanger 100 according to the first embodiment. FIG. 4 is an enlarged view around the upper header 20 of FIG. 2(b). The white arrows shown in FIG. 4 schematically represent an example of the refrigerant flow. A partition member 21 provided inside the upper header 20 of the heat exchanger 100 is formed with a plurality of communication holes 22 . 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 coolant moves from the upper space S2 to the insertion space S1, the coolant passes through the communication holes 22 having a smaller cross-sectional area than the upper space S2. Therefore, the coolant passing through the communication hole 22 flows into the insertion space S1 with an increased flow velocity. In other words, the communication hole 22 is a contraction 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 surface of the refrigerating machine oil 90 staying in the lower part of the insertion space S1, causing the refrigerating machine oil 90 to scatter in the insertion space S1 and be rolled up. The scattered droplets of the refrigerator oil 90 flow into the flat tube 50 from the end surface 53 together with the refrigerant. As a result, the refrigerating machine oil 90 remaining 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. As shown in FIGS. Therefore, the flow of the refrigerant collides with the liquid surface of the refrigerating machine oil 90 positioned below the plurality of communication holes 22, and the refrigerating machine oil 90 is scattered and swirled up in the insertion space S1. In Embodiment 1, the communication hole 22 is arranged between the plurality of flat tubes 50 and is provided at one location for every two gaps 80 between the plurality of flat tubes 50 . However, the number of communication holes 22 to be provided is not limited to that shown in FIG.

FIG. 5 shows a modification of the communication holes 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 have a form in which one communication hole 22 is provided for each gap between the plurality of flat tubes 50 as shown in FIG. 2(c). The upper header 20a of the modified example has, for example, a plurality of communicating holes 22a having a smaller cross-sectional area than the communicating holes 22 at positions corresponding to the gaps 80 between the plurality of flat tubes 50. As shown in FIG. With this configuration, the communication holes 22a can be provided even when the intervals between the flat tubes 50 are narrow. Further, the cross-sectional shape of the communication holes 22 and 22a is not limited to circular, and may be oval, elliptical, rectangular, or the like.

4, the insertion space S1 and the upper space S2 of the upper header 20 are limited to a configuration in which they are partitioned by a partition member 21 arranged perpendicular to the axial direction of the flat tube 50. isn't it. For example, the partition member 21 may be installed with an inclination in FIG.

When the heat exchanger 100 is used as a condenser in the refrigerant circuit 5 shown in FIG. 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 and stay inside the upper header 20 . However, according to the heat exchanger 100, since the refrigerating machine oil 90 can be scattered and flowed into the plurality of flat tubes 50 by the above configuration, the stagnation of the refrigerating machine oil 90 can be suppressed. The heat exchanger 100 is preferably incorporated into the refrigerant circuit 5 such 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 returns the discharged refrigerating machine oil 90 to the compressor 10, thereby preventing the compressor 10 from stopping due to seizure or the like. It is possible to suppress quality deterioration such as shortening the life of the product. Thus, the heat exchanger 100 capable of reducing the stagnation of the refrigerating machine oil 90 and improving the quality and the air conditioner 1 using the same can be realized.

Embodiment 2.
Next, the heat exchanger 200 according to Embodiment 2 will be described. A heat exchanger 200 according to the second embodiment is obtained by changing the shape of the partition member 21 provided in the upper header 20 according to the first embodiment.

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

In the cross section shown in FIG. 6, the partition member 221 is inclined such that the left and right ends are high and the central portion is low. 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, the refrigerating machine oil 90 moves along the inclined surface to the communication hole 22 and passes through the communication hole 22 to the insertion space. Go to S1. Thereby, the heat exchanger 200 can reduce the refrigerating machine oil 90 staying in the upper space S2.

Refrigerant oil 90 that has moved from upper space S2 to insertion space S1 is scattered by the flow of refrigerant accelerated by communication holes 22 and flows into flat tubes 50, as described in the first embodiment. The heat exchanger 200 according to the second embodiment has the advantage of being able to reduce the refrigerating machine oil 90 remaining in the upper space S2 while obtaining the effects of the heat exchanger 100 according to the first embodiment.

In Embodiment 2, the partition member 221 has a cross-sectional shape shown in FIG. 6 in each x-direction cross section. However, the shape of the partition member 221 is not limited to this, and an inclined surface inclined in the gravitational direction toward the communication hole 22 may be provided around the communication hole 22 in the shape of a mortar. Moreover, although the thickness of the partition member 221 differs between the left and right end portions and the central portion of the cross section shown in FIG. 6, it may be formed to have a uniform thickness. For example, the partition member 221 may be formed by bending a flat plate at the central portion where the communication hole 22 is provided.

Embodiment 3.
Next, a heat exchanger 300 according to Embodiment 3 will be described. A heat exchanger 300 according to the third embodiment is obtained by changing the shape of the partition member 21 provided in the upper header 20 according to the first embodiment.

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

As described in the first embodiment, the flow of refrigerant passing through communication holes 22 collides with the liquid surface of refrigerating machine oil 90 remaining in the lower portion of upper header 320, and refrigerating machine oil 90 scatters. The scattered refrigerating machine oil 90 not only flows into the plurality of flat tubes 50 together with the refrigerant, but may also adhere to the lower surface 324 of the partition member 321 . However, since a plurality of projections 325 are provided on the lower surface 324 of the partition member 321 , the refrigerating machine oil 90 adhering to the lower surface 324 aggregates on the tops of the projections 325 due to surface tension and easily falls from the lower surface 324 . The refrigerating machine oil 90 that has dropped from the lower surface 324 stays in the lower portion of the insertion space S1 and is either scattered by the refrigerant again or is scattered by the flow of the refrigerant while falling and flows into the plurality of flat tubes 50 together with the refrigerant.

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

8 and 9 show modifications of the partition member 321 of the upper header 320 of the heat exchanger 300 according to the third embodiment. A partition member 321a according to a modification has a projection 325a extending in the x direction and formed as a ridge. Moreover, in the partition member 321b according to the modification, the hemispherical projections 325b are arranged in two rows. As described above, the protrusion 325 may be changed in shape and arrangement position. Also, if the projection 325 has a sharp tip, the condensation of the refrigerating machine oil 90 is promoted. For example, protrusion 325 may be formed in a conical shape.

In addition, the partition member 321 can cause the refrigerating machine oil 90 to aggregate and drop by roughening the surface of the lower surface 324 to form minute irregularities.

Embodiment 4.
Next, a heat exchanger 400 according to Embodiment 4 will be described. A heat exchanger 400 according to the fourth embodiment is obtained by changing 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 diagram showing an example of a heat exchanger 400 mounted on the air conditioner 1 according to Embodiment 4. As shown in FIG. FIG. 10(a) is a front view of the heat exchanger 400. FIG. FIG. 10(b) is a cross-sectional view of the heat exchanger 400, showing a cross section taken along line AA of FIG. 10(a). FIG. 10(c) is a top view of the heat exchanger 400. FIG. Upper header 420 of heat exchanger 400 according to the fourth embodiment includes partition member 421 . The partition member 421 has a communicating hole 422 elongated in the x direction. The communication hole 422 is arranged so as to straddle the plurality of flat tubes 50 in plan view.

In the heat exchanger 100 according to Embodiment 1, the intervals between the flat tubes 50 may be narrow. In this case, it is difficult to provide the communication holes 22 provided in the partition member 21 at positions corresponding to the gaps 80 between the plurality of flat tubes 50 . When the communicating hole 22 is positioned above the flat tube 50 , the coolant directly collides with the end surface 53 of the flat tube 50 through the communicating hole 22 . In this case, the area where the refrigerant flow from the communication hole 22 collides with the liquid surface of the stagnant refrigerating machine oil 90 is reduced, and there is a concern that the effect of scattering the refrigerating machine oil 90 is reduced. In addition, since the flow of the accelerated refrigerant directly collides with the end surface 53 of the flat tube 50, it becomes difficult to be evenly distributed to the plurality of flow paths inside the flat tube 50, and the heat exchange performance of the heat exchanger 100 is reduced. There is concern that it will decline.

On the other hand, as in the heat exchanger 400 according to Embodiment 4, by arranging the communication hole 422 so as to straddle the flat tubes 50 in plan view, the refrigerant that reliably stays between the plurality of flat tubes 50 The coolant 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 should 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 should be set larger than the interval between adjacent communication holes 422 . By increasing the length of the communicating hole 422 in the x direction, the effect of increasing the flow velocity of the coolant while reducing the pressure loss when the coolant passes through the communicating hole 422 can be obtained.

Embodiment 5.
Next, a heat exchanger 500 according to Embodiment 5 will be described. A heat exchanger 500 according to Embodiment 5 is obtained by changing the arrangement of the plurality of flat tubes 50 according to Embodiment 1 to a plurality. Accordingly, heat exchanger 500 differs from upper header 20 of heat exchanger 100 in the structure of upper header 520 .

FIG. 11 is a schematic diagram showing an example of a heat exchanger 500 mounted on the air conditioner 1 according to Embodiment 5. As shown in FIG. FIG. 11(a) is a front view of the heat exchanger 500. FIG. FIG. 11(b) is a cross-sectional view of the heat exchanger 500, showing a cross section taken along line AA of FIG. 11(a). FIG. 11(c) is a top view of the heat exchanger 500. FIG. A heat exchanger 500 according to Embodiment 5 includes a plurality of flat tube groups 550a and 550b. The first flat tube group 550 a and the second flat tube group 550 b are arranged in series along the flow of 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 horizontally in parallel with the tube axis facing up and down, similar to the plurality of flat tubes 50 of the heat exchanger 100 according to the first embodiment. .

The lower header 30a is connected to the lower end 52 of the first flat tube group 550a. The 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 receives the refrigerant. The inflowing refrigerant flows through the flat tubes 50a of the first flat tube group 550a into the upper header 520, and from the upper header 520 through the flat tubes 50b of the second flat tube group 550b into the lower header 30b. do. The lower header 30b is connected to the refrigerant circuit 5, and the refrigerant flows out from the inlet/outlet.

As shown in FIG. 11(b), the upper header 520 has an inner space vertically partitioned by a partition member 521 to form an upper space S2 and an insertion space S1. Furthermore, the insertion space S1 is divided into a first insertion space S1a into which the upper end portions 51 of the first flat tube group 550a are inserted and a second insertion space S2b into which the upper end portions 51 of the second flat tube group 550b are inserted. partitioned. A partition portion 526 is joined to a lower surface 524 of the partition member 521, and the partition portion 526 partitions the insertion space S1 in the direction in which the flat tube groups 550a and 550b are arranged.

FIG. 12 is an enlarged cross-sectional view of upper header 520 of heat exchanger 500 according to the fifth embodiment. The heat exchanger 500 of Embodiment 5 scatters the staying refrigerating machine oil 90 as follows and sends it to the downstream side. The flow of refrigerant in the first insertion space S1a is indicated by black arrows and white arrows in the figure. Refrigerant flows into the upper header 520 from the first flat tube group 550a. The coolant R that has flowed out from the end surface 53 of the first flat tube group 550a hits the lower surface 524 of the partition member 521, changes its flow direction, and flows downward in the first insertion space S1a so as to convect in the vertical direction, and stays there. It hits the liquid surface of the refrigerating machine oil 90 and flows upward again. At this time, the refrigerant splashes the refrigerating machine oil 90, passes through the communication holes 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 through the communication hole 22 communicating 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. , the refrigerating machine oil 90 staying in the lower part of the second insertion space S1b is scattered and flowed into the second flat tube group 550b together with the refrigerant.

Note that when the heat exchanger 500 according to Embodiment 5 is used as a condenser in the air conditioner 1, the refrigerant that has passed through the first flat tube group 550a is condensed into the first insertion space S1a as a gas-liquid two-phase refrigerant. flow into Therefore, not only the refrigerating machine oil 90 but also the liquid-phase refrigerant may remain in the lower portions of the first insertion space S1a and the second insertion space S2b of the upper header 520 . In the heat exchanger 500 according to Embodiment 5, the liquid-phase refrigerant and refrigerating machine oil 90 that remain in the upper header 520 are sent downstream by the above-described action, and the liquid-phase refrigerant and refrigerating machine oil 90 that remain inside the upper header 520 are removed. A reduction effect is obtained. Even when the heat exchanger 500 is used as an evaporator, the effect of reducing the liquid-phase refrigerant and the refrigerating machine oil 90 that remain due to the above action can be obtained.

FIG. 13 shows a modification of the communication holes 22 provided in the upper header 520 of the heat exchanger 500 according to the fifth embodiment. Communication hole 22 provided in partition member 521 of upper header 520 can have the same shape as communication hole 422 of upper header 420 according to the fourth embodiment. Communicating hole 22 may be replaced with communicating hole 22a shown in FIG.

Although the embodiments have been described above, the present invention is not limited only to the above-described embodiments. For example, each embodiment may be combined as appropriate. Further, in Embodiments 1 to 5, the plurality of heat transfer tubes included in heat exchangers 100, 200, 300, 400, and 500 are 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 are sometimes referred to as heat transfer tubes, first heat transfer tube group, and second heat transfer tube group, respectively.

REFERENCE SIGNS LIST 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 switching device 12 outdoor heat exchanger 13 expansion device 14 indoor heat exchanger 15 outdoor fan 16 fan motor 17 indoor fan 18 fan motor 20 (upper) header 20a upper header 21 partition member 22 communicating hole 22a communicating hole 23 upper surface, 24 lower surface 29 inlet/outlet 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 surface 80 gap, 90 refrigerator oil, 100 heat exchanger, 120 upper header, 126 bottom surface, 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 Bottom surface 325 Projection 325a Projection 325b Projection 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 (6)

a plurality of heat transfer tubes arranged side by side in the horizontal direction with their tube axes extending in the vertical direction;
an upper header that connects the upper ends of the plurality of heat transfer tubes;
The upper header is
A partition member that partitions the interior into an insertion space into which the upper ends of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space,
The partition member is
a communication hole communicating between the insertion space and the upper space ;
an inclined surface inclined in the gravitational direction toward the communication hole on the upper surface on the upper space side ;
The inclined surface is
In a cross section perpendicular to the direction in which the plurality of heat transfer tubes are arranged in parallel, both ends are high and the central portion is inclined so that it is low,
The communication hole is
Located between the plurality of heat transfer tubes from a viewpoint in the direction along the tube axis,
A heat exchanger that increases the flow velocity of refrigerant flowing into the insertion space through the communication hole. The partition member is
2. The heat exchanger according to claim 1 , wherein a plurality of projections are provided on a surface surrounding said communication hole on the lower surface on the side of said insertion space. a plurality of heat transfer tubes arranged side by side in the horizontal direction with their tube axes extending in the vertical direction;
an upper header that connects the upper ends of the plurality of heat transfer tubes;
The upper header is
A partition member that partitions the interior into an insertion space into which the upper ends of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space,
The partition member is
A communication hole communicating between the insertion space and the upper space,
The communication hole is
A heat exchanger positioned across the plurality of heat transfer tubes from a viewpoint in a direction along the tube axis and configured to increase the flow velocity of refrigerant flowing into the insertion space through the communication holes . The length of the communication hole is
4. The heat exchanger according to claim 3 , which is longer than the interval between said adjacent communication holes. a plurality of heat transfer tubes arranged side by side in the horizontal direction with their tube axes extending in the vertical direction;
an upper header that connects the upper ends of the plurality of heat transfer tubes;
The upper header is
A partition member that partitions the interior into an insertion space into which the upper ends of the plurality of heat transfer tubes are inserted and an upper space located above the insertion space,
The partition member is
A communication hole communicating between the insertion space and the upper space,
The communication hole is
Located between the plurality of heat transfer tubes from a viewpoint in the direction along the tube axis,
increasing the flow velocity of the coolant flowing into the insertion space through the communication hole;
The plurality of heat transfer tubes are
a first heat transfer tube group located upstream of the flow of air flowing into the plurality of heat transfer tubes;
A second heat transfer tube group located downstream,
The upper header is
A partition that divides the insertion space 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 has a department,
Each of the first heat transfer tube group and the second heat transfer tube group,
lower ends of the plurality of heat transfer tubes are connected to each other by a lower header,
The lower header is
A heat exchanger with a refrigerant inlet and outlet. A refrigeration cycle apparatus comprising a refrigerant circuit having at least a compressor, a condenser, an expansion device and an evaporator, and equipped with the heat exchanger according to any one of claims 1 to 5 as the condenser or the evaporator. .

Images