JPWO2020079731A1 - Heat exchanger - Google Patents

Abstract

Obtain a heat exchanger capable of efficient heat exchange. The heat exchanger 100 is a confluence in which a distribution header 101 extending in the vertical direction and having a distribution flow path 101e formed therein and a merging flow path 102e extending in the vertical direction and having a merging flow path 102e formed therein are formed. A tubular refrigerant pipe 110 is provided with a header 102, one end of which is connected to the distribution header 101, the other end of which is connected to the merging header 102, and a refrigerant flow path 103a in which the refrigerant flows from one end to the other end. A plurality of refrigerant pipes 110 are provided at different positions in the vertical direction, and the refrigerant pipes 110 are provided with heat transfer portions provided with fins 104 on the outside and fins 104 provided on both ends of the heat transfer portions without external fins 104. The heat transfer portion of the refrigerant pipe 110 having a connecting portion has a first resistance region provided with a spiral groove on the inner surface and a second resistance region having a flow resistance different from that of the first resistance region, and has a first resistance. The region and the second resistance region are formed with an axial length such that the refrigerant pipe 110 has a flow resistance corresponding to the vertical position.

Description

The present invention relates to a heat exchanger that mainly functions as an evaporator in an air conditioner or the like.

The heat exchanger of a conventional air conditioner includes a plurality of heat transfer tubes. When a heat exchanger with multiple heat transfer tubes functions as an evaporator, the mass flow rate of the gas-liquid two-phase refrigerant supplied into each heat transfer tube must be properly distributed or excessive to a specific flow path. While the liquid refrigerant flows, the liquid refrigerant is insufficient in the other flow paths and the gas single-phase region increases, so that the heat exchanger performance deteriorates.

In the heat exchanger described in Patent Document 1, in a heat transfer tube group having a plurality of rows in the air flow direction, the groove height of the spiral groove provided on the inner surface of the heat transfer tube is set from the heat transfer tube group in the windward row. It describes a technique for gradually increasing the height of heat transfer tubes in the leeward row.

In the heat exchanger described in Patent Document 1, the flow resistance of the heat transfer tubes is sequentially increased from the heat transfer tube group in the upper wind side row to the heat transfer tube group in the leeward side row, and inside the heat transfer tube group on the wind side having a large heat load. The heat exchange performance can be improved by increasing the mass flow rate of the refrigerant supplied to the refrigerant and reducing the region where the refrigerant completely evaporates.

The heat exchanger described in Patent Document 2 describes a technique of twisting a heat transfer tube to adjust the lead angle of a spiral groove on the inner surface of the heat transfer tube.

In the heat exchanger described in Patent Document 2, the refrigerant flowing in the heat transfer tube can be agitated by adjusting the lead angle of the spiral groove in the heat transfer tube, so that the heat exchange action can be improved.

In the refrigerant distributor described in Patent Document 3, the refrigerant is supplied into each heat transfer tube by appropriately selecting dimensions such as the inner diameter or length of the spiral groove of the refrigerant distributor that distributes and flows the refrigerant to a large number of heat transfer tubes. A technique for adjusting the mass flow rate of the refrigerant is described.

In the refrigerant distributor described in Patent Document 3, the flow resistance of the refrigerant distributor is changed by appropriately selecting dimensions such as the inner diameter or length of the spiral groove of the refrigerant distributor, and the suction air passing through the heat exchanger is changed. Since the mass flow rate of the refrigerant supplied into each heat transfer tube can be adjusted according to the speed distribution of the above, the heat exchange performance can be improved.

JP-A-4-309792 JP-A-2010-101508 JP 2009-222366

In the heat exchanger described in Patent Document 1, the flow resistance of the heat transfer tube is based on the difference in groove height of the spiral groove provided on the inner surface of the heat transfer tube. Therefore, the flow resistance of the heat transfer tube can be adjusted only by the number of types of groove heights of the spiral grooves provided on the inner surface of the heat transfer tube, so that an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube can be obtained. There is a problem that the excess refrigerant flows in a specific flow path, while the refrigerant is insufficient in the other flow paths, the gas single-phase region increases in the heat transfer tube, and the heat exchange performance deteriorates.
Further, in the heat exchanger described in Patent Document 1, since the lead angle of the spiral groove provided on the inner surface of the heat transfer tube is constant, the refrigerant is in a state of flowing along the lead angle, is difficult to be agitated, and is inside the heat transfer tube. Since the development of the temperature boundary layer cannot be suppressed, there is a problem that the heat exchange performance is deteriorated.

In the heat exchanger described in Patent Document 2, the heat exchange performance can be improved by stirring the refrigerant flowing in the heat transfer tube, but the flow resistance of the heat transfer tube cannot be adjusted. It is not possible to obtain the appropriate mass flow rate of the refrigerant, and the excess refrigerant flows in a specific flow path, while the refrigerant is insufficient in the other flow paths, and the gas single-phase region increases in the heat transfer tube, resulting in heat. There is a problem that the exchange performance is lowered.

In the refrigerant distributor described in Patent Document 3, the flow resistance of the refrigerant distributor can be adjusted, but since the refrigerant distributor is smaller than the heat transfer tube, the flow resistance that can be adjusted only by the refrigerant distributor is limited. , The appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube cannot be obtained, and the excess refrigerant flows in a specific flow path, while the refrigerant is insufficient in the other flow paths, and the gas single phase in the heat transfer tube. There is a problem that the area is increased and the heat exchange performance is lowered.
Further, in the refrigerant distributor described in Patent Document 3, since the spiral groove is not provided on the inner surface of the heat transfer tube, the refrigerant flowing in the heat transfer tube is difficult to be agitated, so that the heat exchange performance as a heat exchanger is deteriorated. There are challenges.

The present invention has been made to solve the above problems, and to obtain a heat exchanger capable of performing efficient heat exchange.

The heat exchanger according to the present invention has one end and the other end provided at both ends in the vertical direction, and a side portion connecting the one end portion and the other end portion, and the refrigerant flows into the one end portion or the side portion. A distribution header having an inflow port for the refrigerant to flow from one end to the other end, and one end and the other end provided at both ends in the vertical direction, and one end. It has a side portion that connects the other end and the other end, and an outlet for the refrigerant to flow out is provided at one end or the side portion, and a merging flow path through which the refrigerant flows from one end to the other end is formed inside. The merging header and one end in the axial direction are connected to the side portion of the distribution header, the other end in the axial direction is connected to the side portion of the merging header, and a refrigerant flow path through which the refrigerant flows from one end to the other end is provided inside. It is provided with a tubular refrigerant pipe, and a plurality of refrigerant pipes are provided at different positions in the vertical direction. The refrigerant pipes are provided in a heat transfer section having fins on the outside and fins on both ends of the heat transfer section. The heat transfer portion of the refrigerant pipe has a first flow resistance and is different from the first resistance region and the first resistance region in which the spiral groove is provided on the inner surface. It has a second resistance region having a second flow resistance, and the first resistance region and the second resistance region are formed with an axial length such that the refrigerant pipe has a flow resistance according to the vertical position. To.

According to the heat exchanger according to the present invention, efficient heat exchange can be performed.

It is a block diagram which illustrates the refrigerating cycle using the heat exchanger which concerns on Embodiment 1 of this invention. It is a perspective view of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which illustrated the value of the mass flow rate of the refrigerant which flows in the heat transfer tube of the heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 2 of this invention. It is sectional drawing of the heat exchanger which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments relating to the heat exchanger disclosed in the present application will be described in detail with reference to the accompanying drawings. The embodiments shown below are examples, and the present invention is not limited to these embodiments.

Embodiment 1.
FIG. 1 is a diagram showing an example of a refrigeration cycle using the heat exchanger 100 according to the first embodiment of the present invention. In FIG. 1, the solid line arrow indicates the flow of the refrigerant during the cooling operation, and the broken line arrow indicates the flow of the refrigerant during the heating operation.

As shown in FIG. 1, the refrigerating cycle includes an outdoor unit 1, an indoor unit 3, and a refrigerant pipe 2 connecting the outdoor unit 1 and the indoor unit 3.

The outdoor unit 1 has a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 100, a throttle mechanism 13, and an outdoor blower 14 inside.

The compressor 11 compresses the supplied refrigerant, changes it into a high-temperature and high-pressure gas refrigerant, and sends it to the four-way switching valve 12. A power supply is connected to the compressor 11.

The four-way switching valve 12 switches the reflux direction of the refrigerant compressed by the compressor 11.

The outdoor heat exchanger 100 exchanges heat with air by evaporating or condensing the inflowing refrigerant to cool or heat the air. For example, during the cooling operation, the outdoor heat exchanger 100 functions as a condenser to condense the inflowing refrigerant. Further, during the heating operation, the outdoor heat exchanger 100 functions as an evaporator to evaporate the inflowing refrigerant.

The throttle mechanism 13 is a decompression device whose opening degree can be changed. The throttle mechanism 13 depressurizes the inflowing refrigerant.

The outdoor blower 14 is installed in the vicinity of the outdoor heat exchanger 100. The outdoor blower 14 generates an air flow that passes through the outdoor heat exchanger 100, and discharges the heat-exchanged air to the outside.

The indoor unit 3 has an indoor heat exchanger 31 and an indoor blower 32 inside.

The indoor heat exchanger 31 exchanges heat with air by evaporating or condensing the inflowing refrigerant, and cools or heats the air. For example, during the cooling operation, the indoor heat exchanger 31 functions as an evaporator to evaporate the inflowing refrigerant. Further, during the heating operation, the indoor heat exchanger 31 functions as a condenser to condense the inflowing refrigerant.

The indoor blower 32 is installed in the vicinity of the indoor heat exchanger 31. The indoor blower 32 generates an air flow passing through the indoor heat exchanger 31 and discharges the heat-exchanged air into the room.

Next, the refrigeration cycle during the heating operation indicated by the broken line arrow will be described. When the power is turned on, the compressor 11 operates. When the compressor 11 operates, the circulation of the refrigerant in the refrigeration cycle circuit is started. The gas refrigerant compressed by the compressor 11 to a high temperature and high pressure passes through the four-way switching valve 12, passes through the refrigerant pipe 2, and is guided to the indoor unit 3. The refrigerant guided to the indoor unit 3 is cooled by the indoor air blown by the indoor blower 32 in the indoor heat exchanger 31 provided in the indoor unit 3 and condensed, and is in a gas-liquid two-phase state or a liquid-phase state. Produces refrigerant. The indoor blower 32 acts as a condenser during the heating operation. The gas-liquid two-phase state or liquid-phase state refrigerant passes through the refrigerant pipe 2 and is sent to the outdoor unit 1 side.

The gas-liquid two-phase state or liquid-phase state refrigerant is depressurized by the throttle mechanism 13, changes to a low-pressure state, and flows into the outdoor heat exchanger 100 provided in the outdoor unit 1. The throttle mechanism 13 is a decompression device whose opening degree can be changed. When the refrigerant flows into the outdoor heat exchanger 100 provided in the outdoor unit 1, it is heated by the external air supplied by the outdoor blower 14 and changes into a high-temperature and low-pressure gas refrigerant. The outdoor heat exchanger 100 provided in the outdoor unit 1 acts as an evaporator during the heating operation. The high-temperature and low-pressure gas refrigerant passes through the four-way switching valve 12 and returns to the compressor 11 again. This constitutes a series of refrigeration cycles in which the refrigerant circulates.

Further, by switching the four-way switching valve 12 as shown by the solid line in FIG. 1, the flow path direction of the refrigerant can be switched, and the cooling operation can be performed. In the case of cooling operation, the outdoor heat exchanger 100 provided in the outdoor unit 1 acts as a condenser, and the indoor heat exchanger 31 provided in the indoor unit 3 acts as an evaporator.

Next, the configuration and operation of the outdoor heat exchanger 100 provided in the outdoor unit 1 that acts as an evaporator during the heating operation will be described. Hereinafter, the outdoor heat exchanger 100 will be referred to as a heat exchanger 100.

FIG. 2 is a perspective view of the heat exchanger 100 according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the heat exchanger 100 according to the first embodiment cut along the line AA of FIG. As shown in FIG. 2, one end of the heat exchanger 100 is connected to a distribution header 101 provided so as to extend in the substantially vertical direction and a merging header 102 provided so as to extend in the substantially vertical direction. A plurality of heat transfer tubes 103 are connected to the distribution header 101 via the pipe 105a, the other end is connected to the merging header 102 via the connection pipe 105b, and are provided so as to extend substantially in the horizontal direction, and the heat transfer pipe 103. A plurality of plate-shaped fins 104, which are inserted in a state orthogonal to the axial direction of the above, are provided. Further, the plurality of heat transfer tubes 103 may be configured in a plurality of rows with respect to the air flow direction Z. Here, the X direction shown in FIG. 2 is the horizontal direction, and the Y direction is the vertical direction.
The shape of the distribution header 101 and the confluence header 102 is not particularly limited, but in the first embodiment, each of the distribution header 101 and the confluence header 102 is formed of a cylindrical tube having one end closed.

A refrigerant inflow port 101b is formed at one end 101a in the vertical direction of the distribution header 101, and the other end 101c in the vertical direction is closed. Here, the side surface connecting the one end 101a and the other end 101c of the distribution header 101 is referred to as the side 101d. The inflow port 101b is connected to a refrigerant pipe 2 (not shown) that constitutes a refrigeration cycle. Inside the distribution header 101, a distribution flow path 101e is formed so as to extend in a substantially vertical direction. The distribution flow path 101e allows the refrigerant flowing in from the inflow port 101b to pass from one end 101a toward the other end 101c.
The refrigerant inflow port 101b may be provided on the side portion 101d.

A refrigerant outlet 102b is formed at one end 102a in the vertical direction of the merging header 102, and the other end 102c in the vertical direction is closed. Here, the side surface connecting the one end 102a and the other end 102c of the merging header 102 is referred to as the side 102d. The outlet 102b is connected to a refrigerant pipe 2 (not shown) that constitutes a refrigeration cycle. Inside the merging header 102, a merging flow path 102e is formed so as to extend in a substantially vertical direction. The merging flow path 102e allows the refrigerant discharged from the plurality of heat transfer tubes 103 to pass from one end 102a to the other end 102c.
The refrigerant outlet 102b may be provided on the side portion 102d.

The heat transfer tube 103 extends in a substantially horizontal direction, and connection pipes 105a and connection pipes 105b are provided at both ends of the heat transfer tube 103. The connection pipe 105a is a pipe for connecting the heat transfer pipe 103 and the side portion 101d of the distribution header 101, and the connection pipe 105b is a pipe for connecting the heat transfer pipe 103 and the side portion 102d of the confluence header 102. One end of the heat transfer tube 103 in the axial direction is connected to the side portion 101d of the distribution header 101 via the connecting pipe 105a, and the other end in the axial direction is connected to the side portion 102d of the merging header 102 via the connecting pipe 105b. .. The plurality of heat transfer tubes 103 are provided at different positions in the vertical direction. Inside each heat transfer tube 103, a refrigerant flow path 103a through which the refrigerant passes from one end to the other end is provided. The opening 103b on the distribution header 101 side of each refrigerant flow path 103a in each heat transfer tube 103 is the inlet of the refrigerant, and the opening 103c on the confluence header 102 side is the outlet of the refrigerant.
The heat transfer tube 103 is tubular. The cross section of the heat transfer tube 103 is not particularly limited in shape, but in the first embodiment, it is formed of a cylindrical tube.

A plurality of plate-shaped fins 104 are arranged on the outer surface of the plurality of heat transfer tubes 103. The fins 104 promote heat exchange between the refrigerant passing through the heat transfer tube 103 and the air (fluid) around the heat exchanger 100.

Since the connection pipe 105a and the connection pipe 105b are not pipes mainly for heat exchange but pipes for connecting the heat transfer pipe 103 to the distribution header 101 and the confluence header 102, the connection pipe 105a and the connection pipe 105b No fin 104 is provided on the outer surface. In the first embodiment, the heat transfer tube 103, the connecting pipe 105a, and the connecting pipe 105b are connected by, for example, brazing.
The shapes of the connecting pipe 105a and the connecting pipe 105b are not particularly limited, but in the first embodiment, they are formed of a cylindrical pipe.

Here, the pipe to which the heat transfer pipe 103, the connecting pipe 105a, and the connecting pipe 105b are connected is referred to as the refrigerant pipe 110. Inside the refrigerant pipe 110, the other end in the axial direction in which the connection pipe 105b and the side portion 102d of the merging header 102 are connected from one end in the axial direction in which the connection pipe 105a and the side portion 101d of the distribution header 101 are connected. A refrigerant flow path 110a through which the refrigerant passes is provided. In the refrigerant pipe 110, the heat transfer pipe 103 is the heat transfer portion, and the connection pipe 105a and the connection pipe 105b are the connection portions.
Further, the heat transfer pipe 103, the connecting pipe 105a and the connecting pipe 105b may be integrally formed as the refrigerant pipe 110. When the heat transfer pipe 103, the connection pipe 105a, and the connection pipe 105b are integrally formed as the refrigerant pipe 110, the section provided with fins on the outer surface is connected to the heat transfer portion, and the section without fins is connected to the outer surface. It is a department.

In the first embodiment, the refrigerant is supplied from the refrigerant pipe to the distribution header 101, flows from the distribution header 101 through the plurality of heat transfer tubes 103 to the confluence header 102, and is discharged from the confluence header 102 to the refrigerant pipe. ..

In the first embodiment, as the material constituting the distribution header 101, the merging header 102, the heat transfer tube 103, the fin 104, the connecting pipe 105a and the connecting pipe 105b, for example, a metal such as copper, iron, aluminum, an iron alloy or an aluminum alloy. Examples thereof include materials and resins having high thermal conductivity.

Next, the configuration of the heat transfer tube 103 will be described. The heat transfer tube 103 has a plurality of resistance regions having different flow resistances. Specifically, as shown in FIG. 3, the heat transfer tube 103 according to the first embodiment is composed of a spiral grooved tube 131 and a smoothing tube 132.

The spiral grooved pipe 131 is an inner surface grooved pipe provided with a spiral groove having a constant lead angle α with respect to the pipe axis P on the inner surface. The smoothing tube 132 is a cylindrical tube having a smooth inner surface. The flow resistance (first flow resistance) of the spiral grooved pipe 131 (first resistance region) is larger than the flow resistance (second flow resistance) of the smooth pipe 132 (second resistance region).

The axial length L shown in FIG. 3 is the axial length of the heat transfer tube 103, the axial length La is the axial length of the spiral grooved tube 131, and the axial length Lb is the smoothing tube 132. Is the axial length of. The axial length L is the sum of the axial length La and the axial length Lb.

Although the axial length L of each heat transfer tube 103 is equal, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is such that the heat transfer tube 103 is connected to the distribution header 101. The flow resistance is set according to the vertical position. Since the flow resistance of the spiral grooved tube 131 is larger than the flow resistance of the smoothing tube 132, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is determined by each heat transfer tube 103. By adjusting the ratio according to the vertical position of the heat transfer tube 103, it is possible to obtain an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103.

Since the axial length L of the heat transfer tube 103 is the sum of the axial length La and the axial length Lb, the axial length of the spiral grooved tube 131 with respect to the axial length L of the heat transfer tube 103. The ratio of La is synonymous with the ratio of the axial length La of the spiral grooved tube 131 to the axial length Lb of the smoothing tube 132. That is, the flow resistance of each heat transfer tube 103 can be adjusted by using the ratio of the axial length La of the spiral grooved tube 131 to the axial length Lb of the smoothing tube 132.

The heat transfer tube 103 is manufactured by connecting the spiral grooved tube 131 and the smoothing tube 132 by, for example, brazing, and integrating them. In order to adjust the ratio of the axial length La to the axial length L, the heat transfer tube 103, for example, connects the spiral grooved tube 131 and the smoothing tube 132 by brazing, and then connects the spiral grooved tube 131 or the smoothing tube 131 or smoothing. It is manufactured by cutting at least one of the tubes 132 to an appropriate length.

4, 5 and 6 are views showing a modified example of the heat transfer tube 103 of the heat exchanger 100 according to the first embodiment. In FIG. 3, the heat transfer tube 103 illustrates a configuration in which the spiral grooved tube 131 is provided on the distribution header 101 side and the smoothing tube 132 is provided on the confluence header 102 side, but the configuration of the heat transfer tube 103 is limited to this. It's not a thing. The heat transfer tube 103 has, for example, a configuration in which the spiral grooved tube 131 is provided on the confluence header 102 side and the smoothing tube 132 is provided on the distribution header 101 side as shown in FIG. 4, and the heat transfer tube 103 has a spiral groove as shown in FIG. As a configuration in which the tube 131 and the smoothing tube 132 are divided into a plurality of tubes and connected to each other, or as shown in FIG. 6, an irregular tube 133 exhibiting a constant flow resistance is provided for each heat transfer tube 103. May be good.

The axial length La1 and the axial length La2 shown in FIG. 5 are the axial lengths of the spiral grooved pipe 1311 and the spiral grooved pipe 1312, which are divided into a plurality of parts, and are the axial lengths La1. And the sum of the axial length La2 and the axial length La2 are defined as the axial length La of the spiral grooved pipe 131 (first resistance region). Further, the axial length Lb1 and the axial length Lb2 shown in FIG. 5 are the axial lengths of the smoothing tube 1321 and the smoothing tube 1322, which are divided into a plurality of parts, and the axial length Lb1 and the axial length Lb1. The sum with the length Lb2 is defined as the axial length Lb of the smoothing tube 132 (second resistance region). Therefore, the axial length of the resistance region is the total of the axial lengths of the regions having the same inner surface shape in each heat transfer tube 103.

Further, in FIG. 6, the axial length L of the heat transfer tube 103 is the axial length La of the spiral grooved tube 131, the axial length Lb of the smoothing tube 132, and the axial length Lc of the irregular tube 133, respectively. Is the sum of the axial lengths of. Here, the irregular tube 133 is, for example, a spiral grooved tube provided with a spiral groove different from the spiral grooved tube 131 on the inner surface. In FIG. 6, since each irregular tube 133 has the same length, the flow resistance of each heat transfer tube 103 is the axial length La of the spiral grooved tube 131 with respect to the axial length L of the heat transfer tube 103. It can be adjusted using the ratio.

Next, a method of determining the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 in the heat exchanger 100 according to the first embodiment will be described.

FIG. 7 is a diagram illustrating the value of the mass flow rate of the refrigerant flowing inside the heat transfer tube 103 with respect to the vertical position of the heat transfer tube 103 in the heat exchanger 100 when the flow resistance of each heat transfer tube 103 is the same. In FIG. 7, the vertical axis shows the vertical position where the heat transfer tube 103 is connected to the distribution header 101, the horizontal axis shows the mass flow rate of the refrigerant flowing in the heat transfer tube 103, and the black circle is the mass flow rate flowing through each heat transfer tube 103. ..

In general, the flow velocity of the refrigerant flowing in the distribution flow path 101e becomes smaller in the vertical upper part than in the vertical lower part due to the action of gravity. Therefore, as shown in FIG. 7, the mass flow rate of the refrigerant flowing inside the heat transfer tube 103 is as small as the heat transfer tube 103 located vertically above the distribution flow path 101e, and vertically below the distribution flow path 101e. It becomes larger as the heat transfer tube 103 is located.

As shown in FIG. 7, when there is a difference in the mass flow rate of the refrigerant flowing inside each heat transfer tube 103, an excess refrigerant flows in the heat transfer tube 103 located vertically below, while the heat transfer tube 103 located vertically above. Due to the shortage of the refrigerant supplied to the heat transfer tube 103, the gas single-phase region increases in the heat transfer tube 103 located in the vertical direction, and the heat exchange performance of the heat exchanger 100 deteriorates.

Therefore, in the heat exchanger 100 according to the first embodiment, in order to suppress the deterioration of the heat exchange performance due to the difference in the mass flow rate of the refrigerant flowing inside each heat transfer tube 103, the refrigerant flowing inside each heat transfer tube 103 is suppressed. The ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 according to the vertical position where the heat transfer tube 103 is connected to the distribution header 101 so that the mass flow rate is leveled. To determine.

Specifically, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is the heat transfer tube connected vertically above the distribution flow path 101e, as shown in FIG. It is determined that the heat transfer tube 103 connected vertically below the distribution flow path 101e gradually increases in size from 103.

Here, since the flow resistance of the spiral grooved tube 131 is larger than that of the smooth tube 132, the smaller the ratio of the axial length La to the axial length L, the smaller the flow resistance of the heat transfer tube 103, and the axial length. The larger the ratio of the axial length La to L, the larger the flow resistance of the heat transfer tube 103.

That is, in the heat exchanger 100 shown in FIG. 3, when the flow resistance of each heat transfer tube 103 is the same, the flow resistance of the heat transfer tube 103 connected vertically below increases the flow velocity of the refrigerant flowing in the distribution flow path 101e. When the flow resistance of each heat transfer tube 103 is the same, the flow resistance of the heat transfer tube 103 connected vertically above the distribution flow path 101e becomes small, and the flow resistance of the heat transfer tube 103 is small.

Therefore, in the heat exchanger 100 according to the first embodiment, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is connected vertically above the distribution flow path 101e. The flow resistance of the heat transfer tube 103 is distributed from the heat transfer tube 103 connected vertically above the distribution flow path 101e in order to determine that the heat pipe 103 is sequentially increased to the heat transfer tube 103 connected vertically below the distribution flow path 101e. The heat transfer tubes 103 connected vertically below the flow path 101e can be sequentially increased, and the mass flow rate of the refrigerant flowing inside each heat transfer tube 103 can be leveled.

When a plurality of rows of heat transfer tubes 103 are provided with respect to the air flow direction Z and the distribution header 101 has heat transfer tubes 103 having the same vertical position to which the heat transfer tubes 103 are connected, the distribution header 101 On the other hand, the heat transfer tubes 103 connected to the same vertical position have the same flow resistance. Further, when the flow resistances of the heat transfer tubes 103 are the same, the heat transfer tubes 103 connected to the vertical section in which the flow velocity of the refrigerant flowing in the distribution flow path 101e does not change significantly may have the same flow resistance. .. That is, the heat exchanger 100 according to the first embodiment has different heat transfer tubes 103 so that at least a part of the heat transfer tubes 103 provided at different positions in the vertical direction has different flow resistances. The axial length La of the spiral grooved tube 131 and the axial length Lb of the smoothing tube 132 are formed.

In the first embodiment, the mass flow rate of the refrigerant flowing in each heat transfer tube 103 can be adjusted by providing a spiral groove in the connection pipe 105a or the connection pipe 105b. However, when the spiral groove is provided only in the connection pipe 105a or the connection pipe 105b to adjust the mass flow rate of the refrigerant flowing in each heat transfer tube 103, the spiral groove is not provided on the inner surface of the heat transfer tube 103, so that the heat transfer tube 103 The refrigerant flowing inside is difficult to be agitated.

The connection pipe 105a and the connection pipe 105b not provided with the fins 104 are not pipes for exchanging heat with the air (fluid) around the heat exchanger 100, but the heat transfer pipe 103 is connected to the distribution header 101 and the confluence header 102. It is a pipe for connecting. That is, even if the mass flow rate of the refrigerant flowing in each heat transfer tube 103 is adjusted by providing the connecting pipe 105a or the connecting pipe 105b with a spiral groove, the heat exchange performance cannot be improved.

On the other hand, in the heat exchanger 100 according to the first embodiment, a spiral grooved tube in which a plurality of fins 104 are arranged on the outer surface in order to exchange heat with the air (fluid) around the heat exchanger 100. The ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103, which is a pipe composed of 131 and the smoothing tube 132, is set in the vertical direction in which the heat transfer tube 103 is connected to the distribution header 101. By changing the position according to the position, it is possible to adjust the appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103, and it is possible to improve the heat exchange performance.

Further, the heat exchanger 100 according to the first embodiment can set an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103 without changing the lead angle of the spiral grooved tube 131 for each heat transfer tube 103.

Further, in the heat exchanger 100 according to the first embodiment, the flow resistance of the heat transfer tube 103 is determined by the ratio of the axial length La of the spiral grooved tube 131 (first resistance region) to the axial length L of the heat transfer tube 103. Therefore, the adjustment range of the flow resistance of the heat transfer tube 103 is large, and an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103 can be set.

Further, the heat transfer tube 103 of the heat exchanger 100 according to the first embodiment has improved heat exchange performance because the refrigerant flowing in the heat transfer tube 103 is agitated by the spiral groove provided on the inner surface of the spiral grooved tube 131. Can be measured.

Further, the heat transfer tube 103 of the heat exchanger 100 according to the first embodiment is configured by connecting the spiral grooved tube 131 and the smoothing tube 132 by brazing or the like. Therefore, the shape of the inner surface of the heat transfer tube 103 is discontinuous, the flow of the refrigerant flowing in the heat transfer tube 103 can be changed, and the stirring action of the refrigerant is improved, so that the heat exchange performance can be improved. it can.

The heat exchanger 100 according to the first embodiment has one end and the other end provided at both ends in the vertical direction, and a side portion connecting the one end and the other end, and the one end or the side portion has a side portion. A distribution header in which an inflow port through which the refrigerant flows is provided and a distribution flow path in which the refrigerant flows from one end to the other end is provided, and one end and the other end provided at both ends in the vertical direction. In addition, it has a side part that connects one end and the other end, and an outlet for the refrigerant to flow out is provided at one end or the side, and a merging flow path in which the refrigerant flows from one end to the other end inside. A refrigerant flow path in which one end in the axial direction is connected to the side portion of the distribution header, the other end in the axial direction is connected to the side portion of the confluence header, and the refrigerant flows from one end to the other end. A plurality of refrigerant pipes are provided at different positions in the vertical direction, and the refrigerant pipes are provided at both ends of a heat transfer portion provided with fins on the outside and a heat transfer portion provided with fins on the outside. It has a connection part without fins on the outside, and the heat transfer part of the refrigerant pipe has a first flow resistance, and has a first resistance region and a first resistance region having a spiral groove on the inner surface. It has a second resistance region with a second flow resistance that is a different flow resistance, and the first resistance region and the second resistance region have axial lengths such that the refrigerant pipe has a flow resistance according to the vertical position. Is formed by.

Further, in the heat exchanger 100 according to the first embodiment, the heat transfer portions of the respective refrigerant pipes are provided so that the flow resistance of at least a part of the refrigerant pipes provided at different positions in the vertical direction is different. The axial length of the first resistance region and the axial length of the second resistance region are formed.

Further, in the heat exchanger 100 according to the first embodiment, the flow resistance of the refrigerant pipe is adjusted by the ratio of the axial length of the first resistance region to the axial length of the heat transfer portion of the refrigerant pipe. And.

Further, in the heat exchanger 100 according to the first embodiment, the second resistance region is characterized in that the inner surface is a smooth surface.

Further, in the heat exchanger 100 according to the first embodiment, the flow resistance of the heat transfer portion of the heat transfer tube is characterized in that the flow resistance gradually increases from the heat transfer tube provided vertically above to the heat transfer tube provided vertically below. To do.

With the above configuration, the heat exchanger 100 according to the first embodiment can set an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103, agitates the refrigerant flowing in the heat transfer tube 103, and efficiently exchanges heat. It can be carried out.

Embodiment 2.
The configuration of the heat exchanger 200 according to the second embodiment of the present invention will be described. The same or corresponding configurations as those in the first embodiment will be omitted, and only the parts having different configurations will be described.

FIG. 8 is a cross-sectional view of the heat exchanger 200 according to the second embodiment. As shown in FIG. 8, the heat exchanger 200 is configured to have a straight grooved pipe 134 having a straight straight groove extending in a direction parallel to the pipe axis P on the inner surface instead of the smoothing pipe 132. The flow resistance (second flow resistance) of the straight grooved pipe 134 (second resistance region) is smaller than the flow resistance (first flow resistance) of the spiral grooved pipe 131 (first resistance region). The axial length Ld shown in FIG. 8 is the axial length of the straight grooved tube 134, and the axial length L of the heat transfer tube 103 is the axial length of the spiral grooved tube 131 (first resistance region). It is the sum of the spiral length La and the axial length Ld of the straight grooved pipe 134 (second resistance region).

In the heat exchanger 200, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is changed according to the vertical position where the heat transfer tube 103 is connected to the distribution header 101. As a result, it is possible to adjust the mass flow rate of the refrigerant appropriately corresponding to each heat transfer tube 103, and it is possible to improve the heat exchange performance. Specifically, the ratio of the axial length La to the axial length L is from the heat transfer tube 103 connected vertically above the distribution flow path 101e to the heat transfer tube 103 connected vertically below the distribution flow path 101e. It gets bigger and bigger.

In the heat exchanger 200 according to the second embodiment, the spiral groove provided in the spiral grooved pipe 131 and the straight groove provided in the straight grooved pipe 134 have a discontinuous groove shape. In the heat exchanger 200 according to the second embodiment, since the groove shape in the heat transfer tube 103 is discontinuous, the refrigerant flowing in the heat transfer tube 103 is agitated, and the heat exchange performance can be improved.

Further, since the heat exchanger 200 according to the second embodiment has a straight grooved pipe 134 having a cross-sectional area larger than that of the smoothing pipe 132 instead of the smoothing pipe 132, the heat exchange efficiency can be improved.

In the heat exchanger 200 according to the second embodiment, the second resistance region is characterized in that a straight straight groove extending in a direction parallel to the pipe axis P is provided on the inner surface thereof.

With the above configuration, the heat exchanger 200 according to the second embodiment can set an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103, agitates the refrigerant flowing in the heat transfer tube 103, and efficiently exchanges heat. It can be carried out.

Embodiment 3.
The configuration of the heat exchanger 300 according to the third embodiment of the present invention will be described. The same or corresponding configurations as those in the first embodiment will be omitted, and only the parts having different configurations will be described.

FIG. 9 is a cross-sectional view of the heat exchanger 300 according to the third embodiment. As shown in FIG. 9, the heat exchanger 300 has a configuration in which, instead of the smoothing tube 132, a spiral grooved tube 135, which is an inner grooved tube having a constant lead angle β with respect to the tube axis P, is provided on the inner surface. is there. Here, the lead angle β of the spiral grooved tube 135 is smaller than the lead angle α of the spiral grooved tube 131.

Since the lead angle β of the spiral groove of the spiral grooved pipe 135 is smaller than the lead angle α of the spiral groove of the spiral grooved pipe 131, the flow resistance (second flow) of the spiral grooved pipe 135 (second resistance region) The resistance) is smaller than the flow resistance (first flow resistance) of the spiral grooved tube 131 (first resistance region). The axial length Le shown in FIG. 9 is the axial length of the spiral grooved tube 135, and the axial length L of the heat transfer tube 103 is the axial length of the spiral grooved tube 131 (first resistance region). It is the sum of La and the axial length Le of the spiral grooved tube 135 (second resistance region).

In the heat exchanger 300, the ratio of the axial length La of the spiral grooved tube 131 to the axial length L of the heat transfer tube 103 is changed according to the vertical position where the heat transfer tube 103 is connected to the distribution header 101. As a result, it is possible to adjust the mass flow rate of the refrigerant appropriately corresponding to each heat transfer tube 103, and it is possible to improve the heat exchange performance. Specifically, the ratio of the axial length La to the axial length L is from the heat transfer tube 103 connected vertically above the distribution flow path 101e to the heat transfer tube 103 connected vertically below the distribution flow path 101e. It gets bigger and bigger.

In the heat exchanger 300 according to the third embodiment, the spiral groove provided in the spiral grooved tube 131 and the spiral groove provided in the spiral grooved tube 135 have a discontinuous groove shape. In the heat exchanger 300 according to the third embodiment, since the groove shape in the heat transfer tube 103 is discontinuous, the refrigerant flowing in the heat transfer tube 103 is agitated, and the heat exchange performance can be improved.

Further, since the heat exchanger 300 according to the third embodiment has a spiral grooved tube 135 having a cross-sectional area larger than that of the smoothing tube 132 instead of the smoothing tube 132, the heat exchange efficiency can be improved.

Further, since the heat transfer tube 103 of the heat exchanger 300 according to the third embodiment is composed of a spiral grooved tube 131 and a spiral grooved tube 135 having spiral grooves having different lead angles, the spiral grooved tube 131 The flow of the refrigerant flowing in the heat transfer tube 103 can be changed more than that of the heat transfer tube 103 composed of the smoothing tube 132, and the stirring action of the refrigerant can be improved.

Here, in the heat exchanger 300 according to the third embodiment, the case where the lead angle β of the spiral grooved tube 135 is smaller than the lead angle α of the spiral grooved tube 131 has been described as an example. The lead angle β of the grooved tube 135 may be larger than the lead angle α of the spiral grooved tube 131. When the lead angle β is larger than the lead angle α, the spiral grooved tube 135 has a larger flow resistance than the spiral grooved tube 131, so that the spiral grooved tube with respect to the axial length L of the heat transfer tube 103 The ratio of the axial length Le of 135 gradually increases from the heat transfer tube 103 connected vertically above the distribution flow path 101e to the heat transfer tube 103 connected vertically below the distribution flow path 101e.

In the heat exchanger 300 according to the third embodiment, the plurality of resistance regions have a spiral groove having a lead angle different from the lead angle of the spiral groove provided on the inner surface of the first resistance region on the inner surface of the second resistance region. It is characterized by being provided.

With the above configuration, the heat exchanger 300 according to the third embodiment can set an appropriate mass flow rate of the refrigerant corresponding to each heat transfer tube 103, agitates the refrigerant flowing in the heat transfer tube 103, and efficiently exchanges heat. It can be carried out.

In the present invention, each embodiment can be freely combined within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 Outdoor unit 2 Refrigerant piping 3 Indoor unit 11 Compressor 12 Four-way switching valve 13 Squeezing mechanism 14 Outdoor blower 31 Indoor heat exchanger 32 Indoor blower 100, 200, 300 Heat exchanger 101 Distribution header 102 Confluence header 103 Heat transfer tube 104 Fin 105a , 105b Connection pipes 101a, 102a One end 101b Inflow port 102b Outlet 101c, 102c Other end 101d, 102d Side 101e Distribution flow path 102e Confluence flow path 103a, 110a Refrigerant flow path 103b, 103c Opening 110 Refrigerant pipe 131, 135 Spiral grooved pipe 132 Smooth pipe 133 Irregular pipe 134 Straight grooved pipe

Claims (8)

It has one end and the other end provided at both ends in the vertical direction, and a side portion connecting the one end portion and the other end portion, and an inflow port through which the refrigerant flows is provided at the one end portion or the side portion. A distribution header in which a distribution flow path through which the refrigerant flows from one end to the other end is formed.
It has one end and the other end provided at both ends in the vertical direction, and a side portion connecting the one end portion and the other end portion, and an outlet for flowing out the refrigerant is provided at the one end portion or the side portion. A merging header in which a merging flow path through which the refrigerant flows from one end to the other end is formed.
A refrigerant flow path in which one end in the axial direction is connected to the side portion of the distribution header, the other end in the axial direction is connected to the side portion of the merging header, and the refrigerant flows from the one end to the other end inside. With a tubular refrigerant pipe provided with
A plurality of the refrigerant pipes are provided at different positions in the vertical direction.
The refrigerant pipe has a heat transfer portion provided with fins on the outside and a connecting portion provided on both ends of the heat transfer portion and not provided with fins on the outside.
The heat transfer portion of the refrigerant pipe has a first flow resistance, and has a first resistance region provided with a spiral groove on the inner surface and a second flow resistance which is a flow resistance different from the first resistance region. Has 2 resistance regions
The first resistance region and the second resistance region are heat exchangers formed with an axial length such that the refrigerant pipe has a flow resistance according to a vertical position. The axial length of the first resistance region of the heat transfer portion of each of the refrigerant pipes so that at least a part of the refrigerant pipes provided at different positions in the vertical direction has different flow resistances. The heat exchanger according to claim 1, wherein the axial length of the second resistance region is formed. The first or second aspect, wherein the flow resistance of the refrigerant pipe is adjusted by the ratio of the axial length of the first resistance region to the axial length of the heat transfer portion of the refrigerant pipe. Heat exchanger. The heat exchanger according to any one of claims 1 to 3, wherein the connecting surface between the first resistance region and the second resistance region is discontinuous. The heat exchanger according to any one of claims 1 to 4, wherein the second resistance region has a smooth inner surface. The heat according to any one of claims 1 to 4, wherein the second resistance region is provided with a linear straight groove extending in a direction parallel to the axial direction on the inner surface. Exchanger. Claims 1 to 4, wherein the second resistance region is provided with a spiral groove having a lead angle different from the lead angle of the spiral groove provided on the inner surface of the first resistance region. The heat exchanger according to any one item. Any of claims 1 to 7, wherein the flow resistance of the heat transfer portion of the refrigerant pipe gradually increases from the refrigerant pipe provided vertically above to the refrigerant pipe provided vertically below. The heat exchanger according to item 1.

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