JP7670962B2 - Heat exchanger - Google Patents

Description

This relates to a heat exchanger equipped with a flow dividing section.

Conventionally, a configuration has been adopted in which a flow divider is used to divide the refrigerant into multiple refrigerant flow paths provided in a heat exchanger. When such a heat exchanger functions as a condenser, the refrigerant is in liquid form at the outlet of the heat exchanger, so the refrigerant density is high and the flow rate is slow. In this way, when the heat exchanger functions as a condenser, the liquid refrigerant tends to stagnate due to the head difference caused by the difference in height between the refrigerant flow path and the flow divider.

As an example of a heat exchanger for reducing the head difference caused by a flow divider, there is a heat exchanger described in Patent Document 1 (WO 2019/150851). When the heat exchanger of Patent Document 1 functions as a condenser, liquid refrigerant flows out from the upper side of the flow divider in the direction of gravity. In addition, refrigerant flows in from multiple thin tubes connected to the lower side of the flow divider in the direction of gravity. The configuration of the flow divider of Patent Document 1 described above can reduce the head difference caused by the installation height of the flow divider. However, the heat exchanger of Patent Document 1 requires a lot of bending of the piping, and the configuration of the piping connected to the flow divider is complicated.

Heat exchangers with a diversion section have the challenge of reducing the head difference caused by the diversion section with a simple configuration.

The heat exchanger of the first aspect includes a first heat transfer tube, a second heat transfer tube to an Nth heat transfer tube, a main body side branch section, a first tube, and a second tube to an Nth tube. The second heat transfer tube to the Nth heat transfer tube are arranged above the first heat transfer tube in the direction of gravity. The first tube connects the main body side branch section and the first heat transfer tube. The second tube to the Nth tube connect the main body side branch section and the second heat transfer tube to the Nth heat transfer tube. The first tube is connected to one side of the main body side branch section, and the second tube to the Nth tube are connected to the other side of the main body side branch section. The first tube extends along a first direction with an inclination of ±45° with respect to the horizontal direction immediately before the main body side branch section.

In the heat exchanger of the first aspect, liquid refrigerant flows through the first heat transfer tube, which is disposed below the second heat transfer tube to the Nth heat transfer tube. The portion of this first heat transfer tube immediately before it is connected to the main body side branch section extends in the first direction. A heat exchanger of this configuration can reduce the head difference compared to a conventional heat exchanger in which the portion of the first heat transfer tube immediately before it is connected to the main body side branch section is disposed so as to extend in the direction of gravity.

The heat exchanger of the second aspect is the heat exchanger of the first aspect, in which the second tube to the Nth tube are arranged horizontally on the other side of the main body side branch section.

In the heat exchanger of the second aspect, the second tube to the Nth tube are arranged horizontally on the other side of the main body side branch section, which makes it easier to evenly distribute the refrigerant from the second tube to the Nth tube in the main body side branch section when it functions as an evaporator.

The heat exchanger of the third aspect is the heat exchanger of the first or second aspect, in which the first heat transfer tube is arranged in the lowest flow path in the direction of gravity.

The heat exchanger of the fourth aspect is any of the heat exchangers of the first aspect to the third aspect, where (N-1) is a multiple of 2.

The heat exchanger of the fifth aspect is any of the heat exchangers of the first to fourth aspects, in which there is one first tube and (N-1) is 2, 4, or 8, there are two first tubes and (N-2) is 4 or 8, or there are four first tubes and (N-4) is 8.

The heat exchanger of the sixth aspect is a heat exchanger of any one of the first aspect to the fifth aspect, and includes a tube plate for fixing the first to Nth heat transfer tubes. The distance from the tube plate to the main body side flow division section is 30 mm or less.

The heat exchanger of the seventh aspect is any one of the heat exchangers of the first aspect to the sixth aspect, in which the first heat transfer tube is arranged on the outlet side when functioning as a condenser, and the second to Nth heat transfer tubes are arranged on the inlet side.

The heat exchanger of the eighth aspect is a heat exchanger of any one of the first aspect to the seventh aspect, in which the second heat transfer tube is located lower in the direction of gravity than the third to Nth heat transfer tubes. The main body side branch section is located lower in the direction of gravity than the second heat transfer tube.

In the heat exchanger of the eighth aspect, it is easier to reduce the head difference compared to when the main body side branch section is located higher in the direction of gravity than the second heat transfer tube.

The heat exchanger of the ninth aspect is any one of the heat exchangers of the first aspect to the eighth aspect, in which the main body side branch section has the first tube connected to the side and the second to Nth heat transfer tubes connected to the top.

In the heat exchanger of the ninth aspect, the number of bends in the tubes between the first tube and the second tube to the Nth tube can be reduced, making it easier to piping the first tube and the second tube to the Nth tube.

1 is a circuit diagram showing an example of an air conditioner equipped with an outdoor heat exchanger. FIG. 4 is an exploded perspective view showing the relationship between the heat transfer tubes, heat transfer fins, and U-shaped tubes of the outdoor heat exchanger. FIG. 2 is a schematic diagram showing an example of a configuration of a side surface of an outdoor heat exchanger. 4 is a block diagram showing a connection relationship between a heat transfer tube of an outdoor heat exchanger and a main body side dividing section. FIG. 5 is a cross-sectional view showing the configuration of first and second main body side branch portions. FIG. 11 is a cross-sectional view for explaining the inclination of the first and second main body side branch portions when they are attached. FIG. 11 is a cross-sectional view for explaining the inclination of the first and second main body side branch portions when they are attached. FIG. FIG. 13 is a block diagram showing a relationship between a heat transfer tube and a main body side dividing portion according to a modified example. FIG. 13 is a block diagram showing the relationship of a main body side branch portion according to a modified example. 11A and 11B are diagrams for explaining a head difference when a conventional main body side branch portion is installed. FIG. 11 is a side view showing another example of a main body side branch portion according to a modified example. FIG. 11 is a top view showing another example of a main body side branch portion according to a modified example. FIG. 11 is a side view showing another example of a main body side branch portion according to a modified example. FIG. 11 is a perspective view showing another example of a main body side branch portion according to a modified example.

(1) Overall Configuration Fig. 1 shows an air conditioner 1 as an example of a refrigeration cycle device to which a heat exchanger is applied. In this disclosure, a case where the refrigeration cycle device is the air conditioner 1 will be described, but the refrigeration cycle device is not limited to the air conditioner 1. The refrigeration cycle device is a device that performs a refrigeration cycle. Examples of refrigeration cycle devices include refrigerators, freezers, water heaters, floor heating devices, and heat pump devices.

The air conditioner 1 in FIG. 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, an indoor heat exchanger 6, an outdoor fan 7, and an indoor fan 8. The heat exchanger that is the subject of this disclosure, which will be described below, is the former of the outdoor heat exchanger 4 and the indoor heat exchanger 6.

The compressor 2, the four-way valve 3, the outdoor heat exchanger 4, the expansion valve 5, and the indoor heat exchanger 6 are connected by a connecting pipe 11 to form a refrigerant circuit 10. In the refrigerant circuit 10, the refrigerant circulates and a vapor compression refrigeration cycle is repeated. In other words, the refrigerant circulates through the refrigerant circuit 10 while alternately decompressing and expanding and releasing heat and condensing. Examples of refrigerants used in the refrigerant circuit 10 in which the vapor compression refrigeration cycle is performed include hydrofluorocarbon (HFC) refrigerants, hydrofluoroolefins (HFOs), unsaturated HFC refrigerants, and natural refrigerants. Examples of HFC refrigerants include R32, R410A, R407C, and R134a. Examples of HFOs include R1234ze and R1234yf. Examples of natural refrigerants include R717.

The flow path of the refrigerant flowing through the refrigerant circuit 10 is switched by the four-way valve 3. The air conditioner 1 can switch between cooling and heating operation by switching the flow path with the four-way valve 3. During cooling operation, the refrigerant flows in the following order: compressor 2, four-way valve 3, outdoor heat exchanger 4, expansion valve 5, indoor heat exchanger 6, four-way valve 3, and compressor 2. During heating operation, the refrigerant flows in the following order: compressor 2, four-way valve 3, indoor heat exchanger 6, expansion valve 5, outdoor heat exchanger 4, four-way valve 3, and compressor 2.

The outdoor heat exchanger 4 and the indoor heat exchanger 6 are fin-and-tube type heat exchangers. During cooling operation, the outdoor heat exchanger 4 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator. During heating operation, the outdoor heat exchanger 4 functions as an evaporator, and the indoor heat exchanger 6 functions as a condenser.

(2) Detailed Configuration (2-1) Outdoor Heat Exchanger Fig. 2 shows a part of the heat transfer tubes 21, the U-shaped tubes 22, and the heat transfer fins 24 of the outdoor heat exchanger 4. As shown in Fig. 2 and Fig. 3, the outdoor heat exchanger 4 includes a plurality of heat transfer tubes 21, a plurality of U-shaped tubes 22, a plurality of connecting tubes 23, a plurality of heat transfer fins 24, a header collecting tube 25, an inlet/outlet side branch section 26, a first main body side branch section 27, a second main body side branch section 28, a first inlet/outlet 31, a second inlet/outlet 32, and a tube plate 35. Fig. 3 shows a schematic diagram of the connection relationship between the heat transfer tubes 21, the U-shaped tubes 22, the connecting tube 23, the inlet/outlet side branch section 26, the first main body side branch section 27, the second main body side branch section 28, and the header collecting tube 25 as viewed from the side of the outdoor heat exchanger 4. Here, the main body side branch section refers to a branch section provided in a heat exchanger other than the header manifold 25 (header type branch section) arranged between the first inlet/outlet 31 and the heat transfer tube 21 or the inlet/outlet side branch section 26 arranged between the second inlet/outlet 32 and the heat transfer tube 21.

When the outdoor heat exchanger 4 functions as a condenser, the refrigerant discharged from the compressor 2 enters the outdoor heat exchanger 4 through the first inlet/outlet 31. When the outdoor heat exchanger 4 functions as an evaporator, the refrigerant that has undergone heat exchange in the indoor heat exchanger 6 exits the outdoor heat exchanger 4 through the first inlet/outlet 31. Whether functioning as a condenser or an evaporator, the refrigerant that passes through the first inlet/outlet 31 is mainly gasified refrigerant.

The header collecting pipe 25 is connected to the first inlet/outlet 31 and the multiple connecting pipes 23. In the outdoor heat exchanger 4 functioning as a condenser, the refrigerant entering from the first inlet/outlet 31 is distributed by the header collecting pipe 25 and flows into the multiple connecting pipes 23. In the outdoor heat exchanger 4 functioning as an evaporator, the refrigerant flowing through the multiple connecting pipes 23 is combined at the header collecting pipe 25 and flows into the first inlet/outlet 31.

The connection pipe 23 is connected to the heat transfer tube 21. The 44 heat transfer tubes 21 of the outdoor heat exchanger 4, shown by circles in FIG. 3, are arranged in two columns and 22 rows. Note that the arrangement in the gravity direction GD, shown by arrows in FIG. 2 and FIG. 3, is the row, and the arrangement in the horizontal direction HD is the column. Here, the column in which the heat transfer tubes 21 connected to the header collecting pipe 25 are arranged is called the second column, and the column in which the heat transfer tubes 21 connected to the first main body side branch section 27 are arranged is called the first column. In other words, the column of the heat transfer tubes 21 on the right side of FIG. 3 is the first column, and the column of the heat transfer tubes 21 on the left side is the second column. The number and arrangement of the heat transfer tubes 21 of the outdoor heat exchanger 4 to which the technology disclosed herein is applied are not limited to the arrangement shown in FIG. 3.

Figure 3 shows a circular cross section of the heat transfer tube 21. In other words, the heat transfer tube 21 extends in a direction perpendicular to the paper surface of Figure 3. A U-shaped tube 22 is connected to the end of the heat transfer tube 21 to which the connecting tube 23 is not connected. The U-shaped tube 22 connects two heat transfer tubes 21. The U-shaped tube 22 is a tube for turning the refrigerant flowing through one heat transfer tube 21 at the end of the outdoor heat exchanger 4 and flowing it to the other heat transfer tube 21. In Figure 3, the U-shaped tube 22 shown by the solid line is arranged in the front, and the U-shaped tube 22 shown by the dashed line is arranged in the back. All of the heat transfer tubes 21 vertically penetrate the multiple heat transfer fins 24. The multiple heat transfer fins 24 are arranged so that their main surfaces are parallel to each other. These multiple heat transfer tubes 21 and multiple U-shaped tubes 22 are fixed to a tube plate 35.

The two heat transfer tubes 21 and the second main body side branch section 28 are connected by two connecting tubes 23. The two heat transfer tubes 21 and the first main body side branch section 27 are connected by two connecting tubes 23. In the outdoor heat exchanger 4 of FIG. 3, when functioning as a condenser, the refrigerant flows from the two heat transfer tubes 21 through the two connecting tubes 23 to the second main body side branch section 28. The refrigerant flows from the two connecting tubes 23 into the second main body side branch section 28 and is combined at the second main body side branch section 28 and flows out from one connecting tube 23. Similarly, the refrigerant flows from the two heat transfer tubes 21 through the two connecting tubes 23 to the first main body side branch section 27. The refrigerant flows from the two connecting tubes 23 into the first main body side branch section 27 and is combined at the first main body side branch section 27 and flows out from one connecting tube 23.

The subcool heat exchange section SC is provided at the bottom of the outdoor heat exchanger 4. The subcool heat exchange section SC has the function of further lowering the temperature of the liquefied refrigerant by heat exchange when the outdoor heat exchanger 4 functions as a condenser. The subcool heat exchange section SC is composed of four heat transfer tubes 21 and two U-shaped tubes 22 arranged at the bottom of the outdoor heat exchanger 4. The first main body side branch section 27 is connected to the first row of heat transfer tubes 21 of the subcool heat exchange section SC. The second main body side branch section 28 is connected to the second row of heat transfer tubes 21 of the subcool heat exchange section SC. In other words, the first row of heat transfer tubes 21 of the subcool heat exchange section SC is included in the flow path of the bottom stage of the outdoor heat exchanger 4. Similarly, the second row of heat transfer tubes 21 of the subcool heat exchange section SC is included in another flow path of the bottom stage of the outdoor heat exchanger 4. The refrigerant that has passed through the first row of heat transfer tubes 21 and the second row of heat transfer tubes of the subcool heat exchange section SC flows into the inlet/outlet side branch section 26. The refrigerant that has flowed from the subcool heat exchange section SC into the inlet/outlet side branch section 26 joins together at the inlet/outlet side branch section 26 and flows out from the second inlet/outlet 32.

In the outdoor heat exchanger 4 functioning as an evaporator, the refrigerant flowing into the inlet/outlet side branch section 26 from the second inlet/outlet 32 is distributed to two connecting pipes 23 at the inlet/outlet side branch section 26. The refrigerant distributed to the two connecting pipes 23 at the inlet/outlet side branch section 26 flows into the first body side branch section 27 and the second body side branch section 28 via the heat transfer tube 21, the U-shaped tube 22, and the connecting tube 23, respectively. The refrigerant flowing into the first body side branch section 27 and the second body side branch section 28 is distributed to two connecting pipes 23 at the first body side branch section 27 and the second body side branch section 28, respectively. The refrigerant divided into two each at the first body side branch section 27 and the second body side branch section 28 flows into the header collecting pipe 25 via the connecting tube 23, the heat transfer tube 21, and the U-shaped tube 22, respectively. The refrigerant that flows into the header collector pipe 25 from the four connecting pipes 23 is combined at the header collector pipe 25 and flows out from the first inlet/outlet 31. Whether it functions as a condenser or an evaporator, the refrigerant that passes through the second inlet/outlet 32 is mainly liquefied refrigerant.

(2-1-1) Heat transfer tubes connected to the main body-side distribution section With respect to the first main body-side distribution section 27, the 22 rows of heat transfer tubes 21 aligned in the direction of gravity in the first column of the outdoor heat exchanger 4 include three heat transfer tubes HR1, HR3, and HR4 (see FIG. 3). With respect to the second main body-side distribution section 28, the 22 rows of heat transfer tubes 21 aligned in the direction of gravity in the second column of the outdoor heat exchanger 4 include the heat transfer tube HR2, and the first column includes the heat transfer tubes HR5 and HR6 (see FIG. 3). These heat transfer tubes HR1 to HR6 are fixed to the tube plate 35.

The heat transfer tubes HR1 to HR6 may be connected to the header collector tube 15 via other heat transfer tubes 21 and U-shaped tubes 22, or may be directly connected to the header collector tube 15. The three connecting tubes 23 connected to the first body side branch section 27 and the three connecting tubes 23 connected to the second body side branch section 28 are respectively labeled with the first tube P1 to the third tube P3, and each connecting tube will be described separately. For example, the heat transfer tube HR6 related to the second body side branch section 28 is connected to the third tube P3 of the second body side branch section 28. For example, the heat transfer tube HR1 is included in the subcool heat exchange section SC. In other words, the heat transfer tube HR1 is arranged in the lowest flow path in the direction of gravity.

When the outdoor heat exchanger 4 functions as a condenser, the first heat transfer tube HR1 is arranged on the outlet side, and the second to Nth heat transfer tubes HR3 and HR4 are arranged on the inlet side. However, in this case, N=3.

(2-1-2) Main-side Dividing Section As shown in Fig. 4 and Fig. 5, the outdoor heat exchanger 4 includes a first tube P1, a second tube P2, and a third tube P3 for the first main-side dividing section 27. The first tube P1 connects the first main-side dividing section 27 to the heat transfer tube HR1, which is the first heat transfer tube. The second tube P2 to the third tube P3 connect the first main-side dividing section 27 to the heat transfer tubes HR3 to HR4. The heat transfer tube HR3 is the second heat transfer tube, and the heat transfer tube HR4 is the third heat transfer tube. The heat transfer tubes HR3 to HR4 are disposed above the heat transfer tube HR1 in the direction of gravity.

Similarly, the outdoor heat exchanger 4 is provided with a first tube P1, a second tube P2, and a third tube P3 for the second main body side branch section 28. The first tube P1 connects the second main body side branch section 28 to the heat transfer tube HR2, which is the first heat transfer tube. The second tube P2 to the third tube P3 connect the second main body side branch section 28 to the heat transfer tube HR5 to the heat transfer tube HR6. The heat transfer tube HR5 is the second heat transfer tube, and the heat transfer tube HR6 is the third heat transfer tube. The heat transfer tubes HR5 to HR6 are positioned above the heat transfer tube HR2 in the direction of gravity.

As shown in FIG. 5, the first pipe P1 is connected to one side S1 of the first body side branch section 27, and the second pipe P2 to the third pipe P3 are connected to the other side S2 of the first body side branch section 27. Similarly, the first pipe P1 is connected to one side S1 of the second body side branch section 28, and the second pipe P2 to the third pipe P3 are connected to the other side S2 of the second body side branch section 28.

The first body side branch section 27 and the second body side branch section 28 each have an insertion section 40. The insertion section 40 is a cylindrical space, and the cylindrical space SP1 extends in the first direction D1. The immediately preceding sections 41 of the first body side branch section 27 and the second body side branch section 28 also extend along the first direction D1. The immediately preceding sections 41 are adjacent to the insertion sections 40 of the first body side branch section 27 and the second body side branch section 28, and are the portions of the first pipe P1 immediately prior to connection to the first body side branch section 27 and the second body side branch section 28.

6A shows a state in which the insertion portion 40 and the immediately preceding portion 41 are inclined by α degrees with respect to the horizontal direction HD. FIG. 6B shows a state in which the insertion portion 40 and the immediately preceding portion 41 are inclined by β degrees with respect to the horizontal direction HD. The first body side branching portion 27 and the second body side branching portion 28 are attached to the outdoor heat exchanger 4 so that the immediately preceding portion 41 extends along the first direction D1 inclined within a range of ±45° with respect to the horizontal direction HD. In other words, the first body side branching portion 27 and the second body side branching portion 28 are attached to the outdoor heat exchanger 4 so that the inclination of the immediately preceding portion 41 satisfies the condition 0≦α≦45 or 0≧β≧-45. In order to prevent a head difference from occurring when the outdoor heat exchanger 4 functions as a condenser, it is preferable to satisfy the condition 0<α≦+45. In other words, it is preferable that the first tube P1 is inclined so as to be lower toward the heat transfer tube 21.

The first tube P1 extends in the first direction D1 to the heat transfer tube HR1 for the first body side branch section 27. Similarly, the first tube P1 extends in the first direction D1 from the heat transfer tube HR2 to the second body side branch section 28 for the second body side branch section 28. The distance di1 from the tube sheet 35 to the first body side branch section 27 and the second body side branch section 28 is 30 mm or less.

The second tube P2 and the third tube P3 are aligned along the horizontal direction HD and attached to the other side S2 of the first body side branch section 27. Therefore, when the refrigerant flows into the first body side branch section 27 and the second body side branch section 28, there is no vertical relationship between the second tube P2 and the third tube P3. As a result, the occurrence of drift caused by the attachment position of the second tube P2 and the third tube P3 is suppressed.

The second heat transfer tube HR3 is located lower in the direction of gravity than the third heat transfer tube HR4 (see FIG. 3). The first body-side branch section 27 is located lower in the direction of gravity than the heat transfer tube HR3 (see FIG. 3). Similarly, the second heat transfer tube HR5 is located lower in the direction of gravity than the third heat transfer tube HR6 (see FIG. 3). The second body-side branch section 28 is located lower in the direction of gravity than the heat transfer tube HR5 (see FIG. 3).

(3) Features (3-1)
In the outdoor heat exchanger 4, when the first main body side dividing section 27 functions as a condenser, the liquid refrigerant flows from the heat transfer tubes HR3 and HR4 to the heat transfer tube HR1. These heat transfer tubes HR3 and HR4 correspond to the second to Nth heat transfer tubes, and the heat transfer tube HR1 corresponds to the first heat transfer tube. The immediately preceding portion 41 of this first tube P1 extends along the first direction D1 that is inclined within a range of ±45° with respect to the horizontal direction HD. In the outdoor heat exchanger 4 configured in this manner, the head difference can be reduced compared to the head difference ΔH of the conventional main body side dividing section 127 in which the insertion portion 140 and the immediately preceding portion 141 shown in FIG. 9 extend along the gravity direction GD.

Conventionally, for example, because an outdoor heat exchanger must be housed in a narrow outdoor unit, the conventional main body side diverter 127 was attached to the outdoor unit so that the direction in which the insertion portion 140 and the immediately preceding portion 141 extend coincides with the direction of gravity GD, as shown in FIG. 9. The head difference ΔH was generated by bending the connecting pipe P102 into an inverted U-shape, or bending the connecting pipe P103 into an inverted U-shape, as shown in FIG. 9. The first main body side diverter 27 and the second main body side diverter 28 of the present disclosure are attached so as to extend along the first direction D1, which is inclined within a range of ±45 degrees, so that it is not necessary to generate such an inverted U-shaped curved portion and therefore it is not necessary to generate a large head difference ΔH. In addition, the connecting pipe P101 of the conventional main body side branch section 127 corresponds to the first pipe P1 connected to the first main body side branch section 27, the connecting pipe P102 corresponds to the second pipe P2, and the connecting pipe P103 corresponds to the third pipe P3.

In addition, in the outdoor heat exchanger 4, when the second body-side branch section 28 functions as a condenser, liquid refrigerant flows from the second heat transfer tube to the heat transfer tubes HR5 and HR6 corresponding to the Nth heat transfer tube toward the heat transfer tube HR2 corresponding to the first heat transfer tube. The immediately preceding portion 41 of this second body-side branch section 28 also extends along the first direction D1 that is inclined within a range of ±45° with respect to the horizontal direction HD. Therefore, the second body-side branch section 28 also has the same effect as the first body-side branch section 27.

(3-2)
The first tube P1 of the first body side branch section 27 extends in the first direction D1 from the heat transfer tube HR1 to the first body side branch section 27. The first tube P1 of the first body side branch section 27 also extends in the first direction D1 from the heat transfer tube HR2 to the second body side branch section 28. Since the first tube P1 extends along the first direction D1 inclined within a range of ±45° with respect to the horizontal direction HD, the range occupied by the first tube P1 in the gravity direction GD can be smaller than when the first tube P1 extends in the gravity direction GD. This configuration makes it easier to arrange the first body side branch section 27 so as to reduce the head difference. Similarly, since the first tube P1 of the second body side branch section 28 extends in the first direction D1 from the heat transfer tube HR1 to the second body side branch section 28, it makes it easier to arrange the second body side branch section 28 so as to reduce the head difference.

(3-3)
In the first main body side branch section 27, the second tube P2 to the third tube P3 corresponding to the second tube to the Nth tube are arranged along the horizontal direction HD on the other side S2 of the first main body side branch section 27. With this configuration, when the outdoor heat exchanger 4 functions as an evaporator, the first main body side branch section 27 is likely to evenly branch the refrigerant from the second tube P2 to the third tube P3. Similarly, in the second main body side branch section 28, the second tube P2 to the third tube P3 are arranged along the horizontal direction HD on the other side S2 of the second main body side branch section 28. Therefore, when the second main body side branch section 28 functions as an evaporator, the second main body side branch section 28 is likely to evenly branch the refrigerant from the second tube P2 to the third tube P3.

(4) Modifications (4-1) Modification A
In the above embodiment, for example, as shown in Fig. 4, when only the first main body-side dividing portion 27 is focused on, the outdoor heat exchanger 4 is shown in the case where N = 3 among the heat exchangers including N first to Nth heat transfer tubes. In other words, Fig. 4 shows heat transfer tubes HR1, HR3, and HR4 formed by dividing a plurality of rows of heat transfer tubes 21 aligned in the gravity direction GD into three groups in a part of the outdoor heat exchanger 4.

However, as shown in FIG. 4, the number N is not limited to 3. For example, FIG. 7 shows an outdoor heat exchanger 4 equipped with heat transfer tubes HR11 to HR15, which are the first to Nth heat transfer tubes, formed by dividing into five groups the heat transfer tubes 21 in multiple rows aligned in the gravity direction GD throughout the entire outdoor heat exchanger 4. The main body side branch section 50 in FIG. 7 branches one refrigerant flow into four, and distributes the four branched refrigerant flows to the four heat transfer tubes HR12 to HR15. In this way, the number N may be an integer of 4 or more.

(4-2) Modification B
In the above embodiment, a case has been described in which one refrigerant flow is divided into two refrigerant flows at the first body-side dividing section 27 and the second body-side dividing section 28, but one refrigerant flow may be divided into four refrigerant flows as in Modification A. When dividing the flow as in Modification A, one refrigerant flow may be divided into two internally, and the two refrigerant flows may be further divided into four, as in the body-side dividing section 50 shown in Fig. 8.

The main body side splitter 50 shown in Figure 8 is an impingement type splitter that splits the refrigerant flow by colliding it with a surface inside the splitter. The main body side splitter 50 in Figure 8 splits one refrigerant flow FL1 flowing in from the first tube P1 into four refrigerant flows FL21 to FL24. In the main body side splitter 50, the refrigerant flow FL1 that flows from the first tube P1 into the opening 51a of the inlet plate 51 collides with the surface 53 of the intermediate plate 52 and is split in two. Furthermore, the refrigerant flows FL11 and FL12 that are split in two by the intermediate plate 52 and pass through the two openings 52a and 52b collide with the surfaces 55 and 56 of the main body 54 and are split in two, respectively. The two refrigerant flows FL21 and FL22, which are formed by dividing the refrigerant flow FL11 in two on the surface 55 of the main body 54, are divided into two openings 54a and 54b and two openings 54c and 54d. The refrigerant flows FL21, FL22, FL23, and FL24 that pass through the four openings 54a, 54b, 54c, and 54d are distributed to the second tube P2 to the fifth tube P5. The inlet plate 51 has an insertion section 40 into which the first tube P1 is inserted at the opening 51a. The portion of the first tube P1 adjacent to the insertion section 40 of the main body side branch section 50 is the immediately preceding section 41.

(4-3) Modification C
In the above embodiment, focusing only on the first main body side dividing section 27, three heat transfer tubes HR1, HR3, and HR4 are shown, which are included in the plurality of heat transfer tubes 21 aligned in the gravity direction GD of the outdoor heat exchanger 4. In terms of the flow path, one heat transfer tube HR1 (subcool heat exchange section SC) is divided into two heat transfer tubes HR3 and HR4 by one first main body side dividing section 27.

In the above embodiment, looking at the first body-side branch section 27 and the second body-side branch section 28, six heat transfer tubes HR1, HR2, HR3, HR4, HR5, and HR6 are shown, which are included in the multiple heat transfer tubes 21 aligned in the gravity direction GD of the outdoor heat exchanger 4. Looking at the flow path, two heat transfer tubes HR1 and HR2 (subcool heat exchange section SC) are branched into four heat transfer tubes HR3, HR4, HR5, and HR6 by the two first body-side branch sections 27 and the second body-side branch section 28.

In the above modification A, five heat transfer tubes HR11 to HR15 are shown, which are included in the multiple heat transfer tubes 21 aligned in the gravity direction GD of the outdoor heat exchanger 4. In terms of the flow path, one heat transfer tube HR11 (subcool heat exchange section SC) is diverted into four heat transfer tubes HR12, HR13, HR14, and HR15 by one main body side diverting section 50.

In addition to the above configuration, for example, for the first to ninth heat transfer tubes arranged in the gravity direction GD for the entire heat exchanger, a configuration can be used in which one first heat transfer tube (subcool heat exchange section) is diverted to eight second to ninth heat transfer tubes at one main body side diverting section.

Alternatively, for the first to tenth heat transfer tubes aligned in the gravity direction GD for the entire heat exchanger, the first and second heat transfer tubes (subcool heat exchange section) can be diverted to eight third to tenth heat transfer tubes at two main body side diverting sections.

Alternatively, for the 12 first to 12th heat transfer tubes included in the multiple heat transfer tubes 21 arranged in the gravity direction GD of the heat exchanger, a configuration can be used in which the first to fourth heat transfer tubes (subcool heat exchange section) are diverted two at a time to the eight fifth to 12th heat transfer tubes at four main body side diverting sections.

(4-4) Modification D
In the above embodiment, the insertion portion 40 of both the first body side branch portion 27 and the second body side branch portion 28 is configured to extend along the first direction D1 inclined within a range of ±45° with respect to the horizontal direction HD. However, the insertion portion 40 of the first body side branch portion 27 may be configured to extend along the first direction D1 inclined within a range of ±45° with respect to the horizontal direction HD. The second body side branch portion 28 configured in this manner is, for example, arranged so that the insertion portion extends along the gravity direction GD. However, even with the second body side branch portion 28 configured in this manner, it is configured so that an inverted U-shaped curved portion is not formed in the first tube, the second tube, and the third tube as in the conventional case.

(4-5) Modification E
In the above embodiment, the first tube P1 to the third tube P3 and the first tube P1 to the fifth tube P5 are each a single tube without a joint. However, the first tube P1 to the third tube P3 and the first tube P1 to the fifth tube P5 may be formed by brazing a plurality of tubes.

(4-6) Modification F
The first body-side branch section 27 and the second body-side branch section 28 of the above embodiment and the body-side branch section 50 of the modification B have an insertion section 40 for inserting the first pipe P1. However, the body-side branch section applied to the technology of the present disclosure may not have an insertion section. For example, a branch-pipe type body-side branch section 60 shown in Figs. 10A and 10B may have no insertion section and may be applied to the technology of the present disclosure. The first pipe P1 connected to the branch-pipe type body-side branch section 60 extends along the first direction D1 in the range of ±45° with respect to the horizontal direction HD, even in the immediately preceding section 41 of the body-side branch section 60.

(4-7) Modification G
In the first body-side branch section 27 and the second body-side branch section 28 of the above embodiment, the body-side branch section 50 of the modification B, and the body-side branch section 60 of the modification F, the direction of the refrigerant flow is not changed within the branch section, and the refrigerant flows along the first direction D1 within the branch section. However, the body-side branch section applied to the technology of the present disclosure may change the direction of the refrigerant flow within the branch section. For example, the body-side branch section applied to the technology of the present disclosure may not have an insertion section. For example, as in the body-side branch section 70 shown in Figures 11A and 11B, the first tube P1 connected to the body-side branch section 70 extends along the first direction D1 in the range of ±45° with respect to the horizontal direction HD at the immediately preceding portion 41 of the body-side branch section 70. Furthermore, the internal flow path 71 adjacent to the first tube P1 of the immediately preceding portion 41 also extends along the first direction D1. However, the internal flow path 71 of the body-side branch section 70 is curved internally so as to flow out along the gravity direction GD. Therefore, the first pipe P1 is connected to the side surface SS of the main body side branch portion 70, and the second pipe P2 and the third pipe P3 are connected to the upper surface US of the main body side branch portion 70.

The body-side branch section 70 having such a configuration can reduce the bending of the pipes between the first pipe P1 and the second pipe P2 to the third pipe P3, making it easier to piping the first pipe P1 and the second pipe P2 to the third pipe P3. As can be seen from FIG. 11A, the flow path changes direction by 90 degrees inside the body-side branch section 70. Therefore, the angle of the flow path change in the first pipe P1 and the second pipe P2 to the third pipe P3 can be reduced by this 90 degrees, and the bending of the flow path can be reduced compared to when the first body-side branch section 27, the second body-side branch section 28, the body-side branch section 50, and the body-side branch section 60 are used.

Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the present disclosure as set forth in the claims.

4 Outdoor heat exchanger 21 Heat transfer tubes 27 First main body side branch section 28 Second main body side branch section 35 Tube plates 50, 60, 70 Main body side branch sections HR1 to HR6, HR11 to HR15 Heat transfer tubes P1 First pipe P2 Second pipe P3 Third pipe P4 Fourth pipe P5 Fifth pipe S1 One side S2 Other side

International Publication No. 2019/150851

Claims (9)

A first heat transfer tube (HR1, HR11);
second to Nth heat transfer tubes (HR4, HR6, HR15) disposed above the first heat transfer tube in a gravitational direction;
A main body side branch portion (27, 28, 50, 60, 70);
A first tube (P1) that connects the main body side branch portion and the first heat transfer tube;
a second tube (P2) to an Nth tube (P3, P5) connecting the main body side branch portion and the second to Nth heat transfer tubes;
Equipped with
The first pipe is connected to one side (S1) of the main body side branch portion, and the second pipe to the N pipe are connected to the other side (S2) of the main body side branch portion,
The first tube extends along a first direction having an inclination of ±45° with respect to a horizontal direction immediately before the main body side branch portion. The second pipe to the Nth pipe are arranged along a horizontal direction on the other side of the main body side branch portion.
A heat exchanger (4) according to claim 1. The first heat transfer tube is disposed in a lowermost flow path in a gravity direction.
A heat exchanger (4) according to claim 1 or claim 2. (N-1) is a multiple of 2,
A heat exchanger (4) according to any one of claims 1 to 3. The number of the first tubes is one and the (N-1) is 2, 4, or 8, or the number of the first tubes is two and the (N-2) is 4 or 8, or the number of the first tubes is four and the (N-4) is 8;
A heat exchanger (4) according to any one of the preceding claims. a tube plate (35) for fixing the first to Nth heat transfer tubes;
The distance from the tube sheet to the main body side branch portion is 30 mm or less.
A heat exchanger (4) according to any one of the preceding claims. When functioning as a condenser, the first heat transfer tube is arranged on an outlet side, and the second to Nth heat transfer tubes are arranged on an inlet side.
A heat exchanger (4) according to any one of the preceding claims. the second heat transfer tube is located lower in a gravitational direction than the third to Nth heat transfer tubes,
The main body side branch portion is located lower than the second heat transfer tube in a gravitational direction.
A heat exchanger (4) according to any one of the preceding claims. The main body side branch portion has the first tube connected to a side surface and the second to Nth heat transfer tubes connected to an upper surface.
A heat exchanger (4) according to any one of the preceding claims.

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