JP2022153026A - Heat exchanger and outdoor unit with the same - Google Patents

Abstract

To provide a heat exchanger which can suppress deterioration of heat exchange amount due to ununiformity of wind speed distribution.SOLUTION: A heat exchanger includes: an inlet header 20; an outlet header 21; a plurality of chambers 31 which are partitioned by partition plates 30 in the inlet header 20; a plurality of flat tubes 22 which are arranged in parallel with each chamber 31 and the outlet header 21 and are connected to each chamber and the outlet header; a distributor 25 which is provided in a refrigerant pipe 10; and a plurality of branch pipes 24 which are connected to each chamber 31 and the distributor 25. The branch pipes 24 have branch sections 27 between the chambers 31 and the distributor 25 according to wind speed distribution in the heat exchanger. The number of branch sections 27 of the branch pipes 24 connected to the chamber 31 to which the flat tube 22 positioned in a portion having large wind speed is connected is smaller than that of the branch sections 27 of the branch pipes 24 connected to the chamber 31 to which the flat tube 22 passing a portion having small wind speed is connected.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a heat exchanger used, for example, in a top-blown outdoor unit in an air conditioner, and to an outdoor unit provided with this heat exchanger.

A top-blown outdoor unit in an air conditioner has a blower fan at the top and a vertically long heat exchanger below the blower fan. It exchanges heat with the refrigerant that flows through the heat exchanger. In this case, since the blower fan is installed at the top, the speed of the air passing through the heat exchanger due to the suction of outside air by the blower fan is faster on the upper side closer to the blower fan and slower on the lower side farther from the fan, resulting in heat. The wind speed distribution of the wind passing through the exchanger becomes uneven. As a result, the capacity of the heat exchanger cannot be effectively used, and there is a problem that the amount of heat exchanged is lowered and the air blowing performance is lowered.

In order to solve this problem, in Patent Document 1, a heat exchanger that flows a refrigerant through a plurality of heat transfer tubes arranged in parallel, is connected to one end of the plurality of heat transfer tubes, and the inside is partitioned by a partition plate. The header has a vertically installed header, a distributor for distributing and inflowing the refrigerant to each room in the header partitioned by partition plates, and a capillary tube connected to each room from the distributor. An invention is disclosed in which a refrigerant distributor is provided and the length and inner diameter of a capillary tube are set according to the wind speed distribution in a heat exchanger.

In the heat exchanger and refrigerant distributor disclosed in Patent Document 1, the length and inner diameter of the capillary tube are set according to the wind speed distribution in the heat exchanger. This is effective in that it is possible to suppress a decrease in the amount of heat exchange due to non-uniform wind speed distribution.

WO2013/160952

However, in the heat exchanger and refrigerant distributor disclosed in Patent Document 1, the length and inner diameter of the capillary tube are set according to the wind speed distribution in the heat exchanger, but the flow resistance is increased by the capillary tube to increase the flow rate. Since it is adjusted, there is a problem that the pressure loss increases and the air conditioning capacity decreases.

In addition, the length and inner diameter of the capillary tube are set according to the air velocity distribution in the heat exchanger. A plurality of types of capillary tubes with different sheath inner diameters must be prepared, which causes a problem of increased cost.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a heat exchanger capable of suppressing a decrease in the amount of heat exchanged due to non-uniform wind speed distribution.

A first aspect of the present invention includes an inlet header that is positioned on the refrigerant inlet side, an outlet header that is positioned on the refrigerant outlet side, and a partition plate inside either the inlet header or the outlet header. and connected in parallel between each of the plurality of rooms provided in either one of the inlet header and the outlet header and the other of the inlet header and the outlet header. In a heat exchanger comprising a plurality of flat tubes, a distributor provided in the refrigerant piping, and a plurality of branch pipes connected to each room and the distributor, depending on the wind speed distribution in the heat exchanger, A branch pipe is provided between the room and the distributor, and the number of branches of the branch pipe connected to the room where the flat pipe located in the part where the wind speed is high is connected is the flat pipe that passes through the part where the wind speed is low. There are fewer heat exchangers than said branches of the branch pipe connecting to the room to which the pipe is connected.

A second aspect of the present invention is a top-blown outdoor unit of an air conditioner having a blower fan at the top and a heat exchanger according to the first aspect of the present invention below the blower fan. .

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a heat exchanger capable of suppressing a decrease in the amount of heat exchanged due to non-uniform wind speed distribution.

1 is a refrigerant circuit diagram of an air conditioner according to an embodiment of the present invention; FIG. 1 is a longitudinal sectional view of an outdoor unit of an air conditioner according to an embodiment of the present invention; FIG. 1 is a schematic diagram of a heat exchanger of an air conditioner according to an embodiment of the present invention; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. As an embodiment, an air conditioner in which an indoor unit is connected to an outdoor unit and the indoor unit can perform cooling operation or heating operation will be described as an example. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.

An air conditioner 1 will be described with reference to FIG. FIG. 1 shows a refrigerant circuit diagram of an air conditioner 1 according to an embodiment of the present invention. An air conditioner 1 is capable of cooling operation and heating operation, and includes an outdoor unit 2 arranged outdoors and an indoor unit 3 arranged indoors. The outdoor unit 2 includes a compressor 4, a four-way valve 5, an outdoor heat exchanger 9, and an outdoor unit side expansion valve 7 connected by refrigerant piping 10. The indoor unit 3 is connected by the refrigerant piping 10 to the indoor unit side. An expansion valve 6 and an indoor heat exchanger 8 are provided. 11. The outdoor heat exchanger 9 is the heat exchanger in the present invention. In addition, the outdoor unit 2 includes a blower fan 16 for sending outside air to the outdoor heat exchanger 12, and the indoor unit 3 includes an indoor fan (not shown) for sending indoor air to the indoor heat exchanger 8. . The four-way valve 5 is connected to the discharge side of the compressor 4 and is a switching valve that changes the direction of flow of the refrigerant circulating in the refrigerant circuit 11 between cooling operation and heating operation. During cooling operation, the refrigerant discharged from the compressor 4 passes through the four-way valve 5 to the outdoor heat exchanger 9, the outdoor unit side expansion valve 7, the indoor unit side expansion valve 6, the indoor heat exchanger 8, the four-way valve 5, the compression During heating operation, the refrigerant discharged from the compressor 4 passes through the four-way valve 5 to the indoor heat exchanger 8, the indoor unit expansion valve 6, the outdoor unit expansion valve 7, and the outdoor heat exchanger. It flows to the exchanger 9 , the four-way valve 5 and the suction side of the compressor 4 . In FIG. 1, the arrows indicated by solid lines indicate the flow of refrigerant during heating operation, and the arrows indicated by broken lines indicate the flow of refrigerant during cooling operation.

The flow of refrigerant in the refrigerant circuit 11 during heating operation will be described. During heating operation, the high-temperature, high-pressure refrigerant compressed by the compressor 4 flows through the indoor heat exchanger 8 via the four-way valve 5 . The high-temperature, high-pressure refrigerant flowing through the indoor heat exchanger 8 exchanges heat with the indoor air blown by the indoor fan to radiate heat, and the indoor air that has exchanged heat with the high-temperature, high-pressure refrigerant is warmed. After passing through the indoor heat exchanger 8 and radiating heat, the refrigerant passes through the indoor unit side expansion valve 6 and is then decompressed by the outdoor unit side expansion valve 7 to become a two-phase refrigerant in which gas refrigerant and liquid refrigerant are mixed. The refrigerant in the state of two-phase refrigerant flows through the outdoor heat exchanger 9 and absorbs heat through heat exchange with the outside air blown by the blower fan 16 when passing through the outdoor heat exchanger 9 to become a gas refrigerant. The refrigerant that absorbs heat and becomes a gaseous refrigerant returns to the compressor 4 via the four-way valve 5 and is again compressed to a high temperature and high pressure.

Next, the flow of refrigerant in the refrigerant circuit 11 during cooling operation will be described. Switching from the heating operation to the cooling operation is performed by changing the direction of the flow of the refrigerant circulating in the refrigerant circuit 11 using the four-way valve 5 . During cooling operation, the high-temperature, high-pressure refrigerant compressed by the compressor 4 flows through the outdoor heat exchanger 9 via the four-way valve 5 . The high-temperature, high-pressure refrigerant flowing through the outdoor heat exchanger 9 exchanges heat with the outside air blown by the blower fan 16 to radiate heat, and the refrigerant that has exchanged heat with the outside air becomes a high-temperature, high-pressure liquid refrigerant. After the high-temperature and high-pressure liquid refrigerant passes through the outdoor unit side expansion valve 7, it is decompressed by the indoor unit side expansion valve 6, and becomes a two-phase refrigerant state in which gas refrigerant and liquid refrigerant are mixed. The two-phase refrigerant flows through the indoor heat exchanger 8 and absorbs heat through heat exchange with the indoor air blown by the indoor fan when passing through the indoor heat exchanger 8 to become a gaseous refrigerant. The refrigerant that absorbs heat and becomes a gaseous refrigerant returns to the compressor 4 via the four-way valve 5 and is again compressed to a high temperature and high pressure.

Next, the outdoor unit 2 will be described with reference to FIG. FIG. 2 is a vertical cross-sectional view of the outdoor unit 2, the upper side shows the upward direction when the outdoor unit 2 is installed, and the lower side shows the downward direction. The outdoor unit 2 is a so-called top-blown type outdoor unit, and has a housing 15 with an opening as a ventilation port 18 at the top and an opening as an intake port 17 at the side. A blower fan 16 is provided inside the housing in the vicinity of a ventilation port 18 , and an elongated outdoor heat exchanger 9 is arranged below the blower fan 16 so as to face the suction port 17 . By driving the blower fan 16, outside air is sucked from the suction port 17, and the sucked outside air passes through the outdoor heat exchanger 9 and exchanges heat with the refrigerant passing through the outdoor heat exchanger 9. The outside air that has passed through is blown out of the outdoor unit 2 through the ventilation port 18 . The arrows in FIG. 2 indicate the magnitude of the wind speed, and the longer the arrow, the higher (faster) the wind speed than the shorter the arrow. Since the outdoor unit 2, which is a top-blown type, is provided with the blower fan 16 at the top, the wind speed of the air passing through the outdoor heat exchanger 9 by the suction of the outside air by the blower fan 16 is indicated by the arrow in FIG. , the upper portion closer to the blower fan 16 is larger (faster) and the lower portion farther from the fan 16 is smaller (slower), so that the wind speed distribution of the wind passing through the outdoor heat exchanger 9 is uneven.

Next, the outdoor heat exchanger 9 will be described with reference to FIG. In FIG. 3, the upper side indicates the upward direction when the outdoor heat exchanger 9 is installed, and the lower side indicates the downward direction. The outdoor heat exchanger 9 includes an inlet header 20, an outlet header 21, a plurality of flat tubes 22, a plurality of heat transfer fins 23, a plurality of branch tubes 24a to 24c having the same diameter, and a distributor 25. I have it. The inlet header 20 and outlet header 21 are based on the flow of refrigerant in the refrigerant circuit 11 during heating operation. During heating operation, refrigerant flows into the inlet header 20 and flows out from the outlet header 21, During cooling operation, refrigerant flows into the outlet header 21 and flows out from the inlet header 20 . In this embodiment, the number of flat tubes 22 is 14 for convenience.

Each of the plurality of flat tubes 22 is formed in a linear belt shape. The plurality of flat tubes 22 are arranged between the inlet header 20 and the outlet header 21 and are stacked vertically with a predetermined spacing therebetween. One end of the plurality of flat tubes 22 is connected to the inlet header 20 and the other end of the plurality of flat tubes 22 is connected to the outlet header 21 . A plurality of through holes (not shown) are formed in the flat tube 22 from one end to the other end, and the coolant flows through the through holes. In FIG. 3, the higher the flat tubes 22 are located, the higher the wind speed received, and the lower the flat tubes 22, the lower the wind speed received. Therefore, the amount of heat exchange between the refrigerant flowing through the flat tubes 22 and the outside air is greater in the upper flat tubes 22 and smaller in the lower areas.

The plurality of heat transfer fins 23 are plate-like fins stacked with a space between the inlet header 20 and the outlet header 21 and air passes therebetween. passes through and is thermally connected.

The inlet header 20 and the outlet header 21 are cylindrically formed, the outlet header 21 is connected to the refrigerant pipe 10, and the inlet header 20 is connected to a plurality of branch pipes 24a to 24c. The interior of the inlet header 20 is partitioned by a partition plate 30 to form a plurality of chambers 31a to 31g. The partition plate 30 is arranged so that the heights of the rooms 31a to 31g are the same, and the sizes of the rooms 31a to 31g are the same. In this embodiment, the interior of the inlet header 20 is partitioned by six partition plates 30 to form seven upper and lower chambers 31a to 31g. Two flat tubes 22 connected to the inlet header 20 are connected to each of the rooms 31a to 31g.

The distributor 25 is connected to the refrigerant pipe 10 extending from the outdoor unit side expansion valve 7 and also connected to three branch pipes 24 a to 24 c extending from the inlet header 20 . The branch pipe 24a, which is one of the three branch pipes 24a to 24c connected to the distributor 25, is connected to the highest room 31a in the height direction of the outdoor heat exchanger 9. ing. A branch pipe 24b, which is one of the three branch pipes 24a to 24c, is divided into two branch pipes 24b by a branching portion 27, and one of the two branch pipes 24b is located in the second-highest room 31b. and the other is connected to room 31c at the third level. Therefore, one branch pipe 24b connected to the distributor 25 is divided into two by one branch portion 27 and connected to the two chambers 31b and 31c, respectively. A branch pipe 24c, which is one of the three branch pipes 24a to 24c, is divided into two branch pipes 24c by a branch portion 27, and one of the two branch pipes 24c is further divided into two by the branch portion 27. One of the two branch pipes 24c is connected to the fourth level room 31d and the other is connected to the fifth level room 31e. Similarly, the other of the two branch pipes 24c is further divided into two branch pipes 24c by a branching portion 27, one of the two branch pipes 24c is connected to the sixth room 31f, The other is connected to room 31g at the seventh level. Therefore, one branch pipe 24c connected to the distributor 25 is first divided into two by the first branch portion 27, and further divided into two by the second branch portion 27 to divide the rooms 31d to 31g. connected to each other.

The amount of refrigerant flowing into each of the rooms 31a to 31g of the outdoor heat exchanger 9 is determined by three branch pipes having the same diameter, assuming that the amount of refrigerant flowing into the distributor 25 from the outdoor unit side expansion valve 7 during heating operation is 1. 24a to 24c are connected to the distributor 25, and since the branch pipe 24a does not have a branch portion 27, 1/3 of the refrigerant flows into the chamber 31a located at the highest height. Since there is one branch 27 in the middle of the branch pipe 24b, ⅙ of the refrigerant flows into the chambers 31b and 31c located at the second and third heights. Similarly, since there are two branch portions 27 in the middle of the branch pipe 24c, 1/12 of the refrigerant flows into the chambers 31d to 31g. Therefore, a large amount of refrigerant flows into the room 31a connected to the flat tubes 22 located in the high wind velocity range, and flows into the rooms 31b and 31c connected to the flat tubes 22 located in the medium wind velocity range. The distribution amount of the refrigerant is moderate, and since the distribution amount of the refrigerant flowing into the rooms 31d to 31g to which the flat tubes 22 located in the range of low wind speed are connected is set to be small, the flow rate of the refrigerant can be adjusted according to the air flow rate. Therefore, the ability of the heat exchanger to make the state of the refrigerant uniform on the outlet side of the flat tube can be sufficiently exhibited. That is, the amount of refrigerant flowing to the upper portion where a large amount of heat exchange can be expected is increased, and the amount of refrigerant flowing to the lower portion where the amount of heat exchange is small is reduced, so that the heat exchanger as a whole can function without waste.

In the embodiment of the present invention, the three branch pipes 24a to 24c connected between the chambers 31a to 31g arranged in the vertical direction of the inlet header 20 and the 25 distributor are provided with the wind speed distribution in the outdoor heat exchanger 9. A branch portion 27 is provided in accordance with. That is, in the branch pipe 24a that connects the room 31a located in the range where the wind speed is high and the distributor 25, the branch portion 27 is not provided between the distributor 25 and the room 31a. In the branch pipe 24b connecting the rooms 31b to 31e located in the medium wind speed range and the distributor 25, one branch portion 27 is provided between the distributor 25 and the rooms 31b to 31e. In the branch pipe 24c that connects the rooms 31d to 31g located in the low wind speed range and the distributor 25, two branch portions 27 are provided between the distributor 25 and the rooms 31b to 31e. As a result, the amount of refrigerant flowing into the rooms 31 decreases as the number of branching portions 27 from the distributor 25 to each room 31 increases.

In the embodiment of the present invention, the three branch pipes 24a to 24c connected between the chambers 31a to 31g arranged in the vertical direction of the inlet header 20 and the distributor 25 are provided with the wind speed distribution in the outdoor heat exchanger 9. Since the branching portion 27 is provided according to , the substantial amount of heat exchange is substantially the same in the vertical direction of the outdoor heat exchanger 9, and the refrigerant condition of the outlet header 21 can be uniformed. Compared to the case where the flow rate is adjusted by increasing the flow resistance using a conventional capillary tube, the refrigerant state in the outlet header 21 can be uniformed without increasing the pressure loss of the refrigerant passing through the heat exchanger. A decrease in the cooling/heating capacity of the air conditioner due to an increase in pressure loss can be suppressed. In addition to this effect, the embodiment of the present invention has the following effect.

The interior of the inlet header 20 is partitioned by a partition plate 30. The partition plate 30 is arranged so that the heights of the rooms 31a to 31g are the same. ) are the same. Therefore, it is not necessary to adjust the height of each of the chambers 31a to 31g according to the wind velocity distribution in the outdoor heat exchanger 9 and the specifications of the outdoor heat exchanger, so the manufacturing cost can be reduced.

The three branch pipes 24a to 24c connected between the chambers 31a to 31g arranged in the vertical direction of the inlet header 20 and the distributor 25 are branch pipes having the same diameter. Therefore, since it is not necessary to adjust the diameter of each branch pipe 24a to 24c according to the wind velocity distribution in the outdoor heat exchanger 9 and the specifications of the outdoor heat exchanger, the manufacturing cost can be suppressed. In addition, by simply setting the number of branches 27 from the distributor 25 to each room 31 according to the wind speed distribution in the outdoor heat exchanger 9 and the specifications of the outdoor heat exchanger, the air can flow into each room 31a to 31g. Since the amount of refrigerant to be used can be adjusted, the manufacturing cost can be suppressed.

In this embodiment, the flow of the refrigerant in the refrigerant circuit 11 during heating operation is used as a reference, and when the refrigerant flows into the inlet header 20 and flows out from the outlet header 21 during heating operation, the inflow side The inside of the inlet header 20 on the inflow side is partitioned by a partition plate 30 to form chambers 31a to 31g of the same height, and three chambers 31a to 31g are provided between the chambers 31a to 31g and the distributor 25. Although the three branch pipes 24a to 24c are connected and the branching portion 27 is provided in the three branch pipes 24a to 24c according to the wind speed distribution in the outdoor heat exchanger 9, the reverse is also possible. That is, based on the flow of the refrigerant in the refrigerant circuit 11 during heating operation, when the refrigerant flows into the inlet header 20 and flows out from the outlet header 21 during the heating operation, the refrigerant flows into the inlet header 20 on the inflow side. The refrigerant flows in via the outdoor unit side expansion valve 7, the distributor 25 is arranged on the outflow side, and the inside of the outlet header 21 on the outflow side is partitioned by the partition plate 30 to create chambers 31a to 31g of the same height. are formed, and three branch pipes 24a to 24c are connected between each room 31a to 31g and the distributor 25, and the three branch pipes 24a to 24c are branched according to the wind speed distribution in the outdoor heat exchanger 9. A portion 27 may be provided. Even in this case, the same effect can be obtained. Further, although the air conditioner 1 of the present embodiment is an air conditioner capable of cooling operation and heating operation, it may be an air conditioner capable of either cooling operation or heating operation.

Although the foregoing has been described with reference to a limited number of embodiments, the scope of rights is not limited thereto, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art.

DESCRIPTION OF SYMBOLS 1... Air conditioner, 2... Outdoor unit, 3... Indoor unit, 4... Compressor, 5... Four-way valve, 6... Indoor unit side expansion valve, 7... Outdoor unit side expansion valve, 8... Indoor heat exchanger, 9 Outdoor heat exchanger 10 Refrigerant pipe 11 Refrigerant circuit 15 Housing 16 Blower fan 17 Suction port 18 Ventilation port 20 Inlet header 21 Outlet header 22 Flat tube , 23 Heat transfer fins 24a to 24c Branch pipe 25 Distributor 27 Branch portion 30 Partition plate 31a to 31g Room

Claims (4)

an inlet header, which is a header located on the coolant inlet side;
an outlet header, which is a header located on the refrigerant outlet side;
a plurality of rooms partitioned by partition plates are provided inside one of the inlet header and the outlet header;
A plurality of flat tubes connected in parallel between each of the plurality of chambers provided in either one of the inlet header and the outlet header and the other of the inlet header and the outlet header. When,
a distributor provided in the refrigerant pipe;
A heat exchanger comprising a plurality of branch pipes connected to each of the chambers and the distributor,
The branch pipe is provided with a branch portion between the room and the distributor according to the wind speed distribution in the heat exchanger,
The number of branch portions of the branch pipe connected to the room to which the flat pipe located in the portion where the wind speed is high is
A heat exchanger, wherein the number of branches of the branch pipes connected to the room to which the flat pipes passing through a portion where the wind velocity is low is connected is smaller than the number of the branch portions. 2. The heat exchanger according to claim 1, wherein each chamber has the same length in the direction in which the flat tubes connected in parallel are arranged. 3. A heat exchanger according to claim 1 or 2, wherein one said header is said inlet header and the other said header is said outlet header. A blower fan is provided in the upper part, and the heat exchanger according to any one of claims 1 to 3 is provided below the blower fan, and the heat exchanger is arranged such that the plurality of flat tubes are arranged in a vertical direction. A top-blown outdoor unit for an air conditioner, wherein the inlet header and the outlet header are vertically installed.

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