JP7132138B2 - Heat exchanger and refrigeration cycle equipment - Google Patents

Description

An embodiment of the present invention relates to a heat exchanger and a refrigerating cycle device.

Conventionally, a heat exchanger used in a refrigeration cycle device such as an air conditioner includes a plurality of heat transfer tubes arranged in parallel in the vertical direction, and a pair of headers extending in the vertical direction and connected to both ends of the heat transfer tubes. Heat exchangers are known. When the heat exchanger functions as an evaporator, gas-liquid two-phase refrigerant that has flowed into one header from the outside of the heat exchanger flows through each heat transfer tube to the other header.

JP 2015-127618 A

However, due to the difference in density between the gaseous refrigerant and the liquid refrigerant, a drift of the refrigerant occurs between the upper heat transfer tube and the lower heat transfer tube, resulting in a decrease in heat exchange performance. Therefore, in one of the headers into which the refrigerant flows, a partition plate is provided to divide the space into two spaces, one on the side where the heat transfer tubes are connected and the other on the side opposite to the side where the heat transfer tubes are connected, thereby forming a refrigerant flow path. A structure is known in which the coolant reaches above the header by narrowing it. However, even with such a structure, it is difficult to evenly guide the refrigerant that has reached the top to the heat transfer tubes.

The problem to be solved by the present invention is to provide a heat exchanger with improved heat exchange performance by suppressing drift of the refrigerant in each heat transfer tube of the heat exchanger.

In order to achieve the above object, the heat exchanger of the embodiment is composed of a plurality of heat transfer tubes arranged in parallel in the vertical direction, and a first header and a second header to which both ends of the heat transfer tubes are connected. ing. Connection pipes through which the refrigerant flows in and out are provided at positions facing the end portions of the heat transfer pipes in the lower portion of the first header. The interior of the first header is partitioned into a first space on the side of the connecting pipes and a second space on the side of the heat transfer tubes, and a communicating portion that communicates the first space and the second space is formed in the upper part. Equipped with a partition plate. The partition plate protrudes toward the second space toward the heat transfer tubes, and includes projections that guide the refrigerant to the heat transfer tubes.

1 is a configuration diagram of a refrigeration cycle according to a first embodiment; FIG. It is a front view of the heat exchanger by the same embodiment. It is an end cap perspective view by the same embodiment. It is a schematic sectional drawing of the 1st header by the same embodiment. 5 is an enlarged view of a main portion of FIG. 4; FIG. It is a graph showing the refrigerant|coolant flow rate with respect to the height of the heat exchanger tube of the same embodiment and the conventional heat exchanger. FIG. 5 is a schematic cross-sectional view of a first header according to a second embodiment;

Embodiments for carrying out the invention will be described below.
(First embodiment)
A heat exchanger and a refrigeration cycle apparatus according to a first embodiment will be described with reference to FIGS. 1 to 6. FIG. FIG. 1 shows the configuration of the refrigeration cycle of an air conditioner 1, which is the refrigeration cycle device of the first embodiment.

The air conditioner 1 includes a compressor 2 , a four-way valve 5 , an outdoor heat exchanger 6 , an expansion device 7 and an indoor heat exchanger 8 . These are sequentially connected by refrigerant pipes 9 to form a refrigeration cycle.
The compressor 2 has a compressor body 3 and an accumulator 4 . The accumulator 4 separates gaseous refrigerant and liquid refrigerant and supplies the gaseous refrigerant to the compressor body 3 . The compressor main body 3 converts the refrigerant supplied from the accumulator 4 into a high-temperature, high-pressure vapor-phase refrigerant.

The four-way valve 5 changes the flow of refrigerant discharged from the compressor 2 to switch between cooling operation and heating operation. During cooling operation, the refrigerant discharged from the compressor 2 flows through the four-way valve 5 through the outdoor heat exchanger 6, the expansion device 7, and the indoor heat exchanger 8 in this order, as indicated by the solid line arrows in FIG. At this time, the outdoor heat exchanger 6 functions as a radiator (condenser), and the indoor heat exchanger 8 functions as a heat absorber (evaporator). During heating operation, the refrigerant flows through the compressor 2, the four-way valve 5, the indoor heat exchanger 8, the expansion device 7, and the outdoor heat exchanger 6 in this order, as indicated by the dashed arrows in FIG. The outdoor heat exchanger 6 functions as a heat absorber (evaporator), and the indoor heat exchanger 8 functions as a radiator (condenser).

Next, the outdoor heat exchanger 6 will be explained. FIG. 2 is a front view of a parallel flow heat exchanger (hereinafter referred to as a heat exchanger), which is the outdoor heat exchanger 6 of this embodiment. In the following description, the height direction of the heat exchanger 6 is defined as the Z direction, and two directions orthogonal to the Z direction are defined as the X direction and the Y direction. Of the X direction, Y direction and Z direction, the arrow direction in the drawing is the plus (+) direction, and the direction opposite to the arrow is the minus (-) direction. The +Z direction is upward in the direction of gravity, and the -Z direction is downward in the direction of gravity.

The heat exchanger 6 includes a plurality of heat transfer tubes 11 and a first header 21 and a second header 22 connected to both ends of the heat transfer tubes 11 . The heat transfer tubes 11 extend in the X direction and are arranged parallel to each other in the Z direction. For the heat transfer tube 11, for example, a flat tube having a plurality of refrigerant flow paths inside is used. The first header 21 and the second header 22 extend in the Z direction, and a plurality of heat transfer tube insertion holes 23 and 24 into which the heat transfer tubes 11 are inserted are formed side by side in the Z direction. The +X direction end 12 of the heat transfer tube 11 is inserted into the heat transfer tube insertion hole 23 of the first header 21, and the −X direction end 13 of the heat transfer tube 11 is inserted into the heat transfer tube insertion hole 24 of the second header 22. , are in communication with each other.

A plurality of fins 14 are arranged between adjacent heat transfer tubes 11 . Plate fins, for example, are used for the fins 14 . A plurality of fins 14 are arranged in the X direction between the first header 21 and the second header 22 . The fins 14 are connected to the heat transfer tubes 11 by means such as brazing. The fins 14 are not limited to plate fins and may be corrugated fins or the like.

End caps 31 and 32 are fitted to the upper and lower ends of the first header 21 and the second header 22 to close them. FIG. 3 shows an end cap 31 in which a linear partition plate positioning groove 33 is formed facing the inner space of the first header 21 .
In the first header 21 and the second header 22, heat exchangers extending in the X direction are provided on the side opposite to the heat transfer tube insertion holes 23, 24 and facing the ends 12, 13 of the heat transfer tubes 11. Connection pipes 34 and 35 connected to the refrigerant pipe 9 outside 6 are provided. The first header 21 is provided with a connection pipe 34 at its lower portion, and the second header 22 is provided with a connection pipe 35 at its upper portion. Holes 36 are formed at arbitrary positions in the connection pipes 34 and 35 for flowing the refrigerant into and out of the heat exchanger 6 . FIG. 4 is a schematic cross-sectional view of the first header 21. As shown in FIG. As shown in FIG. 4, in this embodiment, the hole 36 of the connection pipe 34 opens in the +Z direction inside the first header 21 . Further, in addition to the hole 36, a hole opening in the X direction may be provided at the tip of the connection pipe 34. FIG.

A partition plate 41 is provided inside the first header 21 to partition the internal space of the first header 21 into a first space 25 on the side of the connection pipe 34 and a second space 26 on the side of the heat transfer tube 11 . The connection pipe 34 is fixed at a position where the tip end contacts the partition plate 41 in the first space 25 or does not contact the partition plate 41 . The partition plate 41 has a communicating portion 42 formed at a position higher than or equivalent to the heat transfer tube 11 positioned at the top (+Z direction). A plurality of projecting portions 43 projecting toward the heat transfer tubes 11 are provided on the second space side of the partition plate 41 . The plurality of protrusions 43 are formed so as to alternately incline in the +X direction and the −X direction, and each protrusion 43 is formed to have a triangular shape when viewed from the +Y direction. 5 is an enlarged view of a main part of FIG. 4. FIG. The height of the apex of each projection 43 toward each heat transfer tube 11 in the longitudinal direction (Z direction) of the partition plate 41 is higher than the height direction center of each heat transfer tube 11 closest to the projection 43. positioned. For example, the height H1 of the apex of the protrusion 43a in FIG. 5 is positioned above the center h1 in the height direction of the heat transfer tube 11a closest to the protrusion 43a. Similarly, the height H2 of the apex of the protrusion 43b is located above the center h2 of the heat transfer tube 11b in the height direction. Note that the shape of the protrusion 43 is not limited to this. Also, the number of protrusions 43 may be the same for each heat transfer tube 11 , or may be fewer than the number of heat transfer tubes 11 so as to be arranged every other heat transfer tube 11 , for example.

The partition plate 41 configured in this manner is fixed to the inner peripheral wall of the first header 21 by brazing or the like. Furthermore, as shown in FIG. 4 , the upper and lower ends of the partition plate 41 are fitted into the partition plate positioning grooves 33 formed in the end cap 31 that closes the upper and lower ends of the first header 21 .

Next, operation of the heat exchanger 6 will be described. In the following description, the case where the heat exchanger 6 functions as an evaporator will be described. Arrows in FIG. 4 indicate the flow direction of the coolant flowing through the first header 21 .
First, the gas-liquid two-phase refrigerant decompressed by the expansion device 7 flows into the first header 21 through the connecting pipe 34 . At this time, the coolant is ejected from the hole 36 of the connection pipe 34 in the +Z direction in the first space 25 of the first header 21 . The coolant flows through the first space 25 in the +Z direction, reaches above the first header, and flows into the second space 26 through the communicating portion 42 formed in the partition plate 41 . The refrigerant that has passed through the communicating portion 42 is guided to the heat transfer tube 11 positioned at the top (+Z direction), and the rest of the refrigerant flows downward (−Z direction) in the second space 26 . The refrigerant flows along projections 43 provided on partition plate 41 and is guided to each heat transfer tube 11 .

In the course of passing through the heat transfer tubes 11, the gas-liquid two-phase refrigerant absorbs heat from the air outside the heat exchanger 6, cools it, and changes into a gas-phase refrigerant. The refrigerant flows into the second header 22 , is discharged from the connection pipe 35 provided in the second header 22 to the outside of the heat exchanger 6 , and flows to the four-way valve 5 .

Thus, in the heat exchanger 8 of the present embodiment, the partition plate 41 that divides the two spaces into the first header 21 is arranged, and the second space 19 side of the partition plate 41 that communicates with the heat transfer tubes 11 is provided with each space. A configuration is adopted in which projections 43 are provided to guide the refrigerant to the heat transfer tubes 11 . According to this configuration, the refrigerant flow path in the first space is narrowed, the flow velocity of the refrigerant is increased, and the vapor-phase refrigerant and the liquid-phase refrigerant can reach above the first header 21, and the second Since the refrigerant flowing through the space 26 flows downward along the shape of the protrusion 43 of the partition plate 41 , the refrigerant can be easily guided to each heat transfer tube 11 . Furthermore, the height of the apex of the protrusion 43 is located above the center in the height direction of the heat transfer tube 11 closest to the protrusion 43, and the refrigerant flowing along the shape of the protrusion 43 reaches the heat transfer tube 11. The layout is easy to navigate.

FIG. 6 is a graph showing the relationship between the height of the heat transfer tube 11 and the refrigerant supply amount. A solid line in FIG. 6 indicates the heat exchanger 6 of this embodiment, and a broken line indicates a conventional heat exchanger without the partition plate 41 . As shown in FIG. 6, in the conventional heat exchanger, a large amount of refrigerant is supplied to the lower heat transfer tubes, and a small amount of refrigerant is supplied to the upper heat transfer tubes. On the other hand, in the heat exchanger 6 of the present embodiment, a large amount of refrigerant is supplied to the heat transfer tubes 11 closest to the communicating portion 42 of the partition plate 41, and most of the heat transfer tubes 11 are supplied with the refrigerant substantially uniformly.

In this embodiment, the communicating portion 42 that communicates the first space 25 and the second space 26 is formed only in the upper portion of the partition plate 41, but a communicating portion may be formed in the lower portion of the partition plate 41 as well. good. This communication part sends the refrigerant that has not been guided to the heat transfer tube 11 in the second space 26 to the first space, and again leads it to the heat transfer tube 11 together with the refrigerant flowing from the connection pipe 34 by the above-described operation. can. Also, the oil dissolved in the refrigerant and flowing can be guided to the heat transfer tubes 11 together with the refrigerant.

Further, in the present embodiment, the end caps 31 closing the upper and lower ends of the first header 21 are formed with the partition plate positioning grooves 33 . The end of the partition plate 41 is fitted into the partition plate positioning groove 33, and the side surface of the partition plate 41 is fixed to the inner peripheral wall of the first header 21 by brazing or the like. Therefore, the position of the partition plate 41 can be accurately set during manufacturing, and steps such as brazing can be facilitated.

Further, the structure of the present embodiment can be applied not only to the first header, which is the refrigerant inlet header of the heat exchanger with folds, but also to the header of the folded portion. For example, it includes a partition plate that vertically divides the inside of the first header 21 and the second header 22 into two spaces, and a connection pipe that connects the upper space and the lower space of the second header. A partition plate 41 is provided in the space below the first header 21 to partition the first space and the second space. A partition plate is provided to separate the space from the heat tube side. The refrigerant that has flowed into the heat exchanger 6 flows from the space below the first header 21 through the heat transfer tubes 11 to the space below the second header 22 as described above. The refrigerant is led from the space below the second header 22 to the space above the second header 22 through the connecting pipe. In the space above the second header 22, the refrigerant flows upward in the space on the side of the connecting pipes, in the same way as the flow in the first header 21 described above, and flows in the space on the side of the heat transfer tubes 11 along the projections provided on the partition plate. Since the heat flows downward, it is easily guided to the heat transfer tubes 11 communicating with the space above the first header 21 . In this case, in addition to the end cap 31, it is preferable to provide a partition plate positioning groove in the inner peripheral wall of the header, a partition plate that partitions the upper and lower spaces, and the like, and insert the partition plate 41 for positioning.

(Second embodiment)
A second embodiment will be described with reference to FIG. In the second embodiment, the same reference numerals are assigned to the same parts as in the first embodiment, and the description thereof is omitted. In the heat exchanger 6 of the second embodiment, a partition plate 41 is formed with a plurality of openings 44 aligned in the Z direction. The cross-sectional area of each opening 44 is smaller than the cross-sectional area of the communicating portion 42 of the partition plate 11 .

Refrigerant that has flowed into the first space 25 of the first header 21 through the connection pipe 34 is guided upward in the same manner as in the first embodiment. In the heat exchanger 6 of the second embodiment, the refrigerant flows from the plurality of openings 44 to the second space 26 while the refrigerant moves upward in the first space 25 . As a result, it is possible to suppress the generation of a vortex caused by the refrigerant staying between the adjacent heat transfer tubes 11, 11, and improve the performance of the heat exchanger 6. FIG.
In addition, since the refrigerant is discharged into the second space 26 communicating with the heat transfer tubes 11 at a plurality of height positions, the refrigerant can be easily introduced to the heat transfer tubes 11 evenly.

7, the openings 44 of the present embodiment are formed below the protrusions 43 of the partition plate 41, but may be formed at the top of each protrusion 43. The positions and number thereof are not limited. By providing the openings 44 at positions facing the ends of the heat transfer tubes 11 , it becomes easier to guide the refrigerant to the heat transfer tubes 11 .

According to the heat exchanger 6 of at least one embodiment described above, by dividing the space in the first header 21 into two spaces with the partition plate 41, the first space 25, which is the refrigerant flow path, is narrowed. , the coolant can reach above the first header 21 by increasing the flow velocity of the coolant. Then, in the second space 26 , the refrigerant flows downward along the shape of the projections 43 of the partition plate 41 and can be guided to the heat transfer tubes 11 . It becomes easy to distribute the refrigerant evenly to each heat transfer tube 11, and even if the refrigerant has a low circulation amount or a medium circulation amount, it is possible to suppress the refrigerant drift and improve the heat exchange performance. It should be noted that the same effect can be obtained even when it is applied to the indoor heat exchanger 8 .

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, as well as the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 1... Air conditioner, 2... Compressor, 5... Four-way valve, 6... Outdoor heat exchanger, 7... Expansion device, 8... Indoor heat exchanger, 9... Refrigerant pipe, 11... Heat transfer tube, 14... Fin, 21 1st header 22 2nd header 25 first space 26 second space 31, 32 end cap 33 partition plate positioning hole 34, 35 connection pipe 36 hole 41... Partition plate, 42... Communicating part, 43... Projection part, 44... Opening part

Claims (6)

a plurality of heat transfer tubes arranged in parallel in the vertical direction;
a first header and a second header to which both ends of the heat transfer tubes are connected;
a connection pipe provided in a lower portion of the first header so as to face an end portion side of the heat transfer pipe, through which a refrigerant flows in and out;
It is provided in the first header, and partitions the inside of the first header into a first space on the side of the connection tube and a second space on the side of the heat transfer tube. and a partition plate formed with a communicating portion that communicates with the two spaces,
The heat exchanger according to claim 1, wherein the partition plate has projections projecting toward the heat transfer tubes toward the second space and guiding the refrigerant to the heat transfer tubes. 2. The heat exchanger according to claim 1, wherein said connecting pipe has a hole opening upward in said first space. 3. The heat exchanger according to claim 1 or 2, wherein a portion of the protrusion that protrudes most toward the heat transfer tube is located above the center in the height direction of each of the heat transfer tubes that is closest to each of the protrusions. exchanger. 4. The heat exchanger according to any one of claims 1 to 3, wherein the partition plate has a plurality of openings in the longitudinal direction, and the cross-sectional area of each of the openings is smaller than the cross-sectional area of the communicating portion. vessel. 5. The heat exchanger according to claim 1, wherein said first header is closed at both upper and lower ends with end caps, and at least one of said end caps has a partition plate positioning groove. A refrigeration cycle apparatus comprising the heat exchanger according to any one of claims 1 to 5, a compressor, a radiator, and an expansion device.

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