JP2018162900A - Heat exchanger and air conditioner including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of preventing deviation of liquid refrigerant distribution in a heat exchanger header within a wide refrigerant flow rate range, and having excellent energy saving.SOLUTION: A heat exchanger includes two headers arranged substantially perpendicularly, a plurality of heat transfer pipes connecting the headers substantially horizontally, and a fin configured enlarging a heat transfer area of the heat transfer pipe. The inside of the header is partitioned into a plurality of sections in a height direction by a perforated partition plate arranged substantially horizontally, and to the uppermost section among the plurality of sections, a main pipe into which refrigerant flows is connected.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger that can reduce the bias of a gas-liquid two-phase refrigerant distributed to each of a plurality of heat transfer tubes connecting between headers of the heat exchanger. is there.

  In an air conditioner using a vapor compression refrigeration cycle, a heat exchanger that exchanges heat between a refrigerant flowing inside the refrigeration cycle and outdoor air or indoor air is used.

  As this heat exchanger, for example, there is one using a flat heat transfer tube provided with a large number of minute flow paths inside. This heat exchanger is provided with cylindrical headers at both ends approximately vertically, connecting between both headers with a number of flat heat transfer tubes, and fixing the expanded heat transfer surfaces called fins to each flat heat transfer tube by brazing etc. It is a thing. The refrigerant flowing inside the heat exchanger flows into one header through the inlet pipe, then flows into each heat transfer tube, flows down while exchanging heat with the air flowing outside, and flows through the other header. Merge and flow out of the outlet piping.

  By the way, for example, when this heat exchanger is used in an evaporator, that is, in an application for evaporating an internal refrigerant and cooling air flowing outside, the inside of the header on the refrigerant inlet side is in a gas-liquid two-phase state. As a result, the liquid refrigerant tends to be biased downward, and it is difficult to evenly distribute the liquid refrigerant having an endothermic effect to the heat transfer tubes that are stacked in the vertical direction. When this deviation is large, the liquid refrigerant completes evaporation at an early stage in the upper heat transfer tube with a small liquid refrigerant branching ratio. Therefore, most of the inside of the heat transfer tube is a gas refrigerant having almost no endothermic effect. It will be satisfied. That is, the heat transfer area of the heat exchanger cannot be used effectively, and the energy saving performance of the device may be reduced.

  As a prior art for solving such a problem, for example, there is one shown in FIG. In this example, a partition is provided inside the header leaving a gap above and below, and a plurality of refrigerant inlets are provided so that a loop-shaped refrigerant flow is generated in the header. Thereby, since the gas-liquid two-phase flow circulates in the header, it is intended to realize a good distribution of the liquid refrigerant.

  However, in the configuration of Patent Document 1, when the momentum of the refrigerant flow is small, such as when the refrigerant circulation flow rate of the refrigeration cycle is small, the loop-shaped refrigerant flow in the header is not realized, and the liquid refrigerant having a high density is used as the header. There is a possibility that the liquid refrigerant flows in an uneven manner in the lower heat transfer tubes and the liquid refrigerant flows unbalanced in the lower heat transfer tubes.

JP 2011-85324 A

  It is an object of the present invention to provide an air conditioner that prevents uneven distribution of liquid refrigerant in a heat exchanger header in a wide refrigerant flow range and is excellent in energy saving.

  An object of the present invention includes two headers arranged substantially vertically, a plurality of heat transfer tubes that connect the headers substantially horizontally, and a fin that expands a heat transfer area of the heat transfer tubes, The inside of the header is partitioned into a plurality of sections in the height direction by a perforated partition plate arranged substantially horizontally, and a main pipe into which a refrigerant flows is connected to the uppermost section among the plurality of sections. Achieved by the heat exchanger.

  The subject of the present invention includes two headers arranged substantially vertically, a plurality of heat transfer tubes that connect the headers substantially horizontally, and fins that expand the heat transfer area of the heat transfer tubes. The header is partitioned into a space opposite to the heat transfer tube side space by a partition wall arranged substantially vertically, and the heat transfer tube side space is arranged in a height direction by a perforated partition plate arranged substantially horizontally. A main pipe into which a refrigerant flows is connected to a lower part of the opposite side space, and an uppermost part of the plurality of sections of the heat transfer pipe side space is connected to the upper part of the partition wall. This is achieved by a heat exchanger provided with a main communication hole that communicates the section and the opposite space.

  ADVANTAGE OF THE INVENTION According to this invention, the uneven distribution of the liquid refrigerant in a header can be prevented in the wide refrigerant | coolant flow range, and the air conditioner excellent in energy saving property can be provided.

The figure which shows the refrigerating cycle of the air conditioner of Example 1. FIG. The perspective view which shows the outdoor heat exchanger of the air conditioner of Example 1. FIG. The figure which shows the cross section of the header of Example 1, and the connection state of piping. The figure which shows the cross section of the header of Example 2, and the connection state of piping. The figure which shows the cross section of the header of Example 3, and the connection state of piping. The figure which shows the cross section of the header of Example 4, and the connection state of piping.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a refrigeration cycle of the air conditioner 100 according to the first embodiment. The air conditioner 100 of the present embodiment is one in which an outdoor unit 1 and an indoor unit 8 are connected by connecting pipes 12a and 12b. The outdoor unit 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor fan motor 5, an outdoor fan 6, and an expansion device 7, and the indoor unit 8 includes an indoor heat exchanger 9 and The indoor fan motor 10 and the indoor fan 11 are provided.

  Next, the operation of each element of the air conditioner 100 will be described by taking the operation during the cooling operation as an example. During the cooling operation, the refrigerant flows in the direction of the solid line arrow in the figure. First, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the outdoor heat exchanger 4 after passing through the four-way valve 3, condenses by releasing heat to the outside air in the outdoor heat exchanger 4, It becomes a liquid refrigerant. This liquid refrigerant is depressurized by the action of the expansion device 7, enters a low-temperature low-pressure gas-liquid two-phase state, and flows to the indoor unit 8 through the connection pipe 12a. The gas-liquid two-phase refrigerant that has entered the indoor unit 8 evaporates by absorbing the heat of the indoor air in the indoor heat exchanger 9, thereby realizing indoor cooling. The gas refrigerant evaporated in the indoor unit 8 returns to the outdoor unit 1 through the connection pipe 12b, passes through the four-way valve 3, and is compressed again by the compressor 2. This is the refrigeration cycle during the cooling operation.

  On the other hand, during the heating operation, the refrigerant flow path is switched by the four-way valve 3, and the refrigerant flows in the direction of the broken line arrow in the figure. First, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows to the indoor unit 8 through the four-way valve 3 and the connection pipe 12b. The high-temperature gas refrigerant that has entered the indoor unit 8 is radiated to the indoor air by the indoor heat exchanger 9, thereby realizing indoor heating. At this time, the gas refrigerant condenses and becomes a high-pressure liquid refrigerant. Thereafter, the high-pressure liquid refrigerant flows to the outdoor unit 1 through the connection pipe 12a. The high-pressure liquid refrigerant that has entered the outdoor unit 1 is decompressed by the action of the expansion device 7, becomes a low-temperature low-pressure gas-liquid two-phase state, flows to the outdoor heat exchanger 4, and evaporates by absorbing the heat of the outdoor air. It becomes a gas refrigerant. The gas refrigerant passes through the four-way valve 3 and is compressed again by the compressor 2. This is the refrigeration cycle during heating operation.

  Thus, the direction of the refrigerant flow in the outdoor heat exchanger 4 and the indoor heat exchanger 9 is reversed between the cooling operation and the heating operation. In this embodiment, R32 is used as the refrigerant, but another refrigerant such as R410A may be used.

  Next, the detail of the outdoor heat exchanger 4 is demonstrated using FIG. 2, FIG. FIG. 2 is a perspective view of the outdoor heat exchanger 4, and FIG. 3 is a cross-sectional view showing a detailed structure near one header of the outdoor heat exchanger 4. In addition, the thick line arrow in these figures shows the flow of the refrigerant | coolant at the time of the heating operation in which the outdoor heat exchanger 4 acts as an evaporator (dashed line arrow in FIG. 1), and the header by the expansion apparatus 7 side. A state in which the refrigerant flows from 13a toward the header 13b on the four-way valve 3 side is shown.

  As shown in FIG. 2, the outdoor heat exchanger 4 is arranged between the two substantially cylindrical headers 13 (13 a and 13 b) arranged substantially vertically and the headers 13 having different heights at both ends. It is composed of a plurality of (in this embodiment, 12) flat heat transfer tubes 14 to be connected and a large number of fins 15 that expand the heat transfer area of the flat heat transfer tubes 14, and the refrigerant passing through the flat heat transfer tubes 14 Heat can be exchanged with the air supplied from the fan 6.

  Further, as shown in the sectional view of FIG. 3A, a main pipe 16 to be described later is connected to an upper portion of the substantially cylindrical header 13a, and the inside of the header 13a is heightened by a perforated partition plate 17. It is partitioned into a plurality of (four in FIG. 3) sections in the direction.

  As shown in the top view of FIG. 3 (b), taken along section AA in FIG. 3 (a), a hole 17a is provided in the substantially central part of the perforated partition plate 17, and this hole Adjacent sections are communicated with each other by 17a. FIG. 3B shows a configuration in which one circular hole portion 17a is provided. Alternatively, a configuration in which a rectangular hole or a plurality of holes is provided may be used. 3 shows only the detailed structure of the header 13a on the expansion device 7 side, the header 13b on the four-way valve 3 side may have the same structure.

  The main pipe 16 serving as an inlet for the gas-liquid two-phase refrigerant during the heating operation is connected to the upper portion of the uppermost section in the header 13a, and the connection position is higher than any flat heat transfer pipe 14 included in the section. Is in position.

  The gas-liquid two-phase refrigerant supplied to the header 13a via the main pipe 16 is a refrigerant in which a gas having a low density and a liquid having a high density coexist, and the liquid refrigerant having a high density tends to accumulate on the lower side due to the influence of gravity. In this embodiment, the main pipe 16 is connected to the highest position of the header 13a, and the flat heat transfer pipe 14 is connected to the lower side of the main pipe 16 in the present embodiment. Even in a situation where the refrigerant circulation flow rate is small and liquid refrigerant cannot be expected to rise, the liquid refrigerant can be efficiently supplied from the upper main pipe 16 to the lower flat heat transfer pipe 14.

  In addition to this, in the header 13a of the present embodiment, the inside is divided into a plurality of sections using the perforated partition plate 17, so that when the liquid refrigerant moves downward under the influence of gravity, it passes through the hole 17a. Since time is required, the time that the liquid refrigerant stays in each section can be extended regardless of the refrigerant circulation flow rate, and the supply amount of the liquid refrigerant to the flat heat transfer tube 14 connected to the upper section is increased. Can do. Thereby, compared with the structure which does not use the perforated partition plate 17, it becomes possible to equalize the supply amount of the gas-liquid two-phase refrigerant to each flat heat transfer tube.

  As described above, according to the configuration of the present embodiment, it is possible to suppress uneven distribution of the liquid refrigerant to each flat heat transfer tube 14 regardless of the refrigerant circulation flow rate. Since the same degree of endothermic action can be ensured, an air conditioner with improved energy efficiency and improved efficiency of the outdoor heat exchanger 4 as a whole can be provided.

  Next, an air conditioner according to a second embodiment of the present invention will be described. Since the configuration and operation of the refrigeration cycle are the same as those in the embodiment, a duplicate description is omitted, and the following description will focus on differences from the embodiment 1.

  FIG. 4 is a cross-sectional view of the vicinity of the header 13a of the outdoor heat exchanger 4 according to the second embodiment. The difference from the header 13 a of the first embodiment is that a pipe 16 a communicating with the main pipe 16 is connected to the lower part of each section partitioned by the perforated partition plate 17. The connection position of each pipe 16a is a position lower than the flat-shaped heat transfer tube 14 at the bottom of the section. Further, since the inner diameter of the pipe 16 a is smaller than the inner diameter of the main pipe 16, the flow path cross-sectional area of the pipe 16 a is smaller than the flow path cross-sectional area of the main pipe 16. The pipe 16a is connected in a horizontal or downward gradient from the header 13a to the main pipe 16, so that no upward gradient portion exists.

  During heating operation in which the outdoor heat exchanger 4 is used as an evaporator, the uneven distribution of the liquid refrigerant to each heat transfer tube can be prevented by the configuration and operation described in the first embodiment.

  On the other hand, at the time of cooling operation using the outdoor heat exchanger 4 as a condenser, as shown by the arrow in FIG. 4, the liquid refrigerant flowing into the header 13a from the flat heat transfer tube 14 flows out into the main tube 16 through the pipe 16a. Therefore, the liquid refrigerant in each section in the header 13a can be prevented, that is, the stagnation of the refrigerant flow can be prevented. In addition, since the pipe 16a does not have an upward slope portion on the way from the header 13a to the main pipe 16, the flow of the liquid refrigerant is not hindered and a smooth refrigerant flow can be obtained.

  As explained above, according to the outdoor heat exchanger 4 of the present embodiment, when used as a condenser, it is possible to prevent stagnation of refrigerant flow by the above-described action, and also when used as an evaporator. In addition, it is possible to prevent an uneven distribution of the liquid refrigerant to each heat transfer tube and to provide an air conditioner excellent in energy saving.

  Next, the air conditioner of the third embodiment will be described focusing on the difference from the second embodiment. In addition, about the point which is common in the Example mentioned above, duplication description is abbreviate | omitted.

  FIG. 5 is a cross-sectional view of the header 13a of the outdoor heat exchanger 4 according to the third embodiment. The difference from the second embodiment is that in the second embodiment (FIG. 4), the header 13a and the main pipe 16 are connected to each other by the four pipes 16a, but in this embodiment, the pipes 16a are joined together. The main pipe 16 is connected. Also in this embodiment, the flow passage cross-sectional area of each pipe 16a is smaller than the flow passage cross-sectional area of the main pipe 16, and an upward slope portion exists in the course of the pipe 16a from the header 13a to the main pipe 16. Absent.

  Therefore, as in the second embodiment, the flow of the refrigerant is prevented from being hindered when acting as a condenser, and the distribution of the liquid refrigerant to each heat transfer tube is prevented from being biased when acting as an evaporator. It is possible to provide an air conditioner excellent in energy saving.

  Next, Example 4 will be described. In addition, about the point which is common in the Example mentioned above, duplication description is abbreviate | omitted.

  FIG. 6 is a cross-sectional view of the header 13a of the outdoor heat exchanger 4 of the fourth embodiment. As shown in FIG. 6 (a), the main pipe 16 is connected to the lowermost part of the header 13a of this embodiment, and as shown in FIGS. 6 (a) and 6 (b), the header 13a is substantially vertical. The partition wall 18 is partitioned into a space on the main tube 16 side and a space on the flat heat transfer tube 14 side. The space on the flat heat transfer tube 14 side is divided into a plurality of sections by a perforated partition plate 17 as in the first embodiment. Further, as shown in FIG. 6C, the partition wall 18 is provided with a main communication hole 18a at the uppermost portion, and a sub-communication hole 18b at a position corresponding to the lower part of each section.

  6A indicates the direction of the flow of the gas-liquid two-phase refrigerant when the heating operation is performed, that is, when the outdoor heat exchanger 4 is acting as an evaporator. As shown here, the main communication hole 18a, which is the main supply port for the gas-liquid two-phase refrigerant during the heating operation, is provided at a position higher than any of the heat transfer tubes included in the uppermost section in the header 13a. . Moreover, the height of the sub communicating hole 18b provided corresponding to each division is lower than the heat exchanger tube in the lowest position of each division. The flow passage cross-sectional area of the sub communication hole 18b is smaller than the flow passage cross-sectional area of the main communication hole 18a. Furthermore, the connecting portion between the main pipe 16 and the header 13a is provided at a position lower than the sub communication hole 18b at the lowest position.

  As described in the description of the first embodiment, the gas-liquid two-phase refrigerant flowing inside is a state where a gas having a low density and a liquid having a high density coexist, and the liquid having a high density is lowered by the action of gravity. It is easy to collect on the side and it is difficult to rise upward. However, in this embodiment, since the main communication hole 18a is provided at a position higher than the uppermost flat heat transfer tube 14, each flatness is small even in a situation where the refrigerant circulation flow rate is small and liquid refrigerant cannot be expected to rise. A liquid refrigerant can be supplied to the heat transfer tube 14.

  Further, in this embodiment, the partition on the side to which the heat transfer tube of the header 13 is connected, which is partitioned by the partition wall 18, is divided into a plurality of partitions in the height direction by the perforated partition plate 17, The liquid refrigerant is prevented from dropping directly to the lower part of the header due to the action of gravity, and the time for which the liquid refrigerant stays in each section is extended. Thereby, it becomes possible to distribute liquid refrigerant substantially uniformly to each heat exchanger tube.

  In the cooling operation, when the outdoor heat exchanger 4 acts as a condenser, that is, when the flow direction of the refrigerant is opposite to the thick arrows in FIG. Since the liquid refrigerant of the gas-liquid two-phase refrigerant that has flowed into the header 13a from the flat heat transfer tube 14 flows into the main pipe 16 through the sub-communication hole 18b, the liquid refrigerant accumulates in the lower part of each section in the header 13a, and the refrigerant flow Can be prevented. That is, while preventing the refrigerant flow from being hindered when acting as a condenser, when acting as an evaporator, it prevents uneven distribution of the liquid refrigerant to each heat transfer tube, and has excellent energy saving performance. A harmony machine can be provided.

  In addition, this invention is not limited to the Example mentioned above, Various modifications are included. For example, in this embodiment, the flat heat transfer tubes 14 are twelve heat exchangers, but the present invention can be applied to other heat transfer tubes. Moreover, this invention can also be applied to arbitrary blocks, when the heat exchanger is comprised by the combination of several heat exchanger blocks.

100 air conditioner,
1 outdoor unit,
2 compressors,
3 Four-way valve,
4 outdoor heat exchangers,
5 outdoor fan motor,
6 outdoor fans,
7 Aperture device,
8 indoor units,
9 Indoor heat exchanger,
10 Indoor fan motor,
11 Indoor fans,
12a, 12b connection piping,
13, 13a, 13b header,
14 flat heat transfer tube,
15 fins,
16 Main line,
16a piping,
17 perforated dividers,
17a hole,
18 Bulkhead,
18a Main communication hole,
18b Secondary communication hole

Claims (12)

A heat exchanger comprising two headers arranged substantially vertically, a plurality of heat transfer tubes that connect the headers substantially horizontally, and fins that expand the heat transfer area of the heat transfer tubes,
The inside of the header is partitioned into a plurality of sections in the height direction by a perforated partition plate arranged substantially horizontally,
A heat exchanger in which a main pipe into which a refrigerant flows is connected to the uppermost section among the plurality of sections. The heat exchanger according to claim 1,
The heat exchanger is characterized in that the main pipe is connected at a position higher than the heat transfer pipe connected to the highest position among the heat transfer pipes connected to the uppermost section. The heat exchanger according to claim 1 or 2,
A pipe that communicates with the main pipe is connected to a lower portion of each section of the header. The heat exchanger according to claim 3,
The said piping is connected to the position lower than the heat exchanger tube in the lowest position among the heat exchanger tubes connected to each division, The heat exchanger characterized by the above-mentioned. The heat exchanger according to claim 3 or 4,
The heat exchanger according to claim 1, wherein a flow passage cross-sectional area of the pipe is smaller than a flow passage cross-sectional area of the main pipe. The heat exchanger according to any one of claims 3 to 5,
The heat exchanger is characterized in that the pipe is connected horizontally or downwardly from the header toward the main pipe. A heat exchanger comprising two headers arranged substantially vertically, a plurality of heat transfer tubes that connect the headers substantially horizontally, and fins that expand the heat transfer area of the heat transfer tubes,
The interior of the header is partitioned into a space opposite to the heat transfer tube side space by partition walls arranged substantially vertically, and a plurality of the heat transfer tube side spaces are provided in the height direction by a perforated partition plate arranged substantially horizontally. Divided into compartments,
A main pipe into which the refrigerant flows is connected to the lower part of the opposite side space,
The heat exchanger according to claim 1, wherein a main communication hole is provided in the upper part of the partition wall to communicate the uppermost compartment and the opposite space among the plurality of compartments of the heat transfer tube side space. The heat exchanger according to claim 7,
The main communication hole is provided in a position higher than the heat transfer pipe at the highest position among the heat transfer pipes connected to the uppermost section. The heat exchanger according to claim 7 or 8,
The partition wall is provided with a sub-communication hole communicating with a lower portion of each section of the heat transfer tube side space and the opposite space,
The said sub communicating hole is provided in the position lower than the heat exchanger tube in the lowest position among the heat exchanger tubes connected to each division, The heat exchanger characterized by the above-mentioned. The heat exchanger according to claim 9, wherein
The heat exchanger according to claim 1, wherein a flow passage cross-sectional area of the sub-communication hole is smaller than a flow passage cross-sectional area of the main communication hole. The heat exchanger according to claim 9 or 10,
The main pipe is connected to the header at a position lower than the sub communication hole at the lowest position among the sub communication holes. An air conditioner equipped with an outdoor unit and an indoor unit,
The outdoor unit includes a compressor, a heat exchanger, an outdoor fan, and a throttle device.
The said heat exchanger is a heat exchanger as described in any one of Claims 1-11, The air conditioner characterized by the above-mentioned.

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