JP2020115070A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plurality of flat pipes in a header pipe in a heat exchanger composed of a plurality of flat pipes formed by a plurality of refrigerant flow paths and a pair of header pipes connecting both ends of the flat pipes. The amount of refrigerant flowing through the pipe and the ratio of gas-liquid refrigerant should not be uniform. When a header pipe 3b functions as an evaporator, in a refrigerant outflow section 12 in which a refrigerant flows out to a plurality of flat pipes 2, a connecting side space 8 of the flat pipe 2 and a non-connecting side space of the flat pipe 2 are provided. The partition plate 10 has a partition plate 10 divided into 9 and a refrigerant inflow port 11 into which the refrigerant flows below the vertical intermediate position of the non-connecting side space 9, and the partition plate 10 is in the vertical intermediate direction of the refrigerant outflow section 12. A communication hole 13 is provided above the position, the insertion allowance of the flat tube 2 is equal to or less than that of the flat tube 2 directly above, and the flat tube 2 at the lowermost stage is shorter than the flat tube 2 at the uppermost stage. Has been done. [Selection diagram] Fig. 2

Description

The present invention is composed of a pair of header pipes and a plurality of flat tubes having a plurality of refrigerant channels, air flowing between the plurality of flat tubes, and a refrigerant flowing in the refrigerant channels of the flat tubes. The present invention relates to a heat exchanger for exchanging heat.

Conventionally, it is composed of a pair of header pipes facing each other in the horizontal direction, a plurality of flat tubes having a plurality of refrigerant flow paths, and heat transfer fins provided between the flat tubes. There is known a heat exchanger that performs heat exchange between air flowing between the two and a refrigerant flowing in a refrigerant passage of a flat tube.

In this type of heat exchanger, in order to equalize the amount of refrigerant and the ratio of gas-liquid refrigerant flowing through the plurality of flat tubes in the header pipe, in the header pipe, a partition plate that divides the plurality of flat tubes into a plurality of sections There is disclosed a heat exchanger shunt provided with a connecting pipe that connects the lower part of the upper part of the two separated parts and the upper part of the lower part. (For example, refer to Patent Document 1).

FIG. 6 shows a conventional heat exchanger described in Patent Document 1.

As shown in FIG. 6, the heat exchanger 100 is composed of a plurality of flat tubes 101 formed of a plurality of refrigerant flow paths, and a pair of header pipes 102a and 102b connecting both ends of the flat tubes 101, The header pipes 102a and 102b are provided with partition plates 103a and 103b that divide the plurality of flat tubes 101 into a plurality of sections, and a connection tube 104 that allows the refrigerant to pass through the two divided sections. Refrigerant pipes 105a and 105b are connected to one header pipe 102a.

The connection pipe 104 connects the upper part of the lower section divided by the partition plate 103b and the lower part of the upper section in the other header pipe 102b.

When functioning as an evaporator, the refrigerant flowing from the refrigerant pipe 105b into the header pipe 102a passes through the flat pipe 101 and flows into the lower section of the header pipe 102b. The refrigerant flowing in the lower section of the header pipe 102b flows into the upper section of the header pipe 102b via the connection pipe 104, and therefore the refrigerant due to the influence of gravity when ascending in the header pipe 102b and turning is generated. Gas-liquid separation is suppressed, and the amount of the refrigerant flowing through the plurality of flat tubes 101 connected to the upper section of the header pipe 102b and the ratio of the gas-liquid refrigerant can be distributed so as to be uniform.

JP, 2016-53473, A

However, in the conventional configuration, when functioning as an evaporator, in particular, the refrigerant circulation amount is small, the refrigerant flow velocity is slow, and during partial load operation in which gas and liquid are easily separated, it flows from the flat pipe into the header pipe. Of the gas-liquid two-phase refrigerant, due to the effect of gravity, the gas refrigerant with a low density is upward in the header pipe, the liquid refrigerant with a high density is likely to be biased downward in the header pipe, and the gas refrigerant is present in the upper flat tube. There is a problem that the liquid refrigerant flows through the lower flat tube and the refrigerant state becomes nonuniform in the same heat exchange section.

The present invention is to solve the above-mentioned conventional problems, and a plurality of flat tubes formed of a plurality of refrigerant flow paths, and a pair of header pipes that respectively connect both ends of the flat tubes, and a heat exchange The purpose of the present invention is to make the refrigerant uniformly flow into the plurality of flat tubes.

In order to solve the conventional problems, the heat exchanger of the present invention is composed of a plurality of flat tubes having a plurality of refrigerant flow paths, and a pair of header pipes that respectively connect both ends of the flat tubes. In the heat exchanger, at least one header pipe, when functioning as an evaporator, in the refrigerant outflow section where the refrigerant flows out to the plurality of flat tubes, the connection side space of the flat tubes, the non-connection side space of the flat tubes, And a refrigerant inlet port through which the refrigerant flows below the vertical intermediate position of the non-connection side space, and the partition plate has a communication hole above the vertical intermediate position of the refrigerant outlet section. The insertion allowance of the flat tube is equal to or less than that of the flat tube directly above, and the flat tube at the bottom is shorter than the flat tube at the top.

Accordingly, the gas-liquid two-phase refrigerant at the refrigerant inlet flows into the non-connection side space of the refrigerant outflow section and surely blows up to the upper side of the refrigerant outflow section. Especially in rated/overloaded operation or in a more liquid state (liquid rich), the flow rate of the blown-up refrigerant is high due to the high circulation amount, and when flowing out from the communication hole to the flat tube connection side, the flat tube insertion side Blow out near the wall. When the refrigerant flows down from the upper communication hole, more liquid refrigerant is supplied to the upper part than to the lower part of the header pipe, but the flat tube in the uppermost stage has a longer insertion margin than other flat tubes, so the flat tube is a flat tube. The pressure loss of the flow path becomes large, and it becomes difficult for the refrigerant to flow. Since the insertion allowance of the flat tube becomes shorter toward the lower side, the flow path pressure loss of the flat tube becomes small and the refrigerant easily flows.

The heat exchanger of the present invention, particularly in rated/overload operation, when the refrigerant has a high circulation amount or is in a more liquid state (liquid rich), the liquid refrigerant flows down from above the flat tube connection side, and the refrigerant is Refrigerant does not easily flow in the upper flat tubes, which are often supplied. Therefore, the refrigerant is supplied to the lower flat tubes in which the refrigerant easily flows, so that the liquid refrigerant can be evenly flowed to each flat tube. Thereby, it is possible to reduce the variation in the ratio of the gas-liquid refrigerant flowing through the flat tube and make the refrigerant state uniform.

The perspective view of the heat exchanger of Embodiment 1 of this invention. Sectional drawing of the xy plane of the header pipe of Embodiment 1 of this invention. Sectional drawing of the xz plane of the header pipe of Embodiment 1 of this invention Xz front view showing the internal structure of the outdoor unit to which the heat exchanger is applied Xy front view showing the internal structure of the outdoor unit to which the heat exchanger is applied Sectional drawing of the xy plane of the conventional heat exchanger.

A first aspect of the present invention is a heat exchanger configured with a plurality of flat tubes having a plurality of refrigerant flow paths, and a pair of header pipes that respectively connect both ends of the flat tubes, wherein at least one header pipe is When functioning as an evaporator, in the refrigerant outflow section where the refrigerant flows out to a plurality of flat tubes, the partition plate that separates the space on the connection side of the flat tubes and the space on the non-connection side of the flat tubes, and the vertical direction of the non-connection side space. And a refrigerant inlet port through which the refrigerant flows downward from the intermediate position in the direction, the partition plate has a communication hole above the intermediate position in the vertical direction of the refrigerant outflow section, and the insertion allowance of the flat tube is a flat surface directly above. The flat tube in the lowermost stage is equal to or less than the pipe, and the flat tube in the lowermost stage is shorter than the flattened pipe in the uppermost stage.

Accordingly, the gas-liquid two-phase refrigerant at the refrigerant inlet flows into the non-connection side space of the refrigerant outflow section and surely blows up to the upper side of the refrigerant outflow section. Especially in rated/overloaded operation or in a more liquid state (liquid rich), the flow rate of the blown-up refrigerant is high due to the high circulation amount, and when flowing out from the communication hole to the flat tube connection side, the flat tube insertion side Blow out near the wall. When the refrigerant flows down from the upper communication hole, more liquid refrigerant is supplied to the upper part than to the lower part of the header pipe, but the flat tube in the uppermost stage has a longer insertion margin than other flat tubes, so the flat tube is a flat tube. The pressure loss of the flow path becomes large, and it becomes difficult for the refrigerant to flow. Since the insertion allowance of the flat tube becomes shorter toward the lower side, the flow path pressure loss of the flat tube becomes small and the refrigerant easily flows.

Therefore, especially when the refrigerant is in a high circulation amount or in a more liquid state (liquid rich), such as during rated operation and overload operation, the liquid refrigerant flows down from above the flat pipe connection side, and above the supply of a large amount of refrigerant. Since the refrigerant does not easily flow in the flat tubes, the refrigerant is supplied to the lower flat tubes through which the refrigerant easily flows, and the liquid refrigerant can be evenly flowed to each of the flat tubes. Thereby, it is possible to reduce the variation in the ratio of the gas-liquid refrigerant flowing through the flat tube and make the refrigerant state uniform.

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to this embodiment.

(Embodiment 1)
1 is a perspective view of a heat exchanger according to a first embodiment of the present invention, where the x direction is the flow direction of a refrigerant flowing through a flow path of a flat tube, the y direction is the header pipe axial direction, and the z direction is the air flow direction. Is.

In FIG. 1, the heat exchanger 1 includes a plurality of flat tubes 2 and a pair of header pipes 3a and 3b.

Refrigerant pipes 4a and 4b are connected to one header pipe 3a, respectively. Each of these refrigerant pipes 4a and 4b is configured to function as an inlet or an outlet for the refrigerant.

A partition plate 5 that divides the plurality of flat tubes 2 into a plurality of sections is provided in the header pipe 3a at a position between the refrigerant pipes 4a and 4b in the height direction (y direction).

The header pipes 3a and 3b are formed in a cylindrical shape by extruding a metal material such as aluminum.

The plurality of flat tubes 2 are arranged in the horizontal direction (x direction) so as to be parallel to each other along the axial direction (y direction) of the header pipes 3a and 3b.

Between the plurality of flat tubes 2, a plurality of fins 6 which are vertically continuous and formed in a wavy shape are configured, and air flowing between the plurality of fins 6 and the inside of the plurality of flat tubes 2 flow. Heat exchange with the refrigerant.

As the refrigerant, for example, a mixed refrigerant containing R410A, R32, and R32 is used.

2 is a sectional view taken along the line AA of FIG. 1 (a sectional view taken along the xy plane of the header pipe according to the first embodiment of the present invention), and FIG. 3 is a sectional view taken along the line BB of FIG. 2 is a cross-sectional view of the header pipe of the form 1 in the xz plane).

The plurality of refrigerant flow paths 7 provided in the flat tube 2 communicate with the inside of the header pipes 3a and 3b.

In the other header pipe 3b, when functioning as an evaporator, in the refrigerant outflow section 12 in which the refrigerant flows to the plurality of flat tubes 2, the connection side spaces 8 of the plurality of flat tubes 2 and the plurality of flat tubes 2 are formed. The partition plate 10 that extends in the axial direction (y direction) of the header pipe 3b that divides into the non-connection side space 9, and the refrigerant below the intermediate position in the axial direction (y direction) of the header pipe 3b in the non-connection side space 9. And a refrigerant inlet 11 into which the refrigerant flows.

The partition plate 10 is provided in the refrigerant outflow section 12 and has a communication hole 13 located above an intermediate position in the axial direction (y direction) of the header pipe 3b.

In the flat tube 2, in the same refrigerant outflow section 12, the insertion allowance of the flat tube 2 projecting into the connection side space 8 is equal to or lower than that of the flat tube 2 immediately above, and the flat tube 2 in the lowermost stage is in the uppermost stage. It is configured to be shorter than the flat tube 2.

When the heat exchanger configured as described above functions as an evaporator, the refrigerant at the refrigerant inlet 11 of the header pipe 3b flows into the non-connection side space 9 of the refrigerant outflow section 12 and flows through the header pipe 3b. It rises in the +y direction, passes through the communication hole 13 at the upper end of the partition plate 10, and circulates in the connection side space 8 of the flat tube 2 in the refrigerant outflow section 12.

Next, the use of the present embodiment will be described by taking as an example the case where the heat exchanger 1 of the present embodiment is used in the outdoor unit 20 of the air conditioner.

FIG. 4 is an xz plan view showing the internal structure of the outdoor unit 20 to which the heat exchanger 1 of this embodiment is applied, and FIG. 5 shows the outdoor unit 20 to which the heat exchanger 1 of this embodiment is applied. It is an xy top view which shows an internal structure.

As shown in FIGS. 4 and 5, the outdoor unit 20 includes a compressor 21, a switching valve 22, an outdoor expansion valve 23, a blower 24, and the heat exchanger 1. The outdoor unit 20 and the indoor unit (not shown) are connected by a liquid pipe 25 and a gas pipe 26.

The header pipes 3a and 3b of the heat exchanger 1 are connected to the switching valve 22 via the refrigerant pipe 4a and to the outdoor expansion valve 23 via the refrigerant pipe 4b, respectively.

First, when performing the cooling operation, the heat exchanger 1 functions as a condenser.

The gas refrigerant sent from the compressor 21 of the outdoor unit 20 flows into the header pipe 3a from the refrigerant pipe 4a through the switching valve 22. This gas refrigerant passes through the inside of the header pipe 3a on the connection side of the refrigerant pipe 4a divided by the partition plate 5, flows into the plurality of refrigerant flow paths 7 in the plurality of flat tubes 2, and is horizontally (+x direction, +z direction), and flows out into the connection side space 8 of the flat pipe 2 in the refrigerant outflow section 12 in the section above the header pipe 3b.

The outflowing refrigerant descends in the -y direction in the non-connection side space 9 of the flat tube 2 partitioned by the partition plate 10 through the communication hole 13 above the partition plate 10, and the refrigerant inlet 11 of the header pipe 3b. Through the header pipe 3b into the lower section.

The inflowing refrigerant flows in the horizontal direction (-z direction, -x direction) through the plurality of refrigerant flow paths 7 in the plurality of flat tubes 2. In the flat tube 2, the refrigerant exchanges heat with the air sent by the blower 24 to radiate heat and be condensed.

The condensed refrigerant flows out into the space of the header pipe 3a on the connection side of the refrigerant pipe 4b divided by the partition plate 5, passes through the outdoor expansion valve 23 and the liquid pipe 25 from the refrigerant pipe 4b, and flows out to the indoor unit.

The condensed refrigerant that has flowed into the indoor unit absorbs heat and evaporates by exchanging heat with air in an indoor heat exchanger (not shown). The evaporated refrigerant passes through the gas pipe 26 and circulates to the compressor 21 via the switching valve 22.

When performing the heating operation, the heat exchanger 1 functions as an evaporator.

The gas refrigerant sent from the compressor 21 of the outdoor unit 20 passes through the gas pipe 26 through the switching valve 22 and flows out to the indoor unit.

The gas refrigerant flowing into the indoor unit radiates heat and condenses by exchanging heat with air in an indoor heat exchanger provided in the indoor unit.

The condensed refrigerant passes through the liquid pipe 25 and the outdoor expansion valve 23 to become a gas-liquid two-phase refrigerant, and passes from the refrigerant pipe 4b through the inside of the header pipe 3a on the connection side of the refrigerant pipe 4b separated by the partition plate 5, It flows into the plurality of refrigerant flow paths 7 in the plurality of flat tubes 2, flows in the horizontal direction (+x direction, +z direction), and flows out to the lower section of the header pipe 3b.

The gas-liquid two-phase refrigerant flowing into the header pipe 3b flows into the non-connection side space 9 of the flat pipe 2 in the refrigerant outflow section 12 through the refrigerant inlet 11 of the header pipe 3b, and the header pipe 3b has a partition wall plate. Rise along +10 in the +y direction. The ascended gas-liquid two-phase refrigerant flows into the connection side space 8 of the flat tube 2 from above via the communication hole 13 of the partition plate 10.

The refrigerant flowing into the connection side space 8 of the flat tube 2 flows in the horizontal direction (−z direction, −x direction) via the plurality of refrigerant flow paths 7 in the plurality of flat tubes 2. In the flat tube 2, the refrigerant exchanges heat with the air sent by the blower 24 to absorb heat and evaporate.

The evaporated refrigerant flows out into the space of the header pipe 3a on the connection side of the refrigerant pipe 4a, which is partitioned by the partition plate 5, and circulates from the refrigerant pipe 4a to the compressor 21 via the switching valve 22.

As described above, in the present embodiment, the heat exchanger 1 has the flat tubes 2 having the plurality of refrigerant flow paths 7 and the plurality of flat tubes 2 installed in the horizontal direction, and the both ends of the flat tube 2 are respectively arranged. A pair of header pipes 3a and 3b to be connected are provided, and the plurality of flat tubes 2 are connected in parallel to each other along the axial direction of the header pipes 3a and 3b.

When the header pipe 3b functions as an evaporator, in the refrigerant outflow section 12 in which the refrigerant flows out to the plurality of flat tubes 2, the connection side spaces 8 of the plurality of flat tubes 2 and the non-connection side spaces of the plurality of flat tubes 2 are formed. 9, a partition plate 10 extending in the axial direction (y direction) of the header pipe 3b, and a refrigerant in which the refrigerant flows below an intermediate position in the axial direction (y direction) of the header pipe 3b in the non-connection side space 9. The partition wall plate 10 has a communication hole 13 located above the intermediate position with respect to the axial direction (y direction) of the header pipe 3b, and the flat pipe 2 has the same refrigerant. In the outflow section 12, the insertion allowance of the flat tube 2 projecting into the connection side space 8 is equal to or smaller than that of the flat tube 2 immediately above, and the flat tube 2 at the bottom is shorter than the flat tube 2 at the top. Is configured.

As a result, the gas-liquid two-phase refrigerant in the refrigerant inlet 11 flows into the non-connection side space 9 of the refrigerant outflow section 12 and surely blows up to the upper side of the refrigerant outflow section 12. Especially in rated/overload operation or in a more liquid state (liquid rich), the flow rate of the blown-up refrigerant is high due to the high circulation amount, and when flowing out from the communication hole 13 to the connection side space 8, the flat pipe 2 Blow out near the side wall of the insert. When the refrigerant is made to flow down from the upper communication hole 13, the liquid refrigerant is supplied more to the upper side than to the lower side of the header pipe 3b, but the flat tube 2 at the uppermost stage has a larger insertion allowance than the other flat tubes 2. Since it is long, the flow path pressure loss of the flat tube 2 becomes large, and it becomes difficult for the refrigerant to flow. Since the insertion allowance of the flat tube 2 becomes shorter toward the lower side, the flow path pressure loss of the flat tube 2 becomes small and the refrigerant easily flows.

Therefore, especially when the refrigerant is in a high circulation amount or in a more liquid state (liquid rich), such as during rated operation and overload operation, the liquid refrigerant flows down from above the flat pipe connection side, and above the supply of a large amount of refrigerant. Since it is difficult for the flat tubes to flow the refrigerant, the refrigerant is supplied to the lower flat tubes where the refrigerant easily flows, and the liquid refrigerant can be evenly flowed to the flat tubes 2. Thereby, it is possible to reduce the variation in the ratio of the gas-liquid refrigerant flowing through the flat tube 2 and make the refrigerant state uniform.

In addition, since it is possible to preferentially flow the liquid refrigerant in the header pipe 3b without using a connecting pipe as a separate member, it is possible to suppress an increase in the internal volume of the header pipe 3b, and it is necessary to use the liquid refrigerant in the header pipe 3b. The amount of refrigerant can be reduced.

Although the heat exchangers 1 are installed in one row in the embodiment, for example, two or more heat exchangers may be provided in the air flow direction (z direction), or two or more heat exchanges may be made in the gravity direction (y direction). It goes without saying that the same effect can be obtained even when the configuration in which the devices 1 are stacked is used.

Further, in the embodiment, the plurality of fins 6 are formed in a vertically continuous wave shape between the plurality of flat tubes 2, but the plurality of fins 6 are perpendicular to the plurality of flat tubes 2 so that they are parallel to each other. It is needless to say that the same effect can be obtained even when the plate-shaped structure is inserted so that the same effect can be obtained.

Further, in the embodiment, the insertion allowance of the flat tube 2 is configured to be gradually shortened at the same rate from the upper side to the lower side in the axial direction (y direction) of the header pipe 3b, but is configured to be gradually shortened at different rates. It goes without saying that the same effect can be obtained even in the case of.

The present invention, in a heat exchanger using a flat tube, divides the refrigerant outflow section in the header pipe into a plurality of distribution chambers, and by providing a communication hole above each of the distribution chambers, a gas-liquid two-phase refrigerant is generated. It is a heat exchanger shunt that can distribute the amount of refrigerant and the ratio of gas-liquid refrigerant to a plurality of flat tubes so as to be uniform, and can be applied to applications such as refrigerators, air conditioners, and hot water supply air conditioning complex devices.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Flat pipe 3a, 3b Header pipe 4a, 4b Refrigerant piping 5 Partition plate 6 Fin 7 Refrigerant flow path 8 Connection side space 9 Non-connection side space 10 Partition plate 11 Refrigerant outflow port 13 Refrigerant outflow section 13 Communication hole 20 Outdoor unit 21 Compressor 22 Switching valve 23 Outdoor expansion valve 24 Blower 25 Liquid pipe 26 Gas pipe 100 Heat exchanger 101 Flat pipe 102a, 102b Header pipe 103a, 103b Partition plate 104 Connection pipe 105a, 105b Refrigerant pipe

Claims (1)

In a heat exchanger configured with a plurality of flat tubes having a plurality of refrigerant flow paths and a pair of header pipes that respectively connect both ends of the flat tubes, at least one of the header pipes functions as an evaporator. In the refrigerant outflow section in which the refrigerant flows out to the plurality of flat tubes, a partition plate that separates the connection side space of the flat tubes and the non-connection side space of the flat tubes, and the vertical direction of the non-connection side space. A refrigerant inflow port through which a refrigerant flows in from a direction intermediate position below; and, the partition plate has a communication hole above a vertical direction intermediate position of the refrigerant outflow section, and the insertion allowance of the flat tube is A heat exchanger characterized by being equal to or less than the flat tube directly above, and having the flat tube at the lowermost stage shorter than the flat tube at the uppermost stage.

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