Patent Application
20240240805
The present disclosure relates to an indoor heat exchanger, an indoor unit, an air conditioner, and a method for manufacturing an indoor heat exchanger.
Examples of a known indoor heat exchanger include an indoor heat exchanger in which a connection pipe formed of copper has one end connected to a heat exchanger body and the other end connected to a flare nut (see, for example, JP 2013-155892 A).
In a first aspect, an indoor heat exchanger of the present disclosure includes:
Here, the elongation is measured in accordance with JIS Z2201 and Z2241 and is a ratio, expressed in percentage, between elongation occurring between gauge marks on a test specimen before the test specimen breaks and a gauge length in a tensile test.
In a second aspect, a method for manufacturing an indoor heat exchanger is a method for manufacturing an indoor heat exchanger including a heat exchanger body and a connection pipe connected to the heat exchanger body through a connection portion, the method including:
An indoor unit including an indoor heat exchanger and an air conditioner of the present disclosure will be described in detail below with reference to embodiments illustrated in the drawings. Note that the same parts in the drawings are denoted by the same reference numerals to avoid the description from being redundant. Upper, lower, left, and right in the description correspond to upper, lower, left, and right in a state where an indoor unit is installed in a room.
The refrigerant circuit RC includes a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an electric expansion valve 14, an indoor heat exchanger 15, and an accumulator 16. As the compressor 11 is driven, a refrigerant (for example, an HFC refrigerant such as R410A or R32) circulates in the refrigerant circuit RC.
More specifically, the four-way switching valve 12 has one end connected to a discharge side of the compressor 11. The four-way switching valve 12 has the other end connected to one end of the outdoor heat exchanger 13. The outdoor heat exchanger 13 has the other end connected to one end of the electric expansion valve 14. The electric expansion valve 14 has the other end connected to one end of the indoor heat exchanger 15 via a shutoff valve V1 and a connection pipe L1. The indoor heat exchanger 15 has the other end connected to one end of the accumulator 16 via a connection pipe L2, a shutoff valve V2, and the four-way switching valve 12. The accumulator 16 has the other end connected to an intake-side portion of the compressor 11.
The indoor unit 1 is equipped with the indoor heat exchanger 15 and an indoor fan 18. The indoor fan 18 is, for example, a cross-flow fan, and takes in indoor air through the indoor heat exchanger 15.
The outdoor unit 2 is equipped with the compressor 11, the four-way switching valve 12, the outdoor heat exchanger 13, the electric expansion valve 14, the accumulator 16, and an outdoor fan 17.
The air conditioner switches the four-way switching valve 12 to a switching position indicated by a solid line to activate the compressor 11 for cooling operation and dehumidifying operation, and switches the four-way switching valve 12 to a switching position indicated by a dotted line to activate the compressor 11 for heating operation. A direction of a solid arrow in
As illustrated in
An upper portion of the casing 21 is provided with an intake port 22 through which indoor air is taken in. When the indoor fan 18 is driven, indoor air enters the casing 21 through the intake port 22 and flows toward the indoor fan 18 (cross-flow fan). At this time, in order to prevent dust and the like from entering the casing 21 together with indoor air, a filter (not illustrated) is attached to the intake port 22.
A lower portion of the casing 21 is provided with a blow-out port 23 through which air from the indoor fan 18 (indoor air subjected to heat exchange with the indoor heat exchanger 15) blows out. A horizontal flap 24 is rotatably attached to a peripheral edge portion of the blow-out port 23.
When the cooling operation or the like is started, the horizontal flap 24 changes its position from a stop position to close the blow-out port 23 to an operation position to open the blow-out port 23 to adjust a vertical airflow direction of air blown out from the blow-out port 23.
The indoor heat exchanger 15 includes a heat exchanger body 20, the heat exchanger body 20 including a heat exchange portion 201 and a plurality of heat transfer tubes 202 extending through the heat exchange portion 201 in a left-right direction. The heat exchange portion 201 and the heat transfer tubes 202 are each formed of aluminum or an aluminum alloy.
The indoor heat exchanger 15 further includes a liquid-refrigerant connection pipe 31 and a gas-refrigerant connection pipe 32. The liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 are fluidly connected to the heat transfer tubes 202 of the heat exchanger body 20. The liquid-refrigerant connection pipe 31 is an example of a connection pipe, and constitutes a part of the connection pipe L1 (illustrated in
The liquid-refrigerant connection pipe 31 has includes a first liquid-refrigerant pipe 311 formed of aluminum or an aluminum alloy, and a second liquid-refrigerant pipe 312 formed of copper or a copper alloy. The first liquid-refrigerant pipe 311 has one end fluidly connected to a flow divider 33.
The second liquid-refrigerant pipe 312 has one end fluidly connected to the other end of the first liquid-refrigerant pipe 311 through a third liquid-refrigerant pipe 313 formed of stainless steel. On the other hand, the second liquid-refrigerant pipe 312 has the other end fixed to a liquid-refrigerant flare union 41 by brazing.
The third liquid-refrigerant pipe 313 has one end and the other end that is larger in outer diameter than the one end. The third liquid-refrigerant pipe 313 has the one end connected to the first liquid-refrigerant pipe 311. On the other hand, the third liquid-refrigerant pipe 313 has the other end connected to the second liquid-refrigerant pipe 312.
The gas-refrigerant connection pipe 32 is similar in configuration to the liquid-refrigerant connection pipe 31, and includes a first gas-refrigerant pipe 321 formed of aluminum or an aluminum alloy, and a second gas-refrigerant pipe 322 formed of copper or a copper alloy.
The first gas-refrigerant pipe 321 has one end fluidly connected to a flow divider (not illustrated).
The second gas-refrigerant pipe 322 has one end fluidly connected to the other end of the first gas-refrigerant pipe 321 through a third gas-refrigerant pipe 323 formed of stainless steel. On the other hand, the second gas-refrigerant pipe 322 has the other end fixed to a gas-refrigerant flare union 42 by brazing.
As illustrated in
The first liquid-refrigerant pipe 311 includes a third section 311c closer to the second liquid-refrigerant pipe 312 than the second section 311b. The third section 311c is continuous with an end of the second section 311b adjacent to the second liquid-refrigerant pipe 312, and extends in a horizontal direction or a direction inclined relative to the horizontal direction.
The first liquid-refrigerant pipe 311 has an outer peripheral surface extending from an end of the third section 311c adjacent to the second liquid-refrigerant pipe 312 to an end of the second section 311b adjacent to the first section 311a, the outer peripheral surface entirely covered with a waterproof tube 51. The waterproof tube 51 further covers an outer peripheral surface of the end of the third liquid-refrigerant pipe 313 adjacent to the first liquid-refrigerant pipe 311. The waterproof tube 51 is formed of a tube made of a waterproof material (for example, vinyl chloride, silicone rubber, fluorine-baed based polymer, or the like) and shrunk by heating.
The first liquid-refrigerant pipe 311 includes a fourth section 311d closer to the heat exchanger body 20 than the first section 311a. The fourth section 311d is continuous with an upper end (heat-exchanger-body 20-side end) of the first section 311a, and the fourth section 311d extends upward from the end and then extends downward like a U-turn. The fourth section 311d is an example of a second curved portion.
The first liquid-refrigerant pipe 311 includes a fifth section 311e closer to the heat exchanger body 20 than the fourth section 311d. The fifth section 311e is continuous with a lower end (heat-exchanger-body 20-side end) of the fourth section 311d, and is bent from the lower end toward the flow divider 33. The flow divider 33 is an example of a connection portion.
The first liquid-refrigerant pipe 311 includes a sixth section 311f closer to the heat exchanger body 20 than the fifth section 311e. The sixth section 311f extends from a heat-exchanger-body 20-side end of the fifth section 311e to the flow divider 33.
The flow divider 33 is formed of aluminum or an aluminum alloy. A branch pipe 34 formed of aluminum or an aluminum alloy is fixed to an end of the flow divider 33 adjacent to the heat exchanger body 20 by brazing.
In the first example, the gas-refrigerant connection pipe 32 is similar in configuration to the liquid-refrigerant connection pipe 31.
In the indoor heat exchanger 15 configured as described above, the elongation of the second section 311b (first curved portion) of the liquid-refrigerant connection pipe 31 connected to the heat exchanger body 20 through the flow divider 33 (connection portion) is made greater than or equal to 30%, and the elongation of the first curved portion of the gas-refrigerant connection pipe 32 is made greater than or equal to 30%. This allows the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 to easily bend during installation of the indoor unit accommodating the heat exchanger body 20, thereby increasing work efficiency during installation.
Since the liquid-refrigerant connection pipe 31 includes the fourth section 311d(second curved portion) between the flow divider 33 and the second section 311b, when bending stress acts on the second section 311b, the bending stress is partially received by the fourth section 311d, so that it is possible to prevent stress concentration on the second section 311b and reduce the risk of breakage of the second section 311b (the same applies to the gas-refrigerant connection pipe 32).
It is possible to reduce, by making the elongation of the fourth section 311d of the liquid-refrigerant connection pipe 31 less than or equal to 20%, a stress load applied to the heat exchanger body 20 when bending stress acts on the second section 311b (first curved portion) (the same applies to the gas-refrigerant connection pipe 32).
The indoor heat exchanger 15 is provided with the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32. The liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 includes portions formed of aluminum or aluminum alloy that are lower in tensile strength than portions formed of copper, but is particularly effective in increasing work efficiency.
Alternatively, the elongation of the second section 311b of the liquid-refrigerant connection pipe 31 may be greater than or equal to 40% (the same applies to the gas-refrigerant connection pipe 32). This allows the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 to easily bend during installation of the indoor unit accommodating the heat exchanger body 20, thereby allowing a further increase in work efficiency during installation.
The liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 each have an outer diameter as small as 9.52 mm (≈⅜ inches) or less, thereby making the work of bending the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 easier.
The indoor unit 1 including the indoor heat exchanger 15 and the air conditioner including the indoor unit 1 allow the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 to easily bend during installation of the indoor unit 1, thereby increasing work efficiency during installation.
As illustrated in
Specifically, the first liquid-refrigerant pipe 311 is bent into a predetermined shape to have the second section 311b (first curved portion) and the fourth section 311d(second curved portion) (bending step S1).
Next, the first liquid-refrigerant pipe 311 thus bent, the second liquid-refrigerant pipe 312, the third liquid-refrigerant pipe 313, and the liquid-refrigerant flare union 41 are assembled into the liquid-refrigerant connection pipe 31, and the liquid-refrigerant connection pipe 31, the flow divider 33 (connection portion), and the branch pipe 34 are assembled into a connection pipe assembly (assembling step S2).
Then, the portions of the connection pipe assembly are brazed together and subjected to annealing treatment by in-furnace brazing (annealing step S3).
As described above, an end (side remote from the flow divider 33) of the branch pipe 34 of the connection pipe assembly subjected to the annealing treatment is brazed to the heat exchanger body 20.
The gas-refrigerant connection pipe 32 is also subjected to the bending step S1, the assembling step S2, and the annealing step S3 in a similar manner to complete the indoor heat exchanger 15.
According to the method for manufacturing the indoor heat exchanger 15, in the bending step S1, the second section 311b (first curved portion) of the first liquid-refrigerant connection pipe 311 and the first curved portion of the first gas-refrigerant connection pipe 321 are reduced in elongation by half due to work hardening (the same applies to the gas-refrigerant connection pipe 32). The annealing treatment in the annealing step S3 after the bending step S1 makes the second section 311b of the first liquid-refrigerant connection pipe 311 connected to the heat exchanger body 20 through the flow divider 33 and the first curved portion of the first gas-refrigerant connection pipe 321 larger in elongation than before the annealing step, the annealing treatment allowing the liquid-refrigerant connection pipe 31 and the gas-refrigerant connection pipe 32 to easily bend during installation of the indoor unit 1 accommodating the heat exchanger body 20, thereby increasing work efficiency during installation.
In the annealing step S3, performing the annealing treatment by in-furnace brazing allows each portion to be subjected to the brazing and the annealing treatment at the same time, and it is therefore possible to efficiently perform the brazing and the annealing treatment.
In the air conditioner of the first example, one indoor unit 1 is connected to one outdoor unit 2, or alternatively, a plurality of indoor units 1 may be connected. In other words, the above-described air conditioner is of a pair-type, or alternatively, the air conditioner may be of a multi-type.
The first liquid-refrigerant pipe 311 and the first gas-refrigerant pipe 321 are formed of aluminum or an aluminum alloy in the first example, or alternatively, may be formed of metal other than aluminum and an aluminum alloy.
The second liquid-refrigerant pipe 312 and the second gas-refrigerant pipe 322 are formed of copper or a copper alloy in the first example, or alternatively, may be formed of metal other than copper or a copper alloy.
The flow divider 33 and the branch pipe 34 are interposed between the heat transfer tubes 202 of the heat exchanger body 20 and the one end of the first liquid-refrigerant pipe 311 in the liquid-refrigerant connection pipe 31 in the first example, or alternatively, the one end of the first liquid-refrigerant pipe 311 may be directly connected to the heat transfer tubes 202 of the heat exchanger body 20 with neither the flow divider 33 nor the branch pipe 34 interposed (the same applies to the gas-refrigerant connection pipe 32).
The flow divider 33 that divides one refrigerant flow into two refrigerant flows is used in the first example, or alternatively, a flow divider that divides one refrigerant flow into three or more refrigerant flows may be used.
The tubular member 61 illustrated in
Although not illustrated, most of the gas-refrigerant connection pipe 32 is inserted into the tubular member 61 in a manner similar to the liquid-refrigerant connection pipe 31. Therefore, the tubular member 61 has an inner diameter set larger than a sum of an outer diameter of the liquid-refrigerant connection pipe 31 and an outer diameter of the gas-refrigerant connection pipe 32.
In the indoor heat exchanger 1015 configured as described above, since the tubular member 61 covers the waterproof tube 51, liquid such as dew condensation water is prevented from adhering to the covering member or the waterproof tube 51.
Covering the second section 311b of the first liquid-refrigerant connection pipe 311 with the tubular member 61 allows a reduction in bending stress applied to the second section 311b (the same applies to the gas-refrigerant connection pipe 32).
Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present disclosure. Accordingly, the scope of the disclosure should be limited only by the attached claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-161764 | Sep 2021 | JP | national |
This application is a Continuation of PCT International Patent Application No. PCT/JP2022/018451, filed on Apr. 21, 2022, which claims priority under 35 U.S.C. § 119(a) to Japanese Patent Application No. 2021-161764, filed in Japan on Sep. 30, 2021. The contents of these applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/018451 | Apr 2022 | WO |
| Child | 18622148 | US |
