Air conditioner

Abstract

To reduce noise caused by a flow of a refrigerant.SOLUTION: An air conditioner comprises a compressor for compressing a refrigerant, a heat exchanger 9 for exchanging heat between the refrigerant and another medium, an expansion valve for expanding the refrigerant, a supercooling heat exchanger 20 for supercooling the refrigerant, and refrigerant supply lines 30 and 40 for supplying the refrigerant to the supercooling heat exchanger 20. The refrigerant supply lines 30 and 40 comprise branch pipes 32 and 42 for branching the refrigerant into a plurality of branch parts, first turbulence suppression pipes 33 and 43 of which one end is connected to one of the plurality of branch parts, and second turbulence suppression pipes 34 and 44 of which one end is connected to one of the plurality of branch parts. The other end of each of the first turbulence suppression pipes 33 and 43 and the second turbulence suppression pipes 34 and 44 is connected to the supercooling heat exchanger 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an air conditioner. [Background technology]

[0002] An air conditioner is known that is equipped with a heat exchanger in which multiple tubes are arranged between multiple header pipes to connect multiple refrigerant passages inside the tubes to the inside of the header pipes, and fins are arranged between the tubes (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-178007 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such an air conditioner, a subcooling heat exchanger that subcools the refrigerant may be provided. When the refrigerant is supplied to the subcooling heat exchanger, the refrigerant may be branched into a plurality of branches by a branch pipe or the like so that the flow rate of the refrigerant does not become excessively high. However, the refrigerant is in a turbulent state immediately after being branched. When the turbulent refrigerant flows into the subcooling heat exchanger, the refrigerant generates flow noise, which may increase the noise of the air conditioner.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an air conditioner that can reduce noise caused by the flow of refrigerant. [Means for solving the problem]

[0006] In order to solve the above problems, the air conditioner of the present disclosure employs the following measures. An air conditioner according to one embodiment of the present disclosure includes a compressor that compresses a refrigerant, a heat exchanger that exchanges heat between the refrigerant and another medium, an expansion valve that expands the refrigerant, a subcooling heat exchanger that subcools the refrigerant, and a refrigerant supply line that supplies refrigerant to the subcooling heat exchanger, wherein the refrigerant supply line has a branch pipe that branches the refrigerant into a plurality of branch sections, a first turbulence suppression pipe having one end connected to one of the plurality of branch sections, and a second turbulence suppression pipe having one end connected to one of the plurality of branch sections, and the other ends of the first turbulence suppression pipe and the second turbulence suppression pipe are connected to the subcooling heat exchanger. Effect of the Invention

[0007] According to the present disclosure, noise caused by the flow of refrigerant can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a refrigerant circuit of an air conditioner according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view showing a main portion of an outdoor unit of an air conditioner according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a plan view illustrating a first refrigerant supply line according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a front view illustrating a first refrigerant supply line according to an embodiment of the present disclosure. [Diagram 5] FIG. 4 is a plan view illustrating a second refrigerant supply line according to an embodiment of the present disclosure. [Figure 6] FIG. 4 is a front view illustrating a second refrigerant supply line according to an embodiment of the present disclosure. [Figure 7] 1 is a graph showing the relationship between sound pressure level and frequency of noise generated in an air heat exchanger according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, one embodiment of an air conditioner according to the present disclosure will be described with reference to the drawings. Fig. 1 shows the refrigerant circuit configuration of an air conditioner 1 of this embodiment. The air conditioner 1 can perform heating operation and cooling operation by switching the flow direction of the refrigerant with a four-way valve 4 provided on the discharge side of a compressor 3. The heating operation is an operation in which water (heat medium) is heated by a water heat exchanger 5, and the cooling operation is an operation in which water is cooled by the water heat exchanger 5. In Fig. 1, the dashed arrow indicates the flow direction of the refrigerant when performing heating operation, and the solid arrow indicates the flow direction of the refrigerant when performing cooling operation.

[0010] The air conditioner 1 uses, for example, R32 as a refrigerant. R32 is considered to be a refrigerant with a low boiling point and a low global warming potential (GWP). Note that other refrigerants may be used instead of R32.

[0011] The air conditioner 1 includes a compressor 3 for compressing a refrigerant, a four-way valve 4, a water heat exchanger 5, a receiver 7, an expansion valve 8, an air heat exchanger 9, and an accumulator 10. The compressor 3, the four-way valve 4, the water heat exchanger 5, the receiver 7, the expansion valve 8, the air heat exchanger 9, and the accumulator 10 are connected by refrigerant piping to form a refrigerant circuit for performing a refrigeration cycle. In the air conditioner 1 of this embodiment, the compressor 3, the four-way valve 4, the water heat exchanger 5, the receiver 7, the expansion valve 8, the air heat exchanger 9, and the accumulator 10 are all housed inside the outdoor unit 2. In the air conditioner 1, water heated or cooled by the water heat exchanger 5 is guided to a destination (e.g., an indoor unit) outside the outdoor unit 2 via a water piping 16.

[0012] The compressor 3 is, for example, a scroll compressor or a rotary compressor, and a compression mechanism such as a scroll compression mechanism or a rotary compression mechanism is provided in a housing of the compressor 3. The compression mechanism is driven by an electric motor (not shown). The electric motor is equipped with an inverter device, and the rotation speed can be changed as desired by a command from a control unit (not shown).

[0013] On the discharge side of the compressor 3, a muffler 12 is provided to reduce noise generated by the discharged refrigerant.

[0014] The four-way valve 4 is switched so that the refrigerant discharged from the compressor 3 is guided to the water heat exchanger 5 during heating operation, and is switched so that the refrigerant discharged from the compressor 3 is guided to the air heat exchanger 9 during cooling operation. The four-way valve 4 is controlled by a control unit (not shown).

[0015] The water heat exchanger 5 operates as a condenser during heating operation and as an evaporator during cooling operation. A water pipe 16 for circulating water between the water heat exchanger 5 and an external load (destination of use) is connected to the water heat exchanger 5. In the water heat exchanger 5, heat is exchanged between the water guided from the water pipe 16 and the refrigerant.

[0016] When operating as a condenser, the expansion valve 8 expands the refrigerant condensed and liquefied in the air heat exchanger 9. The opening degree of the expansion valve 8 is controlled by the control unit.

[0017] A strainer 13 is provided on the water-heat exchanger 5 side of the expansion valve 8 to collect foreign matter contained in the refrigerant that flows into the expansion valve 8 during heating operation. Further, a strainer 14 is provided on the air heat exchanger 9 side of the expansion valve 8 to collect foreign matter contained in the refrigerant that flows into the expansion valve 8 during cooling operation.

[0018] The receiver 7 is provided on the water heat exchanger 5 side of the expansion valve 8, and is a container that temporarily stores a part of the refrigerant expanded by the expansion valve 8. The capacity (size) of the receiver 7 is determined according to the amount of refrigerant circulating in the refrigerant circuit.

[0019] The air heat exchanger 9 operates as an evaporator during heating operation and as a condenser during cooling operation. Heat is exchanged between the refrigerant and the air in the air heat exchanger 9. Air is sent to the air heat exchanger 9 from a fan (not shown).

[0020] A distributor 9a is provided on the expansion valve 8 side of the air heat exchanger 9. During heating operation, the distributor 9a distributes the refrigerant condensed in the water heat exchanger 5 to multiple heat transfer tubes provided in the air heat exchanger 9. During cooling operation, the distributor 9a collects the refrigerant condensed in the multiple heat transfer tubes of the air heat exchanger 9.

[0021] A gas header 9b is provided on the four-way valve 4 side of the air heat exchanger 9. During cooling operation, the gas header 9b distributes the gas phase refrigerant compressed by the compressor 3 to multiple heat transfer tubes provided in the air heat exchanger 9. During heating operation, the gas header 9b collects the refrigerant evaporated in the multiple heat transfer tubes of the air heat exchanger 9.

[0022] The accumulator 10 is provided on the upstream side of the compressor 3, that is, on the refrigerant suction side, and is a container for temporarily storing the refrigerant evaporated in the air heat exchanger 9 or the water heat exchanger 5.

[0023] A subcooling heat exchanger 20 is provided between the expansion valve 8 and the air heat exchanger 9. The subcooling heat exchanger 20 subcools the liquid phase refrigerant guided to the air heat exchanger 9 during heating operation. The subcooling heat exchanger 20 also subcools the liquid phase refrigerant discharged from the air heat exchanger 9 during cooling operation.

[0024] A first refrigerant supply line 30 is connected to the subcooling heat exchanger 20. The first refrigerant supply line 30 supplies refrigerant to the subcooling heat exchanger 20 during heating operation. The first refrigerant supply line 30 connects the expansion valve 8 and the subcooling heat exchanger 20. In addition, a second refrigerant supply line 40 is connected to the subcooling heat exchanger 20. The second refrigerant supply line 40 supplies refrigerant to the subcooling heat exchanger 20 during cooling operation. The second refrigerant supply line 40 connects the air heat exchanger 9 (more specifically, the distributor 9a) and the subcooling heat exchanger 20.

[0025] Next, the subcooling heat exchanger 20, the first refrigerant supply line 30, and the second refrigerant supply line 40 will be described in detail with reference to Figs. 2 to 6. The subcooling heat exchanger 20 is provided below the air heat exchanger 9. In detail, the subcooling heat exchanger 20 and the air heat exchanger 9 are integrally formed, and among heat transfer tubes (not shown) provided so as to be stacked in a plurality of stages in the vertical direction, the heat transfer tubes provided in the lowest stage and the second stage from the lowest stage are used as the subcooling heat exchanger 20. The heat transfer tubes provided above the third stage from the lowest stage are used as the air heat exchanger 9.

[0026] As shown in Figures 2 to 4, the first refrigerant supply line 30 has a single pipe 31, a branch pipe 32 connected to the single pipe 31, a first turbulence suppression pipe 33 connected to one branch portion 32b of the branch pipe 32, and a second turbulence suppression pipe 34 connected to the other branch portion 32b of the branch pipe 32.

[0027] One end of the single pipe 31 is connected to the expansion valve 8. The other end of the single pipe 31 is connected to the branch pipe 32.

[0028] 3, the branch pipe 32 is substantially Y-shaped. The branch pipe 32 has one main portion 32a and two branch portions 32b branching off from the main portion 32a. The main portion 32a is connected to the single pipe 31. In addition, each branch portion 32b is connected to a first turbulence suppression pipe 33 or a second turbulence suppression pipe 34.

[0029] 3, one end of the first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 is connected to the branched portion 32b of the branch pipe 32. The other end of the first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 is connected to the subcooling heat exchanger 20. The first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 integrally have a portion extending obliquely downward from the branch pipe 32 and a portion extending from the oblique portion in a substantially horizontal direction while bending.

[0030] The first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 are connected to the subcooling heat exchanger 20 without passing through a muffler.

[0031] As shown in Figures 2, 5 and 6, the second refrigerant supply line 40 has a single pipe 41, a branch pipe 42 connected to the single pipe 41, a first turbulence suppression pipe 43 connected to one branch portion 42b of the branch pipe 42, and a second turbulence suppression pipe 44 connected to the other branch portion 42b of the branch pipe 42.

[0032] One end of the single pipe 41 is connected to the distributor 9a of the air heat exchanger 9. The other end of the single pipe 41 is connected to a branch pipe .

[0033] 5, the branch pipe 42 is substantially Y-shaped. The branch pipe 42 has one main portion 42a and two branch portions 42b branching off from the main portion 42a. The main portion 42a is connected to the single pipe 41. In addition, each branch portion 42b is connected to a first turbulence suppression pipe 43 or a second turbulence suppression pipe 44.

[0034] 5, one end of the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 is connected to the branched portion 42b of the branch pipe 42. The other end of the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 is connected to the subcooling heat exchanger 20. The first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 integrally have a portion extending obliquely downward from the branch pipe 42 and a portion extending from the oblique portion in a substantially horizontal direction while bending.

[0035] The first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 are connected to the subcooling heat exchanger 20 without passing through a muffler.

[0036] The length L of the first turbulence suppression pipe 33 (the length along the central axis of each pipe) is set to be 10 times or more the inner diameter D of the first turbulence suppression pipe 33. In other words, the length L of the first turbulence suppression pipe 33 is set so that the following formula (1) is established. As a result, the turbulent flow of the refrigerant formed in the branching portion 32b can be stabilized by the first turbulence suppression pipe 33, thereby reducing noise caused by the turbulent flow.

[0037] L ≧ 10D (1)

[0038] The first turbulence suppression pipe 33 can more suitably suppress turbulence if the length L is 11 times or more the inner diameter D of the first turbulence suppression pipe 33. The first turbulence suppression pipe 33 can more suitably suppress turbulence if the length L is 15 times or more the inner diameter D of the first turbulence suppression pipe 33.

[0039] Similarly, the lengths of the second turbulence suppression pipe 34, the first turbulence suppression pipe 43, and the second turbulence suppression pipe 44 are also set to 10 times or more the inner diameter of each pipe. Note that by making the lengths of the second turbulence suppression pipe 34, the first turbulence suppression pipe 43, and the second turbulence suppression pipe 44 also 11 times or more or 15 times or more the inner diameter of each pipe, the turbulence suppression effect is increased.

[0040] Next, the flow of the refrigerant in the first refrigerant supply line 30 and the second refrigerant supply line 40 according to this embodiment will be described.

[0041] [Heating operation] When the air conditioner 1 performs heating operation, the refrigerant expanded by the expansion valve 8 flows into the first refrigerant supply line 30. Specifically, the refrigerant first flows into the single pipe 31. The refrigerant flowing through the single pipe 31 branches into the branch pipe 32. At this time, a part of the refrigerant becomes turbulent in the branch pipe 32. The refrigerant branched at the branch pipe 32 flows into the first turbulence suppression pipe 33 and the second turbulence suppression pipe 34. The refrigerant flowing through the first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 gradually attenuates, and the turbulent state is eliminated. In this way, the first refrigerant supply line 30 can stabilize the flow of the refrigerant. The refrigerant stabilized in the first refrigerant supply line 30 flows into the supercooling heat exchanger 20 and is supercooled. The refrigerant supercooled in the supercooling heat exchanger 20 is discharged into the second refrigerant supply line 40. The refrigerant discharged into the second refrigerant supply line 40 is led to the air heat exchanger 9.

[0042] [Cooling operation] When the air conditioner 1 performs cooling operation, the refrigerant that has completed heat exchange in the air heat exchanger 9 flows into the second refrigerant supply line 40. Specifically, the refrigerant first flows into the single pipe 41. The refrigerant that has flowed through the single pipe 41 branches at the branch pipe 42. At this time, a part of the refrigerant becomes turbulent in the branch pipe 42. The refrigerant that has branched at the branch pipe 42 flows into the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44. The refrigerant flowing through the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 gradually attenuates, and the turbulent state is eliminated. In this way, the second refrigerant supply line 40 can stabilize the flow of the refrigerant. The refrigerant stabilized in the second refrigerant supply line 40 flows into the supercooling heat exchanger 20 and is supercooled. The refrigerant supercooled in the supercooling heat exchanger 20 is discharged to the first refrigerant supply line 30. The refrigerant discharged to the first refrigerant supply line 30 is led to the expansion valve 8.

[0043] According to this embodiment, the following advantageous effects are obtained. In this embodiment, the first refrigerant supply line 30 and the second refrigerant supply line 40 have the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44. That is, the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44 are provided between the branch pipe 32 and the subcooling heat exchanger 20. As a result, the refrigerant that has become turbulent by branching at the branch pipe 32 is attenuated while flowing through the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44. This eliminates the turbulent state of the refrigerant. Therefore, the flow of the refrigerant flowing into the subcooling heat exchanger 20 can be stabilized. Therefore, since a stable refrigerant flows into the subcooling heat exchanger 20, noise caused by the flow of the refrigerant can be reduced. In particular, noise caused by the flow of the refrigerant can be reduced in a high frequency band (a frequency band of 5000 Hz or more and 8000 Hz or less).

[0044] Furthermore, in this embodiment, noise is reduced simply by providing the piping (the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44). This allows for a simpler structure than, for example, a case in which a noise reduction device (such as a muffler) is provided. This allows for reduced costs.

[0045] In this embodiment, the length L of the first turbulence suppression pipe 33, 43 in the longitudinal direction is longer than 11 times the inner diameter D of the first turbulence suppression pipe 33, 43. This allows the length of the first turbulence suppression pipe 33, 43 to be sufficiently long. Therefore, the refrigerant is sufficiently stabilized in the first turbulence suppression pipe 33, 43. Therefore, a stable refrigerant flows into the subcooling heat exchanger 20, making it possible to reduce noise caused by the flow of the refrigerant.

[0046] The noise reduction effect will be explained with reference to Fig. 7. In Fig. 7, the solid line shows the noise when the length L of the first turbulence suppression pipe 33 is 15 times the inner diameter D of the first turbulence suppression pipe 33. The dashed line shows the noise when the branch pipe 32 is directly connected to the subcooling heat exchanger 20 without providing the first turbulence suppression pipe 33, etc. 7, it can be seen that when the length L of the first turbulence suppression pipe 33 is 15 times the inner diameter D of the first turbulence suppression pipe 33, the sound pressure level is reduced in the high frequency band. On the other hand, when the branch pipe 32 is directly connected to the subcooling heat exchanger 20, the sound pressure level is not reduced. It can also be seen that when the length L of the first turbulence suppression pipe 33 is 15 times the inner diameter D of the first turbulence suppression pipe 33, the sound pressure level is lower in the high frequency band compared to when the branch pipe 32 is directly connected to the subcooling heat exchanger 20. Therefore, it is clear that when the length L of the first turbulence suppression pipe 33 is set to 15 times the inner diameter D of the first turbulence suppression pipe 33, there is an effect of reducing noise.

[0047] The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present disclosure.

[0048] The air conditioner according to the embodiment described above can be understood, for example, as follows. An air conditioner according to a first aspect of the present disclosure includes a compressor (3) that compresses a refrigerant, a heat exchanger (5, 9) that exchanges heat between the refrigerant and another medium, an expansion valve (8) that expands the refrigerant, a subcooling heat exchanger (20) that subcools the refrigerant, and a refrigerant supply line (30, 40) that supplies refrigerant to the subcooling heat exchanger, the refrigerant supply line having a branch pipe (32) that branches the refrigerant into a plurality of branch portions (32b, 42b), a first turbulence suppression pipe (33, 43) having one end connected to one of the plurality of branch portions, and a second turbulence suppression pipe (34, 44) having one end connected to one of the plurality of branch portions, the other ends of the first turbulence suppression pipe (33, 43) and the second turbulence suppression pipe (34, 44) being connected to the subcooling heat exchanger.

[0049] In the above configuration, the refrigerant supply line has a first turbulence suppression pipe and a second turbulence suppression pipe. That is, the first turbulence suppression pipe and the second turbulence suppression pipe are provided between the branch pipe and the subcooling heat exchanger. As a result, the refrigerant that has become turbulent by branching at the branch pipe is attenuated while flowing inside the first turbulence suppression pipe and the second turbulence suppression pipe. This eliminates the turbulent state of the refrigerant. Therefore, the flow of the refrigerant flowing into the subcooling heat exchanger can be stabilized. Therefore, since a stable refrigerant flows into the subcooling heat exchanger, noise caused by the flow of the refrigerant can be reduced. In particular, noise caused by the flow of the refrigerant can be reduced in the high frequency band (a frequency band of 5000 Hz or more and 8000 Hz or less).

[0050] In addition, in the above configuration, noise is reduced by simply providing piping. This allows the structure to be simplified compared to a case where a noise reduction device (such as a muffler) is provided, for example, and therefore the cost can be reduced.

[0051] The length of the first turbulence suppression pipe may be set to a length that can sufficiently reduce the turbulence of the refrigerant generated in the branching portion.

[0052] Further, in the air conditioner according to a second aspect of the present disclosure, in the above-mentioned first aspect, the length in the longitudinal direction of the first turbulence suppression pipe is longer than 10 times the length of the inner diameter of the first turbulence suppression pipe.

[0053] In the above configuration, the length of the first turbulence suppression tube in the longitudinal direction is longer than 11 times the inner diameter of the first turbulence suppression tube. This allows the length of the first turbulence suppression tube to be sufficiently long. Therefore, the refrigerant is sufficiently stabilized in the first turbulence suppression tube. Therefore, a stable refrigerant flows into the subcooling heat exchanger, making it possible to reduce noise caused by the flow of the refrigerant. [Explanation of symbols]

[0054] 1: Air conditioner 2:Outdoor unit 3: Compressor 4: Four-way valve 5: Water heat exchanger (heat exchanger) 7: Receiver 8: Expansion valve 9: Air heat exchanger (heat exchanger) 9a: Distributor 9b: Gas header 10: Accumulator 12: Muffler 13: Strainer 14: Strainer 16: Water piping 20:Supercooling heat exchanger 30: First refrigerant supply line (refrigerant supply line) 31: Single pipe 32: Branch pipe 32a: One headquarters 32b: Branch 33:First turbulence suppression pipe 34:Second turbulence suppression pipe 40: Second refrigerant supply line (refrigerant supply line) 41: Single pipe 42: Branch pipe 42a: One headquarters 42b: Branch 43:First turbulence suppression pipe 44: Second turbulence suppression tube

Claims

1. A compressor that compresses a refrigerant; A heat exchanger that exchanges heat between the refrigerant and another medium; an expansion valve for expanding the refrigerant; a subcooling heat exchanger for subcooling a refrigerant; a refrigerant supply line for supplying a refrigerant to the subcooling heat exchanger; the refrigerant supply line includes a branch pipe that branches the refrigerant into a plurality of branch portions, a first turbulence suppression pipe having one end connected to one of the plurality of branch portions, and a second turbulence suppression pipe having one end connected to one of the plurality of branch portions, the other ends of the first turbulence suppression pipe and the second turbulence suppression pipe are connected to the subcooling heat exchanger.

2. The air conditioner according to claim 1 , wherein a length in a longitudinal direction of the first turbulence suppression pipe is longer than 10 times an inner diameter of the first turbulence suppression pipe.

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