Air conditioner

Abstract

The purpose of the present invention is to reduce a noise that is caused by the flow of a refrigerant. This air conditioner is provided with: a compressor that compresses a refrigerant; a heat exchanger (9) that exchanges heat between the refrigerant and another medium; an expansion valve that expands the refrigerant; a supercooling heat exchanger (20) that supercools the refrigerant; and refrigerant supply lines (30, 40) that supply the refrigerant to the supercooling heat exchanger (20). The refrigerant supply lines (30, 40) has: branch pipes (32) which cause the refrigerant to branch into a plurality of branch parts; first turbulence inhibition pipes (33, 43) each having one end connected to one of the plurality of branch parts; and second turbulence inhibition pipes (34, 44) each having one end connected to one of the plurality of branch parts. The other ends of the first turbulence inhibition pipes (33, 43) and the second turbulence inhibition pipes (34, 44) are connected to the supercooling heat exchanger (20).

Description

Technical Field

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

[0002] An air conditioner including a heat exchanger in which a plurality of tubes are disposed between a plurality of header pipes to communicate a plurality of refrigerant passages inside the tubes with an inside of the header pipes, and fins are disposed between the tubes is known (for example, PTL 1).Citation ListPatent Literature

[0003] [PTL 1] Japanese Unexamined Patent Application Publication No. 2013-178007Summary of InventionTechnical Problem

[0004] In such an air conditioner, a subcooling heat exchanger that subcools a refrigerant may be provided. In a case of supplying the refrigerant to the subcooling heat exchanger, the refrigerant may be branched into a plurality of flows by a branch pipe or the like such that a flow velocity of the refrigerant does not become excessively large.

[0005] However, the refrigerant immediately after being branched is in a turbulent state. In a case where the refrigerant in the turbulent state flows into the subcooling heat exchanger, a sound of a flow of the refrigerant is generated, and thus the noise of the air conditioner may increase.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide an air conditioner capable of reducing noise caused by a flow of a refrigerant.Solution to Problem

[0007] In order to solve the above problems, an air conditioner of the present disclosure adopts the following means.

[0008] An air conditioner according to an aspect of the present disclosure includes a compressor that compresses a refrigerant; a heat exchanger that performs heat exchange 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 the refrigerant to the subcooling heat exchanger, in which 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, and the other ends of the first turbulence suppression pipe and the second turbulence suppression pipe are connected to the subcooling heat exchanger.Advantageous Effects of Invention

[0009] According to the present disclosure, noise caused by a flow of a refrigerant can be reduced.Brief Description of Drawings

[0010] FIG. 1 is a schematic configuration diagram showing a refrigerant circuit of an air conditioner according to an embodiment of the present disclosure. FIG. 2 is a perspective view showing main parts of an outdoor unit of the air conditioner according to the embodiment of the present disclosure. FIG. 3 is a plan view showing a first refrigerant supply line according to the embodiment of the present disclosure. FIG. 4 is a front view showing the first refrigerant supply line according to the embodiment of the present disclosure. FIG. 5 is a plan view showing a second refrigerant supply line according to the embodiment of the present disclosure. FIG. 6 is a front view showing the second refrigerant supply line according to the embodiment of the present disclosure. FIG. 7 is a graph showing a relationship between a sound pressure level and a frequency of noise generated in an air heat exchanger according to the embodiment of the present disclosure. Description of Embodiments

[0011] Hereinafter, an embodiment of the air conditioner according to the present disclosure will be described with reference to the drawings.

[0012] FIG. 1 shows a refrigerant circuit configuration of an air conditioner 1 according to the present embodiment. The air conditioner 1 can perform a heating operation and a cooling operation by switching a flow direction of the refrigerant by a four-way valve 4 provided on a discharge side of a compressor 3. The heating operation is an operation of heating water (heat medium) in a water heat exchanger 5, and the cooling operation is an operation of cooling the water in the water heat exchanger 5. In FIG. 1, a flow direction of the refrigerant in a case of performing the heating operation is indicated by a broken line arrow, and a flow direction of the refrigerant in a case of performing the cooling operation is indicated by a solid line arrow.

[0013] In the air conditioner 1, for example, R32 is used as the refrigerant. R32 is a low-boiling-point refrigerant and is a refrigerant having a low global warming potential (GWP). It should be noted that another refrigerant may be used instead of R32.

[0014] The air conditioner 1 includes the compressor 3 that compresses the refrigerant, the four-way valve 4, the water heat exchanger 5, a receiver 7, the expansion valve 8, an air heat exchanger 9, and an accumulator 10. A refrigerant circuit that performs a refrigeration cycle is configured by connecting 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 by a refrigerant pipe. In the air conditioner 1 according to the present 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 accommodated in the outdoor unit 2. In the air conditioner 1, the water heated or cooled in the water heat exchanger 5 is led to a destination (for example, an indoor unit) outside the outdoor unit 2 via a water pipe 16.

[0015] 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 includes an inverter device, and a rotation speed thereof is arbitrarily changed in response to an instruction from a control unit (not shown).

[0016] A muffler 12 that reduces noise emitted by the discharged refrigerant is provided on the discharge side of the compressor 3.

[0017] The four-way valve 4 is switched such that the refrigerant discharged from the compressor 3 is led to the water heat exchanger 5 in the heating operation, and is switched such that the refrigerant discharged from the compressor 3 is led to the air heat exchanger 9 in the cooling operation. The four-way valve 4 is controlled by a control unit (not shown).

[0018] The water heat exchanger 5 operates as a condenser in the heating operation and operates as an evaporator in the cooling operation. The water pipe 16 that circulates the water between the water heat exchanger 5 and an external load (destination) is connected to the water heat exchanger 5. The water led from the water pipe 16 and the refrigerant are heat-exchanged in the water heat exchanger 5.

[0019] The expansion valve 8 expands the refrigerant condensed and liquefied in the air heat exchanger 9 in a case of operating as the condenser. An opening degree of the expansion valve 8 is controlled by the control unit.

[0020] A strainer 13 that collects foreign matter contained in the refrigerant flowing into the expansion valve 8 in the heating operation is provided on the water heat exchanger 5 side of the expansion valve 8.

[0021] In addition, a strainer 14 that collects foreign matter contained in the refrigerant flowing into the expansion valve 8 in the cooling operation is provided on the air heat exchanger 9 side of the expansion valve 8.

[0022] The receiver 7 is a container that is provided on the water heat exchanger 5 side with respect to the expansion valve 8 and temporarily stores a part of the refrigerant expanded by the expansion valve 8. A capacity (size) of the receiver 7 is determined according to a refrigerant amount circulating in the refrigerant circuit.

[0023] The air heat exchanger 9 operates as an evaporator in the heating operation and operates as a condenser in the cooling operation. The refrigerant and the air are heat-exchanged in the air heat exchanger 9. The air is sent to the air heat exchanger 9 from a fan (not shown).

[0024] A distributor 9a is provided on the expansion valve 8 side of the air heat exchanger 9. The distributor 9a distributes the refrigerant condensed in the water heat exchanger 5 to a plurality of heat transfer pipes provided in the air heat exchanger 9 in the heating operation. In addition, in the cooling operation, the refrigerant condensed in the plurality of heat transfer pipes of the air heat exchanger 9 is collected.

[0025] A gas header 9b is provided on the four-way valve 4 side of the air heat exchanger 9. The gas header 9b distributes the gas-phase refrigerant compressed by the compressor 3 to the plurality of heat transfer pipes provided in the air heat exchanger 9 in the cooling operation. In addition, in the heating operation, the refrigerant evaporated in the plurality of heat transfer pipes of the air heat exchanger 9 is collected.

[0026] The accumulator 10 is a container that is provided on the upstream side, that is, the refrigerant suction side of the compressor 3, and temporarily stores the refrigerant evaporated in the air heat exchanger 9 or the water heat exchanger 5.

[0027] 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 led to the air heat exchanger 9 in the heating operation. In addition, the subcooling heat exchanger 20 subcools the liquid-phase refrigerant discharged from the air heat exchanger 9 in the cooling operation.

[0028] A first refrigerant supply line 30 is connected to the subcooling heat exchanger 20. The first refrigerant supply line 30 supplies the refrigerant to the subcooling heat exchanger 20 in the heating operation. The first refrigerant supply line 30 connects the expansion valve 8 and the subcooling heat exchanger 20.

[0029] A second refrigerant supply line 40 is connected to the subcooling heat exchanger 20. The second refrigerant supply line 40 supplies the refrigerant to the subcooling heat exchanger 20 in the cooling operation. The second refrigerant supply line 40 connects the air heat exchanger 9 (specifically, the distributor 9a) and the subcooling heat exchanger 20.

[0030] Next, details of the subcooling heat exchanger 20, the first refrigerant supply line 30, and the second refrigerant supply line 40 will be described with reference to FIGS. 2 to 6.

[0031] The subcooling heat exchanger 20 is provided below the air heat exchanger 9. Specifically, the subcooling heat exchanger 20 and the air heat exchanger 9 are integrally formed, and heat transfer pipes (not shown) provided to overlap each other in a plurality of stages in the up-down direction are provided such that heat transfer pipes at the lowest stage and at the second stage from the lowest stage constitute the subcooling heat exchanger 20. The heat transfer pipes provided above the third stage from the lowest stage constitute the air heat exchanger 9.

[0032] As shown in FIGS. 2 to 4, the first refrigerant supply line 30 includes 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.

[0033] 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.

[0034] As shown in FIG. 3, the branch pipe 32 has a substantially Y shape. The branch pipe 32 includes a single pipe portion 32a and two branch portions 32b branched from the single pipe portion 32a. The single pipe portion 32a is connected to the single pipe 31. In addition, each of the branch portions 32b is connected to the first turbulence suppression pipe 33 or the second turbulence suppression pipe 34.

[0035] As shown in FIG. 3, one end of each of the first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 is connected to the branch portion 32b of the branch pipe 32. In addition, the other end of each 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 include a portion that extends obliquely downward from the branch pipe 32 and a portion that is bent from the oblique portion to extend in a substantially horizontal direction.

[0036] The first turbulence suppression pipe 33 and the second turbulence suppression pipe 34 are connected to the subcooling heat exchanger 20 without passing through the muffler.

[0037] As shown in FIGS. 2, 5, and 6, the second refrigerant supply line 40 includes 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.

[0038] 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 the branch pipe 42.

[0039] As shown in FIG. 5, the branch pipe 42 has a substantially Y shape. The branch pipe 42 includes a single pipe portion 42a and two branch portions 42b branched from the single pipe portion 42a. The single pipe portion 42a is connected to the single pipe 41. In addition, each of the branch portions 42b is connected to the first turbulence suppression pipe 43 or the second turbulence suppression pipe 44.

[0040] As shown in FIG. 5, one end of each of the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 is connected to the branch portion 42b of the branch pipe 42. In addition, the other end of each of the first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 are connected to the subcooling heat exchanger 20. The first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 integrally include a portion that extends obliquely downward from the branch pipe 42 and a portion that extends in a substantially horizontal direction in a zigzag manner from the oblique portion.

[0041] The first turbulence suppression pipe 43 and the second turbulence suppression pipe 44 are connected to the subcooling heat exchanger 20 without passing through the muffler.

[0042] A length L (length along a central axis of each pipe) of the first turbulence suppression pipe 33 is 10 times or more an inner diameter D of the first turbulence suppression pipe 33. That is, the length L of the first turbulence suppression pipe 33 is set such that the following expression (1) is satisfied. As a result, the turbulence of the refrigerant formed in the branch portion 32b can be stabilized by the first turbulence suppression pipe 33, so that noise caused by the turbulence can be reduced. L ≥ 10 D

[0043] It should be noted that, in a case where the length L of the first turbulence suppression pipe 33 is 11 times or more the inner diameter D of the first turbulence suppression pipe 33, the turbulence can be more suitably suppressed. In addition, in a case where the length L of the first turbulence suppression pipe 33 is 15 times or more the inner diameter D of the first turbulence suppression pipe 33, the turbulence can be further suitably suppressed.

[0044] In addition, the lengths of the second turbulence suppression pipe 34, the first turbulence suppression pipe 43, and the second turbulence suppression pipe 44 are also 10 times or more the inner diameter of each pipe. It should be noted that, in a case where the lengths of the second turbulence suppression pipe 34, the first turbulence suppression pipe 43, and the second turbulence suppression pipe 44 are 11 times or more or 15 times or more the inner diameter of each pipe, the turbulence suppression effect is increased.

[0045] Next, a flow of the refrigerant in the first refrigerant supply line 30 and the second refrigerant supply line 40 according to the present embodiment will be described.[Heating Operation]

[0046] In a case where the air conditioner 1 performs the heating operation, the refrigerant expanded by the expansion valve 8 flows into the first refrigerant supply line 30. Specifically, first, the refrigerant flows into the single pipe 31. The refrigerant flowing through the single pipe 31 is branched by the branch pipe 32. In this case, a part of the refrigerant in the branch pipe 32 is in a turbulent state. The refrigerant branched by 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 is gradually attenuated, and the turbulent state is eliminated. As described above, 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 subcooling heat exchanger 20 and is subcooled. The refrigerant subcooled in the subcooling heat exchanger 20 is discharged to the second refrigerant supply line 40. The refrigerant discharged to the second refrigerant supply line 40 is led to the air heat exchanger 9.[Cooling Operation]

[0047] In a case where the air conditioner 1 performs the cooling operation, the refrigerant that has completed the heat exchange in the air heat exchanger 9 flows into the second refrigerant supply line 40. Specifically, first, the refrigerant flows into the single pipe 41. The refrigerant flowing through the single pipe 41 is branched by the branch pipe 42. In this case, a part of the refrigerant in the branch pipe 42 is in a turbulent state. The refrigerant branched by 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 is gradually attenuated, and the turbulent state is eliminated. As described above, 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 subcooling heat exchanger 20 and is subcooled. The refrigerant subcooled in the subcooling 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.

[0048] According to the present embodiment, the following operations and effects are obtained.

[0049] In the present embodiment, the first refrigerant supply line 30 and the second refrigerant supply line 40 include 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 is in the turbulent state by being branched by the branch pipe 32 is attenuated while flowing through the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44. As a result, the turbulent state of the refrigerant is eliminated. Therefore, the flow of the refrigerant flowing into the subcooling heat exchanger 20 can be stabilized. Therefore, the stabilized refrigerant flows into the subcooling heat exchanger 20, so that 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).

[0050] In addition, in the present embodiment, the noise is reduced by providing the pipes (the first turbulence suppression pipes 33, 43 and the second turbulence suppression pipes 34, 44). As a result, for example, the structure can be simplified as compared to a case of providing a device (muffler or the like) that reduces the noise. Therefore, the cost can be reduced.

[0051] In the present embodiment, the length L of the first turbulence suppression pipes 33, 43 in the longitudinal direction is longer than the length of 11 times the inner diameter D of the first turbulence suppression pipes 33, 43. As a result, the length of the first turbulence suppression pipes 33, 43 can be sufficiently long. Therefore, the refrigerant is sufficiently stabilized in the first turbulence suppression pipes 33, 43. Therefore, the stabilized refrigerant flows into the subcooling heat exchanger 20, so that noise caused by the flow of the refrigerant can be reduced.

[0052] The noise reduction effect will be described with reference to FIG. 7. In FIG. 7, the noise in a case where the length L of the first turbulence suppression pipe 33 is set to the length of 15 times the inner diameter D of the first turbulence suppression pipe 33 is indicated by a solid line. In addition, the noise in a case where the branch pipe 32 is directly connected to the subcooling heat exchanger 20 without providing the first turbulence suppression pipe 33 or the like is indicated by a broken line.

[0053] From the graph of FIG. 7, it can be seen that, in a case where 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, the sound pressure level is reduced in the high-frequency band. On the other hand, in a case where the branch pipe 32 is directly connected to the subcooling heat exchanger 20, the sound pressure level is not reduced. In addition, it can be seen that, in a case where 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, the sound pressure level is lower in the high-frequency band as compared to a case where the branch pipe 32 is directly connected to the subcooling heat exchanger 20.

[0054] Therefore, it can be seen that, in a case where 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 the noise.

[0055] The present disclosure is not limited to the above-described embodiments and can be appropriately modified within a scope which does not depart from the gist of the present disclosure.

[0056] The air conditioner according to the embodiment described above can be understood as follows.

[0057] 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 performs heat exchange 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 the refrigerant to the subcooling heat exchanger, in which the refrigerant supply line includes 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, and the other ends of the first turbulence suppression pipe (33, 43) and the second turbulence suppression pipe (34, 44) are connected to the subcooling heat exchanger.

[0058] In the above-described configuration, the refrigerant supply line includes the first turbulence suppression pipe and the 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 is in the turbulent state by being branched by the branch pipe is attenuated while flowing through the first turbulence suppression pipes and the second turbulence suppression pipes. As a result, the turbulent state of the refrigerant is eliminated. Therefore, the flow of the refrigerant flowing into the subcooling heat exchanger can be stabilized. Therefore, the stabilized refrigerant flows into the subcooling heat exchanger, so that 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).

[0059] In addition, in the above-described configuration, the noise is reduced by only providing the pipes. As a result, for example, the structure can be simplified as compared to a case of providing a device (muffler or the like) that reduces the noise. Therefore, the cost can be reduced.

[0060] It should be noted that the length of the first turbulence suppression pipe may be a length at which the turbulence of the refrigerant generated in the branch portion can be sufficiently reduced.

[0061] In addition, an air conditioner according to a second aspect of the present disclosure includes the air conditioner according to the first aspect, in which a length of the first turbulence suppression pipe in a longitudinal direction is longer than a length of 10 times an inner diameter of the first turbulence suppression pipe.

[0062] In the above-described configuration, the length of the first turbulence suppression pipes in the longitudinal direction is longer than the length of 11 times the inner diameter of the first turbulence suppression pipes. As a result, the length of the first turbulence suppression pipes can be sufficiently long. Therefore, the refrigerant is sufficiently stabilized in the first turbulence suppression pipes. Therefore, the stabilized refrigerant flows into the subcooling heat exchanger, so that noise caused by the flow of the refrigerant can be reduced.Reference Signs List

[0063] 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 pipe 20: Subcooling heat exchanger 30: First refrigerant supply line (refrigerant supply line) 31: Single pipe 32: Branch pipe 32a: Single pipe portion 32b: Branch portion 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: Single pipe portion 42b: Branch portion 43: First turbulence suppression pipe 44: Second turbulence suppression pipe

Claims

1. An air conditioner comprising: a compressor that compresses a refrigerant; a heat exchanger that performs heat exchange 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 the refrigerant to the subcooling heat exchanger, wherein 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, and 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 of the first turbulence suppression pipe in a longitudinal direction is longer than a length of 10 times an inner diameter of the first turbulence suppression pipe.

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