JP2018128153A - Refrigeration machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress noise, in a refrigeration machine that includes a refrigeration cycle having a compressor, a condenser, an expander, an evaporator, and a pipe sequentially connecting them.SOLUTION: A refrigerator includes: a refrigeration cycle having a compressor, condenser, an expander, an evaporator, and a pipe 12 connecting them sequentially; and an acoustic device 13 that is provided on an outer peripheral side of the pipe 12 and includes a cavity group 15 consisting of a plurality of cavities 16 adjacent to each other in a circumferential direction, the cavity group 15 being laminated in a multistage manner in a radial direction of the pipe 12. In the acoustic device 13, the cavities 16 of cavity group 15a on the first stage contacting with the pipe 12 each communicate with a flow passage in the pipe 12, and the cavities 16 of cavity groups 15b on second and succeeding stages communicate with the cavities 16 of the cavity group 15a on the preceding stage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a refrigerator.

  The refrigerator is a heat source device that is widely used in applications such as factory air conditioning having a clean room such as an electrical and electronic related factory, and district heating and cooling. As the refrigerator, a unit is known in which components such as a centrifugal compressor, a condenser, and an evaporator are arranged in the vicinity to be integrated (see, for example, Patent Document 1).

JP 2002-327700 A

  As the efficiency of refrigerators increases, the increase in noise generated from refrigerators has become an issue. The causes of noise generated from the refrigerator are roughly classified into two types: noise caused by mechanical causes and noise caused by fluid causes.

  It is known that noise due to fluid causes is generated due to pressure drop (pressure change) or flow instability in locations where various valves, piping elbows, rectifying plates, and the like are present. Noise generated by fluid causes as described above has the property of becoming a wide frequency band noise (medium frequency band and high frequency band), resonating with the acoustic impedance of piping inside the refrigerator, etc. Is known to be amplified. It is effective to reduce the excitation force before the acoustic impedance of the pipe or the like and the noise resonate, and noise countermeasures near the sound source are effective.

  An object of the present invention is to provide a refrigerator capable of suppressing noise in a refrigerator including a compressor, a condenser, an expander, an evaporator, and a refrigeration cycle having pipes that sequentially connect them. .

  According to the first aspect of the present invention, the refrigerator is provided on the outer peripheral side of the compressor, the condenser, the expander, the evaporator, and the refrigeration cycle having a pipe that sequentially connects these, A plurality of cavities composed of a plurality of cavities adjacent to each other in the circumferential direction are stacked in the radial direction of the pipe, and the cavities of the first-stage cavities in contact with the pipe are respectively connected to flow paths in the pipe. The cavity of the said cavity group after the 2nd step | paragraph is connected, The acoustic device connected to the cavity of the said 1st previous cavity group is provided.

  According to such a configuration, noise generated from at least one of the compressor, condenser, expander, and evaporator constituting the refrigerator resonates with the resonance space of the other component via the pipe. Noise can be reduced before doing so. Specifically, the noise in the middle frequency band can be reduced by the first-stage cavity group, and the noise in the high-frequency band can be reduced by the second-stage cavity group. Thereby, a big effect can be acquired in a small space regarding noise reduction.

  In the refrigerator, each of the cavities may have a rectangular parallelepiped shape, and a through hole may be formed in at least one of the pair of wall portions facing in the radial direction.

  According to such a configuration, the sound absorbing performance of the acoustic device can be adjusted by adjusting the hole diameter of the through hole.

In the refrigerator, each of the cavities may have the same shape.
According to such a configuration, the acoustic device can be easily manufactured.

In the refrigerator, a plurality of the cavity groups may be provided so as to be adjacent to each other in the axial direction of the pipe.
According to such a configuration, the sound absorption performance of the acoustic device can be adjusted by increasing or decreasing the number of cavity groups.

  According to the present invention, before the noise generated from at least one of the compressor, condenser, expander, and evaporator constituting the refrigerator resonates with the resonance space of the other component via the pipe. In addition, noise can be reduced. Specifically, the noise in the middle frequency band can be reduced by the first-stage cavity group, and the noise in the high-frequency band can be reduced by the second-stage cavity group. Thereby, a big effect can be acquired in a small space regarding noise reduction.

It is a schematic block diagram of the refrigerator of embodiment of this invention. It is a schematic block diagram of the compressor of the refrigerator of embodiment of this invention, a condenser, and piping which connects these. It is a partial cross section perspective view of the acoustic device of the refrigerator of the embodiment of the present invention. It is an expansion perspective view of the cavity of the acoustic device of the refrigerator of embodiment of this invention. It is a graph explaining the sound absorption performance of the acoustic device of the refrigerator of embodiment of this invention.

Hereinafter, a refrigerator 1 according to an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the refrigerator 1 of the present embodiment includes a compressor 2 that compresses a refrigerant W, a condenser 3 that condenses the refrigerant W compressed by the compressor 2 with cooling water, and a condenser 3. A first expansion valve 4 that is an expander that depressurizes the refrigerant W, and an economizer 6 (gas-liquid separator) that separates the refrigerant W from the first expansion valve 4 into a gas-liquid two-phase.

  The refrigerator 1 also includes an inflow path 8 that allows the gas phase W1 from the economizer 6 to flow into the compressor 2, a second expansion valve 5 that depressurizes the liquid phase from the economizer 6, and a second expansion. And an evaporator 7 for evaporating the refrigerant W from the valve 5.

  A hot gas bypass pipe 9 is provided between the vapor phase portion of the condenser 3 and the vapor phase portion of the evaporator 7. The hot gas bypass pipe 9 is provided with a hot gas bypass valve 10 for controlling the flow rate of the high-temperature refrigerant gas flowing through the hot gas bypass pipe 9.

The refrigerator 1 has a refrigeration cycle 11 having a pipe 12 that sequentially connects a compressor 2, a condenser 3, a first expansion valve 4, a second expansion valve 5, and an evaporator 7. Specifically, a pipe 12a that connects the compressor 2 and the condenser 3, a pipe 12b that connects the condenser 3 and the economizer 6, a pipe 12c that connects the economizer 6 and the evaporator 7, and an evaporator 7 and a pipe 12d for connecting the compressor 2 to each other.
As the refrigerant W, for example, alternative fluorocarbon R134a (hydrofluorocarbon) is used.
The piping 12 connecting the compressor 2 and the condenser 3 is provided with an acoustic device 13 that reduces noise generated in the compressor 2.

The compressor 2 is a centrifugal two-stage compressor, and is driven by an electric motor (not shown) whose rotational speed is controlled by an inverter that changes an input frequency from a power source.
The condenser 3 is a device that cools the refrigerant W compressed by the compressor 2 by heat exchange with cooling water or the like, and changes the state to a liquid state. For example, the condenser 3 is a shell and tube heat exchanger.

The first expansion valve 4 adiabatically expands and depressurizes the liquid refrigerant W from the condenser 3 to evaporate part of the liquid, thereby bringing the refrigerant W into a gas-liquid two-phase state.
The economizer 6 is a device that separates the refrigerant W, which is in a gas-liquid two-phase state in the first expansion valve 4, into a gas phase W1 and a liquid phase.

The inflow path 8 is a device that causes the gas phase W1 separated from the gas-liquid two-phase refrigerant W by the economizer 6 to flow into the compressor 2.
Similar to the first expansion valve 4, the second expansion valve 5 adiabatically expands and depressurizes the refrigerant W that is separated only by the economizer 6 and becomes only the liquid phase. In addition, in the refrigerator 1 of this embodiment, it is set as the structure which decompresses the refrigerant | coolant W using an expansion valve, However, It is not restricted to this, You may decompress the refrigerant | coolant W using another means.
The evaporator 7 evaporates the refrigerant W from the second expansion valve 5 by exchanging heat with water or the like to obtain a saturated vapor state.

  As shown in FIG. 2, the acoustic device 13 is a silencer provided in a pipe 12 a that connects the compressor 2 and the condenser 3. The acoustic device 13 is provided over the entire circumference in the circumferential direction on the outer peripheral side of the pipe 12a.

  As shown in FIG. 3, the acoustic device 13 includes a cavity group 15 including a plurality of cavities 16 adjacent in the circumferential direction. Each cavidy functions as a resonator. In other words, the acoustic device 13 is a closed space that is attached to the outer peripheral surface of the pipe 12 and extends in the circumferential direction of the pipe 12, and has a plurality of cavities 16 by a plurality of walls (side wall portions 19). A closed space.

The cavity group 15 is stacked in a plurality of stages in the radial direction of the pipe 12. In other words, the acoustic device 13 has a two-stage cavity group 15 in the radial direction of the pipe 12.
The acoustic device 13 of this embodiment has a two-stage cavity group 15. That is, it has the 1st cavity group 15a of the radial inside, and the 2nd cavity group 15b arrange | positioned adjacent to the radial direction outer side of the 1st cavity group 15a.
A plurality of the cavity groups 15 are arranged so as to be adjacent to each other in the axial direction along the central axis Ad of the pipe 12.

FIG. 4 is an enlarged perspective view of the cavity group 15. In FIG. 4, the wall portion 18a (see FIG. 3) that covers the cavity group 15 from the outside is omitted.
As shown in FIG. 4, each cavity 16 has a rectangular parallelepiped shape (box shape). That is, each cavity 16 has a pair of quadrangular wall portions 18 that face in the radial direction, and four side wall portions 19 that connect the four edges of the pair of wall portions 18. Each cavity 16 has substantially the same shape.

The cavities 16 of the first cavity group 15a (first-stage cavity group 15) in contact with the pipe 12 communicate with the flow path in the pipe 12, respectively. The radially inner wall 18 of the cavity 16 of the first cavity group 15 a may be the outer peripheral surface of the pipe 12.
A through hole 20 is formed in the radially inner wall 18 of the cavity 16 of the first cavity group 15a. The through hole 20 is formed at the center of the wall portion 18. The through hole 20 is circular. The shape of the through hole 20 is not limited to a circular shape, and may be a rectangular shape or a slit shape.

  The cavities 16 of the second and subsequent cavities 15 (the second cavities 15b and the cavities 15 radially outside the second cavities 15b) are the cavities 16 of the cavities 15 immediately before the radially inner cavities 15. Communicate. A through hole 20 is formed in the radially inner wall 18 of the cavity 16 of the cavity group 15 after the second stage.

  As shown in FIG. 3, in the acoustic device 13 of the present embodiment, three cavity groups 15 are adjacent to each other in the axial direction of the pipe 12. The number of the cavity groups 15 adjacent in the axial direction of the pipe 12 is not limited to this. It is not necessary to provide a plurality of cavity groups 15 in the axial direction of the pipe 12.

Next, the effect | action of the acoustic device 13 of the refrigerator 1 of this embodiment is demonstrated.
The noise generated in the compressor 2 is a wide frequency band noise (medium frequency band and high frequency band) generated due to fluid factors. Among these, the NZ sound in the middle frequency band is reduced by the cavity 16 (resonance space) of the first-stage cavity group 15 (first cavity group 15a). That is, the gas in the cavity 16 serves as a spring and absorbs the kinetic energy of sound, thereby reducing noise.
Further, the NZ sound in the high frequency band is reduced by the cavity 16 of the second-stage cavity group 15 (second cavity group 15b).
The refrigerator 1 of this embodiment can adjust the sound absorption performance of the acoustic device 13 by adjusting the volume of the cavity 16 of the acoustic device 13, the diameter of the through hole 20, and the opening ratio of the through hole 20.

FIG. 5 is a graph comparing the sound absorption performance of the acoustic device 13 with the vertical axis representing sound absorption performance and the horizontal axis representing noise frequency (Hz). The comparison target is a one-stage acoustic device (an acoustic device in which the cavities are not stacked in the radial direction).
As shown in FIG. 5, the sound absorbing performance of the acoustic device 13 of the present embodiment can exhibit the sound absorbing performance with respect to noise in a wider frequency band as compared with the acoustic device 13 having a one-stage configuration.

  According to the said embodiment, before the NZ sound (noise of a wide frequency band) of the compressor 2 which comprises the refrigerator 1 resonates with resonance space, NZ sound can be reduced. Specifically, the first-stage cavity group 15 can reduce the NZ sound in the middle frequency band, and the second-stage cavity group 15 can reduce the NZ sound in the high frequency band. Thereby, a big effect can be acquired in a small space regarding noise reduction.

  In addition, the sound absorbing performance of the acoustic device 13 can be adjusted by adjusting the volume of the cavity 16 of the acoustic device 13, the diameter of the through hole 20, and the opening ratio of the through hole 20.

In addition, since each cavity 16 has the same shape, the acoustic device 13 can be easily manufactured.
In addition, since a plurality of the cavity groups 15 are provided so as to be adjacent to each other in the axial direction of the pipe 12, the sound absorption performance of the acoustic device 13 can be adjusted by increasing or decreasing the number of the cavity groups 15.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. .

In the above embodiment, the acoustic device 13 is installed in the pipe 12a between the compressor 2 and the condenser 3. However, the present invention is not limited to this. For example, the acoustic device 13 may be disposed in the pipes 12 b and 12 c between the condenser 3 and the evaporator 7, the pipe 12 d between the evaporator 7 and the compressor 2, and the hot gas bypass pipe 9. Furthermore, the number of acoustic devices 13 is not limited to one. For example, the acoustic devices 13 may be attached to all the pipes 12 or two may be attached to one pipe 12.
Moreover, although the acoustic device 13 of the said embodiment is formed over the perimeter of the circumferential direction of the piping 12, it does not restrict to this. The acoustic device 13 may be formed in a part of the circumferential direction.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Compressor 3 Condenser 4 1st expansion valve 5 2nd expansion valve 6 Economizer 7 Evaporator 8 Inflow path 9 Hot gas bypass pipe 10 Hot gas bypass valve 11 Refrigeration cycle 12 Piping 13 Acoustic device 15 Cavity group 16 Cavity 18 Wall part 19 Side wall part 20 Through-hole W Refrigerant

Claims (4)

A compressor, a condenser, an expander, an evaporator, and a refrigeration cycle having a pipe for sequentially connecting them;
A cavity of the first-stage cavity group that is provided on the outer peripheral side of the pipe and is formed by laminating a plurality of cavities composed of a plurality of cavities adjacent to each other in the circumferential direction in the radial direction of the pipe. Are respectively connected to the flow path in the pipe, and the cavities of the second and subsequent cavities are provided with an acoustic device connected to the cavities of the previous cavities.   2. The refrigerator according to claim 1, wherein each of the cavities has a rectangular parallelepiped shape, and a through hole is formed in at least one of a pair of wall portions facing in a radial direction.   The refrigerator according to claim 1 or 2, wherein each of the cavities has the same shape.   The refrigerator according to any one of claims 1 to 3, wherein a plurality of the cavity groups are provided so as to be adjacent to each other in the axial direction of the pipe.

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