JPH0614685U - Silencer and air conditioner - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the noise reduction effect of a silencer provided in the middle of the refrigerant discharge pipe of an air conditioner. [Structure] A cavity 23 for expanding a pulsating refrigerant discharged from a compressor is formed in a silencer body 22 of a silencer 21. In the cavity 23, the inner end surface 24 and the inner wall surface 2 in the range of at least more than 1/2 in the length direction on the downstream side of the gas flow.
5 is provided with a flocked sound absorbing material 26 and is held by the protrusion 27. The flocked sound absorbing material 26 has a hair-like portion formed on the surface thereof, and the hair-like portion absorbs the kinetic energy of the refrigerant gas to muffle the sound. The muffler 21 absorbs kinetic energy through a process of exchanging mechanical energy associated with viscous friction and inelastic collision between the hair-like portion of the flocked sound absorbing material 26 and the refrigerant gas, and thereby has a high sound reducing effect. To get

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a silencer provided in the middle of a refrigerant discharge pipe of a compressor in a refrigeration cycle, and an air conditioner including the silencer.

[0002]

[Prior art]

 In the conventional heat pump type air conditioner, as shown in FIG. 5, a silencer 2 is provided in the middle of the refrigerant pipe 1 of the refrigeration cycle so as to suppress the vibration and noise generated from the indoor heat exchanger.

In the silencer 2, the silencer main body 3 has a cylindrical shape and a cavity 4 is formed therein, and the pulsating refrigerant gas discharged from the compressor is expanded by the cavity 4 to generate from the indoor heat exchanger. Vibration and noise are suppressed. Further, recently, as shown in FIG. 6, a muffler 2a has been considered in which the inner wall surface of the cavity 4 is covered with a sintered granular metal 5 to improve the sound reduction characteristics.

[0004]

[Problems to be solved by the device]

 However, the conventional muffler 2 shown in FIG. 5 cannot obtain the sound reduction effect due to the resonance frequency determined by the cavity length L. Further, in the muffler 2a shown in FIG. 6, since the inner wall surface is covered with the granular metal 5, the noise reduction effect can be increased by the resonance frequency, but there is a problem that the manufacturing is difficult and the cost becomes very high.

The present invention has been made in consideration of the above points, and a silencer that can obtain a good noise reduction effect and can be manufactured at a low cost with a simple structure, and an air conditioner using the silencer. The purpose is to provide a machine.

[0006]

[Means for Solving the Problems]

 The muffler according to the present invention is characterized in that a flocked sound absorbing material is provided on the inner end surface and the inner wall surface of the cavity inside the muffler body at least on the downstream side of the gas flow in a range exceeding ½ of the length direction. And An air conditioner according to the present invention is characterized in that the silencer is connected to a discharge pipe of a compressor in a refrigeration cycle.

[0007]

[Action]

 Through the process of exchanging mechanical energy associated with viscous friction and inelastic collision between the flocked sound absorbing material installed in the cavity of the silencer body and the refrigerant gas, the reflection edge of the wave in the cavity and the maximum particle velocity The kinetic energy of the refrigerant gas is absorbed in the area, and the pressure wave having the resonance wavelength determined by the cavity length does not grow, and the occurrence of the resonance phenomenon is prevented.

Further, the pulsation of the high temperature and high pressure pulsating refrigerant gas discharged from the compressor is reduced by the muffler, and is generated from the outdoor heat exchanger during the cooling operation and from the indoor heat exchanger during the heating operation. Vibration and noise are reduced.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a refrigerant circuit diagram of a heat pump type air conditioner using a silencer according to the present invention. The refrigerant circuit includes a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an expansion valve 14, and an indoor heat exchanger 15, and a refrigerant pipe 16 that connects the compressor 11 and the four-way switching valve 12 is silenced. A vessel 21 is provided. The muffler 21 will be described in detail later.

Then, by switching the four-way switching valve 12, the cooling operation and the heating operation are switched. FIG. 1 shows the circuit state during the cooling operation, in which a silencer 21 is connected to the outdoor heat exchanger 13 side via a four-way switching valve 12.

During the cooling operation, the high temperature and high pressure pulsating refrigerant gas discharged from the compressor 11 is subjected to outdoor heat exchange through the refrigerant pipe 16 and the silencer 21 and the four-way switching valve 12 as shown by the solid arrow. By entering the container 13 and radiating heat to the outside, the liquid is condensed and liquefied. Then, the liquid refrigerant is adiabatically expanded by being throttled by the expansion valve 14 to become a gas-liquid two phase. Next, this refrigerant enters the indoor heat exchanger 15 where it cools the indoor air to evaporate and become a low-temperature, low-pressure gas refrigerant. This gas refrigerant returns to the compressor 11 via the four-way switching valve 12.

During heating operation, the silencer 21 is connected to the indoor heat exchanger 15 side by switching the four-way switching valve 12. The high-temperature and high-pressure pulsating refrigerant gas discharged from the compressor 11 enters the indoor heat exchanger 15 through the cooling medium pipe 16 and the silencer 21 and the four-way switching valve 12 as shown by the dashed arrow. It condenses and liquefies by heating the indoor air. After being adiabatically expanded by the expansion valve 14, this liquid refrigerant is evaporated and vaporized by the outdoor heat exchanger 13, and returns to the compressor 11 via the four-way switching valve 12.

Next, with reference to FIGS. 2A and 2B, a specific configuration of the silencer 21 will be described. In the muffler 21, the muffler body 22 has a cylindrical shape and a cavity 23 is formed therein. Then, a flocked sound absorbing material 26 is provided on the inner end surface 24 and the inner wall surface 25 in a range (L / 2 + δ) at least on the downstream side of the gas flow of the cavity of the muffler body 22 at least in the longitudinal direction. This flocking-type sound absorbing material 26 is a plate-like substrate having elasticity like artificial turf with flocked polymer material (plastic) such as nylon, polyethylene, etc., having heat resistance and refrigerating properties. It is formed into a cylindrical shape with a bottom according to the shape, and an opening is provided at the bottom thereof so as to fit the refrigerant pipe 16.

Then, the silencer 21 formed in a cylindrical shape as described above is inserted into the silencer main body 22 through an opening end provided in advance on the upstream side. At this time, for example, a protrusion 27 is formed in advance on the inner wall surface 25 of the muffler body 22 so as to abut the end of the flocked sound absorbing material 26. By providing the protrusions 27, the flocked sound absorbing material 26 having elasticity can be locked as shown in FIG. 2B, and the flocked sound absorbing material 26 can be easily mounted in the silencer body 22. Can be done. After the flocked sound absorbing material 26 is mounted in the silencer body 22 as described above, the lid body to which the refrigerant pipe 16 can be connected is attached to the open end of the silencer body 22.

By using the muffler 21 configured as described above, the high-temperature and high-pressure pulsating refrigerant gas discharged from the compressor 11 expands in the cavity 23 of the muffler 21, and the pulsation is reduced. At the same time, the effect of the flocked sound absorbing material 26 prevents the resonance phenomenon and obtains a good sound reduction effect. That is, the kinetic energy of the flocked sound absorbing material 26 is absorbed by the flocked sound absorbing material 26 through a process of exchanging mechanical energy associated with viscous friction and inelastic collision between the flocked sound absorbing material 26 and the refrigerant gas. As a result, the pressure wave having the resonance wavelength determined by the cavity length L of the silencer 21 does not grow, and the resonance phenomenon does not occur. Since the end surface of the cavity 23 in the silencer 21 serves as a reflection end of the wave, the particle velocity of the sound wave becomes "0". Therefore, the model of the amplitude and particle velocity of the sound wave (longitudinal wave and compressional wave) generated in the silencer 21 is as shown in FIGS. 3 (a) and 3 (b).

FIG. 3A shows the sound pressure d1 (broken line) and particle velocity e1 (solid line) of the fundamental vibration (primary vibration) of the standing wave, and FIG. 3B shows the sound pressure d2 of the secondary vibration. (Dashed line) and particle velocity e2 (solid line) are shown. This corresponds to the valley portion (the primary mode frequency f1 and the secondary mode frequency f2) of the sound reduction characteristics shown in FIG. A solid line a in FIG. 4 shows the noise reduction characteristic of the silencer 21 in this embodiment, and a broken line b shows the noise reduction characteristic of the conventional silencer.

Here, if the energy of the wave is absorbed at the reflection end of the wave in the cavity 23, that is, the inner end face 24 and the maximum part of the particle velocity, the sound reduction effect is obtained. Therefore, if there is the sound absorbing material 26 at a specific portion of the inner end surface 24 and the inner wall surface 25, that is, at a position "L / 2" for the fundamental vibration and "L / 4" for the secondary vibration. It will be good.

In the case of the muffler 21 shown in the above-mentioned embodiment, the sound absorbing material 26 is provided with some allowance in the inner end surface 24 of the cavity 23 and in the range of the length of the longitudinal direction L / 2 + δ, so The sound reduction effect can be obtained for all harmonics including.

Further, as shown in FIG. 1, by connecting the silencer 21 to the cooling medium pipe 16 of the compressor 11 in the refrigeration cycle, high-temperature and high-pressure pulsating refrigerant gas discharged from the compressor 11 The pulsation can be reduced, and as a result, the vibration and noise generated from the outdoor heat exchanger 13 during the cooling operation and the indoor heat exchanger 15 during the heating operation can be reliably reduced.

In the above embodiment, the case where the silencer is provided in the refrigerant pipe of the air conditioner has been described. However, also in the case where the silencer is provided in the refrigerant pipe of the refrigerator, a high noise reduction effect is similarly obtained. Obtainable.

[0022]

[Effect of device]

 As described in detail above, according to the present invention, a flocked sound absorbing material is provided on the inner end surface and the inner wall surface of the cavity inside the cavity of the silencer body at least on the downstream side of the gas flow exceeding at least 1/2 of the length direction. Therefore, a good sound reduction effect can be obtained without causing resonance in the cavity.

Further, according to the present invention, since the muffler provided with the flocked sound absorbing material in the cavity is connected to the discharge pipe of the compressor in the refrigeration cycle, high temperature and high pressure pulsation discharged from the compressor is obtained. It is possible to reliably reduce the pulsation of the refrigerant gas and effectively reduce the vibration and noise generated from the outdoor heat exchanger or the indoor heat exchanger.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a heat pump type air conditioner according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a silencer according to the embodiment.

FIG. 3 is a diagram for explaining the operation of the muffler in the embodiment.

FIG. 4 is a diagram for explaining the sound reduction characteristics of the muffler according to the embodiment.

FIG. 5 is a configuration diagram showing an example of a conventional silencer.

FIG. 6 is a configuration diagram showing another example of a conventional silencer.

[Explanation of symbols]

11 ... Compressor, 12 ... Four-way switching valve, 13 ...
Outdoor heat exchanger, 14 ... Expansion valve, 15 ... Indoor heat exchanger, 16 ... Refrigerant piping, 21 ... Silencer, 22 ...
Silencer body, 23 ... cavity, 24 ... inner end surface,
25 ... Inner wall surface, 26 ... Flocked sound absorbing material, 27 ...
Protrusion.

Claims (2)

[Scope of utility model registration request] 1. A silencer characterized in that a flocked sound absorbing material is provided on an inner end surface and an inner wall surface of a cavity inside a silencer body at a downstream side of a gas flow of at least more than ½ of a longitudinal direction. vessel. 2. An air conditioner comprising the silencer according to claim 1 connected to a discharge pipe of a compressor in a refrigeration cycle.