EP3455496A1

EP3455496A1 - A hermetic compressor with reduced noise level

Info

Publication number: EP3455496A1
Application number: EP17725885.2A
Authority: EP
Inventors: Husnu Kerpicci; Furkan Ahmet TOK; Hasim OTUNC; Ercan KURTULDU
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2016-05-09
Filing date: 2017-05-09
Publication date: 2019-03-20
Also published as: TR201606032A2; WO2017194492A1

Abstract

The present invention relates to a hermetic compressor (1) suitable for use for circulation of a refrigerant fluid in a refrigeration cycle in cooling devices, for example in refrigerators, comprising a cylinder (3) that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a cylinder head (6) that enables the refrigerant sucked and pumped into the cylinder (3) with the movement of the piston (4) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the refrigerant fluid pumped during the compression movement of the piston (4) is accumulated, and at least one exhaust muffler (11) that has a hollow, closed volume and that provides the attenuation of the noise generated during the pumping of the refrigerant, wherein the refrigerant-induced noise in the exhaust chamber (7) and the exhaust muffler (11) is reduced.

Description

A HERMETIC COMPRESSOR WITH REDUCED NOISE LEVEL

The present invention relates to a hermetic compressor suitable for use in cooling devices.
In hermetic compressors, the refrigerant is sucked from and pumped back to the refrigeration system by means of a piston operating in a cylinder. During the operation of the hermetic compressors, while the refrigerant fluid moves through the flow path, flow-induced noises occur. In particular, during the exhaust process after the compression movement of the piston, high level of noise is generated. The refrigerant in gas state entering the cylinder after the suction process is compressed with the piston and the exhaust valve in the valve table opens when the refrigerant reaches a certain pressure. The refrigerant passes through the outlet port (exhaust port) on the valve table opened by the exhaust valve and fills in the exhaust chamber in the cylinder head. The refrigerant leaving through the small-diameter exhaust port of the exhaust valve at high pressure after the compression process quickly disperses into a large volume, thus increasing the sound power level defined by decibel unit during the operation of the compressor.
The European Patent No. EP2580475 and the European Patent Application No. EP2917577 disclose a hermetic compressor a exhaust muffler (9) with a hollow, closed volume, that provides the attenuation of the noise generated during the pumping of the refrigerant fluid.
The International Patent Application No. WO2015149833 discloses a reciprocating hermetic compressor wherein the thermodynamic efficiency is improved by providing thermal insulation in the exhaust muffler thereof.
The aim of the present invention is the realization of a compressor wherein the refrigerant-induced noise in the exhaust region is enabled to be reduced.
The compressor realized in order to attain the aim of the present invention is explicated in the claims.
In the hermetic compressors, the refrigerant circulating in the refrigeration cycle is sucked and pumped by means of a piston operating in a cylinder. During the compressor movement of the piston, the refrigerant in gas state first fills into the exhaust chamber that forms a closed volume in the cylinder head, then the refrigerant is delivered from the exhaust chamber to the exhaust muffler and therefrom added back to the refrigeration cycle.
In the compressor of the present invention, a porous noise attenuator is disposed into the exhaust chamber and/or the exhaust muffler having closed volumes, disposed on the flow path followed in the compressor casing by the refrigerant pressurized by the piston.
The noise attenuator can be produced from metal foam or synthetic plastic and shaped in matching form to the geometry of the inner volumes of the exhaust chamber or the exhaust muffler.
The compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 – is the cross-sectional view of the compressor of the present invention.
Figure 2 – is the perspective view of a cylinder head and the noise attenuator disposed into the cylinder head.
Figure 3 – is the perspective view of a valve table and the exhaust port, the exhaust valve and the stopper that are disposed on the valve table.
Figure 4 - is the perspective view of a compressor body having the exhaust muffler thereon and of a noise attenuator.
Figure 5 - is the schematic view of a compressor body having the exhaust muffler thereon and of a noise attenuator in an embodiment of the present invention.
The elements illustrated in the figures are numbered as follows:
1. Compressor
2. Casing
3. Cylinder
4. Piston
5. Body
6. Cylinder head
7. Exhaust chamber
8. Valve table
9. Exhaust port
10. Exhaust valve
11. Exhaust muffler
12. Discharge channel
13. Noise attenuator
14. Stopper
15. Recess
16. Cover
The hermetic compressor (1) suitable for use for circulation of the refrigerant fluid in cooling devices, for example refrigerators, comprises a casing (2); a cylinder (3) that is disposed in the casing (2) and that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a body (5) that supports the cylinder (3) and the piston (4); a cylinder head (6) that enables the refrigerant sucked and pumped by the movement of the piston (4) into the cylinder (3) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the refrigerant fluid pumped during the compression movement of the piston (4) is accumulated; a valve table (8) that is disposed between the cylinder (3) and the cylinder head (6); an exhaust port (9) that is arranged on the valve table (8) and that enables the refrigerant to pass from the cylinder (3) to the exhaust chamber (7) during the compression movement of the piston (4); an exhaust valve (10) that is disposed on the valve table (8) and that opens/closes the exhaust port (9); at least one exhaust muffler (11) that has a hollow, closed volume, that is disposed on the body (5) and that provides the attenuation of the noise generated during the pumping of the refrigerant, and a discharge channel (12) that is arranged in the body (5) and that enables the refrigerant accumulated in the exhaust chamber (7) to be delivered to the exhaust muffler (11). The refrigerant delivered to the exhaust muffler (11) is sent out of the casing (2) therefrom so as to be added to the refrigeration cycle.
The compressor (1) of the present invention comprises a porous noise attenuator (13) that is disposed into at least one closed volume wherein the refrigerant in gas state is accumulated at reduced pressure, the closed volume being located on the flow path followed by the refrigerant in gas state in the casing (2), pumped from the cylinder (3) into the refrigeration cycle during the compression movement of the piston (4).
In an embodiment of the present invention, the noise attenuator (13) is disposed into the exhaust chamber (7) arranged in the cylinder head (6) (Figure 2).
During the compression process in the cylinder (3), the refrigerant in gas state passes through the exhaust port (9) on the valve table (8) and fills into the exhaust chamber (7). While the refrigerant passes through the pores of the noise attenuator (13) disposed into the exhaust chamber (7), the flow rate thereof is reduced by a certain amount and thus vortices generated at this region are interrupted. The noise attenuator (13) attenuates the flow-induced noise generated by the refrigerant leaving the small-diameter exhaust port (9) and immediately filling into a wide volume, that is the exhaust chamber (7), thus enabling the sound power level defined by decibel unit to be reduced.
In addition to reducing the flow-induced noise, the noise attenuator (13) generally provides that the surface temperature of the cylinder hand (6) adversely affecting the effectiveness of the compressor (1) is reduced. The refrigerant gas passing into the exhaust chamber (7) during the compression movement of the piston (4) contacts the noise attenuator (13) before the cylinder head (6), thus leaves its heat on the noise attenuator (13). The porous structure of the noise attenuator (13) increases the contact area with the high-temperature refrigerant gas, thus preventing the cylinder head (6) from heating up excessively and preventing the performance of the compressor (1) from decreasing.
The noise attenuator (13) is shaped in matching form to the geometry of the exhaust chamber (7) so as to be seated in a gapless manner into the exhaust chamber (7) in the cylinder head (6) and fixed to the cylinder head (6) by adhesion or snap-fitting.
In another embodiment of the present invention, the compressor (1) comprises a stopper (14) that is fixed onto the valve table (8), that extends into the exhaust chamber (7) and that limits the movement of the exhaust valve (10). The noise attenuator (13) comprises a recess (15) that is arranged in alignment with the stopper (14) and that is formed so as to receive the stopper (14) (Figure 2). By means of the recess (15), when the cylinder head (6) is connected to the body (5) over the valve table (8) by bolts, the stopper (14) is seated into the recess (15), thus the noise attenuator (13) does not prevent the assembly of the cylinder head (6).
In another embodiment of the present invention, the noise attenuator (13) is disposed into the exhaust muffler (11) (Figure 4).
The refrigerant in gas state filling into the exhaust chamber (7) during the compression process in the cylinder (3) passes through the exhaust pass port (not shown in the figures) on the valve table (8) so as to be delivered to the exhaust muffler (11) by means of the discharge channel (12). While the refrigerant in gas state filling into the exhaust muffler (11) from the discharge channel (12) passes through the pores of the noise attenuator (13) disposed into the exhaust muffler (11), the flow rate thereof is reduced by a certain amount and thus vortices generated at this region are interrupted. The noise attenuator (13) attenuates the flow-induced noise generated by the refrigerant leaving the small-diameter discharge channel (12) and immediately filling into a wide volume that is the exhaust muffler (11).
In this embodiment, the noise attenuator (13) is cylindrical and sized so as to be disposed into the exhaust muffler (13) in a gapless manner.
In another embodiment of the present invention, the compressor (1) comprises a cover (16) that covers the exhaust muffler (11). The cover (16) is fixed onto the exhaust muffler (11) by being screwed to the noise attenuator (13) in the exhaust muffler (11) by means of a screw hole bored from the center of the upper surface of the noise attenuator (13) towards the interior thereof (Figure 5).
In an embodiment of the present invention, the noise attenuator (13) is produced from metal foam, preferably from open-cell metal foam called metal sponge.
In another embodiment of the present invention, the noise attenuator (13) is produced from metal foam aluminum.
In another embodiment of the present invention, the noise attenuator (13) is produced from synthetic plastic sponge. The plastic sponge of the noise attenuator (13) is produced from materials such as polyethylene (PE), polypropylene (PP) or polytetrafluoroethylene (PTFE).
In the compressor (1) of the present invention, by means of the porous noise attenuator (13) disposed into the exhaust chamber (7) and/or the exhaust muffler (11), the flow-induced noise generated by the refrigerant in gas state during the compression movement of the piston (4) is reduced and the sound power level of the compressor (1) defined by decibel unit is decreased. The noise attenuator (13) increases the surface area that the high-temperature refrigerant contacts in the cylinder head (6), thus preventing the cylinder head (6) from excessive heating.

Claims

A hermetic compressor (1) suitable for use in cooling devices, comprising a casing (2); a cylinder (3) that is disposed in the casing (2) and that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a body (5) that supports the cylinder (3) and the piston (4); a cylinder head (6) that enables the refrigerant sucked and pumped by the movement of the piston (4) into the cylinder (3) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the refrigerant fluid pumped during the compression movement of the piston (4) is accumulated; a valve table (8) that is disposed between the cylinder (3) and the cylinder head (6); an exhaust port (9) that is arranged on the valve table (8) and that enables the refrigerant to pass from the cylinder (3) to the exhaust chamber (7) during the compression movement of the piston (4); an exhaust valve (10) that is disposed on the valve table (8) and that opens/closes the exhaust port (9); a stopper (14) that is fixed onto the valve table (8), that extends into the exhaust chamber (7) and that limits the movement of the exhaust valve (10); at least one exhaust muffler (11) that has a hollow, closed volume, that is disposed on the body (5) and that provides the attenuation of the noise generated during the pumping of the refrigerant, and a discharge channel (12) that is arranged in the body (5) and that enables the refrigerant accumulated in the exhaust chamber (7) to be delivered to the exhaust muffler (11), characterized by a porous noise attenuator (13) that is disposed into at least one closed volume wherein the refrigerant in gas state is accumulated, the closed volume being located on the flow path followed by the refrigerant in gas state in the casing (2), pumped from the cylinder (3) into the refrigeration cycle during the compression movement of the piston (4).
A compressor (1) as in Claim 1, characterized by the noise attenuator (13) that is disposed into the exhaust chamber (7) in the cylinder head (6).
A compressor (1) as in Claim 2, characterized by the noise attenuator (13) that is shaped in a matching form to the geometry of the exhaust chamber (7) so as to be seated into the exhaust chamber (7).
A compressor (1) as in any one of the Claims 1 to 3, characterized by the noise attenuator (13) comprising a recess (15) that is arranged in alignment with the stopper (14) and that is formed so as to receive the stopper (14).
A compressor (1) as in Claim 1, characterized by the noise attenuator (13) that is disposed into the exhaust muffler (11).
A compressor (1) as in Claim 5, characterized by the noise attenuator (13) that is cylindrical and that is disposed into the inner volume of the exhaust muffler (11) in a gapless manner.
A compressor (1) as in Claim 5 or 6, characterized by a cover (16) that is fixed onto the exhaust muffler (11) by being screwed to the noise attenuator (13) in the exhaust muffler (11).
A compressor (1) as in any one of the Claim 1, 2 and 5, characterized by the noise attenuator (13) that is produced from metal foam.
A compressor (1) as in Claim 8, characterized by the noise attenuator (13) that is produced from aluminum.
A compressor (1) as in any one of the Claim 1, 2 and 5, characterized by the noise attenuator (13) that is produced from synthetic plastic sponge.
A compressor (1) as in Claim 10, characterized by the noise attenuator (13) that is produced from polyethylene (PE), polypropylene (PP) or polytetrafluoroethylene (PTFE).