EP2549108B1 - Acoustic damping in a coolant circuit - Google Patents

Description

The invention relates to a silencer device for a refrigerant oil carrying refrigerant circuit.

It is known to use in a refrigerant circuit system silencer, with which the pressure pulsations of a refrigerant emerging from a compressor of the refrigerant circuit can be reduced. For example, describes the DE 10 2008 050 01.1 A1 a muffler called a "straight type" in which the inlet pipe through which a refrigerant flows into the muffler chamber is aligned with respect to the outlet pipe through which the refrigerant flows out of the muffler chamber. The refrigerant flows linearly into the sound-absorbing chamber. Further, in said document, a "manifold type" muffler is described, over which the direction in which the inlet pipe is connected to the housing of the sound absorbing chamber is orthogonal to the direction in which the outlet pipe is connected to the housing. Furthermore, from the KR 10 2008 0038784 A a muffler for an air conditioner of a vehicle is known in which an input pipe for a refrigerant and a discharge pipe for a refrigerant are arranged on two opposite sides of the muffler housing and are directed in different directions within the housing.

For lubricating moving parts in the refrigeration system circuit, in particular a compressor, a refrigerant oil is usually used. Such a refrigerant oil is mixed with the refrigerant of the refrigeration system circuit in operation and therefore runs in the refrigerant circuit with. For the refrigerant R 134 A is a suitable refrigerant oil. Polyalkylene glycol.

The refrigerant oil is usually entrained by the flow of the refrigerant in the tubes of the refrigerant piping. However, there is the risk in the known mufflers that a separation of refrigerant oil takes place on a muffler chamber inner wall and the muffler acts as an oil trap.

To prevent oil separation in the muffler, as in the EP 1 811 174 A2 is shown, the silencer be preceded by a Ölabscheidekammer from a return of refrigerant oil to the compressor. Also from the DE 60 30 4550 T2 is known to make an oil separation before the entry of the refrigerant in the muffler chamber.
The document DE 198 82 899 It is considered to be the closest prior art and discloses the features of the preamble of claim 1. The object of the present invention is to provide a sound attenuation in a refrigerant circuit carrying refrigerant oil, with which accumulation of refrigerant oil in the muffler chamber can be reduced or prevented.

The object is achieved with the features of the independent claim.

The silencing device according to the invention for a refrigerant circuit carrying a refrigerant oil comprises a housing in which an upper silencer chamber and a lower silencer chamber are arranged, the upper silencer chamber having an upper feed opening which is connectable to the refrigerant circuit and a lower discharge opening which communicates with the refrigerant circuit is connectable and disposed between the upper and lower muffler chamber and Schalldämpfentrennwand having a the upper muffler chamber with the lower muffler chamber connecting the damping tube which projects with an upper pipe section with an upper opening in the upper muffler chamber, wherein on the upper side of the muffler partition accumulated refrigerant oil at a level exceeding the height of the upper pipe section, together with refrigerant vapor from the lower silencer chamber is manageable.

The volume and dimensions of the upper silencer chamber, the lower silencer chamber and the silencer pipe are designed for interference damping of the pressure pulsation in the gaseous refrigerant. Preferably, the longitudinal extension of the upper muffler chamber in the vertical direction of the longitudinal extent in the horizontal direction. In particular, the length of the upper tube section is matched to the dimensions of the inner space of the upper silencer chamber in order to achieve optimum sound damping. Further, the position of the upper opening to the position of the damping tube is staggered to optimize the sound attenuation, wherein the inflow direction of the refrigerant is oriented in the interior of the sound attenuation chamber parallel to the outflow through the Dämppungsrohr. The position of the lower opening is selected such that the outflow direction of the refrigerant is oriented orthogonal to the inflow direction of the refrigerant through the Dampfungsrohr into the interior of the lower silencing chamber. It is understood that another relative orientation of the flow through the upper or lower opening for orientation of the flow through the damping tube is also encompassed by the invention.

In operation, refrigerant is supplied via the upper supply port of the upper silencer chamber, which carries a refrigerant oil and acts on the inner walls of the upper silencer chamber. In this case, there is an accumulation of oil on the top of the muffler partition. The amount of the accumulated refrigerant oil depends on the height of the upper opening, which, however, can not be arbitrarily reduced so as not to deteriorate the damping characteristics of the device. However, after a certain period of operation of the device, the amount of accumulated oil has increased so much that the level has reached the height of the upper opening. From this point on, part of the accumulated oil in the form of oil droplets can be transported into the lower silencer chamber through the refrigerant gas passing through the damper tube. Since an attenuation of pulsations of the refrigerant has already taken place in the upper silencer chamber, the inner walls of the lower silencer carums are to a lesser extent supplied with refrigerant and entrained refrigerant oil, so that there is less oil separation there. In contrast to the silencers known from the prior art, an oil return takes place to a great extent via the lower discharge opening to the compressor. However, the volume of the upper muffler chamber is reduced by accumulated oil in operation, resulting in a change in the sound damping characteristics of the upper muffling chamber over its Schalldämpfurigseigenschaftn without accumulated refrigerant oil.

The invention is also achieved by a silencing device for a refrigerant circuit with a refrigerant containing a refrigerant oil, comprising a housing in which a first silencer chamber and a second silencer chamber are arranged, wherein the first silencer chamber has a first supply port, which is connectable to the refrigerant circuit and the second silencer chamber has a second discharge opening which is connectable to the refrigerant circuit and between the first and second silencer chamber a Schalldämpfentrennwand is arranged, which has a the first silencer chamber with the second silencer chamber connecting damping tube, which with a first pipe section having a first opening in the first silencer chamber protrudes, wherein in the silencer partition at least one oil bypass opening is arranged, which connects the first and second silencer chamber.

In particular, the object is also achieved by a muffling device comprising a housing in which .An upper Schälldämpferkammer and a lower muffler chamber are arranged, wherein the upper muffler chamber has an upper feed opening, which is connectable to the refrigerant circuit and having a lower discharge opening, which is connectable to the refrigerant circuit and wherein between the upper and lower muffler chamber a muffler partition is arranged, comprising a damping tube connecting the upper muffler chamber to the lower muffler chamber, which projects into the upper muffler chamber with an upper pipe section having an upper opening, wherein at least one oil bypass opening connecting the upper and lower muffler chambers is disposed in the muffler partition wall.

Furthermore, the object is also achieved by a sound damping device comprising a housing in which a left silencer chamber and a right silencer chamber are arranged, wherein the left silencer chamber has a left feed opening, which is connectable to the refrigerant circuit and has a right discharge opening, which with the refrigerant circuit is connectable and that between the left and right muffler chamber a Schalldämpfentrennwand is arranged, which has a left muffler chamber connecting the right muffler chamber damping tube, with a left pipe section with a left opening in the left muffler chamber protrudes, wherein in the muffler partition in a Area below the height of the left opening at least one oil bypass opening is arranged, which connects the left and right muffler chamber. In this embodiment, oil may accumulate in the region of the lower housing wall, but it is ensured by the relatively low arranged oil bypass opening that this oil is present in both the left and right muffler chamber and from the right muffler chamber together with the refrigerant through the right discharge opening can be removed. It goes without saying that the terms "left" and "right" merely serve to define a direction. Therefore, the invention also includes a variant in which a supply of refrigerant into a right silencer chamber and a discharge of refrigerant from a left silencer chamber.

In the two last-described embodiments of the invention, an oil return to the compressor is ensured even if the oil level of the accumulated oil has not yet reached the height of the upper or left opening. In particular, it is also achieved that the volume of the upper muffler chamber is reduced to a lesser extent by accumulated oil during operation.

Advantageously, it is provided that the sound-damping tube has a clear diameter D and the at least one oil-bypass opening has a clear diameter d <D, in particular a diameter d <½ D. If the oil bypass opening has a clear diameter d <D, it is achieved that the damping properties of the chamber are largely determined by the chamber volume and the damping tube and by the oil bypass opening only to a lesser extent.

It is advantageously provided for acoustic optimization of the device that the damping tube protrudes with a lower pipe section with a lower opening in the lower muffler chamber. In particular, the upper and lower pipe sections have the same length.

Analog is provided that the damping tube protrudes with a right pipe section with a right opening in the right muffler chamber.

Another embodiment of the invention is characterized in that at least two oil bypass openings are provided, whereby a faster release of oil into the lower silencer chamber can be achieved.

A further embodiment of the invention is characterized in that the muffler separating wall seen from the interior of the upper muffler chamber has a concave shape, whereby a further acceleration of the delivery of oil into the lower muffler chamber is achieved.

A further embodiment of the invention is characterized in that the housing is designed as a deep-drawn pot made of a sheet metal material, whereby the housing manufacturing technology can be easily manufactured.

A further embodiment of the invention is characterized in that the housing has a circular cross-section in a plane perpendicular to a longitudinal axis of the housing, whereby a housing of tube mechanical stability which is easy to manufacture can be achieved, the acoustic damping properties of which can be calculated very simply.

A further embodiment of the invention is characterized in that the housing has an ellipsoidal cross-section in a plane perpendicular to a longitudinal axis of the housing, whereby a housing of tubular mechanical stability which is easy to produce can be achieved, the acoustic damping properties of which can be calculated very simply.

Further advantages, features and details will become apparent from the following description in which at least one embodiment will be described in detail with reference to the drawing. Described and / or illustrated features, alone or in any meaningful combination, constitute the invention and, where appropriate, also independent of the patent claims and in particular may also be the subject of one or more separate ones Be inventions. The same or similar parts may be provided with the same reference numerals.

Figur 1

eine Schalldämpfervorrichtung mit einer oberen Schalldämpfungskammer und einer unteren Schalldämpfungskammer

Figur 2

Schalldämpfervorrichtungen mit einem verbesserten Ölbypass.

It show in a schematic representation

FIG. 1

a muffler device with an upper silencer chamber and a lower silencer chamber

FIG. 2

Silencer devices with improved oil bypass.

FIGS. 1a to 1c show a schematic representation of a silencer device 1 according to the invention with a housing 10 in which an upper silencer chamber 15 and a lower silencer chamber 20 are arranged. The sound damping device 1 is integrated in a refrigerant circuit, in particular of a motor vehicle, and in particular enables the damping of pressure pulsation in the refrigerant. The upper silencing chamber 15 has an upper supply port 16 for a supply 17 of refrigerant. Between the upper muffler chamber 15 and the lower muffler chamber 20, a partition wall 30 is disposed with a damping tube 40 connecting the upper muffler chamber 15 and the lower muffler chamber 20. The volume and dimensions of the upper muffler chamber 15, the lower muffler chamber 20, and the sound attenuation tube 40 are designed for one Interference damping of pressure pulsation in gaseous refrigerant. Further, the upper opening 16 is arranged offset to the position of the damping tube 40 to optimize the sound attenuation. The lower muffler chamber 20 has a discharge opening 21 for a discharge 22 of refrigerant, which has an orthogonal orientation to the damping tube 40 and to the orientation of the upper opening 16. The damping tube 40 protrudes with an upper part 41 into the interior of the muffler chamber 15. The length of the upper portion 41 is determined depending on the desired damping characteristics of the muffler chamber 15. The damping tube 40 further includes a lower portion 42 which in the lower muffler chamber 20 sticks out. The length of a lower portion 42 of the damping tube 40 is determined by the desired damping properties of the lower muffler chamber 20. The damping tube 40 has a clear diameter D, which is also determined by the desired damping properties of the upper muffler chamber 15 and the lower muffler chamber 20th

In FIG. 1b For example, there is shown a situation in which an oil pool 31 has already formed on top of the partition wall 30 due to an oil separated from the refrigerant gas / oil droplet mixture 18. It is indicated that due to the deposition of the Oil, which is relatively free of refrigerant oil 19 via the discharge port 21 to the refrigerant circuit guided refrigerant gas 19.

In Figure 1c As shown, once the oil pool 31 has reached a level corresponding to the height of the upper opening 41a, refrigerant oil may be returned to the lower muffler chamber 20 via the muffler pipe 40 together with refrigerant gas and optionally to the compressor of the refrigerant cycle via the return line 22.

FIG. 2a shows a further embodiment of a muffler device. In the muffler assembly 1 a, there is disposed in the partition wall 30 an oil bypass port 55 through which refrigerant oil from a refrigerant oil pool 56 can enter the lower muffler chamber 20 and mix with refrigerant gas to form a refrigerant gas / oil droplet mixture 18. The refrigerant oil pool 56 has a smaller volume than the refrigerant oil pool 31 as long as sufficient drainage of refrigerant oil can be made through the oil bypass opening 55 Figure 1c , An accelerated outflow of oil from the refrigeration oil accumulation 56 can be achieved in that the partition wall 50 is lowered in the region of the oil bypass opening 55 and has a concave shape seen from the interior of the upper muffler chamber 15, since in this case refrigerant oil from the farther from the oil bypass opening 56 remote areas of the partition 50 in the region of the oil bypass opening 56 can flow. It is preferred that the sound attenuation tube 40 has a clear diameter D and the oil bypass opening 56 has a clear diameter d <D, in particular a diameter d <½ D.

FIG. 2b shows a further embodiment of a sound damping device 1b with a housing in which a left muffler chamber 15 and a right muffler chamber 20 are arranged. The sound damping device 1b has an orientation rotated at an angle of 90 ° with respect to the device 1a. The left muffler chamber 15 has a left feed opening 16 which is connectable to the refrigerant circuit, the right muffler chamber 20 having a right discharge opening 21 which is connectable to the refrigerant circuit. Disposed between the left and right muffler chambers 15 and 20 is a muffler partition 50 having a muffling pipe 40 connecting the left muffler chamber 15 to the right muffler chamber 20, which projects into the left muffler chamber 15 with a left pipe 41 with a left opening 41b. The damper tube 40 projects into the right muffler chamber 20 with a right pipe section 42. In the muffler partition wall 50, there are disposed a lower oil bypass opening 55a and an upper oil bypass opening 55b connecting the left and right muffler chambers 15 and 20. In the area of a lower housing wall 10a, accumulated oil 56a is shown extending to both the left and right of the muffler partition wall 50. An oil return to the compressor can be done even with very small amounts of accumulated oil, since the oil can flow relatively unhindered from the left silencer chamber 15 through the lower opening 55 a in the right silencer chamber 20.

LIST OF REFERENCE NUMBERS

• 1 silencer arrangement
• 1 a, 1b muffler assembly
• 10 housing
• 10a lower housing wall
• 15 upper silencer chamber
• 16 upper feed opening
• 17 lead
• 18 refrigerant gas / oil droplet mixture
• 19 refrigerants
• 20 lower silencing chamber
• 21 discharge opening
• 22 return
• 30 silencer partition
• 31 oil accumulation
• 40 damping tube
• 41 upper section damping tube
• 41 a upper opening
• 41 b left opening
• 42 lower section damping tube
• 42a lower opening
• 42b right opening
• 50 silencer partition
• 55, 55a, 55b oil bypass opening
• 56, 56a oil accumulation

Claims (8)

1. Refrigerant circuit having a refrigerant comprising a refrigerant oil, having a silencer device comprising a housing (10) in which a first silencer chamber (15) and a second silencer chamber (20) are arranged, wherein the first silencer chamber (15) has a first supply opening (16) which is connectable to the refrigerant circuit, and the second silencer chamber (20) has a second discharge opening (21) which is connectable to the refrigerant circuit, and between the first and second silencer chamber (15, 20) there is arranged a silencer partition (50) which has at least one damping tube (40) which connects the first silencer chamber (15) to the second silencer chamber (20) and which projects, with a first tube section (41) having a first opening (41a), into the first silencer chamber (15), characterized in that in the silencer partition (50) there is arranged at least one oil bypass opening (55) which connects the first and second silencer chamber (15, 20).
2. Refrigerant circuit according to Claim 1, characterized in that the first silencer chamber (15) is an upper silencer chamber and the second silencer chamber (20) is a lower silencer chamber, wherein the first supply opening (16) is designed as an upper supply opening (16) which is connectable to the refrigerant circuit.
3. Refrigerant circuit according to Claim 1, characterized in that the first silencer chamber (15) is a left-hand silencer chamber and the second silencer chamber (20) is a right-hand silencer chamber, wherein the first supply opening (16) is designed as a left-hand supply opening which is connectable to the refrigerant circuit, and the second discharge opening (21) is designed as a right-hand discharge opening.
4. Refrigerant circuit according to one of Claims 1 to 3, characterized in that at least two oil bypass openings (55a, 55b) are provided in the silencer partition (50).
5. Refrigerant circuit according to one of Claims 1 to 4, characterized in that the damping tube (40) has an inside diameter D and at least one oil bypass opening (55, 55a, 55b) has an inside diameter d < D, in particular a diameter d < ½ D.
6. Refrigerant circuit according to one of the preceding claims, characterized in that the housing (10) is designed as a deep-drawn pot made of a sheet-metal material.
7. Refrigerant circuit according to one of the preceding claims, characterized in that the housing (10) has a circular cross section in a plane perpendicular to a longitudinal axis of the housing.
8. Refrigerant circuit according to one of Claims 1 to 6, characterized in that the housing has an ellipsoidal cross section in a plane perpendicular to a longitudinal axis of the housing.

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