Discharge valve arrangement for a scroll compressor

Abstract

Discharge valve arrangement for a scroll compressor. The discharge valve arrangement (13) includes a fluid inlet (14) and at least one fluid outlet (15), the fluid inlet (14) being configured to be fluidically connected to a discharge passage (8) of a compression stage (4) of the scroll compressor (2), and the at least one fluid outlet (15) being configured to be fluidically connected to a discharge chamber (9) of the scroll compressor (2). The discharge valve arrangement (13) further includes a plurality of fluidic diodes (22). Figure 1

Description

Title of the invention: Discharge valve arrangement for a scroll compressor Field of invention

[0001] The present invention relates to a discharge valve arrangement for a scroll compressor. Background of the invention

[0002] A scroll compressor comprises, in known manner, a hermetic casing; a compression stage comprising a fixed scroll element comprising a fixed base plate from which a fixed scroll extends, and a movable scroll element comprising a movable base plate from which a movable scroll extends, the fixed and movable scrolls interpenetrating to provide variable-volume compression chambers; a discharge passage provided in a central portion of the fixed scroll element, the discharge passage comprising a first end opening into a central compression chamber and a second end intended to be placed in communication with a discharge chamber delimited by the hermetic casing and the fixed base plate of the fixed scroll element; and a discharge valve mounted on the fixed base plate at the second end of the discharge passage.

[0003] The discharge valve comprises at least one discharge opening arranged to connect the discharge passage and the discharge chamber, a valve seat surrounding the discharge opening, a closure member movable between a closing position in which the closure member bears against the valve seat and closes the discharge opening, and a release position in which the closure member is moved away from the valve seat and releases the discharge opening, and a retaining structure configured to serve as a stop for the closure member when the latter is in the release position.

[0004] Such a discharge valve makes it possible in particular to avoid, when the compressor is stopped, a flow of fluid from the discharge chamber towards the discharge passage which would be likely to induce a reverse rotation of the movable volute element and therefore a degradation of the scroll compressor which would be detrimental to the performance of the latter.

[0005] However, precise machining of the closure member, retaining structure and valve seat is necessary to ensure proper closure of the discharge valve when the compressor stops, while ensuring proper opening. proper discharge valve operation during compressor operation, under all compressor operating conditions.

[0006] Consequently, the use of such a discharge valve significantly increases the manufacturing costs of the scroll compressor. In addition, the use of such a discharge valve generates noise when the closing member contacts the valve seat. Summary of the invention

[0007] The present invention aims to remedy all or part of these drawbacks.

[0008] The technical problem underlying the invention therefore consists of providing a passive discharge valve arrangement which is reliable and easier to manufacture and assemble, whilst not reducing the efficiency of the scroll compressor.

[0009] To this end, the present invention relates to a discharge valve arrangement for a scroll compressor, the discharge valve arrangement comprising a fluid inlet and at least one fluid outlet, the fluid inlet being configured to be fluidically connected to a discharge passage of a compression stage of the scroll compressor, the at least one fluid outlet being configured to be fluidically connected to a discharge chamber of the scroll compressor, characterized in that the discharge valve arrangement comprises a plurality of fluid diodes.

[0010] As used herein, the term "fluidic diode" refers to any device capable of having a fluid flow therethrough and defining a flow path that has relatively low resistance to fluid flow in a first flow direction (also referred to as a "forward flow direction") and relatively high resistance to fluid flow in a second flow direction (also referred to as a "reverse flow direction") opposite the first flow direction.

[0011] The fact that the discharge valve arrangement comprises a plurality of fluid diodes ensures very high flow resistance in a direction of fluid flow from the discharge chamber to the discharge passage, while ensuring very low flow resistance in a direction of fluid flow from the discharge passage to the discharge chamber.

[0012] Thus, the discharge valve arrangement according to the present invention, which is free of moving parts, is more reliable and generates less noise than a conventional discharge valve, while providing the necessary pressure drop performance to prevent reverse rotation of the scroll element when the compressor is stopped.

[0013] The discharge valve arrangement may further have one or more of the following characteristics, taken alone or in combination.

[0014] According to one embodiment of the invention, each fluidic diode is devoid of any moving part.

[0015] According to one embodiment of the invention, the fluidic diodes are arranged in parallel with each other and define flow paths connected in parallel to the fluid inlet.

[0016] According to one embodiment of the invention, the discharge valve arrangement has a first pressure drop in a first flow direction corresponding to a flow of a fluid from the compression stage to the discharge chamber, and a second pressure drop in a second flow direction which is opposite to the first flow direction and which corresponds to a flow of the fluid from the discharge chamber to the compression stage, the second pressure drop being greater than the first pressure drop.

[0017] According to one embodiment of the invention, the first pressure drop is relatively low, and the second pressure drop is relatively high.

[0018] According to one embodiment of the invention, the discharge valve arrangement has a diodicity value Di greater than 10, in particular greater than 12, in particular greater than 20, where the diodicity value Di is the ratio between the pressure drop in the second flow direction and the pressure drop in the first flow direction for identical flow rates.

[0019] According to one embodiment of the invention, the discharge valve arrangement comprises, proximate the fluid inlet, a mounting portion configured to be secured to a base plate of a scroll element of the compression stage, said base plate comprising the discharge passage.

[0020] According to one embodiment of the invention, the mounting portion comprises a cylindrical wall portion surrounding the fluid inlet and intended to be inserted into a mounting opening formed in the base plate of the volute element.

[0021] According to one embodiment of the invention, the mounting part further comprises a radial bearing portion which is configured to bear against the base plate.

[0022] According to one embodiment of the invention, the cylindrical wall portion projects axially from the radial support portion.

[0023] According to one embodiment of the invention, the discharge valve arrangement comprises a distribution chamber which is fluidically connected to the fluid inlet, and a plurality of distribution channels opening into the distribution chamber.

[0024] According to one embodiment of the invention, each of the fluidic diodes is of the vortex type.

[0025] According to one embodiment of the invention, each of the fluidic diodes comprises, seen in the first flow direction, an inlet channel formed by one of the distribution channels, a vortex chamber into which the respective inlet channel opens, and a tangential outlet channel connected tangentially to the respective vortex chamber.

[0026] According to one embodiment of the invention, the vortex chamber of each of the fluidic diodes is circular in shape.

[0027] According to one embodiment of the invention, each vortex chamber is attached to at least one adjacent vortex chamber. Such a configuration of the discharge valve arrangement increases the rigidity of the latter and reduces vibrations and noise.

[0028] According to one embodiment of the invention, each inlet channel opens axially into the respective vortex chamber.

[0029] According to one embodiment of the invention, each inlet channel has a longitudinal axis which is substantially perpendicular to a lower wall of the respective vortex chamber.

[0030] According to one embodiment of the invention, each inlet channel opens into the respective vortex chamber through a chamber opening formed substantially in the center of the lower wall of said vortex chamber.

[0031] According to one embodiment of the invention, the inlet channel of each fluidic diode has a passage section which decreases from the distribution chamber towards the respective vortex chamber.

[0032] According to one embodiment of the invention, the inlet channel of each fluidic diode has a generally frustoconical shape.

[0033] According to one embodiment of the invention, the inlet channel of each fluidic diode has a taper angle, also called a half-apex angle, of at least 10 degrees and at most 25 degrees. Thus, a fluid flow in the second flow direction will create small vortex areas along the inner surface of the inlet channel of each fluidic diode due to the increasing flow section, thereby increasing the pressure drop in the second flow direction. At the same time, the slight taper of each inlet channel limits the acceleration and thus also the pressure drop in the first flow direction.

[0034] According to one embodiment of the invention, each vortex chamber has a circular disc shape and comprises lower and upper walls which are substantially flat and a circumferential wall which extends substantially perpendicular to the respective lower and upper walls.

[0035] According to one embodiment of the invention, the lower and upper walls of each vortex chamber are substantially parallel to each other.

[0036] According to one embodiment of the invention, an outer surface of the wall in The lower edge of each vortex chamber is connected to an upper edge of the circumferential wall of an adjacent vortex chamber. Thus, a ring structure of the fluidic diodes is created, in which the vortex chambers overlap. Again, such a configuration helps to increase the rigidity and minimize the overall axial height of the discharge valve arrangement.

[0037] According to one embodiment of the invention, the longitudinal axis of each inlet channel extends from the distribution chamber in a radially outward direction.

[0038] According to one embodiment of the invention, the tangential outlet channel of each fluidic diode is connected tangentially to the respective vortex chamber at the circumferential wall of said vortex chamber.

[0039] According to one embodiment of the invention, the tangential outlet channel of each fluidic diode has a constant cross-section.

[0040] According to one embodiment of the invention, each tangential outlet channel comprises a fluid outlet which is configured to open into the discharge chamber and which is oriented opposite to the fluid inlet. Such a configuration ensures, for each fluid diode, a low pressure drop in the first flow direction, since the fluid is discharged from the respective vortex chamber in a direction towards a discharge sleeve of the scroll compressor fixed to the casing of the scroll compressor. Furthermore, such a configuration contributes to minimizing the total axial height of the discharge valve arrangement.

[0041] According to one embodiment of the invention, the fluid outlet of each tangential outlet channel is configured to be oriented away from the base plate of the volute element.

[0042] According to one embodiment of the invention, the fluid outlets of the tangential outlet channels are located substantially in the same outlet plane, which may for example be substantially parallel to the extension plane of the base plate.

[0043] According to one embodiment of the invention, the outer wall of each inlet channel, viewed along the respective longitudinal axis, forms an angle of at least 45 degrees with a lower axial end surface of the cylindrical wall portion of the mounting part. Such a configuration facilitates the possibility of manufacturing the discharge valve arrangement by a 3D printing process.

[0044] For the same reasons, the lower and upper walls of each vortex chamber are each inclined at an angle of at least 45 degrees relative to the lower axial end surface of the cylindrical wall portion of the mounting part.

[0045] According to one embodiment of the invention, the outlet plane of the fluid outlets of the tangential outlet channels is substantially parallel to the lower axial end surface of the cylindrical wall portion.

[0046] According to one embodiment of the invention, the longitudinal axis of each inlet channel forms an angle of between 30 and 60 degrees relative to the lower axial end surface of the cylindrical wall portion of the mounting part.

[0047] According to one embodiment of the invention, the fluidic diodes are of the Tesla type.

[0048] According to one embodiment of the invention, each fluidic diode comprises a An elongated conduit comprising a series of internal recesses and / or internal projections arranged along the elongated conduit and configured such that the elongated conduit has low flow resistance in a first flow direction, and high flow resistance in a second flow direction opposite the first flow direction. Advantageously, the internal recesses or projections form flow barriers in the second flow direction.

[0049] According to one embodiment of the invention, the number of fluidic diodes is greater than or equal to three, in particular greater than or equal to six or more.

[0050] According to one embodiment of the invention, the fluidic diodes are distributed, and advantageously regularly distributed, in a circumferential direction around a central axis of the discharge valve arrangement. Advantageously, the central axis is substantially parallel to the cylindrical wall portion.

[0051] According to one embodiment of the invention, the fluidic diodes are configured to be regularly distributed in a circumferential direction around an axis of the discharge passage of the compression stage.

[0052] According to one embodiment of the invention, the axis of the discharge passage is perpendicular to the base plate of the volute element of the compression stage.

[0053] According to one embodiment of the invention, the discharge valve arrangement is manufactured by an additive manufacturing method, for example by 3D printing.

[0054] According to one embodiment of the invention, the discharge valve arrangement is made of plastic, ceramic or metal.

[0055] According to one embodiment of the invention, the discharge valve arrangement is made of aluminum, an aluminum alloy or stainless steel (for example type 316L).

[0056] The present invention further relates to a scroll compressor comprising a discharge valve arrangement according to the present invention.

[0057] According to one embodiment of the invention, the scroll compressor further comprises a non-return valve arranged adjacent to a discharge sleeve of the scroll compressor. Brief description of the drawings

[0058] In any case, the invention will be better understood with the aid of the description which follows with reference to the appended schematic drawings representing, by way of example not limiting, an embodiment of this discharge valve arrangement.

[0059] [Fig-1] is a partial longitudinal sectional view of a scroll compressor comprising a discharge valve arrangement according to the present invention.

[0060] [Fig.2] is a longitudinal sectional view of the discharge valve arrangement according to the present invention.

[0061] [Fig.3] is a top perspective view of the discharge valve arrangement of [Fig.2],

[0062] [Fig.4] is a perspective view from below of the discharge valve arrangement of [Fig.2].

[0063] [Fig.5] is a partially truncated top perspective view of the arrangement of discharge valve of [Fig.2]. Detailed description of the invention

[0064] Figures 1 to 5 represent a scroll compressor 2 comprising a hermetic casing 3 delimited for example by a shell whose upper and lower ends are closed respectively by a cover and a base.

[0065] The scroll compressor 2 further comprises a compression stage 4 comprising a fixed scroll element 5 comprising a fixed base plate 6 from which extends a fixed scroll 7 facing downwards, and a movable scroll element (not visible in the figures) comprising a movable base plate from which extends a movable scroll facing upwards. In a known manner, the fixed and movable scrolls interpenetrate to provide variable volume compression chambers.

[0066] The fixed base plate 6 more particularly comprises a discharge passage 8 arranged in a central part of the fixed volute element 5. The discharge passage 8 comprises a first end opening into a central compression chamber and a second end intended to be placed in communication with a discharge chamber 9 delimited by the hermetic casing 3 and the fixed base plate 6 of the fixed volute element 5. According to the embodiment shown in the figures, the axis of the discharge passage 8 is perpendicular to the fixed base plate 6 of the fixed volute element 5.

[0067] The scroll compressor 2 may further comprise a non-return valve 11 arranged adjacent to a discharge sleeve 12 fixed to the hermetic casing 3.

[0068] The scroll compressor 2 also comprises a discharge valve arrangement 13 comprising a fluid inlet 14 configured to be fluidically connected to the discharge passage 8 and a plurality of fluid outlets 15 configured to be fluidically connected to the discharge chamber 9. The discharge valve arrangement 13 may for example be made of plastic, ceramic or metal. The discharge valve arrangement 13 may in particular be made of aluminum, an aluminum alloy or stainless steel (for example type 316L). The discharge valve arrangement 13 is advantageously manufactured by an additive manufacturing process, for example by 3D printing.

[0069] The discharge valve arrangement 13 further comprises, proximate the fluid inlet 14, a mounting portion 16 configured to be secured to the fixed base plate 6 of the fixed scroll element 5.

[0070] As shown more particularly in [Fig.2], the mounting part 16 comprises a cylindrical wall portion 17 surrounding the fluid inlet 14 and intended to be inserted into a mounting opening formed in the fixed base plate 6, and further a radial bearing portion 18 which is configured to bear against the fixed base plate 6. Advantageously, the cylindrical wall portion 17 projects axially from the radial bearing portion 16.

[0071] The discharge valve arrangement 13 further comprises a distribution chamber 19 which is fluidically connected to the fluid inlet 14, and a plurality of distribution channels 21 opening into the distribution chamber 19.

[0072] The discharge valve arrangement 13 also comprises a plurality of fluid diodes 22 which are arranged in parallel with each other and which define flow paths connected in parallel to the fluid inlet 14. The number of fluid diodes 22 is advantageously greater than or equal to three, and is in particular greater than or equal to six.

[0073] The fluidic diodes 22 are configured such that the discharge valve arrangement 13 has a first pressure drop Apf in a first flow direction corresponding to a flow of a fluid from the compression stage 4 to the discharge chamber 9, and a second pressure drop Apr in a second flow direction which is opposite to the first flow direction and which corresponds to a flow of the fluid from the discharge chamber 9 to the compression stage 4. Advantageously, the first pressure drop Apf is relatively low, and the second pressure drop Apr is relatively high.

[0074] According to one embodiment of the invention, the discharge valve arrangement 13 has a diodicity value Di greater than 10, in particular greater than 12, in particular greater than 20, where the diodicity value Di is the ratio between the second pressure drop in the second flow direction and the first pressure drop in the first flow direction for identical flow rates.

[0075] The fluidic diodes 22 are advantageously regularly distributed in a circumferential direction around a central axis of the discharge valve arrangement 13 which may for example be substantially coincident with the axis of the discharge passage 8.

[0076] According to the embodiment shown in the figures, each of the fluidic diodes 22 is of the vortex type. Thus, each fluidic diode 22 comprises, seen in the first flow direction, an inlet channel 23 formed by one of the distribution channels 21, a vortex chamber 24 of circular shape and into which the respective inlet channel 23 opens, and a tangential outlet channel 25 connected tangentially to the respective vortex chamber 24.

[0077] According to the embodiment shown in the figures, each vortex chamber 24 has a circular disc shape and comprises lower and upper walls 24.1, 24.2 which are flat and parallel to each other and a circumferential wall 24.3 which extends perpendicular to the respective lower and upper walls 24.1, 24.2. Advantageously, the lower and upper walls 24.1, 24.2 of each vortex chamber 24 are each inclined at an angle of at least 45 degrees relative to a lower axial end surface 26 of the cylindrical wall portion 17 of the mounting part 16.

[0078] According to the embodiment shown in the figures, each vortex chamber 24 is attached to at least one adjacent vortex chamber 24. Thus, an outer surface of the lower wall 24.1 of each vortex chamber 24 may for example be connected to an upper edge of the circumferential wall 24.3 of an adjacent vortex chamber 24.

[0079] As shown more particularly in Figures 2 and 5, each inlet channel 23 opens into the respective vortex chamber 24 through a chamber opening 27 formed substantially in the center of the lower wall 24.1 of said vortex chamber 24. Advantageously, each inlet channel 23 comprises a longitudinal axis A which extends from the distribution chamber 19 in a radially outward direction and which is perpendicular to the lower wall 24.1 of the respective vortex chamber 24. According to the embodiment shown in the figures, the longitudinal axis A of each inlet channel 23 forms an angle of between 30 and 60 degrees with respect to the lower axial end surface 26 of the cylindrical wall portion 17 of the mounting part 16.

[0080] According to the embodiment shown in the figures, the inlet channel 23 of each fluidic diode 22 has a passage section which decreases from the distribution chamber 19 towards the respective vortex chamber 24. The inlet channel 23 of each fluidic diode 22 may for example have a generally frustoconical shape. In this case, the inlet channel 23 of each fluidic diode 22 advantageously has a conicity angle, also called a half-angle at the apex, of at least 10 degrees and at most 25 degrees.

[0081] According to the embodiment shown in the figures, the external wall 28 of each inlet channel 23, seen along the respective longitudinal axis A, forms an angle of at least less than 45 degrees with the lower axial end surface 26 of the cylindrical wall portion 17 of the mounting part 16.

[0082] As shown in [Fig.5], the tangential outlet channel 25 of each fluidic diode 22 has a constant cross-section, and is tangentially connected to the respective vortex chamber 24 at the circumferential wall 24.3 of said vortex chamber 24.

[0083] Advantageously, each tangential outlet channel 25 comprises one of the fluid outlets 15 which is configured to open into the discharge chamber 9. Advantageously, each fluid outlet 15 is oriented opposite the fluid inlet 14, and in particular opposite the fixed base plate 6 of the fixed volute element 5. According to the embodiment shown in the figures, the fluid outlets 15 of the tangential outlet channels 25 are located substantially in the same outlet plane, which may for example be substantially parallel to the extension plane of the fixed base plate 6.

[0084] During operation of the scroll compressor 2, the fluid compressed by the compression stage 4 is discharged through the discharge passage 8 and flows through the various fluidic diodes 22, and more particularly through the inlet channels 23, the vortex chambers 24 and the tangential outlet channels 25 of the various fluidic diodes 22. Then, the compressed fluid is discharged outside the scroll compressor 2 via the discharge chamber 9 and the discharge sleeve 12.

[0085] When the scroll compressor is stopped, the compressed fluid located in the discharge chamber 9 does not tend to flow towards the compression stage 4 because the flow resistance of each of the fluid diodes 22 is very high in the second flow direction. Thus, the discharge valve arrangement 13 according to the present invention ensures a satisfactory pressure drop to prevent reverse rotation of the movable scroll element when the compressor is stopped. In addition, the discharge valve arrangement 13 is more reliable and generates less noise than a conventional discharge valve.

[0086] Furthermore, when the scroll compressor stops, the compressed fluid located downstream of the scroll compressor cannot re-enter the discharge chamber 9 due to the presence of the non-return valve 11.

[0087] According to an embodiment of the invention not shown in the figures, the fluidic diodes 22 could be of the Tesla type. According to such an embodiment of the invention, each fluidic diode 22 comprises an elongated conduit comprising a series of internal recesses and / or internal projections arranged along the elongated conduit and configured such that the elongated conduit has a low resistance to flow in the first direction of flow, and a high resistance to the flow in the second flow direction opposite to the first flow direction. Advantageously, the internal recesses or projections form flow barriers in the second flow direction.

[0088] As goes without saying, the invention is not limited to the single embodiment of this discharge valve arrangement, described above as an example; on the contrary, it encompasses all the variant embodiments thereof.

Claims

Claims

1. A discharge valve arrangement (13) for a scroll compressor (2), the discharge valve arrangement (13) comprising a fluid inlet (14) and at least one fluid outlet (15), the fluid inlet (14) being configured to be fluidically connected to a discharge passage (8) of a compression stage (4) of the scroll compressor (2), the at least one fluid outlet (15) being configured to be fluidically connected to a discharge chamber (9) of the scroll compressor (2), characterized in that the discharge valve arrangement (13) comprises a plurality of fluid diodes (22) which are arranged in parallel to each other and which define flow paths connected in parallel to the fluid inlet (14).

2. A discharge valve arrangement (13) according to claim 1, which has a first pressure drop in a first flow direction corresponding to a flow of a fluid from the compression stage (4) to the discharge chamber (9), and a second pressure drop in a second flow direction which is opposite to the first flow direction and which corresponds to a flow of the fluid from the discharge chamber (9) to the compression stage (4), the second pressure drop being greater than the first pressure drop.

3. A discharge valve arrangement (13) according to claim 1 or 2, which comprises, proximate the fluid inlet (14), a mounting portion (16) configured to be secured to a base plate (6) of a volute element (5) of the compression stage (4), said base plate (6) comprising the discharge passage (8).

4. A discharge valve arrangement (13) according to claim 3, wherein the mounting portion (16) comprises a cylindrical wall portion (17) surrounding the fluid inlet (14) and adapted to be inserted into a mounting opening formed in the base plate (6) of the volute member (5).

5. A discharge valve arrangement (13) according to claim 4, wherein the mounting portion (16) further comprises a radial bearing portion (18) which is configured to bear against the base plate (6).

6. A discharge valve arrangement (13) according to any one of claims 1 to 5, which comprises a distribution chamber (19) which is fluidically connected to the fluid inlet (14), and a plurality of distribution channels (21) opening into the distribution chamber (19).

7. A discharge valve arrangement (13) according to any one of claims 1 to 6, wherein each of the fluidic diodes (22) is of the vortex type.

8. A discharge valve arrangement (13) according to claims 6 and 7, wherein each of the fluidic diodes (22) comprises an inlet channel (23) formed by one of the distribution channels (21), a vortex chamber (24) into which the respective inlet channel (23) opens, and a tangential outlet channel (25) connected tangentially to the respective vortex chamber (24).

9. A discharge valve arrangement (13) according to claim 8, wherein each vortex chamber (24) is attached to at least one adjacent vortex chamber (24).

10. A discharge valve arrangement (13) according to claim 8 or 9, wherein each vortex chamber (24) has a circular disc shape and has lower and upper walls (24.1, 24.2) which are substantially flat and a circumferential wall (24.3) which extends substantially perpendicular to the respective lower and upper walls (24.1, 24.2).

11. A discharge valve arrangement (13) according to claim 10, wherein an outer surface of the lower wall (24.1) of each vortex chamber (24) is connected to an upper edge of the circumferential wall (24.3) of an adjacent vortex chamber (24).

12. A discharge valve arrangement (13) according to any one of claims 8 to 11, wherein the longitudinal axis (A) of each inlet channel (23) extends from the distribution chamber (19) in a radially outward direction.

13. A discharge valve arrangement (13) according to any one of claims 8 to 12, wherein each tangential outlet channel (25) comprises a fluid outlet (15) which is configured to open into the discharge chamber (9) and which is oriented away from the fluid inlet (14).

14. A discharge valve arrangement (13) according to any one of claims 1 to 13, wherein the fluidic diodes (2) are configured to be regularly distributed in a circumferential direction around an axis of the discharge passage (8) of the stage of compression (4).

15. A discharge valve arrangement (13) according to any one of claims 1 to 14, which is manufactured by an additive manufacturing process, for example by 3D printing.

16. A scroll compressor (2) comprising a discharge valve arrangement (13) according to any preceding claim.

17. A scroll compressor (2) according to claim 16, which further comprises a check valve (11) arranged adjacent a discharge sleeve (12) of the scroll compressor (2).

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