A discharge valve arrangement for a refrigeration compressor

Abstract

The discharge valve arrangement (17) comprises a valve-bearing plate (18) having a discharge passage (22); a valve housing (24) fixed to the valve-bearing plate (18) and comprising a bottom portion (25) located opposite the valve-bearing plate (18), a side wall (26) extending from the bottom portion (25) towards the valve-bearing plate (18), and a discharge opening (28) formed in the side wall (26); a valve element (31) movable between closed and open positions in which the valve element (31) respectively closes and opens the discharge passage (22). The valve housing (24) comprises a gas-damped chamber configured to house the valve element (31) in the open position; and an exhaust opening (37) formed in the bottom portion (25) and opening into the gas damping chamber. Figure 3

Description

Title of the invention: A discharge valve arrangement for a refrigeration compressor Scope of the invention

[0001] The invention relates to a discharge valve arrangement for a refrigeration compressor, in particular for a reciprocating refrigeration compressor. Background of the invention

[0002] As is known, a reciprocating refrigeration compressor comprises:

[0003] - a cylinder block defining a cylinder,

[0004] - a valve-carrying plate fixed to the cylinder block and closing one end of the cylinder, the valve-bearing plate having at least one suction passage opening into a compression chamber, defined by the cylinder and the valve-bearing plate, and being configured to be fluidly connected to a suction chamber of the reciprocating refrigeration compressor, the valve-bearing plate further having a discharge opening which is fluidly connected to the compression chamber,

[0005] - a suction valve configured to allow a flow of refrigerant at through at least one suction passage only from the suction chamber to the compression chamber,

[0006] - a valve housing attached to the valve-carrying plate on a side away from the cylinder,

[0007] - a central cone attached to the valve housing and located opposite the cylinder, the cone central, defining, with the discharge opening formed in the valve plate, a ring-shaped discharge passage,

[0008] - a valve element having a flat ring shape and being arranged inside from an internal space of the valve housing, the valve element being movable between a closed position in which the valve element closes the discharge passage and an open position in which the valve element is away from the valve-carrying plate and opens the discharge passage,

[0009] - a stressing element configured to stress the valve element against the valve element, and

[0010] - a piston received in the cylinder and configured to perform a reciprocating motion inside the cylinder along a suction stroke during which a refrigerant is drawn into the compression chamber through at least one suction passage and a compression stroke during which a refrigerant is compressed in the compression chamber and then discharged out of the compression chamber through the discharge passage.

[0011] In particular, the valve element closes the discharge passage as long as the cylinder pressure is less than the sum of the pressure in the discharge chamber and the pressure exerted by the actuating element on the valve element. When the cylinder pressure exceeds this sum, the valve element moves away from the valve-carrying plate and opens the discharge passage.

[0012] Since the valve element and the actuating element are arranged between the valve-carrying plate and a thrust surface of the valve housing, and since the valve element opens at high speed, the subassembly formed by the valve element and the actuating element comes into contact with the thrust surface each time the valve element opens. Such contact during the opening movement of the valve element creates noise with each piston cycle.

[0013] In addition, the relief valve arrangement, formed by the valve-carrying plate, the valve housing, the central cone, the valve element and the stressing element, is complicated to assemble and expensive to manufacture. Summary of the invention

[0014] An object of the present invention is to propose an improved refrigeration compressor which can overcome the disadvantages encountered in conventional refrigeration compressors.

[0015] Another object of the present invention is to propose a discharge valve arrangement, for a refrigeration compressor, which creates less noise and is less expensive to manufacture.

[0016] According to the invention, such a discharge valve arrangement, for example for a reciprocating refrigeration compressor, comprises:

[0017] - a valve-carrying plate configured to be fixed to the refrigeration compressor, the valve-carrying plate having a discharge passage, which is configured to be fluidly connected to a compression chamber of the refrigeration compressor and a valve seat surrounding the discharge passage,

[0018] - a valve housing that is fixed to the valve-carrying plate, the valve housing comprising a bottom portion situated opposite and at a distance from the valve-carrying plate and a side wall extending from the bottom portion towards the valve-carrying plate, the bottom portion and the side wall defining an internal space, the valve housing further comprising at least one discharge opening formed in the side wall of the valve housing and configured to permit a flow of compressed gas from the discharge passage towards a discharge chamber of the refrigeration compressor,

[0019] - a valve element which has a plate shape and which is arranged inside the internal space of the valve housing, the valve element being movable between a a closed position in which the valve element rests against the valve seat and closes the discharge passage, and an open position in which the valve element is away from the valve seat and at least one discharge opening is fluidly connected to the discharge passage, and

[0020] - a stressing element configured to stress the valve element against the valve seat

[0021] wherein the valve housing comprises a gas damping device including:

[0022] - a gas damping chamber defined by the bottom part and the side wall of the valve housing, the stressing element being at least partially arranged inside the gas damping chamber and the gas damping chamber being configured to house the valve element when the valve element is in the open position, and

[0023] - an exhaust opening formed in the bottom part and opening into the gas damping chamber, the exhaust opening being configured to fluidly connect the gas damping chamber with the discharge chamber of the refrigeration compressor.

[0024] When the valve element is moved to the open position and is at least partially lodged in the first gas pocket, the gas contained in the gas damping chamber flows out of the gas damping chamber only through the exhaust opening and a radial gap between the valve element and the side wall of the valve housing. This induces an increase in gas pressure inside the gas damping chamber and thus dampens the valve element. Such damping of the valve element slows it down and thus prevents an impact between the valve element and the bottom surface of the bottom part.

[0025] The presence of such a gas damping device makes it possible to obtain a rapid deceleration of the valve element during its opening movement (in particular as soon as the valve element has passed through at least one discharge opening formed in the side wall) and thus to avoid or substantially reduce a collision of the valve element and / or the stressing element against a stop surface of the valve housing at each opening cycle of the valve element.

[0026] Consequently, the noise generated by the relief valve arrangement at each compression cycle of the reciprocating piston is substantially reduced.

[0027] Furthermore, the configuration of the discharge valve arrangement according to the present invention reduces the assembly time of the various parts of said discharge valve arrangement and thus simplifies the manufacturing process of the discharge valve arrangement.

[0028] The discharge valve arrangement may also include one or more of the following features, taken alone or in combination.

[0029] According to one embodiment of the invention, the exhaust diameter of the exhaust opening is configured to regulate the increase in gas pressure inside the gas damping chamber during the opening movement of the valve element, and thus the slowing down of the valve element.

[0030] According to one embodiment of the invention, the exhaust diameter of the exhaust opening also ensures rapid closure of the valve element at the end of a compression phase of the refrigeration compressor, and in particular at the end of a compression stroke of a compressor piston when the refrigeration compressor is a reciprocating refrigeration compressor, by allowing a flow of gas at the discharge pressure, through the exhaust opening, from the discharge chamber into the gas damping chamber.

[0031] According to one embodiment of the invention, the valve housing is configured to retain the valve element in the internal space of the valve housing.

[0032] According to one embodiment of the invention, the side wall of the valve housing is configured to guide the valve element during its movements between the closed position and the open position.

[0033] According to one embodiment of the invention, the valve element has a circular plate shape, that is to say a disc shape.

[0034] According to one embodiment of the invention, the gas damping chamber comprises:

[0035] - a first gas pocket defined by a bottom surface of the bottom part and the side wall of the valve housing, the first gas pocket housing at least partially the stressing element and being configured to house the valve element when the valve element is in the open position, the first gas pocket having a first pocket depth, and

[0036] - a second gas pocket formed in the bottom surface of the bottom part, the exhaust opening leading into the second gas pocket and being configured to fluidly connect the second gas pocket with the discharge chamber of the refrigeration compressor, the second gas pocket having a second pocket depth.

[0037] According to one embodiment of the invention, the first gas pocket has a circular shape and has a first diameter that is larger, and in particular slightly larger, than an external diameter of the valve element.

[0038] According to one embodiment of the invention, the second gas pocket has a shape circular and has a second diameter smaller than the external diameter of the valve element.

[0039] According to one embodiment of the invention, the first diameter of the first gas pocket is between a minimum diameter value equal to 10 times the sum of the first and second gas pocket depths and a maximum diameter value equal to 20 times the sum of the first and second gas pocket depths. Such a configuration of the first gas pocket induces a rapid increase in gas pressure inside the gas damping chamber during an opening movement of the valve element and therefore a rapid stopping of the valve element.

[0040] According to one embodiment of the invention, the first gas pocket depth of the first gas pocket is between a first minimum depth value equal to 0.1 times the valve element thickness and a first maximum depth value equal to 4 times the valve element stroke. The first gas pocket depth of the first gas pocket is the axial distance between the upper edge of at least one discharge opening formed in the side wall and the bottom surface of the bottom portion of the valve housing.

[0041] According to one embodiment of the invention, the second gas pocket depth of the second gas pocket is between a second minimum depth value equal to 0.1 times the valve thickness of the valve element and a second maximum depth value equal to 4 times the displacement stroke of the valve element. The second gas pocket depth is the axial distance between the bottom surface of the bottom portion and a pocket bottom surface of the second gas pocket.

[0042] According to one embodiment of the invention, the exhaust opening has an exhaust diameter which is between a minimum exhaust diameter which is equal to the valve thickness of the valve element and a maximum exhaust diameter which is equal to 4 times the displacement stroke of the valve element.

[0043] According to one embodiment of the invention, the first and second gas pockets are arranged coaxially.

[0044] According to one embodiment of the invention, the exhaust opening is located in the center of the bottom part.

[0045] According to one embodiment of the invention, the exhaust opening and the first and second gas pockets are arranged coaxially.

[0046] According to one embodiment of the invention, the valve housing has a cup shape.

[0047] According to one embodiment of the invention, the discharge passage provided on the valve-carrying plate has a circular shape. The discharge passage is circular in particular because, unlike the prior art, no central cone element is attached to the valve housing and protrudes into the discharge passage. This configuration of the discharge valve arrangement reduces its manufacturing costs.

[0048] According to one embodiment of the invention, the valve housing further comprises mounting parts projecting radially from an external surface of the side wall of the valve housing, the mounting parts being fixed to the valve-carrying plate, for example by rivets arranged in bores formed in the mounting parts.

[0049] According to one embodiment of the invention, the valve-carrying plate has a first face configured to be oriented towards the compression chamber of the refrigeration compressor and a second face opposite to the first face and oriented towards the valve housing, the valve seat being arranged on the second face of the valve-carrying plate.

[0050] According to one embodiment of the invention, at least one discharge opening is located in the vicinity of the second face of the valve-carrying plate.

[0051] According to one embodiment of the invention, at least one discharge opening extends in a circumferential direction with respect to an axial axis of the valve housing.

[0052] According to one embodiment of the invention, at least one discharge opening extends between two adjacent mounting parts.

[0053] According to one embodiment of the invention, the valve housing has several discharge openings distributed around an axial axis of the valve housing.

[0054] According to one embodiment of the invention, the valve element is movable within the internal space along a direction of movement which is substantially parallel to an axial axis of the valve housing.

[0055] According to one embodiment of the invention, the side wall of the valve housing is cylindrical.

[0056] According to one embodiment of the invention, the side wall of the valve housing extends in a direction perpendicular from the bottom part.

[0057] According to one embodiment of the invention, the stressing element is annular and has an external diameter that is substantially equal to the external diameter of the valve element.

[0058] According to one embodiment of the invention, the stressing element may be a helical spring, a wave spring, a curved spring washer, or a wave spring washer. The wave spring may comprise a single wave ring or may comprise stacked corrugated rings attached to each other in a peak-to-peak configuration.

[0059] According to one embodiment of the invention, in the open position, the valve element floats inside the internal space of the valve housing and is supported only by the stressing element.

[0060] The present invention also relates to a refrigeration compressor, for example a reciprocating refrigeration compressor, comprising a discharge valve arrangement according to the present invention.

[0061] According to one embodiment of the invention, the reciprocating refrigeration compressor comprises a hermetically sealed housing; an electric motor disposed in the hermetically sealed housing and comprising a stator and a rotor; a drive shaft connected to the rotor; a reciprocating compression unit disposed in the hermetically sealed housing and configured to compress a refrigerant, the reciprocating compression unit comprising a cylinder block provided with a cylinder and a piston received alternately in the cylinder and connected by drive to the drive shaft.

[0062] According to one embodiment of the invention, the valve-carrying plate of the discharge valve arrangement is fixed to the cylinder block, and the valve-carrying plate, the cylinder and the piston delimit a compression chamber.

[0063] These advantages and others will become apparent from the reading of the following description in view of the attached drawing representing, by way of non-limiting example, an embodiment of a refrigeration compressor according to the invention. Brief description of the drawings

[0064] The following detailed description of an embodiment of the invention is best understood when read in conjunction with the accompanying drawings, it being understood, however, that the invention is not limited to the specific embodiment disclosed.

[0065] [Fig-1] is a longitudinal cross-sectional view of a reciprocating refrigeration compressor according to the invention.

[0066] [Fig.2] is a longitudinal sectional view of a discharge valve arrangement of the reciprocating refrigeration compressor of [Fig.1] showing a valve element in a closed position.

[0067] [Fig.3] is a longitudinal cross-sectional view of the discharge valve arrangement of [Fig.2] showing the valve element in the open position.

[0068] [Fig.4] is a perspective view of a valve housing of the discharge valve arrangement of [Fig.2].

[0069] [Fig.5] is a cross-sectional perspective view of the discharge valve arrangement of [Fig.2]. Detailed description of the invention

[0070] Figure 1 shows a refrigeration compressor 2, and in particular a reciprocating refrigeration compressor, in a vertical position. However, the refrigeration compressor 2 according to the invention could be in an inclined position, or a horizontal position, without significant modification of its structure.

[0071] The refrigeration compressor 2 includes a hermetically sealed housing 3, a suction inlet 4 provided on the hermetically sealed housing 3 and configured to supply the refrigeration compressor 2 with refrigerant to be compressed and a discharge outlet provided on the hermetically sealed housing 3 and configured to discharge a compressed refrigerant.

[0072] The refrigeration compressor 2 further comprises an electric motor 6, which is disposed in the hermetically sealed housing 3 and has a rotor 7 and a stator 8 disposed around the rotor 7, and a drive shaft 9, also called a crankshaft, which is vertical and can rotate about an axis of rotation A. The drive shaft 9 is coupled to the rotor 7 of the electric motor 6 so that the electric motor 6 is configured to drive the drive shaft 9 in rotation about the axis of rotation A.

[0073] The refrigeration compressor 2 also includes an alternative compression unit 11 disposed in the hermetically sealed housing 3 and configured to compress the refrigerant supplied by the suction inlet 4.

[0074] The reciprocating compression unit 11 comprises a cylinder block 12 having a cylinder 13 partially defining a compression chamber 14, and a piston 15 received alternately in the cylinder 13 and connected by drive to the drive shaft 9 by a connecting rod 16. The connecting rod 16 is in particular configured to convert the rotational motion of the drive shaft 9 into a reciprocating motion of the piston 15 inside the cylinder 13 alternately along a suction stroke during which a refrigerant is drawn into the compression chamber 14 and a compression stroke during which a refrigerant is compressed in the compression chamber 14 and then expelled from the compression chamber 14.

[0075] The refrigeration compressor 2 further includes a discharge valve arrangement 17 configured to control and guide the suction of refrigerant into the compression chamber 14 and the discharge of the compressed refrigerant out of the compression chamber 14.

[0076] The discharge valve arrangement 17 includes a valve-carrying plate 18 fixed to the cylinder block 12 such that the valve-carrying plate 18, the cylinder 13 and the piston 15 delimit the compression chamber 14. According to one embodiment of the invention, the valve-carrying plate 18 has a valve thickness of approximately 1.2 mm.

[0077] The valve-carrying plate 18 has a first face 18.1 oriented towards the compression chamber 14 and a second face 18.2 opposite the first face 18.1. The piston 15 is in particular mounted to slide in the cylinder 13 between an extreme suction position in which the piston 15 is away from the first face 18.1 of the valve-carrying plate 18 and an extreme discharge position in which the piston 15 is located near the first face 18.1 of the valve-carrying plate 18.

[0078] The valve-carrying plate 18 has one or more suction passage(s) 19 opening into the compression chamber 14 and configured to be fluidly connected to a suction chamber 21 of the refrigeration compressor 2, and a suction valve (not shown in the figures) configured to allow refrigerant to flow through the suction passage(s) 19 only from the suction chamber 21 to the compression chamber 14.

[0079] The valve-carrying plate 18 also includes a discharge passage 22 which opens into the compression chamber 14 and extends through the valve thickness of the valve-carrying plate 18. Advantageously, the discharge passage 22 has a circular shape and is located in a central part of the valve-carrying plate 18.

[0080] The valve-carrying plate 18 further includes a valve seat 23 provided on the second face 18.2 of the valve-carrying plate 18. Advantageously, the valve seat 23 is annular and surrounds the discharge passage 22.

[0081] The relief valve arrangement 17 further comprises a valve housing 24 fixed to the second face 18.2 of the valve-carrying plate 18. The valve housing 24 has a cup shape and comprises a bottom portion 25 located opposite and at a distance from the valve-carrying plate 18 and a side wall 26 which is cylindrical and which extends in a perpendicular direction from the bottom portion 25 towards the valve-carrying plate 18.

[0082] The valve housing 24 further comprises several mounting parts 27, for example three, projecting radially from an external surface of the side wall 26 of the valve housing 24. The mounting parts 27 are fixed to the valve-carrying plate 18, for example by rivets arranged in bores formed in the mounting parts 27.

[0083] The valve housing 24 also includes several discharge openings 28 formed in the side wall 26 of the valve housing 24 and distributed around an axial axis B of the valve housing 24. Each discharge opening 28 can, for example, extend in a circumferential direction with respect to the axial axis B of the valve housing 24. Advantageously, each discharge opening 28 is located near the second face 18.2 of the valve-carrying plate 18 and extends between two adjacent mounting parts 27. The discharge openings 28 are in particular configured to allow a flow of compressed gas from the discharge passage 22 and towards a discharge chamber 29 of the refrigeration compressor 2.

[0084] The discharge valve arrangement 17 further comprises a valve element 31 having a plate shape and being arranged inside an internal space defined by the bottom part 25 and the side wall 26 of the valve housing 24. Advantageously, the valve element 31 has a circular plate shape, i.e. a disc shape, and has a valve stroke of about 2 mm.

[0085] The valve element 31 is movable within the internal space along a direction of movement D, which is substantially parallel to the axial axis B of the valve housing 24, and between a closed position (see [Fig. 2]) in which the valve element 31 bears against the valve seat 23 and closes the discharge passage 22, and an open position (see [Fig. 3]) in which the valve element 31 is away from the valve seat 23 and opens the discharge passage 22 so that the discharge openings 28 are fluidly connected to the discharge passage 22. Advantageously, the valve housing 24 is configured to retain the valve element 31 within the internal space of the valve housing 24, and the side wall 26 of the valve housing 24 is configured to guide the valve element 31 during its movements between the positions closed and open positions.

[0086] The relief valve arrangement 17 further includes a stressing element 32 configured to stress the valve element 31 against the valve seat 23. Advantageously, the stressing element 32 is annular and has an external diameter that is substantially equal to the external diameter of the valve element 31. The stressing element 32 may be a helical spring, a wave spring, a curved spring washer, or a wave spring washer. The wave spring may comprise a single wave ring or may comprise stacked wave rings attached to one another in a peak-to-peak configuration. A peak-to-peak spring allows for relatively large strokes, while having a reduced overall height in its compressed state compared to helical springs of the same stiffness.

[0087] According to the present invention, the valve housing 24 further comprises a gas damping device 33 comprising a gas damping chamber 34 defined by the bottom part 25 and the side wall 26 of the valve housing 24, and corresponding to a part of the internal space of the valve housing 24.

[0088] According to the embodiment shown in the figures, the gas damping chamber 34 comprises a first gas pocket 35 which has a circular shape and is defined by a bottom surface 25.1 of the bottom portion 25 and the side wall 26 of the valve housing 24, and a second gas pocket 36 which also has a circular shape and is formed in the bottom surface 25.1 of the bottom portion 25. Tageously, the first and second gas pockets 35, 36 are arranged coaxially, and the second gas pocket 36 has a pocket bottom surface 36.1 which is parallel to the bottom surface 25.1 of the bottom part 25.

[0089] The first gas pocket 35 has a first diameter slightly greater than an external diameter of the valve element 31, and the second gas pocket 36 has a second diameter less than the external diameter of the valve element 31. Advantageously, the first gas pocket 35 at least partially houses the stressing element 32 and is configured to house the valve element 31 when the valve element 31 is in the open position.

[0090] The first gas pocket 35 has a first gas pocket depth H1 which can be between a first minimum depth value equal to 0.1 times the valve thickness of the valve element 31 and a first maximum depth value equal to 4 times the displacement stroke of the valve element 31, and the second gas pocket 36 has a second gas pocket depth H2 which can be between a second minimum depth value equal to 0.1 times the valve thickness of the valve element 31 and a second maximum depth value equal to 4 times the displacement stroke of the valve element 31. It should be noted that the first gas pocket depth H1 of the first gas pocket 35 is the axial distance between the upper edge of the discharge openings 28 and the bottom surface 25.1 of the bottom part 25, and that the second gas pocket depth H2 of the second gas pocket 36 is the axial distance between the bottom surface 25.1 of the bottom part 25 and the bottom pocket surface 36.1 of the second gas pocket 36. .

[0091] According to one embodiment of the invention, the first gas pocket depth H1 can be about 1.6 mm, and the second gas pocket depth H2 can be about 0.5 mm.

[0092] According to one embodiment of the invention, the first diameter of the first gas pocket 35 is between a minimum diameter value equal to 10 times the sum of the first and second gas pocket depths and a maximum diameter value equal to 20 times the sum of the first and second gas pocket depths. According to one embodiment of the invention, the first diameter of the first gas pocket 35 is approximately 32 mm.

[0093] The gas damping device 33 also includes an opening The exhaust 37 is formed in the bottom section 25 and opens into the second gas pocket 36. Advantageously, the exhaust opening 37 and the first and second gas pockets 35, 36 are arranged coaxially. The exhaust opening 37 is specifically configured to fluidly connect the second gas pocket 36 with the discharge chamber 29 of the refrigeration compressor 2.

[0094] According to one embodiment of the invention, the exhaust opening 37 has an exhaust diameter which is between a minimum exhaust diameter which is equal to the valve thickness of the valve element 31 and a maximum exhaust diameter which is equal to 4 times the stroke of the valve element 31. The exhaust diameter of the exhaust opening 37 can be, for example, about 2.5 mm.

[0095] The operation of the discharge valve arrangement 17 is described below.

[0096] During the compression stroke of the piston 15, the pressure in the compression chamber 14 increases until it exceeds the sum of the pressure in the gas damping chamber 34 (i.e., in the discharge chamber 29) and the pressure exerted by the actuating element 32 on the valve element 31. Then, the valve element 31 moves away from the valve-carrying plate 18 and opens the discharge passage 22. When the upper edge of the valve element 31 reaches the upper edge of the discharge openings 28 (i.e., when the valve element 31 is at least partially lodged in the first gas pocket 35), the gas contained in the gas damping chamber 34 flows out of the gas damping chamber 34 only through the exhaust opening 37 and a small radial clearance between the valve element 31 and the side wall 26.Such a reduced gas passage provides a damping effect which slows down the valve element 31 and avoids an impact between the valve element 31 and the bottom surface 25.1 of the bottom part 25.

[0097] The exhaust diameter of the exhaust opening 37 is configured in particular to regulate the increase in gas pressure inside the gas damping chamber 34 during the opening movement of the valve element 31, and thus the slowing down of the valve element 31. The exhaust diameter of the exhaust opening 37 also ensures a rapid closure of the valve element 31 at the end of the compression stroke of the piston 15, by allowing a flow of gas at the discharge pressure, through the exhaust opening 37, from the discharge chamber 29 into the gas damping chamber 34.

[0098] According to another embodiment of the invention not shown in the figures, the cylinder block 12 may comprise several cylinders 13 and the refrigeration compressor 2 may comprise several pistons 15 each received alternately in a respective cylinder 13.

[0099] Of course, the invention is not limited to the embodiment described above by way of non-limiting example, but on the contrary encompasses all its embodiments.

Claims

Demands

1. Discharge valve arrangement (17) for a refrigeration compressor (2), comprising: - a valve-bearing plate (18) configured to be fixed to the refrigeration compressor (2), the valve-bearing plate (18) having a discharge passage (22), which is configured to be fluidly connected to a compression chamber (14) of the refrigeration compressor (2) and a valve seat (23) surrounding the discharge passage (22), - a valve housing (24) which is fixed to the valve-carrying plate (18), the valve housing (24) having a bottom portion (25) situated opposite and at a distance from the valve-carrying plate (18) and a side wall (26) extending from the bottom portion (25) towards the valve-carrying plate (18), the bottom portion (25) and the side wall (26) defining an internal space, the valve housing (24) further having at least one discharge opening (28) formed in the side wall (26) of the valve housing (24) and configured to permit a flow of compressed gas from the discharge passage (22) towards a discharge chamber (29) of the refrigeration compressor (2), - a valve element (31) which has a plate shape and which is arranged inside the internal space of the valve housing (24),the valve element (31) being movable between a closed position in which the valve element (31) bears against the valve seat (23) and closes the discharge passage (22) and an open position in which the valve element (31) is away from the valve seat (23) and at least one discharge opening (28) is fluidly connected to the discharge passage (22), and, - a stressing element (32) configured to stress the valve element (31) against the valve seat (23), in which the valve housing (24) includes a gas damping device (33) comprising: - a gas damping chamber (34) defined by the bottom portion (25) and the side wall (26) of the valve housing (24), the stressing element (32) being at least partially arranged inside the gas damping chamber (34) and the gas damping chamber (34) being configured to house the valve element (31) when the valve element (31) is in the open position, and - an exhaust opening (37) formed in the bottom part (25) and opening into the gas damping chamber (34), the exhaust opening (37) being configured to fluidly connect the gas damping chamber (34) with the discharge chamber (29) of the refrigeration compressor (2).

2. Relief valve arrangement (17) according to claim 1, wherein the valve element has a circular plate shape.

3. A relief valve arrangement (17) according to claim 1 or 2, wherein the gas damping chamber (34) comprises: - a first gas pocket (35) defined by a bottom surface (25.1) of the bottom portion (25) and the side wall (26) of the valve housing (24), the first gas pocket (35) housing at least partially the stressing element (32) and being configured to house the valve element (31) when the valve element (31) is in the open position, the first gas pocket (35) having a first pocket depth (Hl), and - a second gas pocket (36) formed in the bottom surface (25.1) of the bottom portion (25), the exhaust opening (37) opening into the second gas pocket (36) and being configured to fluidly connect the second gas pocket (36) with the chamber discharge (29) of the refrigeration compressor (2), the second gas pocket (36) having a second pocket depth (H2).

4. Discharge valve arrangement (17) according to claims 2 and 3, wherein the first gas pocket (35) has a circular shape and a first diameter greater than an external diameter of the valve element (31).

5. Discharge valve arrangement (17) according to claim 4, wherein the second gas pocket (36) has a circular shape and a second diameter smaller than the external diameter of the valve element (31).

6. Discharge valve arrangement (17) according to claim 4 or 5, wherein the first diameter of the first gas pocket (35) is between a minimum diameter value that is equal to 10 times the sum of the first and second gas pocket depths (H1, H2) and a maximum diameter value that is equal to 20 times the sum of the first and second gas pocket depths (H1, H2).

7. Discharge valve arrangement (17) according to any one of claims 3 to 6, wherein the first pocket depth of gas (Hl) of the first gas pocket (35) is between a first minimum depth value which is equal to 0.1 times the valve thickness of the valve element and a first maximum depth value which is equal to 4 times the displacement stroke of the valve element (31).

8. Discharge valve arrangement (17) according to any one of claims 3 to 7, wherein the second gas pocket depth (H2) of the second gas pocket (36) is between a second minimum depth value which is equal to 0.1 times the valve thickness of the valve element (31) and a second maximum depth value which is equal to 4 times the displacement stroke of the valve element (31).

9. Discharge valve arrangement (17) according to any one of claims 3 to 8, wherein the first and second gas pockets (35, 36) are arranged coaxially.

10. Relief valve arrangement (17) according to any one of claims 1 to 9, wherein the exhaust opening (37) has an exhaust diameter which is between a minimum exhaust diameter which is equal to the valve thickness of the valve element (31) and a maximum exhaust diameter which is equal to 4 times the displacement stroke of the valve element (31).

11. Discharge valve arrangement (17) according to any one of claims 1 to 10, wherein the exhaust opening (37) is located in the center of the bottom portion (25).

12. Relief valve arrangement (17) according to any one of claims 1 to 11, wherein the valve housing (24) has a cup shape.

13. Discharge valve arrangement (17) according to any one of claims 1 to 12, wherein the discharge passage (22) provided on the valve-carrying plate (18) has a circular shape.

14. Relief valve arrangement (17) according to any one of claims 1 to 13, wherein the valve housing (24) further comprises mounting parts (27) projecting radially from an external surface of the side wall (26) of the valve housing (24), the mounting parts (27) being fixed to the valve-carrying plate (18).

15. Refrigeration compressor (2), for example a reciprocating refrigeration compressor, comprising a discharge valve arrangement (17) according to any one of claims 1 to 14.