IT202000004282A1 - ADJUSTABLE DAMPING VALVE - Google Patents

Description

Adjustable damping valve

DESCRIPTION

TECHNICAL FIELD

[0001] The object disclosed herein relates to valves for determining pressure drops in a fluid flow. In particular, the object disclosed in this document relates to adjustable damping valves to reduce pressure pulsations and / or vibrations.

STATE OF THE ART

Existing flow control valves include ball valves, diaphragm valves, gate valves, butterfly valves and ball valves.

A diaphragm valve uses a series of pivoting blades to adjust the size of a central orifice. Disadvantageously, such valves cannot withstand high pressure pulsations, which can? lead to mechanical failure of the valve, especially when used in conjunction with reciprocating motion machines such as reciprocating motion compressors and pumps. In addition, diaphragm valves are made from a relatively large number of moving parts and have complex structures, which lead to high production and maintenance costs and high friction during actuation.

Gate valves include a door which? able to slide in order to partially or totally occlude a cross section of a duct. Such valves have the disadvantage of being bulky, require large casings to securely seat the door, and cause a lot of turbulence in the fluid flow when the cross section? partially occluded due to the irregularly shaped duct so? format.

Butterfly valves include a disc installed within a conduit and adapted to rotate between a closed position perpendicular to the axis of the conduit and an open position parallel to the axis of the conduit. Disadvantageously, the disc inside the duct in the open position disturbs the flow of fluid, thus causing an undesired pressure drop. Furthermore, when the butterfly valves are in intermediate positions between the open and closed positions, turbulence is generated in the fluid flow due to the irregular shape of the resulting conduit and therefore the butterfly valves have a highly non-linear behavior, i.e. relationship between the rotation angle of the valve disc and the pressure drop across the valve? difficult to determine precisely and reproducibly.

[0006] Ball valves consist of a ball installed in a seat along a duct. The ball has a hole and? rotatable between an open position and a closed position; in the open position the hole? aligned with the duct and in the closed position the hole? perpendicular to the duct. The intermediate positions of the ball between the open position and the closed position cause a constriction of the duct and a pressure drop in the fluid flow. Disadvantageously, ball valves create turbulence in the fluid flow when they are in intermediate positions due to the irregularly shaped conduit so. format. Also, do ball valves have highly non-linear behavior, i.e. the relationship between the rotation angle of the valve ball and the pressure drop across the valve? difficult to determine precisely and reproducibly.

SUMMARY

[0007] According to a first aspect, the object disclosed in the present document relates to valves, in particular damping valves, ie valves designed to cause a pressure drop in a fluid flow from the valve inlet to the valve outlet. The valve includes a hollow body and a valve element housed within it. The valve element? rotatable and can? be set in various intermediate positions between an open position and a closed position. The valve element has a flow regulating surface which partially defines a flow passage of the valve. The shape and size of the flow passage depends on the position of the flow regulating surface, which corresponds to the position of the valve element, and determines the pressure drop across the valve. The flow regulation surface can? be designed loosely enough, i.e. there are limited design constraints, so that the turbulence caused by the valve can be low in any operating condition of the valve, and the relationship between the rotation angle of the valve element and the pressure drop through the valve can? be chosen as desired.

[0008] According to a second aspect, the object disclosed in the present document relates to reciprocating motion machines, in particular reciprocating motion compressors and pumps. The reciprocating machine has a compression chamber and at least one valve fluidically coupled to the compression chamber; the valve can? be coupled with the inlet and / or outlet of the compression chamber. The valve causes different pressure drops depending on the valve setting. For example, when installing the reciprocating machine in a system, the valve setting can? be chosen taking into account pressure pulsations and / or vibrations during operation.

According to a third aspect, the object disclosed herein relates to methods of damping pressure pulsations or vibrations in a system. The method includes the steps of fluidly coupling at least one valve with a reciprocating compressor of the system, and of moving a valve member of the valve to regulate a pressure drop across the valve and achieve damping. For example, pressure pulsations or vibrations in the system can be measured using different valve element positions, and then a position is identified and definitively set corresponding to minimal pressure pulsations or vibrations. Note that pressure pulsations and / or vibrations may vary from point to point in the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed embodiments of the invention will be more appreciated. complete and many of the ensuing advantages will be readily obtained thanks to a better understanding of the same by referring to the following detailed description considered in conjunction with the attached drawings, in which:

Fig. 1 shows a side view of a first embodiment of a new valve;

Fig. 2 shows a cross-sectional view of the valve of Fig. 1 according to the section line A-A;

Fig. 3 shows a cross-sectional view of the valve of Fig. 1 according to the section line B-B;

Fig. 4 shows a schematic cross-sectional view of a second embodiment of a new valve;

Fig. 5 shows a schematic cross-sectional view of a third embodiment of a new valve;

Fig. 6 shows another schematic cross-sectional view of the valve of Fig. 5;

Fig. 7 shows a block diagram of an embodiment of a new reciprocating machine, specifically a new reciprocating compressor; And

Fig. 8 shows a flow diagram of an embodiment of a new method of damping pressure pulsations or vibrations in a system.

DETAILED DESCRIPTION OF THE FORMS OF REALIZATION

[0011] A valve? a device in which a fluid flows in a controlled manner. The new valve includes a hollow body and an internally housed valve element; the valve element can? rotate and can? assume various positions. The valve element has a flow regulating surface; the shape and size of the passage through which the fluid flows depend on the position of the valve element and the associated flow regulating surface. By setting the position of the valve element, you can? choose the efficiency of the valve, ie the so-called "pressure drop" across the valve.

[0012] Will it be done? now refer in detail to embodiments of the disclosure, an example of which? illustrated in the drawings. Each example? provided as an explanation of the disclosure, not limiting the disclosure. In fact, it will result? obvious to those skilled in the art that? You may make various changes and variations to this disclosure without departing from the scope or spirit of the disclosure.

[0013] Figures 1, 2 and 3 show a first embodiment of a new valve generally indicated with the reference number 100.

Valve 100 includes a hollow body 110 which has an inlet 111 and an outlet 112, and forms a path such that a fluid can flow in a first direction from inlet 111 to outlet 112. How will this result? evident from the following, a fluid can? also flow in a second sense that? opposite to the first sense, but the valve? specifically designed for one-way fluid flow.

[0015] The valve 100 comprises one or more? valve elements 120 positioned along the aforementioned flow path. The embodiments shown in Figures 1, 2, 3 and 4 have two valve elements 120, while the embodiment of Figures 5 and 6 has only one valve element. The following description of the valve element applies to all embodiments, unless specified.

[0016] The valve element 120? housed in a seat in the hollow body 110 along the flow path and d? hinged to the hollow body 110 in order to be able to rotate around an axis of rotation "R" between an open position and a closed position; the axis of rotation "R"? preferably perpendicular to a direction of flow of the fluid in the area in which? located the valve element.

When the valve element 120 is in its open position, it creates a flow passage that allows fluid to flow from inlet 111 to outlet 112, particularly in the open position the fluid flow does not flow. disturbed or nearly undisturbed by the valve element 120 (this results in a low or no pressure drop across the valve). When the valve element 120 is in its closed position, the flow passage? minor or even there? flow passage, so that the flow of fluid from inlet 111 to outlet 112 is partially or totally stopped. In the illustrated embodiment, the valve element 120 in the closed position defines a relatively small flow passage that allows a fluid portion to pass through the valve with a relatively high pressure drop.

The valve element 120 of the embodiment of Figures 1, 2 and 3 has a plurality of elements. of intermediate positions between the open position and the closed position, and? arranged to partially and gradually restrict the flow passage of the valve.

[0019] The valve element 120 can? be a substantially cylindrical or substantially conical body and has a flow regulating surface 122 on its outer surface which can be also be called the "lateral surface" of the body. The flow regulating surface 122 partially defines a flow passage between inlet 111 and outlet 112. In the embodiments of Figures 1, 2, 3 and 4, the flow passage? also partially defined by a flow regulating surface of another valve element, hence the flow passage of the valve? totally defined by two flow regulating surfaces of movable valve elements; in the embodiment of Figures 5 and 6, the flow passage? partially defined by a guiding surface of a fixed portion of the hollow body 110, hence the flow passage of the valve? totally defined by a flow regulating surface of a movable valve element and a guiding surface of a stationary element; in all embodiments, the flow passage? actually defined by small portions of the aforementioned surfaces, ie portions which in turn face one another (see for example Figures 3, 4 and 6). Rotation of a valve element determines which portion of the flow regulating surface? facing the flow passage; preferably, the flow regulating surface 122? shaped in such a way as to partially and gradually restrict the flow passage by rotating the valve element 120 from the open position to the closed position.

[0020] The flow adjustment surface 122? an outer surface of the valve element 120, and? convex in a cross section perpendicular to the "R" axis of rotation. In other words, an intersection of the flow regulating surface 122 with a plane perpendicular to the axis of rotation "R" defines an intersection line which? convex. The convexity refers to the shape of the valve element 120 about the rotation axis "R" in the cross section perpendicular to the rotation axis "R".

Specifically, in all embodiments of the figures, the polar coordinates of the flow adjustment surface 122 with respect to the axis of rotation "R" are designed to define a predetermined correlation between the size of the flow passage and the angular position of the valve element 120. Advantageously, the convexity is of the flow regulating surface 122 causes a gradual and monotonous correlation between the angular position of the valve element 120 and the size of the flow passage. According to advantageous embodiments, such as for example the embodiment of Figures 1, 2 and 3, the shape of the flow regulating surface 122 defines, for each intermediate position, a gradual narrowing of the flow passage which leads to a constriction and the rotation of the valve element 120 can? set the cross-sectional area of the choke. The gradual narrowing of the flow regulating surface 122 leading the fluid to the restriction avoids the creation of turbulence in the flowing fluid.

Preferably, each intermediate position corresponds to an angular position of the valve element 120 about the axis of rotation "R", and the flow regulating surface 122? shaped in order to define a predetermined dependence between a pressure drop in the flow between inlet 111 and outlet 112 and the angular position of the valve element 120, wherein a given change in the angular position of the valve element 120 leads to a predictable change in the pressure difference between inlet 111 and outlet 112. Such dependence? preferably monotone and could be, for example, substantially linear or substantially quadratic.

[0023] Specifically, the shape of the flow regulating surface 122 may? defining a determined and unambiguous relationship between the angular position of the valve element 120 and the dimension of the flow passage. The required size of the flow passage at various angular positions of the valve element 120? capable of causing the desired pressure drop in the design operating configuration of valve 100.

Preferably, the flow regulating surface 122 defines the only fluid connection between the inlet 111 and the outlet 112. In particular, the valve element 120 has no through hole which can establish a fluid connection between inlet 111 and outlet 112.

In preferred embodiments, the valve element 120 has a circumferential groove 121 which extends circumferentially about the axis of rotation "R". In these embodiments, the aforementioned flow regulating surface 122? the inner surface of the groove 121 and the groove 121 itself at least partially identify the flow passage.

The cross-sectional area of the groove 121 in a plane containing the axis of rotation "R", or "radial cross-section", gradually increases at least along a circumferential portion of the groove. The circumferential portion of the groove 121 which defines the flow passage? selectable by rotating the valve element 120 about the rotation axis "R". Depending on the chosen intermediate position of the valve element 122, a restriction in the flow path is determined by the groove 121, its size depends on the angular position of the valve element 120. Advantageously, the groove 121 also defines a converging portion which carries the flow of fluid from the inlet 111 to the throat and a diverging portion which carries the flow of fluid arriving from the restriction to the outlet 112. Preferably, the radial cross-section of the groove 121? semi-circular or semi-oval in shape.

[0027] In the embodiment of Figures 1, 2 and 3, the groove 121 has a plurality of elements. of consecutive circumferential portions (see Fig. 2), each corresponding to an intermediate position.

Alternatively, the groove 121 has a continuous flow adjustment surface 122 without edges. According to this alternative, the valve element 120 can? be continuously adjustable between the open position and the closed position, defining an indefinite number of intermediate positions.

[0029] Preferably, the radial cross-sectional area of the groove 12 increases in the direction opposite to the direction of flow from inlet 111 to outlet 112, as can be achieved. see in Fig. 2. Advantageously, in this configuration, the flow pressure exerts a torque on a valve element 120 towards the open position, such that the valve 100 has a failopen (normally open) design.

In the embodiments of Figures 1, 2, 3 and 4, the valve 100 has two adjacent valve elements 120 arranged to rotate in counter-rotational directions. Each valve element 120 has a groove 121 as described above. The two grooves 121 are adjacent and face each other in such a way as to define the aforementioned flow passage in the space between the two (see Fig. 2). Preferably, the two grooves are arranged to together define a circular or oval flow passage in each intermediate position or in at least some of the intermediate positions. The area of the circular or oval flow passage depends on the angular position of the valve elements 120.

[0031] Preferably, the two valve elements 120 have toothed wheel portions 123 which engage with each other to kinematically couple in a counter-rotational movement. Preferably, the two valve elements 120 are drum-shaped, with a round side surface and two base surfaces, and have a groove 121 and sprocket portions 123 on the side surface. In the embodiments of Figures 1, 2, 3 and 4, the valve elements have a groove in the central portion of the side surface and two sprocket portions at both sides of the groove. Preferably, the two valve elements mirror each other and have the same intermediate positions.

In the embodiment of Figures 1, 2 and 3 the two valve elements have parallel axes of rotation and have cylindrical gear wheel portions. In the embodiment of Fig. 4, the two valve elements have perpendicular axes of rotation and have bevel gear wheel portions.

[0033] Advantageously, as in the embodiment of Figures 1, 2 and 3, the hollow body has a chamber for housing the or two valve elements and an exhaust duct (see for example reference 125 in Fig. 3) coupled fluidically to the chamber. Preferably, the chamber has a bottom portion (with respect to a valve operating configuration) portion (see for example reference 126 in Fig. 3) converging towards the exhaust duct and arranged to discharge fluid towards it, for example during the maintenance.

In the embodiment of Figures 5 and 6, the valve 100 has only one valve element 120, configured as described above, and an opposing portion 130 integral with or attached to the hollow body 110; in particular, according to this embodiment, the portion 130? a wall. The opposition portion 130? adjacent the valve element 120 and has a rounded recess 131; in particular, according to this embodiment, the wall has a semicircular or semi-oval shaped groove. Note that the opposition portion can? be associated with a guide portion or portions upstream and / or downstream of the opposition portion in order to avoid or limit the creation of turbulence. The recess 131? facing the flow regulating surface 122, in particular? in front of the groove 121, so that it helps define the flow passage.

[0035] According to another aspect, the object disclosed in the present document relates to a reciprocating motion machine, in particular a piston compressor or a piston pump; a block diagram of an embodiment of this new reciprocating machine is shown in Fig. 7.

The reciprocating machine 700 includes a cylinder 710 in which a piston 720 can scroll and perform a reciprocating motion; a 730 compression chamber? defined between the cylinder walls and a piston wall; according to an alternative embodiment, the number of cylinders and / or pistons and / or compression chambers can? be superior. An inlet tube 740 feeds fluid to be compressed into the compression chamber 730 and an outlet tube 750 feeds compressed fluid out of the compression chamber 730; according to alternative embodiments, can? there is only one tube to perform both functions. Tubes 740 and 750 fluidically connect machine 700 to a tubing generally designated 1000; note that the pipe 1000 pu? be connected fluidly to other devices (not shown in Fig. 7); the arrangement of the machine 700, of the pipe 1000 and, in the case, one or more? other devices make up a system. A 745 inlet valve? fluidically connected along inlet tube 740 to selectively inject uncompressed fluid into chamber 730 and an outlet valve? fluidically connected along outlet tube 750 to selectively extract compressed fluid out of chamber 730.

The reciprocating machine 700 also includes another valve 760 for determining a pressure drop; in other words, this valve is not used n? to selectively isolate the compression chamber 730 n? to regulate fluid flow. The 760 valve? fluidically coupled to the compression chamber 730; in particular, ? coupled downstream of the compression chamber 730, ie along the outlet pipe 750; advantageously, it? located downstream of the 755 outlet valve; according to alternative embodiments, such a valve can? be coupled upstream of the compression chamber 730, ie along the inlet pipe 740, in particular upstream of the inlet valve 745; according to still alternative embodiments, can? there be such a valve both upstream and downstream of the compression chamber 730. According to the embodiment of Fig. 7, the valve 760? arranged to cause different pressure drops depending on the valve setting; typically, the valve setting does not change during machine operation,? selected when installing the machine and can? be changed from time to time. The purpose of associating one or two of such valves in addition to isolation valves and / or flow control valves is, for example, to dampen pressure pulsations or vibrations caused by the compressor. The 760 valve can? be identical or similar, for example, to the valve of Fig. 1 or to the valve of Fig. 4 or to the valve of Figures 5 and 6.

According to yet another aspect, the object disclosed herein relates to a method of damping pressure pulsations or vibrations in a system; a flowchart 800 of an embodiment of this new method? shown in Fig. 8.

[0039] The method of Fig. 8 essentially includes two phases:

- a fluidic coupling step 820 of at least one valve with a reciprocating compressor of a system in which pressure pulsations or vibrations must be reduced or kept below certain limits, and

- a step 830 for moving a valve element of the valve so as to regulate a pressure drop across the valve and achieve damping.

Block 810? the beginning of the flowchart and precedes phase 820 and block 840? the end? flowchart and step 830 follows.

[0040] The phase 820 and the phase 830 can be carried out at different and distant times and / or by different people. For example, phase 820 can? be carried out during an installation stage and phase 830 can? be carried out during a start-up stage.

[0041] The method of Fig. 8 can be be used, for example, in the system of Fig. 7. In this case, pressure pulsations or vibrations may occur in the pipeline 1000 due to the operation of the machine 700. In case, the valve in step 820? the 760 valve which? integrated in the machine 700; therefore, when installing the 700 machine, the valve? already? fluidically coupled. However, the method of Fig. 8 does not require the damping valve to be integrated into the reciprocating machine.

[0042] It should be noted that, depending on the embodiment of the method, one or more? damping valves and should be appropriately distributed throughout the system since? pressure pulsations and / or vibrations can vary from point to point in a system; the damping valve or valves may be identical or similar, for example, to the valve of Fig. 1 or to the valve of Fig. 4 or to the valve of Figures 5 and 6.

[0043] In step 820, the valve element can? be moved one or more? times. For example, pressure pulsations or vibrations in the system can be measured using different valve element positions, what next? identified and definitively set a position corresponding to satisfactory pressure pulsations or vibrations (for example minimal).

Claims (17)

CLAIMS 1. Valve (100) comprising: - a hollow body (110) having an inlet (111) and an outlet (112); - at least one valve element (120) housed inside said hollow body (110) and rotatable around an axis of rotation (R) between an open position and a closed position, said valve element (120) being adapted to be set in a selected position among a plurality? of intermediate positions between the open position and the closed position, wherein said valve element (120) has a flow regulating surface (122) which at least partially defines a flow passage between the inlet (111) and the outlet (112), wherein said flow regulating surface (122)? adapted to partially and gradually restrict said flow passage by rotating said valve element (120) around said axis of rotation (R) from said open position to said closed position in order to cause a pressure drop in a fluid flow from entrance (111) to exit (112). 2. Valve (100) according to claim 1, wherein said flow regulating surface (122)? an outer surface of said valve element (120). Valve (100)) according to claim 1 or 2, wherein an intersection of said flow regulating surface (122) with a plane perpendicular to said axis of rotation (R) defines an intersection line, where said intersection line? convex. 4. Valve (100)) according to claim 1 or 2 or 3, wherein said flow regulating surface (122)? shaped so as to define a predetermined dependence between the pressure drop across said valve (100) and the angular position of said valve element (120). 5. Valve (100)) according to any one of claims 1 to 4, wherein said valve element (120) has a circumferential groove (121) which extends circumferentially around said axis of rotation (R) and which defines said flow regulating surface (122), 6. Valve (100)) according to claim 5, wherein a radial cross-sectional area of said groove (121) gradually increases at least along a circumferential portion of said groove (121). 7. Valve (100)) according to claim 5 or 6, wherein a radial cross section of said groove (121)? semi-circular or semi-oval in shape. 8. Valve (100)) according to claim 7, wherein said groove (121) comprises a plurality of of consecutive circumferential portions, each portion corresponding to an intermediate position. Valve (100)) according to claim 1 to 8, comprising an opposition portion (130), wherein the opposition portion (130)? fixed, has a recess (131), and d? adapted to cooperate with said groove (121) to define said flow passage. Valve (100)) according to any one of claims 1 to 8, comprising another valve element (120), wherein said other valve element (120)? rotatable about another rotation axis parallel to said rotation axis (R), has another circumferential groove (121), and? adapted to partially define said flow passage through said other circumferential groove (121). Valve (100)) according to claim 10, wherein said valve elements (120) have toothed wheel portions (123) which engage with each other to kinematically couple said valve elements (120) in a counter-rotational movement. Valve (100)) according to any preceding claim, wherein said hollow body (110) comprises a chamber for housing at least said valve element (120), wherein said valve (100) comprises an exhaust duct (125) fluidically coupled to said chamber, wherein said chamber has a portion arranged to discharge fluid towards said discharge conduit (125). Valve (100)) according to any preceding claim, adapted to be used as an adjustable damping valve to reduce pressure pulsations and / or vibrations. 14. Reciprocating motion machine (700) having at least one compression chamber (730), wherein said reciprocating machine (700) comprises at least one valve (760) for causing a pressure drop, said valve (760) being coupled fluidically to said compression chamber (730) upstream or downstream of said compression chamber (730), said valve (760) being able to cause different pressure drops depending on the setting of the valve. Alternating motion machine (700)) according to claim 14, wherein said at least one valve (760)? a valve according to any of claims 1 to 13. A method (800) of damping pressure pulsations or vibrations in a system, the system comprising a reciprocating compressor (700) and a piping (1000) and at least one valve (760) with said reciprocating compressor (700 ), in which the method includes the step of: - moving (830) a valve element of said at least one valve (760) so as to regulate a pressure drop across the valve (760) and obtain damping. Method (800)) according to claim 16, wherein said at least one valve (760)? a valve according to any of claims 1 to 13.