Gas pressure regulator and method for operating a gas pressure regulator

Abstract

The invention relates to a gas pressure regulator (10) with a pressure regulating piston (11) which is guided so as to be movable back and forth in an axial direction between a pressure chamber (13) which is subjected to an inlet pressure via a gas inlet (14) which can be closed off by the pressure regulating piston (11), and a chamber volume (15) in a counter chamber (16) opposite the pressure chamber (13), which is connected to the pressure chamber (13) via a fluidic resistance (17), from which a gas outlet (18) leads, wherein the pressure regulating piston (11) is assigned a valve spring (19) with a spring force which counteracts a closing movement of the pressure regulating piston (11). In order to reduce unwanted noise during operation of the gas pressure regulator (10), the gas pressure regulator (10) is designed in terms of vibration technology such that unwanted operating noise is effectively reduced during operation of the gas pressure regulator (10) even when the inlet pressure varies between a maximum inlet pressure of more than five hundred bar and a minimum inlet pressure which is significantly lower than the maximum inlet pressure and, for example, is less than one hundred bar, wherein an outlet pressure in the gas outlet (18) regulated by the gas pressure regulator (10) is also significantly lower than the maximum inlet pressure and, for example, is less than sixty bar.

Description

[0001] The invention relates to a gas pressure regulator with a pressure control piston that is guided to move back and forth in an axial direction between a pressure chamber, which is subjected to an inlet pressure via a gas inlet that can be closed by the pressure control piston, and a chamber volume in a counter-chamber opposite the pressure chamber, which is connected to the pressure chamber via a fluidic resistance, from which a gas outlet leads. A valve spring with a spring force that counteracts a closing movement of the pressure control piston is assigned to the pressure control piston. The invention further relates to a method for operating such a gas pressure regulator. State of the art

[0002] The German patent application DE 10 2022 200 298 A1 discloses a fuel cell system comprising a fuel cell stack with an anode which can be supplied with hydrogen from a high-pressure hydrogen tank via a hydrogen path and with recirculated anode gas via an anode circuit, wherein for the recirculation of anode gas a blower is integrated into the anode circuit which can be driven via a turbine arranged in the hydrogen path, wherein a pressure sensor and / or a pressure regulator is / are integrated into the hydrogen path.The German patent application DE 10 2022 202 190 A1 discloses a fuel cell system with a hydrogen supply comprising at least one hydrogen pressure tank which is connected via a pressure regulator to a medium-pressure region in which a metering valve is arranged, via which hydrogen is supplied to a fuel cell, wherein at least one medium-pressure accumulator is arranged between the pressure regulator and the metering valve. Disclosure of the invention

[0003] The object of the invention is to reduce unwanted noise during operation of the gas pressure regulator.

[0004] The problem is solved in a gas pressure regulator with a pressure control piston, which is guided to be movable back and forth in an axial direction between a pressure chamber, which is subjected to an inlet pressure via a gas inlet that can be closed by the pressure control piston, and a chamber volume in a counter-chamber opposite the pressure chamber, which is connected to the pressure chamber via a fluidic resistance, from which a gas outlet leads, wherein the pressure control piston is assigned a valve spring with a spring force that counteracts a closing movement of the pressure control piston, in that the gas pressure regulator is designed in terms of vibration technology in such a way that during operation of the gas pressure regulator, undesirable operating noises are effectively reduced even when the inlet pressure varies between a maximum inlet pressure of more than 500 bar and a minimum inlet pressure,which is significantly lower than the maximum inlet pressure and, for example, amounts to less than 100 bar, whereby an outlet pressure in the gas outlet regulated by the gas pressure regulator is also significantly lower than the maximum inlet pressure and, for example, amounts to less than 60 bar. The inlet pressure is preferably a storage pressure of a gas pressure accumulator, for example a fuel pressure accumulator, in particular a hydrogen pressure accumulator. The inlet pressure decreases during operation when gas is withdrawn from the gas pressure accumulator. The outlet pressure is regulated by the gas pressure regulator. The gas pressure regulator can be single-stage or multi-stage. The outlet pressure, in particular the outlet pressure after a last stage of a multi-stage gas pressure regulator, is preferably a fuel pressure,For example, a hydrogen pressure in front of a fuel cell or in a hydrogen engine. Various measures are proposed to optimize a conventional pressure regulator design such that noise development is reduced to a minimum and, at best, below the perception threshold. In the context of the present invention, it was discovered that unwanted noise development can be reduced at various levels. Firstly, gas vibrations occurring during operation can be reduced or modified in such a way that the mechanical components of the gas pressure regulator are stimulated to a lesser extent or not at all to vibrate. Alternatively or additionally, the inherently undesirable mechanical vibrations can be dampened. In addition, acoustic decoupling can be implemented.to reduce vibration transmission or noise excitation to the housing of the gas pressure regulator.

[0005] A preferred embodiment of the gas pressure regulator is characterized in that a throttle diameter of the fluidic resistance between the pressure chamber and the counter chamber is less than five-tenths of a millimeter. Between the gas inlet and the pressure chamber, a valve seat is advantageously provided, which can be closed by a sealing element in the pressure control piston. The sealing element on the pressure control piston is designed, for example, to close the gas inlet in a valve seat area. The forces in the valve seat area are counteracted by pressure equalization forces in the opposite counter chamber. The two volumes in the pressure chamber and in the counter chamber, which are subjected to different pressures, are connected to one another via a fluidic connection, for example a pipe or a bore, in the pressure control piston, so that pressure oscillations from the valve seat area arrive in the rear chamber volume with a delay.The time it takes for a pressure wave to travel from the valve seat area to the opposing chamber can cause the pressure control piston, also known as the valve, to vibrate. This unwanted vibration excitation can be significantly reduced by the claimed design of the fluidic resistance. An overpressure wave that occurs in the valve seat area when the gas pressure regulator opens arrives in the opposing chamber with a time delay and leads to a closing force contribution there, which in turn leads to a reduction in the stroke of the pressure control piston, whereby the pressure in the valve seat area increases proportionally to a closing movement. This can also cause the pressure control piston to vibrate. The reduced throttle diameter decouples the pressure waves occurring in the pressure chamber and the opposing chamber in time.This reduces gas vibrations that occur during operation of the gas pressure regulator or changes them in such a way that the mechanical components of the gas pressure regulator are stimulated to vibrate less or not at all.

[0006] Another preferred embodiment of the gas pressure regulator is characterized in that the throttle diameter of the fluidic resistance between the pressure chamber and the counter chamber is greater than two-tenths of a millimeter. This has proven advantageous in considerations and / or investigations conducted within the scope of the invention.

[0007] A further preferred embodiment of the gas pressure regulator is characterized in that at least one sliding and friction element is attached to the pressure control piston, which interacts with a housing wall and is tuned to effectively dampen differential pressure-dependent oscillatory movements of the pressure control piston. The sliding and friction element is advantageously axially fixedly connected to the pressure control piston. For this purpose, the sliding and friction element is designed, for example, as a sliding and friction ring and is accommodated in a corresponding annular groove of the pressure control piston. In contrast to the conventional function of sliding rings, friction is deliberately generated here between the sliding and friction element and the housing wall.The sliding and friction element therefore not only advantageously takes over the function of axially guiding the pressure control piston, but also advantageously serves to reduce the vibrations of the pressure control piston relative to the housing wall, which are considered to be the cause of the undesirable noise development.

[0008] Another preferred embodiment of the gas pressure regulator is characterized in that the sliding and friction element is combined with a spring element, by which the sliding and friction element is radially preloaded against the housing wall in such a way that the frictional force is increased. The term "axial" refers to a longitudinal axis of the pressure control piston. Axial means in the direction of or parallel to this longitudinal axis. Analogously, the term "radial" in this context means perpendicular to the longitudinal axis of the pressure control piston. The frictional force always counteracts the movement of the piston and causes vibration energy to be converted into heat. This further dampens the unwanted vibrations.

[0009] A further preferred embodiment of the gas pressure regulator is characterized in that at least one second sliding and friction element is attached to the pressure control piston. According to one embodiment, the second sliding and friction element is arranged to the right or left of a center of mass of the pressure control piston. According to a further embodiment, a distance in the axial direction between the two sliding and friction elements should be greater than a diameter of the pressure control piston. According to a further embodiment, the second sliding and friction element is arranged close to the seat. Close to the seat means that the second sliding and friction element is arranged near the valve seat area. The first-mentioned sliding and friction element is advantageously arranged at an end of the pressure control piston facing away from the valve seat area. The sliding and friction elements improve the guiding properties. Furthermore, friction is significantly increased.

[0010] Another preferred embodiment of the gas pressure regulator is characterized in that the valve spring is arranged between two damping elements. This mechanically decouples the contact surfaces between the valve spring and the housing. The damping elements can be designed, for example, as elastomer discs arranged between a respective end of the valve spring and the housing or a piston collar. The damping elements prevent the transmission of structure-borne sound from the valve spring to the housing or the pressure control piston.

[0011] A further preferred embodiment of the gas pressure regulator is characterized in that pressure equalization channels provided in the pressure control piston are arranged axially offset from a flow path between the gas inlet and the gas outlet. This prevents unwanted excitations in the area of the pressure equalization channels.

[0012] In a method for operating a gas pressure regulator as described above, preferably in a fuel drive system, in particular a fuel cell system, the above-mentioned object is achieved alternatively or additionally in that undesirable operating noises are effectively reduced even when the inlet pressure varies between a maximum inlet pressure of more than 500 bar and a minimum inlet pressure which is significantly lower than the maximum inlet pressure and, for example, less than 30 bar, wherein an outlet pressure in the gas outlet regulated by the gas pressure regulator is likewise significantly lower than the maximum inlet pressure and, for example, less than 20 bar. Fuel, in particular hydrogen, for mobile applications is usually stored as compressed hydrogen in a motor vehicle equipped with the fuel drive.Both fuel cells and hydrogen engines, which convert the chemical energy of hydrogen, require hydrogen at a specific pressure range that is significantly below the storage pressure. The required pressure, for example, is between five and sixty bar, compared to a storage pressure of seven hundred bar with a full storage tank. The pressure is reduced by means of mechanical or electromechanical pressure reducers or pressure regulators installed upstream of the fuel consumer. When the pressure regulator expands the gas to the desired target pressure, interactions can occur between the gas and the mechanical component of the gas pressure regulator, leading to unwanted audible vibrations or noise in the vicinity of the pressure regulator. The claimed method effectively reduces these unwanted operating noises.

[0013] The invention may also relate to a fuel drive system, in particular a fuel cell system, with a single-stage or multi-stage gas pressure regulator as described above.

[0014] The invention further relates to a pressure control piston, in particular a sliding and friction element, a spring element, a damping element, and / or a valve spring for a gas pressure regulator described above. These parts are available separately.

[0015] Further advantages, features and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawing. Short description of the drawing

[0016] They show: Fig. 1 a schematic representation of a gas pressure regulator with a pressure control piston in a longitudinal section according to a first embodiment in a closed state; Fig. 2 the gas pressure regulator Fig. 1 in an open state; Fig. 3 the gas pressure regulator Fig. 1 according to a second embodiment with axially offset pressure equalization channels in a pressure control piston; Fig. 4 the gas pressure regulator Fig. 1 according to a third embodiment with a valve spring arranged between two damping elements; Fig. 5 the gas pressure regulator Fig. 1 according to a fourth embodiment with a specially designed sliding and friction element; and Fig. 6 a schematic representation of a gas pressure regulator arranged between a storage pressure area and a working pressure area. Description of the embodiments

[0017] In Fig. 6 shows a gas pressure regulator 1 only schematically. The gas pressure regulator 1 can be single-stage or multi-stage. A rectangle 4 indicates a first stage of the pressure regulator 1. A rectangle 5 indicates a second stage of the pressure regulator 1. Three dots indicate that the gas pressure regulator 1 can also have more than two stages 4, 5.

[0018] The gas pressure regulator 1 is supplied with gas from a storage pressure area 2, which is subjected to an inlet pressure, as indicated by an arrow 6 in Fig. 6 is indicated. The gas pressure regulator 1 regulates the gas to an outlet pressure that is significantly lower than the inlet pressure.

[0019] An arrow 7 indicates Fig. 6 indicates that the gas is supplied at the discharge pressure to a working pressure region 3. The working pressure region 3 comprises, for example, a fuel cell. The storage pressure region 2 comprises, for example, a fuel pressure accumulator, in particular a hydrogen pressure accumulator.

[0020] In the Fig. 1, Fig. 2; Fig. 3; Fig. 4; Fig. Figure 5 schematically shows a total of four exemplary embodiments of a gas pressure regulator 10 in longitudinal section through a pressure control piston 11. The same reference numerals are used to designate identical or similar parts. The following first describes the common features of the various exemplary embodiments. The differences between the individual exemplary embodiments are then discussed.

[0021] The pressure control piston 11 is arranged along a longitudinal axis 12, i.e. in the Fig. 1 to 5 in a horizontal direction, movable back and forth in a not further designated housing of the gas pressure regulator 10. A gas inlet 14 opens into a Fig. 1 to 5, the pressure chamber 13 is located on the left and is partially designed as an annular chamber. Fig. 1 to 5 right end, the pressure control piston 11 projects into a chamber volume 15 of a counter chamber 16.

[0022] The counter chamber 16 with the chamber volume 15 is connected to the pressure chamber 13 via pressure equalization channels 27, 28; 37, 38 and an axial channel 29 with a throttle 30. The throttle 30 serves to represent a fluidic resistance 17 at the end of the axial channel 29.

[0023] Contrary to what is shown, the throttle 30 or the fluidic resistance 17 shown with the throttle 30 can also be assigned to the pressure equalization channels 27, 28; 37, 38.

[0024] A gas outlet 18 extends into the Fig. 1 to 5 upwards from the pressure chamber 13. Discharged gas with the regulated discharge pressure is indicated by arrow 7. Similarly, gas supplied to the gas pressure regulator 10 with the inlet pressure is indicated by arrow 6.

[0025] A valve spring 19 is arranged axially between a housing shoulder 8 and a piston collar 9 of the pressure control piston 11. The valve spring 19 is arranged in an annular space that is bounded radially inward by the pressure control piston 11 and radially outward by a housing wall 20. The piston collar 9 also serves to accommodate a sliding and friction element 21.

[0026] A second sliding and friction element 22 is in Fig. 1 only indicated. The second sliding and friction element 22 is arranged, for example, close to the seat of the pressure control piston 11. The term "close to the seat" refers to a valve seat area 26. The second in Fig. The sliding and friction element 22 shown in Figure 1 is particularly advantageously arranged in front of or behind the seal 24. When arranging the second sliding and friction element 22, care must be taken to ensure that the second sliding and friction element 22 is not arranged between the valve seat area 26 and the pressure equalization channels 27, 28; 37, 38.

[0027] The pressure equalization channels 27, 28; 37, 38 are preferably designed as radial bores. The seals 23, 24 are preferably designed as high-pressure seals. This applies in particular to seal 24.

[0028] The valve seat area 26 serves together with a sealing element 25 to form a valve seat. The sealing element 25 is mounted on a Fig. 1 to 5 left end of the pressure control piston 11. The sealing element 25 serves in the valve seat area 26 to close the gas inlet 14, as can be seen in the Fig. 1, Fig. 3, Fig. 4 and Fig. 5 sees.

[0029] In Fig. 2, the valve seat area 26 is released from the sealing element 25. Then, a flow path 31 between the gas inlet 14 and the gas outlet 18 is opened.

[0030] Seals 23, 24 are used to seal between the pressure chamber 13 and the counter chamber 16. The seals 23, 24 are, as shown in the Fig. 1 to 5, are preferably substantially V-shaped and allow certain relative movements. An opening of the V-shaped configuration of the seals 23, 24 is advantageously directed against the higher pressure.

[0031] In the Fig. 3, the pressure equalization channels 37, 38 are in contrast to the embodiment shown in Fig. 1, the pressure equalization channels 27, 28 of the pressure control piston 11 are axially offset to the right. This provides, among other advantages, that the pressure equalization channels 37, 38 are no longer located directly in the flow path 31 of the main flow between the gas inlet 14 and the gas outlet 18 when the gas pressure regulator 10 is open.

[0032] In the Fig. In the embodiment of the gas pressure regulator 10 shown in Figure 4, the valve spring 19 is vibrationally decoupled from both the housing of the gas pressure regulator 10 and the pressure control piston 11 by two damping elements 33, 34. The damping elements 33, 34 are designed, for example, as elastomer discs. The damping element 34 is arranged between the housing shoulder 8 and the valve spring 19. The damping element 33 is arranged between the piston collar 9 of the pressure control piston 11 and the valve spring 19.

[0033] In the Fig.In the embodiment shown in Figure 5, the sliding and friction element 21 is preloaded radially outward against the housing wall 20 by a spring element 40. This allows the friction force to be increased in a simple manner.

[0034] The sliding and friction elements 21, 22 can consist of a single component, for example, a suitable plastic material with good sliding properties, such as polytetrafluoroethylene or polyether ketone. The sliding and friction element 21 is mounted, for example, on a metallic, ring-shaped, slotted support. The support is designed, for example, as a spring washer. The spring washer can be made of steel, particularly spring steel. For assembly, the sliding and friction element is preloaded similarly to a piston seal ring and, when installed, presses its sliding layer or the separate sliding ring against the housing wall 20. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 200 298 A1

[0002] DE 10 2022 202 190 A1

[0002]

Claims

[1] Gas pressure regulator (1; 10) with a pressure control piston (11) which is guided to be movable back and forth in an axial direction between a pressure chamber (13) which is subjected to an inlet pressure via a gas inlet (14) which can be closed by the pressure control piston (11), and a chamber volume (15) in a counter chamber (16) opposite the pressure chamber (13), which is connected to the pressure chamber (13) via a fluidic resistance (17), from which a gas outlet (18) leads, wherein the pressure control piston (11) is assigned a valve spring (19) with a spring force which counteracts a closing movement of the pressure control piston (11), characterized byin that the gas pressure regulator (1;10) is designed in terms of vibration technology in such a way that during operation of the gas pressure regulator (1;10) undesirable operating noises are effectively reduced even when the inlet pressure varies between a maximum inlet pressure of more than five hundred bar and a minimum inlet pressure which is significantly lower than the maximum inlet pressure and, for example, is less than one hundred bar, wherein an outlet pressure in the gas outlet (18) regulated by the gas pressure regulator (1;10) is also significantly lower than the maximum inlet pressure and, for example, is less than sixty bar. [2] Gas pressure regulator according to claim 1, characterized by that a throttle diameter of the fluidic resistance (17) between the pressure chamber (13) and the counter chamber (16) is less than five tenths of a millimeter. [3] Gas pressure regulator according to claim 2, characterized bythat the throttle diameter of the fluidic resistance (17) between the pressure chamber (13) and the counter chamber (16) is greater than two tenths of a millimeter. [4] Gas pressure regulator according to one of the preceding claims, characterized by that at least one sliding and friction element (21, 22) is attached to the pressure control piston (11), which interacts with a housing wall (20) and is tuned in such a way that differential pressure-dependent oscillatory movements of the pressure control piston (11) are effectively damped. [5] Gas pressure regulator according to claim 4, characterized by that the sliding and friction element (21,22) is combined with a spring element (40) by means of which the sliding and friction element (21,22) is prestressed radially against the housing wall (20) in such a way that the friction force is increased. [6] Gas pressure regulator according to one of claims 4 or 5, characterized by that at least one second sliding and friction element (22) is attached to the pressure control piston (11). [7] Gas pressure regulator according to one of the preceding claims, characterized by that the valve spring (19) is arranged between two damping elements (33,34). [8] Gas pressure regulator according to one of the preceding claims, characterized by that pressure equalization channels (37, 38) provided in the pressure control piston (11) are arranged axially offset to a flow path (31) between the gas inlet and the gas outlet (18). [9] Method for operating a gas pressure regulator (1; 10) according to one of the preceding claims, preferably in a fuel drive system, in particular a fuel cell system, characterized bythat undesirable operating noises are effectively reduced even when the inlet pressure varies between a maximum inlet pressure of more than five hundred bar and a minimum inlet pressure which is significantly lower than the maximum inlet pressure and is, for example, less than thirty bar, wherein an outlet pressure in the gas outlet (18) regulated by the gas pressure regulator (1; 10) is also significantly lower than the maximum inlet pressure and is, for example, less than twenty bar. [10] Pressure control piston (11), in particular sliding and friction element (21, 22), spring element (40), damping element (33, 34) and / or valve spring (19) for a gas pressure regulator (1; 10) according to one of claims 1 to 8.

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