Actuated valve for regulating a gas and supply system for a consumer such as a heat engine
The actuator-operated valve with a flared seat and flexible seal addresses the challenge of precise gas pressure regulation in internal combustion engines and fuel cells, ensuring efficient and compact operation across a wide pressure range.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- PHINIA DELPHI LUXEMBOURG SARL
- Filing Date
- 2023-12-22
- Publication Date
- 2026-05-08
AI Technical Summary
Existing pressure regulators for internal combustion engines and fuel cells face challenges in adjusting gas pressure levels accurately, particularly for hydrogen engines operating at higher pressures, and often require complex mechanical designs with inefficient power consumption and interface issues.
An actuator-operated valve with a flared seat and flexible seal mechanism, utilizing a needle with a circular groove and a spring, allows for precise gas flow regulation with minimal power consumption and compact size, featuring a flexible seal that ensures effective sealing without high force application.
The valve achieves fine adjustment of gas flow rates while maintaining a compact design and low power consumption, effectively regulating pressures from 2 to 50 bar, suitable for both internal combustion engines and fuel cells.
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Abstract
Description
Title of the invention: Actuator valve for regulating a gas and supplying a consumer such as a heat engine. Technical field
[0001] The present invention generally relates to an actuator valve for regulating the pressure of a gas for a consumer, in particular for a fuel supply system of a consumer such as an internal combustion engine or a fuel cell. Previous technique
[0002] Many stationary and mobile internal combustion engines use a compressed gas as a fuel which, when mixed with air, provides the energy needed to operate the engine. The fuel, for example compressed natural gas (CNG) or liquefied natural gas or hydrogen, is generally stored in a high-pressure tank, which may be, for example, on the order of approximately 700 bar. Such a pressure is generally incompatible with the operation of an internal combustion engine. Therefore, the gas pressure must be reduced to an acceptable level for introduction into the internal combustion engine. The pressure level of the natural gas to be introduced into the internal combustion engine can be on the order of 2 to 10 bar and up to 40 bar for an internal combustion engine running on hydrogen.A pressure regulator is therefore installed between the fuel tank and the fuel rail / injectors to ensure the desired reduction in gaseous fuel pressure.
[0003] Many pressure regulator applications have thus far used a mechanical pressure regulator to reduce gas pressure using a combination of valves, diaphragms and / or pistons, springs, and other mechanical devices. These regulators are insufficient when a specific pressure level needs to be adjusted, for example, between idle and rated operating speed.
[0004] Electronically controlled gas pressure regulators are also known. However, most known electronic gas pressure regulators for CNG applications can only operate at pressures up to 16 bar, making them unsuitable for hydrogen engines that operate at higher pressures, typically between 20 and 40 bar.
[0005] Another disadvantage of conventional pressure regulators for gaseous fuels is related to the interface design. The valve element generally has A conical shape that cooperates with a conical valve seat, and pressure regulation is achieved by controlling the axial position of the valve element relative to the valve seat. Depending on the configuration, maintaining a reduced flow area can be difficult.
[0006] Finally, it is desirable to be able to use an actuator that requires little power and is compact. Description of the invention
[0007] The invention aims to provide an actuator-operated valve to regulate a gas flow by controlling the actuator, allowing fine adjustment of the flow rate while limiting the size and power of the actuator.
[0008] With these objectives in mind, the invention relates to an actuator valve for regulating the flow of a gas, the valve comprising - a body comprising an inlet and an outlet for the gas and a seat between the inlet and the outlet, the seat being flared; - a needle, one end of which comes into contact with the seat in a closed position by the support of a spring; - an actuator tending to lift the needle from the seat towards an open position against the spring; characterized in that the needle has a circular groove containing a flexible seal bearing against the seat in the closed position.
[0009] The movement of the needle until the seal contacts the flared seat allows the gas flow from the inlet to the outlet to be modulated and then stopped completely. The use of a flexible seal allows the gas flow to be shut off with minimal force applied by the needle against the seat. Without actuator intervention, the spring holds the needle in contact and closes the valve. The spring is calibrated according to the maximum gas pressure on the upstream side, i.e., the inlet side. The flared shape of the seat ensures that the increase in the gas passage area as the needle is retracted by the actuator is gradual.
[0010] According to one design, the circular groove has a cylindrical bottom face with the same axis as the axis of the needle, and two flanks extending radially from the bottom face. The first flank is on the side of one needle point, and the second flank is opposite the first. The seal bears against the bottom face, and when the needle rests on the seat, against the second flank. The seal is thus established on one side at the contact with the seat, and on the other side at the contact against the second flank.
[0011] According to a first embodiment, the seal has a substantially polygonal cross-section with a base face opposite the bottom face, a first flank face opposite the first flank, a second flank face opposite the second flank, and a seat face opposite the seat. The straight parts of the cross-section can thus bear against the bottom of the groove, the second flank, and the seat, which provides rigid support and limits the pressure stroke of the seal against the seat.
[0012] According to an improvement, the base face of the seal is inclined with respect to the longitudinal axis in the direction where the direction of the base face is concurrent with the axis of the needle opposite the first end. Thus, when the valve is closed, the retained gas can enter between the groove and the base face, tending to expand the diameter of the seal. Conversely, the seal is compressed against the seat, which helps to achieve excellent sealing without having to apply strong pressure to the needle against the seat.
[0013] According to a second embodiment, the seal is an O-ring with a circular cross-section. When the seal is pressed against the seat, it is retained in the circular groove, and the contact areas are circular. It exhibits good sealing capacity upon closure, with moderate spring pressure. Such a seal is very common.
[0014] According to a third embodiment, the seal is an O-ring with a D-shaped cross-section, the right-hand side of the cross-section being oriented along the axis of the torus and on the inner side of the torus. The right-hand side of the cross-section can thus bear against the bottom of the groove, which provides it with rigid support and limits the pressure travel of the seal against the seat, compared to an O-ring with a circular cross-section.
[0015] According to one embodiment, the seal is made of a material comprising a component from the group including polytetrafluoroethylene (PTFE) and ethylene propylene diene monomer (EPDM). PTFE allows for continued operation with large temperature ranges and very little wear. The EPDM elastomer offers greater elasticity, which facilitates its placement in the groove and optimizes the spring's bearing force.
[0016] According to an improvement, the needle has a nipple at its first end which is inserted snugly into the inlet in the closed position, the nipple being disengaged from the inlet in the open position. When the needle is lifted from its seat, the gas is able to flow through the remaining gap between the inlet and the nipple. This achieves a low gas flow rate without the need for precise adjustment of the needle's position. This flow rate can correspond, for example, to the idle speed of an internal combustion engine.
[0017] In particular, the radial clearance between the nipple and the inlet is between 1 pm and 10 pm.
[0018] According to one design feature, the needle has a stop face to limit the needle's travel in the closed position when in contact with the seat. This limits the compression of the seal, thus preserving its service life.
[0019] According to a constructive arrangement, the spring is dimensioned to provide a pressure force of the needle against the seat of between 40 and 50 N. Such a force is sufficient to keep the needle in the closed position when the gas is supplied at a pressure of up to 50 bar.
[0020] The invention also relates to a gas supply system for a consumer, such as a heat engine or a fuel cell, the system comprising a gas tank connected to a control device comprising a valve as described above, the inlet of the valve being connected to the side of the tank, the outlet being connected to the side of the consumer. Brief description of the figures
[0021] The invention will be better understood and other features and advantages will become apparent upon reading the following description, the description referring to the accompanying drawings, among which: • [Fig.1] is a schematic view of a gas supply system; • Fig. 2 is a cross-sectional view of a valve conforming to a first mode realization of the invention; • [Fig.3] is a detail view similar to [Fig.2] for a second embodiment, in a partially open position; • [Fig.4] is a view similar to [Fig.3] in an open position; • [Fig.5] is a view similar to [Fig.3] in a closed position; • [Fig. 6] is a perspective view of the joint of the second mode of realization ; • [Fig.7] is a cross-sectional view of the joint in the first embodiment; • Fig. 8 is a cross-sectional view of a joint according to a third mode of realization of the invention. Detailed description
[0022] A valve 1 with an actuator is provided for a gas supply system for a consumer 2 such as a heat engine or a fuel cell, schematically represented in [Fig. 1]. The system comprises a pressurized gas reservoir 3 connected to the consumer 2 by a pipe, in which a pressure regulator 30 and a control device 4 incorporating said valve 1 are inserted, allowing the quantity of gas required by the consumer 2 to be delivered on demand. The control device may incorporate functions of a relief valve, not shown, to limit the pressure in the network, a shut-off valve, not shown, and / or a controllable purge valve to put the system into standby mode, not shown. The pressure regulator 30 reduces the gas pressure to a substantially constant level and, in the case of a liquefied gas, allows it to be vaporized. In the case of hydrogen powering an internal combustion engine, this pressure level is, for example, 25 to 50 bar. Valve 1 is configured, for example, to deliver the gas at the outlet at a regulated pressure between 5 and 40 bar. In direct injection applications, the supply pressure can be around 50 bar and regulation is performed between 20 and 40 bar, depending on the engine load. In indirect injection applications, the supply pressure is lower, on the order of 25 bar and above, and regulation is performed from 5 bar.
[0023] The valve according to a first embodiment of the invention is shown in [Fig.2],
[0024] The valve has an inlet 10 connected to the side of the reservoir 3 and an outlet 11 connected to the side of the consumer 2. The valve has a body 12 having the inlet 10 and the outlet 11 for the gas and a seat 120 between the inlet 10 and the outlet 11, the seat 120 being flared. The valve further has a needle 13, a first end 131 of which contacts the seat 120 in a closed position by the pressure of a spring 14, and an actuator 15 tending to lift the needle 13 from the seat 120 towards an open position against the spring 14. The body 12 has a generally cylindrical shape extending along a principal direction. The inlet 10 has the shape of a cylindrical bore at one end of the body 12 and having an axis parallel to the principal direction. The outlet 11 is formed by a plurality of radial holes 110 in the body 12, with an axis perpendicular to the main direction, and opening downstream of the seat 120.
[0025] Opposite the seat 120, the needle 13 is press-fitted onto a hollow weight called the armature 150. The armature 150 is part of the actuator 15 and is designed to be actuated by a coil (solenoid), not shown. When the coil is energized, it creates a magnetic field that acts on the armature 150 to move it to the left and lift it from the seat 120. The spring 14 is housed in the hollow of the armature 150 and acts on it, and therefore on the needle 13, to bring the needle 13 into contact with the seat 120.
[0026] The flared shape of the seat 120 is achieved by two successive conical portions 1201, 1202. The angle between the generatrix of the cone of the first portion 1201 and the principal direction is approximately 40°, while that of the second portion 1202 is approximately 60°. Other shapes are possible, such as a shape with more conical portions, or a continuously varying shape like a bell.
[0027] The needle 13 further comprises a circular groove 130 containing a flexible seal 16 bearing against the seat 120 in the closed position, as shown in the [Fig. 5]. The circular groove 130 has a cylindrical bottom face 1300 with the same axis as the axis of the needle 13, and two flanks extending radially from the bottom face 1300. The first flank 1301 is on the side of one point of the needle 13, and the second flank 1302 is opposite the first flank 1301. Thus, the second flank 1302 has a larger diameter than the first flank 1301. The needle 13 also has a stop face 132 beyond the second flank 1302 to limit the stroke of the needle 13 in the closed position when in contact with the seat 120.
[0028] The needle 13 has at its first end 131 a nipple 133 which is inserted in a snug manner into the inlet 10 in the closed position. The radial clearance between the nipple 133 and the inlet 10 is between 1 µm and 10 µm.
[0029] In this first embodiment, as shown in [Fig. 6], the seal 16 has a substantially polygonal cross-section with a base face 160 opposite the bottom face 1300, a first flank face 161 opposite the first flank 1301, a second flank face 162 opposite the second flank 1302, and a seat face 163 opposite the seat 120. The seal 16 is made of a polytetrafluoroethylene (PTFE)-based component. The junctions between the faces 160, 161, 163, and 162 are chamfered. The base face 160 of the seal 16 is inclined with respect to the longitudinal axis in the direction where the direction of the base face 160 is concurrent with the axis of the needle 13 opposite the first end 131. The seal 16 has for example a Shore D hardness between 60 and 90, in particular 70 and 90.
[0030] Thus, when the valve is closed, the retained gas can enter between the groove 130 and the base face 160 in such a way as to tend to an expansion of the diameter of the seal 16. On the contrary, the seal 16 is put under compression against the seat 120, which helps to obtain an excellent seal without having to apply the needle strongly against the seat.
[0031] The seal is placed in the groove by elastic deformation. In the case of a seal exhibiting plastic deformation, it is provided that the seal is shaped in the groove using a shaping tool.
[0032] During operation, the spring 14 holds the needle 13 against the seat 120, as shown in [Fig. 5], with contact established between the stop face 132 and the seat 120. The inlet 10 receives the pressurized gas from the regulator 30, for example, hydrogen at a pressure of 50 bar. The seal 16 is sufficiently compressed to achieve a gas-tight seal between the inlet 10 and the outlet 11. The gas enters between the bottom face 1300 and the base face 160 and thus tends to increase the diameter of the seal 16, which helps to improve the seal by pressing it against the seat 120.
[0033] At the start of the opening, as shown in [Fig. 3], the coil is actuated to move the armature 150 and the needle 13 against the spring 14, to the left of [Fig. 3]. The gas can then pass between the nipple 133 and the cylindrical part of the inlet 10 in the gap between the two then go towards the outlet 11. The flow rate is quite low and calibrated by the gap between the nipple 133 and the inlet 10.
[0034] As the needle 13 continues its stroke, the nipple 133 disengages from the inlet 10 in the open position, allowing a passage for gas between its end and the seat 120. Due to the flared shape of the seat 120, the more the needle 13 moves against the spring 14 under the action of the coil, the larger the passage area becomes, and the greater the gas flow rate. This leads to the open position shown in [Fig. 4].
[0035] By releasing the action of the coil, the needle 13 returns to the closed position as shown in [Fig.5], under the effect of the spring 14.
[0036] The nipple 133, for example, has a diameter of 2.5 mm and the seal 16 a diameter of 3.5 mm. The total stroke of the needle 13 is, for example, 3 mm. The pressure force exerted by the spring 14 of the needle 13 against the seat 120 is between 40 and 50 N.
[0037] In a second embodiment, the seal 16' is toroidal with a circular cross-section, as shown in [Fig. 7]. The seal 16' is fitted into the same circular groove 130 as described above, with adapted dimensions. The operating mode remains identical.
[0038] In a third embodiment, the 16” seal is toroidal with a D-shaped cross-section, the straight portion 160” of the cross-section being oriented along the axis A of the torus and on the inner side of the torus, as shown in [Fig. 8]. The 16” seal is fitted into the same circular groove 130 as described previously, with adapted dimensions. The operating mode remains identical.
[0039] The seal 16 is, for example, made of a material comprising polytetrafluoroethylene (PTFE). Alternatively, the seal 16 is made of an elastomeric material having a Shore A hardness of 60 to 90, for example comprising ethylene propylene diene monomer (EPDM).
[0040] The choice of one or the other material is made according to the desired hardness, the expected temperature range, the ease of implementation, the lifespan or other parameters.
Claims
Demands
1. Actuator valve for regulating the flow of a gas, the valve comprising - a body (12) having an inlet (10) and an outlet (11) for the gas and a seat (120) between the inlet (10) and the outlet (11), the seat (120) being flared; - a needle (13) having a first end (131) which comes into contact with the seat (120) in a closed position by the support of a spring (14); - an actuator (15) tending to disengage the needle (13) from the seat (120) towards an open position against the spring (14) characterized in that the needle (13) has a circular groove (130) containing a flexible seal (16, 16', 16") bearing against the seat (120) in the closed position, and in that the needle (13) has at its first end (131) a nipple (133) which is inserted in a fitted manner into the inlet (10) in the closed position, the nipple (133) being disengaged from the inlet (10) in the open position,- wherein the circular groove (130) has a cylindrical bottom face (1300) with the same axis as the axis of the needle (13), and two flanks extending radially from the bottom face (1300), of which a first flank (1301) is on the side of a point of the needle (13) and a second flank (1302) is opposite the first flank (1301), - wherein the seal (16) has a substantially polygonal cross-section with a base face (160) opposite the bottom face (1300), a first flank face (161) opposite the first flank (1301), a second flank face (162) opposite the second flank (1302), and a seat face (163) opposite the seat (120), and - wherein the base face (130) of the seal (16) is inclined with respect to the longitudinal axis in the direction that the The direction of the base face (130) is concurrent with the axis of the needle (13) opposite the first end (131).
2. Valve according to any one of the preceding claims, wherein the seal (16, 16', 16") is made of a material comprising a component of the group comprising polytetrafluoroethylene (PTFE) and ethylene-propylene-diene monomer (EPDM).
3. Valve according to any one of the preceding claims, wherein the radial clearance between the nipple (133) and the inlet (10) is between 1 and 10 pm.
4. Valve according to any one of the preceding claims, wherein the needle (13) has a stop face (132) to limit the stroke of the needle (13) in the closed position by being in contact with the seat (120).
5. Valve according to any one of the preceding claims, wherein the spring (14) is dimensioned to provide a support force of the needle (13) against the seat (120) of between 35 and 50 N.
6. Gas supply system for a consumer (2), such as a heat engine or a fuel cell, the system comprising a gas tank (3) connected to a control device comprising a valve (1) according to any one of the preceding claims, the inlet (10) of the valve (1) being connected to the side of the tank (3), the outlet (11) being connected to the side of the consumer (2).
7. System according to claim 6, wherein the fuel is hydrogen stored under pressure in the tank (3), the system further comprising a regulator (30) at the outlet of the tank (3) for reducing the gas to a target pressure of 25 to 50 bar, the valve allowing the gas to be delivered at the outlet at a regulated pressure between 5 and 40 bar.