Safety devices for tanks containing pressurized gas

Abstract

A safety device (3) includes: - a venting channel (9) for fluid communication between an internal volume (10) defined by a storage tank and an external storage tank (2); - a safety piston (5) movable between a closed position of the venting channel (9) and a safe position of the venting channel (9) not being closed; - a deformable first safety member (6) that resists an elastic restoring force that returns the safety piston to the safe position and holds the safety piston in the closed position; - a deformation device (7) for deforming the first safety member (6) and movable between a rest position and a deformed position; and - at least one second safety member (8) for holding the deformation device in the rest position, resisting an elastic restoring force that returns the deformation device to the deformed position, when the second safety member (8) is subjected to a temperature below a predetermined temperature, and for releasing the elastic restoring force that returns the second safety member to the deformed position when the second safety member is subjected to a temperature above a predetermined temperature. The second safety member (8) is formed of a safety cable (16) made of a material with low mechanical fire resistance.

Description

Technical Field

[0001] This invention relates to a safety device for a tank containing pressurized gas and a method for manufacturing such a safety device. The invention also relates to a kit for manufacturing such a safety device. Furthermore, the invention relates to a tank for containing pressurized gas equipped with the safety device according to the invention, and a motor vehicle equipped with such a tank. Background Technology

[0002] Tanks for containing pressurized gases are known in the prior art. These tanks, for example, are used to store compressed dihydrogen for use as fuel tanks in vehicles. These tanks are typically equipped with safety valves that establish fluid communication between the inside of the tank and the outside when the internal pressure becomes too high, thereby releasing the gas stored in the tank to the outside and reducing the risk of explosion. Among the safety valves used, thermal valves, commonly referred to as thermal pressure relief devices (TPRDs), are particularly known. When the tank is exposed to high temperatures, such as when a flame approaches the tank, the pressure inside increases, potentially leading to an explosion. Therefore, thermal pressure relief devices are particularly useful for preventing heat-induced pressure increases within the tank.

[0003] Thermosensitive pressure reducing devices typically include a safety component that holds a piston, used to seal the vent passage of a storage tank, in a closed position. When a heat source is near the safety component, it melts or ruptures, no longer holding the sealing piston in the sealed vent passage position. A reset device, such as a spring, then moves the sealing piston, releasing it from the vent passage, thus allowing fluid communication between the inside and outside of the tank and causing the gas stored in the tank to escape to the outside, thereby preventing an increase in pressure inside the tank. However, such thermosensitive pressure reducing devices only allow the detection of heat sources within a relatively close radius of the safety component. Therefore, if the heat source is far from the thermosensitive pressure reducing device—which is very likely for large storage tanks—the temperature of the safety component may not rise high enough to melt or rupture. Consequently, the pressure inside the tank may increase, creating a risk of explosion. One solution to overcome this problem is to increase the number of thermosensitive pressure reducing devices in the tank to cover a larger area. However, this solution is space-consuming and uneconomical. Furthermore, increasing the number of thermosensitive pressure reducing devices installed in the tank proportionally increases the number of interfaces that need to be sealed between the thermosensitive pressure reducing device and the tank, which also increases the risk of gas leakage.

[0004] One solution is to use a lead wire that contacts the safety component and extends a certain distance over the tank. When a heat source, such as a flame, approaches the lead wire, it is ignited and consumed, simultaneously transferring heat energy to the safety component, causing it to melt or rupture. Such a thermostatic pressure relief device is described, for example, in US 6,382,232 B1. However, this device has drawbacks because the melting or rupture of the safety component is not guaranteed after the lead wire is ignited. In fact, firstly, it is possible that the burning of the lead wire is interrupted before it reaches the safety component. This is, for example, if the lead wire is wet for at least a portion of its journey to the safety component. Secondly, it is difficult to control the duration for which the safety component is exposed to the heat energy transferred by the lead wire. The burning of the lead wire may be too rapid to raise the temperature of the safety component sufficiently to cause it to melt or rupture. Therefore, despite the existence of thermostatic pressure relief devices, the risk of an explosion due to the presence of a temperature source causing an increase in pressure within the tank remains high.

[0005] Document DE102011114724 A1 describes a safety device for a tank containing pressurized gas. The safety device includes a venting channel for fluid communication between the inside and outside of the tank, a safety piston movable between a closed position and a safe position of the venting channel, a fragile ampoule holding the safety piston in the closed position, a screw movable between a rest position and an ampoule breakage position, and a Bowden-type cable that, in the rest position, resists an elastic restoring force that would cause the screw to return to the ampoule breakage position, thus holding the screw in the rest position, and in the working position, releases the elastic restoring force that would cause the screw to return to the ampoule breakage position. Summary of the Invention

[0006] The object of the present invention is particularly to provide a safety device for a tank containing pressurized gas, which is especially safe in the presence of a heat source.

[0007] Therefore, the subject of this invention is a safety device for a storage tank for containing pressurized gas, the safety device comprising:

[0008] - Ventilation channels, which are used to allow fluid communication between the internal volume defined by the tank and the external environment of the tank.

[0009] - A safety piston that can move between a closed position and a safe position. In the closed position, it closes the vent passage; in the safe position, it does not close the vent passage.

[0010] - A deformable first safety component is configured to resist the elastic restoring force that would otherwise return the safety piston to a safe position, thereby holding the safety piston in the closed position.

[0011] The safety device also includes:

[0012] - A deformation device for deforming the first safety component, the deformation device being movable between a resting position and a deformed position of the first safety component, and

[0013] - At least one second safety component is configured to, in a rest position, resist an elastic restoring force that would cause the deformation device to return to the deformed position of the first safety component when the second safety component is subjected to a temperature below a predetermined temperature, thereby holding the deformation device in a rest position; and in a working position, release the elastic restoring force that would cause the deformation device to return to the deformed position of the first safety component when the second safety component is subjected to a temperature above a predetermined temperature.

[0014] The second safety component is formed by a safety cable made of a material with low mechanical fire resistance.

[0015] Therefore, when the second safety component is exposed to a temperature higher than the predetermined temperature, such as when a flame comes into contact with or approaches the second safety component, the deformation device moves from its resting position to the deformation position of its first safety component, thereby deforming the first safety component and causing it to cease performing its function of holding the safety piston in the closed position. Thus, the elastic restoring force that returns the safety piston to the safe position causes the safety piston to elastically return to the safe position, thereby enabling fluid communication between the inside and outside of the tank, allowing the gas contained in the tank to escape to the outside of the tank through the venting passage. In this way, in the presence of a heat source with a temperature higher than the predetermined temperature, an increase in pressure inside the tank is avoided in a simple and economical manner. It should be noted that it is the transition of the second safety component from its resting position to its operating position that allows the safety device to be actuated, and for this purpose, it is advantageous that no heat energy needs to be transferred to the first safety component. Furthermore, using an elastic restoring device to move the closed piston to its safe position and the deformation device to the deformation position of the first safety component is advantageous because it is easy to implement, robust, and economical. Using a second safety component as the detection element is advantageous because it eliminates the need for the first safety component to be positioned as close as possible to the heat source for the use of the safety device.

[0016] "Deformable first safety component" means that the first safety component can be deformed by the action of a deformation device, such as by folding or breaking. The deformation no longer allows the first safety component to perform its function of holding the safety piston in the closed position. When this function is no longer performed, it is understood that an elastic restoring force to return the safety piston to the safe position is subsequently applied to move the safety piston to the safe position.

[0017] The predetermined temperature is selected, in particular, based on the characteristics of the tank and / or the gas it is intended to store. The predetermined temperature is selected such that prolonged exposure of the tank to temperatures below a predetermined temperature, regardless of the duration of exposure, will not increase the pressure within the tank to a level that poses a high risk of tank explosion. In other words, the predetermined temperature is selected such that prolonged exposure (i.e., several minutes, e.g., 5 to 60 minutes) to temperatures above a predetermined temperature is sufficient to cause an increase in pressure within the tank, thereby significantly increasing the risk of tank explosion. The predetermined temperature, depending on the characteristics of the tank and / or the gas to be stored, is typically between 95°C and 150°C, for example, between 100°C and 130°C, preferably between 100°C and 120°C. The predetermined temperature is selected within this temperature range such that it is low enough to trigger the actuation of safety devices if necessary (i.e., when there is a credible risk of tank explosion), and high enough not to trigger the safety devices and thus cause loss of the contents stored in the tank without posing a serious risk of tank explosion. This temperature range typically allows for the detection of the presence of a flame near the tank.

[0018] The mechanical fire resistance of a component refers to the time during which the component continues to function when exposed to fire. Therefore, it can be understood that the lower the mechanical fire resistance of a component, the faster it will cease to function when exposed to fire. In this document, this value represents the time during which the second safety component holds the deformable device in the resting position when exposed to a temperature above a predetermined temperature. Because this time is short, it can be understood that the component will rapidly cease to function when exposed to a temperature above the predetermined temperature. Therefore, this reduces the risk of tank explosion due to increased internal pressure during the fire resistance time.

[0019] Using a safety cable as a second safety component is a simple and economical way to manufacture a second safety component.

[0020] The present invention may also include one or more of the following optional features, used individually or in combination.

[0021] The first safety component is fragile. According to this embodiment, the deformation caused by the deformation device advantageously results in the destruction of the first safety component. This destruction, more than folding, ensures that the first safety component can no longer perform its function of holding the safety piston in the closed position. Therefore, the safety device is more reliable. The term "fragile safety component" should be understood to mean a safety component designed to be easily destroyed by the deformation device when it moves to the deformation position of the first safety component—which may also be referred to here as the destruction position.

[0022] The first safety component is formed from a glass ampoule. This is a simple and economical embodiment for the first safety component. Glass ampoules are prone to breakage using many different deformation devices, which are also simple and economical to implement.

[0023] According to one embodiment, the glass ampoule contains a fluid used to apply pressure to the ampoule when it is subjected to a temperature above a predetermined temperature, causing the ampoule to rupture. Thus, the ampoule can rupture either when the second safety component is subjected to a temperature above the predetermined temperature by a deformation device, or when the ampoule itself is subjected to a temperature above the predetermined temperature. Therefore, since the second safety component allows detection of heat sources away from the glass ampoule, and the glass ampoule allows detection of heat sources located nearby, the safety risks to the storage tank can be dually detected. Consequently, the detection area of ​​heat sources covered by the safety device is wider.

[0024] When the first safety component is exposed to a temperature higher than a predetermined temperature, it becomes fusible. Thus, when the first safety component is exposed to a temperature higher than the predetermined temperature, it melts and ceases to perform its function of holding the safety piston in the closed position. Therefore, since the second safety component allows detection of heat sources at a certain distance from the first safety component, and the first fusible safety component allows detection of heat sources located nearby, the safety risks to the tank can be dually detected. Therefore, the detection area of ​​heat sources covered by the safety device is wider.

[0025] The elastic restoring force that returns the deformation device to the deformed position of the first safety component is provided by a spring supported on a support base having a hole configured to allow the passage of a second safety component. This is a simple, reliable, and compact method for obtaining the elastic restoring force that returns the deformation device to the deformed position of the first safety component.

[0026] Preferably, at least a portion of the hole in the spring's support seat comprises and / or is covered by a lubricant. This facilitates the movement of the second safety member through the hole in the support seat. This is particularly advantageous because it reduces the risk of friction between the second safety member and the hole in the support seat slowing down the release of the elastic restoring force that would allow the deforming device to return to the deformed position of the first safety member. If such slowing occurs, there is a risk that the kinetic energy of the deforming device upon reaching the first safety member may be insufficient to deform (e.g., break or fold) the first safety member. In this case, the use of the safety device may be impossible, thus potentially leading to a risk of tank explosion. The lubricant can be of any type compatible with the operation of the safety device. For example, the lubricant can be solid, liquid, or paste.

[0027] The safety piston has a receiving cavity configured to accommodate at least a portion of the deformation device when the safety piston is in the safe position and the deformation device is in the first safety member deformation position. This reduces the risk that the volume of the deformation device in the first safety member deformation position may obstruct the safety piston from entering the safe position, which could lead to a tank explosion.

[0028] The deformation device includes an impact element. The impact element is a component of the deformation device designed to contact the first safety member to deform it, preferably by breaking it. Therefore, it can have any shape compatible with this function. The impact element can be, for example, the shape of a needle, bayonet, arrowhead, or sheet. Preferably, the impact element is a sheet. This shape has the advantage of being small in size and effective in deforming or even breaking the first safety member. It is particularly noteworthy that although the sheet has a very small thickness (a characteristic of sheets), it can be large enough to cover the entire width of the first safety member. The sheet also has the advantage of a low coefficient of drag, thus not slowing the movement of the deformation device from its resting position to its deformed position relative to the first safety member.

[0029] The second safety component includes an elastic element. Therefore, the second safety component is capable of compensating for possible dimensional changes in the tank due to its fill rate. For example, the second safety component includes an element made of rubber. According to some embodiments, the rubber can be natural or synthetic rubber. In another example, the second safety component includes a tension spring. According to some embodiments, the tension spring can be a coiled circular steel wire.

[0030] The length of the safety cable is between 1m and 10m, preferably between 1m and 3m. This allows the safety cable to cover a larger portion of the length of a large storage tank. Therefore, even for large storage tanks, the cable can detect heat sources over a larger area. Preferably, the length of the safety cable is selected to extend along the entire length of the storage tank.

[0031] The safety cable is made of a material classified as D according to European standard EN 13501-1 or as M3 or M4 according to French standard NF P92-507. It should be understood that the versions of these standards mentioned are in effect at the time of filing of this application. This material has low mechanical fire resistance and, when subjected to temperatures above a predetermined temperature, ensures that the deformation device moves from its resting position to the deformation position of its first safety component, thus deforming the first safety component so that it no longer performs its function of holding the safety piston in the closed position.

[0032] The safety cable is made of materials selected from rubber, polyamide, wool, polyester, high-density polyethylene (preferably high molecular weight polyethylene), polypropylene, and combinations thereof. These materials all have low mechanical fire resistance and are simple and economical to use.

[0033] Preferably, the safety cable is made of polypropylene. Cables made of polypropylene are stiffer and less sensitive to creep, heat aging, and moisture than safety cables made of materials selected from the above-mentioned list of materials. This improves the reliability of the safety device.

[0034] The material used to manufacture the safety cable can be a fiber-filled composite material, such as glass fiber, carbon fiber, graphite fiber, aramid fiber, basalt fiber, mineral fiber, or equivalent. This filler advantageously stabilizes the mechanical properties of the safety cable, ensuring its reliability over time and thus increasing the service life of the safety device.

[0035] Alternatively, the material used to manufacture the safety cable can be covered with another material. This allows for the provision of additional mechanical properties to the safety cable. For example, cables made of polyamide are more sensitive to moisture, but this disadvantage can be mitigated by covering the safety cable with a material less sensitive to moisture.

[0036] The safety cable is made of a material with a mechanical fire resistance between 10 seconds and 1 hour, preferably between 1 minute and 45 minutes, and more preferably between 10 minutes and 30 minutes. This value represents the time the safety cable holds the deformable device in the resting position when exposed to a temperature above a predetermined temperature. Due to this short time, it is understood that the safety cable will quickly cease functioning when exposed to temperatures above the predetermined temperature. This reduces the risk of increased internal pressure within the tank during the fire resistance time, which could lead to a tank explosion.

[0037] The second safety component is connected to the deformation device via a third safety component. The third safety component cooperates with the second safety component to maintain the second safety component in a resting position when it is exposed to a temperature below a predetermined temperature, and to elastically return it to its working position when it is exposed to a temperature above the predetermined temperature. The advantage of this embodiment is that it creates a threshold effect for transitioning the second safety component from its resting position to its working position, thereby causing the deformation device to transition from its resting position to the deformation position of the first safety component. Therefore, the risk that the kinetic energy of the deformation device upon contact with the first safety component is insufficient to deform (e.g., fold or break) the first safety component is reduced. This increases the reliability of the safety device.

[0038] The present invention also relates to a kit for manufacturing the safety device as described above, the kit comprising a second safety component and a third safety component for mounting on a housing of the safety device, the housing including a ventilation passage, a safety piston, and a first safety component. This kit advantageously allows for easy and rapid implementation of the above embodiments, wherein the second safety component is coupled to the deformable device via the third safety component. Therefore, the second and third safety components of this embodiment can be mounted on the body of the safety device according to the invention for implementation when the advantages provided by this embodiment are desired.

[0039] The present invention also relates to a storage tank for containing pressurized gas, the storage tank being equipped with the safety device described above. As previously stated, this storage tank is safer than storage tanks equipped with prior art safety devices.

[0040] A motor vehicle comprising a storage tank as described above is also described. The storage tank is typically a fuel tank, such as a dihydrogen tank.

[0041] Finally, the subject of this invention is a method for manufacturing the safety device as described above, wherein the following steps are performed:

[0042] - The deformation device is fixed to a housing including a ventilation channel, a safety piston, and a first safety component, and

[0043] - Secure the second safety component to the housing. Attached Figure Description

[0044] The invention will be better understood by reading the following description, which is given only as a non-limiting example and with reference to the accompanying drawings, in which:

[0045] Figure 1 This is a schematic diagram of a motor vehicle including a storage tank equipped with a safety device according to the present invention;

[0046] Figure 2 This is a schematic cross-sectional view of a first embodiment of a safety device according to the present invention, shown in a resting position (A) and a safe position (B); and

[0047] Figure 3 This is a schematic cross-sectional view of a second embodiment of a safety device according to the present invention, showing the safety device in a resting position (A) and a safe position (B).

[0048] Figure 4 This is a top view schematic diagram of a fixing device for fixing a second safety component to a deformable device according to a second embodiment. Detailed Implementation

[0049] Figures 1 to 4Two embodiments of the safety device according to the present invention are shown.

[0050] Figure 1 A motor vehicle 1 is schematically shown, which includes a tank 2 for containing pressurized gas, the tank being equipped with a safety device 3 according to the invention.

[0051] In this configuration, tank 2 is used to hold fuel for motor vehicle 1; more specifically, tank 2 is used to hold compressed dihydrogen, typically between 300 and 700 bar. A single safety device 3 is shown in the figure. According to other embodiments, the number of safety devices 3 equipped with tanks is greater, for example, between two and twenty. According to other embodiments, the safety devices 3 may be specified to be equipped with tanks other than fuel tanks or dihydrogen tanks.

[0052] Figure 2 A first embodiment of the safety device 3 according to the present invention is shown, wherein the safety device 3 is shown in a resting position. Figure 2 A) and safe location ( Figure 2 B).

[0053] The safety device 3 includes a body or housing 4, on which a safety piston 5, a first safety component 6, a deformation device 7, and a second safety component 8 are mounted.

[0054] The housing 4 includes a venting channel 9 for fluid communication between the internal volume 10 defined by the storage tank 2 and the external environment of the storage tank 2. A first end of the venting channel 9 opens into the internal volume 10 of the storage tank 2, and a second end of the venting channel 9 opens into the external environment of the storage tank 2.

[0055] The safety piston 5 is slidably mounted within the venting passage 9 and can move between a closed position and a safe position. In the closed position, the safety piston 5 closes the venting passage 9. Figure 2 A), in the safe position, the safety piston 5 does not seal the ventilation passage 9. Figure 2B). In other words, in the closed position, the safety piston 5 prevents fluid communication between the internal volume 10 and the outside of the tank 2. In the closed position, a seal 5a disposed between the safety piston 5 and the inner wall of the vent passage 9 engages with a portion of the safety piston 5 to prevent gas present in the internal volume 10 from escaping through the vent passage 9. In the safe position, the safety piston 5 no longer at least partially closes the vent passage 9, allowing fluid communication between the internal volume 10 of the tank 2 and the outside of the tank. In the safe position, the seal 5a no longer engages with the safety piston 5 to seal the vent passage 9, thus allowing pressurized gas present in the internal volume 10 to escape through the vent passage 9. The seal allows for improved sealing of the vent passage 9 achieved by the safety piston 5. According to an alternative embodiment, the safety device 3 may not include the seal 5a. A sliding ring 5b mounted on the safety piston 5 allows for guiding the sliding of the safety piston 5 between the closed and safe positions. The safety piston 5 is machined to have a recessed receiving cavity 11.

[0056] The first safety component 6 is deformable. It is configured to retain the safety piston 5 in a closed position against an elastic restoring force that would return the safety piston 5 to a safe position. In this example, the first safety component 6 is fragile and is formed from a glass ampoule containing fluid used to apply pressure to the ampoule so that it breaks when subjected to a predetermined temperature. The first safety component 6 retains the safety piston 5 in the closed position by being positioned between the safety piston 5 and the fixing point 12. Therefore, the glass ampoule is sized to press the safety piston 5 into the closed position when not broken. According to another embodiment, the first safety component 6 is fusible when subjected to a predetermined temperature. In this example, the predetermined temperature is between 95°C and 150°C.

[0057] The elastic restoring force that returns the safety piston 5 to the safe position is provided by the compression spring 13. In the closed position, the spring 13 is compressed by the safety piston 5 under the action of the first safety component 6. Figure 2 A). According to other embodiments, the elastic restoring force for returning the safety piston 5 to the safe position can be provided by a component other than the compression spring 13.

[0058] The deformation device 7 is used to deform the first safety component 6. In this example, this deformation results in the destruction of the glass ampoule. The deformation device 7 can be positioned in the resting position ( Figure 2 A) and the deformation position of the first safety component 6 ( Figure 2 B) (in this example, the location of the glass ampoule's destruction (the destroyed ampoule is not shown)). The deformation device 7 includes a needle-shaped impact element. The impact element is part of the deformation device 7, which is used to contact the first safety member 6 to deform it, i.e., destroy the first safety member 6 in this example. According to other embodiments, the impact element is different and, for example, has the shape of a bayonet, arrowhead, or sheet.

[0059] The receiving cavity 11 of the safety piston 5 is configured such that when the safety piston 5 is in the safe position and the deformation device 7 is in the deformed position... Figure 2 B) At least a portion of the deformation device 7 is received, such that the deformation device 7 does not interfere with the safety piston 5 moving to a safe position.

[0060] The impact element of the deformation device 7 rests on the compression spring 14, which elastically returns the impact element to the deformed position of the first safety member 6. The spring 14 and the impact element are housed in a receiving cavity of the housing 4 of the safety device 3. This receiving cavity opens to an external opening of the housing 4 of the safety device 3. A washer 15 is fixed to the external opening of the receiving cavity and forms a support for the spring 14. The washer 15 has an annular shape and a central through-hole. At least a portion of the hole in the washer 15 is composed of and / or covered by a lubricant. The lubricant can be solid, liquid, or paste. Examples of lubricants include grease, lubricating oil, or a solid non-stick coating, such as...

[0061] The second safety component 8 is formed by a two-meter-long safety cable 16, which substantially corresponds to the length of the storage tank 2. According to other embodiments, the length of the safety cable 16 varies, for example, between one meter and ten meters, preferably between one meter and three meters. Advantageously, the length of the safety cable 16 is chosen to substantially correspond to the length of the storage tank 2. The safety cable 16 is made of a material with low fire-resistant mechanical strength. Typically, the safety cable 16 is made of a material classified as D according to European standard EN13501-1 or as M3 or M4 according to French standard NF P92-507. For example, the safety cable 16 is made of rubber, polyamide, wool, polyester, or polypropylene. In particular, the material used for the safety cable 16 is selected according to a predetermined temperature. Therefore, if the safety cable is subjected to a temperature higher than the predetermined temperature for a predetermined time, for example, 10 seconds to 1 hour, preferably 1 minute to 45 minutes, more preferably 10 minutes to 30 minutes, the safety cable must break. Advantageously, the safety cable 16 is made of an elastic material (e.g., rubber) to compensate for possible changes in tank size depending on its filling status.

[0062] The safety cable 16 is tensioned between a static fixing point (not shown) on one side and a fixing device 17 on the other side for fixing to the deformation device 7. According to this first embodiment, the fixing device 17 for fixing to the deformation device 7 is formed by a hook for hooking onto the impact element of the deformation device 7. For this purpose, the impact element has a ring 18, the size of which is determined to accommodate the hook. According to other embodiments, the fixing of the safety cable 16 to the deformation device 7 is achieved in different ways, such as by adhesive, by crimping, by clamping, or by welding.

[0063] The second safety component 8 is used in the rest position ( Figure 2 In position A), when the second safety component 8 is subjected to a temperature lower than a predetermined temperature, it resists the elastic restoring force that would cause the deformation device 7 to return to the deformed position of the first safety component 6, thus keeping the deformation device 7 in the resting position, while in the working position ( Figure 2 In case B), when the second safety component 8 is subjected to a temperature higher than the predetermined temperature, the elastic restoring force that causes the deformation device 7 to return to the deformed position of the first safety component 6 is released.

[0064] The elastic restoring force that returns the deformable device 7 to its deformed position is provided by the compression spring 14. Therefore, in this embodiment, the safety cable 16 is tensioned in the resting position to compress the spring 14 and hold the deformable device in the resting position. Figure 2 A). In the working position, the safety cable 16 no longer compresses the spring 14, and thus releases it, allowing the deformation device 7 to return to the deformed position. Figure 2 B) elastic restoring force.

[0065] The hole in the support of the forming spring 14 of the washer 15 is configured to allow the passage of the second safety component 8, and more specifically, the safety cable 16. The presence of lubricant at the hole in the washer advantageously facilitates the movement of the safety cable 16 relative to the washer 15. Therefore, the risk of friction between the safety cable 16 and the hole in the washer 15 reducing the kinetic energy required for the deformation device 7 to reach the deformation position of the first safety component 6 is reduced. This reduction in kinetic energy can prevent the deformation of the first safety component 6, thereby disabling the safety device 3.

[0066] The following describes an example of the operation of the safety device 3 according to a first embodiment of the present invention.

[0067] Initially, tank 2 is not exposed to any heat source, so safety device 3 is in the off position. Figure 2 A). Therefore, the safety cable 16 is intact and holds the impact element of the deformation device 7 in the resting position against the elastic restoring force provided by the spring 14 that would return the deformation device 7 to its deformed position. The first safety component 6 is not deformed, that is, in this example, the glass ampoule is not broken. Therefore, the first safety component 6 holds the safety piston 5 in the closed position of the closed vent passage 9. Therefore, the internal volume 10 of the storage tank 2 is not in fluid communication with the external environment of the storage tank 2.

[0068] Then, a portion of the storage tank 2 is subjected to a heat source with a temperature higher than a predetermined temperature. For example, if the predetermined temperature is 100°C, this portion of the storage tank is subjected to a heat source with a temperature of 110°C. This heat source is, for example, formed by a flame. Because the safety cable 16 extends along the entire length of the storage tank 2, it is subjected to the heat source regardless of its location along the storage tank 2. Due to the temperature subjected to by the safety cable 16 being higher than the predetermined temperature, the safety cable 16 is burned and breaks, thus entering the working position, in which the safety cable 16 no longer holds the impact element of the deformation device 7 in the resting position and releases the elastic restoring force of the spring 14, causing the impact element to be pushed into the deformation position by the spring 14. When the impact element of the deformation device 7 comes into contact with the glass ampoule of the first safety member 6, the impact element has kinetic energy provided by the spring 14 sufficient to break the glass ampoule. After the ampoule breaks, the first safety member 6 no longer holds the safety piston 5 in the closed position, and the spring 13 moves it to the safe position. In this example, the presence of the receiving cavity 11 of the safety piston 5 facilitates full retraction to a safe position, the cavity 11 being configured to accommodate at least a portion of the impact element of the deformation device 7. The retraction of the safety piston 5 to the safe position allows the vent passage 9 to be opened, enabling fluid communication between the internal volume 10 of the tank 2 and the external environment. Thus, the gas contained in the tank 2 escapes to the outside through the vent passage 9, preventing an increase in internal pressure that could potentially lead to an explosion. Therefore, the safety device 3 allows for a safer tank 2, with a reduced risk of explosion in the presence of a heat source.

[0069] The following reference Figure 3 and Figure 4 The second embodiment of the present invention is described below.

[0070] In this second embodiment, the same reference numerals are used for elements corresponding to those in the first embodiment.

[0071] The following mainly describes the differences from the first embodiment. For the same elements, refer to the description given above for the first embodiment.

[0072] According to the second embodiment, the safety device 3 includes a third safety component 19, which cooperates with the second safety component 8 to keep the second safety component 8 in a resting position when the second safety component 8 is subjected to a temperature below a predetermined temperature. Figure 3 A), and when the second safety component 8 is subjected to a temperature higher than a predetermined temperature, the second safety component 8 elastically returns to its working position. Figure 3 B).

[0073] The third safety component 19 includes a body 20 and a tension spring 21. The body 20 has the shape of a hollow shell. It is fixed to the housing 4 of the safety device 3 at an external opening in a cavity that includes the impact element and the spring 14. In the second embodiment, the body 20 performs the function of a support for the spring 14, a function performed by a washer 15 in the first embodiment. The tension spring 21 is mounted inside the body 20, fixed on one side to the inner wall of the body 20, and on the other side to a fixing device 17 for fixing the second safety component 8 to the deformation device 7. The spring 21 provides an elastic restoring force to the second safety component 8 to the working position.

[0074] The fixing device 17, which secures the second safety component 8 to the deformable device 7, differs from that in the first embodiment. This fixing device includes a connecting component instead of a hook, the connecting component comprising two holes that are sequentially connected along the connecting component. The width of the first hole, referred to as the resting hole 22, is smaller than the width of the second hole, referred to as the working hole 23. Figure 4 ).

[0075] The impact element of the deformation device 7 differs slightly from that of the first embodiment. This impact element includes an elongated end for connection to the connecting member, having a portion with a reduced diameter that can be accommodated in the resting hole 22. The dimensions of the impact element are designed such that it cannot translate longitudinally when its reduced portion is accommodated in the resting hole 22. Furthermore, the dimensions of the impact element are designed such that it can translate longitudinally when its reduced portion is accommodated in the working hole 23.

[0076] In the resting position, the safety cable 16 is tensioned between its fixed end and its end connected to the fixing device 17 for attachment to the deformation device 7. The third safety member 19 is configured such that the resting tension of the safety cable 16 cooperates with the elastic restoring force provided by the tension spring 21 to return the second safety member 8 to the working position, thereby holding the second safety member 8 in the resting position. In this position, the reduced portion of the impact element is received in the resting hole 22, such that the second safety member 8 holds the impact element in the resting position, preventing its longitudinal translation and compression of the compression spring 14.

[0077] The following describes an example of the operation of the safety device 3 according to a second embodiment of the present invention.

[0078] Initially, tank 2 is not exposed to any heat source, so safety device 3 is in the off position. Figure 3A) The safety cable 16 is intact and holds the impact element of the deformation device 7 in the resting position against the elastic restoring force provided by the spring 14 that would return the deformation device 7 to its deformed position. This holding is achieved because the impact element is housed in the resting hole 22 and therefore cannot translate along its longitudinal direction. The first safety member 6 is not deformed, that is, in this example, the glass ampoule is not broken. Therefore, the first safety member 6 holds the safety piston 5 in the closed position of the closed vent passage 9. Therefore, the internal volume 10 of the tank 2 is not in fluid communication with the external environment of the tank 2.

[0079] Then, the tank 2 is subjected to a heat source with a temperature higher than a predetermined temperature. For example, if the predetermined temperature is 100°C, the tank is subjected to a heat source with a temperature of 110°C. This heat source is, for example, formed by a flame. Because the safety cable 16 extends along the entire length of the tank 2, it is subjected to the heat source regardless of its location along the tank 2. Since the temperature subjected to the safety cable 16 is higher than the predetermined temperature, the safety cable 16 is burned and broken. Therefore, the tension of the safety cable 16 no longer allows it to remain in the resting position, and the tension spring 21 causes the second safety member 8 to elastically return to the working position. When switching to the working position, due to the movement of the connecting part fixed to the safety cable 16, the reduced portion of the impact element that was originally accommodated in the resting hole 22 is now accommodated in the working hole 23. Thus, longitudinal translation of the impact element is allowed because the second safety member 8 no longer holds the impact element in the resting position and releases the elastic restoring force of the spring 14, causing the impact element to be pushed by the spring 14 to the deformed position. When the impact element of the deforming device 7 comes into contact with the glass ampoule of the first safety member 6, the impact element has kinetic energy provided by the spring 14 sufficient to rupture the glass ampoule. After the ampoule ruptures, the first safety member 6 no longer holds the safety piston 5 in the closed position, and the spring 13 moves it to a safe position. In this example, the presence of the receiving cavity 11 of the safety piston 5 facilitates its complete movement to the safe position; this receiving cavity 11 is configured to accommodate at least a portion of the impact element of the deforming device 7. The movement of the safety piston 5 to the safe position allows the venting passage 9 to be opened, thereby enabling fluid communication between the internal volume 10 of the reservoir 2 and the external environment of the reservoir 2. Therefore, the gas contained in the reservoir 2 escapes to the outside through the venting passage 9, preventing an increase in pressure inside the reservoir 2 that could potentially lead to an explosion. Thus, the safety device 3 allows for a safer reservoir 2, for which the risk of explosion in the presence of a heat source is reduced. It should also be noted that the third safety member is capable of generating a threshold effect that triggers the deforming device 7. In practice, slight variations in the length of the safety cable 16 (e.g., due to the elasticity of the safety cable 16 and different filling conditions of the reservoir 2, or due to creep or relaxation of the material of the safety cable 16 under the influence of heat or time (aging)) will not allow the impact element to move, because its reduced portion will always be accommodated in the resting hole 22, which does not allow longitudinal translation of the impact element. Therefore, when the second safety component 8 enters the working position, the elastic reserve of the spring 14 will not be activated, and the kinetic energy of the impact element will be at its maximum when it reaches the first safety component 6. Thus, the risk that the safety device 3 will fail to enter the safe position when the second safety component 8 has been subjected to a temperature higher than the predetermined temperature is reduced.

[0080] The present invention is not limited to the described embodiments, and other embodiments will be apparent to those skilled in the art.

[0081] List of reference numerals

[0082] 1: Motor vehicles

[0083] 2: Storage tank

[0084] 3: Safety devices

[0085] 4: Casing

[0086] 5: Safety Piston

[0087] 5a: Seals

[0088] 5b: Sliding ring

[0089] 6: First safety component

[0090] 7: Deformation device

[0091] 8: Second safety component

[0092] 9: Ventilation Channel

[0093] 10: Internal volume of the storage tank

[0094] 11: The receiving chamber of the safety piston

[0095] 12: Fixing point of the first safety component

[0096] 13: Compression spring

[0097] 14: Compression Spring

[0098] 15: Washers

[0099] 16: Safety Cable

[0100] 17: Secure the second safety component to the fixing device of the deformation device.

[0101] 18: Ring

[0102] 19: Third safety component

[0103] 20: The main body of the third safety component

[0104] 21: Tension Spring

[0105] 22: Resting hole for connecting parts

[0106] 23: Working holes of connecting components

Claims

1. A safety device (3) for a storage tank (2) for containing pressurized gas, the safety device comprising: Ventilation channel (9) for fluid communication between the internal volume (10) defined by the storage tank (2) and the external environment of the storage tank (2). A safety piston (5) is movable between a closed position and a safe position, in which the safety piston closes the ventilation passage (9), and in the safe position, the safety piston does not close the ventilation passage (9). The deformable first safety component (6) is configured to resist an elastic restoring force that would cause the safety piston (5) to return to the safe position, thereby holding the safety piston (5) in the closed position. The safety device also includes: A deformation device (7) for deforming the first safety component (6), the deformation device (7) being movable between a resting position and a deformed position of the first safety component (6), and At least one second safety component (8) is configured to, in a rest position, resist an elastic restoring force that would cause the deformable device (7) to return to the deformed position of the first safety component (6) when the second safety component (8) is subjected to a temperature below a predetermined temperature, thereby holding the deformable device (7) in a rest position; and in a working position, release the elastic restoring force that would cause the deformable device (7) to return to the deformed position of the first safety component (6) when the second safety component (8) is subjected to a temperature above a predetermined temperature. The second safety component (8) is formed of a safety cable (16) made of a material with a mechanical fire resistance between 10 seconds and 1 hour. The safety piston (5) has a receiving cavity (11) configured to receive at least a portion of the deformation device (7) when the safety piston (5) is in the safe position and the deformation device (7) is in the deformed position of the first safety member (6).

2. The safety device (3) according to claim 1, wherein, The first safety component (6) is formed of a glass ampoule containing a fluid, which is used to apply pressure to the ampoule when it is subjected to a temperature above a predetermined temperature, so as to cause the ampoule to rupture.

3. The safety device (3) according to any one of claims 1-2, wherein, The elastic restoring force that returns the deformation device (7) to the deformed position of the first safety member (6) is provided by a spring (14) supported on a support having a hole configured to allow the second safety member to pass through.

4. The safety device (3) according to any one of claims 1-2, wherein, The deformation device (7) includes an impact element.

5. The safety device (3) according to any one of claims 1-2, wherein, The second safety component (8) includes an elastic element.

6. The safety device (3) according to any one of claims 1-2, wherein, The security cable (16) is made of material classified as D according to European standard EN 13501-1 or as M3 or M4 according to French standard NF P92-507.

7. The safety device (3) according to any one of claims 1-2, wherein, The security cable (16) is made of a material selected from rubber, polyamide, wool, polyester, high-density polyethylene, polypropylene and combinations thereof.

8. The safety device (3) according to claim 7, wherein, High-density polyethylene is a type of high molecular weight polyethylene.

9. The safety device (3) according to claim 7, wherein, The safety cable (16) is made of polypropylene.

10. The safety device (3) according to claim 1, wherein, The safety cable (16) is made of a material with a mechanical fire resistance between 1 minute and 45 minutes.

11. The safety device (3) according to claim 1, wherein, The safety cable (16) is made of a material with a mechanical fire resistance between 10 and 30 minutes.

12. The safety device (3) according to any one of claims 1-2, wherein, The second safety component (8) is connected to the deformation device (7) via a third safety component (19), the third safety component (19) being used to cooperate with the second safety component (8) so as to keep the second safety component (8) in a resting position when the second safety component (8) is subjected to a temperature below a predetermined temperature, and to elastically return the second safety component (8) to the working position when the second safety component (8) is subjected to a temperature above a predetermined temperature.

13. A storage tank (2) for containing pressurized gas, characterized in that, The storage tank (2) is equipped with a safety device (3) according to any one of claims 1 to 12.

14. A method for manufacturing a safety device (3) according to any one of claims 1 to 12, wherein, Perform the following steps: The deformation device (7) is fixed to the housing (4) including the ventilation channel (9), the safety piston (5) and the first safety component (6), and The second safety component (8) is fixed to the housing (4).

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