Tank for containing a pressurised gas

Abstract

The invention relates to a tank (2) for containing a pressurised gas, comprising: - an inner volume (4) for storing a pressurised gas, referred to as the "internal volume of the tank", - a heating member (12) provided in the internal volume (4) of the tank, - a temperature sensor (14) provided in the internal volume (4) of the tank, and - a protection member (16) for protecting the temperature sensor (14) provided in the internal volume (4) of the tank, between the heating member (12) and the temperature sensor (14).

Description

A tank designed to contain a gas under pressure.

[0001] The invention relates to the field of pressure vessels, particularly for vehicles. More specifically, the invention relates to a tank for containing a gas under pressure and a vehicle comprising such a tank.

[0002] A tank designed to hold a pressurized gas can be equipped with various accessories that perform different functions within the tank. In the case of a hydrogen (H2) storage tank, which is intended for use by a vehicle to produce energy for propulsion, the tank may include a heating element to heat the hydrogen under certain conditions. For example, when the tank is emptied, the temperature inside drops due to the pressure change. This temperature drop can sometimes cause a tank wall and / or internal seals to become mechanically weakened. Such weakening can damage the tank and lead to a gas leak, which must be avoided.It is known that the heating element is activated when the temperature inside the tank falls below a predetermined threshold value to prevent damage to the tank wall and / or the seals inside the tank. For this purpose, the tank is also equipped with a temperature sensor to measure the temperature inside the tank. Document US2022 / 381403A1 discloses an example of a tank equipped with a heating element and a temperature sensor.

[0003] While the heating element and temperature sensor enable temperature control inside the tank, they can also present a reliability issue. When the heating element heats the tank wall and / or the gas inside, it can also heat the temperature sensor, thus distorting its reading. The temperature sensor may then provide a reading higher than the actual temperature of the gas in the tank, posing a risk to the integrity of the tank wall and / or the internal seals. This risk is compounded by the fact that, generally, when the heating element is of the radiant type, it effectively heats the tank wall but also significantly heats the temperature sensor.

[0004] The invention aims in particular to remedy these problems by improving the reliability of the temperature measurement of the gas in the tank when it is equipped with a heating element.

[0005] For this purpose, the invention provides a reservoir for containing a pressurized gas, comprising:

[0006] - an internal storage volume for a gas under pressure called the "internal volume of the tank",

[0007] - a heating element incorporated within the internal volume of the tank,

[0008] - a temperature sensor housed within the internal volume of the tank, and

[0009] - a temperature sensor protection device located in the internal volume of the tank, between the heating element and the temperature sensor.

[0010] Thus, the protective device shields the temperature sensor from the heating element, preventing it from being directly heated, or at least mitigating this direct heating. Consequently, the temperature measured by the sensor is more representative of the actual gas temperature in the tank. This improves the reliability of the gas temperature measurement in the presence of the heating element.

[0011] According to a preferred embodiment, the tank is intended to contain hydrogen under pressure and to be carried in a vehicle, such as a motor vehicle, a truck, a bus, a train, a machine, in particular a construction machine, or even a boat.

[0012] Advantageously, the temperature sensor is located at a distance from the protective device.

[0013] This expression means that the temperature sensor is not in contact with the protective device. This ensures that direct contact between the temperature sensor and the protective device is not permitted, as such contact could promote heat exchange between the temperature sensor and the protective device and thus distort the temperature measurement of the gas contained in the tank.

[0014] Advantageously, the reservoir further includes at least one nozzle attached to the reservoir, with the temperature sensor and the protective device fixed to the nozzle.

[0015] A tank intended to contain a pressurized gas is often equipped with such an end fitting, so that the temperature sensor and the protective device can be easily attached to the tank without having to provide an additional part specifically dedicated to this purpose.

[0016] Advantageously, the protective element is made of a material capable of withstanding temperatures between -60°C and 85°C.

[0017] This ensures that the protective device remains operational regardless of the temperature inside the tank.

[0018] Advantageously, the protective element is made of a material having a reflectivity ρ, a transmissivity τ and an absorptivity α such that the sum ρ + τ + α is equal to 1, and that τ is less than the sum ρ + α.

[0019] Advantageously, the protective element is made of a material having an emissivity less than or equal to 0.03.

[0020] The protective device thus does not form a secondary heat source that would transmit heat to the temperature sensor, which transfer would distort the measurement of the temperature of the gas contained in the tank.

[0021] Preferably, the protective element is made of a material chosen from the group of materials consisting of a polytetrafluoroethylene (PTFE), a polyamide 6 (PA 6) and a polyoxymethylene (POM).

[0022] The protective element is thus made of a material that is both capable of withstanding temperatures between -60°C and 85°C and conforms to the reflectivity, transmissivity, absorptivity and emissivity properties stated above.

[0023] Advantageously, the protective device includes:

[0024] - at least one shield arranged between the heating element and the temperature sensor, and

[0025] - at least one support element connecting, directly or indirectly, at least one shield to at least one end piece.

[0026] The protective device is thus made in a simple form, so that it is inexpensive and easy to fit into the tank.

[0027] Advantageously, at least one shield has a cone shape, a dome shape or a truncated cone shape with a convex part oriented towards the heating element.

[0028] The heat waves directed towards the protective device are thus reflected by the shield in several directions, mainly onto the wall of the tank.

[0029] According to one embodiment, at least one shield has a disc shape, the disc defining a first half-space in which the temperature sensor extends and a second half-space in which the heating element extends.

[0030] The shield is therefore particularly simple to make.

[0031] Advantageously, the protective device comprises several shields, preferably arranged coaxially.

[0032] This improves the thermal protection provided by the protective element for the temperature sensor against the heating element, obtaining an insulating effect comparable to that of double glazing.

[0033] According to a first embodiment of the invention, the protective device comprises several support elements in the form of 'n' pillars distributed around the temperature sensor, 'n' being an integer strictly greater than one, preferably 'n' being equal to three.

[0034] According to a second embodiment of the invention, the support element forms a cylindrical grid surrounding the temperature sensor.

[0035] This ensures that the gas can circulate easily in the protective device and around the temperature sensor, which helps to make the measurement of the gas temperature in the tank more reliable.

[0036] Advantageously, the internal volume of the tank is delimited by a liner. Preferably, the liner is made of plastic.

[0037] The invention can thus be easily implemented in so-called "Type III" and "Type IV" tanks. Without such a liner, the invention can be easily implemented in so-called "Type V" tanks.

[0038] The invention also provides for a vehicle comprising a tank as defined above. The term "vehicle" means any vehicle, such as a motor vehicle, truck, bus, train, machine, including construction equipment, or boat. Brief description of the figures

[0039] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0040] is a schematic view of a vehicle, comprising a tank intended to contain a pressurized gas, according to the invention,

[0041] is a cross-sectional view of a tank intended to contain a gas under pressure according to an embodiment of the invention,

[0042] is a perspective view of a protective device for the tank, according to a first embodiment of the invention,

[0043] is a perspective view from a different angle of the protective organ of the,

[0044] is a perspective view of a protective device according to a variant of the first embodiment of the invention, and

[0045] is a perspective view of a tank protection device, according to a second embodiment of the invention. Detailed description

[0046] A vehicle 1 according to the invention is shown in Figure 1. Vehicle 1 includes a tank 2 (arbitrarily positioned in the vehicle diagram) intended to contain a pressurized gas. The gas is intended to be used by the vehicle to perform a predefined function. In this case, tank 2 is intended to contain hydrogen, which serves as the energy source for the propulsion of vehicle 1.

[0047] Tank 2 has been shown in more detail in Figure 1. Tank 2 comprises an internal storage volume for a pressurized gas, which in this case is hydrogen, as indicated above. In what follows, this volume is referred to as the internal volume of tank 4, or simply internal volume 4. The internal volume 4 is delimited by a wall 6 of the tank. Wall 6 includes a liner, preferably made of plastic, but the liner can be replaced by any other type of wall suitable for storing the pressurized gas. Tank 2 has a central portion generally shaped like a cylinder of revolution and two end portions generally shaped like domes that close the cylinder forming the central portion. Tank 2 thus has a principal axis 8, coinciding with the axis of revolution of the central portion and passing through the center of each of the two end portions.

[0048] The reservoir 2 includes at least one nozzle 10 formed in the center of one or the other of its two end portions. The nozzle 10 serves, for example, as a coupling interface with a pipe (not shown) allowing the filling and / or emptying of the reservoir 2. Here, the reservoir 2 includes two nozzles 10, each end portion receiving one of the two nozzles 10.

[0049] Tank 2 includes a heating element 12 located within the internal volume 4 and configured to heat the wall of tank 2 and / or the pressurized gas contained within the internal volume 4. This is a radiative heating element. Tank 2 also includes a temperature sensor 14 located within the internal volume 4. If the gas is hydrogen, when hydrogen is extracted from tank 2, for example to power a fuel cell or the engine of vehicle 1, the temperature inside tank 2 drops. To prevent this temperature from dropping too low to the point of damaging the wall 6 of tank 2 and / or the seals (not shown) located inside tank 2, the heating element 12 is activated, for example, when the temperature measured by the temperature sensor 14 falls below a predetermined threshold value.Here, the heating element 12 is fixed to one of the ends 10, while the temperature sensor 14 is fixed to the other end 10. Thus, the heating element 12 and the temperature sensor 14 are located in opposite and distant positions within the internal volume 4 along the main axis 8, as shown in the figure.

[0050] The reservoir 2 includes a protective element 16; 16' for the temperature sensor 14 provided in the internal volume 4. The protective element 16; 16' is provided between the heating element 12 and the temperature sensor 14, and is fixed to the same end 10 as the temperature sensor 14. The protective element 16; 16' has a shape such that no point of the heating element 12 can see a point of the temperature sensor 14, or at least cannot see a point of a measuring surface of the temperature sensor 14. In other words, it is not possible to draw a straight line connecting a point of the heating element 12 and a point of the temperature sensor 14 (or at least a point of the measuring surface of the temperature sensor 14) without this line being interrupted by the protective element 16; 16'.This ensures that, thanks to the protective element 16; 16', the heating element 12 cannot directly heat the temperature sensor 14 (or at least its measuring surface).

[0051] The protective element 16; 16' has several general characteristics. The temperature sensor 14 is located at a distance from the protective element 16; 16', meaning that there is no contact surface between the protective element 16; 16' and the temperature sensor 14. The protective element 16; 16' is made of a material capable of withstanding temperatures between -60°C and 85°C, in the sense that it undergoes virtually no deformation or deterioration within this temperature range. The protective element 16; 16' is made of a material with a reflectivity ρ, a transmissivity τ, and an absorptivity α such that the sum ρ + τ + α equals 1, and τ is less than the sum ρ + α. This ensures that the protective element 16; 16' does not form a secondary heat source that would transmit heat, produced by the heating element 12, to the temperature sensor 14.It can also be provided that the protective element 16; 16' is made of a material having an emissivity of 0.03 or less, for the same reason. To ensure that it possesses all these general characteristics, the protective element 16; 16' is, for example, made of a material selected from the group of materials consisting of polytetrafluoroethylene (PTFE), polyamide 6 (PA 6), and polyoxymethylene (POM). The protective element 16; 16' comprises at least one shield 18, arranged between the heating element 12 and the temperature sensor 14, and at least one support element 20 connecting, directly or indirectly, the at least one shield 18 to the end fitting 10 to which the protective element 16; 16' is attached.

[0052] A protective element 16 is shown in a first embodiment. This protective element 16 comprises a shield 18 having a cone shape with a convex part oriented towards the heating element 12. In other words, the tip of the cone is oriented towards the heating element 12, while the temperature sensor 14 extends from the concave side of the shield 18. However, this cone shape can be replaced by a dome shape or a frustoconical shape, these shapes also having a convex side and a concave side.

[0053] The protective element 16 comprises several support elements 20 in the form of n pillars distributed, preferably regularly, around the temperature sensor 14, n being an integer strictly greater than one, here equal to three. The pillars each have a generally cylindrical shape, one end of which is fixed to the nozzle 10 and the other end is fixed to the shield 18 or joined to the shield 18.

[0054] We have represented on the protective element 16 of the according to a different angle which allows to represent the general characteristic according to which the temperature sensor 14 is located at a distance from the protective element 16. We observe in fact on this that there is no contact surface between, on the one hand, the temperature sensor 14 and, on the other hand, the shield 18 and the support elements 20.

[0055] A protective element 16 is shown in Figure 16 according to a variant embodiment of the first embodiment. This protective element 16 differs from that of Figures 3 and 4 only in that the shield 18 has a disc shape, the disc defining a first half-space in which the temperature sensor 14 extends and a second half-space in which the heating element 12 extends.

[0056] A protective element 16' is shown in a second embodiment. This protective element 16' comprises two shields 18', each dome-shaped with a convex portion facing the heating element 12. In other words, the apexes of the domes face the heating element 12, while the temperature sensor 14 extends from the concave side of the shields 18'. However, these dome-shaped shields 18' can be replaced by cone-shaped or frustoconical shields, these shapes also having a convex and a concave side. The shields 18' are connected to each other by means of rods 22 parallel to the main axis 8. The shields 18' are arranged coaxially, meaning that, since each shield 18' defines a central axis, these axes coincide.

[0057] The protective element 16' comprises a support element 20' in the form of a grid surrounding the temperature sensor 14. The support element 20' has the shape of a cylinder of revolution, one end of which is fixed to the end piece 10 to which the temperature sensor 14 is fixed and the other end is fixed to one of the shields 18' or made of the same material as it.

[0058] The invention is not limited to the embodiments shown and other embodiments will be obvious to a person skilled in the art.

[0059] It is possible to combine the different embodiments of the protective devices with each other, particularly with regard to the characteristics relating to the number of shields, the number of support elements, the shape of the shield(s), and the shape of the support element(s). List of references

[0060] 1: vehicle

[0061] 2: reservoir

[0062] 4: internal volume

[0063] 6: wall

[0064] 8: main axis

[0065] 10: nozzle

[0066] 12: heating element

[0067] 14: Temperature sensor

[0068] 16; 16': protective device

[0069] 18; 18': shield

[0070] 20; 20': support element

[0071] 22: stem

Claims

Tank (2) intended to contain a gas under pressure, comprising: - an internal volume (4) for storing a gas under pressure called the "internal volume of the tank", - a heating element (12) provided in the internal volume of the tank (4), and - a temperature sensor (14) provided in the internal volume of the tank (4), characterized in that it further comprises a protection element (16; 16') for the temperature sensor (14) provided in the internal volume of the tank (4), between the heating element (12) and the temperature sensor (14). Reservoir (2) according to the preceding claim, in which the temperature sensor (14) is located at a distance from the protective element (16; 16'). Reservoir (2) according to any one of the preceding claims, further comprising at least one nozzle (10) integral with the reservoir (2), the temperature sensor (14) and the protective element (16; 16') being fixed to the nozzle (10). Reservoir (2) according to any one of the preceding claims, in which the protective element (16; 16') is made of a material capable of withstanding temperatures between -60°C and 85°C. Reservoir (2) according to any one of the preceding claims, wherein the protective element (16; 16') is made of a material having a reflectivity ρ, a transmissivity τ and an absorptivity α such that the sum ρ + τ + α is equal to 1, and that τ is less than the sum ρ + α. Reservoir (2) according to any one of the preceding claims, in which the protective element (16; 16') is made of a material having an emissivity less than or equal to 0.

03. Reservoir (2) according to at least claim 3, in which the protective member (16; 16') comprises: - at least one shield (18; 18') arranged between the heating member (12) and the temperature sensor (14), and - at least one support element (20; 20') connecting, directly or indirectly, the at least one shield (18; 18') to the at least one nozzle (10). Reservoir (2) according to claim 7, in which at least one shield (18; 18') has a cone shape, a dome shape or a frustoconical shape having a convex part oriented towards the heating element (12). Reservoir (2) according to claim 7, in which at least one shield (18; 18') has a disc shape, the disc defining a first half-space in which the temperature sensor (14) extends and a second half-space in which the heating element (12) extends. Reservoir (2) according to any one of claims 7 to 9, in which the protective element (16') comprises several shields (18'), preferably arranged coaxially. Reservoir (2) according to any one of claims 7 to 10, wherein the protective element (16) comprises several support elements (20) in the form of 'n' pillars distributed around the temperature sensor (14), 'n' being an integer strictly greater than one, preferably 'n' being equal to three. Reservoir (2) according to any one of claims 7 to 10, in which the support element (20') forms a cylindrical grid surrounding the temperature sensor (14). Tank (2) according to any one of the preceding claims, wherein the internal volume of the tank (4) is delimited by a liner, preferably the liner is made of plastic material. Vehicle (1) comprising a tank (2) according to any one of the preceding claims.

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