This patent application claims priority from Italian patent application no. 102019000023103 filed on May 12, 2019, the entire disclosure of which is incorporated herein by reference.
The invention relates to a road vehicle provided with a tank for a compressed gas.
In a road vehicle, it is possible to store energy in the form of a high-pressure compressed gas contained inside a tank.
For example, the high-pressure compressed gas could be hydrogen to be supplied to fuel cells for the generation of electrical energy. Alternatively, the high-pressure compressed gas could be compressed air used to drive pneumatic actuators, which drive the valves of an internal combustion engine, or used to drive pneumatic actuators, which generate compressed air jets adapted to change the motion of the vehicle.
Generally speaking, in order to reduce the weight of the tank, the tank itself is made of light materials, such as carbon fibre or other composite materials.
The compression of a high-pressure gas heats the gas itself, which can reach high temperatures that can even exceed the maximum temperature the material making up the tank can stand (especially when the tank is made of composite materials, which have a low heat resistance). In order to avoid overheating the tank, it has been suggested to increase the thickness of the tank wall to make it more resistant to heat, it has been suggested to previously cool the compressed gas through heat exchangers arranged upstream of the tank and it has been suggested to feed the compressed gas to the tank with a very small flow rate (namely, very slowly) so as to attenuate the heating of the tank caused by the hot compressed gas flowing in.
However, known solutions lead to a significant weight and size increase, also because of the need to have suited heat exchangers arranged upstream of the tank, introduce load losses in the compressed gas, due to the fact that the latter has to flow through the heat exchangers, and make the filling of the tank very slow.
U.S. Pat. No. 6,182,717B1 and patent applications CN101162782A, GB870269A and US2013118152A1 describe a tank for a fluid under pressure having a containing chamber, which is delimited by a wall consisting of an inner panel, which directly delimits the containing chamber and is in contact with the fluid, and of an outer panel, which completely surrounds the inner panel and is arranged parallel to and at a constant distance from the inner panel.
The object of the invention is to provide a road vehicle provided with a tank for a compressed gas, said tank not suffering from the drawbacks discussed above, namely being particularly light and capable of standing the inflow of a compressed gas having high temperatures and, at the same time, being simple and economic to be manufactured.
According to the invention, there is provided a road vehicle provided with a tank for a compressed gas according to the appended claims.
The appended claims describe preferred embodiments of the invention and form an integral part of the description.
The invention will now be described with reference to the accompanying drawings, showing a non-limiting embodiment thereof, wherein:
In
The car 1 comprises a frame 5, which supports, among other things, the powertrain system 4 and the wheels 2 and 3; namely, the four wheels 2 and 3 are fitted to the frame 5 in a rotary manner through the corresponding suspensions.
Furthermore, the car 1 comprises a body 6, which covers the frame 5 and is mounted on the frame 5.
The car 1 comprises at least one tank 7 for a compressed gas, for example compressed air, which could have, for example, a nominal pressure of 700-900 bar.
In the embodiments of
According to an embodiment that is not shown herein and is not part of the invention, the compressed gas is compressed air and comes from a compressor or from a further tank arranged on the outside of the road vehicle 1 and to which the compressed gas tank 7 is connected during a filling operation.
According to the embodiment shown in
The wall 10 of the tank 7 has, for example, a cylindrical shape or a spherical shape. Furthermore, the wall 10 of the tank 7 is made of materials having a high resistance and a low weight (such as, for example, titanium, Ti).
According to
Furthermore, a plurality of connection elements 17 (schematically shown in
Furthermore, the connection elements 17 take up only part, for example 10% to 25%, of the total volume of the gap 16; namely, the gap 16 is substantially empty (i.e. it is more empty than full).
The wall 10 further comprises an auxiliary inlet opening 18, which is separate from and independent of the main opening 11 and is configured to allow a cooling fluid to be introduced into the gap 16 through an auxiliary inlet duct 19 (schematically shown in
The wall 10 further comprises an auxiliary outlet opening 21, which is separate from and independent of the main opening 11 of the containing chamber 9 and the auxiliary inlet opening 18 and is configured to connect the gap 16 to an auxiliary outlet duct 22, the latter being separate from the feeding duct 13 and the auxiliary inlet duct 19, so as to allow the cooling fluid to flow out of the gap 16. According to the embodiments in which the cooling fluid is a gas, such as air coming from the outside, the auxiliary outlet duct 22 is connected to the outside and is configured to allow air to flow from the gap 16 to the outside. Alternatively, according to the further embodiment of the invention in which the cooling fluid is a liquid, the auxiliary outlet duct 22 is connected to the cooling circuit 20 (schematically shown in
The tank 7 described above can be manufactured through known manufacturing techniques, such as additive manufacturing processes, for example 3D printing, or through melting processes.
Furthermore, the tank 7 described above can advantageously be used to cool the inner panel 14 when the containing chamber 9 is filled with a high-pressure and, hence, high-temperature compressed gas; indeed, in this case, the inner panel 14, which is in direct contact with the compressed gas, gets heated and the temperature increase of the inner panel 14 itself can lead to a significant variation in the mechanical properties of the inner panel 14. Thanks to the fact that the cooling liquid flows in the gap 16, namely in contact with the inner panel 14, said cooling fluid is capable of lowering the temperature of the inner panel 14 and, hence, of allowing the tank 7 to contain compressed gases with higher pressures and temperatures.
According to
According to
According to
As already mentioned above, the compressor 12 compresses air coming from the atmosphere; the compressed air produced by the compressor 12 and stored in the tank 7 is subsequently used as described in patent application EP3674152A1, which is included herein by reference, so as to supply the gas pushers, which are operated to exert an additional thrust of pneumatic type upon the vehicle.
According to a different embodiment which is not shown herein and is not part of the invention, there is no compressor 12 and, hence, the compressed gas tank 7 is filled only when the road vehicle 1 is parked, through an outer filling system.
The embodiments described herein can be combined with one another, without for this reason going beyond the scope of protection of the invention.
The compressed gas tank 7 described above has numerous advantages.
First of all, the structure of the wall 10 allows the total weight of the compressed gas tank 7 to be significantly reduced, provided that the structural resistance remains the same.
Furthermore, the structure of the wall 10 allows the portion of the tank 7 in contact with the compressed gas (namely, the inner panel 14) to be cooled without having to cool the compressed gas or slowly introduce the compressed gas into the tank 7. In other words, by causing the cooling fluid to flow in the gap 16 it is possible to avoid deformations or perforations of the tank 7 caused by the high temperature of the compressed gas, without having to previously cool the compressed gas and without having to feed the compressed gas very (too) slowly.
Finally, the tank 7 described above is simple and economic to be manufactured.
Number | Date | Country | Kind |
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102019000023103 | Dec 2019 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2020/061511 | 12/4/2020 | WO |