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(11) | EP 4 345 361 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | IMPROVED TANK ARRANGEMENT FOR CRYOGENIC FLUID |
| (57) Tank arrangement (1) for storing a cryogenic fluid for a vehicle, extending along
a longitudinal axis (A) and comprising a first tank (2) defining a first space (4')
isolated from the environment and a second tank (3) housed within first space (4')
and defining a second space (4") isolated from the first space (4'), each tank (2,
3) comprising a head portion (2') and an intermediate portion (2") connected together
to define the first and second spaces (4', 4").
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TECHNICAL FIELD
[0002] The present invention finds its preferred, although not exclusive, application in work vehicles such as agricultural vehicle. Reference will be made to this application by way of example below.
BACKGROUND OF THE INVENTION
[0003] In order to reduce emissions, different fluids are used as fuel for allowing the operations of vehicles such as agricultural vehicles. For instance, natural liquified gas (LNG) or compressed natural gas (CNG) are used for internal feeding combustion engines or hydrogen is used for feeding fuel cell modules.
[0004] The aforementioned fluids need to be maintained at very low temperatures in order to allow to store sufficient mass of fluid to guarantee a sufficient operativity of the vehicle.
[0005] However, it is clear that the maintenance of a tank a very low temperature is a crucial point in order to avoid overheating of the fluid that may lead to a pressure increase in the tank and to a consequent explosion and to reduce energetic losses.
[0006] It is therefore known to provide a double tank arrangement wherein an outer tank houses internally an inner tank configured to store the cryogenic fluid.
[0007] The inner and outer tanks have usually a cylindrical shape and dome-shaped terminal portions, such as a "pill". Even if such portion allows to support high pressures at the low temperatures of the cryogenic fluid contained therein, it is however a bulky solution.
[0008] Indeed, the storing of such "pill"-shaped tank arrangements is complicated on work vehicles due to their encumbrance. The reduction of size would provide a solution that however will lead to store an insufficient quantity of fluid for the vehicle operation.
[0009] Therefore, the need is felt to provide a double tank arrangement for storing a sufficient volume of cryogenic fluid for allowing the operation of the vehicle and that has a reduced shape to facilitate the arrangement on the vehicle.
[0010] An aim of the present invention is to satisfy the above-mentioned needs in a cost-effective and optimized manner.
SUMMARY OF THE INVENTION
[0011] The aforementioned aim is reached by a tank arrangement and a vehicle as claimed in the appended set of claims.
BRIEF DESCRIPTION OF DRAWINGS
[0012] For a better understanding of the present invention, a preferred embodiment is described in the following, by way of a non-limiting example, with reference to the attached drawings wherein:
- Figure 1 is a perspective view of a tank arrangement according to the invention;
- Figure 2 is a perspective exploded view of the tank of figure 1;
- Figure 3 is top view of the tank of figure 1;
- Figure 4 is a side view of the tank of figure 1; and
- Figure 5 is a sectional view of the tank of figure 3 along line IV-IV.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Figure 1 shows a tank arrangement 1 for a vehicle (not shown) such as an agricultural vehicle and configured to store a cryogenic fluid that could be used to feed a power generator, such as an internal combustion engine or a fuel cell module of the vehicle.
[0014] As better shown in combination with figure 2, the tank arrangement 1 comprises a first, outer, tank 2 and a second, inner, tank 3.
[0015] The first tank 2 is dimensioned to define a space 4' configured to house the second tank 3. This latter is configured to define a space 4" configured to house a cryogenic fluid.
[0016] In particular, each tank 2, 3 is realized in more pieces that are connectable together to the define the aforementioned spaces. In the drawings, only portions of the first tank are visible and described, bearing in mind that the second tank 3 is similar but has smaller dimension in order to be contained within space 4'.
[0017] The connection of the second tank 3 to the first tank 2 may be realized in different manner and will be not described in detail for sake of brevity.
[0018] Each tank 2, 3 comprises a pair of head portions 2' configured to be connected to an intermediate portion 2". The head portions 2' are connected to the intermediate portion 2'' at respective extremities along a longitudinal axis A direction.
[0019] The intermediate portion 2'' may be realized by rolling and has a length X along longitudinal direction that may be selected in order to vary the volume of spaces 4', 4".
[0020] Each tank 2, 3 has therefore a prismatic shape since the cross-section of the intermediate portion 2'' is constant along longitudinal axis A direction. Preferably, the head portions 2' have the same shape.
[0021] The cross-section of the intermediate portion 2'' and of the head portions 2' has a trilateral shape that may be contained within a scalene and obtuse-angle triangle.
[0022] In detail, making reference to figures the cross-section comprises three sides 5, 6, 7 that are alternated by joint portions 8, 9, 10 that connected together two-by-two the three sides 5, 6, 7.
[0023] All the sides 5, 6, 7 have a curved shape and in detail a first side 5 has a greater curvature radius with respect to a second side 6 that has a greater curvature radius with respect to a third side 7. In particular, the first side 5 has a high curvature radius thereby leading to a substantially flat shape.
[0024] The second and third sides are spaced along a transversal axis B and the first side 5 is placed substantially below the second and third sides 6, 7 with respect to a vertical axis C. The longitudinal, transversal and vertical axis A, B, C are all perpendicular one with respect to the other.
[0025] A first joint portion 8 connects together the first and second sides 5, 6, a second joint portion 9 connects together the second and third sides 6, 7 and a third joint portion 10 connects together the third and first sides 7, 5.
[0026] The second and the third joint portions 9, 10 have substantially the same curvature radius that is smaller with respect to the curvature radius of the first joint portion 8.
[0027] Furthermore, making reference to figure 3, it is noticed that the head portions 2' have not a constant cross section along longitudinal axis A.
[0028] In particular, a first edge 11 of this latter that is coupled to the intermediate portion 2'' has the cross-section dimension with respect to this latter while a second edge 12 of the head portions 2', opposite to the first edge 11 has a smaller dimension, i.e. it may be contained within the perimeter of first edge 11. Preferably, the second edge 12 is the perimeter of a flat wall having the above described cross-section.
[0029] In particular, the reduction is obtained by non-linear reduction via curved portions 13', 13'' that connects together first and second edges 11, 12.
[0030] In the advantageous disclosed embodiment front curved portions 13' are not equal to the rear curved portion 13'' along transversal axis B, therefore in the trilateral shape of the second edge 12 ratio between second and third sides and the first side is smaller than in the first edge 11.
[0031] In particular, the front curved portion 13' have a smaller curvature radius with respect to the rear curved portions 13".
[0033] Once mounted together the proposed shape of the tank arrangement 1 allows the storing of the cryogenic fluid in the space 4". If, for any reason, it is necessary to have a greater tank arrangement 1, it is sufficient to substituted the intermediate portions of the first and of the second tank thereby obtaining a greater volume without changing the head portions.
[0034] In view of the foregoing, the advantages of the tank according to the invention are apparent.
[0035] Thanks to the proposed shape the volume of the space storing the cryogenic fluid is high while the encumbrance of the tank arrangement is reduced.
[0036] Indeed, the proposed shape allows to store the cryogenic fluid with a smaller extension along longitudinal axis and with a shape that provides a facilitated arrangement on the vehicle.
[0037] Moreover, the proposed shape decreases the stresses to the overall structure of the tank arrangement thereby allowing to store high pressure cryogenic fluid, e.g. about 5 bars.
[0038] Furthermore, the volume of cryogenic fluid storing space may be varied easily by substituting only the intermediate portion and maintaining the same head portion. This provides a great versatility for modification on vehicle and scale economy in the manufacturing of the tank arrangement.
1. Tank arrangement (1) for storing a cryogenic fluid for a vehicle, said tank arrangement
(1) extending along a longitudinal axis (A) and comprising a first tank (2) defining
a first space (4') isolated from the environment and a second tank (3) housed within
said first space (4') and defining a second space (4'') isolated from the first space
(4'), each tank (2, 3) comprising a head portion (2') and an intermediate portion
(2'') connected together to define said first and second spaces (4', 4'').
2. Tank arrangement according to claim 1, wherein said head portions (2') are connected
on opposite sides of said intermediate portion (2") along said longitudinal axis (A).
3. Tank arrangement according to any of the preceding claims, wherein the cross-section
of said intermediate portion (2") is constant along said longitudinal axis (A).
4. Tank arrangement according to claim 3, wherein said cross-section as a trilateral
shape.
5. Tank arrangement according to claim 3 or 4, wherein said cross-section has a shape
that can be contained within an obtuse scalene triangle.
6. Tank arrangement according to any of claims 3 to 5, wherein said cross-section comprises
a first side (5), a second side (6), a third side (7) and a first joint portion (8)
connecting said first and second sides (5, 6), a second joint portion (9) connecting
said second and third sides (6, 7) and a third joint portion (10) connecting said
third and first sides (8, 5), wherein said sides (5, 6, 7) and said joint portions
(8, 9, 10) are curved.
7. Tank arrangement according to claim 6, wherein said first side (6) has a curvature
radius greater than said second side (7) that has a curvature radius greater than
said third side (8) .
8. Tank arrangement according to claim 6 or 7, wherein said joint portions (8, 9, 10)
have a curvature radius smaller than the curvature radius of said sides (5, 6, 7).
9. Tank arrangement according to any of claims 6 to 8, wherein said second and third
joint portions (9, 10) have the same curvature radius.
10. Tank arrangement according to any of claims 6 to 9, wherein said first joint portion
(8) has a curvature radius smaller than the curvature radius of said second and third
joint portions (9, 10).
11. Tank arrangement according to any of the preceding claims, wherein a first edge (11)
of said head portions (2') has the same cross-section of said intermediate portion
(2") and a second edge (12) opposite to said first edge (11), the cross-section of
said head portion (2') varying from said first edge (11) to said second edge (12).
12. Tank arrangement according to claim 11, wherein said second edge (12) is the perimeter
of a flat terminal wall.
13. Tank arrangement according to claim 11 or 12, wherein said second edge (12) is smaller
and contained within said first edge (11).
14. Tank arrangement according to claim 11 to 13, wherein said cross-section varies from
said first edge (11) to said second edge (12) via a non-linear variation.
15. Vehicle comprising a power generator using a fluid as fuel and comprising a tank arrangement
(1) according to any of the preceding claims for storing said fluid.