MOTOR VEHICLE COMPRESSED GAS TANK

Abstract

A method for producing a compressed gas tank for a motor vehicle includes inserting a bundle of heat-conducting elements through an opening in a housing of the compressed gas tank and exerting a force on the bundle that radially expands the bundle within the housing beyond the size of the opening. The heat-conducting elements may be helically wound about a central axis when inserted through the opening with a torsional force applied to unwind the elements while radially expanding and reducing axial length of the bundle. A compressed gas tank for a motor vehicle includes a plurality of heat-conducting elements including at least one tube within a tank housing that extend axially along the tank and radially within the housing to a size exceeding an opening of the housing. The tube is configured to circulate coolant to cool compressed gas within the tank.

Claims

1. A method of producing a compressed gas tank for a vehicle, comprising: inserting a bundle of heat-conducting elements through an opening in one end of a housing of the compressed gas tank; applying a force to the bundle that radially expands at least a portion of the bundle within the housing to a radius that exceeds a radius of the opening; and securing the bundle within the housing.

2. The method of claim 1 wherein the heat-conducting elements are helically wound around a central axis.

3. The method of claim 2 wherein applying a force comprises applying a torsional force to at least partially unwind the helically wound heat-conducting elements.

4. The method of claim 3 wherein the housing includes an engagement region positioned opposite the opening and wherein inserting the bundle comprises non-rotatably coupling a distal end of the bundle to the engagement region to oppose the torsional force.

5. The method of claim 4 wherein the heat-conducting elements comprise a plurality of tubes fluidly coupled by an annular header element.

6. The method of claim 1 wherein the bundle has an axial length that exceeds an axial length of the housing and wherein applying a force to the bundle reduces the axial length of the bundle to fit within the housing.

7. The method of claim 1 wherein the heat-conducting elements comprise at least one tube configured to circulate a coolant.

8. The method of claim 7 wherein the heat-conducting elements comprise a plurality of tubes fluidly coupled by an annular header.

9. The method of claim 8 wherein the annular header comprises a compressed gas valve secured within a central portion thereof.

10. The method of claim 8 wherein the annular header comprises a threaded exterior that cooperates with a threaded interior of the opening in the housing.

11. The method of claim 10 wherein the annular header comprises a threaded interior annulus that cooperates with a threaded exterior of the compressed gas valve.

12. A compressed gas tank for a vehicle, comprising: a housing having an opening with a first radius; a bundle having a plurality of heat-conducting tubes helically wound about a central axis, the bundle having a second radius greater along a central portion of the bundle that exceeds the first radius; an annular header fluidly coupling a coolant inlet to a first end of at least one of the heat-conducting tubes and a coolant outlet to a second end of at least one of the heat conducting tubes.

13. The compressed gas tank of claim 12 wherein the annular header comprises a threaded exterior cooperating with a threaded interior of the opening in the housing.

14. The compressed gas tank of claim 12 further comprising a compressed gas valve disposed along the central axis of the bundle within the opening of the housing.

15. The compressed gas tank of claim 14 wherein the annular header comprises a threaded exterior cooperating with a threaded interior of the opening in the housing and a threaded interior cooperating with a threaded exterior of the compressed gas valve.

16. The compressed gas tank of claim 12 wherein the housing comprises an engagement structure opposite the opening configured to secure a distal end of the bundle from rotation during assembly of the compressed gas tank.

17. A system comprising: a plurality of heat-conducting tubes helically wound about a central axis; a coupler mechanically securing a first end of the heat-conducting tubes, the first coupler including an engagement structure configured to engage a housing of a compressed gas tank and prevent rotation of the coupler relative to the housing; and an annular header fluidly coupled to a second end of the heat-conducting tubes, the annular header having a coolant inlet and a coolant outlet each connected to associated heat-conducting tubes.

18. The system of claim 17 further comprising a compressed gas tank housing having an opening at one end configured to secure the annular header, and a second engagement structure configured to engage the engagement structure of the coupler.

19. The system of claim 18 wherein the annular header comprises exterior threads configured to engage interior threads of the opening.

20. The system of claim 19 further comprising a compressed gas valve positioned along a central axis of the housing and secured within an interior of the annular header.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIGS. 1-4 show a sectional illustration of a compressed gas tank during various phases of assembly according to representative embodiment of a method according to the disclosure;

[0032] FIGS. 5-7 show a detail view of a bundle of heat-conducting tubes during various phases of expansion during assembly according to embodiments of the disclosure;

[0033] FIG. 8 shows a perspective illustration of a cooling bundle with cooling tubes coupled by a header element;

[0034] FIG. 9 shows a partial sectional illustration of part of a cooling bundle coupled by a header element from FIG. 8;

[0035] FIG. 10 shows a sectional illustration in accordance with the line X-X in FIGS. 9; and

[0036] FIG. 11 shows a partial sectional illustration of part of a cooling bundle with an engagement element.

DETAILED DESCRIPTION

[0037] As required, detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely representative and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the claimed subject matter.

[0038] In the various figures, identical parts are in all cases provided with the same reference signs, for which reason they are also generally described only once.

[0039] FIG. 1 shows a sectional view of a compressed gas tank 1 for a motor vehicle, which can be used, for example, in a passenger car, during a first phase of assembly according to one or more embodiments. The section plane in FIG. 1 runs parallel to a housing axis A, which corresponds to an axial direction. The housing axis A forms an axis of symmetry of the compressed gas tank 1. The latter has a housing 2, with a middle section 3 in the form of a cylinder jacket, which is adjoined axially at the ends by a first end section 4 and a second end section. The illustration of the housing 2 is greatly simplified here. Normally, this has an inner jacket of plastic and/or metal, which is surrounded by an outer jacket consisting of wound rovings (continuous fibers) in a polymer matrix. An axially extending housing opening 4.1 is formed in the region of the housing axis A in the first end region 4. In the second end region 5, an engagement region 5.1 is formed, the function of which will be explained in the following.

[0040] Furthermore, FIG. 1 shows a bundle 10 of coolant tubes 11 wound helically around one another. In the present example, the coolant tubes 11 are made of stainless steel. Each coolant tube 11 has at least one through channel 11.1, 11.2, wherein a group of first through-channels 11.1 and a group of second through channels 11.2, which will be explained below, can be functionally distinguished. At a first end 10.1, the coolant tubes 11 are connected to one another by an engagement element 12, which has an engagement structure 12.1 in the form of a projection. This is of complementary design to an engagement structure 5.1 of a second engagement element 5.2, said structure being formed in the end region 5. The ends of each coolant tube 11 can be accommodated in apertures (not illustrated here) of the respective engagement element 12 and can be screwed in, for example. Thus, the coolant tubes 11 could first of all be screwed into the engagement element 12 and then twisted before being introduced into the compressed gas tank 1, thus enabling the illustrated helical configuration to be achieved. However, it is also conceivable for the coolant tubes 11 winding helically around one another to be held in a manner secure against rotation by the engagement element 12, wherein a nonpositive, materially integral or positive joint is envisaged. For example, the engagement element 12 can be embodied in the manner of a sleeve and can hold the bundle in a manner secure against rotation, engaging around the outside of said bundle, wherein the engagement structure 12.1 is arranged on a closed end of the engagement element 12.

[0041] As can be seen in FIG. 11, the engagement element 12 has a plurality of U-shaped deflection channels 12.2, each of which connects a first through channel 11.1 to a second through channel 11.2. At a second end 10.2, the coolant tubes 11 are connected by a header element 13, which is more easily visible in the enlarged illustrations in FIGS. 8-10. Overall, the header element 13 is of annular design and has an external thread 13.1 and, in a through opening 13.2, an internal thread 13.3. A plurality of first branch channels 13.4 is furthermore formed, each of said channels being connected to a first through channel 11.1 of one of the coolant tubes 11, and a plurality of second branch channels 13.5 is also formed, each of said channels being connected to a second through channel 11.2. The first branch channels 13.4 are connected via an annular first collecting channel 13.6 to an inlet coolant connection 13.8, while the second branch channels 13.5 are connected via a likewise annular second collecting channel 13.7 to an outlet coolant connection 13.9. Both coolant connections 13.8, 13.9 are arranged on the header element 13.

[0042] In FIG. 1, the bundle 10 is introduced, with the first end 10.1 in the lead, partially into an interior 2.1 of the housing 2 through a housing opening 4.1 in the first end region 4, said opening passing through in the axial direction. Here, the direction of movement during introduction corresponds at least approximately to the axial direction.

[0043] In FIG. 2, the bundle 10 has been introduced to an extent such that the first engagement element 5.2 comes into positive engagement with the second engagement element 12, thereby preventing twisting of the engagement element 12 relative to the housing 2. The length of the bundle 10 is dimensioned in such a way that a part thereof is still outside the housing 2 with the header 13. As the process continues, a torque (corresponding to a force couple) is exerted on the second end 10.2, leading to a torsional moment acting on the bundle 10. This state is also illustrated in FIG. 5, where only a part of the bundle 10 can be seen.

[0044] As the process continues, the torque exerted has the effect that the twist of the bundle 10 decreases while, at the same time, its length in the axial direction is reduced. As a result, the radial dimension of the bundle 10 (its outer radius) within the compressed gas tank 1 increases, while the header 13 is moved closer to the housing opening 4.1. This is illustrated in FIG. 3 and in FIG. 6.

[0045] The process described is continued until, as illustrated in FIG. 4 and FIG. 7, the bundle 10 has been spread apart to such an extent that the radial dimension thereof has increased by more than 200% relative to the original state. It thus fills the interior 2.1 of the housing 2 significantly better than in the original state shown in FIG. 2. In one embodiment, the largest radial dimension of the bundle (typically in the middle of the bundle) increases beyond the radial dimension of the housing opening 4.1 to about one-half of the radial dimension of the housing 2. Moreover, significant gaps between the individual heat-conducting tubes 11 can be seen. The entire process of spreading the bundle 10 apart is accomplished by primarily elastic deformation of the individual heat-conducting tubes 11. Finally, the external thread 13.1 of the header 13 is screwed into an internal thread 4.2 of the housing opening 4.1. The sense of rotation for screwing in is expediently chosen in such a way that the bundle spreads further apart. In addition, a valve 14 (illustrated in schematic form here) can be screwed into the through opening 13.3. By means of the valve 14, the interior 2.1 of the housing 2 can be filled with a pressurized gas (e.g. hydrogen, natural gas, DME or LPG), which is used to drive the motor vehicle.

[0046] In the installed state, the through channels 11.1, 11.2 of the coolant tubes 11 can be connected to a coolant circuit of the motor vehicle, which carries a liquid coolant (e.g. a water-glycol mixture) and is used for temperature control, i.e. cooling and/or heating, of various vehicle components or zones. More precisely, the inlet coolant connection 13.8 is connected to a coolant feed line (not illustrated), while the outlet coolant connection 13.9 is connected to a coolant discharge line. In this way, coolant can flow into the first through channels 11.1 via the inlet coolant connection 13.8, the first collecting channel 13.6 and the first branch channels 13.4. From there, the coolant passes via the deflection channels 12.2 into the second through channels 11.2 and onward via the second branch channels 13.5 and the second collecting channel 13.7 to the outlet coolant connection 13.9. From there, it passes into the coolant discharge line.

[0047] During refueling, liquefied gas is introduced from an external tank, via a tank line and valve 14, into the compressed gas tank 1. As it flows into the compressed gas tank 1, the gas flows through the gaps between the coolant tubes 11 and has relatively large-area contact with the coolant tubes 11. During this process, there is heat exchange between the gas, which heats up as it is introduced, and the cooling fluid in the through channels 11.1, 11.2. The heating of the gas is reduced by the heat exchange with the cooling fluid that is provided via the wall of the respective coolant tube 11. It is thereby possible to prevent the temperature of the gas and of the compressed gas tank 1 from exceeding a specified threshold, even when refueling takes place relatively quickly. External pre-cooling of the gas is not necessary for this purpose. The heat absorbed by the cooling fluid is dissipated via the coolant circuit and can be released via a heat exchanger, for example, to a vehicle interior or, alternatively, to the surroundings of the vehicle. As an alternative to a cooling circuit of the motor vehicle, a connection to a (partially) external cooling circuit associated with the filling station at which the compressed gas tank 1 is being refilled would also be possible

[0048] While representative embodiments are described above, it is not intended that these embodiments describe all possible forms of the claimed subject matter. Additionally, the features of various implementing embodiments may be combined to form further embodiments that may not be explicitly illustrated or described. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, as one of ordinary skill in the art is aware, one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. Embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not necessarily outside the scope of the disclosure and may be desirable for particular applications.