DE102017201420B4 - Tank, in particular pressure tank, in particular hydrogen pressure tank - Google Patents

Abstract

Tank (1), in particular pressure tank (1), in particular hydrogen pressure tank (1), with
a first element (11), which is designed to define the inner volume (13) of the tank (1) and the shape of the tank (1), and with
a second element (12), which is designed for shape retention and pressure stability of the tank (1),
wherein the first element (11) is arranged at least partially radially inside the second element (12),
wherein both elements (11, 12) are produced separately and then joined together so that the two elements (11, 12) are non-positively and / or positively connected with each other,
characterized in that
the second element (12) comprises an elastomeric material,
wherein tear resistant fibers are embedded in the elastomeric material of the second member (12).

Description

The present invention relates to a tank, in particular a pressure tank, in particular a hydrogen pressure tank, according to the preamble of patent claim 1, a method for producing such a tank according to claim 10, a fuel cell system with such a tank according to the patent claim 13 and a Vehicle with such a fuel cell system according to the patent claim 14.

There are vehicles known whose driving force can be generated at least partially by electric drives. In this case it is known to provide the electrical energy at least partially by means of fuel cells which are filled with hydrogen ( H2 ) are fed. This requires that in such vehicles a hydrogen pressure tank ( H2 Tank) is supplied to supply the drive.

The disadvantage here is that currently on the market hydrogen pressure tanks have a high weight, are largely inelastic and require a lot of space. At the same time, hydrogen pressure tanks must withstand high pressures of up to about 300 bar or even up to about 700 bar. In some cases even burst pressures of up to approx. 1,700 bar must be able to be withstood.

Hydrogen pressure tanks for fuel cell vehicles are divided into type classes Type I to Type IV. The types III and IV are hydrogen pressure tanks with a cylindrical shape of the tank body, which consists of two radially superposed layers or elements. This is, on the one hand, a shaping liner as the first, inner element, which defines the inner volume of the hydrogen pressure tank and its shape. The inner element usually has material properties which prevent the diffusion of the pressurized gas, such as hydrogen here. The inner element thus usually serves both as a diffusion barrier and as a shaping part.

As a second, outer member of the tank body is usually a fiber-resin layer of wound or woven carbon fiber composite material. The outer member is usually used to maintain the shape and pressure stability of the hydrogen pressure tank even at an operating pressure of up to about 700 bar and sometimes even beyond, e.g. to about 1,700 bar.

The two types III and IV differ only in the choice of material of the first, inner element, which consists of an aluminum cylinder in the type III, which is usually designed for operating pressures up to about 350 bar and has more weight for the same properties. In type IV, the first, inner element is made of a special plastic polymer, which is particularly well suited as a diffusion barrier for hydrogen and at the same time reduces the weight and volume of the first, inner element compared to the type III.

A disadvantage of known hydrogen pressure tanks in general that they are relatively expensive and expensive to manufacture, so that the proportion of a hydrogen pressure tank to the total cost of a fuel cell system can be up to about 30%. This results essentially from the fact that hydrogen pressure tanks are very expensive and expensive to manufacture, mainly due to the high proportion of expensive and difficult to process carbon fiber composite material of the second, outer element. The winding and / or weaving of the second outer element with the carbon fiber composite material must be performed separately for each second, outer element and in a tedious, precise process step. This is followed by a curing of the synthetic resin, with which the fibers are impregnated or which is applied to the fiber winding, in a pressure and temperature molding process. Also, this second process step is performed separately for each second, outer element and very time consuming.

An object of the present invention is to provide a tank, in particular a pressure tank, in particular a hydrogen pressure tank, of the type described above, so that the manufacturing costs and / or the weight compared to known tanks of this kind can be reduced. At least an alternative to known such tanks should be created.

The object is achieved by a tank with the features according to claim 1, a method with the features according to claim 10, a fuel cell system with the features according to claim 13 and by a vehicle having the features according to claim 14. Advantageous developments are described in the subclaims.

The US 2014/0197179 A1 describes a high-pressure gas container in which a high-pressure gas is charged, with a lining in which the high-pressure gas is charged, and with a reinforcing sleeve, which encloses an outer surface of the liner. The liner comprises a cylindrical liner body portion and a pair of liner shoulder portions obtained by reducing a diameter of respective end portions of the body Lining hull section are formed. The reinforcing sleeve includes a sleeve body portion adapted to the liner body portion and a pair of sleeve shoulder portions extending from the sleeve stem portion to contact the respective insert shoulder portions.

The DE 41 39 739 A1 describes a double-walled pressure vessel with a thin-walled inner container made of a corrosion-resistant, dense material, in particular stainless steel, and with a pressure-resistant outer container having a sheath, a transition part, a neck part and a bottom part, wherein the bottom part and / or the transition part with neck part inside in a cylindrical or slightly conical end portion of the shell is arranged and wherein the bottom part or the transition part has an outer collar which extends at least partially approximately parallel to the end portion of the shell and is connected thereto by a technical joining connection. This allows the cost-effective production of relatively lightweight pressure vessels, z. B. for pure gases.

The DE 86 19 754 U1 describes a compressed gas cylinder, which consists of a cylindrical or approximately cylindrical main part and of tapered end parts and which is provided with at least one outer, annular and in one piece prefabricated bandage. The wall of the bottle body and the wall of the bandage are inclined by a small angle, less than 5 °, against the bottle axis and thus the shape of the seat is like a tool cone (Morse cone).

The DE 31 03 646 C2 describes a pressure vessel for storage and transport of highly stressed gases and gas mixtures with a tubular metal body which is deformed at least at one end to a dome-shaped end cap. The pressure vessel should be prepared for any type of gas in any state of aggregation at high internal pressure of about 200 bar and more so that it has the lowest possible weight and thus leads to a higher overall payload. Also, the pressure vessel should be particularly inexpensive to manufacture. This is achieved by a pressure vessel in which the wall thickness of the tubular portion of the existing aluminum or aluminum alloy metal body relative to the wall thickness of the dome-cap / s reduced and of a shell of fiber-reinforced, in particular with glass, carbon, aramid or Borfasern surrounded by reinforced plastic. The fibers of the shell should be wrapped around the aluminum body and generate on this at least partially helices.

Thus, the present invention relates to a tank, in particular a pressure tank, in particular a hydrogen pressure tank, with a first element, which is designed to define the internal volume of the tank and the shape of the tank, and with a second element, which for shape maintenance and is designed for pressure stability of the tank. The first element can also be referred to as a liner.

The first element is arranged at least partially radially within the second element. The first element can therefore also be referred to as an inner element and the second element as an outer element. This also includes that at least one further element can be arranged radially within the first element and / or radially outside the second element and / or radially between the first and the second element.

The present invention is characterized in that both elements are manufactured separately and then joined together, so that the two elements are non-positively and / or positively connected with each other. In this case, the present invention is based on the finding that the production compared to known such tanks can be simplified by the two elements are each prepared individually and then joined together. In particular, in pressure tanks and especially in hydrogen pressure tanks can be avoided in this way the previously known production of the second element as a wound or woven carbon fiber composite material. This can reduce the manufacturing costs as well as the weight of the tank.

In order to be able to be joined together and be able to enter into a secure frictional and / or positive connection with one another in this state, the two elements should have a radial distance from one another, but this should be as small as possible. In this way, the two elements can move each other during assembly at least in the longitudinal direction. This radial distance can be in the assembled state, e.g. by shrinking the second element e.g. be closed by heating, so that adjusts the safe non-positive and or or positive connection.

Furthermore, the second element comprises an elastomeric material, wherein tear-resistant fibers are embedded in the elastomeric material of the second element. As a result, the shape-retaining and pressure-stabilizing effect of the second element can be achieved.

Preferably, the tank or the two elements is at least substantially cylindrical educated. This shape can be relatively inexpensive to produce and at the same time, due to their rotational symmetry, can withstand pressure from inside comparatively well in all directions.

The present invention can be applied to any kind of tanks. In particular, the present invention can be applied to any type of pressure tanks, such as e.g. CNG tanks or LPG tanks, and e.g. on pressure tanks for industrial gases, protective gases, fire extinguishers, carbonic acid and the like.

According to one aspect of the present invention, the second element is endlessly closed in the circumferential direction and is open in the longitudinal direction at least on one side, preferably open on both sides. In this way, joining in the longitudinal direction can be ensured because the first element passes through the opening at least from one side into the second element, e.g. can be inserted. Being able to join the two elements from both sides can simplify manufacturing.

According to another aspect of the present invention, the second element is formed in the longitudinal direction at least as long as the first element. In this way it can be achieved that the second element can exert its shape-retaining and pressure-stabilizing effect over the entire length of the first element in the longitudinal direction.

According to a further aspect of the present invention, the second element is designed to be longer in the longitudinal direction than the first element, so that at least one end of the second element comprises an end of the first element at least in sections in the longitudinal direction. As a result, the corresponding end of the first element can also be stabilized by the second element.

According to a further aspect of the present invention, the second element is designed to be longer in the longitudinal direction than the first element, so that in each case one end of the second element in each case comprises an end of the first element at least in sections in the longitudinal direction. As a result, both ends of the first element can also be stabilized by the second element.

According to another aspect of the present invention, the tear resistant fibers are carbon fibers and / or aramid fibers. As a result, the shape-retaining and pressure-stabilizing effect of the second element can be achieved.

According to a further aspect of the present invention, the elastomeric material of the second element has more tear-resistant fibers in the area of at least one end, preferably in the region of both ends, than in the remaining areas. As a result, the shape-retaining and pressure-stabilizing effect of the second element can be increased at one end or at both ends. This may be advantageous to counteract a rupture of the first element at the end or ends, in particular in a pressure tank, since just the ends of a tank, in particular a cylindrical tank, are more prone to bursting than the remaining areas.

According to a further aspect of the present invention, the outer surface of the first element at least partially structuring and the inner surface of the second element at least partially structuring, wherein the structuring of the two elements correspond to each other and are formed so that the structuring at least partially produce a positive connection in the circumferential direction between the two elements. These structurings may preferably be designed in the circumferential direction and ribbed, wedge, toothed or web-shaped. As a result, on the one hand, a positive connection can be effected. On the other hand, the surface can be increased, which establishes a contact between the two elements, so that the adhesion between the two elements can increase as well This also higher pressures within the first element can be allowed.

According to a further aspect of the present invention, the second element is a cylindrical elastomeric body, preferably a bellows, a belt or a conveyor belt. In this way, the second element can be manufactured as an already known product and merely supplied to another application. This can further reduce the manufacturing costs. Furthermore, the knowledge for the production of the known product for the production of a tank according to the invention can be used, whereby the quality of the tank can be increased or ensured.

• • Herstellen des ersten Elements,
• • separates Herstellen des zweiten Elements, und
• • Zusammenfügen des zweiten Elements über das erste Element,

wobei das zweite Element ein elastomeres Material aufweist, wobei in dem elastomeren Material des zweiten Elements reißfeste Fasern eingebettet sind.The present invention also relates to a method of manufacturing a tank as described above comprising the steps of:

• • making the first element,
• • making the second element separately, and
• Joining the second element over the first element,

wherein the second member comprises an elastomeric material, wherein tear resistant fibers are embedded in the elastomeric material of the second member.

In this way, a product according to the invention can be produced. The resulting properties and advantages have already been described above and should therefore not be repeated here.

• • Schrumpfen des zweiten Elements auf dem ersten Element, vorzugsweise durch Erwärmen.

According to one aspect of the present invention, the method comprises the further step:

• Shrinking of the second element on the first element, preferably by heating.

In this way, a radial distance between the two elements can be closed in the assembled state, so that the secure frictional and or or positive connection can be established.

• • Expandieren des ersten Elements innerhalb des zweiten Elements, vorzugsweise durch Erwärmen oder durch einen nach außen gerichteten Unterdruck.

According to one aspect of the present invention, the method comprises the further step:

• Expanding the first element within the second element, preferably by heating or by an outward negative pressure.

In this way, a radial distance between the two elements in the assembled state can be closed in an alternative manner, so that the secure non-positive and / or positive connection can be established.

The present invention also relates to a fuel cell system with at least one tank, in particular a hydrogen pressure tank, as described above and with at least one fuel cell. In this way, the properties and advantages of a tank according to the invention can be used in a fuel cell system.

The present invention also relates to a vehicle having at least one fuel cell system as described above. In this way, the properties and advantages of a fuel cell system according to the invention can be used in a vehicle. Such vehicles may utilize purely electric drives powered by such a fuel cell system or hybrid drives, i. a combination of electric drive with such a fuel cell system and a combustion drive. Alternatively, purely battery-electric drives are known which require no fuel cell system.

• 1 eine perspektivische schematische Darstellung eines erfindungsgemäßen Tanks vor dem Zusammenfügen;
• 2 eine perspektivische schematische Darstellung des erfindungsgemäßen Tanks nach dem Zusammenfügen, und
• 3 ein Ablaufdiagramm zweier alternativer erfindungsgemäßer Verfahren zur Herstellung eines erfindungsgemäßen Tanks.

An embodiment and further advantages of the present invention are explained below in connection with the following figures. It shows:

• 1 a perspective schematic representation of a tank according to the invention prior to assembly;
• 2 a perspective schematic representation of the tank according to the invention after assembly, and
• 3 a flow diagram of two alternative inventive method for producing a tank according to the invention.

In the 1 and 2 becomes a tank according to the invention 1 as a hydrogen pressure tank 1 considered. The Tank 1 has a tank body 10 on, which consists of a first, inner element 11 in the form of a liner 11 and a second, outer element 12 in the form of a belt 12 consists. The first, inner element 11 is radially within the second, outer element 12 arranged, wherein the first, inner element 11 longitudinal X one connection element each 14 having, which in each case by an opening of the second, outer element 12 protrudes outwards.

Within the first, inner element 11 becomes an inner volume 13 of the tank 1 enclosed, so by the first, inner element 11 both the inner volume 13 of the tank 1 as well as the shape of the tank 1 To be defined. To the shape of the tank 1 or the first, inner element 11 Even at very high pressures such as to hold up to about 700 bar, is the first, inner element 11 in the circumferential direction U closed and in the longitudinal direction X almost to the connection elements 14 approach from the second, outer element 12 surround. The second, outer element 12 thus serves both the shape retention and the pressure stability of the tank 1 ,

For this purpose, the second, outer element 12 Tear-resistant fibers such as carbon fibers or aramid fibers to withstand such pressures can. The second, outer element 12 has an elastomeric material, in which the tear-resistant fibers are embedded. The ends encompass this 12a . 12b of the second, outer element 12 the ends 11a . 11b of the first element 11 in order to have a stabilizing effect, in particular in these regions which are particularly prone to bursting. Furthermore, the ends have 12a . 12b of the second, outer element 12 For this reason, a higher proportion of tear-resistant fibers than the remaining areas of the second, outer element 12 ,

In this case, the second, outer element 12 from the belt 12 itself as well as two separately manufactured elements which make up the belt 12 at its ends 12a . 12b encircle where the belt 12 the bent ends 11a . 11b of the first element 11 surrounds. These separately manufactured elements may comprise an elastomeric material in which the tear-resistant fibers are embedded to just the burst endangered ends 11a . 11b of the first element 11 to stabilize. These separately manufactured elements can cohesively with the belt 12 connected and thus a part of the belt 12 so that these elements are the ends 12a . 12b of the belt 12 in the longitudinal direction X can form.

The connection between the two elements 11 . 12 takes place positively and positively. This can be promoted in particular by the fact that the outer surface of the first, inner element 11 a structuring 11c such as one in the circumferential direction U extending tooth profile and the inner surface of the second, outer element 12 a corresponding structuring 12c having. This allows a relative movement of the two elements 11 . 12 in the circumferential direction U safely avoided.

In the 3 is a flow diagram of a method according to the invention for producing a tank according to the invention 1 shown. In a first step 100 becomes the first element 11 manufactured. This can be done as previously known. In a second step 200 becomes the second element 12 made separately. Again, this may be known as a belt 12 take place, with only the dimensions of eg belt in the circumferential direction U as well as in the longitudinal direction X of the tank 1 , which is the transverse direction of the belt 12 corresponds, must be adjusted accordingly. In this way, a known manufacturing method can be used according to the invention to the second, outer element 12 of the tank 1 unlike previously known to produce as a separate component.

In a third step 300 then becomes the second element 12 about the first element 11 pushed to the two elements 11 . 12 put together. For this purpose, the two elements 11 . 12 between them a radial distance, which allows an assembly, but at the same time as low as possible.

In a fourth step 400 then becomes either the second, outer element 12 Shrunk by heating to close this radial distance, so that by shrinking a frictional connection in the circumferential direction U and in the longitudinal direction X is reached. At the same time, this is due to the interlocking structuring 11c . 12c a positive connection in the circumferential direction U causes. Alternatively, in the fourth step 400 then the first element 11 within the second element 12 expanded, so that by expanding a frictional connection in the circumferential direction U and in the longitudinal direction X is reached. The expansion can be carried out by heating or by an outwardly directed negative pressure.

In this way, according to the invention, a tank 1 and in particular a hydrogen pressure tank 1 be created, which has comparable properties as known such tanks 1 but can be made simpler and faster, while having a lower weight. Furthermore, this tank can 1 due to the elastomeric material of the second, outer element 12 more elastic than previously known tanks 1 his.

LIST OF REFERENCE NUMBERS

R

radial direction

U

circumferentially

X

longitudinal direction

1

Tank; (Hydrogen) pressure tank

10

shells

11

first, inner element; liner

11a

first end of the first, inner element 11

11b

second end of the first, inner element 11

11c

Structuring the outer surface of the first, inner element 11

12

second, outer element; cylindrical elastomeric body; Bellows; Belt; conveyor belt

12a

first end of the second, outer element 12

12b

second end of the second, outer element 12

12c

Structuring the inner surface of the second, outer element 12

13

inner volume of the first, inner element 11

14

connection elements

100

Make the first item 11

200

separate production of the second element 12

300

Merging the second element 12 about the first element 11

400

Shrink or expand the second element 12 on the first element 11

Claims (14)

Tank (1), in particular pressure tank (1), in particular hydrogen pressure tank (1), with a first element (11), which is formed, the inner volume (13) of the tank (1) and the shape of the tank (1) and a second element (12), which is designed to maintain the shape and pressure stability of the tank (1), wherein the first element (11) at least partially radially within the second element (12) is arranged, both elements ( 11, 12) are produced separately and then joined together, so that the two elements (11, 12) are non-positively and / or positively connected to each other, characterized in that the second element (12) comprises an elastomeric material, wherein in the elastomeric material the second element (12) tear-resistant fibers are embedded. Tank (1) after Claim 1 , characterized in that the second element (12) in the circumferential direction (U) is endlessly closed and in the longitudinal direction (X) open at least on one side, preferably open on both sides. Tank (1) after Claim 1 or 2 , characterized in that the second element (12) in the longitudinal direction (X) at least as long as the first element (11) is formed. Tank (1) according to one of the preceding claims, characterized in that the second element (12) in the longitudinal direction (X) is longer than the first element (11), so that at least one end (12a, 12b) of the second element (12) comprises an end (11a, 11b) of the first element (11) at least in sections in the longitudinal direction (X). Tank (1) after Claim 4 , characterized in that the second element (12) in the longitudinal direction (X) is longer than the first element (11), so that in each case one end (12a, 12b) of the second element (12) has one end (11a, 11b) of the first element (11) at least in sections in the longitudinal direction (X). Tank (1) according to one of the preceding claims, characterized in that the tear-resistant fibers are carbon fibers and / or aramid fibers. Tank (1) according to one of the preceding claims, characterized in that the elastomeric material of the second element (12) in the region of at least one end (12a, 12b), preferably in the region of both ends (12a, 12b), more tear-resistant fibers than in has the remaining areas. Tank (1) according to one of the preceding claims, characterized in that the outer surface (11c) of the first element (11) at least partially structuring (11c) and the inner surface (12c) of the second element (12) at least partially structuring (12c), wherein the structurings (11c, 12c) of the two elements (11, 12) correspond to each other and are formed so that the structurings (11c, 12c) at least partially a circumferentially (U) positive connection between the two Make elements (11, 12). Tank (1) according to one of the preceding claims, characterized in that the second element (12) is a cylindrical elastomeric body (12), preferably a bellows (12), a belt (12) or a conveyor belt (12). Method for producing a tank (1) according to one of Claims 1 to 9 , comprising the steps of: fabricating (100) the first element (11), fabricating (200) the second element (12) separately, and assembling (300) the second element (12) via the first element (11), the second Element (12) comprises an elastomeric material, wherein in the elastomeric material of the second element (12) tear-resistant fibers are embedded. Method for producing a tank (1) according to Claim 10 with the further step of: shrinking (400) the second element (12) on the first element (11), preferably by heating. Method for producing a tank (1) according to Claim 10 with the further step of: expanding (400) the first element (11) within the second element (12), preferably by heating or by an outwardly directed negative pressure. Fuel cell system, with at least one tank (1), in particular a hydrogen pressure tank (1), according to one of Claims 1 to 9 , and with at least one fuel cell. Vehicle, with at least one fuel cell system after Claim 13 ,

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