AT501106B1 - GAS STORAGE - Google Patents

Abstract

Ultra-sound monitoring (5) of the contents of a flexible wall, double-skin (1, 2) gas holder, requires that the upper reflection surface (15) of the internal skin remains reasonable smooth and crease-free. By constructing the internal skin (2) with some lower areas of heavier fabric, the gravitational collapsing of the deflating inner holder, is controlled to maintain the required surface (15) under uniform tension.

Description

2 AT 501 106 B1

The invention relates to a gas storage with a flexible inner membrane and a flexible outer membrane surrounding this at least partially, wherein the inner membrane closes a variable gas storage space, into or out of the inlet and outlet lines to be stored gas is introduced or derivable, and auxiliary gas in the intermediate space formed between the inner membrane 5 and the outer membrane, and wherein a distance measuring device for determining the distance between a measuring section of the outer membrane and a measuring section of the inner membrane is provided.

A gas storage of this kind is e.g. from AT 391 181 B and serves the Zwischenenspei-io insurance of a gas that can be introduced from at least one gas generator in the gas storage and can be removed from at least one gas consumer from this. In this way, an independent power supply e.g. be ensured in gas production by biological processes, which occur for example in the agricultural sector by itself. Depending on the level of the gas storage, the shape of the inner membrane changes from a folded state to a fully expanded, wrinkle-free state, which in most cases corresponds to a three-quarter hollow sphere shape. It is becoming more and more important to detect the actual memory level metrologically, which is usually done by a distance measuring device which determines the 20 distance between this and the outer membrane by means of ultrasonic sensor / receiver at the highest point of the inner membrane. When the inner membrane is full, very reliable information on the level is possible, but as soon as the gas storage is emptied slowly, this also affects the shape of the inner membrane, which throws more and more wrinkles in the course of volume reduction, until it folds up on the floor. These cause a scattering of the ultrasonic sensor 25 emitted sound signal and increase the uncertainty finally so strong that from a certain level no meaningful measurements are more feasible.

In the gas storage apparatus shown in FR 2 766 255 A, an inner membrane is provided with a disc-shaped weight which lowers the top of the inner membrane during a draining operation in a controlled manner so as to obtain a reproducible height measurement and at the same time a level indicator. The inner membrane is composed of a completely uniform material.

As support of the inner membrane, so that it undergoes a defined change in shape with a volume decrease, connecting steel cables are provided, which connect the equatorial region of the inner membrane at several points with the outer membrane. Each level corresponds to an exactly assignable shape of the inner membrane, so that from the measured height position of the weight, the shape of the inner membrane and thus the trapped gas volume can be determined. Since the inner membrane has a considerable weight of -40, the attachment points of the connecting steel cables must be made stable accordingly. However, it has proven to be disadvantageous in practice that both the weight at the top of the inner membrane and the cable support represent point or line attack points and brittle areas or kinks on the inner membrane out-call or promote their formation, which is a weakening of the Inner membrane and closing 45 lows cause the same.

The object of the invention is therefore to provide a gas storage of the type mentioned above, which allows a reliable measurement of the level even with significant volume reduction of the inner membrane, without causing the mentioned damage the Innenmemb-50 ran.

According to the invention, this is achieved by the inner membrane having an uneven basis weight distribution, so that the inner membrane measuring portion is maintained in a substantially smooth state during a volume changing operation of the gas storage space. 3 AT 501 106 B1

Essential to obtaining a unique ultrasonic measurement signal is obtaining the smooth shape of the inner membrane within the measuring section provided for the measuring operation during a reduction in volume in order to reflect the ultrasound impinging on the inner membrane surface in the direction of the ultrasonic receiver. This is achieved by the nonuniform basis weight distribution of the present invention which maintains the inner membrane measuring section in a substantially smooth condition during a draining operation of the gas storage while the remainder of the volume reduction succeeds to merge. An exact level measurement is essential for the operation of a gas storage, which is why the invention aims at a defined change of the inner membrane in the course of level changes, but this is not realized by punctiform but by planar loads that allows for the life of the inner membrane crucial improvements. In contrast to the prior art, the basis weight of the inner membrane is not uniformly distributed but unevenly so as to cause a clamping force in the inner membrane, which holds an inner membrane measuring section in a substantially smooth state.

Due to the uneven basis weight distribution, neither the attachment of a weight 20 nor the attachment of support cables is required, whereby the above-mentioned disadvantages of the prior art can be eliminated.

The maintenance of the smooth, wrinkle-free state in the area in question therefore requires no additional elements which jeopardize the undamaged state of the membrane because all edged or separate parts are avoided.

According to one embodiment of the invention, a surface weight distribution of the inner membrane which differs from the spherical symmetry with respect to the main axis of the filled inner membrane may be formed. 30

When fully filled, the gas internal pressure completely compensates for the asymmetric surface weight distribution and the inner membrane assumes the perfectly smooth condition, e.g. in the form of a three-quarter hollow sphere. As the level decreases, the asymmetric basis weight distribution effect begins to relocate the inner membrane 35 folding process to the zone where the basis weight is higher than the remaining inner membrane, leaving the inner membrane measuring section in a smooth condition and the ultrasonic signal in the direction of the ultrasound receiver. In this case, the point at which the sound is reflected, during the volume reduction process along the inner membrane surface migrate, so that the inner membrane measuring portion has a this migratory movement 40-taking into account.

The inner membrane can be composed in a conventional manner of several segments, which are connected to each other along Längenkreis sections of the inner membrane, preferably welded, are, so that the inner membrane in the inflated state has a hollow-spherical shape.

In this construction, an asymmetric surface weight distribution in the sense of the invention can be achieved in that a part of the inner membrane segments has a higher basis weight than the other inner membrane segments. The heavier segments are thus first deposited upon emptying of the inner membrane and due to the remaining gas volume thereby pull the remaining inner membrane surface upwards, whereby the zone of the inner membrane measuring section remains smooth or wrinkle-free and provides a suitable reflection surface for the Ulraschallsignal the Abstandsmeßvorrichtung. 55 It is e.g. already given a sufficient clamping effect by the heavier segments, if the inner membrane segments are arranged with the higher basis weight along a quarter-circle of the inner membrane. The arrangement of the heavier and lighter segments is subject to no limitation in the context of the invention and can be done in any manner. 5

Finally, the inner membrane - seen in the operating position - in its lower region have a higher basis weight than in the upper region, wherein such a distribution along the entire circumference of the inner membrane can be provided. The asymmetric weight distribution of the inner membrane segments in the height direction has the consequence that - seen in a plan view - the outer heavier areas are placed first when emptying and thus the inner areas are pushed upwards, whereby the measuring section remains smooth and uniquely assignable Ensures reflection signals, whereby the distance measurement during the entire volume reduction process of the inner membrane with the required measurement reliability is feasible. 15

The invention will be explained in detail with reference to the embodiments illustrated in the drawings. It shows

Figure 1 is a partially broken Schräißißdarstellung a known, partially emptied 20 gas storage.

Fig. 2 is a schematic sectional view of the full gas storage of FIG. 1;

Fig. 3 is a schematic sectional view of the semi-empty gas storage of FIG. 1;

Fig. 4 shows an embodiment of the gas storage according to the invention in a schematic sectional view. 25 Fig. 5 the halbgeleerten gas storage of Figure 4 in sectional view.

FIG. 6 shows the almost completely emptied gas storage according to FIG. 4; FIG.

7 shows the inner membrane of a further embodiment of the gas reservoir according to the invention in a schematic plan view;

8 shows a further embodiment of the gas reservoir according to the invention in a schematic sectional view;

9 shows the inner membrane of the embodiment according to FIG. 8 in a schematic plan view, and FIG. 10 shows a schematic sectional illustration of a further embodiment of the gas reservoir according to the invention. In the known gas reservoir shown in Fig. 1 is a flexible inner membrane 2, which closes inside a variable gas storage space 11 and in the expanded state, a three-quarter hollow sphere (Fig. 2), shown in a partially deflated state, whereby at the top Wavy folds arise. The inner membrane 2 is surrounded by a flexible outer membrane 1. As materials for the outer membrane 1 and the inner membrane 2 40, plastic or rubber foils, coated textile substrates, e.g. with PVC coated fabric od. Like. Are used. Any other type of flexible sheath may also be used for this purpose, provided it meets the tightness and strength requirements. Both the outer membrane 1 and the inner membrane 2 are open at the bottom and the lower edges are fixed by appropriate clamping devices 3 on a foundation 10 sealingly against the environment, the lower edge of the outer membrane 1 and the lower edge of the inner membrane 2 are concentric and spaced along their circumference. Opposite the bottom of the variable gas storage space is sealed by such a gas-tight bottom membrane, not shown, so that no leakage losses can occur and no combustible gas can escape from the variable storage space to the outside.

The inner membrane 1 and the outer membrane 2 are so matched to one another that between them 55 a gap 9 is formed, in which an auxiliary gas, preferably air, via a 5 AT 501 106 B1

Feed line 8 and an inlet port 4 under pressure, e.g. by virtue of a compressed air connection 7, can be introduced in order to exert a counterpressure with respect to the gas pressure prevailing in the interior of the inner membrane 2 and to protect it against overstretching. 5 via an inlet and outlet 6 and a centrally located bottom inlet (not shown), the gas to be stored in the variable gas storage chamber 11 is introduced or removed from this, so depending on the degree of filling the gas storage space 11 upwards final inner membrane 2 an irregular curved Surface forms, as indicated in Fig. 1 io, or inflates and then assumes the shape of a three-quarters hollow sphere (Fig. 2). In the context of the invention, membrane shapes deviating from the hollow spherical shape are also applicable.

Due to the overpressure in the intermediate space 9, the outer membrane 1 can be kept dimensionally stable within wide limits. A wind pressure acting on the outer membrane 1 or e.g. a snow load thus remain without significant influence on the gas pressure in the variable gas storage space eleventh

The structure of the outer membrane 1 and the inner membrane 2 and the Materi-20 alien used for it as well as the attachment of the membranes with the substrate may vary within the scope of the invention.

The auxiliary gas used is preferably air, although other gases, e.g. Inert gases, could be used. Auxiliary gas is therefore understood to mean any type of gas or gas mixtures 25 which are suitable for the purpose of the intermediate filling. The introduction of the auxiliary gas into the outer membrane 1 at only one point, as e.g. is shown in Fig. 1, but is not mandatory but can be done in other ways without thereby having an effect on the effect of the invention. For measuring and controlling the degree of filling of the inner membrane 2, a distance measuring device 5 is arranged at the uppermost point of the outer membrane 1, via which the respective distance between a measuring section 15 of the inner membrane 2 and a measuring section of the outer membrane 1 at this point converted into a measuring signal and to a not shown control device is passed. The distance measuring device 5 comprises an ultrasonic transmitting and receiving device and works according to the sonar principle.

As shown in Fig. 2, the highest point 13 in the expanded state of the inner membrane 2 is exactly opposite the distance measuring device 5. The main axis of symmetry 16 of the filled inner membrane 2 also extends through this point. The ultrasound reflected at point 13, which was emitted by the ultrasound transmitting device, returns to the ultrasound receiving device and generates a detectable reflection pulse, from which distance information is obtained.

In known gas storage results by material assembly and additional facilities 45 in the upper region of the inner membrane 2, a higher basis weight than in the lower region, so that in a volume reduction process, the upper portion of the inner membrane 2 begins to fold first and therefore the folding takes place exactly in the measuring section, where the ultrasonic signal is reflected. The consequence of this is seen in Fig. 3, there is no direct return reflection in the direction of the ultrasound receiving device, resulting in a falsified distance information or due to multiple reflections or scattering results in an ambiguous result, which leads to misinterpretation.

To remedy this, means for exerting a clamping force on the inner membrane measuring section 15 are provided, which the inner membrane measuring section 2 during a Vo lumenverringerungsvorganges the gas storage chamber 11 in a substantially smooth i i 6 AT 501 106 B1

Keep state. Smooth in this context means substantially wrinkle-free, so that an undisturbed reflection of the ultrasonic signal can take place. For the implementation of the clamping force there are several possibilities. Thus, a suitable 5-sized elastic band can act on the surface of the inner membrane 2, which tensions this so that the inner membrane measuring section 15 remains wrinkle-free during a draining process. The inner membrane measuring section 15 results as that imaginary region within whose limits the point of impact of the ultrasound emitted by the ultrasound transmission device can move in the case of level changes and is indicated in FIG. 4 by a line-shaped bordered area.

For reasons of reliability and ease of assembly, an influence of the basis weight of the inner membrane 2 is used as clamping force in practice, so that according to the invention, the inner membrane 2 has an uneven basis weight distribution to -15.

For this purpose, a deviating from the ball symmetry with respect to the main axis 16 of the filled inner membrane 2 different basis weight distribution of the inner membrane 2 is formed, as shown schematically in Fig. 4 in cross section. The part 30 of the inner membrane 2 has a higher weight per unit area than the part 33. Thus, the part 30 sinks to the bottom as the filling level drops and the inner membrane 2 contracts on the side of the part 30 in the region 34, while the part 33 is raised slightly , whereby the measuring section 15 remains smooth or wrinkle-free. As a result, the originally highest point 13 migrates somewhat to the side of the heavy part 30, but the impact point for the ultrasound signal remains in a strained zone of the inner membrane and can therefore emit a clearly detectable reflection signal.

Fig. 5 and Fig. 6 show the further course of the emptying process, during which the folded portion 34 of the inner membrane 2 is always more extensive while the inner membrane measuring section 15 sinks in a smooth or wrinkle-free state and constantly 30 provides a usable ultrasonic measurement signal.

For reasons of production technology, the inner membrane 2 is composed of a plurality of segments 21, 22 (FIG. 7) which are connected together, preferably welded, along segments of length circle, so that the inner membrane 2 has a three-quarter hollow spherical shape in the inflated state. has the advantages in terms of stability and the diameter of the foundation. In principle, however, the inner membrane 2 can also be a different one within the scope of the invention, e.g. take up a hollow cylindrical shape.

The connection of the segments 21, 22 can also be performed by gluing, sewing or the like. 40 downwardly form the interconnected segments 21, 22 together an edge which is clamped by means of the clamping devices on the foundation 9. Towards the top, the tapered segments 4 converge at a point or in an opening into which the distance measuring device 5 is inserted. In the embodiment of the invention shown in FIG. 7, a portion 22 of the inner membrane segments has a higher basis weight than the remaining inner membrane segments 21, with the higher face weight inner membrane segments 22 being disposed along a quarter circumferential circle of the inner membrane 2 , Thus, in the same manner as in the embodiment of FIGS. 4 to 6 a deviating from the ball symmetry Flächenge 50 weight distribution is achieved, which causes the side of the inner membrane 2 with the heavier inner membrane segments 22 during a discharge process first deposits and thereby the measuring section 15th is kept taut or wrinkle-free. The higher basis weight can be achieved either by a specific heavier material or e.g. can be achieved by double occupancy of the segments 22. 55

Claims (6)

7 AT 501 106 B1 Any other fabrications of the inner membrane 2 can be chosen which provide the same end result. For example, the basis weight distribution can be influenced by suitable choice of the cut and / or the overlapping zones for the segments 21, 22 so that an asymmetric weight distribution without different basis weights of Seg-5 elements 21,22 arises. Finally, FIG. 8 and FIG. 9 show a further embodiment of the invention in which the inner membrane 2 has a higher weight per unit area in its lower area than in the upper area, which is caused by inner membrane segments 20 which are in the lower area 40 have a higher basis weight than in the upper area, whereby an asymmetric weight distribution along the main axis 16 is formed. As a result, the lower part of the inner membrane 2 is heavier than the upper part, whereby the outer lower part is first collapsed when emptying the inner membrane 2, while the inner upper part of the inner membrane is pushed up and the Meis ßabschnitt 15 remains smooth or wrinkle-free and provides a uniquely identifiable ultrasonic reflectance signal during the evacuation process. The lower heavier part may e.g. up to a height which is 2/3 of the total height of the inner membrane 2, be formed. As shown in the embodiment of Fig. 10 which is similar to that shown in Figs. 8, 9, by increasing the basis weight in the lower part along the entire circumference of the inner membrane 2, centered lowering of the inner membrane 2 can be effected, so that the Impact point of the ultrasonic signal remains unchanged during a discharge process. In addition to the heavier lower zone 40, any further specially prepared basis weights 41 may be provided, with the aid of which an additional influencing possibility of the clamping effect on the measuring section 15 exists. 1. Gas storage with a flexible inner membrane (2) and this at least partially surrounding the flexible outer membrane (1), wherein the inner membrane (2) closes a variable gas storage space (11), into or out of the over supply and discharge lines gas to be stored can be introduced, and auxiliary gas can be introduced into the intermediate space (9) formed between the inner membrane (2) and the outer membrane (1), and a distance measuring device (5) for determining the distance between a measuring section of the outer membrane (1) and a measuring section (15) of the inner membrane (2), characterized in that the inner membrane (2) has an uneven basis weight distribution, so that the inner membrane measuring section (15) during a volume change operation of the gas storage space (11) in a in It is kept essentially smooth. 2. Gas storage according to claim 1, characterized in that one of the ball symmetry with respect to the main axis (16) of the filled inner membrane (2) deviating basis weight distribution of the inner membrane (2) is formed. 45 3. Gas storage according to claim 1 or 2, characterized in that the inner membrane (2) in a conventional manner from a plurality of segments (20, 21, 22) is composed along along the longitudinal circle sections of the inner membrane (2) connected to each other, preferably welded, are, so that the inner membrane (1) in the inflated state so has a hollow spherical shape. 4. Gas storage according to claim 2 and 3, characterized in that a part (22) of the in-nenmembran segments has a higher basis weight than the other inner membrane segments (21). 55 8 AT 501 106 B1 5. Gas storage according to claim 4, characterized in that the inner membrane segments (22) are arranged with the higher basis weight along a quarter-circumferential circle of the inner membrane (2). 6. Gas storage according to claim 1, characterized in that the inner membrane (2) - seen in the operating position - in its lower region (40) has a higher basis weight than in the upper region. For this purpose 4 sheets of drawings 15 20 25 30 35 40 45 50 55