SYSTEM FOR STORING COMPRESSED FLUID

Abstract

A storage system for storing compressed fluid is described. The system includes an excavation made in the ground, a balloon arrangement mounted within the excavation. The balloon arrangement includes a rebar cage and an inflatable balloon arranged within the rebar cage. The inflatable balloon has a middle portion and two end portions. One end portion includes a balloon inlet port, whereas the other end portion includes a balloon outlet port. The system also includes a filling material fully surrounding the inflatable balloon and configured for providing further reinforcement in conjunction with the rebar cage to the inflatable balloon, and for anchoring the inflatable balloon to the excavation. The system also includes a gas pipe assembly including an inlet gas pipe coupled to the balloon inlet port for filling the inflatable balloon with compressed fluid, and an outlet gas pipe coupled to the balloon output port for releasing the compressed fluid.

Claims

1. A storage system for storing compressed fluid, comprising: an excavation made in the ground having a shape of an inverted rectangular trapezoidal prism; a balloon arrangement mounted within the excavation, the balloon arrangement comprising: a rebar cage arranged within the excavation; and an inflatable balloon arranged within the rebar cage and configured for storing the compressed fluid, said inflatable balloon having a middle portion and two end portions, one end portion of said two end portions includes a balloon inlet port for providing access to an inner volume of the inflatable balloon, whereas the other end portion includes a balloon outlet port for releasing the compressed fluid from the inner volume; a filling material placed within a volume between the inflatable balloon, bottom and walls of the excavation, and extending from the bottom up to a top of the excavation, thereby fully surrounding the inflatable balloon; said filling material being in a rigid and immobile state, and configured for providing further reinforcement in conjunction with the rebar cage to the inflatable balloon, and for anchoring the inflatable balloon to the excavation; and a gas pipe assembly comprising: an inlet gas pipe coupled to the balloon inlet port and configured for filling the inflatable balloon with the compressed fluid; and an outlet gas pipe coupled to the balloon output port, and configured for releasing the compressed fluid.

2. The storage system of claim 1, wherein the rebar cage includes a plurality of rebar rods extending along the inflatable balloon between the two end portions, and rebar hoops configured for binding the rebar rods to form a framework of the rebar cage.

3. The storage system of claim 2, wherein the rebar hoops are bound to the rebar rods by welding thereby forming a weldment structure.

4. The storage system of claim 2, wherein the rebar hoops are bound to the rebar rods by tying them by using steel wires, thereby forming a rigid structure.

5. The storage system of claim 2, wherein the middle portion of the inflatable balloon has a cylindrical shape which is tapered with contraction at the two end portions and towards the balloon inlet and outlet ports.

6. The storage system of claim 5, wherein the rebar rods follow an outer contour of the inflatable balloon to conform to its shape.

7. The storage system of claim 6, wherein diameters of the rebar hoops gradually decrease at the two end portions of the inflatable balloon with contraction towards the balloon inlet and outlet ports.

8. The storage system of claim 1, wherein the gas pipe assembly further includes a drainage pipe extending into the volume of the inflatable balloon.

9. The storage system of claim 1, wherein a bottom width of the excavation is in the range of 0.5 meters to 5 meters, a top width of the excavation is in the range of 1.5 meters to 10 meters, and a depth of the excavation is in the range of 1 meter to 7 meters.

10. The storage system of claim 1, wherein a distance between a ground surface and the rebar cage in the excavation is in the range of 0.2 meters to 2 meters.

11. A method for producing of a storage system for storing compressed fluid, comprising: providing an excavation in the ground having a shape of an inverted rectangular trapezoidal prism; providing a balloon arrangement and mounting the balloon arrangement within the excavation, the balloon arrangement comprising: a rebar cage arranged within the excavation; and an inflatable balloon arranged within the rebar cage and configured for storing the compressed fluid, said inflatable balloon having a middle portion and two end portions, one end portion of said two end portions includes a balloon inlet port for providing access to an inner volume of the inflatable balloon, whereas the other end portion includes a balloon outlet port for releasing the compressed fluid from the inner volume; providing a filling material and placing the filling material within a volume between the inflatable balloon, bottom and walls of the excavation to extend from the bottom up to a top of the excavation, thereby to fully surround the inflatable balloon; said filling material being in a rigid and immobile state, and configured for providing further reinforcement in conjunction with the rebar cage to the inflatable balloon, and for anchoring the inflatable balloon to the excavation; providing a gas pipe assembly comprising an inlet gas pipe configured for filling the inflatable balloon with the compressed fluid and an outlet gas pipe configured for releasing the compressed fluid; and coupling the inlet gas pipe to the balloon inlet port and the outlet gas pipe to the balloon output port.

12. The method of claim 11, further comprising providing a drainage pipe and provide access of the drainage pipe into the volume of the inflatable balloon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0031] FIG. 1A illustrates a schematic longitudinal side cross-sectional view of a compressed fluid storage system, according to an embodiment of the present invention;

[0032] FIG. 1B illustrates a schematic transverse side cross-sectional view of the compressed fluid storage system of FIG. 1A, according to an embodiment of the present invention; and

[0033] FIG. 2 illustrates an elevated perspective view of a balloon arrangement of the compressed fluid storage system of FIG. 1A, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0034] The principles and operation of the underground compressed gas storage system according to the present invention may be better understood with reference to the drawings and the accompanying description. It should be understood that these drawings are given for illustrative purposes only and are not meant to be limiting. It should be noted that the figures illustrating various examples of the system of the present invention are not to scale, and are not in proportion, for purposes of clarity. The same reference numerals and alphabetic characters are utilized for identifying those components which are common in the hydro-pneumatic energy storage system and its components shown in the drawings throughout the present description of the invention. Examples of constructions are provided for selected elements. Those versed in the art should appreciate that many of the examples provided have suitable alternatives which may be utilized.

[0035] Referring to FIGS. 1A and 1B a schematic longitudinal and transverse side cross-sectional views of a compressed fluid storage system 10 are illustrated, correspondingly, according to an embodiment of the present invention. The compressed fluid storage system 10 of the present invention can be successfully employed for storing compressed gas, compressed liquid and any other fluid as well, including a mixture of gases and/or liquids.

[0036] The compressed fluid storage system 10 includes an excavation 11 made in the ground. The excavation 11 has a shape of an inverted rectangular trapezoidal prism, and has a predetermined depth, and predetermined lengths and widths at a top 111 and at a bottom 112, correspondingly. It should be understood that differences between the lengths and widths of the excavation 11 at the top 111 and at the bottom 112 are determined by the soil friction angle and depend on the friction shear resistance of the soil.

[0037] A depth of the excavation 11 can, for example, be in the range of about 1 meter to 7 meters. A length of the excavation 11 can, for example, be in the range of about 5 meters to 50 meters A bottom width of the excavation can, for example, be in the range of 0.5 meters to 5 meters, a top width of the excavation can, for example, be in the range of 1.5 meters to 10 meters.

[0038] According to an embodiment of the present invention, the compressed fluid storage system 10 includes a balloon arrangement 12 mounted within the excavation 11.

[0039] FIG. 2 illustrates an elevated perspective view of a balloon arrangement 12 of the compressed fluid storage system of FIG. 1A, according to an embodiment of the present invention. Referring to FIGS. 1A and 2 together, the balloon arrangement 12 includes a rebar cage 121 arranged within the excavation 11 and an inflatable balloon 122 arranged within the rebar cage 121. A distance between a ground surface and the rebar cage 121 in 10 the excavation 11 can, for example, be in the range of 0.2 meters to 2 meters

[0040] The inflatable balloon 122 is configured for storing compressed gas or any other fluid. The inflatable balloon 122 has a middle portion 123 and two end portions 124 and 125. One end portion 124 includes a balloon inlet port 126 configured for providing access to an inner volume 128 of the inflatable balloon 122. The other end portion 125 15 includes a balloon outlet port 127 for releasing the compressed gas from the inner volume 128.

[0041] The inflatable balloon 122 can, for example, be made of an elastic, durable, strong plastic or rubber material having a braid or other reinforcement that can sustain relatively large deformation. The deformation can, for example, be in the range of about 10% to 500% volume change. It is also required that the balloon's material can resist underground chemical reactions (e.g. soil deposits) and moisture (e.g. rain) infiltration.

[0042] According to an embodiment of the present invention, the rebar cage 121 includes a plurality of rebar rods 1211 extending along the inflatable balloon 122 between the two end portions 124 and 125, and rebar hoops 1212 configured for binding the rebar rods 1211 to form a framework of the rebar cage 121. The rebar hoops 1212 and the rebar rods 1211 can, for example, be made from steel and have a bar cross-sectional diameter in the range of about 1 cm to 3 cm. The rebar hoops 1212 can, for example, be bound to the rebar rods 1211 by welding, thereby to form a grid weldment structure. Alternatively, the rebar hoops 1212 are bound to the rebar rods 1211 by tying them by using steel wires, thereby forming a rigid structure.

[0043] A size of a grid cell of the weldment structure can, for example, be in the range of about 5 cm to 30 cm. It should be noted that fiber-reinforced plastic rebar can also be used in high-corrosion environments.

[0044] In the present invention, the term about means within a statistically meaningful range of a value. The allowable variation encompassed by the term about depends on the particular system under consideration, and can be readily appreciated by one of ordinary skill in the art. This approximation for the purpose of the present invention can, for example, be interpreted so as to include an error of 20% at least, as long as there is no considerable change in the performance of the gas storage system 10 due to the deviation.

[0045] According to an embodiment of the present invention, the compressed gas storage system 10 also includes a filling material 13 placed within a volume 14 between the inflatable balloon 122, the bottom 112 and walls 113 of the excavation 11. The filling material 13 extends from the bottom 112 up to the top 111 of the excavation 11, and fully surrounds the inflatable balloon 122. The filling material 13 is in a rigid and immobile state, and is configured for providing reinforcement in conjunction with the rebar cage to the inflatable balloon 122 and for anchoring the inflatable balloon 122 to the excavation 11. Examples of a filling material suitable for the purpose of the invention include, but are not limited to, a cement based filling material (e.g., grout), concrete, flowable fill, dirt, or any type of cement mixture.

[0046] According to an embodiment of the present invention, the compressed gas storage system 10 also includes a gas pipe assembly 14. The gas pipe assembly 14 includes an inlet gas pipe 141 coupled to the balloon inlet port 126 and configured for filling the inflatable balloon with the compressed fluid. The gas pipe assembly 14 also includes an outlet gas pipe 142 coupled to the balloon output port 127, and configured for releasing the compressed fluid.

[0047] According to an embodiment of the present invention, the gas pipe assembly 14 further includes a drainage pipe 143 extending into the bottom part of the volume of the inflatable balloon 122. The purpose of the drainage pipe 143 is to pump out the fluids (e.g., water, oil, etc.) that can be condensed from the gas as a result of condensation during operation. As shown in FIG. 1A, the drainage pipe 143 can be arranged within the lumen of the inlet gas pipe 141, however other configurations are also contemplated. For example, the drainage pipe 143 can be arranged within the outlet gas pipe 142, or may be a pipe separated from the inlet and outlet gas pipes.

[0048] According to an embodiment of the present invention, the middle portion 123 of the inflatable balloon 122 has a cylindrical shape which is tapered with contraction at the two end portions 124 and 125 towards the balloon inlet and outlet ports 126 and 127 respectively. In this case, the rebar rods 1211 may follow an outer contour of the inflatable balloon 122 to conform to its shape. In turn, diameters of the rebar hoops of the rebar cage 121 may gradually decrease at the two end portions 124 and 125 with contraction towards the balloon inlet and outlet ports 126 and 127 thereby providing additional reinforcement to the inflatable balloon 122 at its ends.

[0049] As such, those skilled in the art to which the present invention pertains, can appreciate that while the present invention has been described in terms of preferred embodiments, the concept upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, systems and processes for carrying out the several purposes of the present invention.

[0050] Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0051] Finally, it should be noted that the words comprising, having and including as used throughout the appended claims are to be interpreted to mean including but not limited to.

[0052] It is important, therefore, that the scope of the invention is not construed as being limited by the illustrative embodiments set forth herein. Other variations are possible within the scope of the present invention as defined in the appended claims. Other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to different combinations or directed to the same combinations, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the present description.