An apparatus for storing large quantities of compressed gas at high pressure underground.

Various embodiments are generally directed to a casing connected to a top cap structure that consists of an adapter flange extending to an adapter barrel that is configured to fit wholly within the casing. The adapter barrel can be separated from the casing by an annulus that is filled to a predetermined annulus pressure while an internal chamber defined by the adapter barrel contains a gas having a small molecular size at a storage pressure that is greater than the predetermined annulus pressure.

A method of storing hydrogen involves forming an excavation in the earth and constructing a storage tank therein comprised of integrated primary and secondary containment structures. The primary containment structure composed of a plurality of joinable cylindrical segments, or pre-fabricated sections joined to form a cylinder within the excavation. The secondary containment structure formed by pumping a curable, flowable composition into the cylinder, allowing it to flow out the bottom and up the second annulus to the earth's surface, and then hardening; thereby encasing the primary containment structure. The bottom of the cylinder is sealed with the bottom assembly. The top assembly is attached to the cylinder and tubing and packer are run into the cylinder creating a first annulus between the cylinder and tubing. Top assembly is sealed, fluids circulated out, and the tank dried. Thereafter, the tank is capable of safely storing hydrogen gas.

An integral side slope structure of a soil-covered tank, includes a tank body, connecting pieces, and reinforcing frameworks. The exterior of the tank body is completely covered with soil, and a side slope is formed after the tank body is covered with the soil; each connecting piece is composed of ribs which are in cross connection to each other; the connecting pieces are connected to the outer wall of the tank body and are laid inside the side slope in the horizontal direction; a single-layer connecting net is formed after a single layer of the connecting pieces is connected to the tank body; a plurality of layers of the connecting pieces are arranged at intervals in the vertical direction; the tank body and the side slope are connected by the multi-layer connecting net to form an integral structure; the reinforcing frameworks are arranged along the side slope.

Storage tank comprising—an outer container (2) having a first closable opening (23), and—an inner bladder container (3) disposed within said outer container (2) and having a second closable opening (30), said outer container (2) and inner container (3) being sealed with respect to each other, said inner container (3) being adapted to be filled and or emptied with a liquid through said second closable opening (30), a space (8) between the outer container (2) and the inner container (3) being adapted to be filled with liquid through the first closable opening (23). The outer container (2) is rigid with at least one flexible portion incorporated in the rigid outer container and configured to flex so as to expand and contract to compensate volume variations caused by pressure and or temperature variations to which the storage tank (1) is subjected.

A subterranean tank can consist of at least a casing string that has a containment section disposed between first and second end regions. The containment section may have a first width while each of the first and second end regions have a second width. The first width can be greater than the second width of the respective first or second end regions. The entire casing string may be sealed to maintain a gas at 5,000 psi or more until a gas delivery assembly attached to the first end region releases gas stored in the casing string.

Embodiments provide systems and methods for taking power from an electric power grid and converting it into higher-pressure natural gas for temporary storage. After temporary storage, the higher-pressure natural gas may be expanded through an expansion engine to drive a generator that converts energy from the expanding natural gas into electrical power, which may then be returned to the electric power grid. In this way, the disclosed systems and methods may provide ways to temporarily store, and then return stored power from the electric power grid. Preferably, the components of the system are co-located at the same natural gas storage facility. This allows natural gas storage, electrical energy storage, and electrical energy generation to take place at the same facility.

An underwater energy storage system includes a tank for storing a compressed gas that is adapted to be stored underwater. The tank includes at least one water opening through which water from surrounding environment can flow into and out of the tank, and at least one gas opening through which the compressed gas is received. The underwater energy storage system further includes at least one duct communicating between the at least one opening for gas flow and a source of compressed gas and a compartment constructed over a roof of the tank, wherein said compartment is adapted for receiving weights at a sinking site of the tank.

A method of storing hydrogen involves forming an excavation in the earth and constructing a storage tank therein comprised of integrated primary and secondary containment structures. The primary containment structure composed of a plurality of joinable cylindrical segments, or pre-fabricated sections joined to form a cylinder within the excavation. The secondary containment structure formed by pumping a curable, flowable composition into the cylinder, allowing it to flow out the bottom and up the second annulus to the earth's surface, and then hardening; thereby encasing the primary containment structure. The bottom of the cylinder is sealed with the bottom assembly. The top assembly is attached to the cylinder and tubing and packer are run into the cylinder creating a first annulus between the cylinder and tubing. Top assembly is sealed, fluids circulated out, and the tank dried. Thereafter, the tank is capable of safely storing hydrogen gas.

The present disclosure provides a system for managing a pressure in an underground cryogenic liquid storage tank and a method for the same. The system includes: a storage tank, which is used for containing cryogenic liquid and is buried underground; an internal pump, which is located below a liquid level of the cryogenic liquid; an evaporator, provided with an upstream end which is in communication with a discharge end of the internal pump and a downstream end which is in communication with a head space via a vapor delivery line; a control valve, which is disposed on the vapor delivery line downstream of the evaporator; and a flow limiter, which is disposed on the vapor delivery line upstream of or downstream of the control valve. The present disclosure can realize efficient pressurization to the storage tank so as to prevent collapsing of the storage tank.