A compressed gas energy storage system may include an accumulator for containing a layer of compressed gas atop a layer of liquid. A gas conduit may have an upper end in communication with a gas compressor/expander subsystem and a lower end in communication with accumulator interior for conveying compressed gas into the compressed gas layer of the accumulator when in use. A shaft may have an interior for containing a quantity of a liquid and may be fluidly connectable to a liquid source/sink via a liquid supply conduit. A partition may cover may separate the accumulator interior from the shaft interior. An internal accumulator force may act on the inner surface of the partition and the liquid within the shaft may exert an external counter force on the outer surface of the partition, whereby a net force acting on the partition is less than the accumulator force.

The disclosed technology generally relates to liquefied natural gas (LNG) and liquefied-compressed natural gas (L-CNG) filling stations, and more particularly to an LNG/L-CNG hydraulic pressurization device and a gas filling station. In one aspect, a LNG/L-CNG hydraulic pressurization device includes an oil tank; a L-CNG pressurization cylinder; a LNG pressurization cylinder; first and second directional valves communicating with the L-CNG pressurization cylinder and the LNG pressurization cylinder respectively; a first hydraulic pump and a second hydraulic pump, whose oil inlets communicate with the oil tank and whose pressure oil outlets communicate with an oil inlet of the first directional valve and an oil inlet of the second directional valve respectively; and a ball valve having a first port communicating with a first communication port between the pressure oil outlet of the first hydraulic pump and the oil inlet of the first directional valve, and a second port communicating with a second communication port between the pressure oil outlet of the second hydraulic pump and the oil inlet of the second directional valve.

A method and system for determining a momentary boil-off rate for a storage tank for a natural gas in liquid phase and gas phase. A mass flow from the gas phase of the natural gas at an discharge pipeline of the storage tank and a mass flow into the liquid phase of the natural gas at an loading/discharge pipeline of the storage tank is determined. A volume, a temperature and a pressure of the gas phase of the natural gas is measured. A dynamical model is applied to the determined values to determine the momentary boil-off rate.

To manage propellant in a spacecraft, the method of this disclosure includes storing propellant in a tank as a mixture of liquid and gas; transferring the propellant out of the tank; converting the mixture of liquid and gas propellant into a single phase, where the single phase is either liquid or gaseous; and supplying the single phase of the propellant to a thruster.

An arrangement comprising at least one liquefaction plant for liquefying a gaseous medium to produce a liquefied medium; and at least one storage tank for storing the liquefied medium. A first transfer line is provided which is connected between the liquefaction plant and the storage tank, for transferring liquefied medium from the liquefaction plant into the storage tank. A second transfer line is connected between the liquefaction plant and the storage tank, for transferring gaseous medium from the storage tank into the liquefaction plant. The second transfer line, which used for transferring medium from the storage tank into the liquefaction plant, is arranged so that it is routed at least partially through the area of the storage tank in which the liquefied medium is stored in use.

A compressed gas energy storage system may include an accumulator for containing a layer of compressed gas atop a layer of liquid. A gas conduit may have an upper end in communication with a gas compressor/expander subsystem and a lower end in communication with accumulator interior for conveying compressed gas into the compressed gas layer of the accumulator when in use. A shaft may have an interior for containing a quantity of a liquid and may be fluidly connectable to a liquid source/sink via a liquid supply conduit. A partition may cover may separate the accumulator interior from the shaft interior. An internal accumulator force may act on the inner surface of the partition and the liquid within the shaft may exert an external counter force on the outer surface of the partition, whereby a net force acting on the partition is less than the accumulator force.

A method for loading liquefied nitrogen (LIN) into a cryogenic storage tank initially containing liquid natural gas (LNG) and a vapor space above the LNG. First and second nitrogen gas streams are provided. The first nitrogen stream has a lower temperature than the second nitrogen gas stream. While the LNG is offloaded from the storage tank, the first nitrogen gas stream is injected into the vapor space. The storage tank is then purged by injecting the second nitrogen gas stream into the storage tank to thereby reduce a natural gas content of the vapor space to less than 5 mol %. After purging the storage tank, the storage tank is loaded with LIN.

An emergency release system includes a first shut-off valve unit which is land-based; and a second shut-off valve unit which is provided for a marine vessel and separably connected to the first shut-off valve unit, and the first shut-off valve unit is provided with a reservoir container which receives liquid air generated in the first shut-off valve unit and dropped, in a state in which the second shut-off valve unit is separated from the first shut-off valve unit, and the system includes a container support mechanism which is capable of retaining the reservoir container at a retracted position in a state in which the first and second shut-off valve units are connected to each other, the container support mechanism being configured to automatically shift the reservoir container to a reserving position, in a state in which the first and second shut-off valve units are separated from each other.

A method for loading liquefied nitrogen (LIN) into a cryogenic storage tank initially containing liquid natural gas (LNG) and a vapor space above the LNG. First and second nitrogen gas streams are provided. The first nitrogen stream has a lower temperature than the second nitrogen gas stream. While the LNG is offloaded from the storage tank, the first nitrogen gas stream is injected into the vapor space. The storage tank is then purged by injecting the second nitrogen gas stream into the storage tank to thereby reduce a natural gas content of the vapor space to less than 5 mol %. After purging the storage tank, the storage tank is loaded with LIN.

A connection structure for pressure vessels is configured such that respective mouth pieces are connected to at least one ends of the pressure vessels, and when adjacent mouth pieces are connected to each other in an intersection direction intersecting with the axial direction, the pressure vessels placed in parallel can be connected to each other. The mouth piece includes a connecting portion along the intersection direction intersecting with the axial direction. The connecting portion includes an external screw thread portion formed on a first side thereof, and a nut rotatably locked to a second side thereof and having an internal screw thread portion threadedly engageable with the external screw thread portion.