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 CO.sub.2 energy storage system includes a storage tank that stores a CO.sub.2 slurry, including dry ice and liquid CO.sub.2, at CO.sub.2 triple point temperature and pressure conditions. The storage system also includes a first pump coupled in flow communication with the storage tank. The first pump is configured to receive the CO.sub.2 slurry from the storage tank and to increase a pressure of the CO.sub.2 slurry to a pressure above the CO.sub.2 triple point pressure. The energy storage system further includes a contactor coupled in flow communication with the first pump. The contactor is configured to receive the high pressure CO.sub.2 slurry from the pump and to receive a first flow of gaseous CO.sub.2 at a pressure above the CO.sub.2 triple point pressure. The gaseous CO.sub.2 is contacted and then condensed by the melting dry ice in the slurry to generate liquid CO.sub.2.

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.

A system for dispensing a cryogenic fluid includes a bulk storage tank configured to contain a supply of the cryogenic fluid. A heat exchanger coil is positioned in the headspace of at least one intermediate fluid tank, which contains an intermediate fluid, and is configured to receive and warm a cryogenic fluid from the bulk storage tank via heat exchange with intermediate fluid vapor in the headspace. A buffer tank receives fluid from the heat exchanger coil. A chiller coil is positioned within the intermediate fluid tank and is submerged within intermediate fluid liquid contained within the at least one intermediate fluid tank. The chiller coil receives fluid from the buffer tank and cools it via heat exchange with intermediate fluid liquid within which the chiller coil is submerged for dispensing.

A low-pressure fuel management and delivery system 10 for a liquefied natural gas (LNG) rail tender is disclosed. The system provides a rail tender that is inherently safer in operation to known LNG rail tenders through its use of a double-hulled tank design 12, which lacks any penetration of the bottom surface of the first inner tank 16 by any portion of the fuel supply portion of the system 10; the lower pressure storage of the fuel 22 in the first inner tank 16; the inclusion of a gas return line 58 for directing fuel 22 trapped in the LNG flow lines 38, the heat exchanger 46, or the multistage gas compressor 52 to the vapor space 32 of the first inner tank 16 at safe pressures and temperatures; the lack of cryogenic pumps within the first inner tank 16 to drive the fuel supply portion of the system 10; and the location of all the flow controlling valves 40, 42, 50, and 56 in positions that afford them improved physical protection from potential damage due to vehicular collisions or other railroad accidents. During operation, the fuel management and delivery system 10 provides required fuel flow rates and temperatures to an associated locomotive through the use of hydrostatic pressure differences between the LNG fuel 22 and the vapor space 32 within first inner tank 16, as well as a heat exchanger 46 and a multi-stage compressor 52, which are preferably located external of the double-hulled fuel storage tank 12, but on the same rolling stock chassis 14.

A compressed-air storage and power generation method according to the present invention is provided with: a first air-compression step; a first air-storage step; a first air-supply step; a first power-generation step; a first heat-exchange step; a heat-medium storage step; a second heat-exchange step; and an air-discharge step. In the air-discharge step, when the amount of compressed air stored in a pressure-accumulation tank (12) exceeds a prescribed amount in the first air-storage step, the air compressed by a first compressor (10) is discharged outside without being stored in the pressure-accumulation tank (12). Therefore, it is possible to provide a compressed-air storage and power generation method by which fluctuating electrical power can be smoothed efficiently even after compressed air is stored up to the storage capacity of the storage space.

A power-saving type liquefied-gas-fuel ship includes: a liquefied gas storage tank storing liquefied gas; an engine using the liquefied gas stored in the liquefied gas storage tank or boil-off gas generated by spontaneous vaporization of the liquefied gas as fuel; a fuel feeder supplying the liquefied gas as fuel for the engine; a compressor compressing the boil-off gas to a pressure required for the engine; a heat exchanger cooling the remaining boil-off gas not supplied to the engine among the boil-off gas compressed by the compressor; a refrigerant circulation line in which the refrigerant supplied to the heat exchanger circulates; a refrigerant compressor compressing the refrigerant discharged from the heat exchanger after heat exchange in the heat exchanger; and a cold heat recovery device recovering cold heat of the liquefied gas supplied as fuel for the engine to cool the refrigerant compressed by the refrigerant compressor.

A fuel storage and distribution system for a gas-fueled sea-going vessel includes a tank room that constitutes a gastight space enclosing tank connections and valves associated with them. A part of a refrigeration or air conditioning circuit reaches into the tank room. A first local heat transfer circuit is configured to receive heat from the part of the refrigeration or air conditioning circuit in the tank room and arranged to transfer such received heat to liquefied gas fuel handled in the fuel storage and distribution system.

A process for regasifying a fluid and generating electrical energy includes subjecting an operating fluid to 1) pumping, the pumping step including a low pressure pumping step 1a) and a high pressure pumping step 1b), 2) heating in a recuperator to obtain a heated flow, the heating step including a low temperature heat recovery step 2a) and a high temperature heat recovery step 2b), 3) further heating through a high temperature source to obtain a further heated flow, 4) expanding in a turbine, with generation of electrical energy to obtain an expanded flow, 5) cooling by heat exchange to obtain a cooled flow, and 6) condensing the flow of the operating fluid and regasifying the fluid. After low pressure pumping, a portion of the flow of the operating fluid is subjected to recompression to obtain a flow combined with the flow of the operating fluid obtained from step 2a).

An exemplary flight storage system for storing a cryogenic fluid and then discharging it as a vapor. The flight storage system includes an inner tank, a heat exchanger that is in fluid communication with the inner tank, an outer jacket assembly, and a cooling assembly. The storage system is configured to store high specific energy fuel such as liquid hydrogen, or other cryogenic fluids, for energy for propulsion use. The cooling assembly is configured to use the flow of the liquid hydrogen for cooling critical sensor packages The outer jacket assembly includes a first jacket cylinder and a second jacket cylinder. The outer jacket assembly further includes a first connector body 30 and a second connector body.