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.

Provided is a flight vehicle which makes it possible to more reliably retain the sealability of a sealing member of a valve provided on a hydrogen tank even in continuous supply of hydrogen or a low-temperature environment. The flight vehicle having a fuel cell, and a hydrogen tank in which hydrogen for generation of electricity by the fuel cell is stored includes: a valve including a sealing member, the valve being disposed on the hydrogen tank, via the valve hydrogen being taken out from a body of the tank; and a warming unit in which fluid conducts part of waste heat from any portion of the flight vehicle to the sealing member.

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 gas storage/supply system includes a gas storage material capable of reversibly absorbing and desorbing a gas, a gas storage tank having the gas storage material sealed therein, a chemical heat storage material capable of making a forward reaction and a reverse reaction with an operation medium, a chemical heat storage tank having the chemical heat storage material sealed therein, a heat exchange mechanism for transferring heat between the gas storage tank and the chemical heat storage tank, and a control mechanism for controlling the gas storage/supply system such that gas absorption heat released upon absorption of the gas to the gas storage material is stored in the chemical heat storage tank and gas desorption heat which is necessary for desorption of the gas from the gas storage material is supplied from the chemical heat storage tank.

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 method and system delivers a cryogenically stored fuel in a gaseous state into the air intake system of a gaseous fuelled internal combustion engine. The method involves measuring the pressure in the vapor space of the cryogenic storage vessel, comparing the measured pressure to a required fuel supply pressure and supplying fuel in gaseous state directly from the vapor space of the cryogenic storage vessel to the fuel delivery line that supplies fuel to the engine, when the pressure measured in the vapor space of the cryogenic storage vessel is equal to or higher than the required fuel supply pressure. The method further involves activating a cryogenic pump to deliver fuel to the internal combustion engine from the liquid space of the cryogenic storage vessel when the measured pressure in the vapor space is lower than the required fuel supply pressure.

A heat exchanger device provides refrigeration in refrigerated vehicles operated by liquefied natural gas (LNG) which must first be regasified. The great temperature difference between heat-discharging cooling chamber air and heat-absorbing LNG evaporating at up to −161° C. conducts the heat flow via an introduced intermediate medium circulating in a closed circuit to avert the risk of combustible natural gas leaking. The intermediate medium is non-combustible, environmentally-benign liquid heat exchange media having low viscosity. The liquid heat exchange media operating temperature is kept above −85° C. using an additional thermal resistance in the heat exchanger which evaporates the LNG, so that the heat flow flows with sufficient temperature drop. A thin protective dry gas layer formed using sheathing tubes enclosing a tubular heat exchanger's tubes coaxially serves as this thermal resistance. Possibly escaping natural gas is determined by monitoring pressure in the layer, and the LNG supply interrupted.

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).

CNG power system (1) comprising a storage tank (6) connected fluidically to a fuel conversion system (2) via an energy transfer system (4), the fuel conversion system (2) comprising a power unit using CNG as fuel and generating gas emissions comprising CO2, the fuel conversion system comprising a CO2 capture unit (16) configured for separating out CO2 from the gas emissions. The energy transfer system comprises a CNG expansion turbine (22) mounted in a fuel circuit (8) between the storage tank and fuel conversion system powered by expansion of the CNG flowing from the storage tank to the fuel conversion system, and a CO2 compressor (24) connected between the fuel conversion system and the storage tank along a CO2 circuit (10) for compressing the CO2, power for driving the CO2 compressor (24) being supplied in part by power generated by the CNG expansion turbine (22).

Systems and methods for using a multi-stage compressor to increase the temperature and pressure of BOG sent to a heat exchanger for cooling a separate liquid refrigerant. The subsequent stage(s) of the multi-stage compressor further compress the BOG, which is then recycled to a liquefaction unit or used as fuel gas for one or more turbines.