A fire engine including a vehicle frame, a liquid nitrogen storage tank, a liquid nitrogen conveying pipeline, a gasification device, a plurality of electric valves, a water pipe adapter, a liquid nitrogen spray gun, and a mixed spray gun. The liquid nitrogen conveying pipeline includes a first pipeline and a second pipeline. The first pipeline connects the lower part of the liquid nitrogen storage tank, the gasification device, and the upper part of the liquid nitrogen storage tank sequentially in that order. The second pipeline connects the liquid nitrogen storage tank, an input end of the liquid nitrogen spray gun, and a first input end of the mixed spray gun. The mixed spray gun includes a first input end, a second input end, a liquid nitrogen nozzle, and a spray pipe. The spray pipe includes a contraction section, an expansion section, and an acceleration section.

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 cryogenic fluid dispensing system having a tank that holds cryogenic liquid and manages heat within the system is disclosed. The cryogenic liquid dispensing system optionally includes a basin and/or a heat exchanger within the tank for managing heat within the system.

A cryogenic storage vessel having an inner vessel defining a cryogen space; an outer vessel spaced apart from and surrounding the inner vessel, defining a thermally insulating space between the inner vessel and the outer vessel; and a receptacle defining passages for delivery of liquefied gas from the cryogen space to outside the cryogenic storage vessel. The receptacle has an elongated outer sleeve defining an interior space in fluid communication with the thermally insulating space that is sealed from the cryogen space; an elongated inner sleeve extending into the interior space defined by the elongated outer sleeve defining an inner receptacle space that is fluidly isolated from the thermally insulating space; and a collar extending around an inner surface of the elongated inner sleeve which seals against a cooperating surface of a pump assembly when a pump assembly is installed in the cryogenic storage vessel thereby dividing a warm end from a cold end of the receptacle. A motor for driving the pump can be installed within the cryogenic storage vessel.

A method for supplying helium to at least one end user is disclosed by feeding helium from at least one container of helium to an end user through at least one supply system, wherein a mass flow meter and a pressure transmitter, in electronic communication with a programmable logic controller measures an amount of helium being supplied to the at least one user, provides the amount to the programmable logic controller which provides a signal to the at least one end user of an amount of helium that remains in the at least one container and the temperature therein.

A vaporizer system includes a defrosting function along with the ability to convert liquefied gas to a use gas. The vaporizer system includes first and second vaporizers and piping that transfers fluid from an inlet port to an outlet port with a portion of the piping being between the first and second vaporizer. The system also includes a trim heater and a number of valves for regulating flow of the fluid through the transfer piping. The valves may be placed in a first configuration where vapor from the first vaporizer is heated and directed to the second vaporizer so that the second vaporizer is defrosted and a second configuration where vapor from the second vaporizer is heated and directed to the first vaporizer so that the first vaporizer is defrosted.

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 method for increasing the reliability and availability of a cryogenic fluid reliquefaction system is provided. Wherein the liquid cryogenic fluid is supplied to a cryogenic liquid user in the absence of a pump by elevating the storage height of the main cryogenic storage tank relative to the liquid cryogenic liquid user to a minimum predetermined height. Wherein the temperature of the liquid cryogenic fluid downstream of the sub-cooler is at least 1 degree Celsius above the freezing point of the cryogenic fluid at the internal pressure. The method also includes controlling the internal pressure of the main cryogenic tank by adjusting the recirculation flow to the, and maintaining the cold supply to the liquid cryogenic fluid user when the sub-cooling line is reduced or stopped by venting the vaporized cryogenic fluid.

A cryogen storage vessel at an installation is filled with liquid cryogen from a liquid cryogen storage tank that has a pressure lower than that of the vessel. After headspaces of the vessel and tank are placed in fluid communication with another via a gas transfer vessel and are pressure-balanced, a pump in a liquid transfer line connected between the tank and the vessel is operated to transfer amounts of liquid cryogen from the tank to the vessel via the liquid transfer line and pump as amounts of gaseous cryogen are transferred, through displacement by the pumped cryogenic liquid, from the vessel to the tank. Following filling, the tank is disconnected and then driven to another location to repeat the filling process with a second vessel that is at a different location.

A cryogen storage vessel at an installation is filled with liquid cryogen from a liquid cryogen storage tank that has a pressure lower than that of the vessel. After headspaces of the vessel and tank are placed in fluid communication with another via a gas transfer vessel and are pressure-balanced, a pump in a liquid transfer line connected between the tank and the vessel is operated to transfer amounts of liquid cryogen from the tank to the vessel via the liquid transfer line and pump as amounts of gaseous cryogen are transferred, through displacement by the pumped cryogenic liquid, from the vessel to the tank.