No-vent liquid hydrogen storage and delivery system

Abstract

A hydrogen storage and delivery system is provided having an orifice pulse tube refrigerator and a liquid hydrogen storage vessel. A cooling system, coupled to the orifice pulse tube refrigerator, cools the vessel and abates ambient heat transfer thereto in order to maintain the liquid hydrogen in the vessel at or below its saturation temperature. Hydrogen boil-off, and the necessity to provide continuous venting of vaporized hydrogen are minimized or avoided. In a preferred embodiment, the hydrogen storage vessel has a toroidal shape, and the pulse tube refrigerator is a two stage pulse tube refrigerator and extends within a central void space defined at the geometric center of the toroidal storage vessel. Also in a preferred embodiment, the cooling system includes first and second thermal jackets, each having a substantially toroidal shape and enclosing the storage vessel, wherein each of the thermal jackets is thermally coupled to one of the first or second stages of the pulse tube refrigerator in order to cool the vessel and to abate ambient heat leak thereto. The hydrogen storage and delivery system is particularly suitable for use in vehicles, such as passenger automobiles.

1 . A hydrogen storage and delivery system comprising a liquid hydrogen storage vessel, an orifice pulse tube refrigerator, and a cooling system coupled to the orifice pulse tube refrigerator, said cooling system being adapted to counteract or abate heat transfer to the storage vessel from the ambient environment, said vessel being adapted to deliver therefrom a metered quantity of hydrogen on demand for use as a fuel, wherein no cold heat exchanger of said orifice pulse tube refrigerator penetrates the liquid hydrogen storage vessel. 
     
     
         2 . The system according to  claim 1 , said storage vessel being in the shape of a hollow toroid having an interior surface that defines a hydrogen storage volume of the storage vessel. 
     
     
         3 . The system according to  claim 2 , said orifice pulse tube refrigerator extending in a void space that is defined by said toroidal storage vessel and is located at the geometric center thereof. 
     
     
         4 . The system according to  claim 1 , said cooling system comprising a first thermal jacket exterior to and substantially enclosing said storage vessel, and a second thermal jacket exterior to and substantially enclosing said first thermal jacket. 
     
     
         5 . The system according to  claim 4 , said orifice pulse tube refrigerator comprising a first stage orifice pulse tube refrigeration unit and a second stage orifice pulse tube refrigeration unit that operates at a lower temperature than the first stage refrigeration unit, said first stage refrigeration unit being thermally coupled to said second thermal jacket, and said second stage refrigeration unit being thermally coupled to said first thermal jacket. 
     
     
         6 . The system according to  claim 5 , said first stage refrigeration unit comprising a first stage cold heat exchanger having a first refrigerant fluid flow passage that is coupled to and in fluid communication with said second thermal jacket, said second stage refrigeration unit comprising a second stage cold heat exchanger having a second refrigerant fluid flow passage that is coupled to and in fluid communication with said first thermal jacket,
 wherein a first refrigerant fluid, refrigerated at said first stage cold heat exchanger to a first temperature, is circulated through said second thermal jacket during operation of said system,   and wherein a second refrigerant fluid, refrigerated at said second stage cold heat exchanger to a second temperature, is circulated through said first thermal jacket during operation of said system.   
     
     
         7 . The system according to  claim 1 , said cooling system comprising a heat transfer body projecting directly into a hydrogen storage volume of said storage vessel, said heat transfer body being thermally coupled to said orifice pulse tube refrigerator. 
     
     
         8 . The system according to  claim 1 , further comprising an oscillatory gas pressure power source coupled to said orifice pulse tube refrigerator via a transfer tube,
 said orifice pulse tube refrigerator comprising a first stage orifice pulse tube refrigeration unit and a second stage orifice pulse tube refrigeration unit, each of the first and second stage refrigeration units comprising a respective regenerator, cold heat exchanger, pulse tube, hot heat exchanger, primary orifice, inertance tube, and reservoir volume,   each of the first and second stage refrigeration units further comprising a secondary orifice connecting the respective hot heat exchanger to the transfer tube.   
     
     
         9 . The system according to  claim 2 , said cooling system comprising a first thermal jacket in the shape of a toroid located concentrically adjacent and substantially enclosing the liquid hydrogen storage vessel. 
     
     
         10 . The system according to  claim 9 , said first thermal jacket comprising a length of tubing coiled in the shape of a toroid around the storage vessel and adapted to accommodate a flow of a first refrigerant fluid therethrough. 
     
     
         11 . A system according to  claim 9 , said cooling system further comprising a second thermal jacket in the shape of a toroid located concentrically adjacent and substantially enclosing said first thermal jacket. 
     
     
         12 . A system according to  claim 11 , said second thermal jacket comprising a length of tubing coiled in the shape of a toroid and adapted to accommodate a flow of a second refrigerant fluid therethrough. 
     
     
         13 . The system according to  claim 1 , further comprising an outer housing defining a primary vacuum chamber therein, said liquid hydrogen storage vessel and said cooling system being disposed within said primary vacuum chamber. 
     
     
         14 . The system according to  claim 13 , wherein operative cold components of said orifice pulse tube refrigeration unit are disposed within said primary vacuum chamber. 
     
     
         15 . A system according to  claim 13 , said housing further defining a secondary chamber, separate and apart from said primary vacuum chamber, said system further comprising relatively high temperature hydrogen conditioning equipment disposed within said secondary chamber. 
     
     
         16 . A system according to  claim 15 , said hydrogen conditioning equipment comprising a vaporizer coupled to said hydrogen storage vessel via a delivery pipe and adapted to receive liquid hydrogen therefrom, and a preheater coupled to said vaporizer and adapted to receive vaporized hydrogen therefrom, said preheater being further adapted to heat hydrogen gas vaporized in the vaporizer to a suitable temperature for delivery to a hydrogen-powered internal combustion engine or to a hydrogen-powered fuel cell. 
     
     
         17 . A system according to  claim 1 , said orifice pulse tube refrigerator comprising a first stage orifice pulse tube refrigeration unit and a second stage orifice pulse tube refrigeration unit that operates at a lower temperature than the first stage refrigeration unit, each of the first and second stage refrigeration units comprising a respective regenerator, cold heat exchanger, pulse tube and hot heat exchanger, said first stage regenerator having a first heat absorptive material therein, said first heat absorptive material having a thermal conductivity not more than 28 W/m-K at 60-100K, a volumetric heat capacity of at least 1 J/cm 3 K at 60-100K, and a porosity of at least 0.55. 
     
     
         18 . A system according to  claim 1 , said orifice pulse tube refrigerator comprising a first stage orifice pulse tube refrigeration unit and a second stage orifice pulse tube refrigeration unit that operates at a lower temperature than the first stage refrigeration unit, each of the first and second stage refrigeration units comprising a respective regenerator, cold heat exchanger, pulse tube and hot heat exchanger, said second stage regenerator having a second heat absorptive material therein, said second heat absorptive material having a volumetric heat capacity of at least 0.23 J/cm 3 K at 13-14K, a volumetric heat capacity of at least 0.5 J/cm 3 K at 18-20K, and a porosity of 0.2-0.5. 
     
     
         19 . A system according to  claim 18 , said second heat absorptive material being provided as a rare earth metal or rare earth metal compound. 
     
     
         20 . A system according to  claim 18 , said second heat absorptive material being selected from the group consisting of erbium compounds. 
     
     
         21 . A system according to  claim 18 , said second heat absorptive material being selected from the group consisting of erbium-praseodymium compounds. 
     
     
         22 . A system according to  claim 8 , said oscillatory gas pressure power source being a flexure bearing linear drive compressor. 
     
     
         23 . An automobile comprising a hydrogen-powered internal combustion engine and/or a hydrogen-powered fuel cell, and a hydrogen storage and delivery system according to  claim 1 . 
     
     
         24 . A hydrogen storage and delivery system comprising a toroidal liquid hydrogen storage vessel and an orifice pulse tube refrigerator,
 said toroidal storage vessel having an interior surface defining a liquid hydrogen storage volume, said storage vessel further defining a void space located at the geometric center of the storage vessel,   said orifice pulse tube refrigerator extending within said void space at the geometric center of the storage vessel.   
     
     
         25 . The system according to  claim 24 , said orifice pulse tube refrigerator comprising a first stage pulse tube refrigeration unit and a second stage pulse tube refrigeration unit, each of the first and second stage refrigeration units comprising a respective regenerator, cold heat exchanger, pulse tube and hot heat exchanger, wherein net refrigeration power for each of the first and second stage refrigeration units is generated at the respective first and second stage cold heat exchangers, and wherein the second stage cold heat exchanger operates at a lower temperature than the first stage cold heat exchanger. 
     
     
         26 . The system according to  claim 24 , further comprising an oscillatory gas pressure power source coupled to said orifice pulse tube refrigerator and adapted to provide periodic pressure surges in a working fluid to drive the orifice pulse tube refrigerator to thereby generate refrigeration power at said first and second stage cold heat exchangers. 
     
     
         27 . The system according to  claim 1 , further comprising a liquid level sensing probe disposed within said storage vessel, said liquid level sensing probe comprising a plurality of adhered flexible dielectric strips and a series of temperature sensing units disposed at spaced intervals along the length of the probe, said probe remaining flexible at a temperature of 80K. 
     
     
         28 . The system according to  claim 1 , further comprising hydrogen conditioning equipment adapted to condition hydrogen drawn from said storage vessel to provide conditioned hydrogen in a suitable state for delivery to an engine or fuel cell that consumes said conditioned hydrogen as fuel.