Station and method for filling gas tanks of hydrogen fuel vehicles

Abstract

A hydrogen refilling station for filling the gas tanks of fuel cell electric vehicles includes a liquid hydrogen tank that supplies liquid hydrogen to the upstream end of a filling circuit, which also includes a heat exchanger. The heat exchanger exchanges heat between the liquid hydrogen and a flow of a heat transfer fluid, thereby cooling the heat transfer fluid and vaporizing the liquid hydrogen to provide a supply of high-pressure hydrogen for filling the hydrogen fuel vehicle's gas tank at the downstream end of the circuit. Because the liquid hydrogen is surrounded by the heat transfer fluid within the heat exchanger, virtually no fogging occurs.

Description

background Technical Field

[0002] The present invention relates to a device for filling a pressurized gas cylinder.

[0003] More specifically, the present invention relates to an apparatus for filling a gas tank of a fuel cell electric vehicle (FCEV), the apparatus comprising a liquefied gas source, a transfer circuit in downstream fluid communication with the liquefied gas source and comprising at least one downstream end adapted and configured to be removably connected to a vehicle hydrogen tank to be filled. Background Art

[0005] Hydrogen refueling stations using a liquid hydrogen source are known. These known devices allow the use of refrigeration from the liquid hydrogen to produce pre-cooled pressurized hydrogen for rapid filling without excessively increasing the temperature of the gas in the tank during the filling process.

[0006] For example, Daney et al. proposed a conceptual refilling station that uses a vaporizer to provide high-pressure gaseous hydrogen at ambient temperature, which is then cooled before being fed into the vehicle's tank. Daney et al., "Hydrogen-fuelled vehicle fueling station," Advances in Cryogenic Engineering, vol. 41, 1996.

[0007] Another such station, implemented at city bus refilling stations, uses a vaporizer that transfers heat from ambient air to a pumped stream of liquid hydrogen to provide a high-pressure gaseous hydrogen stream to the vehicle tanks. Raman et al., “A rapid fill hydrogen fuel station for fuel cell buses,” 12th World Energy conference Hydrogen energy Progress 2, pp. 1629-1642.

[0008] At atmospheric pressure, hydrogen boils at -252.8°C. Because the station disclosed by Raman et al. uses a vaporizer that exchanges heat between liquid hydrogen and ambient air, the surface temperature of the ambient air vaporizer is extremely low. Consequently, water vapor from the ambient air condenses and freezes on the surface of the ambient air vaporizer. Air surrounding the ambient air vaporizer also condenses and drips onto the equipment below. This poses a risk to the equipment below. Equipment, especially equipment made of carbon steel, may become thermally embrittled, and plates may crack, structural beams may fail, and piping may burst. Because oxygen condenses at a higher temperature than nitrogen, an oxygen-rich atmosphere can form. Of course, an oxygen-rich atmosphere carries many known risks. Furthermore, the condensing air exacerbates the cryogenic cloud surrounding the equipment.

[0009] When the depth of frozen water on the surface of an ambient air vaporizer reaches an undesirable depth, thereby reducing effective heat transfer, or even causing bridging between adjacent blades of the ambient air vaporizer, such vaporizer must be defrosted before continuing to be used further. To solve this problem, two ambient air vaporizers can be used in an alternating manner so that while one is defrosting, the other is used to vaporize liquid hydrogen. While this solves the problem, it may undesirably increase capital costs due to the need for two ambient air vaporizers for each filling circuit. For hydrogen filling stations located in areas where real estate is expensive and / or for hydrogen filling stations co-located at retail filling stations where the station space is leased from a retail filling station, capital expenditures may also increase because the necessity of having two vaporizers doubles the floor space or space occupied by the liquid vaporization portion of the station.

[0010] Because the surface temperature of the ambient air vaporizer is very low, water vapor in the ambient air also condenses in the area surrounding the vaporizer, creating fogging conditions.

[0011] While fogging can be a nuisance for refilling stations that are isolated from the public, such as in industrial areas that are generally far from consumers, fogging is a much more serious problem for more conspicuous refilling stations, such as retail hydrogen refilling stations, open demonstration refilling stations, and hydrogen refilling stations that are co-located with retail gas stations. This is because the public can see fog emanating from a hydrogen refilling station and mistakenly believe that a dangerous hydrogen leak has occurred at the station, or even that a fire has occurred at the station. Consequently, a false report of a catastrophic leak or dangerous fire to emergency responders would require the station to conduct an emergency stop, followed by a thorough safety assessment, before the station can be declared safe to operate. For this reason, the use of ambient vaporizers could seriously hinder the development of hydrogen refilling stations that originate from on-site liquid hydrogen tanks and are located in conspicuous areas visible to the public. Summary of the Invention

[0012] The object of the present invention is to overcome all or some of the above-mentioned disadvantages of the prior art.

[0013] A hydrogen refilling station is disclosed, comprising a liquid hydrogen source adapted and configured to store liquid hydrogen, a filling circuit, and a heat exchange fluid circuit. The filling circuit comprises an upstream end in downstream flow communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the source into the filling circuit; a downstream end adapted and configured to removably connect to an FCEV gas tank for filling the tank; and a first heat exchanger disposed between the upstream and downstream ends of the filling circuit. The heat transfer circuit comprises, in flow order, an upstream end in downstream flow communication with the first heat exchanger, a second heat exchanger, a heat transfer fluid pump, and a downstream end in upstream flow communication with the first heat exchanger, the heat transfer fluid pump being adapted and configured to receive heat transfer fluid from the second heat exchanger and direct the heat transfer fluid to the first heat exchanger. The second heat exchanger is adapted and configured to heat the cooled heat transfer fluid received from the first heat exchanger. The first heat exchanger is adapted and configured to exchange heat between a heat transfer fluid flowing through the heat transfer circuit and liquid hydrogen in the filling circuit so as to cool the heat transfer fluid and vaporize the liquid hydrogen to provide pressurized gaseous hydrogen for filling the gas tank, the liquid hydrogen flow within the first heat exchanger being surrounded by the heat transfer fluid flow.

[0014] Also disclosed is a hydrogen refilling station, comprising a liquid hydrogen source adapted and configured to store liquid hydrogen, a first filling circuit and a second filling circuit, a heat transfer fluid reservoir, and a first heat exchange fluid circuit and a second heat exchange fluid circuit, wherein: the first filling circuit has: an upstream end, the upstream end being in downstream fluid communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the source to flow into the first filling circuit; a downstream end, the downstream end being adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the tank; and a first heat exchanger disposed between the upstream and downstream ends of the first filling circuit; the second filling circuit having: an upstream end, the upstream end being in downstream fluid communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the source to flow into the first filling circuit; a downstream end, the downstream end being adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the tank; and a first heat exchanger disposed between the upstream and downstream ends of the first filling circuit; and a downstream fluid connection to allow a flow of liquid hydrogen from the source to flow into the second filling circuit; a downstream end adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the tank; and a first heat exchanger disposed between the upstream and downstream ends of the second filling circuit; the first heat transfer circuit comprising, in flow order, an upstream end in downstream flow communication with the first heat exchanger of the first filling circuit, a second heat exchanger, a heat transfer fluid pump, and a downstream end in upstream flow communication with the first heat exchanger of the first filling circuit, the heat transfer fluid pump of the first heat transfer circuit being adapted and configured to receive heat transfer fluid from the second heat exchanger of the first heat transfer circuit and to introduce the heat transfer fluid into the second heat exchanger of the first heat transfer circuit the heat transfer fluid pump being adapted and configured to receive heat transfer fluid from the second heat exchanger of the second heat transfer circuit and to direct the heat transfer fluid to the first heat exchanger of the second filling circuit; the second heat exchanger of the first heat transfer circuit being adapted and configured to heat the cooled heat transfer fluid received from the first heat exchanger of the first heat transfer circuit; and the second heat exchanger of the second heat transfer circuit being adapted and configured to heat the cooled heat transfer fluid received from the first heat exchanger of the first heat transfer circuit; and the second heat exchanger of the second heat transfer circuit being adapted and configured to heat the cooled heat transfer fluid received from the first heat exchanger of the first heat transfer circuit; the heat transfer fluid reservoir being in flow communication between the second heat exchanger of the first heat transfer loop and a heat transfer fluid pump, and in flow communication between the second heat exchanger of the second heat transfer loop and the heat transfer fluid pump; the first heat exchanger of the first filling loop being adapted and configured to exchange heat between the heat transfer fluid flowing through the first heat transfer loop and liquid hydrogen gas in the first filling loop so as to cool the heat transfer fluid and vaporize the liquid hydrogen gas to provide pressurized gaseous hydrogen gas for filling a gas tank of a hydrogen fuel vehicle, the liquid hydrogen gas flow within the first heat exchanger of the first filling loop being surrounded by the heat transfer fluid flow;The first heat exchanger of the second filling circuit is adapted and configured to exchange heat between a heat transfer fluid flowing through the second heat transfer circuit and liquid hydrogen gas in the second filling circuit so as to cool the heat transfer fluid and vaporize the liquid hydrogen gas to provide pressurized gaseous hydrogen gas for filling a gas tank of a hydrogen fuel vehicle, the liquid hydrogen gas flow within the first heat exchanger of the second filling circuit being surrounded by the heat transfer fluid flow.

[0015] Also disclosed is a method for filling a hydrogen fuel vehicle tank with pressurized hydrogen, the method comprising the following steps. Liquid hydrogen is supplied from a liquid hydrogen source to a filling circuit, the downstream end of the filling circuit being removably connected to the tank of the hydrogen fuel vehicle. A first heat exchanger is disposed in the filling circuit, the first heat exchanger having a liquid hydrogen inlet, a gaseous hydrogen outlet, a heat transfer fluid inlet, and a heat transfer fluid outlet. A heat transfer fluid is pumped through a heat transfer circuit circulating through the first heat exchanger by a heat transfer pump, the heat transfer circuit comprising, in a flow order from the heat transfer fluid outlet to the heat transfer fluid inlet, a second heat exchanger and a heat transfer fluid pump. Heat is exchanged between the heat transfer fluid flowing through the heat transfer fluid circuit and liquid hydrogen supplied from the source to the filling circuit by the first heat exchanger, thereby vaporizing the supplied liquid hydrogen and cooling the heat transfer fluid. The supplied liquid hydrogen within the first heat exchanger is surrounded by the heat transfer fluid. The cooled heat transfer fluid received from the first heat exchanger is heated by the second heat exchanger. The gas tank of the hydrogen fuel vehicle is filled with pressurized gaseous hydrogen from the downstream end of the filling circuit.

[0016] The site or method may include one or more of the following:

[0017] - Pumping liquid hydrogen from the source into the filling circuit using a liquid hydrogen pump.

[0018] - measuring the pressure of the pressurized gaseous hydrogen in the filling circuit downstream of the first heat exchanger with a pressure sensor; and controlling the pressure of the pressurized gaseous hydrogen with a pressure control valve based on the pressure of the pressurized gaseous hydrogen measured by the pressure sensor.

[0019] a liquid hydrogen pump in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger, and adapted and configured to increase the pressure of a liquid hydrogen gas stream from the liquid hydrogen source and direct the pressurized liquid hydrogen gas stream toward the first heat exchanger.

[0020] The filling circuit further comprises a pressure control valve and a pressure sensor downstream of the first exchanger, and the pressure control valve is adapted and configured to control the pressure of the pressurized gaseous hydrogen used to fill the gas tank based on the pressure of the pressurized gaseous hydrogen measured by the pressure sensor.

[0021] - the heat transfer circuit further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line, the downstream line being in flow communication between the three-way flow control valve and the heat transfer fluid pump; the main line extending in flow communication between the first heat exchanger and the three-way flow control valve; the bypass line branching off from the main line and being in flow communication upstream of the three-way flow control valve; the second heat exchanger being disposed in the main line; the three-way flow control valve controlling the flow of heated heat transfer fluid from the main line and unheated heat transfer fluid from the bypass line the heat transfer fluid flow rate of the heated heat transfer fluid from the main line and the unheated heat transfer fluid flow from the bypass line, and directing the combined heat transfer fluid flow to a heat transfer pump; the temperature sensor is disposed in the heat transfer circuit between the three-way flow control valve and the first heat exchanger; and the three-way control valve controls the temperature of the heat transfer fluid between the three-way control valve and the first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

[0022] The heat transfer fluid circuit further comprises a blower adapted and configured to blow ambient air to the second heat exchanger in order to heat the heat transfer fluid with the heat of the blown ambient air.

[0023] - The second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

[0024] - the station includes two or more buffer vessels; a branch line that branches off from the filling circuit downstream of the first heat exchanger, the branch line being adapted and configured to direct the pressurized gaseous hydrogen from the first heat exchanger to the two or more buffer vessels; a set of valves; and a pressure control valve that is adapted and configured to allow the pressurized gaseous hydrogen to flow through the branch line and into one of the buffer vessels but not into another of the buffer vessels, and to allow the pressurized gaseous hydrogen to flow from one of the buffer vessels through the branch line and to the downstream end of the filling circuit, the pressure control valve being adapted and configured to control the pressure of the pressurized gaseous hydrogen flowing out of the downstream end of the filling circuit based on a pressure sensed by a pressure sensor provided in the filling circuit between the branch line and the downstream end of the filling circuit.

[0025] -The filling circuit further includes: a main line that is fluidically connected between an upstream end and a downstream end of the filling circuit; a bypass line that branches off from the main line and recombines with the main line downstream of the first heat exchanger; a flow control valve disposed in the main line; a flow control valve disposed in the bypass line; and a temperature sensor disposed in the filling circuit downstream of a point where the bypass line recombines with the main line and upstream of the downstream end of the filling circuit, the first heat exchanger being disposed in the main line, the flow control valve disposed in the main line being adapted and configured to control a flow of vaporized hydrogen through the main line, the flow control valve disposed in the bypass line being adapted and configured to control a flow of liquid hydrogen through the bypass line, the flow control valves controlling the flow of vaporized hydrogen and liquid hydrogen so as to thereby control the temperature of the pressurized gaseous hydrogen used to fill the gas tank based on a temperature sensed by the temperature sensor.

[0026] - the heat transfer circuit further comprises a heat transfer reservoir in fluid communication between the second heat exchanger and the heat transfer pump, the heat transfer reservoir being adapted and configured to contain a volume of the heat transfer fluid.

[0027] -The station further comprises: a first liquid hydrogen pump, which is in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger of the first filling circuit, the first liquid hydrogen pump being adapted and configured to increase the pressure of the liquid hydrogen gas stream from the liquid hydrogen source and to direct the pressurized liquid hydrogen gas stream toward the first heat exchanger of the first filling circuit; and a second liquid hydrogen pump, which is in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger of the second filling circuit, the second liquid hydrogen pump being adapted and configured to increase the pressure of the liquid hydrogen gas stream from the liquid hydrogen source and to direct the pressurized liquid hydrogen gas stream toward the first heat exchanger of the second filling circuit.

[0028] - Each of these filling circuits further comprises a pressure control valve and a pressure sensor downstream of the associated first exchanger, and the pressure control valve is adapted and configured to control the pressure of the pressurized gaseous hydrogen used to fill the gas tank of the hydrogen fuel vehicle based on the pressure of the pressurized gaseous hydrogen measured by the pressure sensor.

[0029] - Each of the heat transfer circuits further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line, the downstream line being in flow communication between the three-way flow control valve and the heat transfer fluid pump; each main line extends in flow communication between the associated first heat exchanger and the associated three-way flow control valve; each bypass line branches off from the associated main line and is in upstream flow communication with the associated three-way flow control valve; each second heat exchanger is disposed in the associated main line; each three-way flow control valve controls the flow of heated heat transfer fluid from the associated main line and the flow of heated heat transfer fluid from the associated bypass line the associated heat transfer circuit; each three-way control valve controls the flow rate of the unheated heat transfer fluid in the associated main line, combines the heated heat transfer fluid flow from the associated main line and the unheated heat transfer fluid flow from the associated bypass line, and directs the combined heat transfer fluid flow to the associated heat transfer pump; each temperature sensor is disposed in the associated heat transfer circuit between the associated three-way flow control valve and the associated first heat exchanger; and each three-way control valve controls the temperature of the heat transfer fluid between the three-way control valve and the associated first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

[0030] - Each heat transfer fluid circuit further comprises a blower adapted and configured to blow ambient air to the associated second heat exchanger in order to heat the heat transfer fluid with the heat of the blown ambient air.

[0031] - Each second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

[0032] - Each filling circuit further includes: a main line that is fluidically connected between its upstream and downstream ends; a bypass line that branches off from the associated main line and recombines with the associated main line downstream of the associated first heat exchanger; a flow control valve disposed in the associated main line; a flow control valve disposed in the associated bypass line; and a temperature sensor disposed downstream of the point at which the associated bypass line recombines with the associated main line and upstream of its associated downstream end, wherein: the associated first heat exchanger is disposed in the associated main line; the flow control valve disposed in the associated main line is adapted and configured to control the flow of vaporized hydrogen gas flowing through the associated main line; the flow control valve disposed in the associated bypass line is adapted and configured to control the flow of liquid hydrogen gas flowing through the associated bypass line, these flow control valves control the flow of vaporized hydrogen gas and liquid hydrogen gas so as to thereby control the temperature of the pressurized gaseous hydrogen gas used to fill the gas tank of the hydrogen fuel vehicle based on the temperature sensed by the temperature sensor.

[0033] - The downstream end comprises at least two nozzles, each nozzle being adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other unique features and advantages will become apparent upon reading the following description with reference to the accompanying drawings, in which:

[0035] Figure 1 is a schematic diagram of an embodiment of the inventive site and method of the present invention.

[0036] Figure 2 yes Figure 1 Schematic representation of the sites and method variations.

[0037] Figure 3 yes Figure 1 Schematic representation of the sites and method variations.

[0038] Figure 4 yes Figure 2 and Figure 3 Schematic representation of the combination of site and method features.

[0039] Figure 5 yes Figure 4 Schematic representation of the sites and method variations.

[0040] Figure 6 yes Figure 5 Schematic representation of the sites and method variations.

[0041] legend

[0042] Liquid hydrogen source 1

[0043] Filling loop 2

[0044] First heat exchanger 3

[0045] Heat transfer fluid circuit 4

[0046] Pressure control valve 5

[0047] Vehicle 6

[0048] Optional freezer 7

[0049] Pressure sensor 9

[0050] Shut-off valve 10

[0051] Temperature sensor 11

[0052] Second heat exchanger 15

[0053] Heat transfer fluid circuit main line 16

[0054] Heat transfer fluid circuit bypass line 17

[0055] Blower 19

[0056] Three-way control valve 21

[0057] Heat transfer fluid reservoir 23

[0058] Heat transfer fluid pump 25

[0059] Temperature sensor 27

[0060] Temperature sensor 29

[0061] Liquid hydrogen pump 31

[0062] Valve 33

[0063] Buffer container 35

[0064] Branch Road 37

[0065] Filling circuit main line 39

[0066] Filling loop bypass line 41

[0067] Combination point 42

[0068] Temperature control valve 43

[0069] Temperature control valve 45

[0070] Shut-off valve 46

[0071] Shut-off valve 48

[0072] Shut-off valve 50 DETAILED DESCRIPTION

[0073] like Figure 1 As best shown, liquid hydrogen from a liquid hydrogen source 1 is supplied via the upstream end of the filling circuit to a filling circuit 2, which includes a first heat exchanger 3, a pressure control valve 5, and a second heat exchanger 15. The downstream end of the filling circuit 2 is removably connected to a gas tank of a hydrogen fuel cell electric vehicle (FCEV) 6. A heat transfer fluid flows in a heat transfer fluid circuit 4, which includes a heat transfer fluid pump 25, a temperature sensor 27, and a liquid hydrogen pump 31.

[0074] The source optionally includes a pressure-increasing circuit for increasing pressure in the headspace of the source by controlling the amount of liquid hydrogen from the source that exits the source and enters a line thermally connected to ambient air using a flow control valve. The liquid hydrogen vaporizes in the line and is directed into the headspace. A pressure sensor measures the pressure within the headspace. A controller is configured to actuate the flow control valve based on the measured headspace pressure to achieve a desired pressure in the headspace.

[0075] The liquid hydrogen pump 31 is used to supply liquid hydrogen from the source into the filling circuit and pressurize it. The use of the liquid hydrogen pump 31 allows the liquid hydrogen to be pumped to the supercritical pressure required for high-pressure filling of the gas tank of the hydrogen fuel vehicle 6. For example, liquid hydrogen stored in the source 1 at a pressure of approximately 50 bar can be easily pumped to a pressure of 900 bar or even higher. The characteristics and features of the specific liquid hydrogen pump 31 used are generally driven by the desired maximum pressure of the gas tank to be supplied to the FCEV 6 and the desired filling capacity of the filling station. Preferably, each liquid hydrogen pump 31 is characterized by the following operating conditions: a net positive suction head of 2 psi to 5 psi, a nominal flow rate of 45 kg / h, a liquid hydrogen suction pressure of 100 psi, and a maximum discharge pressure of approximately 15,000 psi.

[0076] The liquid hydrogen supplied from the source 1 to the filling circuit 2 is vaporized at the first heat exchanger 3 to provide pressurized gaseous hydrogen for filling the gas tank of the FCEV 6. The first heat exchanger 3 exchanges heat between the heat transfer fluid flowing in the heat transfer fluid circuit 4 and the liquid hydrogen flowing in the filling circuit 2, thereby vaporizing the liquid hydrogen (producing cold hydrogen in a supercritical fluid state) and cooling the heat transfer fluid. The vaporized liquid hydrogen constitutes the pressurized gaseous hydrogen for filling the gas tank of the hydrogen fuel vehicle 6. The driver / customer of the FCEV 6 or the operator of the filling station can access a nozzle (at the downstream end of the filling circuit 2) that is conveniently located at an interface typically found at a standard gas station (i.e., a gas pump), which includes a display of the hydrogen price, the amount of hydrogen delivered, and a start / stop button.

[0077] The cooled heat transfer fluid is heated at the second heat exchanger 15 and pumped back to the first heat exchanger 3 using a heat transfer fluid pump 25. The second heat exchanger 15 may be an ambient air evaporator, wherein the cooled heat transfer fluid is heated by heat from the ambient air blown onto the ambient air evaporator by a blower. Alternatively, the second heat exchanger may be an electric heater.

[0078] While any known heat transfer fluid is in the liquid phase at nominal pressures down to at least -135°C, one non-limiting and particularly suitable example is available from Eastman Corporation under the trade name Therminol Obtain Therminol It is a mixture of methylcyclohexane and trimethylpentane and has a reported liquid heat capacity ranging from 1.29 kJ / (kg·K) at -135°C to 2.04 kJ / (kg·K) at 40°C.

[0079] The temperature of the heat transfer fluid can be controlled as follows. A controller (not shown) controls the speed of the heat transfer fluid pump 25 (such as by increasing or decreasing the speed of the variable frequency drive of the pump 25) based on the temperature of the heat transfer fluid sensed by the temperature sensor 29. If the temperature of the heat transfer fluid just upstream of the first heat exchanger 3 is unsatisfactorily high, this will impair the ability of the heat transfer fluid to heat the liquid hydrogen flowing through the first heat exchanger 3. On the other hand, if the temperature of the heat transfer fluid is too low, it may become too viscous or even freeze. The controller is typically a computer or a programmable logic controller. More specifically, the temperature of the heat transfer fluid downstream of the first heat exchanger can be controlled within a temperature range or according to a temperature set point.

[0080] Within the first exchanger 3, the liquid hydrogen flow is surrounded by a heat transfer fluid flow. This prevents the external surface temperature of the first exchanger 3 from reaching the subcooling temperature experienced by the ambient air vaporizer of a conventional liquid hydrogen source hydrogen filling station. Therefore, the condensation of water vapor on the first heat exchanger 3 and subsequent frosting (and the associated defrosting problem in the prior art as described above) are avoided. In addition, the condensation of water vapor in the area around the first exchanger 3 (and the associated fogging problem in the prior art as described above) is avoided. Typically, the construction of the first heat exchanger 3 is a shell-and-tube type, in which liquid hydrogen flows through an inner tube and a heat transfer fluid flows in an outer tube. For a pressure of approximately 900 bar, a shell-and-tube heat exchanger is simpler and less expensive than a shell-and-tube heat exchanger. The first heat exchanger can alternatively be a shell-and-tube heat exchanger, in which the tube fluid is liquid hydrogen and the shell fluid is a heat transfer fluid. Heat exchangers of types other than tube-in-tube or shell-and-tube configurations may be used for the first heat exchanger 3 and may be used with the present invention, provided that the liquid hydrogen is surrounded by a heat transfer fluid and / or the surface temperature of the exterior of the first heat exchanger 3 does not reach the extremely low temperatures of conventional ambient air vaporizers and fogging and frost formation is avoided. The portion of the fill circuit upstream of the first heat exchanger may be vacuum jacketed to prevent frost and fogging problems.

[0081] The pressure of hydrogen gas used to fill the gas tank of the FCEV 6 can be controlled by a pressure control valve 5. Although the specific method of filling the gas tank is not limited, the gas tank is generally filled according to a standard filling scheme (such as the Society of Automotive Engineers (SAE) standard J2601).

[0082] like Figure 2As best shown in FIG, the hydrogen filling station may also include one or more buffer vessels 35 downstream of the first heat exchanger for containing high-pressure hydrogen. Each buffer vessel may be provided with a pressure-increasing circuit to maintain the desired pressure therein. The vaporized hydrogen is supplied to the buffer vessel via a branch 37 attached from the filling circuit 2. The pressure control valve 5 may be used to fill the gas tank of the hydrogen fuel vehicle using the filling algorithm described above. Figure 1 As shown, liquid hydrogen is pumped to high pressure by liquid hydrogen pump 31 and heated by a heat transfer fluid at first heat exchanger 3. Shut-off valve 48 is closed, shut-off valve 46 is open, and one or more of shut-off valves 50 are open. The cold supercritical hydrogen is used to fill yet another buffer vessel 35 rather than being supplied directly to the FCEV. Alternatively, one of the buffer vessels 35 is at intermediate pressure, while the other is at high pressure. By selectively opening or closing shut-off valve 50, the high-pressure buffer vessel 35 can be filled first, followed by the intermediate-pressure buffer vessel 35. The liquid hydrogen pump 31 does not need to operate continuously unless one or more of the buffer vessels 35 is at an undesirably low pressure. If the buffer vessels 35 are full, the gas tanks of the FCEV 6 can be filled with hydrogen stored in the buffer vessels 35 in a cascade filling process, with the intermediate-pressure buffer vessel 35 balancing the pressure with the gas tanks of the FCEV 6, and then the high-pressure buffer vessel 35 balancing the pressure with the gas tanks, as is known in the art.

[0083] like Figure 3As best shown in FIG. 1 , the second heat exchanger 15 can be an ambient air vaporizer. The filling circuit 2 can also include an optional refrigerator 7 as well as a pressure sensor 9 and a temperature sensor 11. The heat transfer fluid circuit 4 can include a heat transfer fluid reservoir 23 and a temperature sensor 27. Based on the pressure and temperature sensed by the pressure sensor 9 and the temperature sensor 11, the FCEV's gas tank can be filled using the pressure control valve 5 described above. The heat transfer fluid circuit 4 is provided with a main line 16 in which the second heat exchanger 15 is disposed. The cooled heat transfer fluid is heated by heat from the ambient air blown onto the second heat exchanger 15 by a blower 19. Optionally, a bypass line 17 branches off from the main line 16, allowing a portion of the cooled heat transfer fluid to remain unheated at the second heat exchanger 15. In this optional case, a three-way control valve 21 is used to combine the heated heat transfer fluid in the main line 16 with the unheated heat transfer fluid in the bypass line 17. Because the temperature of the ambient air blown by the blower 19 will vary with the time of year, the three-way control valve 21 can be controlled according to a seasonally varying control scheme. For example, during winter in the northern hemisphere, the entire heat transfer fluid flow can be supplied through the main line 16 and heated at the second heat exchanger 15, while during summer, a portion or all of the heat transfer fluid flow can be supplied through the bypass line 17 to produce cooler heat transfer fluid for storage in the heat transfer fluid reservoir 23. This is helpful during particularly hot summer days when heat leakage would impair the ability to maintain the heat transfer fluid below a maximum predetermined temperature.

[0084] The temperature of the combined heat transfer fluid flow from the three-way control valve 21 may alternatively be controlled in the following manner. A controller (which may be the same or different than the controller used to control the temperature of the heat transfer fluid downstream of the first heat exchanger 3) controls actuation of the three-way control valve to achieve a flow ratio of heated heat transfer fluid in the main line to unheated heat transfer fluid in the bypass line based on the temperature measured by the temperature sensor of the heat transfer circuit.

[0085] The pressure sensor 9 and the temperature sensor 11 can be used to input the pressure and temperature of the hydrogen gas delivered to the FCEV gas tank as variables to the filling algorithm described above. Specifically, the filling algorithm complies with SAE standard J2601.

[0086] like Figure 4 Best shown in Figure 2 and Figure 3 Features of the embodiments may be combined.

[0087] like Figure 5As best shown, the filling circuit includes a main line 39 and a bypass line 41 branching off from the main line. A portion of the liquid hydrogen supplied to the main line 39 is vaporized at the first heat exchanger 3, while a portion of the liquid hydrogen supplied to the bypass line 41 is not vaporized. The two hydrogen streams are combined at a point 42 downstream of the first heat exchanger 3 to provide pressurized gaseous hydrogen. The temperature of the pressurized gaseous hydrogen can be controlled by controlling the flow of liquid hydrogen into the main line 39 and the bypass line 41 using temperature control valves 43 and 45. The temperature control valves 43 and 45 can be controlled by a controller (not shown, but examples include a computer or programmable logic controller, which can be the same or different from the controller that controls the operation of the three-way control valve 21 and / or the liquid hydrogen pump variable frequency drive) based on the temperature measured by the temperature sensor 11. Those skilled in the art will recognize that when the temperature sensed by the temperature sensor is too low (high), the flow of liquid hydrogen to the main line 39 can be increased (decreased) and the flow of liquid hydrogen to the bypass line 41 can be increased (decreased) by a corresponding amount. Thus, control of the temperature of the pressurized gaseous hydrogen can be performed without the optional refrigerator 7, or the optional refrigerator 7 can only provide supplemental refrigeration. In this embodiment, the flow of gaseous hydrogen to the FCEV tank is controlled by the pressure control valve 5, optionally based on the pressure and temperature sensed by the pressure sensor 9 and the temperature sensor 11, as explained above.

[0088] If the FCEV tank is not being filled with hydrogen from the buffer container 35, the shut-off valve 50 is closed, and the two hydrogen streams combine at point 42 downstream of the first heat exchanger 3 to provide pressurized gaseous hydrogen for filling the FCEV tank. If one of the buffer containers 35 is being used to fill the FCEV tank, one of the shut-off valves 50 is closed, one of the shut-off valves 50 is opened, and the hydrogen stream from one of the buffer containers 35 combines with the liquid hydrogen stream from the bypass line 41 at point 42 downstream of the first heat exchanger 3. During this filling, the pump 31 can remain operational or, alternatively, can be shut down. Regardless of whether the vaporized hydrogen is obtained directly from the main line 39 or from one of the buffer containers 35, the temperature of the pressurized gaseous hydrogen can be controlled by controlling the liquid hydrogen flow in the main and bypass lines using temperature control valves 43 and 45. The temperature control valves 43 and 45 can be controlled by a controller (not shown, but examples include a computer or programmable logic controller, which can be the same as or different from the controller 29) based on the temperature measured by the temperature sensor. Those skilled in the art will recognize that when the temperature sensed by the temperature sensor is too low (high), the flow of liquid hydrogen to the main line 39 can be increased (decreased) and the flow of liquid hydrogen to the bypass line 41 can be increased (decreased) by a corresponding amount. Thus, control of the temperature of the pressurized gaseous hydrogen can be performed without the optional refrigerator, or the optional refrigerator can simply provide supplemental refrigeration. In this embodiment, the flow of gaseous hydrogen to the FCEV tank is controlled by a pressure control valve based on the pressure sensed by the pressure sensor.

[0089] exist Figure 5 In a variation of the embodiment and as Figure 6 As best shown in FIG, the station can have two filling circuits 4', 4". This allows liquid hydrogen from source 1 to be supplied to either of the liquid hydrogen pumps 31, and compressed liquid hydrogen to be supplied from either of the liquid hydrogen pumps to either of the two filling circuits 4', 4". Although not shown, a single set of buffer vessels 35 can be shared with each of the filling circuits 4', 4", which allows the size of the buffer vessels to be optimized, thereby reducing capital costs.

[0090] In each of the above embodiments, it should be noted that the downstream end can be equipped with at least two nozzles. Each of the nozzles is adapted and configured to removably connect to a gas tank of an FCEV for filling the tank. While any known nozzle configuration can be used, the nozzles are typically part of a hydrogen dispenser available from Tatsuno Corporation for use in retail hydrogen filling stations.

[0091] Regardless of the specific embodiment, while the refilling station can be located anywhere an FCEV gas tank needs to be refilled, it is particularly useful when located at a retail fueling station equipped with a hydrogen dispenser for use by FCEV drivers who may not necessarily have received any training in handling and dispensing high-pressure hydrogen. In a preferred filling order, after the nozzle is connected to the FCEV gas tank in an airtight manner, gaseous hydrogen is first supplied to the gas tank from the lowest pressure buffer container (i.e., at a pressure higher than the hydrogen in the gas tank) to reduce the effects of the Joule-Thomson effect. The specific manner in which filling is performed is determined by a filling algorithm (such as an algorithm that complies with the SAE J2601 standard). Control of the pressure of the gaseous hydrogen from the nozzle is accomplished using a pressure control valve based on the pressure of the gaseous hydrogen through a pressure sensor in the nozzle or gas tank. When the low-pressure buffer container and the gas tank are substantially pressure-balanced, gaseous hydrogen is dispensed into the gas tank from the higher-pressure buffer container instead. This continues until filling is complete as indicated by the algorithm. Liquid hydrogen is pumped from the source to a first heat exchanger and the resulting pressurized gaseous hydrogen is used to refill the buffer vessel before filling another FCEV tank.

[0092] The present invention provides several advantages.

[0093] The vaporizer used in the present invention does not need to be very tall. In fact, it can be kept below 10 feet in height. This is important because in urban areas, the presence of overhead power lines, telephone lines, or trees limits the vertical space that can be occupied by a conventional ambient air vaporizer. Conventional ambient air vaporizers are often over 10 feet tall, compared to the vaporizer used in the present invention.

[0094] Compared to ambient air vaporizers, the vaporizers used in the present invention allow for more precise control of the outlet temperature of the hydrogen at the distributor, which is necessary to meet the strict temperature control curves required by many hydrogen filling protocols (such as SAE J2601). Because conventional ambient air vaporizers exchange heat with the liquefied cryogenic gas in a largely passive manner, the temperature of the vaporized refrigerant will be highly dependent on the ambient temperature. In the present invention, the temperature of the heat transfer fluid leaving the second heat exchanger can be precisely controlled by precisely controlling the blower speed or the electrical power supplied to the heater. This, in turn, allows for more precise control of the vaporized hydrogen leaving the first heat exchanger after exchanging heat with the temperature-controlled heat transfer fluid.

[0095] Although the present invention has been described in conjunction with specific embodiments of the present invention, it is apparent that, in view of the foregoing description, many alternatives, modifications, and variations will be clear to those skilled in the art. Therefore, it is intended to include all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. The present invention can suitably include disclosed elements, be composed of disclosed elements, or be substantially composed of disclosed elements, and can be implemented in the absence of undisclosed elements. In addition, if there is language relating to sequence, such as first and second, it should be understood in an exemplary sense rather than in a restrictive sense. For example, it will be appreciated by those skilled in the art that some steps can be combined into a single step.

[0096] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0097] "Comprising" in the claims is an open transition term that means that the subsequently identified claim elements are a non-exclusive list, i.e., anything else may be additionally included and remain within the scope of "comprising." "Comprising" is defined herein to necessarily encompass the more restrictive transition terms "consisting essentially of" and "consisting of"; thus, "comprising" can be replaced by "consisting essentially of" or "consisting of" and remain within the clearly defined scope of "comprising."

[0098] "Providing" in a claim is defined as meaning supplying, furnishing, making available, or preparing something. The step may instead be performed by any actor in the absence of explicit language in the claim.

[0099] Optional or optionally means that the subsequently described event or circumstance may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0100] Ranges can be expressed herein as from about one particular value and / or to about another particular value. When such a range is expressed, it is understood that another embodiment is from the one particular value and / or to the other particular value, along with all combinations within said range.

[0101] All references identified herein are each hereby incorporated by reference into this application in their entirety, and each individual reference is cited for the specific information provided.

Claims

1. A hydrogen refilling station comprising a liquid hydrogen source adapted and configured to store liquid hydrogen, a filling circuit, and a heat transfer fluid circuit, wherein: The filling circuit has an upstream end in downstream fluid communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the liquid hydrogen source into the filling circuit; a downstream end adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the hydrogen fuel vehicle tank with gaseous hydrogen; and a first heat exchanger disposed between the upstream and downstream ends of the filling circuit. the heat transfer fluid circuit comprising, in flow order, an upstream end in downstream flow communication with the first heat exchanger, a second heat exchanger, a heat transfer fluid pump, and a downstream end in upstream flow communication with the first heat exchanger, the heat transfer fluid pump being adapted and configured to receive heat transfer fluid from the second heat exchanger and direct the heat transfer fluid to the first heat exchanger, the heat transfer fluid being in a liquid phase at a nominal pressure as low as at least -135° C.; the second heat exchanger being adapted and configured to heat the cooled heat transfer fluid received from the first heat exchanger; and The first heat exchanger is adapted and configured to exchange heat between the heat transfer fluid flowing through the heat transfer fluid circuit and the liquid hydrogen gas in the filling circuit so as to cool the heat transfer fluid and vaporize the liquid hydrogen gas to provide pressurized gaseous hydrogen gas for filling the hydrogen fuel vehicle tank, the liquid hydrogen gas flow within the first heat exchanger being surrounded by the heat transfer fluid flow.

2. The station of claim 1 , further comprising a liquid hydrogen pump in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger, the liquid hydrogen pump being adapted and configured to increase the pressure of the liquid hydrogen gas stream from the liquid hydrogen source and to direct the pressurized liquid hydrogen gas stream toward the first heat exchanger.

3. The site according to claim 1, wherein The filling circuit further includes a pressure control valve and a pressure sensor downstream of the first heat exchanger, and the pressure control valve is adapted and configured to control the pressure of the pressurized gaseous hydrogen gas used to fill the hydrogen fuel vehicle tank based on the pressure of the pressurized gaseous hydrogen gas measured by the pressure sensor.

4. The site of claim 1, wherein: The heat transfer fluid circuit further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line in flow communication between the three-way flow control valve and the heat transfer fluid pump; The main line extends in flow communication between the first heat exchanger and the three-way flow control valve; The bypass line branches off from the main line and is in upstream flow communication with the three-way flow control valve; The second heat exchanger is arranged in the main line; the three-way flow control valve controlling the flow of heated heat transfer fluid from the main line and unheated heat transfer fluid from the bypass line, combining the heated heat transfer fluid flow from the main line and the unheated heat transfer fluid flow from the bypass line, and directing the combined heat transfer fluid flow to a heat transfer fluid pump; The temperature sensor is disposed in the heat transfer fluid circuit between the three-way flow control valve and the first heat exchanger; and The three-way flow control valve controls the temperature of the heat transfer fluid between the three-way flow control valve and the first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

5. The site according to claim 1, wherein The heat transfer fluid circuit further includes a blower adapted and configured to blow ambient air to the second heat exchanger so as to heat the heat transfer fluid with heat of the blown ambient air.

6. The site of claim 1, wherein: The second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

7. The station of claim 1, further comprising two or more buffer containers; a branch line branching off from the filling circuit downstream of the first heat exchanger, the branch line being adapted and configured to direct the pressurized gaseous hydrogen from the first heat exchanger to the two or more buffer vessels; a set of valves; and pressure control valves, the set of valves being adapted and configured to allow the pressurized gaseous hydrogen to flow through the branch and into one of the buffer containers but not into the other of the buffer containers, and to allow the pressurized gaseous hydrogen to flow from one of the buffer containers through the branch and to the downstream end of the filling circuit, the pressure control valves being adapted and configured to control the pressure of the pressurized gaseous hydrogen flowing out of the downstream end of the filling circuit based on a pressure sensed by a pressure sensor provided in the filling circuit between the branch and the downstream end of the filling circuit.

8. The site of claim 1, wherein: The filling circuit further includes: a main line that is fluidically connected between an upstream end and a downstream end of the filling circuit; a bypass line that branches off from the main line and recombines with the main line downstream of the first heat exchanger; a flow control valve disposed in the main line; a flow control valve disposed in the bypass line; and a temperature sensor disposed in the filling circuit downstream of a point where the bypass line recombines with the main line and upstream of the downstream end of the filling circuit, the first heat exchanger being disposed in the main line, the flow control valve disposed in the main line being adapted and configured to control a flow of vaporized hydrogen through the main line, the flow control valve disposed in the bypass line being adapted and configured to control a flow of liquid hydrogen through the bypass line, the flow control valves controlling the flow of vaporized hydrogen and liquid hydrogen so as to thereby control the temperature of the pressurized gaseous hydrogen used to fill the hydrogen fuel vehicle tank based on a temperature sensed by the temperature sensor.

9. The site of claim 1, wherein: The heat transfer fluid circuit further includes a heat transfer reservoir in fluid communication between the second heat exchanger and the heat transfer fluid pump, the heat transfer reservoir being adapted and configured to hold a volume of the heat transfer fluid.

10. A hydrogen refilling station comprising a liquid hydrogen source adapted and configured to store liquid hydrogen, a first filling circuit and a second filling circuit, a heat transfer fluid reservoir, and a first heat transfer fluid circuit and a second heat transfer fluid circuit, wherein: The first filling circuit has an upstream end in downstream fluid communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the liquid hydrogen source into the first filling circuit; a downstream end adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the hydrogen fuel vehicle tank with gaseous hydrogen; and a first heat exchanger disposed between the upstream and downstream ends of the first filling circuit. The second filling circuit has an upstream end in downstream fluid communication with the liquid hydrogen source to allow a flow of liquid hydrogen from the liquid hydrogen source into the second filling circuit; a downstream end adapted and configured to be removably connected to a hydrogen fuel vehicle tank for filling the hydrogen fuel vehicle tank with gaseous hydrogen; and a first heat exchanger disposed between the upstream and downstream ends of the second filling circuit. the first heat transfer fluid circuit comprising, in flow order, an upstream end in downstream flow communication with the first heat exchanger of the first fill circuit, a second heat exchanger, a heat transfer fluid pump, and a downstream end in upstream flow communication with the first heat exchanger of the first fill circuit, the heat transfer fluid pump of the first heat transfer fluid circuit being adapted and configured to receive heat transfer fluid from the second heat exchanger of the first heat transfer fluid circuit and direct the heat transfer fluid to the first heat exchanger of the first fill circuit; the second heat transfer fluid circuit comprising, in flow order, an upstream end in downstream flow communication with the first heat exchanger of the second fill circuit, a second heat exchanger, a heat transfer fluid pump, and a downstream end in upstream flow communication with the first heat exchanger of the second fill circuit, the heat transfer fluid pump of the second heat transfer fluid circuit being adapted and configured to receive heat transfer fluid from the second heat exchanger of the second heat transfer fluid circuit and direct the heat transfer fluid to the first heat exchanger of the second fill circuit; the second heat exchanger of the first heat transfer fluid circuit being adapted and configured to heat cooled heat transfer fluid received from the first heat exchanger of the first heat transfer fluid circuit; the second heat exchanger of the second heat transfer fluid circuit being adapted and configured to heat cooled heat transfer fluid received from the first heat exchanger of the second heat transfer fluid circuit; the heat transfer fluid reservoir being in flow communication between the second heat exchanger of the first heat transfer fluid circuit and a heat transfer fluid pump, and between the second heat exchanger of the second heat transfer fluid circuit and a heat transfer fluid pump; the first heat exchanger of the first filling circuit being adapted and configured to exchange heat between a heat transfer fluid flowing through the first heat transfer fluid circuit and liquid hydrogen gas in the first filling circuit so as to cool the heat transfer fluid and vaporize the liquid hydrogen gas to provide pressurized gaseous hydrogen gas for filling a hydrogen fuel vehicle tank, the liquid hydrogen gas flow within the first heat exchanger of the first filling circuit being surrounded by the heat transfer fluid flow; and The first heat exchanger of the second filling circuit is adapted and configured to exchange heat between a heat transfer fluid flowing through the second heat transfer fluid circuit and liquid hydrogen gas in the second filling circuit so as to cool the heat transfer fluid and vaporize the liquid hydrogen gas to provide pressurized gaseous hydrogen gas for filling a hydrogen fuel vehicle tank, the liquid hydrogen gas flow within the first heat exchanger of the second filling circuit being surrounded by the heat transfer fluid flow, Therein, the heat transfer fluid is in a liquid phase at nominal pressures down to at least -135°C.

11. The site of claim 10, further comprising: a first liquid hydrogen pump in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger of the first filling circuit, the first liquid hydrogen pump being adapted and configured to increase the pressure of a liquid hydrogen gas stream from the liquid hydrogen source and direct the pressurized liquid hydrogen gas stream toward the first heat exchanger of the first filling circuit; and a second liquid hydrogen pump in downstream flow communication with the liquid hydrogen source and in upstream flow communication with the first heat exchanger of the second filling circuit, the second liquid hydrogen pump being adapted and configured to increase the pressure of a liquid hydrogen gas stream from the liquid hydrogen source and direct the pressurized liquid hydrogen gas stream toward the first heat exchanger of the second filling circuit.

12. The site of claim 10, wherein: Each of these filling circuits further includes a pressure control valve and a pressure sensor downstream of the associated first heat exchanger, and the pressure control valve is adapted and configured to control the pressure of the pressurized gaseous hydrogen used to fill the hydrogen fuel vehicle tank based on the pressure of the pressurized gaseous hydrogen measured by the pressure sensor.

13. The station of claim 10, wherein: Each of the heat transfer fluid circuits further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line in flow communication between the three-way flow control valve and the heat transfer fluid pump; each main line extending in flow communication between the associated first heat exchanger and the associated three-way flow control valve; Each bypass line branches off from the associated main line and is in upstream flow communication with the associated three-way flow control valve; Each second heat exchanger is disposed in the associated main line; each three-way flow control valve controls the flow of heated heat transfer fluid from the associated main line and unheated heat transfer fluid from the associated bypass line, combines the heated heat transfer fluid flow from the associated main line and the unheated heat transfer fluid flow from the associated bypass line, and directs the combined heat transfer fluid flow to the associated heat transfer fluid pump; Each temperature sensor is disposed in an associated heat transfer fluid circuit between the associated three-way flow control valve and the associated first heat exchanger; and Each three-way flow control valve controls the temperature of the heat transfer fluid between the three-way flow control valve and the associated first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

14. The station of claim 10, wherein: Each heat transfer fluid circuit further includes a blower adapted and configured to blow ambient air to the associated second heat exchanger so as to heat the heat transfer fluid with heat of the blown ambient air.

15. The station of claim 10, wherein: Each second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

16. The station of claim 10, wherein: Each filling circuit further comprises: a main conduit in fluid communication between an upstream end and a downstream end thereof; a bypass line that branches off from an associated main line and recombines with the associated main line downstream of the associated first heat exchanger; a flow control valve disposed in the associated main line; a flow control valve disposed in the associated bypass line; and a temperature sensor disposed downstream of a point where the associated bypass line recombines with the associated main line and upstream of its associated downstream end, wherein: the associated first heat exchanger is disposed in the associated main line; a flow control valve disposed in the associated main line is adapted and configured to control a flow of vaporized hydrogen gas flowing through the associated main line; and a flow control valve disposed in the associated bypass line is adapted and configured to control a flow of liquid hydrogen gas flowing through the associated bypass line, the flow control valves controlling the flow of vaporized hydrogen gas and liquid hydrogen gas to thereby control the temperature of pressurized gaseous hydrogen gas used to fill a hydrogen fuel vehicle tank based on the temperature sensed by the temperature sensor.

17. A method of filling a fuel cell electric vehicle's gas tank with pressurized hydrogen gas, the method comprising the steps of: supplying liquid hydrogen from a liquid hydrogen source to a filling circuit, wherein a downstream end of the filling circuit is removably connected to a gas tank of the fuel cell electric vehicle, wherein a first heat exchanger is disposed in the filling circuit, the first heat exchanger having a liquid hydrogen inlet, a gaseous hydrogen outlet, a heat transfer fluid inlet, and a heat transfer fluid outlet; pumping a heat transfer fluid through a heat transfer fluid circuit circulating to and from the first heat exchanger with a heat transfer fluid pump, the heat transfer fluid being in a liquid phase at a nominal pressure as low as at least -135° C., the heat transfer fluid circuit comprising, in flow order from the heat transfer fluid outlet to the heat transfer fluid inlet, a second heat exchanger and the heat transfer fluid pump; exchanging heat with the first heat exchanger between a heat transfer fluid flowing through the heat transfer fluid circuit and liquid hydrogen gas supplied from the source to the fill circuit, thereby vaporizing the supplied liquid hydrogen gas and cooling the heat transfer fluid, wherein the supplied liquid hydrogen gas within the first heat exchanger is surrounded by the heat transfer fluid; heating, with the second heat exchanger, the cooled heat transfer fluid received from the first heat exchanger; and From the downstream end of the filling loop, the fuel cell electric vehicle's gas tank is filled with pressurized gaseous hydrogen.

18. The method of claim 17, further comprising the step of pumping the liquid hydrogen from the source into the filling loop using a liquid hydrogen pump.

19. The method of claim 17, further comprising the steps of: measuring the pressure of the pressurized gaseous hydrogen in the filling circuit downstream of the first heat exchanger with a pressure sensor; and The pressure of the pressurized gaseous hydrogen gas is controlled with a pressure control valve based on the pressure of the pressurized gaseous hydrogen gas measured by the pressure sensor.

20. The method of claim 17, wherein: The heat transfer fluid circuit further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line in flow communication between the three-way flow control valve and the heat transfer fluid pump; The main line extends in flow communication between the first heat exchanger and the three-way flow control valve; The bypass line branches off from the main line and is in upstream flow communication with the three-way flow control valve; The second heat exchanger is arranged in the main line; the three-way flow control valve controlling the flow of heated heat transfer fluid from the main line and unheated heat transfer fluid from the bypass line, combining the heated heat transfer fluid flow from the main line and the unheated heat transfer fluid flow from the bypass line, and directing the combined heat transfer fluid flow to a heat transfer fluid pump; The temperature sensor is disposed in the heat transfer fluid circuit between the three-way flow control valve and the first heat exchanger; and The three-way flow control valve controls the temperature of the heat transfer fluid between the three-way flow control valve and the first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

21. The method of claim 17, wherein: The heat transfer fluid circuit further includes a blower adapted and configured to blow ambient air to the second heat exchanger so as to heat the heat transfer fluid with heat of the blown ambient air.

22. The method of claim 17, wherein: The second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

23. The method of claim 17 , further comprising two or more buffer containers; a branch line branching off from the filling circuit downstream of the first heat exchanger, the branch line being adapted and configured to direct the pressurized gaseous hydrogen from the first heat exchanger to the two or more buffer containers; a set of valves; and a pressure control valve, the set of valves being adapted and configured to allow the pressurized gaseous hydrogen to flow through the branch line and into one of the buffer containers but not into another of the buffer containers, and to allow the pressurized gaseous hydrogen to flow from one of the buffer containers through the branch line and to the downstream end of the filling circuit, the pressure control valve being adapted and configured to control the pressure of the pressurized gaseous hydrogen flowing out of the downstream end of the filling circuit based on a pressure sensed by a pressure sensor provided in the filling circuit between the branch line and the downstream end of the filling circuit.

24. The method of claim 17, wherein: The filling circuit further includes: a main line that is fluidically connected between an upstream end and a downstream end of the filling circuit; a bypass line that branches off from the main line and recombines with the main line downstream of the first heat exchanger; a flow control valve disposed in the main line; a flow control valve disposed in the bypass line; and a temperature sensor disposed in the filling circuit downstream of a point where the bypass line recombines with the main line and upstream of the downstream end of the filling circuit, the first heat exchanger being disposed in the main line, the flow control valve disposed in the main line being adapted and configured to control a flow of vaporized hydrogen through the main line, the flow control valve disposed in the bypass line being adapted and configured to control a flow of liquid hydrogen through the bypass line, the flow control valves controlling the flow of vaporized hydrogen and liquid hydrogen so as to thereby control the temperature of the pressurized gaseous hydrogen used to fill the gas tank of the fuel cell electric vehicle based on the temperature sensed by the temperature sensor.

25. The method of claim 17, wherein: The heat transfer fluid circuit further includes a heat transfer reservoir in fluid communication between the second heat exchanger and the heat transfer fluid pump, the heat transfer reservoir being adapted and configured to hold a volume of the heat transfer fluid.

26. A method of filling a fuel cell electric vehicle's gas tank with pressurized hydrogen gas, the method comprising the steps of: supplying liquid hydrogen from a liquid hydrogen source to a filling circuit, the downstream end of the filling circuit being removably connected to a gas tank of the fuel cell electric vehicle, the filling circuit being provided with a first heat exchanger having a liquid hydrogen inlet, a gaseous hydrogen outlet, a heat transfer fluid inlet, and a heat transfer fluid outlet; pumping a heat transfer fluid through a heat transfer fluid circuit circulating to and from the first heat exchanger with a heat transfer fluid pump, the heat transfer fluid being in a liquid phase at a nominal pressure as low as at least -135° C., the heat transfer fluid circuit comprising, in flow order from the heat transfer fluid outlet to the heat transfer fluid inlet, a second heat exchanger and the heat transfer fluid pump; exchanging heat with the first heat exchanger between a heat transfer fluid flowing through the heat transfer fluid circuit and liquid hydrogen gas supplied from the source to the fill circuit, thereby vaporizing the supplied liquid hydrogen gas and cooling the heat transfer fluid, wherein the supplied liquid hydrogen gas within the first heat exchanger is surrounded by the heat transfer fluid; heating, with the second heat exchanger, the cooled heat transfer fluid received from the first heat exchanger; directing the vaporized liquid hydrogen gas into one or more buffer vessels; and A gas tank of the fuel cell electric vehicle is filled with pressurized gaseous hydrogen from the one or more buffer vessels.

27. The method of claim 26, further comprising the step of pumping the liquid hydrogen from the source into the filling loop using a liquid hydrogen pump.

28. The method of claim 26, further comprising the steps of: measuring the pressure of the pressurized gaseous hydrogen in the filling circuit downstream of the first heat exchanger with a pressure sensor; and The pressure of the pressurized gaseous hydrogen gas is controlled with a pressure control valve based on the pressure of the pressurized gaseous hydrogen gas measured by the pressure sensor.

29. The method of claim 26, wherein: The heat transfer fluid circuit further includes a main line, a bypass line, a three-way flow control valve, a temperature sensor, and a downstream line in flow communication between the three-way flow control valve and the heat transfer fluid pump; The main line extends in flow communication between the first heat exchanger and the three-way flow control valve; The bypass line branches off from the main line and is in upstream flow communication with the three-way flow control valve; The second heat exchanger is arranged in the main line; the three-way flow control valve controlling the flow of heated heat transfer fluid from the main line and unheated heat transfer fluid from the bypass line, combining the heated heat transfer fluid flow from the main line and the unheated heat transfer fluid flow from the bypass line, and directing the combined heat transfer fluid flow to a heat transfer fluid pump; The temperature sensor is disposed in the heat transfer fluid circuit between the three-way flow control valve and the first heat exchanger; and The three-way flow control valve controls the temperature of the heat transfer fluid between the three-way flow control valve and the first heat exchanger by adjusting the ratio of the flow rate of the heated heat transfer fluid to the flow rate of the unheated transfer fluid in the combined heat transfer fluid flow.

30. The method of claim 26, wherein: The heat transfer fluid circuit further includes a blower adapted and configured to blow ambient air to the second heat exchanger so as to heat the heat transfer fluid with heat of the blown ambient air.

31. The method of claim 26, wherein: The second heat exchanger is an electric heater adapted and configured to heat the heat transfer fluid.

32. The method of claim 26, wherein: The one or more buffer containers include two or more buffer containers, and: a branch branching off from the filling circuit downstream of the first heat exchanger, the branch being adapted and configured to direct the pressurized gaseous hydrogen from the first heat exchanger to the one or more buffer vessels; a set of valves adapted and configured to allow the pressurized gaseous hydrogen to flow through the branch and into one of the two or more buffer vessels but not into other of the two or more buffer vessels, and to allow the pressurized gaseous hydrogen to flow from one of the two or more buffer vessels through the branch and to the downstream end of the filling loop; and The pressure control valve is used to control the pressure of pressurized gaseous hydrogen flowing out of the downstream end of the filling circuit based on a pressure sensed by a pressure sensor provided in the filling circuit between the branch and the downstream end of the filling circuit.

33. The method of claim 26, wherein: The filling circuit further includes: a main line that is fluidically connected between an upstream end and a downstream end of the filling circuit; a bypass line that branches off from the main line and recombines with the main line downstream of the first heat exchanger; a flow control valve disposed in the main line; a flow control valve disposed in the bypass line; and a temperature sensor disposed in the filling circuit downstream of a point where the bypass line recombines with the main line and upstream of the downstream end of the filling circuit, the first heat exchanger being disposed in the main line, the flow control valve disposed in the main line being adapted and configured to control a flow of vaporized hydrogen through the main line, the flow control valve disposed in the bypass line being adapted and configured to control a flow of liquid hydrogen through the bypass line, the flow control valves controlling the flow of vaporized hydrogen and liquid hydrogen so as to thereby control the temperature of the pressurized gaseous hydrogen used to fill the gas tank of the fuel cell electric vehicle based on the temperature sensed by the temperature sensor.

34. The method of claim 26, wherein: The heat transfer fluid circuit further includes a heat transfer reservoir in fluid communication between the second heat exchanger and the heat transfer fluid pump, the heat transfer reservoir being adapted and configured to hold a volume of the heat transfer fluid.

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