Method and system for filling tanks of a hydrogen fuel vehicle

Abstract

Heat is transferred from a first portion of the liquid hydrogen to a heat transfer fluid stream in a first heat exchanger (11) through heat exchange with a heat transfer fluid to produce a vaporized hydrogen stream and a warmed heat transfer fluid stream. The vaporized hydrogen stream is mixed with a second portion of the liquid hydrogen in an amount designed to produce a mixed stream having a desired temperature, and the mixed stream is used to fill one or more buffer vessels (19). Heat is also transferred from the pressurized hydrogen stream from at least one buffer vessel (19) to a cooled heat transfer fluid stream in a second heat exchanger to produce a cooled pressurized hydrogen stream used to fill the tank of a fuel cell electric vehicle.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS none.

[0002] The present invention relates to a method and device for filling a pressurized hydrogen gas tank.

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

[0004] To refuel a fuel cell electric vehicle with high-pressure gaseous hydrogen in a manner consistent with Society of Automotive Engineers (SAE) Standard J2601, the temperature of the gaseous hydrogen immediately upstream of the fuel tank must be controlled within a relatively narrow and cold temperature range, such as -17.5°C to -40°C. The rate of pressure ramp of the gaseous hydrogen must also be controlled according to various physical characteristics, such as ambient temperature, fuel tank type, and the temperature and flow rate of the gaseous hydrogen immediately upstream of the fuel tank. A pressure control valve, often located immediately upstream of a heat exchanger for cooling the hydrogen, is used to implement pressure ramp rate control.

[0005] Hydrogen gas refueling stations that use a liquid hydrogen source are known.

[0006] This type of refueling station uses the cooling from the liquid hydrogen to allow for the production of pre-cooled pressurized hydrogen gas for quick fills without experiencing an excessive increase in the temperature of the gas in the tank during fill.

[0007] For example, Daney et al. proposed a conceptual refueling station that uses a vaporizer to provide high-pressure gaseous hydrogen at ambient temperature that is then cooled before being delivered to the vehicle tank. Daney, et al., "Hydrogen-fuelled vehicle fuelling station," Advances in Cryogenic Engineering, vol. 41, 1996.

[0008] Another such station, implemented in an urban bus refueling station, utilizes a vaporizer that transfers heat from ambient air to a pumped stream of liquid hydrogen, providing a high-pressure stream of gaseous hydrogen to the vehicle tank. Raman, et al. "A rapid fill hydrogen fuel station for fuel cell buses," 12th World Energy conference Hydrogen energy Progress 2, pp. 1629-1642.

[0009] One type of hydrogen gas refueling station that uses a liquid hydrogen source is disclosed in U.S. Patent Application Publication No. 2020-0095113A1. During a vehicle fill mode, a vaporized hydrogen stream and a liquid hydrogen stream are mixed using a control valve to generate a gaseous hydrogen stream (derived from the mixture) having a predetermined low temperature desirable for fast fill. If sufficient gaseous hydrogen is available from one or more buffer vessels, the gaseous hydrogen used to fill a given vehicle is generated by mixing the liquid hydrogen stream with the gaseous hydrogen stream from the buffer vessel. If the required amount of fill exceeds the availability of gaseous hydrogen stored in the one or more buffer vessels, the gaseous hydrogen stream is generated by feeding the liquid hydrogen stream to a vaporizer. Between vehicle fills, the buffer vessel is refilled with gaseous hydrogen generated by mixing the liquid hydrogen stream with the gaseous hydrogen stream from the vaporizer. The temperature of the hydrogen in the buffer vessel immediately after fill may be lower than ambient temperature, but heat leaks into the buffer vessel heat the hydrogen to ambient temperature. This requires that the gaseous hydrogen be cooled to a relatively low temperature (eg, -40°C) before entering the vehicle tank so that fast filling can be achieved. Summary of the Invention [Problem to be solved by the invention]

[0010] The cost of gaseous hydrogen used to fill vehicles (at hydrogen refueling stations that utilize an on-site liquid hydrogen source) is composed of many cost components, including hydrogen production, liquid hydrogen distribution, liquid hydrogen storage, liquid hydrogen vaporization, and gaseous hydrogen cooling. While the approach disclosed by U.S. Patent Application Publication No. 2020-0095113 is highly satisfactory, there remains a need for methods and systems that are more efficient with respect to the overall cost of gaseous hydrogen used to fill vehicle tanks. [Means for solving the problem]

[0011] 1. A system for filling a tank of a fuel cell electric vehicle with pressurized hydrogen, the system comprising: a storage container; a liquid hydrogen pump in downstream flow communication with the liquid hydrogen storage container, the liquid hydrogen pump adapted and configured to receive a stream of liquid hydrogen from the storage container and to pump and pressurize the liquid hydrogen stream to produce a stream of pressurized hydrogen; a first heat exchanger having a warming circuit adapted and configured therein to receive and vaporize a first portion of the pressurized hydrogen stream to produce a vaporized hydrogen stream, the first heat exchanger also having a cooling circuit; a bypass circuit adapted and configured to receive a second portion of the pressurized hydrogen stream from the liquid hydrogen pump; a vaporized hydrogen circuit adapted and configured to receive a vaporized hydrogen stream; a buffer container supply conduit adapted and configured to receive the vaporized hydrogen stream from the vaporized hydrogen circuit and the second portion of the pressurized hydrogen stream from the bypass circuit to form a combined stream; a first temperature control valve adapted and configured to control the flow rate of the vaporized hydrogen stream in the vaporized hydrogen circuit; a second heat exchanger having a cooling circuit adapted and configured to receive and cool the combined stream from the buffer receptacle supply conduit and / or the stream of pressurized hydrogen from the at least one buffer receptacle to produce a cooled stream of pressurized hydrogen, the second heat exchanger also having a warming circuit; a filling circuit comprising, in flow order, the cooling circuit of the second heat exchanger and at least one fill dispenser adapted and configured to engage a fuel cell electric vehicle to enable its tank to be filled with the cooled stream of pressurized hydrogen; a temperature sensor disposed in the buffer receptacle supply conduit, the temperature sensor adapted and configured to measure the temperature of the combined stream; and a heat exchange fluid loop comprising, in flow order, a surge receptacle containing a main heat transfer fluid, a main heat transfer fluid pump adapted and configured to pump the main heat transfer fluid through the heat exchange fluid loop, the cooling circuit of the first heat exchanger, the warming circuit of the second heat exchanger, and the surge receptacle.The first heat exchanger is adapted and configured to exchange heat between a relatively warm main heat transfer fluid and a relatively cool first portion of the pressurized hydrogen stream to produce a vaporized hydrogen stream and a cooling stream of the main heat transfer fluid. The second heat exchanger is adapted and configured to exchange heat between the relatively warm mixed stream and / or the relatively warm pressurized hydrogen stream from the at least one buffer vessel, on the one hand, and the relatively cool cooling stream of the main heat transfer fluid, on the other hand. The first and second temperature control valves control the flow rates of the vaporized hydrogen stream and the second portion, respectively, based on the temperatures measured by the temperature sensors.

[0012] A method for filling a tank of a fuel cell electric vehicle with pressurized hydrogen is also disclosed, which includes the following steps. A system as described above is provided: liquid hydrogen is pumped from a liquid hydrogen storage vessel using a liquid hydrogen pump to produce a pressurized hydrogen stream; a main heat transfer fluid stream is pumped in a heat exchange fluid loop using a main heat transfer fluid pump; the pressurized hydrogen stream is split into first and second portions; the first portion is vaporized in a warming circuit of a first heat exchanger and cools the main heat transfer fluid stream in a cooling circuit of the first heat exchanger through heat exchange therebetween to produce a vaporized hydrogen stream and a cooled main heat transfer fluid stream; the vaporized hydrogen stream is received in a vaporized hydrogen circuit; the second portion is received in a bypass circuit; a combined stream composed of the vaporized hydrogen stream and the second portion from the vaporized hydrogen circuit is received in a buffer can supply conduit; the combined stream is received and stored in at least one buffer can until filling of the vehicle tank is required. When vehicle tank filling is required, the combined stream from the buffer canister supply conduit and / or the stream of pressurized hydrogen from the at least one buffer canister is cooled in the cooling circuit of the second heat exchanger, and the cooled stream of the main heat transfer fluid is warmed through heat exchange therebetween in the warming circuit of the second heat exchanger to produce a cooled stream of pressurized hydrogen and a warmed stream of the main heat transfer fluid. The temperature of the combined stream in the buffer canister supply conduit is measured using a temperature sensor. The flow rates or pressures of the vaporized hydrogen stream and the second portion are controlled using first and second temperature control valves, respectively, based on the temperatures sensed by the temperature sensors. The vehicle tank is filled with the cooled stream of pressurized hydrogen.

[0013] The system and / or method may include one or more of the following aspects. - the at least one filling dispenser includes first and second filling dispensers, each one of the first and second filling dispensers adapted and configured to engage with a respective fuel cell electric vehicle to enable its associated tank to be filled with pressurized hydrogen, and the filling circuit bifurcates into a first branch adapted and configured to supply pressurized hydrogen from the at least one buffer receptacle to the first filling dispenser and a second branch adapted and configured to supply pressurized hydrogen from the at least one buffer receptacle to the second filling dispenser. - the system further includes an auxiliary heat transfer pump and an auxiliary heat exchanger including a heating circuit in flow communication between the heating circuit of said first heat exchanger and the buffer vessel supply conduit, the auxiliary heat transfer circuit being formed from a cooling circuit of the auxiliary heat exchanger and the auxiliary heat transfer pump, the auxiliary heat transfer circuit being adapted and configured to circulate an auxiliary heat transfer fluid from the auxiliary heat transfer pump through the cooling circuit of the auxiliary heat transfer circuit and back to the auxiliary heat transfer pump, and the auxiliary heat exchanger being a tube-in-tube heat exchanger including an inner tube concentrically arranged within an outer tube, the heating circuit of the auxiliary heat exchanger being the inner tube and the cooling circuit of the auxiliary heat exchanger being the outer tube. the system further includes a pressure build-up circuit in flow communication between the liquid hydrogen storage area of ​​the storage vessel and a head space of the storage vessel, the pressure build-up circuit adapted and configured to receive a flow of liquid hydrogen from the liquid hydrogen space of the storage vessel, vaporize the flow of liquid hydrogen received from the storage vessel in a second warming circuit of said first heat exchanger through heat exchange with a mass of the heat exchanger, and return the vaporized liquid hydrogen to the head space to increase the pressure therein. - the system further includes a boil-off gas vent circuit in flow communication between the headspace of the storage vessel and an ambient atmosphere of the system, the boil-off gas vent circuit including a first end in downstream flow communication with the headspace, a second end selectively open to the ambient atmosphere, and a second warming circuit of a first heat exchanger between the first end and the second end, the boil-off gas vent circuit adapted and configured to receive boil-off gas from the headspace, warm the received boil-off gas in the second warming circuit through heat exchange with the mass of the first heat exchanger, and vent the warmed boil-off gas to the ambient atmosphere via the second end. The system further includes a main heat transfer fluid bypass loop having a main heat transfer line in fluid communication between the main heat transfer fluid pump and the cooling circuit of the first heat exchanger, a first end in downstream fluid communication with the main heat transfer fluid line, a second end in upstream fluid communication with the main heat transfer fluid line, and a heat exchanger section therebetween, and a fan heater adapted and configured to blow ambient air over the heat exchange section to warm the pumped flow of main heat transfer fluid before it is cooled in the first heat exchanger. The first heat exchanger comprises a mass of metal formed by high-temperature casting in liquid form around its heating and cooling circuits. - the system further includes a pressure sensor and a temperature sensor, respectively, disposed in the filling circuit, adapted and configured to measure the pressure and temperature, respectively, of the cooling stream of pressurized hydrogen received from the second heat exchanger, and a pressure control valve, disposed in the filling circuit, adapted and configured to control the pressure of the cooling stream of pressurized hydrogen used to fill a tank of the fuel cell electric vehicle, the operation of the pressure control valve being based on the pressure and temperature measured by the pressure and temperature sensors. - the method further includes the steps of pumping an auxiliary heat transfer fluid in an auxiliary heat exchange circuit using the auxiliary heat transfer pump to generate a recirculation flow of auxiliary heat transfer fluid, and warming a stream of vaporized hydrogen in a warming circuit of the auxiliary heat exchanger and cooling the recirculation flow of auxiliary heat transfer fluid in a cooling circuit of the auxiliary heat exchanger through heat exchange between the stream of vaporized hydrogen and the recirculation flow of auxiliary heat transfer fluid. The method further includes the steps of supplying a stream of liquid hydrogen from a storage vessel to a second warming circuit of the first heat exchanger, vaporizing the supplied stream of liquid hydrogen in the second warming circuit of the first heat exchanger through heat exchange with a mass of the first heat exchanger to produce a stream of vaporized liquid hydrogen, and returning the stream of vaporized liquid hydrogen to the headspace of the storage vessel, thereby increasing its pressure. The method further comprises the steps of supplying a stream of gaseous hydrogen from the headspace of the storage vessel to a second warming circuit of the first heat exchanger, and vaporizing the supplied stream of liquid hydrogen in the second warming circuit of the first heat exchanger, and venting the vaporized liquid hydrogen to the ambient atmosphere.

[0014] Other features and advantages will become apparent from the following description and from the drawings. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of the station of the present invention and the method of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a variation of the station and method of FIG. [Figure 3] FIG. 3 is a schematic diagram of a variation of the station and method of FIG. [Figure 4] FIG. 4 is a schematic diagram of a variation of the station and method of FIG. [Figure 5] FIG. 5 is a schematic diagram of a variation of the station and method of FIG. [Figure 6] FIG. 6 is a schematic diagram of a variation of the station and method of FIG. [Figure 7] FIG. 7 is a schematic diagram of a combination of station and method features of FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0016] Legend Liquid Hydrogen Source 1 Liquid hydrogen supply line 3 Liquid hydrogen pump 5 Pressurized hydrogen flow 9 a second portion 10 of pressurized hydrogen First heat exchanger 11 A second portion 12 of pressurized hydrogen Vaporized hydrogen circuit 13 Heating circuit 14 Auxiliary heat exchanger 15 Second temperature control valve 16 Buffer container supply conduit 17 First temperature control valve 18 Temperature Sensor 20 Buffer container 19 Valve 21 Pressurized hydrogen flow 23 First pressurized hydrogen substream 23' Second pressurized hydrogen side stream 23'' Bypass conduit 24 Second heat exchanger 25 cooling circuit 26 The first of the two second heat exchangers 25' Second of two second heat exchangers 25" Pressure Sensor 27 Pressure Sensor 27' Pressure sensor 27'' Temperature Sensor 29 Temperature Sensor 29 Temperature Sensor 29 Filling dispenser 31 Filling dispenser 31' Filling Dispenser 31'' Pressure control valve 33 Fuel Cell Electric Vehicles35 Fuel cell electric vehicle 35' Fuel cell electric vehicle 35'' Surge vessel 37 Heat Transfer Fluid Flow 39 Main HTF Pump 41 Main HTF pumping flow 43 Temperature Sensor 45 Main HTF cooling flow 47 Auxiliary HTF Pump 49 First branch of main HTF 53' Second branch of main HTF 53'' Three-way flow control valve 55 Cooled Mainstream HTF 56 Warmed second stream of heat transfer fluid 57 a heated first portion 57' of the heat transfer fluid; a heated second branch of heat transfer fluid 57'' Cooled Main HTF Bypass Flow 58 First bypass flow 58' of cooled main HTF Second bypass flow 58'' of cooled main HTF Three-way flow control valve 67 Auxiliary heat transfer fluid pump 71 Pumped flow of auxiliary heat transfer fluids 73 Heated flow of auxiliary heat transfer fluid 75 Pressure increase circuit liquid hydrogen supply line 77 Control valve 79 Temperature Sensor 81 Gaseous Hydrogen Line 83 Headspace Supply Line 85 Control valve 87 Vent valve 89 Vent 91 Gaseous hydrogen return line 93 Three-way flow control valve 95' Three-way flow control valve 95'' Main HTF bypass flow 97 Fan heater 99

[0017] In known filling methods utilizing a liquid hydrogen source, such as U.S. Pat. No. 11,155,459, a liquid hydrogen stream is pumped to a very high pressure above its critical pressure. The resulting very cold pressurized fluid is split into two streams. The first stream is heated in a "vaporizer" that contacts the ambient atmosphere. We use the term "vaporizer" broadly because the cold pressurized fluid can be in a dense liquid state (above its critical pressure) or a supercritical state, or even a gaseous state. The second stream bypasses the vaporizer and is recombined with the vaporized first stream in a controlled manner to reach a predetermined combined flue temperature. While this remains a very satisfactory method of filling an FCEV tank from a liquid hydrogen source, the available cooling (i.e., frigory or negative heat) of the cold pressurized fluid in the first stream is therefore lost to the ambient atmosphere in the vaporizer. Depending on the flow rate required at the dispenser used to fill one or more FCEV tanks, the pressurized fluid from the vaporizer may be used to fill the tank directly, optionally supplemented with an amount of hydrogen from one or more buffer vessels, or alternatively stored in one or more buffer vessels and then used to complete the filling of one or more tanks. Given sufficient time and due to thermal leaks in one or more buffer vessels, the temperature of the heated pressurized fluid, which is often still at a very low temperature, will rise to ambient temperature. To efficiently fill one or more tanks, such ambient temperature fluid must be cooled with an external cooling source so that Joule-Thomson heating (at temperatures above the hydrogen inversion temperature) can be accommodated without over-pressurizing the tanks.

[0018] To avoid wasting available refrigeration from the pressurized hydrogen in the vaporizer achieved using such technology, that refrigeration (i.e., frigory or negative heat) is instead captured through heat exchange with the main heat transfer fluid (main HTF) in the practice of the present invention. These captured frigory are then used to cool the pressurized hydrogen used to fill the vehicle tanks through heat exchange between the main HTF and the pressurized hydrogen. This provides improved efficiency compared to conventional technologies that require an external cooling source to cool the pressurized hydrogen.

[0019] In the present invention, the heat exchange fluid loop includes, in order of flow, a surge vessel containing the main HTF, a main HTF pump, a cooling circuit for the first heat exchanger, a warming circuit for the second heat exchanger, and a return to the surge vessel. Each of the first and second heat exchangers includes a warming circuit and a cooling circuit. Liquid hydrogen is pumped by a liquid hydrogen pump and divided into a first portion and a second portion. The first portion is supplied to the warming circuit for the first heat exchanger, while the main HTF is pumped from the surge vessel to the cooling circuit for the first heat exchanger by the main HTF pump and passes through the loop. In the first heat exchanger, the first portion of the pumped hydrogen is warmed through heat exchange with the pumped main HTF to produce vaporized hydrogen and cooled main HTF, which are received in the vaporized hydrogen circuit. The second portion of the pumped hydrogen is received in a bypass circuit that bypasses the first heat exchanger. The vaporized hydrogen corresponding to the first portion is combined with a second portion of the pumped liquid hydrogen, and the amount is controlled by a temperature control valve associated with the vaporized hydrogen circuit and the bypass circuit based on a temperature sensor located in a buffer vessel supply conduit receiving the combined stream. The combined stream is received and stored in one or more buffer vessels until required for filling a vehicle tank. Pressurized hydrogen from one or more buffer vessels or directly from the buffer vessel supply conduit is supplied to the cooling circuit of the second heat exchanger, while cooled main HTF (obtained from the cooling circuit of the first heat exchanger) is supplied to the warming circuit of the second heat exchanger. In the second heat exchanger, the warmed pressurized hydrogen is cooled through a heat exchanger with the cooled main HTF to produce cooled pressurized hydrogen and warmed main HTF, which are used to fill one or more tanks of the FCEV. The warmed main HTF is then returned to the surge vessel.

[0020] Optionally, one or more temperature control schemes may be utilized in the practice of the present invention.

[0021] To ensure that the main HTF is not subcooled through heat transfer with the mass of the first heat exchanger and the frigory of the pumped liquid hydrogen, at least a portion of the pumped main HTF stream may be warmed in a bypass loop, if necessary, before being directed to the cooling circuit of the first heat exchanger.

[0022] To ensure that the temperature of the vaporized hydrogen leaving the first heat exchanger is not too cold, the pressurized hydrogen leaving the first heat exchanger may be further warmed in an auxiliary heat exchanger in flow communication between the first heat exchanger and one or more buffer vessels. In this case, the vaporized hydrogen may then be warmed by heat exchange with an auxiliary heat transfer fluid (auxiliary HTR) flowing through the auxiliary heat transfer circuit. Whether the auxiliary HTF and the main HTF are the same or different types of heat exchange fluid, the heat exchange circuit through which the main HTF flows is separate from the auxiliary heat exchange circuit.

[0023] To ensure that the first heat exchanger does not get too warm, a large portion of the first heat exchanger can be cooled in one or both of two ways. First, the storage vessel pressure buildup circuit can be extended through an additional cooling circuit for the first heat exchanger. In other words, the additional cooling circuit serves as the heat exchanger section of the typical pressure buildup circuit. Second, the boil-off gas vent line can be extended through the additional cooling circuit for the first heat exchanger.

[0024] To ensure that the pressurized hydrogen obtained from the at least one buffer vessel and / or buffer vessel supply conduit used to fill the FCEV's tank is sufficiently cold, a flow control valve can be used to split the cooled main HTF stream from the first heat exchanger into a stream that flows through the warming circuit of the second heat exchanger and a stream that bypasses the warming circuit. When more cooling is needed, more of the cooled main HTF stream is allowed to flow through the cooling circuit of the second heat exchanger, and less stream bypasses the second heat exchanger. When less cooling is needed, less of the stream is allowed to flow through the cooling circuit, and more of the stream is allowed to bypass the second heat exchanger.

[0025] A specific embodiment will now be described.

[0026] As best shown in FIG. 1 , liquid hydrogen stream 3 from liquid hydrogen storage vessel 1 is pumped by liquid hydrogen pump 5 to provide pressurized hydrogen stream 9. Pressurized hydrogen stream 9 is split into a stream consisting of a first portion 10 of pressurized hydrogen received in warming circuit 14 of first heat exchanger 11 and a second portion 12 of pressurized hydrogen received in bypass circuit 24. The hydrogen in stream 10 is vaporized in warming circuit 14 and received in vaporized hydrogen circuit 13. Meanwhile, the hydrogen in stream 12 is not vaporized because bypass circuit 24 bypasses first heat exchanger 11. If the hydrogen in vaporized hydrogen conduit 13 is too cold, it can optionally be warmed in auxiliary heat exchanger 15. The vaporized hydrogen in vaporized hydrogen circuit 13 and the liquid hydrogen in bypass circuit 24 are mixed and received as a combined stream in buffer vessel supply conduit 17.

[0027] A temperature sensor 20 is disposed in the buffer vessel supply conduit 17 and is adapted and configured to measure the temperature of the mixed stream therein. The temperature of the mixed stream is controlled as follows: the flow rates or pressures of the vaporized hydrogen in the vaporized hydrogen conduit 13 and the liquid hydrogen in the bypass conduit 24 are controlled by the first and second temperature control valves 18, 16, respectively, based on the temperatures measured by the temperature sensor 20. If the temperature of the mixed stream in the buffer vessel supply conduit 17 is too low, the flow rate of the liquid hydrogen stream in the bypass conduit 24 is decreased by the second temperature control valve 16, while the flow rate of the vaporized hydrogen stream in the vaporized hydrogen conduit 13 is increased. Conversely, if the temperature of the mixed stream in the buffer vessel supply conduit 17 is too high, the flow rate of the liquid hydrogen stream in the bypass conduit 24 is increased by the second temperature control valve 16, while the flow rate of the vaporized hydrogen stream in the vaporized hydrogen conduit 13 is decreased.

[0028] The combined hydrogen stream in buffer vessel supply conduit 13 may be fed to one or more buffer vessels 19 for storage until vehicle tank filling is required, in which case hydrogen from one or more buffer vessels 19 is fed to second heat exchanger 25 as pressurized hydrogen stream 23. Alternatively, the combined hydrogen stream in buffer vessel supply conduit 13 may bypass one or more buffer vessels 19 and be fed to second heat exchanger 25 as pressurized hydrogen stream 23. Whether the combined hydrogen stream is first fed to one or more buffer vessels 21 and later fed to second heat exchanger 25, or instead fed directly to second heat exchanger 25, such alternative flow configurations are controlled by opening or closing one or more valves 21 that comprise a valve set, as needed.

[0029] The main HTF stream 39 is pumped by a main HTF pump 41 to produce a pumped stream of main HTF 43. The pumped main HTF stream 43 is fed to the cooling circuit of the first heat exchanger 11 to produce a cooled main HTF stream 47.

[0030] Optionally, a temperature representative of the temperature of the material comprising first heat exchanger 11 is measured by temperature sensor 45. Temperature sensor 45 may measure the surface temperature of first heat exchanger 11. Alternatively, it may be embedded in the material from which first heat exchanger 11 is made. Alternatively, it may measure the temperature of the main HTF inside first heat exchanger 11 or the temperature of the main HTF at the outlet of the first heat exchanger's cooling circuit. A controller (such as a programmable logic controller or computer) controls the speed of main HTF pump 41 (such as by increasing or decreasing the speed of a variable frequency drive of pump 41) based on the temperature measured by temperature sensor 45 and a predetermined setpoint temperature or range of setpoint temperatures to be achieved.

[0031] The hydrogen from the liquid hydrogen pumping stream 9 captured by the main HTF 43 pumping stream is at least partially returned to the hydrogen used to fill the FCEV tanks. To accomplish this, pressurized hydrogen stream 23 (from one or more buffer vessels 19 or directly from buffer vessel supply conduit 17 via set of valves 21) is fed to the cooling circuit of second heat exchanger 25, where it is cooled by heat exchange with at least a portion of the main HTF 47 cooling stream fed to the warming circuit of second heat exchanger 25. In this way, the cooled pressurized hydrogen stream is used to fill the FCEV tanks via fill dispenser 31. The main HTF 57 stream thus warmed is then returned to surge vessel 37.

[0032] Optionally, the temperature of the hydrogen (used to fill the FCEV tanks) is measured by temperature sensor 29. A controller (such as the same or different programmable logic controller or computer that controls the main HTF pump) controls three-way flow control valve 55 to allocate the cooled main HTF 23 flow between the main HTF 56 flow that feeds the warming circuit of second heat exchanger 25 and the bypass flow of main HTF 58. This control is based on the temperature measured by temperature sensor 29 and a predetermined setpoint temperature or range of setpoint temperatures to be achieved. The cooled bypass flow of main HTF 58 and the warmed flow of main HTF 57 are combined and returned to surge vessel 37.

[0033] Optionally, the pressure of the cooled pressurized hydrogen from second heat exchanger 25 is controlled by pressure control valve 33 based on the temperature and pressure of the hydrogen (used to fill the tank of FCEV 35), measured by temperature sensor 29 and pressure sensor 27, respectively. Pressure control valve 33 is controlled by a controller (such as a programmable logic controller or computer) coded with a filling algorithm, such as one consistent with SAE standard J2601 for filling light duty vehicles.

[0034] Any type of heat exchanger known in the art of heat transfer involving cryogenic fluids can be used for the first heat exchanger 11. Typically, the first heat exchanger is a cooling holdover medium such as that described in U.S. Patent No. 9,258,657, the contents of which are incorporated by reference in their entirety. The cooling holdover medium is made from a solid metal such as aluminum, stainless steel, copper, or lead. It has a sufficiently high specific heat capacity and thermal conductivity to easily transfer heat (receive cryogenics) and store a sufficient amount of refrigeration (cryogenics). More specifically, the cooling holdover medium typically has a specific heat capacity of 2000-4000 kJ / m. 3 It has a specific heat per unit mass (density x specific heat at constant pressure) of 100 W / mK and a thermal conductivity of 150-400 W / mK. Typically, the cooling medium is formed as a metal mass formed by high-temperature casting in liquid form around the heating and cooling circuits to increase thermal contact between them. The distance between adjacent portions of the heating and cooling circuits in the first heat exchanger 11 can be 1 millimeter or more, preferably at least 5 mm. This allows for a mass between the heating circuits that provides a sufficiently high capacity for storage of fluids received by the pumped flow of the main HTF 43.

[0035] As best shown in FIG. 2 , the pressurized hydrogen stream 23 may be split into first and second pressurized hydrogen substreams 23′, 23″. In the first of the two second heat exchangers 25′, the first pressurized hydrogen substream 23′ is cooled in its cooling circuit. Similarly, in the second of the two second heat exchangers 25″, the second pressurized hydrogen substream 23″ is also cooled in its cooling circuit. The cooled stream of the main HTF 47 is split into corresponding first and second substreams 53′, 53″ of the main HTF, respectively, using a three-way flow control valve 67 controlled by a controller (such as the same or different programmable logic controller or computer as that controlling the main HTF pump 41). After being cooled in the corresponding one of the two second heat exchangers 25′, 25″, the two streams of pressurized hydrogen obtained from the substreams 23′, 23″ are used to fill corresponding tanks of the FCEVs 35′, 35″.

[0036] The embodiments of Figures 2 and 6 can be used to simultaneously fill two tanks of an FCEV. For example, one of the buffer vessels 19 at one pressure can provide pressurized hydrogen used to fill the tank of a first FCEV 35', and another of the buffer vessels 19 at a different pressure can provide hydrogen used to fill the tank of a second FCEV 35''. Those skilled in the art will recognize that the illustration of the set of valves 21, one or more buffer vessels 19, and first and second pressurized hydrogen side streams 23', 23' is simplified. The lines leaving the buffer vessel 19 can be branched to accomplish this simultaneous filling, and need not be limited to the simple illustrated scheme in which a single manifold handles a single stream from the buffer vessel 19.

[0037] Optionally, the temperature of the hydrogen (used to fill the FCEV tanks) is measured by a temperature sensor 29′ associated with the first FCEV 35′, and the temperature of the hydrogen is measured by a temperature sensor 29″ associated with the second FCEV 35″. A controller (such as the same or different programmable logic controller or computer as that controlling the main HTF pump) controls a three-way flow control valve 55 to allocate the cooled main HTF 23 flow between the main HTF 56 flow supplied to the warming circuit of the second heat exchanger 25 and the bypass flow of the main HTF 58. This control is based on the temperature measured by the temperature sensor 29 and a predetermined setpoint temperature or range of setpoint temperatures to be achieved. The cooled bypass flow of the main HTF 58 and the warmed flow of the main HTF 57 are combined and returned to the surge vessel 37.

[0038] As best shown in FIG. 3 , if the warming in the first heat exchanger 11 is insufficient to reach the desired temperature, the resulting vaporized hydrogen stream in the vaporized hydrogen circuit 13 can be further warmed in the auxiliary heat exchanger 15. The vaporized hydrogen stream in circuit 13 is fed to the warming circuit of the auxiliary heat exchanger 15 to produce a further warmed stream of vaporized hydrogen that is combined with the liquid hydrogen stream from the bypass circuit 24. Flowing through the cooling circuit of the auxiliary heat exchanger 15 is an auxiliary heat exchanger fluid (auxiliary HTF). The auxiliary HTF is pumped by an auxiliary HTF pump 49, warmed by a heater 51, sent to the cooling circuit of the auxiliary heat exchanger 15, and returned to the inlet of the auxiliary HTF pump 49. Non-limiting examples of the heater 51 include an electric heater or a radiator heated by an ambient air fan, such as those disclosed in WO2021138169A1. The operation of the auxiliary HTF pump 49 is controlled by a controller (such as the same or a different programmable logic controller or computer as that controlling the main HTF pump) based on the temperature measured by the temperature sensor 52 and a predetermined temperature setpoint or temperature setpoint range. The temperature sensor 52 may measure the surface temperature of the auxiliary heat exchanger 15, the temperature of the auxiliary HTF in the cooling circuit of the second heat exchanger 15, or the temperature of the auxiliary HTF at the outlet of the cooling circuit of the second heat exchanger 15. The auxiliary heat exchanger may have any configuration known in the art of heat transfer involving cryogenic fluids, but is typically a tube-in-tube heat exchanger. The warming circuit is an inner tube concentrically disposed within an outer tube. The cooling circuit is formed by the annular space between the inner and outer tubes.

[0039] As best shown in Figure 4, at least a portion of the pressure buildup circuit for storage vessel 1 extends through the second warming circuit of first heat exchanger 11. Valve 79 can be opened to allow a quantity of liquid hydrogen from storage vessel 1 to flow to the second warming circuit via pressure buildup circuit liquid hydrogen supply line 77. The liquid hydrogen is vaporized in the warming circuit and returned to the headspace of storage vessel 11 via gaseous hydrogen line 83, thereby building up pressure therein. This can be particularly useful when first heat exchanger 11 is a refrigerated holdover medium as described above.

[0040] As best shown in Figure 5, at least a portion of the boil-off gas vent line for storage vessel 1 extends through the second warming circuit of first heat exchanger 11. Valves 87 and 89 can be opened to allow a quantity of boil-off gas from the headspace of storage vessel 1 to flow to the second warming circuit via headspace supply line 85. The cold boil-off gas transfers hydrogen to first heat exchanger 11 as it flows through the warming circuit and is then released to the ambient atmosphere via gaseous hydrogen line 83 and vent 91.

[0041] As best shown in FIG. 6 , if the temperature of the main HTF is deemed too cold, the pumped flow of the main HTF 43 can be warmed by heat exchange with ambient air. Based on the temperature measured by the pressure sensor 81, a controller (such as a programmable logic controller or computer that may be the same as or different from the controller controlling the main HTF pump 41) controls three-way flow control valves 95′, 95″. The three-way flow control valves 95′, 95″ can be selectively opened to allow at least a portion of the flow of main HTF from the main HTF bypass flow 97 to enter a main HTF bypass loop 97 that includes a first end in downstream flow communication with the main HTF line 43 and a second end in upstream fluid communication with the main HTF 43. The relatively cool main HTF is warmed by a fan heater 99 that blows ambient air across a heat exchanger section of the fan heater 99. Typically, the fan heater is a fin fan. A fin fan is a well-known type of heat exchanger that moves ambient air over finned tubes through which a hot or cold (relative to ambient) fluid flows. The main HTF thus warmed can then flow into the cooling circuit of the first heat exchanger 11.

[0042] As best shown in FIG. 7, each of the features described in FIGS. 2-6 can be combined into one system.

[0043] The present invention provides several advantages.

[0044] The present invention does not require an external cooling source because the liquid hydrogen frigory recovered in the first heat exchanger is used in the second heat exchanger to cool the pressurized hydrogen used to fill the FCEV's tanks.

[0045] While the present invention has been described in connection with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist of, or consist essentially of disclosed elements, or may be practiced in the absence of elements not disclosed. Furthermore, where language refers to an order, such as first and second, it should be understood in an illustrative sense and not a limiting sense. For example, one skilled in the art may recognize that certain steps can be combined into a single step.

[0046] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0047] The term "comprising" in the claims is an open transitional term meaning that the claim elements identified thereafter are a non-exclusive enumeration, i.e., anything else may additionally be included and remain within the scope of "comprising." "Comprising" is defined herein as necessarily including the more restrictive transitional terms "consisting essentially of" and "consisting of," and thus "comprising" may be replaced by "consisting essentially of" or "consisting of" and remain within the scope of the expressly defined "comprising."

[0048] "Providing" in the claims is defined to mean providing, supplying, making available, or preparing something. This step may be performed by any actor in the absence of explicit claim language.

[0049] Optionally or optionally means that the subsequently described event or circumstance may or may not occur. The description includes cases where the event or circumstance occurs and cases where it does not occur.

[0050] Ranges may be expressed herein as from about one particular value and / or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and / or to the other particular value, along with all combinations within said ranges.

[0051] All references identified herein are incorporated by reference in their entirety into this application, as are the specific information for which each is cited.

Claims

1. 1. A system for filling a tank of a fuel cell electric vehicle with pressurized hydrogen, comprising: A liquid hydrogen storage container (1), a liquid hydrogen pump (5) in downstream flow communication with the liquid hydrogen storage vessel (1), the liquid hydrogen pump (5) adapted and configured to receive a liquid hydrogen stream (3) from the liquid hydrogen storage vessel (1) and to pump and pressurize the liquid hydrogen stream to produce a pressurized hydrogen stream (9); a first heat exchanger (11) having a warming circuit (14) adapted and configured to receive and vaporize a first portion (10) of the pressurized hydrogen stream therein to produce a vaporized hydrogen stream, the first heat exchanger (11) also having a cooling circuit; a bypass circuit (24) adapted and configured to receive a second portion (12) of the pressurized hydrogen flow from the liquid hydrogen pump (5); a hydrogen vapor circuit (13) adapted and configured to receive said hydrogen vapor stream; a buffer vessel supply conduit (17) adapted and configured to receive the vaporized hydrogen flow from the vaporized hydrogen circuit and the second portion of the pressurized hydrogen flow from the bypass circuit (24) to form a combined flow; a first temperature control valve (18) adapted and configured to control the flow rate of the vaporized hydrogen stream in the vaporized hydrogen circuit; a second temperature control valve (16) adapted and configured to control the flow rate of the second portion in the bypass circuit; at least one buffer vessel (19) adapted and configured to receive and store the mixed stream from the buffer vessel supply conduit (17) until vehicle tank filling is required; a second heat exchanger (25) having a cooling circuit (26) adapted and configured to receive and cool the mixed stream from the buffer vessel supply conduit (17) and / or the stream of pressurized hydrogen from the at least one buffer vessel (19) to produce a cooled stream of pressurized hydrogen, the second heat exchanger (25) also having a warming circuit; a filling circuit comprising, in flow order, the cooling circuit of the second heat exchanger and at least one filling dispenser (31) adapted and configured to engage a fuel cell electric vehicle (35) to enable its tank to be filled with the cooling stream of pressurized hydrogen; a temperature sensor (20) arranged in the buffer vessel supply conduit (17), the temperature sensor (20) being adapted and configured to measure the temperature of the mixed flow; a heat exchange fluid loop (39, 43, 47, 56, 57, 58) comprising, in flow order, a surge receptacle (37) containing a main heat transfer fluid; and a main heat transfer fluid pump (41) adapted and configured to pump the main heat transfer fluid through the heat exchange fluid loop, the cooling circuit of the first heat exchanger, the warming circuit of the second heat exchanger, and the surge receptacle (37); Including, the first heat exchanger (11) adapted and configured to exchange heat between the relatively warm main heat transfer fluid and the relatively cool first portion of the pressurized hydrogen stream to produce a cooled stream of the vaporized hydrogen stream and the main heat transfer fluid; the second heat exchanger is adapted and configured to exchange heat between, on the one hand, the relatively warm mixed stream and / or the relatively warm pressurized hydrogen stream from the at least one buffer vessel (19) and, on the other hand, the relatively cold cooling stream of the main heat transfer fluid; and The first and second temperature control valves (18, 16) control the flow rate of the vaporized hydrogen and the second portion, respectively, based on the temperature measured by the temperature sensor.

2. 2. The system of claim 1, wherein the at least one filling dispenser includes first and second filling dispensers (31′, 31″), each one of the first and second filling dispensers (31′, 31″) adapted and configured to engage with a respective fuel cell electric vehicle (35′, 35″) to enable its associated tank to be filled with pressurized hydrogen, and the filling circuit branches into a first branch (23′) adapted and configured to supply pressurized hydrogen from the at least one buffer receptacle (19) to the first filling dispenser, and a second branch (23″) adapted and configured to supply pressurized hydrogen from the at least one buffer receptacle (19) to the second filling dispenser.

3. an auxiliary heat transfer pump (71) and an auxiliary heat exchanger (49) including a heating circuit in flow communication between the heating circuit of the first heat exchanger and the buffer vessel supply conduit (17); an auxiliary heat transfer circuit is formed from the cooling circuit of the auxiliary heat exchanger and the auxiliary heat transfer pump (71); the auxiliary heat transfer circuit is adapted and configured to circulate an auxiliary heat transfer fluid from the auxiliary heat transfer pump, through the cooling circuit of the auxiliary heat transfer circuit, and back to the auxiliary heat transfer pump; and 2. The system of claim 1, wherein the auxiliary heat exchanger is a tube-in-tube heat exchanger including an inner tube concentrically disposed within an outer tube, the warming circuit of the auxiliary heat exchanger being the inner tube, and the cooling circuit of the auxiliary heat exchanger being the outer tube.

4. 2. The system of claim 1, further comprising a pressure build-up circuit (77, 83) in flow communication between a liquid hydrogen storage area of ​​the liquid hydrogen storage vessel (1) and a head space of the liquid hydrogen storage vessel (1), the pressure build-up circuit adapted and configured to receive a flow of liquid hydrogen from the liquid hydrogen space of the liquid hydrogen storage vessel (1), vaporize the flow of liquid hydrogen received from the liquid hydrogen storage vessel (1) in a second warming circuit of the first heat exchanger through heat exchange with a mass of the heat exchanger, and return the vaporized liquid hydrogen (83) to the head space to increase the pressure therein.

5. 2. The system of claim 1, further comprising a boil-off gas vent circuit in flow communication between a headspace of the liquid hydrogen storage vessel and an ambient atmosphere of the system, the boil-off gas vent circuit including a first end in downstream flow communication with the headspace, a second end selectively open to the ambient atmosphere, and a second warming circuit of the first heat exchanger between the first end and the second end, the boil-off gas vent circuit adapted and configured to receive boil-off gas from the headspace, warm the received boil-off gas in the second warming circuit through heat exchange with a mass of the first heat exchanger, and vent the warmed boil-off gas to the ambient atmosphere via the second end.

6. a main heat transfer line in fluid communication between the main heat transfer fluid pump (41) and the cooling circuit of the first heat exchanger; a main heat transfer fluid bypass loop (97) having a first end in downstream fluid communication with the main heat transfer fluid line, a second end in upstream fluid communication with the main heat transfer fluid line, and a heat exchanger section therebetween; a fan heater (99) adapted and configured to blow ambient air over the heat exchange section to warm the pumped flow of main heat transfer fluid before it is cooled in the first heat exchanger (11); The system of claim 1 further comprising:

7. 2. The system of claim 1, wherein the first heat exchanger (11) comprises a mass of metal formed by high temperature casting in liquid form around the heating and cooling circuits thereof.

8. a pressure sensor (27) and a temperature sensor (29), respectively, located in the charging circuit, adapted and configured to measure the pressure and temperature, respectively, of the cooling stream of pressurized hydrogen received from the second heat exchanger; a pressure control valve (33) arranged in the filling circuit, adapted and configured to control the pressure of the cooling flow of the pressurized hydrogen used to fill a tank of a fuel cell electric vehicle (35), the operation of the pressure control valve (33) being based on the pressure and temperature measured by the pressure and temperature sensors (27, 29); The system of claim 1 further comprising:

9. 1. A method for filling a tank of a fuel cell electric vehicle with pressurized hydrogen, comprising: Providing a system according to claim 1; pumping liquid hydrogen from the liquid hydrogen storage vessel (1) using the liquid hydrogen pump (5) to produce a pressurized hydrogen stream; pumping a flow of main heat transfer fluid through the heat exchange fluid loop using the main heat transfer fluid pump (41); dividing said pressurized hydrogen stream (9) into first and second portions (10, 12); vaporizing the first portion (10) in the warming circuit (14) of the first heat exchanger and cooling the flow of main heat transfer fluid in the cooling circuit of the first heat exchanger through heat exchange therebetween to produce a flow of vaporized hydrogen and a cooling flow of main heat transfer fluid; receiving the vaporized hydrogen stream into the vaporized hydrogen circuit (13); receiving the second portion (12) into the bypass circuit (24); receiving a combined flow comprising the vaporized hydrogen flow from the vaporized hydrogen circuit and the second portion into the buffer vessel supply conduit (17); receiving and storing said mixed stream in said at least one buffer vessel (19) until filling of the vehicle tank is required; when vehicle tank filling is required, cooling the mixed stream from the buffer vessel supply conduit (17) and / or a stream of pressurized hydrogen from the at least one buffer vessel (19) in the cooling circuit (26) of the second heat exchanger and warming the cooled stream of main heat transfer fluid in the warming circuit of the second heat exchanger through heat exchange therebetween to produce a cooled stream of pressurized hydrogen and a warmed stream of main heat transfer fluid; measuring the temperature of the mixed flow in the buffer vessel supply conduit (17) using the temperature sensor (20); controlling the flow rate or pressure of the vaporized hydrogen flow and the second portion using the first and second temperature control valves (18, 16), respectively, based on the temperature sensed by the temperature sensor; filling the vehicle tank with a cooling stream of pressurized hydrogen; A method comprising:

10. pumping an auxiliary heat transfer fluid in the auxiliary heat exchange circuit using an auxiliary heat transfer pump (71) to generate a recirculation flow of said auxiliary heat transfer fluid; warming the vaporized hydrogen stream in a warming circuit of an auxiliary heat exchanger, and cooling the recirculation stream of the auxiliary heat transfer fluid in a cooling circuit of the auxiliary heat exchanger (49) through heat exchange between the vaporized hydrogen stream and the recirculation stream of the auxiliary heat transfer fluid; The method of claim 9 further comprising:

11. supplying a flow of liquid hydrogen from said liquid hydrogen storage vessel (1) to a second warming circuit of said first heat exchanger; vaporizing the supplied liquid hydrogen stream in the second warming circuit of the first heat exchanger through heat exchange with a mass of the first heat exchanger to produce a vaporized liquid hydrogen stream; returning the vaporized liquid hydrogen stream to the headspace of the liquid hydrogen storage vessel (1), thereby increasing its pressure; The method of claim 9 further comprising:

12. supplying a flow of gaseous hydrogen from the headspace of the liquid hydrogen storage vessel (1) to a second warming circuit of the first heat exchanger; vaporizing the supplied liquid hydrogen stream in a second warming circuit of the first heat exchanger and venting the vaporized liquid hydrogen to the ambient atmosphere; The method of claim 9 further comprising:

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