Systems and methods with vaporization management for liquefied gas storage

Abstract

This invention relates to the field of gas or liquid storage or distribution, and discloses a system and method for storing liquefied gases with vaporization management. The system includes a cryogenic tank for storing liquefied fuel, a pump for supplying and compressing a first portion of liquefied fuel, a heat exchanger for providing a cooling load to the first portion of liquefied fuel, and an expansion valve for expanding the first portion of liquefied fuel from the heat exchanger into a multiphase flow comprising a liquid phase and a gas phase, the multiphase flow having a temperature lower than the initial temperature of the first portion of liquefied fuel from the cryogenic tank. The system also includes a liquid-vapor separator for separating the liquid and gas phases in the multiphase flow, the liquid phase being returned to the cryogenic tank. This system and method minimize or eliminate the loss of liquefied fuels such as hydrogen, or have zero hydrogen vaporization loss. The hydrogen or vapor from the liquefied fuel in the cryogenic tank can also be used to provide backup power and to provide a cooling load.

Description

Technical Field

[0001] This invention relates to the field of gas or liquid storage or distribution, and more particularly to systems and methods for liquefied gas storage with vaporization management. Background Technology

[0002] Many motor vehicles are currently powered by internal combustion engines that use fossil fuels. Due to the limited supply and adverse environmental impact associated with burning petroleum-derived fuels, vehicles powered by alternative, environmentally friendly fuels such as hydrogen are now being developed. Fuel cells can be used to produce electricity for motor vehicles through the electrochemical reaction of hydrogen fuel with an oxidant such as air. Other hydrogen-powered vehicles can be powered by the combustion of hydrogen. Supplying fuel, or adding hydrogen, to fuel cell vehicles (FCVs) and other hydrogen-powered vehicles presents different challenges compared to adding petroleum-based fuels such as gasoline to vehicles.

[0003] Hydrogen refueling stations for fuel cell vehicles store fuel in either gaseous or liquid form before dispensing it as compressed gaseous hydrogen to the vehicle. Fuels such as liquefied gas or liquid hydrogen can be stored in cryogenic tanks insulated from the environment. However, as the liquid absorbs heat from the environment, heat leaking into the tank causes the liquefied gas to evaporate, producing “vaporized” vapor. As the vapor continues to accumulate inside the tank, the pressure increases. Excess vapor must be released into the environment through a safety valve to keep the tank below its pressure limits, resulting in the loss of some liquefied fuel or gas. Systems with minimal or zero vaporization are required. Summary of the Invention

[0004] This invention provides a system and method for storing liquefied gases or fuels with vaporization management. For example, the liquefied fuel includes or is hydrogen, and the system is for storing and / or using liquid hydrogen.

[0005] According to some embodiments, a system includes a cryogenic tank configured to store liquefied fuel therein, a pump fluidly connected to the cryogenic tank, a heat exchanger connected to the pump, an expansion valve, and a liquid-vapor separator fluidly connected to the expansion valve. The pump is configured to supply or pump a first portion of liquefied fuel from the cryogenic tank while compressing the first portion of liquefied fuel to a greater pressure. The heat exchanger is configured to provide a cooling load to the first portion of liquefied fuel from the pump. The expansion valve is configured to expand the first portion of liquefied fuel from the heat exchanger into a multiphase flow comprising a liquid phase and a gas phase. The temperature of the multiphase flow is lower than the initial temperature of the first portion of liquefied fuel from the cryogenic tank. The liquid-vapor separator is fluidly connected to the expansion valve and configured to separate the liquid and gas phases in the multiphase flow. The liquid phase is configured to return to the cryogenic tank. In some embodiments, the liquefied fuel comprises or is hydrogen. The pump includes one or more submerged liquid pumps disposed inside the cryogenic tank and configured to compress and increase the pressure of the first portion of liquefied fuel to be pumped out.

[0006] In some embodiments, the system further includes an expansion turbine coupled to a heat exchanger and an expansion valve. The expansion turbine is configured to isentropically expand a first portion of the liquefied fuel from the heat exchanger. In some embodiments, the expansion valve is a Joule-Thomson (JT) valve. The system may also include an interlock chamber fluidly coupled to the cryogenic tank and configured to return the liquid phase to the cryogenic tank. The liquid phase may be mixed with the liquefied fuel or sprayed into the headspace of the cryogenic tank. A vapor phase may be present in the headspace.

[0007] In some embodiments, the liquid-vapor separator is configured to supply a vapor phase to a heat exchanger to provide an additional cooling load to the first portion of liquefied fuel from the pump. Additionally, a cryogenic tank may be configured to supply a vapor phase of the liquefied fuel from the top space of the cryogenic tank to the heat exchanger for providing an additional cooling load to the first portion of liquefied fuel from the pump. The system may also include at least one or both of a refrigeration unit and a backup power unit coupled to the heat exchanger. The refrigeration unit is configured to receive the gas or vapor phase from the heat exchanger and provide a cooling load to a facility such as a data center. The backup power unit is configured to receive the gas or vapor phase from the heat exchanger and generate electricity. The backup power unit includes one or more fuel cells or internal combustion engines for generating electricity.

[0008] In some embodiments, the system may also include a fuel supply station comprising a distributor. The fuel supply station is configured to receive a second portion of liquefied fuel from a cryogenic tank and distribute it, in the form of gaseous or liquid fuel, to receiving fuel tanks, such as onboard fuel tanks for vehicles.

[0009] In another aspect, the present invention provides a method. The method includes the steps of: providing liquefied fuel stored in a cryogenic tank, and pumping a first portion of the liquefied fuel from the cryogenic tank via a pump fluidly connected to the cryogenic tank, while simultaneously compressing the first portion of the liquefied fuel to a higher pressure. The method further includes cooling the first portion of the liquefied fuel from the pump via a heat exchanger, which may be connected to a cryogenic gas flow from the system (a vapor phase in the headspace or a vapor phase after a liquid-vapor separator), and expanding the first portion of the liquefied fuel from the heat exchanger into a multiphase flow via an expansion valve. The cooling process may be substantially isobaric. The multiphase flow comprises a liquid phase and a gas phase and has a temperature lower than the initial temperature of the first portion of the liquefied fuel from the cryogenic tank. The method further includes separating the liquid and gas phases in the multiphase flow via a liquid-vapor separator fluidly connected to the expansion valve, and returning the liquid phase from the liquid-vapor separator to the cryogenic tank.

[0010] In some embodiments, the liquefied fuel comprises or is hydrogen. The pump comprises one or more submerged liquid pumps disposed within the cryogenic tank. The method may also include isentropically expanding a first portion of the liquefied fuel from the heat exchanger via an expansion turbine coupled to a heat exchanger and an expansion valve. In some embodiments, the expansion valve is a Joule-Thomson valve.

[0011] In some embodiments, the liquid phase is fluidly connected to an interlock chamber of the cryogenic tank and returned to the cryogenic tank. The liquid phase is either supplied to the cryogenic tank's liquid phase or can be injected into the vapor phase of the cryogenic tank's top space during top filling.

[0012] In some embodiments, the method further includes providing a gaseous phase from the liquid-vapor separator to a heat exchanger to provide an additional cooling load to the first portion of liquefied fuel from the pump. Additionally, the method may include providing a vapor phase of the liquefied fuel from the top space of a cryogenic tank to the heat exchanger to provide an additional cooling load to the first portion of liquefied fuel from the pump. The method may further include at least one or both of the following: providing a cooling load to the facility in need from a refrigeration unit coupled to the heat exchanger using the gas or vapor phase from the heat exchanger; and generating electricity in a backup power unit using the gas or vapor phase from the heat exchanger. In some embodiments, electricity is generated via one or more fuel cells in the backup power unit. The electricity from the backup power unit may be provided to a data center or a pump. The refrigeration unit provides a cooling load to the facility or environment requiring cooling, such as a data center.

[0013] The method may also include supplying a second portion of liquefied fuel from a cryogenic tank to a fuel supply station including a distributor, and distributing the second portion of liquefied fuel in the form of gaseous or liquid fuel to a receiving fuel tank, such as a vehicle's onboard fuel tank.

[0014] The systems and methods provided in this invention offer numerous advantages as described herein. For example, in some embodiments, the invention provides a system for hydrogen storage and supply. The systems of this invention minimize or eliminate losses of liquefied fuels such as hydrogen, or have zero hydrogen vaporization losses. Hydrogen or vapor from liquefied fuels in cryogenic tanks can also be used to provide backup power (e.g., to provide backup power for pumps) and to provide cooling loads (e.g., to provide cooling loads for data centers). Attached Figure Description

[0015] The invention can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, by convention, the various features in the drawings are not necessarily drawn to scale. Rather, for clarity, the dimensions of the various features have been arbitrarily enlarged or reduced. Throughout the specification and drawings, the same reference numerals denote the same features.

[0016] Figure 1 A block diagram of a first exemplary system and flow path for liquids, vapors, and supercritical fluids according to some embodiments is shown.

[0017] Figure 2 It shows Figure 1 A temperature-entropy (specific entropy) plot (i.e., TS plot) of an exemplary state condition in an exemplary system.

[0018] Figure 3 A block diagram of a second exemplary system and flow path for liquids, vapors, and supercritical fluids according to some embodiments is shown.

[0019] Figure 4 The effect of mass flow rate in the top space of the cryogenic tank on the liquid fraction and cooling efficiency after Joule-Thomson (JT) expansion is shown.

[0020] Figure 5 It shows Figure 3 An example of an exemplary state condition TS diagram in an exemplary system.

[0021] Figure 6 The effect of the mass flow rate of the cryogenic tank top space on the liquid fraction and cooling efficiency after Joule-Thomson (JT) expansion is shown at a pump discharge pressure of 900 bar.

[0022] Figure 7 A block diagram of a third exemplary system according to some embodiments is shown, which integrates vaporization management with downstream power generation using hydrogen from a cryogenic tank.

[0023] Figure 8A block diagram of a fourth exemplary system according to some embodiments is shown, which integrates vaporization management with a refrigeration unit that generates electricity downstream and provides cooling loads.

[0024] Figure 9 A block diagram of a fifth exemplary system including a refueling station according to some embodiments is shown.

[0025] Figure 10 The illustration shows the liquid level in the cryogenic tank, the hydrogen mass flow rate, and the pressure in the headspace of the cryogenic tank during an exemplary fuel supply operation at a liquid hydrogen fuel supply station (LHRS).

[0026] Figure 11A A flowchart of an exemplary method according to some implementations is shown. Figure 11B and 11C A flowchart of some steps is shown. Figure 11A These steps may be included in exemplary methods.

[0027] Figure 12 A thermodynamic cryogen subcooler (TCS) for a launch pad subcooling system reported in the prior art is shown. Detailed Implementation

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] The description of exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. In this specification, related terms such as “down,” “up,” “horizontal,” “vertical,” “above,” “below,” “upward,” “downward,” “top,” and “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to directions as described subsequently or as shown in the drawings discussed. These related terms are for ease of description and do not require the device to be constructed or operated in a particular orientation. Unless otherwise expressly stated, terms relating to connection, linkage, etc., such as “connection” and “interconnection,” refer to a relationship in which structures are directly or indirectly fixed or connected to each other through intermediate structures, and to movable or rigid connections or relationships.

[0030] For the purposes described below, it should be understood that alternative variations and implementations may be taken of the embodiments described below. It should also be understood that the specific products, compositions, and / or methods described herein are exemplary and should not be considered limiting.

[0031] In this invention, "the" includes plural references, and a reference to a particular numerical value includes at least that particular value, unless the context explicitly indicates otherwise. When a value is expressed as an approximation using the antecedent "about," it should be understood that the particular value forms another embodiment. As used herein, "about X" (where X is a numerical value) preferably refers to ±10% of the referenced value, including endpoint values. For example, the phrase "about 8" preferably refers to a value in the range of 7.2 to 8.8 (inclusive of endpoint values ​​7.2 and 8.8). Where present, all ranges are inclusive and composable. For example, when listing a range of "1 to 5," the listed range should be interpreted as including the ranges "1 to 4," "1 to 3," "1-2 and 4-5," "1-3 and 5," "2-5," etc. Furthermore, when a list of alternatives is provided, the list can be interpreted as meaning that any alternative can be excluded, for example, by negative limitation in the claims. For example, when listing the range “1 to 5”, the listed range can be interpreted to include cases where any one of 1, 2, 3, 4, or 5 is negatively excluded; therefore, the statement “1 to 5” can be interpreted as “1 and 3-5, but not 2”, or simply as “excluding 2”. It is intended that any component, element, property, or step expressly referenced herein may be expressly excluded from the claims, whether such component, element, property, or step is listed as an alternative or whether it is referenced separately.

[0032] Unless otherwise explicitly stated, the terms “substantially” and “substantially the same” as used herein shall be understood to cover parameters that fluctuate within a suitable range, such as ±10% or ±15% fluctuation of the parameter. In some implementations, the fluctuation range is within ±10%.

[0033] Unless otherwise explicitly stated, liquefied fuels such as hydrogen are stored in storage tanks and pumped out in liquid form using pumps. They can be dispensed into the vehicle's receiving tanks in either gaseous or liquid form.

[0034] As used herein, when an element or component is described as forming a connection to, coupled to, or in contact with another element or component, that element or component may be directly connected to, coupled to, or in contact with the particular element or component, or may be connected, coupled to, or in contact with the particular element or component through an intermediate element or component. When an element or component is described as being "directly connected to," coupled to, or in contact with another element, no intermediate element or component exists.

[0035] As used herein, the term "thermally connected" or "thermally coupled" will be understood as meaning that components are directly connected together or connected through an intermediate component, such that heat can be transferred between the components and that the components can be in direct contact with each other or in contact through an intermediate component. As used herein, the term "fluidly connected" or "fluidly coupled" will be understood as meaning that a component is connected to a pipe or line and configured to allow gas or liquid to flow through that component. As used herein, the term "electrically connected" or "electrically coupled" will be understood to cover electrical connections using wired or wireless connections.

[0036] The term “ambient temperature” as used in this article will be understood as the temperature under ambient conditions, such as room temperature of 20-22°C.

[0037] Liquefied gases such as liquid hydrogen or fuels are stored in cryogenic tanks. Heat leaking into these tanks causes the liquid to evaporate, producing "vaporized" vapor and increasing the pressure of the gas in the headspace. Over time, the pressure buildup in the tank necessitates venting the gaseous hydrogen from the headspace to keep the cryogenic tank below its pressure limits. As an alternative to venting, the vaporization problem can be addressed by introducing a cooling load into the cryogenic tank to offset the heat leakage.

[0038] The goal of cryogenic liquid hydrogen storage is zero vaporization, which minimizes or eliminates the loss of hydrogen as a gas from the cryogenic tank, thereby improving operational efficiency.

[0039] J. Andersson et al. reviewed the options for large-scale hydrogen storage in "Large-scale hydrogen storage," International Journal of Hydrogen Energy 44 (2019): 11901-11919. Exhausted vapors can be injected into later stages of the liquefaction cycle to avoid their net loss from the system. However, cryogenic tanks used for storage must be located close to the large-scale liquefaction facility, or measures must be taken to collect the exhaust vapors and transport them to the liquefaction system.

[0040] WU Notardonato et al., “Zero boil-off methods for large-scale liquid hydrogen tanks using integrated refrigeration and storage,” IOP Conference Series: Materials Science and Engineering, 278(1), 2017. This paper describes methods for removing energy from liquid hydrogen tanks and controlling the state of the propellant using an integrated refrigeration and storage system (IRAS). Heat leakage into the tank is eliminated using a helium cryogenic cooler with an intercalation heat exchanger. One such cryogenic cooler is the Linde LR1620 cooler, which is a Brayton cycle unit using a closed-loop helium refrigeration system. However, this method faces several challenges, such as temperature and pressure control of the integrated system during zero boil-off operation, challenges in manufacturing cryogenic tanks with intercalation heat exchangers, and the energy consumption of the helium cryogenic cooler, including during cycling to match the requirements of unsteady cooling operations.

[0041] DRZakar et al. reported using a cryogenic loop heatpipe to remove a certain amount of generated vapor from the tank and transport it to a cryogenic cooler, where it condenses back into liquid and returns to the tank. See DRZakar et al., “Zero-boil-off cryogen storage cryogenic loop heatpipe for use in unmanned air vehicles,” 15th International Energy Conversion Engineering Conference, 2017. The heatpipe system requires a cryogenic cooler to reliquefy the vapor extracted from the top space of the tank.

[0042] However, for systems using cryogenic coolers, existing cryogenic coolers capable of providing cooling loads at temperatures below 30 K using expansion cycles are complex and require multiple stages. Alternative cryogenic coolers based on magnetocaloric processes are still under development and await breakthroughs in materials and engineering for large-scale operations. Furthermore, the size of cryogenic cooler systems is also limited when using them. Multiple systems can be installed in parallel, but this presents challenges to scalability due to complexity, energy consumption, and capital costs.

[0043] The concept of a thermodynamic cryogenic supercooler (TCS) was proposed for launch pad supercooling systems. See S. Mustafi et al., “Subcooling cryogenic propellants for long-duration space exploration,” AIAA SPACE 2009 Conference & Exposition (2009). In the theoretical isobaric cooling process, liquid hydrogen expands isenthalpically through a Joule-Thomson valve to supercool the liquid hydrogen circulating from the cryogenic tank using a heat exchanger. The hydrogen from the expansion stream does not return to the tank.

[0044] However, in this TCS concept, the degree of cooling is limited by the initial pressure inside the cryogenic tank and the final pressure after expansion. The expanded hydrogen must be compressed for use outside the tank system. For example, a four-stage compressor is required. The expanded hydrogen does not return to the cryogenic tank. This results in a potential pressure drop, which must be offset by adding cold helium pressurized gas to prevent the cryogenic tank from collapsing.

[0045] The possibility of compressing the liquid stream from the cryogenic tank before isenthalpic expansion has not been considered.

[0046] This invention provides a system and method for storing liquefied gases or fuels with vaporization management. For example, the liquefied fuel includes or is hydrogen, and the system is for storing and / or using liquid hydrogen.

[0047] In some embodiments, the present invention provides a vaporization management system that uses a compression-expansion cycle to counteract at least a portion of heat leakage into a cryogenic tank containing liquid hydrogen, thereby generating a liquid hydrogen stream at a temperature lower than that of the liquid hydrogen in the tank. The compression-expansion cycle includes: a liquid hydrogen stream extracted from the cryogenic tank; a liquid hydrogen pump for compressing the liquid hydrogen stream; a heat exchanger for cooling the compressed liquid hydrogen stream; an expander for generating saturated liquid hydrogen at a temperature lower than that of the initial liquid hydrogen stream; and a reflux mechanism for conveying the liquid hydrogen cooled to a temperature lower than that initially extracted from the cryogenic tank. The system may optionally include a power generation system that uses hydrogen to generate electricity, wherein the power generation system is powered by a portion of the vaporized gas and optionally provides electricity to operate the pump. The present invention also provides systems and methods for supplying fuel while simultaneously providing backup power and cooling loads. For example, the system is a hydrogen refueling station. Backup power and cooling loads are both supplied to the required locations or facilities, such as data centers.

[0048] exist Figure 1 , 3In Figures 7-9, the same items are represented by the same reference numerals, and for the sake of brevity, the descriptions of the structures provided above with reference to the preceding figures will not be repeated. Figure 2 , 4 5-6 and 10 show the relationship with Figure 1 , 3 TS diagrams and characteristic diagrams of examples related to the systems shown in 7-9, Figure 11A-11C The method described herein is a reference. Figure 1 , 3 The exemplary structure described in 7-9 is used to illustrate this. The same logistics at different stages can be labeled with different numbers.

[0049] See Figure 1 The exemplary system 100 includes a cryogenic tank 20, a pump 40, a heat exchanger 60, an expansion valve 80, and a liquid-vapor separator 90. The system may also include an expansion turbine 70.

[0050] Cryogenic tank 20 is configured to store liquefied fuel 14 therein. Cryogenic tank 20 may be an insulated tank suitable for storing liquefied fuel 14 (e.g., liquid hydrogen) at cryogenic temperatures and pressures. In some embodiments, liquefied fuel 14 comprises or is hydrogen. Cryogenic tank 20 may include a headspace 22 in which the vapor phase 16 (vaporization) of liquefied fuel 14 may be present.

[0051] Pump 40 is fluidly connected to cryogenic tank 20 and is configured to supply or pump a first portion 1 of liquefied fuel 14 from cryogenic tank 20 while compressing the first portion 1 of liquefied fuel 14 to a higher pressure. Pump 40 includes one or more submerged liquid pumps disposed within cryogenic tank 20 and configured to compress and increase the pressure of the liquefied fuel stream to be pumped out. The liquefied fuel stream discharged from pump 40 (labeled 2) may be in a supercritical state.

[0052] The heat exchanger 60 is connected to the pump 40 and is configured to provide a cooling load to the liquefied fuel stream 2 from the pump 40, the cooling stream being labeled 3, and the cooling stream 3 may be in a supercritical state.

[0053] The expansion turbine 70 is connected to the heat exchanger 60 and the expansion valve 80. The expansion turbine 70 is configured to expand the cooling flow 3 from the heat exchanger 60 isentropically while producing a lower temperature outlet flow (labeled 4).

[0054] Expansion valve 80 is configured to expand a liquefied fuel stream from heat exchanger 60 or expansion turbine 70 into a multiphase flow 5 comprising a liquid phase 7 and a gas phase 6. In some embodiments, the expansion valve is a Joule-Thomson (JT) valve. The liquid is forced through the JT valve or plug, and its temperature decreases. The multiphase flow 5 is a liquid-vapor mixed-phase flow with a temperature lower than the initial temperature from the first section 1 of cryogenic tank 20.

[0055] The liquid-vapor separator 90 is fluidly connected to the expansion valve 80 and is configured to separate the liquid phase 7 and the gas phase 6 in the multiphase flow 5. The liquid phase 7 is configured to return to the cryogenic tank 20, which provides a cooling load to the cryogenic tank 20 to minimize or eliminate the vaporization of liquefied fuels such as liquid hydrogen.

[0056] The exemplary system 100 may further include an interlock chamber 94 fluidly connected to the cryogenic tank 20 and configured to return the liquid phase 7 to the cryogenic tank 20. The interlock chamber 94 may include at least two ports that can be sequentially opened to allow the delivery of a liquid with a lower pressure to the cryogenic tank 20 at a higher pressure. The interlock chamber 94 may also include a check valve that is associated with operations that reduce the pressure in the cryogenic tank 20 to below the pressure of the cooling liquid (liquid phase 7). The liquid phase 7 may be mixed with liquefied fuel 14 or sprayed into the top space 22 of the cryogenic tank 20 to mix with the vapor phase 16 that may be present in the top space 22.

[0057] The gas phase 6 from the liquid-vapor separator 90 can be supplied to the heat exchanger 60 to provide additional cooling load for the liquefied fuel stream 2 from the liquefied fuel 14 from the pump 40. The gas phase 6 is labeled as gas 8 after passing through the heat exchanger 60.

[0058] As an example 1, the exemplary system 100 has been designed with an immersion liquid pump for isentropic compression to increase the pressure of liquid hydrogen to 450 bar. Figure 2 A thermodynamic state diagram (TS) of hydrogen is shown when hydrogen passes through an exemplary system 100 with vaporization management. In the TS diagram, lines parallel to the horizontal axis represent isothermal processes, and lines parallel to the vertical axis represent isentropic processes.

[0059] exist Figure 2 In this process, the hydrogen flows and states include isentropic compression via pump 40 (hydrogen states from 1 to 2), cooling via heat exchanger 60 (from 2 to 3), liquid expansion via expansion turbine 70 (from 3 to 4), expansion into a multiphase flow via expansion valve 80, such as a JT valve (from 4 to 5), and separation via liquid-vapor separator 90 (from 5 to 6 and 7). The hydrogen flows in states 2 and 3 are supercritical (SC). The gas phase changes from 6 to 8 in heat exchanger 60 provide additional cooling during the cooling process (from 2 to 3).

[0060] The status of logistics at each point is listed in Table 1.

[0061] Table 1

[0062]

[0063] In the thermodynamic cycle of Example 1, a first portion 1 of liquid hydrogen is extracted from a cryogenic tank 20 at a pressure of 5 bar and a temperature of 27 K. The first portion 1 is a saturated liquid. At a temperature of 47.4 K, a pump isentropically compresses the first portion of liquid hydrogen to 450 bar, resulting in a supercritical hydrogen stream 2. This supercritical hydrogen stream undergoes heat exchange with a lower-temperature gas (gas phase 6) to cool the supercritical hydrogen stream to 43.0 K. The supercritical cooled stream 3 is isentropically expanded to 30 bar(a) by an expansion turbine 70 to avoid the formation of a two-phase flow at the turbine outlet. This temperature is 27.3 K. The outlet stream 4 is expanded using a Joule-Thomson valve, producing a multiphase flow 5 of saturated liquid and saturated vapor. In this example, the multiphase flow 5 has a pressure of 1 bar and a temperature of 20.3 K. Based on enthalpy balance, this multiphase flow comprises 77.6% liquid and 22.4% vapor. After separation, saturated liquid 7 and saturated vapor 6 are obtained, both at 1 bar(a). Saturated vapor 6 is used to cool the supercritical hydrogen stream leaving the pump (as described above). The vapor stream cools the supercritical hydrogen stream from 47 K to 43 K, and then the vapor stream leaves the vaporization management system at 38.2 K, losing 44.04 kJ of energy.

[0064] Saturated liquid 7 at 20 K and 1 bar is returned to the cryogenic tank. An interlock chamber is used to control the pressure differential so that the saturated liquid returns to the cryogenic tank at a pressure of 5 bar. The net cooling load supplied to the cryogenic tank is 68 kJ·h / kg H2 pumped. The measured electrical energy requirement using the pump is 720 kJ·e / kg H2 pumped (0.2 kWh / kg), with an energy efficiency of 9.5%. This energy efficiency is advantageous compared to cryogenic cooler systems, which can consume kilowatts of power to provide watt-level cooling power over similar temperature ranges with corresponding efficiencies <1%.

[0065] See Figure 3 An exemplary system 200 is shown. The components of the exemplary system 200 are the same as those in the exemplary system 100, except that the cryogenic tank 20 can be configured to provide the vapor phase 16 of liquefied fuel 14 from the top space 22 of the cryogenic tank 20 to the heat exchanger 60 for providing additional cooling load to the first portion of liquefied fuel (i.e., liquefied fuel stream 2) from the pump 40.

[0066] As an embodiment 2, the exemplary system 200 has been designed with a P200H pump (pumped to 450 bar) and headspace gas 9 (vapor phase 16 becomes headspace gas 9 after leaving cryogenic tank 20) ​​as an additional coolant. Cooling of the compressed gas is achieved using a mixture of headspace gas 9 saturated at the cryogenic tank pressure (5 bar in embodiment 2) and JT flash gas (saturated vapor 6, 1 bar saturated vapor in embodiment 2). This mixture is a mixed stream 10 at a pressure of 1 bar and a temperature of 21.1 K. Ideally, a two-step process is thermodynamically more efficient with less energy loss, where the hotter headspace gas (headspace gas 9) first cools the pump discharge (liquefied fuel stream 2), and then the cooler JT flash gas (saturated vapor 6) further cools the pump discharge; however, this two-step process is more complex and potentially more expensive. Conversely, using mixed stream 10 for cooling the pump discharge is simpler and cheaper.

[0067] Various cooling efficiencies can be obtained by changing the amount of gas in the headspace relative to the JT flash gas, such as... Figure 4 As shown. Figure 4 The effect of the headspace mass flow rate of the cryogenic tank on the liquid fraction and cooling efficiency after JT expansion is shown. The headspace mass flow rate is proportional to the pump discharge flow rate, and the cooling efficiency is the cooling power of the JT flash liquid relative to the pump energy consumption (0.2 kWh / kg) at 1 bar. Higher headspace gas flow rates increase both the liquid fraction and cooling efficiency, but the rate of increase gradually decreases as the liquid fraction approaches 100%. The optimal rate of increase in liquid fraction is likely at a headspace mass flow rate of 0.5 kg / kg_pump, as it is located at the steepest part of the curve. Figure 5 The TS diagram using this condition is shown, which illustrates the thermodynamic state of the material in Example 2. The state of the material is also listed in Table 2.

[0068] Table 2

[0069]

[0070] As an embodiment 3, the exemplary system 200 is also designed to pump isentropically to 900 bar, with headspace cooling. Embodiment 2 shows that using headspace gas improves cooling efficiency, so the absence of headspace gas flow is a special case. In embodiment 3, the exemplary system 200 is used while simultaneously compressing the hydrogen stream 2 to 900 bar.

[0071] Figure 6 The effect of the mass flow rate in the top space of the cryogenic tank on the liquid fraction and cooling efficiency after JT expansion is shown at a pump discharge pressure of 900 bar. The pumping energy required to pump to 900 bar is 0.4 kWh / kg.

[0072] In Example 3, pump 40 is nominally isentropic, and the temperature of hydrogen stream 2 is higher than in Example 1 due to the higher pump outlet pressure. Furthermore, a combination of headspace gas 9 and saturated vapor 6 generated after JT expansion provides the cooling load. Compared to Example 1, even without headspace gas cooling (0.836 vs. 0.776), compressing hydrogen stream 2 to a higher pressure after JT expansion results in a higher liquid fraction. The cooling load increases, but the electrical energy required for pumping also increases—twice that at 450 bar, reaching 0.4 kWh / kg. Moreover, the small amount of vapor following JT expansion means that most of the cooling of hydrogen stream 2 is accomplished using JT flash vapor (saturated vapor 6).

[0073] Table 3 shows the material and thermodynamic conditions of Example 3, in which there is 0.2 kg of headspace gas per kg of pump discharge stream (hydrogen stream 2).

[0074] Table 3

[0075]

[0076] See Figure 7 An exemplary system 300 is illustrated. Exemplary system 300 is identical to exemplary system 200, except that it also includes a backup power unit 120. Exemplary system 300 illustrates the integration of a vaporization management system with a downstream power generation unit. The backup power unit 120 is configured to receive gas 8 from a heat exchanger 60 and generate electricity. Backup power unit 120 includes one or more fuel cells or internal combustion engines for generating electricity. Exhaust gas 11 may be water vapor. Optionally, one or more internal combustion engines may be used in backup power unit 120 to generate electricity via a thermal cycle. Suitable examples of internal combustion engines include, but are not limited to, reciprocating engines, gas turbines, or micro turbines, as well as hydrogen turbines.

[0077] As an example 4, an exemplary system 300 is also designed, in which a polymer electrolyte membrane (PEM) fuel cell or battery pack is used for 450 bar pump discharge and power generation. This embodiment includes the integration of a vaporization management system with downstream power generation using H2 from cryogenic tank 20. This embodiment illustrates the use of a backup power unit 120 with a PEM fuel cell for power generation, where 20 kWh / kg H2 vapor is supplied to the PEM fuel cell. In this embodiment, a portion of the electricity generated by the PEM system is used to power pump 40, equivalent to 0.2 kWh / kg H2 extracted from cryogenic tank 20.

[0078] See Figure 8An exemplary system 400 is illustrated. Exemplary system 400 is identical to exemplary system 200, except that exemplary system 400 also includes a backup power unit 120 and a cooling unit 122 coupled to a heat exchanger 60. Exemplary system 400 illustrates the integration of a vaporization management system with a downstream power generation unit and a cooling unit for cooling a data center. Cooling unit 122 is configured to receive gas 8 from heat exchanger 60 and provide a cooling load to a facility 124, such as a data center. Backup power unit 120 may be coupled to cooling unit 122 and is configured to receive hydrogen from heat exchanger 60 and / or cooling unit 122 and generate electricity. Backup power unit 120 includes one or more fuel cells or internal combustion engines for generating electricity.

[0079] As an example 5, an exemplary system 400 is also designed. For illustrative purposes, the pump discharge pressure is set at 450 bar, and the ratio of headspace gas mass flow rate to pump discharge flow rate is set to 0.5. This embodiment has an integration of a vaporization management system with downstream power generation using H2 from cryogenic tank 20, wherein additional cooling loads (e.g., from gas 8 to gas 12) are extracted from the H2 vapor stream before it is used for power generation. Figure 8 Optional integration is shown in facility 124 with cooling loads such as a data center.

[0080] Example 5 illustrates the extraction of a cooling load from a liquid hydrogen stream using a heat exchanger 60 after exchange with the compressed liquid hydrogen stream, but before it enters a backup power unit 120, such as a PEM fuel cell power generation unit. This cooling load is used to provide cooling for a data center. This cooling load can also be used by any process requiring cooling radiators with temperatures below 0°C. In Example 5, the cryogenic tank pressure is 5 bar, and the outlet temperature of the steam from the heat exchanger is 33.8 K, resulting in a cooling energy of approximately 1.0 kWh·h / kg H2 to raise the steam stream to -20°C.

[0081] See Figure 9 An exemplary system 500 is illustrated. Exemplary system 500 is identical to exemplary system 100, except that exemplary system 500 also includes a fuel supply station 140 containing a distributor. Exemplary system 500 illustrates the integration of a vaporization management system with a hydrogen fuel supply station for a fuel cell vehicle. Fuel supply station 140 is configured to receive a second portion 13 of liquefied fuel 14 from cryogenic tank 20 and distribute it, in the form of a gaseous or liquid fuel, to a receiving fuel tank, such as an onboard fuel tank for a vehicle. Fuel supply station 140 may also include an additional heat exchanger for converting the liquefied fuel 14 from cryogenic tank 20 into the gaseous fuel to be distributed.

[0082] As an example 6, an exemplary system 500 is also designed. In this system, the vaporization management system is integrated with a hydrogen fuel supply station (HRS) for a fuel cell vehicle. In the fuel supply station 140, compressed liquid H2 from pump 40 is ultimately used to fill pre-cooled compressed gas or deliver compressed liquid hydrogen to the on-board H2 storage tank of the hydrogen fuel cell vehicle.

[0083] In addition to its integration with the HRS, Example 6 is characterized by the return of the cooling liquid. The cooled liquid 7 is stored in an interlocked chamber 94 with a check valve, instead of using an interlocking device. Pump 40 is also used to deliver hydrogen as replenishment fuel. Under certain conditions (e.g., high-flow operation), the pressure in cryogenic tank 20 drops. During the HRS operating cycle, the pressure in cryogenic tank 20 increases when the system does not distribute fuel to cryogenic tank 20 due to vaporization associated with static heat leakage. Fuel removal during HRS operation can cause a pressure drop. In this embodiment, when the pressure in the cryogenic tank drops below the pressure of the cooled liquid 7, it can flow into cryogenic tank 20 through the check valve.

[0084] Figure 10 The pressure in the headspace of the cryogenic tank is shown during LHRS fuel supply operations. The pressure dropped from 6.3 bar to 5.5 bar during the continuous refueling of three buses. Figure 10 The figures, from top to bottom, show the liquid level in the cryogenic tank, the hydrogen mass flow rate (kg / hr), and the pressure in the headspace of the cryogenic tank (bar(g)). Curves were generated from the test system database. During three consecutive refueling operations, each lasting approximately 12 minutes, approximately 40 kg of hydrogen was dispensed, and the pressure in the headspace of the cryogenic tank decreased by 0.5 bar or more. However, during the refueling idle time, the pressure in the headspace recovered to approximately 0.2 bar as the two-phase system of the cryogenic tank reached equilibrium and static heat leakage began. Figure 10 The results provide evidence for the pressure drop described above, which may be difficult to achieve in a pump, and also support a dynamic approach of pumping out warmer liquid fuel via fuel supply operation and returning the cooler liquid flow to the cryogenic tank.

[0085] In this system and method, the fuel supply process can be performed periodically. Cooling load can be generated periodically from the fuel supply station. Backup power can be generated intermittently.

[0086] See Figure 11A The present invention also provides an exemplary method 600 as described above and also generally described below.

[0087] In step 602, liquefied fuel 14 is provided and stored in cryogenic tank 20. In some embodiments, liquefied fuel 14 includes or is hydrogen.

[0088] In step 604, a first portion 1 of the liquefied fuel is pumped from the cryogenic tank 20 and compressed to a higher pressure by a pump 40 fluidly connected to the cryogenic tank 20. The first portion 1 of the liquefied fuel and the subsequent flow are referred to as the first portion. The pump 40 may include one or more submersible liquid pumps disposed inside the cryogenic tank 20.

[0089] In step 606, the first portion of the liquefied fuel 14 from pump 40 (i.e., the liquefied fuel flow 2 at this stage) is cooled by heat exchanger 60 connected to pump 40, and the cooling process can be substantially isobaric.

[0090] In step 610, the first portion of the liquefied fuel 14 from the heat exchanger 60 (i.e., the cooling flow 3 at this stage) expands into a multiphase flow 5 via the expansion valve 80. In some embodiments, the expansion valve is a Joule-Thomson valve. The multiphase flow 5 comprises a liquid phase 7 and a gas phase 6, and has a temperature lower than the initial temperature of the first portion from the cryogenic tank 20.

[0091] See Figure 11B The exemplary method 600 may also include a step 608 prior to step 610. In step 608, a first portion of the liquefied fuel (i.e., cooling flow 3) from the heat exchanger 60 isentropically expanded by an expansion turbine 70 connected to the heat exchanger and the expansion valve.

[0092] Refer again Figure 11A In step 612, the liquid phase 7 and the gas phase 6 in the multiphase flow 5 are separated by a liquid-vapor separator 90, which is fluidly connected to the expansion valve 80.

[0093] In step 614, liquid phase 7 is returned from the liquid-vapor separator 90 to the cryogenic tank 20. In some embodiments, liquid phase 7 is returned to the cryogenic tank 20 via a fluidly connected interlock chamber 94 of the cryogenic tank. Liquid phase 7 may be supplied to the liquid phase in the cryogenic tank. Step 614 may include... Figure 11B Step 616. In step 616, the liquid phase 7 can be injected into the vapor phase of the top space 22 of the cryogenic tank 20 during the top filling process.

[0094] In some implementations, in step 604, when using a single pump (e.g., a P200H pump base), the flow rate of the LH2 stream can reach up to 280 kg / h. When using multiple pumps, the flow rate of each pump is up to 280 kg / h, and the pressure of the pumped hydrogen stream is up to approximately 90 MPa. After step 606, the temperature of the cooled high-pressure stream can have the temperature of the liquid hydrogen extracted from the cryogenic tank as a lower limit. The upper limit can be the theoretical temperature at which the pump outlet pressure is reached through isentropic compression (point 2 on the TS diagram, e.g.) Figure 5(At this point, the liquefied fuel stream 2 is not cooled). After expansion step 610, the liquid portion in fluid 6 can range from 0.5 to approximately 0.999. The liquid phase 7 can have a temperature in the range of approximately 20 K as a lower limit and a temperature just below that of the liquid stream extracted from the cryogenic tank as an upper limit. The gas from the headspace used for supplemental cooling, along with the saturated vapor after JT expansion, is pumped at a rate of 0 kg / kg to 10 kg / kg, as a ratio of the headspace gas flow rate to the pump discharge flow rate.

[0095] See Figure 11C and Figure 7-8 The exemplary method 600 may also include one or more of steps 622, 624, 626, 628, and 630. In step 622, the gas phase 6 from the liquid-vapor separator 90 is provided to the heat exchanger 60 to provide additional cooling load to the liquefied fuel stream 2 from the pump 40.

[0096] In step 624, the vapor phase 16 of liquefied fuel from the top space 22 of the cryogenic tank 20 is provided to the heat exchanger 60 to provide additional cooling load to the liquefied fuel stream 2 from the pump 40.

[0097] This exemplary embodiment may also include one or both of steps 626 and 628. In step 626, a cooling load is provided from a refrigeration unit 122 connected to the heat exchanger to the required facility using gas 8 from the heat exchanger 60. The refrigeration unit 122 provides a cooling load to the facility or environment that needs cooling. For example, the cooling load from the refrigeration unit 122 can be used to cool a data center. Backup power and cooling loads can also be supplied to other facilities, such as distribution centers (e.g., for HVAC or cooling).

[0098] In step 628, electricity is generated in the backup power unit 120 using gas 8 from heat exchanger 60. In some embodiments, electricity is generated via one or more fuel cells in the backup power unit 120. Optionally, one or more internal combustion engines can be used in the backup power unit 120 to generate electricity via a thermal cycle. Suitable examples of internal combustion engines include, but are not limited to, reciprocating engines, gas turbines, or micro turbines, as well as hydrogen turbines. Electricity from the backup power unit 120 can be supplied to the data center or pump 40.

[0099] refer to Figure 11C and Figure 9 In step 630, a second portion 13 of liquefied fuel is supplied from the cryogenic tank to a fuel supply station including a distributor, and then distributed in the form of gaseous or liquid fuel to receiving fuel tanks, such as onboard fuel tanks in vehicles.

[0100] See Figure 12The system 150 proposed by Mustafi et al. is shown for comparison. A cryogenic propellant, such as hydrogen (TC1), is drawn from tank 21. A portion is expanded into a two-phase mixture (TC2) at a lower pressure and temperature via valve 81. Most of the liquid hydrogen is pumped as a single-phase liquid into the shell of concentric tube heat exchanger 61 via pump 41. The two-phase hydrogen (TC2) enters the central tube of the concentric tube heat exchanger and extracts heat from the single-phase hydrogen. The two-phase hydrogen completely evaporates and is discharged through compressor 71 (TC3) to the flare stack, with no expanded hydrogen returned to the tank. This system requires a four-stage compressor, which is considered a large and heavy component of the equipment. Helium must be added to prevent tank collapse.

[0101] In comparison, the system provided in this invention has at least the differences described herein. For example, pump 40 is used to increase the pressure of liquid hydrogen before isenthalpic expansion. A portion of the expanded hydrogen (e.g., liquid phase 7) is returned to cryogenic tank 20. A pressure balancing mechanism for returning the liquid phase to cryogenic tank 20 also eliminates the requirement for maintaining the integrity of the helium storage tank. The need for the aforementioned compressor 71 is also eliminated.

[0102] This system and method address challenges related to energy consumption, system complexity, and control by using a single-stage compression step to provide a cooling load to the liquid hydrogen stored in cryogenic tank 20. For example, a first fraction of the liquid hydrogen is extracted from the liquid hydrogen stored in cryogenic tank 20 and compressed to at least 100 bar using a submerged liquid pump 40, which nominally has the same entropy as the liquid hydrogen in cryogenic tank 20 during a theoretically isotropic compression process. The compressed liquefied fuel stream (liquid / supercritical stream) 2 is cooled by heat exchange with the gas phase 6 from JT expansion at a nearly constant pressure. Optionally, vapor 9 from the headspace 22 of cryogenic tank 20 is used to provide additional cooling load. Neither the gas 9 from the headspace of the cryogenic tank nor the gas phase 6 returns to the cryogenic tank after heat exchange, and they can be combined. The cooling (supercritical) flow is first expanded (isentropically) to an intermediate pressure (e.g., 30 bar) by an expansion turbine to prevent the formation of a two-phase mixture, followed by a Joule-Thomson (JT) throttling process to expand to a two-phase mixture at a pressure equal to or less than that from the liquid extracted from the cryogenic tank, producing saturated vapor 6 and a liquid phase 7 at a temperature lower than that of the liquid in cryogenic tank 20. The cooled liquid phase 7 is returned to the cryogenic tank, thus providing a net cooling load to the cryogenic tank. Mechanisms for supplying the liquid include the use of an interlock chamber 94, or by reducing the pressure of cryogenic tank 20 by a fuel supply operation that extracts hydrogen from the cryogenic tank at a rate that reduces the net pressure to the pressure of the expanded liquid flow. As described herein, hydrogen vapor or gas can also be used for power generation after the cooling load is provided.

[0103] The invention can be further optimized by changing the pump discharge pressure, the end temperature of the isobaric cooling process, the end pressure of the expansion turbine expansion process, and the final pressure of the JT expansion process. The pump discharge pressure, the cooling load of the expansion turbine expansion process, and the end temperature of the isobaric cooling process are interrelated and offer opportunities for optimization. For example, Figure 4 Simulation results are shown using a submerged liquid pump operating with saturated liquid hydrogen under different inlet temperatures and pressures, compressing it to varying outlet pressures. The outlet temperature is a function of both inlet conditions and outlet pressure, and is constrained by thermodynamic limits imposed by an ideal isothermal or isentropic compression process. In other words, the lower limit of the temperature is the inlet temperature, and the upper limit is calculated using thermodynamic relations that assume the isentropic compression process utilizes the properties of hydrogen.

[0104] The system described herein can also be integrated with an upstream liquefaction system, wherein the vaporization management system is integrated with a cryogenic tank for storing the products of the liquefaction process. Upstream components of the system may include a liquefier and a hydrogen production unit (e.g., an electrolyzer for converting water into hydrogen and oxygen). At least one or both of the liquefier and the hydrogen production unit may be powered by wind or solar energy.

[0105] The system described herein can also be integrated with a distribution network, wherein LH2 is transported from storage containers to one or more of the following: hydrogen fuel supply stations for ground vehicle transportation, such as heavy-duty vehicles (HDVs), light-duty vehicles (LDVs), and railways; industrial sites that use H2 as part of a steel production process; industrial sites that use H2 as part of a metal production process; and industrial sites that use H2 to provide power and heat during combustion.

[0106] A submerged liquid pump is used to compress the liquid flow, thereby achieving the final temperature and pressure defined by the isothermal and isentropic limits. In the prior art, an external pump is used, and cooling is required (resulting in additional vaporization losses). However, the submerged liquid pump allows for the practical implementation of the compression-expansion cycle described herein. For example, Figure 4 The response curve of a submerged liquid pump approaching the isentropic limit is shown.

[0107] Cooled liquid hydrogen is returned to the cryogenic tank, thus reducing or minimizing vaporization losses. The recirculation mechanism includes an interlock chamber similar to a gas lock; liquid enters the interlock chamber, which is then balanced with the cryogenic tank. The interlock chamber is then closed and pumped back to a low pressure, allowing more liquid to enter. The recirculation mechanism can utilize a dynamic operating process within the cryogenic tank, where a pump is used to distribute H2, intended for vehicle fuel supply, at a sufficiently high rate to reduce the pressure in the cryogenic tank. As the pressure in the cryogenic tank decreases due to H2 distribution, the cooled liquid returns to the cryogenic tank. The pressure then rises again when heat leakage causes vaporization.

[0108] This system and method also offer the following additional benefits. For example, this simplified process uses a submersible liquid pump and a single-stage loop, and eliminates the need for a cryogenic cooler.

[0109] This system and method offer energy efficiency. Providing a cooling load at temperatures below 30 K is a difficult and energy-intensive process. Assuming a pump energy consumption of 0.2 kWh·e / kg, it generates a pumped cooling load of 68 kJ / kg (see Example 1). This cooling load condenses approximately 0.15 kg of hydrogen into a liquid (the latent heat of condensation of hydrogen is 454 kJ / kg). In other words, producing 1 kg of liquid requires an energy input of 1.3 kWh·e / kg. For reference, a fully liquefied method theoretically requires 3.9 kWh·e / kg of energy and in practice approximately 12 kWh / kg to produce liquid hydrogen, although most of the energy is used to cool H2 to its boiling point and provide energy for the para-ortho transition. Since the liquid hydrogen is nominally 100% para-H2, this method avoids the energy losses associated with the ortho-para transition, which can be significant when cooling gaseous H2 during liquefaction.

[0110] This system and method also provide controllability. The cooling load can be provided by starting a submerged liquid pump, and the pump flow rate can be controlled. The pump is submerged and thermally balanced with the liquid hydrogen in the cryogenic tank, so there is no vaporization associated with pump startup.

[0111] This system and method also offer scalability. Submersible liquid pumps have been demonstrated at a scale of 285 kg / hr. For illustrative purposes, the pump used in the system described herein is based on 240 kg / hr. This means that a single pump can provide a kilowatt-level cooling load. Multiple pumps can be used to increase the cooling load on large cryogenic tanks.

[0112] This system and method are also compatible with liquid hydrogen refueling stations. Integration with a liquid hydrogen refueling station that uses liquid pumps to deliver fuel to vehicles is a mechanism that allows cooled liquid to be returned from the vaporization management system to the cryogenic tank. Furthermore, using a liquid tank to deliver the fluid increases the utilization rate of the liquid pumps for value-added activities beyond vaporization management. This integration extends the benefits of simplified design and also improves the economic value of the system by increasing the utilization rate of the liquid pumps.

[0113] The systems and methods provided in this invention offer numerous advantages as described herein. For example, in some embodiments, the invention provides a system for hydrogen storage and fuel supply. The systems of this invention minimize or eliminate the loss of liquefied fuels such as hydrogen, or have zero hydrogen vaporization loss. The hydrogen or vapor produced from the liquefied fuel in the cryogenic tank can also be used to provide backup power (e.g., to pumps) and to provide cooling loads (e.g., to data centers).

[0114] In some embodiments, the system provided in this invention may further include one or more control units or a central unit. Figure 1 , 3 (and not shown in 7-9), for controlling the steps of the method and the amount of fuel in each step or through each component. The control unit may be electrically connected to the relevant components in the system. The control unit may include one or more processors and at least one tangible, non-transitory, machine-readable medium encoded by one or more programs executed by one or more processors. The control unit is configured to coordinate with each component to control operations such as managing vaporization during storage, supplying fuel to the vehicle, cooling the data center, and providing backup power.

[0115] The methods and systems described herein can be embodied, at least in part, in the form of computer-implemented processes and means for implementing these processes. The disclosed methods can also be embodied, at least in part, in the form of a tangible, non-transient machine-readable storage medium encoded with computer program code. The medium may include, for example, RAM, ROM, CD-ROM, DVD-ROM, BD-ROM, hard disk drive, flash memory, or any other non-transient machine-readable storage medium or any combination of these media, wherein the computer becomes a means for practicing the method when the computer program code is loaded into and executed by the computer. The methods can also be embodied, at least in part, in the form of a computer, in which computer program code is loaded into and / or executed, such that the computer becomes a means for implementing the methods. When implemented on a general-purpose processor, computer program code segments configure the processor to create specific logic circuits. The methods can optionally be implemented, at least in part, in a digital signal processor formed by an application-specific integrated circuit for performing the methods. The computer or control unit can be operated remotely using a cloud-based system.

[0116] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A system for liquefied gas storage, comprising: a cryogenic tank configured to store a liquefied fuel therein; a pump fluidly coupled to the cryogenic tank and configured to provide a first portion of the liquefied fuel from the cryogenic tank while compressing the first portion of the liquefied fuel to a higher pressure; a heat exchanger coupled to the pump and configured to provide a cooling load to the first portion of the liquefied fuel from the pump; an expansion valve configured to expand the first portion of the liquefied fuel from the heat exchanger into a multi-phase flow comprising a liquid phase and a gas phase, the multi-phase flow having a lower temperature than an initial temperature of the first portion of the liquefied fuel from the cryogenic tank; and a liquid-vapor separator fluidly coupled to the expansion valve and configured to separate the liquid phase and the gas phase in the multi-phase flow, wherein the liquid phase is configured to be returned into the cryogenic tank. The liquefied fuel comprises hydrogen.

2. The system of claim 1, wherein, The pump comprises one or more immersed liquid pumps disposed inside the cryogenic tank.

3. The system of claim 1, wherein, The system further comprises an expansion turbine coupled to the heat exchanger and expansion valve and configured to isentropically expand the first portion of the liquefied fuel from the heat exchanger.

4. The system of claim 1, wherein, The expansion valve is a Joule-Thomson valve.

5. The system of claim 1, wherein, The system further comprises an interlock chamber fluidly coupled to the cryogenic tank and configured to return the liquid phase into the cryogenic tank.

6. The system of claim 1, wherein, The liquid-vapor separator is configured to provide the gas phase to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump.

7. The system of claim 1, wherein, The cryogenic tank is configured to provide a vapor phase of the liquefied fuel from a headspace of the cryogenic tank to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump.

8. The system of claim 1, wherein, The system further comprises at least one or both of:

9. The system of claim 1, wherein, a refrigeration unit coupled to the heat exchanger, wherein the refrigeration unit is configured to receive the gas from the heat exchanger and provide a cooling load to a facility; and a backup power unit configured to receive the gas from the heat exchanger and generate electricity. The backup power unit comprises one or more fuel cells to generate electricity.

10. The system of claim 9, wherein, The system further comprises a fueling station comprising a dispenser, the fueling station configured to receive a second portion of the liquefied fuel from the cryogenic tank and dispense the second portion of the liquefied fuel in a form of a gaseous fuel or a liquid fuel to a receiving fuel tank.

11. The system of any of claims 1-10, wherein, 12. A method of liquefied gas storage, comprising: providing a liquefied fuel stored within a cryogenic tank; pumping a first portion of the liquefied fuel from the cryogenic tank by a pump fluidly coupled to the cryogenic tank while compressing the first portion of the liquefied fuel to a higher pressure; cooling the first portion of the liquefied fuel from the pump by a heat exchanger coupled to the pump; expanding the first portion of the liquefied fuel from the heat exchanger into a multi-phase flow by an expansion valve, the multi-phase flow comprising a liquid phase and a gas phase and having a lower temperature than an initial temperature of the first portion of the liquefied fuel from the cryogenic tank; and returning the liquid phase into the cryogenic tank. separating a liquid phase and a gas phase in a multi-phase stream through a liquid-vapor separator fluidly coupled to an expansion valve; and returning the liquid phase from the liquid-vapor separator to the cryotank.

13. The method of claim 12, wherein, The liquefied fuel includes hydrogen.

14. The method of claim 12, wherein, The pump includes one or more immersed liquid pumps disposed inside the cryotank.

15. The method of claim 12, wherein, The method further includes: isentropically expanding a first portion of the liquefied fuel from the heat exchanger through an expansion turbine coupled to the heat exchanger and expansion valve.

16. The method of claim 12, wherein, The expansion valve is a Joule-Thomson valve.

17. The method of claim 12, wherein, The liquid phase is returned to the cryotank through an interlock chamber fluidly coupled to the cryotank.

18. The method of claim 12, wherein, Returning the liquid phase to the cryotank includes sparging the liquid phase into a vapor phase of a headspace of the cryotank during a top-off process.

19. The method of claim 12, wherein, The method further includes providing a gas phase from the liquid-vapor separator to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump.

20. The method of claim 19, wherein, The method further includes providing a vapor phase of the liquefied fuel from a headspace of the cryotank to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump.

21. The method of claim 20, wherein, The method further includes at least one or both of: providing a cooling load to a facility in need thereof from a refrigeration unit coupled to the heat exchanger through use of gas from the heat exchanger; and generating power in a backup power unit through use of gas from the heat exchanger.

22. The method of claim 21, wherein, The power is generated through one or more fuel cells in the backup power unit; and / or The power is provided from the backup power unit to a data center or the pump, and a cooling load from the refrigeration unit is used to cool the data center.

23. The method of claim 12, wherein, The method further includes providing a second portion of the liquefied fuel from the cryotank to a fuel supply station including a dispenser, and dispensing the second portion of the liquefied fuel in a form of a gaseous fuel or a liquid fuel to a receiving fuel tank. The liquefied fuel includes hydrogen. The pump includes one or more immersed liquid pumps disposed inside the cryotank. The method further includes: isentropically expanding a first portion of the liquefied fuel from the heat exchanger through an expansion turbine coupled to the heat exchanger and expansion valve. The expansion valve is a Joule-Thomson valve. The liquid phase is returned to the cryotank through an interlock chamber fluidly coupled to the cryotank. Returning the liquid phase to the cryotank includes sparging the liquid phase into a vapor phase of a headspace of the cryotank during a top-off process. The method further includes providing a gas phase from the liquid-vapor separator to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump. The method further includes providing a vapor phase of the liquefied fuel from a headspace of the cryotank to the heat exchanger for providing an additional cooling load to the first portion of the liquefied fuel from the pump. The method further includes at least one or both of: providing a cooling load to a facility in need thereof from a refrigeration unit coupled to the heat exchanger through use of gas from the heat exchanger; and generating power in a backup power unit through use of gas from the heat exchanger. The power is generated through one or more fuel cells in the backup power unit; and / or The power is provided from the backup power unit to a data center or the pump, and a cooling load from the refrigeration unit is used to cool the data center. The method further includes providing a second portion of the liquefied fuel from the cryotank to a fuel supply station including a dispenser, and dispensing the second portion of the liquefied fuel in a form of a gaseous fuel or a liquid fuel to a receiving fuel tank.

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