Systems and methods for filling gas vessels

Abstract

The disclosure relates to systems and methods for filling gas vessels. Specifically, the disclosure relates to systems and methods for filling gas vessels without increasing the density of a cooled gas displacing heated gas in the target vessels, thereby eliminating temperature increase in the filled vessel, caused by filling waves.

Description

SYSTEMSAND METHODS FOR FILLING GAS VESSELS BACKGROUND

[0001] The disclosure is directed to systems and methods for filling gas vessels. Specifically, the disclosure is directed to systems and methods for filling gas vessels without increasing the density of the gas in the target vessels, thereby eliminating temperature increase in the filled vessel.

[0002] The present disclosure relates to gas cylinder filling systems and methods, particularly for compressed natural gas and hydrogen fuel applications in vehicles. Natural gas and hydrogen are increasingly used as alternative fuels for vehicles.Hydrogen fuel applications have expanded significantly in recent years due to the absence of emissions during use (hydrogen combustion produces water).

[0003] During cylinder filling at refueling facilities, gas flows from a high-pressure source into an initially empty or low-pressure cylinder. Each moment during the filling process of the cylinder, a portion of gas reduces the pressure, as it passes into a volume with lower pressure. The reduction in pressure must be accompanied by cooling. However, the opposite process occurs. Filling the cylinders with gas is accompanied by elevating gas temperature substantially above ambient conditions. From a thermodynamic point of view, this heating is a paradoxical phenomenon.Heating the gas reduces the mass of the gas in the cylinder, which consequently reduces the range of vehicles between refills.

[0004] Gas cylinder filling processes are critical across multiple industries, including automotive fuel systems, hydrogen energy distribution, and chemical processing. The technical challenges of rapid gas filling have been studied extensively over recent decades through experimental investigations and computational modeling, with particular focus on temperature management during high-pressure filling operations.

[0005] A comprehensive review publication (T. Bourgeois et al., "The temperature evolution in compressed gas filling processes," International Journal of Hydrogen Energy, Vol. 43, Issue 4, January 2018, p. 2268) analyzing over one hundred prior studies documents the persistent problem of gas heating during cylinder filling. The heating problem directly impacts storage efficiency: at a given pressure, higher gastemperature results in lower gas density and therefore reduced mass of gas stored in the cylinder. An additional concern is temperature rise in composite tanks of hydrogen vehicles during refueling. Safety standards recommend maintaining gas temperature below 85°C throughout the refueling process to ensure tank structural integrity.

[0006] Current approaches to mitigating heating during cylinder filling include precooling the incoming gas to temperatures as low as -40°C, which requires costly refrigeration equipment and substantial energy consumption at refueling facilities.Research efforts have investigated various parameters including cylinder geometry, filling protocols with variable inlet pressure, and mass flow rate control. Despite these investigations, the need remains for more cost-effective solutions to the heating problem.

[0007] Russian patent RU 2163699 discloses a dual-vessel cylinder design for storing compressed or liquefied gases, particularly for vehicle fuel applications. The cylinder comprises an outer high-pressure vessel and an inner vessel separated by a gas-impermeable thermal insulation partition. However, this passive insulation approach does not actively address heating during the filling process itself.

[0008] Russian patent RU 2020107402 discloses a variable-volume storage tank for liquefied natural gas, incorporating a movable partition that allows internal volume expansion as temperature increases. This approach addresses temperature effects in storage but does not prevent heating during the initial filling process.

[0009] Chinese patent CN110715164A discloses a natural gas or hydrogen filling system and method aimed at suppressing temperature increase during the refueling process. This patent represents the closest prior art to the present disclosure. The disclosed system employs temperature control to reduce heating during refueling.Current CNG (compressed natural gas) refueling facilities typically experience temperatures of 55°C or higher at 20 MPa filling pressure, while hydrogen facilities reach 85°C or higher at 70 MPa.

[0010] To store compressed natural gas or hydrogen in vehicle cylinders, rapid filling technology is employed at refueling facilities. During high-pressure filling, temperature increases significantly due to factors including pressure differentials and flow rates. TheChinese patent notes that the underlying physical mechanism of this heating was not fully understood, limiting the effectiveness of filling control methods.

[0011] The patent identifies that heating during filling reduces storage efficiency. Due to temperature increase, the achieved density in vehicle cylinders (approximately 0.112 kg / l) is significantly lower than the achievable at refueling facility’s storage temperatures (0.49 kg / l). This density reduction limits per-cylinder storage capacity to approximately 15 Nm3instead of a potential 63 Nm3, correspondingly limiting vehicle range. Improved temperature management during filling could therefore substantially increase storage capacity and vehicle range while reducing operational costs.

[0012] The disclosed refueling systems employs multiple pressure-staged storage tanks with different gas pressures, along with cooling equipment, gas parameter monitoring, and pipeline switching controls to manage temperature during filling. While this multi-tank approach provides some temperature control through staged pressure filling and cooling, it requires complex infrastructure and does not address the fundamental physical mechanisms underlying gas heating during cylinder filling. The approach therefore has limitations in applicability and cost-effectiveness, leaving room for alternative solutions based on improved understanding of the heating phenomenon.SUMMARY

[0013] In an exemplary implementation, provided herein is a method for substantially reducing increase in gas temperature in the process of transferring compressed gas from a bulk storage tank to a target vessel, implemented in a system comprising: the bulk storage tank, an intermediate vessel maintained at a pressure slightly lower than in the bulk storage tank, a target vessel having a wall, a bottom and an apical filling manifold, the filling manifold having two valves; first valve connected by gas pipes with the bulk storage tank or with the high-pressure vessel and a second valve in liquid connected by gas pipes with the intermediate vessel, high-pressure vessel has a volume smaller than the volume of the target vessel and a Fueling Management Module (FMM) operable to control gas flow rate, pressure and temperature at all control points of the system, the method comprising: using the FMM, opening the first valve, and fillingthe target vessel from the bulk storage tank or by emptying the high-pressure vessel to a predetermined pressure level.

[0014] During the filing process inside the target vessel the gas density increase and the filing waves appear, which heat the gas: when filling from the high-pressure vessel simultaneously inside the high-pressure vessel the gas density decrease while the emptying waves appear, which cool the gas, thus, cooled gas enters the cylinder: if gas temperature within the target vessel higher than the temperature of the gas in the bulk storage tank, using the FMM open the second valve, connecting the cylinder with bulk storage tank, first valve stay opened, since small difference in pressure cooled gas flowing from the bulk storage tank displaces heated gas from the target vessel by ventilating, while the density of the gas in the cylinder does not change, wherein the volume of the cylinder is substantially lower than the volume of the bulk storage tank and the intermediate vessel; opening the first valve, while keeping the second valve open filling the target vessel substantially toward the floor of the target vessel, displacing the heated gas into the intermediate vessel, while optionally using the FMM, cooling the gas flowing from the bulk storage tank to the target vessel; and; using the FMM, close the first and second valves, when pressure and temperature of the gas in cylinder achieved the predetermined magnitudes.BRIEF DESCRIPTION OF THE DRAWINGS:

[0015] For a better understanding of systems and methods for filling gas vessels without substantially increasing the density of the gas in the target vessel thereby eliminating temperature increase in the filled vessel, with regard to the exemplary implementations thereof, reference is made to the accompanying examples and figures, in which:

[0016] FIG. 1 ; is a schematic showing an exemplary implementation of the gas refueling systems.

[0017] FIG. 2, illustrates a schematic diagram of an experimental setup demonstrating the existence of Filling Waves (FW) and Emptying Wave (EW);

[0018] FIG. 3A, is a chart showing the Temperatures (°C) at the nozzle inlet (on the inner wall of pipe), with FIG. 3B showing the increase in gas temperature when fillingthe volume with FW, and the decrease in temperature when emptying the volume, Emptying Wave (EW) shown in FIG. 3C;

[0019] FIG. 4, is a schematic showing simulation set up of filling the target vessel with gas by emptying the high-pressure vessel;

[0020] FIG. 5, is a schematic of a first exemplary implementation of the target vessel;

[0021] FIG. 6A, is a schematic of a second exemplary implementation of the target vessel with a movable partition detailed further in FIG. 6B;

[0022] FIG. 7, is a schematic of a third exemplary implementation of the target vessel with an inflatable volume; and

[0023] FIG. 8A, is a schematic of a fourth exemplary implementation of the target vessel, using a high-pressure vessel, where FIG. 8B being a schematic of FIG. 5, with FIG. 8C showing a Y-Z cross section along line A-A in FIG. 8A, and FIG. 8D, showing an alternative arrangement of Emptying Wave (EW) absorbing elements’ configuration.DETAILED DESCRIPTION

[0024] The disclosure relates to methods and systems for transferring compressible gases in refueling operations, particularly addressing thermal management challenges encountered when filling target vessels such as vehicle fuel tanks with high-pressure compressed gases including hydrogen, natural gas (compressible liquid gas (CLG)), or other compressible fluids suitable for use as vehicular energy sources. The challenge addressed by the disclosure stems from the thermodynamic behavior of real gases during gas transfer operations, whereby rapid density increases inherently generates substantial temperature increases that can compromise both operational efficiency and safety.

[0025] The disclosure is based on understanding the physical basis of the phenomenon that is responsible for gas heating in cylinders when they are filled at e.g., a refuelling station. This description is the first communication (publication) describing this effect. In some publications this effect is mistakenly associated with the process of adiabatic gas compression.

[0026] Another process is taking place When filling cylinders, the gas passes from a high- pressure volume to an empty cylinder. A microvolume of gas passes from a high-pressure volume to a low- pressure cylinder, while reducing the gas pressure. This process should be accompanied by cooling. However, the opposite process occurs. Filling the cylinders with gas is accompanied by heating. From a thermodynamic point of view, this heating is a paradoxical phenomenon The magnitude of heating determined by factors including the initial pressure differential, flow rate, vessel geometry, and thermal properties of the compressed gas. For example, in hydrogen refueling at 70 MPa nominal working pressure, temperature increases can exceed 100 Kelvin (K) under fast-fill conditions, potentially reaching or exceeding the maximum operating temperature of composite pressure vessels, which is typically limited to 358 K for Type IV tanks with polymer liners.

[0027] The temperature rise phenomenon can be further complicated by the Joule-Thomson effect, describing the temperature change that occurs when real gas expands or is throttled through a pressure reduction without heat exchange. Unlike most gases which exhibit cooling upon expansion at ambient conditions, hydrogen demonstrates anomalous behavior with a negative Joule-Thomson coefficient above its inversion temperature of approximately 200 K. The net effect is that when hydrogen is throttled from high-pressure to lower pressure at typical ambient temperatures, it undergoes heating rather than cooling, exacerbating the thermal challenges of the refueling process. The negative Joule-Thomson coefficient results from hydrogen's molecular properties, specifically the weakness of intermolecular attractive forces relative to kinetic energy at ambient temperatures, causing the compressibility factor to remain above unity throughout typical refueling pressure ranges.

[0028] Excessive gas temperatures during refueling can present multiple operational concerns. For example, high temperatures reduce the achievable state of charge, as gas density decreases with temperature at constant pressure, requiring either extended cooling periods or additional gas mass to achieve target fuel quantities. Also, elevated temperatures can further stress the structural materials of pressure vessels, particularly the polymer liners and fiber-reinforced composite overwraps used in Type III, and Type IV hydrogen storage tanks. Furthermore, thermal cycling between ambient and elevated temperatures can accelerate fatigue accumulation in tank materials, potentially leading to delamination of composite layers, degradation of liner materials, and reduced servicelife. Additionally, safety considerations further mandate temperature control, as most compressed gas standards specify maximum operating temperatures, with hydrogen vehicle tanks limited to 358 K to prevent liner degradation and maintain structural integrity.

[0029] As indicated, conventional approaches to managing temperature rise during refueling typically rely on pre-cooling the compressed gas before dispensing, using refrigeration systems to reduce hydrogen temperature to between 233 K and 253 K before it enters the vehicle tank. While effective at limiting final gas temperatures, precooling systems can and do add substantial capital and operating costs to refueling infrastructure, consume significant energy for refrigeration, and introduce complexity to the system through the requirement for cryogenic-compatible materials and controls. The SAE J2601 standard establishes lookup tables and calculation methods for determining appropriate pre-cooling temperatures and pressure ramp rates based on ambient conditions, tank capacity, and initial tank conditions, but implementation of these protocols requires sophisticated control systems and energy-intensive refrigeration equipment.

[0030] The systems and methods disclosed address some of these limitations through a method that leverages the existing infrastructure of cascade storage systems while introducing a displacement strategy that substantially reduces temperature rise without requiring extensive pre-cooling. By intentionally simultaneously filling the target vessel by emptying of high-pressure vessel during an initial filling phase, then strategically displacing the heated gas while introducing cooler gas from bulk storage. The method achieves temperature control through gas displacement rather than purely through refrigeration. This approach provides advantages for refueling operations where infrastructure costs are sought to be minimized, where energy efficiency is paramount, or where rapid refueling must be accomplished without extensive pre-cooling systems.

[0031] In an exemplary implementation, the refueling system used implementing the disclosed method can comprise several interconnected vessels and control elements (See e.g., FIG. 1 ), arranged to enable precise management of gas flow, pressure, and temperature throughout the refueling sequence. The bulk storage tank serves as the primary high-pressure gas reservoir, maintained for example, at pressures exceedinge.g., about 87.5 MPa for 70 MPa refueling applications or proportionally higher pressures for other nominal working pressures. This vessel can be constructed according to applicable pressure vessel standards, most commonly as a Type I seamless steel cylinder with wall thicknesses calculated to withstand maximum operating pressures with appropriate safety factors, or as Type II hoop-wrapped steel cylinders where weight considerations warrant composite reinforcement. The bulk storage tank can be further equipped with pressure transducers providing real-time pressure monitoring with resolution sufficient to detect pressure changes of, for example, 0.1 MPa or finer, as well as temperature sensors positioned to measure gas temperature at representative locations within the vessel volume, and isolation valves rated for the maximum operating pressure and compatible with the stored gas composition. For hydrogen service for example, valve materials are adapted, sized and configured to resist hydrogen embrittlement, employing e.g., stainless steel alloys specifically formulated for hydrogen compatibility or utilizing special coatings on wetted surfaces.

[0032] The intermediate vessel is configured to function as a buffer storage unit, maintained at a pressure level lower than the pre-determent pressure but higher than typical starting pressures of target vessels entering for refueling. In cascade refueling architectures used at compressed natural gas and hydrogen filling facilities, the intermediate vessel pressure can range between about 25 MPa and about 50 MPa for systems designed to refuel to 70 MPa nominal working pressure (in the target vessel), though the specific pressure set point is determined in certain exemplary implementations, by optimization of system efficiency and hydrogen utilization factors. The intermediate vessel volume substantially exceeds the target vessel volume, for example, by factors ranging from 10 to 100, providing sufficient gas capacity to perform multiple refueling operations before requiring replenishment from the bulk storage tank or from compression equipment. This volume relationship are adapted, sized and configured to such that gas transfer from the intermediate vessel to the target vessel results in minimal pressure drop in the intermediate vessel itself, maintaining relatively stable supply pressure throughout the initial filling phase. Construction of the intermediate vessel can deploy similar material and design standards as the bulkstorage tank, with pressure containment achieved e.g., through thick-walled metallic construction or through composite-reinforced designs where applicable. Here, in one exemplary implementation, temperature management of the intermediate vessel can be passive, relying on heat exchange with the surrounding environment to maintain gas temperature near ambient conditions, though active temperature control through heat exchangers or insulation may also be incorporated depending on specific operational requirements.

[0033] The target vessel represents the receiving container sought to be filled using the methods disclosed, and can be for example, the onboard fuel storage tank of a vehicle powered by compressed gas. For hydrogen fuel cell vehicles, target vessels (see e.g., FIG. 5), can be Type III or Type IV composite pressure vessels, with Type III designs employing an aluminum liner overwrapped with carbon fiber-epoxy composite material, while Type IV designs utilize a polymer liner, commonly high-density polyethylene or polyamide, likewise overwrapped with carbon fiber composite. These composite construction methods can be used to achieve substantial weight reduction compared to all-metal designs, which may be beneficial for vehicular applications where payload capacity and energy efficiency can strongly depend on minimizing vehicle mass. The target vessel is characterized in another exemplary implementation by having a bottom section and an apical end, with the bottom typically referring to the base or bottom portion of the vessel when oriented in its normal installation position, while the apical end refers to the top or uppermost section. This orientation distinction can be functionally relevant in the disclosed method during density-driven stratification of gases at different temperatures, with warmer, less dense gas tending to rise toward the apical end while cooler, denser gas settles toward the bottom.

[0034] The filling manifold comprises the piping, valving, and connection hardware through which gas is introduced into the target vessel. This assembly is located at the apical end of the target vessel, a standard practice in compressed gas vehicle tank design configured to facilitate connection to fueling dispensers and to prevent liquid contaminants or condensate from entering the tank through the fill port. In yet another exemplary implementation, the filling manifold comprises two separately controllable flow paths, each equipped with valves that provide positive shut-off and precise flowcontrol. The first valve establishes liquid communication between the bulk storage tank and the target vessel, enabling gas transfer from the high-pressure primary storage when opened, and preventing flow when closed. This valve is adapted, sized and configured to handle the full pressure differential between the bulk storage tank and the target vessel across all phases of the refueling operation, with a pressure rating exceeding e.g., 87.5 MPa for typical 70 MPa refueling systems. The second valve similarly provides liquid communication between the intermediate vessel and the target vessel, controlling gas flow from the buffer storage into the receiving tank. In the context of the disclosure, the term “liquid communication” refers to a fluid flow path, applicable to both liquids and gases, wherein opening a valve permits fluid movement driven by pressure differential while closing the valve creates a positive seal preventing fluid passage.

[0035] Both valves are operable to provide reliable operation across thousands of actuation cycles, maintain leak-tight sealing at all rated pressures, and demonstrate compatibility with the compressed gas being handled. In certain exemplary implementations, for hydrogen service, valve selection can be adapted, sized and configured to handle hydrogen's small molecular size and tendency to cause embrittlement of certain materials. Suitable valve types can be, for example, ball valves constructed from austenitic stainless steels, check valves employing hydrogencompatible elastomeric seals or metal-to-metal seating, and solenoid-actuated valves specifically rated for hydrogen pressure and temperature conditions. Valve actuation may be, for example: pneumatic, hydraulic, or electric depending on system requirements, with response times in the range of between about 0.1 and about 2.0 seconds for full opening or closing cycles. The filling manifold may further comprise additional components, e.g., pressure regulators to control downstream pressure, mass flow meters or volumetric flow meters to quantify gas transfer rates, temperature sensors to monitor gas temperature at the inlet to the target vessel, and check valves, or relief valves to prevent backflow or overpressure conditions. Additionally, and in another exemplary implementation, wetted components within the filling manifold are compatible with the compressed gas composition and are adapted, sized andconfigured to withstand the full range of operating pressures and temperatures encountered during refueling operations.

[0036] The fueling management module (FMM) functions as the control and monitoring center for the refueling operation, coordinating valve actuation, monitoring system parameters, and executing the disclosed method sequence with appropriate timing and conditional logic. This module can be implemented through a combination of sensors, controllers, actuators, and programming logic configured to manage the refueling process according to predetermined parameters and real-time feedback. The sensing subsystem can comprise (see e.g., FIG. 1), pressure transducers monitoring pressures in the bulk storage tank, intermediate vessel, and target vessel, with accuracy within e.g., 0.25 percent of full scale and response times fast enough to track dynamic pressure changes during gas transfer. Temperature sensors can be used to provide measurement of gas temperatures at predetermined locations for example; gas temperatures within storage vessels and at the inlet to the target vessel, utilizing for example; thermocouples, resistance temperature detectors, or other temperature measurement devices appropriate for the pressure and environmental conditions. Flow measurement devices can likewise be incorporated to directly measure mass flow rate or to calculate flow rate from pressure and temperature measurements using equations of state appropriate for the compressed gas composition.

[0037] In an exemplary implementation, the controller component of the FMM can comprise programmable logic controllers (PLCs), microprocessors, or other computing devices executing software or firmware that implements the control algorithms governing the refueling sequence. This controller is configured to receives input signals from sensors, processes these signals according to programmed logic, and generates output commands to valve actuators and other controllable system elements. The control algorithm can further incorporate the sequential steps of the disclosed method, including monitoring for conditions that trigger transitions between filling phases, calculating or retrieving flow rate setpoints appropriate for achieving desired temperature profiles, and commanding valve positions to execute the planned filling sequence. In another exemplary implementation, the controller can also be configured to incorporate safety interlocks to prevent operation under unsafe conditions, such asdetecting overpressure or over-temperature conditions and automatically terminating gas flow, or detecting communication failures with remote monitoring systems and entering a safe state.

[0038] Actuation hardware controlled by the FMM can include, for example; solenoid drivers, pneumatic valve positioners, or other devices that translate controller commands into physical valve motion. For precise flow rate control, the system may employ variable-position valves such as, for example, needle valves with stepper motor actuators or proportional control valves that modulate opening area in response to analog control signals, enabling fine adjustment of flow resistance and therefore flow rate. The FMM may additionally be configured to control active cooling systems if incorporated into the refueling systems, modulating refrigeration equipment output to achieve target gas temperatures for cooled gas supplied from the bulk storage tank. Communication interfaces (e.g., user interface), can be used in certain exemplary implementations to enable the FMM to exchange data with vehicle systems through established protocols such as those defined in SAE J2799 for hydrogen refueling communication, allowing the facility to receive information about target vessel capacity, initial pressure and temperature, and maximum allowable fill parameters, while transmitting fueling status information to the vehicle for display to the operator.

[0039] Accordingly, and in an exemplary implementation (see e.g., FIG.s 1 , 5), the FMM is used to command the second valve 57 to open, establishing fluid communication between the intermediate vessel 120 and the target vessel 100. At this point in the refueling sequence, the target vessel 100 is presumed to be at or near its initial state, which may range from near-empty conditions with residual pressure of, for example, 2 MPa for a vehicle arriving with depleted fuel, to partially filled conditions if the vehicle has remaining fuel. The intermediate vessel 120, maintained at its characteristic lower pressure relative to the pre-set gas pressure. So, when both two valves 56 and 57 are opened, gas from bulk storage tank 110 passes through reducer, maintaining constant pre-set gas pressure, enters the target vessel, and the heated gas is crowded out from target vessel without of density changing to intermediate vessel 120. The ventilation process stops when gas temperature in target vessel reaches thepre-set value, which is lower than the pre-set pressure in intermediate vessel 120, creating a pressure differential that drives gas flow once both valves open.

[0040] When filling the cylinder from the high-pressure vessel 90 (see e.g., FIG.s 1 ,8), upon opening the first valve 56, gas flows from the high-pressure vessel 90 via pressure reducer into the target vessel 100, driven by the pressure gradient between the two vessels. The flow rate during this initial phase is controlled through the FMM, which may regulate flow by adjusting the first valve 56 position if a variable-position valve is employed, or may rely on fixed orifice sizing and the natural pressure differential to establish flow rate. The target flow rate is specifically configured to optimize gas temperature within the target vessel to a temperature permissible up to a level safe for the walls of target vessel. This temperature increase occurs through the emergence of filling waves during the filling process as described.

[0041] As indicated, the primary mechanism generating temperature rise is waves of filling present within the target vessel 100. As gas enters from the high-pressure vessel 90, the mass of gas, the density and pressure within the target vessel 100 increases. A rapid increase in density creates an elastic filling wave. The energy of these waves is absorbed within the volume and responsible for temperature rise. The rate of temperature increase depends on the flow rate of incoming gas, the specific heat ratio of the compressed gas, and the thermal time constant of the specific fueling system 10. By selecting a flow rate, the FMM ensures that the heating, acceptable for the given target vessel (interchangeable with “gas cylinder”).

[0042] The Joule-Thomson effect contributes additional heating when the compressed gas is hydrogen or other gases exhibiting negative Joule-Thomson coefficients at the operating temperature and press sure conditions. As gas expands from the high-pressure vessel 90 pressure through the first valve 56-into the lower pressure environment of the target vessel 100, the throttling action produces a temperature increase rather than the cooling effect observed with most gases under similar conditions. This heating effect supplements the compression heating of gas already in the target vessel 100, further elevating the overall gas temperature. The magnitude of Joule-Thomson heating depends on the pressure drop across the first valve 56, the gas temperature and pressure conditions, and the specific Joule-Thomsoncoefficient of the gas under those conditions. For hydrogen at ambient starting temperatures and pressure drops typical of initial filling from intermediate storage, the Joule-Thomson heating can contribute temperature increases in the range of several K and several tens of K depending on specific system 10 conditions.

[0043] The combination of filling waves heating and Joule-Thomson effects, operating over the duration of the initial filling phase7generates heated gas within the target vessel. This heated gas reaches temperatures exceeding the temperature of gas stored in the bulk storage tank 110, which is typically maintained near ambient temperature through passive equilibration with the surrounding environment or through active temperature management, if employed at the facility. The spatial distribution of this heated gas within the target vessel follows density-driven stratification patterns. Since gas density decreases with increasing temperature at constant pressure, the warmer gas is less dense than cooler gas at the same pressure. In the gravitational field, this density difference causes the warmer, lighter gas to rise toward the apical end 510 of the target vessel 100, while any cooler, denser gas settles toward the floor 58. This natural convection process is enhanced during active filling as incoming gas through pipe 53 outlet 59, creates turbulent mixing and circulation within the target vessel 100, but the net effect over time is accumulation of the warmest gas near the apical end 510 where the filling manifold 55 is located.

[0044] The initial filling phase continues until the pressure within the target vessel 100 reaches predetermined level. The FMM monitors target vessel pressure through e.g., pressure sensors and detects, for example, when the pressure rise rate diminishes. At the point of target pressure, the FMM close the first valve 56, and the target vessel 100 contains a charge of heated gas at predetermined level of pressure, and with this gas stratified by temperature such that the warmest portions occupy regions near the apical end 510 proximate to the filling manifold 55. The internal volume 52 of the target vessel 100 is substantially lower than the volumes of both the bulk storage tank 110 and intermediate vessel 120, e.g., by factors of 10 to 100 or more, meaning that the heated gas created during initial filling represents a relatively small mass compared to the gas inventory in the facility 10 storage vessels 110, 120.

[0045] After the initial filling phase is complete, the FMM connects the first valve 56 to the storage tank 110 and opens both valves 56 and 57. Valve 57 is connected to the intermediate vessel 120. At the same time the gas flow establishing simultaneous fluid communication from the bulk storage tank 110 to the intermediate vessel 120 via the target vessel 100. This configuration creates a flow pattern, as gas now enters the target vessel 100. From the bulk storage tank 110 having pre-set gas parameters, maintained at a higher pressure than the intermediate vessel 120, provides the primary driving force for continued filling, supplying gas at pressure sufficient to increase target vessel 100 pressure. Herewith the warm gas is forced out from the target vessel 100 into the intermediate vessel 120, smoothly close valve 57, increasing the pressure in the target vessel, when the gas parameters in the target vessel are reached to pre-set parameters, both vales closed.

[0046] In an exemplary implementation, the effectiveness of displacement is achieved by maintaining sufficient pressure difference between incoming cool gas in the bulk storage tank 110 and the intermediate vessel 120. Resident warm gas thereby sustaining the “phases” stratification and prevent excessive mixing. The flow rate during this phase is configured to balance competing factors. Excessively rapid flow would generate turbulence that thoroughly mixes incoming cool gas with resident warm gas, eliminating the benefits of displacement. Accordingly, and in another exemplary implementation, the flowrate of the gas flowing from the bulk storage tank is laminar (Re<2100). Conversely, excessively slow flow could allow time for heat transfer from warm gas phase to target vessel 100 walls 51 and from vessel walls 51 to incoming cool gas, reducing temperature differences AT and again diminishing displacement effectiveness. Accordingly, and in another exemplary implementation the FMM is configured to control the flow rate to be fast enough to maintain thermal separation but slow enough to preserve stratified flow patterns, for example in the range of mass flow rates configured to produce pressure rise rates of between about 1 MPa / minute and about 5 MPa / minute, though specific values could depend on target vessel 100 geometry, volume, and initial conditions.

[0047] As displacement proceeds, heated gas progressively exits the target vessel 100 through the second valve 57 and enters the intermediate vessel 120, where it mixeswith the larger volume of gas already present. The volume ratio between the intermediate vessel 120 and target vessel 100 is configured to ensure that the warm gas from the target vessel 100 represents but a small fraction of the intermediate vessel 120 inventory, so the temperature increase in the intermediate vessel 120 remains modest, e.g., less than 10 K even when the displaced gas is 50 K or more above ambient. This heated gas phase can subsequently equilibrate with the intermediate vessel 120 walls and environment over time between refueling operations, or can be cooled through optional active cooling systems included with the system. Continuous or near-continuous operation of compression equipment at most refueling systems can be used to provide ongoing gas circulation through the intermediate vessel 120, further facilitating heat dissipation from any warm gas introduced during displacement operations.

[0048] Furthermore, throughout the displacement and final filling phase, gas temperature within the target vessel 100 could be further managed through both the displacement mechanism and through optional active cooling of gas supplied from the bulk storage tank 110. The FMM may command cooling equipment, when present, to reduce the temperature of gas flowing from bulk storage before it enters the target vessel. This pre-cooling, when combined with the displacement of heated gas, provides synergistic temperature reduction. Even modest pre-cooling, reducing gas temperature by 10 to 20 K below ambient rather than the 40 to 60 K reduction typical of conventional pre-cooling systems, can be sufficient when combined with displacement to maintain gas temperatures within target vessel’s 100 material limits. This reduced cooling requirement can translate to substantial reduction in refrigeration energy consumption and equipment size compared to conventional refueling methods relying solely on aggressive pre-cooling.

[0049] The displacement and filling phase using the systems and methods disclosed, continues until the target vessel reaches a predetermined gas density corresponding to the desired state of charge. The FMM can be configured to monitor this condition through real-time calculation of gas density based on measured pressure and temperature, using state equations appropriate for the compressed gas composition. For hydrogen for example, the Abel-Noble equation of state or more sophisticatedequations incorporating real gas behavior can be used to provide sufficient accuracy for refueling applications. When the calculated gas density reaches the predetermined threshold, indicating that the target vessel contains the intended mass of fuel, the FMM can be configured to command both the first 56 and second 57 valves to close, terminating gas flow and completing the refueling operation. The closed valves isolate the target vessel at final pressure and temperature, with the gas inventory representing the fuel supply for vehicle operation.

[0050] The substantial reduction in temperature using the systems and methods disclosed, harness multiple thermodynamic principles operating in concert throughout the refueling sequence. First, is the inverse relationship between gas density and temperature at constant pressure, creating the stratification (essentially, creating two gas phases), beneficial for displacement. When gas is heated at constant pressure, its density decreases according to the ideal gas law (corrected for real gas behavior), with the specific relationship depending on the state equation applicable to the particular gas composition. For example, hydrogen at 70 MPa and temperatures near ambient, with a temperature increase of 50 K would produce density reduction of approximately 15%, sufficient to drive clear stratification in a gravitational field. This density difference can be used to cause warmer gas to float above cooler gas, naturally segregating the heated gas created during initial filling toward the apical end 510 of the target vessel 100 where it can be subsequently displaced.

[0051] Second, is the energy conservation applied to the displacement process itself. When heated gas is displaced from the target vessel 100 into the intermediate vessel 120, the thermal energy contained in that gas is likewise transferred out of the target vessel 100, removing heat that would otherwise remain to elevate final gas temperature. The magnitude of this energy transfer depends on the mass of the displaced gas and its temperature elevation above the replacement gas entering from bulk storage tank 110. For example, in a target vessel of 150 liters nominal capacity, filled with hydrogen, assuming 30% of the target vessel 100 volume is initially filled with gas 50 K above ambient and this heated gas is subsequently displaced by gas at ambient (or slightly lower) temperature, the energy removed through displacement is approximately 180 kilojoules, equivalent to the refrigeration energy that would otherwise be required to coolthe final gas mass by a corresponding amount. This energy removal through displacement rather than through active refrigeration provides both energy savings and simplification of refueling infrastructure.

[0052] Third is the finite thermal capacitance of the target vessel structure itself. The pressure vessel walls, comprising metal liners and composite overwraps, possess thermal mass that absorbs heat from hot gas and releases heat to cooler gas, acting as a thermal buffer that moderates gas temperature changes. During the initial filling phase when gas temperature rises due to heating by waves of filling, some of this thermal energy can transfer to the walls 51 of the target vessel 100, warming the structure.During subsequent displacement and final filling, introduction of cooler gas from bulk storage tank 110 is partially offset by heat transfer from the now-warm vessel walls back to the gas. However, the thermal time constant for heat transfer between gas and vessel structure is typically minutes to tens of minutes for composite pressure vessels, which have relatively low thermal conductivity. The refueling sequence can be configured to be completed in timeframes of 3 to 10 minutes for typical fast-fill operations, meaning that full thermal equilibration between gas and structure does not occur during the filling process. This incomplete equilibration allows the displacement strategy to remain effective even in the presence of vessel wall thermal effects.

[0053] Furthermore, the selection of flow rate during the initial filling phase can generate heated gas may appear counterintuitive, as conventional wisdom suggests minimizing temperature rise through slow filling that allows time for heat dissipation. However, the methods disclosed recognize that the created heated gas serves a beneficial purpose by establishing a separate gas phase where the thermal stratification is beneficial for subsequent displacement. Furthermore, by concentrating the heating in a relatively small gas mass during initial filling to intermediate pressure rather than distributing temperature rise across the entire final gas mass, the systems and methods disclosed create a more favorable condition for displacement. A small mass of strongly heated gas stratifies more clearly and can be displaced more completely than a large mass of moderately heated gas, even though the total thermal energy may be similar. This insight drives the counterintuitive strategy of rapid initial filling that create heated gas, followed by displacement of that specifically identified thermal load.

[0054] The final temperature rise in the target vessel 100 using the disclosed method is substantially reduced compared to conventional filling without displacement.Quantitative reduction depends in certain exemplary implementations on specific parameters such as, for example; vessel volumes, pressure ratios, flow rates, and ambient conditions, but reductions in peak gas temperature of 20 to 50 K compared to conventional filling are readily achievable with appropriate parameter selection. This temperature reduction provides multiple benefits including improved state of charge by enabling higher final gas density, reduced thermal stress on vessel materials extending service life, and decreased refrigeration requirements reducing both capital and operating costs for refueling infrastructure. The method can be particularly advantageous for hydrogen refueling where the negative Joule-Thomson coefficient exacerbates heating effects and where composite vessel temperature limits constrain filling aggressiveness (while providing low thermal capacitance), but the principles are equally applicable to natural gas, helium, or other compressed gases used in refueling applications.

[0055] System implementation of the disclosed method would require careful specification of materials and equipment to ensure reliable operation under the conditions of high-pressure gas transfer while maintaining compatibility with reactive gases such as hydrogen. Pressure vessel materials for bulk storage tanks and intermediate vessels operating at pressures up to 100 MPa can typically be seamless chrome-molybdenum steel alloys such as AISI 4130X, providing high tensile strength exceeding 800 MPa with adequate ductility and toughness across operational temperature ranges. For hydrogen service, material selection could account for hydrogen embrittlement susceptibility, with testing according to standards such as ASTM G142 to evaluate susceptibility under representative pressure and temperature conditions. Alternative materials for storage vessels can be, for example, austenitic stainless steels such as 316L, which demonstrate resistance to hydrogen embrittlement compared to ferritic or martensitic steels, albeit at higher material cost and potentially greater wall thickness requirements due to lower yield strength.

[0056] Target vessels for vehicular applications can employ composite overwrapped pressure vessel construction to minimize weight while achieving required strength. TypeIll vessels utilize seamless aluminum liners, e.g., 6061 -T6 alloy, with wall thickness designed such that the liner carries hoop stress while axial loads can be supported by the carbon fiber overwrap. The carbon fiber composite comprises continuous carbon fiber tows impregnated with epoxy resin and wound in specific patterns including helical wraps at angles e.g., between about 10° and 30° from the cylinder axis for axial strength, and circumferential hoops can be oriented 90° to the axis for hoop strength. Fiber volume fractions in the cured composite range e.g., from 55% to 65%, with matrix material filling remaining volume. The carbon fiber can be used to provide high specific strength, with tensile strengths exceeding 4000 MPa for aerospace-grade fibers, enabling target vessel designs with burst pressures exceeding 150 MPa while maintaining structural weights below 100 kilograms for vessels storing 5 Kg to 6 Kg of hydrogen.

[0057] Additionally, or alternatively, Type IV vessels can be used to replace the metallic liner with high-density polyethylene (PE) or polyamide (PA) polymer liners that provide gas barrier function but carry minimal structural load, with essentially all pressure loading carried by the carbon fiber overwrap. This construction can be used to achieve additional weight savings of 20% to 30% compared to Type III designs but would impose additional, stringent temperature limitations, as polymer liner materials lose mechanical properties and dimensional stability at elevated temperatures.Maximum operating temperatures for Type IV vessels would therefore be limited to 358 K (85 °C), compared to 398 K (125 °C) for Type III aluminum-lined vessels, making thermal management during refueling even more predetermined for Type IV applications.

[0058] Likewise, piping and fitting materials throughout the gas transfer system would likewise be compatibility with the compressed gas and resistance to environmental conditions. For hydrogen service at pressures exceeding 70 MPa, austenitic stainless-steel tubing with outside diameters of 6 to 12 millimeters and wall thicknesses of 1 to 2 millimeters could provide sufficient strength while maintaining reasonable weight and cost. Compression fittings employing ferrule seals or cone-and-thread seals rated for high-pressure can be used for hydrogen service and provide reliable leak-tight connections while allowing disassembly for maintenance. Weldedconnections can be used for permanent joints in predetermined applications, using tungsten inert gas or laser welding processes that produce full-penetration welds without porosity or inclusion defects that could serve as hydrogen embrittlement initiation sites.

[0059] Valve specifications for the first 56 and second 57 valves controlling gas flow shall address multiple performance requirements simultaneously. Pressure ratings could exceed maximum operating pressure by safety factors defined in applicable codes, e.g., resulting in rated pressures of 100 MPa or greater for components serving 70 MPa systems. Sealing performance could be configured to maintain leak rates below 10’6standard cc / sec. of helium equivalent across rated pressure differentials, verified e.g., through mass spectrometer leak testing. Cycle life could be configured to support tens of thousands of open-close operations without degradation of sealing performance or increase in actuation force, demonstrated through accelerated life testing under representative temperature and pressure conditions. Actuation timing could be configured to enable full opening or closing within specified timeframes, e.g., 0.5 to 2 seconds for solenoid or pneumatic actuators, with position feedback provided through limit switches or position sensors to confirm commanded valve positions.

[0060] Temperature and pressure sensing instrumentation could be configured to provide accuracy and response time adequate for the control algorithms implemented in the FMM. Pressure transducers can employ, e.g., piezoresistive, strain gauge, or capacitive sensing technologies capable of accuracy within 0.25% of full-scale range across operating temperatures from 233 K to 358 K. Electrical outputs can be, e.g., 4-20 milliamp current loops, or 0-10 volt analog signals compatible with controller analog input modules, with digital communication options such as CANbus or Modbus providing enhanced capability for advanced implementations. Temperature measurement can utilize e.g., Type K or Type T thermocouples for economical installations, or resistance temperature detectors utilizing platinum sensing elements for superior accuracy and stability when higher performance justifies additional cost.Sensor response times for process control applications can be characterized e.g., by time constants of 1 to 5 seconds, fast enough to track temperature and pressurechanges during filling operations while slow enough to average out high-frequency fluctuations that do not require control response.

[0061] The FMM controller hardware used in the systems and methods disclosed, can comprise ruggedized industrial PLCs rated for environmental conditions including wide temperature ranges, vibration, dust, moisture, and electrical noise encountered in refueling systems installations. Controller selection can be configured to balance processing capability, input / output capacity, programming environment, and cost, with installations employing e.g., modular PLC systems providing for example, 16 to 32 analog inputs, 8 to 16 analog outputs, and corresponding digital input / output channels for discrete signals such as valve position confirmations and alarm conditions.Programming can be accomplished using e.g., ladder logic, structured text, or function block diagram languages according to IEC 61131 -3 standard, with user interfaces provided through human-machine interface touchscreen panels allowing operators to monitor system status and initiate refueling sequences.

[0062] In an exemplary implementation, (see e.g., FIG.s 1 , and 5), target vessel 100 is further configured to facilitate gas displacement mechanism by providing fluid pathway that directs incoming high-pressure, cooler gas from bulk storage tank 110 toward floor 58 of target vessel 100, thereby promoting efficient stratified flow displacement of heated gas accumulated in upper regions (510) of target vessel 100 during the initial filling phase. Outer cylindrical wall 51 defines pressure boundary of target vessel 100 and in an exemplary implementation, can comprise continuous metallic structure, fabricated from e.g., aluminum alloy Type 6061 -T6, or composite overwrapped pressure vessel (COPV) construction featuring liner of high-density polyethylene or aluminum with carbon fiber or glass fiber reinforcement, adapted sized and configured to withstand internal pressures ranging from between about 35 MPa to about 70 MPa, depending on the particular compressible gas storage application, whether compressed natural gas (ONG) or hydrogen fuel. Cylindrical geometry, is characterized in another exemplary implementation, by length-to-diameter ratio (L / D) e.g., of between 2:1 and 6:1 , configured to provide structural efficiency for resisting hoop stress and longitudinal stress according to thin-walled pressure vessel theory, where hoop stress in MPa, equals pressure in MPa times radius of target vessel 100 incm, divided by wall thickness, in cm., and longitudinal stress equals half hoop stress, thereby minimizing material usage while maximizing volumetric storage capacity. Filling pipe 53 constitutes conduit extending substantially along longitudinal axis of cylindrical volume 52, and can be fabricated from stainless steel or aluminum tubing with inner diameter ranging from between about 6 mm and about 25 mm depending on target flowrate requirements, with basal outlet 59 positioned within between about 50 mm and about 200 mm of floor 58 (interchangeable with base) of cylindrical volume 52 to ensure that incoming gas is directed downward and radially outward in laminar (e.g., RE<2100). or controlled turbulent flow pattern that creates density-stratified displacement front. Apical inlet 54 of filling pipe 53 is coupled to filling manifold 55 at apical end 510 of target vessel 100 through e.g.; threaded connections, compression fittings, or welded joints conforming in one example to SAE J2600 or ISO 19880-1 standards for gaseous hydrogen vehicle fueling, ensuring leak-tight operation at operational pressures.Likewise, coaxial arrangement of filling pipe 53 with respect to cylindrical volume 52, is such that longitudinal centerline of filling pipe 53 substantially coincides with longitudinal centerline of cylindrical volume 52, is configured to further promote axisymmetric flow distribution that minimizes preferential flow channeling and ensures uniform front displacement of heated gas from central axis radially outward toward cylindrical wall 51 , then upward toward apical end 510 and ultimately through second valve 57 into intermediate vessel 120. As indicated herein, this configuration exploits natural buoyancy-driven convection of lower-density heated gas relative to higher-density cooler incoming gas, where density differences arise from ideal gas relationship that density equals pressure times molecular weight divided by product of gas constant and absolute temperature, thereby creating thermally-driven stratification effect that enhances displacement efficiency and reduces mixing between incoming cool dense gas and outgoing warm gas with lower density, ultimately contributing to substantial reduction in final gas temperature within target vessel.

[0063] In another exemplary implementation (see e.g., FIG.s 1 , and 6A-6B), target vessel 100 used in the systems and methods disclosed, further comprises axially movable partition 62 mechanism configured to provide dynamic volumetric control of the filling process, enabling active and adaptive optimization of gas displacement, byphysically separating cylindrical volume into distinct upper 63 and lower 71 portions whose relative volumes can be adjusted in real-time based on, for example; fill state, gas temperature, pressure differential, initial gas mass, and other operating parameters monitored by filling management module (FFM). Axially movable partition 62 can comprises disk-shaped or slightly conical element with diameter closely matching inner diameter of cylindrical wall 61 , incorporating circumferential sealing elements 621 such as, for example; elastomeric O-rings of nitrile rubber, fluorocarbon, or perfluoro elastomer materials, or polytetrafluoroethylene backup rings, or labyrinth seal configurations configured to provide sliding gas-tight or substantially gas-tight sealing while permitting axial translation along length filling pipe 64 in cylindrical volume 63, 71 under control of drivetrain 68. As illustrated, partition 62 is operably coupled to filling pipe 64 through, e.g., mechanical bearing assemblies, sliding seals, or collar mechanisms configured to maintain coaxial alignment while allowing relative axial motion, and partition 62 may incorporate apertures, channels, or porting (not shown), adapted, sized and configured to permit controlled gas communication between upper 63 and lower 71 portions under specific operating conditions, or alternatively may provide complete isolation between portions 63, 71. Additionally, perforated support 69 is provided, positioned between basal outlet 640 of filling pipe 64 and base 610 of target vessel 100, can be comprised of rigid structure of perforated metal plate, wire mesh, sintered metal, or lattice framework with open area fraction ranging for example, between about 30% and about 70%, adapted sized and configured to distribute incoming gas radially across floor 610 area of lower portion 71 while providing mechanical support for axially movable partition 62 when translated to its lowermost position. The perforation pattern may be uniform or graded to facilitate desired flow distribution characteristics. Furthermore, drivetrain 68, which interfaces with FMM (see e.g., FIG. 1), through, for example; electronic control signals, pneumatic actuation lines, or hydraulic circuits, can comprise linear actuators such as electric ball screw mechanisms, rack and pinion drives, pneumatic cylinders, hydraulic cylinders, or linear motors capable of generating axial forces ranging for example, between about 50 N and about 5000 N, operable to provide positional control with resolution of e.g., between about 1 mm and about 50 mm, enabling partition 62 to be translated upward as fillingprogresses, thereby maintaining reduced active volume ahead of the advancing gas front and minimizing upper portion 63 volume of heated gas generated during initial filling phase from intermediate vessel 120, and subsequently allowing partition 62 to translate upward as cooler gas from bulk storage tank 110 enters through basal outlet 640 through support 69 and displaces heated gas upward and outward through second valve 67, with motion of partition 62 optionally synchronized with valve positions and flowrates to maintain optimal displacement front velocity at, for example; between about 0.1 m / s and about 2.0 m / s. The capability of dynamic control of volumes of portions 63 and 71 can provide several technical advantages, such as, for example; reduction of peak gas temperature during filling by limiting volume in upper portion 63 subjected to adiabatic compression heating, enhancement of displacement efficiency by maintaining compact heated gas volume that can be more easily and completely displaced, and enabling adaptive filling strategies wherein partition position, valve timing, and cooling activation are coordinated by FMM are based on real-time measurements of temperature from thermocouples or resistance temperature detectors positioned at multiple axial locations within target vessel 100, pressure from strain gauge or piezoelectric transducers, and mass flowrate from Coriolis, thermal, or differential pressure flowmeters, thereby achieving filling protocols that comply for example with fueling standards such as SAE J2601 for hydrogen, or SAE J2600 for hardware, while simultaneously minimizing final gas temperature and maximizing effective storage density within target vessel.

[0064] The advantage of this design is the ability to fill the cylinder without increasing the gas density, thereby preventing the occurrence of filling waves and gas heating. This partitioning strategy enables quasi-isothermal filling by maintaining constant gas density in upper volume 63. In yet another exemplary implementation, before filling the cylinder, partition 62 is in the lower position at the bottom 610, the remaining gas is in volume 63. FMM (see e.g., FIG. 1) opens second valve 67, and the gas from the intermediate vessel 120 enters the lower volume 71 via the filling pipe, and drivetrain 68 simultaneously translates partition 62 toward filling manifold 65 and compress remaining gas in the upper volume 63. When pressure in the upper volume 63 reaches the pressure of intermediate vessel 120, partition 62 reaches the upper position, FMMopens the first valve 66, the second valve stay open, drivetrain 68 simultaneously translates partition 62 toward bottom 610 and the gas from storage tank 110 or from the high- pressure vessel 90 through the reducer fills the upper volume at a constant preset pressure. The displacement of partition 62 increases the upper volume 63, which is filled with gas at a constant pre-set pressure, while the density of the gas remains unchanged, filling waves do not occur, and the temperature of the gas does not increase. During the displacement of partition 62 to the bottom the gas from lower volume 71 moves into the intermediate vessel 120. At the same time, the pressure and density of the gas in the high- pressure vessel 90 decreases sharply, emptying waves occur and the gas entering the target vessel is cooled. The velocity of partition 62 displacement coordinated with mass flow rate configured to maintain constant pressure in upper volume 63. Drivetrain 68 continues advancing partition 62 while filling occurs at rate maintaining constant gas density in upper portion 63. The process of filling the target vessel stops when partition 62 reaches the bottom 610, and FMM closes the both valves. Optional cooling of gas from bulk storage tank 110 may be implemented through, for example (see e.g., FIG. 1); thermoelectric coolers, heat exchangers utilizing ambient air or liquid coolant, or adiabatic expansion devices integrated upstream of target vessel 100. FMM monitoring these conditions through e.g., pressure transducers and position sensors to determine exact valve closure timing, thereby achieving substantially reduced temperature increase while enabling complete utilization of target vessel's volumetric capacity. The filling method described here can be carried out quickly, which is an advantage.

[0065] In an exemplary implementation, drivetrain 68 mounting is adapted and configured to provides certain advantages for system integration, maintenance accessibility, and operational safety, by having drivetrain disposed entirely within the target vessel rather than externally mounted or partially protruding through the vessel wall. The internal mounting arrangement can be used to eliminate the need for dynamic pressure seals or feedthroughs in target vessel 100 wall 61 that would otherwise be required for external actuators to transmit force to the internal partition 62, thereby removing potential leak paths that would represent significant failure modes in high-pressure gas systems, for example, when operating with hydrogen which exhibits highpermeability through polymeric sealing materials and can cause hydrogen embrittlement of certain metal alloys under cyclic pressure conditions. The internally-disposed drivetrain may comprise a self-contained electromechanical actuator powered by electrical energy transmitted through sealed electrical feedthroughs in the vessel wall.

[0066] Alternatively pneumatic or hydraulic power may be utilized, derived from the pressurized gas within the target vessel itself, with the latter approach offering the advantage of eliminating all dynamic seals by using the process gas as the working fluid for actuation. In this variant, the movement of partition 62 is carried out due to the difference in pressure above and below partition 62. When the drivetrain comprises an electric linear motor, the motor windings and control electronics must be rated for operation in the hydrogen atmosphere and temperature range experienced during filling cycles, typically requiring encapsulation in hermetically sealed housings fabricated from stainless steel or aluminum with appropriate electromagnetic interference shielding, while position feedback may be provided by non-contact magnetic encoders that operate reliably in the gas environment without requiring additional pressure barriers. For pneumatic or hydraulic drivetrain configurations disposed internally, the actuator cylinder may be supplied with pressurized gas tapped from the intermediate vessel or bulk storage tank through dedicated control lines, with miniature solenoid valves integrated into the actuator assembly to enable the FMM to control extension and retraction cycles, and with position control achieved through modulation of supply pressure or flow rate in coordination with position feedback from integrated sensors. The internal mounting configuration also provides thermal management benefits by ensuring the drivetrain components are maintained at similar temperatures to the process gas, thereby avoiding thermal stress that would occur if portions of the mechanism spanned the temperature gradient between the internal gas and external environment, and enabling more accurate position control by eliminating thermal expansion effects in feedthrough components. Furthermore, the entirely internal disposition facilitates serviceability in vehicular fuel tank applications by enabling the entire partition and drivetrain assembly to be serviced as a unit when the vessel is removed, and this configuration is particularly advantageous for composite-wrapped pressure vessels where wall penetrations are minimized to preserve structural integrityand avoid stress concentrations that could initiate delamination or fiber damage under cyclic pressure loading.

[0067] In another exemplary implementation, detachable partition system is provided as a part of the systems used to implement the methods provided, enabling operational flexibility by allowing the partition to be selectively coupled to - and decoupled from the drivetrain 68 under control of the FMM, thereby supporting both advanced thermal management filling operations utilizing the partition mechanism and conventional filling operations without deployment of partition 62, while also facilitating maintenance and component lifecycle management. In the context of the disclosure, the term "operably coupling" is meant to encompass mechanical, magnetic, or pneumatic engagement mechanisms that establish a force-transmitting connection between the drivetrain and partition sufficient to withstand the axial forces generated during partition translation, which may include pressure differential forces across the partition reaching e.g., 35 MPa or more in typical hydrogen refueling applications, corresponding to axial forces of tens of kilonewtons (KN) for partitions sized for vehicle fuel tanks in the range of between about 10O-liter and about 200-liter capacity range. In yet another exemplary implementation, the coupling mechanism may comprise mechanical latches with overcenter locking features that engage corresponding receptacles in the partition when the drivetrain extends a coupling element, with the latches designed to positively retain the partition against separation forces during filling operations while enabling controlled release when disengagement is commanded, and with latch actuation integrated into the drivetrain control system to enable the FMM to command coupling and decoupling through the same control interface used for partition positioning. Alternatively, or additionally, the coupling may be implemented through electromagnetic means, utilizing permanent magnets embedded in the partition that engage with electromagnets in the drivetrain actuator, where energizing the electromagnets provides supplemental holding force during filling operations and de-energizing enables magnetic release, enabling the elimination of mechanical wear while requiring electrical power and control wiring to the electromagnet assembly. Before partitioning operations commence in methods disclosed, FMM executes coupling sequence wherein drivetrain 68 is positioned to align with partition 62, which may be stowed at predetermined location within target vessel100 or inserted through filling manifold 65 prior to coupling, and actuating the coupling mechanism to establish force-transmitting connection, with successful coupling verified through, for example; force sensors, position sensors detecting expected load characteristic changes, or dedicated coupling status sensors providing positive confirmation to FMM that partition 62 is securely attached. Following completion of filling operation when first 66 and second 67 valves are closed, the FMM is configured to commands decoupling sequence wherein coupling mechanism releases partition 62, and partition 62 can be removed from target vessel 100, which, in certain circumstances may involve withdrawing partition 62 through filling manifold 65 if a manifold aperture incorporated in target vessel 100 accommodates partition passage, or alternatively storing partition 62 at designated location within target vessel 100 for subsequent use, with storage location preferably positioned to minimize interference with gas flow during conventional filling operations. Removability of partition 62 is configured to enable reducing parasitic mass carried by target vessel 100 when advanced thermal management filling is not required, which can be particularly beneficial in vehicular applications where minimizing vehicle mass directly improves energy efficiency, while also enabling partition inspection, maintenance, or replacement without requiring target vessel disassembly, and supporting different filling protocols optimized for scenarios such as rapid emergency refueling without partition deployment versus routine refueling with partition deployment for maximum temperature control and gas density optimization.

[0068] In an exemplary implementation illustrated in FIG.s 1, and 7, the systems used to implement the methods disclosed, deploy dual-volume target vessel architecture that partitions the filling space into a primary cylindrical volume 88 and secondary internal volume 83 defined by bladder (inflatable volume) 82, providing enhanced thermal management during compressed gas transfer process. Outer cylindrical wall 81 , constitutes primary structural boundary of target vessel 100 and defines cylindrical volume 88 with base 89, representing main storage capacity where final cooled gas from bulk storage tank 110 will reside. This cylindrical geometry can be advantageous in vehicular fuel tank applications where cylindrical vessels provide optimal structural efficiency under high internal pressures, while maximizing volumetricstorage within constrained vehicle chassis geometries. Bladder 82, is in liquid communication with intermediate vessel 120 through second valve 87, defines internal volume 83 that is partitioned from cylindrical volume 88, meaning bladder 82 creates discrete gas-containing space within overall target vessel 100 that can be filled and emptied independently of cylindrical volume 88. In the context of the disclosure, the term "partitioned" means that during inflation of bladder 82, gas occupies internal volume 83 rather than mixing with gas in cylindrical volume 88, allowing sequential filling operations that leverage thermal stratification principles.

[0069] The space between wall 81 and the shell of the bladder 82 is in fluid communication with the high- pressure vessel 90 or with storage tank 110 through the first valve 86. Bladder 82 is configured to serve as temporary reservoir for initially heated gas generated during rapid filling from intermediate vessel 120, wherein gas is filled at a rate caused temperature increases above bulk storage tank temperature due to heating effects by filling waves and Joule-Thomson coefficient behavior of hydrogen.

[0070] At the beginning of the filling process, the FMM opens the second valve 87 and the bladder 82 quickly filled with gas to a pressure equal to the pressure in the intermediate vessel 120; the gas remaining in the vessel between the wall 81 and the shell of bladder 82 is also compressed to this pressure level. Next, the FMM opens the first valve 86 (the second valve 87 stay open) and gas from the high- pressure vessel 90 with pre-set pressure via the reducer enters the space between the wall 81 and the shell of bladder 82. The pressure difference compresses the shell of bladder 82, forcing the heated gas back into the intermediate vessel 120 and releasing space inside volume 88, and cooler gas from high- pressure vessel 90 enters cylindrical volume 88.

[0071] The filling process is stopped when the gas flows from bladder 82 to intermediate vessel 120 stops and FMM close both valves. In this exemplary implementation the density of the gas filling volume 88 remains unchanged, filling waves do not occur, and the gas temperature does not increase. This configuration effectively isolates compression-heated gas from final storage volume, preventing thermal soaking of cylindrical wall 81 structure and maintaining lower overall gas temperature in target vessel 100 upon completion of filling. The manufacturing implementation involves for example, positioning bladder 82 within cylindrical volume 88using mounting fixtures at apical end 810 near filling manifold 85, allowing bladder 82 to expand downward into cylindrical volume 88 during filling from intermediate vessel 120, then collapse as gas from high- pressure vessel 90 fills cylindrical volume 88.Alternative implementations may employ, for example, multiple smaller bladders distributed within cylindrical volume 88, bladders with variable compliance characteristics achieved through thickness variations or material selection, or bladders integrated with filling manifold 85 assembly to minimize dead volume and optimize thermal isolation effectiveness.

[0072] Opening first valve 86 while maintaining second valve 87 in open position, creates simultaneous communication between both bulk storage tank 110 and intermediate vessel 120 via target vessel 100, which enables continuous gas flow paths during the displacement process. Next, cylindrical volume 88 is filled with gas via reducer from bulk storage tank 110, at constant pre-set pressure, which is greater than pressure in intermediate vessel 120. As pre-set pressure is higher than pressure in intermediate vessel 120, gas leaving bladder 82 through second valve 87 into intermediate vessel 120. This constant density maintenance is achieved in an exemplary implementation, using real-time monitoring via, e.g., pressure transducers positioned in cylindrical volume 88 and mass flow meters in first valve 86 supply line (see e.g., FIG. 1), with FMM configured to execute, for example; proportional-integral-derivative (PID) control algorithms to adjust first valve 86 opening percentage based on measured density deviations from setpoint, typically maintained within ±2% of target density. Additionally, or alternatively, optional cooling of gas flowing from bulk storage tank 110, can be implemented through heat exchangers (see e.g., FIG. 1), using for example; ambient air, chilled water, or refrigerant loops positioned upstream of first valve 86, which is configured to further reduces gas temperature entering cylindrical volume 88, with cooling capacities adapted, sized and configured to remove between about 15 kilojoule and about 45 kilojoules per mole of hydrogen transferred (when H2 is the compressible gas). Heated gas displacement into intermediate vessel 120 can occur through pressure differential created as cylindrical volume 88 fills, compressing bladder 82 and forcing heated gas through second valve 87, with intermediate vessel's 120 (much) larger volume (relative to target vessel 100) and lower initial pressure, providingsufficient capacity to absorb the heated gas without significant pressure rise. Closing both valves 86, 87 can be implemented upon eliminating internal volume 83 of bladder 82, i.e, when bladder 82 has been fully collapsed by gas filling cylindrical volume 88, which indicates complete displacement of heated gas and achievement of target vessel's 100 final fill state with cooler, denser gas throughout cylindrical volume 88, thereby, again, maximizing usable energy storage capacity while minimizing thermal stress on vessel materials and safety system activation risks associated with elevated temperatures.

[0073] In an exemplary implementation, bladder 82 used in the systems implementing the methods disclosed, can be formed from a fiber-reinforced elastomeric laminate comprising e.g., aramid, or carbon fibers embedded within an elastomer matrix, forming a laminate, the laminate having an areal density between 150 g / m2and 650 g / m2, adapted sized and configured to withstand at least 2% elastic radial expansion without permanent deformation. The fiber-reinforced elastomeric laminate construction is adapted, sized and configured to provide balance of flexibility, strength, and durability by combining the elastic properties of an elastomer matrix with the tensile strength and stiffness of aramid or carbon fiber reinforcement, creating a composite structure capable of withstanding the mechanical stresses imposed during repeated inflation and deflation cycles, typically numbering in the thousands over the operational lifetime of a vehicle fuel system. Aramid fibers, such as those sold under the trade names KEVLAR® orTWARON®, enable specific tensile strength exceeding about 3.0 GPa with densities of about 1.44 g / cc, along with excellent chemical resistance to hydrogen embrittlement, and thermal stability across the operating temperature range of between about -40 °C (233 K) and about 85 °C (358 K), typical in automotive environment fueling. Carbon fibers, e.g., PAN-based continuous filament varieties with Young’s moduli ranging from between about 230 GPa and about 640 GPa, can be used to provide an even higher specific strength and stiffness, enabling thinner laminate constructions, minimizing bladder 82 occupied volume 83 when deflated, with surface treatment and sizing implemented to achieve adequate interfacial bonding with the elastomer matrix. The elastomer matrix material selection can be, for example; fluoroelastomers, hydrogenated nitrile rubber, or ethylene propylene diene (EPD)monomer formulations, selected in certain exemplary implementations for compatibility with the specific compressible gas, hydrogen permeation resistance characterized by permeability coefficients below 5x1 O’10cm3cm / (cm2s Pa), and retention of elastic properties under cyclic deformation. The specified areal density (mass / unit area) range between 150 and 650 g / m2refers to the combined mass per unit area of fibers, matrix, and any interface coating layers, with lower areal densities near 150 g / m2achieved deploying e.g., unidirectional fiber architectures providing minimum reinforcement for moderate pressure differentials up to 10 MPa, while higher areal densities approaching 650 g / m2employ woven or braided fiber architectures with increased fiber volume fractions, e.g., between about 40% and about 65% percent, adapted for pressure differentials exceeding 30 MPa. Withstanding at least 2% elastic radial expansion without permanent deformation is configured to enable bladder 82 can accommodate volumetric changes during the displacement process while maintaining dimensional stability and avoiding plastic strain accumulation that could lead to, for example; progressive growth of bladder 82, wrinkle formation, or premature failure. This elastic expansion capability can be quantified e.g., through pressure-volume testing where bladder 82 is inflated to maximum operating pressure while measuring radial displacement via, for example; laser extensometry, or digital image correlation, verifying that upon depressurization the bladder returns to within about 0.5% of its original dimensions, thereby confirming purely elastic deformation behavior.

[0074] In another exemplary implementation, illustrated in FIG.s 1 , and 8A-8D, high-pressure vessel (HPV) is used in the systems and methods disclosed, which is an alternative to direct filling from the bulk storage tank and is used to cool the gas before filling it into target vessel 100. A pressure reducer must be installed on the gas fluids line between the HPC and target vessel, reducing the pressure to the pre-set pressure level to prevent an emergency situation-

[0075] HPV 90 (see e.g., FIG. 8A, as used herein, refers e.g., to a rigid-walled pressure vessel constructed from materials suitable for containing compressible gases at pressures typically ranging from between about 35 MPa and about 90 MPa, such as, for example; carbon fiber reinforced polymer composites, Type IV aluminum-lined composite cylinders, or high-strength steel alloys conforming to ISO 11439 or SAEJ2579 standards (for Hydrogen). In the context of this disclosure instance, the term "in liquid communication" means a fluid pathway allowing gas flow between HPV 90 and target vessel 100 through conduits, valves, and fittings operable to maintain pressure integrity while permitting controlled mass transfer. The phrase "substantially lower than the volume of target vessel 100" refer to HPV 90 volume 98 ranging from between about 1% and about 15% of target vessel 100 volume 52 (see e.g., FIG. 8B), with exemplary implementations having ratios of, for example; 2:100, 5:100, or 10:100, ensuring that HPV 90 stores sufficient gas mass to effect final pressure equalization without requiring excessive storage capacity. The disclosed configuration is operable to enable system 10 to achieve final fill pressures matching bulk storage tank 110 (Pbuik) through controlled pressure boost stage, wherein gas mass contained in HPV 90, when released into target vessel 100, elevates target vessel pressure from intermediate pressure level to final desired pressure corresponding to bulk storage tank 110 conditions. In the context of the disclosure, the phrase "mass of gas configured to cause pressure" refers to predetermined quantity of gas stored in HPV 90 at elevated pressure and potentially different temperature conditions, calculated using e.g., ideal gas law or real gas equations of state such as Redlich-Kwong or Peng-Robinson equations to account for compressibility factors at high-pressures. Implementation methods comprise pre-charging HPV 90 to pressure range of between about 10% and about 50% higher than bulk storage tank 110 operating pressure (Pbuik), utilizing for example; check valves, or electronically actuated solenoid valves, to control gas release timing, and employing pressure transducers at both target vessel 100 and HPV 90 to enable FMM to monitor pressure differential and synchronize mass transfer. Additionally, or alternatively, multiple HPVs arranged in parallel can be utilized to provide redundancy and increased gas mass capacity, incorporate variable orifice flow restrictors to modulate discharge rates. The compressor that increases the pressure mast be includes to refueling sistemlO. The compressor must be equipped with a cooling system that equalizes the gas temperature with the environmental temperature. In all the actions described above, where it is indicated: opening valve 86 on the target vessel 100 to connect to the bulk storage tank 110, there is an alternative - connection to the HPV. When fluid connection established from HPV via reducer to the target vessel, thegas density after reducer practically not changed. But in the HPV the density of gas sharply reduced, the emptying waves are created, which cool the gas before it enters the target vessel 100.

[0076] High-pressure vessel (HPV) 90 (see e.g., FIG. 8A, as used herein, refers e.g., to a rigid-walled pressure vessel constructed from materials suitable for containing compressible gases at pressures typically ranging from between about 35 MPa and about 90 MPa, such as, for example; carbon fiber reinforced polymer composites, Type IV aluminum-lined composite cylinders, or high-strength steel alloys conforming to ISO 11439 or SAE J2579 standards (for Hydrogen). In the context of this disclosure instance, the term "in liquid communication" means a fluid pathway allowing gas flow between HPV 90 and target vessel 100 through conduits, valves, and fittings operable to maintain pressure integrity while permitting controlled mass transfer. The phrase "substantially lower than the volume of target vessel 100" refer to HPV 90 volume 98 ranging from between about 1% and about 15% of target vessel 100 volume 52 (see e.g., FIG. 8B), with exemplary implementations having ratios of, for example; 2:100, 5:100, or 10:100, ensuring that HPV 90 stores sufficient gas mass to effect final pressure equalization without requiring excessive storage capacity. The disclosed configuration is operable to enable system 10 to achieve final fill pressures matching bulk storage tank 110 pressure (Pbuik) through controlled pressure boost stage, wherein gas mass contained in HPV 90, when released into target vessel 100, elevates target vessel pressure from intermediate pressure level to final desired pressure corresponding to bulk storage tank 110 conditions. In the context of the disclosure, the phrase "mass of gas configured to cause pressure" refers to predetermined quantity of gas stored in HPV 90 at elevated pressure and potentially different temperature conditions, calculated using e.g., ideal gas law or real gas equations of state such as Redlich-Kwong or Peng-Robinson equations to account for compressibility factors at high-pressures. Implementation methods comprise pre-charging HPV 90 to pressure range of between about 10% and about 50% higher than bulk storage tank 110 operating pressure (Pbuik), utilizing for example; check valves, or electronically actuated solenoid valves, to control gas release timing, and employing pressure transducers at both target vessel 100 and HPV 90 to enable FMM to monitor pressure differential andsynchronize mass transfer. Additionally or alternatively, multiple HPVs arranged in parallel can be utilized to provide redundancy and increased gas mass capacity.

[0077] Furthermore, at least one insert 94i, see e.g., FIG. 8C, 8D, can be deployed within HPV 90 to accumulate cold inside HPV 90. The emptying wave (EW) phenomenon occurs during rapid gas discharge inside high-pressure vessels HPC accompanied with rapid density reducing.

[0078] An "emptying wave" is kind of elastic waves propagating at sound velocity, EW practically nod absorbed in gases at short distance but reflecting from walls EWs are damping due to interference and the energy of these waves is released in the wall region as cold. Without the use of inserts 94i, a significant portion of the cold will be lost due to heat transfer through the wall. The placement of inserts inside the NRS facilitates the rational use of cold.

[0079] Insert 95 structure can function by increasing internal surface area within HPC by factors ranging between about 10 and about 100 compared to an empty cylinder, creating tortuous flow paths that can be configured to induce multiple flow direction changes, and generating turbulent mixing zones where Reynolds numbers (Re) exceed 4000. Deployment methods include manufacturing inserts from thermally conductive materials such as, for example; aluminum alloys 6061 -T6, or copper to facilitate heat transfer from (de)compressed gas to cylinder walls, while securing inserts 94i can be achieved through e.g.; threaded connections, friction fits, and / or welded attachments that withstand pressure differentials and flow-induced vibrations, and positioning inserts 94i to occupy 30% to 80% (see e.g., FIG. 8D) of HPC 90 internal volume 98, while maintaining adequate open flow area to heat-transfer.

[0080] Alternative implementations may employ open cellular structures providing surface area enhancement while maintaining permeability, permeable structures made from small beads using powder metallurgy and / or perforated plate stacks oriented perpendicular to flow direction to create controlled expansion chambers, and / or helical baffle arrangements configured to impart swirl to flow and extend residence time within cylinder.

[0081] As illustrated in FIG. 8D, insert 94i structure can be comprised of plurality of metallic tubes 94i adapted, sized and configured their geometric configuration andmaterial properties while maintaining sufficient flow conductance for practical refueling rates. The term "plurality" in this context indicates at least 7 tubes and could range from 10 to 200 tubes depending on cylinder diameter and desired flow characteristics, with specific embodiments employing e.g.; 19-tube, 37-tube, or 61 -tube hexagonal close-packed arrangements. In this context, "Metallic tubes" refers to hollow cylindrical conduits manufactured from e.g., corrosion-resistant metals such as stainless steel grades 304, 316, or 316L having wall thicknesses ranging for example between about 0.5 mm and about 3 mm, aluminum alloys 3003 or 5052 with thicknesses ranging for example between about 1 mm and about 4 mm, or copper alloys that provide thermal conductivity exceeding e.g., 200 W / m K, configured to facilitate heat dissipation during gas expansion. The phrase "filling internal volume" indicates that the tube bundle occupies between about 40% and 77% of the cylinder's total internal volume, with the solid material of tube walls ranging for example between about 15% and about 40% of HPC 90 volume 98 and the hollow passages within tubes 94i plus interstitial spaces between tubes providing the remaining open volume for gas storage and flow.

[0082] The technical advantage of this tube bundle configuration lies in creating highly effective flow distribution through multiple parallel flow paths that divide the gas stream into smaller volume elements, each with reduced kinetic energy and momentum, while the tube walls provide substantial surface area for viscous dissipation and heat transfer.

[0083] Additionally, using the metal tubes as disclosed herein, is operable as a heat exchange surface to cool the expanding high-pressure gas, further cooling the gas ente4ring target vessel 100. The tubes function by constraining gas flow and about channels having hydraulic diameters ranging for example between about 3 mm and about 15 mm, thereby inducing boundary layer development and wall friction that attenuates flow velocity, creating velocity gradients that promote turbulent mixing at tube exits where free jets interact and generate shear layers, and providing distributed resistance that reduces the effective wave propagation speed within the cylinder from values approaching the speed of sound in free gas (approximately 450 m / s for hydrogen, 340 m / s for compressed natural gas) and about effective velocities 30% and about 60% lower. Alternative embodiments may employ tubes with internal diameterranging from 3 mm and about 20 mm selected and about balance flow conductance against damping effectiveness, incorporate tubes of varying diameters within a single bundle and about provide frequency-dependent damping characteristics, utilize tubes with internal flow directors such as helical inserts or rifling and about enhance turbulence generation, or arrange tubes in non-parallel orientations including radial or spiral patterns that further disrupt wave propagation while maintaining adequate open flow area for achieving target fill rates.

[0084] Accordingly, and in another exemplary implementation, HPV 90 serves as the primary gas source for initial pressurization of target vessel 100, establishing pressure equilibrium between these two vessels before subsequent filling steps introduce additional gas from bulk storage tank 110 or intermediate vessel 120. In this context, the term "equilibrium pressure" refers to thermodynamic state achieved when gas flow between HPV 90 and target vessel 100 ceases due to pressure differential approaching zero, typically defined as pressure difference less than about 0.5 Mpa or less than 2% of final pressure, and occurring when gas masses and volumes satisfy the relationship (PiVt + P2V2) / (Vi + V2) = Peq accounting for temperature effects and real gas behavior. Accordingly, refuelling system 10 comprise target vessel 100, intermediate vessel 120 and bulk storage tank 110, as well as FMM. In addition, the also provided is HPV 90. In certain exemplary implementations, the number of HPv 90 can corresponds to the number of filling ports (91 , 92, interchangeable with outlet, inlet, and associated valves) of HPV 90 of the system. The gas pressure in HPV 90 significantly exceeds the final pressure sought in target vessel 100. The magnitude of this high-pressure can be limited by considerations of, e.g.; the integrity, and / or safety of the system, as well as economic factors. The volume of HPV 90 is significantly lower than the volume of target cylinder 100. Equilibrium pressure can therefore be achieved depending for example on; initial pressure ratio between HPV 90 and target vessel 100, their respective volumes, and thermal conditions, with equilibrium pressures ranging for example between about 30% and about 70% of HPV 90 initial pressure when volume ratios are in the range disclosed herein.

[0085] In yet another exemplary implementation, the methods disclosed further introduce a predictive thermal-hydraulic algorithm executed by the FMM to dynamicallycontrol maximum permissible gas flowrate (Qmax) during the initial filling phase from intermediate vessel 120 to target vessel 100, thereby preventing excessive temperature rise. This can be done using real-time computational regulation. The predictive thermal-hydraulic algorithm cab comprise a mathematical model configured to continuously receives real-time sensor measurements of bulk storage tank 110 temperature (Tbuik) measured in K using e.g., resistance temperature detectors or thermocouples positioned at multiple vertical locations within bulk storage tank to account for thermal layering, and target vessel 100 pressure (Ptarget) measured in Pascals using e.g., piezoelectric, and / or strain-gauge pressure transducers mounted at filling manifold 55 (65, 85), or within target vessel 100 volume 52. The algorithm can be configured to calculate maximum permissible gas flowrate (Qmax) expressed in kg / mi, by evaluating inequality constraintAT < k-(Tbulk / Ptarget) (EQU. 1 )where AT represents predicted temperature increase within target vessel, and k is a system-specific constant uniquely determined for each target vessel configuration based on, for example; empirical calibration and / or first-principles calculation incorporating target vessel's 100 heat capacity (Cptarget) measured in joules / kg K and target vessel 100 volume (Vtarget) measured in liters. Furthermore, the system-specific constant k, effectively encodes thermodynamic behavior of, for example; particular target vessel geometry, material composition, and thermal mass, and / or may be determined through controlled filling experiments wherein various flowrates are tested while monitoring temperature response, or calculated using relationship, such as: k = / (Cptarget, Vtarget, gas) where Pgas represents gas density. FMM can be configured to implement this algorithm by modulating the opening degree of second valve 57 through, e.g.; proportional control (PID), pulse-width modulation of a solenoid valve, and / or variable-orifice adjustment in electronically-controlled pressure regulators, thereby restricting gas flowrate when algorithm predicts that current flowrate would cause AT to exceed threshold defined by k-(Tbuik / Ptarget). This predictive approach can be configured to provide technical advantage of preventing temperature overshoot before it occurs, rather than reacting to measured temperature increases, which is particularly beneficial given rapid compression heating that can occur during gas transfer where temperaturecan rise several K / sec., at unrestricted flowrates. Alternatively, or additionally, additional measured parameters can be incorporated, such as, for example; ambient temperature, target vessel initial temperature, and / or gas composition into the predictive model, implementing adaptive algorithms that continuously update the value of k, based on historical filling performance data, or employing neural network models trained on filling data to predict optimal flowrate profiles that maximize filling speed while maintaining temperature within acceptable limits.EXAMPLES EXAMPLE I: Filling wave and Emptying wave

[0086] Turning now to FIG.s 2, and 3, illustrating general principles of filling waved (FW) and emptying waves (EW) phenomenon responsible for gas heating in cylinders while being filled at a refuelling facility. During the study of the effects of temperature separation, numerous experiments were performed on vortex tubes, Hartmann-Sprenger tubes and other installations, (see e.g., US Patent 9670938B2,EUR13803934.2. Y. Beliavsky, Method and devise for transfer of energy, 2013) The observed temperature separation was found to be caused by the emergence of elastic waves of the Pressure Gradient Elastic Waves (PGEW). The energy source was compressed air from a compressor (maximum pressure 0.7 MPa).

[0087] The experimental setups included thermocouples placed at temperature control points. It was observed, that when the valve was suddenly opened and air was released to the installation, some thermocouples exhibited a sharp spike in temperature. The temperature increase did not exceed 27 K, the duration of the temperature spike was several seconds. This phenomenon was considered to be an insignificant transient process, since in the experiments the temperatures reached 500°C, and the time to reach the equilibrium was measured in tens of minutes. Comparing these observations with the phenomenon of heating when filling discrete, relatively small volumes with gas, made it clear that this heating had the nature of a wave, which can be called the elastic Filling Wave. The Huygens-Fresnel principle for gases can be formulated as follows; any disturbance associated with a rapid change in gas density can and does generatean elastic wave. (See e.g., Mises R. Mathematical Theory of Compressible Fluid Flow. Chapter 1.4, Academic press, New York, 1958). The wave equation is obtained under the assumption of the occurrence of a single fluctuation associated with an increase or decrease in gas density. This principle is universal for all sound-type waves. Any rapid change in gas density creates an elastic wave propagating at the speed of sound. The process of filling the volume with gas can certainly be associated with a rapid increase in the density of the gas in the volume. Therefore, it stands to reason that during the filling process, an elastic compression Filling Wave would occur.

[0088] As illustrated in FIG. 2, where the arrow shows the direction of air flow from the compressor, where the metal pipe 1 , (internal diameter 2” inches), of the compressed air supply system to the premises, with valve 2 and flexible pipe 3 with an internal diameter of 1 inch, and is 1.5 m long, in liquid communication with metal branch pipe 4 with a diameter of 2 inches, 15 cm long, and the tapering nozzle outlet 5, nozzle orifice diameter at 5 mm. Thermocouple 6 was installed on the inner surface of pipe 4 to control the air temperature at nozzle 5 inlet.

[0089] The diagram in Fig.s 3A-3C show the experimental readings of thermocouple 6 installed on the inner wall surface of pipe 4 (Fig. 2). Air temperature at the nozzle inlet was recorded at 4-second intervals. FIG. 3A shows the temperature throughout the experiment. FIG.s 3B, and 30 show respectively the filling and emptying modes using a larger scale. Temperature recording started from the moment the temperature recording program was turned on. Room temperature was 22°C. At 60 seconds (see e.g., FIG. 3B), valve 2 is opened abruptly, and the temperature increases over 8 seconds, from 22 °C, to 26.4°C. As illustrated, filling of pipe 4 from a pressure of 1 bar to 7 bar occurs in about 8-10 seconds. Following, the temperature drops back to the room temperature level due to the disappearance of Filling Wave (a state of dynamic equilibrium - the gas density at all points in the volume remains unchanged). The experiment lasted 17 minutes. At the end of the experiment, the valve was abruptly closed. FIG. 3C shows a sharp decrease in temperature by 6°C, over 8-10 seconds, followed by a smooth increase to room temperature. It is clear that the decrease in temperature is determined by the same physical effect, namely a sharp decrease in gas density, creating an elastic Emptying Wave, which generates cooling.Example Simulation of the process of filling a gas cylinder for the purpose of numerical calculation

[0090] Now let us turn to Fig. 4, which illustrates the model used to create a program for numerically calculating the process of filling a cylinder with gas by emptying the high-pressure vessel HPC 90.The numbers indicate: 41 - bulk storage tank 110(or high-pressure vessel HPC 90); 42 -target vessel (cylinder) 100: 43 - the layer of compressed gas; 44 - empty layer.

[0091] Consider the process of filling cylinder 42 with gas by emptying high-pressure vessel 41. At the entrance to cylinder 42, a reducer is installed, which passes gas into cylinder 42 at a constant pre-set pressure. The volume of pipes is not taken into account. If we open the valve connecting the volumes, gas from the high-pressure vessel 41 will move to the cylinder 42. During the filling process, the density and pressure of the gas in cylinder 42 increases from the initial values o and Po (To is the initial temperature of the gas in cylinder 42) to the final values p and P. The EWs and FW will change the gas temperatures: the temperature in cylinder 42 will increase, and the temperature in high-pressure vessel 41 from which gas was released will decrease. We will simulate this continuous process in discrete stages. Starting from initial gas parameters: in high-pressure vessel 41 , the gas mass is m = V1PQ and the mass of gas in the cylinder 42 is m = V2pQ. When the valve of the reducer separating the volumes (not shown in the figure) is opened, forming an opening with a flow crosssection S. The gas flow from high-pressure vessel 1 to cylinder 2 will be considered based on well-known flow modes through a nozzle, in which the speed and flow rate depend on the magnitude of the pressures ratio at the volumes. If the pressures ratio is less than or equal to the critical value<the gas enters the cylinder 42 with sound velocity. Over a small interval of time, At compressed gas layer - 43 from high-pressure vessel enters cylinder 42, while an empty layer - 44 is formed in high-pressure vessel 41. At the next stage, the gas in the high-pressure vessel 41 instantly fills the empty layer 44. At each stage of the calculation thegas density in high-pressure vessel 1 decreases, which creates the EWs that cools the gas, and vice versa, in cylinder 2 the gas density increases, which creates the FWs, which increases the temperature, and the compressed gas from layer 43 is instantly distributed throughout cylinder 42. The energy of an elastic wave disturbance in a gas is expressed by the relationis the enthalpy increment, gkiis the kinetic energy (Landau, Lifshitz, Fluid Mechanics, §65, p.267, Pergamon Press, New York, 1987).Knowing the gas flow rate through the hole, we determine the mass of the gas in layer 43, and the kinetic energy. Kinetic energy is a positive value, and it adds to the energy of FW in cylinder 42. However, this energy is generated by enthalpy of high-pressure vessel and is removed from volume 41 , so this portion of energy must be added to the energy of EW in cylinder 41 with a negative value. The terms of next expression have the dimensionness of density of enthalpy (enthalpy of a unit volume)Here index i = 1 ...n corresponds to the stage of emptying the high-pressure vessel 41 and filling the cylinder 42, a - is the speed of sound. In relation w - is specific enthalpy, the enthalpy of a unit mass of a gas. The first term of expression reflects the change in the enthalpy of the elastic wave associated with the change in the mass of gas in a unit volume. In normal sound waves this first term is not considered because compression and rarefaction zones are alternate. The mass of gas in the region of disturbance remains unchanged, so the integral of this first term over volume is zero.In our case, the change in gas mass occurs in different volumes and, accordingly, this component makes the main contribution to the energy of FWs and EWs. The value of Apzat each stage of the calculation of gas emptying in high-pressure vessel 41 has a negative value, this fact indicates that in this process the internal energy decreases, that is, the gas cools. Of course, at each stage of the processes described the temperatures, pressures, and densities of the gas in both volumes are calculated. Gas is assumed to be ideal, and the processes are assumed to be adiabatic. The values of specific enthalpy are determined from published tables, using the gas parameters.

[0092] The described step-by-step calculation method is easy to program and calculate. The process ends when the pressure in cylinder 42 (or target vessel 100) reaches the gas pressure value of pre-set pressure. Both theory and experiment demonstrate to confirm that the heating of gas when filling target vessel 100 at a refuelling facility is due to the occurrence of Filling Waves (FW), due to rapid increase in gas density when filling the cylinder. Understanding the physics of the processes makes it possible to set the task of filling the gas cylinder without increasing the gas density. The methods disclosed, implemented using the systems described, address this problem by displacing heated gas with cold gas without changing its density in the target vessel.

[0093] Accordingly, provided herein is a method for substantially reducing increase in gas temperature in the process of transferring compressed gas from a bulk storage tank to a target vessel, implemented in a refuelling system comprising: the bulk storage tank, an intermediate vessel maintained at a lower pressure than the pre-set pressure, a target vessel having an outer wall, a bottom and an apical end comprising a filling manifold, the filling manifold having a first valve in liquid communication with the bulk storage tank or with high-pressure vessel and a second valve in liquid communication with the intermediate vessel, wherein the volume of the target vessel is substantially lower than the volume of the bulk storage tank and the intermediate vessel; the method comprising: using the FMM, opening the second valve, and filling the target vessel to the pre-set pressure, at a rate configured to increase gas temperature within the target vessel to a temperature higher than the temperature of the gas in the bulk storage tank, using the FMM, opening the first valve, while keeping the second valve opened, the difference of pressure creates the gas flow, and gas from the bulk storage tank is introduced of the target vessel substantially toward the floor of the target vessel, displacing the heated gas into the intermediate vessel without changing the gas density, thereby substantially reducing the gas temperature; while optionally using the FMM, cooling the gas flowing from the bulk storage tank to the target vessel, and, using the FMM, simultaneously closing the first and second valves upon filling of the target vessel to a predetermined gas pressure and temperature, wherein (i) the target vessel further comprises: an outer cylindrical wall, defining a cylindrical volume with a base, and afilling pipe in liquid communication with the first valve, having an outlet disposed toward the bottom of the cylindrical volume, and an apical outlet in liquid communication with an outlet disposed toward the filling manifold (ii) the target vessel further comprises: an outer cylindrical wall, defining a cylindrical volume and a filling pipe, wherein the filling pipe being coaxial with the cylindrical wall, an axially movable partition operably coupled to the filling pipe, the axially movable partition adapted sized and configured variably divide the cylindrical volume of the vessel to an apical portion and a lower portion, a perforated support sandwiched between the basal outlet of the filling pipe and the base of the target cylinder, and optionally, drivetrain in operably coupled to the FMM, configured to axially translate the axially movable partition, the method further comprising (iii): translating the partition axially from the bottom to apical manifold, thereby partitioning the cylindrical volume of the target vessel to a lower volume and an upper volume, the gas remained in lower volume is compressed, using the FMM opening the second valve and displace remained gas to the intermediate vessel, using the FMM, closing the second valve and opening the first valve simultaneously translating the partition axially to the bottom , the gas from the bulk storage tank or from high-pressure vessel enters upper volume via reducer, filling the upper portion of the target vessel with cooled gas is being carried out without changing the gas density during the increase in upper volume, using the FMM, closing the first valve, while the partition reaches the bottom; wherein (iv) the partition is a disc, and wherein the drivetrain is a worm gear coupled to a motor, (v) the drivetrain is disposed entirely within the target vessel, wherein (vi) the drivetrain for moving the axial movable partition is disposed entirely within the FMM, the method further comprising (vii): before the step of partitioning the cylindrical volume of the target vessel to the lower volume and the upper volume, using the FMM, operably coupling the partition to the drivetrain within the target cylinder, and following the step of closing the first and second valves, using the FMM, decoupling the partition from the drivetrain and removing the partition from the target vessel, wherein (viii), the target vessel further comprises: an outer cylindrical wall, defining a cylindrical volume with a bottom base, and a bladder, in liquid communication with the intermediate vessel via second valve, the bladder defining an internal volume partitioned from the cylindrical volume of target vessel, the volume of target vessel, inliquid communication with bulk storage tank or with high-pressure cylinder via first valve, the method further comprising (ix): using the FMM opening the second valve, at a rate configured to increase gas temperature within the bladder to a temperature higher than the pre-set temperature, forming heated gas in the bladder and simultaneously pressurizing the residual gas in the volume of the target vessel, opening the first valve, while keeping the second valve opened, filling the cylindrical volume of the target vessel with the gas from the bulk storage tank to a pre-set pressure, and while using the FMM, optionally cooling the gas flowing from the bulk storage tank to the target vessel, causing the heated gas portion to flow into the intermediate vessel, and using the FMM, closing the first and second valves upon eliminating the internal volume of the bladder, thereby substantially reducing the increase in gas temperature in the process of transferring compressible gas from the bulk storage tank to the target vessel, wherein (x) the system further comprises at least one high-pressure vessel in liquid communication with the target vessel, as well as the high-pressure vessel having a volume that is substantially lower than the volume of the target vessel, and wherein the mass of the gas in the high-pressure vessel configured to cause the pressure in the target vessel to be equal to the pre-set pressure in the bulk storage tank upon filling of the target vessel, using the FMM, opening the first valve and filling the target vessel by emptying the high-pressure vessel, wherein the emptying waves cool down the gas in the high-pressure vessel, using the FMM closing the first valve, when the pressure in the target vessel reached the pre-set value, thereby substantially reducing the increase in gas temperature in the process of transferring compressible gas from the high-pressure cylinder to the target vessel, (xi) the high-pressure vessel further comprises at least one insert configured to absorb emptying wave generated by flow of gas from the high-pressure vessel, (xii) the at least one insert is a plurality of metallic tubes filling internal volume of the high-pressure vessel, wherein (xiii) the step of filling the target vessel comprises filling the target vessel from the high-pressure vessel to an equilibrium pressure between the target vessel and the high-pressure vessel, wherein (xiv) the gas is hydrogen, or (xv) natural gas (LNG), wherein (xvi) the axially movable partition comprises a thermally conductive metallic core encapsulated in a polymeric coating, the polymeric coating having a thermal conductivity of less than 0.4 W / m K, thereby limitingthermal transfer from the heated gas in the upper portion to the lower portion during translation of the partition, wherein (xvii) the bladder is formed of a fiber-reinforced elastomeric laminate comprising e.g., aramid, or carbon fibers embedded within an elastomer matrix, forming a laminate, the laminate having an areal density between 150 g / m2and 650 g / m2, adapted sized and configured to withstand at least 2% elastic radial expansion without permanent deformation, wherein (xviii) the at least one high-pressure vessel has an internal diameter of 40-120 mm and a length-to-diameter ratio of 4:1 to 20:1 , and wherein the at least one insert comprises a stack of metallic tubes having a combined open flow area of between about 25% and about 60% of the cylinder crosssection adapted sized and configured to attenuate emptying pressure wave amplitude by at least 30% during the step of using the high-pressure vessel, filling the target vessel, wherein (xix) the FMM uses a predictive thermal-hydraulic algorithm to calculate a maximum permissible gas flowrate, Qmax, in Kg / min. in the step of filling the target vessel to a pressure equal to the pressure of the intermediate vessel, is based on realtime measurements of the bulk storage tank temperature, Tbuik in K, and the target vessel pressure, Ptarget in Pa, such that the temperature increase, AT, within the target vessel is limited according to the following equation: AT<k-(Tbuik / Ptarget) where k is a system-specific constant associated with the target vessel's heat capacity (Cptarget) and volume Vtarget in L.

Claims

What is Claimed:

1. A method for substantially reducing increase in gas temperature in the process of transferring compressed gas from a bulk storage tank to a target vessel, implemented in a refuelling system comprising: the bulk storage tank, an intermediate vessel maintained at a lower pressure than the pre-set pressure,a target vessel having an outer wall, a floor and an apical end comprising a filling manifold, the filling manifold having a first valve in liquid communication with the bulk storage tank and a second valve in liquid communication with the intermediate vessel, wherein the volume of the target vessel is substantially lower than the volume of the bulk storage tank and the intermediate vessel; the method comprising:a) using the FMM, opening the second valve, and filling the target vessel to a pressure equal to the pressure of the intermediate vessel, at a rate configured to increase gas temperature within the target vessel to a temperature higher than the preset temperature;b) using the FMM, opening the first valve, while keeping the second valve opened, the difference of pressure creates the gas flow, and gas from the bulk storage tank is introduced of the target vessel substantially toward the floor of the target vessel, displacing the heated gas into the intermediate vessel without changing the gas density, thereby substantially reducing the gas temperature, while optionally using the FMM, cooling the gas flowing from the bulk storage tank to the target vessel, and;c) using the FMM, simultaneously closing the first and second valves upon filling of the target vessel to a predetermined gas pressure and temperature.

2. The method of claim 1 , wherein the target vessel further comprises:a) an outer cylindrical wall, defining a cylindrical volume with a base; and i. a filling pipe in liquid communication with the first valve, having an outlet disposed toward the bottom of the cylindrical volume, andii. an apical outlet in liquid communication with the second valve an outlet disposed toward the filling manifold.

3. The method of claim 1 , wherein the target vessel further comprises:a) an outer cylindrical wall, defining a cylindrical volume and a filling pipe, wherein the filling pipe being coaxial with the cylindrical wall,b) an axially movable partition operably coupled to the filling pipe, the axially movable partition adapted sized and configured variably divide the cylindrical volume of the vessel to an apical portion and a lower portion;c) a perforated support sandwiched between the basal outlet of the filling pipe and the base of the target cylinder; andd) optionally, drivetrain in operably coupled to the FMM, configured to axially translate the axially movable partition.

4. The method of claim 3, further comprising:a) translating the partition axially from the bottom to the filling manifold, thereby partitioning the cylindrical volume of the target vessel to a lower volume and an upper volume, the lower volume configured, when filled with gas transferred from the intermediate vessel via the filling pipe having the bottom outlet;b) using the FMM, opening the second valve, and while translating the partition axially toward the filling manifold, filling the lower portion of the target vessel with gas from the intermediate vessel, at a rate configured to increase gas temperature within the lower volume to a temperature higher than the pre-set temperature, forming a heated gas in the lower volume of the target vessel;c) when the partition reached the upper position, reaching the pressure in the lower portion is equal to the pressure in the intermediate vessel, using the FMM opening the first valve, while keeping the second valve opened;d) using the drivetrain, while moving the partition axially toward the bottom filling the upper portion of the target vessel with the gas from the bulk storage tank at a rate configured to maintain the gas density in the upper portion of the target vessel constant, while optionally using the FMM, cooling the gas flowing from the bulk storage tank to the target vessel; ande) using the FMM, closing the first and second valves upon eliminating the lower volume of the target vessel, or upon achieving the pre-set pressure in the target vessel.

5. The method of claim 3, wherein the partition is a disc, and wherein the drivetrain is a worm gear coupled to a motor.

6. The method of claim 5, wherein the drivetrain is disposed entirely within the target vessel.

7. The method of claim 5, wherein the drivetrain for moving the axial movable partition is disposed entirely within the FMM.

8. The method of claim 7, further comprising:a) before the step of partitioning the cylindrical volume of the target vessel to the lower volume and the upper volume, using the FMM, operably coupling the partition to the drivetrain within the target cylinder; andb) following the step of closing the first and second valves, using the FMM, decoupling the partition from the drivetrain and removing the partition from the target vessel.

9. The method of claim 1 , wherein the target vessel further comprises:a) an outer cylindrical wall, defining a cylindrical volume with a bottom base; andb) a bladder, in liquid communication with the intermediate vessel via second valve, the bladder defining an internal volume partitioned from the cylindrical volume of target vessel;c) the volume of target vessel, in liquid communication with bulk storage tank or with high-pressure cylinder via first valve.

10. The method of claim 9 further comprising:a) using the FMM opening the second valve, at a rate configured to increase gas temperature within the bladder to a temperature higher than the pre-set temperature, forming heated gas in the bladder and simultaneously pressurizing the residual gas in the volume of the target vessel;b) opening the first valve, while keeping the second valve opened, c) filling the cylindrical volume of the target vessel with the gas from the bulk storage tank to a pre-set pressure; andd) while using the FMM, optionally cooling the gas flowing from the bulk storage tank to the target vessel, causing the heated gas portion to flow into the intermediate vessel; ande) using the FMM, closing the first and second valves upon eliminating the internal volume of the bladder, thereby substantially reducing the increase in gas temperature in the process of transferring compressible gas from the bulk storage tank to the target vessel.

11. The method of claim 1 , wherein the system further comprises at least one high-pressure vessel in liquid communication with the target vessel, further comprising:a) the high-pressure vessel having a volume that is substantially lower than the volume of the target vessel, and wherein the mass of the gas in the high-pressure vessel configured to cause the pressure in the target vessel to be equal to the pre-set pressure in the bulk storage tank upon filling of the target vessel;b) using the FMM, opening the first valve and filling the target vessel by emptying the high-pressure vessel, wherein the emptying waves cool down the gas in the high-pressure vessel;c) using the FMM closing the first valve, when the pressure in the target vessel reached the pre-set value, thereby substantially reducing the increase in gas temperature in the process of transferring compressible gas from the high-pressure cylinder to the target vessel.12 The method of claim 11 , wherein the high-pressure vessel further comprises at least one insert configured to absorb emptying wave generated by flow of gas from the high-pressure vessel.

13. The method of claim 11 , wherein the at least one insert is a plurality of metallic tubes filling internal volume of the high-pressure vessel.

14. The method of claim 11 , wherein the step of filling the target vessel comprises filling the target vessel from the high-pressure vessel to an equilibrium pressure between the target vessel and the high-pressure vessel.

15. The method of claim 1 , wherein the gas is hydrogen.

16. The method of claim 1 , wherein the gas is natural gas (LNG).

17. The method of claim 3, wherein the axially movable partition comprises a thermally conductive metallic core encapsulated in a polymeric coating, the polymeric coating having a thermal conductivity of less than 0.4 W / m K, therebylimiting thermal transfer from the heated gas in the upper portion to the lower portion during translation of the partition.

18. The method of claim 9, wherein the bladder is formed from a fiber-reinforced elastomeric laminate comprising e.g., aramid, or carbon fibers embedded within an elastomer matrix, forming a laminate, the laminate having an areal density between 150 g / m2and 650 g / m2, adapted sized and configured to withstand at least 2% elastic radial expansion without permanent deformation.

19. The method of claim 11 , wherein the at least one high-pressure vessel has an internal diameter of 40-120 mm and a length-to-diameter ratio of 4:1 to 20:1, and wherein the at least one insert comprises a stack of metallic tubes having a combined open flow area of between about 25% and about 60% of the cylinder cross-section adapted sized and configured to attenuate emptying pressure wave amplitude by at least 30% during the step of using the high-pressure vessel, filling the target vessel.

20. The method of claim 1 , wherein the FMM uses a predictive thermal-hydraulic algorithm to calculate a maximum permissible gas flowrate, Qmax, in Kg / min. in the step of filling the target vessel to a pressure equal to the pressure of the intermediate vessel, is based on real-time measurements of the bulk storage tank temperature, Tbuik in K, and the target vessel pressure, Ptarget in Pa, such that the temperature increase, AT, within the target vessel is limited according to the following equation:AT — k- (T bulk / Ptarget)where k is a system-specific constant associated with the target vessel's heat capacity (Cptarget) and volume Vtarget in L.

21. A vehicle having a powertrain comprising the target vessel filled using the method of any one of claims 1 -19.

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