JP2024503230A - Cryogenic containment system - Google Patents

Abstract

A cryogenic fluid containment system is disclosed. The system is capable of storing fluids such as hydrogen at cryogenic temperatures and pressures. Once the fluid is naturally warmed, the fluid may be directed to a portion of the liquefaction system that is configured to perform cooling techniques on the fluid. The cooling technique may be a Joule-Thomson cooling technique. The liquefaction system may be equipped to perform both non-Joule-Thomson and Joule-Thomson refrigeration techniques. The system is configured to direct the fluid to the appropriate portion of the liquefaction system, which may be based at least in part on the Joule-Thompson coefficient of the fluid. [Selection diagram] Figure 1

Description

The present disclosure relates to systems and methods for handling fluids at cryogenic temperatures and pressures. More particularly, the present disclosure relates to systems and methods for reducing or eliminating boil-off waste.

Large facilities such as data centers consume large amounts of energy and require backup equipment to ensure there is enough power to complete essential tasks in the event of a power loss. Traditionally, diesel generator sets or "gensets" are used to provide backup power to large facilities. Hydrogen fuel cells and engines are increasingly being considered for this purpose, but present their own challenges. The fuel for such engines is stored at cryogenic temperatures and pressures until backup power is needed. Cryogenic fluids are typically stored in tanks that passively maintain the stored fluid at cryogenic temperatures. In most cases, it is considered inefficient to actively cool the fluids stored within these passive storage tanks, and as a result, other systems are used to tank these fluids. It is often cooled beforehand. Passive storage tanks are, of course, imperfect; cryogenic fluids stored in such tanks gradually warm up and increase in pressure over time. When such heating occurs, at least a portion of the stored hydrogen needs to be released as a "boil-off" in order to maintain a safe pressure within the tank. Note that boil-off refers to the natural process in which the amount of cryogenic fluid changes from a liquid phase to a gas phase as the temperature within the storage tank increases. In some conventional systems, the amount of cryogenic fluid that undergoes a phase change from liquid to gas provides passive cooling of the cryogenic fluid as the latent heat of vaporization absorbs thermal energy within the system. . Once this occurs, the gas produced via boil-off can be released to the atmosphere to maintain a safe storage pressure. In some systems, hydrogen can evaporate up to 1% or more per day. In such systems, the hydrogen needs to be completely replaced approximately every 100 days unless a process is employed to capture and at least partially reuse the boil-off.

One system for converting a cryogenic fluid boil-off stream is disclosed in US Pat. No. 6,672,104 (hereinafter referred to as the '104 reference). The '104 reference discloses pressurizing a boil-off stream, cooling the pressurized boil-off stream, and then expanding the boil-off stream. As discussed in reference '104, further expansion of the boil-off stream results in further cooling and at least partially liquefies the boil-off stream. The '104 reference describes the resulting additives obtained by removing from a boil-off stream a first predetermined amount of one or more components having a vapor pressure greater than the vapor pressure of the stored cryogenic fluid. A preselected bubble point temperature of the pressure liquid is disclosed. To obtain a preselected bubble point temperature, the '104 reference uses a second cryogenic fluid having a molecular weight heavier than the molecular weight of the stored cryogenic fluid and a vapor pressure lower than the vapor pressure of the stored fluid. Adding a predetermined amount of one or more additives to the boil-off stream is also described.

Although the system described in the '104 reference may be configured to controllably convert a boil-off stream of stored cryogenic fluid, the system is specifically designed for pressurizing, cooling, and expanding stored fluid. Requires the use of multiple standardized components. Such components increase the cost and complexity of the system. Furthermore, such components are prone to failure over time. Accordingly, the systems described in the '104 reference, and other similar systems, typically suffer from high maintenance costs associated with the repair and/or replacement of such components and corresponding maintenance downtime. suffer from inefficiency.

Examples of the present disclosure are directed to overcoming one or more of the deficiencies mentioned above.

Examples of the present disclosure are directed to a system that includes a storage tank, a liquefaction system, and a boil-off loop configured to store cryogenic hydrogen in a two-phase mixture. Specifically, the liquefaction system may include a Joule-Thomson cooling stage and a non-Joule-Thomson cooling stage fluidly connected to the Joule-Thomson cooling stage. Additionally, the liquefaction system receives hydrogen from an external source, receives the hydrogen in a non-Joule-Thomson cooling stage, cools the hydrogen in the non-Joule-Thomson cooling stage to a first temperature below a temperature threshold, and at the first temperature, the hydrogen is transferring hydrogen from the Joule-Thomson cooling stage to a Joule-Thomson cooling stage; cooling the hydrogen in the Joule-Thomson cooling stage to a second temperature lower than the first temperature; and transferring the hydrogen from the Joule-Thomson cooling stage to a storage tank at the second temperature. may be configured to transfer hydrogen to. Additionally, the boil-off loop may be configured to transfer boil-off hydrogen from the storage tank to the Joule-Thompson cooling stage of the liquefaction system. Accordingly, the Joule-Thomson cooling stage may be configured to cool the boil-off hydrogen to a third temperature and transfer the cooled boil-off hydrogen to a storage tank at the third temperature.

Further examples of the present disclosure are directed to systems that include a storage tank, a liquefaction system, and a controller. Specifically, the storage tank may be configured to store the fluid at cryogenic conditions, below a cryogenic threshold and below a cryogenic pressure threshold. Further, the liquefaction system can include a first stage and a second stage fluidly connected to the first stage. Additionally, the liquefaction system receives a fluid in a first stage, reduces the temperature of the fluid to a storage temperature below a cryogenic threshold, and connects a second stage to a storage tank at the storage temperature and a first fluid path. The device may be configured to transfer fluid through the device. In some examples, the second fluid passageway can fluidly connect the storage tank with the second stage. Further, a controller may be operably connected to the liquefaction system and the one or more fluid control devices, the controller being operable to connect the flow control device from the storage tank to the second stage of the liquefaction system. moving the boil-off fluid to a second stage of the liquefaction system to liquefy the boil-off fluid; and one or more flow control devices configured to transport the liquefied boil-off fluid from the second stage of the liquefaction system to a storage tank. It is composed of

Still further examples of the present disclosure include determining a temperature of hydrogen stored in the storage tank using a first sensor associated with the storage tank; and using a second sensor associated with the storage tank. Determining the pressure of hydrogen using Further, the method includes a controller operably connected to the first sensor and the second sensor to determine at least one of: the temperature of the hydrogen exceeds a temperature threshold; and the pressure of hydrogen exceeds a pressure threshold. may include determining one. Additionally, the method is based, using the controller and at least in part, on determining at least one of: the temperature of the hydrogen exceeds a temperature threshold; and the pressure of the hydrogen exceeds a pressure threshold. The first flow control device operably connected to the controller may include directing boil-off hydrogen from the storage tank to a liquefaction system fluidly connected to the storage tank. The liquefaction system may include a first stage configured to perform a non-Joule-Thomson cooling technique and a second stage fluidly connected to the first stage, the second stage configured to perform a non-Joule-Thomson cooling technique. configured to perform cooling techniques. Accordingly, the method may include using the controller to cause a second flow control device operably connected to the controller to transfer liquid hydrogen from a second stage of the liquefaction system to a storage tank.

FIG. 1 is a schematic diagram of a power system for a large facility, according to an example of the present disclosure. FIG. 2 is a schematic diagram of a cryogenic containment system associated with the power system of FIG. 1, according to an example of the present disclosure. FIG. 3 is a schematic diagram of a cryogenic containment system associated with the power system of FIG. 1, according to a further example of the present disclosure. FIG. 4 is a schematic diagram of a multi-stage liquefaction system according to a further example of the present disclosure. FIG. 5 is a block diagram illustrating a method according to an example of the present disclosure. FIG. 6 is a block diagram illustrating a method according to a further embodiment of the present disclosure in which a single liquefaction stage is used for boil-off purposes.

FIG. 1 is a schematic diagram of a cryogenic fluid boil-off mitigation system 100 according to an embodiment of the present disclosure. The cryogenic fluid boil-off mitigation system 100 can be used with any fluid, in any phase or combination of phases, at various temperatures and pressures, depending on the specific application of the fluid and fluid type as required in each case. can do. Hydrogen is one such fluid that can be stored and maintained by the cryogenic fluid boil-off mitigation system 100. Of course, other fluids may also be used with the cryogenic fluid boil-off mitigation system 100 according to the present disclosure, and any specific reference to hydrogen does not limit the scope of the present disclosure to any fluid type. For example, cryogenic fluids may include methane, carbon dioxide, nitrogen helium, noble gases, and other elements/compounds.

Hydrogen can pose particular challenges regarding storage. For example, hydrogen is volatile and has a low liquefaction temperature (approximately 33 Kelvin). As such, it can be difficult to maintain hydrogen in a safe, efficient manner so that it can be used as fuel or for other applications. Naturally, in any storage system the hydrogen tends to warm up and even evaporate. When this happens, the internal pressure of the tank increases and, if left unchecked, can exceed containment measures. Therefore, internal pressure can cause the tank to rupture, leading to damage to surrounding facilities, equipment, personnel, and/or property. In some cases, vaporized hydrogen can be vented to the atmosphere to maintain pressure levels. Alternatively or additionally, the cryogenic fluid boil-off mitigation system 100 reduces losses associated with releasing stored hydrogen (or cryogenic fluid) to the atmosphere and also reduces pressure build-up within the tank. You can also deal with problems.

The cryogenic fluid boil-off mitigation system 100 can receive hydrogen via an intake mechanism 102 that is coupled to or otherwise provided with hydrogen from a hydrogen source 104 . Additionally, the cryogenic fluid boil-off mitigation system includes two or more flow divider valves 106 connected by an interstage conduit 114 configured to control the distribution of hydrogen from the hydrogen source 104 within the cryogenic fluid boil-off mitigation system 100. A liquefaction system 108 comprised of cooling stages (eg, cooling stage 1 110 and cooling stage 2 112), and a storage tank 116. As mentioned above, liquefaction system 108 may include multiple cooling stages, such as cooling stage 1 110 and cooling stage 2 112, each of which may include one or more cooling systems. Additionally, the diverter valve 106 and/or other components of the cryogenic fluid boil-off mitigation system 100 condition the incoming hydrogen from the hydrogen source 104 and route the incoming hydrogen to one or more destinations. , may be controlled by the intake controller 118. As described in more detail below, such destinations may include cooling stage 1 110 along path A, cooling stage 2 along path B, and/or storage tank 116 along path C. Similarly, tank controller 120 may be configured to regulate the extraction of boil-off from storage tank 116 and direct the boil-off to cooling stage 1 110 along path D. In some examples, tank controller 120 is also configured to direct boil-off to cooling stage 2 112 along path E. Accordingly, hydrogen (or another cryogenic fluid) may be stored for utilization by backup power system 122 if the power demands associated with facility system 124 are not met by primary power system 126, as described herein. Various configurations of the cryogenic fluid boil-off mitigation system 100 described in can help avoid hydrogen loss caused by boil-off.

Intake mechanism 102 is any suitable mechanism by which hydrogen (or another cryogenic fluid) may be injected into and/or received by cryogenic fluid boil-off mitigation system 100. Good too. In some examples, the hydrogen source 104 may include a delivery truck, a delivery pipeline, or any other suitable delivery means from an external hydrogen source. Additionally, the intake mechanism 102 may include valves, flanges, connectors, couplings, and other fastening means that allow the cryogenic fluid boil-off mitigation system 100 to be fluidly connected to the hydrogen source 104. Additionally, the intake mechanism may include temperature sensors (e.g., thermocouples, thermometers, etc.), pressure sensors (e.g., absolute pressure, gauge pressure, differential pressure, etc.), flow sensors (e.g., velocity flow, mass flow, etc.), and/or or may include other sensors configured to identify characteristics of the incoming hydrogen. Similarly, the intake mechanism may be used to control the pressure and flow of hydrogen into the cryogenic fluid boil-off mitigation system 100 by pumping (e.g., causing fluid flow, creating a pressure differential, or otherwise applying work to the fluid). a control valve (e.g., configured to open to permit fluid flow and close to restrict fluid flow in response to a received signal and/or an applied force); control systems), throttle valves (e.g., valves utilized to control fluid flow and system pressure), and other pressure and flow control systems. In some additional examples, the hydrogen received from hydrogen source 104 may be in a mixed phase solution, in a gaseous state, or in a liquid state. Accordingly, the intake mechanism 102 is configured to process incoming fluids associated with different phase conditions, separate the gas phase from the liquid phase, and direct the different phase conditions to the appropriate portions of the cryogenic fluid boil-off mitigation system 100. obtain. In some further examples, the hydrogen source 104 is a hydrolysis system (e.g., a system configured to react with water and a substance to produce at least hydrogen in a chemical process), an electrolysis system (e.g., a water (a system configured to provide an electrical current that splits hydrogen into hydrogen and oxygen), and/or other hydrogen generation systems. In some hydrolysis reactions, substances and water can react such that the target molecule (or parent molecule) of the hydrolysis obtains a hydrogen ion. Furthermore, hydrogen can be produced by a chemical reaction and supplied to the intake mechanism 102. Note that the intake mechanism 102 can receive any form of hydrogen and facilitate entry into the cryogenic fluid boil-off mitigation system 100.

Divert valve 106 may be controlled by intake controller 118 remotely via electronic input or directly via a servo/motor. A diverter valve may be configured to control fluid flow between an inlet connector (eg, a pipe, hose, tube, etc.) and one or more outlet connectors. As mentioned above, one or more sensors (e.g., temperature sensors, pressure sensors, and flow sensors that are components of the intake mechanism 102) may be connected to a physical characteristic of the hydrogen received from the hydrogen source 104. Alternatively, or in addition, the one or more signals may be sent to the intake controller 118 and utilized for hydrogen regulation and routing. The mechanism 102 may involve a delivery service such as a hydrogen vendor that provides hydrogen at a known pressure and a known temperature. In some examples, the intake controller 118 may be configured to monitor the temperature of the hydrogen relative to the inversion temperature of the hydrogen. The inversion temperature is the temperature at which the Joule-Thomson coefficient of hydrogen (or other cryogenic fluid) changes sign (e.g., the Joule-Thomson coefficient is negative at temperatures above the inversion temperature, heating the fluid as it expands). It should be noted that the Joule-Thomson coefficient is positive at temperatures below the inversion temperature, causing the fluid to cool when expanded.Thus, the intake controller 118 ensures that the hydrogen inlet temperature is below the inversion temperature. If so, the intake controller 118 causes the diverter valve 106 to direct the hydrogen along path A to the cooling stage 1 110. Similarly, the intake controller 118 causes the intake controller 118 to direct the hydrogen along path A to the cooling stage 1 110. If the intake controller 118 determines that the hydrogen is below the inversion temperature, the intake controller 118 causes the diverter valve 106 to direct the hydrogen along path B to the cooling stage 2 112. may also be determined to be below another low threshold temperature and may be diverted directly to tank 116 along path C (e.g., if the hydrogen is below the condensation point for the pressure of the hydrogen and in liquid form). In at least one example, the additional threshold temperature may be referred to as a storage temperature, where hydrogen can be safely introduced into storage tank 116 without increasing the temperature or pressure within storage tank 116. Indicates the temperature that can be used.

In some further examples, the intake controller 118 sets the flow divider valve 106 to at least one or more temperature thresholds, one or more pressure thresholds, one or more flow thresholds, or a combination of various thresholds. Based on this, hydrogen received from hydrogen source 104 can be conditioned and routed along Path A, Path B, and Path C. Specifically, the temperature and pressure associated with the hydrogen received from the hydrogen source may be used to cool the hydrogen and/or the thermal energy associated with the hydrogen from the temperature and pressure of the hydrogen source 104 to the temperature and pressure of the storage tank 116. It can be used to determine the amount of work required. Accordingly, intake controller 118 may direct hydrogen received from hydrogen source 104 to cooling stage 1 110 for initial cooling of the hydrogen and to cooling stage 2 112 for additional cooling and/or liquefaction. .

Cryogenic fluid boil-off mitigation system 100 may include a liquefaction system 108. Specifically, liquefaction system 108 may include various components that reduce the temperature and/or pressure of cryogenic fluid provided to liquefaction system 108 at different temperatures, pressures, and/or conditions. In the example shown, liquefaction system 108 includes cooling stage 1 110 and cooling stage 2 112. Cooling stage 1 110 utilizes non-Joule-Thomson effects and Joule-Thomson cooling techniques (where the Joule-Thomson coefficient is negative) to reduce the temperature of hydrogen 104 to a threshold temperature and/or pressure of cooling stage 2 112. Can be done. In some examples, the threshold temperature (and threshold pressure) is at least the inversion temperature of the cryogenic fluid (e.g., hydrogen), the storage temperature or storage pressure of the storage tank 116, the boil-off temperature associated with the boil-off of the storage tank 116. and boil-off pressure, or other determined temperatures and pressures associated with cryogenic fluid boil-off mitigation system 100. Additionally, cooling stage 2 112 may utilize Joule-Thomson cooling techniques to further reduce the temperature of the cryogenic fluid (eg, hydrogen received from hydrogen source 104).

In some examples, a non-Joule-Thomson cooling technique may include any refrigeration cycle that can reduce the temperature of a fluid (e.g., gas, liquid, etc.) or a non-periodic refrigeration technique. Refrigeration cycles include vapor compression cycles, absorption cycles, adsorption cycles, and other refrigeration techniques that periodically utilize work to remove thermal energy from the system (e.g., to cool hydrogen received from hydrogen source 104). may be included. Alternatively, or additionally, aperiodic refrigeration involves the use of working fluids that are dispersed or discarded after cooling (e.g., liquid nitrogen is relatively inexpensive and can be released to the atmosphere after refrigeration). ). As mentioned above, cooling stage 1 110 may utilize non-Joule-Thomson techniques to cool the hydrogen received from hydrogen source 104. Such techniques may utilize heat exchangers having different fluids in various flow paths brought into thermal contact with each other to transfer heat from one fluid to another (optionally a cyclic cooling system or in non-periodic cooling systems). Some exemplary types of heat exchangers are shell and tube heat exchangers, plate heat exchangers, plate and shell heat exchangers, insulated wheel heat exchangers, pillow plate here exchangers, fluid heat exchangers, and It is a dynamic scraped surface heat exchanger.

Some examples of cooling stage 1 110 utilize non-Joule-Thomson cooling techniques to cool hydrogen, or another low inversion temperature fluid (eg, helium, neon, etc.) to an inversion temperature. The Joule-Thompson effect can be used to cool hydrogen (or other cryogenic fluids) by lowering the temperature of the hydrogen below the inversion temperature. Note that hydrogen and some other materials have the somewhat unique property that in the gas phase, the inversion temperature is below room temperature (approximately 20° C.). Accordingly, cooling stage 1 110 of liquefaction system 108 may be configured to utilize non-Joule-Thomson effect cooling for all cryogenic fluids in cooling stage 1 110. Further, cooling stage 1 110 of liquefaction system 108 may be configured to utilize Joule-Thomson effect cooling in cooling stage 1 110 for cryogenic fluids having an inversion temperature that exceeds the operating temperature of cooling stage 1 110. The liquefaction system 108 may include an interstage conduit 114 passing the hydrogen from stage 1 110 to stage 2 112 where Joule-Thomson effect cooling is performed to further reduce the temperature of the hydrogen 104.

Stage 2 112 of liquefaction system 108 may use Joule-Thompson cooling techniques to further reduce the temperature of the hydrogen received from hydrogen source 104. In some examples, Joule-Thomson cooling technology may be utilized to produce liquid hydrogen from the hydrogen processed by cooling stage 1 110. The Joule-Thomson effect (also known as the Joule-Kelvin effect or the Kelvin-Joule effect) is a phenomenon in which, when pressure is applied, no heat is exchanged with the environment (e.g., a cryogenic fluid undergoes an adiabatic or substantially adiabatic expansion). ), describes the temperature change when a real gas or liquid (as distinguished from an ideal gas) is passed through a valve or porous plug while being insulated. This procedure is called the throttling process or Joule-Thomson process. At room temperature, most gases are expanded and cooled by the Joule-Thomson technique. However, as mentioned above, some gases, such as hydrogen, helium, and neon, have inversion temperatures below room temperature that cause them to heat up during expansion until the temperature of the gas is below the inversion temperature. Therefore, the Joule-Thomson technique can be used for hydrogen, helium, and neon when cooled below the inversion temperature. There are many ways to achieve the desired Joule-Thomson cooling, including nozzles, valves, or porous plugs, and cooling stage 2 112 may include any number of these techniques. Additionally, cooling stage 2 112 may include multiple cooling operations. In some embodiments, the plurality of cooling operations may be steps to lower the temperature. In some embodiments, cooling stage 2 112 has multiple redundant cooling operations, and depending on the amount of hydrogen to be cooled, one portion of cooling stage 2 112 may be employed while another portion is idle. .

In some examples, FIG. 1 is an illustration of a cryogenic fluid boil-off mitigation system 100 for a facility according to examples of the present disclosure. Specifically, cryogenic fluid boil-off mitigation system 100 may be configured to maintain cryogenic fluid that may be utilized as a fuel by backup power system 122. Additionally, the cryogenic fluid boil-off mitigation system may be configured to prevent boil-off emissions from storage tank 116 from being released to the atmosphere by treating the boil-off by reliquefying it. Additionally, the cryogenic fluid boil-off mitigation system may be configured to maintain cryogenic temperatures as a power reserve when the power demands of facility system 124 are not met by primary power system 126. In some additional examples, primary power system 126 may be grid power from a municipality or another standard primary power source. Further, facility systems 124 may be associated with power demands determined based on at least the power consumed by various systems within the facility. Therefore, power demand is substantially equal to any and all powered HVAC systems, lighting, heating systems, cooling systems, motors, engines, networks, servers, other computing devices, and other devices that consume power within the facility. May include power requirements for any other mechanisms.

Additionally, cryogenic fluid boil-off mitigation system 100 can manage cryogenic fluid to backup power source 122 in the event of a power outage, shortage, or other situation that results in power demands of facility system 124 that are not met by primary power system 126. can. In some examples, backup power system 126 includes a hydrogen-powered engine and/or fuel cell that converts hydrogen (or other cryogenic fuel) into sufficient energy to meet the power needs of facility system 124. obtain. Accordingly, upon determining that the power demand is not being met by the primary power system 126, the facility and/or backup power system 122 extracts hydrogen from the storage tank 116 and consumes it to provide additional power for the facility system 124. can be generated.

FIG. 2 is an illustration of a potential operating space for a cryogenic fluid boil-off mitigation system. Specifically, FIG. 2 is an approximation of the phase diagram for diatomic hydrogen. However, it is noted that FIG. 2 is an approximation, and the various values and boundaries for individual phases may not map exactly to real-world values. FIG. 2 includes approximations of the temperatures and pressures at which liquid phase 202 can vaporize/evaporate into gas phase 204 and gas phase 204 can condense into liquid phase 202. As shown in FIG. 2, an exemplary vaporization curve 206 may represent a boundary between a liquid phase 202 and a gas phase 204 of a cryogenic fluid. For example, vaporization curve 206 represents a real-world scenario in which atoms or molecules of a cryogenic fluid absorb latent heat of vaporization or radiate latent heat of condensation, allowing a transition between liquid phase 202 and gas phase 204. Can represent a combination of temperature and pressure. Similarly, the exemplary vaporization curve 206 has a triple point 208 representing the pressure and temperature at which the cryogenic fluid exists in equilibrium between three states of matter (e.g., solid, liquid, and gas), and a liquid phase 202. and a critical point 210 representing the pressure and temperature at which the vapor phase of the cryogenic fluid becomes a supercritical fluid. Although FIG. 2 includes an approximation of hydrogen triple point 208 and critical point 210, it is noted that other fluid triple points and critical points may occur at other temperature and pressure combinations. Additionally, FIG. 2 illustrates a first temperature change and a first pressure change associated with the cryogenic fluid caused by a first cooling operation (e.g., the cooling operation performed by cooling stage 1 110 of FIG. 1). a first curve segment 212 representing the first curve segment 212; Similarly, FIG. 2 shows a second temperature change and a second pressure change associated with the cryogenic fluid caused by a second cooling operation (e.g., the cooling operation performed by cooling stage 2 112 of FIG. 1). including a second curve segment 214 representing .

Note that despite the representation of triple point 208 and critical point 210 in FIG. 2, these phenomena have real world temperatures and pressures associated with them. Specifically, the hydrogen triple point at which the solid phase, liquid phase 202, and gas phase 204 exist in equilibrium is approximately 13.84 K/-259.31°C and 7.04 kPa/. Occurs at 0704 bar. Similarly, the critical point for hydrogen, where liquid phase 202 and gas phase 204 cease to coexist and form a supercritical fluid, occurs at approximately 33.20 K/-239.95° C. and 1300 kPa/12.97 bar. Accordingly, vaporization curve 206 represents the temperature and pressure at which hydrogen in liquid phase 202 may vaporize into vapor phase 204 and hydrogen in vapor phase 204 may condense into liquid phase 202.

In some examples, the cryogenic fluid boil-off mitigation system described above with respect to FIG. 1 can be configured to operate within the vapor phase 204 and liquid phase 202 of the cryogenic fluid, as depicted in FIG. 2. Specifically, cooling stage 1 110 and cooling stage 2 112 may be configured to cool hydrogen received from hydrogen source 104 from an inlet temperature and liquefy the hydrogen for storage in storage tank 116. . Additionally, the first cooling operation of cooling stage 1 110 may be represented by a first curve segment 212, in which the temperature of the hydrogen is related to the change in the Joule-Thompson coefficient from a negative value to a positive value. The hydrogen inlet temperature is reduced below a temperature threshold 216. At atmospheric pressure, the Joule-Thomson coefficient changes from negative to positive values at approximately 200K/-73.15°C, but the temperature threshold 216 may be determined based at least in part on the pressure of the hydrogen. . However, the first cooling operation associated with cooling stage 1 110 may be configured to reduce hydrogen below any temperature threshold at a temperature above vaporization curve 206. Additionally, the first cooling operation may generate a pressure increase (as illustrated by first curve segment 212 in FIG. 2) in an isobaric environment or utilized by cooling stage 1 110. The pressure drop can be caused based at least in part on the type of cooling method. Similarly, the second cooling operation associated with cooling stage 2 112 may be configured to reduce hydrogen from the discharge temperature of the first cooling operation to a storage temperature below the condensation temperature for a given pressure ( (as illustrated by first curve segment 212 in FIG. 2).

In some examples, additional cooling operations (not shown) may occur between the first cooling operation associated with first curve segment 212 and the second cooling operation associated with second curve segment 214. ) can be included. Specifically, the first cooling operation utilizes non-Joule-Thomson cooling techniques to calculate the Joule-Thomson coefficient from the inlet temperature of the hydrogen source (e.g., hydrogen tank, hydrogen bender, hydrolysis system, electrolysis system, etc.). The temperature of the hydrogen may be configured to reduce the temperature of the hydrogen to a first cooling operation discharge temperature below a temperature at which the temperature changes from a negative value to a positive value. Additionally, non-Joule-Thomson cooling techniques may increase, hold constant, or decrease the pressure of hydrogen relative to the inlet pressure associated with the hydrogen source 104. After the first cooling operation, the pressurizing operation (e.g., a pump) increases the pressure from the first discharge pressure of the first cooling operation to the inlet pressure associated with the second or additional cooling operation. It can be raised. Accordingly, the additional cooling operation and the second cooling operation may utilize Joule-Thomson cooling technology to cool the hydrogen and liquefy the hydrogen for storage. Additionally, additional pressurization operations may be included during additional cooling operations, secondary cooling operations, and/or storage tanks to maintain system integrity, safety, and operating parameters.

In some additional examples, the second cooling operation and, if included, the additional cooling operation reduces both the temperature and pressure of the hydrogen, as illustrated by the second curve segment 214. It may be configured to include one or more Joule-Thomson cooling operations (eg, passing the hydrogen through a throttle valve, porous plug, or other pressure reducing device to cool the hydrogen). Additionally, the second cooling operation may be configured to reduce the temperature of the hydrogen from the second cooling operation inlet temperature to the storage tank temperature, the second cooling operation inlet temperature being lower than the first cooling operation exhaust temperature. associated with the temperature or the additional cooling operation exhaust temperature (optionally after the hydrogen exhaust from the first cooling operation or the additional cooling operation has been pressurized). Additionally, the second cooling operation may be further configured to receive hydrogen at a temperature and pressure approximately equal to a boil-off temperature threshold and/or boil-off pressure threshold of the storage tank. Accordingly, the second cooling operation may be configured to receive hydrogen at a second cooling operation inlet temperature and a second cooling operation inlet pressure and reduce the temperature of the hydrogen to the storage temperature of the storage tank.

The cryogenic fluid boil-off mitigation system 100 (FIG. 1) is configured such that a second cooling operation (e.g., cooling stage 2 112) is a first cooling operation represented by a previous cooling stage (e.g., first curve segment 212). , an additional cooling operation, cooling stage 1 110), and/or a boil-off hydrogen source that collects gaseous hydrogen from a storage tank for reliquefaction by a second cooling operation. Note that it can be configured. Additionally, the support systems (e.g., pumps, valves, pressure regulators, temperature sensors, flow sensors, pressure sensors, etc.) may be configured such that the hydrogen received from the hydrogen source 104 and the hydrogen received by the second cooling operation are Joule-Thomson cooled. Through technology, a second cooling operation can be associated with both the hydrogen received from the boil-off hydrogen source and at the appropriate pressure to allow cooling from the inlet temperature to the storage temperature of the storage tank. Additionally, the second cooling operation includes passive cooling of the storage tank (by receiving gaseous hydrogen by generating a sufficient amount of boil-off such that a boil-off threshold associated with temperature and/or pressure is met). For example, the vaporization of liquid hydrogen to gaseous hydrogen in the tank may be configured to remove the latent heat of vaporization from the liquid hydrogen, effectively cooling the liquid in the storage tank. Thus, boil-off hydrogen (e.g., gaseous hydrogen produced by boil-off) is collected by a pump, or a pipe that utilizes the internal pressure of the tank to drive the gaseous hydrogen, removing the latent heat of vaporization and transferring it to a storage tank. The boil-off hydrogen may be transferred to a second cooling operation that may be configured to liquefy the boil-off hydrogen for the introduction of hydrogen.

FIG. 3 is a schematic diagram of a cryogenic fluid boil-off mitigation system 300 according to a further example of the present disclosure. Cryogenic fluid boil-off mitigation system 300 may include many of the features described above with reference to FIGS. 1 and 2. Specifically, cryogenic fluid boil-off mitigation system 300 may include an intake mechanism 302 that receives hydrogen from a hydrogen source 304 and directs hydrogen to a liquefaction system 306. The liquefaction system may include multiple cooling systems, including at least stage 1 308 and stage 2 310, that cool and liquefy the liquid hydrogen before placing it into storage tank 312. Additionally, storage tank 312 may be monitored by tank controller 314 via at least temperature sensor 316 and pressure sensor 318. Based on information received from at least the temperature sensor 316 and/or the pressure sensor 318, the tank controller 314 can determine when the boil-off hydrogen in the storage tank is cooled and liquefied by stage 2 312 of the cooling system. . Tank controller 314 may be configured to cause boil-off collection system 320 to collect boil-off hydrogen and transport the boil-off hydrogen to stage 2 312, while liquid hydrogen return system 322 transports liquid hydrogen from stage 2 312. Upon receipt, the liquefied hydrogen can be placed into storage tank 312 .

The cryogenic fluid boil-off mitigation system 300 may utilize the intake mechanism 302 to condition hydrogen received from a hydrogen source 304 where the hydrogen source does not condition hydrogen. Specifically, the intake mechanism includes a connector valve for pipe, hose, and/or other connection with a hydrogen source controlled by an intake controller or by an operator associated with the cryogenic fluid boil-off mitigation system 300. obtain. Connector valves provide a permanent connection to the hydrogen source 304 (e.g., for internal hydrogen sources such as hydrolysis or electrolysis systems, and for external vendors providing pipelines to the facility) and/or temporary connections to the hydrogen source 304. (e.g., the hydrogen source is a tank that connects to the intake mechanism and is brought to the facility by truck and/or rail and injects a fixed amount of hydrogen). Regardless of the nature of the hydrogen source 304, communication with various sensors associated with the intake mechanism 302 and signals sent to various components of the intake mechanism 302 (e.g., the signals may be caused by pressure reduction caused by a throttle valve) and/or the amount of pressurization caused by the pump), the intake mechanism regulates the inlet pressure (e.g., via a throttle valve), regulates the hydrogen flow rate, and controls the inlet pressure (e.g., via a pressure sensor) and the inlet temperature (e.g., via a temperature sensor). Accordingly, the hydrogen inlet temperature, inlet pressure, inlet flow rate, and/or other physical characteristics of the hydrogen can be determined and sent to the liquefaction system 306.

As mentioned above, stage 1 308 may be substantially similar and/or identical to cooling stage 1 110 described with respect to FIG. For example, stage 1 308 may include various cyclic refrigeration techniques (e.g., reverse Carnot cycle, reverse Stirling engine, vapor compression cycle, heat exchange associated with the working fluid, etc.) and/or aperiodic refrigeration techniques (e.g., heat exchanger The hydrogen can be cooled below a threshold temperature using liquid nitrogen (which is passed through the air and then exhausted to the atmosphere). Additionally, the initial cooling of the incoming hydrogen by Stage 1 308 received from the hydrogen source 304 may proceed according to the example described in FIG. 1 with reference to Cooling Stage 1 110. Additionally, stage 2 310 may be substantially similar and/or identical to cooling stage 2 112 described above with respect to FIG. For example, stage 2 310 may utilize Joule-Thomson cooling techniques to further cool and liquefy the hydrogen received from hydrogen source 304 (similar to the techniques described in FIG. 1). Accordingly, hydrogen received from hydrogen source 304 may be cooled, liquefied, and placed in storage tank 312.

In some examples, tank controller 314 may be configured to monitor at least tank temperature and tank pressure associated with storage tank 312. Specifically, storage tank 312 is a cryogenic storage tank that constitutes a cryogenic liquid in a cryogenic environment (e.g., a temperature below −50° C.) and optionally in a pressurized environment. (Note that storage of hydrogen and other flammable cryogenic fluids is generally under pressure to avoid leaks that draw oxidizer into the storage tank/cryogenic fluid boil-off mitigation system 300). The storage tank 312 therefore includes an internal cooling system (although these are generally overridden by the additional thermal energy transfer enabled by the internal cooling system) and one for monitoring the stored cryogenic fluid. or an insulated storage tank (high vacuum between the walls) that may include a plurality of sensors and one or more connectors that allow the stored cryogenic fluid to be extracted from the storage tank 312 and placed into the storage tank 312. (such as a Dewar flask), which is a double-walled container containing In some additional examples, storage tank 312 may include a fluid control device 320 (eg, a valve, opening, etc.) that is operably controlled by tank controller 314. Fluid control device 320 may be coupled to a boil-off processing loop illustrated by streams A', B', C', A'', and B''. The fluid controller 320 extracts boil-off hydrogen from the storage tank 312 and optionally pressurizes the boil-off hydrogen (although the internal pressure of the storage tank 312 causes the boil-off hydrogen to flow A', B', C', A'', and/or B'') for the stated purpose of providing boil-off hydrogen to the cooling system associated with Stage 1 308 and/or Stage 2 310. It may include any combination of valves and pumps to accomplish this. The first fluid control device may be positioned and configured to regulate the flow of boil-off hydrogen through streams A'' and B'' in a manner similar to hydrogen received from hydrogen source 304. A liquefaction system 306 processes the boil-off hydrogen. Alternatively or additionally, the second fluid control device and/or the third fluid control device are positioned to regulate the flow of fluid through stage 2 310 and back into storage tank 312; can be configured. It should be understood that for each of the fluid control devices 320, there may be any number of valves and/or pumps involved to fully regulate fluid flow, and the location of the components may vary. It is.

The hydrogen in storage tank 312 may be a mixed phase solution consisting of liquid hydrogen (the majority of the hydrogen in storage tank 312) and a small amount of hydrogen in the gas phase. As the hydrogen warms up, liquid hydrogen converts from the liquid phase to the gas phase. Tank controller 314 detects when the storage temperature and/or storage pressure of hydrogen in storage tank 312 meets (e.g., exceeds) a temperature threshold and/or a pressure threshold that indicates that the boil-off hydrogen is treated and liquefied. It can be configured as follows. Accordingly, boil-off hydrogen (e.g., hydrogen in the gas phase) is extracted from the storage tank 312 and transferred to stage 2 310 of the liquefaction system 306, where the boil-off hydrogen can be cooled and the latent heat of vaporization removed from the gaseous hydrogen. The gas phase can be converted back to a liquid phase and then returned to storage tank 312. The overall temperature of the fluid within storage tank 312 may be reduced accordingly and boil-off waste may be minimized or completely eliminated.

As mentioned above, tank controller 314 may be configured to monitor the storage temperature and storage pressure of hydrogen within storage tank 312. Specifically, the tank controller may monitor storage temperature via temperature sensor 316 and storage pressure via pressure sensor 318. Tank controller 314 may be configured to monitor storage temperature and storage pressure relative to one or more storage thresholds. These thresholds may include safety thresholds (e.g., the internal pressure and/or temperature of storage tank 312 remains below the threshold to prevent failure of the storage tank), efficiency thresholds (e.g., the hydrogen level within storage tank 312), (to minimize energy requirements in order to maintain the energy requirements) and/or other thresholds determined by operational and/or business parameters. For example, a pressure threshold may be associated with a storage pressure that indicates that a certain amount of hydrogen in storage tank 312 has vaporized and the storage pressure is approaching the pressure limit of storage tank 312 (this includes safety factors). obtain). Accordingly, tank controller 314 detects that the pressure threshold has been exceeded by the storage pressure and causes fluid controller 320 to extract boil-off hydrogen (e.g., gaseous hydrogen) from storage tank 312 via flow A' and The boil-off hydrogen may be directed to the stage 2 310 cooling system via B' and the liquefied hydrogen may be returned to the storage tank 312 via stream C'. Additionally, the additional pressure threshold may be associated with additional storage pressure that is greater than the pressure threshold and indicates that additional boil-off mitigation is implemented. Accordingly, tank controller 314 detects that the additional pressure threshold has been exceeded and causes the fluid controller to extract boil-off hydrogen via stream A'' and to the stage 1 308 cooling system via stream B''. The boil-off hydrogen can be directed and the liquefied hydrogen returned to the storage tank 312. Tank controller 314 may be configured to operate fluid control device 320 to manage the flow of boil-off hydrogen, and may be connected to fluid control device 320 via e-beam and/or wireless control. Further, tank controller 314 can communicate with temperature sensor 316 and pressure sensor 318 to receive storage tank data 322 via e-beam and/or wireless control.

Tank controller 314 , temperature sensor 316 , pressure sensor 318 , and fluid control device 320 may be configured to operate in conjunction to reduce boil-off losses associated with storage tank 312 . If the two-phase mixture in storage tank 312 is above a threshold temperature (e.g., hydrogen inversion temperature of approximately 200 K), at which point non-Joule-Thomson effect cooling is required, tank controller 314 causes fluid control device 320 to: The boil-off hydrogen may be transferred to the stage 1 boil-off loop 326 such that the stage 1 308 of the liquefaction system 306 cools the fluid using non-Joule-Thomson effect cooling and then for Joule-Thomson effect cooling. The fluid can then proceed to stage 2 310 and ultimately be returned to storage tank 312. Alternatively, or additionally, the tank controller 314 causes the fluid controller 320 to utilize the stage 1 boil-off loop 326 and the stage 2 310 cooling because the hydrogen storage pressure exceeds a threshold indicating the amount of cooling. Boil-off hydrogen that exceeds the cooling capacity of the system can be liquefied. Thus, by directing the boil-off hydrogen through both Stage 1 308, Stage 2 310, and optionally through any additional cooling stages within the liquefaction system 306, the Stage 1 boil-off loop 326 reverses the hydrogen It may be configured to cool boil-off hydrogen that is associated with an amount of cooling that exceeds the temperature and/or capacity of stage 2 310.

Additionally, tank controller 314 , temperature sensor 316 , pressure sensor 318 , and fluid control device 320 may be configured to operate in conjunction to reduce boil-off losses associated with storage tank 312 . If the two-phase mixture within the storage tank 312 is below a threshold temperature (e.g., the hydrogen inversion temperature at about 200 K) and above a threshold pressure, the tank controller 314 causes the fluid controller 320 to control the boil-off in the stage 2 boil-off inlet 322. The hydrogen may be transferred and liquid hydrogen may be returned to the storage tank 312 via the stage 2 boil-off discharge 324. Specifically, stage 2 310 of liquefaction system 306 may use Joule-Thomson effect cooling to cool the fluid and then return the liquid hydrogen to storage tank 312. Alternatively or additionally, the tank controller 314 causes the fluid controller 320 to utilize the stage 2 boil-off inflow 322 for a storage temperature of hydrogen that meets a threshold indicative of the amount of refrigeration in the stage 2 310 cooling system. The boil-off hydrogen supplied by the cooling capacity can be liquefied. Accordingly, stage 2 boil-off inlet 322 may be configured to receive boil-off hydrogen that is below the inversion temperature of the hydrogen and/or associated with the amount of cooling that may be provided by stage 2 310.

In some examples, the stage 2 boil-off inlet 322, the stage 2 boil-off discharge 324, and/or the stage 1 boil-off loop 326 flow from the storage tank 312 and/or the stage 2 310 discharge pressure to the stage 1 308, stage 2 310 and/or a pump 328 (shown in conjunction with the stage 1 boil-off loop 326) configured to change the pressure of the fluid to the inlet pressure of the storage tank 312. Accordingly, rotary pumps, piston pumps, diaphragm pumps, screw pumps, centrifugal pumps, and other pumps may be utilized to maintain the discharge pressure of one component of the cryogenic fluid boil-off mitigation system 300 and the inlet pressure of another component. Based on this, the pressure of the fluid can be changed.

After reaching the desired temperature, pressure, and phase, the hydrogen may pass through the stage 2 boil-off discharge 324 and/or the liquefaction system 306 discharge into the storage tank 312. Storage tank 314 can hold hydrogen until such time as the hydrogen is utilized to generate backup power, at which point the hydrogen can be removed from storage tank 312. In some examples, tank outlet conduit hydrogen from storage tank 312 may be present. In some additional examples, tank controller 314 can extract hydrogen from storage tank 314 and cause fluid controller 322 to supply hydrogen to a backup power system (eg, backup power system 122).

Examples of the present disclosure utilize a liquefaction system 306 to maintain hydrogen within the cryogenic fluid boil-off mitigation system 300 during long-term storage of hydrogen (e.g., more than one hour, more than one day, more than one week, etc.). be able to. Although the cryogenic fluid boil-off mitigation system 300 can store some gaseous hydrogen through the Joule-Thomson cooling technology utilized in stage 2 310, it stores the hydrogen in the storage tank essentially as a liquid. may be configured to maintain. The Joule-Thomson effect causes hydrogen to be insulated from source pressure (provided by a pump and/or storage tank) under adiabatic conditions (e.g. to prevent heat transfer to or from the hydrogen). Cooling is achieved by allowing the hydrogen to expand through a throttling device, such as a valve or nozzle, which reduces the pressure to a determined pressure (throttling valve) and allows the hydrogen to cool. Accordingly, tank controller 314 manipulates process parameters (e.g., pressure, flow rate, etc.) via flow controller 322 to achieve the desired cooling and return the hydrogen to the desired cryogenic temperature, as needed. , gaseous hydrogen can be liquefied. In some examples, the stage 2 310 cooling system may be configured to remove latent heat of vaporization from the hydrogen by the tank controller 314 or other controller associated with the liquefaction system 306. In other examples, the stage 2 310 cooling system removes the latent heat of vaporization and additional heat from the hydrogen to a desired temperature and/or pressure at which the hydrogen is admitted to the storage tank 312 via the stage 2 boil-off exhaust 324. may be configured to achieve. In at least one embodiment, the latent heat of vaporization can account for more than 95% of the energy consumed by stage 2 310 (e.g., to generate pressure to cool and/or liquefy the hydrogen via a pump). work required).

FIG. 4 is a schematic diagram of a three-stage liquefaction system 400, according to a further example of the present disclosure. Note that the components shown in FIG. 4 may be similar and/or identical to the corresponding components described with reference to FIGS. 1 and 3. Liquefaction system 400 may include stage 1 402, stage 2 404, and stage 3 406. Liquefaction system 400 may include an intake mechanism 408 and an intake conduit 410 configured to receive and process hydrogen received from a hydrogen source (eg, hydrogen source 104 and/or hydrogen source 304). The liquefaction system 400 may include a conduit 412 configured to transport hydrogen to and/or from each of Stage 1 402, Stage 2 404, Stage 3 406, and/or a storage tank (not shown). . Fluid control devices 414a-e are disposed around the liquefaction system 400 and control fluid movement between stages. Fluid control devices 414a-e may include any number of valves and/or pumps as desired to move fluid through liquefaction system 400. Fluid control device 414a may be configured to control intake conduit 410 and regulate the amount of hydrogen received by the liquefaction system from the hydrogen source. Fluid control devices 414b-d control fluid movement to and from stage 1 402, stage 2 404, and stage 3 406, respectively. Fluid control device 414e controls fluid movement from liquefaction system 400, such as to a storage tank (not shown). The controller 416 may be associated with the fluid control devices 414a-e and generate signals to the fluid control devices 414a-e (eg, the fluid control devices are solenoid valves) and e (e.g., the fluid control device is a pneumatic or hydraulic valve) and actuate valves and/or pumps as necessary to move hydrogen into and out of the liquefaction system 400, as necessary. 402, stage 2 404, and stage 3 406, the valves and/or pumps may be configured to operate. Conduit 412 may include multiple branches and associated valves that fluidly connect intake mechanism 408, stage 1 402, stage 2 404, stage 3 406, and a storage tank (not shown). Accordingly, conduit 412 has sufficient capacity to selectively transfer hydrogen between components of liquefaction system 400 without unnecessarily compromising flow or mixing hydrogen from different components. The fluid path may be configured to provide a fluid pathway. Additionally, although conduit 412 is illustrated as being shared between all components, conduit 412 can be split into individual conduits that fluidly connect two components of liquefaction system 400.

In some examples, liquefaction system 400 may have any desired number of stages. The cryogenic system herein can be used to process hydrogen, which has the somewhat unique properties of a negative Joule-Thomson effect, as discussed above. Other cryogenic fluids have other properties that may require more stages to which different processing principles can be applied to achieve an efficient cooling and liquefaction unit. Therefore, each stage can be a different processing mechanism. In other examples, the steps may be redundant, operating the same liquefaction mechanism on the fluid. Separating the liquefaction system 400 into a greater number of stages may allow higher efficiencies to be achieved. Therefore, liquefaction system 400 can be used at less than full capacity. One application for using a portion of liquefaction system 400 is to remove latent heat of vaporization from boil-off hydrogen. The hydrogen can then be returned to the tank or directed elsewhere for use, and this is accomplished without the need for the entire liquefaction system 400.

FIG. 5 is a block diagram of a method 500 according to examples of the disclosure. Method 500 may be performed by one or more processors of a cryogenic fluid boil-off mitigation system as illustrated and described above with respect to FIGS. 1-4. For example, any of the methods described herein with respect to FIGS. 1), tank controller 314 (FIG. 3), controller 416 (FIG. 4), and/or other control devices. Unless otherwise noted, such processors are described for the remainder of this disclosure without reference to tank controllers 120, 314, controllers 416, and/or other control devices described above.

At 502, a processor can manage the storage and maintenance of a cryogenic fluid, such as hydrogen, in a desired cold and stable environment, such as a storage tank. In particular, the processor may receive temperature, pressure, and/or any other desired parameters from one or more sensors connected to at least the storage tank. Additionally, one or more sensors may be connected to the storage tank such that temperature, pressure, and/or other desired parameters are determined from at least the liquid phase and/or gas phase within the storage tank. .

At 504, the processor can determine whether the boil-off hydrogen in the storage tank meets one or more pressure thresholds and/or one or more temperature thresholds. Further, the processor can determine whether boil-off mitigation operations are desired. Note that the desirability of boil-off mitigation operations may be based on one or more pressure thresholds, one or more temperature thresholds, a schedule, and/or in response to direct intervention by an operator. At 504, the processor determines, based on at least the temperature and/or pressure of the storage tank, that the cryogenic fluid is within an operational threshold of the storage tank (e.g., defining a safe storage environment for a certain amount of cryogenic fluid in the storage tank). (within a temperature range and/or a pressure range) (504-no), the processor can return to monitoring the cryogenic fluid in the storage tank at 502. The check at 504 may be performed as many times as substantially desired or as per a set schedule. For example, the check at 504 can be performed substantially continuously, periodically, and/or irregularly.

On the other hand, at 504, if the processor determines that the cryogenic fluid exceeds a temperature threshold and/or pressure threshold associated with the storage tank based on at least the temperature and/or pressure of the storage tank (steps 504- Yes), the processor may determine that the boil-off cryogenic fluid is extracted from the storage tank and reliquefied via the liquefaction system. Specifically, the temperature threshold and/or pressure threshold is the maximum safe storage pressure for the cryogenic fluid (optionally including a safety factor), the maximum safe storage temperature for the cryogenic fluid (optionally including an additional safety factor), ), a certain amount of boil-off cryogenic fluid stored in the tank, and/or other internal conditions of the storage tank that cause the processor to initiate boil-off mitigation. As described above, the processor monitors the temperature and/or pressure of the storage tank via one or more sensors connected to the storage tank and generates an indication of the pressure and/or temperature within the storage tank. be able to.

At 506, the processor may perform a second check to determine the cooling stage utilized during boil-off mitigation. As discussed above with respect to at least FIGS. 1, 3, and 4, a liquefaction system may include one, two, or more stages in a given example of the present disclosure. Accordingly, the processor may be configured to cause the liquefaction system to cool cryogenic fluid received from the cryogenic fluid source and boil-off cryogenic fluid extracted from the storage tank.

At 506, the processor may determine that the boil-off cryogenic fluid exceeds a temperature threshold and may determine that stage 1 is appropriate. Specifically, and as discussed above, some cryogenic fluids, including hydrogen, have inversion temperatures below room temperature. Additionally, the primary cooling technique for the cryogenic fluid may be ineffective at temperatures above the temperature threshold and effective at additional temperatures below the temperature threshold. Alternatively or additionally, the second cooling technique may be effective to cool the cryogenic fluid both at a temperature above the temperature threshold and at an additional temperature below the temperature threshold. Accordingly, stage 1 may be associated with at least a second cooling technique that is effective at temperatures above the temperature threshold. Additionally, at 506, the processor may determine that the boil-off cryogenic fluid meets a temperature threshold and may determine that stage 2 is appropriate. Stage 2 may be associated with at least a first cooling technique effective at additional temperatures below the temperature threshold.

At 508, and if Stage 1 is appropriate (Step 506-Stage 1), the processor causes the one or more fluid controllers to extract the boil-off cryogenic fluid from the storage tank and extract the boil-off cryogenic fluid from the one or more fluids. The controller may be configured to provide boil-off cryogenic fluid for the stage 1 cooling operation. Specifically, the processor causes one or more pumps, valves, and/or other fluid control devices to extract boil-off cryogenic fluid from a storage tank and pipe the boil-off cryogenic fluid to a stage 1 cooling operation. , conduits, hoses, and/or other connections between the storage tank and the stage 1 cooling operation. In some examples, the pumps, valves, conduits, connections, and other fluid management components utilized to transport the boil-off cryogenic fluid between the storage tank and the Stage 1 cooling operation are as per Figure 3. The illustrated stage 1 boil-off loop 326 may be configured in accordance with the considerations. Additionally, at 510, the processor may perform stage one. Specifically, the processor may reduce boil-off hydrogen from a first temperature to a second temperature in stage 1. Additionally, the processor may moderate the amount of work utilized to cool the boil-off cryogenic fluid, moderate the amount of coolant/freezing agent utilized to cool the boil-off cryogenic fluid, and/or Otherwise, the cooling operation of stage 1 may be configured to control the boil-off cryogenic fluid from the first temperature to the second temperature. In some examples, Stage 1 and Stage 2 may be sequential, meaning that fluid from Stage 1 proceeds to Stage 2. In other examples, fluid may be directed to stage 1 and then discharged from the liquefaction system without reaching stage 2. In other examples, there may be a series of valves and controllers directing fluid from stage 1 to either stage 2 or back to the tank as desired.

At 512, the processor causes the fluid controller to provide boil-off cryogenic fluid to stage 2, and at 514, the stage 2 cooling operation reduces the cryogenic fluid from the second temperature to the third temperature. can receive boiled-off cryogenic fluid from stage 1 (step 506 - stage 1) or can be reduced from a first temperature to a third temperature and can receive boiled-off cryogenic fluid from a storage tank (step 506 ~Stage 2). In some examples, the boil-off cryogenic fluid may be directed to stage 2 directly from the storage tank, as discussed above. Additionally, the processor performs the cooling operation of stage 2 from a first temperature associated with the boil-off cryogenic fluid extracted from the storage tank to a third temperature associated with the temperature at which the boil-off cryogenic fluid may be admitted to the storage tank. The boil-off cryogenic fluid can be cooled to a temperature of . Additionally, the processor may liquefy the boil-off cryogenic fluid such that the liquid cryogenic fluid is placed in a storage tank for a stage 2 cooling operation. In some additional examples, the boil-off cryogenic fluid can be directed to Stage 2 after the Stage 1 cooling operation is complete. Accordingly, the processor may perform a stage 2 cooling operation by cooling and optionally liquefying the boil-off cryogenic fluid received from stage 1 and placing the boil-off cryogenic fluid into a storage tank. After the stage 2 cooling operation is completed, the processor causes the fluid controller to return the boil-off cryogen, the current liquid cryogen, to the storage tank and continue monitoring the storage tank and the cryogen at 502. be able to. If there are other stages in the system, they may be considered in the appropriate order. The stages may be continuous (e.g., allowing the cooling stage to cool over a lower temperature range) to provide greater control over the cooling of the boil-off cryogenic fluid, allowing for greater capacity control. (e.g., parallel cooling operations may have minimal flow requirements, allowing cooling stages to have greater control throughput), and/or sequential cooling stages and Any combination of parallel cooling stages may be used.

Accordingly, the method of FIG. 5 enables boil-off loss mitigation for cryogenic fluids stored by cryogenic fluid boil-off mitigation systems such as those described in FIGS. 1-4. Specifically, constant sensing of the internal temperature and pressure of the storage tank causes the processor of the cryogenic fluid boil-off mitigation system to determine the amount of boil-off cryogenic fluid produced and communicated between the atmosphere and the cryogenic fluid. It becomes possible to track the amount of incident heat. Furthermore, with internal temperature and pressure sensing, safety features can be implemented to ensure accident-free continuous staging of cryogenic fluids. Thus, the processor can extract, liquefy, and reintroduce cryogenic fluid from the storage tank that would otherwise be vented to the atmosphere and lost for safety and maintenance reasons. Additionally, periodic extraction, liquefaction, and reintroduction of boil-off cryogenic fluid enables long-term storage of cryogenic fluid and reduces the amount of cryogenic fluid introduced into the storage tank from external sources.

FIG. 6 is a block diagram of a method 600 according to a further example of the present disclosure, in which a single stage is used for boil-off purposes. Method 600 may be performed by one or more processors of a cryogenic fluid boil-off mitigation system as illustrated and described above with respect to FIGS. 1-4. The cryogenic fluid boil-off mitigation system of the present disclosure may include a liquefaction system controlled by one or more processors. The liquefaction system may also include a dedicated boil-off management stage, designated as Stage 2 above. Of course, the boil-off management stage may not be stage 2 of the process. At 602, a processor can receive a cryogenic fluid, such as hydrogen, from a cryogenic fluid source and store it in a storage tank after being cooled by a liquefaction system. The cryogenic fluid may be a mixed phase solution in a storage tank that exists in both liquid and gas phases. Further, the processor can monitor the internal temperature and pressure of the storage tank via one or more sensors (eg, temperature sensor, pressure sensor, etc.). Thus, the process can store cryogenic fluid and monitor the cryogenic fluid within the storage tank.

At 604, the processor can determine whether a boil-off mitigation operation is desired. For example, as part of this determination, the processor may determine whether the boil-off hydrogen in the storage tank meets one or more pressure thresholds and/or one or more temperature thresholds. The desirability of the boil-off mitigation action determined in step 604 may be determined based on one or more pressure thresholds, one or more temperature thresholds, a schedule, and/or in response to direct intervention by an operator. Please note that.

At 604, the processor determines, based on at least the temperature and/or pressure of the storage tank (stored at 602), that the cryogenic fluid is within an operational threshold of the storage tank (e.g., for a certain amount of cryogenic fluid in the storage tank). (within a temperature range and/or a pressure range that defines a safe storage environment) (step 604 - NO), the processor may return to monitoring the cryogenic fluid in the storage tank at 602. can. The check at 604 may be performed as many times as substantially desired or as per a set schedule. For example, the check at 604 can be performed substantially continuously, periodically, and/or irregularly.

Meanwhile, at 604, the processor determines, based at least on the temperature and/or pressure of the storage tank (stored at 602), that the cryogenic fluid exceeds a temperature threshold and/or pressure threshold associated with the storage tank. If so (step 604 - yes), the processor may determine that the boil-off cryogenic fluid is extracted from the storage tank and reliquefied via the liquefaction system. Specifically, the temperature threshold and/or pressure threshold is the maximum safe storage pressure for the cryogenic fluid (optionally including a safety factor), the maximum safe storage temperature for the cryogenic fluid (optionally including an additional safety factor), ), a certain amount of boil-off cryogenic fluid stored in the tank, an inversion temperature of the cryogenic fluid, and/or other internal conditions of the storage tank that cause the processor to initiate boil-off mitigation. In at least one embodiment, extracting the cryogenic fluid from the storage tank at a temperature above the inversion temperature is due to the pressure drop caused by the boil-off cryogenic fluid extraction causing the remaining cryogenic fluid in the storage tank to heat up. May represent a safety issue. Accordingly, the temperature threshold may be selected or determined such that below the inversion temperature, the boil-off cryogenic fluid is extracted from the storage tank, and extraction of the boil-off cryogenic fluid cools the stored cryogenic fluid. As described above, the processor monitors the temperature and/or pressure of the storage tank via one or more sensors connected to the storage tank and generates an indication of the pressure and/or temperature within the storage tank. be able to.

At 606, cryogenic fluid can be extracted from the storage tank by the processor and provided to stage 2 by one or more fluid controllers. Specifically, the processor operates a valve (e.g., fluid controller 320) (e.g., via an electronic signal, an air pump, a hydraulic pump, etc.) to separate the stage 2 storage tank and cooling operations. The fluid connection may be configured to open. Further, the processor may be configured to cause the internal pressure of the pump and/or the storage tank to transport the boil-off cryogenic fluid from the storage tank to the stage 2 cooling operation.

At 608, the processor may determine the amount of cooling provided by the stage two cooling operation. Specifically, the processor may cause the stage 2 cooling operation to cool the cryogenic fluid from a first temperature to a second temperature and optionally liquefy the cryogenic fluid. Additionally, the processor directs the one or more fluid control devices associated with stage 2 to return the cryogenic fluid to the tank or otherwise drain the cryogenic fluid from stage 2 at an appropriate pressure and temperature. can be done. Of note, step 608 includes the processor causing a step 2 cooling operation (e.g., a Joule-Thomson cooling operation) to cool the boil-off cryogenic fluid from the first temperature to a second temperature and liquefying the boil-off cryogenic fluid. Step 514 may be performed in a manner similar to step 514 to cause the liquid cryogenic fluid to return to the storage tank. Similar to the extraction from the storage tank, the processor instructs one or more fluid control devices (e.g., operating one or more valves and one or more pumps) to perform the stage 2 evacuation and storage tank extraction. A liquid cryogenic fluid can be transported to and from the inlet.

Accordingly, the method of FIG. 6 enables boil-off loss mitigation for cryogenic fluids stored by cryogenic fluid boil-off mitigation systems such as those described in FIGS. 1-4. Specifically, hydrogen and other cryogenic fluids may be associated with an inversion temperature that is within the operating range of a liquefaction system utilized to liquefy incoming hydrogen from a hydrogen source for storage in a storage tank. Additionally, the inversion temperature can represent an operating range in which the Joule-Thomson cooling technique does not cool the hydrogen, but instead causes it to heat up. If not properly managed, extracting hydrogen from a storage tank while the hydrogen is being heated by the pressure drop can lead to a potentially dangerous cycle of heating the stored hydrogen by extracting boil-off hydrogen. Therefore, the processor associated with the cryogenic fluid boil-off mitigation system prevents the stored hydrogen or cryogenic fluid from exceeding the inversion temperature and ensures safe storage and maintenance of the stored hydrogen. It may be configured to cool the hydrogen.

For large facilities such as data centers, backup power can be provided by hydrogen-powered engines (or fuel cells) that consume hydrogen as fuel to power the facility. Hydrogen-powered engines (or fuel cells) can provide lower carbon emissions, cleaner emergency power, and alternative fuel sources compared to diesel generator sets commonly utilized for backup power. Because liquid hydrogen must be stored at very cryogenic temperatures, storage of hydrogen may involve precise control schemes and maintenance of storage tanks (e.g., storage temperature and pressure). The systems and methods of the present disclosure provide a liquefaction system and boil-off loop that can be utilized to recover boil-off hydrogen that would otherwise be exhausted to the atmosphere. For example, the system described herein enables relatively low-power maintenance of stored liquid hydrogen and relatively low-power reuse of boil-off hydrogen that would otherwise be lost. Includes a cooling stage. Low-power cooling stages (e.g. Joule-Thomson cooling stages) can be maintained in series with other more power-intensive cooling systems, but there are alternatives that allow boil-off hydrogen to be cooled if desired. It also provides an influx of information.

As a result of the techniques described herein, various systems of the present disclosure can reduce or prevent hydrogen loss due to natural heating of storage tanks. Natural heating of the storage tank causes the stored liquid hydrogen to evaporate into gaseous hydrogen which increases the internal pressure and temperature of the storage tank. Instead of discharging gaseous hydrogen (resulting in the need to purchase or generate hydrogen on a regular basis), boil-off hydrogen can be collected and processed by a portion of the liquefier. By passing the hydrogen through a relatively low energy cooling system (eg, a Joule-Thomson cooling system), the hydrogen can be liquefied and reintroduced into the storage tank. Accordingly, the described system can reduce the amount of hydrogen obtained from external sources, produced by internal sources, or otherwise introduced to the backup power system. Additionally, the described system may be configured to maintain the internal temperature and pressure of the storage tank within safety parameters. As a result, the disclosed system can maintain a backup power source without incurring the relatively high component cost, complexity, contamination, and frequent maintenance outages associated with known systems.

Although aspects of the present disclosure have been particularly shown and described with reference to the embodiments described above, various additional embodiments may be disclosed without departing from the spirit and scope of the disclosed subject matter. Those skilled in the art will appreciate that modifications to the machines, systems and methods may be contemplated. It is to be understood that such embodiments fall within the scope of this disclosure as determined by the claims and any equivalents thereof.

Claims (20)

A system,
a storage tank configured to store cryogenic hydrogen in a two-phase mixture;
A liquefaction system configured to receive hydrogen from an external source, the liquefaction system comprising a Joule-Thomson cooling stage and a non-Joule-Thomson cooling stage fluidly connected to the Joule-Thomson cooling stage, the liquefaction system comprising:
receiving the hydrogen in the non-Joule-Thomson cooling stage;
in the non-Joule-Thomson cooling step, cooling the hydrogen to a first temperature below a temperature threshold;
transferring the hydrogen from the non-Joule-Thomson cooling stage to the Joule-Thomson cooling stage at the first temperature;
in the Joule-Thomson cooling step, cooling the hydrogen to a second temperature lower than the first temperature;
a liquefaction system further configured to transfer the hydrogen from the Joule-Thomson cooling stage to the storage tank at the second temperature;
the Joule-Thomson cooling stage of the liquefaction system, the Joule-Thomson cooling stage comprising:
cooling the boil-off hydrogen to a third temperature;
a boil-off loop configured to transfer boil-off hydrogen from the storage tank to the Joule-Thomson cooling stage, the boil-off loop configured to transfer the cooled boil-off hydrogen to the storage tank at the third temperature; A system comprising . 2. The system of claim 1, wherein the boil-off loop is configured to increase the pressure of the boil-off hydrogen to a first pressure above a pressure threshold associated with the Joule-Thomson cooling stage. further comprising a controller operably connected to the one or more fluid control devices, the controller comprising:
The temperature of the hydrogen located within the storage tank and the pressure of the hydrogen located within the storage tank are determined from at least one of a temperature sensor associated with the storage tank and a pressure sensor associated with the storage tank. receive at least one of the
determining at least one of: the temperature of the hydrogen located within the storage tank that exceeds a temperature threshold; and the pressure of the hydrogen located within the storage tank that exceeds a pressure threshold;
2. The system of claim 1, wherein the one or more fluid control devices are configured to transfer the boil-off hydrogen to the boil-off loop based on at least the determination. The liquefaction system further comprises a third stage, wherein the controller directs the boil-off hydrogen to the one or more fluid control devices into the non-Joule-Thompson cooling stage, the Joule-Thompson cooling stage, or the third stage. 4. The system of claim 3, wherein the system is configured to transport one or more of the following: a flow control device fluidly connected to the boil-off loop to direct the boil-off hydrogen to the non-Joule-Thomson cooling stage;
further comprising a controller configured to direct the boil-off hydrogen to the Joule-Thomson cooling stage via a fluid passage extending from the non-Joule-Thomson cooling stage to the Joule-Thomson cooling stage. The system of claim 1, comprising: 2. The system of claim 1, wherein the Joule-Thomson cooling stage is configured to remove latent heat of vaporization from the boil-off hydrogen and return liquefied hydrogen to the storage tank. A system,
a storage tank configured to store a fluid at cryogenic conditions, below a cryogenic threshold and below a cryogenic pressure threshold;
A liquefaction system having a first stage and a second stage fluidly connected to the first stage, the liquefaction system comprising:
receiving the fluid in the first stage;
reducing the temperature of the fluid to a storage temperature below the cryogenic threshold;
a liquefaction system configured to transfer the fluid from the second stage to the storage tank via a first fluid passageway at the storage temperature;
a second fluid passage fluidly connecting the storage tank with the second stage;
a controller operably connected to the liquefaction system and one or more fluid control devices, the controller comprising:
causing the one or more fluid control devices to transfer boil-off fluid from the storage tank to the second stage of the liquefaction system;
liquefying the boil-off fluid in the second stage of the liquefaction system;
a controller configured to cause the one or more flow control devices to transfer the liquefied boil-off fluid from the second stage of the liquefaction system to the storage tank. 8. The system of claim 7, wherein the first stage comprises a non-Joule-Thomson cooling stage and the second stage comprises a Joule-Thomson cooling stage. 8. The system of claim 7, wherein the fluid includes hydrogen and the cryogenic threshold includes an inversion temperature of hydrogen and is associated with Joule-Thomson cooling technology. The one or more fluid control devices include a valve operably connected to the controller and configured to control transfer of the boil-off fluid from the storage tank to the second stage of the liquefaction system. 8. The system of claim 7, comprising: the one or more fluid control devices operably connected to the controller, and transporting the boil-off fluid from the storage tank to the second stage of the liquefaction system; and transporting the liquefied boil-off fluid to the second stage of the liquefaction system. 11. The system of claim 10, further comprising a pump configured to at least one of: transfer from the second stage of the liquefaction system to the storage tank. the pump is further configured to increase the pressure of the boil-off fluid from a first pressure to a second pressure associated with the second stage of the liquefaction system and greater than the first pressure; 12. The system of claim 11. The liquefaction system further comprises a third stage fluidly connected to the second stage, the third stage utilizing non-Joule-Thomson cooling techniques to direct the boil-off fluid to the second stage of the liquefaction system. 8. The system of claim 7, configured to cool to an inlet temperature associated with the second stage. the third stage is such that the fluid is cooled by the first stage and the second stage and the boil-off fluid is cooled by the third stage and the second stage; 14. The system of claim 13, implemented in parallel with the steps of. A method,
determining a temperature of hydrogen stored in the storage tank using a first sensor associated with the storage tank;
determining the pressure of the hydrogen using a second sensor associated with the storage tank;
with a controller operably connected to the first sensor and the second sensor;
determining at least one of: the temperature of the hydrogen above a temperature threshold; and the pressure of the hydrogen above a pressure threshold;
the controller is operable to operate the controller based, at least in part, on determining, with the controller, at least one of the temperature of the hydrogen that exceeds the temperature threshold; and the pressure of the hydrogen that exceeds the pressure threshold; a liquefaction system fluidly connected from the storage tank to the storage tank to a first flow control device connected to the liquefaction system, the liquefaction system comprising:
a first stage configured to implement a non-Joule-Thomson cooling technique;
a second stage fluidly connected to the first stage, the second stage configured to perform a Joule-Thomson refrigeration technique; directing the hydrogen;
using the controller to cause a second flow control device operably connected to the controller to transfer liquid hydrogen from the second stage of the liquefaction system to the storage tank. using the controller to determine that the temperature of the hydrogen is greater than a coefficient temperature threshold;
using the controller to cause the first fluid control device to direct the boil-off hydrogen to the first stage of the liquefaction system based at least on determining that the temperature of the hydrogen is greater than the coefficient temperature threshold; 16. The method of claim 15, further comprising: transporting. using the controller to determine that the temperature of the hydrogen is less than a coefficient temperature threshold;
using the controller to direct the boil-off hydrogen to the second stage of the liquefaction system, at least based on determining that the temperature of the hydrogen is less than the coefficient temperature threshold; 16. The method of claim 15, further comprising: transporting to. the liquefaction system comprises a third stage configured to perform a Joule-Thomson refrigeration technique, fluidly connecting the first stage with the second stage, the method comprising: 16. The method of claim 15, further comprising directing at least a portion of the boil-off hydrogen to the third stage based at least on the pressure of the hydrogen. the liquefaction system comprising a third stage configured to perform a Joule-Thomson cooling technique and fluidly connecting the first stage with the storage tank; 16. The method of claim 15, further comprising directing at least a portion of the boil-off hydrogen to the second stage and the third stage based at least on the pressure of . receiving instructions from a remote source to direct the hydrogen to the first stage or the second stage of the liquefaction system using the controller;
using the controller to transfer the boil-off hydrogen from the storage tank to the first stage or the second stage of the liquefaction system, based at least in part on the instructions, to the first fluid control device; 16. The method of claim 15, further comprising causing.