hydrogen cooling

Abstract

Hydrogen liquefaction includes three streams of refrigerant between -320 and -425 degrees F. A fourth stream has ambient temperature and a pressure between 150 and 650 PSIA. The fourth cooling stream is cooled by a heat exchanger to between -320 and -270 degrees F. A first stream segment of these cooling streams is depressurized across a valve to a two-phase mixture that is directed to a fourth heating stream segment. A separate fifth stream has ambient temperature and a pressure between 700 and 1200 PSIA. A fifth cooling stream has a first stream portion split by a splitter between 0 and 60 degrees F, and a second stream portion split between -160 and -100 degrees F. Cooling stream segments of the first and second stream portions are fed into an expander powered by a fifth compressor to reduce the temperature of the fifth stream to serve as the first and second stream portions.

Description

Technical Field

[0001] This invention relates to liquid hydrogen, hydrogen cooling, and hydrogen liquefaction. Background Technology

[0002] Cryogenic liquids, such as hydrogen, are substances that are liquid at extremely low temperatures (typically below -150°C (-238°F)). Cryogenic liquids include liquid nitrogen, liquid helium, liquid hydrogen, and others. These substances are used in a variety of applications, including refrigeration, medicine, and research. Cryogenic liquids are also used to cool materials to extremely low temperatures for scientific experiments and industrial processes. Cryogenic liquids are stored and transported in specially designed containers to prevent them from boiling or evaporating at room temperature.

[0003] In hydrogen liquefaction (e.g., liquefaction), a two-step process is typically used: a precooling system (150 to -320°F) and a cryogenic system (-320 to -425°F). The precooling system can be implemented using several options; existing options include hydrocarbon-mixed refrigerant cycles, liquid nitrogen evaporation cycles, and modified anti-Bretton nitrogen cycles. Most currently operating facilities use liquid nitrogen evaporation cycles, but their relatively low efficiency is driving the use of alternative cycles.

[0004] In existing modified reverse Brayton nitrogen cycles, most of the cooling capacity is generated by one or two turbine expanders that extract work from the process gas (e.g., nitrogen). Due to the large flow rates, these turbine expanders typically operate at discharge pressures of 50 to 150 psia (which may be referred to as intermediate pressure) to maintain a reasonable volumetric flow rate. A small portion of the cooling capacity is also supplied by a stream of nitrogen that is condensed within the cycle and pressured down to near atmospheric pressure (e.g., 14.7 psia) through valves (e.g., Joule-Thomson valves or JT valves). This generates Joule-Thomson cooling in the valve and provides cooling capacity at the coldest temperature of the precooling system. Existing technology combines these two streams, where the near-atmospheric stream is compressed to mix with the turbine expander discharge pressure. The two streams are then compressed through multiple stages (e.g., sub-streams) to a given pressure between 400 and 1200 psi (which may be referred to as the cycle pressure) before being split in the cooling step.

[0005] Many hydrogen liquefaction units are currently envisioned for applications where electricity is derived from variable sources, such as renewable energy. Due to fluctuations in power supply, liquefaction units need to rapidly reduce their power consumption to remain online with reduced production capacity. If a liquefaction unit cannot reduce its power consumption below the available power supply, the system must shut down. These shutdowns result in reduced total output and impact the overall economic viability of hydrogen liquefaction projects.

[0006] The improved reverse Brayton cycle compresses and mixes near-atmospheric nitrogen with turbine expander exhaust nitrogen. This mixture is further compressed by an electric motor-driven and expander-driven compressor until it is split within a heat exchanger and cooled to its respective required temperatures before expanding to lower pressures. By mixing these streams, the two processes become fundamentally coupled—adjustments made to the compressed nitrogen used for turbine expander expansion must also be made to the compressed nitrogen throttled through the JT valve. This coupling limits operational flexibility because both streams must be boosted to the same pressure.

[0007] Centrifugal compressors are typically used to perform the aforementioned nitrogen compression tasks. This type of compressor offers relatively good performance and excellent reliability, but when operating at its design inlet and outlet pressures, it can usually only reduce its flow rate to about 70% of full load. Screw compressors have maximum pressure and size limitations, restricting them to low-pressure and low-power applications only, but generally offer characteristics that allow for relatively deep regulation. They may be used in atmospheric pressure compression stages as initial compression stages if the cycle is adjusted to allow their use. Reciprocating compressors are rarely used because they are expensive and have poor maintenance characteristics.

[0008] If it is necessary to reduce the flow rate to below 70% of full capacity, the flow must be circulated or the process conditions must be changed. If the flow is circulated back from the compressor discharge to the compressor inlet, power is still consumed in compression without any benefit. Centrifugal compressors must operate within a fixed window of volumetric flow rate and head. If the process flow rate changes, these two parameters must be kept within a window close to their original design. These parameters are kept close to the original design by adjusting the density at the compressor suction end, while reducing the mass flow rate and thus reducing power consumption. Since these machines typically operate at temperatures close to ambient conditions, temperature cannot be freely adjusted to drive density changes. Therefore, the pressure around the compressor must be reduced to decrease the density. To maintain a similar head lift on the compressor, the discharge pressure must be reduced in the same proportion as the suction pressure reduction. Intermediate and recirculation pressures can be reduced in this way without problem. However, if the atmospheric suction pressure is also reduced in the same proportion, it will become negative. Negative pressure conditions should be avoided due to concerns about process gas contamination and the mechanical integrity of typical equipment. Therefore, the atmospheric suction pressure must be kept constant during these regulated operations.

[0009] For the aforementioned improved anti-Breen cycle, reducing the intermediate and cycle pressures provides a tangible benefit in reducing the power required for this compression stage, for example, during such conditioning periods. Unfortunately, reducing this pressure introduces a double problem. First, the pressure ratio from atmospheric pressure to the intermediate pressure decreases. This reduces head lift and moves the equipment away from its aerodynamic design point, resulting in reduced compression efficiency and offsetting some of the power savings. Second, and more importantly, the pressure of the high-pressure nitrogen introduced to the JT valve decreases. Reducing this pressure carries the risk of causing the nitrogen to drop below its critical pressure or lowering its condensation temperature. When this occurs, the temperature distribution within the heat exchanger shifts and eventually pinches, leading to poor heat exchange within the system. Ultimately, this poor heat exchange will significantly reduce system efficiency and may cause thermal stress and damage to the heat exchanger.

[0010] There is currently a need for more efficient hydrogen cooling, such as in the pre-cooling phase of liquefied hydrogen systems. This technology and implementation address this issue. Attached Figure Description

[0011] Figure 1 A ball-and-stick model for hydrogen gas.

[0012] Figure 2 A hydrogen model focusing on electrons, protons, and interatomic interactions.

[0013] Figure 3A This is a schematic diagram of a high-efficiency hydrogen cooling system.

[0014] Figure 3B This is a schematic diagram of another highly efficient hydrogen cooling system.

[0015] Figure 4 This is a flowchart of an efficient hydrogen cooling method. Detailed Implementation

[0016] The techniques described herein (e.g., systems, apparatus, and methods) provide a novel variant of the improved reverse Brayton cycle for efficient hydrogen cooling, such as for liquefied hydrogen. The techniques described herein may, but are not necessarily, use a nitrogen cycle, as implementations include the use of alternative fluids (e.g., chemicals or refrigerants) in separate or independent streams or flows D and E. The techniques described herein ensure that the high-pressure nitrogen or methane introduced into the improved reverse Brayton cycle via the JT valve maintains a stable pressure throughout operation, thereby avoiding the problems noted above for improved reverse Brayton cycles. In some cases, this JT valve is valve V_Cond located in flow D between flows D06 and D07. The description herein prevents the mixing of the near-atmospheric pressure nitrogen flow from the improved reverse Brayton cycle with the turbine expander exhaust nitrogen flow, thereby optimizing the ability of the new systems and methods to reduce their capacity without sacrificing efficiency. The techniques described herein can be or include systems such as System 300, which is a precooling system for cooling hydrogen, producing liquid hydrogen, or for hydrogen liquefaction.

[0017] Liquid hydrogen is a versatile and valuable substance with many important applications in various industries. For example... Figure 1 and Figure 2 The molecular structure of hydrogen, as shown, contributes to its unique property as a cryogenic liquid. Hydrogen, or diatomic hydrogen, consists of two hydrogen atoms bonded together by covalent bonds. The molecular formula for hydrogen is H₂. The molecular structure of hydrogen is simple, consisting of only two bonded hydrogen atoms. A key physical property of hydrogen is its low density. Hydrogen is the lightest of all gases, with a density of only 0.08988 g / L at standard temperature and pressure (sometimes rounded to 0.07 g / mL). This low density is attributed to the small size of hydrogen atoms and the low atomic weight of hydrogen. Another important physical property of hydrogen is its flammability. Hydrogen is highly flammable and will ignite in the presence of an ignition source. This flammability is attributed to the chemical reactivity of hydrogen, a result of the high energy content of the bonds between hydrogen atoms in the molecule.

[0018] Hydrogen has an extremely low boiling point, only -252.87°C at standard pressure. This low boiling point is attributed to the weak intermolecular forces between hydrogen molecules, which allows them to easily escape from the liquid phase to the gas phase. This low boiling point also makes hydrogen an excellent cryogenic liquid, as it remains liquid at the temperatures that solidify other chemicals. Liquid hydrogen can be used as rocket fuel. Its extremely light weight and high energy content make it ideal for use in space travel. Besides rocket fuel, liquid hydrogen is also used in some fuel cells. Fuel cells are devices that generate electricity through chemical reactions and have the potential to be a clean and efficient energy source. Liquid hydrogen is used as fuel in some types of fuel cells, particularly those using proton exchange membrane (PEM) technology.

[0019] Liquid hydrogen is also used in semiconductor manufacturing. Some semiconductors are produced through a process called deposition, in which thin layers of material are deposited onto a substrate. Liquid hydrogen is used as a coolant in some deposition processes, helping to maintain the low temperatures required to produce high-quality semiconductors. One of the most common industrial uses of liquid hydrogen is in the research and development of coolants and refrigerants. LH2 (liquid hydrogen, the addition of the L to the chemical symbol indicates that the chemical is in a liquid state) has an extremely low boiling point, making it an effective choice for cooling equipment and materials to extremely low temperatures. This is particularly useful in fields such as cryogenics, which involves the research and use of materials at extremely low temperatures.

[0020] Liquid nitrogen (LN2) is a colorless, odorless, and tasteless cryogenic liquid produced by cooling and compressing atmospheric nitrogen gas. Due to its unique properties and versatility, liquid nitrogen is widely used in a variety of applications. One of its primary uses is as a refrigerant. LN2's extremely low boiling point (-196°C) makes it an effective choice for refrigeration and cryogenic storage.

[0021] Liquid helium is a cryogenic liquid produced by cooling and compressing helium gas. It is the coldest naturally occurring substance on Earth, with a boiling point of -269°C, and possesses many unique properties and uses. One of the most well-known uses of liquid helium is as a coolant. Its extremely low boiling point makes it an effective choice for cooling materials and equipment to extremely low temperatures. It is frequently used in research and development, particularly in the fields of cryogenics and superconductivity.

[0022] Liquid oxygen is a cryogenic liquid produced by cooling and compressing oxygen. When pumped in liquid form in the system disclosed herein, it is pale blue and transparent. One of the main uses of liquid oxygen is as a breathing gas.

[0023] Liquid neon is a cryogenic liquid produced by cooling and compressing neon gas. It is a transparent liquid with many unique properties and uses. One of its main uses is as a refrigerant. Its extremely low boiling point (-246°C) makes it an effective choice for refrigeration and cryogenic storage.

[0024] Liquid argon is a cryogenic liquid produced by cooling and compressing argon gas. In its liquid state, argon is colorless, odorless, and tasteless. One application of liquid argon is as a refrigerant. Argon's extremely low boiling point (-186°C) makes it an effective choice for refrigeration and cryogenic storage. It is commonly used to store materials, such as biological samples and industrial chemicals, at extremely low temperatures.

[0025] Liquid methane is a cryogenic liquid produced by cooling and compressing methane gas. It is a colorless, odorless, and tasteless liquid with many unique properties and uses. One of the main uses of liquid methane is as a fuel.

[0026] The efficient hydrogen cooling technologies (e.g., systems, apparatus, and methods) described herein allow for stable and efficient regulated operation of the precooling section of a hydrogen liquefier. This efficient operation allows for economical operation of the hydrogen liquefier when product demand falls below the plant's nameplate capacity or when grid power availability decreases. Electricity can be measured as electrical power or watts, such as energy in joules per second and / or voltage × current per second.

[0027] Various cryogenic liquids can be mixed together and / or used in the efficient hydrogen cooling technologies described herein. Cryogenic liquids may include those named herein, light hydrocarbons, refrigerants, nitrogen, methane, mixtures of these molecules, and / or blends of various refrigerants.

[0028] Equipment Description Now refer to Figure 3A A system 300 for efficient hydrogen cooling. This cooling may be, or may be part of, a novel variant of an improved anti-Breyton cycle for efficient hydrogen cooling, such as for liquefying hydrogen gas into liquid hydrogen. System 300 may be, or may include, a system that serves as a precooling system for cooling hydrogen gas, producing liquid hydrogen, or for hydrogen liquefaction. System 300 has streams A-302, B-304, and C-306, each or all of which represent the -320 to -425°F portion of the hydrogen cooling system, which may include product hydrogen and refrigerants, such as hydrogen, helium, or neon, or blends of multiple refrigerants. A hydrogen cooling or liquefaction system can be considered efficient when the total power consumption is low after normalization to the total external cooling or total liquid production. This can be further analyzed not only by considering the efficiency at the design point but also by considering the efficiency during regulation periods when the demand for external cooling or liquid production decreases. When such regulation occurs, efficiency will deteriorate unless power can also be reduced using certain design features of the system. When such regulation occurs, the efficiency of hydrogen cooling can be more efficient or “highly efficient” when electricity can also be reduced using certain design features of the system (e.g., using flows D and E as part of the system described herein). In some cases, more efficient or “highly efficient” hydrogen cooling involves a reduction in the amount of electricity required during regulation, such as by the compressor due to a pressure reduction in flow E that does not merge with flow D, thus making the system more efficient. In other cases, more efficient or “highly efficient” hydrogen cooling involves using an expander and shaft to drive the compressor of flow E, instead of using electricity.

[0029] The configuration of streams D-310 and E-312 (or streams D-310 and E-352) is one of the foundations of the technology described herein, in which the nitrogen to be liquefied is held in its stream D or loop (D) and does not mix with the main refrigeration, refrigerant, or cryogenic liquid in stream E or loop (E). That is, no liquid, gas, or chemical in stream D is combined or mixed with any liquid, gas, or chemical in stream E. In some cases, stream D does not contact or interact with stream E except through heat exchangers HEX_1 to HEX_4. As shown, streams D and E can change temperature or exchange temperature with each other through heat exchangers HEX_1-4. Streams D and E can be precooled streams.

[0030] As shown in the figure, flow AE flows through one or more heat exchangers HEX_1-HEX_6. Each flow can be a liquid, gas, or a mixture of gases and fluids that includes cryogenic or refrigerated substances, chemicals, and / or molecules. Each flow includes multiple sub-flows or "segments," such as flow E-312 including segments E01, E02, ... through E18. Each flow may include one or more "stages," such as heating, cooling, compression, and / or cooler stages. Each flow and segment moves or flows in the direction indicated by the arrows in its flow and segment, for example, segment A01 of flow A flows through heat exchanger HEX_1 to become segment A02, and so on. In some cases, heat exchangers can be combined, for example, combining HEX_1 and HEX_2 for flow AD to achieve combined heat exchange between the two exchangers. Each heat exchanger can be a brazed aluminum heat exchanger. These heat exchangers exchange flow AE, where flow AE is relatively warmest at HEX_1 and relatively coldest at HEX_6. For example, as shown in the figure, HEX_1 can cool each stream AE from top to bottom. As shown, the streams AE can change temperature or exchange temperatures with each other via heat exchangers HEX_1-6. For example, each stream AE is cooled as it moves downwards from HEX_1 through HEX_6 (e.g., from stream segment B01 to stream segment B07); and then warmed or heated as it moves upwards from HEX_6 through HEX_1 (e.g., from stream segment B08 to stream segment B14). Each initial stream segment A01, B01 to E01 can be at ambient temperature (e.g., 50-100 degrees Fahrenheit).

[0031] Each stream in stream AE can be or use a different refrigerant or cryogenic liquid. Stream DE can be or use nitrogen or another cryogenic fluid, such as methane. In some cases, stream D is nitrogen and stream E is methane. Using methane in two streams or one stream may require some adjustments (e.g., temperature and pressure) to that stream or streams, but it will be feasible. Stream BC can be precooled by stream DE.

[0032] Flow A-302 can be used as ambient temperature gaseous hydrogen starting at flow section A01 (hydrogen input of system 300) and ending as cooled gaseous hydrogen at flow section A07 (hydrogen output of system 300) to be sent from precooling system 300 to cryogenic system, where the cooled hydrogen in flow section A07 is liquefied in cryogenic system.

[0033] The flows from flow sections B07 to B08, C07 to C08, B14 to B01, and C14 to C01 can be provided by various functions. These functions can be, include, or consist of pressure changes required by the cryogenic system functions. These flows can be compressed on the ambient temperature side (e.g., from flow sections B14 to B01 and C14 to C01) and expanded on the cryogenic side (e.g., from B07 to B08 and C07 to C08).

[0034] Sections D01-D14 of flow D-310 are primarily composed of nitrogen or methane. Section D01 is typically at ambient temperature (60 to 150°F, or about 125°F) and at a moderate pressure (150 to 650 psia, or about 160 psia). In other cases, this moderate pressure may be 150 to 350 psia, or about 160 psia. Section D01 is cooled to a cryogenic (e.g., liquid) temperature (-320 to -270°F, or about -280°F) in section D06 by one or more heat exchangers (HEX_1 to HEX_5). Cryogenic liquid nitrogen or liquid methane at flow segment D06 is depressurized at valve (e.g., JT valve) V_Cond, where the temperature of flow segment D06 decreases due to the Joule-Thomson effect of the valve, becoming a two-phase (e.g., liquid and gas) mixture at flow segment D07. This mixture is directed to one or more heat exchangers (HEX_6 to HEX_1), which heat flow segment D07 to evaporate the liquid and heat the fluid to near-ambient conditions at flow segment D13. The warm flow segment D13 is then compressed by compressor CP_cond to become flow segment D14, which is cooled back to the conditions in flow segment D01 by cooler C_Cond. Compressor CP_cond and cooler C_Cond can represent multiple compression and cooling stages between flow segments D14 and D01. In most cases, each compressor and cooler is a separate unit, but in some cases, they are combined compressor and cooler units. The compressor described herein can be any device or system that increases pressure, and the cooler described herein can be any device or system that cools liquids and / or gases. The compressor can be a centrifugal compressor, and the cooler can be a water-cooled or air-cooled cooler.

[0035] During conditioned operation, the temperature and pressure of all sections of the D flow (e.g., all D flow sections D01-D14) can be maintained near their design values.

[0036] During regulated operation, system 300 is configured to maintain the current temperature and pressure at each segment of flow D while operating the system at a reduced flow rate of flow AE to approximately 30% of its operational capacity or 100% flow rate. Regulated operation of system 300 can be achieved by operating the system at a reduced flow rate of 80%, 70%, or 30% below full load while maintaining the current temperature and pressure at each segment of flow D. The full load flow rate of flow D is determined in the design of the D system to provide sufficient cooling capacity to flow AC to achieve its target temperature.

[0037] During the maintenance of temperature and pressure across all sections of flow D, only the flow rate can be adjusted during regulation. In this case, since the temperature and pressure at section D06 are maintained at a fixed point through non-design conditions, section D06 will always be able to condense to the design level, ensuring that the cold two-phase nitrogen or methane in section D07 is always available to cool flow AC to the desired level, for example, through or using exchanger HEX_6. Section D07 can be the coldest or lowest-temperature point in flow D or flow AE, and can be used to cool all flow AC using exchanger HEX_6. Sections D01 or E01 can be the hottest or highest-temperature point in flow AE, and can be used to heat all flow AC using exchanger HEX_1.

[0038] In some cases, the regulating operation of system 300 may involve reducing the pressure in flow section D06 by valve V_Cond, for example, through the use of a shut-off valve or anti-cavitation valve internals. In other cases, valve V_Cond may use a turbine expander to reduce the pressure in flow section D06.

[0039] This regulating operation of system 300 is achieved through typical compressor regulation methods (inlet guide vanes, slide valves, variable frequency drives, unloaders, or other methods depending on the compressor technology). Because the condensation compressor (D-flow, such as compressor CP_Cond) is relatively small, the cost of the regulating device is significantly reduced compared to incorporating the same technology (e.g., comparable compressors required to meet the function of compressor CP_Cond, such as those in E-flow) onto a larger circulating compressor (e.g., those comparable compressors required to meet the function of compressor CP_Cond). In some embodiments, even without the regulating device, a recirculation valve can be incorporated, whose impact on overall system efficiency is relatively small due to the relatively low power consumption of that compressor.

[0040] Flow E (such as sections E01-E17 of flow E-312) consists of, or is primarily composed of, nitrogen or methane. Section E01 is typically at ambient temperature (60 to 150°F, or about 125°F) and under high pressure (700 to 1200 psia, or about 1100 psia). Section E01 is cooled by one or more heat exchangers (HEX_1 for sections E02, E03, and E05; then via HEX_2 for section E06 as section E05). A portion of section E02 is removed as section E03 by splitter SP2 at a certain temperature (0 to 60°F, or about 45°F), while the remainder is removed as section E06 after HEX_2 at a relatively cooler temperature (-160 to -100°F, or about -155°F). Each of these streams, E03 and E06, is fed into one or more expanders X_WTBX and X_CTBX, which reduce the pressure of the stream (40 to 125 psia, or about 80 psia) and transfer the function from each fluid to shafts Shaft_W and Shaft_C, respectively, causing compressors CP_WTBB and CP_CTBB to produce a cooling effect on each stream, thus becoming streams E15 and E17. Stream E07 can be a gas or a two-phase mixture (gas phase fraction 0 to 20%, or about 16%). Stream E07 is introduced into one or more heat exchangers (HEX_4), where the stream is completely evaporated and heated to become stream E08, and finally mixed with stream E04 via a recombination unit or mixer M2 to become stream E09. The merged flow, known as flow segment E09, is further heated (HEX_3 to HEX_1) to near ambient temperature (60 to 150°F, or about 120°F) to become flow segment E12. Flow segment E12 is then compressed back to the conditions in flow segment E01 through multiple compression stages, which can be driven by potentially multiple main drives, such as electric motors and expanders. The expander can perform the reverse operation of the compressor, for example, by converting pressure changes into work (e.g., mechanical rotation of the shaft).

[0041] These stages or segments of flow E may include compressor CP_Recycle, which generates segment E13 from segment E12; and cooler C_Recycle, which generates segment E14 from segment E13. These stages may include compressor CP_WTBB, which generates segment E15 from segment E14; and cooler C_WTBB, which generates segment E16 from segment E15. These stages may include compressor CP_CTBB, which generates segment E17 from segment E16; and cooler C_CTBB, which generates segment E01 from segment E17. Compressor CP_WTBB may be mechanically driven or powered (e.g., by rotational power, work, or energy) by the rotating shaft Shaft_W of expander X_WTBX or a rotating shaft Shaft_W powered by expander X_WTBX. The compressor CP_WTBB may be powered by the rotation of Shaft_W without requiring any additional electricity to the shaft or the compressor CP_WTBB. The compressor CP_CTBB can be mechanically powered by the rotating shaft Shaft_C of the expander X_CTBX or by the rotating shaft Shaft_C powered by the expander X_CTBX. The compressor CP_WTBB can be powered by the rotation of Shaft_C without requiring any additional power to the shaft or the compressor. In some cases, each set of expanders, shafts, and compressors is a single unit or system. In some cases, each set of expanders, shafts, and compressors reduces the power required to power the system during full flow or regulation.

[0042] In some cases, compressor CP_WTBB, shaft Shaft_W, and expander X_WTBX are absent or unused. In this case, flow segment E03 is not split at splitter SP2 and flow segment E04 is absent (e.g., mixer M2 is absent), or flow segment E04 is the same flow as flow segment E03; and flow segment E16 is the same flow as flow segment E14. In some cases, flow D is only one loop of flow (e.g., flow segments D01-D13 as shown), is cooled only once by one or more heat exchangers, and is heated only once by one or more heat exchangers. In this case, flow D is not cooled and then heated (or heated and then cooled) more than once. In this case, flow D may have only one cooling flow and only one heating flow. In some cases, flow E is only one loop of flow (e.g., flow segments E01-D13 as shown), is cooled only once by one or more heat exchangers, and is heated only once by one or more heat exchangers. In this case, flow E is not cooled and then heated (or heated and then cooled) more than once. In this case, flow E may have only one cooling flow and only one heating flow.

[0043] Furthermore, expander X_WTBX uses section E03 as the input and section E04 as the output to drive shaft Shaft_W, and the pressure difference between sections E03 and E04 powers shaft Shaft_W. Expander X_WTBX can use the pressures of sections E03 and E04, such as the higher pressure gas from section E03 relative to the lower pressure from section E04, instead of an electric motor to drive shaft Shaft_W. Next, expander X_CTBX uses section E06 as the input and section E07 as the output to drive shaft Shaft_C, and the pressure difference between sections E06 and E07 powers shaft Shaft_C. Expander X_CTBX can use the pressures of sections E06 and E07, such as the higher pressure gas from section E06 relative to the lower pressure from section E07, instead of an electric motor to drive shaft Shaft_C. In some cases, each of the expander, shaft, and compressor can be integrated into a single unit.

[0044] During conditioning operation, the mass flow rate of all segments of stream E (e.g., all segments E01-E17) can be reduced by decreasing the pressure of stream E (e.g., at a pressure relief valve) by a given percentage, affecting all segments of stream E. Removing pressure at a location in stream E will relieve pressure throughout stream E and in each segment of stream E. Reducing the pressure of stream E during or for conditioning reduces the electrical power required for any or all compressors to perform stream and / or segment compression during conditioning. Reducing the pressure of stream E during or for conditioning can be performed by releasing coolant, cryogenic fluid, nitrogen, or methane at any location in stream E (such as pressure relief valve PR at segment E12). This pressure reduction will reduce the electrical power required by the motors of compressor CP_Recycle (optionally and / or compressor C-Cond) to perform compression on segment E12 during conditioning. In other cases, increasing the pressure of all sections of flow E afterward (e.g., not during conditioning or loading) can be performed by adding coolant, cryogenic fluid, nitrogen, or methane at any point in flow E (such as at section E12), which will increase the electrical power required by compressor CP_Recycle (optionally and / or compressor C-Cond) to perform compression on section E12. That is, flow E has a much larger flow rate or flow mass than flow D, for example, 5 times, 15 times, 30 times, or up to 60 times larger than the flow rate of flow D.

[0045] All driven compressors can be designed to maintain a constant pressure ratio or head variation across their stages, sections, or flows. This results in relatively stable volumetric flow rates and head variations through the compression and expansion stages of each stage. Therefore, the regulation operating point of each compressor and expander within flow E will be close to its design point, enabling highly efficient operation (e.g., higher than previous precooling and liquid hydrogen production systems) during equipment regulation. Temperatures are generally maintained close to design values, except that section E07 can be a two-phase mixture, and its temperature will decrease as pressure decreases. As the mass flow rate of flow E is reduced in the compressors of that flow, the electrical load of compression (e.g., the electricity required to power the compressors in flow E) decreases in approximately the same proportion as the pressure reduction. Therefore, during regulation, the electrical load may decrease to a small percentage of full load (e.g., 50% to 20%, or about 30%, of full load). In some cases, the electrical load decreases during regulation to 20%, 30%, or 40% of the full load required for system 300 operation. The reduction in this electrical load is mainly determined by flow segment E12, which must be maintained above atmospheric pressure to avoid contamination or mechanical problems in the flow.

[0046] The size of system 300 can be equivalent to that of a family living room or a manufacturing plant. Generally, flow D responds negatively to pressure changes but positively to flow rate changes; in contrast, flow E responds more positively to pressure changes but is more negatively affected by flow rate changes than flow D. In some cases, flow D has only a liquid section D07, while flow E contains gas in section E07.

[0047] In some cases, system 300 is a hydrogen liquefaction system, a liquid hydrogen production system, or a pre-cooled modified anti-Breen cycle system, or a part thereof. System 300 may be a highly efficient pre-cooled modified anti-Breen cycle hydrogen cooling system. System 300 includes a first stream A-302, a second stream B-304, and a third stream C-306, each comprising flow sections A01-A07, B01-B14, and C01-C14 of a chemical refrigerant fluid and / or gas (e.g., a cryogenic liquid). Each or all of these streams may be at a temperature between -320 and -425 degrees Fahrenheit (°F). Flow sections B07 and C07 may be directly or via intermediate devices, functions, and / or stage fluid connections or couplings to flow sections B08 and C08 (respectively). Flow sections B14 and C14 may be directly or via intermediate devices, functions, and / or stage fluid connections or couplings to flow sections B01 and C01 (respectively).

[0048] The fourth stream, D-310, does not mix with any of the first streams, A, B, and C, nor with any of them, and is separated from them. The fourth stream, D-310, is or has a first refrigerant, such as a refrigerant primarily composed of nitrogen. The first refrigerant may have an ambient temperature between 60 and 150 degrees Fahrenheit (inclusive) and a pressure between 150 and 600 psia (pounds per square inch absolute pressure) (inclusive).

[0049] The fourth stream D-310 is cooled to a cryogenic temperature between -320 and -270 degrees Fahrenheit (inclusive) by one or more heat exchangers HEX_1-HEX_5 through the fourth cooling streams D01-D07, wherein the cryogenic liquid (e.g., nitrogen) of the fourth cooling streams is depressurized at the first refrigerant stream D06 at valve V_Cond (e.g., via a Joule-Thomson or JT valve), such that the temperature of the first refrigerant stream D06 drops to the temperature of the cooling stream D07 due to the Joule-Thomson effect of the valve, as well as the two-phase mixture from the first refrigerant stream D06 or stream D07.

[0050] Heat exchangers HEX_1-HEX_5 may be a subset or a first group of heat exchangers HEX_1-HEX_6 in the system. Flow segment D07 is then directed to a fourth heating flow segment D07-D13 of one or more heat exchangers HEX_6-HEX_1 to evaporate the liquid and heat the fluid of the first refrigerant flow to near-ambient conditions in the second refrigerant flow segment D13 of the fourth heating flow segment. The second refrigerant flow segment D13 of the fourth flow (e.g., the evaporated liquid) is then compressed and cooled by at least one compressor and cooling stages CP_Cond and C_Cond, and returns as flow segment D01 to the fourth cooling flow.

[0051] Stream E-312 does not mix with any of Streams A, B, C, and D-310, nor with any of them, and is separated from them. No section of Stream E mixes with any section of Stream D. Stream E-312 is or has a second refrigerant, such as a refrigerant primarily composed of nitrogen or methane. The second refrigerant may have an ambient temperature between 60 and 150 degrees Fahrenheit (inclusive) and a high pressure between 700 and 1200 psia (inclusive).

[0052] The fifth stream E-312 is cooled by one or more heat exchangers HEX_1-HEX_2 via the fifth cooling sections E01, E02, E05, and E06. The first stream portion E03 of the fifth stream E is separated from the first refrigerant section E02 of the fifth cooling stream E by the splitter SP2 and is at a first temperature between 0 and 60 degrees Fahrenheit (inclusive); the second residual stream portion E06 of the fifth stream E is separated from the first refrigerant section E02 by the splitter SP2 and is at a second temperature between -160 and -100 degrees Fahrenheit (inclusive), which is relatively lower than the first temperature.

[0053] The first flow section E03 feeds into the first expander X_WTBX, which mechanically uses its first shaft Shaft_W to power the first compressor CP_WTBB of the fifth chemical flow, increasing the pressure in section E14 or E15 to between 400 and 800 psia (inclusive). The cooling section E06 of the second flow section E06 feeds into the second expander X_CTBX, which mechanically uses its second shaft Shaft_C to power the second compressor CP_CTBB of the fifth chemical flow, increasing the pressure in section E17 to between 800 and 1200 psia (inclusive). In some cases, the cooling section E06 of the first flow portion E03 and the second flow portion E05 of the fifth flow are each fed into an expander, which mechanically uses a shaft to power the fifth compressor to reduce the temperature of the fifth flow, thereby serving as the fifth heating flow section (E04, E09, E10, E11, and E12) and the flow section (E07, E08, E09, E10, E11, and E12), respectively. In other cases, the first flow portion E03 and the cooling section E06 are each fed into an expander, which mechanically uses a shaft to power the fifth compressor to reduce the temperature of the fifth flow, thereby serving as the fifth heating flow section (E09, E10, and E11) and the flow section (E08, E09, E10, and E11), respectively.

[0054] In some cases, each expander X_WTBX and X_CTBX transfers the work of the fluid from each flow segment E03 and E06 to the shafts Shaft_W and Shaft_C, which power the fifth compressor, resulting in a cooling effect in flow segments E04 and E07.

[0055] In some cases, the first stream section E03 of the fifth chemical stream is fed into a first expander, which mechanically uses a first shaft to power a first compressor of the fifth chemical stream to reduce the temperature of the fifth stream, thereby serving as the first stream section of the fifth heated stream (e.g., sections E04, E09, E10, E11, and E12; or sections E09, E10, and E11). Furthermore, the cooling stream section E06 of the second stream section of the fifth chemical stream can be fed into a second expander, which mechanically uses a second shaft to power a second compressor of the fifth chemical stream to reduce the temperature of the fifth stream, thereby serving as the second stream section of the fifth heated stream (e.g., sections E07, E08, E09, E10, E11, and E12; or sections E08, E09, E10, and E11).

[0056] The third stream portion E07 of the fifth stream E07, as a gas or two-phase mixture, is introduced into the fifth heating sections E07-E12 of one or more heat exchangers HEX_4-HEX_1, where the third stream portion E07 is completely evaporated and heated to become section E08. This section E08 is then mixed with the fourth stream portion E04 of the fifth stream via mixer M2, such that the mixed stream section E09 is further heated to near ambient temperature between 60 and 150 degrees Fahrenheit (inclusive) by a portion of one or more heat exchangers HEX_3-HEX_1. The mixed stream section E09 is then compressed and cooled by at least one compressor and cooling stages CP_Recycle and C_Recycle, and is sent as section E14 to the inlet of the fifth compressor CP_WTBB.

[0057] The compressor CP_WTBB outputs flow segment E15 to at least one cooling stage C_WTBB, and from there serves as flow segment E16 as the input to the fifth compressor CP_CTBB. The compressor CP_CTBB outputs flow segment E17, which is cooled by at least one cooling stage C_CTBB and sent as flow segment E01 to the exchanger HEX_1, where it is cooled to become flow segment E02.

[0058] Section E03 serves as the input flow to expander X_WTBX, section E04 serves as its output flow, and the pressure or power difference between sections E03 and E04 powers shaft Shaft W. Section E06 serves as the input flow to expander X_CTBX, section E07 serves as its output flow, and the pressure or power difference between sections E06 and E07 powers shaft Shaft C. In some cases, after the pressure, energy, or power from input sections E03 and E06 has been used to rotate shafts W and C, E04 and E07 become the output flows of the expander.

[0059] During conditioned operation of system 300, the mass flow rate of the fifth stream E is reduced by decreasing the pressure of the second refrigerant (e.g., at the pressure relief valve PR) by a given or selected percentage, based on the desired flow rate conditioned percentage or amount. During conditioned operation, system 300 may operate at a reduced flow rate of 30% or 70% or less of the full-load flow rate achievable by the system. During conditioned operation, the pressure of the fifth stream E may be reduced by releasing the refrigerant, cryogenic fluid, nitrogen, or methane from the fifth stream E, for example at flow segment E12, to reduce or decrease the electrical power required by compressor CP_Recycle (and optionally compressor CP_Cond) to perform compression on the fifth stream E. Reducing the pressure of the second refrigerant may include maintaining a constant pressure ratio or head variation at each stage of the fifth stream E, resulting in relatively stable volumetric flow rate and head variations through the compression and expansion stages of stream E, thereby achieving high operating efficiency with reduced electrical load on stream E and / or system 300.

[0060] Figure 3B This is a schematic diagram of another high-efficiency hydrogen cooling system 350. System 350 is the same as system 300, except that system 350 has a flow E-352, which (e.g., at the splitter SP3) directly diverts flow segment E20 from E01 to X_WTBX, which is then heated in HEX_01 and mixed with flow segment E10 (e.g., with flow segment E22 at mixer M3). The pressure at E20 is now higher than the pressure at E04, requiring compressor CP_Recycle to equalize the pressure before mixing and further compression of CP_Recycle2. This arrangement advantageously reduces the volumetric flow rate that CP_Recycle needs to handle.

[0061] In system 350, the fifth stream E-352 does not mix with any of the first stream A, second stream B, third stream C, and fourth stream D-310, nor with any of them, and is separated from them. No section of the fifth stream E mixes with any section of the fourth stream D. The fifth stream E-352 is or has a second refrigerant, such as a refrigerant primarily composed of nitrogen or methane. The second refrigerant may have an ambient temperature between 60 and 150 degrees Fahrenheit (inclusive) and a high pressure between 700 and 1200 psia (inclusive).

[0062] The fifth stream, E-352, is cooled by one or more heat exchangers HEX_1-HEX_2 via fifth cooling sections E01, E02, and E03. Section E03 is fed into the second expander X_CTBX, which mechanically uses the second shaft Shaft_C to power the second compressor CP_CTBB of the fifth chemical stream, increasing the pressure in section E15 to between 400 and 800 psia (inclusive), thus becoming section E16. Section E20 is fed into the first expander X_WTBX, which mechanically uses the first shaft Shaft_W to power the first compressor CP_WTBB of the fifth chemical stream, increasing the pressure in section E13 to between 400 and 800 psia (inclusive), thus becoming section E14.

[0063] In some cases, sections E03 and E20 of the fifth stream are each fed into an expander, which mechanically powers the fifth compressor using a shaft to reduce the temperature of the fifth stream, thus serving as the fifth heating section (E04-E08) and section (E21-E22), respectively. In other cases, the first stream section E03 and the cooling section E20 are each fed into an expander, which mechanically powers the fifth compressor using a shaft to reduce the temperature of the fifth stream, thus serving as the fifth heating section (E05-E07) and section (E21), respectively.

[0064] In some cases, each expander X_WTBX and X_CTBX transfers the work of the fluid from each flow segment E20 and E03 to the shafts Shaft_W and Shaft_C, which power the fifth compressor, resulting in a cooling effect on flow segments E21 and E04, respectively.

[0065] In system 350, stream E04, as a gas or two-phase mixture, is introduced into the fifth heating streams E05-E08 of one or more heat exchangers HEX_4-HEX_1, where stream E04 is completely evaporated and heated to near-ambient temperature between 60 and 150 degrees Fahrenheit (inclusive). Stream E08, near-ambient temperature, is then compressed and cooled by at least one compressor and cooling stages CP_Recycle and C_Recycle, and discharged as stream E10.

[0066] Flow segment E21 is introduced into the fifth heating flow segments E21-E22 of one or more heat exchangers to become the heated flow segment E22. Flow segments E10 and E22 are mixed by a recombination unit or mixer M3 to become flow segment E11. Flow segment E11 is further compressed and cooled by at least one compressor and cooling stage CP_Recycle2 (which may have a feedback flow segment E12) and C_Recycle2, and is sent out as flow segment E13 as the input of the fifth compressor CP_WTBB.

[0067] In system 350, compressor CP_WTBB outputs flow segment E14 to at least one cooling stage C_WTBB, and from there serves as flow segment E15 as the input to the fifth compressor CP_CTBB. Compressor CP_CTBB outputs flow segment E16, which is cooled by at least one cooling stage C_CTBB and sent as flow segment E01 to splitter SP3 into flow segments E20 and E23. Flow segment E23 is sent to exchanger HEX_1 and cooled to become flow segment E02.

[0068] Section E20 serves as the input flow to expander X_WTBX, section E21 serves as its output flow, and the pressure or power difference between sections E20 and E21 powers shaft Shaft W. Section E03 serves as the input flow to expander X_CTBX, section E04 serves as its output flow, and the pressure or power difference between sections E03 and E04 powers shaft Shaft C. In some cases, after the pressure, energy, or power from input sections E20 and E03 has been used to rotate shafts W and C, E21 and E04 become the output flows of the expander.

[0069] During regulated operation of system 350, the mass flow rate of the fifth stream E is reduced by decreasing the pressure of the second refrigerant (e.g., at pressure relief valve PR) by a given or selected percentage, based on the desired flow rate regulation percentage or amount. During regulated operation, system 350 may operate at a reduced flow rate of 30% or 70% or less of the full-load flow rate achievable by the system. During regulated operation, the pressure of the fifth stream E may be reduced by releasing the refrigerant, cryogenic fluid, nitrogen, or methane from the fifth stream E, for example at flow segment E08, to reduce or decrease the electrical power required by compressor CP_Recycle (and optionally compressor CP_Cond and / or compressor CP_Recycle2) to perform compression on the fifth stream E. Reducing the pressure of the second refrigerant may include maintaining a constant pressure ratio or head variation at each stage of the fifth stream E, resulting in relatively stable volumetric flow rate and head variations through the compression and expansion stages of stream E, thereby achieving high operating efficiency with reduced electrical load on stream E and / or system 350.

[0070] In some cases, the first refrigerant in stream D is not the same refrigerant as the second refrigerant in stream E. The liquids, gases, or chemicals in the fourth stream D are not combined or mixed with any liquids, gases, or chemicals in the fifth stream E. In some cases, the first and second refrigerants are each one of nitrogen, methane, hydrocarbons, oxygen, hydrogen, helium, or a mixture of these molecules. In some cases, each of the first stream A, the second stream B, and the third stream C includes product hydrogen, product methane; or a refrigerant selected from one or more of those refrigerants, such as hydrogen, helium, and neon.

[0071] Alternative configurations include expansioners in the E-circuit operating at different pressures at their outlets. It should also be understood that different numbers of expanders within the E-circuit can operate in series or parallel. Furthermore, it should be understood that expanders can drive other devices, such as electric motors or gearboxes with multiple loads.

[0072] Alternative configurations include refrigerants in stream D or stream E that are not primarily nitrogen, but can be light hydrocarbons, oxygen, hydrogen, helium, or mixtures of these molecules.

[0073] Method Description Now refer to Figure 4 Process 400 for efficient hydrogen cooling begins at 405 and ends at 495. Process 400 can be executed by system 300 or 350. In some cases, process 400 is a method for, or part of, hydrogen liquefaction, liquid hydrogen production, and / or an improved pre-cooling modified anti-Brethon nitrogen cycle.

[0074] Process 400 includes step 405, providing a first stream A, a second stream B, and a third stream C, each comprising stream sections A01-A07, B01-B14, and C01-C14 of a refrigerant at a temperature between -320 and -425 degrees Fahrenheit (°F). Step 405 provides streams A, B, and C as a fluid and / or gaseous refrigerant or cryogenic liquid, including product hydrogen and a refrigerant, such as hydrogen, helium, or neon, or a blend of multiple refrigerants. Step 405 may be as follows: Figures 3A-3B The description indicates that streams A, B, and C are provided.

[0075] Step 410 provides a fourth stream D having a first refrigerant (such as primarily nitrogen) having an ambient temperature between 60 and 150 degrees Fahrenheit and a pressure between 150 and 600 psia. The fourth stream may be separated from each of the first stream A, the second stream B, and the third stream C. Step 410 may provide a fourth stream D that is not mixed with any of the first A, second B, or third C streams. Step 410 may be as follows: Figure 3A -3C provides the flow D as indicated in the description.

[0076] Step 420 involves cooling the fourth stream D via a fourth cooling section to a low temperature ranging from -320 to -270 degrees Fahrenheit using one or more heat exchangers HEX_1 to HEX_5. Cooling the fourth stream D via cooling sections D01-D07 is then performed using one or more heat exchangers HEX_1 to HEX_5. Step 420 may be as follows: Figure 3A The description of -3C indicates that the cooling flow D is via the fourth cooling section.

[0077] Step 430 involves depressurizing the first refrigerant flow across a Joule-Thomson (JT) valve, causing the temperature of the flow to decrease due to the Joule-Thomson effect of the valve. This valve can be a JT valve, which depressurizes the cryogenic liquid first refrigerant flow section D06, causing the temperature of the flow to decrease due to the Joule-Thomson effect, resulting in flow section D07. Step 430 can be performed as follows: Figure 3A The description of -3C indicates that the first refrigerant flow is depressurized by passing through the JT valve V_Cond.

[0078] Step 440 involves guiding the two-phase mixture of the pressure-reducing section D07 of the first refrigerant flow segment D06 to the fourth heating section D07-D13 of one or more heat exchangers HEX_6 to HEX_1. Guiding this pressure-reducing two-phase mixture D7 can be done by guiding the mixture D7 to the fourth heating section D07-D13 of one or more heat exchangers HEX_6 to HEX_1 to evaporate the liquid and heat the fluid in the first refrigerant flow segment D07 to near-ambient conditions in section D13. Step 440 can be as follows: Figure 3A The description of -3C indicates the two-phase mixture of the guiding pressure reduction section D07.

[0079] Step 440 may also, or optionally, include compressing and cooling the second refrigerant stream segment D13 of the fourth stream through at least one compressor and cooling stage. This compression and cooling stream segment D13 can be returned to the fourth cooling stream as segment D14 via compressor CP_Cond, and then as segment D01 via cooler C_Cond. This can be as follows: Figure 3A The description of -3C indicates that the compression and cooling of flow section D13 will become flow section D01.

[0080] Step 450 is to provide a fifth stream E that does not mix with any of the first A, second B, third C, or fourth D streams. The fifth stream E may have a second refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 psia. Providing the fifth stream E may be to provide a fifth stream E that does not mix with any of the streams A, D, or D. The fifth stream has a second refrigerant (such as primarily nitrogen) having an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 psia. Step 450 may be as directed for... Figure 3A The description of -3C indicates the provision of a fifth stream, E. In some cases, the first refrigerant is different from the second refrigerant. In some cases, the first refrigerant is the same as the second refrigerant. In some cases, the liquid, gas, or chemical in the fourth stream, D, does not combine or mix with the liquid, gas, or chemical in the fifth stream, E.

[0081] Step 460 involves cooling the fifth stream E via the fifth cooling sections E02, E03, and E06 through one or more heat exchangers. Stream E01 can be cooled to become, or via the fifth cooling sections E02, E03, E05, and E06, by one or more heat exchangers HEX_1 to HEX_2. Cooling the fifth stream E may involve cooling stream E01 to become stream E02 through exchanger HEX_1, splitting stream E02 into streams E03 and E05 through splitter SP2, and then cooling stream E05 to become stream E06 by exchanger HEX_2. Step 460 may be as follows: Figure 3A The description of -3C indicates the fifth cooling flow E.

[0082] Step 470 involves removing a first flow portion E03 from the first refrigerant flow section E02 via the splitter SP2, bringing it to a first temperature between 0 and 60 degrees Fahrenheit. The removed flow section E03 can be a portion of the removed flow section E02 via the splitter SP2 as the first removed flow portion E03. Step 470 can be as follows: Figure 3A The outflow section E03 is indicated in the description of -3C.

[0083] Step 480 involves removing a second residual flow portion E05 from the first refrigerant flow section E02 via the distributor SP2, bringing it to a second and relatively cooler temperature (compared to the temperature of flow section E03) between -160 and -100°F. Removing the second residual flow portion can be achieved by removing a portion of flow section E02 via the distributor SP2 as the second removed flow portion E05. Flow section E05 is cooled by the exchanger HEX_2 to become the cooling flow section E06. Step 480 can be performed as follows: Figure 3A The description of -3C indicates that the removed flow section E05 is cooled to become flow section E06.

[0084] Step 490 involves feeding the first flow section E03 and the cooling section E06 of the second residual flow section E05 after HEX_2 into expanders X_WTBX and X_CTBX, respectively. The work from the fluids in the first flow section E03 and the cooling section E06 is then transferred to shafts Shaft_W and Shaft_C, which power the fifth compressors CP_WTBB and CP_CTBB, respectively. This work transfer results in a cooling effect on sections E04 and E07 of flow E-312, which are heated in HEX_1-4. Step 490 can be performed as follows: Figure 3A -3C refers to the feed and transfer as indicated in the description.

[0085] Step 490 may involve feeding the cooling section E06 of the first flow portion E03 and the second residual flow portion E05 after passing through HEX_2 into the expanders X_WTBX and X_CTBX, respectively. The expanders mechanically power the fifth compressors CP_WTBB and CP_CTBB to reduce the temperature of the fifth flow, thereby serving as the fifth heating flow, such as the sections (E04, E09, E10, E11 and E12) and sections (E07, E08, E09, E10, E11 and E12), respectively.

[0086] In some cases, step 490 may include feeding a first stream portion E03 of the fifth chemical stream into a first expander, which mechanically powers a first compressor of the fifth chemical stream using a first shaft to reduce the temperature of the fifth stream E, thereby serving as a first stream portion E04-E12 of the fifth heated stream. Step 490 may also include feeding a cooling section E06 of a second stream portion of the fifth chemical stream into a second expander, which mechanically powers a second compressor of the fifth chemical stream using a second shaft to reduce the temperature of the fifth stream E, thereby serving as a second stream portion E07-E12 of the fifth heated stream.

[0087] Step 495 may optionally include regulating operation of the system. Regulating operation of the system may include reducing the mass flow rate of the fifth stream E by decreasing the pressure of the second refrigerant (e.g., at a pressure relief valve) by a given or selected percentage based on the desired regulating flow rate or amount. Regulating operation may include reducing the system flow rate (e.g., the flow rate of stream E) to below 30%, 70%, or 80% of the full-load flow rate at which the system is capable of operating (e.g., when the system is configured to operate under the supply of power, electricity, and / or renewable energy). Regulating operation may include reducing the pressure of the fifth stream E by releasing the refrigerant, cryogenic fluid, or nitrogen from the fifth stream to reduce the electrical power required by the compressor (e.g., a centrifugal compressor CP_Recycle) to perform compression on stream segment E12 at the pressure relief valve PR of the fifth stream. Step 495 may be as directed for… Figure 3A -3C describes the implementation of regulation.

[0088] As indicated by the arrows, steps 490 or 495 can return to step 405. In some cases, any step can return to or proceed to any other step in process 400.

[0089] The steps of process 400 can all be performed simultaneously, at the same time, or within the same time period (such as within minutes, an hour, several hours, or a dozen hours). In other cases, they can occur in the order of their step numbers.

[0090] A process similar to process 400 used for system 300 can be performed for system 350.

[0091] System 300, system 350, and / or process 400 may be controlled by computer hardware and / or software. They may be controlled by a non-transitory medium storing computer instructions that, when executed by a processor, cause the computer to perform and / or exercise control over system 300, system 350, and / or process 400. Example

[0092] Some embodiments include a hydrogen liquefaction system comprising: a first stream, a second stream, and a third stream, each comprising a section of one of a fluid or gas at a temperature between -320 and -425 degrees Fahrenheit (°F); a fourth stream that is not mixed with any of the first, second, and third streams; the fourth stream having a first refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a pressure between 150 and 650 pounds per square inch absolute pressure (PSIA); the fourth stream being cooled by one or more heat exchangers to a cryogenic temperature in the range of -320 to -270 degrees Fahrenheit via a fourth cooling section, wherein the cryogenic liquid first refrigerant section of the fourth cooling section is depressurized across a valve. The pressure causes the temperature of the first refrigerant stream to drop due to the Joule-Thomson effect, and the two-phase mixture of the first refrigerant stream is directed to a fourth heating stream of the one or more heat exchangers to evaporate the liquid and heat the fluid of the first refrigerant stream to near ambient conditions of the second refrigerant stream of the fourth heating stream. The second refrigerant stream of the fourth stream is then compressed and cooled by at least one compressor and cooling stage and returned to the fourth cooling stream; a fifth stream, which does not mix with any of the first, second, third, or fourth streams; the fifth stream has a second refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a temperature between 700 and 1200 degrees Fahrenheit. High pressure between PSIAs; the fifth stream is cooled by the one or more heat exchangers via a fifth cooling section; a first stream portion of the fifth stream is separated from the first refrigerant section of the fifth cooling stream by a splitter SP2 at a first temperature between 0 and 60 degrees Fahrenheit, and a second remaining stream portion of the fifth stream is separated from the first refrigerant section of the fifth cooling stream by the splitter at a second temperature between -160 and -100 degrees Fahrenheit, which is relatively lower than the first temperature; and the cooling sections of the first stream portion and the second stream portion of the fifth stream are each fed into an expander, which mechanically powers a fifth compressor to reduce the temperature of the fifth stream, thereby serving as a fifth heating section.

[0093] The embodiment also includes a configuration in which each expander transfers work from each fluid in the first flow section and the cooling flow section to a shaft that powers the fifth compressor.

[0094] The embodiment further includes introducing a third stream portion of the fifth stream as a gas or two-phase mixture into the fifth heating section of the one or more heat exchangers, wherein the third stream portion of the fifth stream is completely evaporated and heated, and mixed with a fourth stream portion of the fifth stream by a recombination unit or mixer, such that the mixed stream is further heated to near-ambient temperature between 60 and 150 degrees Fahrenheit by a portion of the one or more heat exchangers; the mixed stream is compressed and cooled by at least one compressor and cooling stage, and sent to the inlet of the fifth compressor.

[0095] The embodiment also includes, during the regulated operation of the system, reducing the mass flow rate of the fifth stream by decreasing the pressure of the second refrigerant by a percentage selected based on the desired flow rate regulation percentage or amount.

[0096] The embodiment also includes a provision that, during the regulated operation, the system is configured to operate at a reduced flow rate of 30% or less of the full load flow rate at which the system is capable of operating.

[0097] The embodiment also includes a method in which, during the regulated operation, the pressure of the fifth stream is reduced by releasing coolant, cryogenic fluid, or nitrogen at a pressure relief valve, thereby reducing the power required for the compressor to perform compression on the fifth stream.

[0098] The embodiment also includes a method for reducing the pressure of the second refrigerant, which involves maintaining a fixed pressure ratio or head change at each stage of the fifth flow, resulting in relatively stable volumetric flow rate and head changes through the compression and expansion stages, thereby achieving high operating efficiency under reduced electrical load conditions.

[0099] The embodiment further includes the first refrigerant being nitrogen and the second refrigerant being methane; and the liquid, gas, or chemical in the fourth stream not being combined or mixed with the liquid, gas, or chemical in the fifth stream.

[0100] The embodiments further include wherein the first refrigerant and the second refrigerant are each one of nitrogen, hydrocarbon, oxygen, hydrogen, helium, or a mixture of these molecules; and wherein each of the first stream, the second stream, and the third stream comprises product hydrogen; or a refrigerant selected from one or more blends of those refrigerants selected from hydrogen, helium, and neon.

[0101] Some embodiments include a highly efficient pre-cooled modified anti-Brethon cycle hydrogen cooling system comprising: a first chemical stream, a second chemical stream, and a third chemical stream, each including a flow section of one of a fluid or gas at a temperature between -320 and -425 degrees Fahrenheit (°F); a fourth chemical stream, the flow section of which is separated from the flow sections of each of the first, second, and third chemical streams; the fourth chemical stream being cooled by one or more heat exchangers through a fourth cooling flow section to a cryogenic temperature in the range of -320 to -270 degrees Fahrenheit, wherein the cryogenic liquid in the fourth cooling flow section is first prepared... The refrigerant stream is depressurized across a Joule-Thomson (JT) valve, causing the temperature and pressure of the first refrigerant stream to decrease due to the Joule-Thomson effect; the two-phase mixture of the first refrigerant stream is directed to a fourth heating stream of the one or more heat exchangers to evaporate the liquid and heat the fluid of the first refrigerant stream to near-ambient conditions of the second refrigerant stream of the fourth heating stream; a fifth chemical stream, separated from each of the first, second, third, and fourth chemical streams; the fifth chemical stream contains a refrigerant including nitrogen. The refrigerant has an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 psia; the fifth chemical stream is cooled by the one or more heat exchangers via a fifth cooling section; a first portion of the fifth chemical stream is separated from the first refrigerant section of the fifth cooling stream by a splitter, and is at a first temperature between 0 and 60 degrees Fahrenheit; a second residual portion of the fifth chemical stream is separated from the first refrigerant section of the fifth cooling stream by the splitter, and is at a second and relative temperature between -160 and -100 degrees Fahrenheit. At a temperature below the first temperature; the first flow portion of the fifth chemical stream is fed into a first expander, which mechanically uses a first shaft to power a first compressor of the fifth chemical stream to reduce the temperature of the fifth chemical stream, thereby serving as a first flow portion of the fifth heating stream; and the cooling flow section of the second flow portion of the fifth chemical stream is fed into a second expander, which mechanically uses a second shaft to power a second compressor of the fifth chemical stream to reduce the temperature of the fifth chemical stream, thereby serving as a second flow portion of the fifth heating stream.

[0102] The embodiment further includes wherein each of the first expander and the second expander transfers work from the fluids from each of the first flow portion and the cooling flow portion to the first shaft and the second shaft, which power the first compressor and the second compressor, resulting in a decrease in the temperature of the fifth chemical flow.

[0103] The embodiment also includes a method in which, during the regulated operation of the system, the mass flow rate of the fifth stream is reduced by decreasing the pressure of the second refrigerant at the pressure relief valve by a percentage selected based on the desired flow regulation percentage or amount.

[0104] The embodiments also include the provision that, during the regulated operation of the system, the system is configured to operate at 30% or less of the full load flow rate at which the system is capable of operating.

[0105] The embodiment further includes the following: the first refrigerant and the second refrigerant are not the same refrigerant; and the liquid, gas or chemical in the fourth stream is not combined or mixed with the liquid, gas or chemical in the fifth stream.

[0106] Some embodiments include a method of hydrogen liquefaction, comprising: providing a first stream, a second stream, and a third stream, each comprising a section of one of a fluid or gas at a temperature between -320 and -425 degrees Fahrenheit (°F); and providing a fourth stream, separated from each of the first, second, and third streams, the fourth stream having a first refrigerant primarily composed of nitrogen, the first refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and an ambient temperature between 150 and 650 degrees Fahrenheit. Pressure between psia (pounds per square inch absolute pressure); the fourth stream is cooled via a fourth cooling section to a cryogenic temperature between -320 and -270 degrees Fahrenheit through one or more heat exchangers; the cryogenic liquid first refrigerant stream of the fourth cooling section is depressurized across a Joule-Thomson valve, causing the temperature of the first refrigerant stream to decrease due to the Joule-Thomson effect; the two-phase mixture of the first refrigerant stream is directed to a fourth heating section of the one or more heat exchangers to evaporate the liquid and heat the fluid of the first refrigerant stream to near-ambient conditions of the second refrigerant stream of the fourth heating section; a fifth stream is provided that does not mix with any of the first, second, third, and fourth streams, the fifth stream having a second refrigerant that is primarily nitrogen, the second refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a temperature between 700 and 1200 degrees Fahrenheit. High pressure between psia; cooling the fifth stream via a fifth cooling section through the one or more heat exchangers; separating a first stream portion of the fifth stream from the first refrigerant section of the fifth cooling stream via a splitter at a first temperature between 0 and 60 degrees Fahrenheit; separating a second residual stream portion of the fifth stream from the first refrigerant section of the fifth cooling stream via the splitter at a second temperature between -160 and -100 degrees Fahrenheit, which is relatively lower than the first temperature; and feeding the cooling sections of the first stream portion and the second stream portion of the fifth stream into an expander, which mechanically powers a fifth compressor using a shaft to reduce the temperature of the fifth stream, thereby serving as a fifth heating section.

[0107] The embodiment further includes compressing and cooling the second refrigerant stream of the fourth stream through at least one compressor and cooling stage, and returning it to the fourth cooling stream.

[0108] The embodiment also includes, further comprising, transferring work from the fluids from each of the first flow section and the cooling flow section to a shaft that powers the fifth compressor.

[0109] The embodiment also includes, further comprising, performing conditioning operation of the system, the conditioning operation comprising reducing the mass flow rate of the fifth stream by reducing the pressure of the second refrigerant by a percentage selected based on a percentage of the desired conditioning flow rate.

[0110] The embodiment also includes, wherein the regulated operation includes reducing the system flow rate to less than one of 30%, 70%, or 80% of the full-load flow rate at which the system can operate.

[0111] The embodiment also includes, wherein the regulating operation includes reducing the pressure of the fifth stream by releasing coolant, cryogenic fluid, or nitrogen at a pressure relief valve, thereby reducing the power required for the compressor to perform compression on the fifth stream.

[0112] The embodiment further includes the first refrigerant being nitrogen and the second refrigerant being methane; and the liquid, gas, or chemical in the fourth stream not being combined or mixed with the liquid, gas, or chemical in the fifth stream.

[0113] Conclusion Throughout this specification, the embodiments and examples shown should be considered exemplary and not as limitations on the disclosed or claimed apparatus and procedures. While many examples presented herein relate to specific combinations of method actions or system elements, it should be understood that these actions and elements can be combined in other ways to achieve the same objective. Regarding flowcharts, additional and fewer steps may be taken, and the steps shown may be combined or further refined to implement the methods described herein. Actions, elements, and features discussed in connection with only one embodiment are not intended to exclude similar effects in other embodiments.

[0114] As used herein, “a plurality of” means two or more. As used herein, “logic” can be or include the hardware and / or software required to perform the functions described for that logic. As used herein, a “set” of items can include one or more such items. As used herein, the terms “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” etc., whether in the written description or the claims, should be understood as open-ended, meaning including but not limited to. Only the transitional phrases “consisting of…” and “substantially consisting of…” are closed or semi-closed transitional phrases relative to the claims, respectively. The use of ordinal terms such as “first,” “second,” “third,” etc., to modify a claim element itself in the claims does not imply any priority, order of precedence, or sequence of one claim element relative to another, nor does it imply a chronological order in which the method actions are performed, but is merely used as labels to distinguish one claim element having a certain name from another element having the same name (but using ordinal terms), to differentiate claim elements. As used herein, “and / or” means that the listed items are alternatives, but these alternatives also include any combination of the listed items.

Claims

1. A hydrogen liquefaction system, comprising: The first, second, and third streams each comprise a section of one of the fluids or gases at a temperature between -320 and -425 degrees Fahrenheit (°F); The fourth stream is not mixed with any of the first, second, and third streams; The fourth stream has a first refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a pressure between 150 and 650 pounds per square inch absolute (PSIA). The fourth flow is cooled to a cryogenic temperature ranging from -320 to -270 degrees Fahrenheit by one or more heat exchangers via a fourth cooling section. In this fourth cooling section, the cryogenic liquid first refrigerant flow is depressurized across a valve, causing the temperature of the first refrigerant flow to decrease due to the Joule-Thomson effect. The two-phase mixture of the first refrigerant flow is then directed to a fourth heating section of the one or more heat exchangers to evaporate the liquid and heat the fluid in the first refrigerant flow to near-ambient conditions in the second refrigerant flow of the fourth heating section. The second refrigerant section of the fourth stream is then compressed and cooled by at least one compressor and cooling stage and returned to the fourth cooling stream; The fifth stream, which is not mixed with any of the first, second, third, or fourth streams; The fifth stream has a second refrigerant, which has an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 PSIA. The fifth stream is cooled by the one or more heat exchangers via a fifth cooling section; a first portion of the fifth stream is diverted from the first refrigerant section of the fifth cooling stream by a splitter SP2, at a first temperature between 0 and 60 degrees Fahrenheit, and a second residual portion of the fifth stream is diverted from the first refrigerant section of the fifth cooling stream by the splitter, at a second temperature between -160 and -100 degrees Fahrenheit, relatively lower than the first temperature; and The cooling sections of the first flow portion and the second flow portion of the fifth flow are each fed into an expander, which mechanically powers the fifth compressor to reduce the temperature of the fifth flow, thereby serving as a fifth heating section.

2. The system as described in claim 1, characterized in that, Each expander transfers the work of the fluid from each of the first flow section and the cooling flow section to the shaft that powers the fifth compressor.

3. The system of claim 1, further comprising the third stream portion of the fifth stream being introduced as a gas or two-phase mixture into the fifth heating section of the one or more heat exchangers, wherein the third stream portion of the fifth stream is completely evaporated and heated, and mixed with the fourth stream portion of the fifth stream by a recombination unit or mixer, such that the mixed stream is further heated to near-ambient temperature between 60 and 150 degrees Fahrenheit by a portion of the one or more heat exchangers; the mixed stream is compressed and cooled by at least one compressor and cooling stage, and is sent to the inlet of the fifth compressor.

4. The system as described in claim 1, characterized in that, During the regulated operation of the system, the mass flow rate of the fifth stream is reduced by decreasing the pressure of the second refrigerant by a percentage selected based on the desired flow rate regulation percentage or amount.

5. The system as described in claim 4, characterized in that, During the regulated operation, the system is configured to operate at a reduced flow rate of 30% or less of the full load flow rate at which the system is capable of operating.

6. The system as described in claim 4, characterized in that, During the regulation operation, the pressure of the fifth stream is reduced by releasing coolant, cryogenic fluid, or nitrogen at the pressure relief valve, thereby reducing the power required for the compressor to perform compression on the fifth stream.

7. The system as described in claim 4, characterized in that, Reducing the pressure of the second refrigerant involves maintaining a fixed pressure ratio or head change at each stage of the fifth flow, resulting in relatively stable volumetric flow rate and head changes through the compression and expansion stages, thereby achieving high operating efficiency under reduced power load conditions.

8. The system as described in claim 1, characterized in that, The first refrigerant is nitrogen and the second refrigerant is methane; and the liquid, gas or chemical in the fourth stream does not merge or mix with the liquid, gas or chemical in the fifth stream.

9. The system as described in claim 1, characterized in that, The first refrigerant and the second refrigerant are each one of nitrogen, hydrocarbon, oxygen, hydrogen, helium, or a mixture of these molecules; and each of the first stream, the second stream, and the third stream comprises product hydrogen; or a refrigerant selected from one or more of those refrigerants selected from hydrogen, helium, and neon.

10. A highly efficient pre-cooling improved anti-Breen cycle hydrogen cooling system, comprising: The first chemical flow, the second chemical flow, and the third chemical flow each comprise a section of one of the fluids or gases at a temperature between -320 and -425 degrees Fahrenheit (°F); The fourth chemical flow, the flow segment of which is separated from the flow segments of each of the first chemical flow, the second chemical flow and the third chemical flow; The fourth chemical stream is cooled by one or more heat exchangers to a cryogenic temperature in the range of -320 to -270 degrees Fahrenheit via a fourth cooling section, wherein the cryogenic liquid first refrigerant stream of the fourth cooling section is depressurized across a Joule-Thomson (JT) valve, such that the temperature and pressure of the first refrigerant stream decrease due to the Joule-Thomson effect. The two-phase mixture of the first refrigerant stream is directed to a fourth heating stream of the one or more heat exchangers to evaporate the liquid and heat the fluid in the first refrigerant stream to near-ambient conditions in the second refrigerant stream of the fourth heating stream. A fifth chemical stream, which is separated from each of the first, second, third, and fourth chemical streams; The fifth chemical stream has a refrigerant including nitrogen, the refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 psia; The fifth chemical stream is cooled by the one or more heat exchangers through a fifth cooling section; a first portion of the fifth chemical stream is separated from the first refrigerant section of the fifth cooling stream by a splitter and is at a first temperature between 0 and 60 degrees Fahrenheit. The second residual flow portion of the fifth chemical flow is separated from the first refrigerant flow section of the fifth cooling flow by the splitter and is at a second temperature between -160 and -100 degrees Fahrenheit, which is relatively lower than the first temperature. The first stream portion of the fifth chemical stream is fed into a first expander, which mechanically uses a first shaft to power a first compressor of the fifth chemical stream to reduce the temperature of the fifth chemical stream, thereby serving as the first stream portion of the fifth heated stream; as well as The cooling section of the second flow portion of the fifth chemical flow is fed into the second expander, which mechanically uses a second shaft to power the second compressor of the fifth chemical flow to reduce the temperature of the fifth chemical flow, thereby serving as the second flow portion of the fifth heating flow.

11. The system as claimed in claim 10, characterized in that, Each of the first expander and the second expander transfers work from the fluids in each of the first flow section and the cooling flow section to the first shaft and the second shaft, which power the first compressor and the second compressor, resulting in a decrease in the temperature of the fifth chemical flow.

12. The system as claimed in claim 10, characterized in that, During the regulated operation of the system, the mass flow rate of the fifth stream is reduced by decreasing the pressure of the second refrigerant at the pressure relief valve by a percentage selected based on the desired flow regulation percentage or amount.

13. The system as described in claim 12, characterized in that, During the regulated operation of the system, the system is configured to operate at 30% or less of the full load flow rate at which the system is capable of operating.

14. The system as described in claim 10, characterized in that, The first refrigerant and the second refrigerant are not the same refrigerant; and the liquid, gas or chemical in the fourth stream is not combined or mixed with the liquid, gas or chemical in the fifth stream.

15. A method for hydrogen liquefaction, comprising: Provides a first flow, a second flow, and a third flow, each comprising a section of one of the fluids or gases at a temperature between -320 and -425 degrees Fahrenheit (°F); A fourth stream is provided, which is separated from each of the first, second and third streams, the fourth stream having a first refrigerant that is primarily nitrogen, the first refrigerant having an ambient temperature between 60 and 150 degrees Fahrenheit and a pressure between 150 and 650 psia (pounds per square inch absolute pressure); The fourth stream is cooled to a low temperature ranging from -320 to -270 degrees Fahrenheit via a fourth cooling section through one or more heat exchangers; The first refrigerant flow section of the low-temperature liquid in the fourth cooling section is depressurized by passing it across the Joule-Thomson valve, so that the temperature of the first refrigerant flow section decreases due to the Joule-Thomson effect. The two-phase mixture of the first refrigerant stream is directed to the fourth heating stream of the one or more heat exchangers to evaporate the liquid and heat the fluid in the first refrigerant stream to near-ambient conditions in the second refrigerant stream of the fourth heating stream; A fifth stream is provided that is not mixed with each of the first, second, third and fourth streams, the fifth stream having a second refrigerant that is primarily nitrogen and has an ambient temperature between 60 and 150 degrees Fahrenheit and a high pressure between 700 and 1200 psia. The fifth stream is cooled via a fifth cooling section through one or more heat exchangers; A first portion of the fifth cooling stream is separated from the first refrigerant section of the fifth cooling stream by a splitter, and is at a first temperature between 0 and 60 degrees Fahrenheit. The second residual flow portion of the fifth cooling flow is separated from the first refrigerant flow section of the fifth cooling flow by the splitter, and is at a second temperature between -160 and -100 degrees Fahrenheit, which is relatively lower than the first temperature. as well as The cooling sections of the first flow portion and the second flow portion of the fifth flow are each fed into an expander, which mechanically uses a shaft to power a fifth compressor to reduce the temperature of the fifth flow, thereby serving as a fifth heating section.

16. The method of claim 15, further comprising compressing and cooling the second refrigerant stream of the fourth stream through at least one compressor and a cooling stage, and returning it to the fourth cooling stream.

17. The method of claim 15, further comprising transferring work from the fluids of each of the first flow section and the cooling flow section to a shaft that powers the fifth compressor.

18. The method of claim 15, further comprising performing a regulating operation of the system, the regulating operation comprising reducing the mass flow rate of the fifth stream by reducing the pressure of the second refrigerant by a percentage selected based on a percentage of the desired regulating flow rate.

19. The method as described in claim 18, characterized in that, The regulated operation includes reducing the system flow rate to less than one of 30%, 70%, or 80% of the full-load flow rate at which the system can operate.

20. The method as described in claim 18, characterized in that, The regulating operation includes reducing the pressure of the fifth stream by releasing coolant, cryogenic fluid, or nitrogen at the pressure relief valve, thereby reducing the power required for the compressor to perform compression on the fifth stream.

21. The method as described in claim 15, characterized in that, The first refrigerant is nitrogen and the second refrigerant is methane; and the liquid, gas or chemical in the fourth stream does not merge or mix with the liquid, gas or chemical in the fifth stream.

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